Environ Sci Technol, 2003 Apr 15, 37(8), 1575 - 80 Role of soil freezing events in interannual patterns of stream chemistry at the Hubbard Brook Experimental Forest, New Hampshire; Fitzhugh RD et al.; Soil freezing is a disturbance of the below ground environment, potentially resulting in increased losses of NO3- and surface water acidification . Here, we report the effects of soil freezing on interannual variation in stream chemistry at the Hubbard Brook Experimental Forest, New Hampshire . Data from 1970 to 1997 of soil frost depth, snow cover, precipitation, air temperature, and stream discharge and chemistry were used in a stepwise linear regression model to select the variables that best predicted deviations of annual stream concentrations from 4-year running averages . Variables quantifying soil freezing severity were selected as significant predictors of short-term fluctuations in stream K+, NO3-, Ca2+, and Mg2+ concentrations from 1970 to 1989, explaining 59 and 47% of the short-term variability in K+ and NO3-, respectively . Fine-root mortality and disturbance of root-soil-microbe interactions, with subsequent effects on decomposition and nutrient uptake, likely contributed to the mobilization of K+ and NO3- to streamwater following severe soil freezing events . The relationship between soil freezing and stream chemistry, however, weakened during the period 1990-1997 . Because soil freezing has had inconsistent effects on stream chemistry during the period 1970-1997, it is unclear whether future changes in the frequency, duration, and depth of soil freezing events as the result of changes in the snow cover regime under a warmer climate will have significant impacts on the losses of NO3- and nutrient-base cations from temperate northern ecosystems. J Bacteriol, 2003 May, 185(10), 3147 - 54 Early colonization events in the mutualistic association between Steinernema carpocapsae nematodes and Xenorhabdus nematophila bacteria; Martens EC et al.; The bacterium Xenorhabdus nematophila is a mutualist of the entomopathogenic nematode Steinernema carpocapsae . During its life cycle, the bacterium exists both separately from the nematode and as an intestinal resident of a nonfeeding nematode form, the infective juvenile (IJ) . The progression of X . nematophila from an ex vivo existence to a specific and persistent colonization of IJs is a model to understand the mechanisms mediating the initiation and maintenance of benign host-microbe interactions . To help characterize this process, we constructed an X . nematophila strain that constitutively expresses green fluorescent protein, which allowed its presence to be monitored within IJs . Using this strain, we showed that few bacterial cells initiate colonization of an individual IJ and that these grow inside the lumen of the IJ intestine in a reproducible polyphasic pattern during colonization . In accordance with these two observations, we demonstrated that the final population of bacteria in a nematode is of predominantly monoclonal origin, suggesting that only one or two bacterial clones initiate or persist during colonization of an individual nematode . These data suggest that X . nematophila initiates IJ colonization by competing for limited colonization sites or resources within the nematode intestine . This report represents the first description of the biological interactions occurring between X . nematophila and S . carpocapsae during the early stages of the colonization process, provides insights into the physiology of X . nematophila in its host niche, and will facilitate interpretation of future data regarding the molecular events mediating this process. Arch Microbiol, 2003 Jun, 179(6), 423 - 9 Epub 2003 May 01. Heat-shock response and its contribution to thermotolerance of the nitrogen-fixing cyanobacterium Anabaena sp . strain L-31; Rajaram H et al.; Compared to Escherichia coli, the nitrogen-fixing soil cyanobacterium Anabaena sp . strain L-31 exhibited significantly superior abilities to survive prolonged and continuous heat stress and recover therefrom . Temperature upshift induced the synthesis of heat-shock proteins of similar molecular mass in the two microbes . However, in Anabaena sp . strain L-31 the heat-shock proteins (particularly the GroEL proteins) were synthesised throughout the stress period, were much more stable and accumulated during heat stress . In contrast, in E . coli the heat-shock proteins were transiently synthesised, quickly turned over and did not accumulate . Nitrogenase activity of Anabaena cells of sp . strain L-31 continuously exposed to heat stress for 7 days rapidly recovered from thermal injury, although growth recovery was delayed . Exposure of E . coli cells to >4.5 h of heat stress resulted in a complete loss of viability and the ability to recover . Marked differences in the synthesis, stability and accumulation of heat-shock proteins appear to distinguish these bacteria in their thermotolerance and recovery from heat stress. EMBO J, 2003 May 1, 22(9), 2082 - 90 Rapid invasion of host cells by Toxoplasma requires secretion of the MIC2-M2AP adhesive protein complex; Huynh MH et al.; Vertebrate cells are highly susceptible to infection by obligate intracellular parasites such as Toxoplasma gondii, yet the mechanism by which these microbes breach the confines of their target cell is poorly understood . While it is thought that Toxoplasma actively invades by secreting adhesive proteins from internal organelles called micronemes, no genetic evidence is available to support this contention . Here, we report successful disruption of M2AP, a microneme protein tightly associated with an adhesive protein called MIC2 . M2AP knockout parasites were >80% impaired in host cell entry . This invasion defect was likely due to defective expression of MIC2, which partially accumulated in the parasite endoplasmic reticulum and Golgi . M2AP knockout parasites were also unable to rapidly secrete MIC2, an event that normally accompanies parasite attachment to a target cell . These findings indicate a critical role for the MIC2-M2AP protein complex in parasite invasion. FEMS Microbiol Lett, 2003 Apr 25, 221(2), 187 - 90 Inhibitory effect of L-pyroglutamate on extremophiles: correlation with growth temperature and pH; Park CB et al.; L-Pyroglutamate (PGA) is naturally occurring from L-glutamate solution with accelerated formation rate under high temperature and low pH . Even though PGA has been identified as a neurotoxic agent on brain cells, the effect of PGA on the growth of microorganisms is rarely known . Here various kinds of microorganisms differing in their optimal growth temperature, pH, phylogeny, and isolated biotope were investigated for the effect of PGA . We found that growth of thermoacidophiles, including both archaea and bacteria, was seriously inhibited by the presence of PGA, and the extent of the inhibitory effect was closely related with growth temperature and pH . Interestingly, only microbes that grow at high temperature and low pH are inhibited by PGA, while this compound may stimulate growth rates of organisms that live at neutral pH and low temperature. Med Phys, 2003 Apr, 30(4), 583 - 9 MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility; Brauer-Krisch E et al.; Preclinical experiments are carried out with approximately 20-30 microm wide, approximately 10 mm high parallel microbeams of hard, broad-"white"-spectrum x rays (approximately 50-600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe . Novel physical microdosimetry (implemented with MOSFET chips in the "edge-on" mode) and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue-equivalent phantom . Such microbeam irradiation causes minimal damage to normal tissues, possible because of rapid repair of their microscopic lesions . Radiation damage from an array of parallel microbeams tends to correlate with the range of peak-valley dose ratios (PVDR) . This paper summarizes comparisons of our dosimetric MOSFET measurements with Monte Carlo calculations . Peak doses at depths <22 mm are 18% less than Monte Carlo values, whereas those depths >22 mm and valley doses at all depths investigated (2 mm-62 mm) are within 2-13% of the Monte Carlo values . These results lend credence to the use of MOSFET detector systems in edge-on mode for microplanar irradiation dosimetry. Proc Natl Acad Sci U S A, 2003 May 13, 100(10), 5664 - 9 Epub 2003 Apr 29. The mechanism of ferrichrome transport through Arn1p and its metabolism in Saccharomyces cerevisiae; Moore RE et al.; Siderophores are low molecular weight compounds, synthesized and secreted by microorganisms, that specifically bind ferric iron with exceptionally high affinity . Microbes capture these compounds and take up the bound iron through specific, high-affinity systems . Saccharomyces cerevisiae can take up iron bound to siderophores through the transporters of the ARN family; however, the mechanism by which the siderophore-bound iron enters the cell via these transporters is not known . Here we describe how ferrichrome, a siderophore of the hydroxamate class, is taken up by Arn1p . Arn1p exhibits two surface binding sites for ferrichrome, one that is similar in affinity to the K(T) for uptake and one of a much higher affinity that is specific for the metallated form of ferrichrome . Ferrichrome may gain access to the higher-affinity site through endocytosis . Tracer studies using (14)C-labeled ferrichrome bound to either iron(III) or aluminum(III), a nonreducible ligand for ferrichrome, indicate that ferrichrome enters the cell as the intact metallosiderophore and accumulates in the cytosol . Both ferrichrome chelates were relatively stable within the cell, and metal-free ferrichrome did not accumulate, indicating a role for ferrichrome in intracellular iron storage . Iron stored as ferrichrome was readily mobilized to meet the metabolic needs of the cell. J Exp Med, 2003 May 5, 197(9), 1107 - 17 Epub 2003 Apr 28. Collaborative induction of inflammatory responses by dectin-1 and Toll-like receptor 2; Gantner BN et al.; Toll-like receptors (TLRs) mediate recognition of a wide range of microbial products including lipopolysaccharides, lipoproteins, flagellin, and bacterial DNA, and signaling through TLRs leads to the production of inflammatory mediators . In addition to TLRs, many other surface receptors have been proposed to participate in innate immunity and microbial recognition, and signaling through some of these receptors is likely to cooperate with TLR signaling in defining inflammatory responses . In this report we have examined how dectin-1, a lectin family receptor for beta-glucans, collaborates with TLRs in recognizing microbes . Dectin-1, which is expressed at low levels on macrophages and high levels on dendritic cells, contains an immunoreceptor tyrosine-based activation motif-like signaling motif that is tyrosine phosphorylated upon activation . The receptor is recruited to phagosomes containing zymosan particles but not to phagosomes containing immunoglobulin G-opsonized particles . Dectin-1 expression enhances TLR-mediated activation of nuclear factor kappa B by beta-glucan-containing particles, and in macrophages and dendritic cells dectin-1 and TLRs are synergistic in mediating production of cytokines such as interleukin 12 and tumor necrosis factor alpha . Additionally, dectin-1 triggers production of reactive oxygen species, an inflammatory response that is primed by TLR activation . The data demonstrate that collaborative recognition of distinct microbial components by different classes of innate immune receptors is crucial in orchestrating inflammatory responses. J Comp Neurol, 2003 Jun 9, 460(4), 514 - 24 Nectin-dependent localization of ZO-1 at puncta adhaerentia junctions between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of adult mouse hippocampus; Inagaki M et al.; Nectin and afadin constitute a novel intercellular adhesion system that organizes adherens junctions in cooperation with the cadherin-catenin system in epithelial cells . Nectin is a Ca(2+)-independent immunoglobulin-like adhesion molecule and afadin is an actin filament (F-actin)-binding protein that connects nectin to the actin cytoskeleton . At the puncta adhaerentia junctions (PAs) between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of the adult mouse hippocampus, the nectin-afadin system also colocalizes with the cadherin-catenin system and has a role in the formation of synapses . ZO-1 is another F-actin-binding protein that localizes at tight junctions (TJs) and connects claudin to the actin cytoskeleton in epithelial cells . The nectin-afadin system is able to recruit ZO-1 to the nectin-based cell-cell adhesion sites in nonepithelial cells that have no TJs . In the present study, we investigated the localization of ZO-1 in the mouse hippocampus . Immunofluorescence and immunoelectron microscopy revealed that ZO-1 also localized at the PAs between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of the adult mouse hippocampus, as described for afadin . ZO-1 colocalized with afadin during the development of synaptic junctions and PAs . Microbeads coated with the extracellular fragment of nectin, which interacts with cellular nectin, recruited both afadin and ZO-1 to the bead-cell contact sites in cultured rat hippocampal neurons . These results indicate that ZO-1 colocalizes with nectin and afadin at the PAs and that the nectin-afadin system is involved in the localization of ZO-1 . Arterioscler Thromb Vasc Biol, 2003 Jul 1, 23(7), 1185 - 9 Epub 2003 Apr 24. Endothelial progenitor cells: mobilization, differentiation, and homing; Hristov M et al.; Postnatal bone marrow contains a subtype of progenitor cells that have the capacity to migrate to the peripheral circulation and to differentiate into mature endothelial cells . Therefore, these cells have been termed endothelial progenitor cells (EPCs) . The isolation of EPCs by adherence culture or magnetic microbeads has been described . In general, EPCs are characterized by the expression of 3 markers, CD133, CD34, and the vascular endothelial growth factor receptor-2 . During differentiation, EPCs obviously lose CD133 and start to express CD31, vascular endothelial cadherin, and von Willebrand factor . EPCs seem to participate in endothelial repair and neovascularization of ischemic organs . Clinical studies using EPCs for neovascularization have just been started; however, the mechanisms stimulating or inhibiting the differentiation of EPC in vivo and the signals causing their migration and homing to sites of injured endothelium or extravascular tissue are largely unknown at present . Thus, future studies will help to explore areas of potential basic research and clinical application of EPCs. Mech Ageing Dev, 2003 Apr, 124(4), 419 - 25 Neutrophil immunity of the elderly; Schroder AK et al.; Due to age-related changes of the immune system, elderly people are more susceptible to microbial infections than the young . Most research concerning immune senescence has been done on T and B cells, yet the first cells to migrate into microbe-infected tissue are neutrophils, which phagocytose and kill the pathogens . Long regarded as mere phagocytes, the neutrophils' importance for the immune response has been recognized in current publications, which acknowledge them an active participation in the cytokine network . Similarities in the symptoms of patients with genetical neutrophil deficiencies and those of the elderly indicate a leading role of neutrophils in the effects of immune senescence . While the number of circulating neutrophils remains unaltered in the elderly compared with young controls, phagocytosis and intracellular killing have been reported impaired . Oddly enough, the results for various stimuli differed: while some showed a decrease in neutrophil activation, the response to others remained unaltered . More research needs to be done on this, preferably using preparations of high purity to exclude monocytic interventions . Elucidation of immune deficiencies caused by neutrophil senescence can be an important contribution to a healthier elderly population. Curr Opin Chem Biol, 2003 Apr, 7(2), 160 - 5 Microbe-metal interactions in marine hydrothermal environments; Holden JF et al.; Marine hydrothermal microorganisms respond rapidly to changes in the concentrations and availability of metals within their environment . Hyperthermophilic archaea appear to possess novel mechanisms for metal detoxification, dissimilatory metal reduction and metal assimilation that may be absent in their mesophilic and bacterial counterparts . For example, tungsten was found in high concentrations in a hydrothermal sulfide deposit where hyperthermophiles were also most abundant, consistent with the unique requirement of these organisms for this element . Furthermore, newly isolated genera of iron-reducing hyperthermophiles expand the scope of carbon cycling in hydrothermal environments . The advent of genome sequences and new molecular techniques will facilitate our further understanding of microbe-mineral interactions in these environments. Calcif Tissue Int, 2003 May, 72(5), 567 - 76 Epub 2003 Apr 28. Mineralized microstructure of calcified avian tendons: a scanning small angle X-ray scattering study; Gupta HS et al.; The micrometer level spatial distribution of the size, shape, and orientation of mineral crystallites in the calcifying matrix of tendons near the edge of the mineralizing front was investigated by scanning small angle X-ray scattering using synchrotron X-ray radiation . Using a special microbeam arrangement enabling 20 microm beam resolution and short measurement times, linear diffraction scans were made on sections from the normally calcifying tendons (tibialis cranialis) from the domestic turkey, which calcify in the distal to proximal direction . A change in shape and arrangement of mineral crystals was observed within the first 200 microm of the mineralization front, and the mineral crystal distribution was highly anisotropic with crystals aligned parallel to the fiber axis . In a cross-section of the tendon cut at right angles to the fiber axis, the orientation distribution of crystals was not azimuthally symmetric, and showed a small but nonzero anisotropy and a continuous change in mean orientation angle across the width of the tendon cross-section. Arch Environ Contam Toxicol, 2003 May, 44(4), 493 - 501 Assessment of white blood cell phagocytosis as an immunological indicator of methylmercury exposure in birds; Holloway J et al.; White blood cell (WBC) phagocytosis was investigated as a potential immunological indicator of methylmercury (MeHg) exposure in birds . The assay was first assessed using chicken WBCs dosed with MeHg in vitro either in whole blood or as isolated cells and later using blood of wild common loons exposed in vivo to a range of dietary MeHg and having a range of blood-Hg concentrations . Whole blood and isolated WBCs from captive chickens were exposed to a range of MeHg concentrations for 3 h . After MeHg exposure, cells were incubated with fluorescent latex microbeads (diameter = 1.75 microm), fixed, and analyzed for size, complexity, and fluorescent intensity by flow cytometry . MeHg significantly depressed phagocytic activity when added to isolated WBCs at concentrations > 0.01 microg/ml, but not when added to whole blood up to 50 microg/ml . Similarly, no significant relationship between the concentration of Hg in whole blood and phagocytic capacity of WBCs in free-living loons was observed . Our results suggest that the phagocytosis assay, although rapid and convenient for use in field studies with wildlife species, is not a responsive immunological indicator of MeHg exposure at environmentally realistic concentrations of blood-Hg in wild loons . Assays that measure other immunologic endpoints (e.g., bacterial killing assay, PHA skin test, and mitogen-induced lymphocyte proliferation) should be assessed with respect to their ability to detect MeHg immunotoxicity in wild birds. Radiat Res, 2003 May, 159(5), 632 - 41 Murine EMT-6 carcinoma: high therapeutic efficacy of microbeam radiation therapy; Dilmanian FA et al.; Microbeam radiation therapy is an experimental modality using parallel arrays of thin (<100 micro m) slices of synchrotron-generated X rays (microplanar beams, microbeams) . We used EMT-6 murine mammary carcinoma subcutaneously inoculated in the hind legs of mice to compare the therapeutic efficacies of single-fraction, unidirectional (1) "co-planar" microbeams (an array of vertically oriented microplanar beams), (2) "cross-planar" microbeams (two arrays of parallel microbeams propagated in the same direction, one with vertically and the other with horizontally oriented microplanar beams), and (3) seamless (broad) beams from the same synchrotron source . The microbeams were 90 micro m wide and were spaced 300 micro m on center; the median energy in all beams was 100 or 118 keV . Tumor ablation rates were 4/8, 4/8 and 6/7 for a 410-, 520- and 650-Gy in-slice cross-planar microbeam dose, respectively, and 1/8, 3/8, 3/7 and 6/8 for a 23-, 30-, 38- and 45-Gy broad-beam dose, respectively . When the data were pooled from the three highest doses (same average tumor ablations of 50-60%), the incidences of normal-tissue acute toxicity (moist desquamation and epilation) and delayed toxicity (failure of hair regrowth) were significantly lower for cross-planar microbeams than broad beams (P < 0.025) . Furthermore, for the highest doses in these two groups, which also had the same tumor ablation rate (>75%), not only were the above toxicities lower for the cross-planar microbeams than for the broad beams (P < 0.02), but severe leg dysfunction was also lower (P < 0.003) . These findings suggest that single-fraction microbeams can ablate tumors at high rates with relatively little normal-tissue toxicity. Biosens Bioelectron, 2003 May, 18(5-6), 521 - 7 Taxonomic identification of microorganisms by capture and intrinsic fluorescence detection; Mason HY et al.; Quick and accurate detection of microbial contamination is accomplished by a unique combination of leading edge technologies described in this and the accompanying article . Microbe capture chips, used with a prototype fluorescence detector, are capable of statistically sampling the environment for pathogens (including spores), identifying the specific pathogens/exotoxins, and determining cell viability where appropriate. Biosens Bioelectron, 2003 May, 18(5-6), 511 - 9 Reagentless detection of microorganisms by intrinsic fluorescence; Estes C et al.; Quick and accurate detection of microbial contamination is accomplished by a unique combination of leading-edge technologies described in this and the accompanying paper . In this contribution, a hand-held prototype instrument is described which is capable of statistically sampling the environment for microbial contamination and determining cell viability . The technology is sensitive enough to detect very low levels ( approximately 20 cells/cm(2) or cm(3)) of microbes in seconds. Arch Biochem Biophys, 2003 May 1, 413(1), 41 - 52 Macrophage recognition of externalized phosphatidylserine and phagocytosis of apoptotic Jurkat cells--existence of a threshold; Borisenko GG et al.; Phosphatidylserine (PS) is predominantly confined to the inner leaflet of plasma membrane in cells, but it is externalized on the cell surface during apoptosis . This externalized PS is required for effective phagocytosis of apoptotic cells by macrophages . Because PS trans-bilayer asymmetry is not absolute in different types of nonapoptotic cells, we hypothesized that the amounts of externalized PS may be critical for macrophage discrimination between apoptotic and nonapoptotic cells . We developed a sensitive electron paramagnetic resonance method to quantify the amounts of externalized PS based on specific binding of paramagnetic annexin V-microbead conjugates with PS on cell surfaces . Using this technique, we found that nonapoptotic Jurkat cells externalize 0.9 pmol of endogenous PS/10(6) Jurkat cells . For cells with different amounts of integrated exogenous PS on their surface, no phagocytic response was observed at PS levels <5 pmol/10(6) Jurkat cells; at higher PS concentrations, phagocytosis increased in a concentration-dependent manner . Apoptosis in Jurkat cells caused externalization of approximately 240 pmol PS/10(6) Jurkat cells; these amounts of externalized PS are manyfold higher than the threshold amounts of PS required for phagocytosis . Thus, macrophages have a sensitivity threshold for PS externalized on the cell surface that provides for reliable recognition and distinction between normal cells with low contents of externalized PS and apoptotic cells with remarkably elevated PS levels. Nature, 2003 Apr 17, 422(6933), 711 - 3 Soil invertebrate fauna enhances grassland succession and diversity; De Deyn GB et al.; One of the most important areas in ecology is to elucidate the factors that drive succession in ecosystems and thus influence the diversity of species in natural vegetation . Significant mechanisms in this process are known to be resource limitation and the effects of aboveground vertebrate herbivores . More recently, symbiotic and pathogenic soil microbes have been shown to exert a profound effect on the composition of vegetation and changes therein . However, the influence of invertebrate soil fauna on succession has so far received little attention . Here we report that invertebrate soil fauna might enhance both secondary succession and local plant species diversity . Soil fauna from a series of secondary grassland succession stages selectively suppress early successional dominant plant species, thereby enhancing the relative abundance of subordinate species and also that of species from later succession stages . Soil fauna from the mid-succession stage had the strongest effect . Our results clearly show that soil fauna strongly affects the composition of natural vegetation and we suggest that this knowledge might improve the restoration and conservation of plant species diversity. Toxicol Sci, 2003 May, 73(1), 53 - 9 Epub 2003 Apr 15. Androstenedione and progesterone in the sediment of a river receiving paper mill effluent; Jenkins RL et al.; The Fenholloway River near Perry, Florida, receives effluent from a paper mill and contains populations of masculinized female eastern mosquitofish, Gambusia holbrooki . A previous study identified the androgen precursor androstenedione at a low concentration (0.14 nM) in water samples from the river . The present study makes use of a toxicity identification and evaluation approach that includes solid phase extraction and high pressure liquid chromatography purification, androgen receptor transcription assays, and liquid chromatography mass spectroscopy to identify and characterize steroids in the Fenholloway River sediment . Androstenedione (2.4 nM) and progesterone (155 nM) were identified in the river sediment at concentrations greater than in the river water column (0.14 nM androstenedione, and 6.5 nM progesterone) . Spring Creek, a comparison stream that does not receive mill effluent, contained low levels of progesterone (0.3 nM) but no androstenedione in the sediment . The data are consistent with the hypothesis that pine pulp-derived phytosteroids in the paper mill effluent accumulate in river sediment where they are converted by microbes into progesterone and this into androstenedione and other bioactive steroids . Equally important is that normal streams with much less organic matter still contain progesterone, but at dramatically lower levels . The presence of androgens and androgen precursors in the river water and sediment likely contributes to the masculinized phenotype of the female Gambusia holbrooki in the Fenholloway River. Front Biosci, 2003 May 01, 8, d963 - 81 Repair mechanisms for oxidative DNA damage; Wilson DM 3rd et al.; Reactive oxygen species are formed as by-products of mitochondrial aerobic respiration, as induced products upon exposure to certain environmental/exogenous agents (e.g . ionizing radiation), or as intended products during the immune response against invading foreign microbes . Although serving as essential signaling molecules in certain biological processes (e.g . during gene activation responses), these chemicals, particularly during oxidative stress when at excessive concentrations, can react with cellular components, most notably DNA, and in this capacity, promote mutagenesis or cell death, and in turn, human disease . We review here several of the common oxidative DNA damages as well as the DNA repair mechanisms related to maintaining genome integrity, and thus, preventing cancer formation and age-related disease . We focus mainly on participants of the base excision repair (BER) pathway . In brief, the steps of BER include: (a) excision of the damaged base, (b) incision of the DNA backbone at the apurinic/apyrimidinic (AP) site product, (c) removal of the AP terminal fragment, (d) gap-filling synthesis, and (e) ligation of the final nick. Toxicology, 2003 May 3, 187(2-3), 195 - 203 Low-level sarin-induced alteration of immune system reaction in inbred BALB/c mice; Kassa J et al.; To study the influence of low-level sarin inhalation exposure on immune functions, inbred BALB/c mice were exposed to low concentrations of sarin for 60 min in the inhalation chamber . Two concentrations of sarin were chosen-asymptomatic concentration (LEVEL 1) and non-convulsive symptomatic concentration (LEVEL 2) . The evaluation of immune functions was carried out using phenotyping of CD3 (T-lymphocytes), CD4 (helper T-lymphocytes), CD8 (cytotoxic T-lymphocytes) and CD19 cells (B-lymphocytes) in the lungs, blood and spleen, lymphoproliferation of spleen cells stimulated in vitro by various mitogens (concanavalin A, lipopolysaccharides), phagocyte activity of peritoneal and alveolar macrophages, production of N-oxides by peritoneal macrophages and the measurement of the natural killer cell activity at 1 week following sarin exposure . The results were compared to the values obtained from control mice exposed to pure air instead of sarin . The results indicate that not only symptomatic but also asymptomatic dose of sarin is able to alter the reaction of immune system at 1 week following exposure to sarin . While the number of CD3 cells in the lungs was slightly decreased, an increase in CD19 cells was observed especially in the lungs and blood . The reduced proportion of T-lymphocytes is caused by decay of CD4 positive T-cells . Lymphoproliferation was significantly decreased regardless of the mitogen and sarin concentration used . The production of N-oxides by peritoneal macrophages was stimulated after exposure to LEVEL 2 of sarin whereas their ability to phagocyte the microbes was increased after exposure to LEVEL 1 . The natural killer cell activity was significantly higher in the case of inhalation exposure of mice to LEVEL 2 of sarin . Thus, not only organophosphorus insecticides but also nerve agents such as sarin are able to alter immune functions even at a dose that does not cause clinically manifested intoxication following the inhalation exposure . Nevertheless, the alteration of immune functions following the inhalation exposure to a symptomatic concentration of sarin seems to be more pronounced. Br J Haematol, 2003 Apr, 121(2), 240 - 50 Generation of dendritic cells from CD14+ monocytes positively selected by immunomagnetic adsorption for multiple myeloma patients enrolled in a clinical trial of anti-idiotype vaccination; Motta MR et al.; Circulating monocytes from multiple myeloma patients enrolled in a clinical study of anti-idiotype vaccination were labelled with clinical-grade anti-CD14 microbeads and positively selected with the CliniMACS instrument . Cells were then grown, according to good manufacturing practice guidelines, in fetal-calf-serum-free medium in cell culture bags and differentiated to dendritic cells (DC) with granulocyte-macrophage colony stimulating factor plus interleukin 4 (IL-4), followed by either tumour necrosis factor-alpha (TNF-alpha) or a cocktail of IL-1beta, IL-6, TNF-alpha and prostaglandin-E2 . The CD14+ cell yield was increased from 17.6 +/- 6.5% to 93.8 +/- 6.3% (recovery 64.4 +/- 15.4%, viability > 97%) . After cell culture, phenotypic analysis showed that 86.7 +/- 6.8% of the cells were DC: 2.27 +/- 0.9 x 108 DC/leukapheresis were obtained, which represented 20.7 +/- 4.6% of the initial number of CD14+ cells . Notably, the cytokine cocktail induced a significantly higher percentage and yield (28.6 +/- 3% of initial CD14+ cells) of DC than TNF-alpha alone, with secretion of larger amounts of IL-12, potent stimulatory activity on allogeneic T cells and efficient presentation of tumour idiotype to autologous T cells . Storage in liquid nitrogen did not modify the phenotype or functional characteristics of preloaded DC . The recovery of thawed, viable DC was 78 +/- 10% . Finally, interferon-alpha-2b was at least as efficient as IL-4 in inducing the differentiation of mature, functional DC from monocytes. Clin Microbiol Rev, 2003 Apr, 16(2), 209 - 19 Microbial infections, immunomodulation, and drugs of abuse; Friedman H et al.; The use of recreational drugs of abuse has generated serious health concerns . There is a long-recognized relationship between addictive drugs and increased levels of infections . Studies of the mechanisms of actions of these drugs became more urgent with the advent of AIDS and its correlation with abused substances . The nature and mechanisms of immunomodulation by marijuana, opiates, cocaine, nicotine, and alcohol are described in this review . Recent studies of the effects of opiates or marijuana on the immune system have demonstrated that they are receptor mediated, occurring both directly via specific receptors on immune cells and indirectly through similar receptors on cells of the nervous system . Findings are also discussed that demonstrate that cocaine and nicotine have similar immunomodulatory effects, which are also apparently receptor mediated . Finally, the nature and mechanisms of immunomodulation by alcohol are described . Although no specific alcohol receptors have been identified, it is widely recognized that alcohol enhances susceptibility to opportunistic microbes . The review covers recent studies of the effects of these drugs on immunity and on increased susceptibility to infectious diseases, including AIDS. Science, 2003 Apr 11, 300(5617), 290 - 3 Realizing the potential of the genome revolution: the genomes to life program; Frazier ME et al.; The systems biology revolution is proceeding along multiple pathways as different science agencies and the private sector have adopted strategies suited to their particular needs and cultures . To meet this challenge, the U.S . Department of Energy has developed the Genomes to Life (GTL) program . A central focus of GTL is environmental microbial biology as a way to approach global environmental problems, and its key goal is to achieve, over the next 10 to 20 years, a basic understanding of thousands of microbes and microbial systems in their native environments . This focus demands that we address huge gaps in knowledge, technology, computing, data storage and manipulation, and systems-level integration. Chemosphere, 2003 Feb, 50(6), 683 - 7 Organo-chlorine pesticide (DDT and HCH) residues in the Taihu Lake Region and its movement in soil-water system I . Field survey of DDT and HCH residues in ecosystem of the region; Feng K et al.; The use of organo-chlorine (DDT and HCH) has been banned in China for 20 years . A field survey was carried out during 1999-2000 in the Taihu Lake Region . Organo-chlorine pesticide (OCP) residues in soil, water, fish and sediment samples were investigated . DDT was detected in 5 out of 10 samples with concentration ranging from 0.3 to 5.3 microg/kg in the surface (0-15 cm) layer, 6 out of 10 with 0.5 to 4.0 microg/kg in the subsoil layer (16-30 cm), and 4 of 10 with 0 to 2.7 microg/ kg in the deep soil layer (31-50 cm) . Results for HCH residues in soil samples were similar to those of DDT . These results indicate that OCP residues in 0-50 cm profile had been leached out or degraded to safe level . In river water DDT was detected in 10 out of 13 samples ranging from 0.2 to 9.3 microg/l, with an average of 1.0 microg/l . While HCH was detected in 12 out of 13 samples ranging from 0.02 to 36.1 microg/l, with an average 5.6 microg/l . DDT residues in sediment ranged from 0.1 to 8.8 microg/kg, while HCH ranged from 0.3 to 66.5 microg/kg . DDT residues in fish body ranged from 3.7 to 23.5 microg/kg and HCH ranged from 3.7 to 132 microg/kg . These results demonstrate an accumulation through food chain (from soil-water-sediment-microbes-crop-fish-.. . etc.), also that HCH residues are generally more persistent than DDT residues . However, all these data are well below than the state warning standard limit. Planta, 2003 Apr, 216(6), 891 - 902 Epub 2003 Feb 11. Reactive oxygen intermediates in plant-microbe interactions: who is who in powdery mildew resistance? Huckelhoven R, Kogel KH. Reactive oxygen intermediates (ROIs) such as hydrogen peroxide (H(2)O(2)) and the superoxide anion radical (O*(2)(-)) accumulate in many plants during attack by microbial pathogens . Despite a huge number of studies, the complete picture of the role of ROIs in the host-pathogen interaction is not yet fully understood . This situation is reflected by the controversially discussed question as to whether ROIs are key factors in the establishment and maintenance of either host cell inaccessibility or accessibility for fungal pathogens . On the one hand, ROIs have been implicated in signal transduction as well as in the execution of defence reactions such as cell wall strengthening and a rapid host cell death (hypersensitive reaction) . On the other hand, ROIs accumulate in compatible interactions, and there are reports suggesting a function of ROIs in restricting the spread of leaf lesions and thus in suppressing cell death . Moreover, in situ analyses have demonstrated that different ROIs may trigger opposite effects in plants depending on their spatiotemporal distribution and subcellular concentrations . This demonstrates the need to determine the particular role of individual ROIs in distinct stages of pathogen development . The well-studied interaction of cereals with fungi from the genus Blumeria is an excellent model system in which signal transduction and defence reactions can be further elucidated in planta . This review article gives a synopsis of the role of ROI accumulation, with particular emphasis on the pathosystem Hordeum vulgare L.- Blumeria graminis. Russ J Immunol, 1999 Oct, 4(3), 220 - 223 Cells of Immune System: Development, Activation, Effector Functions; Freidlin IS; While understanding the role of certain cell populations and subpopulations is being more precisely identified, the pool of immunocompetent cells becomes continuously broader . It has rather recently been shown that hematopoietic precursors that express CD34 on their surface may be served as precursors of both monocytes/macrophages (Mn/Mf), and dendritic cells (DC) Huge experimental data obtained for recent years have shown that DC may just be comprehensive APC, capable to present both bacterial, and viral antigens in both primary, and secondary immune response for recognition by both T helpers (CD4(+)) and cytotoxic T lymphocytes (CD8(+)) . Both Mf, and DC are producers of cytokines . After microbe phagocytosis by Mf or after DC infection, microbe components may induce production of IL-12 in these cells followed by IL-12 induction of IFNgamma production in NK and CD4(+) T lymphocytes . IFNgamma production is highly inducible: primary steps of IFNgamma production require, at least, two activation signals: from TCR, from adhesive or costimulatory molecules or from receptor for any additional cytokine, for example, IL-12 . IFNgamma is synergistic agent for IL-12 that is providing costimulatory signal in induction of Th1 differentiation and is enhancing the sensitivity of naive T lymphocytes to stimulatory action of IL-12 . Either Th1, and Th2 express beta1-chain of IL-12 receptor, but only Th1 express beta2-chain of this receptor . Incapability of Th2 to respond to IL-12 by activation is related to such a situation. Oncogene, 2003 Apr 10, 22(14), 2097 - 109 Involvement of nectin in the localization of IQGAP1 at the cell-cell adhesion sites through the actin cytoskeleton in Madin-Darby canine kidney cells; Katata T et al.; IQGAP1, a putative downstream target of the Rho family small G proteins, Cdc42 and Rac, localizes at adherens junctions (AJs) in epithelial cells . It has been suggested that IQGAP1 localizes at AJs through its binding to beta-catenin, and negatively regulates the E-cadherin-mediated cell-cell adhesion . Nectin is a Ca(2+)-independent, immunoglobulin-like cell-cell adhesion molecule that localizes at AJs . Nectin is associated with E-cadherin through their respective cytoplasmic tail-binding proteins, afadin and catenins, and involved in the formation of AJs cooperatively with E-cadherin . Here we investigated a role of nectin in the localization of IQGAP1 at AJs . Ca(2+) chelation from the medium causes disruption of the E-cadherin-mediated cell-cell adhesion, but not the nectin-based cell-cell adhesion, in Madin-Darby canine kidney (MDCK) cells . IQGAP1 remained at the residual nectin-based cell-cell adhesion sites where the E-cadherin immunofluorescence signal disappeared . Restoration of Ca(2+) in the medium causes re-accumulation of E-cadherin to the residual nectin-based cell-cell adhesion sites to re-form AJs . Nectin inhibitors inhibit this re-accumulation of E-cadherin to re-form AJs by impairing the nectin-based cell-cell adhesion . The nectin inhibitors also reduced the localization of IQGAP1 at the cell-cell adhesion sites . When MDCK cells were incubated with microbeads coated with the extracellular fragment of nectin that interacts with cellular nectin, IQGAP1 also accumulated at the bead-MDCK cell contact sites . The accumulation of IQGAP1 at the cell-cell adhesion sites was inhibited by actin filament-disrupting agents, latrunculin A and cytochalasin D . These results indicate that nectin is involved in the localization of IQGAP1 at AJs through the actin cytoskeleton. Trends Genet, 2003 Apr, 19(4), 224 - 31 pH regulation in Aspergillus and parallels with higher eukaryotic regulatory systems; Arst HN et al.; All organisms respond to their environment to some extent, and for many microbes the variation in environment can be enormous . An important asset for coping with environmental variation is physiological versatility--a hallmark of many fungi . The ability of fungi to thrive over a wide range of pH is partly due to a genetic regulatory system that tailors gene expression to the ambient pH . Here we focus on the pH regulatory system of Aspergillus nidulans, where a novel signal transduction (pal) pathway mediates the first of two steps in the proteolytic processing of a transcription factor (PacC) . Such processing is reminiscent of that of some well-known higher eukaryotic transcription factors, such as Cubitus interruptus, NF-kappa B and sterol regulatory element binding proteins . Intriguingly, endocytosis seems to be connected to pH signalling. Curr Pharm Des, 2003, 9(11), 879 - 89 Enhancing marine natural product structural diversity and bioactivity through semisynthesis and biocatalysis; Hamann MT; In the last several decades the plants, animals and microbes from the marine environment have revealed a portion of what is clearly a tremendous resource for structurally diverse and bioactive secondary metabolites . Many of these extraordinarily sophisticated and bioactive natural products can be isolated in significant quantities without great difficulty . As a result these readily available bioactive natural products provide valuable starting materials for the rational generation of libraries of compounds prepared through semisynthesis and biocatalysis . A review of our work using marine natural products to generate rationally designed compound libraries and their biological activity against infectious diseases, cancer and neurological targets is presented . The marine natural products utilized to date as starting materials consist of compounds from a variety of structural classes and include: aureol, puupehenone, sarcophine, palinurin, and the manzamine alkaloids . The possibility to generate diverse bioactive products beginning with a marine natural product scaffold is a direct result of improvements made in the technologies to harvest samples from the ocean, purify and characterize complex natural products quickly and complete chemical reactions and biotransformations in parallel . As a result the vast resources of the ocean can now be utilized routinely to design and produce countless products to be evaluated as part of drug discovery and development programs. Am Surg, 2003 Mar, 69(3), 231 - 7; discussion 237 The effects of varying oxygen conditions and immunoglobulin A on barrier defense to bacterial invasion; Baylor AE et al.; Tissue oxygenation is a critical factor in host defense against bacteria . Gut mucosal tissue oxygenation (partial pressure of O2) is normally low putting the gut at risk of invasion by luminal microbes . Secretory immunoglobulin (Ig) A (sIgA) is the principal immune defense at mucosal surfaces . The protective effect of IgA under low oxygen conditions is unknown . We studied the interaction of varying O2 environments and sIgA on protection against bacterial invasion in our in vitro model . Cell monolayers of Madin-Darby canine kidney (MDCK) cells transfected with the cDNA for polymeric immunoglobulin receptor were established in a two-chamber cell culture system . A commensal strain of Escherichia coli (10(8) colony-forming units) was added to the apical medium and cell cultures were placed in either a 5, 21, or 95 per cent O2 environment at 37 degrees C . Polyclonal sIgA (100 microg/mL) was added to the apical chamber in subsets . Basal medium was sampled at intervals and bacterial translocation quantitated . The cell monolayers of MDCK transfected cells then had 100 microg/mL IgA added to the basal compartment at 4 degrees C for 2 hours followed by various oxygen environments for 90 minutes . Afterwards apical medium was removed at one, 3, and 12 (overnight) hours . The bacterial translocation data showed a significance increase in translocation with hypoxia . Both increased oxygen and IgA abrogated these effects significantly . The transcytosis of IgA was increased during hypoxic conditions . Normal and hyperoxic conditions did not produce any significant difference in IgA transcytosis . We conclude that O2 and sIgA are protective against bacterial invasion at epithelial surfaces . Effects to either boost O2 delivery to the gut or enhance mucosal IgA production and delivery may be protective in the critically ill surgical patient. Appl Environ Microbiol, 2003 Apr, 69(4), 2340 - 8 A new rate law describing microbial respiration; Jin Q et al.; The rate of microbial respiration can be described by a rate law that gives the respiration rate as the product of a rate constant, biomass concentration, and three terms: one describing the kinetics of the electron-donating reaction, one for the kinetics of the electron-accepting reaction, and a thermodynamic term accounting for the energy available in the microbe's environment . The rate law, derived on the basis of chemiosmotic theory and nonlinear thermodynamics, is unique in that it accounts for both forward and reverse fluxes through the electron transport chain . Our analysis demonstrates how a microbe's respiration rate depends on the thermodynamic driving force, i.e., the net difference between the energy available from the environment and energy conserved as ATP . The rate laws commonly applied in microbiology, such as the Monod equation, are specific simplifications of the general law presented . The new rate law is significant because it affords the possibility of extrapolating in a rigorous manner from laboratory experiment to a broad range of natural conditions, including microbial growth where only limited energy is available . The rate law also provides a new explanation of threshold phenomena, which may reflect a thermodynamic equilibrium where the energy released by electron transfer balances that conserved by ADP phosphorylation. J Appl Microbiol, 2003, 94 Suppl, 1S - 11S The traveller and emerging infections: sentinel, courier, transmitter; Wilson ME; The movement of populations shapes the patterns and distribution of infectious diseases globally . The consequences of travel are seen in the traveller and in places and populations visited and may persist long after travel . The traveller can be seen as an interactive biological unit who picks up, processes, carries and drops off microbial genetic material . A traveller can introduce potential pathogens in the absence of signs or symptoms of illness . Travellers can serve as a sentinel population; study of them can provide insights into the presence and level of risk of transmission of infections in other geographical regions . Travellers can also be seen as couriers who inadvertently ferry pathogens and microbial genetic material to regions where researchers can carry out detailed analyses that can help to map the location and movement of strains, genotypes and resistance patterns . The laboratory plays a key role in the identification and characterization of pathogens, which can inform management of individual patients and the public health response . The connectedness and mobility in the world today facilitate the emergence of infectious diseases in humans and also in animals and plants . Many traditional barriers have been breached by travel, roads and technology . Population size and density favour spread of many infections . The rapid generation time of microbes and their capacity to adapt to changes in the physico-chemical and immunological environment will pose continuing challenges. Pediatr Allergy Immunol, 2003 Apr, 14(2), 74 - 80 Immune deviation and the hygiene hypothesis: a review of the epidemiological evidence; Kemp A et al.; The epidemiological evidence for the proposal that early life immune deviation is the principal mechanism by which microbial agents prevent the development of atopy has been reviewed . Seven criteria are proposed which should ideally be fulfilled . The majority of studies only fulfill two or three criteria . For mycobacteria, measles and respiratory viruses there are studies that demonstrate a significant increase in atopy or allergic disease . Parasite infections, which provide a strong TH2 stimulus, are associated with reduced rather than enhanced allergen sensitization . The available epidemiological evidence does not provide support for a mechanism of early life immune deviation . The principal environmental influences on atopic disease are likely to occur throughout life and involve interactions between microbes and other non-infective and lifestyle factors. Int J Colorectal Dis, 2003 May, 18(3), 181 - 7 Epub 2002 Nov 05. The gut as an organ of immunology; Wittig BM et al.; BACKGROUND: In normal conditions human gut mucosa is infiltrated with a large number of mononuclear cells due to continuous stimulation by luminal antigens . This state of "physiological" inflammation is tightly controlled, as several mucosal cells interact to maintain an appropriate local immune response . Moreover, gut-associated lymphoid tissue must constantly distinguish harmless antigens that are present in food and on commensal bacteria from pathogenic microbes . INTERVENTIONS AND RESEARCH: The oral administration of soluble protein antigens induces a state of systemic immunological unresponsiveness specific to the fed protein, termed oral tolerance . The two major mechanisms to explain oral tolerance are anergy/deletion of autoreactive lymphocytes and active suppression . Changes in the pathways of immune activation are detected in chronic intestinal inflammation, such as inflammatory bowel disease or celiac disease . CONCLUSION: An appreciation of the current knowledge of the gut immune system is of importance for understanding and development of new treatment modalities in chronic intestinal inflammation. Clin Oral Investig, 2003 Mar, 7(1), 38 - 40 Epub 2003 Mar 06. Gingival colonization with selective HACEK microbes in children with congenital heart disease; Steelman R et al.; It was previously shown that children with congenital heart disease (CHD) harbored Hemophilus, Actinobacillus, Cardiobacter, Eikenella, and Kingella (HACEK) microbes to a greater extent and had more severe gingival inflammation than a normal group of children . The purpose of this study was to determine if HACEK microbes are more prevalent in children with CHD than in normal children when there is no difference in gingival inflammation . Two groups of 12 children were matched with respect to gingival inflammation . Each child had a gingival index recorded as described by Massler . The experimental group consisted of 12 children with CHD 2.5-10 years old (average 5.5) and the control group consisted of 12 healthy children 2-13 years old (average 5.6) . Subgingival samples were obtained and cultured for HACEK microbes . Fischer's exact test was performed with the significance level defined at P<0.05 . The average gingival indices for the experimental and control groups were 6.5 and 6.4, respectively (N.S.) . Nine of 12 children with CHD had Eikenella corrodens (E.c.) compared to 3/12 control patients ( P<0.05) . Three of 12 CHD patients but no control patient had Actinobacillus actinomycetemcomitans (A.a.) (N.S.) . There were no significant differences in E.c . or A.a . presence between cyanotic and acyanotic CHD patients . This study found that the greater extent of specific HACEK microbes harbored by children with CHD is not associated with cyanosis or the degree of gingival inflammation . Further study is needed to delineate fully the medical significance of this observation. Nature, 2003 Apr 3, 422(6931), 531 - 4 The voltage dependence of NADPH oxidase reveals why phagocytes need proton channels; DeCoursey TE et al.; The enzyme NADPH oxidase in phagocytes is important in the body's defence against microbes: it produces superoxide anions (O2-, precursors to bactericidal reactive oxygen species) . Electrons move from intracellular NADPH, across a chain comprising FAD (flavin adenine dinucleotide) and two haems, to reduce extracellular O2 to O2- . NADPH oxidase is electrogenic, generating electron current (I(e)) that is measurable under voltage-clamp conditions . Here we report the complete current-voltage relationship of NADPH oxidase, the first such measurement of a plasma membrane electron transporter . We find that I(e) is voltage-independent from -100 mV to >0 mV, but is steeply inhibited by further depolarization, and is abolished at about +190 mV . It was proposed that H+ efflux mediated by voltage-gated proton channels compensates I(e), because Zn2+ and Cd2+ inhibit both H+ currents and O2- production . Here we show that COS-7 cells transfected with four NADPH oxidase components, but lacking H+ channels, produce O2- in the presence of Zn2+ concentrations that inhibit O2- production in neutrophils and eosinophils . Zn2+ does not inhibit NADPH oxidase directly, but through effects on H+ channels . H+ channels optimize NADPH oxidase function by preventing membrane depolarization to inhibitory voltages. J Immunol Methods, 2003 Apr 1, 275(1-2), 149 - 60 Flow cytometry based detection of HLA alloantibody mediated classical complement activation; Wahrmann M et al.; Complement-dependent cytotoxicity (CDC) panel reactive antibody (PRA) testing is used to assess recipient presensitization and post-transplant alloantibody formation in transplant recipients . However, CDC test results can be affected by false-positive reactions brought about by autoantibodies or antilymphocyte reagents . As an alternative to the CDC-PRA assay, detection of HLA alloantibodies using HLA antigen-coated microbeads (FlowPRA test) was recently established . FlowPRA testing, however, does not distinguish between (presumably more harmful) complement-fixing and noncomplement-fixing alloantibodies . In this study, we established a novel assay allowing flow cytometric detection of HLA alloantibody dependent classical complement activation using the FlowPRA test . For the detection of complement activation, FlowPRA beads were incubated with sera from highly sensitized dialysis patients (CDC-PRA reactivity >60%) and then stained for C4 (C4d, C4c) and C3 (C3d, C3c) fragments, as well as C1q deposition using indirect immunofluorescence . We demonstrate alloantibody induced induction of C4 fragment, and in parallel C1q deposition to HLA class I or class II beads . As shown by immunoblotting, C4 staining was not due to the presence of preformed C4 fragment-IgG/M complexes . Indeed, C4 fragment deposition in our in vitro system was demonstrated to result from de novo complement activation . First, inactivation of C4 by treatment of sera with methylamine, which inhibits cleavage of the internal thioester, completely abolished C4 fragment deposition . Second, C4 fragment deposition was not observed in the evaluation of C4-free immunoadsorption eluates obtained from highly sensitized dialysis patients . After supplementation with complement, however, eluates induced C4 deposition . Deposition of C4 split products and C1q was temperature-dependent with maximum binding after incubation at 4 degrees C for 60 min . In contrast, maximum C3 fragment deposition was found at 37 degrees C . At this temperature, C3 deposition occurred in an alloantibody and C4-independent fashion, presumably as a result of alternative complement activation . In summary, we describe a novel cell-independent and easy-to-perform PRA test that permits flow cytometry based detection of alloantibody induced classical complement activation . Future studies will have to evaluate its possible relevance as an alternative to CDC-PRA testing in clinical transplantation. J Immunol Methods, 2003 Apr 1, 275(1-2), 123 - 32 Analysis of intra-hepatic peptide-specific cell recruitment in mice immunised with Plasmodium falciparum antigens; Hebert A et al.; The liver stage of Plasmodium spp . now appears as a relevant target of immune effectors triggered by the so-called "anti-sporozoite" vaccine . Since the monitoring of immune responses at the systemic level may not faithfully reflect the local protective mechanisms, the aim of the present work was to set up a model to study the local intra-hepatic cellular responses and to compare these with the peripheral immune responses . This was achieved by intra-portal delivery of epitopic peptides, i.e . peptides containing B and T cell epitopes, which were coated onto the surface of polystyrene microbeads . The peptide-coated beads presumably mimic the hepatic schizont, and when distinct peptides are administered separately, this method of delivery allows us to decipher the immune responses resulting in mice immunised with recombinant proteins spanning several such epitopes . Using the P . falciparum liver stage antigen-3 (LSA3) molecule, which can induce protection against a sporozoite challenge, our results show that 25-microm microbeads could easily access the liver parenchyma by intra-portal injection and were distributed evenly in the liver . Also, LSA3-derived synthetic peptides coated onto microbeads initiated specific cell recruitment within 6 h . Depending on the LSA3 peptide used, the infiltrates induced differed in size, with the strongest cell recruitment obtained using nonrepeat II peptide (NR2)-coated microbeads with a mean leukocyte number of 79 per granuloma . Immunohistological studies of liver sections revealed that, irrespective of the delivered peptide, cells infiltrating the liver towards microbeads were mainly CD3(+) T lymphocytes, both CD4(+) (70 to 80%) and CD8(+) (20 to 30%) subtypes, macrophages and dendritic cells . Cells infiltrating the granuloma had features of activated cells, with evidence of VLA-4 cell-surface expression, and production of IFN-gamma and IL-4 . Analysis of the peripheral B and T-cell responses in the same animals revealed that, whereas the local responses were directed mainly towards NR2 and repeat peptides (RE), the peripheral T-cell response to these peptides was weak and infrequent, although antibody production was high. Mikrobiol Z, 2002 Nov-Dec, 64(6), 62 - 6 {Effect of various anions on the rate of microbe-induced corrosion}; Piliashenko-Novokhatnyi AI et al.; Experimental corroboration of correctness of theoretical thermodynamic calculations of e.m.f . of corrosion reactions induced by soil microorganisms is obtained in the work . A hypothesis is put forward on possible mechanism for stimulation of microbe-induced corrosion by chloride ions . The results obtained permit revealing the reasons of low efficiency conditions of cathode protection in cases of active involvement of soil microorganisms into corrosion processes which are used for maintenance of underground constructions. J Perinat Med, 2003, 31(1), 69 - 74 CSF findings in neonates with seizures; infectious and noninfectious; Mustonen K et al.; In order to evaluate parameters of cerebrospinal fluid (CSF) we studied 105 CSF samples of 50 neonates with seizures of unknown origin for cell count and chemistry (protein, albumin, glucose, IgG-index and albumin-ratio) . Viral studies for 13 different microbes were performed from serum and CSF . CSF parameters of the babies with a suggested viral infection (n = 13) were compared with those without any viral findings (n = 37), and followed up to the age 45 weeks since conception . CSF mononuclear white blood cell count was < or = 20 x 10(6)/l at the age of < or = 40 weeks since conception, and thereafter i.e . at term it was < or = 10 x 10(6)/l in all neonates without viral infection, whereas mononuclear cell count was above these limits in 8 of 13 neonates with viral infection . The rate of IgG-index remained high only in the neonates with a viral infection when studied at the age of over 43 weeks since conception . We conclude that studies of CSF are a valuable diagnostic aid in CNS viral infections of neonates when evaluated in reference to the age since conception, and the limits of mononuclear white blood cells in normal CSF of neonates are in lower limits than reported before. Genomics, 2003 Mar, 81(3), 329 - 35 Pathogen discovery from human tissue by sequence-based computational subtraction; Xu Y et al.; We have recently reported a new pathogen discovery approach, "computational subtraction" . With this approach, non-human transcripts are detected by sequencing cDNA libraries from infected tissue and eliminating those transcripts that match the human genome . We show now that this method is experimentally feasible . We generated a cDNA library from a tissue sample of post-transplant lymphoproliferative disorder (PTLD) . 27,840 independent cDNA sequences were filtered by computational subtraction against the known human sequence to identify 32 nonmatching transcripts . Of these, 22 (0.1%) were found to be amplifiable from both infected and noninfected samples and were inferred to be human DNA not yet contained in the available human genome sequence . The remaining 10 sequences could be amplified only from Epstein-Barr virus (EBV)-infected tissues . All 10 corresponded to the known EBV sequence . This proof-of-principle experiment demonstrates that computational subtraction can detect pathogenic microbes in primary human-diseased tissue. Appl Microbiol Biotechnol, 2003 Mar, 61(1), 21 - 31 Epub 2002 Dec 24. Biotin in microbes, the genes involved in its biosynthesis, its biochemical role and perspectives for biotechnological production; Streit WR et al.; Biotin (vitamin H) is one of the most fascinating cofactors involved in central pathways in pro- and eukaryotic cell metabolism . Since its original discovery in 1901, research has led to the discovery of the complete biotin biosynthesis pathways in many different microbes and much work has been done on the highly intriguing and complex biochemistry of biotin biosynthesis . While humans and animals require several hundred micrograms of biotin per day, most microbes, plants and fungi appear to be able to synthesize the cofactor themselves . Biotin is added to many food, feed and cosmetic products, creating a world market of 10-30 t/year . However, the majority of the biotin sold is synthesized in a chemical process . Since the chemical synthesis is linked with a high environmental burden, much effort has been put into the development of biotin-overproducing microbes . A summary of biotin biosynthesis and its biological role is presented; and current strategies for the improvement of microbial biotin production using modern biotechnological techniques are discussed. Glycobiology, 2003 Jul, 13(7), 41R - 53R Epub 2003 Mar 19. Fucose: biosynthesis and biological function in mammals; Becker DJ et al.; Fucose is a deoxyhexose that is present in a wide variety of organisms . In mammals, fucose-containing glycans have important roles in blood transfusion reactions, selectin-mediated leukocyte-endothelial adhesion, host-microbe interactions, and numerous ontogenic events, including signaling events by the Notch receptor family . Alterations in the expression of fucosylated oligosaccharides have also been observed in several pathological processes, including cancer and atherosclerosis . Fucose deficiency is accompanied by a complex set of phenotypes both in humans with leukocyte adhesion deficiency type II (LAD II; also known as congenital disorder of glycosylation type IIc) and in a recently generated strain of mice with a conditional defect in fucosylated glycan expression . Fucosylated glycans are constructed by fucosyltransferases, which require the substrate GDP-fucose . Two pathways for the synthesis of GDP-fucose operate in mammalian cells, the GDP-mannose-dependent de novo pathway and the free fucose-dependent salvage pathway . In this review, we focus on the biological functions of mammalian fucosylated glycans and the biosynthetic processes leading to formation of the fucosylated glycan precursor GDP-fucose. Tree Physiol, 1998 Oct, 18(10), 665 - 670 Variation in sugar maple root respiration with root diameter and soil depth; Pregitzer KS et al.; Root respiration may account for as much as 60% of total soil respiration . Therefore, factors that regulate the metabolic activity of roots and associated microbes are an important component of terrestrial carbon budgets . Root systems are often sampled by diameter and depth classes to enable researchers to process samples in a systematic and timely fashion . We recently discovered that small, lateral roots at the distal end of the root system have much greater tissue N concentrations than larger roots, and this led to the hypothesis that the smallest roots have significantly higher rates of respiration than larger roots . This study was designed to determine if root respiration is related to root diameter or the location of roots in the soil profile . We examined relationships among root respiration rates and N concentration in four diameter classes from three soil depths in two sugar maple (Acer saccharum Marsh.) forests in Michigan . Root respiration declined as root diameter increased and was lower at deeper soil depths than at the soil surface . Surface roots (0-10 cm depth) respired at rates up to 40% greater than deeper roots, and respiration rates for roots < 0.5 mm in diameter were 2.4 to 3.4 times higher than those for roots in larger diameter classes . Root N concentration explained 70% of the observed variation in respiration across sites and size and depth classes . Differences in respiration among root diameter classes and soil depths appeared to be consistent with hypothesized effects of variation in root function on metabolic activity . Among roots, very fine roots in zones of high nutrient availability had the highest respiration rates . Large roots and roots from depths of low nutrient availability had low respiration rates consistent with structural and transport functions rather than with active nutrient uptake and assimilation . These results suggest that broadly defined root classes, e.g., fine roots are equivalent to all roots < 2.0 mm in diameter, do not accurately reflect the functional categories typically associated with fine roots . Tissue N concentration or N content (mass x concentration N) may be a better indicator of root function than root diameter. J Lab Clin Med, 2003 Mar, 141(3), 229 - 30 Nobel prize winner trading card (CIRCA 1952) . Elie Metchnikoff; Hammerschmidt DE; Russian doctor and bacteriologist, born in Ivanowca in 1845 . He began his studies in Kharkov, continuing them at the Universities of Giessen, Gothingen, and Munich, later being named Professor of Zoology in Odessa in 1870 . In the Canary Islands, he completed some anthropological works, but dedicated himself especially to studies of marine fauna . In 1887, much taken by the work of Pasteur, he wrote to him asking for a position in his laboratories; in a short time he became one of the principal collaborators with the master, especially in works concerning bacteriology . These were an inspiration to him, and led him to his famous theory of phagocytosis, the defensive act whereby white blood cells protect an organism against pathogenic microbes . Metchnikoff supposed that old age was avoidable, and subscribed to the materialistic school of thought . He was awarded the Nobel Prize in 1908 . (With the complements of the Jose Lopez Luis Cigarillo Factory, Tenerife). Expert Rev Mol Diagn, 2003 Mar, 3(2), 153 - 61 Nanodiagnostics: application of nanotechnology in molecular diagnostics; Jain KK; Nanotechnology extends the limits of molecular diagnostics to the nanoscale . Nanotechnology-on-a-chip is one more dimension of microfluidic/lab-on-a-chip technology . Biological tests measuring the presence or activity of selected substances become quicker, more sensitive and more flexible when certain nanoscale particles are put to work as tags or labels . Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms . Magnetic immunoassay techniques have been developed in which the magnetic field generated by the magnetically labeled targets is detected directly with a sensitive magnetometer . Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample . Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads . Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures . DNA nanomachines can function as biomolecular detectors for homogeneous assays . Nanobarcodes, submicrometer metallic barcodes with striping patterns prepared by sequential electrochemical depositon of metal, show differential reflectivity of adjacent stripes enabling identification of the striping patterns by conventional light microscopy . All this has applications in population diagnostics and in point-of-care hand-held devices. Plant Physiol, 2003 Mar, 131(3), 941 - 51 A cluster of genes encodes the two types of chalcone isomerase involved in the biosynthesis of general flavonoids and legume-specific 5-deoxy(iso)flavonoids in Lotus japonicus; Shimada N et al.; Leguminous plants produce 5-deoxyflavonoids and 5-deoxyisoflavonoids that play essential roles in legume-microbe interactions . Together with chalcone polyketide reductase and cytochrome P450 2-hydroxyisoflavanone synthase, the chalcone isomerase (CHI) of leguminous plants is fundamental in the construction of these ecophysiologically active flavonoids . Although CHIs of nonleguminous plants isomerize only 6'-hydroxychalcone to 5-hydroxyflavanone (CHIs with this function are referred to as type I), leguminous CHIs convert both 6'-deoxychalcone and 6'-hydroxychalcone to 5-deoxyflavanone and 5-hydroxyflavanone, respectively (referred to as type II) . In this study, we isolated multiple CHI cDNAs (cCHI1-cCHI3) from a model legume, Lotus japonicus . In contrast to previous observations, the amino acid sequence of CHI2 was highly homologous to nonleguminous CHIs, whereas CHI1 and CHI3 were the conventional leguminous type . Furthermore, genome sequence analysis revealed that four CHI genes (CHI1-3 and a putative gene, CHI4) form a tandem cluster within 15 kb . Biochemical analysis with recombinant CHIs expressed in Escherichia coli confirmed that CHI1 and CHI3 are type II CHIs and that CHI2 is a type I CHI . The occurrence of both types of CHIs is probably common in leguminous plants, and it was suggested that type II CHIs evolved from an ancestral CHI by gene duplication and began to produce 5-deoxy(iso)flavonoids along with the establishment of the Fabaceae. Adv Dent Res, 2001 Aug, 15, 68 - 71 Odontoblast function seen as the response of dentinal tissue to dental caries; Larmas M; Microbes are responsible for the initiation and maintaining of carious processes . They have an efficient machinery for dissolving crystalline hydroxyapatite . When initiating carious processes, microbial acid formation determines the rate of the process in enamel . When the process reaches dentin, the micro-environment changes . Dential fluid in dentin tubules is the liquid where dissolving products of apatites are destroyed . Inorganic composition of dentinal fluid, however, is not altered much during the carious process, indicating that a functional secretory domain is working to pump the dissolved calcium and phosphate ions out of the fluid . Activation of odontoblast alkaline phosphatase and dentin latent collagenases is the known cellular event during the carious process in dentin . Because the caries lesion is by definition undermining, this suggests that, in this degradation process, the extracellular compartment, crystalline hydroxyapatite is dissolved by microbial acids, and a mixture of proteinases degrades the organic matrix . The degradation products of collagen and other matrix components in dentinal fluid must be transported either through the caries lesion in the enamel to saliva or through the odontoblast to the pulp (active transport) . This facilitates further processing of the degradation products intracellularly during the passage through the cell. Arch Microbiol, 2003 May, 179(5), 339 - 53 Epub 2003 Mar 15. Exploring the Penicillium marneffei genome; Yuen KY et al.; Penicillium marneffei is a dimorphic fungus that intracellularly infects the reticuloendothelial system of humans and bamboo rats . Endemic in Southeast Asia, it infects 10% of AIDS patients in this region . The absence of a sexual stage and the highly infectious nature of the mould-phase conidia have impaired studies on thermal dimorphic switching and host-microbe interactions . Genomic analysis, therefore, could provide crucial information . Pulsed-field gel electrophoresis of genomic DNA of P . marneffei revealed three or more chromosomes (5.0, 4.0, and 2.2 Mb) . Telomeric fingerprinting revealed 6-12 bands, suggesting that there were chromosomes of similar sizes . The genome size of P . marneffei was hence about 17.8-26.2 Mb . G+C content of the genome is 48.8 mol% . Random exploration of the genome of P . marneffei yielded 2303 random sequence tags (RSTs), corresponding to 9% of the genome, with 11.7, 6.3, and 17.4% of the RSTs having sequence similarity to yeast-specific sequences, non-yeast fungus sequences, and both (common sequences), respectively . Analysis of the RSTs revealed genes for information transfer (ribosomal protein genes, tRNA synthetase subunits, translation initiation, and elongation factors), metabolism, and compartmentalization, including several multi-drug-resistance protein genes and homologues of fluconazole-resistance gene . Furthermore, the presence of genes encoding pheromone homologues and ankyrin repeat-containing proteins of other fungi and algae strongly suggests the presence of a sexual stage that presumably exists in the environment. J Gravit Physiol, 2001 Jul, 8(1), P43 - 4 Nucleolar structure and function under clinorotation; Sobol MA; A nucleolus is the dynamic part of a cell nucleus where rDNA transcription, rRNA precursor processing and transport are proceeding . Investigations of the influence of microgravity and clinorotation on the structure and function of nucleolus began more than thirty years ago but, unfortunately, now there are only some articles concerning the nucleolar peculiarities in altered gravity . Available data about alterations of nucleolar morphology and function under the influence of high and low temperature, hypoxia and UV-microbeam irradiation allow us to put intent attention to the study of the nucleolus reactions on clinorotation . Therefore, the aim of our work was to investigate the ultrastructural organization and functional activity of nucleoli in Lepidium sativum root meristematic cells under clinorotation in order to understand whether a nucleolus can react to gravity. Environ Sci Technol, 2003 Feb 15, 37(4), 786 - 91 Application of high-angle annular dark field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive X-ray spectrometry, and energy-filtered transmission electron microscopy to the characterization of nanoparticles in the environment; Utsunomiya S et al.; A major challenge to the development of a fundamental understanding of transport and retardation mechanisms of trace metal contaminants (<10 ppm) is their identification and characterization at the nanoscale . Atomic-scale techniques, such as conventional transmission electron microscopy, although powerful, are limited by the extremely small amounts of material that are examined . However, recent advances in electron microscopy provide a number of new analytical techniques that expand its application in environmental studies, particularly those concerning heavy metals on airborne particulates or water-borne colloids . High-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM-energy-dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM) can be effectively used to identify and characterize nanoparticles . The image contrast in HAADF-STEM is strongly correlated to the atomic mass: heavier elements contribute to brighter contrast . Gold nanocrystals in pyrite and uranium nanocrystals in atmospheric aerosols have been identified by HAADF-STEM and STEM-EDX mapping and subsequently characterized by high-resolution TEM (HRTEM) . EFTEM was used to identify U and Fe nanocrystals embedded in an aluminosilicate . A rare, As-bearing nanophase, westerveldite (FeAs), was identified by STEM-EDX and HRTEM . The combined use of these techniques greatly expands the effective application of electron microscopy in environmental studies, especially when applied to metals of very low concentrations . This paper describes examples of how these electron microbeam techniques can be used in combination to characterize a low concentration of heavy metals (a few ppm) on nanoscale particles. J Androl, 2003 Mar-Apr, 24(2), 246 - 52 Deterioration of plasma membrane is associated with activated caspases in human spermatozoa; Paasch U et al.; Spermatozoa with deteriorated plasma membranes can be separated by magnetic-activated cell sorting (MACS) after binding superparamagnetic annexin V-conjugated microbeads (ANMBs) to membrane phosphatidylserine (PS) . Semen samples from 15 donors and 25 infertile patients were divided into 2 spermatozoal fractions by annexin V-MACS . Activated caspases (aCPs), which mediate degradations of cell quality, were determined by CaspaTag in the 2 subpopulations . Spermatozoa from donors showed lower levels of bound annexin V (3.6% +/- 0.5% vs 11.9% +/- 1.1%; P <.01) and aCPs (21.8% +/- 2.6% vs 43.2% +/- 2.1%; P <.01) than did spermatozoa from infertile patients . MACS resulted in a decrease of spermatozoa with aCPs from 21.8% +/- 2.6% (before separation) to 9.2% +/- 1.4% (in the ANMB-negative fraction) in donors and from 43.2% +/- 2.1% to 18.8% +/- 2.6% in infertile patients (mean +/- SEM; P <.01) . Separation effects of the MACS technique were confirmed with flow cytometry using anti-annexin V antibodies and with electron microscopy . ANMB-MACS removes spermatozoa with PS-bound annexin V and produces a higher quality spermatozoal fraction . Spermatozoa with a deteriorated membrane are characterized by an increase in aCPs . A higher percentage of spermatozoa with ANMBs bound to PS and with aCPs were found in infertile patients. World J Gastroenterol, 2003 Mar, 9(3), 479 - 84 Antitumor immunopreventive and immunotherapeutic effect in mice induced by hybrid vaccine of dendritic cells and hepatocarcinoma in vivo; Zhang JK et al.; AIM: To develop atumor vaccine by fusion of H22 hepatocarcinoma cells and DC, and to study its protective and therapeutical effect against H22 cell . METHODS: H22-DC vaccine was produced by PEG fusion of H22 and DC induced by cytokine released from splenic mononuclear cells, sorted by CD11c magnetic microbead marker . It was injected through the tail vein of the mice and the H(22)-DC oncogenesis was detected in the liver, spleen and lung . In order to study the therapeutical and protective effect of H(22)-DC against tumor H(22), two groups were divided: immune group and therapeutic group . Immune group was further divided into P, D, HD and H subgroups, immunized by PBS, DC, H(22)-DC and inactivated H(22), respectively, and attacked by H(22) cell . The tumor size, tumor weight, mice survival time and tumor latent period were recorded and statistically analyzed; Therapeutical group was divided into three subgroups of P, D and HD, and attacked by H(22), then treated with PBS, DC, and H(22)-DC, respectively . Pathology and flow cytometry were also applied to study the mechanism how the H(22)-DC vaccine attacked on the H(22) cell . RESULTS: 1 . No oncogenesis was found in spleen, lung and liver after H22-DC injection . 2 . Hybrid vaccine immunized mice had strongest CTL activity . 3 . In the immune group, latent period was longer in HD subgroup than that in P, H and D subgroup; and tumor size and weight were smaller in HD subgroup than that in P, H and D subgroup . 4 . In therapeutic group, tumor size was smaller in HD subgroup than that in P, D subgroup . CONCLUSION: 1 . H22-DC tumor vaccine is safe without oncogenesis in vivo . 2 . Hybrid vaccine can stimulate potent specific CTL activity against H22 . 3 . H22-DC vaccine has distinctive prophylatic effect on tumor H22 and can inhibit the tumor growth. Eur Biophys J, 2003 Mar, 32(1), 33 - 9 Epub 2003 Jan 28. Combined nanomanipulation by atomic force microscopy and UV-laser ablation for chromosomal dissection; Stark RW et al.; Nanomanipulation and nanoextraction on a scale close to and beyond the resolution limit of light microscopy is needed for many modern applications in biological research . For the manipulation of biological specimens a combined microscope allowing for ultraviolet (UV) microbeam laser manipulation together with manipulation by an atomic force microscope (AFM) was used . In a one-step procedure, human metaphase chromosomes were dissected optically by the UV-laser ablation and mechanically by AFM manipulation . With both methods, sub-400-nm cuts could be achieved routinely . Thus, the AFM is an indispensable tool for in situ quality control of nanomanipulation . However, already on this scale the dilation of the topographic AFM image due to the tip geometry can become significant . Therefore the AFM images were restored using a tip geometry obtained by a blind tip-reconstruction algorithm . Cross-sectional analysis of the restored image reveals a 380-nm-wide UV-laser cut and AFM cuts between 70 nm and 280 nm. Environ Sci Technol, 2003 Feb 1, 37(3), 616 - 23 Interpreting deposition patterns of microbial particles in laboratory-scale column experiments; Tufenkji N et al.; The transport and fate of microbial particles in subsurface environments is controlled by their capture (natural filtration) by sediment grains . Typically, filtration models used to describe microbe removal in porous media predict exponential decrease in microbial particle concentration with travel distance . However, a growing body of laboratory-scale column experiments suggests that the retained microbial particle profiles decay nonexponentially . The observed behavior may be attributed to the heterogeneity in the interactions between microbial particles and sediment grains, most likely due to the inherent variability in the microbial particles . This factor can be incorporated into classical colloid filtration (deposition) theory by inclusion of a distribution in the deposition rate coefficient . We show that certain distributions of the deposition rate coefficient (i.e., log-normal, bimodal, and power-law distributions) give rise to nonexponential deposition patterns . Comparisons of model predictions to experimental data indicate that the observed nonexponential deposition behavior of bacteria and virus particles may be attributed to a broad range (i.e., a power-law distribution) of microbial deposition rates . Other mechanisms such as particle release and blocking by previously deposited microbial particles are also shown to be potential sources of deviation from the classical filtration theory . Our results further suggest that monitoring fluid-phase particle concentration is insufficient for accurate characterization of the deposition and transport behavior of microbial particles in saturated porous media . Rather, the shape of the microbial particle retention profile is shown to be a key indicator of the mechanisms controlling microbial deposition and transport. Crit Care Med, 2003 Mar, 31(3), 787 - 92 Free radical and drug oxidation products in an intensive care unit sedative: propofol with sulfite; Baker MT et al.; OBJECTIVES: Some propofol emulsion formulations contain EDTA or sodium metabisulfite to inhibit microbe growth on extrinsic contamination . EDTA is not known to react with propofol formulation components; however, sulfite has been shown to support some oxidation processes and may react with propofol . This study compared the oxidation of propofol and the formation of free radicals by electron paramagnetic resonance analysis in EDTA and sulfite propofol emulsions during a simulated intensive care unit 12-hr intravenous infusion . DESIGN: Controlled laboratory study . SETTING: University laboratory . MEASUREMENTS AND MAIN RESULTS: Propofol emulsions (3.5 mL) were dripped from spiked 50-mL vials at each hour for 12 hrs . Two propofol oxidation products, identified as propofol dimer and propofol dimer quinone, were detected in sulfite and EDTA propofol emulsions; however, sulfite propofol emulsion contained higher quantities of both compounds . After initiation of the simulated infusion, the quantities of propofol dimer and propofol dimer quinone increased in the sulfite propofol emulsion, but the lower levels in the EDTA propofol emulsion remained constant . Sulfite propofol emulsion began to visibly yellow at about 6-7 hrs . The EDTA propofol emulsion remained white at all times . The absorbance spectra of the propofol dimer and propofol dimer quinone extracted from sulfite propofol emulsion showed that propofol dimer did not absorb in the visible spectrum, but the propofol dimer quinone had an absorbance peak at 421 nm, causing it to appear yellow . Electron paramagnetic resonance analysis of the propofol emulsion containing metabisulfite revealed that the sulfite propofol emulsion yielded a strong free radical signal consistent with the formation of the sulfite anion radical (SO3*-) . The EDTA propofol emulsion yielded no free radical signal above background . CONCLUSION: Sulfite from the metabisulfite additive in propofol emulsion creates an oxidative environment when these emulsions are exposed to air during a simulated intravenous infusion . This oxidation results in propofol dimerization and emulsion yellowing, the latter of which is caused by the formation of propofol dimer quinone . These processes can be attributed to the rapid formation of the reactive sulfite free radical. Amino Acids, 2003, 24(1-2), 73 - 80 Degradation of tryptophan and related indolic compounds by ruminal bacteria, protozoa and their mixture in vitro; Mohammed N et al.; In vitro experiments were conducted to examine the degradation of d- and l-isomers of tryptophan (Trp) and 10 related indolic compounds by mixed rumen bacteria (B), protozoa (P) and a combination of the two (BP) . The analyses were carried out by HPLC . d-Trp (1.0 mM) was not degraded by rumen microorganisms during the 24-h incubation period . The net degradation of 1 mM l-Trp was 46.5%, 8.7% and 80.0% by B, P and BP suspensions, respectively . Trp was degraded into indoleacetic acid, indolelactic acid and indole by rumen bacteria and protozoa, and into skatole, p-cresol and indolepropionic acid by rumen bacteria only . Of them, indoleacetic acid was the major product of Trp found in B (15.4%) and P (3.1%), and skatole in BP (43.2%) . This is the first report of the production of indolelactic acid and p-cresol from Trp by rumen microbes . Starch, d-glucose, salinomycin and monensin inhibited the production of skatole and indole from Trp, and skatole from indoleacetic acid by rumen bacteria. Indian J Exp Biol, 2002 Feb, 40(2), 187 - 91 Inhibition of endocytotic functions in Dictyostelium discoideum treated with a carbamate pesticide; Gurumurthy Y et al.; Administration of a carbamate pesticide carbaryl (1-Naphthyl-N-methyl carbamate) at a concentration of 60 and 100 ppm greatly inhibits the endocytotic functions during growth of the cellular slime mold D . discoideum . The ingestion of fluorescien isothiocynate (FITC) labeled E . coli is reduced between 30 and 40% in the treated cells as compared to controls . Similarly, the uptake of FITC-labeled dextran, which has been used as fluid-phase marker for pinocytosis also show 40-50% inhibition in the treated cells . 3H-leucine uptake and incorporation are also inhibited in the treated cells . SDS-PAGE analysis of cytoskeletal proteins shows a higher actin association with the membrane of treated cells . The results demonstrate the detrimental effects of Carbamate on the soil microbe even at a very low concentration and the efficacy of the slime mold cells as a biosensor for the carbamate-induced cytotoxicity. Phytochemistry, 2003 Feb, 62(3), 377 - 87 Occurrence and non-detectability of maytansinoids in individual plants of the genera Maytenus and Putterlickia; Pullen CB et al.; Individual plants belonging to different species of the family Celastraceae collected from their natural habitats in South Africa (Putterlickia verrucosa (E . Meyer ex Sonder) Szyszyl., Putterlickia pyracantha (L.) Szyszyl., Putterlickia retrospinosa van Wyk and Mostert) and Brazil (Maytenus ilicifolia Mart . ex Reiss., Maytenus evonymoides Reiss., Maytenus aquifolia Mart.) were investigated for the presence of maytansinoids and of maytansine, an ansamycin of high cytotoxic activity . Maytansinoids were not detectable in plants grown in Brazil . Analysis of plants growing in South Africa, however, showed clearly that maytansinoids were present in some individual plants but were not detectable in others . Molecular biological analysis of a Putterlickia verrucosa cell culture gave no evidence for the presence of the aminohydroxybenzoate synthase gene which is unique to the biosynthesis of aminohydroxybenzoate, a precursor of the ansamycins including maytansinoids . Moreover, this gene was not detectable in DNA extracted from the aerial parts of Putterlickia plants . In contrast, observations indicate that this gene may be present in microbes of the rhizosphere of Putterlickia plants . Our observations are discussed with respect to the possibility that the roots of Putterlickia plants may be associated with microorganisms which are responsible for the biosynthesis of maytansine or maytansinoids. Eksp Klin Gastroenterol, 2002, (5), 92 - 6, 129-30 {Antibiotic-associated diarrhea}; Parfenov AI et al.; There are more than 500 species of microbes in the human bowels, and their total amount reaches 10(14), which is much higher than the total quantity of the cellular content in human organism . The history of teaching about microbiocenosis demonstrates various connections of microorganisms with the bowels and other organs and systems of human body . The available data about the significance of the bowels microbe flora for human organism give grounds for comparing it with the nervous, cardiovascular or any other organism system. Br J Cancer, 2003 Mar 10, 88(5), 767 - 74 A proliferation-dependent bystander effect in primary porcine and human urothelial explants in response to targeted irradiation; Belyakov OV et al.; The aim of this study was to test whether radiation-induced bystander effects are involved in the response of multicellular systems to targeted irradiation . A primary explant technique was used that reconstructed the in vivo microarchitecture of normal urothelium with proliferating and differentiated cells present . Sections of human and porcine ureter were cultured as explants and irradiated on day 7 when the urothelial outgrowth formed a halo around the tissue fragment . The Gray Cancer Institute charge particle microbeam facility allowed the irradiation of individual cells within the explant outgrowth with a predetermined exact number of (3)He(2+) ions (which have very similar biological effectiveness to alpha-particles) . A total of 10 individual cell nuclei were irradiated with 10 (3)He(2+) ions either on the periphery, where proliferating cells are located, or at the centre of the explant outgrowth, which consisted of terminally differentiated cells . Samples were fixed 3 days after irradiation, stained and scored . The fraction of apoptotic and micronucleated cells was measured and a significant bystander-induced damage was observed . Approximately 2000-6000 cells could be damaged by the irradiation of a few cells initially, suggesting a cascade mechanism of cell damage induction . However, the fraction of micronucleated and apoptotic cells did not exceed 1-2% of the total number of the cells within the explant outgrowth . It is concluded that the bystander-induced damage depends on the proliferation status of the cells and can be observed in an in vitro explant model. Am J Physiol Lung Cell Mol Physiol, 2003 Apr, 284(4), L566 - 77 Pathophysiological roles of interleukin-8/CXCL8 in pulmonary diseases; Mukaida N; Fifteen years have passed since the first description of interleukin (IL)-8/CXCL8 as a potent neutrophil chemotactic factor . Accumulating evidence has demonstrated that various types of cells can produce a large amount of IL-8/CXCL8 in response to a wide variety of stimuli, including proinflammatory cytokines, microbes and their products, and environmental changes such as hypoxia, reperfusion, and hyperoxia . Numerous observations have established IL-8/CXCL8 as a key mediator in neutrophil-mediated acute inflammation due to its potent actions on neutrophils . However, several lines of evidence indicate that IL-8/CXCL8 has a wide range of actions on various types of cells, including lymphocytes, monocytes, endothelial cells, and fibroblasts, besides neutrophils . The discovery of these biological functions suggests that IL-8/CXCL8 has crucial roles in various pathological conditions such as chronic inflammation and cancer . Here, an overview of its protein structure, mechanisms of production, and receptor system will be discussed as well as the pathophysiological roles of IL-8/CXCL8 in various types of lung pathologies. J Control Release, 2003 Feb 21, 87(1-3), 139 - 51 Targeting caveolae for vesicular drug transport; Gumbleton M et al.; Caveolae are morphologically evident as omega-shaped invaginations of the plasma membrane with a diameter of 50-100 nm . They may also exist in a variety of other forms including flattened domains indistinguishable from the plasma membrane itself . At least in some cell types caveolae undertake transport functions including that of the endocytic and transcytotic movement of macromolecules, and indeed microbes and microbial toxins . Opportunities exist for basic and applied investigators working within the pharmaceutical sciences to exploit caveolae membrane interactions with the aim to develop of novel cellular or transcellular drug delivery strategies . This overview article will provide: pertinent information on the biology of the caveolae membrane system; review the various caveolae isolation methods; highlight some of the literature evidence showing that caveolae are functional with regard to macromolecule transport; discuss the role that caveolae could fulfill in the pulmonary absorption of therapeutic proteins from alveolar airspace to capillary blood following inhalational drug delivery, and finally review some very recent work showing proof-of-principle that caveolae domains can be targeted in a tissue-specific manner with highly selective ligands . J Agric Food Chem, 2003 Mar 12, 51(6), 1710 - 7 Purification and identification of barley (Hordeum vulgare L.) proteins that inhibit the alkaline serine proteinases of Fusarium culmorum; Pekkarinen AI et al.; It has been proposed that microbial proteinase inhibitors, which are present in abundance in cereal grains, protect the seed against plant pathogens . So far, however, very little is known about the interactions of those inhibitors with the proteinases of phytopathogenic microbes . The increased alkaline proteinase activities of Fusarium head blight (FHB) diseased wheat and barley grain imply that the Fusarium fungi synthesize those enzymes during the colonization of the kernel . To study which barley proteins can inhibit Fusarium proteinases, and hence, possibly protect the seed from FHB, the proteins of a grain extract have been separated and tested for their abilities to inhibit two alkaline serine proteinases that we previously isolated from F . culmorum . The proteins were separated by size exclusion, ion exchange, and reversed-phase-HPLC chromatographies . The purified inhibitors were identified by their molecular masses and N-terminal amino acid sequences . The proteins that inhibited the subtilisin-like Fusarium proteinase were the chymotrypsin/subtilisin (CI) inhibitors 1A, 1B, and 2A and the barley alpha-amylase/subtilisin inhibitor (BASI) . Only one of the purified proteins inhibited the trypsin-like proteinase, the barley Bowman-Birk inhibitor (BBBI) . No novel inhibitors were detected. Med Hypotheses, 2003 Apr, 60(4), 567 - 72 The physiology and pharmacology of singlet oxygen; Stief TW; Reactive oxygen species (ROS) are generated by many different cells . Singlet oxygen (1O(2)) and a reaction product of it, excited carbonyls (C=O*), are important ROS . 1O(2) and C=O* are nonradicalic and emit light (one photon/molecule) when returning to ground state oxygen . Especially activated polymorphonuclear neutrophil granulocytes (PMN) produce large amounts of 1O(2) . Via activation of the respiratory burst (NADPH oxidase and myeloperoxidase) they synthesize hypochlorite (NaOCl) and chloramines (in particular N-chlorotaurine) . Chloramines are selective and stable chemical generators of 1O(2) . In the human organism, 1O(2) is both a signal and a weapon with therapeutic potency against very different pathogens, such as microbes, virus, cancer cells and thrombi . Chloramines at blood concentrations between 1 and 2 mmol/L inactivate lipid enveloped virus and chloramines at blood concentrations below 0.5 mmol/L, i.e . at oxidant concentrations that do not affect thrombocytes or hemostasis factors, act antithrombotically by activation of the physiologic PMN mediated fibrinolysis; this thrombolysis is of selective nature, i.e . it does not impair the hemostasis system of the patient allowing the antithrombotic treatment in patients where the current risky thrombolytic treatment is contraindicated . The action of 1O(2) might be compared to the signaling and destroying gunfire of soldiers directed against bandits at night, resulting in an autorecruitment of the physiological inflammatory response . Chloramines (such as the mild and untoxic oxidant chloramine T (N-chloro-p-toluene-sulfonamide)) and their signaling and destroying reaction product 1O(2) might be promising new therapeutic agents against a multitude of up to now refractory diseases . Brain Behav Immun, 2003 Feb, 17(1), 13 - 9 Molecular insights on the cerebral innate immune system; Rivest S; All species need an immediate reply to the microbial pathogens that is part of an effective immune response and is essential for the survival of most organisms . This reply is known as the innate immune response and is characterized by the de novo production of mediators that either kill the microbes directly or activate phagocytic cells to ingest and kill them . The innate immune response can be driven through specific recognition systems, the best example being an interaction between the endotoxin lipopolysaccharide (LPS) and its receptors CD14 and Toll-like receptor 4 (TLR4) . For a long time, the brain was considered to be a privileged organ from an immunological point of view, owing to its inability to mount an immune response and process antigens . Although this is partly true, the CNS shows a well-organized innate immune reaction in response to systemic bacterial infection and cerebral injury . The CD14 and TLR4 receptors are constitutively expressed in the circumventricular organs (CVOs), choroid plexus and leptomeninges . Circulating LPS is able to cause a rapid transcriptional activation of genes encoding CD14 and TLR2, as well as a wide variety of pro-inflammatory molecules in CVOs . A delayed response to LPS takes place in cells located at boundaries of the CVOs and in microglia across the CNS . Therefore, without having direct access to the brain parenchyma, pathogens have the ability to trigger an innate immune reaction throughout cerebral tissue . This review presents evidence supporting the existence of such a system in the brain, which is finely regulated at the transcription level . Transient activation of this system is not harmful toward neuronal elements. Nat Rev Genet, 2003 Mar, 4(3), 195 - 205 Mice, microbes and models of infection; Buer J et al.; We urgently need animal models to study infectious disease . Mice are susceptible to a similar range of microbial infections as humans . Marked differences between inbred strains of mice in their response to pathogen infection can be exploited to analyse the genetic basis of infections . In addition, the genetic tools that are available in the laboratory mouse, and new techniques to monitor the expression of bacterial genes in vivo, make it the principal experimental animal model for studying mechanisms of infection and immunity. Indoor Air, 2003 Mar, 13(1), 65 - 73 The relation between growth of four microbes on six different plasterboards and biological activity of spores; Murtoniemi T et al.; Microbial growth on water-damaged building materials is commonly associated with adverse health effects in the occupants . We examined the growth of Stachybotrys chartarum, Aspergillus versicolor, Penicillium spinulosum, and Streptomyces californicus, isolated from water-damaged buildings, on six different brands of plasterboards . The microbial growth was compared with the biological activity of the spores, that is the potential to induce cytotoxicity and proinflammatory mediators in RAW264.7 macrophages . These results showed that the microbial growth on plasterboard depended on both the microbial strain and the brand of plasterboard used . The biological activity of spores appeared to be regulated by different growth conditions on plasterboards so that good microbial growth was associated with a low bioactivity of the spores, whereas the spores collected from plasterboard supporting only weak growth usually were biologically active . Cytotoxicity of either S . chartarum or A . versicolor did not correlate with any particular growth conditions or induced inflammatory responses . Instead, there were positive correlations between cytotoxicity and levels of induced proinflammatory cytokines for P . spinulosum and S . californicus . These data suggest that both the microbial growth on plasterboard and the resulting bioactivity of spores vary and might be affected by changing the growth conditions provided by the plasterboards. Anal Sci, 2003 Feb, 19(2), 289 - 94 Determination of thiamine in pharmaceutical preparations by sequential injection renewable surface solid-phase spectrofluorometry; Zhu H et al.; Fluorometric determination of thiamine requires the conversion of the analyte to fluorescent thiochrome by hexacyanoferrate(III) oxidation in alkaline solution and the isolation of the produced thiochrome from the reaction medium by solvent extraction . It was observed that thiochrome could be concentrated and separated from the reaction medium by solid-phase extraction . The thiochrome sorpted on the surface of octadecyl-alklylated poly{styrene/divinylbenzene} (C18-PS/DP) microbeads emitted strong fluorescence upon excitation, the maximum excitation and emission wavelengths being 385 nm and 433 nm, respectively . Based on this observation, a sequential injection renewable surface solid-phase spectrofluorometry was developed for the determination of thiamine . A sequential injection system on-line coupled to a chip-based flow-through cell was employed to handle the chemical reaction, bead injection and discharging, and adsorption of thiochrome . Solid-phase fluorometric detection was realized by coupling the chip-based flow-through cell to a spectrofluorometer with a multistrand bifurcated optical fiber . Under the optimized condition, a detection limit of 0.03 microg ml(-1) was achieved at the sample throughput of 30 h(-1) and consumption of 1 mg C18-PS/DP microbeads for each run . Eleven runs of a 2 microg ml(-1) thiamine standard solution gave a relative standard deviation of 1.0% . The developed approach was successfully applied for the determination of thiamine contents in pharmaceutical preparations. J Synchrotron Radiat, 2003 Mar 1, 10(Pt 2), 187 - 90 Epub 2003 Feb 27. Miniature ionization chamber detector developed for X-ray microprobe measurements; Kocsis M et al.; A windowless small ionization chamber detector has been developed for monitoring the intensity of the microbeam at the ID18F microprobe end-station of the European Synchrotron Radiation Facility . The small dimensions of the ionization chamber (10 mm along the beam direction and 5 mm perpendicular to it) make it possible to place it very close to the sample . A pinhole of diameter 50 microm was used for defining the entrance window of the ionization chamber; thus the small counter can be used as an order-selecting aperture while measuring simultaneously the intensity after the aperture . In the present work the technical characteristics, such as the current-voltage curve, stability and linearity, of the small monitor have been tested. Can J Gastroenterol, 2003 Feb, 17(2), 107 - 9 The establishment of a national tissue bank for inflammatory bowel disease research in Canada; Collins SM et al.; The Crohn's and Colitis Foundation of Canada (CCFC) has established a national bank for tissue, serum and blood from patients with inflammatory bowel disease (IBD) . Investigators from across the country submit material to the bank together with clinical data . Investigators may access their own patient information from the bank for their own study purposes, but the distribution of tissue is restricted to specific CCFC-funded projects . Currently, tissues are being collected from newly diagnosed, untreated IBD patients to support a recent initiative aimed at characterizing microbes in colonic and ileal biopsies from such patients . In the future, criteria for the submission of tissue will be tailored to specific research questions . This bank is believed to be the first national bank of its kind dedicated to research in Crohn's disease and ulcerative colitis J Invest Dermatol, 2003 Mar, 120(3), 372 - 8 Memory B cells specific for the NC16A domain of the 180 kDa bullous pemphigoid autoantigen can be detected in peripheral blood of bullous pemphigoid patients and induced in vitro to synthesize autoantibodies; Leyendeckers H et al.; Bullous pemphigoid is a subepidermal blistering disease characterized by the synthesis of autoantibodies against the 180 kDa and the 230 kDa bullous pemphigoid antigens . Whether autoimmunity is also reflected by the presence of circulating autoantigen-specific memory B cells is still a matter of debate . We used a new assay combining two-step immunomagnetic enrichment with multiparameter flow cytometry to detect and characterize bullous pemphigoid 180 kDa-specific IgG+ B cells in blood of bullous pemphigoid patients . In a first magnetic separation, B cells were isolated from peripheral blood mononuclear cells using releasable microbeads conjugated to a CD19 antibody . From pre-enriched B cells, bullous pemphigoid 180 kDa-specific cells were then positively selected using microbeads directly conjugated with a recombinant N-terminal fragment of the bullous pemphigoid 180 kDa ectodomain, containing the noncollagenous 16A domain, which was recently shown to harbor major epitopes of autoantibodies in bullous pemphigoid sera . Noncollagenous 16A domain-specific IgG+ B cells were detectable in blood of most, if not all patients with serum autoantibodies against the noncollagenous 16A domain . The specificity of the cells was confirmed by in vitro differentiation into antibody-forming cells and analysis of the culture supernatant for the presence of noncollagenous 16A domain-specific IgG antibodies . All noncollagenous 16A domain-specific IgG+ B cells showed a clear memory immunophenotype . Noncollagenous 16A domain-specific IgG+ memory B cells may be crucial for continuous noncollagenous 16A domain-specific autoantibody production and/or play a part as antigen-presenting cells for priming and restimulation of bullous pemphigoid 180 kDa-specific T helper cells. Infect Control Hosp Epidemiol, 2003 Feb, 24(2), 139 - 41 Microbial aerosol contamination of dental healthcare workers' faces and other surfaces in dental practice; Prospero E et al.; The purpose of this study was to focus attention on the need to adopt infection control procedures in dentistry . The quantitative and qualitative bacterial contamination of dental healthcare workers' faces and other surfaces in dental practice was determined . Oral fluids become aerosolized during dentistry and oral microbes have been used as the markers of their spread that may carry blood-borne pathogens. Microsc Microanal, 2001 Mar, 7(2), 150 - 158 Wavelength Dispersive Spectrometer and Energy Dispersive Spectrometer Automation: Past and Future Development; McCarthy JJ et al.; As part of the Microbeam Analysis Society (MAS) symposium marking 50 years of electron microprobe analysis, this article reviews the important advances made over the decades to the automation of data collection and computerized analysis of data from the electron microprobe . Out of many innovations that contributed to the advance of microprobe automation, we have chosen to focus on a few developments that the authors feel represent the major trends in advancement of the "state of the art" of this instrumentation . After providing brief summaries of the three generations of advances in the hardware and software of automation systems, several key applications developments are described, followed by our prediction of which current developments may impact the future automation of the microprobe. Biochim Biophys Acta, 2003 Mar 17, 1620(1-3), 218 - 24 Lead-revealed lipid organization in human hair; Bertrand L et al.; Human hair lipids form a complex mixture of composition close to that of sebum . Part of these lipids appears in an organized state that has been studied by diffraction techniques in the literature . Nevertheless, information on the structure of these lipids remains very scarce due to their low contribution to global hair diffraction pattern . Here we show that appropriate lead treatment considerably enhances organized lipid features observed by microbeam synchrotron radiation diffraction experiments . We attribute these features to the formation of lead soaps of free fatty acids . Specific orientation of hair "lipid crystals" in planes parallel to the hair axis is clearly demonstrated . Inclusion of these lipids in the bulk of the hair shaft is shown by diffraction experiments following removal of the cuticular outermost layer of hair . Moreover, microfluorescence and diffraction experiments are consistent with part of the lipids being present as calcium soaps in native hair . We therefore consider lead fixation as a powerful tool to evaluate the lipid organization in human hair for medical, environmental and archaeological purposes, including lead poisoning. Surg Infect (Larchmt), 2001 Summer, 2(2), 103 - 10; discussion 110-2 Hazardous crossing: immunosuppression and nosocomial infections in solid organ transplant recipients; Dunn DL; BACKGROUND: During the past decade, ever-increasing numbers of patients have undergone renal, pancreatic, small bowel, hepatic, cardiac, or lung transplantation as therapy for various types of renal disease requiring dialytic therapy . Indications for solid organ transplantation include type I and, rarely, type II diabetes mellitus; hyperalimentation-dependent short gut syndrome; and formerly fatal liver, cardiac, or pulmonary failure . Significant improvements in patient and allograft survival have been observed in all categories . Unfortunately, despite such improved results, the risks of infection related to immunosuppression continue to be substantial . METHODS: Review of pertinent studies from the English literature . RESULTS: Suppression of host defenses by exogenous immunosuppressive agents renders patients susceptible to invasion by either residen