Microorganisms

Appl Environ Microbiol, 2001 Dec, 67(12), 5474 - 81
Proteins induced during adaptation of Acetobacter aceti to high acetate concentrations; Steiner P et al.; As a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects . In contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions . To characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of Acetobacter aceti by two-dimensional gel electrophoresis . Adaptation was achieved by using serial batch and continuous cultivations with increasing acetate supplementation . Computer-aided analysis revealed a complex proteome response with at least 50 proteins that are specifically induced by adaptation to acetate but not by other stress conditions, such as heat or oxidative or osmotic stress . Of these proteins, 19 were significantly induced in serial batch and continuous cultures and were thus noted as acetate adaptation proteins (Aaps) . Here we present first microsequence information on such Aaps from A . aceti . Membrane-associated processes appear to be of major importance for adaptation, because some of the Aap bear N-terminal sequence homology to membrane proteins and 11 of about 40 resolved proteins from membrane protein-enriched fractions are significantly induced.

Br J Haematol, 2001 Oct, 115(1), 186 - 94
Differentiation and expansion of endothelial cells from human bone marrow CD133(+) cells; Quirici N et al.; We report a method of purifying, characterizing and expanding endothelial cells (ECs) derived from CD133(+) bone marrow cells, a subset of CD34(+) haematopoietic progenitors . Isolated using immunomagnetic sorting (mean purity 90 +/- 5%), the CD133(+) bone marrow cells were grown on fibronectin-coated flasks in M199 medium supplemented with fetal bovine serum (FBS), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and insulin growth factor (IGF-1) . The CD133(+) fraction contained 95 +/- 4% CD34(+) cells, 3 +/- 2% cells expressing VEGF receptor (VEGFR-2/KDR), but did not express von Willebrand factor (VWF), VE-cadherin, P1H12 or TE-7 . After 3 weeks of culture, the cells formed a monolayer with a typical EC morphology and expanded 11 +/- 5 times . The cells were further purified using Ulex europaeus agglutinin-1 (UEA-1)-fluorescein isothiocyanate (FITC) and anti-FITC microbeads, and expanded with VEGF for a further 3 weeks . All of the cells were CD45(-) and CD14(-), and expressed several endothelial markers (UEA-1, VWF, P1H12, CD105, E-selectin, VCAM-1 and VE-cadherin) and typical Weibel-Palade bodies . They had a high proliferative potential (up to a 2400-fold increase in cell number after 3 weeks of culture) and the capacity to modulate cell surface antigens upon stimulation with inflammatory cytokines . Purified ECs were also co-cultivated with CD34(+) cells, in parallel with a purified fibroblastic cell monolayer . CD34(+) cells (10 x 10(5)) gave rise to 17,951 +/- 2422 CFU-GM colonies when grown on endothelial cells, and to 12,928 +/- 4415 CFU-GM colonies on fibroblast monolayers . The ECs also supported erythroid blast-forming unit (BFU-E) colonies better . These results suggest that bone marrow CD133(+) progenitor cells can give rise to highly purified ECs, which have a high proliferative capacity, can be activated by inflammatory cytokines and are superior to fibroblasts in supporting haematopoiesis . Our data support the hypothesis that endothelial cell progenitors are present in adult bone marrow and may contribute to neo-angiogenesis.

Planta, 2001 Oct, 213(6), 977 - 80
X-ray absorption spectroscopy study shows that the rapid selenium volatilizer, pickleweed (Salicornia bigelovii Torr.), reduces selenate to organic forms without the aid of microbes; Lee A et al.; In many plant species, selenium (Se) volatilization is limited by the reduction of selenate and its chemical conversion to organic Se compounds, a process that may be facilitated by rhizosphere microbes . This study was conducted to determine if pickleweed (Salicornia bigelovii Torr.), which is characterized by having high rates of Se volatilization from selenate, is able to reduce selenate into organic forms of Se axenically, or whether it requires the presence of microbes . X-ray absorption spectroscopy analysis showed that shoots and roots of pickleweed plants supplied with 50 microM selenate accumulated Se predominantly in organic Se forms (about 65-75% of the total accumulated Se), regardless of whether the plants were grown axenically or in the presence of microbes . The results suggest that, unlike other species for which selenate reduction appears to be rate limiting . e.g . Indian mustard (Brassica juncea L.) and broccoli (Brassica oleracea L.), pickleweed is unusual in that it has an enhanced capacity to reduce selenate to organic forms that is independent of the presence of rhizosphere microbes.

Curr Biol, 2001 Nov 13, 11(22), R929 - 31
Evolution: constantly avoiding mutation; Sniegowski P; The genomic mutation rate of the archaeon Sulfolobus acidocaldarius, which inhabits a harsh and potentially mutagenic environment, surprisingly agrees well with the previously observed constancy of genomic mutation rates in microbes . The evolutionary explanation for this constancy of genomic mutation rates remains obscure.

J Appl Physiol, 2001 Dec, 91(6), 2720 - 9
On the likelihood of decompression sickness during H(2) biochemical decompression in pigs; Fahlman A et al.; A probabilistic model was used to predict decompression sickness (DCS) outcome in pigs during exposures to hyperbaric H(2) to quantify the effects of H(2) biochemical decompression, a process in which metabolism of H(2) by intestinal microbes facilitates decompression . The data set included 109 exposures to 22-26 atm, ca . 88% H(2), 9% He, 2% O(2), 1% N(2), for 0.5-24 h . Single exponential kinetics described the tissue partial pressures (Ptis) of H(2) and He at time t: Ptis = integral (Pamb - Ptis) . tau(-1) dt, where Pamb is ambient pressure and tau is a time constant . The probability of DCS {P(DCS)} was predicted from the risk function: P(DCS) = 1 - e(-r), where r = integral (Ptis(H(2)) + Ptis(He) - Thr - Pamb) . Pamb(-1) dt, and Thr is a threshold parameter . Inclusion of a parameter (A) to estimate the effect of H(2) metabolism on P(DCS): Ptis(H(2)) = integral (Pamb - A - Ptis(H(2))) . tau(-1) dt, significantly improved the prediction of P(DCS) . Thus lower P(DCS) was predicted by microbial H(2) metabolism during H(2) biochemical decompression.

J Appl Physiol, 2001 Dec, 91(6), 2713 - 9
Increasing activity of H(2)-metabolizing microbes lowers decompression sickness risk in pigs during H(2) dives; Kayar SR et al.; The risk of decompression sickness (DCS) was modulated by varying the biochemical activity used to eliminate some of the hydrogen (H(2)) stored in the tissues of pigs (19.4 +/- 0.2 kg) during hyperbaric exposures to H(2) . Treated pigs (n = 16) received intestinal injections of Methanobrevibacter smithii, a microbe that metabolizes H(2) to water and CH(4) . Surgical controls (n = 10) received intestinal injections of saline, and an additional control group (n = 10) was untreated . Pigs were placed in a chamber and compressed to 24 atm abs (20.6-22.9 atm H(2)) . After 3 h, the pigs were decompressed and observed for symptoms of DCS for 1 h . Pigs with M . smithii had a significantly lower (P < 0.05) incidence of DCS (44%; 7/16) than all controls (80%; 16/20) . The DCS risk decreased with increasing activity of microbes injected (logistic regression, P < 0.05) . Thus the supplemental tissue washout of the diluent gas by microbial metabolism was inversely correlated with DCS risk in a dose-dependent manner in this pig model.

Sci Total Environ, 2001 Nov 12, 279(1-3), 45 - 50
Effects of elevated CO2 on fen peat biogeochemistry; Kang H et al.; Effects of elevated atmospheric CO2 concentration on northern peatland biogeochemistry was studied in a short-term experiment . Eight intact soil cores (11-cm diameter x 40-cm depth) with Juncus and Festuca spp . were collected from a calcareous fen in north Wales . Half of the cores were incubated under 350 ppm CO2 concentration, whilst the other four cores were maintained at 700 ppm CO2 . After a 4-month incubation, significantly higher biomass (root + shoot + algal mat) was determined under elevated CO2 conditions . Higher emissions of N2O and CO2, and higher concentration of pore-water DOC (dissolved organic carbon) were also observed under elevated CO2 . However, no significant differences were found in CH4 emission or soil enzyme activities (beta-glucosidase, phosphatase, and N-acetylglucosaminidase) in the bulk soil . Overall, the results suggest that elevated CO2 would increase the primary productivity of the fen vegetation, and stimulate N2O and CO2 emissions as a consequence of an enhanced DOC supply from the vegetation to the soil microbes.

Biochem Soc Trans, 2001 Nov, 29(Pt 6), 853 - 9
Sepsis begins at the interface of pathogen and host; Beutler B; To the modern mind, the term 'sepsis' conjures up images of microbes . It is easy to forget that the word predates any understanding of the microbial origins of infectious disease . Derived from the Greek 'sepsios' (rotten), sepsis denotes decay: a phenomenon that humans once regarded as a mysterious though inevitable natural process . A living organism does not accept decay passively . Virtually all multicellular life forms are capable of resisting infection through the generation of a vigorous immune response . In mammals, the response is so stereotypic that it has come to define sepsis itself: it is often called the 'septic syndrome' . Our current understanding of the innate immune system is deeply rooted in the study of sepsis . The chain of events linking infection to tissue injury and cardiovascular collapse is not obvious, and affirmation of the concept required three major discoveries . First, the septic syndrome was found to be caused by toxic products of microbes . Secondly, these toxic substances were found to be toxic because of their propensity to activate cells of the innate immune system, prompting cytokine production . Thirdly, the activating events initiated by microbial toxins were traced to members of an ancient family of defensive molecules, versions of which operate in virtually all multicellular life forms . In mammals, proteins of this family are now known as Toll-like receptors . They represent a point of direct contact, and first contact, between a pathogen and the host immune system.

Ground Water, 2001 Nov-Dec, 39(6), 886 - 94
Viral transport in a sand and gravel aquifer under field pumping conditions; Woessner WW et al.; Ground water supplies contaminated with microbes cause more than 50% of the water-borne disease outbreaks in the United States . Proposed regulations suggest natural disinfection as a possible mechanism to treat microbe-impacted ground water under favorable conditions . However, the usefulness of current models employed to predict viral transport and natural attenuation rates is limited by the absence of field scale calibration data . At a remote floodplain aquifer in western Montana, the bacteriophages MS2, phiX174, and PRD1; attenuated poliovirus type-1 (CHAT strain); and bromide were seeded as a slug 21.5 m from a well pumping at a steady rate of 408 L/min . Over the 47-hour duration of the test, resulting in the exchange of 12 to 13 pore volumes, 77% of the bromide, 55% of the PRD1, 17% of the MS2, 7% of the phiX174, and 0.12% of the poliovirus masses were recovered at the pumping well . Virus transport behavior was controlled by mechanical dispersion, preferential flow, time-dependent nonreversible and reversible attachment, and apparent mass transfer to immobile domains within the sand and gravel dominated aquifer . The percentage of virus recovery appears correlated with reported viral isoelectric point (pI) values . Successful modeling of viral transport in coarse-grained aquifers will require separation of viral specific properties from reported lumped viral-transport system parameters.

Proc Natl Acad Sci U S A, 2001 Nov 20, 98(24), 13519 - 24 Epub 2001 Nov 13.
The 2.0-A crystal structure of tachylectin 5A provides evidence for the common origin of the innate immunity and the blood coagulation systems; Kairies N et al.; Because invertebrates lack an adaptive immune system, they had to evolve effective intrinsic defense strategies against a variety of microbial pathogens . This ancient form of host defense, the innate immunity, is present in all multicellular organisms including humans . The innate immune system of the Japanese horseshoe crab Tachypleus tridentatus, serving as a model organism, includes a hemolymph coagulation system, which participates both in defense against microbes and in hemostasis . Early work on the evolution of vertebrate fibrinogen suggested a common origin of the arthropod hemolymph coagulation and the vertebrate blood coagulation systems . However, this conjecture could not be verified by comparing the structures of coagulogen, the clotting protein of the horseshoe crab, and of mammalian fibrinogen . Here we report the crystal structure of tachylectin 5A (TL5A), a nonself-recognizing lectin from the hemolymph plasma of T . tridentatus . TL5A shares not only a common fold but also related functional sites with the gamma fragment of mammalian fibrinogen . Our observations provide the first structural evidence of a common ancestor for the innate immunity and the blood coagulation systems.

Vet Parasitol, 2001 Nov 22, 101(3-4), 261 - 74
Molecular technology and antigenic variation among intraerythrocytic hemoparasites: do we see reality?
Allred DR.
Antigenic variation is one mechanism of immune evasion utilized by many microorganisms--encompassing such broad evolutionary groups as viruses, bacteria, and protozoa--to survive the onslaught of a specifically activated host immune system . Because of its importance to the survival of many infectious agents there is considerable interest in understanding this phenomenon . With knowledge of the molecular mechanisms by which these microbes deliberately manipulate their genomes, it may be possible to disrupt the molecular machinery of the responsible genetic mechanisms . Among intraerythrocytic parasites, genetic mechanisms that have been observed or postulated to control antigenic variation include segmental gene conversion, epigenetically controlled in situ transcriptional switching, alterations of chromosomal structure associated with transcriptional control, and recombination during sexual reproduction . Likely, more than one type of mechanism is used by all organisms that undergo antigenic variation . In this paper, both the observed mechanisms and some of the molecular technology used to detect these mechanisms are discussed . While often seemingly straightforward from a technical standpoint, sometimes subtle differences in the methods used to study this process may affect what is observed . Some examples of this phenomenon are discussed in the context of a small selection of intraerythrocytic parasites.

BMC Bioinformatics . 2001;2(1):9 . Epub 2001 Oct 16.
FastGroup: a program to dereplicate libraries of 16S rDNA sequences; Seguritan V et al.; BACKGROUND: Ribosomal 16S DNA sequences are an essential tool for identifying and classifying microbes . High-throughput DNA sequencing now makes it economically possible to produce very large datasets of 16S rDNA sequences in short time periods, necessitating new computer tools for analyses . Here we describe FastGroup, a Java program designed to dereplicate libraries of 16S rDNA sequences . By dereplication we mean to: 1) compare all the sequences in a data set to each other, 2) group similar sequences together, and 3) output a representative sequence from each group . In this way, duplicate sequences are removed from a library . RESULTS: FastGroup was tested using a library of single-pass, bacterial 16S rDNA sequences cloned from coral-associated bacteria . We found that the optimal strategy for dereplicating these sequences was to: 1) trim ambiguous bases from the 5' end of the sequences and all sequence 3' of the conserved Bact517 site, 2) match the sequences from the 3' end, and 3) group sequences > or =97% identical to each other . CONCLUSIONS: The FastGroup program simplifies the dereplication of 16S rDNA sequence libraries and prepares the raw sequences for subsequent analyses.

Biochemistry, 2001 Nov 20, 40(46), 13753 - 9
Visual detection of specific, native interactions between soluble and microbead-tethered alpha-helices from membrane proteins; Ashish et al.; Using peptides tethered to polymer microbeads, we have developed a technique for measuring the interactions between the transmembrane alpha-helices of membrane proteins and for screening combinatorial libraries of peptides for members that interact with specific helices from membrane proteins . The method was developed using the well-characterized homodimerization sequence of the membrane-spanning alpha-helix from the erythrocyte membrane protein glycophorin A (GPA) . As a control, we also tested a variant with a dimer-disrupting alteration of a critical glycine residue to leucine . To test for detectable, native interactions between detergent-solubilized and microbead-tethered alpha-helices, we incubated fluorescent dye-labeled GPA analogues in sodium dodecyl sulfate solution with microbeads that contained covalently attached GPA analogues . When the dye-labeled peptide in solution and the bead-tethered peptide both contained the native glycophorin A sequence, the microbeads readily accumulated the dye through lateral peptide-peptide interactions and were visibly fluorescent under UV light . When either the peptide in solution or the peptide attached to the beads contained the glycine to leucine change, the beads did not accumulate any dye . The usefulness of this method for screening tethered peptide libraries was tested by incubating dye-labeled, native sequence peptides in detergent solution with a few native sequence beads plus an excess of beads containing the variant glycine to leucine sequence . When the dye-labeled peptide in solution was present at a concentration of > or =2 microM, the few native sequence beads were visually distinguishable from the others because of their bright fluorescence . Using this model system, we have shown that it is possible to visually detect specific, native interactions between alpha-helices from membrane proteins using peptides tethered to polymer microbeads . It will thus be possible to use this method to measure the specific lateral interactions that drive the folding and organization of membrane proteins and to screen combinatorial libraries of peptides for members that interact with them.

Acta Obstet Gynecol Scand, 2001 Nov, 80(11), 1036 - 8
Is preeclampsia an infectious disease?
Trogstad LI, Eskild A, Bruu AL, Jeansson S, Jenum PA.
BACKGROUND: Studies have suggested a strong paternal factor in the etiology of preeclampsia . If preeclampsia is caused by an infectious agent transmitted by the woman's partner, seronegative women who may experience primary infection in pregnancy should be at increased risk of preeclampsia as compared to previously infected women . The aim of this study was to assess the impact of being seronegative for some viruses transmitted by close contact on the risk of developing preeclampsia . METHODS: Nine hundred and seventy-eight women were randomly drawn from a basic study population of 35,940 pregnant women in Norway . A serum sample drawn at the first antenatal visit was analyzed for specific IgG antibodies against herpes simplex virus type-2, cytomegalovirus and Epstein-Barr virus . For comparison, antibody status against Toxoplasma gondii was also assessed . Information on preeclampsia in pregnancy was obtained through linkage to the Medical Birth Registry of Norway . RESULTS: Thirty-three (3%) women developed preeclampsia . The risk of developing preeclampsia seemed to be increased for women who were seronegative for the viruses studied . Seronegativity for Toxoplasma gondii did not show such a pattern . INTERPRETATION: Women who are seronegative for antibodies against viral agents transmitted through close contact seem more likely to develop preeclampsia . This finding indicates that women who are seronegative to such agents may acquire primary infection in pregnancy, and subsequently be at increased risk of preeclampsia . This hypothesis could represent a new approach to the causes of preeclampsia, and encourage search for yet unidentified microbes as a possible causal factor.

Nat Immunol, 2001 Dec, 2(12), 1138 - 43
Critical role of IL-15-IL-15R for antigen-presenting cell functions in the innate immune response; Ohteki T et al.; Activation of dendritic cells (DCs) and macrophages by infectious agents leads to secretion of interleukin 12 (IL-12), which subsequently induces interferon-gamma (IFN-gamma) production by multiple cell types that include DCs and macrophages . In turn, IFN-gamma acts on macrophages to augment IL-12 secretion and to produce nitric oxide (NO), which eradicates infected microbes . We show here that in cytokine common gamma subunit-deficient and/or IL-2 receptor beta-deficient mice, production of IL-12, IFN-gamma and NO by DCs and macrophages was severely impaired, as was up-regulation of major histocompatibility complex class II and CD40 . Similar phenotypes were observed in DCs and macrophages from IL-15-deficient mice but not in those from IL-2-deficient mice . This shows that the IL-15-IL-15R interaction is critical in early activation of antigen-presenting cells and plays an important role in the innate immune system.

Annu Rev Phytopathol, 2000, 38, 443 - 459
ADVANCES IN IMAGING THE CELL BIOLOGY OF PLANT-MICROBE INTERACTIONS; Heath MC; All plant-microbe interactions are initiated at the level of the cell . Recently, the light microscope has increased in popularity as an investigative tool in plant cell biology, in part because of the parallel developments of confocal laser scanning and video microscopy, computerized image processing, and an ever-increasing array of fluorescent probes that can be applied to living cells . In addition, transgenic plants and cells can be generated in which specific components are fluorescently labeled without any invasive experimental manipulation . The application of such techniques to plant-microbe interactions has revealed microbe-induced changes in cytosolic calcium levels, the visualization of reactive oxygen species generation, cytoskeleton rearrangements, DNA cleavage, and the detailed resolution of intercellular and intracellular trafficking of viral components . These techniques, integrated with electron microscopy, molecular genetics, and other types of investigations, are likely to play an increasingly important role in future studies of plant responses to microbial pathogens or mutualists.

J Dent Educ, 2001 Oct, 65(10), 1147 - 53
Clinical decision-making for caries management in root surfaces; Leake JL; This report presents the results of an evidence-based approach to obtaining the best available information on the natural history, prevalence, incidence, diagnosis, and treatment of root caries . Searches of electronic databases produced 807 references; from these and from citations in the selected articles, a final 161 references were used . We found that the information on the natural history of the disease does not provide practitioners with probabilities of, or time estimates for, progression of the disease through stages . For patients aged thirty and older, the prevalence of root caries is roughly 20 to 22 percent less than a person's age . Severity reaches over one lesion by age fifty, two lesions by age seventy, and just over three lesions for those seventy-five and older . About 8 percent (odds of 1:11) of the population would be expected to acquire one or more new root caries lesions in one year . The accuracy of current systems of diagnosis is unknown, although color has been shown to have little validity . Using the criteria of "softness" to define active lesions has been validated by the presence of microbes in the lesion . One strong study and other studies with weaker design or shorter duration add consistent support for the use of fluorides in the remineralization of root caries . Every three-month application of chlorhexidine varnish was shown to be efficacious in one arm of one study . Evidence for restoration of root caries is tentative since the studies were of limited design and duration.

Mar Pollut Bull, 2001 Oct, 42(10), 852 - 63
Incorporation of organic tritium (3H) by marine organisms and sediment in the severn estuary/Bristol channel (UK); McCubbin D et al.; Discharges of tritium (3H) into the Severn estuary/Bristol Channel (UK) arise from the authorized release of wastes from nuclear power plants at Hinkley Point and Berkley/Oldbury and from the Nycomed-Amersham radiochemical plant, via the sewer system, at Cardiff . The wastes from the nuclear power plants probably consist almost entirely of 3H2O, whereas those from the radiochemical plant also include uncharacterized 3H labelled organic compounds . The total 3H concentrations in demersal fish and other benthic organisms in the vicinity of the Cardiff Eastern sewer outfall are significantly elevated compared to those observed around other UK nuclear establishments . Concentrations in filtered seawater were approximately 10 Bq kg(-1) whilst levels in surface sediment, seaweed (Fucus vesiculosis) and mussels (Mytilus edulis)/flounder (Platichthys flesus) were in the order of 6 x 10(2), 2 x 10(3), and 10(5) Bq kg(-1) (dry weight), respectively . Almost all the 3H found in sediment and biota were organically bound tritium (OBT) . The high concentration in these materials, relative to that in seawater, is due to the presence of bioavailable organic 3H labelled compounds in the radiochemical waste . It is suggested that bioaccumulation of 3H by benthic organisms and demersal fish occurs primarily via a pathway of physico-chemical sorption/bacterial transformation of dissolved 3H labelled organic compounds into particulate organic matter, and subsequent transfer up a web of sediment dwelling microbes and meiofauna . Variations in 3H accumulation between individual organisms have been interpreted in terms of their different feeding behaviour . Relatively low concentrations were observed in the herbivorous winkle (Littorina littorea) and the pelagic Sprat (Spratus spratus) compared with other benthic organisms and demersal fish . The elevated 3H concentrations in seafood, due to bioaccumulation of OBT, have low radiological significance even for the local critical group of seafood consumers.

Ann Chir, 2001 Oct, 126(8), 743 - 50
{Coagulation activation with intraportal islets of Langerhans transplantation in swine}; Lamblin A et al.; STUDY AIM: Intraportal islet allograft appears to be one of the promising treatments for type I diabetes . However, many limiting factors persist . An activation of the coagulation cascade upon contact with islets, has been reported recently in vitro and could play a crucial role in a non specific inflammatory reaction and favour the specific immune reaction . The aim of this experimental study was to confirm in vivo this activation of the coagulation cascade . MATERIAL AND METHODS: An allogenic islets preparation or a material control (inert microbeads) was injected intraportally, in Large White pigs (n = 26), associated with or without an anticoagulant treatment (heparin) . Systemic markers of haemostasis were measured in pigs for 72 hours following injection of the studied material . RESULTS: The thrombin-antithrombin complex increased and platelet count decreased in groups receiving preparation of islets, both indicators of an activation of the coagulation cascade . This activation was proportional to the injected volume and was partially attenuated by heparin . No activation was observed in pigs receiving the material control . CONCLUSION: The activation of the coagulation cascade and the non specific inflammatory reaction could be one of the obstacles to the success of the islet allografts . The use of anticoagulant and anti-inflammatory molecules could potentially allow an improvement of the present results of islet allograft.

Andrologia, 2001 Sep, 33(5), 266 - 71
Use of microbeads for the detection of binding sites on the human zona pellucida: a scanning electron microscopy (SEM) assay; Michelmann HW et al.; One prerequisite for fertilization is the specific binding of spermatozoa to the zona pellucida . However, the factors and mechanisms involved in this gamete contact are not well understood . Gamete recognition and binding are species-specific and are controlled by oligosaccharides of the zona and their corresponding carbohydrates on the spermatozoon . By using a specific lectin we developed a technique to detect those oligosaccharides on the human zona pellucida that might be involved in the binding process . Microbeads (O = 2.8 microm), used as artificial spermatozoa, were coated with lectin Con A and cultured together with 75 unfertilized oocytes (group A) remaining after intracytoplasmic sperm injection . Con A binds specifically to alpha-d-mannose and alpha-d-glucose . As a control, 75 unfertilized oocytes after intracytoplasmic sperm injection (group B) were also cultured together with Con A-covered microbeads, but in a medium containing a binding inhibiting sugar (alpha-methyl-mannopyrasosid) . The number and distribution of the microbeads on human oocytes of both groups were analysed on scanning electron microscopy images . Beads on oocytes of group A had binding patterns similar to those of spermatozoa . They were distributed in an extremely heterogeneous way with various numbers of bound beads both on individual and different oocytes . Most of the group A oocytes (85%) had more than 50 beads bound to the zona, in contrast to the control oocytes of group B, where 68% had less than 10 bound beads . The use of an inhibiting sugar abolished the binding capacity of the microbeads nearly completely . This technique is a powerful tool for the detection of binding sites on the zona pellucida, i.e . those sugars that are responsible for contact between spermatozoa and the zona pellucida.

Proteomics, 2001 Aug, 1(8), 1033 - 42
Structural modifications of Methanococcus jannaschii flagellin proteins revealed by proteome analysis; Giometti CS et al.; Methanococcus jannaschii is an autotrophic archaeon originally isolated from an oceanic thermal vent . The primary metabolic pathway for energy production in this hyperthermophilic microbe is methanogenesis from H2 and CO2 . As an autotroph, M . jannaschii requires only CO2 as a carbon source for synthesizing all necessary biomolecules . Changes in the environmental availability of these molecules can be expected to activate regulatory mechanisms manifested as the up and down regulation of specific genes and the concomitant increase and decrease in abundance of the corresponding proteins . In our analysis of the proteome of M . jannaschii, we have observed significant changes in the abundance of a common subset of predominant proteins in response to reduced H2 concentration, limited ammonium availability, and the stage of cell growth (exponential compared with stationary) . The masses of tryptic peptides from these proteins match those predicted by M . jannaschii genome open reading frames annotated as flagellin B1 (MJ0891) and flagellin B2 (MJ0892) . Multiple proteins with different isoelectric points and molecular weights match each of these proteins, and the abundance of these protein variants changes with growth conditions . These data indicate that structural modifications altering both the isoelectric point and size of the M . jannaschii flagellin B1 and B2 proteins occur in response to growth conditions and growth stage of M . jannaschii and further suggest the regulation of M . jannaschii motility through structural modifications of the building blocks of the flagella.

Int J Med Microbiol, 2001 Sep, 291(4), 251 - 60
Toll-like receptors: cellular signal transducers for exogenous molecular patterns causing immune responses; Kirschning CJ et al.; Innate immunity initiates protection of the host organism against invasion and subsequent multiplication of microbes by specific recognition . Germ line-encoded receptors have been identified for microbial products such as mannan, lipopeptide, peptidoglycan (PGN), lipoteichoic acid (LTA), lipopolysaccharide (LPS), and CpG-DNA . The Drosophila Toll protein has been shown to be involved in innate immune response of the adult fruitfly . Members of the family of Toll-like receptors (TLRs) in vertebrates have been implicated as pattern recognition receptors (PRRs) . Ten TLRs are known and six of these have been demonstrated to mediate cellular activation by distinct microbial products . TLR4 has been implicated as activator of adaptive immunity, and analysis of systemic LPS responses in mice led to the identification of LPS-resistant strains instrumental in its identification as a transmembrane LPS signal transducer . Structural similarities between TLRs and receptor molecules involved in immune responses such as CD14 and the IL-1 receptors (IL-1Rs), as well as functional analysis qualified TLR2 as candidate receptor for LPS and other microbial products . Targeted disruption of the TLR9 gene in mice led to identification of TLR9 as CpG-DNA signal transducer . Involvement of TLR5 in cell activation by bacterial flagellin has been demonstrated . Further understanding of recognition and cellular signaling activated through the ancient host defense system represented by Toll will eventually lead to means for its therapeutic modulation.

Med Clin North Am, 2001 Nov, 85(6), 1329 - 47
Host defense in respiratory infections; Welsh DA et al.; Respiratory defenses against infection involve a diverse and complex system . Mechanical barriers limit exposure of the respiratory tract to potential pathogenic organisms, whereas the mucociliary apparatus and cough reflexes work to expel any microbes that may bypass the initial defenses . When microorganisms have gained entry to the lower respiratory tract, the alveolar macrophage and recruited phagocytes may eliminate the culprits before active infection can be established . Only after the failure of the innate immune defenses is a specific immune response mounted . Examination of clinical defects in host defense allows one to understand the importance of the multitude of components of the lung's immune defense system.

Appl Environ Microbiol, 2001 Nov, 67(11), 5143 - 53
Bacteria and Archaea physically associated with Gulf of Mexico gas hydrates; Lanoil BD et al.; Although there is significant interest in the potential interactions of microbes with gas hydrate, no direct physical association between them has been demonstrated . We examined several intact samples of naturally occurring gas hydrate from the Gulf of Mexico for evidence of microbes . All samples were collected from anaerobic hemipelagic mud within the gas hydrate stability zone, at water depths in the ca . 540- to 2,000-m range . The delta(13)C of hydrate-bound methane varied from -45.1 per thousand Peedee belemnite (PDB) to -74.7 per thousand PDB, reflecting different gas origins . Stable isotope composition data indicated microbial consumption of methane or propane in some of the samples . Evidence of the presence of microbes was initially determined by 4,6-diamidino 2-phenylindole dihydrochloride (DAPI) total direct counts of hydrate-associated sediments (mean = 1.5 x 10(9) cells g(-1)) and gas hydrate (mean = 1.0 x 10(6) cells ml(-1)) . Small-subunit rRNA phylogenetic characterization was performed to assess the composition of the microbial community in one gas hydrate sample (AT425) that had no detectable associated sediment and showed evidence of microbial methane consumption . Bacteria were moderately diverse within AT425 and were dominated by gene sequences related to several groups of Proteobacteria, as well as Actinobacteria and low-G + C Firmicutes . In contrast, there was low diversity of Archaea, nearly all of which were related to methanogenic Archaea, with the majority specifically related to Methanosaeta spp . The results of this study suggest that there is a direct association between microbes and gas hydrate, a finding that may have significance for hydrocarbon flux into the Gulf of Mexico and for life in extreme environments.

Biosens Bioelectron, 2001 Dec, 16(9-12), 1021 - 6
Yeast-immobilized SPV device for koji quality control in sake brewing process; Chiyo T et al.; The malted rice, koji, is an indispensable material for the brewing of sake . It saccharifies rice starch and supplies vitamins for the yeast in sake brewing . Since the quality of sake depends strongly on the quality of koji, quality control of koji is very important in the brewing . There are some methods to measure the activity of enzymes and the quantity of vitamins with the quality of koji . None of these methods, however, directly relate to the yeast metabolism . We constructed a sensor system to monitor the yeast metabolism in sake brewing by use of immobilized Saccharomyces cerevisiae and a Surface PhotoVoltage device (SPV) . In this system, S . cerevisiae K701 and K9, designed for use in sake brewing by the Brewing Society of Japan, were employed as immobilized microbe . The pH change due to the production of organic acids in sake brewing is measured using the SPV . A linear relationship was observed between decrease in the photocurrent (the metabolism response) and the concentration to less than 60 mM of glucose (r=0.990) . Then we measured the koji extract and observed the difference of response between K701 and K9 which corresponded to the productivity of acidic substances by batch test.

Immunity, 2001 Oct, 15(4), 579 - 89
Epstein-Barr virus transactivates the human endogenous retrovirus HERV-K18 that encodes a superantigen; Sutkowski N et al.; Superantigens (SAgs) are proteins produced by pathogenic microbes to elicit potent, antigen-independent T cell responses that are believed to enhance the microbes' pathogenicity . Here we show that the human lymphotropic herpesvirus Epstein-Barr virus (EBV) transcriptionally activates the env gene of an endogenous retrovirus, HERV-K18, that possesses SAg activity . SAg activity was demonstrated by MHC class II dependent preferential activation of TCRVB13 T cells in response to murine B cells transfected with the HERV-K18 env gene . This is a unique demonstration of a pathogen inducing a host-encoded Sag and accounts for the previously described EBV associated Sag activity . The T cell activation elicited by the Sag could play a central role in EBV infection and associated diseases.

Respir Res, 2000, 1(3), 129 - 32 Epub 2000 Oct 25.
Mimicking microbial 'education' of the immune system: a strategy to revert the epidemic trend of atopy and allergic asthma?
Matricardi PM, Bonini S.
Deficient microbial stimulation of the immune system, caused by hygiene, may underly the atopy and allergic asthma epidemic we are currently experiencing . Consistent with this 'hygiene hypothesis', research on immunotherapy of allergic diseases also centres on bacteria-derived molecules (eg DNA immunostimulatory sequences) as adjuvants for allergen-specific type 1 immune responses . If we understood how certain microbes physiologically 'educate' our immune system to interact safely with environmental nonmicrobial antigens, we might be able to learn to mimic their beneficial actions . Programmed 'immunoeducation' would consist of safe administration, by the correct route, dose and timing, of those microbial stimuli that are necessary to 'train' the developing mucosal immune system and to maintain an appropriate homeostatic equilibrium between its components . Overall, this would result in a prevention of atopy that is not limited to certain specific allergens . Although such a strategy is far beyond our present potential, it may in principle revert the epidemic trend of atopy and allergic asthma without jeopardizing the fight against infectious diseases.

J Am Dent Assoc, 2001 Sep, 132(9), 1241 - 5
The effects of toothpastes on the residual microbial contamination of toothbrushes; Warren DP et al.; BACKGROUND: Contaminated toothbrushes have been shown to harbor and transmit viruses and bacteria . The authors conducted a study to evaluate the effect of a triclosan-containing toothpaste on the residual anaerobic microbial contamination of toothbrushes . METHODS: Twenty patients who had Type III or Type IV periodontitis participated in this study . One side of each of their mouths served as a control (no toothpaste) . The teeth on the other side were brushed with a regular toothpaste or a triclosan-containing toothpaste . After the toothbrushes were allowed to dry in air for four hours, the authors placed the toothbrush heads in solution, dislodged the microbes from the brushes by vortexing and plated them in culture dishes . The authors anerobically incubated the culture dishes and determined the presence or absence of Prevotella species or Ps; Porphyromonas gingivalis, or Pg; and Actinobacillus actinomycetemcomitans, or Aa . RESULTS: The authors detected Aa and Pg on the control toothbrushes more frequently than they did Ps . This variation in isolation frequency was statistically significant by chi 2 analysis (P < .001) . The authors compared the isolation frequency of the three test organisms between the control and regular-toothpaste groups, between the control and triclosan-containing--toothpaste groups, and between the triclosan-containing--toothpaste and regular-toothpaste groups . They found no significant intergroup differences in the isolation frequencies after using chi 2 analysis . CONCLUSIONS: Toothpaste use reduced the residual microbial contamination for two of three test organisms, but the lower isolation frequencies were not statistically significant . Further study in this area is indicated . CLINICAL IMPLICATIONS: Dental professionals should advise patients who have systemic, localized or oral inflammatory diseases to disinfect or frequently replace their toothbrushes.

Science . 1985 Jan 11;227(4683):153.
Monsanto may bypass NIH in microbe test; Sun M; KIE: The Monsanto Company is planning to ask the Environmental Protection Agency for clearance to field test a genetically engineered microbial pesticide, bypassing the traditional approval process of the National Institutes of Health . Although only federally funded institutions are required to obtain NIH approval for genetic engineering tests, Monsanto is the first company to bypass the NIH regulatory process, which has become mired in a lawsuit brought by Jeremy Rifkin .

Ukr Biokhim Zh, 2001 Mar-Apr, 73(2), 130 - 7
{Features of glutamate dehydrogenase in fetal and adult rumen tissue}; Kalachniuk HI et al.; Glutamate dehydrogenase (GDH) from rumen mucosa of cow fetus, liver and two forms from mucosa (bacterial and tissue) of the adult animal were partly purified and characterized . The activity of the bacterial glutamate dehydrogenase was shown to depend on qualities of a biomass of microbes, adhered on surface of rumen mucosa . All enzymes from tissues (GDHTRF, TRC, TLC), revealed the hypersensibility to increase in the concentration medium of Zn2+, guanosine triphosphate (GTP), acting here in a role of negative modulators, and also adenosine monophosphate (AMP) and leucine, which acted as activators . However, in the same concentrations these effectors do not influence the activity of the bacterial glutamate dehydrogenase . And if all tissues enzymes are highly specific to coenzyme NADH, the bacterial ones almost in 3 times is more active at NADPH use.

Int Arch Allergy Immunol, 2001 Sep, 126(1), 23 - 31
Some aspects of complementarity in the immune system . A bird's eye view; Bakacs T et al.; The burden of this paper is the suggestion that the defence capacity of the immune system is rather limited . It cannot stand in readiness to deal with a practically endless diversity and abundance of microbes . In contrast to conventional thinking the current model proposes: (1) The core idea that cells of the immune system are basically and constantly interconnected with host cells (e.g., through TCR-MHC interactions) and that foreign antigens (peptides) may tend to obstruct such interactions . Peptides presented during a viral infection typically decrease complementarity between the structures that are the products of the major histocompatibility complex (MHC) genes (or other genes related to it) and T cells . The altered MHC profile exposes infected cells to a polyclonal immune attack from other T cells such that tissue destruction occurs in an allograft rejection-like fashion . This may explain why a substantial portion of T cell numbers is activated when only a small number of specific T cells is 'obstructed' from functioning by the presence of nonself peptides . (2) Phagocytes 'see' targets even in a non-immune host because complement distribution associated with polyreactive natural antibodies magnifies sensitization differences between pathogens and host cells . (3) There is only a probability that hypermutation will successfully change the genome in some B cell clones to produce high affinity antibodies that prevent the re-infection of the host by the same pathogen, but cannot conquer primary infections . (4) The history of the development of the immune responses suggests that during prolonged interaction between host and microbes in our natural habitat, carried on over many generations, the adaptive antibody population may facilitate the evolution of the natural antibody repertoire . The model predicts that microbes, which are not a part of the local environment, may invade the organism without significant resistance . The model is discussed in various interactions for survival in the context of infection and tumorigenicity .

Dan Medicinhist Arbog . 1998;:61-76.
Not Available
Rasmussen L.
Louis Pasteur in France saw that microbes might cause disease, Gerhard Armauer Hansen in Norway established a connection between a bacterium and a human disease, and Robert Koch in Germany supplied the final proof that linked bacteria to disease . From then on there was an explosion in interest and techniques for cultivation of bacteria . It lasted about 30 years before Harrison in the USA succeeded in growing cells from multicellular organisms in pure culture . His technique came to Denmark at an early time point and the Rockefeller Foundation in New York and the Carlsberg Foundation in Copenhagen joined forces and built the Biological Institute of the Carlsberg Foundation in order to support Albert Fischer in his study of cell biology . His first assistant at this Institute, Fritz Lipmann, won the Nobel Prize for 1953 for work initiated there . The Institute remained a center for cell biology for almost 50 years . At the neighboring Rockefeller Institute in Copenhagen Einar Lundsgaard obtained results showing in the short perspective that current concepts of cellular utilization of energy were wrong, and in the long perspective his assistant, Herman Kalckar, would formulate modern concepts of cellular oxidative phosphorylations . This review is based in part on films from the 1930's.

Ber Wissenschaftsgesch, 1996, 19(2-3), 81 - 94
Not Available
Gradmann C.
The text analyses metaphors of bacteriology which were extensively used in Germany during the era of William II . These display--in a vivid exchange with the scientific concepts of the age--a specific popular understanding of disease based on bacteriology . Disease is essentially seen as a war of physicians against microbes . While popularizing science bacteriological metaphors became part of the political language of their age . At the same time the prestige of bacteriology was in turn employed to lend credibility to pictures of assumed enemies--by portraying them as infectious diseases . Although the political language of bacteriology differed from the social darwinism of the age in important structural and semantic aspects, it nevertheless influenced the political language of its time, for example by becoming a blueprint of antisemitic rhetorics.

Hist Cienc Saude Manguinhos, 1995, 2(1), 67 - 98
{Domingos José Freire and the beginnings of bacteriology in Brazil}; Benchimol JL; The article examines the trajectory of Domingos Jose Freire, a bacteriologist who attained great national and international renown in the final quarter of the last century for claiming to have discovered the yellow-fever microbe and a vaccine that was administered to thousands of people . The article reviews the main controversies protagonized by this scientist and endeavors to show the role be played in the enthronement of Pasteurian medicine in Brazil.

Zhonghua Yi Shi Za Zhi, 1999 Oct, 29(4), 203 - 6
{A brief history of discovery of Helicobacter pylori}; Li J et al.; The theoretical background for the diagnosis and treatment of upper digestive ulcer, gastritis and stomach carcinema was challenged by H . pylori, a microbe seems only under the microscope . This paper makes a brief review on the brief history of discovery and recent conclusion on the microbe, and explores its challenge to the traditional conception.

Yeni Tip Tarihi Arastirmalari, 1998, 4, 237 - 43
{Some medical documents written by Ahmed Cevdet Pasha}; Izgoer AZ; The assumption that civilization was originated in the East, was one of the most important points emphasized by the intelligentsia of the late Ottoman reign . This conviction was appreciated in the thought of Ahmed Cevdet Pasha (1823 - 1895), a famous figure of the period . Cevdet Pasha, who believed that the source of science and education was started in the East, claimed that Europe was acquainted with Islamic science during the Crusades . In this paper Cevdet Pasha's ideas related with small-pox, cholera, plague, poisons and microbes are mentioned . This study is based on Cevdet Pasha's documents related with these subjects; and the transcriptions of the texts are given.

Proc Natl Acad Sci U S A, 1996 May 14, 93(10), 4600 - 3
Mapping leaf surface landscapes; Mechaber WL et al.; Leaf surfaces provide the ecologically relevant landscapes to those organisms that encounter or colonize the leaf surface . Leaf surface topography directly affects microhabitat availability for colonizing microbes, microhabitat quality and acceptability for insects, and the efficacy of agricultural spray applications . Prior detailed mechanistic studies that examined particular fungi-plant and pollinator-plant interactions have demonstrated the importance of plant surface topography or roughness in determining the outcome of the interactions . Until now, however, it has not been possible to measure accurately the topography--i.e., the three-dimensional structure--of such leaf surfaces or to record precise changes in patterns of leaf surface elevation over time . Using contact mode atomic force microscopy, we measured three-dimensional coordinates of upper leaf surfaces of Vaccinium macrocarpon (cranberry), a perennial plant, on leaves of two age classes . We then produced topographic maps of these leaf surfaces, which revealed striking differences between age classes of leaves: old leaves have much rougher surfaces than those of young leaves . Atomic force microscope measurements were analyzed by lag (1) autocorrelation estimates of leaf surfaces by age class . We suggest that the changes in topography result from removal of epicuticular lipids and that the changes in leaf surface topography influence phylloplane ecology . Visualizing and mapping leaf surfaces permit detailed investigations into leaf surface-mediated phenomena, improving our understanding of phylloplane interactions.

Proc Natl Acad Sci U S A, 1990 Oct, 87(19), 7565 - 9
Sterol phylogenesis and algal evolution; Nes WD et al.; The stereochemistry of several sterol precursors and end products synthesized by two fungal-like micro-organisms Prototheca wickerhamii (I) and Dictyostelium discoideum (II) have been determined by chromatographic (TLC, GLC, and HPLC) and spectral (UV, MS, and 1H NMR) methods . From I and II the following sterols were isolated from the cells: cycloartenol, cyclolaudenol, 24(28)-methylenecycloartanol, ergosterol, protothecasterol, 4alpha-methylergostanol, 4alpha-methylclionastanol, clionastanol, 24beta-ethylcholesta-8,22-enol, and dictyosterol . In addition, the mechanism of C-24 methylation was investigated in both organisms by feeding to I {2-3H}lanosterol, {2-3H}cycloartenol, {24-3H}lanosterol, and {methyl-2H3}methionine and by feeding to II {methyl-2H3}methionine . The results demonstrate that the 24beta configuration is formed by different alkylation routes in I and II . The Delta25(27) route operates in I while the Delta24(28) route operates in II . Based on what is known in the literature regarding sterol distribution and phylogenesis together with our findings that the stereochemical outcome of squalene oxide cyclization leads to the production of cycloartenol rather than lanosterol (characteristic of the fungal genealogy) and the chirality of the C-24 alkyl group is similar in the two nonphotosynthetic microbes (beta oriented), we conclude that Prototheca is an apoplastic Chlorella (i.e., an alga) and that Dictyostelium as well as the other soil amoebae that synthesize cycloartenol evolved from algal rather than fungal ancestors.

Prikl Biokhim Mikrobiol, 2001 Sep-Oct, 37(5), 607 - 11
{Effect of proteinaceous polygalacturonase inhibitors from apple seed tissue on an enzyme isolated from phytopathogenic fungi}; Glinka EM et al.; A protein polygalacturonidase inhibitor isolated from fruit of the apple varieties Antonovka and Mantuanskoe differently affects the polygalacturonidases of different phytopathogenic fungi . Three groups of fungi were recognized by the sensitivity of their polygalacturonidases to the inhibitory effect . Storage of apples after harvesting is accompanied by changes in the inhibitor activity, and the time pattern of these changes depends on the variety . An increase in the inhibitor activity occurs concurrently with the elevation in ethylene release characteristic of the stage of elevated respiration (a climacteric increase) . The data suggest that a decrease in the apple fruit resistance to microbes at the end of the storage period is related, along with other reasons, to a change in the activity of the protein polygalacturonidase inhibitor.

Radiat Res, 2001 Nov, 156(5 Pt 2), 612 - 7
The potential impact of bystander effects on radiation risks in a Mars mission; Brenner DJ et al.; Densely ionizing (high-LET) galactic cosmic rays (GCR) contribute a significant component of the radiation risk in free space . Over a period of a few months-sufficient for the early stages of radiation carcinogenesis to occur-a significant proportion of cell nuclei will not be traversed . There is convincing evidence, at least in vitro, that irradiated cells can send out signals that can result in damage to nearby unirradiated cells . This observation can hold even when the unirradiated cells have been exposed to low doses of low-LET radiation . We discuss here a quantitative model based on the a formalism, an approach that incorporates radiobiological damage both from a bystander response to signals emitted by irradiated cells, and also from direct traversal of high-LET radiations through cell nuclei . The model produces results that are consistent with those of a series of studies of the bystander phenomenon using a high-LET microbeam, with the end point of in vitro oncogenic transformation . According to this picture, for exposure to high-LET particles such as galactic cosmic rays other than protons, the bystander effect is significant primarily at low fluences, i.e., exposures where there are significant numbers of untraversed cells . If the mechanisms postulated here were applicable in vivo, using a linear extrapolation of risks derived from studies using intermediate doses of high-LET radiation (where the contribution of the bystander effect may be negligible) to estimate risks at very low doses (where the bystander effect may be dominant) could underestimate the true risk from low doses of high-LET radiation . It would be highly premature simply to abandon current risk projections for high-LET, low-dose radiation; however, these considerations would suggest caution in applying results derived from experiments using high-LET radiation at fluences above approximately 1 particle per nucleus to risk estimation for a Mars mission.

Radiat Res, 2001 Nov, 156(5 Pt 1), 526 - 34
Low-dose hypersensitivity in Chinese hamster V79 cells targeted with counted protons using a charged-particle microbeam; Schettino G et al.; The Gray Laboratory charged-particle microbeam has been used to assess the clonogenic ability of Chinese hamster V79 cells after irradiation of their nuclei with a precisely defined number of protons with energies of 1.0 and 3.2 MeV . The microbeam uses a 1-microm silica capillary collimator to deliver protons to subcellular targets with high accuracy . The detection system is based on a miniature photomultiplier tube positioned above the cell dish, which detects the photons generated by the passage of the charged particles through an 18-microm-thick scintillator placed below the cells . With this system, a detection efficiency of greater than 99% is achieved . The cells are plated on specially designed dishes (3-microm-thick Mylar base), and the nuclei are identified by fluorescence microscopy . After an incubation period of 3 days, the cells are revisited individually to assess the formation of colonies from the surviving cells . For each energy investigated, the survival curve obtained for the microbeam shows a significant deviation below 1 Gy from a response extrapolated using the LQ model for the survival data above 1 Gy . The data are well fitted by a model that supports the hypothesis that radioresistance is induced by low-dose hypersensitivity . These studies demonstrate the potential of the microbeam for performing studies of the effects of single charged particles on cells in vitro . The hypersensitive responses observed are comparable with those reported by others using different radiations and techniques.

J Am Chem Soc, 2001 Oct 24, 123(42), 10173 - 82
Hydroaromatic equilibration during biosynthesis of shikimic acid; Knop DR et al.; The expense and limited availability of shikimic acid isolated from plants has impeded utilization of this hydroaromatic as a synthetic starting material . Although recombinant Escherichia coli catalysts have been constructed that synthesize shikimic acid from glucose, the yield, titer, and purity of shikimic acid are reduced by the sizable concentrations of quinic acid and 3-dehydroshikimic acid that are formed as byproducts . The 28.0 g/L of shikimic acid synthesized in 14% yield by E . coli SP1.1/pKD12.138 in 48 h as a 1.6:1.0:0.65 (mol/mol/mol) shikimate/quinate/dehydroshikimate mixture is typical of synthesized product mixtures . Quinic acid formation results from the reduction of 3-dehydroquinic acid catalyzed by aroE-encoded shikimate dehydrogenase . Is quinic acid derived from reduction of 3-dehydroquinic acid prior to synthesis of shikimic acid? Alternatively, does quinic acid result from a microbe-catalyzed equilibration involving transport of initially synthesized shikimic acid back into the cytoplasm and operation of the common pathway of aromatic amino acid biosynthesis in the reverse of its normal biosynthetic direction? E . coli SP1.1/pSC5.214A, a construct incapable of de novo synthesis of shikimic acid, catalyzed the conversion of shikimic acid added to its culture medium into a 1.1:1.0:0.70 molar ratio of shikimate/quinate/dehydroshikimate within 36 h . Further mechanistic insights were afforded by elaborating the relationship between transport of shikimic acid and formation of quinic acid . These experiments indicate that formation of quinic acid during biosynthesis of shikimic acid results from a microbe-catalyzed equilibration of initially synthesized shikimic acid . By apparently repressing shikimate transport, the aforementioned E . coli SP1.1/pKD12.138 synthesized 52 g/L of shikimic acid in 18% yield from glucose as a 14:1.0:3.0 shikimate/quinate/dehydroshikimate mixture.

Dev Comp Immunol, 2001 Oct-Dec, 25(8-9), 725 - 43
The acute phase response and innate immunity of fish; Bayne CJ et al.; Tissue trauma or invasion by pathogens or parasites induce changes in the quantities of several macromolecules in animal body fluids . These changes comprise one aspect of the acute phase response (APR), which in toto involves metabolic changes in several organ systems . One clear indication of the response is the increase in synthesis and secretion by the liver of several plasma proteins, with simultaneous decreases in others . These acute phase proteins (APP) function in a variety of defense-related activities such as limiting the dispersal of infectious agents, repair of tissue damage, inactivation of proteases, killing of microbes and other potential pathogens, and restoration of the healthy state . Some APP are directly harmful to microbes, while others modify targets thus marking them for cell responses . Some work alone while others contribute to cascades . Proteins that are APP in mammals, and that have been identified in both teleosts and elasmobranchs include C-reactive protein, serum amyloid P, and several components of the Complement system . Others reported in teleosts include transferrin and thrombin . Of these, only CRP has been reported to increase in acute phase plasma . In trout, a precerebellin-like protein is an APP with unknown functions . A cDNA library enriched in fragments of transcripts that were more abundant in livers from fish undergoing an APR recently yielded sequences resembling 12 additional known APP, and as many others either not known to be APP, or not similar to others yet in public databases . It appears that, as in mammals, hepatocytes are the prime source of APP in fish, and that pro-inflammatory cytokines induce transcription of their genes.

Med Hypotheses, 2001 Oct, 57(4), 484 - 6
Control of skin infections by a combined action of ultraviolet A (from sun or UVA lamp) and hydrogen peroxide (HUVA therapy), with special emphasis on leprosy; Ahmad SI; Despite its abundance and certain therapeutic value, the importance of sunlight in the treatment of infectious skin diseases has not been fully exploited . One reason is that a sufficient amount of the damaging components of sunlight (UVC and most UVB) cannot reach us and the band of UV that can reach (UVA) is a poor inactivator of living cells . UVA, however, can be deleterious to cells in the presence of sensitizers and a number of biological and chemical sensitizers have been identified which can inactivate microbes in the presence of UVA.Of several known agents, I have selected hydrogen peroxide (H(2)O(2)) as a UVA sensitizer and propose that a combined action of H(2)O(2)and UVA (HUVA therapy) can be utilized in controlling skin infections of various types.Of particular interest is infection by Mycobacterium leprae, which is known to affect many millions of humans globally . H(2)O(2)being relatively cheap (and UVA from the sun being free) the cost of application, particularly in third-world countries where leprosy is more common, would be low and therefore the treatment can be employed on a wide scale . A further reason for proposing the use of H(2)O(2)is that, out of several agents we have tested, this was found to be the most potent; it is also easily able to reach target sites, very cheap, relatively safe and there is no known microbial resistance to HUVA .

Rom J Virol, 1999 Jan-Dec, 50(1-4), 53 - 70
Evidence of TNF system activation and high expression of TNF alpha messenger transcripts in necrotizing enterocolitis of HIV-infected children; Ispas D; TNF alpha contributes to the necrotizing enterocolitis (NEC) pathogenesis . To date, this clinical entity of neonates was never described in HIV-infected children . In 15 HIV-positive children with histological evidence of various intestinal lesions resembling NEC, we have studied serum TNF alpha and soluble TNF receptor concentrations by ELISAs, and archived paraffin embedded intestinal tissues by in situ hybridization with DIG-labeled RNA probes for TNF alpha messenger transcripts . We found increased levels of TNF alpha and soluble receptors, proving TNF alpha system activation . We detected TNF alpha messenger transcripts in all cases, regardless of the presence of microbial pathogens at intestinal level . Since HIV can infect many cells of the gastrointestinal tract, also triggering the secretion of TNF alpha, we concluded that factors contributing to NEC pathogenesis in HIV-infected children are complex . At least the nutritional and immunological status are involved, other viral co-infections, opportunistic microbes (such as mycobacteria), and pathogenic activities of HIV . All together enhance both circulating TNF alpha system and its cytotoxic effects at intestinal level.

Burns, 2001 Nov, 27(7), 699 - 707
Strategies to improve the take of commercially available collagen/glycosaminoglycan wound repair material investigated in an animal model; Grant I et al.; Integra Artificial Skin is becoming widely used in burns and reconstructive surgery . However, poor take and loss due to infection remains a concern for some patients . This study describes how the successful bio-integration of Integra Artificial Skin was accomplished in isolated full-thickness wounds in the pig, by the use of sequential protocol modifications that more intimately opposed the material to the wound bed . Further improvement was achieved by measures to reduce bacterial colonisation including the use of topical anti-microbial agents . The level of histologically confirmed Integra 'take' improved from close to zero to a mean 96% of wound area (+/-11 S.D.) . The efficacy of this dermal wound bed was confirmed by the histological analysis of wounds after the subsequent application of extremely thin (<130 microm) widely meshed autologous split-thickness skin grafts . The results of this animal study support the recommendation that the bio-integration of Integra Artificial Skin is best achieved by the elimination of dead space below the material and by measures to hinder the penetration of microbes . The significant improvement in take achieved in this animal model using simple methodological refinements re-identifies priorities for the use of Integra Artificial Skin that can be applied in clinical management.

Environ Toxicol Chem, 2001 Oct, 20(10), 2287 - 95
Pollution-induced community tolerance and functional redundancy in a decomposer food web in metal-stressed soil; Salminen J et al.; Pollution may lead to the development of pollution-induced community tolerance (PICT) in a stressed community . We studied the presence of PICT in soil food webs using soil microcosms . Soil microcosms containing soil invertebrates and microbes were collected from polluted and unpolluted areas and exposed to a range of soil zinc concentrations . A pine seedling was planted in each microcosm to measure the effects of the origin of the community and Zn pollution on above-ground plant production . The effects of the treatments on nutrient content in the soil were also measured . The diversity of soil microarthropods and the soil's mineral nutrient content were low at the Zn-polluted site . We did not observe an increasing Zn tolerance among the soil organisms in the polluted soil . However, low population growth rates of soil invertebrates from the polluted site may indicate the deleterious effects on fitness of long-lasting pollution . In the soil from the nonpolluted site, Zn additions caused changes in the invertebrate food web structure . These changes were explained by the good physiological condition of the animals and their insensitivity to Zn . The fact that the food web structure in soil from the polluted site did not change can be used as a rough indicator of PICT . Structural stability is presumed by the lack of Zn-sensitive species at this site and the inability of populations to acclimate by altering their growth or reproduction patterns in response to changing soil conditions . Although microbial-based soil decomposer systems may have a high functional redundancy, our results indicate that metal stress at the polluted site exceeds the tolerance limits of the system . As a consequence, ecosystem function at this site is endangered . This study also shows that the evolution of metal tolerance by soil decomposer organisms may not be a common reaction to soil pollution, although changes of population and community structure indicated severe metal stress on organisms.

Acta Astronaut, 2001 Jul, 49(2), 105 - 8
Effect of volatile metabolites of dill, radish and garlic on growth of bacteria; Tirranen LS et al.; In a model experiment plants were grown in sealed chambers on expanded clay aggregate under the luminance of 150 W/m2 PAR and the temperature of 24 degrees C . Seven bacterial strains under investigation, replicated on nutrient medium surface in Petri dishes, were grown in the atmosphere of cultivated plants . Microbial response was evaluated by the difference between colony size in experiment and in control . In control, bacteria grew in the atmosphere of clean air . To study the effects of volatile metabolites of various plant on microbial growth, the experimental data were compared with the background values defined for each individual experiment . Expanded clay aggregate, luminance, temperature, and sealed chamber (without plants) for the background were the same . Volatile metabolites from 28-days old radish plants have been reliably established to have no effect on the growth of microbes under investigation . Metabolites of 30-days old dill and 50-days old garlic have been established to have reliable bacteriostatic effect on the growth of three bacterial strains . Dill and garlic have been found to have different range of effects of volatile substances on bacterial growth . Volatile metabolites of dill and garlic differed in their effect on the sensitivity spectrum of bacteria . An attempt has been made to describe the obtained data mathematically . c 2001 International Astronautical Federation . Published by Elsevier Science Ltd.

Analyst, 2001 Sep, 126(9), 1545 - 50
Detection of aflatoxins (G(1-2), B(1-2)), sterigmatocystin, citrinine and ochratoxin A in samples contaminated by microbes; Tuomi T et al.; A method is described for the simultaneous determination of common aflatoxins (G1, G2, B1, B2) and their precursor sterigmatocystin, and also citrinine and ochratoxin A . The method was applied to a building material matrix artificially contaminated with mycotoxin-producing fungi . The method includes extraction, sample pre-treatment and reversed-phase HPLC separation with tandem mass spectrometric identification and quantification using electrospray ionisation on a quadrupole ion trap mass analyser (ESI-MS-MS) . Aqueous methanol was used in the initial extraction and solvent partitioning and solid phase extraction in the purification of samples . The HPLC separation was run on-line with the ESI-MS-MS detection . The limit of quantification of the procedure was 200 ng for all compounds . Recoveries of the sample pre-treatment varied from 28 to 99% . The average compound- and concentration-dependent accuracy and precision (RSD) were 21 and 113%, respectively . The method includes small sample volumes (approximately 1 g in 20 ml) and few, non-labour intensive, sample treatment steps . It should allow for a high throughput of samples with good prospects of automation.

J Biol Chem, 2001 Dec 14, 276(50), 47143 - 9 Epub 2001 Oct 04.
Molecular cloning and functional characterization of chicken toll-like receptors . A single chicken toll covers multiple molecular patterns; Fukui A et al.; Toll-like receptors (TLR) in the innate immune system have not been identified in non-mammalian vertebrates . Two types of TLR were cloned from a chicken bursa cDNA library using degenerate primers based on the consensus sequences of mouse and Drosophila Toll and designated as chicken TLR (chTLR) type 1 and type 2 . Of the nine human TLRs reported to date, these chTLRs showed the highest homology to human TLR2 . The extracellular regions of type 1 and type 2 contained a distinct approximately 200-amino acid stretch and were 45.3 and 46.3% homologous to that of human TLR2 . The intracellular Toll/interleukin-1R homology domain of type 1 and type 2 was perfectly identical to each other and highly homologous (80.7%) to that of human TLR2 . Both types were widely detected by reverse transcriptase-polymerase chain reaction and immunoblotting in various chicken organs, especially those rich in connective tissue . Both genes were mapped to chromosome 4q1.1, suggesting that they arose by gene duplication . By reporter gene assay, type 2 and to a lesser extent type 1, selectively signaled the presence of mycoplasma macrophage-activating lipopeptide-2/M161Ag in the human embryonic kidney 293 cell system . Cotransfection of type 2 and human CD14 or MD-2 into human embryonic kidney 293 cells allowed the response to Escherichia coli lipopolysaccharide (LPS), whereas type 1 did not signal LPS or any other microbial components tested . These results indicated that chTLR type 2 covers two major microbe patterns, lipoproteins and LPS, which are regulated by TLR2 and TLR4 in mammals . In oviparous animals, the duplicated TLRs in the pattern-recognition system may function for host-pathogen discrimination in a manner that is distinct from that in mammals.

Eur Respir J, 2001 Sep, 18(3), 571 - 88
Lung mucosal immunity: immunoglobulin-A revisited; Pilette C et al.; Mucosal defence mechanisms are critical in preventing colonization of the respiratory tract by pathogens and penetration of antigens through the epithelial barrier . Recent research has now illustrated the active contribution of the respiratory epithelium to the exclusion of microbes and particles, but also to the control of the inflammatory and immune responses in the airways and in the alveoli . Epithelial cells also mediate the active transport of polymeric immunoglobulin-A from the lamina propria to the airway lumen through the polymeric immunoglobulin receptor . The role of IgA in the defence of mucosal surfaces has now expanded from a limited role of scavenger of exogenous material to a broader protective function with potential applications in immunotherapy . In addition, the recent identification of receptors for IgA on the surface of blood leukocytes and alveolar macrophages provides an additional mechanism of interaction between the cellular and humoral immune systems at the level of the respiratory tract.

Eur Respir J, 2001 Sep, 18(3), 542 - 8
Inflammatory mediators in nasal lavage, induced sputum and serum of employees with rheumatic and respiratory disorders; Roponen M et al.; Exposure to microbes present in mould-damaged buildings has been linked to increased frequency of various inflammatory diseases . The current study examined differences in inflammatory mediators in nasal lavage (NAL), induced sputum (IS) and serum of occupants with rheumatic or respiratory disorders and their controls, all working in the same moisture-damaged building . Exhaled nitric oxide (NO) measurements, lung function tests, skin-prick tests and health data collection by questionnaire were performed . Concentrations of NO, interleukin (IL)-1, IL-4, IL-6 and tumour necrosis factor-alpha in NAL, IS and serum (excluding NO and IL-1) of the subjects were measured during an occupational exposure period and the vacation period without such exposure . The concentrations of IL-4 in NAL fluid were significantly higher among all occupants during the working period (geometric mean 8.5 microg x mL(-1), range 0-206.5 microg x mL(-1)), as compared to that during vacation (0.4 microng x mL(-1) range 0-3.7 pg x mL(-1)) (p = 0.008) . Absence from the work environment also significantly diminished reporting of symptoms . IL-4 levels in the serum of case subjects were significantly higher than in controls . Moreover, employees with respiratory symptoms had markedly higher exhaled NO values than their controls (p = 0.028) . In summary, these data suggest that mediators in nasal lavage samples reflect the occupational exposure to moulds, whereas possible indicators of existing disorders are detectable in serum.

Biol Sci Space, 2000 Dec, 14(4), 363 - 71
{Biomineralization at hot springs and mineral springs, and their significance in relation to the Earth's history}; Akai J; Recently, there is strong interest on microbe-mineral interactions . This is related also to recent expanded knowledges on extremely severe environments in which microbes live . Interaction between microbes and minerals contains biomineralization processes . Varieties of biomineralization products are found not only in various geologic materials and processes in the earth's history but also in present surface environments . Some hot springs represent such environments similar to those of unique and extremely severe environments for life . In this short review, the author briefly shows some examples of biomineralizations at some hot springs and mineral springs, Japan . In such environments, iron ore was formed and some varieties of growing stromatolites were found . The varieties of stromatolite are siliceous, calcic and manganese types . Cyanobacteria and the other bacteria are related to form the stromatolite structure . In the Gunma iron ore, sedimentary iron ores were mineralogically described in order to evaluate the role of microorganisms and plants in ore formation . The iron ore is composed of nanocrystalline goethite . Algal fossils are clearly preserved in some ores . Various products of biomineralization are found in the present pH 2-3, Fe2(+)- and SO4(2-)-rich streams . Bacterial precipitation had variations from amorphous Fe-P-(S) precipitates near the outlet of mineral spring, to Fe-P-S precipitates and to Fe-S-(P) precipitates . Mosses and green algae are also collecting Fe precipitates in and around the living and dead cells . The Gunma Iron Ore can be said as Biologically Induced Iron Ore . At Onikobe and Akakura hot springs, growing stromatolites of siliceous and calcareous types, were found, respectively . At Onikobe, The stromatolites grow especially near the geyser . Cyanobacterial filaments in stromatolite were well preserved in the siliceous and calcic stromatolites . The filaments oriented in two directions which form the layered structures were found . At Yunokoya hot spring, black and brittle stromatolitic structures which were composed of amorphous Mn minerals are growing . The form of these structures are hemispherical . Many bacteria that were coated with amorphous Mn minerals were found on these structures . Furthermore, Precambrian (Proterozoic : Wittenoom-Chichester region, western Australia) manganese stromatolite was briefly shown in comparison . The black stromatolite has been clarified to be composed of todorokite . Small spotty and donuts-like shaped todorokite aggregates which are very similar to biologically induced Mn-precipitates were found in massive dolomite layers.

J Allergy Clin Immunol, 2001 Oct, 108(4 Suppl), S117 - 20
Overview of infections and cardiovascular diseases; Vercellotti GM; Microbes have been proposed as inciting agents of tissue injury and inflammation, both of which underlie the pathogenesis of atherosclerosis . Viruses, including the herpes simplex virus and cytomegalovirus, as well as bacteria such as Chlamydia pneumoniae, have been implicated in the process . In vitro, these agents promote a proinflammatory and a procoagulant phenotype in vascular cells . Viruses augment cell accumulation through alterations of apoptosis . Infectious agents may play a role in pathogenesis of atherosclerosis by triggering an autoimmune response due to microbial molecular mimicry . It is unlikely that a single agent is the sole cause or modulator of this heterogeneous disease . Contradictory epidemiological studies may be reconciled with a new construct suggesting that multiple pathogens infecting an individual in aggregate may promote an inflammatory and procoagulant environment that underlies the pathogenesis of atherosclerosis.

J Comp Physiol {B}, 2001 Aug, 171(6), 441 - 7
Influences of incubation temperature and various saccharides on the production of organic acids and gases by gut microbes of rainbow trout Oncorhynchus mykiss in a micro-scale batch culture; Kihara M et al.; We studied the influence of incubation temperature and additional saccharides on the metabolism of hindgut microbes of the rainbow trout Oncorhynchus mykiss in a 50 microl-scale batch culture system . Intestinal contents of rainbow trout reared at 15 degrees C were incubated with glucose, lactosucrose, sodium alginate or colloidal chitin (each 10 g/l) at 15 degrees C or 25 degrees C for 12 h . Levels of organic acids at 0 h and 12 h of incubation were quantified with HPLC . We also monitored gas release from these cultures during incubation . The main product was iso-butyric acid, except for the cultures with colloidal chitin where no net production of organic acids was observed . We detected higher levels of iso-butyric acid in cultures with lactosucrose than in the other cultures . Net production of this acid was less in cultures with colloidal chitin than in blank cultures . The volume of released gas was larger when incubated at 25 degrees C than at 15 degrees C . Cultures with colloidal chitin released more gas than blank cultures when they were incubated at 15 degrees C . Cultures with sodium alginate released less gas than blank cultures irrespective of incubation temperature . These results indicate that the hindgut microbes of this carnivorous fish mainly produce branched-chain fatty acids, very likely by microbial digestion of nitrogenous materials rather than saccharides . However, additional saccharides affected production of branched-chain fatty acids . The influence of incubation temperature in the present study also suggested that the environmental temperature of host fish should affect microbial digestion in the fish gut.

Ann Occup Hyg, 2001 Oct, 45(7), 577 - 83
Assessment of exposure to organic dust in a hemp processing plant; Fishwick D et al.; The aim of this preliminary study was to assess exposure to various constituents of the organic dust generated during the processing of hemp in a small group of exposed workers . Airborne levels of inhalable dust, endotoxin and soluble protein, and the respirable, thoracic and inhalable fractions of fungal, bacterial and actinomycete contamination were measured in the personal breathing zone of exposed workers . Inhalable dust, endotoxin, fungal and bacterial contamination all exceeded levels found in similar vegetable fibre processing factories, since inhalable dust levels ranged from 10.4 to 79.8 mg/m(3) and inhalable bacterial levels between 4.7 and 190 x 10(6) cfu/m(3) . Soluble protein and endotoxin (r=0.99, P<0.0001), endotoxin and inhalable dust (r=0.94, P<0.005) and inhalable dust and protein (r=0.98, P<0.0001) were significantly correlated, suggesting that there was little variation in the composition of the dust from different sites or activities around the workplace . Andersen sampling gave an indication of background microbe levels, although no attempt was made to identify the specific microorganisms as all plates were significantly overgrown . Airborne assessments demonstrated that exposures were highly task specific . For example, sweeping the floor generated the highest exposure levels of total dust, protein, endotoxin, bacteria and fungi . Therefore, we have shown that a modern-day hemp fibre processing plant produces significant quantities of respirable dust which is highly contaminated with endotoxin and microorganisms . This organic dust has the potential to cause a range of ill health problems.

J Anim Sci, 2001 Sep, 79(9), 2491 - 8
Rumen microbial sequestration of {2-(13)C}acetate in cattle; Kristensen NB; To investigate the impact of rumen microbial sequestration of VFA carbon on estimates of acetate availability based on intraruminal infusion of {2-(13)C} acetate, three nonlactating or low-yielding dairy cows were continuously intraruminally infused with {2-(13)C}acetate for 26 h . The 13C content of ruminal VFA, duodenal carbon, and fatty acids (FA) and AA isolated from liquid-associated ruminal microbes and duodenal DM was measured by an isotope ratio mass spectrometer interfaced to an elemental analyzer or a gas-liquid chromatograph . The ruminal gross production of acetate was 38 +/- 4 mol/d and could account for about 38% of the DE intake . Of the intraruminally infused 13C in {2-(13)C}acetate, 7.6 +/- 0.9% was recovered at the duodenum . The 13C content of ruminal propionate, butyrate, and valerate increased (P < 0.05) with intraruminal infusion of {2-(13)C}acetate . It was estimated that about 28% of the 13C intraruminally infused in {2-(13)C}acetate could be accounted for by duodenal 13C flow and absorption of non-acetate VFA . A number of FA isolated from liquid-associated ruminal microbes (C6, C12, C14, anteiso C15, and iso C15) were enriched with 13C (P < 0.05) at a level comparable to the enrichment of ruminal butyrate . Any absorption of these FA from the rumen would further contribute to non-acetate 13C uptake . A maximum of 72% of the ruminal gross production of acetate represented acetate absorption from the rumen in the present study . Consequently, previously used models using intraruminal isotope dilution techniques seem not to be appropriate for measuring acetate availability in ruminants . The number of metabolites exchanging carbon with acetate was found to be so high that assessments of the entire range of inter conversions seem to be practically impossible . Portal absorption studies are discussed as an alternative method of estimating VFA availability to the metabolism in ruminants.

Can J Microbiol, 2001 Aug, 47(8), 773 - 6
Influence of the zinc hyperaccumulator Thlaspi caerulescens J . & C . Presl . and the nonmetal accumulator Trifolium pratense L . on soil microbial populations; Delorme TA et al.; Metal hyperaccumulator plants like Thlaspi caerulescens J . & C . Presl . are used for phytoremediation of contaminated soils . Since little is known about the rhizosphere of hyperaccumulators, the influence of T . caerulescens was compared with the effects of Trifolium pratense L . on soil microbes . High- and low-metal soils were collected near a zinc smelter in Palmerton, Penn . Soil pH was adjusted to 5.8 and 6.8 by the addition of Ca(OH)2 . Liming increased bacterial populations and decreased metal toxicity to levels allowing growth of both plants . The effects of the plants on total (culturable) bacteria, total fungi, as well as cadmium- and zinc-resistant populations were assessed in nonrhizosphere and rhizosphere soil . Both plants increased microbial populations in rhizosphere soil compared with nonrhizosphere soil . Microbial populations were higher in soils planted with T . pratense, but higher ratios of metal-resistant bacteria were found in the presence of T . caerulescens . We hypothesize that T . caerutescens acidifies its rhizosphere . Soil acidification in the rhizosphere of T . caerulescens would affect metal uptake by increasing available metals around the roots and consequently, increase the selection for metal-resistant bacteria . Soil acidification may be part of the hyperaccumulation process enhancing metal uptake from soil.

Lakartidningen, 2001 Aug 22, 98(34), 3510 - 4
{Infection a dreaded central venous catheter-related complication . A reminder of the significance of good aseptics is justified}; Hammarskjold F et al.; The use of central venous catheters has increased markedly . Large numbers of patients are therefore at risk for catheter-related infections . This paper reviews the literature on prevention of intravascular catheter-related complications . Microbes colonising the catheter hubs and the skin around the insertion site are the source of most of these infections . By simple routines it is possible to reduce the risk for microbial spread from these sites to the bloodstream.

Ann Allergy Asthma Immunol, 2001 Sep, 87(3), 181 - 8
A superantigen hypothesis for the pathogenesis of chronic hypertrophic rhinosinusitis, allergic fungal sinusitis, and related disorders; Schubert MS; BACKGROUND: Chronic eosinophilic-lymphocytic respiratory mucosal inflammatory disorders include hypertrophic sinus disease, allergic fungal sinusitis, allergic bronchopulmonary aspergillosis, and chronic severe asthma . They have many analogous or shared aspects of pathology at molecular, cellular, and clinical levels of analysis . OBJECTIVE: To propose a theory, and supporting data through comprehensive literature review, that unifies these diseases' pathogenesis . METHODS AND DATA SOURCES: Current medical literature was used as supportive background information . Reinterpretation of existing studies and reasoned speculation were used when necessary and identified where used . English language MEDLINE articles that referenced sinusitis, rhinosinusitis, allergic fungal sinusitis, asthma, allergic bronchopulmonary aspergillosis, nasal polyp, superantigen, and T cell receptor from 1983 to present were potentially used as background or supportive information . Additional referenced articles, published abstracts, and National Center for Biotechnology Information Entrez protein database searches were used . Case reports, studies, review articles, and textbooks were included . RESULTS: Multiple lines of evidence support the proposed hypothesis that microbial T cell superantigen production, persistence, and host-responsiveness are the fundamental components that unify the pathogenesis of all common chronic eosinophilic-lymphocytic respiratory mucosal inflammatory disorders . Superantigen amplification of preexisting immunopathology is the proposed mechanism for disease induction and maintenance . Preexisting immunopathology is created in the individual by a potential heterogeneity of immunopathologic signals that can include type I immediate hypersensitivity, other antigen-specific immune responses, cytokine dysregulation, eicosanoid dysregulation, various genetic mutations, and other molecular pathology . Although the ability to develop chronic severe inflammatory disease is dependent upon this immunopathology, host T cell receptor V beta genetics and persistent superantigen production/exposure at the respiratory mucosa by relevant superantigen-producing extra- or intracellular microbes are postulated to be required . This mechanism for disease pathogenesis may also apply to other disorders . Approaches to prove this theory and its predictions are presented . CONCLUSIONS: The pathogenesis of all the disorders discussed can be unified through the superantigen hypothesis proposed . Multiple lines of evidence support this hypothesis . How we view these common conditions will change, and new research into pathogenesis and treatment will occur if this proves true.

Chir Organi Mov, 1999 Jul-Sep, 84(3), 247 - 51
Vancomycin prophylaxis in joint arthroplasty; Savarese A et al.; Postoperative infections in prosthetic surgery still constitute a serious problem, and one that is difficult to treat, because of the occurrence of agglomerates of microbes that are resistant to immune defenses and antibiotics . In nearly all cases, removal of the prosthesis is the only possible means of solving the problem of infection . The systematic use of antibiotic prophylaxis in surgery of this sort offers advantages in terms of a reduction in the risk of infection . The authors present a personal case series relative to the strategies of perioperative antibiotic prophylaxis used in cases of hip and knee arthroplasty; we refer to 233 joint arthroplasties performed between October 1993 and April 1996 . In all of the cases, perioperative prophylaxis with vancomycin chlorohydrate at a dose of 1 g i.v . 1 hour prior to surgery, and 6-8 hours after surgery was carried out . The choice of the antibiotic was based on the epidemiological knowledge of the literature and the experience on the ward.

Science, 2001 Sep 21, 293(5538), 2248 - 51
Effects of size and temperature on metabolic rate; Gillooly JF et al.; We derive a general model, based on principles of biochemical kinetics and allometry, that characterizes the effects of temperature and body mass on metabolic rate . The model fits metabolic rates of microbes, ectotherms, endotherms (including those in hibernation), and plants in temperatures ranging from 0 degrees to 40 degrees C . Mass- and temperature-compensated resting metabolic rates of all organisms are similar: The lowest (for unicellular organisms and plants) is separated from the highest (for endothermic vertebrates) by a factor of about 20 . Temperature and body size are primary determinants of biological time and ecological roles.

Curr Rheumatol Rep, 2001 Oct, 3(5), 428 - 34
Insights into the Role of Infection in the Spondyloarthropathies; Liu Y et al.; Certain infections play an important role in the pathogenesis of the human leukocyte antigen (HLA)-B27-associated reactive arthritis . Whether infections play a role in other forms of spondyloarthropathies is not as clear . The role of HLA-B27 as an antigen-presenting molecule is important in the pathogenesis of these diseases . Recent evidence has been obtained indicating that this molecule may have other functions unrelated to antigen-presentation in the interaction of reactive arthritis-triggering microbes and host . This paper reviews the recent studies on the role of infection in the spondyloarthropathies.

Int Immunopharmacol, 2001 Sep, 1(9-10), 1651 - 67
Inflammation, carcinogenesis and cancer; Fitzpatrick FA; To fulfill their role in host-defense, granulocytes secrete chemically reactive oxidants, radicals, and electrophilic mediators . While this is an effective way to eradicate pathogenic microbes or parasites, it inevitably exposes epithelium and connective tissue to certain endogenous genotoxic agents . In ordinary circumstances, cells have adequate mechanisms to reduce the genotoxic burden imposed by these agents to a negligible level . However, inflammation persisting for a decade eventually elevates the risk of cancer sufficiently that it is discernible in case control epidemiological studies . Advances in our understanding of tumor suppressors and inflammatory mediators offer an opportunity to assess the molecular and cellular models used to guide laboratory investigations of this phenomenon . Disappointing results from recent clinical trials with anti-oxidant interventions raise questions about the risks from specific endogenous agents such as hydrogen peroxide and oxy radicals . Simultaneously, the results from the anti-oxidant trials draw attention to an alternate hypothesis, favoring epigenetic inactivation of key tumor suppressors, such as p53, and the consequent liability this places on genomic integrity.

Virchows Arch, 2001 Aug, 439(2), 152 - 7
Identification of syt-ssx fusion transcripts in both epithelial and spindle cell components of biphasic synovial sarcoma in small tissue samples isolated by membrane-based laser microdissection; Nishio J et al.; In order to confirm the presence of SYT-SSX fusion gene in epithelial and spindle cell components of synovial sarcoma, we performed a nested reverse transcriptase-polymerase chain reaction (RT-PCR) using microbeam microdissection of membrane-mounted native tissue (MOMeNT) technique applied on formalin-fixed, paraffin-embedded tumor specimens from two biphasic synovial sarcomas and a control tissue of adamantinoma . Small targeted portions of either an epithelial or spindle cell component of the tumor tissue were microdissected together with the supporter membrane, by using an ultraviolet (337-nm) pulsed laser microbeam coupled into a robot-stage microscope with infinity optics . The SYT-SSX fusion transcript was detected in epithelial and spindle cell components of both biphasic synovial sarcomas, but not in the control tissue . Southern blot analysis also confirmed that the detected messages were derived from the SYT-SSX fusion gene . In conclusion, the microbeam MOMeNT is a useful method for isolating selected small portions from tissue sections . The SYT-SSX fusion gene is present in both cellular components of biphasic synovial sarcoma and is involved in oncogenesis of the synovial sarcoma rather than in morphologic epithelial differentiation . Therefore, in spite of the variable proportions of each component, our results confirm that the synovial sarcoma is of monoclonal origin.

J Exp Med, 2001 Sep 17, 194(6), 863 - 9
Subsets of human dendritic cell precursors express different toll-like receptors and respond to different microbial antigens; Kadowaki N et al.; Toll-like receptors (TLRs) are ancient microbial pattern recognition receptors highly conserved from Drosophila to humans . To investigate if subsets of human dendritic cell precursors (pre-DC), including monocytes (pre-DC1), plasmacytoid DC precursors (pre-DC2), and CD11c(+) immature DCs (imDCs) are developed to recognize different microbes or microbial antigens, we studied their TLR expression and responses to microbial antigens . We demonstrate that whereas monocytes preferentially express TLR 1, 2, 4, 5, and 8, plasmacytoid pre-DC strongly express TLR 7 and 9 . In accordance with these TLR expression profiles, monocytes respond to the known microbial ligands for TLR2 (peptidoglycan {PGN}, lipoteichoic acid) and TLR4 (lipopolysaccharide), by producing tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 . In contrast, plasmacytoid pre-DCs only respond to the microbial TLR9-ligand, CpG-ODNs (oligodeoxynucleotides {ODNs} containing unmethylated CpG motifs), by producing IFN-alpha . CD11c(+) imDCs preferentially express TLR 1, 2, and 3 and respond to TLR 2-ligand PGN by producing large amounts of TNF-alpha, and to viral double-stranded RNA-like molecule poly I:C, by producing IFN-alpha and IL-12 . The expression of distinct sets of TLRs and the corresponding difference in reactivity to microbial molecules among subsets of pre-DCs and imDCs support the concept that they have developed through distinct evolutionary pathways to recognize different microbial antigens.

Curr Infect Dis Rep, 2001 Oct, 3(5), 419 - 426
Genetic Analysis of Host Responses in Sepsis; Beutler B et al.; During much of the past century, the microbe itself stood at the heart of microbial pathogenesis . Little thought was devoted to the host per se, though it was granted that differences in susceptibility to certain infections did exist between individuals, and between different ethnic groups . During the past 20 years, extraordinary strides in our grasp of mammalian genetics have made the host side of the equation far more approachable . A restricted collection of genes now presents itself as the likely repository for genetic differences that foretell susceptibility to infectious disease . The Toll-like receptors, of which 10 are presently known to exist in humans, offer an excellent example of this genetic reductionism, in that they embody the afferent component of the innate immune system, and strongly influence the containment of an infection from its earliest stages . The Toll-like receptors were identified as the culmination of a long and relentless inquiry into the yet-unsolved clinical problem of sepsis.

Phytochemistry, 2001 Oct, 58(3), 395 - 401
Production of loline alkaloids by the grass endophyte, Neotyphodium uncinatum, in defined media; Blankenship JD et al.; Lolines (saturated 1-aminopyrrolizidines with an oxygen bridge) are insecticidal alkaloids produced in symbioses of certain Epichloe (anamorph-Neotyphodium) species (fungal endophytes) with grasses, particularly of the genera Lolium and Festuca . Prior to the present study, it was unknown whether lolines were of plant or fungal origin . Neotyphodium uncinatum, the common endophyte of meadow fescue (Lolium pratense=Festuca pratensis) produced loline, N-acetylnorloline, and N-formylloline when grown in the defined minimal media at pH 5.0-7.5, with both organic and inorganic nitrogen sources and sugars as carbon sources . In contrast, lolines were not detected in complex medium cultures . GC-MS and 13C NMR spectroscopic analyses confirmed the identity of the alkaloids isolated from the defined medium cultures . Lolines accumulated to ca . 700 mg/l (4 mM) in cultures with 16.7 mM sucrose and 15-30 mM asparagine, ornithine or urea . Kinetics of loline production and fungal growth were assessed in defined medium with 16.7 mM sucrose and 30 mM ornithine . The alkaloid production rate peaked after the onset of stationary phase, as is common for secondary metabolism in other microbes.

Curr Opin Rheumatol, 2001 Jul, 13(4), 300 - 4
Infectious agents in chronic rheumatic diseases; Hyrich KL et al.; The possible role of infectious microorganisms in the disease process of both arthritis and autoimmunity continue to attract both basic and clinical researchers . However, proving a causal role for these suspects is a very difficult and complicated task . This article provides an update on various mechanisms in which microbes may play roles as inciting or perpetuating factors in the pathogenesis of connective tissue disease . It also focuses on current theories that specific microorganisms may play a role in rheumatoid arthritis and ankylosing spondylitis.

Birth, 2001 Sep, 28(3), 161 - 5
Does bathing newborns remove potentially harmful pathogens from the skin?
Medves JM, O'Brien B.
BACKGROUND: Newborn infants are routinely bathed after birth partly to reduce the possibility of transmitting potential pathogens to others . The extent to which a mild soap reduces the quantity and type of microbes found on the skin through normal colonization has not been reported . The objective of the study was to compare colonization rates between infants bathed in soap and water and infants bathed in plain water . METHOD: One hundred and forty infants were randomly assigned to one group bathed in a mild pH neutral soap and water or to another group bathed in water alone . Microbiology swabs were taken on three occasions (before the first bath, 1 hour after the bath, and 24 hours after birth) from two sites (anterior fontanelle and umbilical area) . RESULTS: No difference occurred between groups on type or quantity of organisms found at each time period . Skin colonization is a function of time, and the quantity of organisms identified increased over time (Friedman A 2 = 111.379, df = 5, p < 0.001) . CONCLUSIONS: Bathing with mild soap as opposed to bathing in water alone has minimal effect on skin bacterial colonization . Skin colonization increased over time . The findings did not support the efficacy of bathing with soap and water to reduce skin colonization of bacterial pathogens . Although the incidence of potential pathogens colonizing the skin during the first day of life is low and unlikely to pose a risk to healthy newborns, health care professionals may wish to wear gloves until the infant has been bathed.

Adv Drug Deliv Rev, 2001 Jul 28, 49(3), 301 - 15
Caveolae in the uptake and targeting of infectious agents and secreted toxins; Norkin LC; A variety of microbial pathogens, including viruses, intracellular bacteria, and prions, as well as certain secreted bacterial toxins, can now be added to the list of ligands that enter cells via caveolae or caveolae-like membrane domains . In general, the caveolae-mediated entry pathway results in transport of these microbes and toxins to intracellular destinations that are different from that of cargo entering by other means . As a result, the caveolae-mediated entry pathway can profoundly affect the host cell-pathogen interaction long after entry has occurred . Furthermore, some microbes such as SV40 that enter via cavolae will be valuable as probes to analyze certain poorly understood intracellular trafficking pathways, such as retrograde transport to the ER . Also, viruses that enter via caveolae may have unique potential as gene and drug delivery vectors . In addition, some extracellular microbial pathogens, such as Pneumocystis carinii, may also interact with host cells via caveolae . Finally, caveolae may play a role in host immune defense mechanisms.

Methods Cell Sci, 2000, 22(4), 329 - 41
A method to purify bacteria-containing phagosomes from infected macrophages; Luhrmann A et al.; When small particles, such as microorganisms, are taken up by macrophages, they are wrapped with a portion of the host cell plasma membrane and ingested, creating a new organelle, the phagosome . This phagosome matures stepwise as newly formed endosomes do, finally forming a phagolysosome, a process that contributes to killing of ingested microbes and to the presentation of microbial antigens on the surface of the phagocyte . Some pathogenic bacteria, however, reprogram the phagocytic cell in such a way that the phagosome will either be arrested in an early stage of maturation or will be diverted and create an unusual, novel phagosomal compartment . To study the molecular processes that underly biogenesis of bacteria-containing phagosomes, we have established a method to isolate and to biochemically analyse bacteria- containing phagosomes . This method consists of mechanical lysis of infected macrophages, production of a postnuclear supernatant followed by fractionation in a discontinuous sucrose density gradient, separation through a Ficoll cushion, and by a final concentration step . These phagosome preparations contain very little endosomal or lysosomal contamination (the organelles of most concern when studying phagosome biogenesis) and very little Golgi- and plasma membrane-derived contamination, but do contain some mitochondrial and ER contamination . This method could also be used to study bacterial factors (proteins, RNA) produced while in phagosomes.

Cell Transplant, 2001, 10(4-5), 403 - 8
Functional comparison of the single-layer agarose microbeads and the developed three-layer agarose microbeads as the bioartificial pancreas: an in vitro study; Xu B et al.; In this study, the insulin secretory characteristics of the microencapsulated hamster islets were studied during long-term culture . The hamster islets were encapsulated as single-layer agarose microbeads or three-layer agarose microbeads with agarose and agarose containing poly(styrene sulfonic acid) (PSSa), respectively . The influence of PSSa on the function of the rat islets microencapsulted in three-layer microbeads was primarily monitored . The aim of this study was to examine the influence of the PSSa on the in vitro function of the islets encapsulated in the agarose/PSSa microbeads compared with single-layer agarose microbeads during long-term culture . The microbeads were cultured for 30 days in medium of Eagle's MEM at 37 degrees C in 5% CO2 and 95% air . The basal insulin secretion into the culture medium was measured daily during the first 12 days and two times per week until 30 days . The microbeads were subjected to static incubation test on the 10th, 20th, and 30th day during culture . The basal insulin secretion level of the agarose/PSSa microbeads was significantly higher than that of single-layer agarose microbeads . The static incubation tests revealed a similar pattern of insulin secretion from both microbeads when they were exposed to high glucose challenge . In the static incubation test, both could significantly increase insulin release to more than 6.61 times (stimulation index) in response to high glucose stimulation and could significantly decrease when glucose concentration returned from high glucose to low glucose on the 10th, 20th, and 30th day of culture . This study demonstrated that the hamster islets enclosed in agarose/PSSa hydrogel not only continuously secreted basal amounts of insulin, but also maintained their response to high glucose stimulation similar to the agarose microbeads . The above results together with those of our previous in vivo study suggest that the three-layer microbeads (agarose/PSSa) are well suitable for xenotransplantation of islets for the clinical application.

Appl Microbiol Biotechnol, 2001 Aug, 56(3-4), 326 - 38
Microbial xylanases and their industrial applications: a review; Beg QK et al.; Despite an increased knowledge of microbial xylanolytic systems in the past few years, further studies are required to achieve a complete understanding of the mechanism of xylan degradation by microorganisms and their enzymes . The enzyme system used by microbes for the metabolism of xylan is the most important tool for investigating the use of the second most abundant polysaccharide (xylan) in nature . Recent studies on microbial xylanolytic systems have generally focussed on induction of enzyme production under different conditions, purification, characterization, molecular cloning and expression, and use of enzyme predominantly for pulp bleaching . Rationale approaches to achieve these goals require a detailed knowledge of the regulatory mechanism governing enzyme production . This review will focus on complex xylan structure and the microbial enzyme complex involved in its complete breakdown, studies on xylanase regulation and production and their potential industrial applications, with special reference to biobleaching.

Annu Rev Microbiol, 2001, 55, 357 - 80
A community of ants, fungi, and bacteria: a multilateral approach to studying symbiosis; Currie CR; The ancient and highly evolved mutualism between fungus-growing ants and their fungi is a textbook example of symbiosis . The ants carefully tend the fungus, which serves as their main food source, and traditionally are believed to be so successful at fungal cultivation that they are able to maintain the fungus free of microbial pathogens . This assumption is surprising in light of theories on the evolution of parasitism, especially for those species of ants that have been clonally propagating their cultivars for millions of years . Recent work has established that, as theoretically predicted, the gardens of fungus-growing ants are host to a specialized, virulent, and highly evolved fungal pathogen in the genus Escovopsis . In addition, the ants have evolved a mutualistic association with filamentous bacteria (actinomycetes) that produce antibiotics that suppress the growth of Escovopsis . Thus, the attine symbiosis appears to be a coevolutionary "arms race" between the garden parasite Escovopsis on the one hand and the ant-fungus-actinomycete tripartite mutualism on the other . These recent findings indicate that microbes may be key components in the regulation of other symbiotic associations between higher organisms.

J Sediment Res A Sediment Petrol Process, 2000 May, 70(3), 565 - 85
Depositional facies and aqueous-solid geochemistry of travertine-depositing hot springs (Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, U.S.A.); Fouke BW et al.; Petrographic and geochemical analyses of travertine-depositing hot springs at Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, have been used to define five depositional facies along the spring drainage system . Spring waters are expelled in the vent facies at 71 to 73 degrees C and precipitate mounded travertine composed of aragonite needle botryoids . The apron and channel facies (43-72 degrees C) is floored by hollow tubes composed of aragonite needle botryoids that encrust sulfide-oxidizing Aquificales bacteria . The travertine of the pond facies (30-62 degrees C) varies in composition from aragonite needle shrubs formed at higher temperatures to ridged networks of calcite and aragonite at lower temperatures . Calcite "ice sheets", calcified bubbles, and aggregates of aragonite needles ("fuzzy dumbbells") precipitate at the air-water interface and settle to pond floors . The proximal-slope facies (28-54 degrees C), which forms the margins of terracette pools, is composed of arcuate aragonite needle shrubs that create small microterracettes on the steep slope face . Finally, the distal-slope facies (28-30 degrees C) is composed of calcite spherules and calcite "feather" crystals . Despite the presence of abundant microbial mat communities and their observed role in providing substrates for mineralization, the compositions of spring-water and travertine predominantly reflect abiotic physical and chemical processes . Vigorous CO2 degassing causes a +2 unit increase in spring water pH, as well as Rayleigh-type covariations between the concentration of dissolved inorganic carbon and corresponding delta 13C . Travertine delta 13C and delta 18O are nearly equivalent to aragonite and calcite equilibrium values calculated from spring water in the higher-temperature (approximately 50-73 degrees C) depositional facies . Conversely, travertine precipitating in the lower-temperature (< approximately 50 degrees C) depositional facies exhibits delta 13C and delta 18O values that are as much as 4% less than predicted equilibrium values . This isotopic shift may record microbial respiration as well as downstream transport of travertine crystals . Despite the production of H2S and the abundance of sulfide oxidizing microbes, preliminary delta 34S data do not uniquely define the microbial metabolic pathways present in the spring system . This suggests that the high extent of CO2 degassing and large open-system solute reservoir in these thermal systems overwhelm biological controls on travertine crystal chemistry.

Icarus, 2000 Aug, 146(2), 343 - 59
The ultraviolet environment of Mars: biological implications past, present, and future; Cockell CS et al.; A radiative transfer model is used to quantitatively investigate aspects of the martian ultraviolet radiation environment, past and present . Biological action spectra for DNA inactivation and chloroplast (photosystem) inhibition are used to estimate biologically effective irradiances for the martian surface under cloudless skies . Over time Mars has probably experienced an increasingly inhospitable photobiological environment, with present instantaneous DNA weighted irradiances 3.5-fold higher than they may have been on early Mars . This is in contrast to the surface of Earth, which experienced an ozone amelioration of the photobiological environment during the Proterozoic and now has DNA weighted irradiances almost three orders of magnitude lower than early Earth . Although the present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer . Microbial strategies for protection against UV radiation are considered in the light of martian photobiological calculations, past and present . Data are also presented for the effects of hypothetical planetary atmospheric manipulations on the martian UV radiation environment with estimates of the biological consequences of such manipulations.

Space Med Med Eng (Beijing), 2000 Jun, 13(3), 210 - 4
{Detection of microbes adherent to particles in a closed environment}; Yu F et al.; Objective: In order to provide reference for controlling and monitoring the environmental contamination in the spacecraft, the species and amount of microbes, which adhere to the suspended particles with different size in a closed environment were detected . Method: According to USA EPA IP-10, particles were continuously sampled by an impactor in a closed environment . The particles were divided into three grades by their aerodynamic diameters (AD): 100 micrometers > or = AD > 10 micrometers, 10 micrometers > or = AD>2 micrometers and AD < or = 2 micrometers . Clean outdoor air was collected as control by the same way . The collected particles were precisely weighed . The microbes that adhere to the particles were cultivated, counted and identified . Result: By calculating total suspended particles (TSP) and inhalant particles (IP) of the closed environment, counting, clarifying and identifying the microbes, 6 kinds of bacteria, 2 genus of actinomyces and 6 kinds of fungi that adhere to the particles were detected . Conclusion: The particles in a closed environment may have some effect on human health and instruments.

Gravit Space Biol Bull, 2000 Jun, 13(2), 5 - 11
Extremophiles in astrobiology: per Ardua ad Astra; Trent JD; As we consider the possibilities of finding life on other planets, it behooves us to evaluate what we know about the limits for life on planet Earth . In our continued exploration of Earth, we are finding microbes in a variety of unexpected habitats . In geothermal hot springs, we have discovered organisms thriving at temperatures near the boiling point of water and at pH values down to 0.5; in the deepest parts of the oceans, those that grow optimally at pressures above 1000 bars and die at pressures below 500 bars; and at the poles, those that grow below the freezing point of water and die at temperatures above 10 degrees C . All of these organisms are living proof that the biochemical "machinery" of life can be adapted to conditions that, from our anthropocentric perspective, appear to be extreme . By studying the molecular adaptations of extremophiles, we begin to identify the critical cellular components that expand the envelope for life . As an example, I will discuss what we have learned about the role of the proteins we call "heat shock proteins" in pushing the upper temperature limit of life and how our studies have provided a new perspective on the function of these proteins.

Space Med Med Eng (Beijing), 1998 Oct, 11(5), 368 - 70
{Effect of single alpha-particle on cells}; Wei Z et al.; The mechanisms of biological effect of charged particles in space was studied through the inactivation effect of very low-density charged particles on very low-density cells at different impact parameters . A small type of microbeam facility with alpha-radioactive source and CN track detector were used . A diploid wild type Saccharomyces cerevisiae served as experimental eukaryotic cell . The correlation between cell inactivation and impact parameter of alpha-particles on cells was obtained through a CCD-camera system . The results showed that inactivation range of 1.13 MeV/u alpha-particles on cell-agarose mixture was about 5.5 micrometers, larger than the sum (about 3.l micrometers) of ion track-penumbra radius and yeast cell radius . The cell inactivation rate was 0.36-0.33 . It suggests that multi-hit on a cell is necessary for killing it . However, in case of miss, the inactivation rate may not be zero at certain impact parameters.

Adv Space Res, 2000, 25(10), 2095 - 101
Single ion actions: the induction of micronuclei in V79 cells exposed to individual protons; Prise KM et al.; Understanding the effects of single-particles from conventional radiation biology experiments is problematic due to the stochastics of particle tracks . This complicates the determinations of risk associated with low doses . We have developed a charged particle microbeam, which allows individually counted particles to be delivered to precise cellular locations . The system is capable of delivering a single charged particle with > 99% efficiency . Of these particles 90% are delivered with a resolution of +/- 2 micrometers and 96% with a resolution of +/- 5 micrometers . We have carried out preliminary studies in Chinese hamster V79 cells to monitor the effectiveness of low energy protons at inducing cytological damage . We have used the micronucleus assay as a measure of predominantly lethal chromosome damage . The effects of a single 3.2 MeV proton delivered individually to cells could be measured, with less than 2% of the exposed cells producing micronuclei 24 hours later . The yield of micronuclei formation was essentially linear up to the highest dose (30 particles per cell nucleus) delivered . Ultimately, the ability to target particles to different parts of the cell nucleus may start to impact on models available for chromosome aberration formation and chromosomal Organisation and mechanisms underlying genomic instability.

Adv Space Res, 1997, 20(10), 1949 - 58
Significance of rhizosphere microorganisms in reclaiming water in a CELSS; Greene C et al.; Plant-microbe interactions, such as those of the rhizosphere, may be ideally suited for recycling water in a Controlled Ecological Life Support System (CELSS) . The primary contaminant of waste hygiene water will be surfactants or soaps . We identified changes in the microbial ecology in the rhizosphere of hydroponical1y grown lettuce during exposure to surfactant . Six week old lettuce plants were transferred into a chamber with a recirculating hydroponic system . Microbial density and population composition were determined for the nutrient solution prior to introduction of plants and then again with plants prior to surfactant addition . The surfactant Igepon was added to the recirculating nutrient solution to a final concentration of 1.0 g L-1 . Bacteria density and species diversity of the solution were monitored over a 72-h period following introduction of Igepon . Nine distinct bacterial types were identified in the rhisosphere; three species accounted for 87% of the normal rhizosphere population . Microbial cell number increased in the presence of Igepon, however species diversity declined . At the point when Igepon was degraded from solution, diversity was reduced to only two species . Igepon was found to be degraded directly by only one species found in the rhizosphere . Since surfactants are degraded from the waste hygiene water within 24 h, the potential for using rhizosphere bacteria as a waste processor in a CELSS is promising.

IEEE Trans Nucl Sci, 1998 Dec, 45(6), 2700 - 10
Charge collection and radiation hardness of a SOI microdosimeter for medical and space applications; Bradley PD et al.; The first results obtained using a SOI device for microdosimetry applications are presented . Microbeam and broadbeam spectroscopy methods are used for determining minority carrier lifetime and radiation damage constants . A spectroscopy model is presented which includes the majority of effects that impact spectral resolution . Charge collection statistics were found to substantially affect spectral resolution . Lateral diffusion effects significantly complicate charge collection.

J Gravit Physiol, 1998 Jul, 5(1), P143 - 4
Effects of microgravity on the susceptibility of soybean to Phytophthora sojae; Nedukha OM et al.; The study of pathogenicity of higher plants under conditions of microgravity is of great importance for the future production of food in space . Previous work suggests that microgravity affects both microbes and plants . Bacterial numbers increased after 17 days in an algae-bacterium association on the biosatellite "Kosmos-1887" . This was speculated to result from an increase in the multiplication rate of the bacteria . Sporangia of both Actinomices brevis, in the shuttles "Soyuz-19" and "Appolon", and Phycomyces blakes, in biosatellite "Kosmos-936", formed after 10 days in microgravity . Sporangia did not form in the ground controls in the same time suggesting that the rate of fungal development is enhanced in microgravity . Plant responses to pathogens in microgravity have not been studied, however, microgravity profoundly impacts plant cell development, cytology, and physiology . In microgravity, developing cell walls are thinner and contain less lignin than ground-grown plants . The demonstrated effects of microgravity on both plants and microbes lead us to hypothesize that plants may be more susceptible to pathogens under conditions of microgravity . The aim of this study was to determine the influence of microgravity on the susceptibility of soybean to the fungal root rot pathogen, Phytophthora sojae.

Acta Astronaut, 1998 Jan-Apr, 42(1-8), 37 - 50
Real time confocal laser scanning microscopy: potential applications in space medicine and cell biology; Rollan A et al.; Photodynamic therapy (PDT), in which tissues may be rendered fatally light-sensitive represents a relatively novel treatment for cancer and other disorders such as cardiovascular disease . It offers significant application to disease control in an isolated environment such as space flight . In studying PDT in the laboratory, low energy lasers such as HeNe lasers are used to activate the photosensitized cellular target . A major problem associated with these studies is that events occurring during actual exposure of the target cells to the system cannot be examined in real time . In this study HeLa cells were photosensitized and photodynamic activation was accomplished using the scanning microbeam from a confocal laser scanning microscope . This form of activation allowed for simultaneous photoactivation and observation and facilitated the recording of events at a microscopic level during photoactivation . Effects of photodynamic activation on the target cells were monitored using the fluorophores rhodamine 123 and ethidium homodimer-1 . Potential applications of these forms of analyses to space medicine and cell biology are discussed.

Precambrian Res, 1997 Dec 1, 85(3-4), 201 - 39
Paleobiology of the Mesoproterozoic-Neoproterozoic transition: the Sukhaya Tunguska Formation, Turukhansk Uplift, Siberia; Sergeev VN et al.; Silicified carbonates of the latest Mesoproterozoic Sukhaya Tunguska Formation, northwestern Siberia, contain abundant and diverse permineralized microfossils . Peritidal environments are dominated by microbial mats built by filamentous cyanobacteria comparable to modern species of Lyngbya and Phormidium . In subtidal to lower intertidal settings, mat-dwelling microbenthos and possible coastal microplankton are abundant . In contrast, densely woven mat populations with few associated taxa characterize more restricted parts of tidal flats; the preservation of vertically oriented sheath bundles and primary fenestrae indicates that in these mats carbonate cementation was commonly penecontemporaneous with mat growth . Eoentophysalis mats are limited to restricted environments where microlaminated carbonate precipitates formed on or just beneath the sediment surface . Most microbenthic populations are cyanobacterial, although eukaryotic microfossils may occur among the simple spheroidal cells interpreted as coastal plankton . Protists are more securely represented by large (up to 320 micrometers in diameter) but poorly preserved acritarchs in basinal facies . The Sukhaya Tunguska assemblage contains 27 species in 18 genera . By virtue of their stratigraphic longevity and their close and predictable association with specific paleoenvironmental conditions, including substrates, Proterozoic cyanobacteria support a model of bacterial evolution in which populations adapt rapidly to novel environments and, thereafter, resist competitive replacement . The resulting evolutionary pattern is one of accumulation and stasis rather than the turnover and replacement characteristic of Phanerozoic plants and animals.

Geology, 1996 Jan, 24(1), 79 - 82
Microbenthic distribution of Proterozoic tidal flats: environmental and taphonomic considerations; Kah LC et al.; Silicified carbonates of the late Mesoproterozoic to early Neoproterozoic Society Cliffs Formation, Baffin Island, contain distinctive microfabrics and microbenthic assemblages whose paleo-environmental distribution within the formation parallels the distribution of these elements through Proterozoic time . In the Society Cliffs Formation, restricted carbonates--including microdigitate stromatolites, laminated tufa, and tufted microbial mats--consist predominantly of synsedimentary cements; these facies and the cyanobacterial fossils they contain are common in Paleoproterozoic successions but rare in Neoproterozoic and younger rocks . Less restricted tidal-flat facies in the formation are composed of laminated microbialites dominated by micritic carbonate lithified early, yet demonstrably after compaction; these strata contain cyanobacteria that are characteristic in Neoproterozoic rocks . Within the formation, the facies-dependent distribution of microbial populations reflects both the style and timing of carbonate deposition because of the strong substrate specificity of benthic cyanobacteria . A reasonable conclusion is that secular changes in microbenthic assemblages through Proterozoic time reflect a decrease in the overall representation of rapidly lithified carbonate substrates in younger peritidal environments, as well as concomitant changes in the taphonomic window of silicification through which early life is observed.

Plant Physiol, 1996, 110, 1063 - 8
Laser microsurgery of higher plant cell walls permits patch-clamp access; Henriksen GH et al.; Plasma membranes of guard cells in epidermal peels of Vicia faba and Commelina communis can be made accessible to a patch-clamp pipet by removing a small portion (1-3 micrometers in diameter) of the guard cell wall using a microbeam of ultraviolet light generated by a nitrogen laser . Using this laser microsurgical technique, we have measured channel activity across plasma membranes of V . faba guard cells in both cell-attached and isolated patch configurations . Measurements made in the inside-out patch configuration revealed two distinct K(+)-selective channels . Major advantages of the laser microsurgical technique include the avoidance of enzymatic protoplast isolation, the ability to study cell types that have been difficult to isolate as protoplasts or for which enzymatic isolation protocols result in protoplasts not amenable to patch-clamp studies, the maintenance of positional information in single-channel measurements, reduced disruption of cell-wall-mediated signaling pathways, and the ability to investigate intercellular signaling through studies of cells remaining situated within tissue.

Ecol Eng, 1996, 6, 99 - 108
Considerations in miniaturizing simplified agro-ecosystems for advanced life support; Volk T; Miniaturizing the Earth's biogeochemical cycles to support human life during future space missions is the goal of the NASA research and engineering program in advanced life support . Mission requirements to reduce mass, volume, and power have focused efforts on (1) a maximally simplified agro-ecosystem of humans, food crops, and microbes; and, (2) a design for optimized productivity of food crops with high light levels over long days, with hydroponics, with elevated carbon dioxide and other controlled environmental factors, as well as with genetic selection for desirable crop properties . Mathematical modeling contributes to the goals by establishing trade-offs, by analyzing the growth and development of experimental crops, and by pointing to the possibilities of directed phasic control using modified field crop models to increase the harvest index.

Protoplasma, 1992, 168(3-4), 141 - 52
Hydrostatic pressure mimics gravitational pressure in characean cells; Staves MP et al.; Hydrostatic pressure applied to one end of a horizontal Chara cell induces a polarity of cytoplasmic streaming, thus mimicking the effect of gravity . A positive hydrostatic pressure induces a more rapid streaming away from the applied pressure and a slower streaming toward the applied pressure . In contrast, a negative pressure induces a more rapid streaming toward and a slower streaming away from the applied pressure . Both the hydrostatic pressure-induced and gravity-induced polarity of cytoplasmic streaming respond identically to cell ligation, UV microbeam irradiation, external Ca2+ concentrations, osmotic pressure, neutral red, TEA Cl-, and the Ca2+ channel blockers nifedipine and LaCl3 . In addition, hydrostatic pressure applied to the bottom of a vertically-oriented cell can abolish and even reverse the gravity-induced polarity of cytoplasmic streaming . These data indicate that both gravity and hydrostatic pressure act at the same point of the signal transduction chain leading to the induction of a polarity of cytoplasmic streaming and support the hypothesis that characean cells respond to gravity by sensing a gravity-induced pressure differential between the cell ends.

Bioscience, 1994 Mar, 44(3), 173 - 7
Thinking of biology: asteroid impacts, microbes, and the cooling of the atmosphere; Oberbeck VR et al.; NASA: The authors examine the cooling of the Earth's surface from 3.75 to 1 billion years ago . Three effects of the bombardment of Earth by asteroids and comets that may have delayed surface cooling include time to form continents, volatilization of carbonate rocks which released carbon dioxide into the atmosphere, and inability of microbes to inhabit land masses during large impact events . Continental microbes may have helped reduce high temperatures from 3.75 to 3.5 billion years ago . If so, the evolutionary sequence of microbes is proposed to be anaerobic heterotrophs, chemoautotrophs, and then photoautotrophs .

J Br Interplanet Soc, 1992 Jan, 45(1), 13 - 4
An approach to the detection of microbe life in planetary environments through charge-coupled devices; Nussinov MD et al.; The use of charge-coupled devices is suggested as a means for detecting growth of micro-organism colonies . The accuracy of the method is determined by channel width and the sensitivity by the signal/noise ratio . The method was tested on a dense nutrient medium, which is to be considered more suitable to micro-organisms of the dry Martian soil than the water solution of nutrients employed in the Viking's strategy.

Nat Hist, 1994 Jun, 103(6), 14, 16, 18 - 20
Life's expanding realm; Knoll A; NASA: Geologic sediments from the Nullagine Range in Australia are used to illustrate the early existence of microbial communities in the oceans . These communities survived in oxygen-free environments . Some microbes, particularly cyanobacteria, developed the ability to synthesize energy from light, which led to the evolution of creatures with oxygen-dependent metabolism . Only recently has geologic evidence been discovered that supports the theory that animals developed only when there was enough oxygen in the atmosphere to support higher forms of life .

Palaios, 1993, 8, 512 - 25
Calcified microbes in Neoproterozoic carbonates: implications for our understanding of the Proterozoic/Cambrian transition; Knoll AH et al.; Tidal flat and lagoonal dolostones of the Neoproterozoic Draken Formation, Spitsbergen, exhibit excellent preservation of carbonate fabrics, including heavily calcified microfossils . The crust-forming cyanobacterium Polybessurus is preserved locally by carbonate precipitated on and within sheaths in mildly evaporitic upper intertidal to supratidal environments . In contrast, calcified filaments in columnar stromatolites reflect subtidal precipitation . Filament molds in dolomicrites independently document extremely early lithification . The presence of heavily calcified cyanobacteria in Draken and other Proterozoic carbonates constrains potential explanations for the widespread appearance of calcified microorganisms near the Proterozoic-Cambrian boundary . We propose that the rarity of Proterozoic examples principally reflects the abundance and wide distribution of carbonate crystals precipitated on the sea floor or in the water column . Cyanobacterial sheaths would have competed effectively as sites for carbonate nucleation and growth only where calcitic and/or aragonitic nuclei were absent . In this view, the Proterozoic-Cambrian expansion of calcified microfossils primarily reflects the emergence of skeletons as principal agents of carbonate deposition.

Icarus, 1992 Aug, 98(2), 233 - 9
Survival of microorganisms in smectite clays: implications for Martian exobiology; Moll DM et al.; Manned exploration of Mars may result in the contamination of that planet with terrestrial microbes, a situation requiring assessment of the survival potential of possible contaminating organisms . In this study, the survival of Bacillius subtilis, Azotobacter chroococcum, and the enteric bacteriophage MS2 was examined in clays representing terrestrial (Wyoming type montmorillonite) or Martian (Fe(3+)-montmorillonite) soils exposed to terrestrial and Martian environmental conditions of temperature and atmospheric pressure and composition, but not to UV flux or oxidizing conditions . Survival of bacteria was determined by standard plate counts and biochemical and physiological measurements over 112 days . Extractable lipid phosphate was used to measure microbial biomass, and the rate of 14C-acetate incorporation into microbial lipids was used to determine physiological activity . MS2 survival was assayed by plaque counts . Both bacterial types survived terrestrial or Martian conditions in Wyoming montmorillonite better than Martian conditions in Fe(3+)-montmorillonite . Decreased survival may have been caused by the lower pH of the Fe(3+)-montmorillonite compared to Wyoming montmorillonite . MS2 survived simulated Mars conditions better than the terrestrial environment, likely due to stabilization of the virus caused by the cold and dry conditions of the simulated Martian environment . The survival of MS2 in the simulated Martian environment is the first published indication that viruses may be able to survive in Martian type soils . This work may have implications for planetary protection for future Mars missions.

Plant Cell Environ, 1996 Oct, 19(10), 1179 - 87
Buder revisited: cell and organ polarity during phototropism; Nick P et al.; The induction of a radial polarity by environmental stimuli was studied at the cellular and organ levels, with phototropism chosen as a model . The light gradient acting on the whole coleoptile was opposed to the light direction acting upon individual cells in the classical Buder experiment, irradiating from the inside out . Alternatively, the stimulus was administered to the coleoptile tip with a microbeam-irradiation device . Tropistic curvature was assayed as a marker for the response of the whole organ, whereas cell elongation and the orientation of cortical microtubules were taken as markers for the responses of individual cells . Upon tip irradiation, signals much faster than basipetal auxin transport migrate towards the base . The data are discussed in terms of an organ polarity that is the primary result of the asymmetric light signal and affects, in a second step, an endogenous radial polarity of epidermal cells.

Trends Ecol Evol, 1990 May, 5(5), 140 - 4
Microbial mats and the early evolution of life; Des Marais DJ; Microbial mats have descended from perhaps the oldest and most widespread biological communities known . Mats harbor microbes that are crucial for studies of bacterial phylogeny and physiology . They illustrate how several oxygen-sensitive biochemical processes have adapted to oxygen, and they show how life adapted to dry land long before the rise of plants . The search for the earliest grazing protists and metazoa in stromatolites is aided by observations of mats: in them, organic compounds characteristic of ancient photosynthetic protists can be identified . Recent mat studies suggest that the 13C/12C increase observed over geological time in stromatolitic organic matter was driven at least in part by a long-term decline in atmospheric carbon dioxide levels.

J Paleontol, 1991, 65(4), 531 - 70
Paleobiology of a Neoproterozoic tidal flat/lagoonal complex: the Draken Conglomerate Formation, Spitsbergen; Knoll AH et al.; Carbonates and rare shales of the ca 700-800 Ma old Draken Conglomerate Formation, northeastern Spitsbergen, preserve a record of environmental variation within a Neoproterozoic tidal flat/lagoon complex . Forty-two microfossil taxa have been recognized in Draken rocks, and of these, 39 can be characterized in terms of their paleoenvironmental distributions along a gradient from the supratidal zone to permanently submerged lagoons . Supratidal to subtidal trends include: increasing microbenthic diversity, increasing abundance and diversity of included allochthonous (presumably planktonic) elements, decreasing sheath thickness of mat-building organisms (with significant taphonomic consequences), and an increasing sediment/fossil ratio in fossiliferous rocks . Five principal and several minor biofacies can be distinguished . The paleoecological resolution obtainable in the Draken Conglomerate Formation rivals that achieved for most Phanerozoic fossil deposits . It documents the complexity and diversity of Proterozoic coastal ecosystems and indicates that both environment and taphonomy need to be taken into explicit consideration in attempts to understand evolutionary trends in early fossil record . Three species, Coniunctiophycus majorinum, Myxococcoides distola, and M . chlorelloidea, are described as new; Siphonophycus robustum, Siphonophycus septatum, and Gorgonisphaeridium maximum are proposed as new combinations.

J Paleontol, 1988, 62(6), 835 - 52
Microfossils from oolites and pisolites of the Upper Proterozoic Eleonore Bay Group, Central East Greenland; Green JW et al.; Silicified oolites and pisolites from Bed 18 of the Upper Proterozoic (about 700-800 Ma) Limestone-Dolomite "Series" of the Eleonore Bay Group, central East Greenland, contain a diverse suite of organically preserved microfossils that is, for the most part . {Of the} assemblages previously described from Proterozoic cherts and shales . Three principal assemblages occur in these rocks: 1) a class bound assemblage found in detrital carbonate grains (now silicified) that served as nuclei for ooid and pisoid growth, as well as in uncoated mud and mat clasts that were carried into the zone of ooid and pisoid deposition; 2) an epilithic and interstitial assemblage consisting of microorganisms that occurred on top of and between grains; and 3) a euendolithic assemblage composed of microbes that actively bored into coated grains . The Upper Proterozoic euendolithic assemblage closely resembles a community of euendolithic cyanobacteria found today in shallow marine ooid sands of the Bahama Banks . Thirteen species are described, of which eight are new, five representing new genera: Eohyella dichotoma n . sp., Eohyella endoatracta n . sp., Eohyella rectoclada n . sp., Thylacocausticus globorum n . gen . and sp., Cunicularius halleri n . gen . and sp., Graviglomus incrustus n . gen . and sp., Perulagranum obovatum n . gen . and sp., and Parenchymodiscus endolithicus n . gen . and sp.

Icarus, 1990, 88, 246 - 60
Earth analogs for Martian life . Microbes in evaporites, a new model system for life on Mars; Rothschild LJ; The prospect of life on Mars today is daunting . Especially problematic for a potential life form is a lack of water, particularly in a liquid state; extremely cold temperatures; ultraviolet and ionizing radiation; and soil oxidants . Yet, "oases" where life might persist have been suggested to occur in rocks (in analogy with endolithic microorganisms described from deserts around the world), in polar ice caps (in analogy with snow and ice algae) and in possible volcanic regions (in analogy with chemoautotrophs living in deep sea hydrothermal vents); all are critically examined . Microorganisms are known to be able to survive in salt crystals, and recently it has been shown that organisms can metabolize while encrusted in evaporites . Because evaporites are thought to occur on Mars and can attenuate light in the UV range while being far more transparent to radiation useful for photosynthesis (400-700 nm), and because of the properties of these "endoevaporitic" organisms, I propose that such communities provide a new model system for studying potential life on Mars . On the basis of this model, I suggest possibilities for site selection for future exobiological experiments on Mars.

Adv Space Res, 1992, 12(4), 121 - 8
Planetary protection issues and the future exploration of Mars; DeVincenzi DL; A primary scientific theme for the Space Exploration Initiative (SEI) is the search for life, extant or extinct, on Mars . Because of this, concerns about Planetary Protection (PP), the prevention of biological cross-contamination between Earth and other planets during solar system exploration missions, have arisen . A recent workshop assessed the necessity for, and impact of, PP requirements on the unmanned and human missions to Mars comprising the SEI . The following ground-rules were adopted: 1) information needed for assessing PP issues must be obtained during the unmanned precursor mission phase prior to human landings; 2) returned Mars samples will be considered biologically hazardous until proven otherwise; 3) deposition of microbes on Mars and exposure of the crew to Martian materials are inevitable when humans land; and, 4) human landings are unlikely until it is demonstrated that there is no harmful effect of Martian materials on terrestrial life forms . These ground-rules dictated the development of a conservative PP strategy for precursor missions . Key features of the proposed strategy include: 1) for prevention of forward contamination, all orbiters will follow Mars Observer PP procedures for assembly, trajectory, and lifetime . All landers will follow Viking PP procedures for assembly, microbial load reduction, and bioshield; and, 2) for prevention of back contamination, all sample return missions will have PP requirements which include fail-safe sample sealing, breaking contact chain with the Martian surface, and containment and quarantine analysis in an Earth-based lab . In addition to deliberating on scientific and technical issues, the workshop made several recommendations for dealing with forward and back contamination concerns from non-scientific perspectives.

Adv Space Res, 1992, 12(5), 151 - 6
Biosphere 2 Test Module: a ground-based sunlight-driven prototype of a closed ecological life support system; Nelson M et al.; Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments . It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters . It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR) . The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber ("lung") permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward . Several series of closed ecological system investigations have been carried out in this facility . One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions . Another series of experiments included one human in the closed system for three, five and twenty-one days . During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system . Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases . Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

Orig Life Evol Biosph, 1993 Feb, 23(1), 29 - 36
Roles of water molecules in bacteria and viruses; Cox CS; In addition to water, microbes mainly comprise lipids, carbohydrates, proteins and nucleic acids . Their structure and function singularly and conjointly is affected by water activity . Dessication leads to dramatic lipid phase changes whereas carbohydrates, proteins and nucleic acids initially suffer spontaneous, reversible low activation energy Maillard reactions forming products that more slowly re-arrange, cross-link etc . to give non-native states . While initial products spontaneously may reverse to native states by raising water activity, later products only do so through energy consumption and enzymatic activity eg . repair . Yet, native states of lipid membranes and associated enzymes are required to generate energy . Consequently, good reserves of high energy compounds (e.g . ATP) and of membrane stabilisers (e.g . trehalose) may be expected to enhance survival following drying and rehydration (e.g . anhydrobiotic organisms).

Science, 1992 Jan 3, 255(5040), 74 - 7
The antiquity of oxygenic photosynthesis: evidence from stromatolites in sulphate-deficient Archaean lakes; Buick R; The Tumbiana Formation, about 2700 million years old, was largely deposited in ephemeral saline lakes, as judged by the unusual evaporite paragenesis of carbonate and halite with no sulfate . Stromatolites of diverse morphology occur in the lacustrine sediments, some with palimpsest fabrics after erect filaments . These stromatolites were probably accreted by phototropic microbes that, from their habitat in shallow isolated basins with negligible sulfate concentrations, almost certainly metabolized by ozygenic photosynthesis.

J Biol Chem, 2001 Nov 2, 276(44), 40991 - 7 Epub 2001 Aug 31.
Characterization of the B12- and iron-sulfur-containing reductive dehalogenase from Desulfitobacterium chlororespirans; Krasotkina J et al.; The United Nations and the U.S . Environmental Protection Agency have identified a variety of chlorinated aromatics that constitute a significant health and environmental risk as "priority organic pollutants," the so-called "dirty dozen." Microbes have evolved the ability to utilize chlorinated aromatics as terminal electron acceptors in an energy-generating process called dehalorespiration . In this process, a reductive dehalogenase (CprA), couples the oxidation of an electron donor to the reductive elimination of chloride . We have characterized the B12 and iron-sulfur cluster-containing 3-chloro-4-hydroxybenzoate reductive dehalogenase from Desulfitobacterium chlororespirans . By defining the substrate and inhibitor specificity for the dehalogenase, the enzyme was found to require an hydroxyl group ortho to the halide . Inhibition studies indicate that the hydroxyl group is required for substrate binding . The carboxyl group can be replaced by other functionalities, e.g . acetyl or halide groups, ortho or meta to the chloride to be eliminated . The purified D . chlororespirans enzyme could dechlorinate an hydroxylated PCB (3,3',5,5'-tetrachloro-4,4'-biphenyldiol) at a rate about 1% of that with 3-chloro-4-hydroxybenzoate . Solvent deuterium isotope effect studies indicate that transfer of a single proton is partially rate-limiting in the dehalogenation reaction.

Biochimie, 2001 Aug, 83(8), 841 - 7
Glycan mimicry as a basis for novel anti-infective drugs; Mulvey G et al.; The idea of using carbohydrate-based drugs to prevent attachment of microbial pathogens to host tissues has been around for about three decades . This concept evolved from the observation that many pathogenic microbes bind to complex carbohydrate sequences on the surface of host cells . It stands to reason, therefore, that analogs of the carbohydrate sequences pathogens bind to could be used to competitively inhibit these interactions, thereby preventing microbial damage to the host . This article will summarize some of the recent advances in developing such carbohydrate-based anti-infective drugs.

Appl Environ Microbiol, 2001 Sep, 67(9), 4215 - 24
Microbial population structures in soil particle size fractions of a long-term fertilizer field experiment; Sessitsch A et al.; Soil structure depends on the association between mineral soil particles (sand, silt, and clay) and organic matter, in which aggregates of different size and stability are formed . Although the chemistry of organic materials, total microbial biomass, and different enzyme activities in different soil particle size fractions have been well studied, little information is available on the structure of microbial populations in microhabitats . In this study, topsoil samples of different fertilizer treatments of a long-term field experiment were analyzed . Size fractions of 200 to 63 microm (fine sand fraction), 63 to 2 microm (silt fraction), and 2 to 0.1 microm (clay fraction) were obtained by a combination of low-energy sonication, wet sieving, and repeated centrifugation . Terminal restriction fragment length polymorphism analysis and cloning and sequencing of 16S rRNA genes were used to compare bacterial community structures in different particle size fractions . The microbial community structure was significantly affected by particle size, yielding higher diversity of microbes in small size fractions than in coarse size fractions . The higher biomass previously found in silt and clay fractions could be attributed to higher diversity rather than to better colonization of particular species . Low nutrient availability, protozoan grazing, and competition with fungal organisms may have been responsible for reduced diversities in larger size fractions . Furthermore, larger particle sizes were dominated by alpha-Proteobacteria, whereas high abundance and diversity of bacteria belonging to the Holophaga/Acidobacterium division were found in smaller size fractions . Although very contrasting organic amendments (green manure, animal manure, sewage sludge, and peat) were examined, our results demonstrated that the bacterial community structure was affected to a greater extent by the particle size fraction than by the kind of fertilizer applied . Therefore, our results demonstrate specific microbe-particle associations that are affected to only a small extent by external factors.

Planta, 2001 May, 213(1), 121 - 31
Involvement of local intercellular communication in the differentiation of zinnia mesophyll cells into tracheary elements; Motose H et al.; The transdifferentiation of isolated mesophyll cells of zinnia (Zinnia elegans L.) into tracheary elements (TEs) has been well studied as a model of plant cell differentiation . In order to investigate intercellular communication in this phenomenon, two types of culture method were developed, in which mesophyll cells were embedded in a thin sheet of agarose gel and cultured on solid medium, or embedded in microbeads of agarose gel and cultured in liquid medium . A statistical analysis of the two-dimensional distribution of TEs in the thin-sheet cultures demonstrated their aggregation . In the microbead cultures, the frequency of TE differentiation was shown to depend on the local cell density (the cell density in each microbead): TE differentiation required local cell densities of more than 10(5) cells ml(-1) . These results suggest that TE differentiation involves cell-cell communication mediated by a locally acting diffusible factor . This presumptive factor was characterized by applying a modified version of the sheet culture, which used two sheets of different cell densities, a low-density sheet and a high-density sheet . Differentiation of TEs in the former could be induced only by bringing it into contact with the latter . Insertion of a 25-kDa-cutoff membrane between the high-density and low-density sheets severely suppressed such induction of TEs in the low-density sheet while a 300-kDa-cutoff membrane suppressed induction only slightly . Insertion of agarose sheets containing immobilized pronase E or trypsin also interfered with the induction of TEs in the low-density sheets . Thus, a proteinaceous macromolecule of 25-300 kDa in molecular weight was assumed to mediate the local intercellular communication required for TE differentiation . This substance was designated "xylogen" with reference to its xylogenic activity . The time of requirement for xylogen during TE differentiation was assessed by experiments in which cells in the low-density sheet were separated from xylogen produced in the high-density sheet at various times by insertion of a 25-kDa-cutoff membrane between the two sheets, and was estimated to be from the 36th hour to the 60th hour of culture (12-36 h before visible thickening of secondary cell walls of TEs).

Nucleic Acids Res, 2001 Sep 1, 29(17), E86 - 6
Quantitative target display: a method to screen yeast mutants conferring quantitative phenotypes by 'mutant DNA fingerprints'; Sharma VM et al.; Whole genome sequencing of several microbes has revealed thousands of genes of unknown function . A large proportion of these genes seem to confer subtle quantitative phenotypes or phenotypes that do not have a plate screen . We report a novel method to monitor such phenotypes, where the fitness of mutants is assessed in mixed cultures under competitive growth conditions, and the abundance of any individual mutant in the pool is followed by means of its unique feature, namely the mutation itself . A mixed population of yeast mutants, obtained through transposon mutagenesis, was subjected to selection . The DNA regions (targets) flanking the transposon, until nearby restriction sites, are then quantitatively amplified by means of a ligation-mediated PCR method, using transposon-specific and adapter-specific primers . The amplified PCR products correspond to mutated regions of the genome and serve as 'mutant DNA fingerprints' that can be displayed on a sequencing gel . The relative intensity of the amplified DNA fragments before and after selection match with the relative abundance of corresponding mutants, thereby revealing the fate of the mutants during selection . Using this method we demonstrate that UBI4, YDJ1 and HSP26 are essential for stress tolerance of yeast during ethanol production . We anticipate that this method will be useful for functional analysis of genes of any microbe amenable to insertional mutagenesis.

Indoor Air, 2001 Sep, 11(3), 179 - 84
Differences in inflammatory responses and cytotoxicity in RAW264.7 macrophages induced by Streptomyces Anulatus grown on different building materials; Roponen M et al.; Streptomyces anulatus, an indicator microbe of mold in buildings, was grown on different building materials in order to study the impact of growth conditions on the ability of the spores of this microbe to induce toxicity and inflammatory responses . The microbes were grown for 2 months on sterilized and unsterilized wood, chipboard, concrete, plaster board and mineral wool in tight glass vessels under humid conditions . The highest microbial spore concentration was detected on the sterilized mineral wool followed by the sterilized plaster board and the unsterilized mineral wool . Mouse RAW264.7 macrophages were exposed in vitro for 24 h to the spores of S . anulatus and the production of the inflammatory mediators, nitric oxide (NO), tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), interleukin-10 (IL-10) and cytotoxicity, were measured . The dose equivalent to 5 x 10(5) spores/ml of medium was used to compare the different materials . The most intense production of NO (11.6 microM), TNF alpha (560 pg/ml) and IL-6 (2800 pg/ml) in macrophages was induced by the spores grown on sterilized plaster board . They also caused the greatest loss of cell viability (39%) . The spores grown on sterilized concrete induced significant production of NO (1.5 microM) and decreased cell viability (22%), and the spores grown on unsterilized and sterilized mineral wool increased production of NO (4.1 microM and 0.8 microM, respectively) . The spores did not stimulate production of the anti-inflammatory cytokine IL-10 . These results indicate that the ability of S . anulatus to induce inflammatory responses and cytotoxicity in macrophages is dependent on the growth conditions provided by different building materials.

J Endotoxin Res, 2000, 6(5), 397 - 9
A horseshoe crab receptor structurally related to Drosophila Toll; Inamori K et al.; Innate immunity against microbial pathogens relies on the pattern recognition of cell wall components on invading microbes . Recent evidence has shown that a mammalian Toll-like receptor (TLR) is activated by bacterial lipopolysaccharides (LPS) . The innate immunity in invertebrates is also triggered by LPS, as seen in the hemolymph coagulation in horseshoe crab . We report the cloning of a TLR from the Japanese horseshoe crab Tachypleus tridentatus . A cDNA coding for Tachypleus Toll was isolated from a hemocyte cDNA library and the open reading frame codes for a proprotein including a signal sequence . Like Drosophila Toll, Tachypleus Toll is a type I transmembrane protein with an extracellular domain consisting of two leucine-rich repeats flanked by two cystein-rich clusters and a cytoplasmic domain exhibiting striking similarity with the cytoplasmic domain of interleukin-1 receptor . Tachypleus Toll is most similar to Drosophila Toll in the domain architecture and the overall length.

Kekkaku, 2001 Jul, 76(7), 545 - 8
{Cat scratch disease showing clinical picture resembling tuberculous lymphadenitis: a case report}; Machi T; On February 18th, 1997, a 61-year-old woman visited our hospital because of a left inguinal mass . On physical examination, the mass was soft without inflammatory sign . About one month later, the node was excised . Pathological examination revealed granulomas with caseous necrosis and Langhans giant cells, suggesting tuberculosis, although acid fast stain was negative . Thereafter, re-history taking in detail disclosed that a kitten had often scratched her . We reexamined the pathology and checked her for serum antibodies to Bartonella henselae, the etiological microbe of cat scratch disease (CSD), using enzyme immunoassay . Histopathological reexamination of the excised mass revealed suppurative granulomas in addition to caseous ones . The level of IgG (negative: < 12 units) to B . henselae was 78 units on March 25th, 138 units on April 19th, and 18 units on July 18th, while the level of IgM (negative: < 12 units) was negative at each determination . These serological results strongly suggested current infection of B . henselae . The diagnosis of CSD could be established based on the history and the laboratory findings . When one encounters a case of granulomatous lymphadenitis, CSD should be considered for the differential diagnosis, and in this regard, anamnesis about contact with cats should be asked.

Cytometry, 2001 Aug 15, 46(4), 247 - 53
Preoperative prediction of postoperative edema and effusion in pediatric cardiac surgery by altered antigen expression patterns on granulocytes and monocytes; Tarnok A et al.; Postoperative edema and effusion (POEE) following cardiopulmonary bypass (CPB) surgery in children retards recovery and may aggravate postpericardiotomy (PPS), capillary leak syndrome (CLS), or multiorgan failure (MOF) . Compared with complication-free children, POEE affected children have different preoperative serum levels of circulating cytokines and adhesion molecules . These levels may be used preoperatively to assess POEE, but their determination is time consuming, costly, and a substantial blood volume is required . Altered serum levels of cytokines and adhesion molecules also may be reflected in altered antigen expression on circulating blood leukocytes . The predictive potential of flow cytometric (FCM) leukocyte immunophenotyping was explored as a sensitive and fast method that required small blood samples . Blood samples taken 24 h preoperatively from 49 patients (3-18 years old) were stained with monoclonal antibodies for adhesion molecules (ICAM-1, LFA-1, Mac-1) or constitutive/activation markers (CD4, CD14, CD16, CD25, CD54, CD69, HLA-DR) and measured on a microbead calibrated FCM . Neutrophils, monocytes, and eosinophils from POEE patients express higher preoperative levels of LFA-1, monocytes, HLA-DR, and other activation markers (all P < 0.03) . Over 89% of the patients were classified correctly by using two discriminant analysis methods (sensitivity, >76%; specificity, >86%; positive prediction, >80%; negative prediction, >83%) . Granulocytes and monocytes of postoperative POEE patients exhibit significant preoperative immune activation, suggesting an increased risk for patients with atopic/allergic predisposition . Surgical trauma and CPB cause additional immune activation, leading to POEE by a summative response . Most patients at risk for POEE can be identified preoperatively by using data pattern analysis on FCM-derived parameters .

Biochim Biophys Acta, 2001 Sep 3, 1514(1), 65 - 75
Conformational limitations of glycylsarcosine as a prototypic substrate for peptide transporters; Payne JW et al.; Peptide transporters are present in all species to absorb the small peptides that occur ubiquitously as products of proteolysis . The broad substrate specificities of these systems allow them to be exploited therapeutically for delivery of peptidomimetic drugs in microbes and man . To this end, glycylsarcosine is currently used as a standard substrate for assaying peptidomimetic transport by peptide transporters . However, in this study we find it is unsuitable as a general substrate, based on assays of its transport by model bacterial peptide transporters and computer-based conformational analysis of its structure . Of the two generic transporters for di- and tripeptides, exemplified by Dpp and Tpp in Escherichia coli, only Dpp can transport glycylsarcosine . The explanation for this finding came from molecular modelling, which indicated that glycylsarcosine can adopt only a restricted range of conformers compared with typical dipeptides, and that of the conformers with a trans peptide bond, the majority have the specific psi and phi backbone torsion angles needed for molecular recognition and transport by Dpp but none possessed psi and phi torsions required for recognition by Tpp; moreover, 38% of its conformers have cis peptide bonds that are not substrates for any peptide transporter . Thus, using glycylsarcosine as substrate in competition assays with compounds that typically form conformers recognised by both types of peptide transporter will underestimate their transport . These findings have implications for assays of oral availability of peptidomimetic drugs such as beta-lactams, ACE inhibitors and anti-viral compounds, for which glycylsarcosine is routinely used.

J Synchrotron Radiat, 2001 Mar 1, 8(Pt 2), 943 - 5
An EXAFS study of zinc coordination in microbial cells; Webb SM et al.; Five microbes were isolated from metal amended enrichment cultures derived from the sediments of a lake contaminated by a zinc smelter . Each of these organisms was grown in pure culture in the presence of zinc . Quick Extended X-ray Absorption Fine Structure (QEXAFS) spectroscopy was used to investigate the average coordination environment of the zinc associated with the microbial biomass . Fitting of the first coordination shell of zinc shows that significant differences exist for each microbial species examined . The coordination environment of zinc varies between sulfurs to six-fold nitrogen/oxygen . with two microbial strains showing mixed coordination shells . Further study is required in order to characterize these sites and their locations within the cell.

J Synchrotron Radiat, 2001 Mar 1, 8(Pt 2), 342 - 4
XAFS at the Pacific Northwest Consortium-Collaborative Access Team undulator beamline; Heald S et al.; The Pacific Northwest Consortium-Collaborative Access Team (PNC-CAT) has begun operating an insertion device beamline at the Advanced Photon Source . The beamline has been extensively used for XAFS studies . This paper summarizes its capabilities, and our initial operational experience . The beamline is based on APS undulator A, and incorporates full undulator scanning . The monochromator is liquid nitrogen cooled and has both Si(111) and Si(311) crystals in a side-by-side configuration . Crystal changes only take a few minutes . The crystals cover the energy range from 3-50 keV with fluxes as high as 2x10(13) ph/sec . Microbeams can be produced using Kirkpatrick-Baez mirrors (spot size 1-3 microm) or tapered capillaries (sub-microm spots) . When these optics are combined with a 13-element Ge detector, the beamline provides powerful microbeam imaging and spectroscopy capabilities . Experimental examples from the environmental field and in-situ UHV film growth will be discussed.

J Synchrotron Radiat, 2001 Mar 1, 8(Pt 2), 328 - 30
Generation of an X-ray microbeam for spectromicroscopy at SPring-8 BL39XU; Hayakawa S et al.; A pair of elliptical mirrors (KB mirror) was designed and fabricated to realize an energy tunable x-ray microbeam for spectromicroscopy at SPring-8 BL39XU . As is commonly recognized, the obtainable beam size with the aspherical total reflection mirrors is strongly affected with the slope error of the mirror . Considering that the extremely high brilliance of the undulator radiation from the SPring-8, the small mirror size and the small mirror-to-focus distance were employed to minimize effects of the slope error . Preliminary evaluation of the KB mirror was carried out using 10 keV monochromatized undulator radiation . Alignment of the mirror was assisted by the beam monitor system composed of a scintillator and a CCD, and the beam size less than 5 microm can be easily achieved even when the source was fully used . The beam size obtained with this experiment was 2 x 4 microm2 with the photon flux of 1 x 10(10) photons/s . Smaller beam size may be expected with the use of intermediate slits . Characterization of trace elements with the spatial resolution will be carried out by using x-ray fluorescence (XRF) analysis and x-ray absorption fine structure (XAFS) measurements with XRF yield method.

Intervirology, 2001, 44(4), 199 - 208
Dendritic cells and chronic hepatitis virus carriers; Akbar SM et al.; Many individuals infected with hepatitis B virus (HBV) and hepatitis C virus (HCV) are unable to clear these viruses following an acute infection and become chronically infected . There are more than 400 million HBV and HCV carriers in the world and a considerable number of these patients would eventually develop more severe complications like liver cirrhosis and hepatocellular carcinoma . It is not clearly known how an individual develops a chronic hepatitis virus carrier state; however, a defective immune response of the host is thought to play a critical role in the underlying pathogenetic mechanism . On the other hand, dendritic cells (DCs), the most potent antigen-presenting cells, are widely distributed in both lymphoid and nonlymphoid tissues . Recognition of the microbes or microbial antigens by DCs is one of critical events for the initiation of an immune response . DCs also play a cardinal role during the progression and termination of an immune response . The aim of this overview is to provide information regarding the role of DCs in the pathogenesis of chronic hepatitis due to HBV and HCV in humans and in animal models of HBV and HCV carrier states . First, we summarize our current understanding of the pathogenesis of hepatitis virus carrier states and also of general properties of DCs . Next, we discuss the data on the phenotypes and functions of DCs in both human and murine HBV and HCV carriers . We also discuss vaccine therapy in murine HBV carriers because activation of DCs due to vaccination-initiated HBsAg-specific immune responses in HBV transgenic mice (HBV-Tg), which in turn resulted in complete clearance of hepatitis B surface antigen and hepatitis B e antigen and decreased levels of HBV DNA in some HBV-Tg . Finally, we discuss the extracted questions and future research directions .

J Appl Physiol, 2001 Sep, 91(3), 1152 - 9
Measurement of cell microrheology by magnetic twisting cytometry with frequency domain demodulation; Puig-De-Morales M et al.; Magnetic twisting cytometry (MTC) (Wang N, Butler JP, and Ingber DE, Science 260: 1124-1127, 1993) is a useful technique for probing cell micromechanics . The technique is based on twisting ligand-coated magnetic microbeads bound to membrane receptors and measuring the resulting bead rotation with a magnetometer . Owing to the low signal-to-noise ratio, however, the magnetic signal must be modulated, which is accomplished by spinning the sample at approximately 10 Hz . Present demodulation approaches limit the MTC range to frequencies <0.5 Hz . We propose a novel demodulation algorithm to expand the frequency range of MTC measurements to higher frequencies . The algorithm is based on coherent demodulation in the frequency domain, and its frequency range is limited only by the dynamic response of the magnetometer . Using the new algorithm, we measured the complex modulus of elasticity (G*) of cultured human bronchial epithelial cells (BEAS-2B) from 0.03 to 16 Hz . Cells were cultured in supplemented RPMI medium, and ferromagnetic beads (approximately 5 microm) coated with an RGD peptide were bound to the cell membrane . Both the storage (G', real part of G*) and loss (G", imaginary part of G*) moduli increased with frequency as omega(alpha) (2 pi x frequency) with alpha approximately equal to 1/4 . The ratio G"/G' was approximately 0.5 and varied little with frequency . Thus the cells exhibited a predominantly elastic behavior with a weak power law of frequency and a nearly constant proportion of elastic vs . frictional stresses, implying that the mechanical behavior conformed to the so-called structural damping (or constant-phase) law (Maksym GN, Fabry B, Butler JP, Navajas D, Tschumperlin DJ, LaPorte JD, and Fredberg JJ, J Appl Physiol 89: 1619-1632, 2000) . We conclude that frequency domain demodulation dramatically increases the frequency range that can be probed with MTC and reveals that the mechanics of these cells conforms to constant-phase behavior over a range of frequencies approaching three decades.

Br J Nutr, 2001 May, 85 Suppl 2, S75 - 80
Immunobiology of mild micronutrient deficiencies; Bhaskaram P; Nutrition is a critical determinant of the outcome of host microbe interactions through a modulation of the immune response . Besides macronutrient malnutrition, deficiencies of several macronutrients also influence immune homeostasis and thus affect infection-related morbidity and mortality . Deficiencies of micronutrients like vitamin A, iron and zinc are widely prevalent among populations living in developing countries . Besides their severe deficiencies, subclinical deficiencies are known to impair biological functions in the host, immune function being one of them . The effects of these micronutrients on various immune mechanisms are briefly reviewed in this article.

Shock, 2001 Aug, 16(2), 83 - 96
Sepsis syndromes: understanding the role of innate and acquired immunity; Oberholzer A et al.; An intact innate and acquired immune response are essential for defeating systemic microbial infections . Recognition molecules, inflammatory cells, and the cytokines they produce are the principal means for host tissues to recognize invading microbes and to initiate intercellular communication between the innate and acquired immune systems . However, activation of host innate immunity may also occur in the absence of microbial recognition, through expression of internal "danger" signals produced by tissue ischemia and necrosis . When activation of the innate immune system is severe enough, the host response itself can propel the patient into a systemic inflammatory response syndrome (SIRS), or even multiple system organ failure (MSOF) and shock . Although most patients survive the initial SIRS insult, these patients remain at increased risk of developing secondary or opportunistic infections because of the frequent onset of a compensatory anti-inflammatory response syndrome (CARS) . The initial activation of the innate immune response often leads to macrophage deactivation, T-cell anergy, and the rapid apoptotic loss of lymphoid tissues, which all contribute to the development of this CARS syndrome and its associated morbidity and mortality . Initial efforts to treat the septic patient with anticytokine therapies directed at the SIRS response have been disappointing, and therapeutic efforts to modify the immune response during sepsis syndromes will require a more thorough understanding of the innate and acquired immune responses and the increased apoptosis in the lymphoid tissue.

Life Sci, 2001 Jul 27, 69(10), 1105 - 13
Role of receptor editing and revision in shaping the B and T lymphocyte repertoire; Kouskoff V et al.; B and T lymphocytes that carry antigen receptors are able to change specificity through subsequent receptor gene rearrangements . Receptor editing and receptor revision are terms used to distinguish those rearrangements occurring, respectively, in central lymphoid organs and the periphery . Secondary rearrangement appears to be a major player at two levels in the life of B lymphocytes . First, editing preserves a diverse repertoire without compromising self-tolerance, and revision further increases this repertoire once B cells have been engaged in an immune response, most likely for a better interaction with microbes . Recent studies have likewise suggested a role for receptor editing and revision in shaping the T cell repertoire during development and tolerance.

Environ Sci Technol, 2001 Aug 1, 35(15), 3144 - 50
Rhizosphere bacteria mobilize Zn for hyperaccumulation by Thlaspi caerulescens; Whiting SN et al.; Thlaspi caerulescens has a remarkable ability to hyperaccumulate Zn from soils containing mostly nonlabile Zn . The present study shows that rhizosphere microbes play an important role in increasing the availability of water-soluble Zn in soil, thus enhancing Zn accumulation by T . caerulescens . The addition of bacteria to surface-sterilized seeds of T . caerulescens sown in autoclaved soil increased the Zn concentration in shoots 2-fold as compared to axenic controls; the total accumulation of Zn was enhanced 4-fold . When the same experiment was conducted with Thlaspi arvense, a nonaccumulator, bacteria had no effect on shoot Zn accumulation although they increased water-soluble Zn concentrations available to both Thlaspi species by 22-67% as compared to the axenic controls . Further evidence that bacteria increase the availability of water-soluble Zn in soil was obtained when liquid media that had supported bacterial growth mobilized 1.3-1.8-fold more Zn from soil as compared to axenic media . Other experiments with agar media showed that bacteria did not facilitate an increase in the rate of soluble Zn transport into the root nor did they enlarge the surface area of the roots of either Thlaspi species . Thus, the bacterially mediated increase in the dissolution of Zn from the nonlabile phase in soil may enhance Zn accumulation in T . caerulescens shoots.

Crit Rev Toxicol, 2001 Jul, 31(4-5), 353 - 424
Hormesis: a generalizable and unifying hypothesis; Calabrese EJ et al.; The present article represents a comprehensive effort to assess the hypothesis that hormesis is a highly generalizable biological phenomenon independent of environmental stressor, biological endpoint, and experimental model system . The evaluative methodology and complementary approaches employed to assess this question are (1) evolutionary biology-based theoretical paradigm; (2) evaluation of > 20,000 toxicology articles using a priori entry and evaluative criteria; (3) evaluation of 17 large-scale studies each providing data on numerous agents tested in the same experimental model by the same research team; (4) the assimilation of experimental pharmacological data on 24 receptor systems in which biphasic dose responses have been established reproducibly along with hormetic mechanism elucidation; and (5) assessment of the original hormesis database with 1600 dose-response relationships demonstrating evidence consistent with the hormesis hypothesis . The complementary approaches for assessing hormesis provided strong support for its credibility as a central biological theory based on its high frequency of occurrence and quantitative features of expression within microbe, plant, and invertebrate and vertebrate animal systems . The findings suggest that hormetic effects represent evolutionary-based adaptive responses to environmentally induced disruptions in homeostasis . Such adaptive responses, which are incorporated into organismal integrative physiological systems and now clarified at the mechanistic level for more than two dozen receptor systems, provide a cogent basis for the application of hormetic mechanisms in the elucidation of fundamental evolutionary-based biological processes and in the development of novel clinical modalities.

Cell Mol Biol (Noisy-le-grand), 2001 Jun, 47(4), 679 - 87
Cytokines, from atopy to asthma: the Th2 dogma revisited; Magnan A et al.; Asthma is a spreading condition in Western countries, in most cases in relationship with atopy . Atopy is defined by an individual predisposition to develop allergic diseases in response to environmental allergens . The atopic immune system is characterized by a Th2 deviation determined by genetic and environmental factors . Among these factors, the role of allergen exposure, dietary behavior, air pollution and early exposure to microbes is discussed . In asthma, a Th2 cell activation is evident, but is accompanied by a Tc1 cell activation . These Tc1 cells probably down-regulate Th2 cells, but are also relevant to the bronchial hyperresponsiveness characterizing asthma . We propose that Tc1 activation in asthma could be the link between allergy and bronchial hyperresponsiveness.

Radiat Res, 2001 Sep, 156(3), 251 - 8
Production of delayed death and neoplastic transformation in CGL1 cells by radiation-induced bystander effects; Lewis DA et al.; Other investigators have demonstrated by transfer of medium from irradiated cells and by irradiation with low-fluence alpha particles or microbeams that cells do not have to be directly exposed to ionizing radiation to be detrimentally affected, i.e . bystander effects . In this study, we demonstrate by transfer of medium from X-irradiated human CGL1 hybrid cells that the killing of bystander cells reduces the plating efficiency of the nonirradiated CGL1 cells by 33 +/- 6% . In addition, we show that the amount of cell death induced by bystander effects is not dependent on X-ray dose, and that the induction of apoptosis does not appear to be responsible for the cell death . Furthermore, we found that the reduction in plating efficiency in bystander cells is evident for over 18 days, or 22 cell population doublings, after medium transfer, despite repeated refeeding of the cell cultures . Finally, we report the novel observation that bystander effects induced by the transfer of medium from irradiated cells can induce neoplastic transformation . Exposing unirradiated CGL1 cells to medium from cells irradiated with 5 or 7 Gy increased the frequency of neoplastic transformation significantly from 6.3 x 10(-6) in unirradiated controls to 2.3 x 10(-5) (a factor of nearly four) . We conclude that the bystander effect induces persistent, long-term, transmissible changes in the progeny of CGL1 cells that result in delayed death and neoplastic transformation . The data suggest that neoplastic transformation in bystander cells may play a significant role in radiation-induced neoplastic transformation at lower doses of X rays.

Transfus Clin Biol, 2001 Jun, 8(3), 226 - 30
Molecular diversity in the biosynthesis of GI tract glycoconjugates . A blood-group-related chart of microorganism receptors; Henry SM; This paper examines the potential of carbohydrate blood-group antigens present on mucosal surfaces in acting as receptors for microorganisms . Mucosal surfaces express significant amounts of carbohydrate blood-group antigens under the control of the Secretor, Lewis and ABO systems . The exact glycoconjugate profile an individual presents to the lumen is complex, and can only be correctly determined by a combination of serology and genotyping . We have isolated and structurally resolved the glycolipids expressed in the small intestine of group O individuals having various common or rare phenotypes . Using this information, we have been able to construct a biosynthetic pathway and propose that the type, size and glycotopes expressed, are controlled to a major extent by blood-group-related glycosyltransferases . Many of these glycotopes are potential receptors for microorganisms; some resemble tumour antigens, while others resemble the lipopolysaccharides of some pathogens . Although the origins of the blood-group glycosyltransferases remain uncertain, it is evident that they significantly diversify the mucosal glycotopes exposed to microbes; and therein may be found a potential explanation for their existence.

Curr Opin Immunol, 2001 Aug, 13(4), 410 - 6
Innate immune responses of epithelial cells following infection with bacterial pathogens; Philpott DJ et al.; The ability to discriminate between pathogenic and non-pathogenic bacteria is extremely important for epithelial cells lining mucosal surfaces and is particularly so in colonic epithelial cells . Accumulating evidence suggests that bacterial recognition systems used by epithelial cells are very different from those in cells of the myeloid lineage and are likely to have developed to maintain mucosal surfaces in a state of homeostasis with the normal microbial flora . Bacterial invasion of epithelial cells or breach of the epithelial barrier provides a signal to epithelial cells to initiate inflammatory responses, which are key events for the clearance of the infecting microbe . Therefore, elucidation of the mechanisms by which epithelial cells recognize bacteria and bacterial products, and of the nature of the innate immune responses that are triggered by these factors are important for our understanding of both the immunology of mucosal surfaces and bacterial pathogenesis.

Fresenius J Anal Chem, 2001 Jun, 370(4), 303 - 15
Modification and characterization of artificially patterned enzymatically active surfaces by scanning electrochemical microscopy; Wittstock G; This review summarizes the characterization of localized enzymatic activity by scanning electrochemical microscopy (SECM) . After introducing the concepts of feedback imaging and generator-collector experiments with enzyme-modified solid surfaces, a comparison of the merits and limitations of both approaches is given and further illustrated by selected applications . They include enzyme-modified patterned monolayers, enzyme-modified polymer microstructures and enzyme-modified metal microstructures . Such configurations are important for the development of miniaturized bioanalytical systems with proteins, such as miniaturized enzyme electrode arrays . SECM has emerged as an ideal tool for prototyping of such systems . It also offers several mechanisms for local surface modifications under conditions compatible with conservation of protein functionality of enzymes and antibodies . The subsequent imaging of the immobilized activity provides direct information about local immobilized enzyme activity . The range of biotechnological applications can be expanded by labeling other biomolecules, such as monoclonal antibodies, with appropriate enzymes . Miniaturized electrochemical enzyme immunoassays that apply the sandwich format and SECM as the detection method are reviewed . They have been performed on microstructured supports after reagent spotting or on agglomerates of surface-modified magnetic microbeads . Finally, current challenges are listed with indications of ongoing research to overcome current limitations by means of instrumental improvements.

Microbes Infect, 2001 Jul, 3(9), 755 - 61
Caveolae as portals of entry for microbes; Shin JS et al.; Many pathogens, including many traditionally extracellular microbes, now appear capable of entry into host cells with limited loss of viability . A portal of entry shared by some bacteria, bacterial toxins, viruses and parasites are caveolae (or lipid rafts), which are involved in the import and intracellular translocation of macromolecules in host cells . A requirement for caveolae-mediated endocytosis of microbes appears to be that the respective receptor is a constituent of caveolae or must move to caveolae following ligation.

J Mol Diagn, 2001 Aug, 3(3), 105 - 10
Laser-assisted microdissection of membrane-mounted paraffin sections for polymerase chain reaction analysis: identification of cell populations using immunohistochemistry and in situ hybridization; Gjerdrum LM et al.; Laser microbeam microdissection (LMM) is an increasingly important method for obtaining pure cell samples for genetic and proteomic analysis . Immunohistochemistry (IHC) and in situ hybridization (ISH) are useful techniques for targeting specific cell populations for microdissection but are difficult to apply with the tissue support membranes often used during LMM . Using detection of cytokeratins and Epstein-Barr virus gene products in head and neck carcinoma as a model, we describe optimized protocols for membrane and section preparation and for low temperature antigen retrieval that allow IHC and ISH to be used reliably on membrane mounted paraffin tissue sections . Visualization of cellular targets was markedly improved by staining and this could be further improved using a variety of optical media before microdissection . Tissue fragments thus stained were suitable for subsequent polymerase chain reaction analysis of extracted DNA using standard techniques . These IHC and ISH procedures are generally applicable and will be useful for detecting a wide range of antigens and nucleic acids in paraffin sections in conjunction with LMM.

Trends Genet, 2001 Aug, 17(8), 425 - 8
On the total number of genes and their length distribution in complete microbial genomes; Skovgaard M et al.; In sequenced microbial genomes, some of the annotated genes are actually not protein-coding genes, but rather open reading frames that occur by chance . Therefore, the number of annotated genes is higher than the actual number of genes for most of these microbes . Comparison of the length distribution of the annotated genes with the length distribution of those matching a known protein reveals that too many short genes are annotated in many genomes . Here we estimate the true number of protein-coding genes for sequenced genomes . Although it is often claimed that Escherichia coli has about 4300 genes, we show that it probably has only approximately 3800 genes, and that a similar discrepancy exists for almost all published genomes.

Immunity, 2001 Jul, 15(1), 83 - 93
MICA engagement by human Vgamma2Vdelta2 T cells enhances their antigen-dependent effector function; Das H et al.; Vgamma2Vdelta2 T cells comprise 2%-5% of human peripheral blood T cells, recognize ubiquitous nonpeptide antigens, and expand up to 50-fold during microbial infection . It is not clear why these Vgamma2Vdelta2 T cells expand only after microbial infection . We show here that the stress-inducible molecule, MICA, is induced on the surface of dendritic and epithelial cells by infection with M . tuberculosis in vitro and in vivo . MICA engagement by the activating receptor, NKG2D, present on Vgamma2Vdelta2 T cells, resulted in a substantial enhancement of the TCR-dependent Vgamma2Vdelta2 T cell response to nonpeptide antigens and protein superantigens alike . Thus, a MICA-NKG2D interaction may be necessary for an effective innate immune response to microbe-associated antigens that also are constitutively present in vivo.

Parasite, 2001 Jun, 8(2 Suppl), S126 - 32
Assessment of efficacy and safety of various adjuvant formulations with a total soluble extract of Trichinella spiralis; Aucouturier J et al.; Trichinellosis, a re-emerging zoonosis in several countries and pig, is the main species responsible for its transmission to human . Vaccination of swine could be an alternative to prevent the risk of human contamination . In order to develop an efficient and safe inactivate vaccine, the choice of the adjuvant is an important issue . The aim of this study was to develop and select potent and safe adjuvants by screening them in an experimental model with a crude soluble antigen from L1 muscular larvae (ML) of Trichinella spiralis (Ts) . The efficacy was checked by the quantification of specific antibody levels . Specific and non-specific IgE antibody levels were also assessed . Safety was checked by the assessment of the local reaction at the injection site . Various Montanide ISA adjuvant formulations including water in oil, oil in water and multiphasic emulsions, but also nanoparticles or microbeads were tested . The results clearly showed differences between the antibody responses induced by the adjuvants and demonstrated the necessity to use an adjuvant to obtain a specific IgG (IgG1 or IgG2a) response directed against the total soluble extract of Ts . All the formulations enhanced the humoral immune response . The origin of the oil contained in the emulsions played an important role on the efficacy . Indeed emulsions based on mineral oils were more efficient than those based on metabolisable oils . However it was linked with stronger local reactions . Multiphasic and oil in water emulsions but also nanoparticles failed to induce IgG2a antibody levels . Microbeads and water in oil formulations based on mineral oils were more efficient . This experimentation allowed then the selection of several adjuvants which efficacy will be further investigated by a challenge test and an analysis of the cellular populations involved in the mechanism of the immune response.

J Virol, 2001 Sep, 75(17), 7803 - 10
Different levels of T-cell receptor triggering induce distinct functions in hepatitis B and hepatitis C virus-specific human CD4(+) T-cell clones; Diepolder HM et al.; CD4(+) T cells play a major role in the host defense against viruses and intracellular microbes . During the natural course of such an infection, specific CD4(+) T cells are exposed to a wide range of antigen concentrations depending on the body compartment and the stage of disease . While epitope variants trigger only subsets of T-cell effector functions, the response of virus-specific CD4(+) T cells to various concentrations of the wild-type antigen has not been systematically studied . We stimulated hepatitis B virus core- and hepatitis C virus NS3-specific CD4(+) T-cell clones which had been isolated from patients with acute hepatitis during viral clearance with a wide range of specific antigen concentrations and determined the phenotypic changes and the induction of T-cell effector functions in relation to T-cell receptor internalization . A low antigen concentration induced the expression of T-cell activation markers and adhesion molecules in CD4(+) T-cell clones in the absence of cytokine secretion and proliferation . The expression of CD25, HLA-DR, CD69, and intercellular cell adhesion molecule 1 increased as soon as T-cell receptor internalization became detectable . A 30- to 100-fold-higher antigen concentration, corresponding to the internalization of 20 to 30% of T-cell receptor molecules, however, was required for the induction of proliferation as well as for gamma interferon and interleukin-4 secretion . These data indicate that virus-specific CD4(+) T cells can respond to specific antigen in a graded manner depending on the antigen concentration, which may have implications for a coordinate regulation of specific CD4(+) T-cell responses.

Transplantation, 2001 Jul 15, 72(1), 147 - 55
Characteristics of immunoglobulin gene usage of the xenoantibody binding to gal-alpha(1,3)gal target antigens in the gal knockout mouse; Nozawa S et al.; BACKGROUND: Natural antibodies that react with galactose-alpha(1,3)galactose {galalpha(1,3)gal} carbohydrate epitopes exist in humans and Old World primates because of the inactivation of the alpha1,3-galactosyltransferase (alpha1,3GT) gene in these species and the subsequent production of antibodies to environmental microbes that express the galalpha(1,3)gal antigen . The Gal knockout (Gal o/o) mouse, produced by homologous disruption of the alpha1,3GT gene, spontaneously makes anti-galalpha(1,3)gal antibodies and can be used to study the genetic control of humoral immune responses to this carbohydrate epitope . METHODS: Six hybridomas that produce monoclonal antibodies (mAbs) to galalpha(1,3)gal were generated in Gal o/o mice . The mAbs were tested to characterize the binding activity with flow cytometry using pig aortic endothelial cells and ELISA with galalpha(1,3)gal carbohydrates . The VH and VK genes of these hybridomas were cloned, sequenced, and analyzed . RESULTS: The mAbs showed distinct patterns of antibody binding to galalpha(1,3)gal antigens . The VH genes that encode the mAb binding activity were restricted to a small number of genes expressed in their germline configuration . Four of six clones used closely related progeny of the same VH germline gene (VH441) . Comparison of the mouse gene VH441 to the human gene IGHV3-11, a gene that encodes antibody activity to galalpha(1,3)gal in humans, demonstrates that these two genes share a nonrandom distribution of amino acids used at canonical binding sites within the variable regions (complimentary determining regions 1 and 2) of their immunoglobulin VH genes . CONCLUSIONS: These results demonstrate the similarity of the Gal o/o mice and humans in their immune response to galalpha(1,3)gal epitopes . Gal o/o mouse can serve as a useful model for examining the genetic control of antibody/antigen interactions associated with the humoral response to pig xenografts in humans.

Dev Genes Evol, 2001 Jul, 211(7), 361 - 6
Laser-mediated microdissection of paraffin sections from Xenopus embryos allows detection of tissue-specific expressed mRNAs; Imamichi Y et al.; One of the key end points for understanding the molecular basis of embryogenesis is the analysis of spatiotemporal patterns of gene expression . Methodical limitations due to low mRNA levels often prevent a tissue-specific resolution . In this study, we developed an improved laser microdissection technique and RT-PCR that allows marker gene detection in small tissue areas from sections of formalin-fixed paraffin-embedded Xenopus embryos . Tissue pieces were isolated by laser microbeam microdissection and captured by laser pressure catapulting . Neither laser treatment nor conventional histological or immunochemical staining impaired subsequent RNA analysis . Transcripts of tissue-specific marker genes such as endodermin (endoderm), epidermal cytokeratin (epidermal ectoderm), N-CAM (neural tube), myoD (somites), and sonic hedgehog (floor plate) were amplified by nested RT-PCR analysis from small areas of single sections.

Nature, 2001 Jun 14, 411(6839), 789 - 92
Large-scale forest girdling shows that current photosynthesis drives soil respiration; Hogberg P et al.; The respiratory activities of plant roots, of their mycorrhizal fungi and of the free-living microbial heterotrophs (decomposers) in soils are significant components of the global carbon balance, but their relative contributions remain uncertain . To separate mycorrhizal root respiration from heterotrophic respiration in aboreal pine forest, we conducted a large-scale tree-girdling experiment, comprising 9 plots each containing about 120 trees . Tree-girdling involves stripping the stem bark to the depth of the current xylem at breast height terminating the supply of current photosynthates to roots and their mycorrhizal fungi without physically disturbing the delicate root-microbe-soil system . Here we report that girdling reduced soil respiration within 1-2 months by about 54% relative to respiration on ungirdled control plots, and that decreases of up to 37% were detected within 5 days . These values clearly show that the flux of current assimilates to roots is a key driver of soil respiration; they are conservative estimates of root respiration, however, because girdling increased the use of starch reserves in the roots . Our results indicate that models of soil respiration should incorporate measures of photosynthesis and of seasonal patterns of photosynthate allocation to roots.

J Am Chem Soc, 2001 Mar 21, 123(11), 2559 - 70
Development of multianalyte sensor arrays composed of chemically derivatized polymeric microspheres localized in micromachined cavities; Goodey A et al.; The development of a chip-based sensor array composed of individually addressable polystyrene-poly(ethylene glycol) and agarose microspheres has been demonstrated . The microspheres are selectively arranged in micromachined cavities localized on silicon wafers . These cavities are created with an anisotropic etch and serve as miniaturized reaction vessels and analysis chambers . A single drop of fluid provides sufficient analysis media to complete approximately 100 assays in these microetch pits . The cavities possess pyramidal pit shapes with trans-wafer openings that allows for both fluid flow through the microreactors/analysis chambers and optical access to the chemically sensitive microspheres . Identification and quantitation of analytes occurs via colorimetric and fluorescence changes to receptor and indicator molecules that are covalently attached to termination sites on the polymeric microspheres . Spectral data are extracted from the array efficiently using a charge-coupled device allowing for the near-real-time digital analysis of complex fluids . The power and utility of this new microbead array detection methodology is demonstrated here for the analysis of complex fluids containing a variety of important classes of analytes including acids, bases, metal cations, metabolic cofactors, and antibody reagents.

Lik Sprava, 2000 Sep, (6), 104 - 6
{Effect of terginan on treatment of patients with inflammatory processes in the cervix uteri}; Sukhanova AA; Expediency was studied of use of the drug terginan in a combined treatment of uterine neck pathologies in patients presenting with local inflammatory processes . The drug was found to be capable of dispelling an unspecific inflammatory process, normalizing the vaginal microbe landscape, promoting the postcryodestruction epithelization processes as evidenced by the analysis of the results obtained.

Science, 2001 Jul 13, 293(5528), 253 - 6
Sensing pathogens and tuning immune responses; Pulendran B et al.; The immune system is capable of making qualitatively distinct responses against different microbial infections, and recent advances are starting to reveal how it manages this complex task . An integral component of the immune system is a network of cells known as dendritic cells (DCs), which sense different microbial stimuli and convey this information to lymphocytes . A better understanding of DC biology has allowed a model to be constructed in which the type of immune response to an infection is viewed as a function of several determinants, including the subpopulation of DCs, the nature of the microbe, microbe recognition receptors, and the cytokine microenvironment.

Crit Rev Microbiol, 2001, 27(2), 57 - 73
Environmental and food safety aspects of Escherichia coli O157:H7 infections in cattle; Rasmussen MA et al.; The presence of E . coli O157:H7 in cattle illustrates the complex, interrelated nature of the environment, livestock production practices, food safety, and the science of microbiology, particularly microbial ecology . Enterohemorrhagic E . coli, including E . coli O157:H7, can cause severe human diseases that can be debilitating and life threatening . Cattle are currently considered to be the definitive source for E . coli O157:H7 in the food supply, but this view may be simplistic and incomplete . E . coli O157:H7, appears widespread among U.S . cattle herds, while individual animal prevalence is low and transient . Most individual animals appear to be a transient reservoir for E . coli O157:H7 although the issue of carrier animals still remains unresolved . Epidemiological studies of the cattle production system have not clearly identified risk factors or management practices that affect E . coli O157:H7 prevalence in cattle feces . The problem of E . coli O157:H7 increases during the summer and fall months, but the environmental factors that contribute to this increase are poorly understood . Possible environmental factors that may influence E . coli O157:H7 shedding in cattle include livestock feed and waste handling practices as well as insects and microbial interactions in soil and water . Studies of E . coli O157:H7 ecology in cattle and the environment have been limited, but they suggest that a consideration of other independent, environmental sources of this microbe seems appropriate . The natural ecology of cholera may serve as a useful environmental model for pursuing additional environmental research on the occurrence and transmission of E . coli O157:H7 in nature.

Radiat Res, 2001 Aug, 156(2), 210 - 4
The Columbia University single-ion microbeam; Randers-Pehrson G et al.; A single-ion microbeam facility has been constructed at the Columbia University Radiological Research Accelerator Facility . The system was designed to deliver defined numbers of helium or hydrogen ions produced by a van de Graaff accelerator, covering a range of LET from 30 to 220 keV/microm, into an area smaller than the nuclei of human cells growing in culture on thin plastic films . The beam is collimated by a pair of laser-drilled apertures that form the beam-line exit . An integrated computer control program locates the cells and positions them for irradiation . We present details of the microbeam facility including descriptions of the collimators, hardware, control program, and the various protocols available . Various contributions to targeting and positioning precision are discussed along with our plans for future developments . Beam time for outside users is often available (see www.raraf.org).

Radiat Res, 2001 Aug, 156(2), 177 - 80
Adaptive response and the bystander effect induced by radiation in C3H 10T(1/2) cells in culture; Sawant SG et al.; This paper discusses two phenomena of importance at low doses that have an impact on the shape of the dose-response relationship . First, there is the bystander effect, the term used to describe the biological effects observed in cells that are not themselves traversed by a charged particle, but are neighbors of cells that are; this exaggerates the effect of small doses of radiation . Second, there is the adaptive response, whereby exposure to a low level of DNA stress renders cells resistant to a subsequent exposure; this reduces the effect of low doses of radiation . The present work was undertaken to assess the relative importance of the adaptive response and the bystander effect induced by radiation in C3H 10T(1/2) cells in culture . When the single-cell microbeam delivered from 1 to 12 alpha particles through the nuclei of 10% of C3H 10T(1/2) cells, more cells were inactivated than were actually traversed by alpha particles . The magnitude of this bystander effect increased with the number of particles per cell . An adaptive dose of 2 cGy of gamma rays, delivered 6 h beforehand, canceled out about half of the bystander effect produced by the alpha particles.

Am J Physiol Gastrointest Liver Physiol, 2001 Aug, 281(2), G303 - 10
Microbes and microbial toxins: paradigms for microbial-mucosal interactions . VIII . Pathological consequences of rotavirus infection and its enterotoxin; Morris AP et al.; Rotaviral infection in neonatal animals and young children leads to acute self-limiting diarrhea, but infected adults are mainly asymptomatic . Recently, significant in-roads have been made into our understanding of this disease: both viral infection and virally manufactured nonstructural protein (NSP)4 evoke intracellular Ca(2+) ({Ca(2+)}i) mobilization in native and transformed gastrointestinal epithelial cells . In neonatal mouse pup mucosa models, {Ca(2+)}i elevation leads to age-dependent halide ion movement across the plasma membrane, transepithelial Cl(-) secretion, and, unlike many microbial enterotoxins, initial cyclic nucleotide independence to secretory diarrhea . Similarities between rotavirus infection and NSP4 function suggest that NSP4 is responsible for these enterotoxigenic effects . NSP4-mediated {Ca(2+)}i mobilization may further facilitate diarrhea by signaling through other Ca(2+)-sensitive cellular processes (cation channels, ion and solute transporters) to potentiate fluid secretion while curtailing fluid absorption . Apart from these direct actions in the mucosa at the onset of diarrhea, innate host-mediated defense mechanisms, triggered by either or both viral replication and NSP4-induced {Ca (2+)}i mobilization, sustain the diarrheal response . This secondary component appears to involve the enteric nervous system and may be cyclic nucleotide dependent . Both phases of diarrhea occur in the absence of significant inflammation . Thus age-dependent rotaviral disease represents an excellent experimental paradigm for understanding a noninflammatory diarrhea.

Small Rumin, Res. . 2001 Aug, 41(2), 181 - 190
General anti-microbial properties of the integument in fleece producing sheep and goats; Meyer W et al.; Based on lectin histochemical methods, this study describes the production and distribution of various terminal sugars in the integument of Merino sheep and Angora goats . Additionally, pH measurements were performed for information about environmental conditions of microbes on the skin surface and in the fleece . The results demonstrated strongly positive reactions for alpha-L-fucose in the stratum corneum of Merino sheep, and in the secretions of the skin glands of Angora goats . Moreover, alpha-D-mannose, beta-D-N-acetylglucosamine, alpha-D-N-acetylgalactosamine, alpha-D-galactose and beta-D-galactose were very distinct in the secretions of the skin glands of both species . The skin products containing saccharide residues are deposited on the skin surface and in the fleece as part of wool grease, and the terminal sugars may be liberated by bacterial and fungal activities . All of these sugars are of specific interest because of their ability of inhibiting the adherence of different bacteria and fungi to the epidermal cells . Thus, free sugars impede attacks of skin micro-inhabitants against the integrity of the epidermal barrier . In contrast to these results, the skin pH-conditions were strongly alkaline, particularly in the fleece of Merino sheep (pH 6-9), so that proliferation of microbes may be promoted . This negative influence can only be countered by high production rates of sugar-containing skin products, which is normally the case based on long and intense activity of hair follicles in fine-wool producing sheep and goats.In conclusion, this study demonstrates that a basic anti-microbial biological system exists on the skin surface and within the hair coat, that operates with free sugars before the immune system is activated.

Cytokine, 2001 Jun 7, 14(5), 253 - 63
Developmental expression of two CXC chemokines, MIP-2 and KC, and their receptors; Luan J et al.; CXC chemokines, macrophage inflammatory protein-2 (MIP-2) and KC, (a cloning designation based on ordinate and abscissa position) as well as the CXC chemokine receptor, CXCR2, are expressed in a variety of cells and tissues in adult mice . Targeted deletion of the gene encoding murine CXCR2 does not result in obvious changes in the development of the organ system of the mouse, though the CXCR2-/- mouse is compromised with regard to its ability to resist infection, heal wounds, and maintain homeostasis when challenged with microbes and/or chemicals . In an attempt to develop insight into additional possible subtle roles of CXCR2 and its ligands in the development of the mouse, we examined the expression of MIP-2, KC, CXCR2, as well as the Duffy antigen binding protein for chemokines during embryonic (p.c.) days 11.5 through 14.5 in the mouse . We observed strong correlation between the expression of MIP-2 and CXCR2 in the developing brain, cardiovascular system and condensing mesenchyme between 11.5 and 13.5 days . Moreover, the expression of KC was parallel to the expression of the Duffy antigen binding protein for chemokines with regard to temporal pattern and tissue localization . MIP-2 and CXCR2 are highly expressed in the brain, first in the cerebellum and in the head mesenchyme, the meninges and the floor plate, and by 14.5 days are also present in the telencephalon, thalamus and hypothalamus . In the developing brain KC and Duffy were prominently expressed in the neuronal tracts, the forebrain, sympathetic ganglia, and along the periphery of the neural tube . However, KC and Duffy were less prevalent in the developing cardiovascular system, lung and other organs, muscle and bone, than are CXCR2 and MIP-2 . These data suggest that the roles for these chemokines and their receptors during development may be more significant than was initially thought based upon the phenotype of the mice with targeted deletion of CXCR2 and Duffy .

J Infect Dis, 2001 Aug 1, 184(3), 337 - 44 Epub 2001 Jun 27.
Host-pathogen interactions: the attributes of virulence; Casadevall A et al.; Virulence is one of a number of possible outcomes of host-microbe interaction . As such, microbial virulence is dependent on host factors, as exemplified by the pathogenicity of avirulent microbes in immunocompromised hosts and the lack of pathogenicity of virulent pathogens in immune hosts . Pathogen-centered views of virulence assert that pathogens are distinguished from nonpathogens by their expression of virulence factors . Although this concept appears to apply to certain microbes that cause disease in normal hosts, it does not apply to most microbes that cause disease primarily in immunocompromised hosts . The study of virulence is fraught with the paradox that virulence, despite being a microbial characteristic, can only be expressed in a susceptible host . Thus, the question "What is a pathogen?" begs the question, "What is the outcome of the host-microbe interaction?" We propose that host damage provides a common denominator that translates into the different outcomes of host-microbe interaction.

Cell Mol Biol (Noisy-le-grand), 2001 May, 47(3), 485 - 93
Response of avian embryonic brain to spatially segmented x-ray microbeams; Dilmanian FA et al.; Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain . Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three . Other types of treatment for pediatric brain tumors are frequently ineffective . Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors . In our studies, duck embryos were irradiated at 3-4 days prior to hatching . Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam . The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm . Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam . The biological end point employed in the study was ataxia . This neurological symptom of radiation damage to the brain developed within 75 days of hatching . Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group . However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group . These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality . When the microbeam dose was normalized to the full volume of the irradiated tissue . i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation.

Mol Plant Microbe Interact, 2001 Jul, 14(7), 848 - 56
Responses of a model legume Lotus japonicus to lipochitin oligosaccharide nodulation factors purified from Mesorhizobium loti JRL501; Niwa S et al.; Lotus japonicus has been proposed as a model legume for molecular genetic studies of symbiotic plant-microbe interactions leading to the fixation of atmospheric nitrogen . Lipochitin oligosaccharides (LCOs), or Nod factors, were isolated from the culture of Mesorhizobium loti strain JRL501 (MAFF303099), an efficient microsymbiont of L . japonicus B-129 cv . Gifu . High-performance liquid chromatography and mass spectrometric analyses allowed us to identify at least five different structures of LCOs that were produced by JRL501 . The major component was NodMl-V(C18:1, Me, Cb, AcFuc), an N-acetyl-glucosamine pentamer in which the nonreducing residue is N-acylated with a C18:1 acyl moiety, N-methylated, and carries a carbamoyl group and the reducing N-acetylglucosamine residue is substituted with 4-O-acetyl-fucose . Additional novel LCO structures bearing fucose instead of acetyl-fucose at the reducing end were identified . Mixtures of these LCOs could elicit abundant root hair deformation on L . japonicus roots at a concentration of 10(-7) to 10(-9) M . Spot inoculation of a few nanograms of LCOs on L . japonicus roots induced the formation of nodule primordia in which the early nodulin genes, ENOD40 and ENOD2, were expressed in a tissue-specific manner . We also observed the formation of a cytoplasmic bridge (preinfection thread) in the swollen outermost cortical cells . This is the first description of cytoplasmic bridge formation by purified LCOs alone in a legume-forming determinate nodules.

Sarcoidosis Vasc Diffuse Lung Dis, 2001 Jun, 18(2), 149 - 64
Sarcoidosis: genes and microbes--soil or seed?
McGrath DS, Goh N, Foley PJ, du Bois RM.
Sarcoidosis is a multi-organ granulomatous disorder that is characterised by the accumulation of CD4+ T-lymphocytes resulting in a Th-1 type immune response . Although our understanding of the immune response in sarcoidosis has improved in recent years through studies of bronchoalveolar lavage cells and fluid, the genetic predisposition and trigger factors (and their interrelationship) remain unclear . Previous reports of familial clustering and varying prevalence of sarcoidosis in different populations suggested molecular epidemiological heterogeneity . This review focuses specifically on two pivotal areas that have been the subjects of intensive investigation recently: a) triggering by infective agents and b) host genetic susceptibility and relates these to broader issues of pathogenesis . It is concluded that one or more microbes behaving in a non-infectious fashion in a genetically predisposed individual trigger the sarcoidosis granulomatous response.

Ann Diagn Pathol, 2001 Jun, 5(3), 184 - 9
The microbe, creator of the pathologist: an inter-related history of pathology, microbiology, and infectious disease; Rosati LA; This brief historical review of pathology stresses the impact of microbial discovery on the development of pathology as a medical specialty . If, as it has been said, the microscope invented the pathologist, it was the microbe, especially the pathogenic bacterium, that gave him his name and made him clinically relevant.

Thromb Res, 2001 Jul 1, 103(1), 47 - 55
Assessment of in vitro-generated platelet microparticles using a modified flow cytometric strategy; Tocchetti EV et al.; Quantification of platelet microparticles (PMPs) may be a useful marker for the detection of in vivo platelet activation . Optimisation of flow cytometric methods for detection and quantification of PMPs has not been systemically evaluated . This study reports the optimisation of flow cytometric procedures for the detection of PMPs, the determination of limits of size detection using microbeads, and the characterisation of PMP generation by in vitro activation of platelets using collagen and adenosine 5' diphosphate (ADP) . Fluorescent and plain microbeads proved useful for defining the limits of the flow cytometer in detecting PMPs . A systematic calibration of the forward scatter (FS) threshold parameter (size) of the flow cytometer using microbeads allowed for the detection of very small particles (down to 0.1 microm diameter) . PMPs generated in vitro using ADP and collagen were reliably detected by flow cytometry using monoclonal antibodies (MAb) directed towards platelet surface membrane glycoproteins (Gp) . The PMP events were detected in the FS low (i.e., small size events) and fluorescence (FL) high (i.e., platelet Gp MAb-labelled events) region . PMPs of different size profiles were observed for each of the agonists . Flow cytometry can be used as a tool in the assessment of PMPs . As detection of particles of this type is at the limit of resolution of flow cytometers, careful attention is required with the choice of platelet-specific MAb, isotype control, and optimisation of procedure setup and performance.

Eur J Immunol, 2001 Jun, 31(6), 1857 - 66
Endogenous ligands of carbohydrate recognition domains of the mannose receptor in murine macrophages, endothelial cells and secretory cells; potential relevance to inflammation and immunity; Linehan SA et al.; The macrophage mannose receptor (MR) has an established role in the phagocytosis of a wide range of microbes, and also functions in viral endocytosis, and clearance of a number of endogenous glycoproteins from the circulation . Its broad ligand specificity is mediated by tandemly linked carbohydrate recognition domains (CRDs) . Recent studies suggest that binding or internalization of both natural and synthetic ligands of MR CRDs may modulate macrophage (MPhi ) function, for example to increase cidal capacity or cytokine synthesis . To identify endogenous ligands in the normal mouse we used an Fc-fusion protein (CRD4-7Fc) bearing four of the CRDs of MR . CRD4-7Fc recognized endocytic compartments of cultured MPhi, consistent with lysosomal enzymes being major ligands of MR . CRD4-7Fc also recognized MPhi and some endothelial cells in tissues, and intensely labeled secretory cells of the exocrine pancreas, salivary gland and thyroid . Strongly MR-positive interstitial cells were found in close proximity to the ligand-rich secretory cells, suggesting a role for MR in uptake of secretory glycoproteins, including thyroglobulin which was identified as a novel ligand in vitro . Endocytosis of these ligands by MR may have implications for tissue homeostasis and immunity, including antigen presentation, in secretory organs.

Nat Biotechnol, 2001 Jul, 19(7), 631 - 5
Quantum-dot-tagged microbeads for multiplexed optical coding of biomolecules; Han M et al.; Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots (zinc sulfide-capped cadmium selenide nanocrystals) into polymeric microbeads at precisely controlled ratios . Their novel optical properties (e.g., size-tunable emission and simultaneous excitation) render these highly luminescent quantum dots (QDs) ideal fluorophores for wavelength-and-intensity multiplexing . The use of 10 intensity levels and 6 colors could theoretically code one million nucleic acid or protein sequences . Imaging and spectroscopic measurements indicate that the QD-tagged beads are highly uniform and reproducible, yielding bead identification accuracies as high as 99.99% under favorable conditions . DNA hybridization studies demonstrate that the coding and target signals can be simultaneously read at the single-bead level . This spectral coding technology is expected to open new opportunities in gene expression studies, high-throughput screening, and medical diagnostics.

Nihon Kokyuki Gakkai Zasshi, 2001 Mar, 39(3), 157 - 65
{The role of airway submucosal glands in the airway mucosal defense system}; Tamada T et al.; Despite constant inhalation of air-borne particles including a variety of microbes and antigens, the normal lungs hardly ever develop infection or airway injury . This is because the normal lung is equipped with sophisticated defense mechanisms against foreign substances . It has been reported that the airway mucosa, especially the submucosal glands, play important roles not only in nonspecific defense using airway secretions but also in specific defense in cooperation with immune cells . In contrast to the nasopharyngeal or intestinal mucosa, which is always exposed to many foreign antigens, the mucosal surface of the lower respiratory tract in known to be kept in a germ-free condition . This fact indicates that immunological information derived from the antigen-rich mucosa, such as the intestine, might be transmitted to the airway mucosa, thus resulting in efficient removal of unwanted substances . This immunological elimination requires specific antibodies (Abs) against harmful antigens, and the major population of Abs in the airway is dimeric IgA . Airway submucosal glands synthesize a secretory component (SC), a transporter of secretory IgA, and immunoglobulin-containing plasma cells have been identified preferentially around the glandular tissue . Overall, the submucosal glands play a key role in the integrity of airway mucosal immunity.

Science, 2001 Jun 29, 292(5526), 2495 - 8
Nitrogen fixation by symbiotic and free-living spirochetes; Lilburn TG et al.; Spirochetes from termite hindguts and freshwater sediments possessed homologs of a nitrogenase gene (nifH) and exhibited nitrogenase activity, a previously unrecognized metabolic capability in spirochetes . Fixation of 15-dinitrogen was demonstrated with termite gut Treponema ZAS-9 and free-living Spirochaeta aurantia . Homologs of nifH were also present in human oral and bovine ruminal treponemes . Results implicate spirochetes in the nitrogen nutrition of termites, whose food is typically low in nitrogen, and in global nitrogen cycling . These results also proffer spirochetes as a likely origin of certain nifHs observed in termite guts and other environments that were not previously attributable to known microbes.

Nat Immunol, 2001 Jul, 2(7), 585 - 9
Dendritic cell lineage, plasticity and cross-regulation; Liu YJ et al.; Dendritic cells (DCs) are professional antigen-presenting cells that have an extraordinary capacity to stimulate naive T cells and initiate primary immune responses . Here we review progress in understanding the additional functions of DCs in regulating the types of T cell-mediated immune responses and innate immunity to microbes . In addition, evidence for the existence of myeloid and lymphoid DC lineages and their different functions are summarized . We propose that the diverse functions of DCs in immune regulation are dictated by the instructions they received during innate immune responses to different pathogens and from their evolutionary lineage heritage.

Transpl Infect Dis, 1999 Mar, 1(1), 65 - 75
Immunosuppression without immunosuppression? How to be a tolerant individual in a dangerous world; Kirk AD; The field of transplantation has developed based on two principles: allografts are rejected because they express foreign antigens, and the immune system must be suppressed to prevent rejection . Recently, in vitro and in vivo experimental evidence has accumulated that calls both of these beliefs into question . This article reviews an alternative approach to transplantation that focuses on tissue injury as the instigator of graft rejection and employs physiological mechanisms of tolerance to avoid graft loss . Methods that allow for defense against infectious microbes while at the same time allowing for graft survival are proposed . In particular, the rationale behind the use of anti-CD154 antibody treatment is highlighted . A model is introduced that takes into consideration the experimental successes seen with anti-CD154 therapies.

Clin Exp Immunol, 2001 May, 124(2), 239 - 47
Effects of recombinant granulocyte-colony stimulating factor administration during Mycobacterium avium infection in mice; Goncalves AS et al.; Granulocyte colony-stimulating factor (G-CSF) administration in vivo has been shown to improve the defence mechanisms against infection by different microbes . Here we evaluated a possible protective role of this molecule in a mouse model of mycobacterial infection . The administration of recombinant G-CSF promoted an extensive blood neutrophilia but failed to improve the course of Mycobacterium avium infection in C57Bl/6 or beige mice . G-CSF administration also failed to improve the efficacy of a triple chemotherapeutic regimen (clarithromycin + ethambutol + rifabutin) . G-CSF treatment did not protect interleukin-10 gene disrupted mice infected with M . avium . Spleen cells from infected mice treated with G-CSF had a decreased priming for antigen-specific production of interferon gamma compared to control infected mice . Our data do not substantiate previous reports on the protective activity of G-CSF in antimycobacterial immunity using mouse models.

Res Microbiol, 2001 Apr-May, 152(3-4), 291 - 301
ABC transporter-mediated uptake of iron, siderophores, heme and vitamin B12; Koster W; Microbes have developed a number of different strategies to utilize iron, which is a vital element for most organisms but not always readily available from the environment . Based on experimental studies and sequence analysis data, this article gives a short overview of ABC transporters related to iron uptake: components of three distinct families mediate the translocation of iron, siderophores, heme and vitamin B12 across the cytoplasmic membrane of bacteria.

Res Microbiol, 2001 Apr-May, 152(3-4), 205 - 10
ABC transporters: physiology, structure and mechanism--an overview; Higgins CF; ABC transporters form one of the largest of all protein families with a diversity of physiological functions . In Escherichia coli almost 5% of the genome is occupied by genes encoding components of these transporters, and there are examples in all species from microbes to man . In this overview, the importance of studies on bacteria in elucidating many basic principles pertaining to ABC transporters is emphasised . The family is described and a general overview of the structure and function of these transporters is presented.

Lang Speech, 2000 Oct-Dec, 43(Pt 4), 403 - 28
Kinematic event patterns in speech: special problems; Westbury JR et al.; The view that each utterance is fundamentally a pattern of serially-ordered events underlies a group of well-known speech kinematic studies emphasizing temporal coordination among articulators . Methodological problems that might affect the validity and significance of conclusions from these studies are identified . Results from a new analysis of synchronous acoustic and fleshpoint-kinematic data, recorded from 53 normal young-adult speakers of American English, are then reported . The kinematic data represented speech-related actions of the tongue blade and dorsum, both lips, and the mandible, during the test words special and problem, and were drawn from an existing X-ray microbeam speech production database . Distributions of event patterns across speakers revealed four main results: (1) different patterns for the two test words; (2) a comparable degree of cross-speaker agreement about relative tongue and jaw movement timing, but marked disagreement about lip and jaw movement timing, between test words; (3) highly distinctive movement patterns for some speakers; and, (4) a general conclusion that serial event order, alone, provides very limited understanding of movement patterns produced by individual speakers . By design, these results focus attention on methods of kinematic event pattern analyses, and the general value of such analyses for insights about speech production.

Int J Dev Biol, 2001, 45(3), 497 - 507
Of microbes, mice and man; Monk M; This chapter reviews my 18 years of research in Anne's Unit including studies on temporal and spatial aspects of X-chromosome inactivation and imprinting and the role of methylation in X-inactivation in these processes during female mouse embryo development . To enable molecular studies of embryos, we developed a plethora of single cell assays for specific enzyme activity, gene mutation and methylation, and RNA transcription . While in Anne's Unit, I used these same single cell assays to pioneer the procedures for preimplantation diagnosis of genetic disease, now an established clinical approach to prevention of the birth of children with severe genetic disease . At the Institute of Child Health in London, we continue to develop new highly sensitive molecular procedures--currently for the creation of cDNA libraries from human preimplantation embryos, primordial germ cells and embryonal stem cells . We are using these cDNA preparations to isolate human developmental genes and embryo/cancer genes . One of the more fascinating aspects arising from my time in Anne's Unit is the way in which my research findings challenged a number of accepted dogmas in development concerned with the origin and totipotency of the germ line and the possibility of transgenerational genetic inheritance by epigenetic modification of the germ line.

Mol Cell Neurosci, 2001 Jun, 17(6), 931 - 44
Chick ciliary neurotrophic factor is secreted via a nonclassical pathway; Reiness CG et al.; In contrast to mammalian ciliary neurotrophic factors (CNTFs), chick CNTF is secreted, although it lacks an N-terminal signal . We determined that a 52 aa region of chick CNTF containing an internal hydrophobic domain could direct secretion of rat CNTF . Using a stable cell line that overexpressed chick CNTF, we found that chick CNTF immunoreactivity was punctate throughout the cytosol . Cellular fractionation confirmed chick CNTF to be protected by vesicles . Chick CNTF did not colocalize with fibronectin, calreticulin, wheat germ agglutinin binding sites, or with transferrin receptor . The distribution of chick CNTF was altered neither by brefeldin A nor by chloroquine treatment . Although the punctate pattern of chick CNTF immunoreactivity was not due to reuptake, chick CNTF could be found in a cellular compartment labeled after a brief incubation with dextran microbeads . When synthesized in vitro, chick CNTF did not translocate into microsomes . We conclude that chick CNTF is secreted via a nonclassical pathway .

Trans Am Clin Climatol Assoc, 2001, 112, 215 - 22; discussion 222-3
Microbes, inflammation and atherosclerosis: will old pathology lessons guide new therapies?
Vercellotti GM.
Although attractive, the microbial pathogenesis theory for atherosclerosis remains unproven . Over the last century, microbiologists have invoked fulfillment of Koch's postulates to determine pathogen causality . Certainly a multifactorial disease process such as atherosclerosis unlikely will be due to a single microbial agent, an agent when transferred to another host, will always induce atherosclerosis . Conflicting epidemiological data also do not support a single causative agent . However, as presented here, considerable in vitro, animal, and human epidemiological data support the plausibility that infectious agents can promote a proinflammatory, procoagulant and proatherogenic environment in the vessel wall . Microbial genes and molecules can catalyze these processes and foil normal cellular events . But, must intact microbes enter the vessel wall or can microbial molecules incite immune responses from afar? A new focus on pathogen-induced auto-immunity toward vasculature has been presented . For example, microbes contain molecules that mimic host cellular components (55) . An immune response to a pathogen may cross react with vessel wall cellular structures . This immune response enhanced by infection may lead to high levels of cross reacting auto-antibodies or auto-aggressive T-cells . Epstein has championed the concept of pathogen burden in support of this auto-immune theory (56) . Individuals infected with multiple pathogens such as HSV-1, HSV-2, CMV, Helicobacter pylori, and Hepatitis A, have high C-reative protein levels (markers of inflammation) and the greatest relative risk for coronary artery disease (57) . Thus, pathogens might contribute to the atherosclerotic process by promoting inflammatory responses . It is this author's view that microbes and inflammation do play a role in the pathogenesis of atherosclerosis (58) . Infection may contribute to the process promoting vessel wall injury initiated by oxidized lipids, smoking derived oxidants, hypertensive shear or diabetes glyoxidized molecules . Inflammation and immune reactions in response to infection can exacerbate and act synergistically with all of the aforementioned vasculotoxic moieties . Continued investigations in the 21st century will determine if vaccines, antibiotics, anti-inflammatory agents or immunosuppressants will alter the picture the early 19th century pathologists observed under their monocular microscopes.

Alcohol Clin Exp Res, 2001 Jun, 25(6), 829 - 34
4-Methylpyrazole decreases salivary acetaldehyde levels in aldh2-deficient subjects but not in subjects with normal aldh2; Vakevainen S et al.; BACKGROUND: Carcinogenic acetaldehyde is produced from ethanol locally in the upper digestive tract via alcohol dehydrogenases (ADHs) of oral microbes, mucosal cells, and salivary glands . Acetaldehyde is further oxidized into less harmful acetate mainly by the aldehyde dehydrogenase-2 (ALDH2) enzyme . ALDH2-deficiency increases salivary acetaldehyde levels and the risk for upper digestive tract cancer in heavy alcohol drinkers . 4-methylpyrazole (4-MP) is an ADH-inhibitor which could reduce the local production of acetaldehyde from ethanol in the saliva . METHODS: Five ALDH2-deficient subjects and six subjects with normal ALDH2 ingested a moderate dose of alcohol (0.4 g/kg of body weight), whereafter their salivary acetaldehyde levels, heart rate, skin temperature, and blood pressure were followed for up to four hours . Blood acetaldehyde and ethanol levels were determined at 60 min . The experiment was repeated after a week . Two hours before the second study day, the volunteers received 4-MP, 10-15 mg/kg of body weight orally . RESULTS: Total ethanol elimination rate decreased with 4-MP by 38-46% in all subjects . 4-MP also reduced blood acetaldehyde levels and suppressed the cardiocirculatory responses of the ALDH2-deficient volunteers . In addition, salivary acetaldehyde production in ALDH2-deficient subjects was significantly reduced when correlated with salivary ethanol levels . On the contrary, 4-MP did not have any effect on salivary or blood acetaldehyde levels in subjects with normal ALDH2 . CONCLUSIONS: A single dose of 4-MP before ethanol ingestion reduces ethanol elimination rate, the flushing reaction, and both blood and salivary acetaldehyde levels in ALDH2-deficient subjects but not in subjects with the normal ALDH2 genotype . These results suggest that the role of oral mucosal and glandular ADHs in salivary acetaldehyde production is minimal and support earlier findings indicating that salivary acetaldehyde production is mainly of microbial origin in subjects with normal ALDH2.

Philos Trans R Soc Lond B Biol Sci, 2001 Jun 29, 356(1410), 957 - 77
The Leeuwenhoek Lecture 2001 . Animal origins of human infectious disease; Weiss RA; Since time immemorial animals have been a major source of human infectious disease . Certain infections like rabies are recognized as zoonoses caused in each case by direct animal-to-human transmission . Others like measles became independently sustained with the human population so that the causative virus has diverged from its animal progenitor . Recent examples of direct zoonoses are variant Creutzfeldt-Jakob disease arising from bovine spongiform encephalopathy, and the H5N1 avian influenza outbreak in Hong Kong . Epidemics of recent animal origin are the 1918-1919 influenza pandemic, and acquired immune deficiency syndrome caused by human immunodeficiency virus (HIV) . Some retroviruses jump into and out of the chromosomal DNA of the host germline, so that they oscillate between being inherited Mendelian traits or infectious agents in different species . Will new procedures like animal-to-human transplants unleash further infections? Do microbes become more virulent upon cross-species transfer? Are animal microbes a threat as biological weapons? Will the vast reservoir of immunodeficient hosts due to the HIV pandemic provide conditions permissive for sporadic zoonoses to take off as human-to-human transmissible diseases? Do human infections now pose a threat to endangered primates? These questions are addressed in this lecture.

Curr Genet, 2001 Apr, 39(2), 109 - 16
Marker free transgenic plants: engineering the chloroplast genome without the use of antibiotic selection; Daniell H et al.; Chloroplast genetic engineering offers several advantages over nuclear transformation including high levels of gene expression and gene containment . However, a consequence of placing a transgene in the chloroplast genome is that the antibiotic resistance genes used as selectable markers are highly amplified . Engineering genetically modified (GM) crops without the use of antibiotic resistance genes should eliminate the potential risk of their transfer to the environment or gut microbes . Therefore, the betaine aldehyde dehydrogenase (BADH) gene from spinach was used in this study as a selectable marker . The selection process involves conversion of toxic betaine aldehyde (BA) by the chloroplast BADH enzyme to non-toxic glycine betaine, which also serves as an osmoprotectant . Chloroplast transformation efficiency was 25-fold higher in BA selection than with spectinomycin . In addition, rapid regeneration was obtained . Transgenic shoots appeared within 12 days in 80% of leaf disks (up to 23 shoots per disk) under BA selection compared to 45 days in 15% of disks (1 or 2 shoots per disk) under spectinomycin selection . Southern blots confirmed stable integration of foreign genes into all of the chloroplast genomes (approximately 10,000 copies per cell) resulting in homoplasmy . Transgenic tobacco plants showed 15- to 18-fold higher BADH activity at different developmental stages than untransformed controls . Transgenic plants were morphologically indistinguishable from untransformed plants and the introduced trait was inherited stably in the subsequent generation . This is the first report of genetic engineering of the higher plant chloroplast genome without the use of antibiotic selection . The use of naturally occurring genes in spinach for selection, in addition to gene containment, should ease public concerns regarding GM crops.

Curr Opin Biotechnol, 2001 Jun, 12(3), 248 - 53
Microbial detoxification of metals and radionuclides; Lloyd JR et al.; Microorganisms have important roles in the biogeochemical cycling of toxic metals and radionuclides . Recent advances have been made in understanding metal-microbe interactions and new applications of these processes to the detoxification of metal and radionuclide contamination have been developed.

Am J Physiol Gastrointest Liver Physiol, 2001 Jul, 281(1), G1 - 7
Microbes and microbial toxins: paradigms for microbial-mucosal interactions . VII . Enteropathogenic Escherichia coli: physiological alterations from an extracellular position; Hecht G; Enteropathogenic Escherichia coli (EPEC) is primarily associated with infantile diarrhea in developing countries . This intriguing pathogen exerts numerous physiological effects on its host target tissue, the intestinal epithelium, all from an extracellular location . Expression of a type III secretory apparatus allows this organism to transfer bacterial effector molecules directly into host cells . As a result of EPEC attachment to and/or translocation of proteins into intestinal epithelial cells, many signaling cascades are activated . Ultimately, host functions are perturbed, including alteration of ion transport, disruption of the tight junction barrier, and activation of the inflammatory response.

Plant Physiol, 2001 Jun, 126(2), 631 - 42
The three-dimensional structure of cystathionine beta-lyase from Arabidopsis and its substrate specificity; Breitinger U et al.; The pyridoxal 5'-phosphate-dependent enzyme cystathionine beta-lyase (CBL) catalyzes the penultimate step in the de novo biosynthesis of Met in microbes and plants . Absence of CBL in higher organisms makes it an important target for the development of antibiotics and herbicides . The three-dimensional structure of cystathionine beta-lyase from Arabidopsis was determined by Patterson search techniques, using the structure of tobacco (Nicotiana tabacum) cystathionine gamma-synthase as starting point . At a resolution of 2.3 A, the model was refined to a final crystallographic R-factor of 24.9% . The overall structure is very similar to other pyridoxal 5'-phosphate-dependent enzymes of the gamma-family . Exchange of a few critical residues within the active site causes the different substrate preferences between Escherichia coli and Arabidopsis CBL . Loss of interactions at the alpha-carboxyl site is the reason for the poorer substrate binding of Arabidopsis CBL . In addition, the binding pocket of Arabidopsis CBL is larger than that of E . coli CBL, explaining the similar binding of L-cystathionine and L-djenkolate in Arabidopsis CBL in contrast to E . coli CBL, where the substrate binding site is optimized for the natural substrate cystathionine.

Plant Cell, 2001 Jun, 13(6), 1401 - 9
Production of 6-methylsalicylic acid by expression of a fungal polyketide synthase activates disease resistance in tobacco; Yalpani N et al.; Salicylic acid (SA) has been shown to act as a signal molecule that is produced by many plants subsequent to the recognition of potentially pathogenic microbes . Increases in levels of SA often trigger the activation of plant defenses and can result in increased resistance to subsequent challenge by pathogens . We observed that the polyketide 6-methylsalicylic acid (6-MeSA), a compound that apparently is not endogenous to tobacco, can mimic SA . Tobacco leaves treated with 6-MeSA show enhanced accumulation of the pathogenesis-related (PR) proteins PR1, beta-1,3-glucanase, and chitinase and also develop increased resistance to tobacco mosaic virus . We transformed tobacco with 6msas, the 6-methylsalicylic acid synthase (6MSAS) gene from Penicillium patulum, to generate plants that constitutively accumulate 6-MeSA . Analysis of primary transformants and the first generation progeny of 6MSAS tobacco revealed that plants can be engineered to accumulate significant amounts of 6-MeSA as a conjugate . Levels of total 6-MeSA increased with plant age . Increased 6-MeSA accumulation correlated with increased levels of PR1 and chitinase proteins and resulted in enhanced resistance of NN genotype 6MSAS tobacco to tobacco mosaic virus . Our results demonstrate that a multistep biosynthetic pathway can be engineered into plants using a single fungal polyketide synthase gene . The functional expression of 6msas can be used to activate disease resistance pathways that normally are induced by SA.

Intensive Care Med, 2001 Apr, 27(4), 665 - 72
Pharmacokinetics of ciprofloxacin in ICU patients on continuous veno-venous haemodiafiltration; Wallis SC et al.; OBJECTIVES: To investigate the pharmacokinetics of intravenous ciprofloxacin 200 mg every 8 h in critically ill patients on continuous veno-venous haemodiafiltration (CVVHDF), one form of continuous renal replacement therapy (CRRT) . DESIGN AND SETTING: Open, prospective clinical study in a multidisciplinary, intensive care unit in a university-affiliated tertiary referral hospital . PATIENTS: Six critically ill patients with acute renal failure on CVVHDF . INTERVENTIONS: Timed blood and ultrafiltrate samples were collected to allow pharmacokinetics and clearances to be calculated of initial and subsequent doses of 200 mg intravenous ciprofloxacin . CVVHD was performed with 1 l/h of dialysate and 2 l/h of predilution filtration solution, producing 3 l/h of dialysis effluent . The blood was pumped at 200 ml/min using a Gambro BMM-10 blood pump through a Hospal AN69HF haemofilter . MEASUREMENTS AND RESULTS: Ten pharmacokinetic profiles were measured . The CVVHDF displayed a urea clearance of 42 +/- 3 ml/min, and removed ciprofloxacin with a clearance of 37 +/- 7 ml/min . This rate was 2-2.5 greater than previously published for ciprofloxacin in other forms of CRRT . On average the CVVHDF was responsible for clearing a fifth of all ciprofloxacin eliminated (21 +/- 10%) . The total body clearance of ciprofloxacin was 12.2 +/- 4.3 l/h . The trough concentration following the initial dose was 0.7 +/- 0.3 mg/l . The area under the plasma concentration time curves over a 24-h period ranged from 21 to 55 mg.h l-1 . CONCLUSIONS: Intravenous ciprofloxacin 600 mg/day in critically ill patients using this form of CRRT produced adequate plasma levels for many resistant microbes found in intensive care units.

Am J Clin Nutr, 2001 Jun, 73(6), 1131S - 1141S
Microbial modulation of innate defense: goblet cells and the intestinal mucus layer; Deplancke B et al.; The gastrointestinal epithelium is covered by a protective mucus gel composed predominantly of mucin glycoproteins that are synthesized and secreted by goblet cells . Changes in goblet cell functions and in the chemical composition of intestinal mucus are detected in response to a broad range of luminal insults, including alterations of the normal microbiota . However, the regulatory networks that mediate goblet cell responses to intestinal insults are poorly defined . The present review summarizes the results of developmental, gnotobiotic, and in vitro studies that showed alterations in mucin gene expression, mucus composition, or mucus secretion in response to intestinal microbes or host-derived inflammatory mediators . The dynamic nature of the mucus layer is shown . Available data indicate that intestinal microbes may affect goblet cell dynamics and the mucus layer directly via the local release of bioactive factors or indirectly via activation of host immune cells . A precise definition of the regulatory networks that interface with goblet cells may have broad biomedical applications because mucus alterations appear to characterize most diseases of mucosal tissues.

Environ Int, 2001 May, 26(5-6), 315 - 22
Microbial ecology of soils surrounding nuclear and thermal power plants in Taiwan; Yang CK et al.; This paper reports a study of the effect of three nuclear and one thermal power plants on the microbial ecology of soils . Populations of bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes and nitrogen-fixing microbes in the soil in the vicinity of each plant were studied . Soils were acidic at three sites, and moisture contents of the power plant soils were lower than those of the surrounding areas . Microbial populations of the topsoils (0-20 cm deep) were higher than the subsoils (21-40 cm deep), and only 10-15% of them showed significant difference (P < .05) . Thirty-three percent of the samples from the surrounding areas had higher microbial population than those from the power plant areas, but 19% was the reverse . Populations of cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes varied with sampling locations, season and environmental conditions . Ratios of cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes to total viable counts in some samples of the surrounding areas were significantly higher than in the power plant areas . Although the microbial populations of power plant soil and its surrounding area were somewhat different, it cannot be attributed as an effect of power plant operation, as the differences were not consistent.

Environ Toxicol Chem, 2001 Jun, 20(6), 1167 - 74
Indirect effects of zinc on soil microbes via a keystone enchytraeid species; Salminen J et al.; Effects of Zn pollution on a keystone species of forest soils, the enchytraeid Cognettia sphagnetorum, and its consequent indirect effects on microbial biomass and activity were studied in a microcosm experiment using experimentally contaminated humic soil . Microbial growth and decomposition were enhanced in the presence of C . sphagnetorum . At high Zn concentrations (< 2,393 mg/kg dry soil), populations of C . sphagnetorum went extinct, resulting in negative indirect effects on microbial activity as measured by soil respiration . Results indicate that pollution may affect species interactions in a soil food web and indirectly affect ecosystem processes such as decomposition rate . Effects of pollution on keystone organisms may radically alter soil ecosystem functioning and should be taken into account during risk-assessment procedures.

News Physiol Sci, 2000 Dec, 15, 298 - 303
Inflammatory Cytokines in Nonpathological States; Cannon JG; During infection, inflammatory cytokines induce regulated changes in the host's internal milieu that create a hostile environment to an invading pathogen . Recent evidence indicates that these cytokines are constitutively produced, their production is increased by environmental stressors other than microbes, and they modulate "normal" physiological processes.

Novartis Found Symp, 2001, 236, 233 - 9; discussion 240-1
Developing transgenic grains with improved oils, proteins and carbohydrates; Mazur BJ; DuPont has developed cereals and oilseeds with improved proteins, carbohydrates, and oils for food, feed, and industrial applications . Products which have been or will be introduced include corn and soybeans with increased oil content, improved oil composition, increased amino acid content, altered protein content and functional qualities, altered starch composition, reduced oligosaccharide content, increased sucrose content, and combinations of these traits . These products have been developed using both mutation breeding and molecular biology-based transgenic approaches . We have also worked on improving the underlying technologies in order to accelerate product introductions . Gene discovery has been expedited through a genomics program that now has a database of more than two million sequences from a variety of plants, insects and microbes . Plant cell transformation for elite lines of crop species is being addressed through production laboratories with high throughput processes and through technology improvements . High-throughput, rapid and small-scale assays for biochemical parameters are used to identify plants carrying traits of interest . Small-scale functionality analyses, in which grains are broken down into their component parts and assayed for functional properties, indicate which seeds carry a trait of commercial value . Finally, a number of DNA marker systems are being used to accelerate trait introgression timelines.

Ecotoxicol Environ Saf, 2001 May, 49(1), 1 - 16
Ecotoxicity tests for compost applications; Kapanen A et al.; Interest in the ecological effects of composting has been growing recently . However, no established methods are available for testing the toxicity of composted materials . Despite this, international and national quality requirements define that compost shall not contain any environmentally harmful substances . Safety requirements have to be fulfilled if the produced compost is intended for agricultural use . This literature review focuses on methods that could potentially be used to evaluate the ecotoxicity of compost . The toxicity test methods discussed are those employing microbes, enzymes, soil fauna, and plants .

J Acoust Soc Am, 2001 May, 109(5 Pt 1), 2153 - 64
Dynamic consequences of differences in male and female vocal tract dimensions; Simpson AP; Phonetic differences between male and female speakers are generally considered in terms of the static acoustic and perceptual consequences of different articulatory dimensions . This article investigates the dynamic acoustic and articulatory implications of differences in mean male and female vocal tract dimensions . The temporal acoustic consequences of time-varying twin-tube resonators of different dimensions are explored, and the possible implications for human speech production are considered . Empirical support for the theoretical predictions is sought by investigating the kinematic and acoustic patterns in diphthong productions from 26 female and 22 male speakers in the University of Wisconsin X-ray Microbeam Speech Production Database . Aside from expected acoustic differences, the shape of male and female formant tracks plotted in Bark space is found to be very similar . Male and female patterns of tongue movement, however, are found to be very dissimilar . The mean male diphthong, defined by the tracks of four midsagittal pellets, is characterized by greater pellet excursions, higher pellet speed, and consistently larger dorso-palatal strictures than its female counterpart . The empirical findings suggest that gender-specific dynamic behavior could be an important factor in accounting for nonuniform vowel system differences, but at the same time having more wide-ranging implications for transitional phenomena and undershoot.

Sci Prog, 2001, 84(Pt 1), 1 - 16
The origin of life . I: When and where did it begin?
Davies P.
For decades most scientists assumed that life emerged billions of years ago in a "primordial soup" somewhere on the Earth's surface . Evidence is mounting, however, that life may have begun deep beneath the surface, perhaps near a volcanic ocean vent or even inside the hot crust itself . Since there are hints that life's history on Earth extends back through the phase of massive cosmic bombardment, it may be that life started on Mars and came here later, perhaps inside rocks ejected from the Red Planet by large impacts . The traffic of intact rocks between Mars and Earth is now an established fact, and experiments confirm that microbes could survive the rigours of the journey through space if cocooned within such material . Unfortunately, this planetary cross-contamination compromises astrobiologists' hope of finding a second genesis in the solar system.

Cytometry, 2001 Jun 1, 44(2), 137 - 47
Measurement of CD2 expression levels of IFN-alpha-treated fibrosarcomas using cell tracking velocimetry; McCloskey KE et al.; METHODS: A methodology and a mathematical relationship have been developed that allow quantitation of the expression levels of cellular surface antigens, in terms of antibody binding capacities (ABC) . This methodology uses immunomagnetically labeled cells and calibration microbeads combined with cell tracking velocimetry (CTV) technology to measure magnetophoretic mobilities corresponding to cellular ABC . The mobility measurements were accomplished by microscopically recording and calculating the velocity of immunomagnetically labeled QSC microbeads and cells in a nearly constant magnetic energy gradient . RESULTS: Transformed fibrosarcoma cells were given controlled treatments of interferon-alpha in order to manipulate CD2 antigen expression levels . These cells were then immunomagnetically labeled with anti-CD2 FITC antibodies and anti-FITC MACS paramagnetic nanoparticles . Measured magnetophoretic mobilities were used to calculate ABC for these cells, corresponding to CD2 expression levels . CONCLUSION: The results from CTV and flow cytometry (FCM) qualitatively verify that these fibrosarcoma cells express elevated levels of CD2 molecules with increasing interferon-alpha treatment from 0 to 24 h . The mean basal CD2 expression level, in terms of ABC, was calculated to be 27,000 from CTV analysis, whereas FCM indicates a comparable ABC value of 33,000 .

Free Radic Res, 2001 May, 34(5), 439 - 43
The iron paradox of heart and lungs and its implications for acute lung injury; Gutteridge JM et al.; Iron is an essential requirement for the growth, development, and long term survival of most aerobic organisms . When control over safe iron sequestration is lost or compromised, leading to the release of low molecular mass forms of iron, the heart appears to be particularly sensitive to iron toxicity with cardiomyopathies often developing as a consequence . Iron toxicity, leading to iron-overload, is often treated in humans with the iron chelator desferrioxamine mesylate . Such treatment regimens designed to protect the heart can, however, often lead to lung injury and, in fact, several compounds with known iron chelating properties can induce severe lung dysfunction and injury . Based on these clinical observations and our recent laboratory data, we propose that the lungs actively accumulate reactive forms of iron for use in cellular growth and proliferation, and for the oxidative destruction of microbes, whereas the heart responds in the opposite way by actively removing iron which it finds extremely toxic.

Curr Opin Microbiol, 2001 Jun, 4(3), 290 - 5
Microbial seascapes revisited; DeLong EF; A remarkable array of new discoveries is emerging from studies of naturally occurring marine microbes . These discoveries originate from novel applications of evolving technologies, ranging from molecular phylogenetics to stable isotope analyses, to advanced microscopic techniques, to genomics . As a consequence, new perspectives on the natural history of marine microbes, the inseparable nature of the geological and biological worlds, and a plethora of unexpected new genotypes, phenotypes and physiologies are now being revealed . As our observations of naturally occurring microbes become increasingly more sophisticated, so will theory, technical applications and predictive capabilities in microbial ecology.

Curr Opin Microbiol, 2001 Jun, 4(3), 246 - 50
Analysis of host responses to microbial infection using gene expression profiling; Kagnoff MF et al.; Gene expression profiling offers new opportunities for understanding host-cell responses to microbial pathogens and their products . Current strategies involve either first identifying mRNAs that differ in their expression status under different experimental conditions and later defining the identity of the respective genes (for example, differential display or serial analysis of gene expression), or alternatively assessing changes in the expression of already defined genes (for example, cDNA or oligonucleotide microarrays) . Early studies indicate the power of gene expression profiling for providing new insights into groups of genes whose expression is altered during the course of host-microbe interactions, and for the discovery of cellular genes that were not previously recognized to be regulated by infection.

EMBO Rep, 2001 May, 2(5), 376 - 81
Ecological fitness, genomic islands and bacterial pathogenicity . A Darwinian view of the evolution of microbes; Hacker J et al.; The compositions of bacterial genomes can be changed rapidly and dramatically through a variety of processes including horizontal gene transfer . This form of change is key to bacterial evolution, as it leads to 'evolution in quantum leaps' . Horizontal gene transfer entails the incorporation of genetic elements transferred from another organism-perhaps in an earlier generation-directly into the genome, where they form 'genomic islands', i.e . blocks of DNA with signatures of mobile genetic elements . Genomic islands whose functions increase bacterial fitness, either directly or indirectly, have most likely been positively selected and can be termed 'fitness islands' . Fitness islands can be divided into several subtypes: 'ecological islands' in environmental bacteria and 'saprophytic islands', 'symbiosis islands' or 'pathogenicity islands' (PAIs) in microorganisms that interact with living hosts . Here we discuss ways in which PAIs contribute to the pathogenic potency of bacteria, and the idea that genetic entities similar to genomic islands may also be present in the genomes of eukaryotes.

Curr Microbiol, 2001 Jul, 43(1), 26 - 32
Disruption of a global regulatory gene to enhance central carbon flux into phenylalanine biosynthesis in Escherichia coli; Tatarko M et al.; Genetic engineering of microbes for commercial metabolite production traditionally has sought to alter the levels and/or intrinsic activities of key enzymes in relevant biosynthetic pathway(s) . Microorganisms exploit similar strategies for flux control, but also coordinate flux through sets of related pathways by using global regulatory circuits . We have engineered a global regulatory system of Escherichia coli, Csr (carbon storage regulator), to increase precursor for aromatic amino acid biosynthesis . Disruption of csrA increases gluconeogenesis, decreases glycolysis, and thus elevates phosphoenolpyruvate, a limiting precursor of aromatics . A strain in which the aromatic (shikimate) pathway had been optimized produced twofold more phenylalanine when csrA was disrupted . Overexpression of tktA (transketolase) to increase the other precursor, erythrose-4-phosphate, yielded approximately 1.4-fold enhancement, while both changes were additive . These effects of csrA were not mediated by increasing the regulatory enzymes of phenylalanine biosynthesis . This study introduces the concept of "global metabolic engineering" for second-generation strain improvement.

Proc R Soc Lond B Biol Sci, 2001 May 22, 268(1471), 1033 - 9
Weeding and grooming of pathogens in agriculture by ants; Currie CR et al.; The ancient mutualism between fungus-growing ants and the fungi they cultivate for food is a textbook example of symbiosis . Fungus-growing ants' ability to cultivate fungi depends on protection of the garden from the aggressive microbes associated with the substrate added to the garden as well as from the specialized virulent garden parasite Escovopsis . We examined ants' ability to remove alien microbes physically by infecting Atta colombica gardens with the generalist pathogen Trichoderma viride and the specialist pathogen Escovopsis . The ants sanitized the garden using two main behaviours: grooming of alien spores from the garden (fungus grooming) and removal of infected garden substrate (weeding) . Unlike previously described hygienic behaviours (e.g . licking and self-grooming), fungus-grooming and garden-removal behaviours are specific responses to the presence of fungal pathogens . In the presence of pathogens, they are the primary activities performed by workers, but they are uncommon in uninfected gardens . In fact, workers rapidly eliminate Trichoderma from their gardens by fungus grooming and weeding, suggesting that these behaviours are the primary method of garden defence against generalist pathogens . The same sanitary behaviours were performed in response to the presence of the specialist pathogen Escovopsis . However, the intensity and duration of these behaviours were much greater in this treatment . Despite the increased effort, the ants were unable to eliminate Escovopsis from their gardens, suggesting that this specialized pathogen has evolved counter-adaptations in order to overcome the sanitary defences of the ants.

Transplantation, 2001 Apr 27, 71(8), 1106 - 12
Impact of donor-specific antibodies on chronic rejection occurrence and graft loss in renal transplantation: posttransplant analysis using flow cytometric techniques; Piazza A et al.; BACKGROUND: Improvements in immunosuppressive therapy have greatly reduced acute rejection (ARj) episodes, ensuring better short-term graft outcome, but have not modified long-term survival in renal transplantation . It is now well accepted that chronic rejection (CRj) can be determined by both immune and/or nonimmune mechanisms . The aim of this study was to evaluate the importance of the posttransplant humoral immune response towards mismatched HLA graft antigens in CRj occurrence and graft outcome . METHODS: Serum samples from 120 nonpresensitized renal transplant recipients were prospectively screened for 1 year after surgery by means of flow cytometry cross-match (FCXM) and FlowPRA beads (microbeads coated with purified HLA class I and class II antigens) assays . All transplants were followed-up for 2 years or until graft removal . RESULTS: FCXM monitoring identified donor-specific antibodies (DS-Abs) in 29 (24.2%) of 120 transplanted patients . Correlation with clinical data highlighted a higher incidence of ARj in DS-Abs-positive patients compared to negative patients (62% vs . 13%, P<0.00001) . Furthermore, graft failure occurred more frequently among FCXM-positive patients than among negative patients (34% vs . 1%, P<0.00001) . The deleterious effect of DS-Abs on graft function was confirmed by serum creatinine levels 2 years after transplantation . These were in fact higher in subjects producing DS-Abs than in subjects with only ARj (mean creatinine: 2.5+/-1.3 mg/dL vs.1.7+/-0.5 mg/dL, P=0.04) . FlowPRA analysis of DS-Ab HLA specificity highlighted the presence of anti-HLA class I antibodies in 85% of FCXM-positive patients, who also presented with a higher incidence of HLA-B mismatches than FCXM-negative patients (1.23+/-0.66 vs . 0.92+/-0.59, P=0.02) . CONCLUSIONS: Flow cytometric techniques are precious tools for investigating the activation of the humoral response against HLA antigens of the graft in renal transplantation . DS-Abs production has a worse impact on organ function and survival than ARj episodes . These findings represent further proof of the threat posed by DS-Abs on long-term graft function and draw attention to the need for a specific immunosuppressive therapy aimed at counteracting the different kinds of immune activation toward graft.

Mt Sinai J Med, 2001 May, 68(3), 106 - 66
Dendritic cells and the control of immunity: enhancing the efficiency of antigen presentation; Steinman RM; BACKGROUND: Relevant antigens often are known for diseases that involve the immune system . Yet purified antigens by themselves do not control immunity, especially T-cell immunity . For example, many antigens have been defined for HIV-1 and melanoma, but good HIV-1 vaccines and melanoma immune therapies are lacking . Dendritic cells (DCs) are important intermediaries between antigens and better control of the immune system . METHODS: Some properties that allow DCs to control immunity are reviewed, followed by new studies using DCs as adjuvants in humans . An emerging area is then detailed, the special mechanisms whereby DCs enhance the formation of ligands for T-cells, i.e., complexes of major histocompatibility complex (MHC) products and antigenic peptides . RESULTS: Once criteria were developed to identify and isolate DCs, several functional properties became evident . DCs are unusually potent in initiating T-cell mediated immunity in culture . In vivo, DCs are positioned to capture antigens and migrate to T-cell areas of lymphoid organs . There, DCs are able to prime animals, controlling the MHC restriction of the primed T-cells and inducing resistance to pathogens . DCs pulsed ex vivo with antigens are now being used to induce and expand T-cell immunity in humans . To optimize their use, two areas of DC function need to be harnessed: their terminal differentiation or maturation, and antigen uptake . DCs capture most types of antigens at an immature stage of development, but the cells must receive additional stimuli prior to acquiring potent T-cell stimulatory activity . Stimuli from microbes, inflammation and trauma mature DCs . These change the DCs in several ways, even inducing the formation of MHC II-peptide complexes or T-cell receptor (TCR) ligands . The latter move to the surface in nonlysosomal vesicles that simultaneously carry CD86 costimulatory molecules for T-cell activation . Both MHC and CD86 remain co-clustered in patches at the DC surface . DCs also express a receptor, DEC-205, that enhances antigen uptake and presentation . DEC-205 recycles in an unusual manner through MHC class II-rich, late endosomes or lysosomes, dramatically increasing the presentation of bound ligands . Additionally and importantly, DCs can process dying cells and immune complexes onto MHC class I products, events that are termed the "exogenous pathway" or "cross presentation." CONCLUSIONS: The control of the immune system by DCs reflects numerous specializations, not a single "magic bullet." These specializations include a number of mechanisms that increase the efficiency of antigen uptake and MHC-peptide complex formation . The harnessing of these and other features of DCs provides opportunities for improving immune-based therapies and vaccine design.

Acta Biotheor, 2001 Mar, 49(1), 1 - 21
How microbes can achieve balanced growth in a fluctuating environment; van den Berg HA; A microbial colony needs several essential nutrients in order to grow . Moreover, the colony requires these nutrients in fixed combinations, which are dictated by the chemical composition of its biomass . Unfortunately, ambient availabilities of the various nutrients vary all the time . This poses the question of how microbes can achieve balanced growth . The present solution to this problem is novel in that the allocation of molecular building blocks among assimilatory machineries within the cell is regarded as dynamic . This paper shows that allocation can be adapted so as to achieve balanced growth, nearly regardless of environmental conditions . Moreover, it is shown that a feedback mechanism, which monitors internal stores, is able to achieve this allocation.

Arch Biochem Biophys, 2001 Apr 15, 388(2), 207 - 15
Characterization of three members of murine alpha1,2-fucosyltransferases: change in the expression of the Se gene in the intestine of mice after administration of microbes; Lin B et al.; We cloned three members of a GDP-fucose:beta-galactoside alpha1,2-fucosyltransferase (alpha1,2-fucosyltransferase) family, MFUT-I, -II, and -III, from a cDNA of murine small intestine, and determined their enzymatic properties after transfection of the genes into COS-7 cells, and their expression in murine tissues by Northern blotting . MFUT-I, -II, and -III exhibited sequence homology with the human H (78.4%), Se (79.0%), and Sec1 (74.9%) gene products, respectively . COS-7 cells transfected with MFUT-I and -II exhibited alpha1,2-fucosyltransferase activity and the best acceptor substrate for both gene products was GA1 to yield a fucosyl GA1 structure, but no activity was detected in COS-7 cells with MFUT-III . MFUT-II yielded a 3.5-kb mRNA transcript in several tissues, whereas MFUT-I and -III were predominantly expressed in epididymis and testis, respectively . The administration of microbes into germ-free mice resulted in a rapid increase of the MFUT-II gene (Se gene) for the synthesis of fucosyl GA1 in the intestine.

Int Immunopharmacol, 2001 Mar, 1(3), 365 - 92
Genetic, structural and functional diversities of human complement components C4A and C4B and their mouse homologues, Slp and C4; Blanchong CA et al.; The complement protein C4 is a non-enzymatic component of the C3 and C5 convertases and thus essential for the propagation of the classical complement pathway . The covalent binding of C4 to immunoglobulins and immune complexes (IC) also enhances the solubilization of immune aggregates, and the clearance of IC through complement receptor one (CR1) on erythrocytes . Human C4 is the most polymorphic protein of the complement system . In this review, we summarize the current concepts on the 1-2-3 loci model of C4A and C4B genes in the population, factors affecting the expression levels of C4 transcripts and proteins, and the structural, functional and serological diversities of the C4A and C4B proteins . The diversities and polymorphisms of the mouse homologues Slp and C4 proteins are described and contrasted with their human homologues . The human C4 genes are located in the MHC class III region on chromosome 6 . Each human C4 gene consists of 41 exons coding for a 5.4-kb transcript . The long gene is 20.6 kb and the short gene is 14.2 kb . In the Caucasian population 55% of the MHC haplotypes have the 2-locus, C4A-C4B configurations and 45% have an unequal number of C4A and C4B genes . Moreover, three-quarters of C4 genes harbor the 6.4 kb endogenous retrovirus HERV-K(C4) in the intron 9 of the long genes . Duplication of a C4 gene always concurs with its adjacent genes RP, CYP21 and TNX, which together form a genetic unit termed an RCCX module . Monomodular, bimodular and trimodular RCCX structures with 1, 2 and 3 complement C4 genes have frequencies of 17%, 69% and 14%, respectively . Partial deficiencies of C4A and C4B, primarily due to the presence of monomodular haplotypes and homo-expression of C4A proteins from bimodular structures, have a combined frequency of 31.6% . Multiple structural isoforms of each C4A and C4B allotype exist in the circulation because of the imperfect and incomplete proteolytic processing of the precursor protein to form the beta-alpha-gamma structures . Immunofixation experiments of C4A and C4B demonstrate > 41 allotypes in the two classes of proteins . A compilation of polymorphic sites from limited C4 sequences revealed the presence of 24 polymophic residues, mostly clustered C-terminal to the thioester bond within the C4d region of the alpha-chain . The covalent binding affinities of the thioester carbonyl group of C4A and C4B appear to be modulated by four isotypic residues at positions 1101, 1102, 1105 and 1106 . Site directed mutagenesis experiments revealed that D1106 is responsible for the effective binding of C4A to form amide bonds with immune aggregates or protein antigens, and H1106 of C4B catalyzes the transacylation of the thioester carbonyl group to form ester bonds with carbohydrate antigens . The expression of C4 is inducible or enhanced by gamma-interferon . The liver is the main organ that synthesizes and secretes C4A and C4B to the circulation but there are many extra-hepatic sites producing moderate quantities of C4 for local defense . The plasma protein levels of C4A and C4B are mainly determined by the corresponding gene dosage . However, C4B proteins encoded by monomodular short genes may have relatively higher concentrations than those from long C4A genes . The 5' regulatory sequence of a C4 gene contains a Spl site, three E-boxes but no TATA box . The sequences beyond--1524 nt may be completely different as the C4 genes at RCCX module I have RPI-specific sequences, while those at Modules II, III and IV have TNXA-specific sequences . The remarkable genetic diversity of human C4A and C4B probably promotes the exchange of genetic information to create and maintain the quantitative and qualitative variations of C4A and C4B proteins in the population, as driven by the selection pressure against a great variety of microbes . An undesirable accompanying byproduct of this phenomenon is the inherent deleterious recombinations among the RCCX constituents leading to autoimmune and genetic disorders.

Newsline People AIDS Coalit N Y . 1998 Dec;:34-5.
Imaging AIDS; High-dose IL-2 without HAART; {No authors listed}

AIDS: Australian researchers recruited 115 HIV-positive subjects for a study of high-dose IL-2 with at least one antiviral drug . The study lasted one year, and some of the subjects received IL-2 booster injections while others did not . Study details are specified . In the study group, three subjects taking IL-2 developed AIDS, as determined by fungal infections of the brain and mouth . Two not taking IL-2 developed AIDS, in the form of a bacterial infection and parasitic infection . Through the course of the study, IL-2 boosted CD4+ counts by 25 percent in 90 percent of the subjects and preserved immunity against microbes . There appeared to be no effect on viral load .

Posit Aware . 1998 Nov-Dec;9(6):28.
Understanding the immune system; Rossi A; AIDS: The function of the immune system is to protect the body from foreign organisms . Different types of immunity are described . Natural immunity is composed of innate defenses that react instinctively to a foreign body . Acquired immunity reacts only in the presence of a foreign body . Once exposed to microbes, acquired immunity cells learn how to fight these invaders and retain this information for subsequent encounters . Both types of immunities can work in tandem and are employed in the fight against HIV . However, rather than producing antibodies, one type of cell, the T-lymphocyte, becomes a haven for the virus to reproduce . Over time, the immune system loses the ability to destroy the infected cells and the body cannot fight certain diseases .

Treatmentupdate, 1998 Sep, 10(7), 3 - 5
PCP prevention--more cases of resistance to sulfa drugs; Lethal new worm discovered in PWA; AIDS: Doctors recently identified a new form of parasitic worm that was associated with the death of a person with AIDS from the San Francisco Bay area about 1 year ago . The man acquired HIV 5 years ago, but was hospitalized in 1994 with stomach and back pain, weight loss, night sweats and fever . After the worm destroyed parts of the liver and intestines, doctors suspected a new variety of HIV-related cancer . Upon examining the tissue using polymer chain reaction technology, the doctors were able to see that the large amount of scar tissue was caused by the fast growth of the worm . Many questions remain unanswered, such as: how often the new worm causes disease in humans, whether the weakened immune system of a person with AIDS was a factor in susceptibility, where the microbe exists in nature, and whether the infestation can be treated effectively using drugs known to be effective against similar parasites .

Acta Pharmacol Sin, 2000 Jul, 21(7), 577 - 86
Functional implications of sole and selective activation of intravascular coronary endothelial hormonal receptors; Rubio R et al.; The purpose of this review is to present evidence that the lumen of the coronary vascular endothelium is an important site of hormonal action . This review is based on work performed for the last eight years in our laboratories . To demonstrate that selective and exclusive activation or blockade of coronary luminal hormonal receptors is feasible, we have covalently bound to microbeads or large size dextrans (2000 kDa) several hormones or their receptor blockers . These large molecular complexes when administered intravascularly because of their size, remain confined to the blood vessel lumen . The cardiac effects of these large size complexes are identical to those induced by their small size counterparts . The hormones we have used are: adenosine, acetylcholine, bradykinin, substance P, testosterone, and vasopressin . Furthermore, we have also determined the endothelial mediators responsible for the cardiac effects of these hormones . These findings demonstrate that intravascular hormone receptors are indeed physiologically functional and important . In summary, our results support the concept that hormonal stimuli confined to the intravascular endothelial surface trigger the endothelium to release messengers that modulate specific target functions of vicinal parenchymal cells.

Biochem, Eng . J. . 2001 Jul, 8(1), 31 - 37
Chemometric optimisation of parameters for biocatalytic reduction of copper ion by a crude enzyme lysate of Saccharomyces cerevisiae grown under catabolic repression conditions; Bennett Chandran C et al.; The capacity of the microbes to reduce the metal has been demonstrated . The immobilised induced microbes with toxic chemical CuCl(2) was used to reduce the Cu ions as elemental metal and by using the response surface methodology the parameters such as the inducer concentration, the time of inducer addition which are concerned with the growth and formation of specific enzymes and the initial substrate concentration, initial pH of the substrate solution and the time of reaction which are concerned with the biocatalytic reduction of the metal ions were optimised for maximum reduction . The elemental copper reduced and removed experimentally from its ionic state at the optimum conditions was 54.82ppm.

Am J Physiol Gastrointest Liver Physiol, 2001 Jun, 280(6), G1049 - 54
Microbes and microbial toxins: paradigms for microbial-mucosal interactions . VI . Entamoeba histolytica: parasite-host interactions; Stanley SL Jr et al.; The protozoan intestinal parasite Entamoeba histolytica remains a significant cause of morbidity and mortality worldwide . E . histolytica causes two major clinical syndromes, amebic colitis and amebic liver abscess . Recent advances in the development of in vitro and in vivo models of disease, new genetic approaches, the identification of key E . histolytica virulence factors, and the recognition of crucial elements of the host response to infection have led to significant insights into the pathogenesis of amebic infection . E . histolytica virulence factors include 1) a surface galactose binding lectin that mediates E . histolytica binding to host cells and may contribute to amebic resistance to complement, 2) amebapores, small peptides capable of lysing cells, which may play a role in killing intestinal epithelial cells, hepatocytes, and host defense cells, and 3) a family of secreted cysteine proteinases that play a key role in E . histolytica tissue invasion, evasion of host defenses, and parasite induction of gut inflammation . Amebae can both lyse host cells and induce their suicide through programmed cell death . The host response is also an important factor in the outcome of infection, and neutrophils may play a key role in contributing to the tissue damage seen in amebiasis and in controlling amebic infection.

Radiat Res, 2001 Jun, 155(6), 759 - 67
Radiation-induced bystander effects: past history and future directions; Mothersill C et al.; There has been a recent upsurge of interest in the phenomenon now known as radiation-induced bystander effects . This is largely due to the increased awareness of the contribution of indirect and delayed effects, such as genomic instability, to cellular outcomes after low-dose exposures . It is also due to the availability of tools such as the microbeam and advanced cell culture systems and to the ability to study end points such as gene or protein expression at low doses which were previously difficult to study . This review looks at the history of bystander effects in the earlier literature, in which the clastogenic effect of plasma from irradiated patients was well known . The effect was known to persist for several years and to cause transgenerational effects, making it similar to what we now call genomic instability . The review then examines the current data and controversies which are now beginning to resolve the questions concerning the mechanisms underlying the induction and transmission of both bystander effects and genomic instability . Finally, the possible impact of data concerning radiation-induced bystander effects on radiotherapy and radiation protection is discussed.

Virology, 2001 May 25, 284(1), 26 - 36
Neuraminidase from a bacterial source enhances both HIV-1-mediated syncytium formation and the virus binding/entry process; Sun J et al.; Neuraminidases, also termed sialidases, which catalyze the removal of sialic acid residues from various glycoconjugates, have been previously reported to modulate HIV-1 replication . Given that some of the known opportunistic microbes found in patients infected with HIV-1 harbor neuraminidase (NA) activity, we speculated that pathogen-derived NA might be envisaged as an important factor in the pathogenesis of this retroviral infection . In the present study, we have monitored the putative modulation of HIV-1-mediated syncytium formation and virus replication by highly purified bacterial-derived NA from Arthrobacter ureafaciens . Taking advantage of a luciferase-based syncytium quantitative assay, we demonstrate here that the level of HIV-1-mediated syncytium formation is enhanced in the presence of NA and that it necessitates interaction between gp120 and CD4/chemokine coreceptor . By using pseudotyped recombinant luciferase-encoding HIV-1 particles, we found that NA treatment of human CD4-positive target cells (i.e., T lymphoid, monocytoid, and peripheral blood mononuclear cells) significantly augmented single-round infection by T- and macrophage-tropic isolates of HIV-1 . The observed increase in HIV-1 infection was linked with an enhancement in the initial steps of the virus replicative cycle as monitored by viral binding and entry assays . Interestingly, NA treatment also enhances infectivity of HIV-1 pseudotypes with envelope glycoprotein from the amphotropic murine leukemia virus or the vesicular stomatitis virus . Taken together, our results provide useful information regarding the possible contribution of microbial agents carrying NA activity to HIV-1 pathogenesis .

Int Rev Cytol, 2001, 207, 237 - 70
Migration of dendritic cells into lymphatics-the Langerhans cell example: routes, regulation, and relevance; Romani N et al.; Dendritic cells are leukocytes of bone marrow origin . They are central to the control of the immune response . Dendritic cells are highly specialized in processing and presenting antigens (microbes, proteins) to helper T lymphocytes . Thereby, they critically regulate further downstream processes such as the development of cytotoxic T lymphocytes, the production of antibodies by B lymphocytes, or the activation of macrophages . A new field of dendritic cell biology is the study of their potential role in inducing peripheral tolerance . The immunogenic/tolerogenic potential of dendritic cells is increasingly being utilized in immunotherapy, particularly for the elicitation of antitumor responses . One very important specialization of dendritic cells is their outstanding capacity to migrate from sites of antigen uptake to lymphoid organs . Much has been learned about this process from studying one particular type of dendritic cell, namely, the Langerhans cell of the epidermis . Therefore, the migratory properties of Langerhans cells are reviewed . Knowledge about this "prototype dendritic cell" may help researchers to understand migration of other types of dendritic cells.

Science, 2001 May 11, 292(5519), 1112 - 5
Why we don't get sick: the within-host population dynamics of bacterial infections; Levin BR et al.; To pathogenic microparasites (viruses, bacteria, protozoa, or fungi), we and other mammals (living organisms at large) are little more than soft, thin-walled flasks of culture media . Almost every time we eat, brush our teeth, scrape our skin, have sex, get bitten by insects, and inhale, we are confronted with populations of microbes that are capable of colonizing the mucosa lining our orifices and alimentary tract and proliferating in fluids and cells within us . Nevertheless, we rarely get sick, much less succumb to these infections . The massive numbers of bacteria and other micro- and not-so-micro organisms that abound and replicate in our alimentary tract and cover our skin and the mucosa lining our orifices normally maintain their communities in seemingly peaceful coexistence with the somatic cells that define us . Why don't these microbes invade and proliferate in the culture media within the soft, thin-walled flask that envelops us? Why don't they cause disease and lead to our rapid demise?

Environ Sci Technol, 2001 Jan 1, 35(1), 192 - 5
Harvesting energy from the marine sediment--water interface; Reimers CE et al.; Pairs of platinum mesh or graphite fiber-based electrodes, one embedded in marine sediment (anode), the other in proximal seawater (cathode), have been used to harvest low-level power from natural, microbe established, voltage gradients at marine sediment-seawater interfaces in laboratory aquaria . The sustained power harvested thus far has been on the order of 0.01 W/m2 of electrode geometric area but is dependent on electrode design, sediment composition, and temperature . It is proposed that the sediment/anode-seawater/cathode configuration constitutes a microbial fuel cell in which power results from the net oxidation of sediment organic matter by dissolved seawater oxygen . Considering typical sediment organic carbon contents, typical fluxes of additional reduced carbon by sedimentation to sea floors < 1,000 m deep, and the proven viability of dissolved seawater oxygen as an oxidant for power generation by seawater batteries, it is calculated that optimized power supplies based on the phenomenon demonstrated here could power oceanographic instruments deployed for routine long-term monitoring operations in the coastal ocean.

Am J Physiol Cell Physiol, 2001 Jun, 280(6), C1475 - 84
Twisting integrin receptors increases endothelin-1 gene expression in endothelial cells; Chen J et al.; A magnetic twisting stimulator was developed based on the previously published technique of magnetic twisting cytometry . Using ligand-coated ferromagnetic microbeads, this device can apply mechanical stresses with varying amplitudes, duration, frequencies, and waveforms to specific cell surface receptors . Biochemical and biological responses of the cells to the mechanical stimulation can be assayed . Twisting integrin receptors with RGD (Arg-Gly-Asp)-containing peptide-coated beads increased endothelin-1 (ET-1) gene expression by >100% . In contrast, twisting scavenger receptors with acetylated low-density lipoprotein-coated beads or twisting HLA antigen with anti-HLA antibody-coated beads did not lead to alterations in ET-1 gene expression . In situ hybridization showed that the increase in ET-1 mRNA was localized in the cells that were stressed with the RGD-coated beads . Blocking stretch-activated ion channels with gadolinium, chelating Ca2+ with EGTA, or inhibiting tyrosine phosphorylation with genistein abolished twist-induced ET-1 mRNA elevation . Abolishing cytoskeletal tension with an inhibitor of the myosin ATPase, with an inhibitor of myosin light chain kinase, or with an actin microfilament disrupter blocked twisted-induced increases in ET-1 expression . Our results are consistent with the hypothesis that the molecular structural linkage of integrin-cytoskeleton is an important pathway for stress-induced ET-1 gene expression.

Am J Obstet Gynecol, 2001 May, 184(6), 1241 - 8
Amniotic fluid lipopolysaccharide-binding protein and soluble CD14 as mediators of the inflammatory response in preterm labor; Gardella C et al.; OBJECTIVE: Our purpose was to determine the association of lipopolysaccharide-binding protein (LBP) and soluble CD14 (sCD14) with the proinflammatory response among women in preterm labor . The binding of lipopolysaccharide (LPS) with LBP and sCD14 activates macrophages at LPS concentrations up to 1000 times lower than required with LPS alone . LBP and sCD14 in amniotic fluid could explain the high concentrations of cytokines present in the amniotic fluid of culture-positive women and the presence of cytokines in the amniotic fluid of culture-negative women . STUDY DESIGN: A cohort of 169 afebrile women in preterm labor with intact membranes had amniotic fluid collected by transabdominal amniocentesis for culture and for LBP, sCD14, and interleukin 6 (IL-6) determinations by enzyme-linked immunosorbent assay . IL-6 levels of >2 ng/mL were considered elevated . Statistical analyses included analysis of variance, multiple comparisons with Bonferroni correction, and linear regression . RESULTS: All 169 amniotic fluid samples had measurable LBP and sCD14 . Subjects were categorized by amniotic fluid culture results and IL-6 concentration into 3 groups: (1) positive amniotic fluid culture, (2) negative amniotic fluid culture, elevated IL-6 concentration, and (3) negative amniotic fluid culture, low IL-6 level . Geometric mean LBP and sCD14 levels differed significantly among groups such that levels were approximately twice as high among pregnancies with positive amniotic fluid culture or elevated IL-6 compared with those without evidence of inflammation (both P <.001) . sCD14 was inversely associated with enrollment gestational age independent of amniotic fluid culture results and IL-6 concentrations . Among culture negative, low IL-6 pregnancies, sCD14 decreased 3.5% for each additional week of gestation (95% confidence interval {CI}, 0.01%-6.4%; P =.02) . LBP levels showed a similar trend in this group (P =.09) . One hundred eleven subjects had detectable IL-6 levels . Among these subjects, IL-6 increased by 2.1-fold for every 10-fold increase in LBP (95% CI, 1.1-4.0; P =.02) and by 28.4-fold for every 10-fold increase in sCD14 (95% CI, 10.4-77.4; P <.001) with adjustment for gestational age by linear regression . CONCLUSIONS: LBP and sCD14 are present in amniotic fluid of preterm pregnancies and are linearly associated with amniotic fluid IL-6 concentrations . These molecules may amplify the cytokine response and thereby help explain the presence of cytokines in amniotic fluid when culturable quantities of microbes are absent.

Proc Natl Acad Sci U S A, 2001 May 8, 98(10), 5471 - 6
Declines of biomes and biotas and the future of evolution; Woodruff DS; Although panel discussants disagreed whether the biodiversity crisis constitutes a mass extinction event, all agreed that current extinction rates are 50-500 times background and are increasing and that the consequences for the future evolution of life are serious . In response to the on-going rapid decline of biomes and homogenization of biotas, the panelists predicted changes in species geographic ranges, genetic risks of extinction, genetic assimilation, natural selection, mutation rates, the shortening of food chains, the increase in nutrient-enriched niches permitting the ascendancy of microbes, and the differential survival of ecological generalists . Rates of evolutionary processes will change in different groups, and speciation in the larger vertebrates is essentially over . Action taken over the next few decades will determine how impoverished the biosphere will be in 1,000 years when many species will suffer reduced evolvability and require interventionist genetic and ecological management . Whether the biota will continue to provide the dependable ecological services humans take for granted is less clear . The discussants offered recommendations, including two of paramount importance (concerning human populations and education), seven identifying specific scientific activities to better equip us for stewardship of the processes of evolution, and one suggesting that such stewardship is now our responsibility . The ultimate test of evolutionary biology as a science is not whether it solves the riddles of the past but rather whether it enables us to manage the future of the biosphere . Our inability to make clearer predictions about the future of evolution has serious consequences for both biodiversity and humanity.

Trends Biochem Sci, 2001 May, 26(5), 291 - 7
Signaling at zero G: G-protein-independent functions for 7-TM receptors; Brzostowski JA et al.; Eukaryotic cells, whether free-living, single-celled microbes or components of complex metazoa, can sense environmental cues through specialized seven-transmembrane (7-TM) receptors (also called heptahelical or G-protein-coupled receptors) . 7-TM receptors detect "inputs" such as light, peptide hormones, neurotransmitters, pheromones, odorants, morphogens and chemoattractants, linking extracellular stimuli to intracellular signaling networks via heterotrimeric G proteins . Recently, this obligatory paradigm has been challenged . A growing body of evidence indicates that 7-TM receptors can also transmit extracellular signals through mechanisms that function independently of G-protein coupling . This review discusses pathways and protein interactions for 7-TM receptors signaling "at zero G" in Dictyostelium and mammalian cells.

Nature, 2001 Jan 4, 409(6816), 78 - 81
Symbiotic fungal endophytes control insect host-parasite interaction webs; Omacini M et al.; Symbiotic microorganisms that live intimately associated with terrestrial plants affect both the quantity and quality of resources, and thus the energy supply to consumer populations at higher levels in the food chain . Empirical evidence on resource limitation of food webs points to primary productivity as a major determinant of consumer abundance and trophic structure . Prey quality plays a critical role in community regulation . Plants infected by endophytic fungi are known to be chemically protected against herbivore consumption . However, the influence of this microbe-plant association on multi-trophic interactions remains largely unexplored . Here we present the effects of fungal endophytes on insect food webs that reflect limited energy transfer to consumers as a result of low plant quality, rather than low productivity . Herbivore-parasite webs on endophyte-free grasses show enhanced insect abundance at alternate trophic levels, higher rates of parasitism, and increased dominance by a few trophic links . These results mirror predicted effects of increased productivity on food-web dynamics . Thus 'hidden' microbial symbionts can have community-wide impacts on the pattern and strength of resource-consumer interactions.

J Toxicol Environ Health B Crit Rev, 2001 Apr-Jun, 4(2), 207 - 22
Toxicology of metam sodium; Pruett SB et al.; Metam sodium is the third most commonly used agricultural pesticide (by weight) in the U.S . A spill of 19,000 gallons of metam sodium into the Sacramento River in 1991 clearly demonstrated that a major uncontrolled release can have adverse ecological and human health effects . Furthermore, this incident revealed that estimates of Reference Exposure Levels for the major breakdown product of metam sodium (methylisothiocyanate, MITC) were reasonable with regard to the induction of discomfort . In fact, the irritant properties of MITC seem to account for many of the most commonly reported symptoms in this incident . However, neurotoxicity may also account for some of these symptoms . There is evidence that metam sodium can act as a contact sensitizer in humans, inducing allergic dermatitis . It also may exacerbate or induce respiratory allergy (asthma) . The ecological impact of routine use of metam sodium is not clear, but adverse effects on non-target plants have been inferred from modeling studies, and adverse effects on soil microbes have been observed . These issues deserve further study . Human health effects of occupational or routine environmental exposure to metam sodium are not known, but there is limited evidence for immunological (hypersensitivity) and developmental effects as well as irritation and associated symptoms . Animal studies suggest a potential for immunological, developmental, carcinogenic, and atherogenic effects . Metam sodium and some of its breakdown products have a wide variety of molecular and cellular actions that could explain the health effects noted here . However, further studies are needed to relate specific molecular or cellular actions to specific health effects.

Environ Health Perspect, 2001 Mar, 109(3), 275 - 82
Stimulation of contraction of pregnant rat uterus in vitro by non-dechlorinated and microbially dechlorinated mixtures of polychlorinated biphenyls; Bae J et al.; A previous study of six polychlorinated biphenyl (PCB) congeners showed that PCBs with four or fewer chlorines and ortho substitution stimulate uterine contraction frequency in vitro, whereas congeners with a greater number of chlorines or non-ortho substitution are inactive in vitro . We tested the hypothesis that PCB mixtures stimulate uterine contractions in a manner inversely related to the degree of chlorination and the presence of chlorines in the ortho- position of the biphenyl constituents of the mixtures . Uterine strips from pregnant rats were suspended in standard muscle baths and analyzed for changes in isometric contractions in response to in vitro exposure to commercial PCB mixtures (Aroclors) and their dechlorinated products after microbial degradation . The PCB mixtures Aroclor 1242, 1248, and 1254 significantly stimulated uterine contraction frequency, and the least chlorinated mixture, Aroclor 1242, was the most potent stimulant . Microbes from Hudson River sediment dechlorinated Aroclor 1242 and Aroclor 1254 under reducing conditions to produce mixtures with an increased proportion of ortho-substituted congeners with one or two chlorine substitutions . The PCB mixtures that had undergone microbial reductive dechlorination stimulated uterine contraction frequency to a significantly greater extent than the parent mixtures . These results show that increased uterotonic activity was associated with decreased chlorination and increased ortho substitution of the biphenyl constituents of the mixtures.

Gig Sanit, 2000 Nov-Dec, (6), 46 - 8
{Sanitary-epidemiological characteristics of preschool institutions}; Grebniak NP et al.; A specific microbial landscape forms in children of preschool institutions (PSI) . To identify their sanitary and epidemiological hazards, the authors proposes to use the most common PSI pathogenic and opportunistic microbes that allow specific risk factors to be detected . The pinworm egg seeding index is used to estimate the pollution of the institutional environment.

J Perinatol, 2001 Mar, 21(2), 141 - 6
Congenital varicella-zoster virus infection after maternal subclinical infection: clinical and neuropathological findings; Mustonen K et al.; OBJECTIVE: It is known that varicella-zoster virus (VZV) can cause asymptomatic infections, but it has not been described that congenital infection can be caused by maternal subclinical infection . The purpose of this study is to evaluate clinical and neuropathologic findings of infants with neonatal seizures and cerebrospinal fluid (CSF) VZV antibodies, but no maternal clinical VZV infection during the pregnancy . STUDY DESIGN: Screening of 201 neonates were studied for congenital viral infections, because of neurologic problems of unknown origin . Antibodies to 16 different microbes were investigated from the CSF and the serum of the neonates, as well as from the first trimester and postpartum serum of their mothers . Clinical symptoms and signs as well as neuropathology of those infants with antibodies to VZV in CSF were evaluated in this study . RESULTS: Four neonates with antibodies to VZV in CSF were identified and CSF findings were reported earlier . Their mothers had laboratory evidence of infection, based on a significant rise in serum VZV antibody level during pregnancy in three mothers, and a constantly high antibody level to VZV in one mother . All four children had seizures and abnormalities in muscular tone during the neonatal period, but no typical manifestations of a congenital VZV infection . One child died at the age of 4 months . At autopsy, neuropathologic examination showed foci of astrocytic hyperplasia and hypertrophy but no specific signs of viral infection . CONCLUSION: Maternal subclinical VZV infection can cause congenital infection with neurologic symptoms and signs in the child.

J Biol Chem, 2001 Jun 29, 276(26), 23748 - 56 Epub 2001 Apr 25.
Molecular cloning, genomic mapping, and expression of two secretor blood group alpha (1,2)fucosyltransferase genes differentially regulated in mouse uterine epithelium and gastrointestinal tract; Domino SE et al.; Fucosylated oligosaccharides have been proposed to be involved in multiple cell-cell interactions, including mouse blastocyst adhesion and intestine-microbe interactions . To begin to define the regulation and function of terminal alpha(1,2)fucosylated carbohydrates in these and other tissues, we isolated and characterized a 85-kilobase (kb) genomic region of mouse chromosome 7, 23.2 centimorgans analogous to human chromosome 19q13.3 that encodes three alpha(1,2)fucosyltransferases . Gene-specific DNA probes from the open reading frames of the mouse fucosyltransferase genes corresponding to human FUT1, FUT2, and SEC1 demonstrate distinct tissue-specific expression patterns by Northern blot analyses . Flow cytometry profiles of cultured cells transfected with DNA segments containing the open reading frames of the mouse genes confirm that each encodes an alpha(1,2)fucosyltransferase . In uterus and colon, a 3.3-kb FUT2 mRNA represents the major fucosyltransferase gene expressed . Steady-state FUT2 mRNA levels are cyclically regulated during the estrus cycle, increasing 10-fold from early diestrus to a relative maximum in proestrus . In contrast, SEC1 and FUT1 do not show prominently regulated expression in uterus . FUT2 expression localizes to luminal uterine epithelium by in situ hybridization, implying that this gene determines expression of cell surface Fucalpha1-->2Galbeta epitopes proposed to mediate blastocyst adhesion.

Can J Microbiol, 2001 Mar, 47(3), 237 - 52
Intact soil-core microcosms compared with multi-site field releases for pre-release testing of microbes in diverse soils and climates; Gagliardi JV et al.; Intact soil-core microcosms were used to compare persistence of Pseudomonas chlororaphis 3732RN-L11 in fallow soil and on wheat roots with field releases at diverse sites . Parallel field and microcosm releases at four sites in 1996 were repeated with addition of one site in 1997 . Microcosms were obtained fresh and maintained at 60% soil water holding capacity in a growth chamber at 70% relative humidity, a 12-hour photoperiod, and constant temperature . Persistence of 3732RN-L11 was measured at each site in field plots and microcosms at 7-21 day intervals, and in duplicate microcosms sampled at an independent laboratory . Linear regression slopes of field plot and microcosm persistence were compared for each site, and between identical microcosms sampled at different sites, using log10 transformed plate counts . Microcosm persistence closely matched field plots for wheat roots, but persistence in fallow soil differed significantly in several instances where persistence in field plots was lower than in microcosms . Analysis of weather variations at each site indicated that rainfall events of 30-40 mm caused decreased persistence in fallow soil . Cooler temperatures enhanced persistence in field plots at later time points . Inter-laboratory comparison of regression slopes showed good agreement for data generated at different sites, though in two instances, longer sampling periods at one site caused significant differences between the sites . Soil characteristics were compared and it was found that fertility, namely the carbon to nitrogen ratio, and the presence of expanding clays, were related to persistence . These microcosm protocols produced reliable data at low cost, and were useable for pre-release risk analyses for microorganisms.

Clin Infect Dis, 2001 May 1, 32(9), 1348 - 56 Epub 2001 Apr 10.
Creutzfeldt-Jakob disease: recommendations for disinfection and sterilization; Rutala WA et al.; Prion diseases constitute a unique infection control problem because prions exhibit unusual resistance to conventional chemical and physical decontamination methods . Recommendations to prevent cross-transmission of infection from medical devices contaminated by Creutzfeldt-Jakob disease (CJD) have been based primarily on prion inactivation studies . The recommendations in this article consider inactivation data but also use epidemiological studies of prion transmission, infectivity of human tissues, and efficacy of removing microbes by cleaning . On the basis of the scientific data, only critical (e.g., surgical instruments) and semicritical devices contaminated with high-risk tissue (i.e., brain, spinal cord, and eye tissue) from high-risk patients--those with known or suspected infection with CJD--require special treatment.

Cell Microbiol, 2001 May, 3(5), 277 - 87
Cellular mechanisms of microbial proteins contributing to invasion of the blood-brain barrier; Huang SH et al.; One of the least understood issues in the pathogenesis and pathophysiology of microbial infection of the central nervous system (CNS) is how microorganisms cross the blood-brain barrier (BBB), which separates brain interstitial space from blood and is formed by the tight junctions of brain microvascular endothelial cells (BMEC) . BMEC monolayer and bilayer culture systems have been developed as in vitro models to dissect the mechanisms of adhesion and invasion involved in pathogenesis of CNS infection caused by microbes . Viral, bacterial, fungal and parasitic pathogens may breach the BBB and enter the CNS through paracellular, transcellular and/or Trojan horse mechanisms . Conceivable evidence suggests that microbial proteins are the major genetic determinants mediating penetration across the BBB . Several bacterial proteins including IbeA, IbeB, AslA,YijP, OmpA, PilC and InlB contribute to transcellular invasion of BMEC . Viral proteins such as gp120 of HIV have been shown to play a role in penetration of the BBB . Fungal and parasitic pathothogens may follow similar mechanisms . SAG1 of Toxoplasma gondii has been suggested as a ligand to mediate host-cell invasion . Understanding the fundamental mechanisms of microbial penetration of the BBB may help develop novel approaches to prevent the mortality and morbidity associated with central nervous system (CNS) infectious diseases.

Inhal Toxicol, 2001 Mar, 13(3), 233 - 47
Induction of cytotoxicity and production of inflammatory mediators in raw264.7 macrophages by spores grown on six different plasterboards; Murtoniemi T et al.; Dampness and microbial growth in buildings are associated with respiratory symptoms in the occupants, but details of the phenomenon are not sufficiently understood . The current study examined the effects of growth conditions provided by six plasterboards on cytotoxicity and inflammatory potential of the spores of Streptomyces californicus, Penicillium spinulosum, Aspergillus versicolor, and Stachybotrys chartarum . The microbes were isolated from mold problem buildings and thereafter grown on six different plasterboards . The spores were harvested, applied to RAW264.7 macrophages (10(4), 10(5), 10(6) spores/10(6) cells), and evaluated 24 h after exposure for the ability to cause cytotoxicity and to stimulate production of nitric oxide (NO), interleukin-1 beta (IL-1beta), tumor necrosis factor alpha (TNFalpha) and interleukin-6 (IL-6) . The data indicate clear differences between spores of different microbes in their ability to induce the production of these inflammatory mediators and to cause cell death in macrophages . Also, for each microbe, the induction ability specifically depended on the brand of plasterboard . The spores of Streptomyces californicus collected from all plasterboards were the most potent at inducing NO and cytokine production . Cytotoxicity caused by P . spinulosum and Streptomyces californicus spores was consistent with NO, IL-1beta and IL-6 production induced by those microbes . However, the production of these inflammatory mediators by the spores of Stachybotrys chartarum was not parallel to their ability to cause cell death . The low productions of NO and cytokines were associated with high cytotoxicity caused by the spores of the A . versicolor . These data suggest that growth condition of microbes on different plasterboards affect the ability of microbial spores to induce inflammatory responses and cytotoxicity in macrophages.

J Inorg Biochem, 2001 Feb, 83(4), 269 - 79
Crystal structures of substrate free and complex forms of reactivated BphC, an extradiol type ring-cleavage dioxygenase; Uragami Y et al.; BphC derived from Pseudomonas sp . strain KKS102, an extradiol type catecholic dioxygenase, is a non-heam iron-containing enzyme, playing an important role in the degradation of biphenyl/PCB (Poly Chlorinated Biphenyls) in the microbe . Although we had earlier solved the crystal structure of KKS102 BphC, it was the inactive form with Fe(III) in the active site . In order to determine the active form structure, BphC was re-activated by anaerobic incubation with Fe(II) and ascorbate, and crystallized anaerobically . The crystal structures of activated BphC and its substrate complex (E x S complex) were determined at 2.0 A resolution under cryogenic condition . In addition, crystal structures of unactivated BphC in substrate free and complex forms were also re-determined . Comparison of activated and unactivated E x S complexes reveals that the orientation of the bound substrate in the active site is significantly different between the two . The structural comparison of the substrate free and complex forms of activated BphC show certain small conformational shifts around the active site upon substrate binding . As a result of the conformational shifts, His194, which has been suggested as the catalytic base, takes part in a weak hydrogen bond with hydroxyl group of the substrate.

Development, 2001 May, 128(9), 1629 - 41
Establishment of segment polarity in the ectoderm of the leech Helobdella; Seaver EC et al.; The segmented ectoderm and mesoderm of the leech arise via a stereotyped cell lineage from embryonic stem cells called teloblasts . Each teloblast gives rise to a column of primary blast cell daughters, and the blast cells generate descendant clones that serve as the segmental repeats of their particular teloblast lineage . We have examined the mechanism by which the leech primary blast cell clones acquire segment polarity - i.e . a fixed sequence of positional values ordered along the anteroposterior axis of the segmental repeat . In the O and P teloblast lineages, the earliest divisions of the primary blast cell segregate anterior and posterior cell fates along the anteroposterior axis . Using a laser microbeam, we ablated single cells from both o and p blast cell clones at stages when the clone was two to four cells in length . The developmental fate of the remaining cells was characterized with rhodamine-dextran lineage tracer . Twelve different progeny cells were ablated, and in every case the ablation eliminated the normal descendants of the ablated cell while having little or no detectable effect on the developmental fate of the remaining cells . This included experiments in which we specifically ablated those blast cell progeny that are known to express the engrailed gene, or their lineal precursors . These findings confirm and extend a previous study by showing that the establishment of segment polarity in the leech ectoderm is largely independent of cell interactions conveyed along the anteroposterior axis . Both intercellular signaling and engrailed expression play an important role in the segment polarity specification of the Drosophila embryo, and our findings suggest that there may be little or no conservation of this developmental mechanism between those two organisms.

Electrophoresis, 2001 Jan, 22(2), 283 - 8
High-speed separation system of randomly suspended single living cells by laser trap and dielectrophoresis; Arai F et al.; We developed a new system for random separation of a single microorganism, such as a living cell and a microbe, in the microfluidic device under the microscope by integrating the laser-trapping force and dielectrophoretic (DEP) force . An arbitrarily selected single microbe could be isolated in a microchannel, despite the presence of a large number of microbes in solution . Once the target microbe is trapped at the focal point of the laser, we can easily realize exclusion of excess microbes around the target by controlling the electric field, while keeping the target trapped by the laser at the focal point . To realize an efficient separation system, we proposed a new separation cell and produced it by microfabrication . Flow speed in the microchannel is adjusted and balanced to realize high-speed and high-purity extraction of the target . Some preliminary experiments are conducted to show the effectiveness . The target is trapped by the laser, transported, and is taken out from the extraction port . Total separation time is less than 20 s . Our method is extremely useful in the pure cultivation of the cell and will be a promising method for biologists in screening useful microbes.

J Dairy Sci, 2001 Mar, 84(3), 649 - 64
Accuracy and precision of computer models to predict passage of crude protein and amino acids to the duodenum of lactating cows; Bateman HG 2nd et al.; To evaluate the ability of several models to accurately and precisely predict the passage of crude protein (CP) and amino acids to the duodenum of lactating cows, we simulated data from six published studies using the 1989 National Research Council equations, the Mepron Dairy Ration Evaluator (version 1.1), the University of Pennsylvania release of the Net Carbohydrate and Protein System (version 2.12p), the Cornell Net Carbohydrate and Protein System (version 3), and CPM Dairy (version 1.0) . Models overestimated the passage of CP from microbes by an average of 323 g/d, and underestimated the passage of CP from feed by an average of 874 g/d . These two errors were partially canceled when CP from microbes and feed were summed to estimate passage of total CP to the duodenum . Many dietary composition variables appeared to bias the predictions; however, the influence of any one variable was small . The efficiency of modeling was high for most predictions but was variable for predicting passage of specific individual amino acids to the small intestine depending on the model selected . These simulations indicated no obvious advantage for any model over the others tested . The models responded to changes in diets by altering the amount of protein from microbes and feed that reached the duodenum, resulting in improved accuracy of predictions of duodenal CP passage compared with simply assuming a constant value for passage of CP to the duodenum.

Environ Technol, 2001 Jan, 22(1), 101 - 11
Methane oxidation in three Alberta soils: influence of soil parameters and methane flux rates; Stein VB et al.; Current concern over the potentially negative impacts of climate change has brought attention to anthropogenic sources of methane, a primary greenhouse gas . Two such emission sources are methane leakage at heavy oil wells and sanitary landfills . At both of these sources, substantial quantities of methane could potentially be oxidised by methanotrophic microbes living in soils . Optimisation of this phenomenon may serve as an inexpensive technique for reducing methane emissions . Soil column and batch incubation experiments were performed on a landfill loam, an agricultural loam and a sedge peat to gain a better quantitative understanding of the biological and physical processes limiting CH4 oxidation in soils that undergo the freeze-thaw cycles associated with northern climates . Moisture content emerged as a critical variable that can limit a soil's CH4 oxidation potential . For example, the oxidation rate of the agricultural soil was seen to increase by an order of magnitude after increasing its moisture content from 6% to 10% of its dry weight.

Arch Microbiol, 2001 Feb, 175(2), 86 - 93
Inheritance of the replication complex: a unique or common phenomenon in the control of DNA replication?
Wegrzyn A, Wegrzyn G.
Early models of the regulation of initiation of DNA replication by protein complexes predicted that binding of a replication initiator protein to a replicator region is required for initiation of each DNA replication round, since after the initiation event the replication initiator should dissociate from DNA . It was, therefore, assumed that binding of the replication initiator is a signal for triggering DNA replication . However, more recent investigations have revealed that in many replicons this is not the case . Studies on the regulation of the replication of plasmids derived from bacteriophage lambda demonstrated that, once assembled, the replication complex can be inherited by one of the two daughter plasmid copies after each replication round and may function in subsequent replication rounds . Since this DNA-bound protein complex bears information about specific initiation of DNA replication, this phenomenon has been called "protein inheritance." A similar phenomenon has recently been reported for oriJ-based plasmids . Moreover, the current model of the initiation of DNA replication in the yeast Saccharomyces cerevisiae proposes that the origin recognition complex (ORC) remains bound to one copy of the ori sequence (the ARS region) after initiation of DNA replication . Thus, it seems plausible that protein inheritance is not unique for lambda plasmids, but may be a common phenomenon in the control of DNA replication, at least in microbes.

J Clin Periodontol, 2001 Mar, 28(3), 233 - 40
Soluble antagonists to interleukin-1 (IL-1) and tumor necrosis factor (TNF) inhibits loss of tissue attachment in experimental periodontitis; Delima AJ et al.; BACKGROUND, AIMS: Periodontal disease is a significant cause of tooth loss among adults and is characterized by the alteration and permanent destruction of the deeper periodontal tissues . Although the presence of pathologic microbes is required to trigger this process, the amplification and progression of the diseased state is believed to rely heavily on the production of host mediators in response to bacteria or their metabolic products . The inflammatory response is effective in preventing large-scale colonization of the gingival tissues by bacteria that lie in close proximity to the tooth surface or within the gingival sulcus . It has been postulated that the host-response in some individuals may lead to an over-reaction to invading oral pathogens resulting in the destruction of periodontal tissues . METHODS: Several host-derived mediators are believed to contribute to this response . Two agents considered to be essential in periodontal destruction are interleukin-1 (IL-1) and tumor necrosis factor (TNF) . We investigated the role of IL-1 and TNF in the loss of connective tissue attachment in a Macaca fascicularis primate model of experimental periodontitis . Silk ligatures impregnated with the periodontal pathogen, Porphyromonas gingivalis were wrapped around the posterior teeth and the activity of IL-1 and TNF were inhibited by soluble receptors to these proinflammatory cytokines via local injection into interdental papillae . RESULTS: Histomorphometric analysis indicates that IL-1 and TNF antagonists significantly reduced the loss of connective tissue attachment by approximately 51% and the loss of alveolar bone height by almost 91%, both of which were statistically significant . CONCLUSION: This investigation demonstrates that the loss of connective tissue attachment and progression of periodontal disease can be retarded by antagonists to specific host mediators such as IL-1 and TNF and may provide a potential treatment modality to combat the disease process.

Nat Biotechnol, 2001 Apr, 19(4), 371 - 4
Suppression of a P450 hydroxylase gene in plant trichome glands enhances natural-product-based aphid resistance; Wang E et al.; Trichome glands on the surface of many higher plants produce and secrete exudates affecting insects, microbes, and herbivores . Metabolic engineering of gland exudation has potential for improving pest/disease resistance, and for facilitating molecular farming . We identified a cytochrome P450 hydroxylase gene specific to the trichome gland and used both antisense and sense co-suppression strategies to investigate its function . P450-suppressed transgenic tobacco plants showed a > or =41% decrease in the predominant exudate component, cembratriene-diol (CBT-diol), and a > or =19-fold increase in its precursor, cembratriene-ol (CBT-ol) . Thus, the level of CBT-ol was raised from 0.2 to > or =4.3% of leaf dry weight . Exudate from antisense-expressing plants had higher aphidicidal activity, and transgenic plants with exudate containing high concentrations of CBT-ol showed greatly diminished aphid colonization responses . Our results demonstrate the feasibility of significantly modifying the natural-product chemical composition and aphid-interactive properties of gland exudates using metabolic engineering . The results also have implications for molecular farming.

J Exp Med, 2001 Apr 2, 193(7), 863 - 72
L-selectin shedding regulates leukocyte recruitment; Hafezi-Moghadam A et al.; The physiologic role of L-selectin shedding is unknown . Here, we investigate the effect of L-selectin shedding on firm adhesion and transmigration . In a tumor necrosis factor alpha-induced model of inflammation, inhibition of L-selectin shedding significantly increased firm adhesion and transmigration by a lymphocyte function-associated antigen (LFA)-1 and intercellular adhesion molecule (ICAM)-1-dependent mechanism . We examined the quality of leukocyte rolling and L-selectin-mediated signaling . Blockade of L-selectin shedding significantly reduced the "jerkiness" of leukocyte rolling, defined as the variability of velocity over time . A low level of jerkiness was also observed in the rolling of microbeads conjugated with L-selectin, a model system lacking the mechanism for L-selectin shedding . Inhibition of L-selectin shedding potentiated activation of LFA-1 and Mac-1 induced by L-selectin cross-linking as shown by activation epitope expression and binding of ICAM-1-conjugated beads . We conclude that inhibition of L-selectin shedding increases leukocyte adhesion and transmigration by (a) increasing leukocyte exposure to the inflamed endothelium by decreasing jerkiness and (b) promoting leukocyte activation by outside-in signaling . These observations help to resolve the apparent discrepancy between the minor contribution of L-selectin to rolling and the significant leukocyte recruitment defect in L-selectin knockout mice.

Am J Respir Crit Care Med, 2001 Mar, 163(4), 983 - 8
The effect of aging on nasal mucociliary clearance, beat frequency, and ultrastructure of respiratory cilia; Ho JC et al.; The increased susceptibility of the elderly to lower respiratory tract infection cannot be fully explained . Although mucociliary clearance, which is affected by ciliary beating and ultrastructure, plays a crucial role in the defense of the airways against inhaled microbes, little is known of the effects of aging on these parameters . We studied the nasal mucociliary clearance (NMCC) time, ciliary beat frequency, and ultrastructure of respiratory cilia in a cohort of healthy volunteers (age range 11 to 90 yr) . Ciliary beat frequency of ciliated nasal epithelial cells was obtained via an established photometric method, and NMCC time was measured with the saccharine test . There was a correlation of ciliary beat frequency (r = -0.48, p = 0.0001) and NMCC time r = 0.64, p < 0.001) with increasing age . Transmission electron microscopy revealed an increase in the percent of subjects exhibiting microtubular disarrangement and single central microtubules with aging (p = 0.002 and p = 0.005, respectively) . Subjects older than 40 yr of age had significantly slower ciliary beat frequency, higher percent of ciliary cross-sections displaying single tubules, and longer NMCC time than their younger counterparts (p < 0.05) . These findings may help explain the frequent occurrence of respiratory infection in the elderly.

Curr Opin Microbiol, 2001 Apr, 4(2), 160 - 5
Revisiting the stringent response, ppGpp and starvation signaling; Chatterji D et al.; Microbial adaptation to environmental stress plays an important role in survival . It is necessary to understand the mechanisms underlying the survival of microbes under stress, as they may eventually aid in the successful control of the growth and persistence of these organisms . During nutrient starvation, Escherichia coli elicits a stringent response to conserve energy . The hallmark of the stringent response is the accumulation of guanosine tetra- (ppGpp) and pentaphosphates (pppGpp), which probably bind RNA polymerase to regulate gene expression at certain promoters . Recently, there has been renewed interest in the stringent responses of other microbes, with a view to correlating it with sporulation, virulence and long-term persistence.

Exp Parasitol, 2001 Feb, 97(2), 70 - 6
Ancylostoma caninum: the finger cell neurons mediate thermotactic behavior by infective larvae of the dog hookworm; Bhopale VM et al.; Bhopale, V . M., Kupprion, E . K., Ashton, F . T., Boston, R., and Schad, G . A . 2001 . Ancylostoma caninum: The finger cell neurons mediate thermotactic behavior by infective larvae of the dog hookworm . Experimental Parasitology 97, 70-76 . In the amphids (anteriorly positioned, paired sensilla) of the free-living nematode Caenorhabditis elegans, the so-called finger cells (AFD), a pair of neurons, each of which ends in a cluster of microvilli-like projections, are known to be the primary thermoreceptors . A similar neuron pair in the amphids of the parasitic nematode Haemonchus contortus is also known to be thermoreceptive . The hookworm of dogs, Ancylostoma caninum, has apparent structural homologs of finger cells in its amphids . The neuroanatomy of the amphids of A . caninum and H . contortus is strikingly similar, and the amphidial cell bodies in the lateral ganglia of the latter nematode have been identified and mapped . When the lateral ganglia of first-stage larvae (L1) of A . caninum are examined with differential interference contrast microscopy, positional homologs of the recognized amphidial cell bodies in the lateral ganglia of H . contortus L1 are readily identified in A . caninum . The amphidial neurons in A . caninum were consequently given the same names as those of their apparent homologs in H . contortus . It was hypothesized that the finger cell neurons (AFD) might mediate thermotaxis by the skin-penetrating infective larvae (L3) of A . caninum . Laser microbeam ablation experiments with A . caninum were conducted, using the H . contortus L1 neuronal map as a guide . A . caninum L1 were anesthetized and the paired AFD class neurons were ablated . The larvae were then cultured to L3 and assayed for thermotaxis on a thermal gradient . L3 with ablated AFD-class neuron pairs showed significantly reduced thermotaxis compared to control groups . The thermoreceptive function of the AFD-class neurons associates this neuron pair with the host-finding process of the A . caninum infective larva and shows functional homology with the neurons of class AFD in C . elegans and in H . contortus .

Artif Cells Blood Substit Immobil Biotechnol, 2001 Jan, 29(1), 57 - 70
A system establishment compatibility profiles for artificial oxygen carriers and other substances; Dinkelmann S et al.; Worldwide, great efforts are being made to develop a clinically useful artificial oxygen carrier . Toxicological and immunological compatibility is generally tested using animal experiments but inflammatory parameters in particular show large species-specific differences . Therefore, we developed an in vitro system using human components to establish a compatibility profile of unknown compounds . The test system comprises induction of hemolysis, activation of complement (C3a), induction/suppression of cytokine production, influence on cell proliferation, direct toxicity on peripheral leukocytes, and phagocytosis of the material under test and of microbes . The test system will be described, along with results of various perfluorocarbon emulsions . When testing lecithin-based perfluorodecalin (PFD) emulsions, and comparing them to Pluronic-based PFD emulsions, we could show that Pluronic-based emulsions were virtually untoxic to peripheral human leukocytes . They neither inhibited cell proliferation nor caused any hemolysis, but caused mild to moderate inhibition of endotoxin-induced cytokine production . At the same time, lecithin-based PFD emulsion caused substantial cytotoxicity in phagocytic cells like monocytes (60-100% after 24 h incubation) and granulocytes (10-20% after 24 h incubation) . They also suppressed endotoxin-induced cytokine production in monocytes to more than 98% and inhibited cell proliferation of an endothelial (ECV 304) and a monocytic cell line (MonoMac6) to more than 95%.

Pathobiology, 2000, 68(4-5), 218 - 26
Diagnosis of papillary thyroid carcinoma is facilitated by using an RT-PCR approach on laser-microdissected archival material to detect RET oncogene activation; Lahr G et al.; OBJECTIVE: The purpose of this study was to investigate the value of the expression of the RET oncogene (rearranged during transfection) in papillary thyroid carcinomas (PTC) and its variants in the differential diagnosis of thyroid neoplasias . According to the literature RET oncogene activation by chromosomal rearrangements has been exclusively implicated in PTCs . METHODS: To establish the incidence of RET activation in PTCs we used 5- to 10-microm sections from archival paraffin blocks . Either parts of the tissue slices were manually dissected or a few distinct cells were microdissected by laser-mediated manipulation with the Robot-MicroBeam system . RNA was extracted from paraffin-embedded thyroid tumors and the corresponding normal tissue . RT and nested PCR were performed using primers for RET/PTC1, PTC2 and PTC3, or for RET exons 12 and 13 . PCR products were resolved by gel electrophoresis . RESULTS: We detected RET transcription in approximately 85% of the PTCs including follicular variants and in isolated cells of the same tissues, but not in nonmalignant thyroid tissue . CONCLUSIONS: Our method may serve as an additional diagnostic tool to characterize ambiguous neoplasias and to identify especially nonpapillary, i.e . follicular tumors, as papillary carcinomas . Additionally, this study has demonstrated that expressed genes can be analyzed from routine histopathological tissue slides or pooled single cells . Large retrospective studies can also be performed with this method .

Proc Natl Acad Sci U S A, 2001 Mar 27, 98(7), 3988 - 91
Cytomegalovirus in autoimmunity: T cell crossreactivity to viral antigen and autoantigen glutamic acid decarboxylase; Hiemstra HS et al.; Antigens of pathogenic microbes that mimic autoantigens are thought to be responsible for the activation of autoreactive T cells . Viral infections have been associated with the development of the neuroendocrine autoimmune diseases type 1 diabetes and stiff-man syndrome, but the mechanism is unknown . These diseases share glutamic acid decarboxylase (GAD65) as a major autoantigen . We screened synthetic peptide libraries dedicated to bind to HLA-DR3, which predisposes to both diseases, using clonal CD4(+) T cells reactive to GAD65 isolated from a prediabetic stiff-man syndrome patient . Here we show that these GAD65-specific T cells crossreact with a peptide of the human cytomegalovirus (hCMV) major DNA-binding protein . This peptide was identified after database searching with a recognition pattern that had been deduced from the library studies . Furthermore, we showed that hCMV-derived epitope can be naturally processed by dendritic cells and recognized by GAD65 reactive T cells . Thus, hCMV may be involved in the loss of T cell tolerance to autoantigen GAD65 by a mechanism of molecular mimicry leading to autoimmunity.

Proc Natl Acad Sci U S A, 2001 Apr 10, 98(8), 4540 - 5 Epub 2001 Mar 27.
Galactosides in the rhizosphere: utilization by Sinorhizobium meliloti and development of a biosensor; Bringhurst RM et al.; Identifying the types and distributions of organic substrates that support microbial activities around plant roots is essential for a full understanding of plant-microbe interactions and rhizosphere ecology . We have constructed a strain of the soil bacterium Sinorhizobium meliloti containing a gfp gene fused to the melA promoter which is induced on exposure to galactose and galactosides . We used the fusion strain as a biosensor to determine that galactosides are released from the seeds of several different legume species during germination and are also released from roots of alfalfa seedlings growing on artificial medium . Galactoside presence in seed wash and sterile root washes was confirmed by HPLC . Experiments examining microbial growth on alpha-galactosides in seed wash suggested that alpha-galactoside utilization could play an important role in supporting growth of S . meliloti near germinating seeds of alfalfa . When inoculated into microcosms containing legumes or grasses, the biosensor allowed us to visualize the localized presence of galactosides on and around roots in unsterilized soil, as well as the grazing of fluorescent bacteria by protozoa . Galactosides were present in patches around zones of lateral root initiation and around roots hairs, but not around root tips . Such biosensors can reveal intriguing aspects of the environment and the physiology of the free-living soil S . meliloti before and during the establishment of nodulation, and they provide a nondestructive, spatially explicit method for examining rhizosphere soil chemical composition.

J Asian Nat Prod Res, 1998, 1(2), 99 - 102
Biotransformation of podophyllotoxin to picropodophyllin by microbes; Guo HZ et al.; Biotransformation of podophyllotoxin (PT) by several microbial species has been investigated . Among the fungi tested, it was found that Penicillium strains can isomerize PT to picropodophyllin (PPT) in 8% yield and other strains also transform the substrate into the same product but with lower yield.

Int J Radiat Biol, 2001 Mar, 77(3), 329 - 39
A higher micronucleus yield in B-versus T-cells after low-dose gamma-irradiation is not linked with defective Ku86 protein; Vral A et al.; PURPOSE: To elaborate the B-cell micronucleus (MN) response in the low-dose region in detail and to investigate the postulated deficiency in DNA-PK in B-cells . MATERIALS AND METHODS: Lymphocytes of five healthy volunteers were irradiated with low LET gamma-rays and high LET fast neutrons with doses ranging between 0.01 and 2 Gy . After post-irradiation incubation, B- and T-cells were isolated via CD3 and CD19 immunomagnetic microbeads . MN were analysed in both subpopulations . To study the underlying mechanism of chromosomal radiosensitivity, cell extracts prepared from purified B- and T-cells were subjected to SDS-electrophoresis and electroblotting using antibodies directed against the DNA-PK repair enzymes Ku70/86 and DNA-PKcs . Activity measurements were performed using the SignaTECT DNA-dependent protein kinase assay . DNA double-strand break (DSB) induction and rejoining was determined using constant-field gel electrophoresis . RESULTS: For low LET gamma-rays a higher MN yield was observed in B-cells than in T-cells, but only in those samples exposed to doses < 1 Gy . For 1 Gy, the MN yields were comparable and for 2Gy even lower in B-cells compared with T-cells . After high LET neutron irradiation no significant differences in MN yields were observed between both subsets . The results of the DNA-PK experiments demonstrate that there is no difference between T- and B-cells in the basal expression and activity of DNA-PK repair proteins . No differences in DNA DSB induction and rejoining were found between T- and B-cells using constant-field gel electrophoresis . CONCLUSIONS: From the results, it was concluded that the enhanced chromosomal radiosensitivity in B-cells is restricted to low doses (<1 Gy) of low LET radiation and that the chromosomal behaviour of B-cells to low LET radiation cannot be attributed to aberrant forms of the DNA-PK components . A type of chromosomal induced radioresistance (IRR) may be a possible explanation for the observed effect.

Hist Philos Life Sci, 2000, 22(1), 59 - 79
Money and microbes: Robert Koch, tuberculin and the Foundation of the Institute for Infectious Diseases in Berlin in 1891; Gradmann C; Starting from an assessment of how far Robert Koch's bacteriology had developed in the late 1880s this paper attempts to analyse different aspects of the process that led to the foundation of the Berlin Institute for Infectious Diseases in 1891 . With the development of his supposed cure against tuberculosis, tuberculin, Koch attempted to give his research a new direction, earn a fortune with the profits and become more independent of Prussian government officials who, up to that point, had had a major influence on his career . In the period following the presentation of the cure in autumn 1890, however, it became clear that tuberculin's value in treatment was at most dubious . Thus, the failure of tuberculin meant that Koch had to drop his own plans and accommodate those of the Prussian Ministry of Culture . As a result he assumed directorship of the newly founded Institute for Infectious Diseases in Berlin . Even though this was definitely a prestigious position it reaffirmed Koch's dependency on Prussian government officials and was by no means the kind of institution he had aimed for at the outset.

J Neurobiol, 2001 Apr, 47(1), 1 - 15
Laser ablation reveals regulation of ciliary activity by serotonergic neurons in molluscan embryos; Kuang S et al.; Early in embryonic development, the pond snail Helisoma trivolvis exhibits a rotational behavior that is generated by beating of cilia in the dorsolateral and pedal bands . Although previous anatomical and pharmacological studies provided indirect evidence that a pair of serotonergic neurons, Embryonic Neurons C1 (ENC1s), is involved in regulating embryonic rotation, direct evidence linking ENC1 to ciliary function is still lacking . In the present study, we used laser microbeams to perturb ENC1 in vivo while monitoring ciliary activity in identified ciliary bands . A laser treatment protocol to specifically ablate ENC1 without damaging the surrounding cells was established . Unilateral laser treatment of ENC1 caused transient increases in the activity of the pedal and ipsidorsolateral cilia, lasting 30-50 min . In contrast, activity of cilia that were not anatomically associated with ENC1 was unaffected by laser treatment . Mianserin, an effective serotonin antagonist in Helisoma ciliated cells, decreased the overall CBF of pedal and dorsolateral cilia by reducing the occurrence of spontaneous CBF surges in these cilia . Finally, the cilioexcitatory action of ENC1 laser treatment was mimicked by serotonin and reduced in the presence of mianserin . These results suggest that laser treatment provokes a release of serotonin from ENC1, resulting in a prolonged elevation of activity in the target ciliary cells . We conclude that, in addition to their previously established role in regulating neurodevelopment, ENC1s also function as serotonergic motor neurons to regulate ciliary activity, and therefore the rotational behavior of early embryos .

Rev Immunogenet, 2000, 2(3), 339 - 58
Chemokines and innate immunity; Matsukawa A et al.; Our environment contains a great variety of infectious microbes that may be potentially destructive and threaten our survival . As soon as microbes try to establish a site of infection, the host launches a complex defense system . Innate immunity is a non-specific response and serves as the first-line of defense where phagocytes, such as neutrophils and macrophages, and NK cells play central roles in neutralizing and clearing microorganisms . Thus, migration of cells into infectious foci and subsequent activation of these cells appear to be a critical step, enabling the host to achieve effective and efficient removal of microbes . Over the past decade, chemokines have been identified as chemotactic cytokines that attract and activate specific types of leukocyte populations in vitro . There is now evidence that the magnitude of chemokines' expression in infectious diseases is strongly associated with the severity of the inflammatory responses . Blocking chemokines or their receptors with neutralizing antibodies or gene targeting technology has allowed us to understand the pathological significance of chemokines in animal models of infectious diseases . Growing evidence suggests that chemokines play an important beneficial role in immune system development, homeostasis and in innate immunity, which may pave the way for new therapeutic strategies for the treatment of infectious diseases.

Rev Immunogenet, 2000, 2(3), 294 - 304
Toll and Toll-like proteins: an ancient family of receptors signaling infection; Imler JL et al.; Innate immunity is the first-line host defense of multicellular organisms that rapidly operates to limit infection upon exposure to microbes . It involves intracellular signaling pathways in the fruit-fly Drosophila and in mammals that show striking similarities . Recent genetic and biochemical data have revealed, in particular, that proteins of the Toll family play a critical role in the immediate response to infection . We review here the recent developments on the structural and functional characterization of this evolutionary ancient and important family of proteins, which can function as cytokine receptors (Toll in Drosophila) or pattern recognition receptors (TLR4 in mammals) and activate similar, albeit non identical signal transduction pathways, in flies and mammals.

Microb Comp Genomics, 2000, 5(3), 153 - 61
A novel microarray strategy for detecting genes and pathways in microbes with unsequenced genomes; Ramarathnam R et al.; Expression profile analysis of genes provides valuable information concerning the genetic response of cells to stimuli . We describe an adaptation of this technology that can be used to probe for the expression of specific families of genes in microbial species . In our method a combination of sets of oligonucleotide probes representing fingerprint sequences specific to protein families is used to identify the presence and expression levels of family homologs in a microbial cell . We demonstrate computationally, using exemplars, that when the cDNA complement from an organism is sequentially screened against a set of specific motif oligonucleotides, statistically significant information can be obtained concerning the expression of the corresponding genes . This method can be used to identify specific genes and pathways simultaneously in several organisms of interest even in the absence of sequence information from the organisms.

Curr Opin Mol Ther, 1999 Feb, 1(1), 39 - 42
DNA vaccines: a role for liposomes; Gregoriadis G; Vaccination with attenuated or killed microbes, purified or recombinant subunit proteins and synthetic peptides is often hampered by toxicity, the presence of infectious agents, weak immune responses and prohibiting costs, especially in the developing world . Such problems may be circumvented by genetic immunization, which, by the use of plasmid DNA encoding antigens from bacteria, viruses, protozoa and cancers leads to protective humoral and cell-mediated immunity . This review deals with the background and progress made so far with DNA vaccines and evaluates the role of liposomes in their optimization.

Vestn Ross Akad Med Nauk, 2000, (10), 16 - 9
{Use of laser flow-type fluorescence aerosol particle counter to evaluate the concentration of microbes in the surface air under high dust content}; Kalinin IuT et al.; The paper deals with the use of a laser flow-type fluorescence aerosol particle counter to evaluate the concentrations of microbes in the surface air under high dust content . Various circuits of flow-type optic aerosol recorders are analyzed . Flow spectral luminescence analysis of some particles flow while exciting the fourth harmonics of a pulse laser on yttrium-aluminium garnet with neodymium by ultraviolet radiation is shown to be the most optimum method for indication of individual aerosol particles . Experiments were conducted on the authors' model of a pilot plant based on this method . The model of a laser flow-type optic analyzer was developed for experimental studies that give a clear display of biological aerosols in complex aerosols . The laser flow-type analyzer-based unit developed may provide a fluorescence signal of aerosol particles in the flow of a sample and that light diffusion signal from them at an exciting light wavelength of 266 nm . Experiments with BVC aerosols and soil dust particles were conducted in different regions of Russia . They showed it possible to detect and to rapidly calculate soil microorganisms by laser flow-type fluorescence assay of individual particles when excited by ultraviolet radiation.

Brain Res, 2001 Mar 9, 894(1), 12 - 20
Biotinylated m4-toxin demonstrates more M4 muscarinic receptor protein on direct than indirect striatal projection neurons; Santiago MP et al.; The striatum has nearly equal numbers of striatonigral and striatopallidal projection neurons . All are GABAergic and inhibitory, but they lie in separate neuronal circuits ('direct' and 'indirect', respectively) that appear to exert opposite effects on movement . Methods are needed to evaluate the function of each circuit . A potential way to control striatonigral neurons selectively is via M4 muscarinic receptors . The striatum has many more M4 receptors than other tissues, they are located on approximately half of all projection neurons, and mRNA for M4 receptors is prevalent only in striatonigral neurons . In order to more rigorously compare the distribution of M4 receptors on rat neurons in these pathways a toxin that binds with very high specificity to M4 receptors (m4-toxin) was biotinylated for use as a selective probe for M4 receptor protein . Pooled biotin-toxin complexes were found to retain high M4-specificity and affinity . Neurons were first labeled by retrograde transport of fluorescent microbeads (FluoSpheres) injected into the substantia nigra and globus pallidus . Coincident labeling of only 4% of the cells confirmed the validity of the retrograde labeling technique . Labeled neurons were probed for M4 receptor protein using biotinylated m4-toxin and fluorescent avidin . M4 receptors were found on 14% of indirect and 86% of direct neurons . It may be concluded that there is a relative abundance of M4 receptors controlling the direct pathway . This work supports the hypothesis that M4-selective drugs will prove useful to control the function of striatonigral neurons in the direct projection pathway.

Annu Rev Immunol, 2001, 19, 423 - 74
Interleukin-18 regulates both Th1 and Th2 responses; Nakanishi K et al.; Although interleukin-18 is structurally homologous to IL-1 and its receptor belongs to the IL-1R/Toll-like receptor (TLR) superfamily, its function is quite different from that of IL-1 . IL-18 is produced not only by types of immune cells but also by non-immune cells . In collaboration with IL-12, IL-18 stimulates Th1-mediated immune responses, which play a critical role in the host defense against infection with intracellular microbes through the induction of IFN-gamma . However, the overproduction of IL-12 and IL-18 induces severe inflammatory disorders, suggesting that IL-18 is a potent proinflammatory cytokine that has pathophysiological roles in several inflammatory conditions . IL-18 mRNA is expressed in a wide range of cells including Kupffer cells, macrophages, T cells, B cells, dendritic cells, osteoblasts, keratinocytes, astrocytes, and microglia . Thus, the pathophysiological role of IL-18 has been extensively tested in the organs that contain these cells . Somewhat surprisingly, IL-18 alone can stimulate Th2 cytokine production as well as allergic inflammation . Therefore, the functions of IL-18 in vivo are very heterogeneous and complicated . In principle, IL-18 enhances the IL-12-driven Th1 immune responses, but it can also stimulate Th2 immune responses in the absence of IL-12.

Spine, 2001 Mar 1, 26(5), 583 - 7
Late operative site pain with isola posterior instrumentation requiring implant removal: infection or metal reaction?
Gaine WJ, Andrew SM, Chadwick P, Cooke E, Williamson JB.
OBJECTIVES: To elucidate the cause of late operative site pain in six cases of scoliosis managed with Isola posterior instrumentation that required removal of the implants . METHOD: Microbiologic examination of wound swabs and enriched culture of operative tissue specimens was undertaken in all cases . Histologic study of the peri-implant membranes also was conducted . RESULTS: The presentation in all cases was similar: back pain appearing between 12-20 months after surgery, followed by a local wound swelling leading to a wound sinus . In only one of these cases was the discharge positive for bacterial growth . Implant removal was curative . Histologic examination of tissue specimens revealed a neutrophil-rich granulation tissue reaction suggestive of an infective etiology despite the failure to isolate organisms . Within the granulation tissue was metallic debris that varied from very sparse to abundant from fretting at the distal cross-connector junctions . A review of recent literature describing similar problems suggests that late onset spinal pain is a real entity and a major cause of implant removal . CONCLUSIONS: On reviewing the evidence for an infective etiology versus a metallurgic reaction etiology for these cases of late onset spinal pain, it was concluded that a subacute low-grade implant infection was the main cause . Histologic findings would seem to confirm low-grade infection . There may be more than one causative factor for late operative site pain, as it is possible that fretting at cross connection junctions may provide the environment for the incubation of dormant or inactive microbesPublication Types:

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