Appl Microbiol Biotechnol, 2001 Oct, 57(3), 287 - 93 Photobioreactors: production systems for phototrophic microorganisms; Pulz O; Microalgae have a large biotechnological potential for producing valuable substances for the feed, food, cosmetics and pharmacy industries as well as for biotechnological processes . The design of the technical and technological basis for photobioreactors is the most important issue for economic success in the field of phototrophic biotechnology . For future applications, open pond systems for large-scale production seem to have a lower innovative potential than closed systems . For high-value products in particular, closed systems of photobioreactors seem to be the more promising field for technical developments despite very different approaches in design. Appl Microbiol Biotechnol, 2001 Oct, 57(3), 274 - 81 Introduction of specialty functions by the position-specific incorporation of nonnatural amino acids into proteins through four-base codon/anticodon pairs; Sisido M et al.; Position-specific incorporation of nonnatural amino acids into proteins (nonnatural mutagenesis) via an in vitro protein synthesizing system was applied to incorporate a variety of amino acids carrying specialty side groups . A list of nonnatural amino acids thus far successfully incorporated through in vitro translation systems is presented . The position of nonnatural amino acid incorporation was directed by four-base codon/anticodon pairs such as CGGG/CCCG and AGGU/ACCU . The four-base codon strategy was more efficient than the amber codon strategy and could incorporate multiple nonnatural amino acids into single proteins . This multiple mutagenesis will find wide applications, especially in building paths of electron transfer on proteins . The extension of translation systems by the introduction of nonnatural amino acids, four-base codon/anticodon pairs, orthogonal tRNAs, and artificial aminoacyl tRNA synthetases, is a promising approach towards the creation of "synthetic microorganisms" with specialty functions. Biosci Biotechnol Biochem, 2001 Oct, 65(10), 2364 - 7 Characterization of the RcsC-->YojN-->RcsB phosphorelay signaling pathway involved in capsular synthesis in Escherichia coli; Chen MH et al.; Escherichia coli and other enteric microorganisms produce an extracellular polysaccharide capsule, called colanic acid, under certain environmental conditions . This capsular synthesis is regulated by the RcsC (sensor kinase)-->YojN (phosphotransfer intermediate)-->RcsB (response regulator) phosphorelay signal transduction under certain growth conditions . Nonetheless, little is known about signals that exaggerate the Rcs-system . To gain insight into signals that activate the Rcs-system, here we searched for genes that activate the Rcs-system, provided that those on a multicopy plasmid were introduced into E . coli . We identified several such genes, namely, rcsB, rcsA, djlA, lolA, and ompG . The DjlA, LolA, and OmpG proteins are particularly interesting in that they are all located on the cell surface, where the primary sensor RcsC histidine-kinase is localized . Implications of these findings are discussed with special reference to the mechanism by which RcsC perceives external signals. J Environ Sci Health B, 2001 Nov, 36(6), 709 - 27 Isoproturon degradation as affected by the growth of two algal species at different concentrations and pH values; Mostafa FI et al.; Metabolism of {14C-u-phenyl}isoproturon {3-(4-isopropylphenyl)-1,1-dimethylurea} by two soil and freshwater microorganisms, green alga Chlorella kesslerei and cyanobacterium Anabaena inaequalis, was studied as a function of pH, pesticide concentration, and incubation time . Metabolized isoproturon, in the media, ranged from 0% (Chlorella at pH 5.5 after 1 d) to 22% (Anabaena at pH 5.5 after 10 d) . Twenty-five percent faster degradation of isoproturon by Anabaena occurred at pH 5.5 versus pH 7.5, when measured over 10 d . Increased 14C incorporation into tissue, with time and at lower pH, was due mainly to bioaccumulation of {14C}isoproturon and/or its metabolites in the cells . Metabolic degradation resulted in four identifiable (by TLC) metabolites . Based on this, a degradation pathway is proposed, involving mono- and di-N-demethylation, hydroxylation of the isopropyl moiety, and hydrolysis to 4-isopropylaniline . Similarity in the metabolites produced suggests that the enzyme systems responsible for metabolizing isoproturon are almost identical in both photosynthetic micro-algae. Environ Sci Technol, 2001 Nov 15, 35(22), 4449 - 56 Further biogeochemical characterization of a trichloroethene-contaminated fractured dolomite aquifer: electron source and microbial communities involved in reductive dechlorination; Hohnstock-Ashe AM et al.; A recent article presented geochemical and microbial evidence establishing metabolic adaptation to and in-situ reductive dechlorination of trichloroethene (TCE) in a fractured dolomite aquifer . This study was designed to further explore site conditions and microbial populations and to explain previously reported enhancement of reductive dechlorination by the addition of pulverized dolomite to laboratory microcosms . A survey of groundwater geochemical parameters (chlorinated ethenes, ethene, H2, CH4, DIC, DOC, and delta13C values for CH4, DIC, and DOC) indicated that in situ reductive dechlorination was ongoing and that an unidentified pool of organic carbon was contributing, likely via microbial respiration, to the large and relatively light on-site DIC pool . Petroleum hydrocarbons associated with the dolomite rock were analyzed by GC/MS and featured a characteristically low delta13C value . Straight chain hydrocarbons were extracted from the dolomite previously found to stimulate reductive dechlorination; these were particularly depleted in hexadecane (HD) . Thus, we hypothesized that HD and related hydrocarbons might be anaerobically respired and serve both as the source of on-site DIC and support reductive dechlorination of TCE . Microcosms amended with pulverized dolomite demonstrated reductive dechlorination, whereas a combusted dolomite amendment did not . HD-amended microcosms were also inactive . Therefore, the stimulatory factor in the pulverized dolomite was heat labile, but that component was not HD . Amplified Ribosomal DNA Restriction Analysis (ARDRA) of the microbial populations in well waters indicated that a relatively low diversity, sulfur-transforming community outside the plume was shifted toward a high diversity community including Dehalococcoides ethenogenes-type microorganisms inside the zone of contamination . These observations illustrate biogeochemical intricacies of in situ reductive dechlorination reactions. Ying Yong Sheng Tai Xue Bao, 2001 Apr, 12(2), 309 - 14 {Coarse woody debris and its function in forest ecosystem}; Hou P et al.; Coarse woody debris (CWD) is an important structural and functional element in forest ecosystem . In this paper, the definition, dynamics, and role of CWD in a forest ecosystem were overviewed . CWD include all woody debris above and under the ground with a diameters > or = 2.5 cm, and mainly comes from the dead trees resulted from competition and disturbances . The biomass of CWD changes like "U" form along with the development of a forest community . The decay rate of CWD is determined by the compound course of the respiration and natural fragmentation . Insects and microorganisms play an important role in the course . CWD basically has two functions in an ecosystem . One is as the nutrition pool for some living creatures, and the other is that the large CWD can form some special habitats for animals and plants . Conclusively these two functions are helpful to reserve the biodiversity and the integrity of ecological process in a natural ecosystem . Gaps are formed while dead trees falling down, and all gaps in a forest succeed one another randomly in the development of a forest ecosystem, which pushes the inner circulation of the forest . Because of the vital roles of CWD in a forest ecosystem, much more attention should be paid in the management of forest ecosystem. J Biol Chem, 2002 Mar 8, 277(10), 8194 - 201 Epub 2001 Dec 26. A novel tryptophan synthase beta-subunit from the hyperthermophile Thermotoga maritima . Quaternary structure, steady-state kinetics, and putative physiological role; Hettwer S et al.; Tryptophan synthase catalyzes the last two steps in the biosynthesis of the amino acid tryptophan . The enzyme is an alpha beta beta alpha complex in mesophilic microorganisms . The alpha-subunit (TrpA) catalyzes the cleavage of indoleglycerol phosphate to glyceraldehyde 3-phosphate and indole, which is channeled to the active site of the associated beta-subunit (TrpB1), where it reacts with serine to yield tryptophan . The TrpA and TrpB1 proteins are encoded by the adjacent trpA and trpB1 genes in the trp operon . The genomes of many hyperthermophilic microorganisms, however, contain an additional trpB2 gene located outside of the trp operon . To reveal the properties and potential physiological role of TrpB2, the trpA, trpB1, and trpB2 genes of Thermotoga maritima were expressed heterologously in Escherichia coli, and the resulting proteins were purified and characterized . TrpA and TrpB1 form the familiar alpha beta beta alpha complex, in which the two different subunits strongly activate each other . In contrast, TrpB2 forms a beta(2)-homodimer that has a high catalytic efficiency k(cat)/K(m)(indole) because of a very low K(m)(indole) but does not bind to TrpA . These results suggest that TrpB2 acts as an indole rescue protein, which prevents the escape of this costly hydrophobic metabolite from the cell at the high growth temperatures of hyperthermophiles. Obstet Gynecol, 2001 Dec, 98(6), 1080 - 8 Amniotic fluid infection, cytokines, and adverse outcome among infants at 34 weeks' gestation or less; Hitti J et al.; OBJECTIVE: We examined the hypothesis that amniotic fluid (AF) infection and elevated cytokine concentrations may cause neonatal injury beyond that expected solely from prematurity . METHODS: The effects of exposure to AF infection and elevated cytokine concentrations were measured in 151 infants born to afebrile women in preterm labor with intact membranes at less than or equal to 34 weeks' gestation . Amniotic fluid was collected by amniocentesis for culture and determination of tumor necrosis factor-alpha and interleukin-6 . Cytokine concentrations, stratified by AF infection, were compared for three gestational age groups . We then examined the associations between a positive AF culture or elevated AF tumor necrosis factor-alpha concentration and adverse neonatal outcomes, adjusted for birth weight . RESULTS: Amniotic fluid from 45 (30%) of 151 pregnancies had microorganisms, an elevated tumor necrosis factor-alpha concentration, or both . Amniotic fluid cytokine concentrations were significantly higher among women in preterm labor at less than or equal to 30 weeks, compared with 31-34 weeks . Nine of 11 infants who died at less than or equal to 24 hours of age had AF infection or elevated AF tumor necrosis factor-alpha . For the 140 surviving infants, AF infection and/or an elevated AF tumor necrosis factor-alpha was associated with respiratory distress syndrome (adjusted odds ratio {OR} 1.7), grade 3-4 intraventricular hemorrhage (adjusted OR 2.2), necrotizing enterocolitis (adjusted OR 1.8), and multiple organ dysfunction (adjusted OR 3.0) . CONCLUSION: Among infants born at less than or equal to 34 weeks to women who have intact membranes and are initially afebrile, those exposed to AF bacteria or cytokines have more adverse neonatal outcomes than unexposed infants of similar birth weight. Z Gastroenterol, 2001 Dec, 39(12), 1015 - 22 {Intestinal tuberculosis: Easier overlooked than diagnosed}; Goke MN et al.; Intestinal tuberculosis: Easier overlooked than diagnosed.The medical history of two Asian immigrants suffering from intestinal tuberculosis demonstrates the difficulties in finding the correct diagnosis . Intestinal tuberculosis resembles Crohn's disease with regard to clinical symptoms, macroscopic and microscopic intestinal findings . Sonographic, radiologic, endoscopic, and histological examinations facilitate distinguishing both entities . Diagnosis of intestinal tuberculosis is made by identification of the causative microorganism in tissue specimens . As this may be difficult and time-consuming, a therapeutic trial with anti-tuberculous agents may be warranted. Can Respir J, 2001 Nov-Dec, 8(6), 457 - 9 An unusual example of Aspergillus species lung disease; Pardy RL et al.; A 37-year-old man developed persistent hemoptysis after sustaining a gunshot wound to the right shoulder and lung . A right upper lobectomy was performed, in which Aspergillus species microorganisms were identified within retained bullet fragments . The role of infected bullet fragments in the pathogenesis of hemoptysis in this patient is discussed. Curr Opin Hematol, 2002 Jan, 9(1), 30 - 5 Leukocyte adhesion deficiency syndromes: adhesion and tethering defects involving beta 2 integrins and selectin ligands; Bunting M et al.; Leukocyte adhesion deficiency (LAD) syndromes are failures of innate host defenses against bacteria, fungi, and other microorganisms resulting from defective tethering, adhesion, and targeting of myeloid leukocytes to sites of microbial invasion . LAD I and variant LAD I syndromes are caused by mutations that impair expression or function of integrins of the beta 2 class (CD11/CD18 integrins, or "leukocyte" integrins) . In contrast, subjects with LAD II have similar clinical features but intact leukocyte integrin expression and function . The molecular basis for LAD II is defective glycosylation of ligands on leukocytes recognized by the selectin family of adhesion molecules as well as defective glycosylation of other glycoconjugates . The defect has recently been attributed to mutations in a novel fucose transporter localized to the Golgi apparatus . Establishing the molecular basis for LAD syndromes has generated insights into mechanisms of leukocyte accumulation relevant to a broad variety of immunodeficiency syndromes as well as to diseases and disorders of unregulated inflammation that result in tissue damage. Int Arch Allergy Immunol, 2001 Nov, 126(3), 248 - 56 Highly active antiretroviral therapy responders exhibit a phenotypic lymphocyte pattern comparable to that of long-term nonprogressors; Knapp S et al.; BACKGROUND: The implementation of highly active antiretroviral therapy (HAART) in patients with progressive HIV-1 disease has resulted in a marked reduction of HIV-1-associated morbidity and mortality . In fact, the risk of HAART responders to develop opportunistic infections becomes similar to that of long-term nonprogressors (LTNPs) . METHODS: Reasoning that HAART may ultimately have consequences on both the quantity and quality of immune responses of a HIV-1-infected person, we assessed CD4+ and CD8+ T cell subsets in HAART recipients over a time period of 15 months and compared them to the lymphocyte phenotype of LTNPs and healthy controls . Evaluations included quantitative determinations of memory (CD45RO+CD62L-), naive (CD45RO-CD62L+), effector (CD27-, CD28-) and activated (HLA-DR+, CD38+, CD95+) CD4+ and CD8+ lymphocytes . The T cell function was assayed by skin tests . RESULTS: Compared to healthy persons, treatment-naive patients with progressive disease exhibited a considerable reduction of CD4+ T cells with many of the remaining T cells showing signs of activation at baseline . CD8+ T cells were greatly increased in number, mainly because of an expansion of CD28- effector and memory CD8+ T cells . LTNPs, in contrast, had stable CD4+ and elevated CD8+ T cell counts, the latter being mainly due to a marked increase in CD27- effector cells . Essentially, the same immunophenotype was seen in HAART responders after 15 months of treatment when compared to LTNPs . CONCLUSIONS: It is tempting to speculate that a HAART-induced reduction in viral load may influence the immune system's capacity to mount protective responses to pathogenic microorganisms . J Biol Chem, 2002 Feb 22, 277(8), 6207 - 13 Epub 2001 Dec 19. Trialysin, a novel pore-forming protein from saliva of hematophagous insects activated by limited proteolysis; Amino R et al.; We have characterized a pore-forming lytic protein from the saliva of the hematophagous insect Triatoma infestans, a vector of Chagas disease . This protein, named trialysin, has 22 kDa and is present in the saliva at about 200 microg/ml . Purified trialysin forms voltage-dependent channels in planar lipid bilayers with conductance of 880 +/- 40 pS . It lyses protozoan parasites and bacteria indicating that it has a role in the control of microorganism growth in the salivary glands . At higher concentrations, but below those found in saliva, trialysin can also permeabilize and lyse mammalian cells, suggesting that it might also facilitate insect blood feeding by interfering with the cell response of the host . The translated cDNA sequence of trialysin shows a basic, lysine-rich protein in which the N-terminal region is predicted to form an amphipathic alpha-helical structure with positive charges on one side and hydrophobic amino acids on the opposite side . A synthetic peptide corresponding to this cationic amphipathic alpha-helix induces protozoan lysis and mammalian cell permeabilization, showing that this region is involved in lytic activity . However, the lytic peptide G6V32 is 10-fold less efficient than trialysin in lysing parasites and 100-fold less efficient in permeabilizing mammalian cells . Trialysin activity is about 10-fold reduced in salivary gland homogenates prepared in the presence of an irreversible serine-protease inhibitor . Since trialysin precursor contains an anionic pro-sequence of 33 amino acids contiguous to the cationic amphipathic putative alpha-helix, we propose that removal of the acidic pro-sequence by limited proteolysis activates trialysin by exposing this lytic basic amphipathic motif. FEMS Microbiol Lett, 2001 Dec 18, 205(2), 247 - 52 Sulfur compound production by Geotrichum candidum from L-methionine: importance of the transamination step; Bonnarme P et al.; L-methionine degradation products and catabolic enzymatic activities involved in methanethiol generation were investigated in Geotrichum candidum GcG . L-methionine was easily degraded by G . candidum and the transamination product, 4-methylthio-2-oxobutyric acid (KMBA), was found to transiently accumulate . In parallel, considerable L-methionine aminotransferase activity was found in this microorganism . L-methionine and KMBA demethiolating activities were also detected . The degradation of KMBA corresponded to an overall increase in the production of volatile sulfur compounds . These results show that the transamination pathway is of major importance in the initial breakdown of L-methionine by this cheese-ripening microorganism. Infect Immun, 2002 Jan, 70(1), 257 - 67 Fimbria-dependent activation of cell adhesion molecule expression in Porphyromonas gingivalis-infected endothelial cells; Khlgatian M et al.; Porphyromonas gingivalis is an oral pathogen that has recently been associated with chronic inflammatory diseases such as atherosclerosis . The strength of the epidemiological associations of P . gingivalis with atherosclerosis can be increased by the demonstration that P . gingivalis can initiate and sustain growth in human vascular cells . We previously established that P . gingivalis can invade aortic, heart, and human umbilical vein endothelial cells (HUVEC), that fimbriae are required for invasion of endothelial cells, and that fimbrillin peptides can induce the expression of the chemokines interleukin 8 and monocyte chemotactic protein . In this study, we examined the expression of surface-associated cell adhesion molecules on endothelial cells in response to P . gingivalis infection by fluorescence-activated cell sorting FACS analysis and confocal microscopy . Coculture of HUVEC with P . gingivalis strain 381 or A7436 resulted in the induction in the expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and P- and E-selectins, which was maximal at 48 h postinfection . In contrast, we did not observe induction of ICAM-1, VCAM-1, or P- or E-selectin expression in HUVEC cultured with the noninvasive P . gingivalis fimA mutant DPG3 or when P . gingivalis was incubated with fimbrillin peptide-specific anti-sera prior to the addition to HUVEC . Furthermore, the addition of a peptide corresponding to the N-terminal domain of fimbrillin to HUVEC resulted in an increase in ICAM-1, VCAM-1, and P- and E-selectins, which was maximal at 48 h and similar to that observed for live P . gingivalis . Treatment of P . gingivalis-infected HUVEC with cytochalsin D, which prevented P . gingivalis invasion, also resulted in the inhibition of ICAM-1, VCAM-1, or P- and E-selectin expression . Taken together, these results indicate that active P . gingivalis invasion of HUVEC mediated via the major fimbriae stimulates surface-associated cell adhesion molecule expression . Stimulation of adhesion molecules involved in the recruitment of leukocytes to sites of inflammation by P . gingivalis may play a role in the pathogenesis of systemic inflammatory diseases associated with this microorganism, including atherosclerosis. Infect Immun, 2002 Jan, 70(1), 211 - 7 Biological characterization of lipopolysaccharide from Treponema pectinovorum; Kesavalu L et al.; This study investigated the endotoxic and biological properties of purified lipopolysaccharide (LPS) isolated from an oral spirochete, Treponema pectinovorum . Endotoxicity, measured by Limulus amoebocyte lysate kinetic assay, showed that the LPS contained 1.28 endotoxin units per microg of purified LPS, which was approximately 4,000 times less than Escherichia coli O55:B5 LPS . To determine in vivo endotoxicity, LPS responder mice were administered LPS following galactosamine (GalN) sensitization . The LPS induced neither endotoxic symptoms nor lethality for 96 h, suggesting negligible or very low endotoxicity . In contrast, infection with live T . pectinovorum induced 100% lethality within 12 h in GalN-sensitized LPS responder mice, indicating an endotoxin-like property of this treponeme . Heat-killed microorganisms exhibited no lethality in GalN-sensitized mice, suggesting that the endotoxicity was associated with heat-labile components . To determine cytokine and chemokine induction by LPS, human gingival fibroblasts were stimulated and secretion of interleukin 1beta (IL-1beta), granulocyte-macrophage colony-stimulating factor, gamma interferon, IL-6, IL-8, and monocyte chemoattractant protein 1 (MCP-1) was assessed . The purified LPS induced significant amounts of only IL-6, IL-8, and MCP-1, although they were substantially lower than levels after challenge with live T . pectinovorum . After injection of LPS or live or heat-killed T . pectinovorum, serum was collected from mice and analyzed for proinflammatory cytokines IL-1beta, tumor necrosis factor alpha (TNF-alpha), and IL-6 . LPS induced only IL-6 consistently . Both live and heat-killed T . pectinovorum induced serum IL-6, which was higher than the level detected following LPS administration . Importantly, live bacteria elicited systemic TNF-alpha and IL-1beta levels similar to those induced by a lethal dose of live E . coli O111 . The results indicated that T . pectinovorum LPS has very low or no endotoxicity, although it can elicit low levels of cytokines from host cells . In contrast to the LPS, live T . pectinovorum demonstrated in vivo toxicity, which was associated with serum IL-1beta, TNF-alpha, and IL-6, suggesting an endotoxin-like property of a heat-labile molecule(s) of the spirochete. Infect Immun, 2002 Jan, 70(1), 19 - 26 Serum stimulates growth of and proteinase secretion by Aspergillus fumigatus; Gifford AH et al.; Serum contains iron-binding proteins, which inhibit the growth of most pathogenic microorganisms, including fungi . The purpose of this research was to investigate the effect of serum on growth of the opportunistic fungal pathogen Aspergillus fumigatus . Supplementing minimal essential medium (MEM) with up to 80% human serum or up to 80% fetal bovine serum (FBS) stimulated growth and increased the amount of A . fumigatus dry biomass approximately fourfold . In addition, a 100-fold increase in proteinase secretion, as measured by azocasein hydrolysis, was observed when 10% human serum or 10% FBS was added to MEM . The fungal proteinases secreted in serum-containing media were shown to degrade (3)H-labeled basal lamina proteins . The factor in serum that stimulated proteinase secretion was larger than 10 kDa and was 85% inactivated when the serum was heated for 30 min at 66 degrees C . The proportions of proteinases of each catalytic class secreted by A . fumigatus in the presence of serum were different from the proportions secreted in media containing single proteins . Proteinase secretion did not result from increased protein concentration in the medium per se because bovine serum albumin (BSA) at a concentration equivalent to the concentration of serum produced only 20% of the proteinase activity per milligram (dry weight) that was produced by FBS . Addition of BSA plus 100 microM FeCl(3) to MEM resulted in the same level of growth as addition of serum, indicating that a combination of nutritional factors in serum may stimulate growth . However, the level of proteinase secretion was still only 30% of the level observed with FBS . These data indicate that serum does not inhibit the growth of A . fumigatus and that the nutrients in serum result in high levels of proteinase secretion, potentially increasing the invasiveness of this species. Phytother Res, 2001 Nov, 15(7), 638 - 42 Evaluation of the flora of Puerto Rico for in vitro antiplasmodial and antimycobacterial activities; Antoun MD et al.; The emergence of resistant strains of Plasmodium falciparum and Mycobacterium tuberculosis underscores the need for novel drugs that are effective against these microorganisms . As part of our screening programme of the flora of Puerto Rico, we tested a number of ethanol extracts of higher plants for antiplasmodial and antimycobacterial activities . A total of 40 extracts belonging to 23 plant families and 37 species were tested for antiplasmodial activity . Five extracts demonstrated activity against Plasmodium falciparum in vitro (50%-100% parasite suppression at 5 microg/mL) . Another 63 extracts belonging to 30 plant families and 50 species were tested in vitro against Mycobacterium tuberculosis . Two extracts were found to be active, Ficus citrifolia and Pisonia borinquena (85% or more inhibition of microbial growth at 100 microg/mL of extract) . J Agric Food Chem, 2001 Dec, 49(12), 5999 - 6005 Action of protein-glutaminase on alpha-lactalbumin in the native and molten globule states; Gu YS et al.; The action of a novel protein-glutaminase from microorganisms on alpha-lactalbumin was investigated . When alpha-lactalbumin in the native state was incubated with protein-glutaminase, the deamidation proceeded gradually, i.e., the deamidation degree increased to 20% and 55% after 4 and 24 h, respectively . The transformation of alpha-lactalbumin from the native state to the molten globule state caused an increase in the rate of the enzyme-catalyzed deamidation, particularly in the early stage . The deamidation degree for the molten globule state reached 61% after 4 h, followed by a gradual increase to 66% after 24 h . CD spectral analyses of deamidated alpha-lactablumin revealed that the stability of the tertiary structure of alpha-lactablumin was closely related to the degree of deamidation, whereas the secondary structure was not affected by deamidation . Glutamine residues in alpha-lactalbumin to be modified by protein-glutaminase were identified as Gln{39}, {43}, {54}, and {65} . Conformational characteristics of the amino acid sequence around these glutamine residues are discussed. J Bacteriol, 2002 Jan, 184(1), 183 - 90 Regulation of the acuF gene, encoding phosphoenolpyruvate carboxykinase in the filamentous fungus Aspergillus nidulans; Hynes MJ et al.; Phosphoenolpyruvate carboxykinase (PEPCK) is a key enzyme required for gluconeogenesis when microorganisms grow on carbon sources metabolized via the tricarboxylic acid (TCA) cycle . Aspergillus nidulans acuF mutants isolated by their inability to use acetate as a carbon source specifically lack PEPCK . The acuF gene has been cloned and shown to encode a protein with high similarity to PEPCK from bacteria, plants, and fungi . The regulation of acuF expression has been studied by Northern blotting and by the construction of lacZ fusion reporters . Induction by acetate is abolished in mutants unable to metabolize acetate via the TCA cycle, and induction by amino acids metabolized via 2-oxoglutarate is lost in mutants unable to form 2-oxoglutarate . Induction by acetate and proline is not additive, consistent with a single mechanism of induction . Malate and succinate result in induction, and it is proposed that PEPCK is controlled by a novel mechanism of induction by a TCA cycle intermediate or derivative, thereby allowing gluconeogenesis to occur during growth on any carbon source metabolized via the TCA cycle . It has been shown that the facB gene, which mediates acetate induction of enzymes specifically required for acetate utilization, is not directly involved in PEPCK induction . This is in contrast to Saccharomyces cerevisiae, where Cat8p and Sip4p, homologs of FacB, regulate PEPCK as well as the expression of other genes necessary for growth on nonfermentable carbon sources in response to the carbon source present . This difference in the control of gluconeogenesis reflects the ability of A . nidulans and other filamentous fungi to use a wide variety of carbon sources in comparison with S . cerevisiae . The acuF gene was also found to be subject to activation by the CCAAT binding protein AnCF, a protein homologous to the S . cerevisiae Hap complex and the mammalian NFY complex. J Arthroplasty, 2001 Dec, 16(8), 1010 - 7 Ultrasound for diagnosis of infection in revision total hip arthroplasty; Eisler T et al.; Eighty consecutive patients (85 hips; 43 women; median age, 74 years {range, 33-90 years}) underwent a revision total hip arthroplasty . Preoperatively and guided by ultrasound, biopsy specimens of the joint pseudocapsule were taken, and joint fluid was aspirated for culture . Capsule morphology was investigated with light microscopy . When septic loosening was defined as 2 intraoperative cultures yielding the same microorganism, the prevalence was 12% . Sensitivity of the capsule biopsy cultures was 67%; specificity, 68%; positive predictive value, 22%; and negative predictive value, 94% . Joint fluid was often sparse and always falsely sterile . One specimen from a hip with septic loosening showed histologic changes (> or =3 foci, each with > or =3 plasma cells/high-power field) consistent with chronic infection . The remaining 8 septic loosenings eluded histologic detection, yielding 11% sensitivity . All aseptic loosenings were classified correctly (specificity 100%) . Positive and negative predictive values were 100% and 89% . Ultrasound-guided aspiration and capsule biopsy with cultures and histology does not seem to be sufficiently accurate in the preoperative diagnosis of infected total hip arthroplasty. Respir Physiol, 2001 Dec, 129(1-2), 231 - 45 Acid detection by taste receptor cells; DeSimone JA et al.; Sourness is a primary taste quality that evokes an innate rejection response in humans and many other animals . Acidic stimuli are the unique sources of sour taste so a rejection response may serve to discourage ingestion of foods spoiled by acid producing microorganisms . The investigation of mechanisms by which acids excite taste receptor cells (TRCs) is complicated by wide species variability and within a species, apparently different mechanisms for strong and weak acids . The problem is further complicated by the fact that the receptor cells are polarized epithelial cells with different apical and basolateral membrane properties . The cellular mechanisms proposed for acid sensing in taste cells include, the direct blockage of apical K(+) channels by protons, an H(+)-gated Ca(2+) channel, proton conduction through apical amiloride-blockable Na(+) channels, a Cl(-) conductance blocked by NPPB, the activation of the proton-gated channel, BNC-1, a member of the Na(+) channel/degenerin super family, and by stimulus-evoked changes in intracellular pH . Acid-induced intracellular pH changes appear to be similar to those reported in other mammalian acid-sensing cells, such as type-I cells of the carotid body, and neurons found in the ventrolateral medulla, nucleus of the solitary tract, the medullary raphe, and the locus coceuleus . Like type-I carotid body cells and brainstem neurons, isolated TRCs demonstrate a linear relationship between intracellular pH (pH(i)) and extracellular pH (pH(o)) with slope, DeltapH(i)/DeltapH(o) near unity . Acid-sensing cells also appear to regulate pH(i) when intracellular pH changes occur under iso-extracellular pH conditions, but fail to regulate their pH when pH(i) changes are induced by decreasing extracellular pH . We shall discuss the current status of proposed acid-sensing taste mechanisms, emphasizing pH-tracking in receptor cells. Curr Opin Chem Biol, 2001 Dec, 5(6), 677 - 82 Chemistry and biology of arabinofuranosyl- and galactofuranosyl-containing polysaccharides; Houseknecht JB et al.; Polysaccharides containing galactofuranosyl and arabinofuranosyl residues are key components of many microorganisms . Recent investigations have provided a greater understanding of the biosynthetic pathways by which these glycans are assembled . Concomitant with these biochemical studies, an increasing number of chemical syntheses of oligofuranosides have been reported and new methods for their assembly have been developed. Xenotransplantation, 2001 Nov, 8(4), 310 - 6 Porcine endogenous retroviruses (PERVs): generation of specific antibodies, development of an immunoperoxidase assay (IPA) and inhibition by AZT; Stephan O et al.; Xenotransplantation may be associated with the risk of transmission of microorganisms . In particular, the porcine endogenous retroviruses (PERV) have raised concerns as in vitro experiments show susceptibility of human cells for PERV infection . However, it remains unclear whether PERVs are able to infect transplant recipients in vivo and whether they are pathogenic . It is therefore essential that the risks are evaluated and for this purpose specific and sensitive screening methods for PERVs have to be developed . We generated specific antibodies against all major structural proteins of PERV and developed several assays which allow antibodies against PERV to be detected as indirect evidence of infection . For direct detection of PERV production, reverse transcriptase (RT) assays were used . PCR methods were used to detect provirus integration and the presence of viral mRNA . Here we present an immunoperoxidase assay (IPA), which would allow the detection of viral proteins in infected cells as well as antibodies against PERV in the serum of an infected host . The specificity of the sera used in the assay was determined by several methods, including immunoelectron microscopy, and the sensitivity of the assay was compared with other methods . This IPA was used to detect PERV infection in in vitro experiments for evaluation of the virus host range, for titrating the virus and for testing anti-viral properties of AZT . Using this method it was shown that AZT inhibits replication of PERV . This IPA may be very useful for the surveillance of preclinical and clinical xenotransplantations. Pediatr Dermatol, 2001 Sep-Oct, 18(5), 411 - 4 Acute juvenile pityriasis rubra pilaris: a superantigen mediated disease? Betlloch I, Ramon R, Silvestre JF, Carnero L, Albares MP, Banuls J. Juvenile acute pityriasis rubra pilaris (JAPRP) is a form of pityriasis rubra pilaris (PRP) with particular clinical characteristics and course . It is usually preceded by an infectious condition . We report a boy, initially thought to have Kawasaki disease, and subsequently diagnosed as having JAPRP, who made a satisfactory recovery . In this case, prior antibiotic treatment made it impossible to show the presence of any microorganism . However, the clinical characteristics of these patients and the similarities with other disorders involving the skin that are mediated by superantigens led us to think that these antigens may be involved in the development of this disease . Also, in view of the obvious differences between JAPRP and the other PRP, we suggest that, in the future this disorder may be considered a separate entity as a reactive exanthem. Oral Microbiol Immunol, 2001 Dec, 16(6), 326 - 31 The purification and characterization of an 88-kDa Porphyromonas endodontalis 35406 protease; Rosen G et al.; A Porphyromonas endodontalis ATCC 35406 protease was purified from Triton X-114 cell extracts by preparative SDS-PAGE followed by electroelution . The purified enzyme exhibits a molecular size of 88 kDa and was dissociated into two polypeptides of 43 and 41 kDa upon heating in the presence of sodium dodecyl sulfate with or without a reducing agent . The protease (pH optimum 7.5-8.0) degraded the extracellular matrix proteins fibrinogen and fibronectin . Collagen IV was also degraded at 37 degrees C but not at 28 degrees C . The protease also cleaved the bioactive peptide angiotensin at amino acid residue phenylalanine-8 and tyrosine-4 but failed to hydrolyze bradykinin, vasopressin and synthetic chromogenic substrates with phenylalanine or tyrosine at the P1 position . In addition, two peptidases were detected in P . endodontalis cells: a proline aminopeptidase that remained associated with the cell pellet after detergent extraction and peptidase/s that partitioned into the Triton X-114 phase after phase separation and degraded the bioactive peptides bradykinin and vasopressin . These P . endodontalis peptidases and proteases may play an important role in both the nutrition and pathogenicity of these assacharolytic microorganisms . The inactivation of bioactive peptides and degradation of extracellular matrix proteins by bacterial enzymes may contribute to the damage of host tissues accompanied with endodontic infections. Infect Control Hosp Epidemiol, 2001 Sep, 22(9), 542 - 9 Decontaminated single-use devices: an oxymoron that may be placing patients at risk for cross-contamination; Heeg P et al.; OBJECTIVE: To determine whether reprocessed single-use devices would meet regulatory standards for sterility and meet the same materials standards as a new device . DESIGN: The study included single-use and reusable biopsy forceps and papillotomes and a reusable stone retrieval basket . The suitability of these devices for cleaning and disinfection or sterilization was examined . METHODS: Testing of cleanability was conducted on devices contaminated with technetium 99-radiolabeled human blood . Instruments were cleaned using hospital recommended practices for manual cleaning . Gamma counts per second were determined before and after cleaning to localize contaminants, which were additionally visualized using light and scanning electron microscopy . X-ray photoelectron spectroscopy was used to quantify contamination elements on the materials tested . Residual bioburden testing on instruments contaminated with microorganisms suspended in coagulable sheep blood was carried out to establish the efficacy of disinfection and sterilization . RESULTS: All devices remained contaminated after cleaning, but single-use devices and the stone basket tended to be more heavily contaminated than reusable forceps and papillotomes . Cleaning procedures facilitated distribution of contaminants further into the lumens of the disposable forceps . Decreased concentrations of silicon and increased concentrations of carbon and nitrogen suggested that layers of silicon lubricant had been removed and contaminants were organic material . Reusable devices were effectively disinfected, but single-use devices were not . Sterilization could not eliminate the challenge microorganisms completely . CONCLUSIONS: None of the reprocessed single-use instruments were effectively cleaned, disinfected, or sterilized . This condition may provide an opportunity for the viability of nonresistant or nosocomial organisms and viruses . Additionally, reprocessing procedures may result in material destruction of fragile devices . Cost-saving initiatives that have inspired reprocessing of single-use devices, despite the absence of data establishing the efficacy of decontamination and the durability of materials throughout reprocessing, should be pushed into the background. Protoplasma, 2001, 218(1-2), 45 - 53 Ultrastructure, distribution, and transmission of endosymbionts in the whitefly Aleurochiton aceris Modeer (Insecta, Hemiptera, Aleyrodinea); Szklarzewicz T et al.; The body of the whitefly Aleurochiton aceris contains specialized cells, termed mycetocytes, that enclose endosymbiotic microorganisms . The endosymbionts are transmitted from one generation to the next transovarially . In contrast to other insects, in whiteflies whole intact mycetocytes migrate into the ovaries, traverse the follicular epithelium, and reach the oocyte surface (i.e., perivitellin space) . The migration of mycetocytes begins in the last instar, called puparium, from which imagines emerge . During this stage the cytoplasm of mycetocytes is tightly packed with pleomorphic bacteria and less numerous coccoid microorganisms . In adult females the mycetocytes gather extracellularly in the depression of the vitellarial oocyte . Till the end of oogenesis neither pleomorphic nor coccoid microorganisms are released from mycetocytes into the oocyte. FEMS Microbiol Lett, 2001 Nov 13, 204(2), 277 - 80 A fluorescence quenching test for the detection of flavonoid transformation; Schoefer L et al.; A novel fluorescence quenching test for the detection of flavonoid degradation by microorganisms was developed . The test is based on the ability of the flavonoids to quench the fluorescence of 1,6-diphenyl-1,3,5-hexatriene (DPH) . Several members of the anthocyanidins, flavones, isoflavones, flavonols, flavanones, dihydroflavanones, chalcones, dihydrochalcones and catechins were tested with regard to their quenching properties . The anthocyanidins were the most potent quenchers of DPH fluorescence, while the flavanones, dihydroflavanones and dihydrochalcones, quenched the fluorescence only weakly . The catechins had no visible impact on DPH fluorescence . The developed test allows a quick and easy differentiation between flavonoid-degrading and flavonoid-non-degrading bacteria . The investigation of individual reactions of flavonoid transformation with the developed test system is also possible. Water Sci Technol, 2001, 44(8), 33 - 40 Recalcitrance as a catalyst for new developments; Field JA; Humic substances are very recalcitrant in anaerobic environments as substrates, mostly due to their non-hydrolyzable high molecular weight structure, which is incompatible for cell uptake . The recalcitrant nature can be applied towards immobilizing pollutants into non-toxic humic substances . Certain anaerobic bioconversions such as demethylation of lignin and reduction of nitro- or azo groups can activate pollutants for humification processes upon subsequent exposure to air . Although humic substances provide no carbon or energy for microorganisms, the evidence presented here indicates that they are very active as terminal electron acceptors and redox mediators promoting the anaerobic degradation and biotransformation of priority pollutants. Adv Anat Embryol Cell Biol, 2001, 161, III - XIII, 1-151 Cooperation of liver cells in health and disease; Kmiec Z; The liver lobule is formed by parenchymal cells, i.e., hepatocytes and nonparenchymal cells . In contrast to hepatocytes that occupy almost 80% of the total liver volume and perform the majority of numerous liver functions, nonparenchymal liver cells, which contribute only 6.5% to the liver volume, but 40% to the total number of liver cells, are localized in the sinusoidal compartment of the tissue . The walls of hepatic sinusoid are lined by three different cell types: sinusoidal endothelial cells (SEC), Kupffer cells (KC), and hepatic stellate cells (HSC, formerly known as fat-storing cells, Ito cells, lipocytes, perisinusoidal cells, or vitamin A-rich cells) . Additionally, intrahepatic lymphocytes (IHL), including pit cells, i.e., liver-specific natural killer cells, are often present in the sinusoidal lumen . It has been increasingly recognized that both under normal and pathological conditions, many hepatocyte functions are regulated by substances released from neighboring nonparenchymal cells . Liver sinusoidal endothelial cells constitute the lining or wall of the hepatic sinusoid . They perform important filtration function due to the presence of small fenestrations that allow free diffusion of many substances, but not of particles of the size of chylomicrons, between the blood and the hepatocyte surface . SEC show huge endocytic capacity for many ligands including glycoproteins, components of the extracellular matrix (ECM; such as hyaluronate, collagen fragments, fibronectin, or chondroitin sulphate proteoglycan), immune complexes, transferrin and ceruloplasmin . SEC may function as antigen-presenting cells (APC) in the context of both MHC-I and MHC-II restriction with the resulting development of antigen-specific T-cell tolerance . They are also active in the secretion of cytokines, eicosanoids (i.e., prostanoids and leukotrienes), endothelin-1, nitric oxide, and some ECM components . Kupffer cells are intrasinusoidally located tissue macrophages with a pronounced endocytic and phagocytic capacity . They are in constant contact with gut-derived particulate materials and soluble bacterial products so that a subthreshold level of their activation in the normal liver may be anticipated . Hepatic macrophages secrete potent mediators of the inflammatory response (reactive oxygen species, eicosanoids, nitric oxide, carbon monoxide, TNF-alpha, and other cytokines), and thus control the early phase of liver inflammation, playing an important part in innate immune defense . High exposure of Kupffer cells to bacterial products, especially endotoxin (lipopolysaccharide, LPS), can lead to the intensive production of inflammatory mediators, and ultimately to liver injury . Besides typical macrophage activities, Kupffer cells play an important role in the clearance of senescent and damaged erythrocytes . Liver macrophages modulate immune responses via antigen presentation, suppression of T-cell activation by antigen-presenting sinusoidal endothelial cells via paracrine actions of IL-10, prostanoids, and TNF-alpha, and participation in the development of oral tolerance to bacterial superantigens . Moreover, during liver injury and inflammation, Kupffer cells secrete enzymes and cytokines that may damage hepatocytes, and are active in the remodeling of extracellular matrix . Hepatic stellate cells are present in the perisinusoidal space . They are characterized by abundance of intracytoplasmic fat droplets and the presence of well-branched cytoplasmic processes, which embrace endothelial cells and provide focally a double lining for sinusoid . In the normal liver HSC store vitamin A, control turnover of extracellular matrix, and regulate the contractility of sinusoids . Acute damage to hepatocytes activates transformation of quiescent stellate cells into myofibroblast-like cells that play a key role in the development of inflammatory fibrotic response . Pit cells represent a liver-associated population of large granular lymphocytes, i.e., natural killer (NK) cells . They spontaneously kill a variety of tumor cells in an MHC-unrestricted way, and this antitumor activity may be enhanced by the secretion of interferon-gamma . Besides pit cells, the adult liver contains other subpopulations of lymphocytes such as gamma delta T cells, and both "conventional" and "unconventional" alpha beta T cells, the latter containing liver-specific NK T cells . The development of methods for the isolation and culture of main liver cell types allowed to demonstrate that both nonparenchymal and parenchymal cells secrete tens of mediators that exert multiple paracrine and autocrine actions . Co-culture experiments and analyses of the effects of conditioned media on cultures of another liver cell type have enabled the identification of many substances released from non-parenchymal liver cells that evidently regulate some important functions of neighboring hepatocytes and non-hepatocytes . To the key mediators involved in the intercellular communication in the liver belong prostanoids, nitric oxide, endothelin-1, TNF-alpha, interleukins, and chemokines, many growth factors (TGF-beta, PDGF, IGF-I, HGF), and reactive oxygen species (ROS) . Paradoxically, the cooperation of liver cells is better understood under some pathological conditions (i.e., in experimental models of liver injury) than in normal liver due to the possibility of comparing cellular phenotype under in vivo and in vitro conditions with the functions of the injured organ . The regulation of vitamin A metabolism provides an example of the physiological role for cellular cross-talk in the normal liver . The majority (up to 80%) of the total body vitamin A is stored in the liver as long-chain fatty acid esters of retinal, serving as the main source of retinoids that are utilized by all tissues throughout the body . Hepatocytes are directly involved in the uptake from blood of chylomicron remnants, and the synthesis of retinol-binding protein that transfers retinol to other tissues . However, more than 80% of the liver retinoids are stored in lipid droplets of hepatic stellate cells . HSC are capable of both uptake and release of retinol depending on the body's retinol status . The activity of some major enzymes of vitamin A metabolism have been found to be many times higher per protein basis in stellate cells than in hepatocytes . Despite progress in the understanding of the roles played by these two cell types in hepatic retinoid metabolism, the way in which retinoids move between the parenchymal cells, stellate cells, and blood plasma has not been fully elucidated . Sinusoidal blood flow is, to a great extent, regulated by hepatic stellate cells that can contract due to the presence of smooth muscle alpha-actin . The main vasoactive substances that affect constriction or relaxation of HSC derive both from distant sources and from neighboring hepatocytes (carbon monoxide, leukotrienes), endothelial cells (endothelin, nitric oxide, prostaglandins), Kupffer cells (prostaglandins, NO), and stellate cells themselves (endothelin, NO) . The cellular cross-talk reflected by the fine-tuned modulation of sinusoidal contraction becomes disturbed under pathological conditions, such as endotoxemia or liver fibrosis, through the excess synthesis of vasoregulatory compounds and the involvement of additional mediators acting in a paracrine way . The liver is an important source of some growth factors and growth factor-binding proteins . Although hepatocytes synthesize the bulk of insulin-like growth factor I (IGF-I), also other types of nonparenchymal liver cells may produce this peptide . Cell-specific expression of distinct IGF-binding proteins observed in the rat and human liver provides the potential for specific regulation of hepatic IGF-I synthesis not only by growth hormone, insulin, and IGF-I, but also by cytokines released from activated Kupffer (IL-1, TNF-alpha, TGF-beta) or stellate cells (TGF-alpha, TGF-beta) . Hepatic stellate cells may affect turnover of hepatocytes through the synthesis of potent positive as well as negative signals such as, respectively, hepatocyte-growth-factor or TGF-beta . Although hepatocytes seem not to produce TGF-beta, a pleiotropic cytokine synthesized and secreted in the latent form by Kupffer and stellate cells, they may contribute to its actions in the liver by the intracellular activation of latent TGF-beta, and secretion of the biologically active isoform . Many mediators that reach the liver during inflammatory processes, such as endotoxins, immune-complexes, anaphylatoxins, and PAF, increase glucose output in the perfused liver, but fail to do so in isolated hepatocytes, acting indirectly via prostaglandins released from Kupffer cells . In the liver, prostaglandins synthesized from arachidonic acid mainly in Kupffer cells in a response to various inflammatory stimuli, modulate hepatic glucose metabolism by increasing glycogenolysis in adjacent hepatocytes . The release of glucose from glycogen supports the increased demand for energetic fuel by the inflammatory cells such as leukocytes, and additionally enables enhanced glucose turnover in sinusoidal endothelial cells and Kupffer cells which is necessary for effective defense of these cells against invading microorganisms and oxidative stress in the liver . Leukotrienes, another oxidation product of arachidonic acid, have vasoconstrictive, cholestatic, and metabolic effects in the liver . A transcellular synthesis of cysteinyl leukotrienes (LTC4, LTD4, and LTE4) functions in the liver: LTA4, an important intermediate, is synthesized in Kupffer cells, taken up by hepatocytes, converted into the potent LTC4, and then released into extracellular space, acting in a paracrine way on Kupffer and sinusoidal endothelial cells . Thus, hepatocytes are target cells for the action of eicosanoids and the site of their transformation and degradation, but can not directly oxidate arachidonic acid to eicosanoids . (ABSTRACT TRUNCATED) Microbiol Mol Biol Rev, 2001 Dec, 65(4), 497 - 522, table of contents Aspergillus enzymes involved in degradation of plant cell wall polysaccharides; de Vries RP et al.; Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes . Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes . Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes . The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes . This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi . This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded. Invest Ophthalmol Vis Sci, 2001 Dec, 42(13), 3228 - 32 Characterization of Toxoplasma gondii-specific T cells recovered from vitreous fluid of patients with ocular toxoplasmosis; Feron EJ et al.; PURPOSE: The mechanisms involved in reactivations of latent ocular Toxoplasma gondii (Tg) infections in immunocompetent patients are poorly understood . In view of the possible role of T cells in the immunopathogenesis of the disease, ocular infiltrating T cells obtained from patients with recurrent ocular toxoplasmosis were characterized phenotypically and functionally . METHODS: Ocular infiltrating T cells were recovered from vitreous fluid (VF) samples of 10 patients with active recurrent ocular toxoplasmosis . Two patients with uveitis of other origins were included as control subjects . T-cell lines (TCLs) were generated by mitogenic stimulation and tested for reactivity to Tg and human retinal protein extracts . The TCLs of three patients were cloned by limiting dilution . Tg-reactive T-cell clones (TCCs) were characterized with respect to their phenotype, T-cell receptor variable (TCR V)-beta gene usage, HLA restriction, and cytokine secretion profile . RESULTS: Reactivity to Tg could be detected only in the TCLs of patients with ocular toxoplasmosis . None of the TCLs showed reactivity to human retinal antigens . All tested intraocular Tg-specific TCCs (n = 23) were CD3+CD4+ and displayed differential TCR Vbeta usage . Twenty-one TCCs were HLA-DR restricted and two TCCs were restricted by HLA-DP . The majority of the intraocular Tg-specific TCCs showed a bias toward a T-helper (Th)0-Th2 cytokine profile . CONCLUSIONS: The data indicate that T cells specific for the triggering microorganism infiltrate the eye of patients with recurrent ocular toxoplasmosis . The functional characteristics of the VF-derived Tg-specific T cells and their presence at the site of inflammation suggest their involvement in the local inflammatory response of ocular toxoplasmosis. EMBO J, 2001 Dec 3, 20(23), 6772 - 82 Calreticulin and calnexin in the endoplasmic reticulum are important for phagocytosis; Muller-Taubenberger A et al.; Calreticulin and calnexin are Ca2+-binding proteins with chaperone activity in the endoplasmic reticulum . These proteins have been eliminated by gene replacement in Dictyostelium, the only microorganism known to harbor both proteins; family members in Dictyostelium are located at the base of phylogenetic trees . A dramatic decline in the rate of phagocytosis was observed in double mutants lacking calreticulin and calnexin, whereas only mild changes occurred in single mutants . Dictyostelium cells are professional phagocytes, capable of internalizing particles by a sequence of activities: adhesion of the particle to the cell surface, actin-dependent outgrowth of a phagocytic cup, and separation of the phagosome from the plasma membrane . In the double-null mutants, particles still adhered to the cell surface, but the outgrowth of phagocytic cups was compromised . Green fluorescent protein-tagged calreticulin and calnexin, expressed in wild-type cells, revealed a direct link of the endoplasmic reticulum to the phagocytic cup enclosing a particle, such that the Ca2+ storage capacity of calreticulin and calnexin might directly modulate activities of the actin system during particle uptake. J Food Prot, 2001 Nov, 64(11), 1841 - 3 Evaluation of the petrifilm plate method for the enumeration of aerobic microorganisms and coliforms in retailed meat samples; Park YH et al.; This study was designed to compare the effectiveness and applicability of the Petrifilm plate method with the Association of Official Analytical Chemists' (AOAC) standard aerobic count method and violet red bile agar method for meat products . The comparison was carried out using 303 meat samples collected from various retailers: 110 pork samples, 87 chicken samples, and 107 beef samples . In the comparison of the correlation coefficient (R) between the conventional method and the Petrifilm plate method by a linear regression analysis, the correlation coefficient in total microorganisms was 0.99, 0.95, and 0.94 in pork, beef, and chicken samples, respectively . The correlation coefficient in coliform count was 0.83, 0.96, and 0.81 in pork, beef, and chicken samples, respectively . Based on the high correlation in the total microorganism count, it might be possible to replace the conventional methods with the Petrifilm plate method . For coliform counts, the Petrifilm plate method also showed a generally high correlation coefficient, except for pork samples, which are more subject to contamination . The Petrifilm plate method was simpler and less time-consuming in sample preparation and, in procedures, faster than the conventional method . These results suggested that the 3M Petrifilm plate method could replace the conventional methods in the analysis of microorganism contamination measurement in meat products. J Food Prot, 2001 Nov, 64(11), 1806 - 11 Sucrose, sodium dodecyl sulfate, urea, and 2-mercaptoethanol affect the thermal inactivation of R-phycoerythrin; Orta-Ramirez A et al.; Thermal inactivation kinetics (D- and z-values) of the algal protein, R-phycoerythrin (R-PE), were studied under different buffer conditions (pH 4.0, 7.0, and 10.0) and concentrations of sucrose, sodium dodecyl sulfate (SDS), urea, and 2-mercaptoethanol (ME) . R-PE solutions were heated in capillary tubes at temperatures between 40 and 90 degrees C depending on buffer conditions . Thermal inactivation parameters for R-PE, calculated on the basis of fluorescence loss, were modified by addition of chemicals . Overall, sucrose and ME had a thermostabilizing effect, while SDS and urea decreased thermal stability of R-PE . The z-values ranged from 5.9 degrees C in 50 mM NaCl, 20 mM glycine buffer, pH 10.0, to 37.8 degrees C in 60% sucrose, 50 mM NaCl, 20 mM phosphate buffer, pH 7.0 . The z-values obtained for R-PE closely matched the z-values of some target microorganisms in food processes, suggesting R-PE might be used as a time-temperature integrator to verify thermal processing adequacy. J Food Prot, 2001 Nov, 64(11), 1674 - 8 Acid tolerance and survival of Escherichia coli O157:H7 inoculated in fruit pulps stored under refrigeration; Marques PA et al.; The adaptation of Escherichia coli O157:H7 cells to acid conditions has been reported . This study showed the behavior of three strains of E . coli O157:H7 in two different physiological stages (acid shocked and control cells), inoculated in five fruit pulps stored at 4 degrees C for up to 30 days . The three strains of E . coli O157:H7 inoculated in grape pulp could be recovered up to day 30 . E . coli O157:H7 strains survived for 4 days in all fruit pulps tested with different pH values (2.51 to 3.26), with the exception of acid-shocked cells of E . coli O157:H7 strain 933, which did not survive in "caja" (Spodias lutea L.) pulp . The results clearly indicated that acid resistance can persist for long periods during storage at 4 degrees C . The protection conferred by acid adaptation suggests that acid-resistant organisms will be better equipped to outlast these acid challenges . The survival of E . coli O157:H7 in fruit pulps with a low pH, stored under refrigeration, is of extreme importance due to the high virulence of this microorganism . The viability of microorganisms was dependent on the viscosity index of fruit pulps . Less viscous pulps supported the bacteria survival longer than more viscous fruit pulps. J Clin Microbiol, 2001 Dec, 39(12), 4468 - 71 Culture with BACTEC Peds Plus/F bottle compared with conventional methods for detection of bacteria in synovial fluid; Hughes JG et al.; An evaluation was undertaken to determine the utility of the BACTEC Peds Plus/F bottle and the BACTEC 9240 instrument (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) for the detection of clinically significant microorganisms in synovial fluid specimens . The Peds Plus/F bottle was used because in our laboratory the quantity of synovial fluid available for culture is frequently in the range of 0.5 to 3.0 ml . The culture results obtained with the Peds Plus/F bottle were compared to those obtained by a conventional agar plate method for a total of 805 synovial fluid specimens . Microbial growth was produced by 74 cultures (9.2%) from 60 patients, yielding a total of 77 microorganisms . Organisms were classified as pathogens (n = 62), contaminants (n = 12), or indeterminate (n = 3) on the basis of a review of the patients' medical histories . Culture using BACTEC Peds Plus/F bottle detected statistically significantly more pathogens overall (62 versus 51 pathogens {P = 0.001}) and statistically fewer contaminants overall (1 versus 11 contaminants {P = 0.006}) than culture by the agar plate method . These results indicate the superior performance of the BACTEC Peds Plus/F bottle over the conventional agar plate method for the detection of clinically significant microorganisms from synovial fluid specimens. J Clin Microbiol, 2001 Dec, 39(12), 4328 - 31 Evaluation of BacT/ALERT system for detection of Mycoplasma hominis in simulated blood cultures; Waites KB et al.; We used simulated blood cultures inoculated with clinical isolates of Mycoplasma hominis to determine whether liquid media of the BacT/ALERT (Organon Teknika, Durham, N.C.) will support growth of this fastidious organism and whether its presence can generate a positive signal with the instrument . Viability of clinical isolates of M . hominis was maintained for 7 days in BacT/ALERT media, and organisms were able to multiply when 1% gelatin was added to neutralize the mycoplasmastatic effects of the sodium polyanetholsulfonate anticoagulant . Without the addition of gelatin to BacT/ALERT bottles, the mycoplasmas declined in numbers or became completely nonviable . Mycoplasmal growth was further enhanced in BacT/ALERT PF both supplemented with gelatin, arginine, and DNA in comparison to broth with only gelatin added . No BacT/ALERT bottles containing M . hominis in simulated blood cultures were flagged positive by the instrument, despite growth of microorganisms of up to 10(7) CFU/ml after incubation for up to 7 days, suggesting that inadequate CO(2) production or some other mechanism prevents the instrument from recognizing the presence of the organism and its metabolic products . The fastidious cultivation requirements and relatively slow growth of M . hominis warrant that dependence on automated systems and techniques designed to detect conventional bacteria will not be reliable for recovery of M . hominis and that specialized media and incubation conditions designed for optimum cultivation of mycoplasmas should be employed when this organism is suspected on clinical grounds. Crit Rev Biochem Mol Biol, 2001, 36(5), 435 - 99 Lens crystallins and their microbial homologs: structure, stability, and function; Jaenicke R et al.; abg-Crystallins are the major protein components in the vertebrate eye lens--a as a molecular chaperone and b and g as structural proteins . Surprisingly, the latter two share some structural characteristics with a number of microbial stress proteins . The common denominator is not only the Greek key topology of their polypeptide chains but also their high intrinsic stability, which, in certain microbial crystallin homologs, is further enhanced by high-affinity Ca2+-binding . Recent studies of natural and mutant vertebrate bg-crystallins as well as spherulin 3a from Physarum polycephalum and Protein S from Myxococcus xanthus allowed the correlation of structure and stability of crystallins to be elucidated in some detail . From the thermodynamic point of view, stability increments come from (1) local interactions involved in the close packing of the cooperative units, (2) the all-b secondary structure of the Greek-key motif, (3) intramolecular interactions between domains, (4) intermolecular domain interactions, including 3D domain swapping and (v) excluded volume effects due to "molecular crowding" at the high cellular protein concentrations . Apart from these contributions to the Gibbs free energy of stability, significant kinetic stabilization originates from the high activation energy barrier determining the rate of unfolding from the native to the unfolded state . From the functional point of view, the high stability is responsible for the long-term transparency of the eye lens, on the one hand, and the stress resistance of the microorganisms in their dormant state on the other . Local structural perturbations due to chemical modification, wrong protein interactions, or other irreversible processes may lead to protein aggregation . A leading cataract hypothesis is that only after a-crystallin, a member of the small heat-shock protein family, is titrated out does pathological opacity occur . Understanding the structural basis of protein stability in the healthy eye lens is the route to solve the enormous medical and economical problem of cataract. J Environ Sci (China), 2001 Oct, 13(4), 385 - 90 Optimization of control parameters for petroleum waste composting; Ma Y et al.; Composting is being widely employed in the treatment of petroleum waste . The purpose of this study was to find the optimum control parameters for petroleum waste in-vessel composting . Various physical and chemical parameters were monitored to evaluate their influence on the microbial communities present in composting . The CO2 evolution and the number of microorganisms were measured as the activity of composting . The results demonstrated that the optimum temperature, pH and moisture content were 56.5-59.5 degrees C, 7.0-8.5 and 55%-60%, respectively . Under the optimum conditions, the removal efficiency of petroleum hydrocarbon reached 83.29% after 30 days composting. Appl Environ Microbiol, 2001 Dec, 67(12), 5700 - 4 Role of beta-oxidation enzymes in gamma-decalactone production by the yeast Yarrowia lipolytica; Wache Y et al.; Some microorganisms can transform methyl ricinoleate into gamma-decalactone, a valuable aroma compound, but yields of the bioconversion are low due to (i) incomplete conversion of ricinoleate (C(18)) to the C(10) precursor of gamma-decalactone, (ii) accumulation of other lactones (3-hydroxy-gamma-decalactone and 2- and 3-decen-4-olide), and (iii) gamma-decalactone reconsumption . We evaluated acyl coenzyme A (acyl-CoA) oxidase activity (encoded by the POX1 through POX5 genes) in Yarrowia lipolytica in lactone accumulation and gamma-decalactone reconsumption in POX mutants . Mutants with no acyl-CoA oxidase activity could not reconsume gamma-decalactone, and mutants with a disruption of pox3, which encodes the short-chain acyl-CoA oxidase, reconsumed it more slowly . 3-Hydroxy-gamma-decalactone accumulation during transformation of methyl ricinoleate suggests that, in wild-type strains, beta-oxidation is controlled by 3-hydroxyacyl-CoA dehydrogenase . In mutants with low acyl-CoA oxidase activity, however, the acyl-CoA oxidase controls the beta-oxidation flux . We also identified mutant strains that produced 26 times more gamma-decalactone than the wild-type parents. Appl Environ Microbiol, 2001 Dec, 67(12), 5444 - 52 Iron stress in open-ocean cyanobacteria (Synechococcus, Trichodesmium, and Crocosphaera spp.): identification of the IdiA protein; Webb EA et al.; Cyanobacteria are prominent constituents of the marine biosphere that account for a significant percentage of oceanic primary productivity . In an effort to resolve how open-ocean cyanobacteria persist in regions where the Fe concentration is thought to be limiting their productivity, we performed a number of Fe stress experiments on axenic cultures of marine Synechococcus spp., Crocosphaera sp., and Trichodesmium sp . Through this work, we determined that all of these marine cyanobacteria mount adaptive responses to Fe stress, which resulted in the induction and/or repression of several proteins . We have identified one of the Fe stress-induced proteins as an IdiA homologue . Genomic observations and laboratory data presented herein from open-ocean Synechococcus spp . are consistent with IdiA having a role in cellular Fe scavenging . Our data indicate that IdiA may make an excellent marker for Fe stress in open-ocean cyanobacterial field populations . By determining how these microorganisms respond to Fe stress, we will gain insight into how and when this important trace element can limit their growth in situ . This knowledge will greatly increase our understanding of how marine Fe cycling impacts oceanic processes, such as carbon and nitrogen fixation. Int J Hematol, 2001 Oct, 74(3), 309 - 15 Novel synthesized trimannose conjugate induces endocytosis and expression of immunostimulatory molecules in monocytic leukemia cells; Kanbe E et al.; Macrophage mannose receptor (MMR) recognizes the pattern of carbohydrates exposed on microorganisms and mediates endocytosis in macrophages . We have synthesized glycoconjugate cationic polymers carrying 3,6-branched alpha-D-mannoside, a trimannose conjugate (TMC) with a high affinity for mannose-specific lectins . Culture with 10 microM TMC for 6 hours induced adhesion and aggregation in NKM-1, a human myelomonocytic leukemia cell line . TMC also stimulated the accumulation of fluorescein isothiocyanate (FITC)-dextran (FITC-DX) . This accumulation seemed to be mediated by endocytosis via MMR because mannan, which specifically binds to MMR, inhibited FITC-DX accumulation . Expression of CD14, adhesion molecules, and costimulatory molecules was induced for 24 hours in NKM-1 and in fresh leukemia blasts from 4 patients with acute myeloid leukemia (AML) M4 and M5 subtypes (French-American-British classification) . To clarify the binding mechanism, we compared mannose conjugates and a monomer of mannose regarding their effects on endocytosis and enhancement of CD14 and CD86 expression . A polymer of monomannose clusters with a lower affinity for lectins slightly stimulated exdocytosis, whereas a monomer of trimannose had no effect . These findings suggest that concatenation between MMR and TMC may play an important role in the activation of monocytic leukemia cells . TMC may become a good candidate to target MMRs of leukemia cells. Am J Respir Crit Care Med, 2001 Nov 1, 164(9), 1628 - 32 Bronchial inflammation and colonization in patients with clinically stable bronchiectasis; Angrill J et al.; To evaluate the bronchial inflammatory response and its relationship to bacterial colonization in bronchiectasis, we performed a bronchoalveolar lavage (BAL) in 49 patients in stable clinical condition and in nine control subjects . BAL was processed for differential cell count, quantitative bacteriologic cultures, and measurement of inflammatory mediators . An increase was observed in the percentage of neutrophils (37 {0 to 98}) (median{range}) versus 1{0 to 4}%, p = 0.01), in the concentration of elastase (90.5 {8 to 2,930} versus 34 {9 to 44}, p = 0.03), myeloperoxidase (9.1 {0 to 376} versus 0.3 {0.1 to 1.4}, p = 0.01), and in the levels of TNF-alpha (4 {0 to 186} versus 0 {0 to 7}, p = 0.03), IL-8 (195 {0 to 5,520} versus 3 {0 to 31}, p = 0.001), and IL-6 (6 {0 to 115} versus 0 {0 to 3}, p = 0.001) in patients with bronchiectasis compared with control subjects . Noncolonized patients showed a more intense bronchial inflammatory reaction than did control subjects . This inflammatory reaction was exaggerated in patients colonized by microorganisms with potential pathogenicity (MPP), with a clear relationship with the bronchial bacterial load . Patients with bronchiectasis showed a slight systemic inflammatory response, with poor correlations between systemic and bronchial inflammatory mediators, suggesting that the inflammatory process was mostly compartmentalized . We conclude that patients with bronchiectasis in a stable clinical condition present an active neutrophilic inflammation in the airways that is exaggerated by the presence of MPP, and the higher the bacterial load the more intense the inflammation. Trends Cell Biol, 2001 Dec, 11(12), 504 - 11 SH2 domains, interaction modules and cellular wiring; Pawson T et al.; SH2 domains serve as the prototype for a growing family of protein-interaction modules, characteristic of polypeptides involved in transmitting signals from external and internal cues . The specific interactions of proteins with one another, and with other cellular components such as phospholipids and nucleic acids, provide a very general device to organize cellular behavior . We discuss the idea that rewiring of the cell's interaction network by pathogenic microorganisms and mutant cellular proteins contributes to dysregulation of cell signaling and thus to disease. J Bacteriol, 2001 Dec, 183(24), 7058 - 66 Use of transposon Tn5367 mutagenesis and a nitroimidazopyran-based selection system to demonstrate a requirement for fbiA and fbiB in coenzyme F(420) biosynthesis by Mycobacterium bovis BCG; Choi KP et al.; Three transposon Tn5367 mutagenesis vectors (phAE94, pPR28, and pPR29) were used to create a collection of insertion mutants of Mycobacterium bovis strain BCG . A strategy to select for transposon-generated mutants that cannot make coenzyme F(420) was developed using the nitroimidazopyran-based antituberculosis drug PA-824 . One-third of 134 PA-824-resistant mutants were defective in F(420) accumulation . Two mutants that could not make F(420)-5,6 but which made the biosynthesis intermediate FO were examined more closely . These mutants contained transposons inserted in two adjacent homologues of Mycobacterium tuberculosis genes, which we have named fbiA and fbiB for F(420) biosynthesis . Homologues of fbiA were found in all seven microorganisms that have been fully sequenced and annotated and that are known to make F(420) . fbiB homologues were found in all but one such organism . Complementation of the fbiA mutant with fbiAB and complementation of the fbiB mutant with fbiB both restored the F(420)-5,6 phenotype . Complementation of the fbiA mutant with fbiA or fbiB alone did not restore the F(420)-5,6 phenotype, but the fbiA mutant complemented with fbiA produced F(420)-2,3,4 at levels similar to F(420)-5,6 made by the wild-type strain, but produced much less F(420)-5 . These data demonstrate that both genes are essential for normal F(420)-5,6 production and suggest that the fbiA mutation has a partial polar effect on fbiB . Reverse transcription-PCR data demonstrated that fbiA and fbiB constitute an operon . However, very low levels of fbiB mRNA are produced by the fbiA mutant, suggesting that a low-level alternative start site is located upstream of fbiB . The specific reactions catalyzed by FbiA and FbiB are unknown, but both function between FO and F(420)-5,6, since FO is made by both mutants. BMC Microbiol . 2001;1(1):27 . Epub 2001 Oct 23. Bacterial response to siderophore and quorum-sensing chemical signals in the seawater microbial community; Guan LL et al.; BACKGROUND: Oceans are iron-deficient and nutrient-poor environments . These conditions impart limitations on our understanding of and our ability to identify microorganisms from the marine environment . However, less of knowledge on the influence of siderophores and N-acyl homoserinelactone as interspecies communication signals on the bacterial diversity of seawater has been understood . RESULTS: In the presence of 0.1 nM of the commercial siderophore desferroixamine and the known quorum-sensing chemical signals, synthetic N-(3-oxo)-hexanoylhomoserine lactone (0.1 nM) or N-octanoylhomoserine lactone (0.1 nM), the total numbers of bacteria in S9905 seawater increased nearly three-fold, and nearly eight-fold in S0011 seawater as determined by DAPI staining and counting, and increased three-fold by counting colony forming units in S9905 seawater after 7 days of incubation . Similar bacterial changes in bacterial abundance were observed when high concentration of desferroixamine (1 microM) and each of homoserine lactone compounds (1 microM) were presented in seawater samples . The number of cultivable bacterial species observed was also found to increase from 3 (without addition) to 8 (with additions) including three unknown species which were identified by phylogenetic analysis of 16S rDNA sequences . The growth of unknown species was found to be related to their siderophore production with response to the addition of desferroixamine and N-acyl homoserine lactones under iron-limited conditions . CONCLUSION: Artificial addition of siderophores and HSLs may be a possible method to aid in the identification and isolation of marine bacterial species which are thought to be unknown. Nahrung, 2001 Oct, 45(5), 364 - 7 Substitution of sugar cane bagasse in the chicken diet and immune response; Hegazy RA et al.; Total proteins and protein electrophoresis were made in the sera of broiler chicken (Arber Acres) to evaluate the effect of substitution of basal diet for 4 weeks by either 8% sugar cane bagasse +2% wheat germ or 16% sugar cane bagasse +4% wheat germ whether untreated or incubated with rumen liquor for 72 h and then sterilized with 2 Mrad gamma-irradiation (treated) . Both levels of untreated sugar can bagasse (8 and 16%) showed significant decrease in gamma globulins but this decrease had no effect on broiler chicken (45 days) while there was significant increase in total proteins in treated sugar cane bagasse 8% with concomitant increase in alpha 2, beta 1, beta 2 and gamma globulins . These results denoted that addition of rumen liquor to 8% sugar cane bagasse diet have resulted in an improvement in the transportation of micro nutrients and immune response most probably due to its high content of microorganisms constituting high quality animal protein; also more vaccines were recommended in feeding of chicken with sugar cane bagasse for a longer period e.g . laying hens to overcome its suppressive effect on the gamma globulins. Curr Opin Pharmacol, 2001 Aug, 1(4), 364 - 9 Natural products in anticancer therapy; da Rocha AB et al.; Many pharmaceutical agents have been discovered by screening natural products from plants, animals, marine organisms and microorganisms . Vincristine, irinotecan, etoposide and paclitaxel are examples of plant-derived compounds that are being employed in cancer treatment, and dactinomycin, bleomycin and doxorubicin are anticancer agents derived from microbial sources . Citarabine is an example of an anticancer agent originating from a marine source . Other agents originating from marine sources are bryostatin-1, aplidine, dolastatin 10 and ET-743, which have recently entered phase I and II clinical trials. Biodegradation, 2001, 12(2), 81 - 103 Molecular and cellular fundamentals of aerobic cometabolism of trichloroethylene; Arp DJ et al.; Cometabolism recognizes that microorganisms can transform non-growth-supporting substrates . The term "cometabolism" was first introduced over 30 years ago and has been redefined, criticized, and used widely ever since . In this review we have examined the aerobic cometabolism of chlorinated solvents, with a particular emphasis on the cometabolism of trichloroethylene . Monooxygenases or dioxygenases with relaxed substrate ranges initiate these transformations . The physiological role of the oxygenases is to initiate the metabolism of growth-supporting substrates (e.g., methane, propane, butane, toluene, ethylene, and ammonia) . Diverse enzymes catalyze these oxidative reactions with chlorinated solvents . Synthesis of most of these enzymes is induced by the presence of the growth-supporting substrate and is largely regulated at the level of gene transcription . The genes that code for a given oxygenase are usually clustered together in a single operon and often share homology with counterparts that code for the subunits of related oxygenases in other bacteria . During cometabolism the growth-supporting and non-growth-supporting substrates can both bind to the oxygenase . Transformation of chlorinated solvents by these enzymes presents the cell with a new set of compounds . Some of these compounds are toxic to the cells, others are stable products that are expelled from the cell, and in a few cases the cells utilize the products . The combined effects of cometabolism can have a profound influence on a cell. J Theor Biol, 2001 Nov 7, 213(1), 31 - 51 An ultrasonic motor model for bacterial flagellar motors; Atsumi T; A model for the transduction of energy occurring in bacterial flagellar motors is presented . In this model, the influx of ions across the channel causes the cyclic conformational change of the channel itself, which in turn produces travelling waves in one of the subcomponents of the motor, the C ring . This wave stabilizes the cyclical movement of the channel which generates the rotating force . The estimated frequency of cyclic conformational change is between 36 kHz and 6.3 MHz, i.e . in the ultrasonic range . This phenomenon is therefore referred to as the ultrasonic micromotor of microorganisms . Biochem Biophys Res Commun, 2001 Nov 23, 289(1), 57 - 61 Biosurfactants of MEL-A increase gene transfection mediated by cationic liposomes; Inoh Y et al.; Many microorganisms growing on water-insoluble substrates have been known to produce surface-active compounds called biosurfactants . Although biosurfactants have received increasing attention due to their special properties, there has been no information available until now of a role for them with regard to gene transfection . Thus, we studied here the effects of biosurfactants on gene transfection by cationic liposomes with a cationic cholesterol derivative . Our results showed clearly that a biosurfactant of mannosylerythritol lipid A (MEL-A) increased dramatically the efficiency of gene transfection mediated by cationic liposomes with a cationic cholesterol derivative . Among them, the liposomes with a cationic cholesterol derivative, cholesteryl-3 beta-carboxyamindoethylene-N-hydroxyethylamine (I), were much more effective for gene transfection than the liposomes with DC-Chol (cholesteryl-3 beta-oxycarboxyamidoethylenedimethylamine) or liposomes without MEL-A in various cultured cells . This demonstrates that this new finding has great potential in the experiment of gene transfection and gene therapy mediated by nonviral vectors such as cationic liposomes . Cell Mol Life Sci, 2001 Oct, 58(11), 1650 - 65 Epimerases: structure, function and mechanism; Allard ST et al.; Carbohydrates are ideally suited for molecular recognition . By varying the stereochemistry of the hydroxyl substituents, the simple six-carbon, six-oxygen pyranose ring can exist as 10 different molecules . With the further addition of simple chemical changes, the potential for generating distinct molecular recognition surfaces far exceeds that of amino acids . This ability to control and change the stereochemistry of the hydroxyl substituents is very important in biology . Epimerases can be found in animals, plants and microorganisms where they participate in important metabolic pathways such as the Leloir pathway, which involves the conversion of galactose to glucose-1-phosphate . Bacterial epimerases are involved in the production of complex carbohydrate polymers that are used in their cell walls and envelopes and are recognised as potential therapeutic targets for the treatment of bacterial infection . Several distinct strategies have evolved to invert or epimerise the hydroxyl substituents on carbohydrates . In this review we group epimerisation by mechanism and discuss in detail the molecular basis for each group . These groups include enzymes which epimerise by a transient keto intermediate, those that rely on a permanent keto group, those that eliminate then add a nucleotide, those that break then reform carbon-carbon bonds and those that linearize and cyclize the pyranose ring . This approach highlights the quite different biochemical processes that underlie what is seemingly a simple reaction . What this review shows is that each position on the carbohydrate can be epimerised and that epimerisation is found in all organisms. Cell Mol Life Sci, 2001 Oct, 58(11), 1607 - 26 The Arp2/3 complex: a central regulator of the actin cytoskeleton; May RC; In recent years the Arp2/3 complex has emerged as a central regulator of actin dynamics, assembling and cross-linking actin filaments to produce a diverse array of cellular structures . Here I discuss our current state of knowledge about this actin-remodelling machine . The predicted structure of the Arp2/3 complex can be directly correlated with its ability to nucleate, cap and cross-link actin filaments . A growing family of Arp2/3 complex activators such as the WASP family, type I myosins, and the newly identified activators cortactin and Abplp tightly regulate this activity within the cell . Localised activation of the Arp2/3 complex produces structures such as lamellipodia or actin patches via a process termed dendritic nucleation . Furthermore, several pathogenic microorganisms have evolved strategies to 'hijack' the Arp2/3 complex to their own advantage . Finally, I discuss some of the questions which remain unanswered about this fascinating complex. Pesqui Odontol Bras, 2001 Jul-Sep, 15(3), 187 - 95 Candida spp . biotypes in the oral cavity of school children from different socioeconomic categories in Piracicaba-SP, Brazil; Moreira D et al.; Two hundred and thirty-nine (239) Brazilian children, distributed into five distinct socioeconomic categories (A to E) were studied . Saliva samples were analyzed as to flow rate, pH, buffer capacity and microbial parameters . The results revealed the presence of Candida spp . in 47.3% of the samples . The most commonly isolated species was C . albicans, in all socioeconomic categories, followed by C . tropicalis, C . krusei and C . parapsilosis . There was no statistical correlation between secretion rate, buffer capacity and Candida spp . CFU/ml . The prevalence of Candida spp . did not differ substantially among the groups; however the microorganisms were more detected in categories B and C . Among all species, C . albicans was the most prevalent . Only 5% of the sample presented more than one species--C . albicans associated with C . tropicalis, C . parapsilosis or C . krusei . It was possible to detect a significant correlation between caries indices and the socioeconomic categories . All categories presented increased caries indices; however the studied population was considered of low caries risk . There was no positive correlation between the presence of Candida and caries risk in the analyzed population. Rev Endocr Metab Disord, 2000 Jan, 1(1-2), 87 - 95 Pathogenesis of ophthalmopathy in autoimmune thyroid disease; Heufelder AE; What causes GO is still a mystery, but the disease process results from a complex interplay of genetic and environmental factors . Genes such as those for HLA genes may determine a patient's susceptibility to the disease and its severity, but environmental factors, often unknown, may determine its course . Once established, the chronic inflammatory process within the orbital tissues appears to take on a momentum of its own . Given our current state of knowledge, the following working scheme for the pathogenesis of GO can be proposed (Fig . 1): On the background of a permissive immunogenetic milieu, circulating T cells in patients with GD, directed against certain antigens on thyroid follicular cells, recognize antigenic epitopes that are shared by tissues contained in the orbital space . Of the cell types residing in these tissues, preadipocytes and fibroblasts, most likely act as target and effector cells of the orbital immune process, respectively . This includes preadipocyte fibroblasts present in the perimysium of extraocular muscles, which do not appear to be immunologically different from those located in the orbital connective tissue . Orbital preadipocyte fibroblasts may be stimulated by unknown circulating or locally produced factors to differentiate into mature adipocytes that express increased levels of TSHr . How autoreactive T cells escape deletion and control by the immune system and come to be directed against a self-antigen presented by cells residing in the thyroid gland and extrathyroidal locations, is still unknown . Proliferation and expansion of autoreactive T cell clones may be due to mimicry of a host antigen by a microorganism, but this remains speculative . T cell recruitment into the orbital tissues is facilitated by certain chemokines and cytokines, which help to attract T cells by stimulating the expression of certain adhesion molecules (e.g., ICAM-1, VCAM-1, CD44) in vascular endothelium and connective tissue cells . These adhesion receptors are known to also play an important costimulatory role by activating T cells and facilitating antigen recognition, which amplifies the cellular immune process . Analysis of variable region genes of T cell antigen receptors in orbital T cells of patients with active GO has revealed their restricted TcR V gene usage, suggesting that antigen-driven selection and/or expansion of specific T cells may occur early in the evolution of GO . T cells and macrophages populating the orbital space are known to synthesize and release a {figure: see text} number of cytokines (most likely a Th1-type spectrum) into the surrounding tissue . Cytokines, oxygen free radicals and fibrogenic growth factors, released both from infiltrating inflammatory and residential cells, act upon orbital preadipocytes in a paracrine and autocrine manner to stimulate adipogenesis, fibroblast proliferation, glycosaminoglycan synthesis, and the expression of immunomodulatory molecules . Smoking, a well-known aggravating factor in GO, may aggravate tissue hypoxia and exert important immunomodulatory effects . The long held hypothesis of a thyroid cross-reactive antigen within the orbital tissues has recently gained significant support by an animal model of GO, and by in vitro and ex vivo studies . If confirmed in immunological studies, these data may well explain the localized infiltration of the orbital tissues by autoreactive lymphocytes that share intriguing molecular features with intrathyroidal lymphocytes . Local release of particular cytokines, TSHr-directed antibodies, or other factors might further enhance adipogenesis, glycosaminoglycan synthesis and expression of immunomodulatory proteins within the orbit . Other factors, including inflammatory cytokines, might act as counterbalancing inhibitors of these effects . However, if the net effect of these changes is to increase the volume of the fatty connective tissues within the orbit, then proptosis, extraocular muscle dysfunction, and periorbital congestion will ensue . Whether this hypothetical sequence of events will finally explain the involvement of the orbit in GD is unknown . Future studies will be aimed at identifying factors that might modulate adipogenesis in orbital cells and clarifying the link between adipogenesis and TSHr expression in the orbit . Taken together, a number of important details in the complex pathogenesis of GO have been resolved in recent years, but many challenges are still ahead . Elucidation of the primary antigen and how it is recognized by the immune system will be key issues. Am J Physiol Lung Cell Mol Physiol, 2001 Dec, 281(6), L1523 - 30 Altered lung gene expression in CCSP-null mice suggests immunoregulatory roles for Clara cells; Watson TM et al.; Clara cell secretory protein (CCSP) is one of the most abundant proteins present in airway lining fluid of mammals . In an effort to elucidate the function of CCSP, we established CCSP-null {CCSP(-/-)} mice and demonstrated altered sensitivity to various environmental agents including oxidant pollutants and microorganisms . Although CCSP deficiency itself may be central to the observed changes in environmental susceptibility, altered lung gene expression associated with CCSP deficiency may contribute to the observed phenotype . To determine whether CCSP deficiency results in altered lung gene expression, high-density cDNA microarrays were used to profile gene expression in the total lung RNA of wild-type and CCSP(-/-) mice . Genes that were differentially expressed between wild-type and CCSP(-/-) mice included a previously non-annotated expressed sequence tag (EST W82219) and immunoglobulin A (IgA), both of which were elevated with CCSP deficiency . mRNA expression of EST W82219 and IgA was localized in the lungs of wild-type and CCSP(-/-) mice to airway Clara cells and peribronchial lymphoid tissues, respectively . We conclude that CCSP deficiency is associated with 1) altered gene expression in Clara cells of the conducting airway epithelium and 2) alterations to peribronchial B lymphocytes . These findings identify new roles for Clara cells and their secretions in airway homeostasis. Heredity, 2001 Aug, 87(Pt 2), 220 - 6 What causes inefficient transmission of male-killing Wolbachia in Drosophila? Hurst GD, Jiggins FM, Robinson SJ. Selfish genetic elements that distort the sex ratio are common in arthropods . Theory predicts they will invade and spread to fixation if they are vertically transmitted with perfect fidelity, potentially leading to host extinction . For inherited microorganisms that distort the sex ratio, inefficient vertical transmission or incomplete sex ratio distorting ability is required for host persistence . However, the relative roles of genetic and environmental factors in permitting the survival of male hosts and preventing parasite transmission are poorly understood . We examined the causes of transmission infidelity and male survival for a male-killing Wolbachia strain in Drosophila bifasciata . Under standard laboratory conditions (18 degrees C), in its standard genetic background, males are produced very rarely, and no case of reversion has been observed in 20 generations of laboratory rearing . To investigate the role of host genetic factors, Wolbachia was crossed into 27 different inbred lines of D . bifasciata, but in no case was reversion observed at preferred environmental temperatures . The role of elevated temperature in inducing inefficient transmission was examined . Whilst vertical transmission was perfect over three generations of maintenance at 23.5 degrees, transmission infidelity was observed at 25 degrees . We conclude that there is no evidence for the presence of either fixed or polymorphic host genes that repress transmission at standard environmental temperatures . However, severe temperature treatment does make vertical transmission imperfect . We suggest that the case of Wolbachia in D . bifasciata is one that is naturally balanced, the population being maintained polymorphic without the evolution of host resistance genes. Med Parazitol (Mosk), 2001 Apr-Jun, (2), 35 - 40 {Functional phenotypic variability in a plague pathogen and plague enzootics}; Anisimov PI et al.; In the bacterial population, phenotypic variability plays a part of structural and functional subsystem that occupies a special place in the relations of heterogenic populations by performing an important adaptive function in the common system of ecological connections of parasitocenosis . At the same time regularly varying microorganism phenotypes act as an independent system that are closely related with the conditions of the niches occupied by the causative agent . Each subsystem as part of parasitocenosis is provided by its intrinsic adaptive mechanisms, which in combination ensures the stability of biocenosis based on self-regulation of evolutionarily established ecosystems . With the total complexity of parasitocenosis, the causative agent of plague is essential in forming its focus . For objective analysis of an epizootic process, it is necessary to include the established mechanisms of phenotypic variability of the causative agent of plague as a key link of the structural and functional interaction ecosystem that determines the mechanism of plague entozootics. Annu Rev Phytopathol, 2001, 39, 461 - 90 Molecular determinants of rhizosphere colonization by Pseudomonas; Lugtenberg BJ et al.; Rhizosphere colonization is one of the first steps in the pathogenesis of soilborne microorganisms . It can also be crucial for the action of microbial inoculants used as biofertilizers, biopesticides, phytostimulators, and bioremediators . Pseudomonas, one of the best root colonizers, is therefore used as a model root colonizer . This review focuses on (a) the temporal-spatial description of root-colonizing bacteria as visualized by confocal laser scanning microscopal analysis of autofluorescent microorganisms, and (b) bacterial genes and traits involved in root colonization . The results show a strong parallel between traits used for the colonization of roots and of animal tissues, indicating the general importance of such a study . Finally, we identify several noteworthy areas for future research. Annu Rev Phytopathol, 2001, 39, 259 - 84 Common mechanisms for pathogens of plants and animals; Cao H et al.; The vast evolutionary gulf between plants and animals--in terms of structure, composition, and many environmental factors--would seem to preclude the possibility that these organisms could act as receptive hosts to the same microorganism . However, some pathogens are capable of establishing themselves and thriving in members of both the plant and animal kingdoms . The identification of functionally conserved virulence mechanisms required to infect hosts of divergent evolutionary origins demonstrates the remarkable conservation in some of the underlying virulence mechanisms of pathogenesis and is changing researchers' thinking about the evolution of microbial pathogenesis. Annu Rev Phytopathol, 2000, 38, 181 - 205 CITRUS BLIGHT AND OTHER DISEASES OF RECALCITRANT ETIOLOGY; Derrick KS et al.; Several economically important diseases of unknown or recently determined cause are reviewed . Citrus blight (CB), first described over 100 years ago, was shown in 1984 to be transmitted by root-graft inoculations; the cause remains unknown and is controversial . Based on graft transmission, it is considered to be an infectious agent by some; others suggest that the cause of CB is abiotic . Citrus variegated chlorosis, although probably long present in Argentina, where it was considered to be a variant of CB, was identified as a specific disease and shown to be caused by a strain of Xylella fastidiosa after if reached epidemic levels in Brazil in 1987 . Citrus psorosis, described in 1933 as the first virus disease of citrus, is perhaps one of the last to be characterized . In 1988, it was shown to be caused by a very unusual virus . The cause of lettuce big vein appears to be a viruslike agent that is transmitted by a soilborne fungus . Double-stranded RNAs were associated with the disease, suggesting it may be caused by an unidentified RNA virus . Rio Grande gummosis, dry rot root, peach tree short life, and some replant diseases may be diseases of complex etiology . Various microorganisms have been isolated from trees with these diseases, but the diseases may be attributable in part to environmental factors . Determination of the cause of these diseases of complex etiology has proven difficult, in part, because they affect only mature trees. Annu Rev Phytopathol, 2000, 38, 145 - 180 THE ECOLOGY AND BIOGEOGRAPHY OF MICROORGANISMS ON PLANT SURFACES; Andrews JH et al.; The vast surface of the plant axis, stretching from root tips occasionally buried deeply in anoxic sediment, to apical meristems held far aloft, provides an extraordinarily diverse habitat for microorganisms . Each zone has to a greater or lesser extent its own cohort of microorganisms, in aggregate comprising representatives from all three primary domains of life-Bacteria, Archaea, and Eucarya . While the plant sets the stage for its microbial inhabitants, they, in turn, have established varied relationships with their large partner . These associations range from relatively inconsequential (transient epiphytic saprophytes) to substantial (epiphytic commensals, mutualistic symbionts, endophytes, or pathogens) . Through recent technological breakthroughs, a much better perspective is beginning to emerge on the nature of these relationships, but still relatively little is known about the role of epiphytic microbial associations in the life of the plant. Annu Rev Phytopathol, 1999, 37, 81 - 125 THE THREE DS OF PCR-BASED GENOMIC ANALYSIS OF PHYTOBACTERIA: Diversity, Detection, and Disease Diagnosis; Louws F et al.; The advent of molecular biology in general and the polymerase chain reaction in particular have greatly facilitated genomic analyses of microorganisms, provide enhanced capability to characterize and classify strains, and facilitate research to assess the genetic diversity of populations . The diversity of large populations can be assessed in a relatively efficient manner using rep-PCR-, AFLP-, and AP-PCR/RAPD-based genomic fingerprinting methods, especially when combined with computer-assisted pattern analysis . Genetic diversity maps provide a framework to understand the taxonomy, population structure, and dynamics of phytobacteria and provide a high-resolution framework to devise sensitive, specific, and rapid methods for pathogen detection, plant disease diagnosis, as well as management of disease risk . A variety of PCR-based fingerprinting protocols such as rDNA-based PCR, ITS-PCR, ARDRA, T-RFLPs, and tRNA-PCR have been devised, and numerous innovative approaches using specific primers have been adopted to enhance both the detection and identification of phytobacteria . PCR-based protocols, combined with computer-based analysis, have provided novel fundamental knowledge of the ecology and population dynamics of bacterial pathogens, and present exciting new opportunities for basic and applied studies in plant pathology. Environ Toxicol Chem, 2001 Nov, 20(11), 2639 - 43 Background zinc concentrations in soil affect the zinc sensitivity of soil microbial processes--a rationale for a metalloregion approach to risk assessments; McLaughlin MJ et al.; Soil microbial processes are particularly sensitive to Zn, but great difficulty exists in deriving soil standards based on laboratory toxicity tests . Zinc toxicity data for soil microbial processes were collated from the literature, and their variability with soil properties was assessed . Data were screened for quality and reliability, and analysis was based on the highest metal dose at which no adverse effect was found (HNOAED) . The HNOAED values were expressed on a pore-water basis and were found to be positively related to background concentrations of Zn in soil, also expressed on a pore-water basis . This suggests that soil microorganisms acclimate to indigenous concentrations of Zn in soil pore water, and this acclimation affects the subsequent response to Zn added as a pollutant . Thus, regions having low background Zn concentrations in soil pore water will be much more sensitive to Zn pollution than others having high background concentrations . A method to account for effects of background Zn on assessments of Zn toxicity is suggested where metalloregions are defined having common sets of abiotic and biotic factors that affect the toxicity of Zn . This approach could markedly improve regional or continental risk assessments for metals in the environment. Environ Toxicol Chem, 2001 Nov, 20(11), 2406 - 10 Effect of sediment toxicity on anaerobic microbial metabolism; Togna MT et al.; Mineralization of a readily biodegradable aromatic compound (benzoate) by intrinsic microorganisms in the anoxic sediment was used to quantify the inhibitory effect of heavily contaminated sediment from the Arthur Kill estuary (NY/NJ Harbor system, USA) on the anaerobic metabolism by naturally present bacterial populations . In anoxic microcosms, the effect of varying ratios of contaminated sediment:site water and contaminated sediment:noncontaminated sediment (Flax Pond, Stony Brook, NY, USA) were investigated . In all cases, increasing the ratio of Arthur Kill sediment in the microcosms showed an inhibitory effect on the rate of 14C-benzoate mineralization as measured by the evolution of 14CO2 . This inhibitory effect could be alleviated through dilution of the sediment with noncontaminated sediment, resulting in some cases in mineralization rates that were greater by an order of magnitude . The toxicity of the sediment was confirmed by whole-sediment Microtox bioassay . Analysis of the sediment revealed high (>200 mg/kg) levels of Pb, Cu, Zn, and Cr, suggesting that heavy metals may contribute to overall sediment toxicity. Extremophiles, 2001 Oct, 5(5), 323 - 32 Characterization of a catalase-peroxidase from the hyperthermophilic archaeon Archaeoglobus fulgidus; Kengen SW et al.; A putative perA gene from Archaeoglobus fulgidus was cloned and expressed in Escherichia coli BL21(DE3), and the recombinant catalase-peroxidase was purified to homogeneity . The enzyme is a homodimer with a subunit molecular mass of 85 kDa . UV-visible spectroscopic analysis indicated the presence of protoheme IX as a prosthetic group (ferric heme), in a stoichiometry of 0.25 heme per subunit . Electron paramagnetic resonance analysis confirmed the presence of ferric heme and identified the proximal axial ligand as a histidine . The enzyme showed both catalase and peroxidase activity with pH optima of 6.0 and 4.5, respectively . Optimal temperatures of 70 degrees C and 80 degrees C were found for the catalase and peroxidase activity, respectively . The catalase activity strongly exceeded the peroxidase activity, with Vmax values of 9600 and 36 U mg(-1), respectively . Km values for H2O2 of 8.6 and 0.85 mM were found for catalase and peroxidase, respectively . Common heme inhibitors such as cyanide, azide, and hydroxylamine inhibited peroxidase activity . However, unlike all other catalase-peroxidases, the enzyme was also inhibited by 3-amino-1,2,4-triazole . Although the enzyme exhibited a high thermostability, rapid inactivation occurred in the presence of H2O2, with half-life values of less than 1 min . This is the first catalase-peroxidase characterized from a hyperthermophilic microorganism. J Periodontol, 2001 Oct, 72(10), 1354 - 63 Treponema socranskii, Treponema denticola, and Porphyromonas gingivalis are associated with severity of periodontal tissue destruction; Takeuchi Y et al.; BACKGROUND: The aim of the present study was to identify Treponema socranskii in addition to Treponema denticola and Porphyromonas gingivalis by polymerase chain reaction (PCR), and to clarify the relationship between the presence of these microorganisms and the severity of clinical periodontal parameters . METHODS: Saliva and subgingival plaque collected from 123 subjects (38 aggressive periodontitis patients, 65 chronic periodontitis patients, 20 healthy patients) were subjected to PCR to detect the aforementioned 3 microorganisms . RESULTS: Detection frequencies of T . socranskii, T . denticola, and P . gingivalis in plaque samples from aggressive periodontitis patients (71.1%, 73.7%, 84.2%, respectively) and chronic periodontitis patients (89.2%, 93.8%, 95.3%) were much higher than those from healthy subjects (30%, 5.0%, 10.0%) . In aggressive and chronic periodontitis patients, these 3 species of bacteria were detected frequently at sites that showed deep periodontal pockets and severe attachment loss . The percentage of these bacteria-positive sites increased as the gingival index score of chronic periodontitis patients increased . T . socranskii was frequently detected together with T . denticola or P . gingivalis at the same sites, and coexistence of these microorganisms was frequently observed in deep periodontal pockets of aggressive periodontitis patients . CONCLUSIONS: T . socranskii, T . denticola, and P . gingivalis were frequently detected in periodontitis patients by PCR . The prevalence of these 3 microorganisms was correlated with various clinical parameters . Taken together, our findings suggest that T . socranskii, T . denticola, and P . gingivalis are associated with the severity of periodontal tissue destruction. Exp Hematol, 2001 Nov, 29(11), 1319 - 25 Gene-scan method for the recognition of carriers and patients with p47(phox)-deficient autosomal recessive chronic granulomatous disease; Dekker J et al.; OBJECTIVE: We devised a method to recognize carriers and patients with p47(phox)-deficient chronic granulomatous disease (A47 CGD), the most common autosomal form of the disease . CGD is characterized by the inability of phagocytic leukocytes to kill microorganisms, due to a defective NADPH oxidase system . The predominant genetic defect leading to p47(phox)-deficient CGD is a GT deletion at the beginning of exon 2 in the p47(phox) gene NCF1, most likely caused by recombination events between the NCF1 and one of its pseudogenes . It is hardly possible to investigate sequences of patients, carriers, and normal individuals using standard PCR/sequencing techniques, due to greater than 99% homology between NCF1 and its pseudo