Bacteria

Environ Sci Technol, 2001 May 1, 35(9), 1785 - 90
Anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA); Finneran KT et al.; The potential for anaerobic degradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) was investigated in laboratory incubations of sediments from a petroleum-contaminated aquifer and in aquatic sediments . The addition of humic substances (HS) stimulated the anaerobic degradation of MTBE in aquifer sediments in which Fe(III) was available as an electron acceptor . This is attributed to the fact that HS and other extracellular quinones can stimulate the activity of Fe(III)-reducing microorganisms by acting as an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides . MTBE was not degraded in aquifer sediments without Fe(III) and HS . {14C}-MTBE added to aquatic sediments adapted for anaerobic MTBE degradation was converted to 14CO2 in the presence or absence of HS or the HS analog, anthraquione-2,6-disulfonate . Unamended aquatic sediments produced 14CH4 as well as 14CO2 from {14C}-MTBE . The aquatic sediments also rapidly consumed TBA under anaerobic conditions and converted {14C}-TBA to 14CH4 and 14CO2 . An adaptation period of ca . 250-300 days was required prior to the most rapid anaerobic MTBE degradation in both sediment types, whereas TBA was metabolized in the aquatic sediments without a lag . These results demonstrate that, under the appropriate conditions, MTBE and TBA can be degraded in the absence of oxygen . This suggests that it may be possible to design strategies for the anaerobic remediation of MTBE in petroleum-contaminated subsurface environments.

Am J Physiol Regul Integr Comp Physiol, 2001 Jun, 280(6), R1897 - 901
Influence of barometric pressure on interleukin-1 beta secretion; Becker WJ et al.; Monocytes and macrophages are activated by various environmental challenges, including microorganisms, radiation, and pollutants . These cells release cytokines, such as interleukin (IL)-1 beta, that mediate physiological adaptations to stress . This study sought to define further the role of IL-1 beta in general adaptation to environmental stress by testing the hypothesis that high altitude (20,000 ft, 6,096 m) would stimulate IL-1 beta secretion from isolated human blood mononuclear cells . Cells from six young men (aged 22--26 yr) were divided into separate cultures incubated in either standard ambient conditions or in one of three test conditions, hypobaric hypoxia (simulating 20,000 ft), hypobaric normoxia (20,000 ft, O(2) supplemented), and normobaric hypoxia (10% O(2)) . This design allowed differentiation between pressure-related vs . oxygen-related effects . Each subject made multiple blood donations in order that cells from all subjects were tested in all conditions . Contrary to the hypothesis, IL-1 beta secretion was not induced at simulated altitude in basal cell cultures . In lipopolysaccharide-stimulated cell cultures, exposure to altitude inhibited IL-1 beta secretion by approximately 40%, and the inhibition was due to the change in pressure (P = 0.039) rather than the change in oxygen . Secretion of other factors (IL-1 receptor antagonist and soluble IL-1 receptor type II) was not inhibited . Although these results are in opposition to the original hypothesis, they provide insight regarding adaptations necessary for hematopoiesis in response to high altitude and also provide a cellular rationale for the mountain sanatoriums of the 19th and early 20th centuries.

Acc Chem Res, 2001 May, 34(5), 399 - 408
Enzymology, structure, and dynamics of acetohydroxy acid isomeroreductase; Dumas R et al.; Acetohydroxy acid isomeroreductase is a key enzyme involved in the biosynthetic pathway of the amino acids isoleucine, valine, and leucine . This enzyme is of great interest in agrochemical research because it is present only in plants and microorganisms, making it a potential target for specific herbicides and fungicides . Moreover, it catalyzes an unusual two-step reaction that is of great fundamental interest . With a view to characterizing both the mechanism of inhibition by potential herbicides and the complex reaction mechanism, various techniques of enzymology, molecular biology, mass spectrometry, X-ray crystallography, and theoretical simulation have been used . The results and conclusions of these studies are described briefly in this paper.

Acc Chem Res, 2001 May, 34(5), 339 - 49
The central enzymes of the aspartate family of amino acid biosynthesis; Viola RE; The aspartate pathway is responsible for the biosynthesis of lysine, threonine, isoleucine, and methionine in most plants and microorganisms . The absence of this pathway in humans and animals makes the central enzymes potential targets for inhibition, with the aim of developing new herbicides and biocides, and also for enhancement, to improve the nutritional value of crops . Our current state of knowledge of these enzymes is reviewed, including recently determined structural information and newly constructed bifunctional fusion enzymes.

Science, 2001 May 11, 292(5519), 1119 - 22
Factors that alter rumen microbial ecology; Russell JB et al.; Ruminant animals and ruminal microorganisms have a symbiotic relationship that facilitates fiber digestion, but domestic ruminants in developed countries are often fed an abundance of grain and little fiber . When ruminants are fed fiber-deficient rations, physiological mechanisms of homeostasis are disrupted, ruminal pH declines, microbial ecology is altered, and the animal becomes more susceptible to metabolic disorders and, in some cases, infectious disease . Some disorders can be counteracted by feed additives (for example, antibiotics and buffers), but these additives can alter the composition of the ruminal ecosystem even further.

Environ Sci Technol, 2001 Mar 1, 35(5), 894 - 900
Metal speciation dynamics and bioavailability . 2 . Radial diffusion effects in the microorganism range; Pinheiro JP et al.; The free ion activity model for the biouptake of metals from complex media is limited to cases where mass transfer is not flux determining . This paper follows a previous paper (Van Leeuwen, H . P . Environ . Sci . Technol . 1999, 33, 3743) where speciation dynamics and bioavailability of metals are analyzed in terms of bioconversion kinetics and simultaneous metal transport in the medium coupled with dissociation kinetics . Such analysis shows under what conditions labile complex species contribute to the biouptake process or, equivalently, under what conditions the free ion activity model is not obeyed . The present work addresses the theoretical extension of the expressions for the metal flux in the medium by a radial diffusion term so that these are also applicable in the microorganism size range . The transition from macroscopic to microscopic surfaces affects not only the nature of the flux but also the extent of lability of complex species (Van Leeuwen, H . P.; Pinheiro, J . P . J . Electroanal . Chem . 1999, 471, 55), and this can have a dramatic influence on the rate of biouptake of metal ions . Labilities of metal complexes and the ensuing limiting metal fluxes are therefore systematically analyzed for various dimensions of the uptaking surface . Different conditions of bioaffinities and bioconversion capacities are considered, and a number of examples of metal complexes with specified kinetic features are discussed.

Environ Toxicol Chem, 2001 Jan, 20(1), 84 - 98
Toxicity of pesticides to aquatic microorganisms: a review; DeLorenzo ME et al.; Microorganisms contribute significantly to primary production, nutrient cycling, and decomposition in estuarine eco-systems; therefore, detrimental effects of pesticides on microbial species may have subsequent impacts on higher trophic levels . Pesticides may affect estuarine microorganisms via spills, runoff, and drift . Both the structure and the function of microbial communities may be impaired by pesticide toxicity . Pesticides may also be metabolized or bioaccumulated by microorganisms . Mechanisms of toxicity vary, depending on the type of pesticide and the microbial species exposed . Herbicides are generally most toxic to phototrophic microorganisms, exhibiting toxicity by disrupting photosynthesis . Atrazine is the most widely used and most extensively studied herbicide . Toxic effects of organophosphate and organochlorine insecticides on microbial species have also been demonstrated, although their mechanisms of toxicity in such nontarget species remain unclear . There is a great deal of variability in the toxicity of even a single pesticide among microbial species . When attempting to predict the toxicity of pesticides in estuarine ecosystems, effects of pesticide mixtures and interactions with nutrients should be considered . The toxicity of pesticides to aquatic microorganisms, especially bacteria and protozoa, is an area of research requiring further study.

Ann Rheum Dis, 2001 Jun, 60(6), 632 - 4
Intra-articular co-infection by Borrelia burgdorferi and Chlamydia trachomatis; Putschky N et al.; OBJECTIVE: Chlamydia trachomatis and Borrelia burgdorferi infections are frequently the cause of unexplained oligoarthritis, as shown by identification of bacteria specific DNA in joint material from patients with reactive arthritis, Lyme arthritis, and undifferentiated oligoarthritis . The aim of this study was to determine whether the two organisms occur simultaneously in joint material from patients with arthritis . METHODS: Seventy six patients with unexplained arthritis were prospectively studied . Synovial fluid was obtained from all patients and examined for DNA from C trachomatis and B burgdorferi using specific polymerase chain reaction (PCR) protocols . Data concerning prior genitourinary infection or a history of tick bite were recorded and serum antibodies to C trachomatis and B burgdorferi were determined . RESULTS: Six patients (8%) had DNA from both C trachomatis and B burgdorferi in the same synovial fluid specimen (mean leucocyte count 11.925/mm(3), 65% granulocytes) . These patients (four men, two women; mean age 33.7 years) all had oligoarthritis of the knee, ankle, or both (mean disease duration 11.3 months) . From the history and serological examination, four patients had some evidence of actual or previous infection with one or other of the bacteria, while the other two patients had a positive serological test for Chlamydia only . CONCLUSIONS: DNA from two different microorganisms which are known to be triggering agents for arthritis may be present simultaneously in joint material from patients with unexplained oligoarthritis . This finding raises the question as to whether, in such cases, one or both bacteria contribute to the pathogenesis of the disease or whether they are only innocent bystanders.

Przegl Epidemiol, 2000, 54(3-4), 367 - 74
{Exposure to toxocariasis and tularemia among workers at Białowieza National Park}; Lapinski TW et al.; Everyday contact of the workers of Bialowieza sanctuary with animals may create a risk of infection by microorganisms attacking animals . The reported study was undertaken for carrying out an epidemiological analysis of tularemia and toxocarosis in this group of workers . Tularaemia infection was not found in then . In 12% of these workers antibodies to Toxocara canis were found, and fire workers had articular borreliosis . Antibodies to taxocara were disclosed in 10% of the Bialowieza population not employed in the sanctuary and 30% of the population of the village Kruklanka in the Pisz Forests . The workers of the Bialowieza Sanctuary are not exposed to Toxocara canis infection more than the remaining population of Bialowieza and the population in the Kruklanka village in a region far from Bialowieza.

Environ Sci Technol, 2001 Feb 15, 35(4), 682 - 9
Signature metabolites attesting to the in situ attenuation of alkylbenzenes in anaerobic environments; Elshahed MS et al.; Accurate assessment of the fate of hydrocarbons spilt in aquifers is essential for gauging associated health and ecological risks . Regulatory pressure to actively remediate such contaminated ecosystems can be substantially diminished if solid evidence for in situ microbial destruction of pollutants is obtained . In laboratory incubations, sediment-associated microorganisms from a gas condensate-contaminated aquifer anaerobically biodegraded toluene, ethylbenzene, xylene, and toluic acid isomers with stoichiometric amounts of sulfate consumed or methane produced . The activation of the alkylated aromatic contaminants involved conversion to their corresponding benzylsuccinic acid derivatives, a reaction known to occur for toluene and m-xylene decay, but one previously unrecognized for ethylbenzene, o- and p-xylene, and m-toluate metabolism . Benzylsuccinates were further biodegraded to toluates, phthalates, and benzoate . In laboratory incubations, these metabolites were transiently produced . Several of the metabolites were also detected in groundwater samples from an aquifer where alkylbenzene concentrations decreased over time, suggesting that anaerobic microbial metabolism of these contaminants also occurs in situ . Our studies confirm the utility of the aforementioned compounds as signature metabolites attesting to the natural attenuation of aromatic hydrocarbons in anaerobic environments.

Environ Sci Technol, 2001 Feb 15, 35(4), 658 - 62
Widespread potential for microbial MTBE degradation in surface-water sediments; Bradley PM et al.; Microorganisms indigenous to stream and lake bed sediments, collected from 11 sites throughout the United States, demonstrated significant mineralization of the fuel oxygenate, methyl-tert-butyl ether (MTBE) . Mineralization of {U-14C}MTBE to 14CO2 ranged from 15 to 66% over 50 days and did not differ significantly between sediments collected from MTBE contaminated sites and from sites with no history of MTBE exposure . This result suggests that even the microbial communities indigenous to newly contaminated surface water systems will exhibit some innate ability to attenuate MTBE under aerobic conditions . The magnitude of MTBE mineralization was related to the sediment grain size distribution . A pronounced, inverse correlation (p < 0.001; r2 = 0.73) was observed between the final recovery of 14CO2 and the percentage content of silt and clay sized grains (grain diameter < 0.125 mm) . The results of this study indicate that the microorganisms that inhabit the bed sediments of streams and lakes can degrade MTBE efficiently and that this capability is widespread in the environment . Thus aerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States and may contribute to the reported transience of MTBE in some surface waters.

Infect Immun, 2001 Jun, 69(6), 3562 - 8
Mycobacterium bovis BCG recA deletion mutant shows increased susceptibility to DNA-damaging agents but wild-type survival in a mouse infection model; Sander P et al.; Pathogenic microorganisms possess antioxidant defense mechanisms for protection from reactive oxygen metabolites which are generated during the respiratory burst of phagocytic cells . These defense mechanisms include enzymes such as catalase, which detoxifies reactive oxygen species, and DNA repair systems, which repair damage resulting from oxidative stress . To (i) determine the relative importance of the DNA repair system when oxidative stress is encountered by the Mycobacterium tuberculosis complex during infection of the host and to (ii) provide improved mycobacterial hosts as live carriers to express foreign antigens, the recA locus was inactivated by allelic exchange in Mycobacterium bovis BCG . The recA mutants are sensitive to DNA-damaging agents and show increased susceptibility to metronidazole, the first lead compound active against the dormant M . tuberculosis complex . Surprisingly, the recA genotype does not affect the in vitro dormancy response, nor does the defect in the DNA repair system lead to attenuation as determined in a mouse infection model . The recA mutants will be a valuable tool for further development of BCG as an antigen delivery system to express foreign antigens and as a source of a genetically stable vaccine against tuberculosis.

Environ Sci Technol, 2001 Jan 15, 35(2), 354 - 61
Kinetics of mass transfer-limited bacterial growth on solid PAHs; Wick LY et al.; The importance of mass transfer relative to the intrinsic microbial activity was examined in a laboratory system using Mycobacterium sp . LB501T and poorly soluble anthracene as sole carbon source . M . sp . LB501T was grown on various amounts of solid anthracene in batch cultures, and microbial biomass formation was compared to independently determined dissolution fluxes . Provision of only a few anthracene crystals (< or = 2 g L(-1)) resulted in pseudolinear growth due to low dissolution fluxes, whereas exponential growth was only obtained when high amounts of solid anthracene (30 g L(-1)) were provided . The influence of substrate bioavailability on microbial growth was predicted successfully by a dynamic, flux-based approach (Best-Equation), which combines substrate dissolution from crystals into solution, substrate uptake by microorganisms from solution, and concurrent biomass formation.

Biomed Sci Instrum, 2001, 37, 191 - 6
Real time biodetection of individual pathogenic microorganisms in food and water; Johnson PE et al.; The primary objective of this research is to examine the feasibility of using an innovative technique based on laser-induced fluorescence coupled with flow cytometry to detect pathogenic microorganisms in food or water in real time . Our initial application is the rapid detection of E . coli O157:H7 in ground beef . The research performed demonstrated conclusively that this approach is feasible, and that the technique has key advantages over current alternatives including: it is (1) able to totally examine a large volume of food or water in real time, (2) capable of detecting single microorganisms (alternative techniques require in excess of 10(4) microorganisms), (3) intrinsically automatic, and (4) sensitive only to the selected bacteria . We have demonstrated the feasibility of detecting individual E . coli bacteria with a breadboard system . The performance of this system allows for rapid detection of individual specific pathogenic microorganisms . Two of the most significant commercial applications of this technique are the detection of infectious microorganisms in contaminated food and water . Food-borne microbial pathogens account for approximately 7 million illnesses and 9,000 deaths in the U.S . annually, with an estimated economic loss of at least $6 billion {1} . In addition, this method has the potential for a broad range of other commercial applications, including the detection of small numbers of molecules, such as the ultrasensitive detection of explosives and groundwater contaminants.

Environ Technol, 2001 Mar, 22(3), 339 - 44
Quantitative bioregeneration of granular activated carbon loaded with phenol and 2,4-dichlorophenol; Vinitnantharat S et al.; Lignite based granular activated carbon of 20x30 mesh size was used to investigate the extent of bioregeneration of phenol and 2,4-DCP in a batch system . The adsorption isotherm fits very well with the Freundlich isotherm and it is apparent that 2,4-DCP is more adsorbable than phenol . The degree of reversible adsorption for phenol and 2,4-DCP were 32.9 and 10.6 %, respectively . The low percentages of their reversibility meant that the adsorption phenomena of both phenol and 2,4-DCP were not fully physicosorption . The microorganisms can regenerate 31.4% (21.2 mg g(-1)) of GAC loaded with phenol and 14.3% (24.8 mg g(-1)) of GAC loaded with 2,4-DCP over a period of 7-10 days . The bioregeneration of phenols closely followed the first order kinetics with the rate constant of 0.046 day(-1) at initial phenol concentration of 100 mg l(-1) and biomass concentration of 20 mg l(-1) MLVSS . The rate constant was 0.021 day(-1) at initial 2,4-DCP concentration of 200 mg l(-1) and 200 mg l(-1) MLVSS . In addition, the increasing in initial concentration of biomass in the solution shortened the time required to reach the asymptotic limit on the bioregeneration but rendered little impact on the bioregeneration percentage.

Environ Toxicol Chem, 2001 Apr, 20(4), 721 - 6
Kinetics of polychlorinated biphenyl dechlorination and growth of dechlorinating microorganisms; Rhee GY et al.; The present study has investigated a correlation between the kinetics of polychlorinated biphenyl (PCB) dechlorination and the growth of dechlorinating microbial populations . Microorganisms were eluted from Aroclor 1248-contaminated St . Lawrence River (NY, USA) sediments and inoculated into clean sediments spiked with Aroclor 1248 at 10 concentrations ranging from 0 to 3.12 micromol/g sediment (0-900 ppm) . The time course of PCB dechlorination and population growth were concurrently determined by congener-specific analysis and the most probable number technique, respectively . The specific growth rate was a saturation function of PCB concentrations above the threshold concentration (0.14 micromol/g sediment, or 40 ppm), below which no dechlorination or growth of dechlorinations were observed . The maximum growth rate was 0.20/d with a half-saturation constant of 1.23 micromol/g sediment . The yield of dechlorinating microorganisms showed a peak at 0.70 micromol/g sediment (200 ppm), with a value of 10.3 x 10(12) cells/mol Cl removed, and decreased below and above this concentration . The dechlorination rate (micromol Cl removed/g sediment/d) was a linear function of Aroclor concentration . Both the log of this rate and the maximum level of dechlorination were significantly correlated with growth rate . The biomass-normalized dechlorination rate (micromol Cl removed/g sediment/cell/d) was first order because of the exponential manner of the population growth . The first-order rate constant was a saturation function of Aroclor concentrations, with a maximum of 0.24/d (a half-life of 2.9 d) and a half-saturation constant of 1.18 micromol/g sediment, which are similar to the constants for growth . These results indicate that the dechlorination rate is tightly linked to the population growth of dechlorinating microorganisms.

J Clin Invest, 1974 Feb, 53(2), 343 - 53
Serum heat-labile opsonins in systemic lupus erythematosus; Jasin HE et al.; To study possible mechanisms responsible for the increased susceptibility to infection of patients with active systemic lupus erythematosus (SLE), a study of the serum heat-labile opsonic capacity (HLOC) in such patients was undertaken . With leukocytes from normal donors, the sera of 12 of 30 patients with active SLE demonstrated decreased HLOC for E . coli 075 . The phagocytic activity was partially restored by normal serum, suggesting that decreased HLOC was responsible for the defective phagocytosis . While 8 of 10 patients with active SLE and concomitant infections showed deficient opsonic capacity to E . coli 075, only 4 of 20 such patients without infections showed the defect (P = 0.01) . None of 12 patients with inactive disease had deficient opsonic capacity . Similar results were obtained with S . aureus 502A as the test bacterium . In the patients surviving infection, recovery of normal serum opsonic capacity was rapid and usually coincided with an increase of serum complement to normal levels . In three patients with active SLE and infection, the causative microorganisms were isolated and opsonic capacity for these organisms tested with the individual patients' sera . In each case, sera obtained at the onset of the infectious episode had low opsonic capacity when compared with normal sera . Serum C3 proactivator levels were low in 9 of 11 sera with deficient opsonic capacity . However, similar low values were found in other SLE sera with normal HLOC, suggesting that other factors of the opsonic system were also depleted . Addition of the classical complement components C1, C4, C2, C3, and C5 to sera with deficient HLOC failed to restore activity . Addition of pure C3 proactivator also failed to restore activity . However, addition of C3 proactivator together with 50 degrees C-heated normal serum restored activity, indicating that factors active at the early steps of opsonic activation via the alternative pathway of complement were necessary to restore opsonic activity . These findings indicate that in active SLE, a decrease of components of the alternate pathway of complement activation results in an acquired defect of serum HLOC and perhaps other related complement-mediated functions . This defect may be an important factor in the increased susceptibility to infections of patients with active systemic lupus erythematosus.

J Allergy Clin Immunol, 2001 May, 107(5), 856 - 62
Group 13 grass allergens: structural variability between different grass species and analysis of proteolytic stability; Petersen A et al.; BACKGROUND: Determination of the allergen composition of an extract is essential for the improvement of hyposensitization therapy . Surprisingly, although grass pollen extracts have been studied intensively for 20 years, a further major allergen, Phl p 13, was detected recently in timothy grass pollen . OBJECTIVES: We sought to determine the occurrence and importance of group 13 allergens in various grass species and to investigate their proteolytic stability . METHODS: The group 13 allergens were determined by means of 2-dimensional PAGE blotting with patient sera and group 13-specific mAbs . The allergens were isolated chromatographically from several pollen extracts and analyzed by means of microsequencing . Cross-reactivity among various grass species was studied by using Western blots and immunoblot inhibition tests . The stability of the allergens was tested under defined extraction conditions . RESULTS: Group 13 allergens are detectable in all common grasses and show IgE cross-reactivity among them . The allergenic components were identified in the neutral pH range with molecular masses of 50 to 60 kd, and in the case of Phl p 13, maximal binding of the isoforms was observed at 55 kd and at an isoelectric point of 6 to 7.5 . Protein sequencing clearly confirms structural identities between different grass species, although individual variations are found . If low-molecular-mass components were depleted by means of gel filtration, a rapid degradation of group 13 allergens was observed . This is in contrast to other pollen allergens described thus far . CONCLUSION: Group 13 allergens are widespread and are major allergens in the grasses . Predicted from their primary structures, these allergens are polygalacturonases . This class of enzymes is already known from microorganisms, and these enzymes are recognized as potential inducers of asthma . Our studies indicate that the group 13 allergens show a considerable microheterogeneity and degradation, especially after depletion of low-molecular-mass components . One has to be aware of this pivotal fact when soluble grass pollen extracts are prepared for diagnostics and hyposensitization therapy.

Dig Dis Sci, 2001 May, 46(5), 1127 - 32
Acute pancreatitis and bacterial translocation; Cicalese L et al.; Infectious complications are the most frequent and severe complications of acute narcotizing pancreatitis (AP) with a mortality rate up to 80% . Although experimental and clinical studies suggest that the microbiologic source of pancreatic infection could be enteric, information in this regard is scant . This study evaluated bacterial translocation (BT) using mild and severe models of AP . Mild AP was induced by 6-hr continuous intravenous infusion of cerulein, while severe AP was induced by additional infusion of glycodeoxycholic acid into the biliopancreatic duct . BT was evaluated with organ cultures performed when animals were killed (24 hr) . To confirm the gastrointestinal origin of the translocating microorganisms, fluorescent microspheres were also given to the animals in drinking water 24 hr before induction of AP . At the time of death beads were counted with a (fluorescence-activated cell sorter) (FACS) in peritoneal lavages and with fluorescent microscopy in frozen sections of the pancreata . Morphology of the distal small bowel showed significant changes in the animals with AP compared to controls, such as reduction of villus high and altered microvasculature . Mild AP induced BT to the pancreas in 100% of the animals, compared to pancreata from control groups . Severe AP induced increased BT to the pancreas . BT to liver and spleen was also significantly increased with AP . The presence of fluorescent microspheres confirmed their enteric derivation . This study provides evidence for the enteric origin of microorganisms responsible for pancreatic infectious complications during AP . The evidence of BT after laparotomy suggests an increased risk of infections with the association of these conditions . This could provide an explanation for the high mortality associated with laparotomy in course of AP.

Appl Microbiol Biotechnol, 2001 Apr, 55(3), 290 - 5
Production of 3-nitrocatechol by oxygenase-containing bacteria: optimization of the nitrobenzene biotransformation by Nocardia S3; Kieboom J et al.; Twenty-one microorganisms were screened for their ability to convert nitroaromatics into 3-nitrocatechol as a result of the action of an oxygenase . Cultures containing toluene dioxygenases and phenol monooxygenases accumulated 3-nitrocatechol during incubation with nitrobenzene and nitrophenol, respectively . Nocardia S3 was selected and studied in more detail . Toluene-pregrown cultures were able to degrade nitrobenzene with a concomitant formation of 3-nitrocatechol . The rates of nitrobenzene utilization decreased throughout the biotransformation period and finally the accumulation ceased . The gradual deterioration of the biotransformation rates was not a consequence of depletion of the NADH pool, but was due to the accumulation of 3-nitrocatechol . The inhibition of nitrobenzene biotransformation by 3-nitrocatechol greatly impacts 3-nitrocatechol production processes.

Ground Water, 2001 May-Jun, 39(3), 348 - 55
In situ determination of subsurface microbial enzyme kinetics; Istok JD et al.; The single-well, push-pull test has been used in previous field studies to measure in situ zero- and first-order rates for aerobic and anaerobic microbial respiration in the saturated zone . In this paper we demonstrate that the test can also be used to obtain more generalized descriptions of the kinetics of microbially mediated enzymatic reactions . Laboratory and field tests were performed with the model enzyme substrate p-nitrophenyl-beta-D-glucopyranoside (PNG) . During a push-pull test, injected PNG is hydrolyzed in situ to p-nitrophenol (PNP); the rate of PNP production is taken as a measure of the beta-glucosidase activity expressed by indigenous microorganisms . Laboratory tests were performed in physical aquifer models packed with natural aquifer sediment; field tests were performed in a shallow unconfined alluvial aquifer at a petroleum contaminated site . The laboratory and field tests demonstrate that it is possible to compute the in situ rate of PNP production as a function of PNG concentration using only data from a single push-pull test . These data can then be used to estimate the Michaelis-Menton kinetic parameters Vmax and Km for the hydrolysis reaction . This approach potentially extends the range of applicability of the push-pull test approach for use in determining kinetic parameters for a wide range of microbial processes in situ . These could include the broad class of substituted nitrophenyl substrates used to assay other enzyme systems, as well as microbially mediated redox reactions that occur during contaminant transformations.

Clin Infect Dis, 2001 Jun 1, 32(11), 1589 - 601 Epub 2001 Apr 30.
Infectious disease pathology; Procop GW et al.; The anatomic pathologist performs an important role in the diagnosis or exclusion of infectious diseases . The morphologic interpretation of biopsies and cytologic preparations allows for the definitive establishment or exclusion of a wide variety of diseases . Once the pathologist has determined that a disease is likely to be due to an infection and has characterized the inflammatory response, associated microorganisms or viral-associated cytopathic effects should be recorded . Although some microorganisms or their cytopathic effects may be clearly visible on routine hematoxylin and eosin-stained sections, additional histochemical stains are often needed for their complete characterization . Highly specific molecular techniques, such as immunohistochemistry, in situ hybridization, and nucleic acid amplification, may be needed in certain instances to establish the diagnosis of infection . Through appropriate morphologic diagnoses and interlaboratory communication and collaboration, the anatomic pathologist contributes greatly to the diagnosis and treatment of infectious diseases.

Mikrobiologiia, 2001 Jan-Feb, 70(1), 106 - 10
{Effect of certain environmental factors on Bradyrhizobium japonicum}; Kurdish IK et al.; Dependence of motility and chemotaxis was studied in two strains of Bradyrhizobium japonicum upon several environmental factors . In both strains, chemotaxis was found to increase with an increasing concentration of the attractant (glucose) to 5.6 x 10(-2) M . Both motility and chemotaxis reached their maximum in the two- to three-day cultures at neutral pH . The maximum motility of these bacteria occurred at 40 degrees C . The maximum values of chemotaxis in these microorganisms were, however, observed at 20-25 degrees C . Chemotaxis in acidic or alkaline media and at low temperatures was found to be markedly weaker . Nonoptimal values of these parameters in soil may be a limiting factor for the interaction of the given bacteria with soybean roots.

Am J Clin Pathol, 2000 Dec, 114(6), 880 - 9
Quantitative analysis of valvular lesions during Bartonella endocarditis; Lepidi H et al.; Cardiac valve pathology was evaluated in 15 patients with confirmed diagnosis of Bartonella endocarditis . Ten were infected by Bartonella quintana and 5 by Bartonella henselae . Histologic features of these cases, including fibrosis, calcification, vegetation, pattern of inflammation, and vascularization, were compared with those of valves from 25 cases of non-Bartonella endocarditis as controls using a computerized quantitative image analysis . Pathologic and immunohistologic testing for localization of Bartonella species in resected valves included Warthin-Starry stain and polyclonal antibody-based immunodetection . Compared with other cases of infective endocarditis, cases of Bartonella endocarditis are more fibrotic and calcified, less vascularized, with less extensive vegetation and chronic inflammation . These pathologic changes are suggestive of a prolonged infection . Warthin-Starry stain and immunohistologic testing demonstrated the presence of the organism, respectively, in 11 and 10 of the 13 tested valves . Results of both staining methods showed microorganisms in extracellular locations and in regions unaccompanied by inflammation . Pathology and immunohistology may contribute to the etiologic diagnosis of Bartonella endocarditis when serology and molecular techniques are not available.

Vestn Ross Akad Med Nauk, 2001, (3), 18 - 21
{Cold shock in bacteria}; Basnak'ian IA; Various species and genera of bacterial show the same responses to low temperature . Cold induces cold shock genes, by causing significant changes in the regulation of protein synthesis . The synthesis of major proteins in the microbial cell is suppressed . However, there is synthesis of a great deal of new proteins, the so-called cold shock ones . The chief protein in this family is E . coli CspA that activates the translation of other cold shock genes and negatively regulates the expression of its own gene . E . coli CspA homologies were identified in many bacteria . They can be also identified in other microorganisms, including the pathogens of infectious diseases . This can be attributable to the presence of common antigens in different bacteria . The data presented should be borne in mind in identifying bacteria and in designing immunodiagnostic agents if there is a culture cooling stage in their technology.

Ann Clin Lab Sci, 2001 Apr, 31(2), 157 - 61
Cytomegalovirus seropositivity and serum total cholesterol levels in young patients; Froberg MK et al.; Atherosclerosis is a chronic inflammatory disease of arteries, associated with multiple genetic and environmental factors, including hypertension, diabetes mellitus, cigarette smoking, modified and elevated LDL cholesterol, elevated plasma homocysteine, and infectious microorganisms such as Chlamydia pneumoniae and cytomegalovirus (CMV) . CMV has been implicated in atherogenesis by epidemiological studies, animal research, and molecular analyses that have demonstrated CMV nucleic acids within human atherosclerotic lesions . Studies have suggested that CMV infection may alter lipid metabolism and lead to accumulation of cholesterol within atheromatous plaques . Few studies have examined the relationship between CMV infection and serum cholesterol levels in younger individuals when much of atherogenesis occurs . To test if CMV-seropositivity is associated with high levels of serum total cholesterol in relatively young patients, CMV IgG levels and total cholesterol concentrations were analyzed in serums from 172 patients, age < 50 yr . Based on univariate analysis of variance, serum total cholesterol was significantly correlated to age and to CMV-seropositivity when gender was a cofactor, but not to gender or CMV-seropositivity alone . In 39 CMV-seropositive women, serum total cholesterol concentration averaged 218 +/- 50 mg/dL (mean +/- SD), which was significantly higher than in 53 CMV-seronegative women (194 +/- 39 mg/dL, p < 0.02) . No significant difference was observed between the serum total cholesterol concentrations in 26 CMV-seropositive men and 51 CMV-seronegative men (198 +/- 42 mg/dL versus 212 +/- 48 mg/dl, respectively) . Thus, this study provides evidence that CMV-seropositivity is associated with higher serum total cholesterol levels in female patients under 50 yr of age, but not in male patients of comparable age.

Environ Toxicol Chem, 2001 May, 20(5), 1133 - 40
The relation between extrapolated risk, expressed as potentially affected fraction, and community effects, expressed as pollution-induced community tolerance; Van Beelen P et al.; The results of toxicity tests can be used to calculate the potentially affected fraction (PAF) of species in an ecosystem at a given pollutant concentration using statistical extrapolation methods . The PAF curve indicates the fraction of species from the original community that may become inhibited at each elevated pollutant concentration and is a measure of the ecotoxicological risk . Pollution-induced community tolerance (PICT) is a true community response that is measured under controlled conditions in the laboratory, using organisms from contaminated field sites . Microorganisms from experimental field plots with added Zn were exposed to various concentrations of Zn in the laboratory and the mineralization of 14C acetate was monitored . Microorganisms from plots with Zn concentrations above 124 mg/kg showed a significant increase in the effect concentration 10% (EC10) and, therefore, had a significant PICT . The pore-water concentrations of Zn in these field soils were in the same magnitude as the EC10 of the microorganisms from these soils . The PAF curve was calculated from previously reported toxicity tests with five different microbial species using the average and the standard deviation of the logarithmically transformed EC10 values . The average sensitivity of this PAF curve was similar to the EC50 of the acetate mineralization curve from the field plot without added Zn2+, but the PAF curve was less steep . Our experiments indicated that 27 to 84% of the original microbial species were inhibited at Zn concentrations from 334 to 1,858 mg/kg soil, respectively . Our results suggest that the PICT method can now also be used to quantify the fraction of the original species composition that is inhibited at a specific pollutant concentration.

J Biol Chem, 2001 Jul 13, 276(28), 25894 - 902 Epub 2001 May 03.
Stoichiometry of complexes between mannose-binding protein and its associated serine proteases . Defining functional units for complement activation; Chen CB et al.; Serum mannose-binding protein (MBP) initiates the lectin branch of the complement cascade by binding to sugars on the surfaces of microorganisms and activating two MBP-associated serine proteases (MASP-1 and MASP-2) . Rat serum MBP consists of oligomers containing up to four copies of a subunit that is composed of three identical polypeptide chains . Biophysical analysis of intact and truncated MASPs indicates that each MASP is a homodimer that is stabilized through interactions involving an N-terminal CUB domain . The binding sites for MBP are formed from the three N-terminal MASP domains, in which two CUB modules interact with MBP . Each MASP dimer contains binding sites for two MBP subunits . Both sites must be occupied by subunits from a single MBP oligomer to form a stable complex . Thus, the smallest functional unit for complement activation consists of MBP dimers bound to MASP-1 or MASP-2 homodimers . Trimers and tetramers of MBP form complexes containing up to two MASPs . The results reveal how MASP-1 and MASP-2 can function independently to activate the complement cascade.

Diagn Microbiol Infect Dis, 2001 Mar, 39(3), 161 - 4
Trichosporon species infection in bone marrow transplanted patients; Moretti-Branchini ML et al.; Trichosporon species are emerging as opportunistic agents that cause systemic diseases in immunocompromised patients . Patients undergoing bone marrow transplant are submitted to intense and prolonged periods of neutropenia and consequently to several risk factors to fungal infections as the use of broad spectrum antibiotics and invasive devices . Two cases of fungal infections caused by Trichosporon asahii var . asahii and T . inkin in patients with bone marrow transplant are described T . asahii var . asahii was responsible for fungemia and the identification of this microorganism was later performed . T . inkin caused vascular accesses infection and was recovered from an implanted Hickman-Broviac catheter . Both patients were under oral fluconazole prophylaxis . The patient with systemic infection died despite the therapy with amphotericin B and the patient with catheter-related infection recovered from the fungal infection after catheter removal . Difficulties in the identification of this microorganism lead to delays in treatment and post-mortem diagnosis.

Trends Microbiol, 2001 May, 9(5), 228 - 37
Maturation of the {NiFe} hydrogenases; Casalot L et al.; The high degree of similarity that exists between all the {NiFe} hydrogenase operons and the near universality of hydrogen metabolism among microorganisms suggest that the microbial ability to metabolize hydrogen is of great importance and ancient origin . The large number of genes present in these operons, which are mostly involved in the maturation of the structural subunit, is indicative of the complexity of the hydrogenase molecular structure . Two main groups of maturation genes can be differentiated based on the resulting phenotypes when mutated: the 'cis-genes', encoding narrow specificity proteins, are mainly located on the same transcription unit as the structural genes, and the 'trans-genes', encoding broad specificity proteins, are located on a different operon . The maturation of the large subunit starts with the formation of a complex with the chaperone HypC, which remains bound to the amino terminus throughout processing . The ligands CN and CO, which are derived from carbamoylphosphate, are then inserted via HypF and probably other accessory proteins . HypB is responsible for nickel atom delivery in a GTP-hydrolysis-dependent reaction . The last identified step in the large subunit maturation process is proteolytic cleavage at the carboxyl terminus . The possible roles of the other maturation proteins are also discussed.

Med Clin (Barc), 2001 Feb 24, 116(7), 256 - 8
{Reduction of hematogenous infection in HIV positive patients following highly active antiretroviral therapy}; Luisa Pedro-Botet M et al.; BACKGROUND: Bloodstream infections have probably decreased in HIV patients since highly active antiretroviral therapy (HAART) usage . PATIENTS AND METHOD: Hematogenous infections, including mycobacteria and fungi in HIV patients, stratified into two periods (I: 1995-1996 and II: 1997-1998) were included to evaluate changes attributable to HAART . RESULTS: 226 episodes were attended (incidence: 38.8 in period I and 15.3 in period II; p < 0.01) . A significant decrease was observed in immunosuppression related microorganisms . HAART usage increased from 6.4% in period I to 31.2% in period II . Immunological parameters of HIV patients significantly improved in period II . CONCLUSIONS: Hematogenous infections have significantly decreased in HIV patients since the use of HAART.

Gastroenterol Hepatol, 2001 Apr, 24(4), 186 - 90
{Infectious complications associated with liver transplantation: analysis of 104 patients}; Cubiella J et al.; OBJECTIVE: Infectious complications are the main cause of morbidity and mortality during the first year after liver transplantation . The aim of the present study was to determine the incidence, microorganisms and factors associated with the development of infectious complications . PATIENTS AND METHOD: Retrospective analysis of infectious episodes during the first year after transplantation in 104 patients undergoing transplantation between April 1995 and December 1996 . The various clinical variables related to the pre-transplant disease, the surgical intervention and post-transplant evolution were evaluated with the aim of identifying predictive factors for the development of bacterial infectious complications . RESULTS: During the first year, 51 patients (49%) presented 111 infectious episodes . The most frequent infections were bacterial (66%); 21% were cytomegalovirus infections and 22% were fungal . The incidence of bacterial infections was highest during the first month (80% of all infectious episodes in this period) . Two variables were independently associated with the development of bacterial infections in the first month following transplantation: prolonged ischemia of the graft (p = 0.002) and length of stay in the intensive care unit (p = 0.002) . Infectious complications caused 8 of the 11 deaths that occurred during the 1-year follow-up . Mortality associated with invasive fungal infections was 100% . CONCLUSIONS: Although the overall incidence of infections and associated mortality has decreased, it remains the main cause of mortality and morbidity in the first year after transplantation.

Physiol Biochem Zool, 2001 May-Jun, 74(3), 398 - 403
Effect of age on seed digestion in parrots (Amazona aestiva); Vendramin-Gallo M et al.; The objective of this study was to compare the capacity of adult (more than 3 yr old) and young (less than 1 yr old) true parrots to digest seeds that are normally included in their diet in captivity, particularly soybean, sunflower, and corn . All the seeds were offered for 5 d with an interval of 15 d between different diets . The seeds of soybean and corn were boiled for 15 min and soaked in water at ambient temperature for 12 h before being fed to the birds . There were no differences in the digestibilities of crude protein and fats (ether extract) among animals, but the digestibilities of dry matter and crude fiber by the adult animals were higher than those of the young ones . The digestibility of carbohydrate (nitrogen-free extract) by adult birds was higher only for sunflower seeds . It is concluded that the capacity of parrots to digest fiber may change according to the age of the animal . Since the digestion of fiber depends on the action of microorganisms, these results suggest that the colonization of the gastrointestinal tract is delayed or very slow in young parrots.

Appl Microbiol Biotechnol, 2001 Mar, 55(2), 219 - 25
Studies on the possibility of histidine biosynthesis from histodinol, imidazolepyruvic acid, imidazoleacetica acid, and imidazolelactic acid by mixed ruminal bacteria, protozoa, and their mixture in vitro; Wadud S et al.; The possibility of histidine (His) synthesis using a main biosynthetic pathway involving histidinol (HDL) and also the recycling capability of imidazolic compounds such as imidazolepyruvic acid (ImPA), imidazoleacetic acid (ImAA), and imidazolelactic acid (ImLA) to produce His were investigated using mixed ruminal bacteria (B), protozoa (P), and a mixture of both (BP) in an in vitro system . Rumen microorganisms were anaerobically incubated at 39 degrees C for 18 h with or without each substrate (2 mM) mentioned . His and other related compounds produced in both the supernatants and hydrolyzates of the incubation were analyzed by high-performance liquid chromatography . B, P, and BP suspensions failed to show His synthesizing ability when incubated with HDL . His was synthesized from ImPA by B, P, and BP . Expressed in units "per gram of microbial nitrogen (MN)", ImPA disappearance was greatest in B (72.7 micromol/g MN per hour), followed by BP (33.13 micromol/g MN per hour) and then P (18.6 micromol/g MN per hour) for the 18-h incubation period . The production of His from ImPA in B (240.0, 275.9, and 261.2 micromol/g MN in 6, 12, and 18 h incubation, respectively) was about 3.5 times higher than that in P (67.3, 83.8, and 72.7 micromol/g MN in 6, 12, and 18 h incubation, respectively) . Other metabolites produced from ImPA were ImLA, ImAA, histamine (HTM), and urocanic acid (URA), found in all microbial suspensions . ImLA as a substrate remained without diminution in all microbial suspensions . Although ImAA was found to be degraded to a small extent (3.4-6.3%) only after 18 h incubation, neither His nor other metabolites were detected on the chromatograms . These results have been demonstrated for the first time in rumen microorganisms and suggest that His may be an essential amino acid for rumen microorganisms.

Appl Microbiol Biotechnol, 2001 Mar, 55(2), 143 - 9
Plate screening methods for the detection of polysaccharase-producing microorganisms; Ruijssenaars HJ et al.; Polysaccharide-degrading enzymes (polysaccharases) are widely applied in industry . One of the sources of these enzymes are polysaccharide-degrading microorganisms . To obtain such microorganisms from enrichment cultures, strain collections or gene libraries, efficient plate screening methods are required that discriminate between intact and degraded polysaccharide . This can be achieved by making use of specific physicochemical properties of the polysaccharide, such as complex formation with dyes and gelling capacity, or by the application of dye-labelled polysaccharides . This review presents a survey of plate methods based on these principles . Both theoretical and practical aspects of the methods are discussed.

Biosci Biotechnol Biochem, 2001 Mar, 65(3), 570 - 8
Investigation of various genotype characteristics for inosine accumulation in Escherichia coli W3110; Matsui H et al.; For the derivation of an inosine-overproducing strain from the wild type microorganism, it is known that the addition of an adenine requirement, removal of purine nucleoside hydrolyzing activity, removal of the feedback inhibition, and repression of key enzymes in the purine nucleotides biosynthetic pathway are essential . Thus, the disruption of purA (adenine requirement), deoD (removal of purine nucleosides phosphorylase activity), purR (derepression of the regulation of purine nucleotides biosynthetic pathway), and the insensitivity of the feedback inhibition of phosphoribosylpyrophosphate (PRPP) amidotransferase by adenosine 5'-monophosphate (AMP) and guanosine 5'-monophosphate (GMP) were done in the Escherichia coli strain W3110, and then the inosine productivity was estimated . In the case of using a plasmid harboring the PRPP amidotransferase gene (purF) that encoded a desensitized PRPP amidotransferase, purF disrupted mutants were used as the host strains . It was found that the innovation of the four genotypes brought about a small amount of inosine accumulation . Furthermore, an adenine auxotrophic mutant of E . coli showed inappropriate adenine use because its growth could not respond efficiently to the concentration of adenine added . As the presence of adenosine deaminase is well known in E . coli and it is thought to be involved in adenine use, a mutant disrupted adenosine deaminase gene (add) was constructed and tested . The mutant, which is deficient in purF, purA, deoD, purR, and add genes, and harboring the desensitized purF as a plasmid, accumulated about 1 g of inosine per liter . Although we investigated the effects of purR disruption and purF gene improvement, unexpectedly an increase in the inosine productivity could not be found with this mutant.

Epidemiol Mikrobiol Imunol, 2001 Apr, 50(2), 87 - 91
{Free radicals in immunology and infectious diseases}; Racek J et al.; Free radicals contribute significantly in modification of immune processes and inflammatory reactions . They are produced by activated phagocytes which use them for killing microorganisms . Free radicals facilitate production of cytokines, which are important as modifiers of inflammatory reactions . Formation of free radicals is influenced by antioxidants which can thus modify the intensity of inflammatory reaction and immune response . The authors describe in detail the contribution of free radicals in etiology and pathogenesis of autoimmune diseases including rheumatoid arthritis, multiple sclerosis or amyotrophic lateral sclerosis . The role of free radicals and modifying influence of antioxidants in viral, bacterial, parasitic and mycotic diseases is described in the second part of the review . Finally, influence of free radicals and antioxidants on immunity changes in patients with malignant tumours, during aging and physical exercise is discussed.

Xenotransplantation, 2001 May, 8(2), 125 - 35
Sensitive and specific immunological detection methods for porcine endogenous retroviruses applicable to experimental and clinical xenotransplantation; Tacke SJ et al.; The use of organs from transgenic pigs for xenotransplantation may be associated with the risk of transmission of microorganisms, especially when the transgenic pigs express human proteins influencing complement activation . The porcine endogenous retroviruses (PERVs) are of particular concern as they can infect human cells in vitro . However, it is unknown whether PERVs can infect transplant recipients in vivo and, if so, whether they are pathogenic . It is therefore essential for experimental and clinical xenotransplantation procedures that specific and sensitive screening methods for PERVs are established . We developed Western blot and enzyme-linked immunosorbant assays (ELISA) based on purified PERVs produced by pig and human cells or recombinant viral protein and synthetic peptides corresponding to PERVs' transmembrane envelope protein, respectively . PERV-specific anti-sera generated against purified virus particles, purified viral proteins and synthetic peptides served as positive controls . Both assays were used for screening the sera of healthy blood donors, pregnant women, patients treated with pig tissues, and butchers with extensive contact to living porcine material to detect antibodies against PERV . None of the individuals showed an antibody pattern characteristic for retroviral infections . Some individuals had antibodies reactive against the major capsid protein p27, against smaller viral proteins of the group specific antigen (Gag) in Western blot assays, or against peptides in the ELISA, probably due to cross-reactivity . Here, we present specific and highly sensitive screening methods applicable for future xenotransplantation procedures, but using these methods we found no evidence of PERV-infection among humans potentially at risk.

Acta Neurol Scand, 2001 Apr, 103(4), 207 - 13
Respiratory complications related to bulbar dysfunction in motor neuron disease; Hadjikoutis S et al.; Bulbar dysfunction resulting from corticobulbar pathway or brainstem neuron degeneration is one of the most important clinical problems encountered in motor neuron disease (MND) and contributes to various respiratory complications which are major causes of morbidity and mortality . Chronic malnutrition as a consequence of bulbar muscle weakness may have a considerable bearing on respiratory muscle function and survival . Abnormalities of the control and strength of the laryngeal and pharyngeal muscles may cause upper airway obstruction increasing resistance to airflow . Bulbar muscle weakness prevents adequate peak cough flows to clear airway debris . Dysphagia can lead to aspiration of microorganisms, food and liquids and hence pneumonia . MND patients with bulbar involvement commonly display an abnormal respiratory pattern during swallow characterized by inspiration after swallow, prolonged swallow apnoea and multiple swallows per bolus . Volitional respiratory function tests such as forced vital capacity can be inaccurate in patients with bulbofacial weakness and/or impaired volitional respiratory control . Bulbar muscle weakness with abundant secretions may increase the risk of aspiration and make successful non-invasive assisted ventilation more difficult . We conclude that an evaluation of bulbar dysfunction is an essential element in the assessment of respiratory dysfunction in MND.

IUBMB Life, 2000 Oct-Nov, 50(4-5), 267 - 9
The NADPH oxidase of endothelial cells; Babior BM; The best known NADPH oxidase is that of phagocytes-neutrophils and monocytes . In these cells, the enzyme manufactures large quantities of O2- and other reactive oxidants that are used for the purpose of killing invading microorganisms . Recent studies, however, have suggested that a number of other tissues contain NADPH oxidases . In contrast to the very vigorous production of oxidants by phagocytes, rates of oxidant production by these other cell types are quite low . Oxidant production by these cells is generally thought to serve a signaling function.

J Rheumatol, 2001 Apr, 28(4), 802 - 4
Musculoskeletal manifestations in patients positive for human immunodeficiency virus: correlation with CD4 count; Casado E et al.; OBJECTIVE: To determine the relationship between the CD4+ lymphocyte count and musculoskeletal manifestations of human immunodeficiency virus (HIV) infection . METHODS: All patients from 1991 to 1998 who were positive for HIV with osteoarticular manifestations were reviewed retrospectively . HIV positivity was confirmed by ELISA and Western blot . CD4 count was performed by flow cytometry . RESULTS: We studied 74 patients with osteoarticular manifestations . The study group comprised 61 men (82.4%) and 13 women (17.5%) with a mean age of 34.2 years (range 17-62) . Fifty-two patients were iv drug users (70.3%) . Septic arthritis was present in 20 cases (23.0%), soft tissue infections in 9 cases (12.2%), spondyloarthropathies in 6 cases (8.1%), lymphomas in 9 cases (12.2%), osteomyelitis in 6 (8.1%), and 24 miscellaneous cases (32.4%) . The mean CD4 count was as follows: septic arthritis 164.7 cells/mm3, soft tissue involvement 127.1 cells/mm3, spondyloarthropathies 245.8 cells/mm3, lymphoma 132.8 cells/mm3, and osteomyelitis 233.6 cells/mm3 . CONCLUSION: Osteoarticular manifestations in the setting of HIV infection tend to be predominantly infectious . S . aureus is the microorganism most frequently involved . Ostearticular infections always appeared when the CD4 count was < 200 and pyomyositis and lymphoma appeared when CD4 was < 150 . CD4 counts may be useful predictors to determine the type of musculoskeletal manifestation.

J Calif Dent Assoc, 2000 Mar, 28(3), 204 - 14
Oral microorganisms and cardiovascular disease; Pallasch TJ et al.; The list of etiological factors for cardiovascular disease is long, complicated, intertwined, and yet to be completed . This paper will evaluate the current evidence for the pathogenic role of certain microorganisms, including those of the oral cavity, in the etiology of cardiovascular disease.

J Calif Dent Assoc, 2000 Mar, 28(3), 194 - 200
The focal infection theory: appraisal and reappraisal; Pallasch TJ et al.; This paper discusses the past, present, and future of the focal infection theory of disease . A focal infection is a localized or general infection caused by the dissemination of microorganisms or toxic products from a focus of infection . The resurgence of the focal infection theory of disease has been greeted with great enthusiasm in some quarters; however, the present evidence for the relationship of oral microorganisms and systemic disease is very limited due not only to a dearth of prospective studies and a complete lack of interventional studies but also to very significant methodological difficulties associated with the clinical studies that have been performed.

Mol Psychiatry, 2001 May, 6(3), 329 - 33
Low avidity of human serum antibodies for Borna disease virus antigens questions their diagnostic value; Allmang U et al.; Borna disease virus (BDV) can induce neurological disease in animals . Since viral nucleic acid, infectious particles and antibodies recognizing BDV antigens were found at higher frequencies in psychiatric patients than in healthy controls, BDV is suspected to cause psychiatric disorders in humans . However, the human origin of these viruses has recently been questioned . To diagnose BDV infections, sera are usually analyzed for antiviral antibodies by indirect immunofluorescence (IFA) on virus-infected cells . This study reveals that the reactive antibodies in human sera mainly recognized the BDV phosphoprotein, whereas animal sera preferentially detected the viral nucleoprotein . Immunoglobulin (Ig) G in sera of experimentally or naturally infected animals bound to the viral antigen with high avidity, ie resisting 3 M urea, whereas reactive IgG in human sera did not . Longitudinal studies showed that reactive human antibodies persisted for many years without gaining high avidity for BDV antigens, indicating that they were probably not induced by BDV but rather by infection with an antigenically related microorganism of unknown identity or by exposure to other related immunogens.

Nature, 2001 Apr 26, 410(6832), 1103 - 7
TREM-1 amplifies inflammation and is a crucial mediator of septic shock; Bouchon A et al.; Host innate responses to bacterial infections are primarily mediated by neutrophils and monocytes/macrophages . These cells express pattern recognition receptors (PRRs) that bind conserved molecular structures shared by groups of microorganisms . Stimulation of PRR signalling pathways initiates secretion of proinflammatory mediators, which promote the elimination of infectious agents and the induction of tissue repair . Excessive inflammation owing to bacterial infections can lead to tissue damage and septic shock . Here we show that inflammatory responses to microbial products are amplified by a pathway mediated by triggering receptor expressed on myeloid cells (TREM)-1 . TREM-1 is an activating receptor expressed at high levels on neutrophils and monocytes that infiltrate human tissues infected with bacteria . Furthermore, it is upregulated on peritoneal neutrophils of patients with microbial sepsis and mice with experimental lipopolysaccaride (LPS)-induced shock . Notably, blockade of TREM-1 protects mice against LPS-induced shock, as well as microbial sepsis caused by live Escherichia coli or caecal ligation and puncture . These results demonstrate a critical function of TREM-1 in acute inflammatory responses to bacteria and implicate TREM-1 as a potential therapeutic target for septic shock.

J Mol Microbiol Biotechnol, 2001 Apr, 3(2), 145 - 50
Comparative genomics of microbial drug efflux systems; Paulsen IT et al.; The complete genome sequences of 36 microorganisms have now been published and this wealth of genome data has enabled the development of comparative genomic and functional genomic approaches to investigate the biology of these organisms . Comparative genomic analyses of membrane transport systems have revealed that transporter substrate specificities correlate with an organism's lifestyle . The types and numbers of predicted drug efflux systems vary dramatically amongst sequenced organisms . Microarray and gene knockout studies to date have suggested that predicted drug efflux genes often appear to be a) non-essential and b) expressed at detectable levels under standard laboratory growth conditions.

Environ Microbiol, 2001 Feb, 3(2), 81 - 91
Chemical properties of catechols and their molecular modes of toxic action in cells, from microorganisms to mammals; Schweigert N et al.; Catechols can undergo a variety of chemical reactions . In this review, we particularly focus on complex formations and the redox chemistry of catechols, which play an inportant role in the toxicity of catechols . In the presence of heavy metals, such as iron or copper, stable complexes can be formed . In the presence of oxidizing agents, catechols can be oxidized to semiquinone radicals and in a next step to o-benzoquinones . Heavy metals may catalyse redox reactions in which catechols are involved . Further chemical properties like the acidity constant and the lipophilicity of different catechols are shortly described as well . As a consequence of the chemical properties and the chemical reactions of catechols, many different reactions can occur with biomolecules such as DNA, proteins and membranes, ultimately leading to non-repairable damage . Reactions with nucleic acids such as adduct formation and strand breaks are discussed among others . Interactions with proteins causing protein and enzyme inactivation are described . The membrane-catechol interactions discussed here are lipid peroxidation and uncoupling . The deleterious effect of the interactions between catechols and the different biomolecules is discussed in the context of the observed toxicities, caused by catechols.

Environ Microbiol, 2001 Feb, 3(2), 145 - 8
BMRI-2, Rossendorf/Dresden, Germany (30 August - 1 September 2000); Hobman JL; Clearly, there is much left to be understood about microbial processes and interactions with metals, but much progress has been made, and the multidisciplinary approach of groups who are studying both the microbial populations and the chemistry of biotransformations of metals by bacteria will ensure rapid progress in our understanding of these issues . Several major points from different speakers summarize this meeting and are usefully reiterated at this point: Toxic metal ions, unlike organic pollutants, are immutable, and their bioavailability is a critical feature of their toxicity . The mobility, transport and fate of toxic metals and radionuclides in the environment are dependent on chemical and geochemical processes in which micro-organisms are intimately involved . Metals can be mobilized as well as immobilized by microorganisms . Metal/radionuclide valencies and chemical properties are critical to their environmental mobility . Bacterial- or fungal-metal interactions will be complicated by the presence of other pollutants . The identification of bacteria from environmental samples should not rely on one methodology, as these have been shown to be biased . Sonja Selenska-Pobell organized both BMRI-1 in 1998 and BMRI-2, which had well over 100 participants from Europe, Russia, USA and Japan in attendance . Thirty-one oral presentations were given, and over 30 posters were displayed over two poster sessions . BMRI-3 is provisionally planned for 2002 at GBF, Braunschweig, Germany.

Clin Hemorheol Microcirc, 2000, 23(2-4), 345 - 8
In vivo identification of parasinus macrophages in the mesenteric lymph node; Nagata H et al.; Macrophages beneath the marginal sinus in the lymph nodes may play a role in defense against microorganism . The purpose of this study was to directly visualize the parasinus macrophages in the mesenteric lymph node . Fluorescent latex particles were injected into the appendix submucosa of rats . The mesenteric lymph node was epi-illuminated and observed with a fluorescent microscope . Fluorescent particles entered the marginal sinus of the mesenteric lymph node through the afferent lymphatic vessels, and distributed diffusely all over the marginal sinus . The particles became aggregated and interspersed 3 hr after injection, suggesting that particles were incorporated by phagocytes . The number of these particle-laden phagocytes increased up to 12 hr after injection, and then declined . Some phagocytes migrated rapidly within the marginal sinus . Morphology of these phagocytes in cell suspension was consistent with macrophages . In conclusion, we successfully visualized parasinus macrophages in vivo, which incorporated foreign bodies and migrated within the marginal sinus.

Med Pregl, 2000 Nov-Dec, 53(11-12), 600 - 2
{Effect of alcohol consumption on recurrence of venereal diseases}; Bjekic M et al.; INTRODUCTION: Sexually transmitted diseases (STDs) comprise a large group of infections caused by different microorganisms including spirochetes, bacteria, chlamydia, mycoplasma, protozoa, fungi, parasites, and viruses . A considerable number of patients with sexually transmitted diseases are STD recurrences . As reported by Marijanovic and Lalosevic, in Belgrade, among patients who visited the City Department of Skin and Venereal Diseases, during 1985 and 1986 because of syphilis or gonorrhea, 22.8% had these diseases two or more times during their lives (male/female ratio 10:1) . The aim of this study was to test the hypothesis that there is a relationship between alcohol use and recurrence of STD . MATERIAL AND METHODS: A case-control study was performed in Belgrade population, from June, 1997 to April, 1998 . Participants were recruited among patients attending the City Department of Skin and venereal Diseases of Belgrade because of sexually transmitted diseases (syphilis, gonorrhea, nongonoccocal urethritis and genital warts) . The case group comprised 101 patients who already had STD two or more times in their personal histories . The control group consisted of 210 patients treated at the same institution for micotic diseases, patients who either never had STD or had it only once (13% of controls) in their personal histories . All participants were men aged 20 to 50 years and all were from Belgrade . Data on demographic characteristics, sexual history and sexual behavior, and data on antisocial behavior were collected from all participants using an anonymous questionnaire . In the present paper only data on alcohol use are presented . In the analysis of data chi 2-test was used . RESULTS: STD recurrence patients in comparison to their controls used alcohol more frequently (56.3%:16.1%), especially hard liquors, and 55.5% of them used alcohol at the time of STD infection . DISCUSSION: In the present study STD recurrence patients consumed alcohol more frequently than their controls, especially hard liquors . In the study of Myliueva et al, 50% of venereal disease patients consumed alcohol now and then and 10% consumed alcohol frequently . Scheidt and Windle found that 60% of alcoholics had at least one sexually transmitted disease as the result of a high number of sexual partners, low use of condoms and practicing sex for drugs or money . Alcohol has a depressive effect on central nervous system, reduces anxiety and increases libido . CONCLUSION: The obtained results support the hypothesis that alcohol use is related to recurrence of STDs.

Cancer Chemother Pharmacol, 2001 Mar, 47(3), 277 - 9
Typhlitis (neutropenic enterocolitis) after a single dose of vinorelbine; Ferrazzi E et al.; We report a case of a 50-year-old man with pretreated adenocarcinoma of the lung, who developed fatal neutropenic enterocolitis (typhlitis) after a standard dose of the cytotoxic drug vinorelbine . Blood cultures were negative for all microorganisms tested for . Stool cultures were negative for enteric rods but direct examination of fresh stool revealed the presence of Giardia lamblia . Abdominal pain and diarrhoea developed very rapidly while the patient was only moderately neutropenic . Metronidazole was prescribed without clinical benefit: the abdominal pain remained stable . The duration of neutropenia was very short (4 days) . The abdominal catastrophe ending in shock occurred after complete recovery of the neutrophil count . Neutropenic colitis has been reported with increasing frequency in solid tumours after the introduction of taxanes . This complication has been observed mainly in phase I studies, near the maximally tolerated doses (MTD) . The combined use of vinorelbine has recently been reported to exacerbate the toxic effects of taxane on the colon . The case presented here demonstrates that typhlitis can occur even with vinorelbine alone, used at a standard recommended dose (30 mg/m2).

J Ind Microbiol Biotechnol, 2000 Dec, 25(6), 281 - 287
Human pathogens associated with raw produce and unpasteurized juices, and difficulties in decontamination; Burnett SL et al.; The ability of public health agencies to identify, through enhanced epidemiologic and surveillance techniques, raw fruits, vegetables, and unpasteurized juices as probable sources of infectious microorganisms, has undoubtedly resulted in increased numbers of documented outbreaks . Changes in agronomic, harvesting, distribution, processing, and consumption patterns and practices have also likely contributed to this increase . The risk of illness associated with raw produce and unpasteurized produce products can be reduced by controlling or preventing contamination, or by removing or killing pathogenic microorganisms by washing or treating them with sanitizers . However, the hydrophobic cutin, diverse surface morphologies, and abrasions in the epidermis of fruits and vegetables limit the efficacy of these treatments.

Acta Crystallogr D Biol Crystallogr, 2001 May, 57(Pt 5), 737 - 9 Epub 2001 Apr 24.
Purification, crystallization and preliminary X-ray analysis of two crystal forms of ribonuclease Sa3; Hlinkova V et al.; RNase Sa3 produced by Streptomyces aureofaciens strain CCM 3239 belongs to the T1 family of microbial ribonucleases . It is closely related both to RNase Sa, studied in detail earlier, and to RNase Sa2 produced by the same microorganism . The most important property of RNase Sa3 is the relatively high cytotoxic activity, which was not observed for RNase Sa and Sa2 . Recombinant RNase Sa3 was overexpressed in Escherichia coli and purified to high homogeneity . The hanging-drop vapour-diffusion method was used for crystallization . The two crystal forms are trigonal P3(1)21 and tetragonal P4(1)2(1)2, with unit-cell parameters a = b = 64.7, c = 69.6 A, gamma = 120 degrees and a = b = 34.0, c = 147.2 A, respectively . They diffract to 2.0 and to 1.7 A resolution, respectively, using synchrotron radiation . The asymmetric units of crystal forms I and II contain one molecule of the enzyme, which corresponds to V(M) = 3.8 A(3) Da(-1) with a solvent content of 68% and V(M) = 1.9 A(3) Da(-1) with a solvent content of 37%, respectively.

Acta Crystallogr D Biol Crystallogr, 2001 May, 57(Pt 5), 734 - 6 Epub 2001 Apr 24.
Crystallization and preliminary X-ray crystallographic analysis of FlhD/FlhC complex from Escherichia coli; Wang S et al.; The heterotetrameric (C(2)D(2)) FlhD/FlhC complex was first discovered as a transcriptional activator of the flagellar genes in Escherichia coli . Recent studies now show that FlhD/FlhC also regulates several non-flagellar target genes in E . coli . The FlhD/FlhC complex also plays several important roles in other microorganisms . The molecular interactions between FlhD and FlhC, as well as the mechanisms by which the complex may vary its DNA-binding specificity, are not clear . Determination of the FlhD/FlhC crystal structure will provide insight into these protein-protein and protein-DNA interactions . The initial steps in this investigation are reported here: the overexpression, purification and crystallization of the FlhD/FlhC complex, the characterization of this crystal form and the recording and processing of an initial diffraction data set . The obtained crystal form of the FlhD/FlhC complex is hexagonal (space group P6(1), unit-cell parameters a = b = 150.5, c = 115.9 A) . The crystal density is very low (V(M) = 5.5), with 81.7% of its volume occupied by solvent . A single C(2)D(2) tetramer is present in the crystallographic asymmetric unit . A complete native data set has been collected to 4.5 A resolution.

Appl Environ Microbiol, 2001 May, 67(5), 2336 - 44
Natural communities of novel archaea and bacteria growing in cold sulfurous springs with a string-of-pearls-like morphology; Rudolph C et al.; We report the identification of novel archaea living in close association with bacteria in the cold (approximately 10 degrees C) sulfurous marsh water of the Sippenauer Moor near Regensburg, Bavaria, Germany . These microorganisms form a characteristic, macroscopically visible structure, morphologically comparable to a string of pearls . Tiny, whitish globules (the pearls; diameter, about 0.5 to 3.0 mm) are connected to each other by thin, white-colored threads . Fluorescent in situ hybridization (FISH) studies have revealed that the outer part of the pearls is mainly composed of bacteria, with a filamentous bacterium predominating . Internally, archaeal cocci are the predominant microorganisms, with up to 10(7) cells estimated to be present in a single pearl . The archaea appear to be embedded in a polymer of unknown chemical composition . According to FISH and 16S rRNA gene sequence analysis, the archaea are affiliated with the euryarchaeal kingdom . The new euryarchaeal sequence represents a deep phylogenetic branch within the 16S rRNA tree and does not show extensive similarity to any cultivated archaea or to 16S rRNA gene sequences from environmental samples.

Am J Respir Crit Care Med, 2001 Apr, 163(5), 1198 - 205
Attenuation of interleukin 8-induced nasal inflammation by an inhibitor peptide; Cooper JA Jr et al.; Polymorphonuclear neutrophils (PMNs) infiltrate tissue in response to chemoattractants, including interleukin 8 (IL-8) . Infiltrating PMNs clear microorganisms but also cause tissue damage . We previously reported the presence in human bronchial lavage of a peptide that inhibits PMN functions . The current project assessed (1) effects of a synthetic analog of this peptide (synthetic neutrophil inhibitor peptide, SNIP) on IL-8-induced nasal inflammation in humans, (2) effects of SNIP on PMN apoptosis and chemotaxis, (3) specific binding of SNIP to PMNs, and (4) evidence of larger molecules with the SNIP sequence . Results show that SNIP attenuates IL-8-induced nasal inflammation, inhibits in vitro PMN chemotaxis to IL-8, and accentuates PMNs apoptosis . PMNs contain specific SNIP-binding sites and the integrin CR3 (CD11b/CD18), or a CR3-associated molecule, is one SNIP-binding molecule . Chemotaxis to IL-8 is most potently inhibited by SNIP in the presence of fibrinogen, a CR3 ligand . Antiserum against the SNIP sequence recognizes a 70-kDa protein in bronchoalveolar lavage and an anti-SNIP immunoaffinity column binds a 70-kDa protein in U937 cell culture supernatant . U937 cell mRNA contains a 1.8-kb transcript detected with degenerate oligonucleotides designed from the SNIP sequence . These studies demonstrate that a synthetic inhibitor peptide can attenuate in vivo nasal inflammation through downregulatory effects on PMNs.

Am J Respir Crit Care Med, 2001 Apr, 163(5), 1097 - 100
Increased frequency of Chlamydia pneumoniae antibodies in patients with asthma; Gencay M et al.; The worldwide increase in asthma incidences and the impact of the disease on public health care have led to new investigations of the cause of the disease . Besides well-defined environmental causes, accumulating evidence suggests that respiratory tract infections play an important role in the pathogenesis of asthma . Among these microorganisms Chlamydia pneumoniae is an intracellular pathogen causing persistent infection . Chlamydia pneumoniae infection has been discussed as possibly inducing the development of asthma . This study was designed to investigate the presence of C . pneumoniae-specific IgG, IgA, and IgM antibodies in serum samples of 33 adults with a clinical history of asthma, positive methacholine test, and reduced FEV(1) . Patients with asthma were compared with age-, sex-, and locality-matched control subjects (n = 33) . We observed no acute infection either in patients with asthma or in control subjects, but 63% of all investigated individuals had signs of past infection . Chlamydia pneumoniae-specific IgA was detected in 52% of the patients with asthma and in 15% of the healthy control subjects (p < 0.01) . Serological evidence of chronic infection with C . pneumoniae (high IgG {> pr = 1:512} and high IgA {> or = 1:40}) was more frequent in patients with asthma (18.2%) compared with control subjects (3.0%) (p < 0.01) . Our results provide further evidence that chronic infection with C . pneumoniae is linked to asthma.

Res Microbiol, 2001 Mar, 152(2), 123 - 9
Genetic interference in protozoa; Bastin P et al.; RNA interference first described in Caenorhabditis elegans and transgene-induced post-transcriptional gene silencing first described in plants and fungi now appear as different means of activating a conserved and ancient mechanism that can protect genomes against viruses and transposons and perhaps also control expression of endogenous genes . We present here similar genetic interference phenomena in highly divergent protozoa, Trypanosoma and Paramecium, and look ahead to what contribution these microorganisms could bring to this fast-moving area.

Mikrobiologiia, 2000 Sep-Oct, 69(5), 727 - 36
{Regulation of the biomass and activity of soil microorganisms by microfauna}; Mamilov ASh et al.; Microcosm experiments showed that the microbial biomass and the respiration activity in soil were regulated by nematodes . Depending on nematode number and plant residue composition, the trophic activity of nematodes can either stimulate or inhibit microbial growth and respiration as compared to soil containing no nematodes . The stimulating effect was observed when nitrogen-free (starch) or low-nitrogen (wheat straw, C:N = 87) organic substrates were applied . Inhibition occurred when a substrate rich in nitrogen (alfalfa meal, C:N = 28) was decomposed and the nematode population exceeded the naturally occurring level . A conceptual model was developed to describe trophic regulation by microfauna (nematodes) of the microbial productivity and respiration activity and decomposition of not readily decomposable organic matter in soil . The stimulating and inhibiting influence of microfauna on soil microorganisms was not a linear function of the rate of microbial consumption by nematodes . These effects are largely associated with the induced change in the physiological state of microorganisms rather than with the mobilization of biogenic elements from the decomposed microbial biomass.

Mikrobiologiia, 2000 Sep-Oct, 69(5), 597 - 605
{Distant informational interactions in bacteria}; Nikolaev IuA; Exchange of information between bacteria via physical signals, referred to as "distant interactions" (DI), is the subject of this review . All cases of DI reported to date are discussed, as well as the history of these studies and the place of DI in bacterial communication . Bacterial DI are a particular case of DI occurring in nature (in plants, animals, and fungi) . Along with the chemical signals of intracellular communications, DI play a significant role in the life of microorganisms, especially during critical periods.

Mem Inst Oswaldo Cruz, 2001 Apr, 96(3), 415 - 25
Coevolutionary networks: a novel approach to understanding the relationships of humans with the infectious agents; Tosta CE; Human organism is interpenetrated by the world of microorganisms, from the conception until the death . This interpenetration involves different levels of interactions between the partners including trophic exchanges, bi-directional cell signaling and gene activation, besides genetic and epigenetic phenomena, and tends towards mutual adaptation and coevolution . Since these processes are critical for the survival of individuals and species, they rely on the existence of a complex organization of adaptive systems aiming at two apparently conflicting purposes: the maintenance of the internal coherence of each partner, and a mutually advantageous coexistence and progressive adaptation between them . Humans possess three adaptive systems: the nervous, the endocrine and the immune system, each internally organized into subsystems functionally connected by intraconnections, to maintain the internal coherence of the system . The three adaptive systems aim at the maintenance of the internal coherence of the organism and are functionally linked by interconnections, in such way that what happens to one is immediately sensed by the others . The different communities of infectious agents that live within the organism are also organized into functional networks . The members of each community are linked by intraconnections, represented by the mutual trophic, metabolic and other influences, while the different infectious communities affect each other through interconnections . Furthermore, by means of its adaptive systems, the organism influences and is influenced by the microbial communities through the existence of transconnections . It is proposed that these highly complex and dynamic networks, involving gene exchange and epigenetic phenomena, represent major coevolutionary forces for humans and microorganisms.

J Biol Chem, 2001 Jun 29, 276(26), 23456 - 63 Epub 2001 Apr 19.
Human intelectin is a novel soluble lectin that recognizes galactofuranose in carbohydrate chains of bacterial cell wall; Tsuji S et al.; Galactofuranosyl residues are present in various microorganisms but not in mammals . In this study, we identified a human lectin binding to galactofuranosyl residues and named this protein human intelectin (hIntL) . The mature hIntL was a secretory glycoprotein consisting of 295 amino acids and N-linked oligosaccharides, and its basic structural unit was a 120-kDa homotrimer in which 40-kDa polypeptides were bridged by disulfide bonds . The hIntL gene was split into 8 exons on chromosome 1q21.3, and hIntL mRNA was expressed in the heart, small intestine, colon, and thymus . hIntL showed high levels of homology with mouse intelectin, Xenopus laevis cortical granule lectin/oocyte lectin, lamprey serum lectin, and ascidian galactose-specific lectin . These homologues commonly contained no carbohydrate recognition domain, which is a characteristic of C-type lectins, although some of them have been reported as Ca(2+)-dependent lectins . Recombinant hIntL revealed affinities to d-pentoses and a d-galactofuranosyl residue in the presence of Ca(2+), and recognized the bacterial arabinogalactan of Nocardia containing d-galactofuranosyl residues . These results suggested that hIntL is a new type lectin recognizing galactofuranose, and that hIntL plays a role in the recognition of bacteria-specific components in the host.

Gastroenterology, 2001 May, 120(6), 1485 - 501
The lymphoid liver: considerations on pathways to autoimmune injury; Kita H et al.; Immunologic injury in the liver involves immigrant T and B lymphocytes and a resident lymphoid population that comprises distinct lymphocytic cells and accessory cells . The forerunner to autoimmunity is breaching of natural self-tolerance and hence the disruption of a fundamental property of the immune system . Such breaching occurs by processes that include inflammatory activation of immunocytes and macrophages, spillage of intracellular constituents, and epitope mimicry by constituents of microorganisms, with these acting on a genetically conditional phenotype; compounding factors include aberrations of apoptosis, whether insufficient or excess . The downstream end requires specifically directed inflammatory leukocyte traffic as an essential component of autoimmune expressions in the liver . The culmination is an orchestrated attack on hepatocytes or biliary epithelial cells by multiple effector pathways . Progress in type 1 autoimmune hepatitis still requires knowledge of a disease-specific autoantigen(s) involved in T-cell reactivity, although such knowledge in type 2 autoimmune hepatitis, in which the known autoantigen is cytochrome P4502D6, has not yet been integrated into a clearly defined scheme of pathogenesis . For PBC there has been a very promising amalgamation of molecular knowledge of the mitochondrial autoantigens . Future insights require deeper analysis of molecular, genetic, macroenvironmental, and microenvironmental elements in predisposition.

Eur J Med Res, 2001 Jan 29, 6(1), 33 - 8
Surfactant proteins D and A in sputum; Griese M et al.; The surfactant proteins SP-D and SP-A are collectins and central components of the innate immune system of the peripheral lungs . They bind to carbohydrates on microorganisms and promote their removal . In the larger airways their role and concentrations are not yet known . Sputum may thus potentially be useful to characterize the collectins in this compartment . Induced sputum was obtained from healthy adults and spontaneous sputum from patients with cystic fibrosis . ELISA and carbohydrate binding assays were used to quantify the amount and functional capacity of the collectins in plugs or sol-fractions, prepared by centrifugation of the plugs . SP-D and SP-A were detectable in only about 50% of the sputum plugs . Varying the salt, detergent and calcium conditions of the assay did not improve the results . In samples with reproducibly detectable SP-D or SP-A, their carbohydrate binding capacity was zero . Sputum sol fraction and LPS inhibited the binding of the collectins to carbohydrate in the presence of calcium . Whereas SP-D and SP-A are abundant in the peripheral lung, their presence in sputum derived from the larger airways is variable and their carbohydrate binding capacity is lost.

Biotechnol Prog, 2001 Mar-Apr, 17(2), 379 - 82
Enzymatic hydrolysis of waste office paper using viscosity as operating parameter; Park EY et al.; Enzymatic hydrolysis of waste office (WO) paper with feeding WO paper in a reactor was investigated using apparent viscosity as operating parameter . Since the apparent viscosity was correlated with the concentration of pulping WO paper, the amount of hydrolyzed WO paper was assumed by measuring the decrease in the apparent viscosity . Then the amount of hydrolysis WO paper and the amount of enzyme corresponding to the desired ratio were fed into the reactor . When the WO paper and 1% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 87 g/L of reducing sugar (RS) with a hydrolytic yield of 42.2% was obtained for a 24-h hydrolysis . However, when nonpulping WO paper and 5% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 120 g/L of RS with a hydrolytic yield of 40% was obtained for a 24-h hydrolysis . Therefore, the RS concentration from this hydrolysis process feeding WO paper using apparent viscosity as operating parameter may be of sufficient concentration to serve as a carbon source in microorganism culture or chemical feedstock.

Luminescence, 2001 Mar-Apr, 16(2), 193 - 8
Applications of biochemiluminescence to HACCP; Champiat D et al.; The hazard analysis critical control point) (HACCP) system is set up with the aim of ensuring the harmlessness of food along the process chain, from the producer to the ultimate consumer . To set up this system, it is necessary to perform an analysis to identify the dangers and the critical points of the process in real time . Living organisms are detected on the principle of measurement of cellular energy in the form of adenosine triphosphate (ATP), which is produced by all living cells and of particularly by microorganisms . The principle of the bioluminescence of firefly luciferase is applied, whereby a reduced form of luciferin, together with a molecule of oxygen and ATP in the presence of the enzyme luciferase, produces a reaction in which oxyluciferine is released, together with AMP . This is accompanied by a simultaneous release of photons, which are then quantified . The emission spectra recorded with the firefly luciferin/luciferase system is obtained with absolute sensitivity . The method of ATP assays here proposed is adapted for measuring the total content of different adenylates in the cell, i.e . the adenylate pool . ATP concentration is then measured through bioluminescence, i.e . the light is measured by a photomultiplier tube detector and the signal is converted to relative light units (RLU) . Thus, RLU have a relationship with the amount of ATP present in the sample, which is not the case with traditional methods . Adequate levels of sensitivity are calculated with appropriate controls and the readings are translated into a statistical designation of positive or negative result . There are numerous illustrations of HACCP applications using biochemiluminescence (BCL) techniques as detection technology in food industry production lines and in control of critical points in real time in industrial applications .

J Biol Chem, 2001 Jun 22, 276(25), 23056 - 64 Epub 2001 Apr 18.
A spirochete surface protein uncouples store-operated calcium channels in fibroblasts: a novel cytotoxic mechanism; Wang Q et al.; The cytotoxicity of infectious agents can be mediated by disruption of calcium signaling in target cells . Outer membrane proteins of the spirochete Treponema denticola, a periodontal pathogen, inhibit agonist-induced Ca(2+) release from internal stores in gingival fibroblasts, but the mechanism is not defined . We determined here that the major surface protein (Msp) of T . denticola perturbs calcium signaling in human fibroblasts by uncoupling store-operated channels . Msp localized in complexes on the cell surface . Ratio fluorimetry showed that in cells loaded with fura-2 or fura-C18, Msp induced cytoplasmic and near-plasma membrane Ca(2+) transients, respectively . Increased conductance was confirmed by fluorescence quenching of fura-2-loaded cells with Mn(2+) after Msp treatment . Calcium entry was blocked with anti-Msp antibodies and inhibited by chelating external Ca(2+) with EGTA . Msp pretreatment reduced the amplitude of {Ca(2+)}(i) transients upon challenge with ATP or thapsigargin . In experiments using cells loaded with mag-fura-2 to report endoplasmic reticulum Ca(2+), Msp reduced Ca(2+) efflux from endoplasmic reticulum stores when ATP was used as an agonist . Msp alone did not induce Ca(2+) release from these stores . Msp inhibited store-operated influx of extracellular calcium following intracellular Ca(2+) depletion by thapsigargin and also promoted the assembly of subcortical actin filaments . This actin assembly was blocked by chelating intracellular Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester . The reduced amplitude of agonist-induced transients and inhibition of store-operated Ca(2+) entry due to Msp were reversed by latrunculin B, an inhibitor of actin filament assembly . Thus, Msp retards Ca(2+) release from endoplasmic reticulum stores, and it inhibits subsequent Ca(2+) influx by uncoupling store-operated channels . Actin filament rearrangement coincident with conformational uncoupling of store-operated calcium fluxes is a novel mechanism by which surface proteins and toxins of pathogenic microorganisms may damage host cells.

Peptides, 2001 Apr, 22(4), 557 - 65
Recognition and oxidative metabolism of cyclodipeptides by hepatic cytochrome P450; Delaforge M et al.; Possible recognition of peptide derivatives by hepatic cytochrome P450 3A has been suggested by binding and metabolism of numerous pseudopeptidic compounds such as ergot derivatives and cyclosporin.Natural linear or cyclic dipeptides containing hydrophobic amino acids produced by microorganisms and present in mammals are able to interact with the P450 active site through either iron-amine interactions (Type II) or hydrophobic Type I interactions . P450 3A from dexamethasone-treated rats or yeast-expressed P450 human 3A4 are the most potent in such interactions, which are particularly strong with peptides containing a histidyl residue.Some cyclodipeptides are rapidly transformed by rat cytochrome P450 3A to mono- or dihydroxylated metabolites, with turnovers around 3 nmoles min(-1) P450(-1) . Linear peptides are poorly transformed in these conditions . This metabolism of cyclodipeptides occurs in 8 species including man.Such interactions and metabolism have only minor consequences in terms of P450 3A binding and metabolism of classical P450 3A substrates . These data reinforce the concept that, in addition to their effect on the regulation of P450 neosynthesis, naturally occurring endogenous peptides are also substrates of P450 3A . The physiological activities of these peptides may be modulated by their metabolism.

Biosystems, 2001 Mar, 59(3), 159 - 83
Modelling of hexadecane degradation in continuous-flow cultures; Ebenhoh W et al.; Microorganisms of Wadden Sea sediments are able to degrade hydrocarbons in suspensions . (Berthe-Corti, L., Bruns, A., Hulsch, R., 1997 . J . Microb . Methods 29, 129-137) have observed in continuous culture experiments that the growth rate of microorganisms increases roughly proportional to the dilution rate . The growth rate is nearly independent of the oxygen saturation down to about 0.5% . Even at very low oxygen supply, corresponding to an oxygen saturation far below 0.1%, growth takes place at a reduced rate . In this paper, a model is presented which can reproduce the results of these experiments . The model treats the following processes, selection of the active fraction of microorganisms growing on hexadecane, uptake of hexadecane and transformation into palmitate as a first metabolic step, synthesis of biomass, respiration and exudation . The processes are regulated by the substrate concentration, the internal palmitate quota, the exudates' concentration and an inhibiting factor . For the experiments under very low oxygen conditions, the observed growth with reduced O(2)-consumption and CO(2)-production is modelled by assuming an anoxic metabolic pathway.

Virus Res, 2001 May, 75(1), 69 - 73
Comparison of the sialic acid binding activity of transmissible gastroenteritis coronavirus and E . coli K99; Schwegmann C et al.; Transmissible gastroenteritis coronavirus (TGEV) and Escherichia coli K99 are both enteropathogenic for pigs with infections being most severe in neonate animals . For both microorganisms, a sialic acid binding activity has been shown to be an essential pathogenicity factor . Here we demonstrate with haemagglutination and haemagglutination-inhibition assays that TGEV and E . coli K99 differ in their sialic acid binding activities with respect to the type and amount of sialic acid residues required on the erythrocytes surface as well as with respect to the type of sialoglycoconjugate preferentially recognized . Intestinal mucins from piglets (12-14 days old) and adult animals were shown to inhibit TGEV to the same extent . From our results we conclude that E . coli K99 and TGEV interact with different sialoglycoconjugates to establish an intestinal infection . The implications for the enteropathogenicity of TGEV are discussed.

J Microbiol Methods, 2001 Jun, 45(2), 77 - 87
An advanced molecular strategy to identify bacterial communities on art objects; Schabereiter-Gurtner C et al.; The application of culture-independent techniques based on molecular biological methods, especially on the PCR amplification of 16S rRNA genes, attempts to overcome some shortcomings of conventional cultivation methods and reveals far more complex bacterial communities on art objects than can be shown by cultivation methods . One of the major challenges of investigating microbial growth on art objects by molecular means is the extraction of DNA, due to small sample amounts and PCR inhibitors . In the present study, we introduce a DNA extraction protocol, which allowed the extraction of PCR-amplifiable DNA from samples derived from lime wall paintings and loamy soil underground . The DNA extracts were used to amplify 16S ribosomal fragments, which were subsequently analyzed by denaturing gradient gel electrophoresis (DGGE) . In parallel with the DGGE analysis, clone libraries containing PCR fragments of the ribosomal gene were constructed and clones were screened by DGGE . Clone libraries allow the inclusion of the entire 16S rDNA sequence in the phylogenetic analyses of microorganisms, providing a more reliable phylogenetic identification of microorganisms than is obtained from sequence analyses of excised and directly sequenced DGGE bands.

Bioorg Med Chem, 2001 Mar, 9(3), 793 - 800
Biotransformation of a 4(20),11(12)-taxadiene derivative; Sun DA et al.; A 4(20),11(12)-taxadiene derivative was converted to hydroxylated derivatives by Cunninghamella elegans AS3.2033 and Cunninghamella elegans var chibaensis ATCC 20230 . Both microorganisms led to C-1 hydroxylations and conversion to a C-15-hydroxylated abeo-taxane . Additional products from the two fungi differed: a C-14 oxidation and a trans-cis isomerization of the cinnamoyl for one and an unprecedented hydroxylation at C-17 for the other.

PDA J Pharm Sci Technol, 2001 Mar-Apr, 55(2), 65 - 86
Retention of water-borne bacteria by membrane filters . Part I: Bacterial challenge tests on 0.2 and 0.22 micron rated filters; Sundaram S et al.; The results of bacterial challenge tests conducted on several 0.2 and 0.22 micron rated "sterilizing grade" filter cartridge types with bacteria from a natural water source are presented . Eight different 0.2/0.22 micron rated "sterilizing grade" filter types from four different filter manufacturers, claimed to be capable of retaining Brevundimonas diminuta at a challenge level of 10(7) CFU/cm2, were tested . The filters tested included nylon 6.6 and polyamide filters from two manufacturers, modified or hydrophilic PVDF filters from two manufacturers, modified or asymmetric PES filters from three manufacturers, and cellulose acetate filters from a single manufacturer . Consistent bacterial penetration was observed, over the 18-24 h challenge period, for all twenty-five integral 0.2 and 0.22 micron rated filter cartridges tested, at challenge levels of about 10(1)-10(4) CFU/cm2, indicating that natural waterborne bacteria were more penetrative than B . diminuta . The observed penetration was thus qualitatively independent of filter media type or manufacturer . These results add to the growing body of evidence that shows 0.2 and 0.22 micron rated filters may not remove all microorganisms under all conditions . These results further establish that bacterial penetration of 0.2/0.22 micron rated filters is not limited just to (1) specific membrane types, or (2) extended duration challenges (>> 24 h), or (3) extremely high challenge levels, or (4) bacteria that can only exist in a penetrative state in an artificial laboratory setting.

J Food Prot, 2001 Apr, 64(4), 451 - 5
Hot water immersion to eliminate Escherichia coli O157:H7 on the surface of whole apples: thermal effects and efficacy; Fleischman GJ et al.; The effect of hot water immersion on both the reduction of Escherichia coli O157:H7 on the apple surface and internal temperatures of the apple was assessed in this study . Microbial reductions were measured experimentally, whereas internal temperatures were calculated through a mathematical analysis of experimental heat transfer data obtained from the apples . A method was developed to provide a purely surface-based inoculation of E . coli O157:H7 . Rinsing produced no reduction, and treatments at 80 and 95 degrees C produced reductions of more than 5 logs in 15 s or less . The heat transfer analysis based on experimental data was used to calculate surface heat transfer coefficients and predict temperatures throughout the apple . The analysis indicated a low heat transfer rate . Although it reduces thermal degradation, a low heat transfer rate precludes thermal-based reduction of any internalized microorganisms.

Int Endod J, 2000 Jan, 33(1), 1 - 18
Root canal treatment and general health: a review of the literature; Murray CA et al.; REVIEW: The focal infection theory was prominent in the medical literature during the early 1900s and curtailed the progress of endodontics . This theory proposed that microorganisms, or their toxins, arising from a focus of circumscribed infection within a tissue could disseminate systemically, resulting in the initiation or exacerbation of systemic illness or the damage of a distant tissue site . For example, during the focal infection era rheumatoid arthritis (RA) was identified as having a close relationship with dental health . The theory was eventually discredited because there was only anecdotal evidence to support its claims and few scientifically controlled studies . There has been a renewed interest in the influence that foci of infection within the oral tissues may have on general health . Some current research suggests a possible relationship between dental health and cardiovascular disease and published case reports have cited dental sources as causes for several systemic illnesses . Improved laboratory procedures employing sophisticated molecular biological techniques and enhanced culturing techniques have allowed researchers to confirm that bacteria recovered from the peripheral blood during root canal treatment originated in the root canal . It has been suggested that the bacteraemia, or the associated bacterial endotoxins, subsequent to root canal treatment, may cause potential systemic complications . Further research is required, however, using current sampling and laboratory methods from scientifically controlled population groups to determine if a significant relationship between general health and periradicular infection exists.

Eur J Clin Microbiol Infect Dis, 2001 Feb, 20(2), 127 - 31
Specificity of a polymerase chain reaction assay of a target sequence on the 31-kilodalton Brucella antigen DNA used to diagnose human brucellosis; Casanas MC et al.; The aim of this study was to evaluate the specificity of a polymerase chain reaction assay for detecting Brucella DNA using primers specific for the amplification of a 223 bp region of the sequence encoding a 31 kDa immunogenic Brucella abortus protein (BCSP31) . DNA from all Brucella strains, including type, reference, vaccine and field strains, were correctly amplified . With the exception of Ochrobactrum spp., no other amplification was detected with a broad panel of microorganisms serologically or phylogenetically related to Brucella spp . This very good degree of specificity, together with its high yield demonstrated in previous clinical studies, confirms that this polymerase chain reaction assay could be a useful tool for the diagnosis of human brucellosis.

J Clin Pathol, 2001 Apr, 54(4), 293 - 7
The physiological expression of inducible nitric oxide synthase (iNOS) in the human colon; Roberts PJ et al.; BACKGROUND: Inducible nitric oxide synthase (iNOS) is expressed in the colonic epithelium in both inflammatory bowel disease and colorectal cancer . Nitric oxide (NO), the product of this enzyme, has been implicated in the pathogenesis of both conditions . However, there are conflicting data on whether iNOS is expressed in the normal, uninflamed human colon . AIMS: To evaluate the expression of iNOS in histologically normal, non-inflamed human colonic mucosa . PATIENTS/METHODS: Reverse transcription polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemistry were used to investigate the expression of iNOS in 17 histologically normal specimens obtained at colectomy performed for colorectal neoplasia . In addition, 16 endoscopic mucosal biopsies, taken from normal individuals, were also evaluated . Eleven surgical specimens and 16 endoscopic biopsies from patients with refractory ulcerative colitis were used as inflammatory controls . RESULTS: All types of specimens expressed iNOS mRNA . Immunoblotting revealed a protein of approximately 130 kDa consistent with iNOS in mucosal extracts of 77% of normal individuals, and 85% of diseased controls . Immunolabelling localised this protein to the surface epithelium in most of the normal specimens and also to the crypt epithelium and inflammatory cells in the diseased controls . CONCLUSIONS: These findings provide evidence that iNOS is often expressed in the surface epithelium of non-inflamed human colon, suggesting that it is induced by local luminal factors, such as bacterial lipopolysaccharide (endotoxin) . The resultant NO produced at this site might act as an oxidative barrier, reducing bacterial translocation and providing a means of defence against pathogenic microorganisms.

Biochem Biophys Res Commun, 2001 Apr 20, 282(5), 1237 - 43
Roles of histidine residues in tobacco acetolactate synthase; Oh KJ et al.; Acetolactate synthase (ALS) catalyzes the first common step in the biosynthesis of valine, leucine, and isoleucine in plants and microorganisms . ALS is the target of several structurally diverse classes of herbicides, including sulfonylureas, imidazolinones, and triazolopyrimidines . The roles of three well-conserved histidine residues (H351, H392, and H487) in tobacco ALS were determined using site-directed mutagenesis . Both H487F and H487L mutations abolished the enzymatic activity as well as the binding affinity for the cofactor FAD . Nevertheless, the mutation of H487F did not affect the secondary structure of the ALS . The K(m) values of H351M, H351Q, and H351F are approximately 18-, 60-, and fivefold higher than that of the wild-type ALS, respectively . Moreover, the K(c) value of H351Q for FAD is about 137-fold higher than that of wALS . Mutants H351M and H351Q showed very strong resistance to Londax (a sulfonylurea) and Cadre (an imidazolinone), whereas mutant H351F was weakly resistant to them . However, the secondary structures of mutants H351M and H351Q appeared to be different from that of wALS . The mutation of H392M did not have any significant effect on the kinetic parameters nor the resistance to ALS-inhibiting herbicides . These results suggest that the His487 residue is located at the active site of the enzyme and is likely involved in the binding of cofactor FAD in tobacco ALS . Mutational analyses of the His351 residue imply that the active site of the ALS is probably close to its binding site of the herbicides, Londax and Cadre .

Z Naturforsch {C}, 2001 Jan-Feb, 56(1-2), 58 - 64
Screening of biotransformation products of carvone enantiomers by headspace-SPME/GC-MS; Demirci F et al.; In the course of our continuing work on transformation of monoterpenes by microorganisms, the biotransformation of (+)- and (-)-carvone was carried out . The metabolites formed during microbial transformations were screened using a simple, rapid and efficient technique: Headspace-solid phase microextraction (SPME)/GC-MS . The results as well as the application of this technique are described.

Mikrobiol Z, 2000 Jan-Feb, 62(1), 3 - 10
{Activity of tricarboxylic acid cycle enzymes in cyanobacteria Spirulina platensis}; Mendzhul MI et al.; The activity level and some physico-chemical properties of enzymes of the tricarboxylic acid cycle (TCA cycle) and the associated enzymes isocitrate lyase and glutamate dehydrogenase of cyanobacterium Spirulina platensis grown under illumination of 5000 lk in batch conditions, have been studied . High activities of most of the studied enzymes except for alpha-ketoglutarate dehydrogenase (alpha-KGDH) and succinate dehydrogenase have been estimated . In some cases the activities were by an order higher than that of similar enzymes in other cyanobacteria . This reflects the microorganism ability to synthesize intensively organic substances and first of all protein . Absence of alpha-KGDH activity proves that TCA cycle of spirulina has a limited value for energy generation and mainly performs the biosynthetic function.

Plant Physiol, 2001 Apr, 125(4), 2053 - 8
Azospirillum brasilense and Azospirillum lipoferum hydrolyze conjugates of GA20 and metabolize the resultant aglycones to GA1 in seedlings of rice dwarf mutants; Cassan F et al.; Azospirillum species are plant growth-promotive bacteria whose beneficial effects have been postulated to be partially due to production of phytohormones, including gibberellins (GAs) . In this work, Azospirillum brasilense strain Cd and Azospirillum lipoferum strain USA 5b promoted sheath elongation growth of two single gene GA-deficient dwarf rice (Oryza sativa) mutants, dy and dx, when the inoculated seedlings were supplied with {17,17-2H2}GA20-glucosyl ester or {17,17- 2H2}GA20-glucosyl ether . Results of capillary gas chromatography-mass spectrometry analysis show that this growth was due primarily to release of the aglycone {17,17-2H2}GA20 and its subsequent 3beta-hydroxylation to {17,17-2H2}GA1 by the microorganism for the dy mutant, and by both the rice plant and microorganism for the dx mutant.

Physiol Plant, 2001 Apr, 111(4), 419 - 426
Plant acquisition of organic nitrogen in boreal forests; Nasholm T et al.; Research on plant nitrogen (N) uptake and metabolism has more or less exclusively concerned inorganic N, particularly nitrate . Nevertheless, recent as well as older studies indicate that plants may have access to organic N sources . Laboratory studies have shown that ectomycorrhizal and ericoid mycorrhizal plants can degrade polymeric N and absorb the resulting products . Recent studies have also shown that some non-mycorrhizal plants are able to absorb amino acids . Moreover, amino acid transporters have been shown to be present in both plant roots and in mycorrhizal hyphae . Although both mycorrhizal and non-mycorrhizal plants appear to have a capacity for absorbing a range of organic N compounds, is this capacity realized in the field? Several lines of evidence show that plants are outcompeted by microorganisms for organic N sources . Such studies, however, have not addressed the issue of spatial and temporal separation between plants and microorganisms . Moreover, competition studies have not been able to separate uptake by symbiotic and non-symbiotic microorganisms . Qualitative assessment of organic N uptake by plants has been performed with dual-labelled glycine in several studies . These studies arrive at different conclusions: some indicate that plants do not absorb this organic N source when competing with other organisms in soil, while others conclude that significant fractions of amino acid N are absorbed as intact amino acid . These variable results may reflect species differences in the ability to absorb glycine as well as differences in experimental conditions and analytical techniques . Although theoretical calculations indicate that organic N might add significant amounts of N to plant N uptake, direct quantitative assessment of the fraction of plant N derived from uptake by organic N sources is a challenge for future research.

J Med Entomol, 2001 Mar, 38(2), 172 - 9
Evaluation of Beauveria bassiana (hyphomycetes) strains as potential agents for control of Triatoma infestans (Hemiptera: Reduviidae); Lecuona RE et al.; Chagas disease constitutes a major human health problem in most Latin American countries . This endemic disease is transmitted by several species of triatomine bugs, the most important being Triatoma infestans (Klug) . In this article, we report on the selection of strains of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill . virulent to T . infestans for possible use as bioinsecticides . Four strains of B . hassiana isolated from Argentina (Bb 1, 10, 25, and 65) were evaluated . To calculate mortality and mean lethal time, nymphs and adults of T . infestans were treated with conidia produced on complete agar medium and wheat brain and rice husk medium (WH) . The LD50 for nymphs and adults of T . infestans was calculated . The effect of different temperatures (18, 22, 26, 30, and 34 degrees C) and relative humidities (35 and 90% RH) on mortality of nymphs were studied . We evaluated the compatibility of strains with Deltamethrin and Beta-Cypermethrin . Although the strain Bb 25 failed to grow on WH, the other three strains showed similar mortality values independent of the culture medium used to grow the microorganisms . The lowest LD50 values for nymphs were obtained with the strains Bb 10 and 65 and for adults were Bb 1, 10, and 65 . The highest mean mortality was obtained with strain Bb 10, and among temperatures the highest mean mortality was observed at 26 degrees C . Relative humidity did not affect the mortality of T . infestans nymphs with all strains and temperatures assayed . Deltamethrin did not affect any of the three strains for the four studied doses, and Beta-Cypermethrin could be used in combination with the fungus only at low doses . The strain Bb 10 was selected for future assays under natural climatic conditions.

Proc Natl Acad Sci U S A, 2001 Apr 24, 98(9), 5110 - 5 Epub 2001 Apr 10.
Gene discovery and gene function assignment in filamentous fungi; Hamer L et al.; Filamentous fungi are a large group of diverse and economically important microorganisms . Large-scale gene disruption strategies developed in budding yeast are not applicable to these organisms because of their larger genomes and lower rate of targeted integration (TI) during transformation . We developed transposon-arrayed gene knockouts (TAGKO) to discover genes and simultaneously create gene disruption cassettes for subsequent transformation and mutant analysis . Transposons carrying a bacterial and fungal drug resistance marker are used to mutagenize individual cosmids or entire libraries in vitro . Cosmids are annotated by DNA sequence analysis at the transposon insertion sites, and cosmid inserts are liberated to direct insertional mutagenesis events in the genome . Based on saturation analysis of a cosmid insert and insertions in a fungal cosmid library, we show that TAGKO can be used to rapidly identify and mutate genes . We further show that insertions can create alterations in gene expression, and we have used this approach to investigate an amino acid oxidation pathway in two important fungal phytopathogens.

Chest, 2001 Apr, 119(4), 1160 - 5
Pneumonia in patients with severe burns : a classification according to the concept of the carrier state; de La Cal MA et al.; OBJECTIVE: To establish baseline values of pneumonia incidence and mortality and to distinguish primary endogenous from secondary endogenous and exogenous pneumonias in a homogeneous patient population with severe burns . DESIGN: Cohort study . SETTING: A six-bed burn ICU . PATIENTS: All patients of > or = 14 years admitted to the ICU between January 1995 and June 1996 with a total body surface area burn of > or = 20% . INTERVENTION: Collection of data on surveillance samples from throat and rectum on admission and twice weekly afterward, and pneumonias during the ICU stay . MEASUREMENTS AND RESULTS: Fifty-six patients fulfilled the criteria of the study . Mean age was 43 +/- 19.8 years; total body surface area burn, 41 +/- 18.2%; the area of full-thickness burn was 24 +/- 17.7% . Forty-one patients required mechanical ventilation . Twenty-seven patients (48%) experienced 37 episodes of pneumonia . Twenty-one pneumonias were of primary endogenous development, ie, caused by potential pathogens carried in the admission flora . There were 14 secondary endogenous and 2 exogenous infections caused by microorganisms acquired on the burn unit . Inhalation injury was identified in 26 patients . The pneumonia rate was two times higher in the subset of patients with inhalation injury compared with the group of patients without inhalation injury (p < 0.001) . Overall mortality was 25% . CONCLUSIONS: This study shows that pneumonia in burn patients is mainly an endogenous problem . Interventions that prevent the development of endogenous infections deserve prospective evaluation in patients with severe burns.

J Microbiol Methods, 2001 May, 45(1), 61 - 7
Host and pathogen interaction during vaginal infection by Trichomonas vaginalis and Mycoplasma hominis or Ureaplasma urealyticum; van der Schee C et al.; Vaginal infections by Trichomonas vaginalis and Mycoplasma hominis have been shown to be associated . Since M . hominis and Ureaplasma urealyticum are similar pathogens, both belonging to the class of the mycoplasmata, we describe here a molecular study into the interdependence of U . urealyticum and T . vaginalis during infection . Susceptibility towards infection by U . urealyticum depends on genetic polymorphism in the interleukin-1 receptor antagonist (IL-1RA) gene . Now, we defined the relation between IL-1RA genotypes and infection by M . hominis and T . vaginalis . Finally, we also developed a restriction fragment length polymorphism (RFLP) tool for mapping variation in the T . vaginalis AP33 adhesin in order to define putative associations between parasite subtype and mycoplasmata or host . Studies using crudepellets from T . vaginalis culture broth clearly confirm the association between T . vaginalis and M . hominis infection . The association between IL-1RA genotype 2,2 and lack of U . urealyticum infection is corroborated as well . U . urealyticum infection and infection by T . vaginalis are independent . Furthermore, T . vaginalis and M . hominis infection are not depending on IL-1RA genotypes . Interestingly, one of the three AP33 RFLP types identified appeared to be associated with the absence of U . urealyticum infection . In conclusion, the complex interaction between bacterial and parasitic pathogens and the infected host is determined by genetic characteristics of host and microorganisms involved.

Emerg Infect Dis, 2001 Mar-Apr, 7(2), 312 - 8
Molecular approaches to diagnosing and managing infectious diseases: practicality and costs; Pfaller MA; As molecular techniques for identifying and detecting microorganisms in the clinical microbiology laboratory have become routine, questions about the cost of these techniques and their contribution to patient care need to be addressed . Molecular diagnosis is most appropriate for infectious agents that are difficult to detect, identify, or test for susceptibility in a timely fashion with conventional methods.

Emerg Infect Dis, 2001 Mar-Apr, 7(2), 272 - 6
Emerging waterborne infections in health-care settings; Emmerson AM; Water is used in vast quantities in health-care premises . Many aquatic microorganisms can survive and flourish in water with minimal nutrients and can be transferred to vulnerable hospital patients in direct (e.g., inhalation, ingestion, surface absorption) and indirect ways (e.g., by instruments and utensils) . Many outbreaks of infection or pseudoinfection occur through lack of prevention measures and ignorance of the source and transmission of opportunistic pathogens.

J Am Osteopath Assoc, 2001 Feb, 101(2), 92 - 4
Partial spectrum of microorganisms found in dentures and possible disease implications; Glass RT et al.; While it would appear that denture surfaces alone become colonized by microorganisms, this study showed that the porosity of denture material allows for contamination throughout the entire denture . Further, the numerous opportunistic and pathogenic microorganisms found in this study were unexpected and are known to produce not only substantial oral infections, but also systemic diseases.

Biotechnol Bioeng, 2000-2001, 71(3), 208 - 16
Use of lipophilic anions for estimation of biomass and cell viability; Daugelavicius R et al.; A method is described to estimate the microbial biomass of a sample, to enumerate the cells, and to distinguish the portion of metabolically active cells in the population by measuring the binding of phenyldicarbaundecaborane (PCB(-)) to the cells . This method can also be used for the analysis of a complex population of microorganisms if the cells composing the sample are sensitive to different biocidal agents . In addition, the analysis of PCB(-) binding is useful for the enumeration of the phage-infected cells and phage particles .

J Immunol, 2001 Apr 15, 166(8), 5068 - 77
Interaction properties of human mannan-binding lectin (MBL)-associated serine proteases-1 and -2, MBL-associated protein 19, and MBL; Thielens NM et al.; The mannan-binding lectin (MBL) activation pathway of complement plays an important role in the innate immune defense against pathogenic microorganisms . In human serum, two MBL-associated serine proteases (MASP-1, MASP-2) and MBL-associated protein 19 (MAp19) were found to be associated with MBL . With a view to investigate the interaction properties of these proteins, human MASP-1, MASP-2, MAp19, as well as the N-terminal complement subcomponents C1r/C1s, Uegf, and bone morphogenetic protein-1-epidermal growth factor (CUB-EGF) segments of MASP-1 and MASP-2, were expressed in insect or human kidney cells, and MBL was isolated from human serum . Sedimentation velocity analysis indicated that the MASP-1 and MASP-2 CUB-EGF segments and the homologous protein MAp19 all behaved as homodimers (2.8-3.2 S) in the presence of Ca(2+) . Although the latter two dimers were not dissociated by EDTA, their physical properties were affected . In contrast, the MASP-1 CUB-EGF homodimer was not sensitive to EDTA . The three proteins and full-length MASP-1 and MASP-2 showed no interaction with each other as judged by gel filtration and surface plasmon resonance spectroscopy . Using the latter technique, MASP-1, MASP-2, their CUB-EGF segments, and MAp19 were each shown to bind to immobilized MBL, with K:(D) values of 0.8 nM (MASP-2), 1.4 nM (MASP-1), 13.0 nM (MAp19 and MASP-2 CUB-EGF), and 25.7 nM (MASP-1 CUB-EGF) . The binding was Ca(2+)-dependent and fully sensitive to EDTA in all cases . These data indicate that MASP-1, MASP-2, and MAp19 each associate as homodimers, and individually form Ca(2+)-dependent complexes with MBL through the CUB-EGF pair of each protein . This suggests that distinct MBL/MASP complexes may be involved in the activation or regulation of the MBL pathway.

Cell Mol Life Sci, 2001 Feb, 58(2), 244 - 58
Polyamines in cell growth and cell death: molecular mechanisms and therapeutic applications; Thomas T et al.; Polyamines are aliphatic cations with multiple functions and are essential for life . Cellular polyamine levels are regulated by multiple pathways such as synthesis from amino acid precursors, cellular uptake mechanisms that salvage polyamines from diet and intestinal microorganisms, as well as stepwise degradation and efflux . Investigations using polyamine biosynthetic inhibitors indicate that alterations in cellular polyamine levels modulate normal and cancer cell growth . Studies using transgenic mice overexpressing polyamine biosynthetic enzymes support a role of polyamines in carcinogenesis . Many, if not all, signal transduction pathways intersect with polyamine biosynthetic pathways and the regulation of intracellular polyamine levels . Direct binding of polyamines to DNA and their ability to modulate DNA-protein interactions appear to be important in the molecular mechanisms of polyamine action in cell proliferation . Consistent with the role of polyamines as facilitators of cell growth, several studies have shown their ability to protect cells from apoptosis . However, polyamines also have a role in facilitating cell death . The basis of these diverse cellular responses is currently not known . Cell death response might be partly mediated by the production of hydrogen peroxide during polyamine catabolism . In addition, the ability of polyamines to alter DNA-protein and protein-protein interactions might be disruptive to cellular functions, when abnormally high levels are accumulated due to defects in polyamine catabolic or efflux pathways . A large body of data indicates that polyamine pathway can be a molecular target for therapeutic intervention in several types cancers . Inhibitors of biosynthesis, polyamine analogues as well as oligonucleotide/polyamine analogue combinations are promising drug candidates for chemoprevention and/or treatment of cancer.

J Periodontol, 2001 Feb, 72(2), 183 - 9
The effect of alcohol consumption on periodontal disease; Tezal M et al.; BACKGROUND: Alcohol consumption, like smoking, may be related to periodontal disease independently of oral hygiene status . This study assessed the relationship between alcohol consumption and severity of periodontal disease . METHODS: A cross-sectional study of 1,371 subjects ages 25 to 74 in the Erie County, NY population was performed . Alcohol intake was assessed by means of previously validated self-reported questionnaires . Outcome variables were gingival bleeding, clinical attachment loss, alveolar bone loss, and presence of subgingival microorganisms . RESULTS: Logistic regression analyses adjusting for age, gender, race, education, income, smoking, diabetes mellitus, dental plaque, and presence of any of 8 subgingival microorganisms showed that those consuming > or =5 drinks/week had an odds ratio (OR) of 1.65 (95% CI: 1.22 to 2.23) of having higher gingival bleeding, and OR of 1.36 (95% CI: 1.02 to 1.80) of having more severe clinical attachment loss compared to those consuming <5 drinks/week . Those consuming > or =10 drinks/week had an odds ratio (OR) of 1.62 (95% CI: 1.12 to 2.33) of having higher gingival bleeding and OR of 1.44 (95% CI: 1.04 to 2.00) of having more severe clinical attachment loss compared to those consuming <10 drinks/week . Alcohol consumption was not significantly related to alveolar bone loss nor to any of the subgingival microorganisms . CONCLUSIONS: The results suggest that alcohol consumption is associated with moderately increased severity of periodontal disease . Longitudinal studies are needed to determine whether alcohol is a true risk factor for periodontal disease.

Klin Khir, 2000 Jun, (6), 45 - 7
{The role of the intestine in the pathogenesis of the multi-organ dysfunction syndrome in diffuse peritonitis}; Krivoruchko IA et al.; Extraction of oxygen (O2), ultrastructural organization of intestinal macrophages and translocation of microorganisms were studied on 50 male rats of Wistar line in 2, 6, 12, 24 and 48 hours after the stimulation operation performance (control group) and modelling of an acute purulent peritonitis (APP)--basic group . Increase of common and lowering of intestinal extraction of O2 in early terms of the APP occurrence, accompanied by intensive reproduction of microorganisms and change of intestinal biocenosis, was noted . These infringements correlated with translocation of microorganisms through mesenteric lymphatic nodes--ductus toracicus--systemic blood flow (basic way) in term up to 24 hours and through portal vein--hepar--systemic blood flow (additional way)--up to 48 hours after the APP beginning.

J Environ Qual, 2001 Mar-Apr, 30(2), 668 - 74
Hydrologic influence on stability of organic phosphorus in wetland detritus; Pant HK et al.; Accretion of organic matter in wetlands provides long-term storage for nutrients and other contaminants . Water-table fluctuations and resulting alternate flooded and drained conditions may substantially alter the stability of stored materials including phosphorus (P) . To study the effects of hydrologic fluctuation on P mobilization in wetlands, recently accreted detrial material (derived primarily from Typha spp.) was collected from the Everglades Nutrient Removal Project (ENRP), a constructed wetland used to treat agricultural drainage water in the northern Everglades . The detrital material was subjected to different periods of drawdown and consecutive reflooding under laboratory conditions . The 31P nuclear magnetic resonance (31P NMR) spectroscopy analysis revealed that sugar phosphate, glycerophosphate, polynucleotides, and phospholipids (glycerophosphoethanolamine and glycerophosphocholine) were the major forms of P in the detrital material . After 30 d of drawdown, polynucleotides were reduced to trace levels, whereas sugar phosphate, glycerophosphate, and phospholipids remained the major fractions of organic P . Microorganisms seemed to preferentially utilize nucleic acid P, perhaps to obtain associated nutrients including carbon and nitrogen . At the end of the 30-d reflooding period, cumulative P flux from detritus to water column accounted for 3% of the total P (< or = 15 d of drawdown) and further decreased to 2% at 30 d of drawdown, but increased to 8% at 60 d of drawdown . The drawdown (< or = 30 d) not only reduced P flux to the water column, but also increased the humification and microbial immobilization of P . Excessive drawdown (60 d), however, triggered the release of P into the water column as the water content of detritus decreased from 95 to 11%.

J Membr Biol, 2001 Mar 1, 180(1), 33 - 48
Formation of flat lamellar intramembrane lipid structures in microorganisms; Duda VI et al.; Analysis of freeze-fracture replicas and thin sections of cells of the bacteria Sulfobacillus thermosulfidooxidans and Anaerobacter polyendosporus showed that their cytoplasmic membranes contain some regions in the form of flat lamellar inverted lipid membranes a few tenths of nanometers to a few microns in size . The specific features of these membrane structures are as follows: (i) they contain no familiar intramembrane particles commonly present on freeze-fracture replicas; (ii) in cross thin sections, intramembrane structures are bi-furcate on the periphery and look like thylakoids; and (iii) the leaflets of intramembrane structures in S . thermosulfidooxidans cells are corrugated . These structures were revealed in bacterial cells cultivated under normal growth conditions . The data obtained suggest the occurrence of a complex type of compartmentalization in biological membranes.

Appl Environ Microbiol, 2001 Apr, 67(4), 1751 - 65
Phylogenetic diversity of ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes from deep-sea microorganisms; Elsaied H et al.; The phylogenetic diversity of the ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO, E.C . 4.1.1.39) large-subunit genes of deep-sea microorganisms was analyzed . Bulk genomic DNA was isolated from seven samples, including samples from the Mid-Atlantic Ridge and various deep-sea habitats around Japan . The kinds of samples were hydrothermal vent water and chimney fragment; reducing sediments from a bathyal seep, a hadal seep, and a presumed seep; and symbiont-bearing tissues of the vent mussel, Bathymodiolus sp., and the seep vestimentiferan tubeworm, Lamellibrachia sp . The RuBisCO genes that encode both form I and form II large subunits (cbbL and cbbM) were amplified by PCR from the seven deep-sea sample DNA populations, cloned, and sequenced . From each sample, 50 cbbL clones and 50 cbbM clones, if amplified, were recovered and sequenced to group them into operational taxonomic units (OTUs) . A total of 29 OTUs were recorded from the 300 total cbbL clones, and a total of 24 OTUs were recorded from the 250 total cbbM clones . All the current OTUs have the characteristic RuBisCO amino acid motif sequences that exist in other RuBisCOs . The recorded OTUs were related to different RuBisCO groups of proteobacteria, cyanobacteria, and eukarya . The diversity of the RuBisCO genes may be correlated with certain characteristics of the microbial habitats . The RuBisCO sequences from the symbiont-bearing tissues showed a phylogenetic relationship with those from the ambient bacteria . Also, the RuBisCO sequences of known species of thiobacilli and those from widely distributed marine habitats were closely related to each other . This suggests that the Thiobacillus-related RuBisCO may be distributed globally and contribute to the primary production in the deep sea.

Appl Environ Microbiol, 2001 Apr, 67(4), 1728 - 38
Metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "Syntrophus aciditrophicus" strain SB in syntrophic association with H(2)-using microorganisms; Elshahed MS et al.; The metabolism of benzoate, cyclohex-1-ene carboxylate, and cyclohexane carboxylate by "Syntrophus aciditrophicus" in cocultures with hydrogen-using microorganisms was studied . Cyclohexane carboxylate, cyclohex-1-ene carboxylate, pimelate, and glutarate (or their coenzyme A {CoA} derivatives) transiently accumulated during growth with benzoate . Identification was based on comparison of retention times and mass spectra of trimethylsilyl derivatives to the retention times and mass spectra of authentic chemical standards . (13)C nuclear magnetic resonance spectroscopy confirmed that cyclohexane carboxylate and cyclohex-1-ene carboxylate were produced from {ring-(13)C(6)}benzoate . None of the metabolites mentioned above was detected in non-substrate-amended or heat-killed controls . Cyclohexane carboxylic acid accumulated to a concentration of 260 microM, accounting for about 18% of the initial benzoate added . This compound was not detected in culture extracts of Rhodopseudomonas palustris grown phototrophically or Thauera aromatica grown under nitrate-reducing conditions . Cocultures of "S . aciditrophicus" and Methanospirillum hungatei readily metabolized cyclohexane carboxylate and cyclohex-1-ene carboxylate at a rate slightly faster than the rate of benzoate metabolism . In addition to cyclohexane carboxylate, pimelate, and glutarate, 2-hydroxycyclohexane carboxylate was detected in trace amounts in cocultures grown with cyclohex-1-ene carboxylate . Cyclohex-1-ene carboxylate, pimelate, and glutarate were detected in cocultures grown with cyclohexane carboxylate at levels similar to those found in benzoate-grown cocultures . Cell extracts of "S . aciditrophicus" grown in a coculture with Desulfovibrio sp . strain G11 with benzoate or in a pure culture with crotonate contained the following enzyme activities: an ATP-dependent benzoyl-CoA ligase, cyclohex-1-ene carboxyl-CoA hydratase, and 2-hydroxycyclohexane carboxyl-CoA dehydrogenase, as well as pimelyl-CoA dehydrogenase, glutaryl-CoA dehydrogenase, and the enzymes required for conversion of crotonyl-CoA to acetate . 2-Ketocyclohexane carboxyl-CoA hydrolase activity was detected in cell extracts of "S . aciditrophicus"-Desulfovibrio sp . strain G11 benzoate-grown cocultures but not in crotonate-grown pure cultures of "S . aciditrophicus" . These results are consistent with the hypothesis that ring reduction during syntrophic benzoate metabolism involves a four- or six-electron reduction step and that once cyclohex-1-ene carboxyl-CoA is made, it is metabolized in a manner similar to that in R . palustris.

J Biol Chem, 2001 May 4, 276(18), 14759 - 66 Epub 2001 Feb 08.
An extended conformation of the macrophage mannose receptor; Napper CE et al.; The macrophage mannose receptor mediates phagocytosis of pathogenic microorganisms and endocytosis of potentially harmful soluble glycoproteins by recognition of their defining carbohydrate structures . The mannose receptor is the prototype for a family of receptors each having an extracellular region consisting of 8-10 domains related to C-type carbohydrate recognition domains (CRDs), a fibronectin type II repeat and an N-terminal cysteine-rich domain . Hydrodynamic analysis and proteolysis experiments performed on fragments of the extracellular region of the receptor have been used to investigate its conformation . Size and shape parameters derived from sedimentation and diffusion coefficients indicate that the receptor is a monomeric, elongated and asymmetric molecule . Proteolysis experiments indicate the presence of close contacts between several pairs of domains and exposed linker regions separating CRDs 3 and 6 from their neighboring domains . Hydrodynamic coefficients predicted for modeled receptor conformations are consistent with an extended conformation with close contacts between three pairs of CRDs . The N-terminal cysteine-rich domain and the fibronectin type II repeat appear to increase the rigidity of the molecule . The rigid, extended conformation of the receptor places domains with different functions at distinct positions with respect to the membrane.

J Biol Chem, 2001 May 25, 276(21), 17800 - 7 Epub 2001 Feb 15.
Bcl-XL expression correlates with primary macrophage differentiation, activation of functional competence, and survival and results from synergistic transcriptional activation by Ets2 and PU.1; Sevilla L et al.; Depriving primary bone marrow-derived macrophages of colony-stimulating factor-1 (CSF-1) induces programmed cell death by apoptosis . We show that cell death is accompanied by decreases in the expression of anti-apoptotic Bcl-x(L) protein and the Ets2 and PU.1 proteins of the Ets transcription factor family . Macrophages require both priming and triggering signals independent of CSF-1 to kill neoplastic cells or microorganisms, and this activation of macrophage competence is accompanied by increased expression of bcl-x(L), ets2, and PU.1 . Furthermore, we show that only Ets2 and PU.1, but not Ets1, function in a synergistic manner to transactivate the bcl-x promoter . The synergy observed between PU.1 and Ets2 is dependent on the transactivation domains of both proteins . Although other transcription factors like Fos, c-Jun, Myc, STAT3, and STAT5a are implicated in the activation of macrophage competence or in CSF-1 signaling, no synergy was observed between Ets2 and these transcription factors on the bcl-x promoter . We demonstrate that the exogenous expression of both Ets2 and PU.1 in macrophages increases the number of viable cells upon CSF-1 depletion and that Ets2 and PU.1 can functionally replace Bcl-x(L) in inhibiting Bax-induced apoptosis . Together, these results demonstrate that PU.1 and Ets2 dramatically increase bcl-x activation, which is necessary for the cytocidal function and survival of macrophages.

Pediatr Neurol, 2001 Feb, 24(2), 123 - 7
Cavernous sinus thrombophlebitis in children; Visudtibhan A et al.; Eight Thai patients less than 15 years of age who were diagnosed with cavernous sinus thrombophlebitis at Ramathibodi Hospital, Bangkok, Thailand over the past 30 years were reviewed retrospectively . The predisposing infections and causative microorganisms were similar to previous reports in children and adults . Despite severe neurologic dysfunction during admission, including blindness, there was neither death nor severe permanent deficit found in the majority of the patients . Only one patient experienced mild hemiparesis caused by cerebral infarction, which was secondary to this condition . Early recognition of this condition, the appropriate selection of empirical antibiotic therapy, and the awareness of associated complication were the key factors leading to excellent outcome.

Trends Immunol, 2001 Apr, 22(4), 205 - 11
IgA and the IgA Fc receptor; van Egmond M et al.; IgA has traditionally been regarded a non-inflammatory antibody . This might indeed be true for secretory IgA (SIgA), which exerts its function at mucosal surfaces where commensal microorganisms and dietary antigens prevail . Serum IgA, however, potently triggers (pro)-inflammatory activity upon binding to the myeloid IgA receptor, FcalphaRI . Here, new insights in the roles of IgA and FcalphaRI are addressed and a model integrating the various functions of IgA in immunity is discussed.

Physiol Rev, 2001 Apr, 81(2), 569 - 628
Nonvertebrate hemoglobins: functions and molecular adaptations; Weber RE et al.; Hemoglobin (Hb) occurs in all the kingdoms of living organisms . Its distribution is episodic among the nonvertebrate groups in contrast to vertebrates . Nonvertebrate Hbs range from single-chain globins found in bacteria, algae, protozoa, and plants to large, multisubunit, multidomain Hbs found in nematodes, molluscs and crustaceans, and the giant annelid and vestimentiferan Hbs comprised of globin and nonglobin subunits . Chimeric hemoglobins have been found recently in bacteria and fungi . Hb occurs intracellularly in specific tissues and in circulating red blood cells (RBCs) and freely dissolved in various body fluids . In addition to transporting and storing O(2) and facilitating its diffusion, several novel Hb functions have emerged, including control of nitric oxide (NO) levels in microorganisms, use of NO to control the level of O(2) in nematodes, binding and transport of sulfide in endosymbiont-harboring species and protection against sulfide, scavenging of O(2 )in symbiotic leguminous plants, O(2 )sensing in bacteria and archaebacteria, and dehaloperoxidase activity useful in detoxification of chlorinated materials . This review focuses on the extensive variation in the functional properties of nonvertebrate Hbs, their O(2 )binding affinities, their homotropic interactions (cooperativity), and the sensitivities of these parameters to temperature and heterotropic effectors such as protons and cations . Whenever possible, it attempts to relate the ligand binding properties to the known molecular structures . The divergent and convergent evolutionary trends evident in the structures and functions of nonvertebrate Hbs appear to be adaptive in extending the inhabitable environment available to Hb-containing organisms.

Circulation, 2001 Mar 27, 103(12), 1613 - 7
Distribution of Chlamydia pneumoniae in the human arterial system and its relation to the local amount of atherosclerosis within the individual; Vink A et al.; BACKGROUND: Chlamydia pneumoniae has been suggested to play a role in the origin of atherosclerosis . We studied the prevalence of C pneumoniae at multiple locations in the arterial system within the same individual . Studying the association between atherosclerosis and C pneumoniae within the individual excludes confounding by interindividual variability . METHODS AND RESULTS: Postmortem, the presence in the intima/plaque and media of C pneumoniae membrane protein was determined by use of a C pneumoniae-specific monoclonal antibody . In 24 individuals, 33 arterial locations were studied (n=738 segments) . Area stenosis was determined in adjacent cross sections . In all individuals, immunostaining of C pneumoniae was observed in >/=1 artery . The highest prevalences were observed in the abdominal aorta (67%), internal and common iliac arteries (41%), and coronary arteries (33%) . The lowest prevalences were observed in the radial (0%) and cerebral (2%) arteries . Within the individual, area stenosis was larger in cross sections with immunoreactivity compared with cross sections without immunoreactivity (31.0+/-11.9% versus 14.3+/-6.1%, respectively; P:<0.001) . In the individual, immunoreactivity was observed in 15+/-10% of the arteries (range, 3% to 45%) . Between individuals, the percentage of arteries with immunoreactivity to C pneumoniae was associated with the average area stenosis throughout the arterial system (r(2)=0.56, P:<0.001) . CONCLUSIONS: C pneumoniae was mostly observed at locations that are related to clinically relevant features . Within the individual, the distribution of C pneumoniae is associated with the distribution of atherosclerosis . The role of the microorganism in atherosclerotic disease remains to be elucidated.

Folia Microbiol (Praha), 2000, 45(2), 143 - 6
Polysaccharide hydrolases of Aureobasidium pullulans; Augustin J; The polysaccharide hydrolase activity of a group of selected strains of the genus Aureobasidium pullulans was investigated using a new gel testing assay . A total of 31 strains were tested for alpha-amylase, alpha-glucosidase and glucoamylase, beta-glucosidase, lichenase, cellulase, xylanase and xylosidase, mannanase and mannosidase production during growth of microorganisms on respective meshed polysaccharide gels . Attempts were made to increase the polysaccharide hydrolase activity through selection of some A . pullulans strains by passaging them on the respective modified xylanase- and cellulase-containing gels . The individual saccharide degradation cleavage products were investigated by chromatography.

Arch Microbiol, 2001 Jan, 175(1), 70 - 4
Mycoplasma hominis and Trichomonas vaginalis symbiosis: multiplicity of infection and transmissibility of M . hominis to human cells; Rappelli P et al.; We recently reported that most Trichomonas vaginalis isolates cultured in vitro are infected by Mycoplasma hominis . In this work, we have characterized some aspects of the relationships between the two microorganisms . PCR, cultivation, and immunological methods revealed that the number of M . hominis organisms carried by T . vaginalis in culture varied from isolate to isolate, suggesting a specific multiplicity of infection . Moreover, infected T . vaginalis isolates were able to pass bacteria not only to M . hominis-free protozoa, but also to human-derived epithelial cells . The in vitro transmission of the bacterium from T . vaginalis to both uninfected parasite isolates and human epithelial cells suggests a role for T . vaginalis as a carrier of the M . hominis infection in vivo.

Water Res, 2001 Apr, 35(5), 1318 - 24
Microorganisms' activity and energy fluxes in Lake Varese (Italy): a field method; Rossetti C et al.; Microorganisms are fundamental components of energy fluxes in aquatic ecosystems . Interest in plankton production and respiration has recently stimulated exploration of the use of electron transfer system (ETS) activity in oceanography and limnology . If we consider microorganism production (MP) and microorganism respiration (MR), due to aerobic and anaerobic metabolism, microorganism growth efficiency can be defined as MGE = MP/(MP + MR) . In order to calculate MGE, we measured independently the two components of ETS (photosynthesis electron transfer system activity (PETS) and respiration electron transfer system activity (RETS)) during an annual cycle using a portable biosensor microorganisms amperometric detector system (MiDAS) on the site . MGE was calculated in samples collected from the photic and aphotic zones and the superficial sediment and ranged between 0.60 and 0.45 and dropped to 0.15 at the end of the summer . This substantial decrease is probably due to the prevalence of the anaerobic-heterotrophic metabolism after a pronounced state of anoxia during the summer algal bloom.

Ann N Y Acad Sci, 2000, 917, 248 - 57
Natural immunity and neuroimmune host defense; Berczi I et al.; Innate resistance is mediated by non-immune defense and by natural immunity . Non-immune defense includes diverse mechanisms (e.g., physico-chemical defense by bile acids) . Natural killer (NK) cells, gamma delta T lymphocytes and CD5+ B lymphocytes are key mediators of natural immunity . These cells utilize germ-line coded receptors that recognize highly conserved, homologous epitopes (homotopes) . Typically, it is not the antigen, but cytokines and hormones that regulate the level of NK-mediated cytotoxicity . These include interleukin-2, interferons, prolactin and growth hormone . Less is known about gamma delta T lymphocytes . CD5+ B lymphocytes produce germ-line coded antibodies (predominantly IgM) that are polyspecific, and able to recognize a great variety of microorganisms, cancer-cells and self-components . Antigen is not an effective stimulus for natural antibody (NAb), but bacterial lipopolysaccharide (LPS) is . During the acute phase response (febrile illness) the T-cell-regulated adaptive immune response is switched off and natural immune mechanisms are amplified several hundred to a thousand times within 24-48 hours (immunoconversion) . This immunoconversion is initiated by immune-derived cytokines, and involves profound neuroendocrine and metabolic changes, all in the interest of host defense . Immune recognition is assured by natural antibodies and by some liver-derived acute phase proteins, such as C-reactive protein or endotoxin-binding protein, the level of which is elevated in the serum . Thus, natural immunity is essential for a first and last line of defense and the neuroendocrine system is an important promoter of this activity.

Pediatr Res, 2001 Apr, 49(4), 589 - 93
Evidence for an innate immune response in the immature human intestine: toll-like receptors on fetal enterocytes; Fusunyan RD et al.; The intestinal epithelium is an active participant in the mucosal immune response against luminal pathogens . Microorganisms and their cell wall products, i.e . lipopolysaccharide (LPS), can stimulate the enterocyte to produce an innate immune response with the increased production of IL-8 via an activation of the transcription factor NFkappaB . The innate response mechanism, however, has not been understood until the recent description of a family of human toll-like receptors (hTLR) on immune cells that interact with LPS and modulate the IL-8 response via an intracellular signal transduction pathway similar to that of the IL-1 receptor family . Accordingly, in this study we have sought to determine the constitutive and regulated expression of hTLR on a nonmalignant human fetal primary small intestinal cell line (H4 cells) and on small intestinal samples of ileum from human fetuses (age 18-21 wk) . Specimens were examined by reverse-transcription PCR, Western blot analysis, and immunofluorescence for hTLR2 and hTLR4 mRNA and protein and to determine whether their expression was regulated by LPS or by an endogenous inflammatory stimulus, IL-1beta . hTLR2 and hTLR4 were expressed constitutively on H4 cells and on human fetal small intestinal enterocytes, predominantly on the basolateral surface of crypt enterocytes . Inflammatory stimuli appeared to regulate hTLR transcription (IL-1beta increased both hTLR2 and hTLR4 whereas LPS decreased hTLR4) and possibly translation (qualitative observations) . The presence of hTLR on human fetal enterocyte suggests a mechanism for the innate immune response to pathogens and could provide the basis for further study of the accentuated inflammatory response in age-dependent gastrointestinal diseases such as necrotizing enterocolitis.

Rev Med Virol, 2001 Mar-Apr, 11(2), 117 - 33
Mucosal immune network in the gut for the control of infectious diseases; Iijima H et al.; The common mucosal immune system (CMIS) consists of an integrated cross-communication pathway of lymphoid tissues made up of inductive and effector sites for host protection against pathogenic microorganisms . Major effector molecules of the CMIS include IgA antibodies and cytokines, chemokines and their corresponding receptors . Secretory IgA (S-IgA), the major immunoglobulin, is induced by gut-associated lymphoreticular tissue (GALT)-derived B cells with the help of Th1- and Th2-type CD4(+) T lymphocytes . Cytotoxic T lymphocytes (CTLs) in the mucosal epithelium, a subpopulation of intraepithelial lymphocytes (IELs), also help maintain the mucosal barrier . The CMIS is unique in that it can provide both positive and negative signals for the induction and regulation of immune responses in both the mucosal and systemic compartments after oral or nasal antigen exposure . Prevention of infection through mucosal surfaces can be achieved by the CMIS through connections between inductive (e.g . GALT) and effector tissues . When vaccine antigens are enterically administered together with mucosal adjuvants {e.g . cholera toxin (CT), heat-labile toxin produced by Escherichia coli (LT) and IL-12}, antigen-specific Th1/Th2 and IgA B cell responses are induced simultaneously in the mucosal effector compartment . Since these antigen-specific immune responses are not generated by oral vaccine without mucosal adjuvant, safe and effective adjuvants for the induction of antigen-specific S-IgA and CTL responses are essential for the development of mucosal vaccines for protection against infectious diseases . Finally, recent findings suggest the presence of a CMIS-independent IgA induction pathway, which also must be considered in the development of mucosal vaccines .

J Agric Food Chem, 2001 Feb, 49(2), 664 - 8
Polygalacturonase, pectinesterase, and lipoxygenase activities in high-pressure-processed diced tomatoes; Shook CM et al.; High-pressure processing (HPP) can inactivate pathogenic microorganisms and degradative enzymes without the use of heat, thereby minimizing the destruction of flavors, nutrients, and other quality attributes . Lipoxygenase plays a role in the off-flavor production of tomatoes, whereas pectinesterase and polygalacturonase impact tomato texture . The purpose of this study was to determine HPP's ability to inactivate lipoxygenase, pectinesterase, and polygalacturonase in diced tomatoes . Processing conditions used were 400, 600, and 800 MPa for 1, 3, and 5 min at 25 and 45 degrees C . The magnitude of applied pressure had a significant effect on inactivating lipoxygenase and polygalacturonase (p < 0.05), with complete loss of activity occurring at 800 MPa . Pectinesterase was very resistant to pressure treatment . Percent soluble solids, pH, titratable acidity, and color a/b values did not differ significantly among the high-pressure-processed samples as compared to the control, but color L values increased . This change in L values was not considered of practical importance . Apparent protein content decreased in the pressure-processed samples, due possibly to protein denaturation, loss of solubility, and/or a decrease in dye binding sites to assay protein content.

Recenti Prog Med, 2001 Jan, 92(1), 63 - 7
{Articular involvement in the course of primary hypogammaglobulinemia}; Pipitone N et al.; The Authors describe the main features of the most common forms of primary hypogammaglobulinaemia (PH) focusing on the articular involvement . Patients with Bruton's agammaglobulinemia (BA) and common variable immune deficiency (CVID) are predisposed to develop septic arthritis (including arthritis due to atypical microorganisms such as mycoplasma), arthralgia and symmetrical (usually non-erosive) polyarthritis . In BA and CVID complicated by recurrent infections, amyloidosis, which may be itself a cause of arthropathy, can occur . In addition, patients with CVID and selective IgA deficiency show an increased prevalence of juvenile rheumatoid arthritis, systemic lupus erythematosus, Sjogren's syndrome and primary biliary cirrhosis, while patients with selective IgA deficiency are prone to developing seronegative spondylarthropathies, including ankylosing spondylitis . The mainstay of treatment for BA and CVID is replacement therapy with human immunoglobulins . Septic arthritis should be promptly treated with antibiotics, whereas other types of arthritis usually respond well to non-steroidal antiinflammatory medications . In contrast, the second line agents commonly used to treat rheumatoid arthritis do not appear to be beneficial in patients with PH-associated arthritis.

Hist Philos Life Sci, 2000, 22(1), 43 - 58
Linking cause and disease in the laboratory: Robert Koch's method of superimposing visual and 'functional' representations of bacteria; Schlich T; Robert Koch based his claim that specific microorganisms cause particular diseases on laboratory studies . This paper examines how Koch set up a plausible line of argument by using special methods of representing bacteria . One kind of representation consisted in making the bacteria visible; the other mode of representation was based on disease phenomena . Using a range of techniques of isolating and controlling microorganisms, Koch combined these different modes of representation in a way that made his claims convincing . Thus, the microorganism as a specific cause of disease emerged through a chain of repeated processes of selection and representation in the laboratory.

Apoptosis, 2000 Nov, 5(5), 459 - 71
Regulation of T cell apoptosis; Holtzman MJ et al.; Proliferative expansion of lymphoid cells is required for effective immune responses against invading microorganisms, but after the infection is controlled, the expanded effector cells must be eliminated to prevent non-adaptive accumulation of cells . Higher vertebrates have developed extensive networks of signal transduction pathways to ensure controlled activation and expansion of cells during immune responses and apoptotic deletion of lymphoid cells that are no longer needed at the end of immune responses . Extracellular signals received by cell surface receptors that trigger intracellular signaling cascades are essential elements that control both processes . These signal transduction pathways converge to regulate cell fate at both transcriptional and post-transcriptional levels . Here we review the role of pathways, especially those triggered by TNF receptor-related molecules, that determine the fate of T cells during development and activation . In addition, we introduce the possibility that these same pathways may be abnormally programmed and so lead to immune cell accumulation during inflammatory diseases such as asthma.

Arch Environ Health, 2001 Jan-Feb, 56(1), 30 - 6
Nasal lavage biomarkers: effects of water damage and microbial growth in an office building; Walinder R et al.; Selected nasal symptoms were studied in personnel who worked in a damp office building that had microbial growth (including Stachybotrys sp.) in mineral fiber insulation and gypsum board . There were also signs of dampness in the floor . Clinical examinations included nasal lavage and peak expiratory flow measurements in 12 subjects in the damp building; an additional 8 subjects in a control building (i.e., no signs of dampness or microbial growth) were also examined . Hygienic air measurements of microorganisms and volatile organic compounds were performed in both buildings . The concentrations of eosinophil cationic protein, myeloperoxidase, and albumin, and the number of subjects with eosinophils in lavage fluid, were higher among office workers in the damp building than among controls . The damp biiilding had greater amounts of total molds and bacteria in its construction than the building materials in nondamp buildings . In addition, an increase of 2-ethyl-1-hexanol in the indoor air was detected in the damp building-a sign of dampness-related alkaline degradation of diethyl-hexyl phthalate in polyvinyl chloride floor coatings . In conclusion, the results of this study indicate that exposures in a damp office building may cause an inflammatory nasal mucosal response . The results also support conclusions of earlier studies, indicating that building dampness is related to respiratory inflammation.

Rev Immunogenet, 1999, 1(1), 75 - 90
Emerging principles for T cell receptor recognition of antigen in cellular immunity; Garcia KC et al.; The structural basis of antigen recognition in cellular immunity has been elucidated through the determination of crystal structures of major histocompatibility complex (MHC) molecules bound to antigenic peptides, T cell receptors (TCR), CD8 and CD4 co-receptors and, most recently, TCRs in complex with peptide-MHC (pMHC) . The mechanisms that generate the diversity of the immune response to invading microorganisms were first realized at a genetic level and are necessary in order to cope with the enormous number of potential antigens . This diversity is manifested in the protein products of the genes which code for the components of the TCR signalling complex . The structure of the TCR reveals both striking similarities with and fundamental differences from its functional counterpart, the antibody, in the humoral immune system . The conserved manner in which the TCR recognizes and interacts with its peptide-MHC ligand allows the TCR great latitude in its potential to form productive interactions with antigen-presenting cells that bear numerous ligands to which the TCR has not been previously exposed . This phenomenon of cross-, or alloreactivity arises from a combination of conserved structural features across all MHC molecules, both self and foreign, and some degree of molecular mimicry . Non-classical MHC ligands presenting either modified or specialized peptides, lipids, carbohydrates, or no ligand at all, are now thought to play increasingly important roles in cellular immunity . We review some of the recent structural results and our current state of knowledge about TCR structure, and how this relates to its function.

Infect Immun, 2001 Apr, 69(4), 2520 - 6
Activation of protein tyrosine kinases by Coxiella burnetii: role in actin cytoskeleton reorganization and bacterial phagocytosis; Meconi S et al.; Coxiella burnetii, the agent of Q fever, is an obligate intracellular microorganism that grows in monocytes/macrophages . The internalization of virulent organisms by monocytes is lower than that of avirulent variants and is associated with actin cytoskeleton reorganization . We studied the activation of protein tyrosine kinases (PTKs) by C . burnetii in THP-1 monocytes . Virulent organisms induced early PTK activation and the tyrosine phosphorylation of several endogenous substrates, including Hck and Lyn, two Src-related kinases . PTK activation reflects C . burnetii virulence since avirulent variants were unable to stimulate PTK . We also investigated the role of PTK activation in C . burnetii-stimulated F-actin reorganization . Tyrosine-phosphorylated proteins were colocalized with F-actin inside cell protrusions induced by C . burnetii, and PTK activity was increased in Triton X-100-insoluble fractions . In addition, lavendustin A, a PTK inhibitor, and PP1, a Src kinase inhibitor, prevented C . burnetii-induced cell protrusions and F-actin reorganization . We finally assessed the role of PTK activation in bacterial phagocytosis . Pretreatment of THP-1 cells with lavendustin A and PP1 upregulated the uptake of virulent C . burnetii but had no effect on the phagocytosis of avirulent organisms . Thus, it is likely that PTK activation by C . burnetii negatively regulates bacterial uptake by interfering with cytoskeleton organization.

Comp Biochem Physiol A Mol Integr Physiol, 1998 Jan, 119(1), 17 - 26
Structure and function of the axillary organ of the gulf toadfish, Opsanus beta (Goode and Bean); Maina JN et al.; The structure of the axillary organ of a batrachoidid species, the gulf toadfish (Opsanus beta Goode and Bean 1879), has been examined and several simple experiments designed to elucidate its function performed . Electron microscopy (EM) studies revealed cells and structures suggesting secretory and iono regulatory roles (e.g., abundant intracytoplasmic secretory particles, rough endoplasmic reticulum, sparse Golgi bodies, indented epithelial cells with microvilli, numerous endocytotic vesicles, etc.) . Our physiological experiments allowed us to reach several conclusions: the organs do not excrete significant quantities of urea relative to other areas of the fish (head and gills), the organs do not secrete a substance that is toxic to a teleost test fish (Gambusia affinis), the secretions do not induce short-term modifications in locomotory activity of other gulf toadfish (e.g., by pheromonal means) and the secretions do not inhibit the growth of several species of microorganisms in culture . The function of the organ and its secretions remains unknown, representing a fertile area for research on structure and function in comparative physiology.

Aviakosm Ekolog Med, 2000, 34(6), 35 - 7
{Sensitivity in vitro of test-cultures and collection s of microoganisms isolated from surfaces of a pressurized complex to detergents}; Andreeva EA et al.; Human subjects are a prime source of microbial contamination of the diving gear and the interior of deep-water diving complexes (DWDC) . Disinfecting measures cannot ensure infectious safety of deep-water dives . Investigations in vitro were to compare effectiveness of a standard and a novel detergent against the microorganisms isolated from DWDC-250 at SRC-IBMP . It was discovered that 21% of microbial strains were resistant to the standard 3% solution of hydrogen peroxide . Diluted in ratio 1:10, polycept Demos (alkyl dimethyl benzyl ammonium chloride AB 0.5%) demonstrated 100% effectiveness in usual conditions and in hyperbaric experiments with various gaseous mixtures . Biocide Demos should be further tested during simulation of dives in DWDC-250.

Radiats Biol Radioecol, 2001 Jan-Feb, 41(1), 119 - 23
{Experimental study of the intensity of phosphorus radionuclide uptake by samples of algobacterial community of the Yenisei river}; Bolsunovskii AIa et al.; The experiments in which phosphorus radionuclide was added to samples of algobacterial community of the Yenisei River taken near the production area of the Mining-and-Chemical Combine (Zheleznogorsk) made possible determining the uptake rates and coefficients of radionuclide accumulation by microorganisms . Ratios between processes of adsorption and accumulation of phosphorus radionuclide by components of water seston (suspended matter) have been determined . The portion of the specific radioactivity of phosphorus adsorbed by unit mass of seston (and algae) has been found to be not more than 7% of the activity accumulated by algal cells.

Biometrics, 2001 Mar, 57(1), 224 - 31
The K-function for nearly regular point processes; Taylor CC et al.; We propose modeling a nearly regular point pattern by a generalized Neyman-Scott process in which the offspring are Gaussian perturbations from a regular mean configuration . The mean configuration of interest is an equilateral grid, but our results can be used for any stationary regular grid . The case of uniformly distributed points is first studied as a benchmark . By considering the square of the interpoint distances, we can evaluate the first two moments of the K-function . These results can be used for parameter estimation, and simulations are used to both verify the theory and to assess the accuracy of the estimators . The methodology is applied to an investigation of regularity in plumes observed from swimming microorganisms.

Int J Food Microbiol, 2001 Feb 28, 64(1-2), 13 - 9
Effectiveness of immersion treatments with acids, trisodium phosphate, and herb decoctions in reducing populations of Yarrowia lipolytica and naturally occurring aerobic microorganisms on raw chicken; Ismail SA et al.; Yarrowia lipolytica, one of the predominant yeasts in raw poultry, is believed to play a role in spoilage . This study was undertaken to investigate treatments to control the growth of Y . lipolytica on raw chicken stored at refrigeration temperature . Raw chicken wings inoculated with a mixture of five strains of Y . lipolytica isolated from raw poultry were dipped in solutions containing 2, 5, or 8% lactic acid, 2% lactic acid containing 0.2, 0.4, or 0.8% potassium sorbate or sodium benzoate, and 4, 8, or 12% trisodium phosphate solution . Populations of the yeast and total aerobic microorganisms were determined before and after treatment . Immersion of wings in 2% lactic acid (with or without 0.2% potassium sorbate or sodium benzoate) or 4% trisodium phosphate caused a significant (alpha = 0.05) reduction in numbers of Y . lipolytica and aerobic microorganisms . Treatment with 2% lactic acid containing 0.4 or 0.8% preservative did not result in additional significant reductions . Treatment of chicken wings with 2% lactic acid or 8% trisodium phosphate significantly reduced numbers of Y . lipolytica by 1.47 and 0.65 log10 cfu/g, respectively, and aerobic microorganisms by 2.60 and 1.21 log10 cfu/g, respectively, compared to controls . Growth of Y . lipolytica on wings stored at 5 degrees C for up to 9 days, however, was not affected by these treatments . Significant reductions in the population of Y . lipolytica occurred when the yeast was inoculated into 100% basil, marjoram, sage, and thyme decoctions, but not in 100% oregano or rosemary decoctions, held at 5 degrees C for 24 h . Treatment of chicken wings with 100% sage or thyme decoctions significantly reduced populations of Y . lipolytica but did not control its growth during storage at 5 degrees C for up to 9 days . The small, temporary decreases in numbers of Y . lipolytica and aerobic microorganisms resulting from immersion treatment of chicken wings with sage and thyme decoctions render these treatments of questionable value as preservation interventions.

Microb Ecol, 2001 Jan, 41(1), 20 - 35
Microbial Community Composition and Ecology of an Acidic Aquatic Environment: The Tinto River, Spain; Lopez-Archilla AI et al.; We studied the correlation between physicochemical and biological characteristics of an acidic river, the Tinto River, in Southwestern Spain . The Tinto River is an extreme environment characterized by its low pH (mean of 2.2) and high concentrations of heavy metals (Fe 2.3 g/L, Zn 0.22 g/L, Cu 0.11 g/L) . These extreme conditions are the product of the metabolic activity of chemolithotrophic microorganisms, including iron- and sulfur-oxidizing bacteria, that can be found in high concentrations in its waters . The food chain in the river is very constrained and exclusively microbial . Primary productivity in the Tinto River is the sum of photosynthetic and chemolithotrophic activity . Heterotrophic bacteria and fungi are the major decomposers and protists are the major predators . A correlation analysis including the physicochemical and biological variables suggested a close relationship between the acidic pH values and abundance of both chemolithotrophic bacteria and filamentous fungi . Chemolithotrophic bacteria correlated with the heavy metals found in the river . A principal component analysis of the biotic and abiotic variables suggested that the Tinto River ecosystem can be described as a function of three main groups of variables: pH values, metal concentrations, and biological productivity.

Int J Pediatr Otorhinolaryngol, 2001 Apr 6, 58(1), 69 - 73
Bacteremia during tonsillectomy; Kaygusuz I et al.; OBJECTIVE: To investigate bacteremia in patients who underwent tonsillectomy with a dissection method due to chronic tonsillitis, which may lead to dramatic results in patients that have a cardiovascular infection risk . In this study, it was explored whether the tonsil surface and the tonsil tissue interior microorganisms are different or not, and whether these microorganisms carry bacteremia development risk . METHODS: Forty patients were enrolled in the study in ENT Clinic, Firat University . A bacteriological research was performed on patients with no treatment with antibiotics for a month before the operation . Tonsil surface and deep tissue cultures were performed, and venous blood samples were taken for cultures before and after the operation . RESULTS: Surface and deep tissue cultures of tonsils of the cases represented a different result in 27.5% of the patients . No reproduction was observed regarding the blood cultures taken before tonsillectomy . Bacteremia was found in blood samples of ten patients (25%) taken immediately after tonsillectomy . CONCLUSION: Hence, it has been concluded that different microorganisms may be present among the tonsil surface and tonsil deep tissue cultures and that bacteremia may develop after tonsillectomy . Therefore, to prevent the possible dramatic outcomes after tonsillectomy the required measures during the preoperative period should be taken into consideration, especially in patients that have chronic tonsillitis with cardiovascular disease.

Syst Appl Microbiol, 2000 Dec, 23(4), 573 - 81
Optimization of reverse hybridization in microplates coated with rRNA targeted oligonucleotide probes; Schedl M et al.; Among the modern molecular techniques for the identification of microorganisms the most straightforward way is through direct hybridization with rRNA/rDNA targeted probes . In this study, the optimization of the experimental procedures for the reverse hybridization technique in 96-well microplates is described using both synthetic model oligonucleotides (18 b) and amplified DNA (app . 4500 bp) . Three different types of plates were compared (Maxi Sorp, NucleoLink, CovaLink) . Plates made from nonchemically modified polystyrene which are conventionally used in immunoassays (MaxiSorp) proved to be an economic alternative for plates offering chemically modified tailor-made surfaces . Phosphorylation of the oligonucleotide probe was not necessary for successful immobilization whereas with 5'-terminal hexa-deoxyadenosine tailed capture oligonucleotides an enhanced sensitivity of the assay was observed . Variation of the stringency by adjusting different concentrations of formamide during the washing step ensures high probe specificity and therefore allows reliable identification of the microorganisms . The assay can be performed in less than 4 hours using pre-coated plates which can be stored for several weeks . After dissociation of the target DNA/capture probe duplex with an alkaline denaturing solution rehybridization is possible.

ALTEX, 2001, 18(1), 41 - 6
{A new application for the human whole blood test: development of an assay to assess the health risk of air-borne microbial contaminations}; Fennrich S et al.; The pathogenic properties of environmental microorganisms as well as pyrogens as fragments of those bacteria (especially endotoxins) for humans is increasingly recognised . Various clinical syndromes are described after contact with airborne microbial contaminants via the respiratory tract: Sick-building-syndrome, humidifier lung (a form of hypersensitive pneumonitis), "Monday sickness" etc . Air-conditioning and ventilation systems intensify this problem as well as storage of compost within the household which represents a considerable source of airborne pollutants . In 1995 a new method for the detection of pyrogenic (fever-inducing) hazardous substances was described by Hartung and Wendel . This whole blood assay utilises the natural reaction of the immune system in order to detect a broad spectrum of pyrogens very sensitively in the relevant species . Injectable drugs are the main area of application in which this innovative test has already proven effective and is currently validated for inclusion into European Pharmacopoeia . In co-operation with the FU Berlin we could demonstrate in ventilation systems in animal stables that the whole blood pyrogen test can also detect airborne environmental microorganisms very sensitively . The filtration technique for collection of these germs is an established method for air-conditioning and ventilation systems . In co-operation with the FU Berlin (Institut fur Tier-und Umwelthygiene) and the filter producer Sartorius this method is currently developed for the detection of airborne contaminations.

Mikrobiol Z, 2000 Nov-Dec, 62(6), 51 - 6
{Accumulation of uranium, plutonium and americium by granulated microbial biosorbent}; Tashirev AB; A possibility of efficient extraction of 238U, 239Pu and 241Am by microorganisms from solutions with activity 520-3200 Bq/l has been shown on the example of microbial biosorbent (MBS) . MBS presents water-resistant granules consisting of living microorganisms and nutrient substances . The ratio MBS:solution being equal to 1:100 and 1:20, microorganisms extracts 98.9 and 99.8% of 238U; 99.1 and 99.8% of 239Pu, 241Am, respectively . The worked out MBC granules may be utilized by burning with the 4-8 decrease of the volume . It is foreseen to use MBS in industrial processes of treatment of liquid radioactive waste (LRW) for uranium and transuranium elements.

Mikrobiol Z, 2000 Sep-Oct, 62(5), 3 - 13
{Screening of alpha-N-acetylgalactosaminidase producers among microorganisms of different taxonomic groups}; Borzova NV et al.; Screening of producers of alpha-N-acetylgalactosaminidase among 854 strains of micromycetes, 171 yeast and 357 bacterial cultures has been carried out . A capacity to synthesize the enzyme was revealed in 11% of cultures . Representatives of Aspergillus genus (activity--0.11-0.142 un./ml) were most active in producing the enzyme . It has been established that glucosidases spectrum in the culture liquid of 18 most active strains was characterized by complete homogeneity and by the presence of a rather high level (0.5-0.9 un./ml) of alpha-galactosidase activity . Complex preparations of alpha-N-acetylgalactosaminidase and alpha-galactosidase have been obtained from the culture liquid of producers by fractionation by ammonium sulphate (30 and 90% saturation); their pH- and thermo-optimum, pH- and thermal stability have been studied . It was shown possibility to induce alpha-N-acetylgalactosaminidase synthesis by a number of carbohydrates (galactose, glucose, galactosamine, and glucosamine), complex-forming substances (guanidine HCl), nitroaminoguanidin and guanidine carbonate and bovine blood . As a result the strain of Aspergillus niger 185 III was chosen which activity level could be increased more than 3 times (activity--0.6 un./ml as compared to initial one).

Prim, Care Update Ob Gyns . 2001 Mar, 8(2), 65 - 68
Amebiasis; Zlobl TL; Human amebiasis is caused by the protozoan parasite Entamoeba histolytica . Invasion of the colonic mucosa by the trophozoite form of this parasite generally results in the clinical syndrome of amebic dysentery, although there is a wide range of clinical presentations . Some patients will progress to disseminated disease, with resulting amebic liver abscesses . Although it is estimated that 10% of the world's population is infected with E . histolytica, only 1% of these patients will manifest disease . The diagnosis is usually made by microscopically identifying the microorganism in a stool specimen . The antibiotic of choice for treatment of amebiasis is metronidazole, 750 mg, three times daily for 10 days.

Trends Ecol Evol, 2001 Apr 1, 16(4), 178 - 183
The evolution of social behavior in microorganisms; Crespi BJ; Recent studies of microorganisms have revealed diverse complex social behaviors, including cooperation in foraging, building, reproducing, dispersing and communicating . These microorganisms should provide novel, tractable systems for the analysis of social evolution . The application of evolutionary and ecological theory to understanding their behavior will aid in developing better means to control the many pathogenic bacteria that use social interactions to affect humans.

Hautarzt, 2001 Feb, 52(2), 91 - 7
{New developments in medical mycology}; Korting HC et al.; Not only have the systemic mycoses clearly increased in number but also mycoses of the skin are more common than presumed in the past . Today onychomycosis is found in up to 10% of human beings . Onychomycosis can compromise quality of life markedly . Common tinea pedis is one of the most important risk factors for erysipelas of the lower legs . The clinical presentation of oral candidosis in HIV-infected patients is changing; Candida dubliniensis has been identified as another important causative microorganism . Onychomycosis today in most cases can be cured using terbinafine or itraconazole . When choosing the ideal drug in a given case, both the benefit risk ratio and the benefit cost ratio have to be taken into account . Liposomally encapsulated amphotericin B represents a major breakthrough in the treatment of systemic mycoses or fever of unknown origin . The same applies to liposomally encapsulated econazole with respect to tinea pedis . In regard to the pathogenesis of Candida infections the family of secreted aspartic proteinases plays a major role as a virulence factor and possible future target for antimycotic treatment.

Harefuah, 2001 Jan, 140(1), 12 - 5, 87
{Antioxidant profile of human saliva and its biological significance}; Nagler RM et al.; Saliva is the first biological medium to come in contact with materials entering the body through the oral cavity . These materials are contained in food and drink (or inhaled as volatile ingredients) . Accordingly, saliva contains various defense mechanisms which have been thoroughly investigated . They include immunological and enzymatic systems aimed at pathological microorganisms . Saliva also can protect the mucosa against mechanical insults and when required, promote its healing via agents such as the epidermal growth factor . Another defense mechanism in saliva which has been gaining increased attention and seems to be of paramount importance is its antioxidant system . We discuss both the molecular and enzymatic components of the salivary antioxidant system in respect to mixed, parotid, submandibular and sublingual saliva and under various physiological conditions of secretion.

Arkh Patol, 2001 Jan-Feb, 63(1), 47 - 51
{Chronic and slow neuroinfections . Current status of problem}; Antonov PV et al.; Some causes and conditions of chronic and slow neuroinfections were reviewed: brain immunological "priveledge"; congenital immunodeficiencies including clinically latent; immunomodulation induced by microorganisms due to infection of immune cells, inactivation of cytokines making difficulties to antibodies; disorders of genetic control of immune reaction; immunopathologic processes are of great importance for the agents persistence including autoimmunity . Microorganisms can locate in the neurons, glyocytes, endothelium . Neuroinfections chronic course depends on the agents properties and peculiarities of nervous system reactivity.

Trends Plant Sci, 2001 Mar, 6(3), 114 - 21
Plant meiosis: the means to 1N; Bhatt AM et al.; Meiosis is pivotal in the life history of plants . In addition to providing an opportunity for genetic reassortment, it marks the transition from diploid sporophyte to haploid gametophyte . Recent molecular data suggest that, like animals, plants possess a common set of genes (also conserved in eukaryotic microorganisms) responsible for meiotic recombination and chromosome segregation . However, unlike animals, plant meiocytes do not differentiate from a pool of primordial germ cells, but rather arise de novo from a germline formed from sub-epidermal cells in the anthers and ovules . Mutants defective in the specification of these reproductive cell lines and disrupted in different aspects of the meiotic process are beginning to reveal many features unique to plant meiosis.

Trends Pharmacol Sci, 2001 Mar, 22(3), 140 - 6
Arylamine N-acetyltransferases - of mice, men and microorganisms; Upton A et al.; Arylamine N-acetyltransferases (NATs) catalyse the transfer of an acetyl group from acetyl CoA to the terminal nitrogen of hydrazine and arylamine drugs and carcinogens . These enzymes are polymorphic and have an important place in the history of pharmacogenetics, being first identified as responsible for the polymorphic inactivation of the anti-tubercular drug isoniazid . NAT has recently been identified within Mycobacterium tuberculosis itself and is an important candidate for modulating the response of mycobacteria to isoniazid . The first three-dimensional structure of the unique NAT family shows the active-site cysteine to be aligned with conserved histidine and aspartate residues to form a catalytic triad, thus providing an activation mechanism for transfer of the acetyl group from acetyl CoA to cysteine . The unique fold could allow different members of the NAT family to play a variety of roles in endogenous and xenobiotic metabolism.

Nature, 2001 Feb 15, 409(6822), 836 - 8
A genomic view of immunology; Fahrer AM et al.; The outstanding problems facing immunology are whole system issues: curing allergic and autoimmune disease and developing vaccines to stimulate stronger immune responses against pathogenic organisms and cancer . We hope that the human genome sequence will reveal the molecular checks and balances that ensure both an effective immunogenic response against pathogenic microorganisms and a suitably tolerogenic response to self antigens and innocuous environmental antigens . Three synergistic approaches--sequence homology searches, messenger RNA expression profiling on microarrays, and mutagenesis in mice--provide the best opportunities to reveal, in the genome sequence, key proteins and pathways for targeting by new immunomodulatory treatments.

Zh Mikrobiol Epidemiol Immunobiol, 2001 Jan-Feb, (1), 14 - 7
{Seroimmunologic monitoring of microorganisms of Rickettsia and Bartonella species microorganisms in the Moscow region}; Ignatovich VF et al.; Serological study of 788 blood sera, taken from residents of the Moscow region was conducted using antigens of microorganisms of the genera Rickettsia and Bartonella . The first group under examination consisted of 355 patients with diagnosed diseases of nonreckettsial nature . The second group includes 433 healthy adults working at a meat processing and packing factory . The main method used for sera survey was the indirect immunofluorescence test . In the sera taken from the first group of subjects specific antibodies to R . prowazekii, R . typhi, B . quintana, B . henselae antigens were detected in 2.3%, 5.1%, 4.0% and 2.9% of serum samples respectively . In the serum samples taken from the second group the proportion of antibodies to R . prowazekii, R . typhi, B . quintana, B . henselae antigens was different: 0.5%, 3.3%, 1.7% and 4.0% respectively . In total, specific antibodies to R . typhi and B . henselae prevailed over specific antibodies to R . prowazekii and B . quintana twofold.

Water Res, 2001 Mar, 35(4), 943 - 52
Release of trace elements in wetlands: role of seasonal variability; Olivie-Lauquet G et al.; Dissolved concentrations were determined for Fe, Mn, Al, Cu, Zn, La, U, Th, Cd and As in a wetland and its recipient stream to reveal the effect of seasonal changes in environmental conditions on the cycling and transfer of trace elements at the transition between terrestrial and aquatic ecosystems . These preliminary results from the wetland show marked seasonal changes in dissolved concentration for all elements except Zn and Cu . Concentrations are found to be low until about mid-February and then increase abruptly . The onset of trace element release appears to coincide with a marked decline in redox potential and increase of organic carbon content . Because this decline is itself correlated with a pronounced increase in temperature and dissolved Fe . Mn and organic carbon content, we suggest that the microorganisms which use soil iron and manganese oxy-hydroxides as electron acceptors catalyzed the change in redox conditions and induced an increase of DOC . Temporal changes were also observed in the recipient stream which showed marked positive concentration peaks during stormflow events (except Zn) . The seasonal processes occurring in the wetland appear to play a major role in determining the amount of trace elements which are transferred from the wetland to the river.

Water Res, 2001 Mar, 35(4), 1100 - 5
Effect of adding phosphate to drinking water on bacterial growth in slightly and highly corroded pipes; Appenzeller BM et al.; The effect of phosphate addition in drinking water was tested under static conditions as batch tests and under dynamic conditions using continuously fed reactors . Phosphate supplements in batch tests from 0.1 to 2 mg P-PO4 L(-1) did not show any relationship between bacterial growth and phosphate concentration . Dynamic tests in slightly corroded reactor (stainless steel) treated at 1 mg P-PO4 L(-1) showed only a moderate improvement in the growth of microorganisms . On the contrary, phosphate treatment applied to the highly corroded reactor (unlined cast iron) led to an immediate, drastic drop in iron oxide release and bacterial production . Phosphate uptake by the reactor wall was less than 14% with the stainless-steel reactor and 70-90% with the corroded cast iron reactor . Moreover, about 5% of the phosphate associated to corroded iron pipe walls was released for 20 days after the end of treatment.

Water Res, 2001 Mar, 35(4), 1052 - 60
The roles of calcium in sludge granulation during UASB reactor start-up; Yu HQ et al.; Six upflow anaerobic sludge blanket (UASB) reactors were concurrently operated for 146 d to examine the effects of calcium on the sludge granulation process during start-up . Introduction of Ca2+ at concentrations from 150 to 300 mg/l enhanced the biomass accumulation and granulation process . The calcium concentration in the granules was nearly proportional to the calcium concentration in the feed, and calcium carbonate was the main calcium precipitate in the granules . The specific activity of granules decreased with increasing influent calcium concentration . The optimum calcium concentration for the granulation was from 150 to 300 mg/l . The addition of low-concentration calcium to the UASB reactors appeared to enhance the three steps of sludge granulation: adsorption, adhesion and multiplication, but it did not lead to a different proliferation of predominant microorganisms in the granules.

Environ Pollut, 2001, 112(2), 269 - 83
Impact of composting strategies on the treatment of soils contaminated with organic pollutants; Semple KT et al.; Chemical pollution of the environment has become a major source of concern . Studies on degradation of organic compounds have shown that some microorganisms are extremely versatile at catabolizing recalcitrant molecules . By harnessing this catabolic potential, it is possible to bioremediate some chemically contaminated environmental systems . Composting matrices and composts are rich sources of xenobiotic-degrading microorganisms including bacteria, actinomycetes and lignolytic fungi, which can degrade pollutants to innocuous compounds such as carbon dioxide and water . These microorganisms can also biotransform pollutants into less toxic substances and/or lock up pollutants within the organic matrix, thereby reducing pollutant bioavailability . The success or failure of a composting/compost remediation strategy depends however on a number of factors, the most important of which are pollutant bioavailability and biodegradability . This review discusses the interactions of pollutants with soils; look critically at the clean up of soils contaminated with a variety of pollutants using various composting strategies and assess the feasibility of using composting technologies to bioremediate contaminated soil.

Nature, 2001 Feb 22, 409(6823), 1060 - 3
Identification of CRE1 as a cytokinin receptor from Arabidopsis; Inoue T et al.; Cytokinins are a class of plant hormones that are central to the regulation of cell division and differentiation in plants . It has been proposed that they are detected by a two-component system, because overexpression of the histidine kinase gene CKI1 induces typical cytokinin responses and genes for a set of response regulators of two-component systems can be induced by cytokinins . Two-component systems use a histidine kinase as an environmental sensor and rely on a phosphorelay for signal transduction . They are common in microorganisms, and are also emerging as important signal detection routes in plants . Here we report the identification of a cytokinin receptor . We identified Arabidopsis cre1 (cytokinin response 1) mutants, which exhibited reduced responses to cytokinins . The mutated gene CRE1 encodes a histidine kinase . CRE1 expression conferred a cytokinin-dependent growth phenotype on a yeast mutant that lacked the endogenous histidine kinase SLN1 (ref . 10), providing direct evidence that CRE1 is a cytokinin receptor . We also provide evidence that cytokinins can activate CRE1 to initiate phosphorelay signalling.

Environ Microbiol, 2000 Oct, 2(5), 555 - 63
A gene containment strategy based on a restriction-modification system; Torres B et al.; Engineering barriers to the spread of specific genes are of great interest both to increase the predictability of recombinant microorganisms used for environmental applications and to study the role of gene transfer in the adaptation of microbial communities to changing environments . We report here a new gene containment circuit based on a toxin-antidote pair that targets the cell DNA, i.e . the type II EcoRI restriction-modification system . The set-up involved linkage of the ecoRIR lethal gene encoding the EcoRI endonuclease (toxin) to the contained character in a plasmid and chromosomal insertion of the ecoRIM gene encoding the cognate EcoRI methylase (antidote) that protects the target DNA from restriction . Transfer of the contained character to a recipient cell lacking the antidote caused EcoRI-mediated chromosomal breaks, leading to cell death, thereby preventing gene spread . Using transformation and conjugation as mechanisms of DNA transfer and different environmentally relevant bacteria as recipients, we have shown that the potentially universal EcoRI-based containment system decreases gene transfer frequencies by more than four orders of magnitude . Analyses of the survivors escaping killing revealed a number of possible inactivation mechanisms.

Asian J Androl, 2000 Jun, 2(2), 131 - 4
Comparative study on efficacy of three sperm-separation techniques; Xu L et al.; AIM: To evaluate the comparative effectiveness of real-time sperm separation technique (Wang's tube method) and other two conventional methods in isolating high-quality sperm preparation, and to compare the spouse pregnancy rate in intrauterine insemination (IUI) with sperm preparations isolated by these methods . METHODS: The effectiveness of the real-time sperm separation technique, the conventional swim-up and the Percoll discontinuous density gradient methods in isolating sperm preparations from 60 infertile patients (20 with apparently normal semen and 40, abnormal semen contaminated with microorganisms and other impurities) was evaluated and compared . The microorganisms to be removed included bacteria, virus, Chlamydia trachomaticum, Ureaplsama urealyticum, etc . The spouse pregnancy rates in IUI with sperm preparations isolated by these three techniques from 80 oligoasthenoteratospermic patients were also compared . RESULTS: The quality (including the percentages of normal form, normal-chromatin and motile sperm, and the grade of motility) of sperm obtained by the real-time sperm separation technique was much higher (P < 0.01) as compared with those by the other two methods . The Wang's tube method was also more effective in removing microorganisms and other impurities . The method provided a higher IUI pregnancy rate than the other two sperm separation techniques (P < 0.05) . CONCLUSION: The real-time sperm separation technique is the most effective method so far available in isolating high-quality sperm samples to be used in assisted reproduction.

Gastroenterology, 2001 Mar, 120(4), 799 - 805
Efficacy and tolerability of racecadotril in acute diarrhea in children; Cezard JP et al.; BACKGROUND & AIMS: Oral rehydration therapy is the only treatment recommended by the World Health Organization in acute diarrhea in children . Antisecretory drugs available could not be used because of their side effects, except for racecadotril, which is efficient in acute diarrhea in adults . METHODS: The efficacy and tolerability of racecadotril (1.5 mg/kg administered orally 3 times daily) as adjuvant therapy to oral rehydration were compared with those of placebo in 172 infants aged 3 months to 4 years (mean age, 12.8 months) who had acute diarrhea . The treatment groups were comparable in terms of age, duration of diarrhea, number of stools, and causative microorganism at inclusion . RESULTS: During the first 48 hours of treatment, patients receiving racecadotril had a significantly lower stool output (grams per hour) than those receiving placebo . The 95% confidence interval was 43%-88% for the full data set (n = 166; P = 0.009) and 33%-75% for the per-protocol population (n = 116; P = 0.001) . There was no difference between treatments depending on rotavirus status . Significant differences between treatment groups were also found after 24 hours of treatment: full data set (n = 167; P = 0.026) and per-protocol population (n = 121; P = 0.015) . Tolerability was good in both groups of patients . CONCLUSIONS: This study demonstrates the efficacy (up to 50% reduction in stool output) and tolerability of racecadotril as adjuvant therapy to oral rehydration solution in the treatment of severe diarrhea in infants and children.

Acta Trop, 2001 Feb 23, 78(2), 127 - 37
Trypanosoma cruzi: presence of the two major phylogenetic lineages and of several lesser discrete typing units (DTUs) in Chile and Paraguay; Barnabe C et al.; Multilocus enzyme electrophoresis (MLEE) of 99 Chilean and 11 Paraguayan stocks of Trypanosoma cruzi, the agent of Chagas disease, was performed for 22 variable genetic loci . As previously shown for this parasite in other geographic areas, a pattern of long-term clonal evolution of T . cruzi genotypes was inferred, both by strong departures of Hardy-Weinberg expectations and high linkage disequilibrium . The presence of the two major phylogenetic lineages that subdivide the species T . cruzi {Tibayrenc, M., 1995 . Population genetics of parasitic protozoa and other microorganisms . In: Baker, J.R., Muller, R., Rollinson, D . (Eds.), Advances in Parasitology, vol . 36, Academic Press, New York, pp . 47-115; Souto, R.P., Fernandes, O., Macedo, A.M., Campbell, D.A., Zingales, B., 1996 . DNA markers define two major phylogenetic lineages of Trypanosoma cruzi . Mol . Biochem . Parasitol . 83, 141-152}, and of several lesser genetic subdivisions ('discrete typing units' or DTUs; Tibayrenc, M., 1998a . Genetic epidemiology of parasitic protozoa and other infectious agents: the need for an integrated approach . Int . J . Parasitol . 28 (1), 85-104; Tibayrenc, M., 1998b . Beyond strain typing and molecular epidemiology: integrated genetic epidemiology of infectious diseases . Parasitol . Today 14, 323-329; Tibayrenc, M., 1998c . Integrated genetic epidemiology of infectious diseases: the Chagas model . Mem . Inst . Oswaldo Cruz 93 (5), 577-580), was recorded in this region . Comparison between clonal populations in sylvatic and domestic transmission cycles of the disease in Chile strongly suggests that these two cycles are at least partially separated from one another.

Appl Environ Microbiol, 2001 Mar, 67(3), 1363 - 5
Acetate oxidation coupled to Fe(iii) reduction in hyperthermophilic microorganisms; Tor JM et al.; No hyperthermophilic microorganisms have previously been shown to anaerobically oxidize acetate, the key extracellular intermediate in the anaerobic oxidation of organic matter . Here we report that two hyperthermophiles, Ferroglobus placidus and "Geoglobus ahangari," grow at 85 degrees C by oxidizing acetate to carbon dioxide, with Fe(III) serving as the electron acceptor . These results demonstrate that acetate could potentially be metabolized within the hot microbial ecosystems in which hyperthermophiles predominate, rather than diffusing to cooler environments prior to degradation as has been previously proposed.

Appl Environ Microbiol, 2001 Mar, 67(3), 1044 - 51
Microbial populations involved in cycling of dimethyl sulfide and methanethiol in freshwater sediments; Lomans BP et al.; Although several microorganisms that produce and degrade methanethiol (MT) and dimethyl sulfide (DMS) have been isolated from various habitats, little is known about the numbers of these microorganisms in situ . This study reports on the identification and quantification of microorganisms involved in the cycling of MT and DMS in freshwater sediments . Sediment incubation studies revealed that the formation of MT and DMS is well balanced with their degradation . MT formation depends on the concentrations of both sulfide and methyl group-donating compounds . A most-probable number (MPN) dilution series with syringate as the growth substrate showed that methylation of sulfide with methyl groups derived from syringate is a commonly occurring process in situ . MT appeared to be primarily degraded by obligately methylotrophic methanogens, which were found in the highest positive dilutions on DMS and mixed substrates (methanol, trimethylamine {TMA}, and DMS) . Amplified ribosomal DNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis of the total DNA isolated from the sediments and of the DNA isolated from the highest positive dilutions of the MPN series (mixed substrates) revealed that the methanogens that are responsible for the degradation of MT, DMS, methanol, and TMA in situ are all phylogenetically closely related to Methanomethylovorans hollandica . This was confirmed by sequence analysis of the product obtained from a nested PCR developed for the selective amplification of the 16S rRNA gene from M . hollandica . The data from sediment incubation experiments, MPN series, and molecular-genetics detection correlated well and provide convincing evidence for the suggested mechanisms for MT and DMS cycling and the common presence of the DMS-degrading methanogen M . hollandica in freshwater sediments.

Water Res, 2001 Mar, 35(3), 808 - 16
Composition, structure and size distribution of suspended particulates from the Rhine River; Lartiges BS et al.; Fluvial suspended particulates collected from the Rhine River were investigated in terms of composition, structure and size distribution . Elemental analysis and Diffuse Reflectance Infrared Spectroscopy reveal that most particulate organic matter is formed from material derived from microorganisms . Transmission Electron Microscopy observations on resin-embedded samples and structural characterization from break-up experiments, show that fluvial particulate matter should be viewed as fractal aggregates organized by bacterial exopolymeric substances . The shape of particulate size distribution suggests that the formation and dynamics of suspended particulate matter are controlled mainly by physical processes . Finally, particulate growth and structure are consistent with a cluster-cluster aggregation scheme.

Trends Parasitol, 2001 Feb, 17(2), 88 - 94
Inherited microorganisms, sex-specific virulence and reproductive parasitism; Bandi C et al.; Parasites show an amazing repertoire of adaptations, highlighted by complex life cycles that allow both survival in the host and transmission among hosts . However, there is one heterogeneous group of microorganisms whose adaptations are perhaps even more surprising: parthenogenesis induction, feminization of genetic males, killing of male hosts and sperm-mediated sterilization of uninfected eggs . The common feature of these microorganisms is their mode of transmission: inheritance from mother to offspring . Here, we present an introduction to hereditary symbiosis, focusing on microsporidia and bacteria that manipulate host reproduction in arthropods (reproductive parasites) . We also discuss the implications of one of these microorganisms, Wolbachia, for the control of arthropod pests and vectors and for the therapy of filarial diseases . Finally, we discuss whether some parasites of vertebrates might show sex-specific virulence.

Rev Med Chil, 2000 Dec, 128(12), 1361 - 70
{Natural killer cells and the innate immune system in infectious pathology}; Sepulveda C et al.; Natural killer (NK) cells form a unique third group of lymphocytes that differs from T and B cells in surface phenotype, target cell recognition and function . NK cells have two relevant functions, related to the innate immune response against pathogens microorganisms . One is cytotoxicity, mediated by the recognition and lysis of target cells such as virus and bacteria infected-cells . The second NK cell function is to produce cytokines, mainly IFN-gamma, that can modulate innate and specific immune responses . Cytotoxicity and cytokine secretion contribute to host resistance against microorganisms and both functions are significantly altered in infectious diseases.

Microbes Infect, 2001 Jan, 3(1), 61 - 72
Evolutionary trends in the genus Bordetella; Gerlach G et al.; The genus Bordetella comprises seven species with pathogenic potential for different host organisms . This article attempts to review our current knowledge about the systematics and evolution of this important group of pathogens, their relationship to environmental microorganisms and about molecular mechanisms of host adaptation.

Proc Natl Acad Sci U S A, 2001 Feb 27, 98(5), 2158 - 63
A novel microbial habitat in the mid-ocean ridge subseafloor; Summit M et al.; The subseafloor at the mid-ocean ridge is predicted to be an excellent microbial habitat, because there is abundant space, fluid flow, and geochemical energy in the porous, hydrothermally influenced oceanic crust . These characteristics also make it a good analog for potential subsurface extraterrestrial habitats . Subseafloor environments created by the mixing of hot hydrothermal fluids and seawater are predicted to be particularly energy-rich, and hyperthermophilic microorganisms that broadly reflect such predictions are ejected from these systems in low-temperature ( approximately 15 degrees C), basalt-hosted diffuse effluents . Seven hyperthermophilic heterotrophs isolated from low-temperature diffuse fluids exiting the basaltic crust in and near two hydrothermal vent fields on the Endeavour Segment, Juan de Fuca Ridge, were compared phylogenetically and physiologically to six similarly enriched hyperthermophiles from samples associated with seafloor metal sulfide structures . The 13 organisms fell into four distinct groups: one group of two organisms corresponding to the genus Pyrococcus and three groups corresponding to the genus Thermococcus . Of these three groups, one was composed solely of sulfide-derived organisms, and the other two related groups were composed of subseafloor organisms . There was no evidence of restricted exchange of organisms between sulfide and subseafloor habitats, and therefore this phylogenetic distinction indicates a selective force operating between the two habitats . Hypotheses regarding the habitat differences were generated through comparison of the physiology of the two groups of hyperthermophiles; some potential differences between these habitats include fluid flow stability, metal ion concentrations, and sources of complex organic matter.

Fresenius J Anal Chem, 2000 Mar-Apr, 366(6-7), 769 - 79
Reporter gene bioassays in environmental analysis; Kohler S et al.; In parallel to the continuous development of increasingly more sophisticated physical and chemical analytical technologies for the detection of environmental pollutants, there is a progressively more urgent need also for bioassays which report not only on the presence of a chemical but also on its bioavailability and its biological effects . As a partial fulfillment of that need, there has been a rapid development of biosensors based on genetically engineered bacteria . Such microorganisms typically combine a promoter-operator, which acts as the sensing element, with reporter gene(s) coding for easily detectable proteins . These sensors have the ability to detect global parameters such as stress conditions, toxicity or DNA-damaging agents as well as specific organic and inorganic compounds . The systems described in this review, designed to detect different groups of target chemicals, vary greatly in their detection limits, specificity, response times and more . These variations reflect on their potential applicability which, for most of the constructs described, is presently rather limited . Nevertheless, present trends promise that additional improvements will make microbial biosensors an important tool for future environmental analysis.

Fresenius J Anal Chem, 2000 Mar-Apr, 366(6-7), 752 - 9
Bio- and chemiluminescence in bioanalysis; Roda A et al.; Analytical chemiluminescence and bioluminescence represent a versatile, ultrasensitive tool with a wide range of applications in diverse fields such as biotechnology, pharmacology, molecular biology, clinical and environmental chemistry . Enzyme activities and enzyme substrates and inhibitors can be efficiently determined when directly involved in luminescent reactions, and also when they take part in a reaction suitable for coupling to a final light-emitting reaction . Chemiluminescence detection has been exploited in the fields of flow-injection analysis and column-liquid chromatographic and capillary-electrophoretic separative systems, due to its high sensitivity when compared with colorimetric detection . It has widely been used as an indicator of reactive oxygen species formation in cells and whole organs, thus allowing the study of a number of pathophysiological conditions related to oxidative stress . Chemiluminescence represents a sensitive and rapid alternative to radioactivity as a detection principle in immunoassays for the determination of a wide range of molecules (hormones, food additives, environmental pollutants) and in filter membrane biospecific reactions (Southern, Northern, Western, dot blot) for the determination of nucleic acids and proteins . Chemiluminescence has also been used for the sensitive and specific localization and quantitation of target analytes in tissue sections and single cells by immunohistochemistry and in situ hybridization techniques . A relatively recent application regards the use of luminescent reporter genes for the development of bioassays based on genetically engineered microorganisms or mammalian cells able to emit visible light in response to specific inorganic and organic compounds . Finally, the high detectability and rapidity of bio- and chemiluminescent detection make it suitable for the development of microarray-based high throughput screening assays, in which simultaneous, multianalyte detection is performed on multiple samples.

Environ Microbiol, 2001 Jan, 3(1), 19 - 31
The effects of copper on the microbial community of a coral reef sponge; Webster NS et al.; Marine sponges often harbour communities of symbiotic microorganisms that fulfil necessary functions for the well-being of their hosts . Microbial communities associated with the sponge Rhopaloeides odorabile were used as bioindicators for sublethal cupric ion (Cu2+) stress . A combined strategy incorporating molecular, cultivation and electron microscopy techniques was adopted to monitor changes in microbial diversity . The total density of sponge-associated bacteria and counts of the predominant cultivated symbiont (alpha-proteobacterium strain NW001) were significantly reduced in response to Cu2+ concentrations of 1.7 microg l(-1) and above after 14 days of exposure . The number of operational taxonomic units (OTUs) detected by restriction fragment length polymorphism (RFLP) decreased by 64% in sponges exposed to 223 microg l(-1) Cu2+ for 48 h and by 46% in sponges exposed to 19.4 microg l(-1) Cu2+ for 14 days . Electron microscopy was used to identify 17 predominant bacterial morphotypes, composing 47% of the total observed cells in control sponges . A reduction in the proportion of these morphotypes to 25% of observed cells was evident in sponges exposed to a Cu2+ concentration of 19.4 microg l(-1) . Although the abundance of most morphotypes decreased under Cu2+ stress, three morphotypes were not reduced in numbers and a single morpho-type actually increased in abundance . Bacterial numbers, as detected using fluorescence in situ hybridization (FISH), decreased significantly after 48 h exposure to 19.4 microg l(-1) Cu2+ . Archaea, which are normally prolific in R . odorabile, were not detected after exposure to a Cu2+ concentration of 19.4 microg l(-1) for 14 days, indicating that many of the microorganisms associated with R . odorabile are sensitive to free copper . Sponges exposed to a Cu2+ concentration of 223 microg l(-1) became highly necrosed after 48 h and accumulated 142 +/- 18 mg kg(-1) copper, whereas sponges exposed to 19.4 microg l(-1) Cu2+ accumulated 306 +/- 15 mg kg(-1) copper after 14 days without apoptosis or mortality . Not only do sponges have potential for monitoring elevated concentrations of heavy metals but also examining changes in their microbial symbionts is a novel and sensitive bioindicator for the assessment of pollution on important microbial communities.

Semin Respir Infect, 2000 Dec, 15(4), 327 - 35
Infection control in intensive care units and prevention of ventilator-associated pneumonia; Bonten MJ et al.; Ventilator-associated pneumonia (VAP) is considered the most frequent infection in the intensive care unit (ICU), although incidence rates depend on the diagnostic methods . Because VAP has been associated with increased mortality and greater costs for medical care, prevention remains an important goal for intensive care medicine . Selective digestive decontamination (SDD), the most frequently studied method of infection prevention, is still controversial despite more than 30 prospective randomized trials and 6 metaanalyses . SDD reduces the incidence of VAP diagnoses, but beneficial effects on duration of ventilation or ICU stay, antibiotic use, and patient survival have not been shown unequivocally . Although recent metaanalyses suggest a 20% to 40% decrease in ICU mortality for SDD used with systemic prophylaxis, this benefit should be confirmed in a large, prospective, randomized study, preferably with a cost-benefit analysis . Selection of pathogens resistant to the antibiotics used in SDD remains the most important drawback of SDD, rendering SDD contraindicated in wards with endemic resistant problems . Other methods of infection prevention that do not create a selective growth advantage for resistant microorganisms may be more useful . Among these are the use of endotracheal tubes with the possibility of continuous aspiration of subglottic secretions, oropharyngeal decontamination with antiseptics, or the semirecumbent treatment position of patients . Although these methods were successful in single studies, more data are needed . Notwithstanding the potential benefits of these interventions, such classic infection control measures as handwashing remain the cornerstone of infection prevention.

Environ Microbiol, 2000 Apr, 2(2), 217 - 26
Matching molecular diversity and ecophysiology of benthic cyanobacteria and diatoms in communities along a salinity gradient; Nubel U et al.; The phylogenetic diversity of oxygenic phototrophic microorganisms in hypersaline microbial mats and their distribution along a salinity gradient were investigated and compared with the halotolerances of closely related cultivated strains . Segments of 16S rRNA genes from cyanobacteria and diatom plastids were retrieved from mat samples by DNA extraction and polymerase chain reaction (PCR), and subsequently analysed by denaturing gradient gel electrophoresis (DGGE) . Sequence analyses of DNA from individual DGGE bands suggested that the majority of these organisms was related to cultivated strains at levels that had previously been demonstrated to correlate with characteristic salinity responses . Proportional abundances of amplified 16S rRNA gene segments from phylogenetic groupings of cyanobacteria and diatoms were estimated by image analysis of DGGE gels and were generally found to correspond to abundances of the respective morphotypes determined by microscopic analyses . The results indicated that diatoms accounted for low proportions of cells throughout, that the cyanobacterium Microcoleus chthonoplastes and close relatives dominated the communities up to a salinity of 11% and that, at a salinity of 14%, the most abundant cyanobacteria were related to highly halotolerant cultivated cyanobacteria, such as the recently established phylogenetic clusters of Euhalothece and Halospirulina . Although these organisms in cultures had previously demonstrated their ability to grow with close to optimal rates over a wide range of salinities, their occurrence in the field was restricted to the highest salinities investigated.

Med Res Rev, 2001 Mar, 21(2), 105 - 28
Adenosine deaminase: functional implications and different classes of inhibitors; Cristalli G et al.; Adenosine deaminase (ADA) is an enzyme of the purine metabolism which catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine, respectively . This ubiquitous enzyme has been found in a wide variety of microorganisms, plants, and invertebrates . In addition, it is present in all mammalian cells that play a central role in the differentiation and maturation of the lymphoid system . However, despite a number of studies performed to date, the physiological role played by ADA in the different tissues is not clear . Inherited ADA deficiency causes severe combined immunodeficiency disease (ADA-SCID), in which both B-cell and T-cell development is impaired . ADA-SCID has been the first disorder to be treated by gene therapy, using polyethylene glycol-modified bovine ADA (PEG-ADA) . Conversely, there are several diseases in which the level of ADA is above normal . A number of ADA inhibitors have been designed and synthesized, classified as ground-state and transition-state inhibitors . They may be used to mimic the genetic deficiency of the enzyme, in lymphoproliferative disorders or immunosuppressive therapy (i.e., in graft rejection), to potentiate the effect of antileukemic or antiviral nucleosides, and, together with adenosine kinase, to reduce breakdown of adenosine in inflammation, hypertension, and ischemic injury .

Clin Oral Investig, 2000 Mar, 4(1), 35 - 41
Infection of primary human gingival fibroblasts by Porphyromonas gingivalis and Prevotella intermedia; Dogan S et al.; Adhesion and penetration of clinical isolates of Porphyromonas gingivalis and Prevotella intermedia in human gingival fibroblast monolayers were studied by transmission electron microscopy (TEM) . Fibroblasts were cultured from biopsies of human healthy gingiva . Porphyromonas gingivalis and Prevotella intermedia were isolated from patients with periodontitis . Fibroblasts were incubated with microorganisms in an antibiotic-free medium for 24 h . Then cultures were washed to remove nonadherent bacteria . Consecutively, infected cultures were grown for another 24 h . Thereafter, the treated monolayers were prepared for TEM investigations . Internalized Porphyromonas gingivalis and Prevotella intermedia were visible after 24 h of incubation . Prevotella intermedia showed only division in cytoplasm of fibroblasts after 24 h and 48 h incubations . Infected fibroblasts revealed various morphological alterations such as extensive vacuolization and breakdown of mitochondria . These findings demonstrate that Porphyromonas gingivalis and Prevotella intermedia may invade human gingival fibroblasts and thus may damage these cells directly or due to the release of microbial cytotoxic components.

Nippon Rinsho, 2001 Feb, 59(2), 286 - 90
{Genetic diagnosis of H . pylori strains}; Azuma T; Helicobacter pylori strains are divided into two broad families, type I and type II, based on whether or not they possess the cag pathogenicity island (cagPAI) . It has been suggested that cagPAI is inherited by horizontal transfer from an unknown microorganism, and the genes of cag are thought to be encoded by a putative type IV secretory system . In addition, CagA may be delivered from attached H . pylori into the host crytoplasm by this system and is tyrosine phosphorylated in gastric epithelial cells . The phosphorylated CagA may play a crucial role in promoting the inflammatory responses of gastric mucosa . These findings suggest that type I H . pylori is a pathogenic H . pylori.

Adv Biochem Eng Biotechnol, 2001, 71, 51 - 79
Polyesters from microorganisms; Kim YB et al.; Bacterial polyesters have been found to have useful properties for applications as thermoplastics, elastomers, and adhesives and are biodegradable and biocompatible . Poly(3-hydroxyalkanoates) (PHAs) and poly(beta-malate) are the most representative polyesters synthesized by microorganisms . PHAs containing a wide variety of repeating units can be produced by bacteria, including those containing many types of pendant functional groups which can be synthesized by microorganisms that are grown on unnatural organic substrates . Poly(beta-malate) is of interest primarily for medical applications, especially for drug delivery systems . In this chapter, the bacterial production and properties of poly(3-hydroxyalkanoates) and poly(beta-malate) are described with emphasis on the former.

Adv Biochem Eng Biotechnol, 2001, 71, 263 - 91
Properties, modifications and applications of biopolyesters; van der Walle GA et al.; Poly(hydroxyalkanoates) (PHAs), of which poly(hydroxybutyrate) (PHB) is the most common, can be accumulated by a large number of bacteria as energy and carbon reserve . Due to their biodegradability and biocompatibility these optically active biopolyesters may find industrial applications . A general overview of the physical and material properties of PHAs, alongside with accomplished applications and new developments in this field is presented in this chapter . The properties of PHAs are dependent on their monomer composition and therefore it is of great interest that recent research has revealed that, in addition to PHB, a large variety of PHAs can be synthesized microbially . The monomer composition of PHAs depends on the nature of the carbon source and microorganism used . PHB is a typical highly crystalline thermoplastic whereas medium chain length PHAs are elastomers with low melting points and a relatively lower degree of crystallinity . By (chemical) modification of the PHAs, the ultimate properties of the materials can be adjusted even further, when necessary . Applications that have been developed from PHB and related materials (e.g . Biopol) can be found in very different application areas and cover packaging, hygienic, agricultural and biomedical products . Recent application developments based on medium chain length PHAs range from high solid alkyd-like paints to pressure sensitive adhesives, biodegradable cheese coatings and biodegradable rubbers . Technically, the prospects for PHAs are very promising . When the price of these materials can be further reduced, application of biopolyesters will also become economically very attractive.

Biofactors, 2000, 12(1-4), 113 - 21
Role of antimutagens/anticarcinogens in cancer prevention; Shankel DM et al.; Recently it has become increasingly clear that chemicals found in our foods and beverages can prevent the genetic damage that leads to cancer initiation . Such substances may also affect subsequent events in the pathways that lead to cancer, and may have the potential to inhibit the mutations that allow tumor cells to become resistant to antitumor agents . We describe here the antimutagenic potential of Glabrene analogs against EMS-induced mutations utilizing modified Ames tests in S . typhimurium TA 100 and E . coli JC 5088 . Results of studies of the ability of well-known antioxidants such as EGCG and related compounds to prevent drug resistance mutations in microorganisms are described, and their possible significance in the prevention of chemotherapeutic drug-resistance in tumor cells is discussed.

J Environ Qual, 2001 Jan-Feb, 30(1), 147 - 50
The relationship between microbial carbon and the resource quality of soil carbon; Webster EA et al.; The biological health of soil is an important aspect of soil quality because of the many critical functions performed by organisms in soil . Various indicators of soil quality have been proposed, but measurements of microbial biomass are most commonly used . During decomposition of plant residues in soil the relative intensities of the O-alkyl-C signal decreases and the alkyl-C signal increases in nuclear magnetic resonance (NMR) spectra . This leads to the suggestion that the alkyl-C to O-alkyl-C ratio of a soil may indicate the degree of decomposition . Consequently, the overall resource quality of soil C as a substrate for heterotrophic microorganisms may be inversely related to the alkyl-C to O-alkyl-C ratio . Our hypothesis is that a relationship exists between the size of the soil microbial community (microbial biomass) and the quality of soil carbon as a resource for microorganisms . New data have been combined with previously published data to show that there was a significant, negative correlation between the biomass C to total C (Cmic, to Corg) ratio and the alkyl-C to O-alkyl-C ratio (p < 0.01), which supports our hypothesis.

Ultramicroscopy, 2001 Jan, 86(1-2), 113 - 20
Probing molecular interactions and mechanical properties of microbial cell surfaces by atomic force microscopy; Dufrene YF et al.; Knowledge of the surface properties of microbial cells is a key to gain a detailed understanding of their functions in the natural environment and to efficiently exploit them in biotechnological processes . In this paper, we present force-distance curves recorded, by atomic force microscopy (AFM) in aqueous solutions, on various microbial samples: reconstituted S-layers, whole fungal spores and several bacterial strains . The approach and retraction curves exhibited important differences--depending on the type of microorganism, on the physiological state (dormancy versus germination) and on the environmental conditions (ionic strength)--which were shown to reflect differences in long-range surface forces, adhesion forces and mechanical properties . These data illustrate the great potential of AFM force measurements to elucidate the physical properties of microbial cells and to understand, at the molecular level, biointerfacial phenomena such as cell adhesion and cell aggregation.

Rev Med Panama, 1998 Sep, 23(2), 27 - 33
{Importance of Mycoplasma pneumoniae and Chlamydia pneumoniae in children with community-acquired pneumonia}; Saez-Llorens X et al.; OBJECTIVES: To determine the importance of Mycoplasma pneumoniae and Chlamydia pneumoniae in community-acquired pneumonia (CAP) of children from different latitudes and to compare clinical outcome using azithromycin (AZM) versus either amoxicillin-clavulanate (A-C) or erythromycin estolate (EE) . METHODS: Ambulatory patients with CAP were identified at either the Children's Medical Center of Dallas, Texas or the Hospital del Nino of Panama City, Panama . Children 6 months to 15 years of age were enrolled and randomized to receive either AZM for 5 days or a 10 day course of either A-C or EE, for those younger or older than 5 years of age, respectively . Mycoplasma pneumoniae and C . pneumoniae were identified by measuring acute and convalescent serum antibody titers and by performing nasopharyngeal (NP) and oropharyngeal (OP) swabs for culture and polymerase chain reaction (PCR) testing . RESULTS: Overall 335 patients (168 in Dallas and 167 in Panama) were evaluated from February 1996 through December 1997 . Acute M . pneumoniae infection was detected in 12 (7%) patients each in Dallas and Panama . Acute C . pneumoniae infection was observed in 10 (6%) children at each site . Infection caused by these "atypical" microorganisms occurred more frequently in children older than 5 years of age (23% vs 9%, P = 0.001, RR 2.5, 95% CI 1.4-4.3) . No distinctive pattern of clinical or radiologic abnormalities was seen in relation to etiology . Clinical cure was achieved in 43 of 44 children infected by these bacteria regardless of treatment assignment . CONCLUSION: Mycoplasma pneumoniae and C . pneumoniae are common etiologic agents of CAP in older children from different latitudes . Children with CAP present with similar clinical and radiologic findings to those caused by other etiologic agents . Outcome was excellent for the three treatment regimens studied.

J Med Liban, 2000 Jul-Aug, 48(4), 264 - 9
Community-acquired respiratory infections: spectrum of organisms and treatment; McKellar PP; The respiratory infections addressed in this paper include otitis media, sinusitis, and community-acquired pneumonia . The morbidity and mortality of respiratory infections are assessed from the American standpoint ; their worldwide significance is even greater . The emphasis is on specific diagnosis . Treatment options vary from country to country . Therapeutic decisions are usually easy once a specific etiologic organism is isolated . Since in many of these common respiratory infections a specific microorganism is not documented and empiric therapy is designed based on past clinical studies, resistance patterns need to be known for each country.

Korean J Ophthalmol, 2000 Dec, 14(2), 90 - 6
Congenital nasolacrimal duct obstruction: irrigation or probing?
Kim YS, Moon SC, Yoo KW.
The authors investigated the efficacy of antibiotic irrigation as the therapeutic option in congenital nasolacrimal duct obstruction . We retrospectively reviewed the medical record of 76 patients' eyes in whom congenital nasolacrimal duct obstruction had been diagnosed . In 50 of these patients, the colonizing microorganism was identified and, irrigation through canaliculi was performed using antibiotics of suitable sensitivity . Nasolacrimal system probing was performed on 26 patients as the control group . Treatment was regarded successful when over a 4 week period epiphora or mucous discharge disappeared and when saline passed without resistance on irrigation . 96.0% of patients in the irrigation group and 84.6% of patients in probing group were treated successfully . There was no statistical difference in the success rate between the two groups (P = 0.173) . The recovery period based on culture results was 3.22 +/- 0.37 months in the group in which microorganisms were isolated and 2.39 +/- 0.35 months in the group in which no organisms were isolated . There were no statistically significant differences in the success rates between the group in which there was growth and the group in which there was no growth (P = 0.1308) . Thus a similar result was obtained using nasolacrimal probing and canaliculus antibiotic irrigation in congenital nasolacrimal duct obstruction . Antibiotic irrigation is a safe and simple therapeutic option in congenital nasolacrimal duct obstruction.

Laryngoscope, 2001 Feb, 111(2), 297 - 300
How does endotoxin trigger inflammation in otitis media with effusion?
Schousboe LP, Ovesen T, Eckhardt L, Rasmussen LM, Pedersen CB.
OBJECTIVES: The relationship among microorganisms, endotoxin, and inflammatory mediators in otitis media with effusion (OME) was examined . STUDY DESIGN: Analysis of 152 middle ear effusions aspirated at the time of ventilation tube insertion from children with OME . METHODS: Effusion samples were cultured for pathogenic bacteria The two primary cytokines, interleukin-1beta (IL1beta) and tumor necrosis factor (TNFalpha), and the adhesion molecules, intercellular and vascular adhesion molecule (ICAM-1 and VCAM-1), were quantified using the enzyme-linked immunosorbent assay (ELISA) technique . Endotoxin concentration was measured with a limulus amebocyte lysate assay, and total protein concentration was quantified using the Biorad microassay . RESULTS: The cultures of pathogenic bacteria were positive in 33 of the 152 effusions (22%), which contained more endotoxin and more of the primary cytokines than the 119 culture-negative effusions . Endotoxin and the primary cytokines were positively correlated, both in the whole material and in the sterile effusions alone . The adhesion molecules were positively correlated with each other, but not with endotoxin or the primary cytokines . CONCLUSIONS: We found a positive correlation between endotoxin and the primary cytokines TNFalpha and IL1beta in culture-positive OME effusions as well as in culture-negative ones, suggesting endotoxin-induced local production of TNFalpha and IL1beta in the middle ear . ICAM-1 and VCAM-1 were also present in the middle ear, but their concentrations were not directly correlated to endotoxin or the primary cytokines.

Zh Mikrobiol Epidemiol Immunobiol, 2000 Nov-Dec, (6), 61 - 4
{Identification of nontuberculous mycobacteria by methods of molecular biology}; Stepanshina VN et al.; A number of clinical and laboratory strains of microorganisms belonging to different species of mycobacteria of the nontuberculous complex were tested with the use of the polymerase chain reaction and the restriction analysis . The unique restriction profiles of the following species of mycobacteria have been obtained: M . fortuitum VI, M . kansasii I, M . intracellulare, M . avium.

Braz Dent J, 2001, 12(1), 23 - 6
Relationship between the presence or absence of gingival bleeding and the enzymatic BANA test; Grisi MF et al.; When periodontal disease started to be considered a bacterial infection mainly mediated by subgingival plaque, the basic problem faced by periodontists was the identification and/or quantification of periodontopathogenic bacteria . However, clinical methods continue to be of great value for the diagnosis of periodontal disease . In the present study we show a significant correlation between an index widely used in clinical practice, the Gingival Index of Loe (1967), based on the presence or absence of bleeding on probing, and the methodology of the BANA test for the detection of the specific enzymatic activity of microorganisms involved in periodontal disease . More sensitive and specific clinical parameters, taken together with other microbiologic methods, will be useful in daily clinical practice even before periodontal treatment.

J Dairy Sci, 2001 Jan, 84(1), 1 - 11
Fluid dairy product quality and safety: looking to the future; Boor KJ; The fiercely competitive nature of the US beverage industry will drive the fluid milk sector of the dairy industry to improve product quality and shelf life to enable dairy beverages to compete with innovative new introductions as well as with currently popular shelf-stable products . The recent substantial growth in the volume of flavored milk sales specifically suggests that attention is needed to improve these products . Further, increasing public awareness and regulatory attention directed toward food safety issues highlight the need for the dairy industry to proactively address and eliminate emerging food safety issues that may negatively impact the image of dairy products . Shelf life and sensory profiles of high temperature short time pasteurized fluid milk products are presented, illustrating the need for greater attention to controlling contaminating microorganisms in processed fluid milk products . Bacterial spoilage patterns of flavored versus unflavored milks are compared, and suggestions are presented for extending flavored product shelf lives . Strategies currently applied to extend shelf life are reviewed . Food safety issues facing the dairy industry are presented within the context of an overview of foodborne illnesses in the United States . The pressing need to determine thermal resistance characteristics of Mycobacterium paratuberculosis is described.

New Microbiol, 2001 Jan, 24(1), 77 - 83
Development of a set of multiplex PCR assays for the simultaneous identification of enterotoxigenic, enteropathogenic, enterohemorrhagic and enteroinvasive Escherichia coli; Rappelli P et al.; Diarrheagenic E . coli comprise a diverse group of microorganisms responsible for gastrointestinal diseases in humans . On the basis of their virulence traits they are distinguished from the non-pathogenic E . coli and classified in several categories . Molecular methods represent the most reliable techniques for distinguishing pathogenic from non-pathogenic E . coli and characterising their pathogenic features . In this paper we report the development of a set of three multiplex PCR assays for the simultaneous and rapid identification of diarrheagenic E . coli belonging to ETEC, EPEC, EHEC and EIEC groups . Assay 1 utilizes primer pairs specific for genes coding for ST and LT toxins of ETEC, and for the E . coli beta-glucuronidase (uidA); assay 2 detects the presence of the eae and bfpA genes of EPEC, and assay 3 recognizes stx1 and stx2 of EHEC, and ial of EIEC . This technique has been validated on 190 E . coli isolated in Angola, Italy and Mozambique from feces of children with diarrhea . Results obtained with the set of multiplex PCR demonstrated 100% accordance with those obtained for the same isolates by PCR on single target genes . The proposed set of multiplex PCRs is the first reported assay that allows the simultaneous characterization of the four categories of diarrheagenic E . coli.

J Heart Valve Dis, 2001 Jan, 10(1), 129 - 35
Diagnostic value of intraoperative swabs of heart valves in infective endocarditis; Thiele H et al.; BACKGROUND AND AIM OF THE STUDY: Intraoperative swabs of heart valves are obtained regularly from patients undergoing heart valve surgery for infective endocarditis (IE) in order to confirm the preoperative diagnosis and to adjust the antibiotic regimen . The study aim was to assess the diagnostic value of intraoperative swabs of heart valves in IE . METHODS: A total of 83 patients was referred for surgical treatment of active IE between October 1994 and May 1999 . Preoperatively, microorganisms were isolated using a minimum of two positive blood cultures; results were compared with those obtained from intraoperative heart valve swab cultures . RESULTS: Preoperatively, 73 patients (88%) had a positive blood culture, and 10 (12%) had culture-negative endocarditis . The intraoperative swab confirmed the preoperative diagnosis in 31 cases (37%) . Bacteria were isolated in three of the ten patients with preoperative culture-negative IE . Despite positive histopathological findings in seven patients, no microorganisms were cultured either pre- or intraoperatively . Among the remaining 42 patients (51%) with active IE, 25 valve cultures were sterile and 17 valve swabs were presumed to be contaminated . CONCLUSION: In patients with active IE in whom the causative agent could be isolated and identified before surgery, intraoperative valve swabs did not contribute further to patient management . In isolating contaminants, the risk of inappropriate modification of the antibiotic regimen is imminent . The diagnostic validity in culture-negative IE appears negligible.

Nature, 2001 Jan 25, 409(6819), 507 - 10
Archaeal dominance in the mesopelagic zone of the Pacific Ocean; Karner MB et al.; The ocean's interior is Earth's largest biome . Recently, cultivation-independent ribosomal RNA gene surveys have indicated a potential importance for archaea in the subsurface ocean . But quantitative data on the abundance of specific microbial groups in the deep sea are lacking . Here we report a year-long study of the abundance of two specific archaeal groups (pelagic euryarchaeota and pelagic crenarchaeota) in one of the ocean's largest habitats . Monthly sampling was conducted throughout the water column (surface to 4,750 m) at the Hawai'i Ocean Time-series station . Below the euphotic zone (> 150 m), pelagic crenarchaeota comprised a large fraction of total marine picoplankton, equivalent in cell numbers to bacteria at depths greater than 1,000 m . The fraction of crenarchaeota increased with depth, reaching 39% of total DNA-containing picoplankton detected . The average sum of archaea plus bacteria detected by rRNA-targeted fluorescent probes ranged from 63 to 90% of total cell numbers at all depths throughout our survey . The high proportion of cells containing significant amounts of rRNA suggests that most pelagic deep-sea microorganisms are metabolically active . Furthermore, our results suggest that the global oceans harbour approximately 1.3 x 10(28) archaeal cells, and 3.1 x 10(28) bacterial cells . Our data suggest that pelagic crenarchaeota represent one of the ocean's single most abundant cell types.

Chemistry, 2001 Jan 5, 7(1), 27 - 31
The concept of docking and protecting groups in biohydroxylation; de Raadt A et al.; The hydroxylation of unactivated carbon atoms employing methods developed in the realms of classical organic chemistry is difficult to achieve and the processes available lack the degree of chemo-, regio- and enantioselectivity required for organic synthesis . To improve this situation, the concept of docking/protecting groups should enable the organic chemist to employ biohydroxylation as an easy tool for preparative work . Similar to the common practice of using protective groups in organic chemistry, a docking/protecting (d/p) group is introduced first, then the biotransformation is performed, and finally the d/p group is removed . The aim of this concept is not only to avoid time consuming microorganism screening methods, but also to improve hydroxylation position predictability, prevent undesired side reactions, aid substrate detection, and product recovery . This approach is successfully applied to carboxylic acids, ketones, aldehydes, and alcohols.

Environ Pollut, 2001, 111(3), 367 - 75
Microbial cellulose decomposition in soils from a rifle range contaminated with heavy metals; Chew I et al.; The objective of this study was to assess the effects of heavy metals on microbial decomposition of cellulose in heavy metal-contaminated soils using a cotton strip assay . The assay is a measure of the potential of soil microorganisms to decompose the plant polymer, cellulose . Cellulolytic activity in soil was assessed by determining the reduction in tensile strength of the buried cotton strips over a 25- and 45-day period . Soils were obtained from a rifle range that contain high levels of lead, copper and zinc . The site has been used for approximately 50 years, resulting in metal levels of up to 30,000 mg/kg of lead, 4000 mg/kg of copper and 600 mg/kg of zinc in the most contaminated soils . All the metal-contaminated soils had lower degradation rates than the uncontaminated soils tested . Among the contaminated soils, however, the heavy metal concentration was not the major factor in determining the loss in tensile strength of the cotton strips, where cellulose decomposition was governed by other soil physicochemical properties . Soil with a higher cation exchange capacity, readily oxidisable material and volatile solids content had the greatest loss in tensile strength of cotton strips . Microbial adaptation to the presence of high concentrations of soil heavy metals and reduced bioavailability of metals is the likely explanation for this phenomenon.

Lipids, 2000 Dec, 35(12), 1377 - 86
Electron microscopy may reveal structure of docosahexaenoic acid-rich oil within Schizochytrium sp; Ashford A et al.; Schizochytrium sp . is an algae-like microorganism utilized for commercial production of docosahexaenoic acid (DHA)-rich oil and dried microalgae for use as a source of DHA in foods, feeds, and nutritional supplements . Electron microscopic analysis of whole cells of Schizochytrium sp . employing sample preparation by high-pressure freeze substitution suggests the presence of secondary and tertiary semicrystalline structures of triacylglycerols within the oil bodies in Schizochytrium sp . A fine secondary structure consisting of alternating light- and dark-staining bands was observed inside the oil bodies . Dark bands were 29 +/- 1 A in width, and light bands were 22 +/- 1 A in width . The tertiary (three-dimensional) structure may be a multilayered ribbon-like structure which appears coiled and interlaced within the oil body . In freeze-fracture photomicrographs, Schizochytrium oil bodies exhibited fracture planes with terraces averaging 52 +/- 7 A in height which could correspond to the combined width of two halves of two light bands and one dark band observed in the high-pressure freeze substitution photomicrographs . The results suggest that triacylglycerols within Schizochytrium sp . oil bodies may be organized in a triple chain-length structure . High-pressure freeze substitution electron micrographs of two other highly unsaturated oil-producing species of microalgae, Thraustochytrium sp . and Isochrysis galbana, also revealed this fine structure, whereas microalgae containing a higher proportion of saturated oil did not . The results suggest that the staining pattern is not an artifact of preparation and that the triple chain-length conformation of triacylglycerols in Schizochytrium sp . oil bodies may be caused by the unique fatty acid composition of the triacylglycerols.

J Toxicol Sci, 2000 Dec, 25(5), 381 - 92
A search for chemical agents causing human cancer--lessons learned from rodent carcinogenicity studies; Enomoto M; Analysis of classical life-time rodent bioassays conducted over the past 20 years under conditions of Good Laboratory Practice Regulations has led to an improved understanding of possible factors involved in oncogenesis in humans . Improvements in study design coupled with more detailed pathological examinations have led to new insights whereby neoplastic processes can be more clearly identified and understood with confidence in animal models . Improvements in the ability to identify potential risks through continued animal testing combined with incorporation of advances in genetics and molecular biology in elucidating mechanistic factors will greatly facilitate future research efforts to identify causative agents of human cancer . A great deal of attention will have to be paid to the concept of threshold doses and exposure levels that may be required to achieve preneoplastic conditions or the induction of carcinogenic processes . Future concerns of hazards, risk assessment and the evaluation of carcinogenic potential will involve an amalgamation and understanding of radiological and biological events, especially those of carcinogenic microorganisms, the effects of food and air borne carcinogens, effects of pollution, exposure to xenobiotics and imbalances and disruption of normal biologic functioning of endogenous physiologically active substances, to achieve a better understanding and ultimate prevention of human cancer.

Environ Microbiol, 2000 Jun, 2(3), 324 - 32
Characteristics of attachment and growth of Thiobacillus caldus on sulphide minerals: a chemotactic response to sulphur minerals?
Edwards KJ, Bond PL, Banfield JF.
To further our understanding of the ecological role of sulphur-oxidizing microorganisms in the generation of acid mine drainage (AMD), growth and attachment of the chemoautotrophic sulphur-oxidizing bacterium, Thiobacillus caldus, on the sulphide minerals pyrite, marcasite and arsenopyrite was studied . Growth curves were estimated based on total cells detected in the system (in suspension and attached to mineral surfaces) . In general, higher cell numbers were detected on surfaces than in suspension . Fluorescent in situ hybridizations to cells on surfaces at mid-log growth confirmed that cells on surfaces were metabolically active . Total cell (both surface and solution phase) generation times on pyrite and marcasite (both FeS2) were calculated to be approximately equals 7 and 6 h respectively . When grown on pyrite (not marcasite), the number of T . caldus cells in the solution phase decreased, while the total number of cells (both surface and solution) increased . Additionally, marcasite supported about three times more total cells (approximately equals 3 x 10(9)) than pyrite (approximately equals 8 x 10(8)) . This may be attributed to the dissolution rate of marcasite, which is twice that of pyrite . Epifluorescent and scanning electron microscopy (SEM) were used to analyse the cell orientation on surfaces . Results of Fourier transform analysis of fluorescent images confirmed that attachment to all three sulphides occurred in an oriented manner . Results from high-resolution SEM imaging showed that cell orientation coincides with dissolution pit edges and secondary sulphur minerals that develop during dissolution . Preferential colonization of surfaces relative to solution and oriented cell attachment on these sulphide surfaces suggest that T . caldus may chemotactically select the optimal site for chemoautotrophic growth on sulphur (i.e . the mineral surface).

J Leukoc Biol, 2001 Jan, 69(1), 43 - 9
Iron transport into mycobacterium avium-containing phagosomes from an Nramp1(Gly169)-transfected RAW264.7 macrophage cell line; Kuhn DE et al.; Nramp1 is an important determinant of innate resistance of macrophages to the growth of intracellular microorganisms . We previously showed that Nramp1 functions to transport iron from the cytoplasm into phagosomes of Mycobacterium avium-infected macrophages . The purpose of this investigation was to further characterize the factors that regulate Nramp1-mediated iron transport into phagosomes . Treatment of Nramp1(Gly169) macrophages with the lysomotrophic agents chloroquine or ammonium chloride reduced the import of iron significantly . We found that macrophage-activating cytokines, including TNF-alpha, IFN-gamma, IL-1alpha, and GM-CSF, when added prior to M . avium, increased the transport of iron into the phagosome . This increase in iron transport was not a result of an increased amount of Nramp1 protein in the phagosome nor to new protein synthesis . Treatment of Nramp1(Gly169)-transfected macrophages with inhibitors of protein kinase C (PKC) diminished the import of iron into the phagosomes . Iron import was inhibited by an anti-Nramp1 antibody against the putative fourth outer-loop region of Nramp1 but not by an anti-Nramp1 antibody against the carboxy terminus . The significance of these results on the orientation of Nramp1 in the phagosome membrane and on the transport of iron is discussed.

J Basic Microbiol, 2000, 40(5-6), 351 - 61
Biological and molecular characterization of cellular differentiation in Tetrahymena vorax: a potential biocontrol protozoan; Green MM et al.; Tetrahymena vorax (T . vorax) is an indigenous fresh water protozoan with the natural biological potential to maintain a specific aquatic microbial flora by ingesting and eliminating specific microorganism . To investigate the molecular mechanisms controlling Tetrahymena vorax (T . vorax) cellular differentiation from a small-mouth vegetative cell to a voracious large-mouth carnivore capable of ingesting prey ciliates and bacteria from aquatic environments, we use DNA subtraction and gene discovery techniques to identify and isolate T . vorax differentiation-specific genes . The physiological necessity for one newly discovered gene, SUBII-TG, was determined in vivo using an antisense oligonucleotide directed against the 5' SUBII-TG DNA sequence . The barriers to delivering antisense oligonucleotides to the cytoplasm of T . vorax were circumvented by employing a new but simple procedure of processing the oligonucleotide with the differentiation stimulus, stomatin . In these studies, the antisense oligonucleotide down-regulated SUBII-TG mRNA expression, and blocked differentiation and ingestion of prey ciliates . The ability to down-regulate SUBII-TG expression with the antisense oligonucleotide suggests that the molecular mechanisms controlling the natural biological activities of T . vorax can be manipulated to further study its cellular differentiation and potential as a biocontrol microorganism.

Scand J Gastroenterol, 2000 Dec, 35(12), 1251 - 4
No evidence of an association between Helicobacter pylori infection and Raynaud phenomenon; Savarino V et al.; BACKGROUND: Raynaud phenomenon (RP) is a vasospastic condition that manifests itself as cold-induced ischemic attacks of the fingers with skin color changes . It may be classified as primary (PRP) or secondary (SRP), if associated to other diseases, mainly connective-tissue diseases . Recently, the association between PRP and Helicobacter pylori infection has been reported . The aims of this study were to evaluate the prevalence of gastric H . pylori infection in a large group of patients affected by PRP and SRP and to assess whether it was more evident in patients with more recent onset of RP . METHODS: Ninety-eight consecutive patients (93 F and 5 M), referring to our videocapillaroscopic service for the diagnosis of vascular and connective-tissue diseases, were evaluated . Forty-nine of them were affected by PRP and 49 by SRP . Patients were classified as having PRP on the basis of normal serological and immunological findings, normal videocapillaroscopic examination and exclusion of other conditions inducing RP . H . pylori infection was diagnosed by 13C-urea breath test (UBT) . Two groups of 49 age-and sex-matched controls, respectively, were also evaluated . RESULTS: Patients with SRP resulted significantly older than those with PRP (P < 0.006) . UBT was found positive in 22/49 patients with PRP (45%) and in 29/49 patients with SRP (59%) . The positivity of the respective control groups was 36% and 53% (P = NS) . There was no higher prevalence of H . pylori infection in patients with RP lasting for less than 4 years . CONCLUSIONS: The results do not confirm the previously reported high prevalence of H . pylori infection in patients with PRP . A high association was not even found between the presence of the microorganism and SRP . There was no difference in the prevalence of H . pylori infection among the subgroups with more recent onset of both PRP and SRP.

J Food Prot, 2001 Jan, 64(1), 87 - 93
Cleanability of soiled stainless steel as studied by atomic force microscopy and time of flight secondary ion mass spectrometry; Boyd RD et al.; The hygienic status of food contact surfaces can deteriorate with wear . Effective cleaning regimes must remove any adsorbed organic material as well as microorganisms . Previous work has determined the extent of surface wear occurring on a stainless steel surface within the food industry, and we have reproduced representative samples in vitro . Two surface analytical techniques, atomic force microscopy and time of flight secondary ion mass spectrometry were combined with fluorescence microscopy to give detailed analysis of stainless steel surfaces fouled with starch and milk powder, then cleaned with water either by a spray or brushing method . It was found that the surface cleanability is affected by the cleaning regime and the surface roughness, not only the average vertical roughness but also by the shape of the surface defects, with sharp scratches more difficult to clean than wider surface defects . Spray cleaning with distilled water was found to be a selective method by preferentially removing proteinaceous material more easily than fatty acid ester material . The analytical techniques employed provided information on selective cleanability and surface topography at a hitherto unexplored level, and the information gained may be of value in the design and investigation of novel cleaning regimes and hygienic surfaces.

Int Ophthalmol Clin, 2001 Winter, 41(1), 83 - 102
Neuroretinitis; Ray S et al.; Despite the growing list of agents that can present as neuroretinitis, nearly one-half remain idiopathic . However, many of the candidate etiologies are treatable conditions, and accurate diagnosis can result in visual rehabilitation . A complete workup in patients presenting with acute neuroretinitis should include a thorough history and general medical evaluation . Exposure history should be thoroughly explored, including recent travel, unpasteurized and uncooked foods, sexual experience, and animal contacts . A detailed physical examination should be performed to note hidden rashes and inoculation sites and should include routine measurements of blood pressure and heart rate . Laboratory tests should be tailored to the history and may include complete blood count; erythrocyte sedimentation rate; bacterial, fungal, and viral blood cultures; antinuclear antibody test; angiotensin-converting enzyme; anti-double-stranded DNA; and C3 . Serological evaluation should look for syphilis, Lyme disease, histoplasmosis, brucellosis, chlamydia, HIV, toxoplasmosis, Epstein-Barr virus, viral hepatitis B and C, and tuberculin skin test . Neuroretinitis is a clinical entity in which there is inflammation of the retinal architecture and optic nerve . There are numerous entities that can cause a picture of neuroretinitis ranging from vascular to infectious to autoimmune . With regards to the infectious etiologies, it is interesting to note that many of these organisms are obligate intracellular pathogens . The microorganisms B . henselae, T . gondii, R . typhi, T . pallidum, Mycobacterium tuberculosis, Histoplasma capsulatum, and various viruses, such as HIV, mumps, and HSV, are known intracellular agents . Other major infectious agents, such as B . burgdorferi and Leptospirosis spp . are known to remain sequestered within the circulatory system . It is possible that in this way these agents are able to breach the delicate blood-brain barrier . The implication of such findings on the treatment and management of neuroretinitis remains to be explored . Interestingly, the vast majority of infected patients do not develop neuroretinitis or demonstrate CNS involvement . Detailed examination of this variability may provide further insight into the pathogenic properties of these infectious agents, host tissue susceptibility, and mechanisms of blood-retina barrier integrity . A detailed retinal examination can provide an unobstructed view of the CNS . Careful inspection of this delicate interface may reveal subtle findings critical for accurate and rapid diagnosis of underlying systemic pathology . The varied visual and neurological symptoms of neuroretinitis attest to the fact that this is a disease of both the retina and contiguous neuronal elements . Such involvement significantly elevates the risk to the patient and emphasizes the need for early detection and prompt treatment.

Arkh Patol, 2000 Nov-Dec, 62(6), 47 - 52
{Pathogenetic and morphological characteristics of acute inflammation of the central nervous system}; Tsinzerling VA et al.; Virus, bacteria, mycoplasma, protozoa can be the causes of acute neuroinfections . The agents can penetrate into the brain by blood, nerve, lymphatic vessels, from the sinuses directly . Peculiarities of manifestations of acute neuroinfections depend on the agent tropism to receptors of nervous cell and specificity of brain immunoreactivity . The brain injuries can be induced by microorganism action or through immunopathologic processes . Dynamics of morphological changes in acute neuroinfections of different etiology are summarized . Histological, cytological, bacteriological, serological, immunofluorescent, histochemical methods are evaluated . Acute neuroinfection pathogenesis has many unresolved problems.

Ann N Y Acad Sci, 2000, 915, 171 - 83
Role of M cells in intestinal barrier function; Kucharzik T et al.; M cells are known as specialized epithelial cells of the follicle-associated epithelium of the gastrointestinal tract . As M cells have a high capacity for transcytosis of a wide range of microorganisms and macromolecules, they are believed to act as an antigen sampling system . The primary physiological role of M cells seems to be the rapid uptake and presentation of particular antigens and microorganisms to the immune cells of the lymphoid follicle to induce an effective immune response . In contrast to absorptive enterocytes, M cells do not exert direct defense mechanisms to antigens and pathogens in the gut lumen . Therefore, they provide functional openings of the epithelial barrier . Although M cells represent a weak point of the epithelial barrier, even under noninflamed conditions, there seems to be a balance between antigen uptake and immunological response . The low number of M cells in the gastrointestinal tract and the direct contact to immune cells in the lamina propria usually prevent the occurrence of mucosal inflammation . During chronic intestinal inflammation we observe an increase of M cell number and apoptosis selectively in M cells . M cell damage seems to be responsible for the increase of the uptake of microorganisms that is observed during intestinal inflammation . Under inflammatory conditions in the intestine, the maintenance of the epithelial barrier is broken and M cells seem to play a major role during this process.

Mol Pathol, 2000 Dec, 53(6), 289 - 94
Microarray techniques in pathology: tool or toy?
Snijders AM, Meijer GA, Brakenhoff RH, van den Brule AJ, van Diest PJ.
Microarray technology allows the simultaneous analysis of up to thousands of different genes in histological or cytological specimens . Although microarray technology has so far mainly been applied in the research setting, its clinical application in pathology is expected in the foreseeable future . This paper presents an overview of the technical "ins and outs" of microarray technology, and discusses several putative applications in diagnostic pathology, which include tumour classification, the prediction of responses to certain chemotherapeutical or hormonal agents, the biological staging of tumours, the risk assessment of premalignant lesions, and the detection of microorganisms.

Ann N Y Acad Sci, 2000, 926, 226 - 35
Opsonization of apoptotic cells . Implications for uptake and autoimmunity; Mevorach D; As a part of innate immunity, soluble host proteins called opsonins, which include complement ligands and immunoglobulins, initially coat microorganisms that penetrate the mammalian sterile milieu . The main purpose of opsonization is to allow subsequent clearance of opsonized particles by specific receptors on the surface of leukocytes . Similarly, several proteins that may act as opsonins and have a role in uptake of apoptotic cells and bodies include thrombospondin I, the complement system, beta 2GPI, immunoglobulins, CRP, and some unidentified others . The surface changes that lead to opsonization include the appearance of phosphatidylserine that acts as an activator molecule for some known opsonins as the complement system and beta 2GPI . The consequence of altered opsonization is demonstrated by the development of autoimmunity in C1q deficient mice, and the pro-inflammatory response by macrophages ingesting apoptotic cell opsonized by an autoantibody.

Basic Res Cardiol, 2000, 95 Suppl 1, I59 - 64
Coronary artery disease: an inflammatory or infectious process; Jahn J et al.; It is well accepted that coronary artery disease is linked to an inflammatory process . It is unknown which agents may cause or accelerate coronary artery disease . An inflammation of the vessel wall may be caused by a number of mechanisms such as accumulation of glycosylated proteins in diabetic patients, oxidised LDL in patients with hypercholesterolemia or infectious agents . Among the possible infectious agents Chlamydia pneumoniae is the most likely microorganism involved in atherosclerosis . The arguments in favour of Chlamydia pneumoniae result from seroepidemiologic studies and from detection of chlamydial DNA in atherosclerotic plaques by polymerase chain reaction (PCR) . In addition this microorganism is the only one that could be isolated from atherosclerotic tissue . This review summarises the present understanding of the role of an inflammatory process in the development or progression of coronary artery disease.

AIHAJ, 2000 Nov-Dec, 61(6), 788 - 97
Identifying the determinants of viable microorganisms in the air and bulk metalworking fluids; Virji MA et al.; Exposure assessment was conducted for an epidemiologic study of the respiratory effects of exposure to metalworking fluids (MWF) . As part of the study, airborne microorganisms were collected with a two-stage microbial impactor, and a sample of the bulk soluble MWF was collected from each machine sump, as well as information about the work environment . These data were then used to develop multivariate statistical models of the determinants bulk MWF and airborne microbial levels . Microbial concentrations in the bulk MWF ranged from 5 x 10(4) to 5 x 10(10) colony-forming units (CFU)/mL, with a geometric mean of 3.4 x 10(7) CFU/mL . The geometric mean airborne microbial level was 182 CFU/m3 (for particles size <8 microm) with a range of 1 to 8,308 CFU/m3 . In modeling the determinants of bulk microorganisms, fluid-related factors were the most important characteristics associated with microbial levels, followed by process-related and environmental factors . The final full multivariate model predicted a significant reduction in bulk microbial levels by increasing pH of the fluid and reducing the amount of tramp oil leaking into the fluid . For the airborne microbial models, process-related factors were the major characteristics associated with microbial levels, followed by factors related to worker activities and environmental factors . The final full multivariate model predicted a significant control of airborne microorganisms by increasing worker distance from the machine, reducing the number of machines within 10 feet of the worker, decreasing the bulk microbial levels, and adding machine enclosures . These models can be used to prioritize nonbiocidal interventions to control microbial contamination of the bulk MWF and the air.

Minerva Stomatol, 2000 Jun, 49(6), 293 - 311
{Congenital neutrophil defects and periodontal diseases}; Del Fabbro M et al.; An alteration of the immune system function is one of the main factors involved in the development of periodontal disease . Polymorpho-nuclear neutrophil leukocytes (PMN) play a crucial role in the cell-mediated immune response against bacterial challenge . The mechanism of neutralization of pathogen microorganisms by PMNs involves many different steps: adhesion to capillary endothelium in the inflamed region, trans-endothelial migration, chemotaxis, phagocytosis and, ultimately, bacterial killing by oxidative and non-oxidative mechanisms . A defect in one of these steps leads to altered neutrophil function and, consequently, to a higher host susceptibility to periodontal tissue infection . The main intrinsic neutrophil diseases such as neutropenia, leukocyte adhesion deficiency (LAD-1), Chediak-Higashi syndrome, Papillon-Lefevre syndrome, chronic granulomatous disease (CGD), are often related to severe and early-onset forms of periodontitis, as described by many evidences in the literature . Therefore PMN dysfunctions, both intrinsic and extrinsic, represent an important risk factor for periodontal disease . Studies on the basic molecular mechanisms of such dysfunctions, also in terms of genetic polymorphisms, recently allowed to identify some specific markers related to a higher susceptibility to the development of disease . Many researches have yet to be performed aiming to gain insight on the dynamics of PMN activation and interaction with other cells, in order to improve and modulate neutrophil function and to develop specific approaches for care and prevention of periodontal diseases.

Med Sci Monit, 2000 Nov-Dec, 6(6), 1213 - 22
Blood brain barrier and infection; Chaudhuri JD; The blood brain barrier (BBB) is a highly dynamic structure and consists of endothelial cells, which are characterized by the presence of tight junctions and relative lack of endocytic vesicles . The tight junctions are reinforced by the foot processes of the astrocytes . The BBB functions through these specialised structures, to maintain the environment of the brain in a steady state by regulating the influx and efflux of substances . The protective effect of the BBB is however, lost during bacterial and viral infections . The primary mechanism operative are an increase in the permeability of the BBB and/or direct invasion of the brain by microorganisms . Since the BBB is relatively impermeable to chemotherapeutic agents the treatment of CNS infections is difficult . This paper aims to examine the various mechanisms by which infection spreads to the brain, and suggest measures for successful drug delivery into the brain during infections.

Cell Microbiol, 2000 Oct, 2(5), 431 - 41
Interaction of Bartonella henselae with endothelial cells results in rapid bacterial rRNA synthesis and replication; Kempf VA et al.; Bartonella henselae is a slow-growing microorganism and the causative pathogen of bacillary angiomatosis in man . Here, we analysed how interaction of B . henselae with endothelial cells might affect bacterial growth . For this purpose, bacterial rRNA production and ribosome content was determined by fluorescence in situ hybridization (FISH) using rRNA-targeted fluorescence-labelled oligonucleotide probes . B . henselae grown on agar plates showed no detectable rRNA content by means of FISH, whereas B . henselae co-cultured with endothelial cells showed a rapid increase of rRNA production within the first 18 h after inoculation . The increased rRNA synthesis was paralleled by a approximately 1000-fold intracellular bacterial replication, whereas bacteria grown on agar base showed only a approximately 10-fold replication within the first 48 h of culture . Pretreatment of host cells with paraformaldehyde prevented adhesion, invasion, intracellular replication and bacterial rRNA synthesis of B . henselae . In contrast, inhibition of host cell protein synthesis by cycloheximide did not affect bacterial adhesion and invasion, but prevented intracellular replication although bacterial rRNA content was increased . Inhibition of actin polymerization by cytochalasin D did not affect adhesion, invasion, increased rRNA content or intracellular replication of B . henselae . These results demonstrate that rRNA synthesis and replication of B . henselae is promoted by viable host cells with intact de novo protein synthesis.

Cell Microbiol, 1999 Jul, 1(1), 61 - 7
CpG-DNA upregulates the major acute-phase proteins SAA and SAP; Schmidt U et al.; The acute-phase response is an immediate reaction of the host against invading microorganisms . We show here that oligodeoxynucleotides (ODNs) containing a CpG motif rapidly induce the major murine acute-phase proteins in vivo, i.e . serum amyloid A (SAA) and serum amyloid P (SAP) . Serum levels of these proteins are elevated within 12 h and peak at 24 h after the injection of CpG-ODN or endotoxin . Liver cells produce the proteins with the same kinetics . Injection of interleukin 6 (IL-6), IL-1beta and tumour necrosis factor alpha (TNF-alpha) induces SAA and SAP in vivo, but the CpG-ODN-mediated induction does not depend on the presence of the TNF receptor p55, as the acute-phase response in TNF receptor p55-deficient mice does not differ from that of wild-type mice . Aside from CpG-ODN, bacterial genomic DNA also induces the acute-phase response in LPS-resistant C3H/Hej mice . The induction of the major acute-phase proteins SAA and SAP is blocked by the simultaneous injection of CpG-ODN together with D-galactosamine (D-GalN) . As D-GalN sensitizes the host for the toxic effects of TNF-alpha, a possible mechanism could be the prevention of synthesis of the major acute-phase proteins SAA and SAP.

Annu Rev Physiol, 2001, 63, 521 - 54
Surfactant proteins a and d and pulmonary host defense; Crouch E et al.; The lung collectins, SP-A and SP-D, are important components of the innate immune response to microbial challenge and participate in other aspects of immune and inflammatory regulation within the lung . Both proteins bind to surface structures expressed by a wide variety of microorganisms and have the capacity to modulate multiple leukocyte functions, including the enhanced internalization and killing of certain microorganisms in vitro . In addition, transgenic mice with deficiencies in SP-A and SP-D show defective or altered responses to challenge with bacterial, fungal, and viral microorganisms and to bacterial lipopolysaccharides in vivo . Thus collectins could play particularly important roles in settings of inadequate or impaired specific immunity, and acquired alterations in the levels of active collectins within the airspaces and distal airways may increase susceptibility to infection.

Helicobacter, 2000 Dec, 5(4), 232 - 9
Distinction of gastric Helicobacter spp . in humans and domestic pets by scanning electron microscopy; Stoffel MH et al.; BACKGROUND: A number of different Helicobacter spp . can colonize the stomach of humans and domestic pets . Difficulties encountered with primary isolation of these spiral microorganisms and their unusual inertia with respect to biochemical reactions still represent considerable obstacles to their characterization with classic tools . In addition, the high degree of similarity in the 16S rRNA sequence hampers differentiation of Helicobacter spp . using routine molecular biological assays . MATERIALS AND METHODS: Samples from experimentally monoinfected mice, of naturally infected hosts, and of cultured strains were examined by scanning electron microscopy (SEM) . In parallel, all samples were analyzed by molecular techniques to ascertain the Helicobacter spp . involved . RESULTS: Using the mouse samples as a reference, microorganisms found in naturally infected hosts were identified by SEM as belonging to H . pylori, H . felis, or a group consisting of H . bizzozeronii and H . heilmannii . A further spiral microorganism with unique morphology was found in a dog that was positive for H . salomonis, but the organism could not be recovered from experimentally infected mice . In culture, most Helicobacter strains lost their ultrastructural characteristics . CONCLUSIONS: When gastric Helicobacter spp . were collected from their natural habitat and examined by SEM, relevant differences could be detected between H . felis, H . bizzozeronii and H . heilmannii, and H . salomonis, respectively . SEM, therefore, seems to be a useful auxillary tool for the distinction of various gastric Helicobacter spp . as based on their ultrastructure.

Trends Biotechnol, 2001 Mar, 19(3), 102 - 8
The biotechnological potential of piezophiles; Abe F et al.; Microorganisms that prefer high-pressure conditions are termed piezophiles (previously termed barophiles) . The molecular basis of piezophily is now being investigated extensively focusing on aspects of gene regulation and the function of certain proteins in deep-sea isolates . Little attention has been paid, however, to the potential biotechnological applications of piezophiles compared with other extremophiles . Based on the fundamental knowledge available, we will try to answer the following questions: How can we exploit the biotechnological potential of piezophiles? What can be understood by the application of high-pressure in biological systems?

FEMS Microbiol Lett, 2001 Feb 20, 195(2), 253 - 8
Differences in Fe(III) reduction in the hyperthermophilic archaeon, Pyrobaculum islandicum, versus mesophilic Fe(III)-reducing bacteria; Childers SE et al.; The discovery that all hyperthermophiles that have been evaluated have the capacity to reduce Fe(III) has raised the question of whether mechanisms for dissimilatory Fe(III) reduction have been conserved throughout microbial evolution . Many studies have suggested that c-type cytochromes are integral components in electron transport to Fe(III) in mesophilic dissimilatory Fe(III)-reducing microorganisms . However, Pyrobaculum islandicum, the hyperthermophile in which Fe(III) reduction has been most intensively studied, did not contain c-type cytochromes . NADPH was a better electron donor for the Fe(III) reductase activity in P . islandicum than NADH . This is the opposite of what has been observed with mesophiles . Thus, if previous models for dissimilatory Fe(III) reduction by mesophilic bacteria are correct, then it is unlikely that a single strategy for electron transport to Fe(III) is present in all dissimilatory Fe(III)-reducing microorganisms.

FEMS Microbiol Lett, 2001 Feb 20, 195(2), 121 - 6
The cell surface associated phosphatase activity of Mycobacterium bovis BCG is not regulated by environmental inorganic phosphate; Braibant M et al.; Non-specific phosphomonoesterase activities (alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2)) were examined at the cell surface of Mycobacterium bovis BCG . Using p-nitrophenylphosphate as the substrate, peaks of phosphatase activity were detected at pH 6.0, pH 10.0 and pH 12.0, suggesting the presence of one acid phosphatase and two alkaline phosphatases with distinct optimum pH values . Contrary to the situation observed in several other microorganisms, the expression of these enzymes is not regulated by the environmental inorganic phosphate concentration.

Arch Med Res, 2000 Sep-Oct, 31(5), 515 - 9
Reduction in hospitalization costs, morbidity, disability, and mortality in patients with aids treated with protease inhibitors; Lavalle C et al.; BACKGROUND: The objective of this study was to analyze hospitalization costs, morbidity, disability, and mortality in patients with acquired immunodeficiency syndrome (AIDS) treated with protease inhibitors (PI) . METHODS: This is a self-controlled, ambispective study of a total of 581 patients with human immunodeficiency virus (HIV)/AIDS seen at the Hospital de Infectologia, Centro Medico La Raza, IMSS, in Mexico City during 1997 . A total of 210 (36.14%) patients initiated protease inhibitor (PI) treatment at the onset of the study . Thirty-eight patients satisfied the inclusion criteria for this study and were analyzed retrospectively during the year prior to PI treatment, and then prospectively throughout the year on PI treatment . As concerns main outcome measures, financial costs, number of hospitalizations, number of infections, and productivity and laboratory parameters (CD4(+) counts and viral load) were analyzed during the year prior to PI treatment and then prospectively during the year on PI prescription . Our hypothesis was that the hospital costs, morbidity, disability, and mortality of patients with AIDS decreased while on PI treatment . RESULTS: During the year prior to PI prescription, the 38 patients enrolled in the study were admitted on a total of 59 occasions (1.55 hospitalizations/patient), whereas during the year on PI therapy, all 38 patients had only seven admissions (0.18 hospitalizations/patient) . Hospitalization costs decreased 35% when annual PI costs for the 38 patients studied were taken into account . The number of microorganisms detected during hospitalization decreased from 24 prior to PI to five on PI . The number of disability days involved in patients on PI decreased significantly (p <0.0002) . None of the 38 patients studied died during the year of follow-up under PI treatment . Mortality decreased significantly, from 116/481 (23.2%) in 1996, to 77/581 (13.2%) in 1997, to 40/740 (6.4%) in 1998 . There were no deaths among the 38 patients studied during the 1-year follow-up period; when the observation period was extended 1 additional year, only one patient died (2.63%) . Only six (3.48%) of the 172 PI-treated patients with AIDS not included in the study died during the same period . CD4(+) cell counts increased from 190.56 +/- 169.5 cells/mm(3) to 235.00 +/- 112.65 cells/mm(3) (p <0.05) after 12 months of PI treatment . Viral loads decreased from 5 logs to 2.4 logs at 12 months of PI treatment (p <0.001) . CONCLUSIONS: Introduction of PI to antiretroviral treatment in patients with AIDS was associated with a lower rate of hospital admissions, lower costs, and a lesser number of infections/year, disabilities, and mortalities . Increase of CD4(+) cell counts and decrease in viral loads in the 38 patients were associated with decreased morbility and mortality.

Am J Respir Crit Care Med, 2001 Feb, 163(2), 389 - 97
Deficiencies in lung surfactant proteins A and D are associated with lung infection in very premature neonatal baboons; Awasthi S et al.; Surfactant proteins A (SP-A) and D (SP-D) are important in the innate host defense against pathogenic microorganisms . A deficit in these proteins in premature infants, either because of immaturity or as a consequence of superimposed chronic lung disease (CLD), could increase their susceptibility to infection . The study reported here examined infection in CLD in the premature newborn baboon, and correlated it with the amounts of SP-A and SP-D in lung tissue and lavage fluid . Two groups of baboons were delivered prematurely, at 125 d gestational age (g.a.), and differed principally in whether they developed naturally acquired pulmonary infections and sepsis . Group I animals were ventilated with clinically appropriate oxygen for 6 d and 14 d without clinical incident . Group II animals were ventilated for 5 to 71 d, but differed from those in Group I in that most developed pulmonary infection and/or sepsis . In Group I animals, tissue pools of both SP-A and SP-D were equal to or exceeded those in adults, and lavage pools of SP-A increased progressively with the time of ventilation to about 35% of adult levels after 14 d . In contrast, most Group II animals had concentrations of lavage SP-A that were less than 20% of that in adult animals . A low concentration of lavage SP-A correlated with the release of interleukin-8, and with a high "infection index" based on histopathology, microbiologic cultures, and clinical indications of sepsis . Our data suggest that the amounts of SP-A and SP-D in lavage fluid are indicators of the risk of infection in the evolution of neonatal CLD . Deficits in the amount of lavage SP-A, even after 60 d of ventilation, may have inhibited the resolution of infection and thereby contributed to the developing injury among our Group II animals.

Rev Assoc Med Bras, 2000 Oct-Dec, 46(4), 335 - 41
{Toxoplasmosis: occurrence of antibodies antitoxoplasma gondii and diagnosis}; Cantos GA et al.; Toxoplasmosis is a zoonosis of broad geographic distribution, being an opportunist infection mainly in AIDS patients . The incidence of serum antibodies of the type anti-Toxoplasma gondii is variable and growing according the different age groups . The laboratory test for the diagnostic of this disease, include the exam of the pathologic species as well as immunologic tests . Although the serum tests have limitations, they are still utilized in the Clinical Analysis laboratories . To improve the congenital toxoplasmosis diagnosis in AIDS patients, the polymerase chain reaction (PCR) and Nested-PCR have been utilized alternatively . PURPOSES: To focus the occurrence of toxoplasmosis, considering the different techniques and shapes of point of views in the serological analysis . METHODS: The antibodies (Ac) anti-Toxoplasma gondii of 2994 patients from the Santa Catarina Federal University Hospital, in the period from February 28, 1996 to July 28, 1998 were evaluated . This evaluation was accomplished by the Immunofluorescency Indirect reaction, which was confirmed by the ELISA method . RESULTS: The results showed that 41.91% of the patients had the antibodies anti-Toxoplasma gondii . From this total we concluded that 0.87% of these patients had the IgM in different titles which can be or not classified in the acute phase of the disease . This study demonstrates that the incidence of toxoplasmosis in our orment is relatively high . It shows too that in the identification of the acute process of the disease, the serologic tests can be added to a more sensible and specific techniques that allows the evidentiation of the microorganism thus contributing to a better diagnosis.

Digestion, 2001, 63 Suppl 1, 43 - 7
Role of granuloma in the immunopathogenesis of Crohn's disease; Matsumoto T et al.; Inflammatory bowel diseases (ulcerative colitis and Crohn's disease) are chronic long-lasting inflammatory diseases with yet unknown etiology . Recent advancement revealed that both diseases are associated with genetic predisposition and environmental factors such as luminal microorganisms and antigens . Crohn's disease is associated with histopathologic features such as granuloma formation and longitudinal ulceration . In this article we describe the role of granuloma in the immunopathogenesis of Crohn's disease . Granuloma of Crohn's disease may play crucial roles as antigen-presenting cites to memory type T cells, which leads to activation and proliferation of T cells . Antigens presented at granuloma may be closely related to the disease .

Trends Microbiol, 2001 Feb, 9(2), 79 - 86
Microbiology of ancient and modern hydrothermal systems; Reysenbach AL et al.; Hydrothermal systems have prevailed throughout geological history on earth, and ancient ARCHAEAN hydrothermal deposits could provide clues to understanding earth's earliest biosphere . Modern hydrothermal systems support a plethora of microorganisms and macroorganisms, and provide good comparisons for paleontological interpretation of ancient hydrothermal systems . However, all of the microfossils associated with ancient hydrothermal deposits reported to date are filamentous, and limited STABLE ISOTOPE analysis suggests that these microfossils were probably autotrophs . Therefore, the morphology and mode of carbon metabolism are attributes of microorganisms from modern hydrothermal systems that provide valuable information for interpreting the geological record using morphological and isotopic signatures.

J Stored Prod Res, 2001 Jul, 37(3), 303 - 312
Safe storage time of high moisture wheat; Karunakaran C et al.; Deterioration rates were determined for 15-19% moisture content (m.c., wet basis) wheat (Triticum aestivum L . cv . 'Barrie') stored at constant temperatures or with a step decrease in storage temperatures . Deterioration rates were determined by measuring germination capacity of the grain and respiration rates of grain and microorganisms . Safe storage time was defined as the time for germination to decrease to 90% . Safe storage times of 19% m.c . wheat stored at constant temperatures ranged from 2.5 d at 30 and 35 degrees C to 37 d at 10 degrees C . Deterioration rates of 19% m.c . wheat stored with a step decrease in storage temperatures (35-25, 30-20, 25-20, and 20-15 degrees C) were determined and safe storage times were satisfactorily predicted . Safe storage times of 17% m.c . wheat were 5, 7, and 15 d at 35, 30, and 25 degrees C, respectively . Respiration rates and germination percentages of 15 and 16% m.c . wheat stored at 25 degrees C remained constant for 70 d . The respiration rates of 17-19% m.c . wheat at 25 degrees C increased while the germination percentages decreased with storage time . Germination dropped from 98 to 92-89% when the dry matter losses were about 0.05% and visible mould occurred when the dry matter losses were about 0.1% in 17-19% m.c . wheat . Safe storage times of 17% m.c . wheat stored at 35-25 degrees C were compared with those determined in similar previous work with cultivars 'Domain' and 'Katepwa' . 'Domain' had the longest and 'Barrie' had the shortest storage times.

Int J Mol Med, 2001 Feb, 7(2), 211 - 6
Comparison between xanthine oxidases from buttermilk and microorganisms regarding their ability to generate reactive oxygen species; Wippich N et al.; Xanthine oxidase (XO) forms uric acid from xanthine . It is assumed that at the same time oxygen is reduced by the XO to reactive oxygen species (ROS), mainly to .O2- and to H2O2 . Under certain conditions such ROS can be highly damaging to cellular structures . Therefore, XO was frequently used as a model system, in which the impact of ROS on cellular compounds and structures has been investigated . In this in vitro study xanthine oxidases from buttermilk and from microorganisms were compared regarding their ability to generate ROS . It could be shown that both enzymes are able to transform xanthine to uric acid but differ significantly in their reductive properties to oxygen . XO from buttermilk reduces oxygen to both .O2- and H2O2 whereas XO from microorganisms generates H2O2, but fails to form .O2- . Since .O2- are involved in maintaining transition metal-mediated formation of hydroxyl radicals (.OH) from H2O2, we conclude that XO from microorganisms is therefore largely unsuitable in studies investigating just the interaction of .O2- with other ROS on cellular compounds.

Mol Diagn, 2000 Dec, 5(4), 279 - 84
Detection of herpes simplex virus and varicella-zoster virus in clinical swabs: frequent inhibition of PCR as determined by internal controls; Bezold G et al.; BACKGROUND: PCR-based detection of microorganisms is widely used for diagnostic purposes . Most routine PCR applications do not control for inhibition of PCR, thus leading to false-negative results . METHODS AND RESULTS: One hundred eighteen swab samples obtained from skin and mucosa were investigated for the presence of herpes simplex virus (HSV), varicella-zoster virus (VZV), and the control gene betaglobin by internally controlled PCR with purified and unpurified DNA in parallel . With unpurified DNA, inhibition of PCR was detected in 23% of betaglobin PCRs, 25% of VZV PCRs, and 16% of HSV PCRs versus 3% each for purified DNA . Approximately 20% of the samples with positive results for HSV or VZV had negative or inhibited results using unpurified DNA . CONCLUSION: These results indicate that PCR from clinical swab specimens should be performed exclusively with internal controls because the positive control alone cannot exclude PCR inhibition in individual samples . Purification of DNA will decrease, but not exclude, PCR inhibition.

Proc Natl Acad Sci U S A, 2001 Feb 13, 98(4), 1577 - 82 Epub 2001 Feb 06.
Real-time visualization of intracellular hydrodynamics in single living cells; Potma E et al.; Intracellular water concentrations in single living cells were visualized by nonlinear coherent anti-Stokes Raman scattering (CARS) microscopy . In combination with isotopic exchange measurements, CARS microscopy allowed the real-time observation of transient intracellular hydrodynamics at a high spatial resolution . Studies of the hydrodynamics in the microorganism Dictyostelium discoideum indicated the presence of a microscopic region near the plasma membrane where the mobility of water molecules is severely restricted . Modeling the transient hydrodynamics eventuated in the determination of cell-specific cytosolic diffusion and plasma membrane permeability constants . Our experiments demonstrate that CARS microscopy offers an invaluable tool for probing single-cell water dynamics.

Clin Microbiol Infect, 2000 Jul, 6(7), 350 - 6
Hand hygiene-beliefs or science?
Hugonnet S, Pittet D.
Over a century has passed since Ignaz P . Semmelweis demonstrated the association between hand hygiene and nosocomial infections, but this simple procedure is still not recognized by many healthcare workers as one of the most important measures to prevent cross-transmission of microorganisms . A relatively large amount of research has been done, in particular to try to understand why compliance remains so low, in order to implement successful promotion campaigns . This research has generated a fair amount of strong scientific data which are sometimes misunderstood and misused because of myths or certain beliefs . Observational or intervention studies have consistently shown a number of risk factors associated with non-compliance, such as high workload, professional category, or type of ward . Others are thought to be barriers to adequate compliance but have not yet been properly assessed . These include skin irritation due to hand hygiene agents, lack of knowledge of hand hygiene recommendations, or lack of institutional policy . Future interventions to promote hand hygiene will need to address these risk factors, and target the individual healthcare worker, as well as the group or institution if a significant degree of success is to be achieved.

Allergy, 2001 Feb, 56(2), 175 - 9
Increased prevalence of atopy among children exposed to mold in a school building; Savilahti R et al.; BACKGROUND: The purpose of this study was to assess the occurrence of immunoglobulin E sensitization to common environmental allergens (atopy) and new allergic diseases among schoolchildren after starting school in a water-damaged school building . The staff and pupils of a Finnish elementary school with visible water damage and mold complained of respiratory and skin symptoms . The school building was examined and widespread moisture damage was found . A control school with no visible water damage was also examined . No indication of exceptional microbial growth was found in the samples taken from this school . METHODS: History of allergic diseases and the year of diagnosis were established by a questionnaire . IgE antibodies to the common environmental allergens were determined from randomly selcted groups from both schools . RESULTS: Elevated IgE values were significantly more common among the exposed children, as was the occurrence of new allergic diseases after the children started at the school . CONCLUSIONS: The odds ratios for the IgE values of the study groups indicated a possible relationship between exposure to microorganisms and IgE sensitization . Exposure to spores, toxins, and other metabolites of molds may have complex results with unknown immunogenic effects that may act as a nonspecific trigger for allergic sensitization leading to the development of atopy.

Enzyme Microb Technol, 2001 Feb 1, 28(2-3), 145 - 154
Novel microbial lipases: catalytic activity in reactions in organic media; Cardenas F et al.; 2,000 microbial strains were isolated from soil samples and tested to determine their lipolytic activity by employing screening techniques on solid and in liquid media . Culture broths were initially tested with 1,2-O-dilauryl-rac-glycero-3-glutaric acid-resorufinyl ester, a chromogenic substrate specific for lipases . Fourteen lipase-producing microorganisms were selected and their taxonomic identification was carried out . Hydrolysis of tributyrin or olive oil and the esterification of oleic acid with heptanol were selected to preliminary evaluate the catalytic activity of these lipases . All the selected lipases catalysed this esterification reaction with good yields . Resolution of (R,S)-2-(4-isobutylphenyl) propionic acid, (R,S)-1-phenylethanol, (R,S) 1-phenylethylamine and of (R) or (S) glycidol were performed to evaluate the stereoselectivity of these novel enzymes as biocatalysts in reactions in organic media . Lipases from the fungi Fusarium oxysporum and Ovadendron sulphureo-ochraceum gave the best yields and enantioselectivities in the resolution of racemic ibuprofen and 1-phenylethanol . Several lipases displayed a high stereoselectivity in the resolution of chiral amines by an alcoxycarbonylation reaction.

Curr Opin Chem Biol, 2001 Feb, 5(1), 67 - 73
Recent advances in large-scale transposon mutagenesis; Hamer L et al.; Transposons were identified as mobile genetic elements over fifty years ago and subsequently became powerful tools for molecular-genetic studies . Recently, transposon-mutagenesis strategies have been developed to identify essential and pathogenicity-related genes in pathogenic microorganisms . Also, a number of in vitro transposition systems have been used to facilitate genome sequence analysis . Finally, transposon mutagenesis of yeast and complex eukaryotes has provided valuable functional genomic information to complement genome-sequencing projects.

J Microbiol Methods, 2001 Feb 1, 44(1), 1 - 11
Sampling with adhesive tape strips: an easy and rapid method to monitor microbial colonization on monument surfaces; Urzi C et al.; An easy and fast non-destructive method for sampling from monument and art object surfaces is proposed . The results obtained after sampling in regions of black spots and discoloration using adhesive tape strips showed that the method is useful for monitoring microbial colonization as well as for the identification of biodeteriogens . This technique is easy to apply, inexpensive and reproducible . The presence of fungi or algae on stone surfaces can be checked at an early stage of colonization or after cleaning procedures, without damage to the sampled surface . In addition, it is possible to obtain information on the morphology and taxonomy of microorganisms, and their relationships with the colonized material surfaces.

Mech Ageing Dev, 2000 Dec 20, 121(1-3), 47 - 58
Interferon-gamma (IFN-gamma) levels finally become stable with increasing age as revealed by using an ELISA corresponding to the bioactivity; Scheffer C et al.; The immune status is a parameter of the capacity of the immune system to fend off microorganisms . The use of leukocyte subtyping to define the immune status is clinically established . IFN-gamma is a key cytokine directing the immune response . In this study, we investigated whether IFN-gamma is a more sensitive parameter of the immune status . All persons tested showed stable quantities of white blood cell counts over the whole study . Analyses of the lymphocyte subpopulations of two time points resulted in a strong correlation with high statistical significance for the percentage of CD3, CD4, CD8, CD19, CD45 -subtypes and CD56/16 positive cells . IFN-gamma production by the individuals correlates between these time points also, but only if an ELISA strongly correlating to IFN-gamma bioactivity was used instead of other commercial IFN-gamma ELISAs . The IFN-gamma production by males was less variable than by females . Furthermore, intraindividual differences in IFN-gamma secretion were minimal after the age of 46 . In conclusion, our data demonstrate that IFN-gamma is a more sensitive parameter for the actual status of the immune system, since its titer shows alterations faster than leukocyte subtyping . Furthermore, leukocyte subtypes do not correspond to the production capacity of the regulatory cytokine IFN-gamma in healthy individuals.

Trends Plant Sci, 2001 Jan, 6(1), 14 - 7
Genetic manipulation of carotenoid biosynthesis: strategies, problems and achievements; Sandmann G; Carotenoids, some of which are provitamin A, have a range of diverse biological functions and actions, especially in relation to human health . For example, carotenoids are known to be crucial for normal vision and have been associated with reducing the risk of several degenerative diseases including cancer . The putative advantage of modifying and engineering the carotenoid biosynthetic pathways is obvious: to provide sources for the isolation of desired carotenoids or to generate food plants with increased carotenoid content . This article reviews the studies of carotenoid production in heterologous microorganisms and the engineering of crop plants using manipulated carotenoid biosynthesis.

Rev Palaeobot Palynol, 2000 Dec, 113(1-3), 1 - 14
Ordovician palynology: balance and future prospects at the beginning of the third millennium; Servais T et al.; Ordovician palynologic studies started in the 1930s when Eisenack first described Palaeozoic "hystrichospheres" (later named acritarchs), and defined the chitinozoans and melanosclerites . During the ensuing two decades, Ordovician palynologic investigations were mostly descriptive . It was the rise of the oil industry in the 1950s and 1960s, which accelerated palynologic research, particularly with the recognition that acritarchs and chitinozoans were biostratigraphically important groups for Ordovician stratigraphy . Today, more than 700 publications deal with Ordovician acritarchs, and about 400 papers concern Ordovician chitinozoans . In addition to these two palynomorph groups, other less important organic-walled microorganisms have been studied . These include plant remains (spores, cuticles), scolecodonts and such enigmatic groups as the melanosclerites and the mazuelloids . This paper summarises the research on Ordovician palynomorphs during the 20th century and looks ahead to the types of research that may be important and most fruitful for Ordovician palynology at the beginning of the new millenium . Particular attention is paid to the C.I.M.P./I.G.C.P . no . 410 joint meeting "Ordovician Palynology and Palaeobotany," held in Prague during the 8th International Symposium on the Ordovician System . A brief account is given concerning the global Ordovician chronostratigraphy and the correlation of the main regional series and stages.

Metab Eng, 2001 Jan, 3(1), 64 - 77
Biosynthesis of natural products on modular peptide synthetases; Doekel S et al.; Microbial nonribosomally processed peptides represent a large class of natural products including numerous important pharmaceutical agents, as well as other representatives that play a prevalent role in pathogenicity of certain microorganisms {M . A . Marahiel, T . Stachelhaus, and H . D . Mootz (1997) . Chem . Rev . 97, 2651-2673} . Although diverse in structure, nonribosomally synthesized peptides have a common mode of biosynthesis . They are assembled on very large protein templates called peptide synthetases that exhibit a modular organization, allowing polymerization of monomers in an assembly-line-like mechanism .

J Clin Microbiol, 2001 Feb, 39(2), 509 - 13
Improved, low-cost selective culture medium for Actinobacillus actinomycetemcomitans; Alsina M et al.; Actinobacillus actinomycetemcomitans is considered to be one of the major oral putative pathogens, especially in cases of juvenile periodontitis . This microorganism requires nutritionally complex media for growth, and therefore the media for its primary isolation usually include blood agar or serum in their base . In this study we present a new medium, Dentaid-1, which improves the detection of A . actinomycetemcomitans in periodontal samples . In its composition, blood and serum have been omitted, hence reducing its cost and making it a more restrictive medium against the growth of other microorganisms with high nutritional requirements . The growth yields of pure cultures of the bacteria on Dentaid-1 were comparable to those on nonselective blood agar . Moreover, clinical efficacy was evaluated in subgingival samples from 77 subjects with adult periodontitis . Dentaid-1 detected A . actinomycetemcomitans in 24 subjects, while a previously described tryptic soy-serum-bacitracin-vancomycin agar detected the microorganism in only 19 subjects (79.1%) . Dentaid-1 is a low-cost, noninhibitory formula for the improved diagnosis and monitoring of patients subgingivally infected by this important oral putative pathogen.

Am J Clin Nutr, 2001 Feb, 73(2 Suppl), 361S - 364S
Probiotics, prebiotics, and synbiotics--approaching a definition; Schrezenmeir J et al.; Definitions of different pro-, pre-, and synbiotics suggested by different investigators are critically discussed . On the basis of this analysis, the probiotic concept is confined to effects exerted by viable microorganisms but is applicable independent of the site of action and route of administration . It therefore may include sites such as the oral cavity, the intestine, the vagina, and the skin.

Appl Environ Microbiol, 2001 Feb, 67(2), 623 - 31
Novel bacterial lineages at the (sub)division level as detected by signature nucleotide-targeted recovery of 16S rRNA genes from bulk soil and rice roots of flooded rice microcosms; Derakshani M et al.; Using a newly developed 16S rRNA gene (rDNA)-targeted PCR assay with proposed group specificity for planctomycetes, we examined anoxic bulk soil of flooded rice microcosms for the presence of novel planctomycete-like diversity . For comparison, oxic rice roots were included as an additional sample in this investigation . The bacterial diversity detectable by this PCR assay was assessed by using a combined approach that included terminal restriction fragment length polymorphism (T-RFLP) analysis and comparative sequence analysis of cloned 16S rDNA . T-RFLP fingerprint patterns generated from rice roots contained 12 distinct terminal restriction fragments (T-RFs) . In contrast, the T-RFLP fingerprint patterns obtained from the anoxic bulk soil contained 33 distinct T-RFs, a clearly higher level of complexity . A survey of 176 bulk soil 16S rDNA clone sequences permitted correlation of 20 T-RFs with phylogenetic information . The other 13 T-RFs remained unidentified . The predominant T-RFs obtained from rice roots could be assigned to members of the genus Pirellula within the Planctomycetales, while most of the T-RFs obtained from the bulk soil corresponded to novel lines of bacterial descent . Using a level of 16S rDNA sequence dissimilarity to cultured microorganisms of approximately 20% as a threshold value, we detected 11 distinct bacterial lineages for which pure-culture representatives are not known . Four of these lineages could be assigned to the order Planctomycetales, while one lineage was affiliated with the division Verrucomicrobia and one lineage was affiliated with the spirochetes . The other five lineages either could not be assigned to any of the main lines of bacterial descent or clearly expanded the known diversity of division level lineages WS3 and OP3 . Our results indicate the presence of bacterial diversity at a subdivision and/or division level that has not been detected previously by the so-called universal 16S rDNA PCR assays.

Appl Environ Microbiol, 2001 Feb, 67(2), 586 - 90
Viability of Giardia intestinalis cysts and viability and sporulation state of Cyclospora cayetanensis oocysts determined by electrorotation; Dalton C et al.; Electrorotation is a noninvasive technique that is capable of detecting changes in the morphology and physicochemical properties of microorganisms . Electrorotation studies are reported for two intestinal parasites, Giardia intestinalis and Cyclospora cayetanensis . It is concluded that viable and nonviable G . intestinalis cysts can be differentiated by this technique, and support for this conclusion was obtained using a fluorogenic vital dye assay and morphological indicators . The viability of C . cayetanensis oocysts (for which no vital dye assay is currently available) can also be determined by electrorotation, as can their sporulation state . Modeling of the electrorotational response of these organisms was used to determine their dielectric properties and to gain an insight into the changes occurring within them . Electrorotation offers a new, simple, and rapid method for determining the viability of parasites in potable water and food products and as such has important healthcare implications.

Stroke, 2001 Feb, 32(2), 385 - 91
Detection of Helicobacter pylori in human carotid atherosclerotic plaques; Ameriso SF et al.; BACKGROUND AND PURPOSE: Several lines of evidence point toward a relationship between infection and atherosclerotic vascular disease . Thus, infection and inflammation often precede ischemic neurological events . Transient alterations in coagulation and direct arterial invasion by certain microorganisms have been reported . Helicobacter pylori infection is the major cause of peptic ulcer disease and appears to be a risk factor for ischemic cerebrovascular disease . However, in contrast to other chronic infectious agents, H pylori has not been consistently isolated from atherosclerotic lesions . METHODS: We investigated the presence of H pylori in 38 atherosclerotic plaques obtained at carotid endarterectomy by using morphological and immunohistochemical techniques and a highly sensitive polymerase chain reaction method . We performed immunohistochemical detection of intercellular adhesion molecule-1, a marker related to inflammatory cell response . We also examined 7 carotid arteries obtained at autopsy from subjects without carotid atherosclerosis . RESULTS: H pylori DNA was found in 20 of 38 atherosclerotic plaques . Ten of the H pylori DNA-positive plaques also showed morphological and immunohistochemical evidence of H pylori infection . None of 7 normal carotid arteries was positive for H pylori . Intercellular adhesion molecule-1 was expressed in 75% of H pylori-positive plaques and in 22% of H pylori-negative plaques . The presence of the microorganism was associated with male sex but was independent of age, vascular risk factor profile, and prior neurological symptoms . CONCLUSIONS: H pylori is present in a substantial number of carotid atherosclerotic lesions and is associated with features of inflammatory cell response . This study provides additional evidence of the relationship between H pylori infection and atherosclerotic disease.

Bioresour Technol, 2001 Jan, 76(2), 85 - 90
Accumulation of poly-beta-hydroxybutyrate in cyanobacterium Synechocystis sp . PCC6803; Wu GF et al.; Accumulation of poly-beta-hydroxybutyrate (PHB) by photoautotrophic microorganisms makes it possible to reduce the production cost of PHB . The Synechocystis sp . PCC6803 cells grown in BG11 medium under balanced, nitrogen-starved or phosphorus-starved conditions were observed by transmission electron microscope . Many electron-transparent granules in the nitrogen-starved cells had a diameter up to 0.8 micron . In contrast, the number of granules in the normally cultured cells decreased obviously and only zero to three much smaller granules were in each cell . These granules were similar to those in bacteria capable of synthesizing PHB . They were proved to be PHB by gas chromatography after subjecting the cells to methanolysis . Effects of glucose as carbon source and light intensity on PHB accumulation in Synechocystis sp . PCC6803 under nitrogen-starved cultivation were further studied . Glucose and illumination promoted cell growth but did not favor PHB synthesis . After 7 days of growth under nitrogen-starved photoautotrophic conditions, the intracellular level of PHB was up to 4.1% of cellular dry weight and the PHB concentration in the culture broth was 27 mg/l.

J Virol, 2000 May, 74(9), 4028 - 38
Establishment and characterization of molecular clones of porcine endogenous retroviruses replicating on human cells; Czauderna F et al.; The use of pig xenografts is being considered to alleviate the shortage of allogeneic organs for transplantation . In addition to the problems overcoming immunological and physiological barriers, the existence of numerous porcine microorganisms poses the risk of initiating a xenozoonosis . Recently, different classes of type C porcine endogenous retoviruses (PERV) which are infectious for human cells in vitro have been partially described . We therefore examined whether completely intact proviruses exist that produce infectious and replication-competent virions . Several proviral PERV sequences were cloned and characterized . One molecular PERV class B clone, PERV-B(43), generated infectious particles after transfection into human 293 cells . A second clone, PERV-B(33), which was highly homologous to PERV-B(43), showed a G-to-A mutation in the first start codon (Met to Ile) of the env gene, preventing this provirus from replicating . However, a genetic recombinant, PERV-B(33)/ATG, carrying a restored env start codon, became infectious and could be serially passaged on 293 cells similar to virus clone PERV-B(43) . PERV protein expression was detected 24 to 48 h posttransfection (p . t.) using cross-reacting antiserum, and reverse transcriptase activity was found at 12 to 14 days p.t . The transcriptional start and stop sites as well as the splice donor and splice acceptor sites of PERV mRNA were mapped, yielding a subgenomic env transcript of 3 . 1 kb . PERV-B(33) and PERV-B(43) differ in the number of copies of a 39-bp segment in the U3 region of the long terminal repeat . Strategies to identify and to specifically suppress or eliminate those proviruses from the pig genome might help in the production of PERV-free animals.

Life Sci, 2000 Feb 25, 66(14), 1359 - 67
Mycelial protoplast isolation and regeneration of Lentinus lepideus; Kim BK et al.; Generation of fungal protoplast is essential for fusion and transformation systems . Protoplast fusion offers great potential for the improvement of industrially important microorganisms . To establish conditions for the protoplast isolation and regeneration of the mycelia of Lentinus lepideus, various enzymes and osmotic stabilizers were examined . To investigate suitable medium for the culture of L . lepideus, the mycelia were grown in ten different media at 28 degrees C for 10 days . Among them potato dextrose agar (PDA) medium was found to be the best for colony growth . When Novozym 234, cellulase and beta-glucuronidase were added to the mycelia in combination or alone, Novozym 234 alone at the concentration of 10 mg/ml was the most effective for the protoplast yield . Purified spherical protoplasts of the mycelia were osmotically hypersensitive and further incubation of the mycelia with the lytic enzyme resulted in the older parts of the hyphae swollen . When we applied various osmotic stabilizers at the fixed concentration of 0.6 M on the protoplasts, the yields of protoplasts were increased until 4-hr incubation . However application of sucrose or MgSO4 led to further protection of protoplasts after that time and reached a plateau on 5- and 7-hr incubations, respectively . The suitable incubation time and optimal pH with the lytic enzyme for the maximum release of protoplasts were 6 hrs of incubation and pH 5, respectively . When we examined various osmotic stabilizers for the regeneration of the protoplast, the complete medium containing 0.6 M sucrose induced highest hyphal growth with regeneration frequency of 3.28%.

J Immunol, 2000 Apr 15, 164(8), 4229 - 34
Nitric oxide mediates intestinal pathology but not immune expulsion during Trichinella spiralis infection in mice; Lawrence CE et al.; The relationship between intestinal pathology and immune expulsion of gastrointestinal (GI) nematodes remains controversial . Although immune expulsion of GI helminth parasites is usually associated with Th2 responses, the effector mechanisms directly responsible for parasite loss have not been identified . We have previously shown that while the intestinal pathology accompanying the expulsion of the GI parasite Trichinella spiralis may be dependent on IL-4 and mediated by TNF, parasite loss is independent of TNF . In contrast, intestinal pathology in other disease models has been attributed to Th1 cytokines, although it closely resembles that seen in helminth infections . Whereas production of inducible NO synthase (iNOS) in the gut is important for both homeostasis of the epithelial layer and in protection against pathogenic microorganisms, overproduction of NO has been implicated in the pathogenesis of a number of inflammatory conditions . We therefore investigated the role of NO in T . spiralis infection using iNOS-deficient mice . iNOS-/- and iNOS-/+ mice were infected with T . spiralis, and parasite expulsion and intestinal pathology were followed . Parasite expulsion proceeded similarly in both groups of animals, but significant intestinal pathology was only observed in the heterozygous mice . Thus it appears that, although the protective effects of Th2 responses in GI helminth infection do not require NO, this mediator contributes substantially to the associated enteropathy . NO may therefore be an important mediator of enteropathy in both Th1- and Th2-inducing conditions.

Curr Opin Biotechnol, 2000 Apr, 11(2), 209 - 14
Metabolic engineering and directed evolution for the production of pharmaceuticals; Chartrain M et al.; The tools of metabolic and enzyme engineering have been well developed in academic laboratories and are now being applied for the optimization of biocatalysts used in the production of a wide range of pharmaceutically important molecules . Engineered microorganisms with a diverse set of modified or non-native enzyme activities are being used both to generate novel products and to provide improved processes for the manufacture of established products, such as in the production of precursors, intermediates, and complete compounds of importance to the pharmaceutical industry, including polyketides, nonribosomal peptides, steroids, vitamins, and unnatural amino acids . The use of directed evolution has rapidly emerged to be the method of choice for the development and selection of mutated enzymes with improved properties . A variety of such methods have been used to alter the activity, stability and availability of an array of enzymes . The industrial practice of these technologies at large scale is, however, in its infancy and stands as an exciting challenge for process scientists today.

J Agric Food Chem, 1998 Jan 19, 46(1), 206 - 210
Effects of Microwave Heating on the Loss of Vitamin B(12) in Foods; Watanabe F et al.; To clarify the effects of microwave heating on the loss of vitamin B(12) in foods, raw beef, pork, and milk were treated by microwave heating and then their vitamin B(12) contents were determined according to a chemiluminescent vitamin B(12) assay with hog intrinsic factor . Appreciable loss ( approximately 30-40%) of vitamin B(12) occurred in the foods during microwave heating due to the degradation of vitamin B(12) molecule by microwave heating . When hydroxo vitamin B(12), which predominates in foods, was treated by microwave heating and then analyzed by silica gel 60 thin layer chromatography, two vitamin B(12) degradation products were found . One of the compounds with a R(f)() of 0.16 was purified and partially characterized . The vitamin B(12) degradation product did not show any biological activity in the growth of a vitamin B(12) requiring microorganism, Euglena gracilis Z, and was not bound to hog intrinsic factor, a mammalian vitamin B(12) binding protein . Intravenous administration of the compound (1 microg/day) for 7 days to rats showed that the compound neither has toxicity nor acts as a vitamin B(12) antagonist in mammals . These results indicate that the conversion of vitamin B(12) to the inactive vitamin B(12) degradation products occurs in foods during microwave heating.

Oral Microbiol Immunol, 2000 Oct, 15(5), 335 - 7
Detection of Treponema denticola in endodontic infections by 16S rRNA gene-directed polymerase chain reaction; Siqueira JF Jr et al.; A 16S rDNA-based polymerase chain reaction (PCR) method was used to detect the occurrence of Treponema denticola in root canal infections . Samples were collected from 21 single-root teeth having carious lesions, necrotic pulps and radiographic evidences of periradicular bone loss . DNA extracted from the samples was amplified using the PCR assay, which yielded specific fragment of T . denticola 16S rDNA . T . denticola was detected in 11 of 21 cases (52.4%), regardless of the presence or absence of symptoms . Since this spirochete was found in a relatively high percentage of the endodontic infections examined and because it is a pathogenic microorganism involved in periodontal diseases, there are reasons to believe that T . denticola can also participate in the pathogenesis of periradicular lesions of endodontic origin.

Oral Microbiol Immunol, 2000 Jun, 15(3), 181 - 7
Polarization of Porphyromonas gingivalis-specific helper T-cell subsets by prior immunization with Fusobacterium nucleatum; Choi JI et al.; Antigen-specific T-cell clones were obtained from mice immunized with Fusobacterium nucleatum ATCC 10953 and/or Porphyromonas gingivalis 381 . 10 BALB/c mice per group were immunized with F . nucleatum followed by P . gingivalis, or with P . gingivalis alone by intraperitoneal injection of viable microorganisms . Spleen T cells were isolated and stimulated in vitro with viable P . gingivalis cells to establish P . gingivalis-specific T-cell clones . T-cell phenotypes and cytokine profiles were determined along with T-cell responsiveness to F . nucleatum or P . gingivalis . Serum immunoglobulin G antibody titers to F . nucleatum or P . gingivalis were also determined by enzyme-linked immunosorbent assay . All the T-cell clones derived from mice immunized with F . nucleatum followed by P . gingivalis demonstrated Th2 subsets, while those from mice immunized with P . gingivalis alone demonstrated Th1 subsets based on the flow cytometric analysis and cytokine profiles . All T-cell clones from both groups were cross-reactive to both P . gingivalis and F . nucleatum antigens . Phenotypes of T-cell clones were all positive for CD4 . Mean post-immune serum IgG antibody levels to F . nucleatum or P . gingivalis were significantly higher than the pre-immune levels (P < 0.05, P < 0.01, respectively) . There were no significant differences in the antibody titers between the two groups . It was concluded that P . gingivalis-specific T cells initially primed by cross-reactive F . nucleatum antigens were polarized to Th2 subset, while T cells stimulated with P . gingivalis alone maintained the profile of Th1 subset.

Biologist (London), 2000 Sep, 47(4), 194 - 6
Talking rot .. . and mildew on textiles; Hamlyn PF et al.; Nature has evolved some very elegant elementary mechanisms for re-cycling of organic substances in the environment . These processes are normally beneficial . This article describes why microorganisms may attack textiles during production and in use, causing financial losses, and what can be done to prevent this happening.

J Mol Biol, 2001 Jan 19, 305(3), 481 - 90
The molecular mechanism of sulfated carbohydrate recognition by the cysteine-rich domain of mannose receptor; Liu Y et al.; The mannose receptor (MR) binds foreign and host ligands through interactions with their carbohydrates . Two portions of MR have distinct carbohydrate recognition properties . One is conferred by the amino-terminal cysteine-rich domain (Cys-MR), which plays a critical role in binding sulfated glycoproteins including pituitary hormones . The other is achieved by tandemly arranged C-type lectin domains that facilitate carbohydrate-dependent uptake of infectious microorganisms . This dual carbohydrate binding specificity enables MR to bind ligands by interacting with both sulfated and non-sulfated polysaccharide chains . We previously determined crystal structures of Cys-MR complexed with 4-SO(4)-N-acetylglucosamine and with an unidentified ligand resembling Hepes (N-{2-hydroxyethyl}piperazine-N'-{2-ethanesulfonic acid}) . In continued efforts to elucidate the mechanism of sulfated carbohydrate recognition by Cys-MR, we characterized the binding affinities between Cys-MR and potential carbohydrate ligands using a fluorescence-based assay . We find that Cys-MR binds sulfated carbohydrates with relatively high affinities (K(D)=0.1 mM to 1.0 mM) compared to the affinities of other lectins . Cys-MR also binds Hepes with a K(D) value of 3.9 mM, consistent with the suggestion that the ligand in the original Cys-MR crystal structure is Hepes . We also determined crystal structures of Cys-MR complexed with 3-SO(4)-Lewis(x), 3-SO(4)-Lewis(a), and 6-SO(4)-N-acetylglucosamine at 1.9 A, 2.2 A, and 2.5 A resolution, respectively, and the 2.0 A structure of Cys-MR that had been treated to remove Hepes . The conformation of the Cys-MR binding site is virtually identical in all Cys-MR crystal structures, suggesting that Cys-MR does not undergo conformational changes upon ligand binding . The structures are used to rationalize the binding affinities derived from the biochemical studies and to elucidate the molecular mechanism of sulfated carbohydrate recognition by Cys-MR .

FEBS Lett, 2000 Dec 29, 487(2), 199 - 202
Intracellular trehalose improves osmotolerance but not desiccation tolerance in mammalian cells; Garcia de Castro A et al.; Trehalose has been shown to play a role in osmotolerance or desiccation tolerance in some microorganisms, anhydrobiotic invertebrates and resurrection plants . To test whether trehalose could improve stress responses of higher eukaryotes, a mouse cell line was genetically engineered to express bacterial trehalose synthase genes . We report that the resulting levels of intracellular trehalose ( approximately 80 mM) are able to confer increased resistance to the partial dehydration resulting from hypertonic stress, but do not enable survival of complete desiccation due to air drying.

Gastroenterol Hepatol, 2000 Dec, 23(10), 474 - 6
{Mycobacterium chelonae and solitary rectal ulcer}; Rodriguez JC et al.; Solitary rectal ulcer is of varied etiology and the appearance of this syndrome due to Mycobacterium chelonae is exceptional . We present a case of a solitary rectal ulcer associated with Mycobacterium chelonae subspecies chelonae in an immunocompetent individual . This microorganism is involved in cutaneous, ocular, pulmonary and soft tissue infections . Treatment of infections has traditionally been surgical, although various antibiotic treatments have been used depending on the sensitivity of the microorganism, the severity of the infection and the surgical possibilities.

Arch Biochem Biophys, 2000 Dec 1, 384(1), 9 - 23
Structural basis for recognition of dipeptides by peptide transporters; Payne JW et al.; Our objective in this work was to identify the structural basis for the molecular recognition of peptides by peptide transporters . Various assays for dipeptide transport by the dipeptide and tripeptide permeases of Escherichia coli were performed, together with measurements of thermodynamic parameters of substrate binding to the dipeptide binding protein using isothermal titration calorimetry . Computer-based conformational analysis of the test dipeptides was performed to define the repertoire of conformers that each dipeptide adopts in solution . Strict correlations were identified between the complement of particular conformers adopted by a peptide and its bioactivity as a substrate for each transporter . Details of the structural and electronic parameters that define the molecular recognition templates (MRTs) of the dipeptide substrates of these transporters are presented; similar MRTs are likely to apply with dipeptidases . These MRTs provide the essential information for the rational design of peptide-based drugs tailored for exploitation of peptide transporters in microorganisms and man.

Mil Med, 2000 Nov, 165(11), 816 - 20
Feasibility determination for use of polymerase chain reaction in the U.S . Air Force air-transportable hospital field environment: lessons learned; Niemeyer DM et al.; At present, the use of molecular probes and polymerase chain reaction (PCR) for the identification of microorganisms in body fluids or tissues is becoming more commonplace . There is an added advantage when serological or culture methods are difficult, expensive, or unavailable . Slow-growing or fastidious microorganisms, including Mycobacterium tuberculosis, spirochetes, viruses, and the dimorphic fungi, can be detected rapidly using these techniques . The presence of different chromosomal or plasmid-mediated antibiotic-resistant markers can also be determined . PCR is an extremely powerful tool that has been applied to research, and more recently it has been used to augment standard clinical applications . It is a very simple process that can amplify nucleic acid sequences, both DNA and RNA, a million times over . The sensitivity, rapidity, broad applicability, and compactness of this technology make it an ideal candidate for use in the military arena . We recently established a molecular biology laboratory at a Deployable Medical System at the Camp Parks Army Reserve Training Facility in Dublin, California . This article will briefly summarize the use of PCR and its applicability in the air-transportable hospital field environment . Proper handling, processing, and testing as well as the requirements for setting up a molecular biology laboratory will be discussed . Finally, the benefits and disadvantages of using PCR-based techniques in the deployed field environment will be considered.

Mem Inst Oswaldo Cruz, 2000, 95 Suppl 1, 141 - 4
Immunocompromised host: from the early events until the impact of acquired immunodeficiency syndrome; da Costa SC; The concept that microorganisms can modulate the host resistance was historically reviewed in the present article . The importance of African trypanosomiasis in the development of the research on immunosuppression as well as the impact of human immunodeficiency virus infection are discussed . Each day new opportunistic organisms establish a constant challenge for the correct diagnosis of concomitant infections in acquired immunodeficiency syndrome . The importance of parasite infection in the balance of host resistance in the third world was emphasized . Finally, some aspects of Leishmania as opportunistic organisms were presented.

Int J Fertil Womens Med, 2000 Nov-Dec, 45(6), 358 - 67
Vaginal infection: prophylaxis and perinatal outcome--a review of the literature; Oleszczuk JJ et al.; Vaginal discharge is the symptom that most often prompts a woman to consult a physician in order to determine the presence of an infection . However, much vaginal infection, particularly bacterial vaginosis, is nearly asymptomatic . In all cases, diagnosis is based on evaluation of the vaginal ecosystem and demonstration of the presence of the suspected microorganism . Besides bacteria, fungi (Candida) and protozoans (Trichomonas) are very common pathogens and produce characteristic findings . When present during pregnancy, these infections have been linked to low birth weight and obstetric disorders . There is a great need for a full understanding of the connection between what appears to be "normal" discharge in pregnancy and important adverse perinatal outcomes.

Nucleic Acids Res, 2001 Jan 15, 29(2), 545 - 52
A phylogenomic approach to microbial evolution; Sicheritz-Ponten T et al.; To study the origin and evolution of biochemical pathways in microorganisms, we have developed methods and software for automatic, large-scale reconstructions of phylogenetic relationships . We define the complete set of phylogenetic trees derived from the proteome of an organism as the phylome and introduce the term phylogenetic connection as a concept that describes the relative relationships between taxa in a tree . A query system has been incorporated into the system so as to allow searches for defined categories of trees within the phylome . As a complement, we have developed the pyphy system for visualising the results of complex queries on phylogenetic connections, genomic locations and functional assignments in a graphical format . Our phylogenomics approach, which links phylogenetic information to the flow of biochemical pathways within and among microbial species, has been used to examine more than 8000 phylogenetic trees from seven microbial genomes . The results have revealed a rich web of phylogenetic connections . However, the separation of Bacteria and Archaea into two separate domains remains robust.

Int J Food Microbiol, 2000 Dec 5, 62(1-2), 113 - 21
Presence and changes in populations of yeasts on raw and processed poultry products stored at refrigeration temperature; Ismail SA et al.; A study was undertaken to determine populations and profiles of yeast species on fresh and processed poultry products upon purchase from retail supermarkets and after storage at 5 degrees C until shelf life expiration, and to assess the potential role of these yeasts in product spoilage . Fifty samples representing 15 commercial raw, marinated, smoked, or roasted chicken and turkey products were analyzed . Yeast populations were determined by plating on dichloran rose bengal chloramphenicol (DRBC) agar and tryptone glucose yeast extract (TGY) agar . Proteolytic activity was determined using caseinate and gelatin agars and lipolytic activity was determined on plate count agar supplemented with tributyrin . Populations of aerobic microorganisms were also determined . Initial populations of yeasts (log10 cfu/g) ranged from less than 1 (detection limit) to 2.89, and increased by the expiration date to 0.37-5.06, indicating the presence of psychrotrophic species . Highest initial populations were detected in raw chicken breast, wings, and ground chicken, as well as in turkey necks and legs, whereas roasted chicken and turkey products contained less than 1 log10 cfu/g . During storage, yeast populations increased significantly (P < or = 0.05) in whole chicken, ground chicken, liver, heart and gizzard, and in ground turkey and turkey sausage . Isolates (152 strains) of yeasts from poultry products consisted of 12 species . Yarrowia lipolytica and Candida zeylanoides were predominant, making up 39 and 26% of the isolates, respectively . Six different species of basidiomycetous yeasts representing 24% of the isolates were identified . Most Y . lipolytica strains showed strong proteolytic and lipolytic activities, whereas C . zeylanoides was weakly lipolytic . Results suggest that yeasts, particularly Y . lipolytica, may play a more prominent role than previously recognized in the spoilage of fresh and processed poultry stored at 5 degrees C.

Chem Biol, 2000 Dec, 7(12), 931 - 42
Biosynthesis of L-p-hydroxyphenylglycine, a non-proteinogenic amino acid constituent of peptide antibiotics; Hubbard BK et al.; BACKGROUND: The non-proteinogenic amino acid p-hydroxyphenylglycine is a crucial component of certain peptidic natural products synthesized by a non-ribosomal peptide synthetase mechanism . In particular, for the vancomycin group of antibiotics p-hydroxyphenylglycine plays a structural role in formation of the rigid conformation of the central heptapeptide aglycone in addition to being the site of glycosylation . Initial labeling studies suggested tyrosine was a precursor of p-hydroxyphenylglycine but the specific steps in p-hydroxyphenylglycine biosynthesis remained unknown . Recently, the sequencing of the chloroeremomycin gene cluster from Amycolatopsis orientalis gave new insights into the biosynthetic pathway and allowed for the prediction of a four enzyme pathway leading to L-p-hydroxyphenylglycine from the common metabolite prephenate . RESULTS: We have characterized three of the four proposed enzymes of the L-p-hydroxyphenylglycine biosynthetic pathway . The three enzymes are encoded by open reading frames (ORFs) 21, 22 and 17 (ORF21: {PCZA361.1, O52791, CAA11761}; ORF22: {PCZA361 . 2, O52792, CAA11762}; ORF17: {PCZA361.25, O52815, CAA11790}), of the chloroeremomycin biosynthetic gene cluster and we show they have p-hydroxymandelate synthase, p-hydroxymandelate oxidase and L-p-hydroxyphenylglycine transaminase activities, respectively . CONCLUSIONS: The L-p-hydroxyphenylglycine biosynthetic pathway shown here is proposed to be the paradigm for how this non-proteinogenic amino acid is synthesized by microorganisms incorporating it into peptidic natural products . This conclusion is supported by the finding of homologs for the four L-p-hydroxyphenylpyruvate biosynthetic enzymes in four organisms known to synthesize peptidic natural products that contain p-hydroxyphenylglycine . Three of the enzymes are proposed to function in a cyclic manner in vivo with L-tyrosine being both the amino donor for L-p-hydroxyphenylglycine and a source of p-hydroxyphenylpyruvate, an intermediate in the biosynthetic pathway.

Rapid Commun Mass Spectrom, 2001, 15(1), 50 - 6
Automated nanoflow liquid chromatography/tandem mass spectrometric identification of proteins from Shewanella putrefaciens separated by two-dimensional polyacrylamide gel electrophoresis; Devreese B et al.; The implementation of nanoflow liquid chromatography offers unique opportunities for automation of proteomics research . We demonstrate that automated nanoflow LC/MS/MS allowed the unambiguous identification of proteins from the omnipotent bacterium Shewanella putrefaciens, based on similarity searches against the completely determined genome of related microorganisms and against non-redundant databases . Total protein extracts were separated by 2-dimensional polyacrylamide electrophoresis . Only 1/20th of a tryptic digest mixture obtained from a single Coomassie Blue stained spot was loaded on the nanoflow LC column using a preconcentration/desalting step, and analyzed on-line on a hybrid quadrupole time-of-flight mass spectrometer with an automated MS-to-MS/MS switching protocol . This method allowed the de novo peptide sequence determination of several tryptic fragments and the identification of different proteins . Copyright

Appl Environ Microbiol, 2001 Jan, 67(1), 51 - 8
Aspects of bioavailability of mercury for methylation in pure cultures of Desulfobulbus propionicus (1pr3); Benoit JM et al.; We have previously hypothesized that sulfide inhibits Hg methylation by decreasing its bioavailability to sulfate-reducing bacteria (SRB), the important methylators of Hg in natural sediments . With a view to designing a bioassay to test this hypothesis, we investigated a number of aspects of Hg methylation by the SRB Desulfobulbus propionicus, including (i) the relationship between cell density and methylmercury (MeHg) production, (ii) the time course of Hg methylation relative to growth stage, (iii) changes in the bioavailability of an added inorganic Hg (Hg(I)) spike over time, and (iv) the dependence of methylation on the concentration of dissolved Hg(I) present in the culture . We then tested the effect of sulfide on MeHg production by this microorganism . These experiments demonstrated that under conditions of equal bioavailability, per-cell MeHg production was constant through log-phase culture growth . However, the methylation rate of a new Hg spike dramatically decreased after the first 5 h . This result was seen whether methylation rate was expressed as a fraction of the total added Hg or the filtered Hg(I) concentration, which suggests that Hg bioavailability decreased through both changes in Hg complexation and formation of solid phases . At low sulfide concentration, MeHg production was linearly related to the concentration of filtered Hg(I) . The methylation of filtered Hg(I) decreased about fourfold as sulfide concentration was increased from 10(-6) to 10(-3) M . This decline is consistent with a decrease in the bioavailability of Hg(I), possibly due to a decline in the dissolved neutral complex, HgS(0).

Curr Microbiol, 2001 Feb, 42(2), 73 - 7
Biosynthesis of threonine from homoserine by mixed rumen microorganisms: an in vitro study; Or-Rashid MM et al.; The biosynthesis of threonine (Thr) by using the main biosynthetic pathway involving homoserine (Hser) was quantitatively investigated by mixed rumen bacteria (B), protozoa (P), and their mixture (BP) in an in vitro system . Rumen contents were collected from fistulated goats to prepare the microbial suspensions and were incubated anaerobically at 39 degrees C for 12 h with or without Hser (2 mm) as a substrate . Thr and other related compounds produced in both the supernatants and hydrolysates of the incubation were analyzed by HPLC . During a 12-h incubation period, 84.2%, 58.1%, and 92.0% of Hser disappeared in B, P, and BP suspensions, respectively . Rumen bacteria and the mixture of rumen bacteria and protozoa were demonstrated for the first time to produce Thr from Hser, and the production of Thr from Hser in BP (371.9 and 297.2 micromol/g MN) (MN, microbial nitrogen) was about 13.0% and 9.1% higher than that in B alone (329.2 and 272.5 micromol/g MN) during 6- and 12-h incubations, respectively . On the other hand, mixed rumen protozoa were unable to synthesize Thr from Hser . Other metabolites produced from Hser were found to be glycine (Gly) and 2-aminobutyric acid (2AB) in B and BP . In P, Gly and 2AB were not found . The results mentioned above indicated the abilities of rumen bacteria and the mixture of rumen bacteria and protozoa to synthesize Thr de novo from Hser and appeared as first-time report.

J UOEH, 2000 Dec 1, 22(4), 339 - 49
{A survey on contamination by microorganisms and the effect of handwashing by doctors and nurses at the UOEH Hospital}; Ogawa M et al.; Handwashing is very basic and important in controlling nosocomial infection . We researched the effect of handwashing by doctors and nurses at the UOEH Hospital . One hundred and eight doctors and 114 nurses of 19 wards were examined . The number of bacteria was determined by a palm stamp check agar plate for general bacteria before and after handwashing . The difference in the condition of microorganism contamination among the wards was found by the number of bacteria before handwashing, and by comparing the number of bacteria before and after handwashing, the effect of handwashing was determined . Handwashing by water or soap is not effective in killing bacteria . Therefore, we suggest that doctors and nurses use an effective disinfectant when washing their hands before and after contact with patients . We also think that the results noted in this paper will help doctors and nurses to have a better understanding of the importance of infection control.

Transgenic Res, 2000, 9(4-5), 323 - 43; discussion 321
Engineering the plant cell factory for secondary metabolite production; Verpoorte R et al.; Plant secondary metabolism is very important for traits such as flower color, flavor of food, and resistance against pests and diseases . Moreover, it is the source of many fine chemicals such as drugs, dyes, flavors, and fragrances . It is thus of interest to be able to engineer the secondary metabolite production of the plant cell factory, e.g . to produce more of a fine chemical, to produce less of a toxic compound, or even to make new compounds, Engineering of plant secondary metabolism is feasible nowadays, but it requires knowledge of the biosynthetic pathways involved . To increase secondary metabolite production different strategies can be followed, such as overcoming rate limiting steps, reducing flux through competitive pathways, reducing catabolism and overexpression of regulatory genes . For this purpose genes of plant origin can be overexpressed, but also microbial genes have been used successfully . Overexpression of plant genes in microorganisms is another approach, which might be of interest for bioconversion of readily available precursors into valuable fine chemicals . Several examples will be given to illustrate these various approaches . The constraints of metabolic engineering of the plant cell factory will also be discussed . Our limited knowledge of secondary metabolite pathways and the genes involved is one of the main bottlenecks.

Cell Mol Life Sci, 2000 Apr, 57(4), 569 - 78
Epitope mimics and determinant spreading: pathways to autoimmunity; Farris AD et al.; Infectious microorganisms have evolved molecules which mimic the host in order to aid in their undetected propagation . In response, mammalian hosts have evolved a highly diverse immune repertoire designed to eradicate rapidly changing pathogens . The generation of diversity in the immune repertoire results in potentially damaging self cross-reactivities which require multiple regulatory controls to keep autoreactive lymphocytes in check . Here, we review how molecular mimicry at the T cell level might be important in the development of systemic autoimmunity.

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