Microorganism

Biol Sci Space, 1996 Dec, 10(4), 271 - 82
{Way to the detection of Mars life}; Kawasaki Y; In this review, I would like to introduce how we can detect the possible life on Mars . Even though the quantitative estimation of the possibility of biogenesis on Mars is difficult, Dr . McKay and his colleagues work has thrown a tiny light for this possibility . Considering Mars environmental conditions, the possible life is microorganisms . The detection of microorganisms in natural environments is not easy even on Earth due to the premature detection technique . We have developed a method based on the fluorescence microscopic technique . This method proved to be successful for the detection of terrestrial microorganisms . Even some pre-biotic cells can be detected . We are developing a miniature detection apparatus which meet the required standard for installing on the Mars landers . We also propose the ground based experiments using Martian meteorites or pseudo-Martian rocks.

Adv Space Res, 1994 Nov, 14(11), 383 - 6
The structure and function of microbial communities in recirculating hydroponic systems; Garland JL; Strategies to control the microbial community associated with plant growth systems need to be based on a fundamental understanding of the factors which structure and regulate the community . Spatial and temporal patterns in the abundance and production rate of microorganisms in hydroponic systems containing wheat were examined to evaluate how root-derived carbon is processed . The relevance of results to monitoring and control strategies is discussed.

Adv Space Res, 1994 Nov, 14(11), 367 - 75
Control of microorganisms in flowing nutrient solutions; Evans RD; Controlling microorganisms in flowing nutrient solutions involves different techniques when targeting the nutrient solution, hardware surfaces in contact with the solution, or the active root zone . This review presents basic principles and applications of a number of treatment techniques, including disinfection by chemicals, ultrafiltration, ultrasonics, and heat treatment, with emphasis on UV irradiation and ozone treatment . Procedures for control of specific pathogens by nutrient solution conditioning also are reviewed.

Adv Space Res, 1994 Nov, 14(11), 349 - 55
Identification and origin of plant pathogenic microorganisms in recirculating nutrient solutions; Stanghellini ME et al.; Avoidance of root-infecting microorganisms was originally considered one of the advantages of cultivation of crops in a soilless, recirculating nutrient solution . However, to date, four viral, three bacterial and 21 fungal pathogens have been identified as causal agents of root disease in hydroponically-grown crops . Root-infecting fungi, particularly those which produce a motile stage known as a zoospore, have been the primary pathogens associated with extensive crop losses . Documented sources of these root pathogens in hydroponic systems include peat, surface water such as rivers and streams, and insects . The severity of disease caused by these introduced root pathogens is primarily governed by the genetic susceptibility of each crop and the temperature of the recirculating nutrient solution.

Adv Space Res, 1994 Oct, 14(10), 389 - 93
Dictyostelium discoideum, a lower eukaryote model for the study of DNA repair: implications for the role of DNA-damaging chemicals in the evolution of repair proficient cells; Deering RA; The evolution of the ability of living cells to cope with stress is crucial for the maintenance of their genetic integrity . Yet low levels of mutation must remain to allow adaptation to environmental changes . The cellular slime mold D . discoideum is a good system for studying molecular aspects of the repair of lethal and mutagenic damage to DNA by radiation and chemicals . The wild-type strains of this soil microorganism are extremely resistant to DNA damaging agents . In nature the amoeboid cells in their replicative stage feed on soil bacteria and are exposed to numerous DNA-damaging chemicals produced by various soil microorganisms . It is probable that the evolution of repair systems in this organism and perhaps in others is a consequence of the necessity to cope with chemical damage which also confers resistance to radiation.

Food Technol, 1994 Sep, 48(9), 113 - 22, 127, 204
Conditions and constraints of food processing in space; Fu B et al.; NASA: Requirements and constraints of food processing in space include a balanced diet, food variety, stability for storage, hardware weight and volume, plant performance, build-up of microorganisms, and waste processing . Lunar, Martian, and space station environmental conditions include variations in atmosphere, day length, temperature, gravity, magnetic field, and radiation environment . Weightlessness affects fluid behavior, heat transfer, and mass transfer . Concerns about microbial behavior include survival on Martian and lunar surfaces and in enclosed environments . Many present technologies can be adapted to meet space conditions .

J Paleolimnol, 1994, 10, 85 - 114
Paleolimnology of the McMurdo Dry Valleys, Antarctica; Doran PT et al.; The McMurdo Dry Valleys presently contain more than 20 permanent lakes and ponds, which vary markedly in character . All, with the exception of a hypersaline pond, have a perennial ice-cover . The dry valley lakes, and lakes in other ice-free regions of continental Antarctica, are unique on this planet in that they consistently maintain a thick year-round ice cover (2.8-6.0 m) over liquid water . The persistent ice covers minimize wind-generated currents and reduce light penetration, as well as restricting sediment deposition into a lake and the exchange of atmospheric gases between the water column and the atmosphere . From a paleolimnological perspective, the dry valley lakes offer an important record of catchment and environmental changes . These lakes are also modern-day equivalents of periglacial lakes that were common during glacial periods at temperate latitudes . The present lakes are mostly remnants of larger glacial lakes that occupied the valleys in the past, perhaps up to 4.6 Ma ago . Two of the valleys contain evidence of being filled with large glacial lakes within the last 10000 years . Repeated drying and filling events since then have left a characteristic impression on the salt profiles of some lakes creating a unique paleo-indicator within the water column . These events are also marked in the sediments by the concentration and dilution of certain chemical constituents, particularly salts, and are also corroborated by carbonate speciation and oxygen isotope analysis . Stratigraphic analysis of dry valley lake sediments is made difficult by the occurrence of an 'old carbon' reservoir creating spurious radiocarbon dates, and by the high degree of spatial variability in lake sedimentation . From a biological perspective, the lakes are relatively simple, containing various taxa of planktonic and benthic microorganisms, but no higher forms of life, which is an advantage to paleolimnologists because there is no bioturbation in the sediments . Useful biological paleo-indicators found in the sediments include cyanobacterial filament sheaths, diatom frustules and other eukaryotic algal cells, protozoan cysts, photosynthetic pigments, and minerals (e.g . carbonates) associated with microbial activity . Future work will benefit from fully characterizing the connection between the ice covers, environmental conditions, and paleo-indicators, thereby allowing refinement of inferences made concerning the paleoenvironment . New dating techniques need to be tested in this environment to overcome the problems associated with radiocarbon dating . The establishment of a detailed and focused paleolimnological campaign is proposed.

Geochim Cosmochim Acta, 1989, 53, 619 - 32
Reactive iron in marine sediments; Canfield DE; A combined field/laboratory study has been undertaken to explore the mineralogy, concentrations and reactivity (towards sulfide) of iron in marine sediments . Also considered is the importance of bacterial Fe liberation in regulating pore-water chemistry . Two contrasting marine environments are included; one is the relatively Fe-poor FOAM site and the other is the Fe-rich sediments of the subaqueous Mississippi Delta . Results show that oxide minerals are the most important Fe phases in early diagenetic pyrite formation . However, viewed separately, lepidocrocite and ferrihydrite are more reactive towards sulfide than goethite and hematite . When Fe oxides are present in relatively high concentrations, dissolved sulfide is nearly absent from sediment pore waters (with concomitant high concentrations of dissolved Fe), even in the presence of active sulfide production by sulfate reduction . A combination of experimental results and diagenetic modelling shows that in some sediments pore water Fe finds it origin in the bacterial reduction of iron oxides . This seems the case even though greater amounts of Fe are reduced by reaction of sulfide with iron oxides . It appears that distinct microenvironments may exist in marine sediments, where, in one microenvironment, sulfide reacts with Fe oxides locally precipitating Fe sulfide minerals . In another, Fe reduced and solubilized by microorganisms migrates freely into solution.

Polar Biol, 1985, 4, 19 - 25
The cryptoendolithic microbial environment in the Antarctic cold desert: temperature variations in nature; McKay CP et al.; In the Antarctic cold desert, cryptoendolithic microorganisms live under the surface of porous sandstone rocks . During the austral summer, the environment of the near-surface rock layers colonized by organisms is characterized by two kinds of temperature oscillations, both occurring across the freezing point . Low-frequency (diurnal) and large-amplitude (up to about 20 degrees C) oscillations on the sunlit surface of rocks result in a daily freeze-thaw cycle . This is a result of the diurnal changes in the sun altitude and angle with respect to the rock surface . The biological effect of this oscillation is the regulation of the onset and cessation of metabolic activity . The high-frequency (few minutes) oscillations occur only under certain weather conditions (sunny days with light winds) and are superimposed on the low-frequency oscillations . They are caused by the cooling effect of wind gusts on rock surfaces that are much warmer than ambient air temperatures . High-frequency oscillations result in a rapid freeze-thaw cycle on the surface, which, however, does not reach the microbial zone . These high-frequency freeze-thaw oscillations are probably the cause of the abiotic nature of the rock surface . Both oscillations seem to have an effect on rock weathering.

Science, 1987 Jul 3, 237, 70 - 3
Early Archean (3.3-billion to 3.5-billion-year-old) microfossils from Warrawoona Group, Australia; Schopf JW et al.; Cellularly preserved filamentous and colonial fossil microorganisms have been discovered in bedded carbonaceous cherts from the Early Archean Apex Basalt and Towers Formation of northwestern Western Australia . The cell types detected suggest that cyanobacteria, and therefore oxygen-producing photosynthesis, may have been extant as early as 3.3 billion to 3.5 billion years ago . These fossils are among the oldest now known from the geologic record; their discovery substantiates previous reports of Early Archean microfossils in Warrawoona Group strata.

Geotimes, 1994 Mar, 39(3), 13 - 4
Hydrothermal systems and the emergence of life; Shock EL; NASA: The author reviews current thought about life originating in hyperthermophilic microorganisms . Hyperthermophiles obtain food from chemosynthesis of sulfur and have an RNA nucleotide sequence different from bacteria and eucarya . It is postulated that a hyperthermophile may be the common ancestor of all life . Current research efforts focus on the synthesis of organic compounds in hydrothermal systems .

Precambrian Res, 1994, 65, 231 - 54
Microfossils in cherts from the Middle Riphean (Mesoproterozoic) Avzyan Formation, southern Ural Mountains, Russian Federation; Sergeev VN; A diverse assemblage of well-preserved microorganisms has been detected in black cherts from the approximately 1200 Ma-old Avzyan Formation (Suite) of the southern Ural Mountains, Russian Federation . The lower Kataskin Member contains a diverse, abundant microbiota dominated by mat-forming filamentous cyanobacteria, several types of colonial unicells, and morphologically distinctive stalked cyanobacteria . The upper Revet Member contains a less diverse biota dominated by unicellular cyanobacteria . Palaeoecological evidence indicates that the microbial community of the Kataskin Member inhabited a shallow water, presumably marine, carbonate environment . Revet microorganisms possibly lived in restricted peritidal environments . The biostratigraphic significance of the Avzyan microbiota is limited . Many of the taxa are long-ranging; they were already abundant in Palaeoproterozoic successions and continue into the Neoproterozoic . Nevertheless, in many respects, the Kataskin assemblage is comparable to those reported from the Middle-Late Riphean deposits of Northern America, Australia and Eurasia . The following taxa are here described: Chroococcaceae-Eogloeocapsa avzyanica Sergeev, Gloeodiniopsis lamellosa Schopf emend . Knoll et Golubic; Entophysalidaceae-Eoentophysalis belcherensis Hofmann; Dermocarpaceae-Polybessurus bipartitus Fairchild ex Green et al.; Nostocaceae-Eosphaeronostoc kataskinicum Sergeev; Nostocaceae or Oscillatoriaceae-Siphonophycus robustum (Schopf) emend . Knoll et Golubic emend . Knoll et al., Siphonophycus sp.; Incertae sedis-Eosynechococcus amadeus Knoll et Golubic.

G Bot Ital, 1993, 127(3), 369 - 76
Extreme environments and exobiology; Friedmann EI; Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars . If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth . Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme" . Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared . The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples . The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible . In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.

Chem Geol, 1993, 107, 159 - 72
Stable isotopic biogeochemistry of carbon and nitrogen in a perennially ice-covered Antarctic lake; Wharton RA Jr et al.; Lake Hoare (77 degrees 38' S, 162 degrees 53' E) is an amictic, oligotrophic, 34-m-deep, closed-basin lake in Taylor Valley, Antarctica . Its perennial ice cover minimizes wind-generated currents and reduces light penetration, as well as restricts sediment deposition into the lake and the exchange of atmospheric gases between the water column and the atmosphere . The biological community of Lake Hoare consists solely of microorganisms -- both planktonic populations and benthic microbial mats . Lake Hoare is one of several perennially ice-covered lakes in the McMurdo Dry Valleys that represent the end-member conditions of cold desert and saline lakes . The dry valley lakes provide a unique opportunity to examine lacustrine processes that operate at all latitudes, but under an extreme set of environmental conditions . The dry valley lakes may also offer a valuable record of catchment and global changes in the past and present . Furthermore, these lakes are modern-day equivalents of periglacial lakes that are likely to have been common during periods of glacial maxima at temperate latitudes . We have analyzed the dissolved inorganic carbon (DIC) of Lake Hoare for delta 13C and the organic matter of the sediments and sediment-trap material for delta 13C and delta 15N . The delta 13C of the DIC indicates that 12C is differentially removed in the shallow, oxic portions of the lake via photosynthesis . In the anoxic portions of the lake (27-34 m) a net addition of 12C to the DIC pool occurs via organic matter decomposition . The dissolution of CaCO3 at depth also contributes to the DIC pool . Except near the Canada Glacier where a substantial amount of allochthonous organic matter enters the lake, the organic carbon being deposited on the lake bottom at different sites is isotopically similar, suggesting an autochthonous source for the organic carbon . Preliminary inorganic carbon flux calculations suggest that a high percentage of the organic carbon fixed in the water column is remineralized as it falls through the water column . At nearby Lake Fryxell, the substantial (relative to Lake Hoare) glacial meltstream input overprints Fryxell's shallow-water biological delta 13C signal with delta 13C-depleted DIC . In contrast, Lake Hoare is not significantly affected by surface-water input and mixing, and therefore the delta 13C patterns observed arise primarily from biological dynamics within the lake . Organic matter in Lake Hoare is depleted in 15N, which we suggest is partially the result of the addition of relatively light inorganic nitrogen into the lake system from terrestrial sources.

Adv Space Res, 1995 Mar, 15(3), 277 - 80
Planetary protection considerations for MarsNet and Mars sample return missions; Lindberg C et al.; The ESA MarsNet mission proposal consists most probably of a trio of Mars landers . These landers each contain a variety of scientific equipment . The network of stations demands for a definition of its planetary protection requirements . With respect to the MarsNet mission only forward contamination problems will be considered . Future involvement of European efforts in planetary exploration including sample returns will also raise the problem of back contamination . A tradeoff study for the overall scientific benefit with respect to the approximative cost is necessary . Planetary protection guide-lines will be proposed by an interdisciplinary and international board of experts working in the fields of both biology and planetary science . These guide-lines will have to be flexible in order to be modified with respect to new research results, e.g . on adaptation of microorganisms to extreme (space) conditions . Experiments on the survival of microorganisms at conditions of simulated Mars surface and subsurface will have to be conducted in order to obtain a baseline data collection as a reference standard for future guide-lines.

Adv Space Res, 1995 Mar, 15(3), 251 - 5
Modern aspects of planetary protection and requirements to sterilization of space hardware; Demidov VV et al.; The viewpoint of working group of Russian experts on the problem of planetary protection for future manned and unmanned Mars mission is presented . Recent data of Martian environment and on survival of terrestrial microorganisms in extreme conditions were used for detailed analysis and overview of planetary protection measures in regard to all possible flight situations including accidental landing . The special emphasis on "Mars-94" mission was done . This analysis resulted in revised formulation of spacecraft sterilization requirements and possible measures for their best implementation . New general combined approach to spacecraft sterilization was proposed . It includes penetrating radiation and heat treatment of spacecraft parts and components which is to be carried out before the final assembly of spacecraft and gaseous radiation sterilization of the whole spacecraft during the flight to Mars (or from Mars for return missions).

Adv Space Res, 1995 Mar, 15(3), 243 - 6
A primitive cyanobacterium as pioneer microorganism for terraforming Mars; Friedmann EI et al.; The primitive characteristics of the cyanobacterium Chroococcidiopsis suggest that it represents a very ancient type of the group . Its morphology is simple but shows a wide range of variability, and it resembles certain Proterozoic microfossils . Chroococcidiopsis is probably the most desiccation-resistant cyanobacterium, the sole photosynthetic organism in extreme arid habitats . It is also present in a wide range of other extreme environments, from Antarctic rocks to thermal springs and hypersaline habitats, but it is unable to compete with more specialized organisms . Genetic evidence suggests that all forms belong to a single species . Its remarkable tolerance of environmental extremes makes Chroococcidiopsis a prime candidate for use as a pioneer photosynthetic microorganism for terraforming of Mars . The hypolithic microbial growth form (which lives under stones of a desert pavement) could be used as a model for development of technologies for large-scale Martian farming.

Adv Space Res, 1995 Mar, 15(3), 229 - 36
A physical and chemical characterization of Martian permafrost as a possible habitat for viable microorganisms; Ostroumov V; Data from experiments with model samples show that ion transfer coefficients in the water-rich permafrost on Mars must be three orders of magnitude less than those of terrestrial permafrost . The effects of low temperatures and of carbon dioxide have been accounted for . Exchange between cells and the environment is impeded in Martian permafrost . The microscopic distributional heterogeneity of concentration, pH, Eh, and other physicochemical parameters may be more pronounced in the permafrost of Mars . We present a classification of unfrozen water types in the permafrost that is based on the structures of unfrozen water films and on their functions with respect to cells . Any viable microorganisms on Mars probably exist with minimum metabolism in compact zones with energy carriers and high transfer coefficients . These zones may be microvolumes of unfrozen water in which cells accumulate.

Plant Sci, 1987, 51, 311 - 6
Protection of wheat against leaf and stem rust and powdery mildew diseases by inhibition of polyamine metabolism; Weinstein LH et al.; In higher plants, polyamines arise from arginine by one of two pathways: via ornithine and ornithine decarboxylase or via agmatine and arginine decarboxylase but in fungi, only the ornithine decarboxylase pathway is present . Since polyamines are required for normal growth of microorganisms and plants and since the ornithine pathway can be irreversibly blocked by alpha-difluoromethylornithine (DFMO) which has no effect on arginine decarboxylase, fungal infection of green plants might be controlled by the site-directed use of such a specific metabolic inhibitor . DFMO at relatively low concentrations provided effective control of the three biotrophic fungal pathogens studied, Puccinia recondita (leaf rust), P . graminis f . sp . tritici (stem rust), and Erysiphe graminis (powdery mildew) on wheat (Triticum aestivum L.) Effective control of infection by leaf or stem rust fungi was obtained with sprays of DFMO that ranged from about 0.01 to 0.20 mM in experiments where the inhibitor was applied after spore inoculation . The powdery mildew fungus was somewhat more tolerant of DFMO, but good control of the pathogen was obtained at less than 1.0 mM . In general, application of DFMO after spore inoculation was more effective than application before inoculation . Less control was obtained following treatment with alpha-difluoromethylarginine (DFMA) but the relatively high degree of control obtained raises the possibility of a DFMA to DFMO conversion by arginase.

Adv Space Res, 1996, 18(1-2), 323 - 32
Planetary protection program for Mars 94/96 mission; Rogovski G et al.; Mars surface in-situ exploration started in 1975 with the American VIKING mission . Two probes landed on the northern hemisphere and provided, for the first time, detailed information on the martian terrain, atmosphere and meteorology . The current goal is to undertake larger surface investigations and many projects are being planned by the major Space Agencies with this objective . Among these projects, the Mars 94/96 mission will make a major contributor toward generating significant information about the martian surface on a large scale . Since the beginning of the Solar System exploration, planets where life could exist have been subject to planetary protection requirements . Those requirements accord with the COSPAR Policy and have two main goals: the protection of the planetary environment from influence or contamination by terrestrial microorganisms, the protection of life science, and particularly of life detection experiments searching extra-terrestrial life, and not life carried by probes and spacecrafts . As the conditions for life and survival for terrestrial microorganisms in the Mars environment became known, COSPAR recommendations were updated . This paper will describe the decontamination requirements which will be applied for the MARS 94/96 mission, the techniques and the procedures which are and will be used to realize and control the decontamination of probes and spacecrafts.

Adv Space Res, 1996, 18(1-2), 223 - 32
NASA's Advanced Life Support Systems Human-Rated Test Facility; Henninger DL et al.; Future NASA missions to explore the solar system will be long-duration missions, requiring human life support systems which must operate with very high reliability over long periods of time . Such systems must be highly regenerative, requiring minimum resupply, to enable the crews to be largely self-sufficient . These regenerative life support systems will use a combination of higher plants, microorganisms, and physicochemical processes to recycle air and water, produce food, and process wastes . A key step in the development of these systems is establishment of a human-rated test facility specifically tailored to evaluation of closed, regenerative life supports systems--one in which long-duration, large-scale testing involving human test crews can be performed . Construction of such a facility, the Advanced Life Support Program's (ALS) Human-Rated Test Facility (HRTF), has begun at NASA's Johnson Space Center, and definition of systems and development of initial outfitting concepts for the facility are underway . This paper will provide an overview of the HRTF project plan, an explanation of baseline configurations, and descriptive illustrations of facility outfitting concepts.

J Gravit Physiol, 1994 May, 1(1), P82 - 4
Gravitaxis in the flagellate Euglena gracilis--results from NiZeMi, clinostat and sounding rocket flights; Hader DP; Many motile microorganisms including flagellates such as the green Euglena gracilis move up and down within the water column and use a number of external clues for their orientation, the most important of which may be light and gravity . The cells use positive phototaxis and negative gravitaxis to move closer to the surface of the water column which for energetic reasons is vital for their survival . However, most phytoplankton organisms cannot tolerate the bright irradiance of unfiltered solar radiation at the surface which also bleaches the photosynthetic pigments, disables the photosynthetic apparatus and impairs phototaxis, gravitaxis and motility in Euglena . Thus, it is not surprising that at higher irradiances negative phototaxis operates antagonistically to the responses described above to guide the cells into deeper water where they are protected from excessive radiation . Phototaxis and gravitaxis are not independent from one another: in a vertically positioned cuvette negative gravitaxis can be "titrated" by light impinging from above and is compensated at about 30 W m-2 . While the photoreceptor for phototaxis has been identified in Euglena gracilis biochemically and spectroscopically, the gravireceptor is not yet known . Young cultures of Euglena gracilis show a positive gravitaxis, the ecological signficance of which is not yet understood while older cultures show negative gravitaxis . One hypothesis concerning the nature of graviperception is based on a passive physical process such as an asymmetric distribution of the mass within the cell . However, the observation that short term UV irradiation decreases the precision of negative gravitaxis rather indicates the involvement of an active physiological gravireceptor . Furthermore, some heavy metal ions have been found to change the direction of movement from positive to negative gravitaxis in young cells.

Adv Space Res, 1996, 17(6-7), 11 - 20
A theory of gravikinesis in Paramecium; Machemer H; The archaic eukaryote unicellular microorganism, Paramecium, is propelled by thousands of cilia, which are regulated by modulation of the membrane potential . Ciliates can successfully cope with gravity, which is the phylogenetically oldest stimulus for living things . One mechanism for overcoming sedimentation is negative gravitaxis, an orientational response antiparallel to the gravity vector . We have postulated the existence of a negative gravikinesis in Paramecium, i.e . a modulation of swimming speed as a function of cellular orientation in space . With negative gravikinesis, an upward oriented cell actively augments the rate of forward swimming and depresses active locomotion during downward orientation . A brief outline of the gravikinesis hypothesis is given on a quantitative basis and experimental data are presented which have confirmed the major assumptions.

Physiologist, 1993 Feb, 36(1 Suppl), S31 - 3
Changing gravity level and the development of animals; Serova LV; Space biology has accumulated a great body of information concerning the influence of microgravity upon objects of varying levels of biological organization: from microorganisms to higher animals and humans . However, the choice of biological objects was in most cases random, and there has been no attempt at a comparative biological analysis of the results obtained . A similar situation is noted in hypergravity research, where responses in various animal classes are compared mainly with respect to differences in body masses rather than in the level of biological organization . Without any claims to solve this serious problem in this presentation, I'll try to at least raise it, using as a starting point the conception about evolution of resistance and reactivity, created by my teacher N.N . Sirotinin (1981).

Polarforschung, 1988, 58(2-3), 251 - 9
Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica; Friedmann EI et al.; Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi . Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described . Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated . The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.

Polarforschung, 1988, 58(2-3), 199 - 200
Preliminary report on radiocarbon dating of cryptoendolithic microorganisms; Bonani G et al.; NASA: The existence of microbial communities living inside desert rocks has been reported by FRIEDMANN et al . (1967, 1976), first in rocks collected from the hot and dry Negev desert and later in rocks in the frigid Ross Desert of Southern Victoria Land, Antarctica . The extremely inhospitable climatic conditions in both places has led to the suggestion that these organisms have very low rates of metabolism and may, in addition, be very old (FRIEDMANN 1982) . Our preliminary measurements showed a 14C deficiency indicating a carbon age in the order of magnitude of 10(3) years . NASA Edited

Polarforschung, 1988, 58(2-3), 121 - 4
Temperature response of Antarctic cryptoendolithic photosynthetic microorganisms; Ocampo-Friedmann R et al.; Growth responses to temperatures between 12.5 {degrees} C and 25 degrees C were determined for five photosynthetic microorganisms isolated from the Ross Desert cryptoendolithic community . Among eukaryotic algae, two strains of Trebouxia sp . have an upper temperature limit of 20 degrees C, and two strains of Hemichloris antarctica of 25 degrees C . The cyanobacterium Chroococcidiopsis sp., in contrast, grows at temperatures above 25 degrees C . These and earlier studies suggest that the eukaryotic algae of the Antarctic cryptoendolithic community have an upper temperature limit near 25 degrees C.

Antarct J US, 1987, 22(5), 240 - 1
Antarctic cryptoendolithic microbial ecosystem research, 1986-1987
Friedmann EI, Meyer MA.
The apparent lifelessness of the Ross Desert is in marked contrast to the diversity of cryptoendolithic microorganisms inhabiting the interstices of sandstone rocks . The endolithic habitat provides a protective niche for lichens, bacteria, algae, and fungi, enabling them to exist in an extremely dry and cold climate . Composed solely of microorganisms living under the surface of rocks and totally lacking animals and protozoa, this ecosystem is controlled by measurable physical variables and well suited for ecosystem study and modeling . The work of the antarctic cryptoendolithic microbial ecosystem research group has involved physical measurements of nanoclimate (microbial environment inside rocks) (Friedmann, McKay, and Nienow 1987), taxonomy (Darling, Friedmann, and Broady 1987; Hale 1987), microdistribution, organism-substrate interactions including the ongoing process of fossilization (Friedmann and Weed 1987), physiological ecology, and quantification of the nitrogen economy.

Geochim Cosmochim Acta, 1993 Jul, 57(14), 3219 - 30
Deep-sea smokers: windows to a subsurface biosphere?
Deming JW, Baross JA.
Since the discovery of hyperthermophilic microbial activity in hydrothermal fluids recovered from "smoker" vents on the East Pacific Rise, the widely accepted upper temperature limit for life (based on pure culture data) has risen from below the boiling point of water at atmospheric pressure to approximately 115 degrees C . Many microbiologists seem willing to speculate that the maximum may be closer to 150 degrees C . We have postulated not only higher temperatures than these (under deep-sea hydrostatic pressures), but also the existence of a biosphere subsurface to accessible seafloor vents . New geochemical information from the Endeavour Segment of the Juan de Fuca Ridge indicative of subsurface organic material caused us to re-examine both the literature on hyperthermophilic microorganisms cultured from deep-sea smoker environments and recent results of microbial sampling efforts at actively discharging smokers on the Endeavour Segment . Here we offer the case for a subsurface biosphere based on an interdisciplinary view of microbial and geochemical analyses of Endeavour smoker fluids, a case in keeping with rapidly evolving geophysical understanding of organic stability under deep-sea hydrothermal conditions.

Icarus, 1991, 94, 354 - 67
CH4/NH3/H2O spark tholin: chemical analysis and interaction with Jovian aqueous clouds; McDonald GD et al.; The organic solid (tholin) produced by spark discharge in a CH4 + NH3 + H2O atmosphere is investigated, along with the separable components of its water-soluble fraction . The chemistry of this material serves as a provisional model for the interaction of Jovian organic heteropolymers with the deep aqueous clouds of Jupiter . Intact (unhydrolyzed) tholin is resolved into four chemically distinct fractions by high-pressure liquid chromatography (HPLC) . Gel filtration chromatography reveals abundant components at molecular weights approximately or equal to 600-700 and 200-300 Da . Gas chromatography/mass spectrometry of derivatized hydrolysis products of unfractionated tholin shows about 10% by mass protein and nonprotein amino acids, chiefly glycine, alanine, aspartic acid, beta-alanine, and beta-aminobutyric acid, and 12% by mass other organic acids and hydroxy acids . The stereospecificity of alanine is investigated and shown to be racemic . The four principal HPLC fractions yield distinctly different proportions of amino acids . Chemical tests show that small peptides or organic molecules containing multiple amino acid precursors are a possibility in the intact tholins, but substantial quantities of large peptides are not indicated . Candidate 700-Da molecules have a central unsaturated, hydrocarbon- and nitrile-rich core, linked by acid-labile (ester or amide) bonds to amino acid and carboxylic acid side groups . The core is probably not HCN "polymer." The concentration of amino acids from tholin hydrolysis in the lower aqueous clouds of Jupiter, about 0.1 micromole, is enough to maintain small populations of terrestrial microorganisms even if the amino acids must serve as the sole carbon source.

J Chromatogr, 1992, 598(2), 267 - 76
Novel long-chain anteiso-alkanes and anteiso-alkanoic acids in Antarctic rocks colonized by living and fossil cryptoendolithic microorganisms; Matsumoto GI et al.; Saponified extracts of rock samples colonized by cryptoendolithic microbial communities from the McMurdo Dry Valleys of Southern Victoria Land, Antarctica, were separated into hydrocarbon and fatty acid fractions by silica gel column chromatography . Hydrocarbons and methyl esters of fatty acids were analyzed by capillary gas chromatography-mass spectrometry . Unusually, a suite of long-chain anteiso-alkanes (a-C20 to a-C30) and anteiso-alkanoic acids (a-C20 to a-C30) were detected in many samples, together with straight-chain, branched and/or cyclic and acyclic isoprenoid compounds . These novel compounds are probably derived from unidentified heterotrophic bacteria or symbiotic processes in a unique microbial community in the Antarctic cold desert and suggest the occurrence of a special biosynthetic pathway . Long-chain anteiso-alkanes are probably formed through microbial decarboxylation of corresponding anteiso-alkanoic acids . They may serve as new biomarkers in environmental and geochemical studies.

Adv Space Res, 1994, 14(11), 435 - 43
Use of lunar regolith as a substrate for plant growth; Ming DW et al.; Regenerative Life Support Systems (RLSS) will be required to regenerate air, water, and wastes, and to produce food for human consumption during long-duration missions to the Moon and Mars . It may be possible to supplement some of the materials needed for a lunar RLSS from resources on the Moon . Natural materials at the lunar surface may be used for a variety of lunar RLSS needs, including (i) soils or solid-support substrates for plant growth, (ii) sources for extraction of essential, plant-growth nutrients, (iii) substrates for microbial populations in the degradation of wastes, (iv) sources of O2 and H2, which may be used to manufacture water, (v) feed stock materials for the synthesis of useful minerals (e.g., molecular sieves), and (vi) shielding materials surrounding the outpost structure to protect humans, plants, and microorganisms from harmful radiation . Use of indigenous lunar regolith as a terrestrial-like soil for plant growth could offer a solid support substrate, buffering capacity, nutrient source/storage/retention capabilities, and should be relatively easy to maintain . The lunar regolith could, with a suitable microbial population, play a role in waste renovation; much like terrestrial waste application directly on soils . Issues associated with potentially toxic elements, pH, nutrient availability, air and fluid movement parameters, and cation exchange capacity of lunar regolith need to be addressed before lunar materials can be used effectively as soils for plant growth.

Adv Space Res, 1986, 6(12), 265 - 8
The Antarctic cold desert and the search for traces of life on Mars; Friedmann EI; The cryptoendolithic microorganisms that live inside rocks in the frigid Ross Desert of Antarctica can serve as a terrestrial model for what may have happened to life forms on Mars when the planet became dry and cold . Trace fossils of microbial rock colonization exist in Antarctica, and similar structures could have formed on Mars . In some respects, such trace fossils could be an easier target for life-detection systems than fossils of cellular structures.

Adv Space Res, 1984, 4(12), 291 - 5
Revised planetary protection policy for solar system exploration; DeVincenzi DL et al.; In order to control contamination of planets by terrestrial microorganisms and organic constituents, U.S . planetary missions have been governed by a planetary protection (or planetary quarantine) policy which has changed little since 1972 . This policy has recently been reviewed in light of new information obtained from planetary exploration during the past decade and because of changes to, or uncertainties in, some parameters used in the existing quantitative approach . On the basis of this analysis, a revised planetary protection policy with the following key features is proposed: deemphasizing the use of mathematical models and quantitative analyses; establishing requirements for target planet/mission type (i.e., orbiter, lander, etc.) combinations; considering sample return missions a separate category; simplifying documentation; and imposing implementing procedures (i.e., trajectory biasing, cleanroom assembly, spacecraft sterilization, etc.) by exception, i.e., only if the planet/mission combination warrants such controls.

Adv Space Res, 1984, 4(12), 251 - 62
BLSS: a contribution to future life support; Skoog AI; For extended duration missions in space the supply of basic life-supporting ingredients represents a formidable logistics problem . Storage volume and launch weight of water, oxygen and food in a conventional non-regenerable life support system are directly proportional to the crew size and the length of the mission . In view of spacecraft payload limitations this will require that the carbon, or food, recycling loop, the third and final part in the life support system, be closed to further reduce logistics cost . This will be practical only if advanced life support systems can be developed in which metabolic waste products are regenerated and food is produced . Biological Life Support Systems (BLSS) satisfy the space station environmental control functions and close the food cycle . A Biological Life Support System has to be a balanced ecological system, biotechnical in nature and consisting of some combination of human beings, animals, plants and microorganisms integrated with mechanical and physico-chemical hardware . Numerous scientific space experiments have been delineated in recent years, the results of which are applicable to the support of BLSS concepts . Furthermore ecological life support systems have become subject to intensified studies and experiments both in the U.S . and the U.S.S.R . The Japanese have also conducted detailed preliminary studies . Dornier System has in recent years undertaken an effort to define requirements and concepts and to analyse the feasibility of BLSS for space applications . Analyses of the BLSS energy-mass relation have been performed, and the possibilities to influence it to achieve advantages for the BLSS (compared with physico-chemical systems) have been determined . The major problem areas which need immediate attention have been defined, and a programme for the development of BLSS has been proposed.

Acta Astronaut, 1992, 27, 239 - 42
Toxicological implications of extended space flights; Weiss B et al.; The dominant reason for exposing humans to the risks of space flight is their ability to perform complex tasks and make complex decisions . To fulfill such a role, crews must be shielded against even incipient degradation of performance capacity . The space environment contains potential hazards ranging from microgravity to infectious microorganisms to chemical toxicants . An extensive literature indicates that incipient disruptions of function may occur at low levels of exposure to toxic agents and degrade performance . Such questions need to be pursued before irreversible decisions are made about space vehicle design.

Adv Space Res, 1989, 9(6), 191 - 5
Peroxides and the survivability of microorganisms on the surface of Mars; Mancinelli RL; Results of the Viking mission seem to indicate that there is a ubiquitous layer of highly oxidizing aeolian material covering the Martian surface . This layer is thought to oxidize organic material that may settle on it, and is therefore responsible for the lack of detection of organic matter on the planet's surface by Viking . The mechanism that creates the oxidizing condition is not well understood, nor is the extent of the oxidation potential of this material . It has been suggested that the oxidizing nature of the soil is due to photochemical reactions which create hydrogen peroxide and superoxides in the surface soil . One question of importance to planetary protection regarding this material is, what is its potential for destroying terrestrial microorganisms, thus making the surface of Mars "self-sterilizing"? Using data obtained by the gas exchange experiment on Viking, and for simplicity assuming that all of the O2 released came from H2O2, the concentration range for H2O2 on the surface of Mars can be calculated to be 25-250 ppm . The microbial disinfection rate by H2O2 is concentration dependent, and is highly variable within the microbial community . Data from our laboratory indicate that certain soil bacteria survive and grow to stationary phase in 30,000 ppm H2O2 . However, the total number of organisms decreases in the presence of H2O2 . These results indicate that it is doubtful that the presence of H2O2 alone on Mars would make the surface "self-sterilizing".

Adv Space Res, 1989, 9(6), 173 - 6
Biological nitrogen fixation under primordial Martian partial pressures of dinitrogen; Klingler JM et al.; Early Earth and early Mars were similar enough such that past geochemical and climatic conditions on Mars may have also been favorable for the origin of life . However, one of the most striking differences between the two planets was the low partial pressure of dinitrogen (pN2) on early Mars (18 mb) . On Earth, nitrogen is a key biological element and in many ecosystems the low availability of fixed nitrogen compounds is the main factor limiting growth . Biological fixation of dinitrogen on Earth is a crucial source of fixed nitrogen . Could the low availability of dinitrogen in the primordial Martian atmosphere have prevented the existence, or evolution of Martian microbiota? Azotobacter vinelandii and Azomonas agilis were grown in nitrogen free synthetic medium under various partial pressures of dinitrogen ranging from 780-0 mb (total atmosphere=1 bar) . Below 400 mb the biomass, cell number, and growth rate decreased with decreasing pN2 . Both microorganisms were capable of growth at a pN2 as low as 5 mb, but no growth was observed at a pN2 < or = 1 mb . The data appear to indicate that biological nitrogen fixation could have occurred on primordial Mars (pN2=18 mb) making it possible for a biotic system to have played a role in the Martian nitrogen cycle . It is possible that nitrogen may have played a key role in the early evolution of life on Mars, and that later a lack of available nitrogen on that planet (currently, pN2=0.2 mb) may have been involved in its subsequent extinction.

Adv Space Res, 1986, 6(11), 117 - 25
Microdosimetric considerations of effects of heavy ions on microorganisms; Takahashi T et al.; An estimation of dose around the trajectory of an ion has been made by use of Tabata and Ito's energy deposition algorithm for electrons which takes into account transmission coefficient . The result of the calculation, as well as Butts and Katz's dose, is successfully applied to the interpretation of inactivation cross sections of vegetative cells of E . coli Bs-1, and E . coli B/r and of B . subtilis spores for He, C and N ions.

ASGSB Bull, 1991 Jul, 4(2), 97 - 105
The dynamics of unicellular swimming organisms; Kessler JO; Swimming microorganisms, such as motile algal cells, are oriented passively by gravity and also by velocity gradients of the fluid which surrounds them . They may actively orient themselves as well, in response to sensory signals such as illumination . These axial alignments are degraded by molecular collisions which generate rotational Brownian motion and by endogenously generated random turning behavior . The geometry of the track traced out by an individual cell's swimming is governed by the joint competitive action of these orienting influences . These determinants of the cell trajectories are considered . It is also shown that, although gravity may not directly interact with cell metabolism, it can affect the energy consumption accompanying taxis, by suppressing pathway tortuosity and by supplying an orientational bias . This paper also reviews the role of gravity in organizing patterns--collective modes of the fluid and of the suspended swimmers which energize the dynamics.

Adv Space Res, 1992, 12(5), 33 - 6
Pilot CELSS based on a maltose-excreting Chlorella: concept and overview on the technological developments; Brechignac F et al.; A typical ecosystem is composed of three compartments: photosynthetic producer (anabolizing processes), consumer and decomposer (catabolizing processes) . It is still far too much complex, however, to form the basis on which establishing an engineered artificial ecosystem, dedicated to support life (of the consumer) in space . A simpler, two compartments, pilot model to start with has been selected . It is based on a symbiotic Chlorella (strain 241.80), which can be tuned, at low pH, to produce maltose . This feature prevents the accumulation of useless biomass, not readily edible by the consumer . Being excreted, maltose is easily recoverable, and constitutes a direct source of carbon suitable for many consumers . Since they will totally catabolize it back to CO2, the necessity for a decomposer compartment is avoided . The present status of the technological concept designed to support life of small consumers (animals, microorganisms) will be presented, taking into account the space compatibility of the technologies developed.

Icarus, 1993 Jan, 101(1), 129 - 43
Preservation of biological information in thermal spring deposits: developing a strategy for the search for fossil life on Mars; Walter MR et al.; Current interpretations of the early history of Mars suggest many similarities with the early Earth and therefore raise the possibility that the Archean and Proterozoic history of life on Earth could have a counterpart on Mars . Terrestrial experience suggests that, with techniques that can be employed remotely, ancient springs, including thermal springs, could well yield important information . By delivering water and various dissolved species to the sunlit surface of Mars, springs very likely created an environment suitable for life, which could have been difficult, if not impossible, to attain elsewhere . The chemical and temperature gradients associated with thermal springs sort organisms into sharply delineated, distinctive and different communities, and so diverse organisms are concentrated into relatively small areas in a predictable and informative fashion . A wide range of metabolic strategies are concentrated into small areas, thus furnishing a useful and representative sampling of the existing biota . Mineral-charged springwaters frequently deposit chemical precipitates of silica and/or carbonate which incorporate microorganisms and preserve them as fossils . The juxtaposition of stream valley headwaters with volcanoes and impact craters on Mars strongly implies that subsurface heating of groundwater created thermal springs . On Earth, thermal springs create distinctive geomorphic features and chemical signatures which can be detected by remote sensing . Spring deposits can be quite different chemically from adjacent rocks . Individual springs can be hundreds of meters wide, and complexes of springs occupy areas up to several kilometers wide . Benthic microbial mats and the resultant stromatolites occupy a large fraction of the available area . The relatively high densities of fossils and microbial mat fabrics within these deposits make them highly prospective in any search for morphological evidence of life, and there are examples of microbial fossils in spring deposits as old as 300 Myr.

Orig Life Evol Biosph, 1997 Aug, 27(4), 319 - 24
Prebiotic transamination; Bishop JC et al.; Biological amino acids and alpha keto acids directly condense with decarboxylation and transamination to yield product amino acids . This process is closely related to unusual amino acid decarboxylase enzymes in certain microorganisms and may represent a primordial mode of amino acid metabolism.

Orig Life Evol Biosph, 1989, 19(6), 549 - 60
Estimates of the maximum time required to originate life; Oberbeck VR et al.; Fossils of the oldest microorganisms exist in 3.5 billion year old rocks and there is indirect evidence that life may have existed 3.8 billion years ago (3.8 Ga) . Impacts able to destroy life or interrupt prebiotic chemistry may have occurred after 3.5 Ga . If large impactors vaporized the oceans, sterilized the planets, and interfered with the origination of life, life must have originated in the time interval between these impacts which increased with geologic time . Therefore, the maximum time required for the origination of life is the time that occurred between sterilizing impacts just before 3.8 Ga or 3.5 Ga, depending upon when life first appeared on Earth . If life first originated 3.5 Ga, and impacts with kinetic energies between 2 x 10(34) and 2 x 10(35) were able to vaporize the oceans, using the most probable impact flux, we find that the maximum time required to originate life would have been 67 to 133 million years (My) . If life first originated 3.8 Ga, the maximum time to originate life was 2.5 to 11 My . Using a more conservative estimate for the flux of impacting objects before 3.8 Ga, we find a maximum time of 25 My for the same range of impactor kinetic energies . The impact model suggest that it is possible that life may have originated more than once.

Science, 1987 May 8, 236(4802), 703 - 5
Microbial trace-fossil formation, biogenous, and abiotic weathering in the Antarctic cold desert; Friedmann EI et al.; In the Antarctic cold desert (Ross Desert), the survival of the cryptoendolithic microorganisms that colonize the near-surface layer of porous sandstone rocks depends on a precarious equilibrium of biological and geological factors . An unfavorable shift of this equilibrium results in death, and this may be followed by formation of trace fossils that preserve the characteristic iron-leaching pattern caused by microbial activity . Similar microbial trace fossil may exist in the geological record . If life ever arose on early Mars, similar processes may have occurred there and left recognizable traces.

Orig Life Evol Biosph, 1993 Feb, 23(1), 77 - 90
Life in hot springs and hydrothermal vents; Segerer AH et al.; Hot springs and hydrothermal systems occurring within volcanic areas are inhabited by hyperthermophilic microorganisms, some of which grow at temperatures up to 110 degrees C . Hyperthermophiles grow anaerobically or aerobically by diverse metabolic types . Within the high temperature ecosystems, primary production is independent from solar energy.

Phytother Res, 2001 Sep, 15(6), 511 - 8
Antioxidant activity of extracts from plants growing in Sardinia; Dessi MA et al.; The present work was carried out to study the effect of some plant methanol extracts and essential oils on lipid peroxidation in simple in vitro systems . The tested extracts were obtained from four plants, commonly known in the Mediterranean area, indigenous to Sardinia: Artemisia arborescens L., Calycotome villosa L., Daphne gnidium L . or naturalized in the island, Eucalyptus globulus Labill . The activity of the extracts was investigated during both autoxidation and iron or EDTA-mediated oxidation of linoleic acid at 37 degrees C in the absence of solvent, and compared with that of BHT, alpha-tocopherol and EDTA . During linoleic acid autoxidation all the extracts were active, showing an antioxidant activity in the order: BHT >alpha- tocopherol >Daphne gnidium (methanol extract) >Eucalyptus globulus (essential oil) >Calycotome villosa (essential oil) >Artemisia arborescens (essential oil and methanol extract) >Calycotome villosa (methanol extract) . None showed any prooxidant activity . During the iron-catalysed oxidation of linoleic acid the oils were not active, while all the methanol extracts showed some efficiency in preventing the oxidation process . All the extracts were also tested on cell cultures to investigate their cytotoxic activity or their ability to inhibit the growth of some pathogenic microorganisms .

Eur J Immunol, 2001 Sep, 31(9), 2771 - 80
Bordetella pertussis binds to human C4b-binding protein (C4BP) at a site similar to that used by the natural ligand C4b; Berggard K et al.; Human complement regulators are important targets for pathogenic microorganisms . In one such interaction, Bordetella pertussis binds human C4b-binding protein (C4BP), a high-molecular-weight plasma protein that acts as inhibitor of the classical pathway of complement activation . At least two different B . pertussis surface components, one of which is the virulence factor filamentous hemagglutinin (FHA), contribute to the binding . We used a set of C4BP mutants and monoclonal antibodies to characterize the region in C4BP that binds B . pertussis and analyzed the salt sensitivity of the interaction . These studies indicated that positively charged residues at the interface between complement control protein modules 1-2 in the C4BP alpha-chain are important for binding, and that the site in C4BP that binds B . pertussis is very similar, but not identical, to the C4b-binding site . Bacteria-bound C4BP retained its complement regulatory function and B . pertussis selectively bound C4BP in human plasma, indicating that binding occurs also in vivo . Together, these findings indicate that B . pertussis exploits a site in C4BP, resembling that used by the natural ligand C4b.

Eur J Immunol, 2001 Sep, 31(9), 2539 - 46
Transcriptional reprogramming of dendritic cells by differentiation stimuli; Granucci F et al.; Immature and mature dendritic cells (DC) have been well characterized functionally and phenotypically . Microorganisms or bacterial products such as lipopolysaccharide (LPS) and inflammatory molecules, including tumor necrosis factor (TNF-alpha), are both believed to activate the DC maturation program which allows DC to initiate and amplify innate and adaptive immune responses . However, there is increasing evidence that the functional state of DC, induced by different stimuli, may be relevant for the immune response outcome . Thus, we compared the transcriptional program of mature, transitional and immature DC, after either LPS or TNF-alpha stimulation . GeneChip oligonucleotide microarrays, representing approximately 6,500 murine genes and ESTs, were used for this analysis . A very diverse modulation of gene expression was observed with the two stimuli . Only LPS-treated cells showed a pattern of expression of genes compatible with a definitive growth arrest and with a suitable activation and control of the immune response.

Biotechnol Bioeng, 2001 Oct 20, 75(2), 170 - 80
Microbial growth by a net heat up-take: a calorimetric and thermodynamic study on acetotrophic methanogenesis by Methanosarcina barkeri; Liu JS et al.; To answer the intriguing question whether or not endothermic microbial growth exists, and in particular, to verify Heijnen and van Dijken's prediction (1992), acetotrophic methanogen, Methanosarcina barkeri, has been cultivated in a highly sensitive bench-scale calorimeter (an improved Bio-RC1 reaction calorimeter) in a pH auxostat fashion . A growth yield of 0.043 C-mol C-mol(-1) has been obtained and a cell density as high as 3 g L(-1) was attained . Heat uptake during growth has indeed been quantitatively measured with calorimetry, resulting in a heat yield of +145 kJ C-mol(-1) . Thermodynamics of the growth of acetotrophic methanogens was analyzed in detail . The changes in Gibbs energy, enthalpy, and entropy during growth of M . barkeri were compared with some typical aerobic and anaerobic growth processes of different microorganisms on various substrates . In the growth of M . barkeri on acetate, the retarding effect of the positive enthalpy change on the driving force of growth is overcompensated by the large positive entropy change, resulting from converting one organic molecule (acetic acid) to two gaseous products, CH(4) and CO(2) . Both the enthalpy and the entropy increases are due partially to the transition of these two products into the gaseous phase . The thermodynamic role of this phase transition for the growth process is analyzed . Microbial growth characterized by enthalpy increase and correspondingly by a large increase in entropy may be called enthalpy-retarded growth .

J Biol Chem, 2001 Nov 23, 276(47), 44078 - 82 Epub 2001 Sep 04.
Crystal structure of the tumor-promoter okadaic acid bound to protein phosphatase-1; Maynes JT et al.; Protein phosphatase-1 (PP1) plays a key role in dephosphorylation in numerous biological processes such as glycogen metabolism, cell cycle regulation, smooth muscle contraction, and protein synthesis . Microorganisms produce a variety of inhibitors of PP1, which include the microcystin class of inhibitors and okadaic acid, the latter being the major cause of diarrhetic shellfish poisoning and a powerful tumor promoter . We have determined the crystal structure of the molecular complex of okadaic acid bound to PP1 to a resolution of 1.9 A . This structure reveals that the acid binds in a hydrophobic groove adjacent to the active site of the protein and interacts with basic residues within the active site . Okadaic acid exhibits a cyclic structure, which is maintained via an intramolecular hydrogen bond . This is reminiscent of other macrocyclic protein phosphatase inhibitors . The inhibitor-bound enzyme shows very little conformational change when compared with two other PP1 structures, except in the inhibitor-sensitive beta12-beta13 loop region . The selectivity of okadaic acid for protein phosphatases-1 and -2A but not PP-2B (calcineurin) may be reassessed in light of this study.

Rev Esp Cardiol, 2001 Sep, 54(9), 1075 - 80
{Clinical Characteristics and Evolution of Recurrent Infectious Endocarditis in non Drug Addicts}; Rodriguez M et al.; INTRODUCTION AND OBJECTIVES: Recurrence of infection is observed in a high proportion of patients who have had infective endocarditis in the past . The aim of our study was to evaluate the possible differences between the first and the recurrent episodes of endocarditis, as well as to assess the outcome and prognosis of patients with recurrent endocarditis . PATIENTS AND METHOD: We reviewed a series of 13 episodes of recurrent endocarditis from among 196 cases of infective endocarditis involving non-drug-addict patients in two hospitals from 1987 to 2000 . RESULTS: There were no differences between recurrent and first episodes of endocarditis according to age, sex, heart valve involved or causal microorganisms . Prosthetic valve endocarditis was more common in patients with recurrent endocarditis (86% versus 27%; p < 0.001) . Although there were no differences in the rate of complications or early surgery, overall mortality was significantly higher in patients with recurrent endocarditis (53% versus 27%: p < 0.05) . When early and late mortality were analysed separately, the differences did not achieve significance . CONCLUSIONS: Recurrent endocarditis was frequent in our series (7% of all cases) . The features were similar to those of the first episode except for a higher rate of prosthetic valve endocarditis and a higher overall mortality.

Adv Ren Replace Ther, 2001 Jul, 8(3), 164 - 72
Innovative approaches to the preservation of the peritoneal membrane: from bench to bedside; Jorres A; The functional integrity of the peritoneal membrane is of critical importance for the long-term success of peritoneal dialysis therapy . In addition to water and solute transport properties, the function of the membrane encompasses complex interactions with immune cells, invading microorganisms, and dialysis fluid components . During chronic peritoneal dialysis, intraperitoneal homeostasis is threatened by the repeated exposure to an unphysiologic environment that is created by the instilled solutions . Whereas their acidic pH and hyperosmolality were shown to primarily induce alterations of acute cell function, long-term peritoneal function might be affected by the repeated exposure to high concentrations of glucose and glucose degradation products . In addition to their intrinsic toxicity, these might induce or accelerate glycation processes, such as formation and deposition of advanced glycation end products in the peritoneal membrane . Presently, a new generation of dual-chambered peritoneal dialysis solutions combining the advantages of neutral pH and reduced glucose degradation products content is being introduced into clinical practice . In addition to an improved in vitro biocompatibility profile, emerging clinical trials of these novel solutions indicate that they might also improve the host defense status, membrane transport characteristics, ultrafiltration capacity, and effluent markers of peritoneal membrane integrity, while being safe and effective in correcting uremic acidosis and providing relief of inflow pain . Overall, these findings suggest that these new dialysis solutions might constitute an important step toward better preservation of long-term peritoneal membrane function during peritoneal dialysis .

Int J Pharm, 2001 Sep 11, 226(1-2), 1 - 21
Low-temperature sterilization using gas plasmas: a review of the experiments and an analysis of the inactivation mechanisms; Moisan M et al.; Utilizing an ionized gas (plasma) to achieve sterilization is an alternative to conventional sterilization means as far as sterilization of heat-sensitive materials and innocuity of sterilizing agents are concerned . The literature on plasma sterilization is reviewed . A major issue of plasma sterilization is the respective roles of UV photons and reactive species such as atomic and radicals . Insight into this matter is obtained by analyzing the survival curves of microorganisms . In contrast to classical sterilization where such plots show a unique straight line, plasma sterilization yields survival diagrams with two or three different linear segments . Three basic mechanisms are involved in the plasma inactivation of microorganisms: (A) direct destruction by UV irradiation of the genetic material of microorganisms; (B) erosion of the microorganisms atom by atom, through intrinsic photodesorption by UV irradiation to form volatile compounds combining atoms intrinsic to the microorganisms; (C) erosion of the microorganisms, atom by atom, through etching to form volatile compounds as a result of slow combustion using oxygen atoms or radicals emanating from the plasma . In some cases, etching is further activated by UV photons, increasing the elimination rate of microorganisms . These mechanisms make plasma sterilization totally different from classical sterilization techniques and suggest its use to inactivate nonconventional infectious agents such as the abnormal prions.

Prikl Biokhim Mikrobiol, 2001 Jul-Aug, 37(4), 413 - 7
{Study of the stability association of oil-degrading microorganisms in an open system}; Kobzev EN et al.; Investigation of the stability of an association of active hydrocarbon-oxidizing microorganisms grown on diesel fuel showed that not all members of the association were competitive in an open flow system . The abundance of some strains considerably decreased during cultivation . One of the strain groups had consistently high cell titers, both in the medium and on a support . This prompts the authors to use these strains as degraders of diesel fuel.

Prikl Biokhim Mikrobiol, 2001 Jul-Aug, 37(4), 387 - 97
{Laboratory photobioreactors}; Tsygankov AA; Growing phototrophic microorganisms consume the light energy . These microorganisms most often suffer from light deficiency because of exponential decrease in the energy of light passing through an absorbing medium . Therefore, effective distribution of light within the cultures is needed for their intensive cultivation . This is possible in special devices called photobioreactors . The photobioreactors described in the literature are classified into several types according to their geometric features . Their advantages and drawbacks are analyzed . Criteria currently used for comparing various photobioreactors are specified.

Lancet, 2001 Aug 25, 358(9282), 637 - 8
Association between deficiency of mannose-binding lectin and severe infections after chemotherapy; Peterslund NA et al.; The plasma protein mannose-binding lectin (MBL) activates the complement system by binding to carbohydrate structures presented by microorganisms and thus could be an important component of the innate immune defence system . We measured MBL in patients with leukaemia who were scheduled to undergo chemotherapy (ie, a population especially susceptible to infection) and related the results to severity of infection after chemotherapy . We showed a significant association between low concentrations of MBL and serious infections related to chemotherapy (p<0.0001) . These results suggest that increasing concentrations of MBL in patients having chemotherapy could reduce susceptibility to infection.

J Leukoc Biol, 2001 Sep, 70(3), 439 - 46
Interleukin-12 increases interleukin 8 production and release by human polymorphonuclear neutrophils; Ethuin F et al.; Interleukin (IL) 12 is a heterodimeric cytokine mainly produced by phagocytes-important target cells for IL-12 in particular with a chemotactic effect-and antigen-presenting cells in response to various microorganisms . Because IL-8 is a strong chemokine for polymorphonuclear neutrophils (PMNs), we investigated the effect of IL-12 on PMN IL-8 production . IL-12 alone had no significant effect, but with lipopolysaccharide (LPS) it was additive at both protein and mRNA levels . Actinomycin D at the beginning of culture inhibited IL-8 mRNA induction, whereas late addition affected IL-8 transcript stability, suggesting gene transcription involvement . Results with parthenolide and tyrphostin AG490 suggest that nuclear factor-kappaB and signal transducer and activator of transcription 4 play a role . The IL-12 additive effect was restricted to IL-8 release, with no action on cell-associated IL-8 . IL-12 additive effects occurred after 18 h of culture, with no marked up-regulation of IL-12 receptor expression, and were blocked by actinomycin D added after 16 h of culture . Tumor necrosis factor (TNF) alpha and interferon (IFN) gamma had intermediate roles; their specific inhibition reduced IL-12's effect . IL-12's chemotactic mechanism seemed mediated by overproduction and release of IL-8 by human PMNs in the presence of LPS, an effect involving TNF-alpha and IFN-gamma secretion . These results point to a new role for IL-12 in inflammation, through an autocrine amplification loop.

Clin Diagn Lab Immunol, 2001 Sep, 8(5), 997 - 1002
Seroprevalence of antibodies to microorganisms known to cause arterial and myocardial damage in patients with or without coronary stenosis; Stollberger C et al.; Infections are assumed to play a role in coronary artery disease (CAD) and cardiomyopathies . It is unknown whether the seroprevalence of antibodies to these microorganisms is higher in patients with than without CAD . The seroprevalence of antibodies to Bartonella henselae, Borrelia burgdorferi, Chlamydia pneumoniae, Coxiella burnetii, Helicobacter pylori, human granulocytic Ehrlichia, Leptospira, Rickettsia conorii, and Treponema pallidum was assessed prospectively in patients with exertional dyspnea or anginal chest pain who underwent coronary angiography because of suspected CAD . Patients with normal angiograms (NA) were those in whom no more than 50% stenosis of any coronary artery was found . Patients with CAD were patients who underwent percutaneous transluminal coronary angioplasty . There were 50 patients with CAD (9 female) and 62 with NA (25 female), with a mean age of 62 years . All patients had antibodies to at least one microorganism: to B . henselae, 8% of CAD patients and 5% of NA patients; to B . burgdorferi IgG, 14% CAD and 6% NA; to B . burgdorferi IgM, 6% CAD and 3% NA; to C . pneumoniae lipopolysaccharide (LPS) IgA, 76% CAD and 77% NA; to C . pneumoniae LPS IgG, 80% CAD and 90% NA; to C . burnetii, 0% CAD and 5% NA; to H . pylori, 92% CAD and 68% NA; to human granulocytic Ehrlichia, 8% CAD and 3% NA; to Leptospira IgG, 4% CAD and 2% NA; to R . conorii, 10% in both groups; and to T . pallidum, 2% CAD and 0% NA . The seroprevalence of antibodies to micro-organisms known to induce arterial and myocardial damage does not differ between patients with CAD and NA.

Minerva Ginecol, 2001 Feb, 53(1 Suppl 1), 134 - 8
{Gestational HSV in the work setting}; Passaro M et al.; OBJECTIVE: The purpose of our studies has been that to individualize the in partnership factors of risk to infection Herpes Simplex Virus-Type 2 in pregnant women and to appraise the role of the job in such context . METHODS: A champion of 79 pregnant women with infection from HSV-2 has responded to a questionnaire regarding the appearance of the infection, her own job and the degree of stress, if they used services hygienic public . RESULTS: In this champion of pregnant women 63% they are workers . Of these the 85% they introduced signs of a reinfection . For the housewives in 67% there was a reinfection . 84% of the housewives it uses services hygienic privacies . The infection from HSV has appeared in 28.5% of the been born by women with first infection from HSV genitalis, and in 12.5% of the been born by women with reinfection from HSV . CONCLUSIONS: The women that work are mostly to risk of reinfection, they have more evident troubles . This is consequence of a style of life that contemplates a state of superior stress and a great tiredness from the same and of the appearance of vulvo-vaginal infections sustained by microorganisms transmitted through the hygienic services.

Proc Natl Acad Sci U S A, 2001 Aug 28, 98(18), 10119 - 24
A hemoglobin from plants homologous to truncated hemoglobins of microorganisms; Watts RA et al.; We have identified a nuclear-encoded Hb from plants (GLB3) that has a central domain similar to the "truncated" Hbs of bacteria, protozoa, and algae . The three-dimensional structure of these Hbs is a 2-on-2 arrangement of alpha-helices, distinct from the 3-on-3 arrangement of the standard globin fold {Pesce, A., Couture, M., Dewilde, S., Guertin, M., Yamauchi, K., Ascenzi, P., Moens, L . & Bolognesi, M . (2000) EMBO J . 19, 2424-2434} . GLB3-like genes are not found in animals or yeast, but our analysis reveals that they are present in a wide range of Angiosperms and a Bryophyte . Although cyanobacteria and Chlamydomonas have 2-on-2 Hbs (GLBN), GLB3 is more likely related to GLBO-type 2-on-2 Hbs from bacteria . Consequently, GLB3 is unlikely to have arisen from a horizontal transfer between the chloroplast and nuclear genomes . Arabidopsis thaliana GLB3 protein exhibits unusual concentration-independent binding of O(2) and CO . The absorbance spectrum of deoxy-GLB3 is unique; the protein forms a transient six-coordinate structure after reduction and deoxygenation, which slowly converts to a five-coordinate structure . In A . thaliana, GLB3 is expressed throughout the plant but responds to none of the treatments that induce plant 3-on-3 Hbs . Our analysis of the sequence, ligand interactions, and expression profile of GLB3 indicates that this protein has unique biochemical properties, evolutionary history, and, most likely, a function distinct from those of other plant Hbs.

J Clin Microbiol, 2001 Sep, 39(9), 3222 - 7
Direct identification of mycobacteria from MB/BacT alert 3D bottles: comparative evaluation of two commercial probe assays; Scarparo C et al.; The new INNO-LiPA Mycobacteria (Innogenetics, Ghent, Belgium), a reverse-hybridization-based line probe assay, and the AccuProbe assay (Gen-Probe Inc., San Diego, Calif.) were applied to MB/BacT Alert 3D (MB/BacT) system (Organon Teknika, Boxtel, The Netherlands) culture bottles and evaluated for mycobacterial identification . From 2,532 respiratory and extrapulmonary specimens submitted for culture, 168 were flagged positive by the MB/BacT system and promptly evaluated for identification (within 24 h) . Each of 163 vials grew one mycobacterial isolate, including Mycobacterium tuberculosis complex (n = 73), M . avium complex (n = 3), M . avium (n = 8), M . intracellulare (n = 5), M . kansasii (n = 15), M . gordonae (n = 8), M . malmoense (n = 3), M . chelonae (n = 13), M . abscessus (n = 2), M . xenopi (n = 11), M . scrofulaceum (n = 2), M . fortuitum (n = 7), M . terrae (n = 3), M . simiae (n = 2), M . celatum (n = 3), M . flavescens (n = 1), M . interjectum (n = 1), M . bohemicum (n = 1), and M . pulveris (n = 2) . Five cultures yielded mixed growth of two mycobacterial species: M . tuberculosis complex plus M . gordonae (n = 2), M . tuberculosis complex plus M . chelonae (n = 1), M . tuberculosis complex plus M . xenopi (n = 1), and M . avium plus M . chelonae (n = 1) . In testing of one-isolate vials, both systems showed excellent sensitivity and specificity for all species and complexes for which they are licensed (nine for INNO-LiPA Mycobacteria versus six for AccuProbe) . There were minor discrepancies in results for two isolates identified by INNO-LiPA Mycobacteria as M . avium - M . intracellulare - M . scrofulaceum (MAIS) complex and by AccuProbe as M . intracellulare . In testing of two-isolate vials, INNO-LiPA Mycobacteria correctly identified all isolates, while the AccuProbe assay failed to identify three M . tuberculosis complex isolates and one M . avium isolate . The AccuProbe assay was completed within 2 h, while INNO-LiPA Mycobacteria required a 6-h period . In our opinion, INNO-LiPA Mycobacteria offers the following advantages: (i) it contains a genus-specific probe that, in addition to being used in genus identification, may be used as an internal control for both the amplification and hybridization steps; (ii) it simultaneously identifies M . tuberculosis complex, MAIS complex, and seven other mycobacterial species, even from mixed cultures; (iii) its mycobacterial DNA amplification ensures reliable results independent from the concentration of viable microorganisms; and (iv) it genotypically identifies M . kansasii and M . chelonae . In conclusion, even though INNO-LiPA Mycobacteria is considerably less easy to use than AccuProbe, requiring personnel skilled in molecular biology techniques, it represents an excellent approach for routine identification of frequently encountered mycobacteria.

Int Immunol, 2001 Sep, 13(9), 1185 - 92
Distinct requirements for IL-6 in polyclonal and specific Ig production induced by microorganisms; Markine-Goriaynoff D et al.; The role of IL-6 in Ig production induced in the mouse by lactate dehydrogenase-elevating virus (LDV), Toxoplasma gondii or lipopolysaccharide (LPS) was assessed . Following infection with LDV, a strong activator of B cells, an early and transient IL-6 production was observed, that originated predominantly from macrophages . Whereas LDV-induced B lymphocyte proliferation appeared independent of IL-6, mice deficient for this cytokine showed a marked reduction in their total T-dependent IgG2a production when compared to their normal counterparts . By contrast, specific responses directed against either LDV or non-viral antigens administered at the time of infection were not decreased in the absence of IL-6 . Similarly, polyclonal, but not anti-parasite IgG2a production triggered by T . gondii infection was strongly dependent on the presence of IL-6 . Finally, T-independent total IgG3 secretion triggered by LPS was also markedly reduced in IL-6-deficient mice . These results suggest that IL-6 plays a major role in T-dependent and T-independent polyclonal Ig production following B lymphocyte activation by viruses, and parasites, but not in specific antibody responses induced by the same microorganisms.

Int Immunol, 2001 Sep, 13(9), 1099 - 107
Molecular mimicry: anti-DNA antibodies may arise inadvertently as a response to antibodies generated to microorganisms; Wun HL et al.; The origin of anti-DNA antibodies remains speculative . We argue that some of these antibodies may arise inadvertently in nature during the course of a normal immune response due to their induction by antibodies which bear structures (mimotopes) that mimic DNA . These antibodies are not necessarily DNA specific but, like the T15 idiotype (id)-positive antibodies which bind to phosphorylcholine, are produced normally to some environmental or microbial antigen . Such a mimotope was found in a T15(+) antibody at the highly specific region encoded principally by the D gene, DFL16.1 . This mimotope was also found in human antibodies that are encoded by DXP'1, the human counterpart of DFL16.1 and which is used commonly in anti-DNA antibodies . The mimotope is closely related to the epitope responsible for the T15 id and appears to be cryptic or normally hidden in the native protein . The existence of such a common, conserved sequence raises questions about how easily anti-DNA antibodies can be generated in nature and what purpose these proteins may serve . Molecular mimicry with regard to autoimmunity must thus be viewed as existing not necessarily between the infectious agent and self-antigens, but also between the antibodies induced by the organism and the self-antigens.

Biol Bull, 2001 Aug, 201(1), 26 - 33
Theoretical and experimental dissection of gravity-dependent mechanical orientation in gravitactic microorganisms; Mogami Y et al.; Mechanisms of gravitactic behaviors of aquatic microorganisms were investigated in terms of their mechanical basis of gravity-dependent orientation . Two mechanical mechanisms have been considered as possible sources of the orientation torque generated on the inert body . One results from the differential density within an organism (the gravity-buoyancy model) and the other from the geometrical asymmetry of an organism (the drag-gravity model) . We first introduced a simple theory that distinguishes between these models by measuring sedimentation of immobilized organisms in a medium of higher density than that of the organisms . Ni2+-immobilized cells of Paramecium caudatum oriented downwards while floating upwards in the Percoll-containing hyper-density medium but oriented upwards while sinking in the hypo-density control medium . This means that the orientation of Paramecium is mechanically biased by the torque generated mainly due to the anterior location of the reaction center of hydrodynamic stress relative to those of buoyancy and gravity; thus the torque results from the geometrical fore-aft asymmetry and is described by the drag-gravity model . The same mechanical property was demonstrated in gastrula larvae of the sea urchin by observing the orientation during sedimentation of the KCN-immobilized larvae in media of different density: like the paramecia, the gastrulae oriented upwards in hypo-density medium and downwards in hyper-density medium . Immobilized pluteus larvae, however, oriented upwards regardless of the density of the medium . This indicates that the orientation of the pluteus is biased by the torque generated mainly due to the posterior location of the reaction center of gravity relative to those of buoyancy and hydrodynamic stress; thus the torque results from the fore-aft asymmetry of the density distribution and is described by the gravity-buoyancy model . These observations indicate that, during development, sea urchin larvae change the mechanical mechanism for the gravitactic orientation . Evidence presented in the present paper demonstrates a definite relationship between the morphology and the gravitactic behavior of microorganisms.

Appl Environ Microbiol, 2001 Sep, 67(9), 3897 - 903
Combination of competitive quantitative PCR and constant-denaturant capillary electrophoresis for high-resolution detection and enumeration of microbial cells; Lim EL et al.; A novel quantitative PCR (QPCR) approach, which combines competitive PCR with constant-denaturant capillary electrophoresis (CDCE), was adapted for enumerating microbial cells in environmental samples using the marine nanoflagellate Cafeteria roenbergensis as a model organism . Competitive PCR has been used successfully for quantification of DNA in environmental samples . However, this technique is labor intensive, and its accuracy is dependent on an internal competitor, which must possess the same amplification efficiency as the target yet can be easily discriminated from the target DNA . The use of CDCE circumvented these problems, as its high resolution permitted the use of an internal competitor which differed from the target DNA fragment by a single base and thus ensured that both sequences could be amplified with equal efficiency . The sensitivity of CDCE also enabled specific and precise detection of sequences over a broad range of concentrations . The combined competitive QPCR and CDCE approach accurately enumerated C . roenbergensis cells in eutrophic, coastal seawater at abundances ranging from approximately 10 to 10(4) cells x ml(-1) . The QPCR cell estimates were confirmed by fluorescent in situ hybridization counts, but estimates of samples with <50 cells x ml(-1) by QPCR were less variable . This novel approach extends the usefulness of competitive QPCR by demonstrating its ability to reliably enumerate microorganisms at a range of environmentally relevant cell concentrations in complex aquatic samples.

Crit Care Clin, 2001 Jul, 17(3), 531 - 70, vii-viii
Infectious morbidity in critically ill patients with cancer; Safdar A et al.; Infection frequently complicates the course of cancer treatment and often adversely affects the outcome . Patients have a greater tendency for acquiring infections caused by opportunistic microorganisms . Agents with low virulence potential may lead to invasive and often life-threatening infections because of altered host immune function . The immune dysfunction may be caused by the underlying malignancy, by antineoplastic chemotherapy, or by invasive procedures during supportive care.

Mol Genet Genomics, 2001 Aug, 265(6), 1112 - 9
Identification of genes required for growth under ethanol stress using transposon mutagenesis in Saccharomyces cerevisiae; Takahashi T et al.; The yeast Saccharomyces cerevisiae exhibits high ethanol tolerance compared with other microorganisms . The mechanism of ethanol tolerance in yeast is thought to be regulated by many genes . To identify some of these genes, we screened for ethanol-sensitive S . cerevisiae strains among a collection of mutants obtained using transposon mutagenesis . Five ethanol-sensitive (ets) mutants were isolated from approximately 7,000 mutants created by transforming yeast cells with a transposon (mTn-lacZ/LEU2)-mutagenized genomic library . Although these mutants grew normally in a rich medium, they could not grow in the same medium containing 6% ethanol . Sequence analysis of the ets mutants revealed that the transposon was inserted in the coding regions of BEM2, PAT1, ROM2, VPS34 and ADA2 . We constructed deletion mutants for these genes by a PCR-directed disruption method and confirmed that the disruptants, like the ets mutants, were ethanol sensitive . Thus, these five genes are indeed required for growth under ethanol stress . These mutants were also more sensitive than normal cells to Calcofluor white, a drug that affects cell wall architecture, and Zymolyase, a yeast lytic enzyme containing mainly beta-1,3- glucanase, indicating that the integrity of the cell wall plays an important role in ethanol tolerance in S . cerevisiae.

J Chem Ecol, 2001 Aug, 27(8), 1701 - 12
Methodological setup to study allelochemical translocation in radish seedlings; Chiapusio G et al.; {Ring-U14C} p-hydroxybenzoic acid (POH) translocation during radish germination and early seedling growth was studied to compare two culture conditions (sterile/non-sterile) and two modes of POH extraction (ethanol/oxidizing) . Quantification of POH in organs was performed by grinding them in a mortar with ethanol or by combusting them in a biological oxidizer . Comparison of these extraction methods revealed that the oxidizer provides higher POH concentrations than grinding . Uptake and translocation of POH into radish seedlings occurred in the first 24 hr with the highest accumulation in cotyledons . POH in cotyledons ranged from 8 to 12.4 mumol g-1 FW . Two forms of POH were found in seedlings, an ethanol-soluble one and a "bound" one . After 96 hr incubation, half of the recovered POH was "bound" in roots and hypocotyls . POH recovery in seedlings was also higher under axenic rather than non-axenic conditions . POH was degraded into 14CO2 by microorganisms under non-sterile cultures, its concentration in culture medium decreased from 10(-3) to 10(-4) M between the first and the fourth day of incubation . Choice between sterile and non-sterile culture conditions as a method depends on particular research objectives . Non-sterile methods can be used to reflect natural processes whereas sterile methods can be used if the objective is to determine allelochemical penetration and biological effects on target plants.

Semin Respir Infect, 2001 Jun, 16(2), 102 - 8
Cell-mediated immunity to Histoplasma capsulatum; Newman SL; Histoplasma capsulatum is a facultative intracellular pathogen, and the causative agent of the most common systemic fungal infection . Over the past several years, many new insights have been learned concerning the biology, biochemistry, and molecular genetics of this microorganism . This review focuses on the immunology of host defense against H . capsulatum yeasts with emphasis on the development of cell-mediated immunity, and the strategies used by the fungus to survive and multiply within macrophages .

FEMS Microbiol Lett, 2001 Aug 21, 202(2), 181 - 7
The sites of interaction of triphenyltetrazolium chloride with mitochondrial respiratory chains; Rich PR et al.; The inability of cells and microorganisms to reduce the colourless electron acceptor triphenyltetrazolium chloride (TTC) to a red formazan precipitate is commonly used as a means of screening for cells that have a dysfunctional respiratory chain . The site of reduction of TTC is often stated to be at the level of cytochrome c oxidase where it is assumed to compete with oxygen for reducing equivalents . However, we show here that TTC is reduced not by cytochrome c oxidase but instead by dehydrogenases, particularly complex I, probably by accepting electrons directly from low potential cofactors . The reduction rate is fastest in coupled membranes because of accumulation in the matrix of the positively charged TTC+ cation . However, the initial product of TTC reduction is rapidly reoxidised by molecular oxygen, so that generation of the stable red formazan product from this intermediate occurs only under strictly anaerobic conditions . Colonies of mutants defective in cytochrome oxidase do not generate sufficiently anaerobic conditions to allow the intermediate to form the stable red formazan . This revision of the mode of interaction of TTC with respiratory chains has implications for the types of respiratory-defective mutants that might be detected by TTC screening.

Acta Microbiol Pol, 2001, 50(1), 75 - 82
Distribution of tannic acid degrading microorganisms in the soil and comparative study of tannase from two fungal strains; Mondal KC et al.; A quantitative survey on microbial population including tannase producing organisms have been made from different soil samples . Most of the samples harbour negligible number of tannase producers in comparison to total microbial flora . Among the tannase producers, fungal members are more frequent than bacteria . Tannase production and tannic acid degradation have been studied in two newly isolated potent fungal strains . Both the strains produce maximum tannase at their stationary phases of growth . Enzymes produced by both the strains remain active within pH 3.5-6.0 and temperature 30-60 degrees C.

Vet Parasitol, 2001 Jul 12, 98(1-3), 215 - 38
Wolbachia in filarial nematodes: evolutionary aspects and implications for the pathogenesis and treatment of filarial diseases; Bandi C et al.; The presence of intracellular bacteria in the body of various species of filarial nematodes, including important parasites such as Brugia malayi, Dirofilaria immitis, and Onchocerca volvulus, was observed as early as the mid-1970s . These bacteria were shown to be transovarially transmitted (from the female worm to the offspring) and to be present in significant amounts in the body of the nematode . As highlighted by their discoverers, the potential importance of these bacteria is fairly obvious: (1) bacteria-derived molecules should be considered as having an immunological and pathological role in filarial diseases; (2) the interaction between the bacteria and the filarial host deserves investigation, in view of the possibility that the bacteria are needed by the host nematode and could thus represent a target for therapy . Other authors, independently from the discovery of these intracellular bacteria, showed that the antibiotic tetracycline (which is well known for its efficacy on intracellular bacteria) had detrimental effects on two species of filarial nematodes (Brugia pahangi and Litomosoides sigmodontis) . It is therefore surprising that for more than 20 years, no further investigations focused on the bacteria of filarial nematodes, nor on the anti-filarial properties of tetracycline . Recently, the bacteria of filarial nematodes have been independently "rediscovered" by research groups from the schools of Hamburg, Liverpool and Milan . These bacteria are now classified as Wolbachia, and the basic aspects of their phylogenetic history and relationship with the Wolbachia of arthropods have been reconstructed . In addition, their implications for the pathogenesis and treatment of filarial diseases have started to be uncovered . This paper, which is authored by representatives of the three European schools who reopened this research area, reviews our present knowledge of these fascinating microorganisms, highlighting the complexity of a symbiotic system which involves, in addition to the nematode and its bacterium, the vertebrate host.

J Bacteriol, 2001 Sep, 183(18), 5279 - 84
Molecular evidence for independent occurrence of IS6110 insertions at the same sites of the genome of Mycobacterium tuberculosis in different clinical isolates; Fang Z et al.; Several characteristics of Mycobacterium tuberculosis (e.g., conserved genome and low growth rate) have severely restricted the study of the microorganism . The discovery of IS6110 raised hopes of overcoming these obstacles . However, our knowledge of this IS element is relatively limited; even its two basic characteristics (transposition mechanism and target site selection) are far from well understood . In this study, IS6110 insertions in ipl loci (iplA and iplB) in two collections of clinical isolates of M . tuberculosis from different geographic locations, one from Scotland and the other from Thailand, were investigated . Five different IS6110 insertions in the loci were identified: ipl-4::IS6110, ipl-5::IS6110, ipl-11::IS6110, ipl-12::IS6110, and ipl-13::IS6110 . An attempt to establish the phylogenetic relationship of the isolates containing these insertions was unsuccessful, suggesting that some of these insertions may have arisen from more than one event . This possibility is further supported by the observation that IS6110 copies existed in the same site but with different orientations in different isolates, and the insertion site of ipl-1::IS6110 harbored IS6110 copies in both iplA and iplB in different strains . All these suggest the independent occurrence of IS6110 insertions at the same sites of the genome of M . tuberculosis in different clinical isolates . The implications of this finding are discussed.

Am J Surg, 2001 Jun, 181(6), 564 - 6
How often does glove perforation occur in surgery? Comparison between single gloves and a double-gloving system; Laine T et al.; BACKGROUND: In surgery, intact gloves protect the surgeon from bloodborne pathogens and the surgical wound from microorganisms on the skin of the surgeon . However, glove perforation is very common, and puncture rates as high as 61% are published in the literature . One objective of this study was to compare puncture rates between a unique double-gloving puncture indication system and single-use gloves, and another was to determine the extent to which glove perforations remain undetected during surgery . METHODS: The study material comprised all gloves used in surgical operations at our hospital for a period of 2 months . The analysis was made by the glove type in a prospective and randomized manner . Gloves were tested immediately after the surgical procedure using the approved standardized water-leak method for 2 minutes to detect any holes . The gloves used in this study were either a double-gloving puncture indication system or the standard glove used at our hospital . RESULTS: In 885 operations altogether, 2,462 gloves were tested; 1,020 single gloves, 1,148 double-glove systems, and 294 combination gloves were studied . The overall perforation rate was 192 out of 2,462 gloves (7.80%), and 162 out of 885 operations (18.3%) . The detection of perforation during surgery was 28 out of 76 (36.84%) with single gloves, 77 out of 89 with the double-gloving system (86.52%), and 9 out of 27 with combination gloves (33.33%; P <0.001) . The inner glove of the double-gloving system was punctured in 6 out of 88 outer glove perforations (6.82%) . CONCLUSIONS: In view of the critical importance of safety at work by having a sterile barrier between surgeon and patient, it is very important to use a double-gloving puncture indication system, at least in operations where there is a high risk of glove perforation.

Chemosphere, 2001 Sep, 44(6), 1413 - 20
Reductive dechlorination of polychlorinated biphenyls as affected by sediment characteristics; Kim J et al.; The effect of sediment sources on the selection of polychlorinated biphenyl (PCB) dechlorinating competence was investigated using sediments from two different locations, the Grasse River and Owasco Lake . These two sediments had a similar organic carbon content but different particle size distribution . The two PCB-free sediments were spiked with Aroclor 1248 and inoculated with microorganisms from the Reynolds and General Motors sites in the St . Lawrence River, which exhibited different dechlorination patterns . When each inoculum was serially transferred into fresh sediments four times (every 8-10 weeks), they still maintained the initial dechlorination patterns regardless, the source of sediments and the number of transfers, and dechlorination patterns of the two inocula in the same sediments did not converge . In a parallel approach, when the acclimated microorganisms from the Reynolds site were inoculated into fresh sediments from both sources as well as sediments enriched with organic carbon (2%, w/v), the dechlorination pattern remained unchanged after a 40-week incubation . These results suggest that the sediment characteristics or organic carbon content did not play a role in the selection of dechlorinating populations.

Skin Pharmacol Appl Skin Physiol, 2001, 14 Suppl 1, 87 - 91
Oxidative targets in the stratum corneum . A new basis for antioxidative strategies; Thiele JJ; As the outermost layer of skin, the stratum corneum (SC) is continuously exposed to an oxidative environment, including air pollutants, ultraviolet radiation, chemical oxidants, and aerobic microorganisms . Human SC reveals characteristic antioxidant and protein oxidation gradients with increasing antioxidant depletion and protein oxidation towards the outer layers . SC antioxidants, lipids, and proteins are oxidatively modified upon treatments with ultraviolet A/ultraviolet B, ozone, and benzoyl peroxide . alpha-Tocopherol represents the predominating SC antioxidant with respect to its concentration and its unique susceptibility to the various oxidative challenges tested . In sites rich in sebaceous glands, alpha-tocopherol is physiologically delivered to the surface via secretion of sebum . Oxidative damage in the human SC represents an early pathophysiological event preceding barrier disruption and inflammation in environmentally challenged skin . Furthermore, oxidative gradients in SC proteins may have implications for the process of desquamation in human skin .

Huan Jing Ke Xue, 2001 May, 22(3), 44 - 8
{Accumulation of heavy metals in urban soils and impacts on microorganisms}; Yang Y et al.; Compared with rural soils, urban soils in Aberdeen city possessed obviously different microbial features: higher in microbial basal respiration strength, and microbial ecophysiological parameters Cmic/Corg and qCO2, but lower in microbial biomass, also much more rapid in consuming carbon sources deduced from Biolog data . Urban soils showed different characteristics in heavy metals as well . Apparent accumulation of Pb, Zn, Cu, Ni were observed, in which Pb mainly related with iron oxides, Ni, Zn existed in residual forms, Cu exhibited same importance of different chemical forms but for soluble forms . Principal component analysis results reflected the overwhelming factor to control the difference of microbial features between urban and rural soils was soluble Pb, then soluble Zn, soluble and organic bonded Cu and Ni also contributed in some degree.

J Nephrol, 2001 Jul-Aug, 14(4), 304 - 6
Successful therapy combined with surgery for severe post-transplant nocardiosis; Kayacan SM et al.; We report a case of a 35-year-old man with nocardiosis infection involving soft tissue and the central nervous system who had received a cadaveric donor kidney . The patient was admitted with fever, malaise and right shoulder pain . Soft tissue abscess was seen on ultrasound examination . It was presumed due to gram (+) microorganisms, so 4 g day (IV) ampicillin/sulbactam was started empirically once the abscess was drained . Nocardia asteroides was found in the pus specimen . On the second day in hospital, severe headache, ataxia and signs of meningeal irritation appeared . The cranial CT showed two intracranial abscesses in the frontal lobe and cerebellum . We assumed Nocardia asteroides was the infective agent for the cerebral abscesses, so antibiotic therapy was switched to trimethoprim-sulphamethox-asole (3x160/800 mg/d) . Nausea and vomiting occurred on the fifth day of therapy, improving after drainage from the frontal abscess . However, these complaints recurred five days later . CT showed cerebellar abscess had become bigger . The patient's complaints improved after the second surgical drainage . N . asteroides was again grown in the aspiration fluids of both cerebral abscesses . Complete regression of the abscesses was seen in the CT after two months . Co-trimoxazole was continued for six months then withdrawn . Graft dysfunction was not observed . Early medical and surgical interventions may be life-saving in this potentially lethal disease.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2001 Aug, 92(2), 221 - 7
Study of the expression of CD68+ macrophages and CD8+ T cells in human granulomas and periapical cysts; Rodini CO et al.; In the periapex, the interaction among inflammatory cells and microorganisms and their products results both in specific and nonspecific immune responses . Many studies have reported quantitative analysis of the immunocompetent cells in periapical lesions, but the exact ratio of these cells in cysts and granulomas remains unknown . In the present study, we undertook a quantitative analysis of CD68+ cells and CD8+ T cells in human periapical granulomas and cysts . Immunoperoxidase staining revealed that CD68+ cells were present in both lesions, with no statistically significant difference, mainly distributed in the inner portion of the lesion, where the inflammation site is more active . On the other hand, CD8+ lymphocytes were more numerous in cysts . Thus, it appears that CD8+ T cells may play a more important role in a later phase of periapical lesion progression, probably exerting regulatory or cytotoxic functions in cellular immune response, which may lead to the stabilization of these lesions.

Can J Surg, 2001 Aug, 44(4), 284 - 8
Empyema thoracis: lack of awareness results in a prolonged clinical course; Chu MW et al.; OBJECTIVE: To assess the hypothesis that empyema thoracis (ET) is a problem often not optimally treated . Long delays in diagnosis are common, long hospital stays are typical and recovery with surgery is relatively rapid . DESIGN: A chart review . SETTING: The Regina Health District associated hospitals, a tertiary referral centre . PATIENTS: The charts of 34 consecutive patients having primary respiratory tract disease and seen during the 6-year period Apr . 1, 1991, to Mar . 31, 1997, were identified . OUTCOME MEASURES: Patient presentation, time until diagnosis of ET, number of radiologic investigations, microbiologic features, treatment methods, postoperative course and mortality . RESULTS: The mean delay in diagnosis, defined as the time of admission to the time of correct diagnosis, was 44.2 days (range from 0 to 573 days) and the mean delay until thoracic surgery referral was 47.4 days (range from 0 to 578 days) . On average each patient underwent CT 10.1 times, had 2.6 percutaneous drainage procedures and 2.0 chest tube insertions . The mean time from the first percutaneous chest drainage to the date of diagnosis was 29.8 days (range from 0 to 564 days) . Of the 26 patients who underwent CT, the mean time from the first CT of the chest to the date of diagnosis was 9.5 days (range from 0 to 75 days) . Cultures of pleural fluid grew no organisms in 17 patients; in the remaining 17 patients cultures grew 23 different microorganisms . Of 26 patients who were referred for surgical opinion, 18 underwent decortication; 8 were not considered to be surgical candidates . Pathological examination showed 17 cases of inflammatory empyema and 1 case of mesothelioma (unrecognized clinically) . The mean length of hospital stay postoperatively was 15.2 days . CONCLUSIONS: Early suspicion of ET facilitates its treatment, resulting in fewer investigations and shorter hospital stays . When percutaneous drainage does not eliminate pleural effusions, empyema must be considered . Recovery from surgical decortication is rapid in comparison with the typical protracted preoperative hospital course.

J Endod, 2001 Aug, 27(8), 527 - 32
Regional bond strengths of adhesive resins to pulp chamber dentin; Belli S et al.; Microleakage of oral microorganisms, which can occur due to the lack of sealing ability of permanent restorative materials, may cause failure of root canal treatments . Although a great deal of research has been done on sealing enamel and coronal dentin with resins, little research has been done on the adhesion of resins to the walls of pulp chambers . The purpose of this study was to evaluate regional bond strengths of two adhesive systems to the walls of pulp chambers . A section was made horizontally through the middle of the pulp chamber of extracted human third molars to divide the chamber into upper and lower halves . The pulp tissue was removed and the tooth segments were then divided into treatment subgroups . The pulp chambers were bonded with C&B Metabond (Parkell) or One-Step (Bisco), with or without 5% NaOCI pretreatment . The microtensile bond strengths of these resins to four different pulp chamber regions (bottom, wall, roof, and pulp horn areas) were then measured using an Instron machine . The data were expressed in MPa and were analyzed by a three-way ANOVA . Statistically significant differences were found among the test groups (p < 0.001) . One-Step produced higher bond strengths to all pulp chamber regions except the floor, compared with C&B Metabond . The results indicated that high bond strengths can be achieved between adhesive resins and the various regions of the pulp chamber . This should permit the use of a thick layer of unfilled resin along the floor of the pulp chamber and over the canal orifices as a secondary protective seal after finishing root canal therapy.

Adv Drug Deliv Rev, 2001 Sep 1, 50(3), 205 - 27
Veterinary drug delivery: potential for skin penetration enhancement; Magnusson BM et al.; A range of topical products are used in veterinary medicine . The efficacy of many of these products has been enhanced by the addition of penetration enhancers . Evolution has led to not only a highly specialized skin in animals and humans, but also one whose anatomical structure and skin permeability differ between the various species . The skin provides an excellent barrier against the ingress of environmental contaminants, toxins, and microorganisms while performing a homeostatic role to permit terrestrial life . Over the past few years, major advances have been made in the field of transdermal drug delivery . An increasing number of drugs are being added to the list of therapeutic agents that can be delivered via the skin to the systemic circulation where clinically effective concentrations are reached . The therapeutic benefits of topically applied veterinary products is achieved in spite of the inherent protective functions of the stratum corneum (SC), one of which is to exclude foreign substances from entering the body . Much of the recent success in this field is attributable to the rapidly expanding knowledge of the SC barrier structure and function . The bilayer domains of the intercellular lipid matrices within the SC form an excellent penetration barrier, which must be breached if poorly penetrating drugs are to be administered at an appropriate rate . One generalized approach to overcoming the barrier properties of the skin for drugs and biomolecules is the incorporation of suitable vehicles or other chemical compounds into a transdermal delivery system . Indeed, the incorporation of such compounds has become more prevalent and is a growing trend in transdermal drug delivery . Substances that help promote drug diffusion through the SC and epidermis are referred to as penetration enhancers, accelerants, adjuvants, or sorption promoters . It is interesting to note that many pour-on and spot-on formulations used in veterinary medicine contain inert ingredients (e.g., alcohols, amides, ethers, glycols, and hydrocarbon oils) that will act as penetration enhancers . These substances have the potential to reduce the capacity for drug binding and interact with some components of the skin, thereby improving drug transport . However, their inclusion in veterinary products with a high-absorbed dose may result in adverse dermatological reactions (e.g., toxicological irritations) and concerns about tissue residues . These are important considerations when formulating a veterinary transdermal product when such compounds are added, either intentionally or otherwise, for their penetration enhancement ability.

Transfus Clin Biol, 2001 Jun, 8(3), 291 - 6
DNA chips: a new tool for genetic analysis and diagnostics; Cuzin M; DNA chips are miniaturized microsystems based on the ability of DNA to spontaneously find and bind its complementary sequence in a highly specific and reversible manner, known as hybridization . Labeled DNA molecules in a sample are analyzed by DNA probes tethered at distinct sites on a solid support . The composition of the DNA sample is then deduced by analyzing the signal generated by labels present at each probe site . Applications are widespread: fundamental research, cancer or microbiology diagnostics, genotyping, gene expression, pharmacogenomics, and environmental control . Medical application consists, for example, in the identification and detection of mutations in genes responsible for cancers, or DNA chip analysis of individual polymorphisms which may provide a guide towards the most efficient treatment . In the environmental and agro-industrial fields, DNA chips show great promise in rapidly testing microorganism content, contamination or pathogenicity . DNA chip dimensions offer hybridization sites in the 50-200 micron range, producing arrays ranging from 100 to 1,000,000 different probes per cm2.

Clin Nephrol, 2001 Jul, 56(1), 52 - 9
Dialysis membrane-induced neutrophil apoptosis is mediated through free radicals; Nahar N et al.; Patients on hemodialysis are prone to infection . Neutrophils are the host's first line of defense against certain invading pathogenic microorganisms . Since apoptotic neutrophils are functionally compromised we examined the effect of dialysis membranes on neutrophil apoptosis . Dialysis patients showed greater (p < 0.001) neutrophil apoptosis when compared with control subjects . Cellulose acetate membranes directly promoted (p < 0.001) neutrophil apoptosis . Cellulose acetate membrane-treated neutrophils exhibited greater apoptosis (p < 0.01) when compared with polysulfone membrane-treated neutrophils . Superoxide dismutase (SOD) partly inhibited the cellulose acetate membrane-induced neutrophil apoptosis, whereas both catalase and dimethylthiourea (DMTU) inhibited the polysulfone membrane-induced neutrophil apoptosis . Similarly, L-NAME, a nitric oxide synthase inhibitor, attenuated both the cellulose acetate and the polysulfone membrane-induced neutrophil apoptosis . In addition, cellulose acetate and monocyte interaction products promoted (p < 0.001) neutrophil apoptosis . These results suggest that dialysis membranes can promote neutrophil apoptosis directly as well as through their interaction with monocytes . The direct effect of dialysis membranes seems to be mediated partly through the generation of reactive oxygen species.

Ann Transplant, 2000, 5(4), 5 - 11
Leukocytes and endothelium interaction as rate limiting step in the inflammatory response and a key factor in the ischemia-reperfusion injury; Maroszynska I et al.; Leukocyte-endothelium interactions play a key role in regulation of the inflammatory response, leukocytes migration and ischaemia-reperfusion injury . These adhesive reactions controlling the circulation of leukocytes, are key parts of immune surveillance arising from extravasation of neutrophils, and migration into tissue to eliminate invading microorganism . They also play important role in the generation of ischaemic-reperfusion injury of different organs including brain . Plasma levels of soluble adhesion molecules may be a diagnostic marker of the systemic endothelial injury . It is likely that the next few years bring new therapies to control leukocyte-endothelial interaction by directly inhibiting the adhesion molecules or by modulating their expression.

New Microbiol, 2001 Jul, 24(3), 259 - 64
Detection of Legionella pneumophila at thermal spas; Martinelli F et al.; Water samples were collected at three therapeutic thermal spas in the area of Brescia, between February and October 2000: 34.8% of the samples contained Legionella pneumophila; the predominant isolates (30%) belonged to Legionella pneumophila serogroup 1 . The microorganism was present in the spa water at high concentrations, generally higher than 10000 cfu/l . The large number of positive Legionella pneumophila samples indicates a potential risk of infection to patients, especially those undergoing inhalation treatment with thermal water, or those using a whirlpool or taking a shower even if, during the study, no clinical cases of Legionnaires' disease were observed . In some inhalators in use we detected Legionella pneumophila: after a treatment to eradicate the microorganism, no sanitary fittings currently show contamination . Thus, in our opinion, they are not sources of infection when they are mantained and serviced properly . Thermal disinfection and service checks at regular intervals are suggested for contaminated systems.

Nature, 2001 Aug 9, 412(6847), 635 - 8
Unicellular cyanobacteria fix N2 in the subtropical North Pacific Ocean; Zehr JP et al.; Fixed nitrogen (N) often limits the growth of organisms in terrestrial and aquatic biomes, and N availability has been important in controlling the CO2 balance of modern and ancient oceans . The fixation of atmospheric dinitrogen gas (N2) to ammonia is catalysed by nitrogenase and provides a fixed N for N-limited environments . The filamentous cyanobacterium Trichodesmium has been assumed to be the predominant oceanic N2-fixing microorganism since the discovery of N2 fixation in Trichodesmium in 1961 (ref . 6) . Attention has recently focused on oceanic N2 fixation because nitrogen availability is generally limiting in many oceans, and attempts to constrain the global atmosphere-ocean fluxes of CO2 are based on basin-scale N balances . Biogeochemical studies and models have suggested that total N2-fixation rates may be substantially greater than previously believed but cannot be reconciled with observed Trichodesmium abundances . It is curious that there are so few known N2-fixing microorganisms in oligotrophic oceans when it is clearly ecologically advantageous . Here we show that there are unicellular cyanobacteria in the open ocean that are expressing nitrogenase, and are abundant enough to potentially have a significant role in N dynamics.

Indian J Exp Biol, 2001 Apr, 39(4), 310 - 22
Role of garlic (Allium sativum L.) in human and plant diseases; Singh UP et al.; A resurgence of interest in garlic due to recent revelations of its beneficial effects in the treatment of various human and plant diseases and also due to validation of claims made in traditional systems of medicine has resulted a plethora of publications on different aspects of garlic in recent years . Chemical constituents of garlic and their variations on the methods of isolation have been discussed in the present review . Effect of garlic and its constituents against various human and plant pathogenic and saprophytic microorganisms has also been reviewed.

Environ Toxicol Chem, 2001 Aug, 20(8), 1690 - 7
Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil . 5 . Probabilistic risk assessment of linear alkylbenzene sulfonates in sludge-amended soils; Jensen J et al.; Linear alkylbenzene sulfonates (LAS) can be found in high concentrations in sewage sludge and, hence, may enter the soil compartment as a result of sludge application . Here, LAS may pose a risk for soil-dwelling organisms . In the present probabilistic risk assessment, statistical extrapolation has been used to assess the risk of LAS to soil ecosystems . By use of a log-normal distribution model, the predicted no-effect concentration (PNEC) was estimated for soil fauna, plants, and a combination of these . Due to the heterogeneous endpoints for microorganisms, including functional as well as structural parameters, the use of sensitivity distributions is not considered to be applicable to this group of organisms, and a direct, expert evaluation of toxicity data was used instead . The soil concentration after sludge application was predicted for a number of scenarios and used as the predicted environmental concentration (PEC) in the risk characterization and calculation of risk quotients (RQ = PEC/PNEC) . A LAS concentration of 4.6 mg/kg was used as the current best estimate of PNEC in all RQ calculations . Three levels of LAS contamination (530, 2,600, and 16,100 mg/kg), three half-lives (10, 25, and 40 d), and five different sludge loads (2, 4, 6, 8, and 10 t/ha) were included in the risk scenarios . In Denmark, the initial risk ratio would reach 1.5 in a realistic worst-case consideration . For countries not having similar sludge regulations, the estimated risk ratio may initially be considerably higher . However, even in the most extreme scenarios, the level of LAS is expected to be well beyond the estimated PNEC one year after application . The present risk assessment, therefore, concludes that LAS does not pose a significant risk to fauna, plants, and essential functions of agricultural soils as a result of normal sewage sludge amendment . However, risks have been identified in worst-case scenarios.

Environ Toxicol Chem, 2001 Aug, 20(8), 1664 - 72
Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil . 2 . Effects on soil microbiology as influenced by sewage sludge and incubation time; Elsgaard L et al.; The anionic surfactant linear alkylbenzene sulfonate (LAS) may inhibit soil microorganisms and may occur in agricultural soil through the application of sewage sludge . For five microbial parameters (microbial biomass C and the potentials of iron reduction, ammonium oxidation, dehydrogenase activity, and arylsulfatase activity), we compared the effects of aqueous LAS and LAS-spiked sewage sludge added to existing levels of 0, 3, 8, 22, 22, 62, 174, and 488 mg/kg soil (dry wt) in a Danish sandy agricultural soil that was incubated for 5 d to eight weeks . Arylsulfatase activity (measured after four weeks of incubation) was rather insensitive to LAS, with an EC 10 of 222 and more than 488 mg/kg in soil samples treated with aqueous LAS and LAS-spiked sewage sludge, respectively . For the other microbial parameters, the short-term effects (approximately one to two weeks) of aqueous LAS were characterized by an EC10 in the range of 3 to 39 mg/kg . Application of LAS via sewage sludge generally reduced the short-term effects for the microbial parameters, and the EC10 for LAS in sludge-amended soil after approximately one to two weeks of incubation ranged from less than 8 to 102 mg/kg . Recovery potential was seen for most microbial parameters as a result of prolonged incubation, both under conditions of LAS persistence (anaerobic conditions, the iron-reduction test) and LAS depletion (aerobic incubations, all other assays) . In conclusion, the short-term inhibitory effects of LAS on soil microbiology were decreased in the presence of sewage sludge and by a prolonged (two to eight weeks) laboratory incubation period.

Environ Toxicol Chem, 2001 Aug, 20(8), 1656 - 63
Effects and risk assessment of linear alkylbenzene sulfonates in agricultural soil . 1 . Short-term effects on soil microbiology; Elsgaard L et al.; Linear alkylbenzene sulfonates (LAS) may occur in sewage sludge that is applied to agricultural soil, in which LAS can be inhibitory to biological activity . As a part of a broader risk assessment of LAS in the terrestrial environment, we tested the short-term effects of aqueous LAS on microbial parameters in a sandy agricultural soil that was incubated for up to 11 d . The assays included 10 microbial soil parameters; ethylene degradation; potential ammonium oxidation; potential dehydrogenase activity; beta-glucosidase activity; iron reduction; the populations of cellulolytic bacteria, fungi and actinomycetes; the basal soil respiration; and the phospholipid fatty acid (PLFA) content . Except for beta-glucosidase activity, basal respiration, and total PLFA content, all soil parameters were sensitive to LAS, with EC10 values in the range of less than 8 to 22 mg/kg dry weight . This probably reflected a similar mode of LAS toxicity, ascribed to cell membrane interactions, and showed that sensitivity to LAS was common for various soil microorganisms . The extracellular beta-glucosidase activity was rather insensitive to LAS (ECI10, 47 mg/kg dry wt), whereas the basal soil respiration was not inhibited even at 793 mg/kg dry weight . This was interpreted as a combined response of inhibited and stimulated compartments of the microbial community . The PLFA content, surprisingly, showed no decrease even at 488 mg/kg . In conclusion, LAS inhibited specific microbial activities, although this could not be deduced from the basal respiration or the total PLFA content . The lowest EC10 values for microbial soil parameters were slightly higher than the predicted no-effect concentrations recently derived for plants and soil fauna (approximately 5 mg/kg dry wt).

J Immunol, 2001 Aug 15, 167(4), 2106 - 11
A point mutation in the IL-12R beta 2 gene underlies the IL-12 unresponsiveness of Lps-defective C57BL/10ScCr mice; Poltorak A et al.; Lps-defective C57BL/10ScCr (Cr) mice are homozygous for a deletion encompassing Toll-like receptor 4 that makes them refractory to the biological activity of LPS . In addition, these mice exhibit an inherited IL-12 unresponsiveness resulting in impaired IFN-gamma responses to different microorganisms . By positional cloning methods, we show here that this second defect of Cr mice is due to a mutation in a single gene located on mouse chromosome 6, in close proximity to the Igkappa locus . The gene is IL-12Rbeta2 . Cr mice carry a point mutation creating a stop codon that is predicted to cause premature termination of the translated IL-12Rbeta2 after a lysine residue at position 777 . The truncated beta2 chain can still form a heterodimeric IL-12R that allows phosphorylation of Janus kinase 2, but, unlike the wild-type IL-12R, can no longer mediate phosphorylation of STAT4 . Because the phosphorylation of STAT4 is a prerequisite for the IL-12-mediated induction of IFN-gamma, its absence in Cr mice is responsible for their defective IFN-gamma response to microorganisms.

Aliment Pharmacol Ther, 2001 Jun, 15 Suppl 1, 22 - 7
Review article: Helicobacter pylori and NSAID gastropathy; Lazzaroni M et al.; Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori are known to share a number of pathogenic mechanisms, but there is no evidence to show a significant synergic action between the two risk factors . Studies assessing this subject have differed in almost every aspect of their methodology, including the definition of a NSAID user as well as the types, doses, duration and their indications for NSAID use . They also differed in their end-points, the definition of dyspepsia and the regimes used for eradication of H . pylori . However, some conclusions may be drawn from the results of clinical trials . In H . pylori-positive patients without mucosal lesions, NSAIDs may aggravate dyspeptic symptoms but, with the exception of elderly patients, they do not present a definite major risk of gastric and duodenal lesions and, above all, of ulcer-correlated complications . So what recommendations can be made with regard to H . pylori eradication in patients requiring treatment with NSAIDs? The microorganism and the anti-inflammatory drugs are undoubtedly independent causes of gastric and duodenal damage . Patients taking NSAIDs who are found to have gastric or duodenal ulcers should therefore be tested for the bacterium and specifically treated, since H . pylori and NSAID-induced ulcers may be macroscopically indistinguishable . Whether asymptomatic patients taking NSAIDs should be tested and treated for H . pylori infection is still a matter of debate.

Acta Medica (Hradec Kralove), 2001, 44(2), 69 - 75
The toxins of Cyanobacteria; Patocka J; Cyanobacteria, formerly called "blue-green algae", are simple, primitive photosynthetic microorganism wide occurrence in fresh, brackish and salt waters . Forty different genera of Cyanobacteria are known and many of them are producers of potent toxins responsible for a wide array of human illnesses, aquatic mammal and bird morbidity and mortality, and extensive fish kills . These cyanotoxins act as neurotoxins or hepatotoxins and are structurally and functionally diverse, and many are derived from unique biosynthetic pathways . All known cyanotoxins and their chemical and toxicological characteristics are presented in this article.

Water Res, 2001 Sep, 35(13), 3077 - 84
Reductive dehalogenation of chlorinated ethenes with elemental iron: the role of microorganisms; Lampron KJ et al.; Trichloroethene (TCE) transformation and the product distribution in an aqueous medium containing zero-valent iron (Fe(0)) was investigated in the presence of an anaerobic mixed culture to assess the potential role of microorganisms in permeable iron barriers . The presence of the culture increased the rate of TCE disappearance and changed the product distribution . Rapid formation and degradation of cis-dichloroethene (cis-DCE) was observed in reactors containing cells plus Fe(0) or H2 as a bulk reducing agent . High levels of vinyl chloride (VC) were formed and very similar profiles were obtained in the Fe(0) plus cell and H2 plus cell reactors, but not in Fe(0)-only reactors . The similar trends observed in Fe(0)-cell and H2-cell reactors suggest that most cis-DCE and VC in the Fe(0)-cell reactors were produced and transformed biologically rather than abiotically . Accumulation of methane in the Fe(0)-cell system indicates that hydrogen gas generated during anaerobic iron corrosion could support a methanogenic culture . Digital confocal images showed that the microorganisms were able to colonize the iron surface . The results suggest that potential development of dechlorinating populations in Fe(0) barriers may alter the TCE reduction pathway and produce VC, which would have significant impact on the performance of Fe(0) barriers.

Pediatr Pathol Mol Med, 2001 Jul-Aug, 20(4), 319 - 39
Localization and functions of SP-A and SP-D at mucosal surfaces; van Rozendaal BA et al.; Pulmonary surfactant protein A (SP-A) and D (SP-D), members of the collectin family, are implicated in innate host defense of the lung . Collectins consist of a collagen-like domain and a carbohydrate recognition domain . SP-A and SP-D recognize and interact with glycoconjugates on the surface of microorganisms . They protect the lung by interacting with a wide variety of potential pathogens, including viruses, bacteria, and fungi . This may result in enhanced killing and/or clearance by phagocytes . Although most extensively studied in the lung, both SP-A and SP-D, or proteins closely resembling SP-A and SP-D, are found in a number of other sites in the body and therefore may play a protective role at other sites than the lung . SP-A and SP-D protein and/or mRNA have been detected at various sites of the body: the respiratory tract, the gastrointestinal tract, the middle ear, and in the peritoneal cavity . The presence of SP-A and SP-D at these mucosal surfaces, in close contact with numerous potentially harmful microorganisms, supports a role for these "lung"-collectins in innate mucosal defense . SP-A and SP-D may be important molecules in a threefold innate defense, particularly in the neonatal period between maternally acquired immunity and a fully developed adaptive immune system; the time interval between first exposure to a pathogen and generation of specific antibodies; and states of impaired immune function.

Pediatr Pathol Mol Med, 2001 Jul-Aug, 20(4), 249 - 68
Role of surfactant protein A (SP-A)/lipid interactions for SP-A functions in the lung; Casals C; Surfactant protein A (SP-A), an oligomeric glycoprotein, is a member of a group of proteins named collectins that contain collagen-like and Ca(2+)-dependent carbohydrate recognition domains . SP-A interacts with a broad range of amphipathic lipids (glycerophospholipids, sphingophospholipids, glycosphingolipids, lipid A, and lipoglycans) that are present in surfactant or microbial membranes . This review summarizes SP-A/lipid interaction studies regarding the lipid system used (i.e., phospholipid vesicles, phospholipid monolayers, and lipids immobilized on silica or adsorbed on a solid support) . The effect of calcium, ionic strength, and pH on the binding of SP-A to lipids and the subsequent lipid aggregation process is discussed . Current evidence suggests that hydrophobic-binding forces are involved in the peripherical association of SP-A to membranes . It is also proposed that fluid and liquid-ordered phase coexistence in surfactant membranes might favor partition of SP-A into those membranes . The binding of SP-A to surfactant membranes containing hydrophobic surfactant peptides makes possible the formation of a membrane reservoir in the alveolar fluid that is protected by SP-A against inactivation and improves the rate of surfactant film formation . In addition, the interaction of SP-A with membranes might enhance the affinity of SP-A for terminal carbohydrates of glycolipids or glycoproteins on the surface of invading microorganisms.

Am J Infect Control, 2001 Aug, 29(4), 228 - 31
Hygiene and health - the need for a holistic approach; Exner M et al.; The holistic principles of hygiene and public health have contributed substantially to an increase in life expectancy by more than 30 years and in life quality since the beginning of the 20th century . Frank, Pettenkofer, Nightingale, Pasteur, Lister, and Koch have been pioneering protagonists of the holistic approach to hygiene and public health . Socioeconomic development and related factors such as nutrition status and food hygiene, housing conditions, water supply and sewage systems, and education (including motivation for personal hygiene) have obviously been of more importance for life expectancy and life quality than progress in curative medicine, such as availability of microbial diagnosis, vaccination, and antibiotics . Today, new risk factors for infectious diseases arise, even in developed countries . These risk factors arise from emerging pathogens, antibiotic-resistant microorganisms, changing demographic patterns, an increasing amount of ambulatory and home care, socioeconomic and environmental changes, technical environments, worldwide distribution of food, and changing human behavior with a decreased awareness of microbial threats . These new challenges worldwide make a renewal of the holistic approach of hygiene and public health both urgent and necessary . On the basis of historic experience, policies that focus on surveillance and control, diagnosis, and therapy only can be assumed to be both insufficient and inefficient in controlling the new challenges in infectious diseases . Experiences in Germany with a holistic hospital hygiene strategy since 1976 provide encouragement for the promotion of holistic health concepts . Risk assessment, risk management, and risk communication are basic steps of a modern holistic strategy . Hygiene has the potential to act as a moderator of diverging positions of different disciplines within this renewed approach.

Am J Infect Control, 2001 Aug, 29(4), 211 - 7
The correlation between sustainable development and home hygiene; Terpstra MJ; Hygiene refers to the science of the establishment and maintenance of (human) health . In everyday life, hygiene is closely associated with good housekeeping . This article will focus on home hygiene in relation to cleaning, on microorganisms, and on sustainable development of domestic technology . In domestic cleaning there are two beneficial effects: the aesthetic aspects of cleanness and the removal of microorganisms . In cleaning science substantial attention is paid to the interrelation between cleaning and removal of microorganisms . It appears that the parameters of the cleaning process and the detergent properties play a significant role in this interrelation . Changing technology to reduce the environmental impact of household cleaning not only influences the household activities and the functional performance of the cleaning processes but also has an impact on the level of hygiene . Results are presented of research in which the hygiene has been evaluated in relation to such changes . One option recently studied to reduce the environmental impact of households is the reduction of water consumption by water reuse . In such concepts water is used in successive steps for various processes before it is drained . The potential impact of such systems and of the use of rain water on the level of home hygiene is discussed.

Immunity, 2001 Jul, 15(1), 149 - 58
The Crohn's disease-associated bacterial protein I2 is a novel enteric t cell superantigen; Dalwadi H et al.; An aberrant T cell response to enteric bacteria is important in inflammatory bowel disease . However, the identity of relevant microbial antigens is unknown . Here, we report the presence of I2, a Crohn's disease-associated microbial gene, in the murine intestine . The I2 protein induced a proliferative and IL-10 response by CD4(+) T cells from unimmunized mice . The I2 response was dependent on MHC class II-mediated recognition but did not require antigen processing . Selective activation was observed for the TCR-Vbeta5 subpopulation . These findings indicate that the I2 protein is a new class of T cell superantigen and suggest that colonization by the I2 microorganism in susceptible hosts may provide a superantigenic stimulus pertinent to Crohn's disease pathogenesis.

Nat Rev Genet, 2001 Aug, 2(8), 597 - 606
The role of selfish genetic elements in eukaryotic evolution; Hurst GD et al.; 'Selfish genetic elements', such as transposons, homing endonucleases, meiotic drive chromosomes and heritable microorganisms, are common features of eukaryotes . However, their importance in the evolution of eukaryotic genomes is still controversial . In this review, we discuss these diverse elements and their potential importance in the evolution of genetic systems, adaptation, and the extinction and birth of species.

J Vet Diagn Invest, 2001 May, 13(3), 263 - 4
Multiplex polymerase chain reaction for distinguishing Taylorella equigenitalis from Taylorella equigenitalis-like organisms; Arata AB et al.; It is difficult to distinguish isolates of Taylorella equigenitalis, the cause of contagious equine metritis, from a T . equigenitalis-like organism isolated from asymptomatic donkeys and horses . Although T . equigenitalis is responsible for a severe, contagious disease of the reproductive tract of equids, the T . equigenitalis-like organism, although contagious, does not appear to produce disease . Because of the economic consequences of correctly distinguishing isolates of these 2 microorganisms, a polymerase chain reaction (PCR)-based assay was developed that will distinguish isolates of T . equigenitalis from the T . equigenitalis-like microorganism . The primers used in the PCR assay were designed to amplify unique regions of the gene encoding the 16S ribosomal RNA.

Int J Food Microbiol, 2001 Jul 20, 67(1-2), 63 - 9
A temperature-type model for describing the relationship between fungal growth and water activity; Sautour M et al.; Growth of Penicillium chrysogenum, Aspergillus flavus, Cladosporium cladosporioides and Alternaria alternata at their respective optimum temperatures was studied in Potato Dextrose Agar (PDA) medium at different water activities (a(w)) adjusted with glycerol . The growth rate (mu) was expressed as the increase in colony radius per unit of time . This paper extends the model that showed the relationship between temperature and bacterial growth rate developed by Rosso et al . {J . Theor . Biol . 162 (1993) 447} to describe the influence of a(w) on fungal development . An excellent correlation between the experimental data and the model predictions was obtained, the regression coefficients (r2) were greater than 0.990, with the exception of that for A . flavus (r2 = 0.982) . In addition, the use of such a model allows predictions of the cardinal water activities: a(wmin), a(wopt) and a(wmax) . The estimation of the minimum water activity (a(wmin)) was in accordance with data literature for all the moulds considered here, but seemed to be slightly underestimated for P . chrysogenum and A . flavus when compared to our experimental values . The estimations of the optimal water activity (a(wopt)) and the optimal growth rate (muopt) were in excellent agreement to the experimental results for the four moulds . Through this example, it is suggested that the same approach for modelling can be used for various microorganisms (e.g . bacteria and moulds), and different environmental parameters (e.g . temperature and water activity).

Klin Khir, 2001 Mar, (3), 38 - 40
{Bacteriological investigation and treatment strategies of patients with diabetic foot complicated by purulent necrosis}; Bidnenko SI et al.; Results of examination of 48 patients with diabetic foot (DF), in whom bacteriological investigation of tissues was conducted on various distance from inflammatory focus and in the blood serum (in 30 patients), were analyzed . The role of endogenous mechanism of infection and spread of microorganisms far away the purulent focus borders was established . The data obtained are permitting to perform rational treatment of patients with DF.

Proc Natl Acad Sci U S A, 2001 Aug 14, 98(17), 9877 - 82 Epub 2001 Jul 31.
Analysis of the chromosome sequence of the legume symbiont Sinorhizobium meliloti strain 1021; Capela D et al.; Sinorhizobium meliloti is an alpha-proteobacterium that forms agronomically important N(2)-fixing root nodules in legumes . We report here the complete sequence of the largest constituent of its genome, a 62.7% GC-rich 3,654,135-bp circular chromosome . Annotation allowed assignment of a function to 59% of the 3,341 predicted protein-coding ORFs, the rest exhibiting partial, weak, or no similarity with any known sequence . Unexpectedly, the level of reiteration within this replicon is low, with only two genes duplicated with more than 90% nucleotide sequence identity, transposon elements accounting for 2.2% of the sequence, and a few hundred short repeated palindromic motifs (RIME1, RIME2, and C) widespread over the chromosome . Three regions with a significantly lower GC content are most likely of external origin . Detailed annotation revealed that this replicon contains all housekeeping genes except two essential genes that are located on pSymB . Amino acid/peptide transport and degradation and sugar metabolism appear as two major features of the S . meliloti chromosome . The presence in this replicon of a large number of nucleotide cyclases with a peculiar structure, as well as of genes homologous to virulence determinants of animal and plant pathogens, opens perspectives in the study of this bacterium both as a free-living soil microorganism and as a plant symbiont.

J Biochem (Tokyo), 2001 Aug, 130(2), 257 - 61
A high molecular weight glutamyl endopeptidase and its endogenous inhibitors from cucumber leaves; Yamauchi Y et al.; We purified a glutamyl endopeptidase that is a major foliar endopeptidase in cucumber . The endopeptidase had a molecular mass of 400 kDa, consisted of four subunits of 97 kDa, and was inactivated by SH-modifying reagents . Its optimum pH and optimum temperature were 8.0 and 30-37 degrees C, respectively . An internal amino acid sequence of the endopeptidase was highly homologous to a partial sequence of unidentified proteins deduced from genetic information for Arabidopsis thaliana, soybean and rice, but not to the sequences of bacterial glutamyl endopeptidases or animal proteases . Therefore, the unidentified proteins might be glutamyl endopeptidases and be widely distributed only among plant species . The activity of the cucumber glutamyl endopeptidase was inhibited by at least three inhibitors existing in cucumber leaves . One of the inhibitors was a competitive inhibitor of 25 kDa, which did not significantly inhibit commercial endopeptidases derived from animals and microorganisms . This suggests that the cucumber glutamyl endopeptidase might be controlled by endogenous inhibitors in vivo.

Bioresour Technol, 2001 Sep, 79(2), 135 - 46
Copper and zinc fractions affecting microorganisms in long-term sludge-amended soils; Kunito T et al.; The influences of Zn and Cu on soil enzyme activities (acid phosphatase, alkaline phosphatase, arylsulfatase, cellulase, dehydrogenase, protease (z-FLase), urease, beta-D-glucosidase and beta-D-fructofuranosidase (invertase)) and microbial biomass carbon were investigated in agricultural soils amended with municipal sewage sludge or compost since 1978 . The trace metals in the soils were fractionated using a sequential extraction method . Long-term application of the sewage sludge and composts caused accumulations of Cu and Zn in the soils, ranging from 140 to 144 and from 216 to 292 mg kg(-1), respectively . The percentage of Cu was highest in the NaOH- and HNO3-extractable fractions (44-51% and 38-46%, respectively), while the percentage of Zn was highest in the HNO3- and EDTA-extractable fractions (65-83% and 11-32%, respectively) . Although the percentage of the bioavailable fractions (sum of KNO3 + H2O-, NaOH-, and EDTA-extractable amounts) of Cu (53-64%) was higher than that of Zn (15-37%), the percentage of the most labile fractions (KNO3 + H2O) of Zn (2.1-5.9%) was larger than that of Cu (1.1-2.4%) . The size of the microbial biomass carbon increased with the application of sewage sludge or compost . For some enzymes, however, the ratio of the enzyme activity to microbial biomass was lower in the soils amended with sewage sludge or compost than that in the control soil . The soil enzyme activities were more adversely affected by Zn than by Cu . From a multiple regression analysis, it was found that dehydrogenase, urease, and beta-D-glucosidase activities were reduced by the KNO3 + H2O-extractable fraction of Zn in the soils . These microbial activities seem to be sensitive to Zn stress, indicating the possibility that they might be useful bioindicators for evaluation of the toxic effects of Zn on microorganisms in the soils.

Int J Lepr Other Mycobact Dis, 2001 Mar, 69(1), 26 - 33
Factors influencing the development of leprosy: an overview; Naafs B et al.; The clinical manifestations of leprosy vary, seemingly depending on the host's immune response . Mode and route of infection, such as skin versus nasal mucosa, insect bites, sexual and gastroenteral transmission, together with genetic factors that may contribute to the outcome of the infection, including HLA, Lewis factor, Nramp1 and more subtle inherited alterations, are discussed . It is theorized that a balance between host responses elicited by different routes of infection and size and spacing of inocula is responsible for the clinical and immunological manifestations of the disease . Genetic factors and contact with environmental microorganisms may modulate these responses . The final result, resistance, delayed-type hypersensitivity, tolerance, disease or no disease, spectrum and reactions, is most likely reached via the orchestration of the induced cyto- and chemokines.

Nippon Ishinkin Gakkai Zasshi, 2001, 42(3), 109 - 11
{Fungal allergy -clinical aspect-}; Akiyama K; Fungus is known to be one of the important causative allergens of allergic diseases such as bronchial asthma, allergic rhinitis and atopic dermatitis . Not only outdoor airborne fungi but also indoor fungi such as Aspergillus restrictus and Eurotium have recently received attention as causative fungal allergens of allergic diseases . In addition to careful history taking, in vivo testing methods such as skin test and conjunctival or bronchial provocation tests are sometimes necessary to diagnose the causative allergen . Problems requiring resolution are: 1 . fungal allergens composed of multiple allergenic components, 2 . difficulty of environmental monitoring of fungal allergens, 3 . special characteristics as microorganisms, and 4 . characteristics of normal flora allergy, etc.

Plant Cell Physiol, 2001 Jul, 42(7), 763 - 7
Azospirillum spp . metabolize {17,17-2H2}gibberellin A20 to {17,17-2H2}gibberellin A1 in vivo in dy rice mutant seedlings; Cassan FD et al.; Azospirillum spp . are endophytic bacteria with beneficial effects on cereals--effects partially attributed to gibberellin production by the microorganisms . Azospirillum lipoferum and Azospirillum brasilense inoculated to rice dy mutant reversed dwarfism in seedlings incubated with {17,17-2H2}GA20 with formation of {17,17-2H2}GA1, showing the in vivo capacity to perform the 3beta-hydroxylation . When prohexadione-Ca, an inhibitor of late steps in gibberellin biosynthesis, was added to the culture medium, no complementation was observed and no {17,17-2H2}GA1 was produced . The latter suggests that the bacterial operating enzyme may be a 2-oxoglutarate-dependent dioxygenase, similar to those of plants.

J Biol Chem, 2001 Oct 12, 276(41), 38320 - 8 Epub 2001 Jul 30.
Cyanobacteria perceive nitrogen status by sensing intracellular 2-oxoglutarate levels; Muro-Pastor MI et al.; The regulatory circuits that control nitrogen metabolism are relatively well known in several bacterial model groups . However, much less is understood about how the nitrogen status of the cell is perceived in vivo . In cyanobacteria, the transcription factor NtcA is required for regulation (activation or repression) of an extensive number of genes involved in nitrogen metabolism . In contrast, how NtcA activity is regulated is largely unknown . Assimilation of ammonium by most microorganisms occurs through the sequential action of two enzymes: glutamine synthetase (GS) and glutamate synthase . Interestingly, regulation of the expression of NtcA-dependent genes in the cyanobacterium Synechocystis sp . PCC 6803 is altered in mutants with modified levels of GS activity . Two types of mutants were analyzed: glnA null mutants that lack GS type I and gif mutants unable to inactivate GS in the presence of ammonium . Changes in the intracellular pools of 19 different amino acids and the keto acid 2-oxoglutarate were recorded in wild-type and mutant strains under different nitrogen conditions . Our data strongly indicate that the nitrogen status in cyanobacteria is perceived as changes in the intracellular 2-oxoglutarate pool.

Environ Sci Technol, 2001 Jul 15, 35(14), 2956 - 60
Formation and emission of volatile polonium compound by microbial activity and polonium methylation with methylcobalamin; Momoshima N et al.; We observed biologically mediated emission of Po from culture solution inoculated sea sediment extract and incubated under natural light/dark cycle condition or dark condition the emitted Po compound would be lipophilic because of effective collection in organic solvent . Sterilization of the culture medium with antibiotics or CuSO4 completely suppressed growth of microorganisms and resulted in no emission of Po, indicating biological activity of microorganisms is responsible for formation and emission of volatile Po compound . Po emission also occurred when seawater was used as a culture medium . Our finding indicates a possibility of biotic source for atmospheric Po in the environment, which has been believed to be originated from abiotic sources . We compared emission behavior of Po and S in the culture experiments, the elements belong to XVI group in the Periodical Table, and consider that their emission mechanisms involved would be different though the emission of both elements is supported by biological activity of microorganisms . One of the chemical forms of S emitted was confirmed to be dimethyl sulfide (DMS) but that of Po is not known . Methylation experiments of Po with methylcobalamin demonstrated a formation and emission of volatile Po compound . The methylation of Po with methylcobalamin might be related to the observed Po emission in the culture experiments.

Nat Immunol, 2001 Aug, 2(8), 675 - 80
Toll-like receptors: critical proteins linking innate and acquired immunity; Akira S et al.; Recognition of pathogens is mediated by a set of germline-encoded receptors that are referred to as pattern-recognition receptors (PRRs) . These receptors recognize conserved molecular patterns (pathogen-associated molecular patterns), which are shared by large groups of microorganisms . Toll-like receptors (TLRs) function as the PRRs in mammals and play an essential role in the recognition of microbial components . The TLRs may also recognize endogenous ligands induced during the inflammatory response . Similar cytoplasmic domains allow TLRs to use the same signaling molecules used by the interleukin 1 receptors (IL-1Rs): these include MyD88, IL-1R--associated protein kinase and tumor necrosis factor receptor--activated factor 6 . However, evidence is accumulating that the signaling pathways associated with each TLR are not identical and may, therefore, result in different biological responses.

J Med Entomol, 2001 Jul, 38(4), 471 - 4
Evidence of ehrlichiosis agents found in ticks (Acari: Ixodidae) collected from migratory birds; Alekseev AN et al.; Two Ehrlichia pathogens were found in immature Ixodes ricinus (L.) ticks collected from migratory passerine birds in the Curonian Spit area of the Baltic Region of Russia (Kaliningrad enclave) . During the spring and fall of 2000, 1,606 passerine birds (eight species) were collected; 6.8% of them (110/1,606) were infested by ticks, and 51.8% (57/110) of tick clusters contained various human pathogenic microorganisms . Human monocytic ehrlichiosis (HME) and human granulocytic ehrlichiosis (HGE) agents were found in 14% (8/57) of cases . Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi sensu stricto were found in 92.9% (53/57) of the ticks . In five out of eight cases, infection of both Ehrlichia and Borrelia were obtained . In one case, a single nymph contained HME, B . afzelii, and B . garinii . Borrelia burgdorferi s.s . and B . afzelii were found together in one pool of four nymphs and one larva . All agents were identified using polymerase chain reaction and species-specific primers . In 8.8% of the ticks collected from birds in the fall and 22% in the spring, pathogens were isolated from attached co-feeding nymphs and larvae . These data demonstrate that Ehrlichia exchange could occur between co-feeding ticks on animals without systemic infection.

Vojnosanit Pregl, 2001 Mar-Apr, 58(2), 151 - 6
{Septic encephalopathy--prognostic value of the intensity of consciousness disorder to the outcome of sepsis}; Raicevic R et al.; Septic encephalopathy (SE) is a common term indicating the development of signs of progressing cerebral dysfunction and is associated with the presence of microorganisms and their toxins in the blood . Aim of this investigation was to analyze the frequency of this complication considering the consciousness disorders in quantitative sense and prognosis of the survival in patients with SE . The investigation comprised patients (n = 54) with positive hemoculture and signs of septic syndrome by the accepted criteria (fever, clinical signs of infection, respiratory frequency, heart rate, plasma lactate, oliguria) . Patients with confirmed cerebral injury, hemorrhage or cerebral ischemia were excluded from the study . Lumbar punction and CT-scan of the brain were performed in all patients in order to exclude visible lesions of cerebral parenchyma and eventual presence of cerebral nervous system (CNS) infection as the causes of sepsis . Results of the investigation demonstrated that in 30 (55%) of patients existed mild consciousness disorder at the level of somnolescence, in 18 (33%) consciousness disorder at the level of sopor and in 6 (11%) consciousness disorder at the level of deep coma . Level of consciousness disorder was in positive correlation with the outcome of sepsis syndrome, which was additionally confirmed by the fact that only in the group of patients with deep coma lethal outcome was observed in 3 cases (50% of this subgroup) regardless of intensive antibiotic, metabolically active and symptomatic therapy . It can be concluded that SE syndrome has a favorable prognosis if macroscopic lesion and dissemination of microorganisms in CNS are not present, and simultaneously it represents changes in metabolic-electrolytic state with early presentation of consciousness disorders that represent clinically significant indicator for sepsis syndrome outcome.

Acta Gastroenterol Belg, 2001 Apr-Jun, 64(2), 150 - 2
Detection of Helicobacter pylori in dental plaque and gastric biopsy samples of Turkish patients by PCR-RFLP; Sahin FI et al.; Helicobacter pylori is regarded as an important pathogen playing a key role in the pathogenesis of peptic ulcer . Different studies about the mode of transmission of the microorganism report conflicting results about dental plaque as the source of H . pylori infection . In the present study we aimed to detect the presence of H . pylori in dental plaque of Turkish patients by polymerase chain reaction (PCR) and if any to do typing by restriction fragment length polymorphism (RFLP) analysis . Fifty dyspeptic patients, to whom upper gastrointestinal endoscopy was performed, were included in the study . Dental plaques were obtained before endoscopic examination . Both dental plaque and gastric biopsy samples were amplified with Ure A and Cag A gene primers . There were no positive dental plaque samples even in the 23 patients whose gastric biopsy specimens were positive . Our findings showed that there is not a correlation between dental presentation of the microorganism and H . pylori gastritis.

Gastrointest Endosc, 2001 Aug, 54(2), 214 - 8
Bacteremia after endoscopic injection of N-butyl-2-cyanoacrylate for gastric variceal bleeding; Chen WC et al.; BACKGROUND: Cyanoacrylate may form a barrier that prevents bacterial invasion when used in tissue . Because cyanoacrylate polymerizes within seconds on contact with aqueous media, it is used worldwide to arrest gastric variceal bleeding . The aim of this study was to determine the frequency of bacteremia after endoscopic cyanoacrylate injection for gastric variceal bleeding . METHODS: Patients with cirrhosis who underwent endoscopic cyanoacrylate injection for gastric variceal bleeding were included . Patients with cirrhosis who underwent upper endoscopy for nonvariceal upper GI bleeding were recruited as controls . Patients with infection before endoscopy were excluded . Blood was cultured in both groups . Injection needles and endoscope accessory channels were cultured in the cyanoacrylate injection group . RESULTS: More patients injected with cyanoacrylate had positive blood cultures in comparison with the control group (15/47 vs . 1/47, p < 0.0001) . In the cyanoacrylate injection group, the volume of blood transfused and Child-Pugh score were factors associated with the occurrence of bacteremia . Most episodes of bacteremia were transient, except for 1 patient who died of sepsis . Most of the microorganisms cultured from blood samples were identical to those cultured from injection needles (65%) and accessory channels (90%) . CONCLUSIONS: Endoscopic cyanoacrylate injection for gastric varices does not limit the spread of bacteria . The endoscope accessory channel was the major source of bacteria . Most episodes of bacteremia were transient and uneventful.

Appl Environ Microbiol, 2001 Aug, 67(8), 3645 - 9
Rapid evolution of novel traits in microorganisms; Selifonova O et al.; The use of natural microorganisms in biotransformations is frequently constrained by their limited tolerance to the high concentrations of metabolites and solvents required for effective industrial production . In many cases, more robust strains have to be generated by random mutagenesis and selection . This process of directed evolution can be accelerated in mutator strains, which carry defects in one or more of their DNA repair genes . However, in order to use mutator strains, it is essential to restore the normal low mutation rate of the selected organisms immediately after selection to prevent the accumulation of undesirable spontaneous mutations . To enable this process, we constructed temperature-sensitive plasmids that temporarily increase the mutation frequency of their hosts by 20- to 4,000-fold . Under appropriate selection pressure, microorganisms transformed with mutator plasmids can be quickly evolved to exhibit new, complex traits . By using this approach, we were able to increase the tolerance of three bacterial strains to dimethylformamide by 10 to 20 g/liter during only two subsequent transfers . Subsequently, the evolved strains were returned to their normal low mutation rate by curing the cells of the mutator plasmids . Our results demonstrate a new and efficient method for rapid strain improvement based on in vivo mutagenesis.

Appl Environ Microbiol, 2001 Aug, 67(8), 3549 - 56
Phosphorus-31 nuclear magnetic resonance study of the effect of pentachlorophenol (PCP) on the physiologies of PCP-degrading microorganisms; Lohmeier-Vogel EM et al.; Free and agarose-encapsulated pentachlorophenol (PCP)-degrading Sphingomonas sp . isolates UG25 and UG30 were compared to Sphingomonas chlorophenolica ATCC 39723 with respect to the ability to degrade PCP . Pretreatment of the UG25 and UG30 strains with 50 microg of PCP per ml enabled the cells to subsequently degrade higher levels of this environmental pollutant . Similar treatment of ATCC 39723 cells had no effect on the level of PCP degraded by this strain . Phosphorus-31 nuclear magnetic resonance spectra of agarose-immobilized strains UG25 and UG30 grown in the absence of PCP showed that there was marked deenergization of the cells upon exposure to a nonlethal concentration of PCP (120 microg/ml) . For example, no transmembrane pH gradient was observed, and the ATP levels were lower than the levels obtained in the absence of PCP . The transmembrane pH gradient and ATP levels were restored once the immobilized cells had almost completely degraded the PCP in the perfusion medium . PCP-pretreated cells, on the other hand, maintained their transmembrane pH gradient and ATP levels even in the presence of high levels of PCP . The ability of PCP-pretreated strain UG25 and UG30 cells to remain energized in the presence of PCP was shown to correlate with an altered membrane phospholipid profile; these cells had a higher concentration of cardiolipin than cells cultured in the absence of PCP . Strain ATCC 39723, which did not degrade higher levels of PCP after PCP pretreatment, did not show this response.

An Esp Pediatr, 2001 Aug, 55(2), 165 - 8
{Metastatic Crohn's disease in childhood}; Gonzalez Gomez JM et al.; Crohn's disease (CD) is an intestinal inflammatory disease of unknown origin that is sometimes associated with cutaneous manifestations . These skin lesions are usually nonspecific (erythema nodosum, erythema multiforme and pyoderma gangrenosum) and should be differentiated from the cutaneous lesions corresponding to the typical histological pattern of CD; most of these extend directly from the involved bowel . Noncaseating granulomatous infiltration in skin anatomically distant from areas of gastrointestinal CD and separated by normal skin is extremely rare . This entity, known as metastatic Crohn's disease, can be the first symptom of CD or even more unusually can appear during the course of the disease.We report the case of a 9-year-old boy, previously diagnosed with ileocolic and perianal CD, who had been receiving treatment with mesalazine, prednisone and 6-mercaptopurine for 3 years . He presented with swelling of the penis and scrotum of 2 weeks' evolution, without any other symptoms . Testicular ultrasound showed thickening of the scrotal wall and increased flux at this site . Skin biopsy showed noncaseating granulomas . Results of special staining techniques were negative for the presence of microorganisms . The prednisone dose was increased and metronidazole was added, with noticeable improvement in the lesions . Due to reappearance of cutaneous lesions when the prednisone dose was reduced, the patient currently receives maintenance treatment.

Curr Issues Mol Biol, 2001 Jan, 3(1), 7 - 14
NMR and microorganisms; Grivet JP; This article is an introduction to the use of NMR for the investigation of microbial physiology and metabolism . NMR parameters which determine the sensitivity and resolving power of the method are reviewed . A broad survey of current applications follows . Qualitative uses are described first; they include compound identification and localisation . Quantitative aspects, such as pH, concentration and flux measurements are then examined, as well as the corresponding experimental constraints . The review ends with suggestions of possible future developments in instrument capabilities aimed at improving sensitivity: higher fields, spectroscopic and imaging microprobes.

Am J Phys Anthropol, 2001 Aug, 115(4), 380 - 7
Epidemiological approach to the paleopathological diagnosis of leprosy; Boldsen JL; In paleopathology it is usually assumed that modern diagnostic criteria can be applied to infectious diseases in the past . However, as both the human species and populations of pathogenic microorganisms undergo evolutionary changes, this assumption is not always well-founded . To get valid estimates of the frequency (the point prevalence at death) of leprosy in skeletal samples, sensitivity, specificity, and sample frequency must be estimated simultaneously . It is shown that more than three symptoms must be evaluated in at least three samples in order to reach estimates with well-described properties . The method is applied to three skeletal samples from Medieval Denmark; the samples were scored for the presence of seven osteological conditions indicating leprosy . For the osteological conditions, sensitivity varied from 0.36-0.80, and specificity from 0.58-0.98 . The frequency of leprosy in the three samples was: Odense (a lepers' institution), 0.98, 95% CI 0.64-1.00; Malmo (urban cemetery), 0.02, 95% CI 0.00-0.07; and Tirup (rural cemetery), 0.36, 95% CI 0.23-0.46 . It is concluded that it is indeed possible to estimate disease frequencies without reference to modern standards, and that leprosy occurred with widely differing frequencies in different segments of the Medieval population in southern Scandinavia .

Mycopathologia, 2001, 150(3), 143 - 50
Fungal populations on sunflower (Helianthus annuus) anthosphere and their relation to susceptibility or tolerance to Sclerotinia sclerotiorum attack; Rodriguez MA et al.; Analysis of the fungal flora from different floret parts of various sunflower (Helianthus annuus) varieties showed that there are differences in both fungal species and frequency, depending on whether the sunflower variety is susceptible (SV) or tolerant (TV) to attack of the flower heads by the ascomycete pathogen Sclerotinia sclerotiorum . The sunflower varieties analyzed were SV: HA 300 and Z 20028, and TV: HA 302, Z AV 8410 and Z 30629 . The isolates showed different "in vitro" behavior as biocontrol agents . The most common types of interaction with Sclerotinia sclerotiorum were D2 and D2+ (hyphal contact) for isolates from SV and TV, while some of the isolates from TV displayed antibiosis . The microorganisms that colonize TV florets play a part in an indirect mechanism that protects flowers from ascospore germination and pathogen growth.

Can J Microbiol, 2001 Jun, 47(6), 541 - 7
Modification of the protein expression pattern induced in the nitrogen-fixing actinomycete Frankia sp . strain ACN14a-tsr by root exudates of its symbiotic host Alnus glutinosa and cloning of the sodF gene; Hammad Y et al.; Two-dimensional (2-D) polyacrylamide gel electrophoresis was used to detect proteins induced in Frankia sp . strain ACN14a-tsr by root exudates of its symbiotic host, Alnus glutinosa . The 5 most prominent proteins were purified from 2-D gels and characterized by N-terminal sequencing . All of these proteins had a high percentage of similarity with known stress proteins . One protein match was the Fe superoxide dismutase (Fe-SOD), another was a tellurite resistance protein (Ter), the third was a bacterioferritin comigratory protein (Bcp); and two matches, differing only by their isoelectric point, were the same small heat shock protein (Hsp), a major immune reactive protein found in mycobacteria . This suggests that the symbiotic microorganism Frankia, first responds with a normal stress response to toxic root products of its symbiotic host plant . To confirm its identity, the gene corresponding to the Fe-SOD protein, sodF was isolated from a genomic library by a PCR-approach and sequenced . It is the first stress response gene characterized in Frankia.

Pediatr Infect Dis J, 2001 Jul, 20(7), 703 - 6
Lack of association between Kawasaki syndrome and infection with Rickettsia conorii, Rickettsia typhi, Coxiella burnetii or Ehrlichia phagocytophila group; Kafetzis DA et al.; BACKGROUND: The etiology of Kawasaki syndrome (KS) is unknown . Rickettsiae, intracellular microorganisms that invade the vascular endothelium, might cause KS . OBJECTIVES: To investigate whether there is an association between KS and infection with Rickettsia conorii, Rickettsia typhi, Coxiella burnetii or Ehrlichia phagocytophila group . METHODS: All children who were diagnosed with KS at the University of Athens Second Department of Pediatrics from December, 1999, through November, 2000, were prospectively studied . Paired serum specimens were obtained from all patients and antibody titers against R . conorii, R . typhi, C . burnetii and E . phagocytophila group were assessed by microimmunofluorescence assay . RESULTS: Eleven children with a median age of 2.5 years were included in the study . A 15-month-old child had a 4-fold rise of antibody titers against C . burnetii, which is indicative of acute Q fever . The patient had a history of recent exposure to possible sources of C . burnetii . The remaining patients tested negative for the presence of antibodies against R . conorii, R . typhi, C . burnetii and E . phagocytophila group . CONCLUSIONS: Our study does not provide serologic evidence that KS is the result of infection with R . conorii, R . typhi, C . burnetii or E . phagocytophila group . It is suggested that C . burnetii may cause a KS-like illness in young children.

Ann Thorac Surg, 2001 Jul, 72(1), 143 - 8
Pneumonia after cardiac surgery is predictable by tracheal aspirates but cannot be prevented by prolonged antibiotic prophylaxis; Carrel TP et al.; BACKGROUND: The purpose of this study was to assess the value of tracheal aspirate as a predictor of pneumonia after coronary artery bypass grafting and to evaluate the efficacy of prolonged perioperative antibiotic prophylaxis . METHODS: Tracheal aspirates of 500 patients undergoing coronary artery bypass grafting were taken immediately after intubation and analyzed for microorganisms by Gram stain and semiquantitative microbiologic cultures . All patients received 2 g ceftriaxone as a single-dose perioperative antibiotic prophylaxis before operation . Results of Gram stains were available before the patients were transferred to the intensive care unit . After the results were known, both groups of patients (positive Gram stain, group 1; negative Gram stain, group 2) were randomly assigned to either conventional antibiotic prophylaxis (A), consisting of ceftriaxone 2 g on postoperative day 1, or prolonged antibiotic prophylaxis (B), with ticarcillin + clavulanic acid 3 x 5.2 g during 72 hours . RESULTS: From 500 patients, 91 had a positive Gram stain whereas 409 had a negative one . The incidence of pneumonia was significantly higher in patients with preoperative positive tracheal aspirates (15.3%) than in patients with a negative one (3.6%; p < 0.01) . However, prolonged prophylaxis did not reduce the rate of postoperative pneumonia, which was as high as 13% in untreated positive patients versus 17% in treated positive patients, and 2% in untreated negative patients versus 4% in treated patients . In patients who had pneumonia, there was a high correlation between the microorganisms found in preoperative aspirates and those observed when aspirates were repeated (100% correlation in patients with conventional antibiotic prophylaxis and 87% in those with prolonged prophylaxis) . CONCLUSIONS: Early postoperative pneumonia (<7 days) is most likely caused by microorganisms that colonize the respiratory tract before operation . The risk of pulmonary infection after coronary artery bypass grafting can be predicted from the preoperative tracheal aspirates . Prolonged perioperative antibiotic prophylaxis has no efficacy in reducing the incidence of pulmonary infections.

Water Sci Technol, 2001, 43(12), 81 - 7
Tirane, Albania: survey on drinking water quality and facilities; Palombi L et al.; To develop a realistic model of the situation, a study was carried out in four different socioeconomic and hygienic areas of Tirane, namely in the modern and historical centre as well as in the intermediate and peripheral areas . In each area interviewers from the city's Public Health Directorate, contacted randomly, door-to-door, the residents, submitting a questionnaire and collecting water samples at the same time . Our data show relevant differences regarding distribution and quality of drinking water between the centre and peripheral areas . One third of water samples revealed the presence of microorganisms, whereas one fifth had no residual chlorine . Altogether more than 200,000 people in the peripheral areas of Tirane live under low level hygienic conditions . The recent outbreaks of cholera, poliomyelitis and the hyperendemic hepatitis A disease are the dramatic results of the low quality drinking water.

Science, 2001 Jul 20, 293(5529), 484 - 7
Methane-consuming archaea revealed by directly coupled isotopic and phylogenetic analysis; Orphan VJ et al.; Microorganisms living in anoxic marine sediments consume more than 80% of the methane produced in the world's oceans . In addition to single-species aggregates, consortia of metabolically interdependent bacteria and archaea are found in methane-rich sediments . A combination of fluorescence in situ hybridization and secondary ion mass spectrometry shows that cells belonging to one specific archaeal group associated with the Methanosarcinales were all highly depleted in 13C (to values of -96 per thousand) . This depletion indicates assimilation of isotopically light methane into specific archaeal cells . Additional microbial species apparently use other carbon sources, as indicated by significantly higher 13C/12C ratios in their cell carbon . Our results demonstrate the feasibility of simultaneous determination of the identity and the metabolic activity of naturally occurring microorganisms.

J Biol Chem, 2001 Sep 21, 276(38), 35818 - 25 Epub 2001 Jul 19.
The Ca2+-binding proteins S100A8 and S100A9 are encoded by novel injury-regulated genes; Thorey IS et al.; To gain insight into the molecular mechanisms underlying cutaneous wound repair, we performed a large scale screen to identify novel injury-regulated genes . Here we show a strong up-regulation of the RNA and protein levels of the two Ca(2+)-binding proteins S100A8 and S100A9 in the hyperthickened epidermis of acute murine and human wounds and of human ulcers . Furthermore, both genes were expressed by inflammatory cells in the wound . The increased expression of S100A8 and S100A9 in wound keratinocytes is most likely related to the activated state of the keratinocytes and not secondary to the inflammation of the skin, since we also found up-regulation of S100A8 and S100A9 in the epidermis of activin-overexpressing mice, which develop a hyperproliferative and abnormally differentiated epidermis in the absence of inflammation . Furthermore, S100A8 and S100A9 expression was found to be associated with partially differentiated keratinocytes in vitro . Using confocal microscopy, both proteins were shown to be at least partially associated with the keratin cytoskeleton . In addition, cultured keratinocytes efficiently secreted the S100A8/A9 dimer . These results together with previously published data suggest that S100A8 and S100A9 are novel players in wound repair, where they might be involved in the reorganization of the keratin cytoskeleton in the wounded epidermis, in the chemoattraction of inflammatory cells, and/or in the defense against microorganisms.

J Biol Chem, 2001 Sep 21, 276(38), 35512 - 7 Epub 2001 Jul 19.
Fusion of human neutrophil phagosomes with lysosomes in vitro: involvement of tyrosine kinases of the Src family and inhibition by mycobacteria; Peyron P et al.; The intracellular killing of microorganisms in phagocytes involves the fusion of lysosomes containing bactericidal factors with phagosomes, and several intracellular pathogens are able to inhibit this fusion event . In this study, we report the reconstitution of phagosome-lysosome fusion in vitro, using an assay based on resonance energy transfer between fluorescent phospholipid analogues that were inserted into whole human NB4-neutrophil membranes from liposomes containing positively charged lipids . Cytosol was required for fusion, and fusion was stimulated 3-fold if this cytosol had been prepared from neutrophils activated by using opsonized zymosan or a combination of the calcium ionophore (A23187) and phorbol myristate acetate (PMA) . Fusion was inhibited by the addition of PP1, an inhibitor of Src family protein kinases, or GTPgammaS . We have previously reported that the biogenesis of phagolysosomes in human neutrophils is inhibited by mycobacteria . Here we show that cytosol from cells having internalized live (not heat-killed) Mycobacterium smegmatis or cytosol simply incubated with mycobacteria inhibited fusion, indicating that soluble factors are involved in mycobacterial inhibition of phagosome-lysosome fusion.

Metab Eng, 2001 Jul, 3(3), 195 - 206
13C metabolic flux analysis; Wiechert W; Metabolic flux analysis using 13C-labeled substrates has become an important tool in metabolic engineering . It allows the detailed quantification of all intracellular fluxes in the central metabolism of a microorganism . The method has strongly evolved in recent years by the introduction of new experimental procedures, measurement techniques, and mathematical data evaluation methods . Many of these improvements require advanced skills in the application of nuclear magnetic resonance and mass spectrometry techniques on the one hand and computational and statistical experience on the other hand . This minireview summarizes these recent developments and sketches the major practical problems . An outlook to possible future developments concludes the text .

J Environ Sci Health A Tox Hazard Subst Environ Eng, 2001 May, 36(5), 793 - 806
Bioleaching of metals from anaerobic sewage sludge: effects of total solids, leaching microorganisms, and energy source; Lombardi AT et al.; The effects of municipal sewage sludge solids concentration, leaching microorganisms (Thiobacillus thiooxidans or Thiobacillus ferrooxidans) and the addition of energy source (S0 or Fe(II)) on the bioleaching of metals from sewage sludge has been investigated under laboratory conditions using shake flasks . The results show that metal solubilization was better accomplished if additional energy source is supplemented to the microorganisms and that T . thiooxidans furnishes, in general, more adequate conditions for the bioleaching than T . ferrooxidans . At a total solids concentration of 70 g L-1 (originally present in the sludge) pH drop and ORP increase are attenuated, so metal solubilization is negatively affected . It was also demonstrated that if lead (Pb) solubilization is to be achieved, than a special combination of microorganism/energy source must be applied.

FEBS Lett, 2001 Jul 13, 501(1), 11 - 8
Evolutionary relationship of Rickettsiae and mitochondria; Emelyanov VV; Phylogenetic data support an origin of mitochondria from the alpha-proteobacterial order Rickettsiales . This high-rank taxon comprises exceptionally obligate intracellular endosymbionts of eukaryotic cells, and includes family Rickettsiaceae and a group of microorganisms termed Rickettsia-like endosymbionts (RLEs) . Most detailed phylogenetic analyses of small subunit rRNA and chaperonin 60 sequences consistently show the RLEs to have emerged before Rickettsiaceae and mitochondria sister clades . These data suggest that the origin of mitochondria and Rickettsiae has been preceded by the long-term mutualistic relationship of an intracellular bacterium with a pro-eukaryote, in which an invader has lost many dispensable genes, yet evolved carrier proteins to exchange respiration-derived ATP for host metabolites as envisaged in classic endosymbiont theory.

Biochemistry, 2001 Jul 24, 40(29), 8548 - 56
Site-directed mutation of the highly conserved region near the Q-loop of the cytochrome bd quinol oxidase from Escherichia coli specifically perturbs heme b595; Zhang J et al.; Cytochrome bd is one of the two quinol oxidases in the respiratory chain of Escherichia coli . The enzyme contains three heme prosthetic groups . The dioxygen binding site is heme d, which is thought to be part of the heme-heme binuclear center along with heme b(595), which is a high-spin heme whose function is not known . Protein sequence alignments {Osborne, J . P., and Gennis, R . B . (1999) Biochim . Biophys Acta 1410, 32--50} of cytochrome bd quinol oxidase sequences from different microorganisms have revealed a highly conserved sequence (GWXXXEXGRQPW; bold letters indicate strictly conserved residues) predicted to be on the periplasmic side of the membrane between transmembrane helices 8 and 9 in subunit I . The functional importance of this region is investigated in the current work by site-directed mutagenesis . Several mutations in this region (W441A, E445A/Q, R448A, Q449A, and W451A) resulted in a catalytically inactive enzyme with abnormal UV--vis spectra . E445A was selected for detailed analysis because of the absence of the absorption bands from heme b(595) . Detailed spectroscopic and chemical analyses, indeed, show that one of the three heme prosthetic groups in the enzyme, heme b(595), is specifically perturbed and mostly missing from this mutant . Surprisingly, heme d, while known to interact with heme b(595), appears relatively unperturbed, whereas the low-spin heme b(558) shows some modification . This is the first report of a mutation that specifically affects the binding site of heme b(595).

J Food Prot, 2001 Jul, 64(7), 964 - 9
Reduction in levels of Escherichia coli O157:H7 in apple cider by pulsed electric fields; Iu J et al.; Many studies have demonstrated that high voltage pulsed electric field (PEF) treatment has lethal effects on microorganisms including Escherichia coli O157:H7; however, the survival of this pathogen through the PEF treatment is not fully understood . Fresh apple cider samples inoculated with E . coli O157:H7 strain EC920026 were treated with 10, 20, and 30 instant charge reversal pulses at electric field strengths of 60, 70, and 80 kV/cm, at 20, 30, and 42 degrees C . To accurately evaluate the lethality of apple cider processing steps, counts were determined on tryptic soy agar (TSA) and sorbitol MacConkey agar (SMA) to estimate the number of injured and uninjured E . coli O157:H7 cells after PEF treatment . Cell death increased significantly with increased temperatures and electric field strengths . A maximum of 5.35-log10 CFU/ml (P < 0.05) reduction in cell population was achieved in samples treated with 30 pulses and 80 kV/cm at 42 degrees C . Cell injury measured by the difference between TSA and SMA counts was found to be insignificant (P > 0.05) . Under extreme conditions, a 5.91-log10 CFU/ml reduction in cell population was accomplished when treating samples with 10 pulses and 90 kV/cm at 42 degrees C . PEF treatment, when combined with the addition of cinnamon or nisin, triggered cell death, resulting in a reduction in E . coli O157:H7 count of 6 to 8 log10 CFU/ml . Overall, the combination of PEF and heat treatment was demonstrated to be an effective pasteurization technique by sufficiently reducing the number of viable E . coli O157:H7 cells in fresh apple cider to meet U.S . Federal Drug Administration recommendations.

J Food Prot, 2001 Jul, 64(7), 1079 - 84
Standardization of a method to determine the efficacy of sanitizers in inactivating human pathogenic microorganisms on raw fruits and vegetables; Beuchat LR et al.; The efficacy of sanitizers in killing human pathogenic microorganisms on a wide range of whole and fresh-cut fruits and vegetables has been studied extensively . Numerous challenge studies to determine the effects of storage conditions on survival and growth of pathogens on raw produce have also been reported . Results of these studies are often difficult to assess because of the lack of sufficient reporting of methods or, comparatively, because of variations in procedures for preparing and applying inocula to produce, conditions for treatment and storage, and procedures for enumerating pathogens . There is a need for a standard method to accurately determine the presence and populations of pathogenic microorganisms on produce . The adoption of standard, well-characterized reference strains would benefit a comparative assessment of a basic method among laboratories . A single protocol will not be suitable for all fruits and vegetables . Modifications of a basic method will be necessary to achieve maximum recovery of pathogens on various types of produce subjected to different sanitizer or storage treatments . This article discusses parameters that must be considered in the course of developing a basic standard method against which these modifications could be made.

Salud Publica Mex, 2001 May-Jun, 43(3), 237 - 47
Helicobacter pylori: recent advances in the study of its pathogenicity and prevention; Aguilar GR et al.; Helicobacter pylori has acquired great importance during the last two decades, after being recognized as an important pathogen that infects a great portion of the human population . This microorganism is recognized as the main causal agent of chronic gastritis and duodenal ulcers, and it is associated with the subsequent development of gastric carcinoma . The pathogenic mechanisms of H . pylori and their relation to gastric ailments have not been clearly defined . However, at present it is well established that urease, vacuolating cytotoxin VacA, and the pathogenicity island (cag PAI) gene products, are the main factors of virulence of this organism . Thus, individuals infected with strains that express these virulence factors probably develop a severe local inflammation that may induce the development of peptic ulcer and gastric cancer . The way the infection spreads throughout the world suggests the possibility that there are multiple pathways of transmission . Due to the importance that H . pylori has acquired as a human pathogen, laboratories worldwide are attempting to develop a vaccine that confers long-term immunological protection against infection by this microorganism . Hence, the objective of this review is to present the most relevant findings of the biology of H . Pylori and its interaction with the human host.

Nature, 2001 Jul 5, 412(6842), 66 - 9
Morphological and ecological complexity in early eukaryotic ecosystems; Javaux EJ et al.; Molecular phylogeny and biogeochemistry indicate that eukaryotes differentiated early in Earth history . Sequence comparisons of small-subunit ribosomal RNA genes suggest a deep evolutionary divergence of Eukarya and Archaea; C27-C29 steranes (derived from sterols synthesized by eukaryotes) and strong depletion of 13C (a biogeochemical signature of methanogenic Archaea) in 2,700 Myr old kerogens independently place a minimum age on this split . Steranes, large spheroidal microfossils, and rare macrofossils of possible eukaryotic origin occur in Palaeoproterozoic rocks . Until now, however, evidence for morphological and taxonomic diversification within the domain has generally been restricted to very late Mesoproterozoic and Neoproterozoic successions . Here we show that the cytoskeletal and ecological prerequisites for eukaryotic diversification were already established in eukaryotic microorganisms fossilized nearly 1,500 Myr ago in shales of the early Mesoproterozoic Roper Group in northern Australia.

Burns, 2001 Aug, 27(5), 439 - 45
Selective decontamination of the digestive tract in severely burned pediatric patients; Barret JP et al.; Infection is still one of the leading causes of morbidity and mortality in severely burned patients . Evidence suggests that many of the responsible organisms are endogenous . Systemic antibiotic prophylaxis is not effective, and produces resistant strains of microorganisms . SDD has been postulated to be beneficial for controlling and decreasing infections in critically ill patients . Its efficacy in severely burned patients, however, remains controversial . In order to analyze the efficacy of selective decontamination of the digestive (SDD) tract, to decrease the bacterial colonization of the aerodigestive tract and burn wounds, and the incidence of septic complications in severely burned children, 23 pediatric patients affected of severe burns were prospectively randomized in a double-blinded study . Eleven patients received SDD (Polymyxin E, Tobramycin, and Amphotericin B), and 12 placebo . Demographics, hospital course, microbiology results, complications, infectious episodes, and serum levels of IL-1beta, IL-6, IL-10, and TNF-alpha were compared to determine the efficacy of SDD . Colonization rates to the wound, sputum, nasogastric aspirates, and feces were similar . Pneumonia, sepsis and other complications had similar incidence in both groups . Serum levels of all cytokines studied were also comparable, suggesting a similar inflammatory status in all patients, regardless of the treatment received . Patients in the SDD group, however, had a significantly higher incidence of diarrhea (P=0.003) . We can conclude that selective decontamination of the digestive tract with Polymixin E, Tobramycin and Amphotericin B is not effective to decrease bacterial colonization and infectious episodes in severely burned pediatric patients.

FEMS Microbiol Ecol, 2001 Jul, 36(2-3), 93 - 104
Reversible transition between active and dormant microbial states in soil; Stenstrom J et al.; The rate of respiration obtained in the substrate-induced respiration (SIR) method can be divided into the respiration rate of growing (r) and non-growing (K) microorganisms . The fraction of r is generally small (5-20%) in soils with no recent addition of substrates, but can be 100% in soils with high substrate availability . This suggests that substrate availability determines the proportion of biomass between these groups, and implies that transitions between them can take place reversibly . These hypotheses were tested by adding three different amounts of glucose which induced first-order, zero-order, and growth-associated respiration kinetics to three soils at four pre-incubation times (4, 12, 27, and 46 days) before the SIR measurement . An abiotic flush of CO(2) in the SIR measurement was detected and corrected for before data analysis . Accumulated CO(2)-C over 4 days after glucose addition, corrected for the respiration in unamended controls, corresponded to 41-50% mineralization of the glucose-C, and the relative amount mineralized by each soil was independent of the glucose amount added . The high glucose concentration gave an increased SIR, which reverted to the initial value within 27-46 days . In a specific sample, the maximum respiration rate induced during the pre-incubation, and the amount of organisms transformed from the K to the r state, as quantified in respiration rate units in the SIR measurement, were identical to each other, and these parameters were also highly correlated to the initial glucose concentration . The K-->r transition was very fast, probably concurrent with the instantaneous increase in the respiration rate obtained by the glucose amendment . Thereafter, a slow first-order back-transition from the r to the K state ensued, with half-lives of 12, 23, and 70 days for the three soils . The results suggest the existence of community-level controls by which growth within or of the whole biomass is inhibited until it has been completely transformed into the r state . The data also suggest that the microbial specific activity is not related to the availability of exogenous substrate in a continuous fashion, rather it responds as a sharp transition between dormant and fully active . Furthermore, the inherent physiological state of the microbial biomass is strongly related to its history . It is proposed that the normal dynamics of the soil microbial biomass is an oscillation between active and dormant physiological states, while significant growth occurs only at substantial substrate amendment.

Crit Rev Microbiol, 2001, 27(2), 75 - 131
A metabolic node in action: chorismate-utilizing enzymes in microorganisms; Dosselaere F et al.; The shikimate pathway has been described as a metabolic tree with many branches that led to the synthesis of an extensive range of products . This pathway is present only in bacteria, fungi, and plants . While there is only little difference in the sequence of the chemical reactions of the pathway, significant differences exist in terms of organization and regulation . In the main trunk of the shikimate pathway, D-erythrose 4-phosphate and phosphoenolpyruvate are converted via shikimate to chorismate . Chorismate is the common precursor for the biosynthesis of the aromatic amino acids, phenylalanine, tyrosine, and tryptophan, but also for other products as diverse as folate cofactors, benzoid and naphthoid coenzymes, phenazines, and siderophores . Five chorismate-utilizing enzymes have been characterized in microorganisms: chorismate mutase, anthranilate synthase, aminodeoxychorismate synthase, isochorismate synthase, and chorismate pyruvate-lyase . In this review these enzymes are discussed in terms of the corresponding gene structures and regulation, nucleotide and protein sequences, protein structures, and reaction mechanisms . The main emphasis is on transcriptional and posttranslational regulatory mechanisms, in view of how a microbial cell exploits its chorismate pool in diverse anabolic pathways . Comparison of the chorismate-utilizing enzymes has shown that some of them share sequence similarity, suggesting divergent evolution and commonality in reaction mechanisms . However, other chorismate-utilizing enzymes are examples of convergent evolution toward similar reaction capabilities.

Mikrobiologiia, 2001 May-Jun, 70(3), 360 - 4
{Use of polymerase chain reaction for searching for producers of ergot alkaloids from among microscopic fungi}; Boichenko LV et al.; The potential of the polymerase chain reaction for the detection of ergot alkaloid producers among microscopic fungi of the genera Penicillium and Claviceps was evaluated . Twenty-three strains of various species of fungi with a previously studied capacity for alkaloid production were used . The internal fragment of the gene encoding 4-dimethylallyltryptophan synthase, the enzyme catalyzing the first step in the biosynthesis of ergot alkaloids, was amplified using degenerated primers . This approach revealed an about 1.2-kb specific DNA fragment in micromycetes synthesizing ergot alkaloids with complete tetracyclic ergoline system . Microorganisms that produce alkaloids with modified C or D ergoline rings, as well as alpha-cyclopiazonic acid, did not yield the PCR fragment of the expected size . This fragment was also not found in fungi incapable of ergot alkaloid production.

Adv Microb Physiol, 2001, 45, 199 - 270
Quorum sensing as a population-density-dependent determinant of bacterial physiology; Swift S et al.; The discovery that bacterial cells can communicate with each other has led to the realization that bacteria are capable of exhibiting much more complex patterns of co-operative behaviour than would be expected for simple unicellular microorganisms . Now generically termed 'quorum sensing', bacterial cell-to-cell communication enables a bacterial population to mount a unified response that is advantageous to its survival by improving access to complex nutrients or environmental niches, collective defence against other competitive microorganisms or eukaryotic host defence mechanisms and optimization of population survival by differentiation into morphological forms better adapted to combating environmental threats . The principle of quorum sensing encompasses the production and release of signal molecules by bacterial cells within a population . Such molecules are released into the environment and, as cell numbers increase, so does the extracellular level of signal molecule, until the bacteria sense that a threshold has been reached and gene activation, or in some cases depression or repression, occurs via the activity of sensor-regulator systems . In this review, we will describe the biochemistry and molecular biology of a number of well-characterized N-acylhomoserine lactone quorum sensing systems to illustrate how bacteria employ cell-to-cell signalling to adjust their physiology in accordance with the prevailing high-population-density environment.

Dtsch Tierarztl Wochenschr, 2001 Jun, 108(6), 249 - 51
{Probiotics: Is there a scientific basis for their effects?}; Gorke B et al.; Probiotic microorganisms have been used with increasing frequency in nutrition and for therapeutic purposes during the last years . Their application is generally based upon empirical experiences, since their mode of action has been the topic of investigations only recently . It became apparent that probiotics exert a wide spectrum of different effects ranging from direct antagonism against pathogens to influence upon intestinal epithelium and immune system of the host's organism . In this review, the current knowledge is summarized.

Mol Gen Mikrobiol Virusol, 2001, (2), 26 - 30
{Comparative analysis of the immune response of a rabbit to antigens to live and killed Francisella species bacteria}; Aronova NV et al.; Serum antibodies were analyzed in rabbits immunized with live and formalin-killed Francisella (F . tularensis, F . novicida, F . novicida-like, and F . philomiragia) . Passive hemagglutination test with erythrocytes sensitized by these bacteria' LPS showed much higher titers of species-specific antibodies in all sera to live microorganisms than sera to killed bacteria . The results of immunoblotting with purified LPS and bacterial lysates indicate that sera to live bacteria contained mainly immunoglobulins to species-specific antigenic epitopes of LPS O-polysaccharide chain and few antibodies to the protein component of the cell . By contrast, killed bacterial cells induced weak production of antibodies to S-LPS and a pronounced antibody response to protein antigens . Besides the quantitative differences, live and killed bacteria differed by the qualitative spectrum of immunodominant proteins . Serum to live F . tularensis 15/10 contained antibodies to at least 3 immunodominant antigens of the cell, while serum to killed bacteria contained antibodies to only two of these . Immunoglobulins to protein antigens, absent in homologous sera to live bacteria, were detected in the sera to killed F . novicida and F . novicida-like bacteria . Both sera to F . philomiragia had antibodies reacting with LPS epitopes and immunodominant complex containing protein . In contrast to other Francisella, F . philomiragia was found to synthesize an uncommon LPS representing two major lipooligosaccharides with different molecular weights and antigenic specificity . Therefore, immune response of the host to live and killed Francisella is different: live cells more effectively induce the production of antibodies to S-LPS epitopes, while killed ones to protein antigens.

Plant Sci, 2001 Jul, 161(2), 347 - 358
Compatibility of a wild type and its genetically modified Sinorhizobium strain with two mycorrhizal fungi on Medicago species as affected by drought stress; Vazquez MM et al.; The effect of double inoculation with two strains of Sinorhizobium meliloti {the wild type (WT) strain GR4 and its genetically modified (GM) derivative GR4(pCK3)}, and two species of arbuscular mycorrhizal (AM) fungi (Glomus deserticola and Glomus intraradices) was examined in a microcosm system on three species of Medicago (M . nolana, M . rigidula, M . rotata) . Two water regimes (80 and 100% water holding capacity, WHC) were assayed . The efficiency of each AM fungus increasing plant growth, nutrient content, nodulation and water-stress tolerance was related to the Sinorhizobium strains and Medicago species . This indicates selective and specific compatibilities between microsymbionts and the common host plant . Differential effects of the mycorrhizal isolates were not associated with their colonizing ability . Nodulation and mycorrhizal dependency (MD) changed in each plant genotype in accordance with the Sinorhizobium strain and AM fungi involved . Generally, Medicago sp . MD decreased under water-stress conditions even when these conditions did not affect AM colonization (%) . Proline accumulation in non-mycorrhizal plant leaves was increased by water stress, except in M . rotata plants . Differences in proline accumulation in AM-colonized plants suggest that both the AM fungus and the Sinorhizobium strain were able to induce different degrees of osmotic adjustment . Mycorrhizal plants nodulated by the WT strain accumulated more proline in M . rigidula and M . rotata under water stress than non-mycorrhizal plants . Conversely, mycorrhizal plants nodulated by the GM strain accumulated less proline in response to both AM colonization and drought . These results indicated changes in the synthesis of this nitrogenous osmoregulator product associated with microbial inoculation and drought tolerance . Mycorrhizal plants nodulated by the GM Sinorhizobium strain seem to suffer less from the detrimental effect of water stress, since under water limitation relative plant growth, percentage of AM colonization, root dry weight and the highest R/S ratio remained the same . The fact that GM nodulated plants are better adapted to drought stress could be of practical interest and the management of GM microorganism inoculation may be crucial for biotechnological approaches to improving crop yield in dry environments.

Carbohydr Res, 2001 Jul 3, 333(2), 123 - 8
Synthesis of beta-D-galactofuranosyl nucleoside analogues . A new type of beta-D-galactofuranosidase inhibitor; Marino C et al.; The development of beta-D-galactofuranosidase inhibitors provides a good chemotherapeutic target for treatment of major human diseases, because beta-D-galactofuranose is a constituent of important pathogen microorganisms but is absent in mammals . With this purpose we have prepared beta-D-galactofuranosyl nucleoside analogues, derived by the addition of nucleophiles to perbenzoylated beta-D-galactofuranosyl isothiocyanate, a compound previously prepared in this laboratory . N-beta-D-Galactofuranosyl-O-ethylthiourethane, N-beta-D-galactofuranosyl-4-oxoimidazolidine-2-thione, N-beta-D-galactofuranosyl-4-imidazoline-2-thione, and N-beta-D-galactofuranosyl-4-methoxyimidazolidine-2-thione, were prepared . The biological assays showed that imidazoline and imidazolidine-2-thione derivatives act as a new type of exo beta-D-galactofuranosidase inhibitor.

Am J Surg, 2001 May, 181(5), 411 - 5
A pancreatic ductal leak should be sought to direct treatment in patients with acute pancreatitis; Lau ST et al.; BACKGROUND: The end result of leakage of pancreatic juice into the peripancreatic space can be sterile necrosis, infected necrosis, or rupture into an adjacent hollow viscus or blood vessel (eg, colon, small bowel, or pseudoaneurysm) . If a pancreatic duct (PD) leak is present, should treatment be aimed at minimizing the sequela of the leakage of pancreatic juice and not just supportive observation until a necrosectomy is required? METHODS: In 144 patients with severe pancreatitis we investigated whether the presence of a PD leak was associated with necrosis and also asked if PD leak might predict other outcomes such as a length of stay (LOS), mortality, and need for surgery . Furthermore, we questioned whether the use of endoscopic retrograde cholangiopancreatography (ERCP) to search for a PD leak might worsen the clinical outcome because of the potential for introducing microorganisms into an undrained space or exacerbating pancreatitis . RESULTS: The presence of a demonstrable pancreatic duct leak was observed in 37% of patients and was significantly associated with both a higher incidence of necrosis and prolonged LOS (> or = 20 days) . These patients were 3.4 times more likely to have necrosis and 2.6 times more likely to have a prolonged LOS . When treated with a combination of percutaneous drains, pancreatic duct stents, and surgery as necessary, a PD leak (even with its higher necrosis rate) was not significantly correlated with either mortality or the need for necrosectomy . The use of ERCP was not associated with LOS, mortality, or the need for necrosectomy, provided discovered PD leaks were immediately drained . CONCLUSIONS: A PD leak is common in patients with pancreatic necrosis but it is also important to locate and decompress in order to impede progression of the disease and keep mortality low.

J Am Chem Soc, 2001 Jul 18, 123(28), 6756 - 66
Mechanistic investigation of UDP-galactopyranose mutase from Escherichia coli using 2- and 3-fluorinated UDP-galactofuranose as probes; Zhang Q et al.; The galactofuranose moiety found in many surface constituents of microorganisms is derived from UDP-D-galactopyranose (UDP-Galp) via a unique ring contraction reaction catalyzed by UDP-Galp mutase . This enzyme, which has been isolated from several bacterial sources, is a flavoprotein . To study this catalysis, the cloned Escherichia coli mutase was purified and two fluorinated analogues, UDP-{2-F}Galf (9) and UDP-{3-F}Galf (10), were chemically synthesized . These two compounds were found to be substrates for the reduced UDP-Galp mutase with the Km values determined to be 65 and 861 microM for 9 and 10, respectively, and the corresponding kcat values estimated to be 0.033 and 5.7 s(-1) . Since the fluorine substituent is redox inert, a mechanism initiated by the oxidation of 2-OH or 3-OH on the galactose moiety can thus be firmly ruled out . Furthermore, both 9 and 10 are poorer substrates than UDP-Galf, and the rate reduction for 9 is especially significant . This finding may be ascribed to the inductive effect of the 2-F substituent that is immediately adjacent to the anomeric center, and is consistent with a mechanism involving formation of oxocarbenium intermediates or transition states during turnover . Interestingly, under nonreducing conditions, compounds 9 and 10 are not substrates, but instead are inhibitors for the mutase . The inactivation by 10 is time-dependent, active-site-directed, and irreversible with a K(I) of 270 microM and a k(inact) of 0.19 min(-1) . Since the K(I) value is similar to Km, the observed inactivation is unlikely a result of tight binding . To our surprise, the inactivated enzyme could be regenerated in the presence of dithionite, and the reduced enzyme is resistant to inactivation by these fluorinated analogues . It is possible that reduction of the enzyme-bound FAD may induce a conformational change that facilitates the breakdown of the putative covalent enzyme-inhibitor adduct to reactivate the enzyme . It is also conceivable that the reduced flavin bears a higher electron density at N-1, which may play a role in preventing the formation of the covalent adduct or facilitating its breakdown by charge stabilization of the oxocarbenium intermediates/transition states . Clearly, this study has led to the identification of a potent inactivator (10) for this enzyme, and study of its inactivation has also shed light on the possible mechanism of this mutase.

Anat Histol Embryol, 2001 Jun, 30(3), 135 - 9
Mucous cells in micropogonias furnieri gills: histochemistry and ultrastructure; Diaz AO et al.; The characteristics of the mucous cells located in the gills of the fish Micropogonias furnieri were investigated . Using histochemical procedures that included methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cell contents of the primary and secondary lamellae . The GPs were identified with (a) oxidizable vecinal diols; (b) sialic acids and some of their chain variants, C7 or C9; (c) carboxyl groups and (d) sulphate groups . The electron microscope showed large mucous globules of different electro densities from mucous cells located deep in the epithelium between the other epithelial cells; the release of mucus by exocytosis was observed . GPs secreted on the surface of the mucous cells was suggested to be important for the lubrication, protection and inhibition of microorganisms . It is possibility that GPs could have similar roles in Micropogonias furnieri gills.

Infect Immun, 2001 Aug, 69(8), 5157 - 61
Phagocytosis of wild-type Legionella pneumophila occurs through a wortmannin-insensitive pathway; Khelef N et al.; Wild-type Legionella pneumophila grows in human macrophages within a replicative phagosome, avoiding lysosomal fusion, while nonreplicative mutants are killed in lysosomes . Wortmannin, a phosphatidylinositol 3-kinase (PI3K) inhibitor, blocks phagocytosis of an avirulent mutant, but not of wild-type L . pneumophila, without affecting membrane ruffling and actin polymerization . These results show that wild-type and mutant Legionella strains use different entry pathways . They suggest that PI3Ks are involved in phagocytosis of an avirulent L . pneumophila mutant and regulate the ability of microorganisms to generate a replicative phagosome.

Glycobiology, 2001 Jul, 11(7), 533 - 9
Redirection of sialic acid metabolism in genetically engineered Escherichia coli; Ringenberg M et al.; Most microorganisms do not produce sialic acid (sialate), and those that do appear to use a biosynthetic mechanism distinct from mammals . Genetic hybrids of nonpathogenic, sialate-negative laboratory Escherichia coli K-12 strains designed for the de novo synthesis of the polysialic acid capsule from E . coli K1 proved useful in elucidating the genetics and biochemistry of capsule biosynthesis . In this article we propose a dynamic model of sialometabolism to investigate the effects of biosynthetic neu (N-acetylneuraminic acid) and catabolic nan (N-acylneuraminate) mutations on the flux of intermediates through the sialate synthetic pathway . Intracellular sialate concentrations were determined by high pH anion exchange chromatography with pulsed amperometric detection . The results indicated that a strain carrying a null defect in the gene encoding polysialyltransferase (neuS) accumulated > 50 times more CMP-sialic acid than the wild type when strains were grown in a minimal medium supplemented with glucose and casamino acids . Metabolic accumulation of CMP-sialic acid depended on a functional sialic acid synthase (neuB), as shown by the inability of a strain lacking this enzyme to accumulate a detectable endogenous sialate pool . The neuB mutant concentrated trace sialate from the medium, indicating its potential value for quantitative analysis of free sialic acids in complex biological samples . The function of the sialate aldolase (encoded by nanA) in limiting intermediate flux through the synthetic pathway was determined by analyzing free sialate accumulation in neuA (CMP-sialic acid synthetase) nanA double mutants . The combined results demonstrate how E . coli avoids a futile cycle in which biosynthetic sialate induces the system for its own degradation and indicate the feasibility of generating sialooligosaccharide precursors through targeted manipulation of sialate metabolism.

Analyst, 2001 Jun, 126(6), 766 - 71
Synthetic receptors as sensor coatings for molecules and living cells; Dickert FL et al.; Non-covalent molecularly imprinted polymers are applied as sensitive coatings to planar waveguides and mass-sensitive devices for the selective detection of various groups of analytes in the gaseous and aqueous phases . Cavity imprinting in the bulk of the sensor material as well as surface imprinting techniques are used to enrich analytes ranging from sub-nanometres to micrometres in analyte size . The coated devices provide sensitivity to e.g . polycyclic aromatic hydrocarbons, xanthine derivatives, complex coffee samples and whole microorganisms.

Crit Care Med, 2001 Jul, 29(7), 1311 - 7
Accuracy of delayed cultures of plugged telescoping catheter samples for diagnosing bacterial pneumonia; de Lassence A et al.; OBJECTIVE: It is not always feasible to culture immediately bacteriologic samples of protected pulmonary specimens on a 24-hr basis before starting antibiotic treatment . We have evaluated the effect of delaying the culture of immediate plugged telescoping catheter (PTC) samples performed before starting antibiotherapy . DESIGN: Prospective paired comparisons study . SETTING: Intensive care unit in a university hospital . PATIENTS: Ninety-nine PTCs were performed on 68 intensive care unit patients suspected of nosocomial or community- acquired bacterial pneumonia . INTERVENTION: PTC samples were divided into two aliquots: one for immediate (H0) analysis and one for storage at 4 degrees C (H24) for 24 hrs before being cultured . MEASUREMENTS AND MAIN RESULTS: The results from these delayed cultures (H24) were compared with those from immediate ones (H0) . All negative H0 samples (n = 59) were also negative at H24 . Forty PTCs yielded one or more microorganisms, with a total of 69 microorganisms in one or both samples . H0 and H24 cultures were concordant in 119 of 128 (97.9%) cases (kappa coefficient value 0.79) with a threshold of 103 colony-forming units (cfu)/mL . Agreement between paired cultures was very good . The bias calculated as the mean difference between paired culture results was 0.128 +/- 1.024 (Deltalog) . Concordance using the 103 cfu/mL threshold (102/107 cases, kappa coefficient value 0.82) and agreement were enhanced (0.067 +/- 0.645) when possible contaminants were excluded (n = 21) . CONCLUSIONS: Storing PTC specimens for 24 hrs at 4 degrees C is an acceptable alternative when culturing cannot be performed immediately . This allows starting antibiotic treatment without any delay.

Scand J Gastroenterol, 2001 Jul, 36(7), 744 - 50
Effect of sodium butyrate on reactive oxygen species generation by human neutrophils; Liu Q et al.; BACKGROUND: Short-chain fatty acids enema has been shown to be effective in the treatment of ulcerative colitis (UC) . However, the mechanisms that lead to this response have not been well characterized . The aims of this study were to investigate the effect sodium butyrate has on reactive oxygen species (ROS) generation by human neutrophils, which are responsible for mucosal injury . METHODS: Human neutrophils incubated with or without sodium butyrate were stimulated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA) . ROS generation was largely differentiated with flow cytometry assays of hydroethidine oxidation and dichlorofluorescein oxidation for superoxide anion and hydrogen peroxide respectively, and luminol-dependent chemiluminescence for myeloperoxidase-mediated oxidants . RESULTS: Sodium butyrate (up to 50 mM) did not alter hydroethidine oxidation upon stimulation of the OZ or PMA . However, sodium butyrate at a concentration of 25 mM elevated dichlorofluorescein oxidation to 125 + 8% (P = 0.028) of control upon stimulation of OZ and to 191 +/- 30% (P = 0.0016) upon stimulation of PMA . Contrary to these results, sodium butyrate greatly inhibited chemiluminescence responses in a dose-dependent manner . The inhibition by 50 mM sodium butyrate was 61 +/- 6% upon OZ and 71 +/- 9% upon PMA, respectively . CONCLUSIONS: These data indicate that sodium butyrate up-regulates hydrogen peroxide generation but down-regulates generation of myeloperoxidase-mediated oxidants, the latter being more potent in killing microorganisms and in inducing tissue injury . A possible mechanism is suggested whereby sodium butyrate may inhibit myeloperoxidase activity and hence attenuate the destructive activities of neutrophils in UC.

Water Sci Technol, 2001, 43(11), 181 - 8
UV dose distribution characterization using fractal concepts for system performance evaluation; Lin LS et al.; This paper presents a mathematical model for estimating the UV dose distribution delivered by continuous-flow UV disinfection processes . The model adopts fractal concepts and a stochastic method to simulate microorganism (particle) trajectories through the irradiation zone of an open-channel UV system . The irregularity of particle trajectories attributable to random movements was characterized by fractal dimension . In turn, trajectory-specific doses were calculated by integrating UV intensity over travel time . Results of these simulations indicated that radiation intensities along the trajectories could be highly variable . Therefore, microorganisms are expected to receive a broad range of radiation doses as a result of variations in radiation intensity along their trajectories and spatial heterogeneity in the radiation intensity field . This supports previous assertions that the conventional averaged-dose approach will result in substantial deviations between predicted and actual system performance . Implications of the results in terms of treatment efficiency and system design are discussed . The presented approach is found to be useful as a tool for rapid estimation of the dose distribution delivered by UV processes.

Prikl Biokhim Mikrobiol, 2001 May-Jun, 37(3), 338 - 43
{Enzymatic proteinaceous hydrolyzate from the processing waste of the Iceland scallop Chlamys islandica}; Mukhin VA et al.; Dry enzymatic hydrolyzate was derived from the protein containing wastes of the Iceland scallop fishery using the complex of proteinases from the king red crab hepatopancreas . The finished product contains not less than 80% of free amino acids and the lowest peptides . Leucine, isoleucine, arginine, lysine and aspartic acids account for to 50% of free amino acids . The applicability appraisal of proteinaceous hydrolyzate from the wastes of the Iceland scallop fishery to use them as the constituents in the nutrient medium for microorganisms was conducted . The approbation of hydrolyzate in the composition of nutrient medium on the test--cultures indicated the high sensibility and germinating capacity of microorganisms.

J Bacteriol, 2001 Aug, 183(15), 4517 - 25
Genome size determination and coding capacity of Sodalis glossinidius, an enteric symbiont of tsetse flies, as revealed by hybridization to Escherichia coli gene arrays; Akman L et al.; Recent molecular characterization of various microbial genomes has revealed differences in genome size and coding capacity between obligate symbionts and intracellular pathogens versus free-living organisms . Multiple symbiotic microorganisms have evolved with tsetse fly, the vector of African trypanosomes, over long evolutionary times . Although these symbionts are indispensable for tsetse fecundity, the biochemical and molecular basis of their functional significance is unknown . Here, we report on the genomic aspects of the secondary symbiont Sodalis glossinidius . The genome size of Sodalis is approximately 2 Mb . Its DNA is subject to extensive methylation and based on some of its conserved gene sequences has an A+T content of only 45%, compared to the typically AT-rich genomes of endosymbionts . Sodalis also harbors an extrachromosomal plasmid about 134 kb in size . We used a novel approach to gain insight into Sodalis genomic contents, i.e., hybridizing its DNA to macroarrays developed for Escherichia coli, a closely related enteric bacterium . In this analysis we detected 1,800 orthologous genes, corresponding to about 85% of the Sodalis genome . The Sodalis genome has apparently retained its genes for DNA replication, transcription, translation, transport, and the biosynthesis of amino acids, nucleic acids, vitamins, and cofactors . However, many genes involved in energy metabolism and carbon compound assimilation are apparently missing, which may indicate an adaptation to the energy sources available in the only nutrient of the tsetse host, blood . We present gene arrays as a rapid tool for comparative genomics in the absence of whole genome sequence to advance our understanding of closely related bacteria.

J Invest Dermatol, 2001 Jul, 117(1), 106 - 11
Expression of the peptide antibiotics human beta defensin-1 and human beta defensin-2 in normal human skin; Ali RS et al.; Normal human skin is remarkably resistant to infection from the large numbers of microorganisms that routinely colonize its surface . In addition to the role of skin as a mechanical barrier, it has long been recognized that skin and other epithelia can produce a range of anti-microbial chemicals that play an important part in eliminating potential cutaneous pathogens . Anti-microbial peptides are an important evolutionarily conserved innate host defense mechanism in many organisms . Human beta defensin-1 and -2 are cysteine-rich, cationic, low molecular weight anti-microbial peptides that have recently been shown to be expressed in epithelial tissues . In this study, we describe the characterization of human beta defensin-1 and -2 mRNA and peptide expression in normal human skin . Using reverse transcription-polymerase chain reaction we demonstrate that human beta defensin-1 is consistently expressed in skin samples from various body sites . Human beta defensin-2 demonstrates expression that is more variable and is more readily detectable in facial skin and foreskin compared with skin from abdomen and breast . In situ hybridization localizes the human beta defensin-1 and -2 transcripts to keratinocytes within interfollicular skin . Using specific antibodies, we have shown that human beta defensin-1 and -2 peptides are localized to the Malpighian layer of the epidermis and/or stratum corneum and that there are interindividual and site-specific differences in intensity of immunostaining and the pattern of peptide localization . The localization of human beta defensins to the outer layer of the skin is consistent with the hypothesis that human beta defensins play an essential part in cutaneous innate immunity.

Arch Med Res, 2001 Jul-Aug, 32(4), 304 - 11
Risk factors for intrahospital infection in newborns; Tapia-Rombo CA et al.; BACKGROUND: Intrahospital infection (IHI) in the newborn (NB) is a morbidity problem that increases mortality rates in this age group because the infecting microorganism is more aggressive . The objective of this study was to compare risk factors for localized or systemic IHIs between groups of NBs with and without IHIs . METHODS: This was a retrospective study of two groups of patient records from January 1995 to December 1998 . Group A (cases) was made up of 73 patients with documented IHIs and Group B (controls), 105 patients without IHIs . Descriptive and inferential statistics (Student t, Mann-Whitney U, Wilcoxon rank sum, Chi square, and Fisher exact tests) were used . Odds ratio (OR) and multiple logistic regression were used to study risk factors . Statistical significance was considered at p <0.05 . RESULTS: Average gestational age was 35.4 +/- 4.3 weeks in Group A patients and 37.4 +/- 3.2 weeks for Group B patients with p = 0.001 . Risk factors studied by means of OR (low birth weight, prematurity of 30 weeks of gestational age or less, prolonged intrahospital stay, etc.) showed statistical significance . Also showing significance were other not-well-studied factors such as higher numbers of diagnoses and blood transfusions . After multivariate analysis, the group of risk factors more associated with IHIs included vein dissection for insertion of central venous catheter, orotracheal intubation, and prolonged intrahospital stay (12 days or more) with an accumulative r of 0.6112 . CONCLUSIONS: We conclude that there are several known risk factors for IHIs and others not well described to date that must be avoided to the extent possible in the NB, particularly in the premature newborn population.

Biodegradation, 2000, 11(2-3), 107 - 16
Anaerobic benzene degradation; Lovley DR; Although many studies have indicated that benzene persists under anaerobic conditions in petroleum-contaminated environments, it has recently been documented that benzene can be anaerobically oxidized with most commonly considered electron acceptors for anaerobic respiration . These include: Fe(III), sulfate, nitrate, and possibly humic substances . Benzene can also be converted to methane and carbon dioxide under methanogenic conditions . There is evidence that benzene can be degraded under in situ conditions in petroleum-contaminated aquifers in which either Fe(III) reduction or methane production is the predominant terminal electron-accepting process . Furthermore, evidence from laboratory studies suggests that benzene may be anaerobically degraded in petroleum-contaminated marine sediments under sulfate-reducing conditions . Laboratory studies have suggested that within the Fe(III) reduction zone of petroleum-contaminated aquifers, benzene degradation can be stimulated with the addition of synthetic chelators which make Fe(III) more available for microbial reduction . The addition of humic substances and other compounds that contain quinone moieties can also stimulate anaerobic benzene degradation in laboratory incubations of Fe(III)-reducing aquifer sediments by providing an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides . Anaerobic benzene degradation in aquifer sediments can be stimulated with the addition of sulfate, but in some instances an inoculum of benzene-oxidizing, sulfate-reducing microorganisms must also be added . In a field trial, sulfate addition to the methanogenic zone of a petroleum-contaminated aquifer stimulated the growth and activity of sulfate-reducing microorganisms and enhanced benzene removal . Molecular phylogenetic studies have provided indications of what microorganisms might be involved in anaerobic benzene degradation in aquifers . The major factor limiting further understanding of anaerobic benzene degradation is the lack of a pure culture of an organism capable of anaerobic benzene degradation.

Biosci Biotechnol Biochem, 2001 May, 65(5), 1258 - 60
Microbial resolution of 2-hydroxy-3-nitropropionic acid for synthesis of optically active isoserine; Yasohara Y et al.; The biocatalytic stereoselective hydrolysis of 2-hydroxy-3-nitropropionic acid esters was studied . Forty enzymes and three hundred microorganism strains were examined for their ability to hydrolyze ethyl 2-hydroxy-3-nitropropionic acid . Nocardia globerula IFO13150 gave n-butyl (R)-2-hydroxy-3-nitropropionate with a 92% enantiomeric excess (ee) and the corresponding carboxylic acid with a 92%ee, which was easily converted to (S)-isoserine, a useful beta-amino acid.

Biosci Biotechnol Biochem, 2001 May, 65(5), 1191 - 4
Isolation of poly(3-hydroxybutyrate) (PHB)-degrading microorganisms and characterization of PHB-depolymerase from Arthrobacter sp . strain W6; Asano Y et al.; Microbial degraders of poly(3-hydroxybutyrate) (PHB) were isolated from soil . Arthrobacter sp . strain W6 used not only PHB as a carbon source, but also PHAs such as poly(3-hydroxybutyrate-co-{5%}3-hydroxyvalerate), poly(3-hydroxybutyrate-co-{14%}3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-{22%}3-hydroxyvalerate) . PHB-depolymerase was purified to homogeneity from the culture broth of Arthrobacter sp . strain W6 by a procedure involving DEAE- and butyl-Toyopearl column chromatographies . The Mr of the enzyme was estimated to be about 47,000 by SDS-polyacrylamide gel electrophoresis . The enzyme was most active at pH 8.5 and 50 degrees C, and was inhibited by phenylmethylsulfonyl fluoride, Hg2+, Ag+, and Pb2+.

Aviat Space Environ Med, 2000 Dec, 71(12), 1239 - 47
Antiorthostatic suspension for 14 days does not diminish the oxidative response of neutrophils in mice; Smolen JE et al.; The effects of long-term spaceflight on inflammatory responses have not been well-studied in either humans or animals . It is thus important to determine if the functions of immune and inflammatory cells are altered in models of spaceflight . One such animal model is antiorthostatic suspension (AOS), in which the experimental animal is subjected to a head-down tilt that mimics both the stress and the cephalad fluid shift experienced in spaceflight . A previous study reported that the peritoneal neutrophils from mice experiencing AOS generated less superoxide than unsuspended controls . We expanded on this study using several different stimuli and measuring the oxidative response of murine neutrophils in a variety of ways . These responses included the rate, lag period, and dose/response characteristics for superoxide generation, FACS analysis with dihydrodichlorofluorescein as a substrate, and a chemiluminescence response with luminol as a substrate . We also examined phagocytosis of three different microorganisms . While some effects of orthostatic suspension (attributable to the stress of the apparatus) were observed, no clear effects of AOS on oxidative function of the peritoneal neutrophils were seen.

Oral Oncol, 2001 Sep, 37(6), 521 - 6
In situ staining with DNA-binding fluorescent dye, Hoechst 33258, to detect microorganisms in the epithelial cells of oral leukoplakia; Mizuki H; This study was performed to investigate the presence of microorganisms in the epithelial cells of leukoplakia . Frozen sections of 20 specimens of leukoplakia were stained with DNA-binding bisbenzimide Hoechst 33258 . As a control, 20 specimens of normal oral mucosa and five specimens of normal skin were used . In all preparations of leukoplakia, small granular fluorescing structures were observed within the cytoplasm of the epithelial cells, predominantly within the cytoplasm of prickle cells, although the amount of the granular structures varied between specimens, layers of the epithelium and even areas of the epithelium within a single section . Less granular structures were observed, or none at all, in the cytoplasm of the epithelial cells of normal mucosa . No structures were observed in the cytoplasm of the epithelium of skin . The results in this study strongly suggest that microorganisms are present in the epithelial cells of oral mucosa, and that they are closely associated with the development of oral leukoplakia . It is postulated that the microorganisms in the epithelial cells could be bacteria, particularly mycoplasmas.

Trends Microbiol, 2001 Jul, 9(7), 295 - 8
Borna disease virus and neuropsychiatric disease--a reappraisal; Lipkin WI et al.; Despite progress in understanding the molecular biology and pathobiology of Borna disease virus, its epidemiology and role in human disease remain controversial . The challenges encountered in this field are a paradigm for the investigation of diseases potentially linked to complex host-microorganism interactions.

Mol Biotechnol, 2001 Mar, 17(3), 249 - 60
Procedures for microencapsulation of enzymes, cells and genetically engineered microorganisms; Chang TM et al.; Methods to microencapsulate enzyme, cells, and genetically engineered cells have been described in this article . More specific examples of enzyme encapsulation include the microencapsulation of xanthine oxidase for Lesch-Nyhan disease; phenylalanine ammonia lyase for pheny, ketonuria and microencapsulation of multienzyme systems with cofactor recycling for multistep enzyme conversions . Methods for cell encapsulation include the details for encapsulating hepatocytes for liver failure and for gene therapy . This also includes the details of a novel two-step method for encapsulation of high concentrations of smaller cells . Another new approach is the detailed method of the encapsulation of genetically engineered Escherichia coli DH5 cells for lowering urea, ammonia, and other metabolites in kidney or, liver failure and other diseases.

Nat Rev Genet, 2001 Jul, 2(7), 516 - 27
The arms race is ancient history in Arabidopsis, the wildflower; Holub EB; Plant pathology was born after the nineteenth-century potato famine, and since then insightful genetic experiments have contributed to the great progress in our understanding of disease control . Our current view of plant resistance focuses on numerous polymorphic resistance loci, which contain genes known as R genes . The complete sequence of the Arabidopsis thaliana genome provides a framework for exploring the 'big bang' of R genes that occurred and how R genes evolved in plants from their associations with microorganisms, and for improving strategies for more sustainable deployment of disease resistance in crops.

Med Sci Monit, 2001 Jul-Aug, 7(4), 652 - 8
In vitro response of phagocytic cells to immunomodulating agents; Stoika R et al.; BACKGROUND: Phagocytes (polymorphonuclear cells and monocyte-macrophages) are the first line of defence of the host against infectious microorganisms and other foreign antigens . Agents which participate in activation of phagocytic cells possess a potential immunomodulating action . Thus, search for convenient in vitro test-systems and study of mechanisms of action of these agents are of practical interest . MATERIAL AND METHODS: Human blood polymorphonuclear (PMN) cells and murine macrophages (line J774.2) were used as cellular test-systems for study of phagocytosis-stimulating action of immunomodulating agents . Indexes of phagocytic activity were estimated by the phagocyte ingestion of yeast cells . NO-synthase activity, nitrite production, and nitroblue tetrazolium test were determined after phagocyte stimulation . RESULTS: It was revealed that indexes of phagocytic activity can be used as quantitative indicators for measurement immunomodulating activity . Zymosan A-induced phagocytosis in almost 100% PMN cells and macrophages and thus can be used as a positive control . Wheat germ agglutinin (WGA, 0.5-1.0 microg/ml) stimulated phagocytosis in PMN cells 1.8 times after 2-3 h incubation, although in higher concentrations (5-10 microg/ml) it strongly inhibited phagocytosis . TGF-b1 (10 ng/ml) suppressed phagocytosis in WGA-stimulated PMN cells . Mistletoe agglutinin-1 stimulated phagocytosis in PMN cells, although its effect in macrophages was weak, while concanavalin A stimulation of phagocytosis in macrophages was well expressed . Vasodilating peptide bradykinin increased phagocytosis 2.5 times in macrophages . We did not reveal changes in NO-synthase activity and nitrite production in macrophages and PMN cells activated by different immunomodulatig agents . Only lipopolysacharide stimulated such activity in macrophages . CONCLUSIONS: Cultured macrophages and PMN cells can provide reproducible quantitative results in screening phagocytic activity of different immunomodulating agents . Both positively and negatively acting immunomodulators might be studied using these test cells.

Trends Pharmacol Sci, 2001 Jul, 22(7), 376 - 84
Proteomics--post-genomic cartography to understand gene function; Naaby-Hansen S et al.; The completion of the genomic sequences of numerous organisms from human and mouse to Caenorhabditis elegans and many microorganisms, and the definition of their genes provides a database to interpret cellular protein-expression patterns and relate them to protein function . Proteomics technologies that are dependent on mass spectrometry and involve two-dimensional gel electrophoresis are providing the main window into the world of differential protein-expression analysis . In this article, the limitations and expectations of this research field are examined and the future of the analytical needs of proteomics is explored.

Cytometry, 2001 Jul 1, 44(3), 247 - 56
Phytoplankton group dynamics in the Bay of Marseilles during a 2-year survey based on analytical flow cytometry; Gregori G et al.; BACKGROUND: The Bay of Marseilles is under the influence of a large urban concentration and its maritime activities . All of them discharge compounds (hydrocarbons, excess nutrients, heavy metals, chemicals, etc.) that can alter the marine ecosystem . To investigate whether ultraphytoplankton (<10 microm) could be used as biosensors for their own ecosystem, a 2-year survey was conducted in the Bay of Marseilles . METHODS: Seven stations monitored water mass and potential anthropic effects in the bay . Seawater samples were collected monthly or bimonthly at three depths, prefiltered, fixed, and kept in liquid nitrogen until flow cytometric analysis . RESULTS: Five categories were created: Prochlorococcus, picoeukaryotes (<2 microm), nanoeukaryotes I (2--6 microm), nanoeukaryotes II (6--10 microm), and Synechococcus (<1.5 microm) . Artificial neural network analysis (Kohonen self-organizing maps) produced the same number of clusters as cluster analysis with Winlist software (Verity Software House) . CONCLUSIONS: In addition to the wide variabilities in abundance and biomass, there were a strong seasonal signal and sporadic events . Lessons are derived from this study for future monitoring of marine microorganisms .

Cytometry, 2001 Jul 1, 44(3), 226 - 35
Flow cytometric analysis of chronic and acute toxicity of copper(II) on the marine dinoflagellate Amphidinium carterae; Lage OM et al.; BACKGROUND: Copper(II) is a heavy metal whose levels have increased in some marine ecosystems to polluting levels . Dinoflagellates, an important phytoplankton group, are at the base of aquatic food chains and bioaccumulation of copper by these microorganisms can result in complex ecosystem alterations, so we investigated how copper disturbs those cells . METHODS: Cytotoxic effects of sublethal and lethal copper concentrations ranging from 4.2 nM (control condition) to 3.13 microM estimated labile copper were studied in batch cultures of Amphidinium carterae . Cell morphology, motility, autofluorescence, and fluorescein diacetate (FDA)-dependent fluorescence generation were evaluated by flow cytometry (FCM) and microscopy . RESULTS: Exposure of A . carterae to toxic levels of copper impaired cell mobility, delayed cell proliferation, led to increased green autofluorescence, and at 3.13 microM labile copper also induced encystment and death . Chlorophyll fluorescence, however, was not affected . Kinetic FCM assay of FDA-dependent fluorescence generation showed a dose-dependent enhancement of fluorescein fluorescence immediately after copper addition and in cultures with sustained exposure to this toxicant . CONCLUSIONS: Our data suggest that copper toxicity occurs quickly at the membrane level in relation to oxidative stress generation . Based on fluorescence kinetic studies, the Na(+)/H(+) antiporter seemed to be affected by copper, thereby affecting intracellular pH .

Cytometry, 2001 Jul 1, 44(3), 164 - 72
Flow cytometry in oceanography 1989--1999: environmental challenges and research trends; Legendre L et al.; BACKGROUND: The present review is based on the identification of four major environmental crises that have been approached from a biological oceanographic viewpoint . These crises are the release of contaminants in near shore marine waters, the collapse of marine resources that were renewable until recently, the loss of biodiversity, and global climate change METHODS: The review examines the contribution of cytometry-based biological oceanography to the resolution of the four environmental crises . Using a database of 302 papers, flow cytometric (FCM) studies in biological oceanography over the 1989--1999 decade are examined . Future biological oceanographic applications of FCM are discussed . RESULTS: Most of the published FCM oceanographic studies focus on phytoplankton and bacterioplankton . Analysis of our 1989-1999 database shows the predominance of studies dedicated to phytoplankton (77%), followed by heterotrophic bacteria (21%) . The latter progressively increased over the last decade, together with the improved understanding of the biogeochemical and trophic roles of marine bacteria . Most studies on these two microorganisms were conducted in vitro until 1996, after which the trend reversed in favor of in situ research . The most investigated areas were those with major international sampling efforts, related to the changing climate . Concerning environmental topics, 62% of papers on phytoplankton and bacterioplankton focused on the structure of microbial communities and fluxes (e.g., production, grazing); this provides the basis for biological oceanographic studies on resources and climate change . CONCLUSIONS: Future progress in the biological oceanographic use of FCM will likely fall into two categories, i.e., applications where FCM will be combined with the development of other methods and those where FCM will be the main analytical tool . It is expected that FCM and other cytometric approaches will improve the ability of biological oceanography to address the major environmental challenges that are confronting human societies .

Transpl Infect Dis, 2001 Mar, 3(1), 2 - 7
Diagnostic yield of bronchoalveolar lavage following renal transplantation; Reichenberger F et al.; Organ transplant recipients are at high risk of infectious pulmonary complications . In this retrospective study, the diagnostic yield of bronchoalveolar lavage (BAL) was evaluated in renal transplant recipients . The results were analysed in special regard to the clinical presentation of pulmonary infections and the possible impact of new immunosuppressive agents . Over a 5-year period 91 BAL were performed in 71 renal transplant recipients . Microorganisms were isolated from 69% of BAL (63/91): bacteria 32%; cytomegalovirus (CMV) 27%; Pneumocystis carinii (PC) 22%; other viruses 9% (HSV; EBV, RSV, adenovirus, HHV8); Aspergillus fumigatus 1% . Total cell counts and neutrophil counts in BAL were significantly elevated in bacterial infection, whereas BAL positive for PC showed eosinophilia (P<0.05) . There was no association between clinical symptoms and the radiological pattern of infiltrates and the type of infection . Immunosuppression containing tacrolimus or mycophenolate mofetil was associated with a significantly higher percentage of PC and CMV infections compared to cyclosporin-based immunosuppression (65% vs . 30%, P<0.005) . A considerable number of PC and CMV infections occurred beyond 6 months after transplantation . In conclusion, BAL has a high diagnostic yield in renal transplant recipients . Infection with CMV and PC should also be considered beyond 6 months after transplantation, and prophylaxis for opportunistic infections should be given if the immunosuppression is intensified.

Transpl Infect Dis, 1999 Mar, 1(1), 50 - 64
Prevention of infections in solid organ transplant recipients; Villacian JS et al.; Solid organ transplantation has become an important therapeutic option for multiple chronic diseases . With the advent of newer and potent immunosuppressive regimens, graft survival has improved, but at the expense of an increased risk for the development of infections secondary to bacterial, fungal, viral and parasitic pathogens . Prevention of such infectious complications with effective, well tolerated, and cost-effective anti-microbials would be ideal to improve the outcome of transplanted patients . However, the emergence of multi-drug resistant pathogens, medication toxicity and drug-drug interactions need to be carefully evaluated . This review summarizes the most relevant data pertaining to our current understanding of infection prevention for solid organ transplant recipients . Specific recommendations are given for the prevention of each group of microorganisms and types of solid organ transplant.

Skin Res Technol, 2000 May, 6(2), 87 - 91
Axillary pH and influence of deodorants; Stenzaly-Achtert S et al.; BACKGROUND/AIMS: In moist intertriginous regions, such as the armpit, the pH value is physiologically higher than in other skin regions . The regulation of the axillary pH-value was examined in an open study with 48 subjects in three groups with n=16 each . METHODS: In the first 10 days (run-in) the subjects received a standard treatment in the axilla with shaving, cleansing and application of a pH-neutral deodorant . This was followed by a 5 day treatment period with the three test products (pH5 Eucerin(R) Deodorant Roll-on, Deodorant Balsam Spray, Deodorant Cream) . The study was concluded by a wash-out period with procedures identical to the run-in phase . The pH was measured with a calibrated pH-meter . RESULTS: A significant pH reduction was shown during the treatment period when compared to the run-in phase . The Deodorant Roll-on induced a reduction of the mean pH values from 6.1 to 5.3, the Deodorant Balsam Spray from 6.5 to 5.7 and the Deodorant Cream from 6.2 to 5.3 . During the wash-out period all pH values returned to baseline . CONCLUSION: All of the deodorants tested demonstrated a significant reduction in axillary pH . There is evidence that a high skin pH promotes the growth of several microorganisms that produce malodor . Therefore, the regulation of pH may contribute to the deodorant efficacy of the test products.

Proc Natl Acad Sci U S A, 2001 Jul 3, 98(14), 7875 - 8 Epub 2001 Jun 26.
Wheat leaves emit nitrous oxide during nitrate assimilation; Smart DR et al.; Nitrous oxide (N(2)O) is a key atmospheric greenhouse gas that contributes to global climatic change through radiative warming and depletion of stratospheric ozone . In this report, N(2)O flux was monitored simultaneously with photosynthetic CO(2) and O(2) exchanges from intact canopies of 12 wheat seedlings . The rates of N(2)O-N emitted ranged from <2 pmol x m(-2) x s(-1) when NH(4)(+) was the N source, to 25.6 +/- 1.7 pmol x m(-2) x s(-1) (mean +/- SE, n = 13) when the N source was shifted to NO(3)(-) . Such fluxes are among the smallest reported for any trace gas emitted by a higher plant . Leaf N(2)O emissions were correlated with leaf nitrate assimilation activity, as measured by using the assimilation quotient, the ratio of CO(2) assimilated to O(2) evolved . (15)N isotopic signatures on N(2)O emitted from leaves supported direct N(2)O production by plant NO(3)(-) assimilation and not N(2)O produced by microorganisms on root surfaces and emitted in the transpiration stream . In vitro production of N(2)O by both intact chloroplasts and nitrite reductase, but not by nitrate reductase, indicated that N(2)O produced by leaves occurred during photoassimilation of NO(2)(-) in the chloroplast . Given the large quantities of NO(3)(-) assimilated by plants in the terrestrial biosphere, these observations suggest that formation of N(2)O during NO(2)(-) photoassimilation could be an important global biogenic N(2)O source.

J Clin Microbiol, 2001 Jul, 39(7), 2494 - 9
Recombinant major antigenic protein 2 of Ehrlichia canis: a potential diagnostic tool; Alleman AR et al.; The major antigenic protein 2 (MAP2) of Ehrlichia canis was cloned and expressed . The recombinant protein was characterized and tested in an enzyme-linked immunosorbent assay (ELISA) format for potential application in the serodiagnosis of canine monocytic ehrlichiosis . The recombinant protein, which contained a C-terminal polyhistidine tag, had a molecular mass of approximately 26 kDa . The antigen was clearly identified by Western immunoblotting using antihistidine antibody and immune serum from an experimentally infected dog . The recombinant MAP2 (rMAP2) was tested in an ELISA format using 141 serum samples from E . canis immunofluorescent antibody (IFA)-positive and IFA-negative dogs . Fifty-five of the serum samples were from dogs experimentally or naturally infected with E . canis and were previously demonstrated to contain antibodies reactive with E . canis by indirect immunofluorescence assays . The remaining 86 samples, 33 of which were from dogs infected with microorganisms other than E . canis, were seronegative . All of the samples from experimentally infected animals and 36 of the 37 samples from naturally infected animals were found to contain antibodies against rMAP2 of E . canis in the ELISA . Only 3 of 53 IFA-negative samples tested positive on the rMAP2 ELISA . There was 100% agreement among IFA-positive samples from experimentally infected animals, 97.3% agreement among IFA-positive samples from naturally infected animals, and 94.3% agreement among IFA-negative samples, resulting in a 97.2% overall agreement between the two assays . These data suggest that rMAP2 of E . canis could be used as a recombinant test antigen for the serodiagnosis of canine monocytic ehrlichiosis.

Ann Agric Environ Med, 2001, 8(1), 51 - 6
Work-related skin symptoms and type I allergy among eastern-Polish farmers growing hops and other crops; Spiewak R et al.; 73 eastern-Polish farmers growing hops and other crops were examined . They were questioned by a dermatologist and subsequently skin prick-tested with allergens of hops, grain dust, straw dust, hay dust, storage mites, and antigens of microorganisms typical for farm environment . Results: 14 farmers (19.2%) complained of work-related skin symptoms, caused most often by hops (11%), followed by grain (5.6%), hay (5.5%) and straw (4.1%) . Five farmers (6.8%) complained of hand dermatitis, four (5.5%) of airborne dermatitis, and eight (11.0%) of pruritus . In two farmers, two skin diseases co-existed . The skin symptoms were mostly mild, however, one case of severe invalidating airborne dermatitis to hops was found . On skin prick tests, 14 farmers (19.2%) showed positive skin reaction to at least one allergen; 5.5% of farmers reacted to grain dust, 5.5% to straw dust, 11% to hay dust, and 8.2% to hops . Tests with storage mites showed positive reactions to Acarus siro in 9.6%, Lepidoglyphus destructor in 17.8%, and to Tyrophagus putrescentiae in 13.7% . Tests with microbial allergens elicited positive reactions to Pantoea agglomerans in 4.1%, Saccharopolyspora rectivirgula in 4.1%, Aspergillus fumigatus in 4.1% and to Streptomyces albus in 1.4% of farmers . Although results of skin prick tests in general did not correlate well with the work- related skin symptoms, in three of 14 farmers with skin symptoms the tests results played a crucial role in identifying the cause of their work-related skin disease.

Appl Environ Microbiol, 2001 Jul, 67(7), 3275 - 9
Reductive precipitation of gold by dissimilatory Fe(III)-reducing bacteria and archaea; Kashefi K et al.; Studies with a diversity of hyperthermophilic and mesophilic dissimilatory Fe(III)-reducing Bacteria and Archaea demonstrated that some of these organisms are capable of precipitating gold by reducing Au(III) to Au(0) with hydrogen as the electron donor . These studies suggest that models for the formation of gold deposits in both hydrothermal and cooler environments should consider the possibility that dissimilatory metal-reducing microorganisms can reductively precipitate gold from solution.

Electrophoresis, 2001 May, 22(9), 1652 - 68
Rapid quantitative measurements of proteomes by Fourier transform ion cyclotron resonance mass spectrometry; Smith RD et al.; The patterns of gene expression, post-translational modifications, protein/biomolecular interactions, and how these may be affected by changes in the environment, cannot be accurately predicted from DNA sequences . Approaches for proteome characterization are generally based upon mass spectrometric analysis of in-gel digested two dimensional polyacrylamide gel electrophoresis (2-D PAGE) separated proteins, allowing relatively rapid protein identification compared to conventional approaches . This technique, however, is constrained by the speed of the 2-D PAGE separations, the sensitivity limits intrinsic to staining necessary for protein visualization, the speed and sensitivity of subsequent mass spectrometric analyses for identification, and the limited ability for accurate quantitative measurements based on differences in spot intensity . We are presently developing alternative approaches for proteomics based upon the combination of fast capillary electrophoresis, or other suitable chromatographic separations, and the high mass accuracy and sensitivity obtainable with unique Fourier transform ion cyclotron resonance (FTICR) mass spectrometers available at our laboratory . Several approaches are presently being pursued; one based upon the analysis of intact proteins and the second upon approaches for global protein digestion and accurate peptide mass analysis . Quantitation of protein/peptide levels are based on using two or more stable-isotope labeled versions of proteomes which are combined to obtain precise quantitation of relative protein abundances . We describe the status of our efforts towards the development of a high-throughput proteomics capability and present initial results for application to several microorganisms and discuss our efforts for extending the developed capability to mammalian proteomes.

J Anim Sci, 2001 Jun, 79(6), 1621 - 30
Resistance of feed enzymes to proteolytic inactivation by rumen microorganisms and gastrointestinal proteases; Morgavi DP et al.; Potential feed enzyme additives for ruminants were tested in vitro for their stability to ruminal microbial and gastrointestinal proteolysis . Four commercial preparations from Trichoderma longibrachiatum (A, B, C, and D) and one from an undisclosed source (E) were incubated up to 6 h with ruminal fluid taken from four lactating dairy cows before or 2 h after feeding . The stability of preparation B was also tested in the presence of pepsin at pH 3 and pancreatin at pH 7 . Cellulase (EC 3.2.1.4), cellulose 1,4-beta-cellobiosidase (EC 3.2.1.91), beta-glucanase (EC 3.2.1.6), xylanase (EC 3.2.1.8), beta-glucosidase (EC 3.2.1.21), and beta-xylosidase (EC 3.2.1.37) activities were monitored throughout the incubations . Polysaccharidase activities of all enzyme preparations were remarkably stable in ruminal fluid taken after feeding . Ruminal fluid obtained before feeding inactivated the polysaccharidases in preparations B and D to a greater extent than ruminal fluid obtained after feeding . Cellulase and cellulose 1,4-beta-cellobiosidase activities were the least stable, declining (P < 0.05) by 35 and 60% for preparations B and D, respectively . Xylanase activity of preparation D decreased (P < 0.05) by up to 30% after 6 h of incubation, whereas beta-glucanase activity was not affected . The ability to degrade exogenous enzymes also differed among cows (P < 0.05) . Pepsin and acid (pH 3.0) did not affect polysaccharidases in preparation B but decreased glycosidase activities by 10 to 15% (P < 0.05) after 1 h of incubation . Pancreatin, at the maximum concentration used, inactivated cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase activities at a rate of 0.55, 1, and 0.45%/min, respectively . beta-Glucosidase and beta-xylosidase activities decreased by 1 and 0.75%/min, respectively . Partial proteolysis of cellulase, cellulose 1,4-beta-cellobiosidase, and xylanase by pancreatin produced a transient increase in activity . This twofold increase for cellulase and fourfold increase for cellulose 1,4-beta-cellobiosidase was directly proportional to pancreatin concentration . These results suggest that the enzyme feed additives tested were stable in the rumen of animals after feeding . Exogenous enzymes are likely to be more susceptible to the host gastrointestinal proteases in the abomasum and intestines than to ruminal proteases . However, exogenous polysaccharidases may survive for a considerable period of time in the small intestine and they probably maintain activity against target substrates in this environment.

J Anim Sci, 2001 Jun, 79(6), 1359 - 69
Chemical, physical, and environmental properties of pelleted newspaper compared to wheat straw and wood shavings as bedding for horses; Ward PL et al.; Two experiments were conducted comparing pelleted recycled newspaper (PN) to wheat straw (S) and kiln-dried pine wood shavings (WS) as an animal bedding material . Adult horses housed 20 to 21 h/d in boxstalls served as the animal model for comparisons . In Exp . 1 eight boxstalls, each housing one horse, were each bedded with two types of PN (0.32 and 0.64 x 2.54 cm), S, and WS over four 5-d periods (replicated 4 x 4 Latin square) . Initial amounts of bedding materials surpassed most commercial conditions, but stalls were cleaned daily of feces only and additional clean bedding was added as needed to maintain animal cleanliness, thus challenging the bedding properties of each material . In Exp . 2 nine boxstalls were bedded with PN (0.32 x 2.54 cm), S, and WS over three 14-d periods (three 3 x 3 Latin squares) during summer and autumn . Feces and wet spots were removed daily and clean bedding was added to reestablish working volume and simulate commercial conditions . In Exp . 1 and 2 daily additions of clean bedding varied (P < 0.05) with material (S > WS > PN) . The higher water-holding capacity of PN and WS contributed to fewer bedding replacements . Usage of each material was greater (P < 0.05) during the autumn; PN had the greatest increase . Type of material and season also influenced bedding environment . Bedding pH increased (P < 0.05) with use and was highest in PN and lowest in S . Higher concentrations of breathable NH3 N were present in stalls bedded with PN and during autumn . Higher pH of used PN and decreased ventilation due to closed doors and windows during autumn were contributing factors . Season, type of bedding, and duration of its use affected (P < 0.05) numbers as well as species of microorganisms present in the breathing zone, nasal cavity, and on the leg of the horse . Clean and used WS contained greater (P < 0.05) quantities of particle fines, but with 5 d of use, particle fines in PN also increased . Quantities of breathable dust during cleaning of stalls varied (P < 0.05) with material and duration of its use; dust peaked at d 7 with PN but continued to decrease with S and to increase with WS through d 14 . These data indicate that management of bedding materials varies with type of material and season of year . Use of PN as a bedding material has high potential.

Acta Biomed Ateneo Parmense, 2000, 71(3-4), 49 - 52
{From atopic eczema to respiratory allergy}; Caffarelli C et al.; The prevalence of atopic eczema in childhood is increasing . This is probably related with a deviation of immune system to Th2 directed to allergen instead of Th2 directed to microorganisms . Atopic eczema is genetically linked, but its expression is principally determined by environmental factors, allergens and infections . In children with atopic eczema, the immune system is altered . The number of Langheran's cells is augmented . Th2 cells infiltrate the skin and produce cytokines which mediate both immediate and late allergic reaction . Most of eczematous children is allergic to food . A IgE-mediated reaction take place at the mucosal intestinal site . The food challenge test is the most reliable mean to identify offending foods . Soy formula can be used in the treatment of cow milk allergy . The tolerance of formulae based on cow milk hydrolysed protein should be tested under medical supervision in children with cow milk allergy . Prevention of atopic disease with dietary interventions has not been successful . To prevent asthma, the administration of immunotherapy in children with allergic rhinitis seems to be promising . In eczematous children with elevated total IgE and specific IgE to inhalant allergens, cetarizine seems to prevent onset of asthmatic symptoms.

J Ind Microbiol Biotechnol, 1999 Oct, 23(4-5), 326 - 331
Colonization of contaminated soil by an introduced bacterium: effects of initial pentachlorophenol levels on the survival of Sphingomonas chlorophenolica strain RA2; Colores GM et al.; The survival of a Sphingomonas species that was introduced into pentachlorophenol (PCP)-contaminated soil was monitored with two complementary methods, a respiration-based assay and a most probable number (MPN) technique . Sphingomonas chlorophenolicastrain RA2 is a PCP-mineralizing bacterium that was introduced into soil contaminated with a range of PCP concentrations (0-300 &mgr;g PCP g(-1) soil) . The population of introduced microorganisms was followed for 170 days using a substrate-induced growth-response method and a MPN assay that specifically targets PCP-mineralizing bacteria . Varying the initial PCP concentration resulted in the emergence of three distinct patterns of survival . In soil contaminated with 300 &mgr;g PCP g(-1) the population of S . chlorophenolica strain RA2 immediately declined following introduction, increased by 200-fold and leveled off by the end of the 170-day incubation . In contrast, populations of S . chlorophenolica strain RA2 declined to levels below detection limits in uncontaminated soil by the end of the experiment . Intermediate PCP concentrations (10-100 &mgr;g PCP g(-1) soil) resulted in the establishment of S . chlorophenolica strain RA2 that slowly declined in numbers . These results indicate that Sphingomonas chlorophenolica strain RA2 is an effective colonizer of PCP-contaminated soil but will not persist in the absence of PCP.

Small Rumin, Res. . 2001 Jul, 41(1), 1 - 7
Relationship between mammary gland infections and some milk immune parameters in Sardinian breed ewes; Moroni P et al.; Over the last few years an increased rate of intramammary infections caused by environmental and opportunistic pathogens has been observed in sheep farms . The presence of these microorganisms is mainly related to poor conditions of environmental hygiene and/or to decreased defenses of the mammary gland . The work we present here is a part of a project on the immune status of ewe mammary gland and its influence on mastitis development.In this paper, we have studied how intramammary infections caused by opportunistic pathogens reflect on immune parameters in ewe milk . Milk samples collected monthly before the morning milking, were screened for the presence of microorganisms and tested for somatic cell counts (SCC), polymorphonuclear neutrophil leukocytes (PMN), phagocytic activity, lysozyme content, and NAGase activity.Data showed that phagocytic activity was significantly higher in bacteriologically negative udders (156mV/1000 PMNs) than in infected udders (10mV/1000 PMNs).These results suggest that intramammary infection might be associated with a decrease of mammary gland immune status.

Glycoconj J, 2000 Jul-Sep, 17(7-9), 485 - 99
Achievements and challenges of sialic acid research; Schauer R; Slalic acids are one of the most important molecules of life, since they occupy the terminal position on macromolecules and cell membranes and are involved in many biological and pathological phenomena . The structures of sialic acids, comprising a family of over 40 neuraminic acid derivatives, have been elucidated . However, many aspects of the regulation of their metabolism at the enzyme and gene levels, as well as of their functions remain mysterious . Sialic acids play a dual role, not only are they indispensable for the protection to and adaptation of life, but are also utilised by life-threatening infectious microorganisms . In this article the present state of knowledge in sialobiology, with an emphasis on my personal experience in this research area, is outlined including a discussion of necessary future work in this fascinating field of cell biology.

Res Microbiol, 2001 Apr-May, 152(3-4), 279 - 90
Bacterial transporters for sulfate and organosulfur compounds; Kertesz MA; Microorganisms require sulfur for growth, and obtain it either from inorganic sulfate or from organosulfur compounds such as sulfonates, sulfate esters, or sulfur-containing amino acids . Transport of sulfate into the cell is catalyzed either by ATP binding cassette (ABC)-type transporters (SulT family) or by major facilitator superfamily-type transporters (SulP family) . By contrast, the sulfonate and sulfate ester transporters identified to date are all ABC-type systems, whose synthesis is tightly regulated by the sulfur supply to the cell, mediated by the CysB protein and other transcriptional regulators of the LysR-family.

Arch Pathol Lab Med, 2001 Jul, 125(7), 913 - 20
Characterization of microorganism identification in the United States in 1996; Steindel SJ et al.; CONTEXT: The National Inventory of Clinical Laboratory Testing Services (NICLTS) was designed to give an unbiased estimate of all patient testing performed by laboratories registered under the Clinical Laboratory Improvement Amendments in 1996 . OBJECTIVE: Survey data were used to develop a profile of laboratory testing primarily intended to identify microorganisms or antibodies to these microorganisms . DESIGN: Estimates of the extent of microorganism identification were derived from the NICLTS database by identifying associated tests and methods . The volumes for tests performed at locations that primarily prepared blood components for distribution were excluded . Organisms of public health importance were identified from the National Notifiable Disease list maintained by the Centers for Disease Control and Prevention . PARTICIPANTS: Laboratories that were enrolled in the 1996 Online Certification Survey and Reporting System, maintained by the US Health Care Finance Administration, and that performed laboratory testing in 1996 . OUTCOME MEASURE: Estimated volumes and associated confidence limits by test, method, specimen type, public health importance, and testing location . RESULTS: Excluding testing of the blood supply, 315 million tests (95% confidence limits, 280-354 million tests) were performed in the United States for microorganism identification . Those tests for which public health consensus requires national reporting represented 38% of this total . Although hospitals performed 46% of all microorganism identification, they only performed 33% of the testing for microorganisms of public health importance . Independent and specialty laboratories performed 38% of all testing but 65% of the testing for microorganisms of public health importance . Direct methods (methods not involving culture) were used in 77% of the tests for microorganisms of public health importance and in 42% of all identification tests . CONCLUSIONS: The distribution of microorganism identification testing found using NICLTS data is consistent with plans to modernize the public health surveillance system in the United States.

J Immunol, 2001 Jul 1, 167(1), 66 - 74
Novel roles of CpG oligodeoxynucleotides as a leader for the sampling and presentation of CpG-tagged antigen by dendritic cells; Shirota H et al.; Oligodeoxynucleotides containing CpG motifs have been highlighted as potent Th1 activators . We previously reported that Ag and CpG, when conjugated together, synergistically promoted the Ag-specific Th1 development and inhibited the Th2-mediated airway eosinophilia . In this study, we examined the mechanisms underlying the synergism of the covalent conjugation . The CpG-OVA conjugate enhanced the Th1 activation and development . These characteristic features of the conjugate could not be ascribed to the polymerization of OVA, but mirrored the augmented binding of the CpG-tagged Ag to dendritic cells (DCs) in a CpG-guided manner, because phycobiliprotein, R-PE, conjugated to CpG stained a higher proportion of DCs with higher intensity than the mixture . R-PE fluorescence was emitted from cytoplasmic portions of the DCs, which simultaneously expressed costimulatory molecules and IL-12 . The CpG-conjugated R-PE trafficking described above actually served as a potent Ag . These results indicate that CpG conjugated to Ag exhibit novel joint properties as promoters of Ag uptake and DC activators, thereby potentiating the ability of DCs to generate Th1 cells . The DNA-mediated promotion of Ag uptake would be advantageous for evoking host immune responses against invading microorganisms.

Org Lett, 2001 Jun 28, 3(13), 1981 - 4
Cloning and heterologous expression of a natural product biosynthetic gene cluster from eDNA; Brady SF et al.; {reaction: see text} To study the natural products produced by uncultured microorganisms, an environmental DNA (eDNA) cosmid library was constructed and screened for the heterologous production of small molecules . A blue clone, CSL51, found in the eDNA library produces deoxyviolacein and the broad spectrum antibiotic violacein . The full sequence of the 6.7 kb eDNA violacein gene cluster and the characterization of violacein and deoxyviolacein from an eDNA clone are reported here.

Immunol Rev, 2001 Apr, 180, 35 - 48
Structure and biology of complement protein C3, a connecting link between innate and acquired immunity; Sahu A et al.; Complement protein C3 is a central molecule in the complement system whose activation is essential for all the important functions performed by this system . After four decades of research it is now well established that C3 functions like a double-edged sword: on the one hand it promotes phagocytosis, supports local inflammatory responses against pathogens, and instructs the adaptive immune response to select the appropriate antigens for a humoral response; on the other hand its unregulated activation leads to host cell damage . In addition, its interactions with the proteins of foreign pathogens may provide a mechanism by which these microorganisms evade complement attack . Therefore, a clear knowledge of the molecule and its interactions at the molecular level not only may allow the rational design of molecular adjuvants but may also lead to the development of complement inhibitors and new therapeutic agents against infectious diseases.

Dan Med Bull, 2001 May, 48(2), 77 - 80
Bordetella pertussis in the aetiology of chronic cough in adults . Diagnostic methods and clinic; Birkebaek NH; Cough is one of the most common complaints causing patients to seek medical attention, and chronic cough, defined as a cough period of at least three weeks, accounts for more than a third of referrals to a chest physician . Cough is an important factor in the spread and survival of microorganisms, but until recently little attention has been given to Bordetella pertussis (B . pertussis) in patients with chronic cough . This review summarizes the B . pertussis diagnostic methods--culture--polymerase chain reaction (PCR), and serology--and surveys the literature on B . pertussis and chronic cough in adults . There is growing evidence that B . pertussis is an important cause of persistent cough in adults; thus prevalence of pertusssis of 12.4-26% has been reported in studies from US, Australia and Germany . Recently we found evidence of pertussis as the cause of chronic cough in 16% of otherwise healthy adults in Denmark . Therefore, patients with chronic cough should be examined for B . pertussis infection . The demonstration of B . pertussis in an adult patient with chronic cough has two advantages: 1) the patient can be reassured that symptoms will disappear spontaneously, why more or less invasive examinations and empirical therapeutic trials can be omitted, 2) the source of infection can be eradicated, and contact persons, particularly non vaccinated infants in whom pertussis might be very severe, can be treated in order to avoid or attenuate clinical symptoms.

In Vitro Cell Dev Biol Anim, 2001 Apr, 37(4), 203 - 8
Impairment of antigen-specific cellular immune responses under simulated microgravity conditions; Sastry KJ et al.; Microgravity has been implicated to play a role in the observed immune dysfunction of astronauts and cosmonauts after either short-term or long-term space travel . These reports, together with studies describing increased levels of microorganisms in the space cabin environment suggest potential risk for in-flight incidences of infectious diseases . In order to understand the mechanism underlying these immune defects, it is important to have a ground-based model that would reliably mimic the effects of microgravity on antigen-specific immune function . We tested the utility of the rotating wall vessel (RWV) technology developed at NASA as a model system because in the RWV the culture medium and the cells rotate synchronously with the vessel, thereby creating simulated microgravity conditions . We compared the RWV to the conventional tissue culture flask (T-flask), for culturing immune precursor cells with cytotoxic T lymphocyte (CTL) activity against synthetic viral peptides . We observed a significant loss of antigen-specific CTL activity in RWV cultures, but not in those from the T-flask, irrespective of the peptide immunogen used for inducing the primary immune response in different mouse strains . Loss of CTL activity in RWV cultures coincided with a significant reduction in CD8+ cells as well as CD4+ cells and DEC205+ dendritic cells, suggesting adverse effects of RWV culturing on both the effector and accessory cells for the loss of antigen-specific CTL function . These results provide a strong parallel to the reported defects in cell-mediated immunity during space travel and strongly support the utility of the RWV technology as an effective ground-based model for identifying key steps in immune cell dysfunction related to microgravity.

Lasers Surg Med, 2001, 28(5), 445 - 50
Effect of diode laser irradiation on the survival rate of gingival fibroblast cell cultures; Kreisler M et al.; BACKGROUND AND OBJECTIVE: The present study is part of a basic research program investigating the cellular effects of the GaAlAs-diode laser with a wavelength of 810 nm on human periodontal tissues . The aim of the investigation was to evaluate the effects of the laser treatment on the survival rate of human gingival fibroblasts (HGF) in monolayer cell culture at different power settings and durations . STUDY DESIGN/MATERIALS AND METHODS: HGF were obtained from a human gingival connective tissue explant . Cells were cultured on 24-well tissue culture plates . One hundred and thirty multi well cell cultures were laser treated . The variable parameters were power output (0.5-2.5 W) and exposure time (60-240 seconds per well) . The cultures were analyzed by means of trypan blue staining, and the cell numbers counted under a light microscope . Photographs before and after irradiation were taken and evaluated . RESULTS: Depending on different settings, the laser irradiation caused significant (P < 0.05, t-test) reductions of cell numbers . Exposure time was more relevant to this phenomenon than the power output . Linear regression analysis revealed no unambiguous correlation between power output and cell death, when exposure time was kept constant . CONCLUSIONS: When used for periodontal pocket decontamination, the laser beam may cause damage to collateral periodontal tissues, if the power setting and the duration of the treatment are not adequate . Further investigation, especially with regard to the effects on hard tissue and microorganisms, are needed to give a secure recommendation for irradiation parameters at pocket decontamination .

Cornea, 2001 Jul, 20(5), 467 - 70
Microwave treatment of contact lens cases contaminated with acanthamoeba; Hiti K et al.; PURPOSE: Microbially contaminated contact lens cases are a predisposing risk factor for Acanthamoeba keratitis . Several findings have shown that microwave irradiation kills the six Food and Drug Administration test challenge microorganisms . We aimed to determine what effect microwave irradiation has on Acanthamoeba trophozoites and cysts . METHODS: Different types of contact lens cases were contaminated with trophozoites and cysts of three different Acanthamoeba species (A . comandoni, A . castellanii, A . hatchetti) and were exposed to microwave irradiation for 3, 5, and 8 minutes, respectively . RESULTS: Trophozoites, as well as cysts of the different Acanthamoeba strains, were effectively killed, even by only 3 minutes of microwave irradiation, and there were no negative effects of irradiation on the contact lens cases themselves . CONCLUSION: We demonstrate that microwave treatment is a very effective, easy, and cheap method to keep contact lens cases free of Acanthamoeba, thus considerably reducing the risk of an Acanthamoeba keratitis.

J Microbiol Methods, 2001 Jul 30, 46(1), 69 - 75
Combination of ATP-bioluminescence and PNA probes allows rapid total counts and identification of specific microorganisms in mixed populations; Stender H et al.; We have combined ATP-dependent bioluminescence with a novel chemiluminescent in situ hybridization (CISH) method using peroxidase-labeled peptide nucleic acid (PNA) probes targeting species-specific rRNA sequences to provide total counts and subsequent identification of specific microorganisms . Both methods are applied to the same membrane filter following a short incubation time and both methods provide results in the form of spots of light that are captured by the MicroStar detection system . Each spot of light represents individual micro-colonies detected by either ATP bioluminescence or PNA CISH . This new concept is particularly intended for in process and quality control of non-sterile products to rapidly provide total counts as well as presence/absence of specific indicators and/or pathogens in non-sterile, filterable samples.

J Appl Microbiol, 2001 Jun, 90(6), 953 - 61
The impact of flow rate (simulated leaching) on plasmid transfer frequency between bacteria in a model rhizosphere system; Pearce DA et al.; AIMS: To investigate the effect of flow rate and inoculation order on plasmid transfer frequency between bacteria in a model rhizosphere system . METHODS AND RESULTS: A physical model system was constructed and used to demonstrate that although flow rate did affect plasmid transfer frequency for an introduced strain, the flow rates necessary for a significant effect on an established population were much higher than typical water flow rates found through soil . Plasmid transfer frequency was highly sensitive to strain inoculation order . CONCLUSION: Flow rate may not have a significant effect on plasmid transfer frequency between established bacterial populations in the rhizosphere . SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to the current debate over the release and spread of genetically modified organisms into the environment . It also demonstrates that model controlled systems may be used to rapidly obtain initial data about the potential behaviour of microorganisms, prior to more costly and lengthy glasshouse and field trials.

Lancet, 2001 Jun 9, 357(9271), 1851 - 3
Variation in antibiotic use in the European Union; Cars O et al.; Data on antibiotic use are not publicly available in most European Union countries . We obtained data for non-hospital antibiotic sales for 1997 from the 15 member states and analysed these according to the Anatomic Therapeutic Chemical classification system, and expressed them as defined daily doses per 1000 people per day . Sales of antibiotics varied more than four-fold: France (36.5), Spain (32.4), Portugal (28.8), and Belgium (26.7) had the highest sales, whereas the Netherlands (8.9), Denmark (11.3), Sweden (13.5), and Germany (13.6) had the lowest . There was also profound variation in use of different classes of antibiotics . Detailed knowledge of antibiotic use is necessary to implement national strategies for optimum antibiotic use, and to address the threat posed by resistant microorganisms.

Biochim Biophys Acta, 2001 May 28, 1519(1-2), 117 - 21
Molecular cloning of mouse allantoicase cDNA; Vigetti D et al.; The uric acid degradation pathway is progressively lost during vertebrate evolution . In mammals, the end product of this catabolic pathway is allantoin and, therefore, no allantoicase should be present in mouse tissues . Surprisingly, we have found an expressed sequence tag (EST) from mouse testis with high similarity to allantoicase . To characterize this transcript, we have completely sequenced the corresponding EST clone insert and found a 1495 bp long cDNA coding for a 414 amino acid long protein . Identities of mouse versus microorganism allantoicases range from 25 to 30% . Identity reaches 54% when compared to Xenopus allantoicase . Among the tested tissues, only testis possesses the allantoicase transcript . Although no deleterious mutations were found in the coding region, no allantoicase activity could be detected in mouse testis.

Curr Genet, 2001 Apr, 39(2), 101 - 8
Characterization of two genes encoding the mitochondrial alternative oxidase in Chlamydomonas reinhardtii; Dinant M et al.; Two cDNA clones (AOX1 and AOX2) and the corresponding genes encoding the alternative oxidases (AOXs) from Chlamydomonas reinhardtii were isolated and sequenced . The cDNAs, AOX1 and AOX2, contained open reading frames (ORFs) encoding putative proteins of 360 amino acids and 347 amino acids, respectively . For each of the ORFs, a potential mitochondrial-targeting sequence was found in the 5'-end regions . In comparison to AOX enzymes from plants and fungi, the predicted amino acid sequences of the ORFs showed their highest degree of identity with proteins from Aspergillus niger (38.1% and 37.2%) and Ajellomyces capsulatus (37% and 34.9%) . Several residues supposed either to be Fe ligands or to be involved in the ubiquinol-binding site were fully conserved in both C . reinhardtii putative AOX proteins . In contrast, a cysteine residue conserved in the sequences of all higher plants and probably involved in the regulation of the enzyme activity was missing both from the AOX1 and AOX2 amino acid sequences and from protein sequences from various other microorganisms . The transcriptional expression of the AOX1 and AOX2 genes in wild-type cells and in mutant cells deficient in mitochondrial complex III activity was also investigated.

Prim Dent Care, 2000 Jan, 7(1), 19 - 22
The impact of advances in dental sciences on primary dental care; Scully C; The next century will see phenomenal changes especially and, most importantly, in patient empowerment, in the improvement of health in the disadvantaged, and in the harmonisation of standards of healthcare throughout the world . Advances in the dental sciences will facilitate these improvements but the major changes surely will be largely stimulated and motivated by the information revolution and the advances in molecular and materials sciences . The identification, and protection against disease, of patients who, because of a genetic predisposition, are at particular risk of disease is likely to become possible . Simple, sensitive, effective, non-invasive and safe diagnostic procedures will become available, as will chairside diagnostic test kits that would identify specific microorganisms causal of oral disease . The advances in digital imaging will be taken further and linked to record-keeping . Specific safe agents targeted at responsible microorganisms will be devised, and systems to deliver therapeutic agents effectively and prevent tissue damage simply will be perfected . Painless, minimally-invasive techniques for the removal of diseased oral tissues will become available, as will biocompatible materials for replacement of lost oral tissues.

Curr Opin Biotechnol, 2001 Jun, 12(3), 231 - 6
The identification of microorganisms by fluorescence in situ hybridisation; Amann R et al.; Fluorescence in situ hybridisation (FISH) with rRNA-targeted oligonucleotide probes facilitates the rapid and specific identification of individual microbial cells in their natural environments . Over the past year there have been a number of methodological developments in this area and new applications of FISH in microbial ecology and biotechnology have been reported.

Gene, 2001 May 30, 270(1-2), 113 - 20
Phylogeny and origin of 82 zygomycetes from all 54 genera of the Mucorales and Mortierellales based on combined analysis of actin and translation elongation factor EF-1alpha genes; Voigt K et al.; True fungi (Eumycota) are heterotrophic eukaryotic microorganisms encompassing ascomycetes, basidiomycetes, chytridiomycetes and zygomycetes . The natural systematics of the latter group, Zygomycota, are very poorly understood due to the lack of distinguishing morphological characters . We have determined sequences for the nuclear-encoded genes actin (act) from 82 zygomycetes representing all 54 currently recognized genera from the two zygomycetous orders Mucorales and Mortierellales . We also determined sequences for translation elongation factor EF-1alpha (tef) from 16 zygomycetes (total of 96,837 bp) . Phylogenetic analysis in the context of available sequence data (total 2,062 nucleotide positions per species) revealed that current classification schemes for the mucoralean fungi are highly unnatural at the family and, to a large extent, at the genus level . The data clearly indicate a deep, ancient and distinct dichotomy of the orders Mucorales and Mortierellales, which are recognized only in some zygomycete systems . Yet at the same time the data show that two genera - Umbelopsis and Micromucor - previously placed within the Mortierellales on the basis of their weakly developed columella (a morphological structure of the sporangiophore well-developed within all Mucorales) are in fact members of the Mucorales . Phylogenetic analyses of the encoded amino acid sequences in the context of homologues from eukaryotes and archaebacterial outgroups indicate that the Eumycota studied here are a natural group but provide little or no support for the monophyly of either zygomycetes, ascomycetes or basidiomycetes . The data clearly indicate that a complete revision of zygomycete natural systematics is necessary.

Ultrastruct Pathol, 2001 Mar-Apr, 25(2), 129 - 35
Unidentified bacterial microorganisms entrapped within blood capillary spaces of tissue from different epidemiological types of Kaposi's sarcoma; Marquart KH; Tissue specimens of different epidemiological types of Kaposis sarcoma (KS) from various geographical regions were investigated by transmission electron microscopy . Freshly fixed KS biopsies originated from 9 German patients: 3 classic KS cases, 5 AIDS-associated KS cases, and 1 atypical classic KS case . Additionally, KS autopsy material from the brain of a German AIDS patient was examined . Further biopsies came from 29 Ugandan patients: 16 endemic KS cases and 13 AIDS-associated KS cases . While investigating the ultrastructure, we discovered relatively small-sized bacterial microorganisms within blood capillary spaces of tumor tissue from 5 KS cases of different epidemiological type . The microorganisms often occurred in clusters . They were of coccoid-bacillary form and limited by a wrinkled multilayered cell wall . Many of them were encapsulated . They were not observed outside of the capillary lumen . The bacterial structures were often seen attached to capillary endothelial cells, which sometimes showed blistering into the capillary lumen . The observed bacterial microorganisms obviously represented agents of a bloodstream infection and must have been entrapped and accumulated within capillary spaces of KS tissue . The bacteria, which had an almost identical morphology in all 5 KS cases, could not be identified . If they are of pathogenic significance, it remains unknown.

Biologist (London), 2001 Jun, 48(3), 125 - 8
Culture collections in the twenty-first century; Smith D et al.; Culture collections conserve the living tools for biotechnology . Without them there would be no reference organisms, and no stocks of crucial or rare microorganisms that are so valuable for biotechnology and biomedical research . The expertise that drives these collections is under threat, but the collections themselves may survive by pooling their knowledge.

Am J Respir Crit Care Med, 2001 Jun, 163(7), 1534 - 9
Role of molds in farmer's lung disease in Eastern France; Reboux G et al.; Farmer's lung disease (FLD) is common in the east of France . In the absence of the primary recognized FLD agent, Saccharopolyspora rectivirgula, its etiology remains unknown . A prospective case-control study was performed to find the etiology of FLD in this area . Eleven patients were matched with 11 healthy control farmers . Twenty-two urban subjects constituted the nonexposed control group . Microorganisms from cowshed air and fodder were identified and counted . The antigens of the microorganisms most frequently isolated at the 22 farms were used for serological tests . Farms of patients with FLD contained more Absidia corymbifera than those of healthy farmers (p < 0.05 in air, p < 0.01 in fodder) . Electrosyneresis, performed with A . corymbifera somatic antigen, differentiated 9 of 11 patients with FLD from control subjects (p < 0.01) . Other significant results were obtained with Eurotium amstelodami (p < 0.01) and Wallemia sebi (p < 0.05) . In contrast, no significant results were obtained with the other seven antigens tested, including S . rectivirgula . Absidia corymbifera and, to a lesser degree, W . sebi or E . amstelodami are likely to be the main causes of FLD in this area . Modifications in working conditions over time could explain the emergence of these new contributing etiologies.

Mol Microbiol, 2001 May, 40(4), 1000 - 8
Heterogeneity of stress gene expression and stress resistance among individual cells of Saccharomyces cerevisiae; Attfield PV et al.; Knowledge of gene expression and cellular responses in microorganisms is derived from analyses of populations consisting of millions of cells . Analytical techniques that provide data as population averages fail to inform of culture heterogeneity . Flow cytometry and fluorescence techniques were used to provide information on the heterogeneity of stress-responsive gene expression and stress tolerance in individual cells within populations . A sequence of DNA encoding the heat shock and stress response elements of the Saccharomyces cerevisiae HSP104 gene was used to express enhanced green fluorescent protein (EGFP) . When integrated into the genome of yeast strain W303-1A, intrinsic expression of EGFP increased about twofold as cells progressed from growth on glucose to ethanol utilization in aerobic batch cultures . Staining of cells with orange/red fluorescent propidium iodide (PI), which only enters cells that have compromised membrane integrity, revealed that the population became more tolerant to 52 degrees C heat stress as it progressed from growth on glucose and through the ethanol utilization phase of aerobic batch culture . Exposure of cultures growing on glucose to a mild heat shock (shift from 25 degrees C to 37 degrees C) resulted in significantly increased expression of EGFP in the population . However, there was heterogeneity in the intensity of fluorescence of individual cells from heat-shocked cultures, indicating variability in the strength of stress response in the clonal population . Detailed analysis of the heterogeneity showed a clear positive trend between intensity of stress response and individual cell resistance, measured in terms of PI exclusion, to heat stress at 52 degrees C . Further experiments indicated that, although the mean gene expression by a population is influenced by the genetic background, the heterogeneity among individual cells in clonal populations is largely physiologically based.

Biochem Biophys Res Commun, 2001 Mar 30, 282(2), 595 - 601
Actinohivin, a novel anti-HIV protein from an actinomycete that inhibits syncytium formation: isolation, characterization, and biological activities; Chiba H et al.; Blocking human immunodeficiency virus (HIV) entry into target cells is an important goal of HIV and acquired immune deficiency syndrome (AIDS) therapies . We have searched for anti-HIV substances from microorganisms using a syncytium formation assay system constructed with HeLa/CD4/Lac-Z and HeLa/T-env/Tat cells . We discovered a novel anti-HIV protein that inhibits syncytium formation, designated as actinohivin, from a cultured broth of a soil isolate, actinomycete strain K97-0003 . ESI mass spectrometry of actinohivin isolated from the culture filtrate showed an ion with molecular mass of 12,520.3 Da . The amino acid sequence was determined by N-terminal Edman degradation of the intact protein and peptide fragments formed by endoproteinase digestions . Actinohivin consists of a 114-amino-acid chain that exhibits internal sequence triplication . Actinohivin inhibited both T-cell and macrophage tropic syncytium formation, with IC(50) values of 60 and 700 nM, respectively, and the cytopathic effect of HIV-1(IIIB) in MT-4 cells, with IC(50) value of 230 nM .

Anal Biochem, 2001 Apr 15, 291(2), 290 - 6
Selective and sensitive detection of pectin lyase activity using a colorimetric test: application to the screening of microorganisms possessing pectin lyase activity; Nedjma M et al.; Several methods have been described for the detection and quantification of polygalacturonase (PG) and pectin lyase (PL) activities . The most frequently used tests are the Nelson method using copper(II) and an arsenomolybdate reagent to detect PG activity, and the colorimetric method using thiobarbituric acid (TBA) to detect PL activity . We observed that none of these methods are suitable to differentiate between these two enzymatic activities . Therefore, we optimized the test conditions of the TBA method . As a result, the detection of the enzymatic beta-elimination (PL activity) became sensitive and selective . A basic pretreatment at 80 degrees C for 5 min of the solution which contains the pectin fragments of the PL activity furnished aldehydes which were condensed with TBA or its derivatives . After acidification of the medium, a pink fluorescent dye was detected spectrophotochemically (lambda = 550 nm) . The interference of galacturonic acid or oligomers resulting from PG activity was completely eliminated . The most sensitive reagent was N-(pyridin-2-yl)-thiobarbituric acid . The application of this method with the new reagent was extended to the screening of microorganisms possessing the PL activity . The obtained results confirm that Aspergillus niger strain and a Saccharomyces cerevisiae SCPP strain possess this activity .

J Environ Qual, 2001 May-Jun, 30(3), 776 - 85
A micrometeorological technique to monitor total hydrocarbon emissions from landfarms to the atmosphere; Ausma S et al.; Landfarming is used to treat petroleum hydrocarbon-contaminated soils and a variety of waste streams from industrial operations . Wastes are applied to a soil surface and indigenous soil microorganisms utilize the hydrocarbons in the applied waste as a carbon source for metabolism, thereby biodegrading the applied material . Concerns have been expressed that abiotic losses, such as volatilization, play a significant role in hydrocarbon reduction within the soil . To assist in better defining atmospheric releases of total hydrocarbons from landfarms treating petroleum hydrocarbons, a flux gradient micrometeorological approach was developed and integrated with a custom-built total hydrocarbon detector, and a novel air sampling system and averaging algorithm . The micrometeorological technique offers unobtrusive spatially averaged real-time continuous measurements, thereby providing a time history of emissions . This provides opportunities to investigate mechanisms controlling emissions and to evaluate landfarm management strategies . The versatility of the technique is illustrated through measurements performed at a remote landfarm used to treat diesel fuel-contaminated soil in northern Ontario and during routine operations at two active refinery landfarms in southwestern Ontario.

Can J Microbiol, 2001 May, 47(5), 431 - 42
Monitoring of bacteria in acid mine environments by reverse sample genome probing; Leveille SA et al.; A variety of microorganisms can exist in acid mine drainage (AMD) environments, although their contribution to AMD problems is unclear . Environmental strains of Thiobacillus ferrooxidans and Thiobacillus acidophilus were purified by repeated plating and single-colony isolation on iron salts and tetrathionate media, respectively . Thiobacillus thiooxidans was enriched on sulfur-containing media . For the isolation of Leptospirillum ferrooxidans, iron salts and pyrite media were inoculated with environmental samples . However, L . ferrooxidans was never recovered on solid media . Denatured chromosomal DNAs from type and (or) isolated strains of T . ferrooxidans, T . acidophilus, T . thiooxidans, and L . ferrooxidans were spotted on a master filter for their detection in a variety of samples by reverse sample genome probing (RSGP) . Analysis of enrichments of environmental samples by RSGP indicated that ferrous sulfate medium enriched T . ferrooxidans strains, whereas all thiobacilli grew in sulfur medium, T . thiooxidans strains being dominant . Enrichment in glucose medium followed by transfer to tetrathionate medium resulted in the selection of T . acidophilus strains . DNA was also extracted directly (without enrichment) from cells recovered from AMD water or sediments, and was analyzed by RSGP to describe the communities present . Strains showing homology with T . ferrooxidans and T . acidophilus were found to be major community components . Strains showing homology with T . thiooxidans were a minor community component, whereas strains showing homology with L . ferrooxidans were not detected.

Appl Microbiol Biotechnol, 2001 May, 55(4), 500 - 9
Characterisation of the microbial 16S rDNA diversity of an aerobic phosphorus-removal ecosystem and monitoring of its transition to nitrate respiration; Dabert P et al.; The microbial community of a conventional anaerobic-aerobic sequencing batch reactor was investigated by cloning and sequencing bacterial 16S rDNA . The 92 16S rDNA sequences analysed ranged across 50 different operational taxonomic units (OTU) . The majority of these sequences were not closely related to known species . They belonged to 12 different groups, but essentially to the Cytophagales and the Proteobacteria beta, which represented 38% and 17% of the retrieved sequences respectively . No OTU numerically outnumbered the others . However, similarities were observed with previous reports on molecular characterisation of phosphorus-accumulating ecosystems, suggesting an enrichment in microorganisms belonging to the Rhodocyclus group . Thereafter, the ability of this anaerobic-aerobic microbial community to accumulate phosphorus with nitrate as its energy source was investigated . The reactor was shifted from anaerobic-aerobic running conditions to anaerobic-anoxic conditions by injection of nitrate; and its microbial community was monitored by PCR-single strand conformation polymorphism (SSCP) . The reactor maintained a good phosphorus accumulation and similar SSCP microbial community patterns for a period of 17 days, suggesting that the same microbial community was able to respire both oxygen and nitrate . However, this situation was unstable, since a breakdown in phosphorus accumulation occurred thereafter.

J Theor Biol, 2001 Jun 7, 210(3), 347 - 65
The influence of turbulence on plankton predation strategies; Lewis DM et al.; The importance of predation in regulating the size of competing plankton and larval fish populations has long been appreciated . However, it has only recently been recognized that turbulence must have a significant influence on predator-prey interactions because most rival species of microorganisms co-exist in oceanic or fast moving fresh water flows . Turbulence is likely to influence predation strategies in two ways . The extra energy imparted to a micro-organism from the flow field will enhance the number of encounters or "contacts" between predators and prey . At the same time, because the velocity of a predator relative to its potential prey will be increased, the time-scale over which a capture must be completed is reduced . Balancing the benefits of extra encounters with the drawbacks of more difficult captures, will dictate an optimal predation strategy, either foraging behaviour or ambush feeding, on the predator . This will depend on its own and the prey's swimming capabilities, as well as the characteristics of the turbulent environment . In this paper some previous work, examining the increased encounter rate in turbulence, will be extended to look at the capture problem . The main proposal is that the capture event should be encapsulated in a capture probability function, from which the optimal predation strategy can be derived . As an illustration, plausible capture probability functions will be postulated and the resulting predictions tested against numerical simulations carried out in a turbulent-like flow field . Good agreement between the predictions and the simulations is demonstrated .

Cytokine, 2001 May 7, 14(3), 152 - 61
Expression of IL-1 beta and IL-8 by human gingival epithelial cells in response to Actinobacillus actinomycetemcomitans; Uchida Y et al.; The interaction between epithelial cells and microorganisms is the most important step in bacterial infections . Epithelial cells in response to exposure to pathogenic bacteria produce cytokines that initiate inflammation . However, little is known about the cytokine response of gingival epithelial cells to periodontopathogenic bacteria . Actinobacillus actinomycetemcomitans is thought to play a significant role in the initiation of periodontitis because of its bacteriological characteristics . In the present study, we investigated the cytokine induction by human gingival epithelial cells (HGEC) following exposure to A . actinomycetemcomitans in comparison with human gingival fibroblasts (HGF) in culture . Northern blot analysis showed that mRNAs of interleukin 1beta (IL-1beta) and IL-8, but not IL-6, in HGEC were induced in response to A . actinomycetemcomitans . Secretion of IL-8 by HGEC was also increased following A . actinomycetemcomitans challenge, whereas production of IL-1beta could not be detected . The levels of IL-8 and its mRNA were increased depending on the concentration of A . actinomycetemcomitans . The co-culture with HGF and A . actinomycetemcomitans resulted in an increase in the levels of IL-6 and IL-8 mRNA in HGF . However, HGF exposed to A . actinomycetemcomitans, showed no expression of IL-1beta mRNA . These findings demonstrated that HGEC and HGF stimulated with A . actinomycetemcomitans have different profiles in cytokine mRNA expression . Furthermore, A . actinomycetemcomitans may play an important role in amplifying the local immune response and in initiating inflammatory reaction through release of IL-8 from gingival epithelial cells .

Annu Rev Biochem, 2001, 70, 649 - 76
Regulation of actin filament network formation through ARP2/3 complex: activation by a diverse array of proteins; Higgs HN et al.; Actin filament assembly and turnover drive many forms of cellular motility, particularly extension of the leading edge of locomoting cells and rocketing of pathogenic microorganisms through host cell cytoplasm . De novo nucleation of actin filaments appears to be required for these movements . A complex of seven proteins called Arp2/3 complex is the best characterized cellular initiator of actin filament nucleation . Arp2/3 complex is intrinsically inactive, relying on nucleation promoting factors for activation . WASp/Scar family proteins are prominent cellular nucleation promoting factors . They bring together an actin monomer and Arp2/3 complex in solution or on the side of an existing actin filament to initiate a new filament that grows in the barbed end direction . WASp and N-WASP are intrinsically autoinhibited, and their activity is regulated by Rho-family GTPases such as Cdc42, membrane polyphosphoinositides, WIP/verprolin, and SH3 domain proteins . These interactions provide a final common pathway for many signaling inputs to regulate actin polymerization . Microorganisms either activate Arp2/3 complex directly or usurp N-WASP to initiate actin polymerization.

Annu Rev Biochem, 2001, 70, 1 - 37
Advancing our knowledge in biochemistry, genetics, and microbiology through studies on tryptophan metabolism; Yanofsky C; I was fortunate to practice science during the last half of the previous century, when many basic biological and biochemical concepts could be experimentally addressed for the first time . My introduction to research involved isolating and identifying intermediates in the niacin biosynthetic pathway . These studies were followed by investigations focused on determining the properties of genes and enzymes essential to metabolism and examining how they were alterable by mutation . The most challenging problem I initially attacked was establishing the colinear relationship between gene and protein . Subsequent research emphasized identification and characterization of regulatory mechanisms that microorganisms use to control gene expression . An elaborate regulatory strategy, transcription attenuation, was discovered that is often based on selection between alternative RNA structures . Throughout my career I enjoyed the excitement of solving basic scientific problems . Most rewarding, however, was the feeling that I was helping young scientists experience the pleasure of performing creative research.

Water Res, 2001 Jul, 35(10), 2484 - 8
Extracellular enzyme activities during slow sand filtration in a water recharge plant; Hendel B et al.; Activities of the extracellular enzymes beta-glucosidase and phosphatase and bacterial densities were investigated during the filtration process at several sites in a groundwater recharge plant at the Ruhr river (Hengsen recharge plant in Schwerte . Germany) . Low numbers of microorganisms and low levels of activity in this type of habitat, compared to most surface waters, caused methodological problems when determining microbial activity . In this study, fluorigenic model substrates, which enable hydrolytic rates as low as 1 nmol (L x h)(-1) to be measured, were used to determine extracellular enzyme activities . Highest activities were determined in surface water (107 nmol (L x h)(-1) for beta-glucosidase and 252 nmol (L x h)(-1) for phosphatase) . which decreased during the filtration process in the gravel prefilter and the main sand filter until the end of subsurface flow (1.6 nmol (L x h)(-1) and 6.8 nmol (L x h)(-1), respectively) . Similarly, bacterial numbers decreased from 3.4 x 10(6) to 0.29 x 10(6) cells mL(-1) . These data showed that microbial activity within the prefilter and the shallow layers of the sand filter had the greatest impact on water quality . In addition to its involvement in the continuous purification of surface water, the microbial community in the sand filter probably acts as a biological buffer against ephemeral increases in the loads of organic matter and nutrients in the recharge plant.

J Chromatogr B Biomed Sci Appl, 2001 May 5, 755(1-2), 321 - 9
Convenient method for the determination of arginine and its related compounds in rumen fluid by reversed-phase high-performance liquid chromatography; Sultana H et al.; In order to clarify arginine (Arg) metabolism by rumen microorganisms and by the tissues of ruminant animals, a convenient method for the simultaneous determination of Arg, citrulline (Cit), ornithine (Orn), proline (Pro) and 5-aminovaleric acid (5AV), and 4-aminobutyric acid (4AB) and lysine (Lys), incidentally, in goat rumen fluid was established by reversed-phase high-performance liquid chromatography (RP-HPLC) . The separation was carried out by stepwise isocratic elution with two mobile phases (solvent A and solvent B) on a LiChrospher 100 RP-18 column (150x4.6 mm I.D., 5 microm particle size) equipped with a guard column (4.0x4 mm, 5 microm particle size) . Solvent A is composed of acetonitrile-sodium citrate buffer (pH 7.2) (15:85, v/v) containing tetrahydrofuran (5 ml/100 ml), with solvent B comprising acetonitrile-sodium citrate buffer (pH 5.4) (40:60, v/v) . Five compounds (Cit, Arg, Pro, 4AB and 5AV) were separated within 33 min in solvent A and the other two (Orn and Lys) in solvent B . Solvent A was automatically switched to solvent B with the help of a valve controller . Complete separation needs 62 min after sample injection in a single chromatogram . Samples were derivatized with 9-fluorenylmethyloxycarbonyl chloride (FMOC-Cl) and detected on a fluorescence detector at excitation and emission wavelengths of 263 and 611 nm, respectively . The minimum detectable concentrations (microM) (signal-to-noise ratio, S/N 3:1) of these compounds were: 0.65 for Cit, 0.65 for Arg, 1.9 for Pro, 1.3 for 4AB, 1.9 for 5AV, 0.12 for Orn and 0.48 for Lys . When applied to rumen fluid from goats, recoveries of all compounds added to the rumen fluid were 96.6-100.6% for an intra-day study and 93.9-99.4% for inter-day (5 days) studies . The average contents of Orn, 5AV and Lys in the rumen fluid of three goats before morning feeding were 7.3, 13.5 and 3.6 microM, but Cit, Arg, Pro, and 4AB were not found, although all these four compounds were detected 1 h after feeding . Pro (390 microM) and 5AV (497.6 microM) were highest 1 h after feeding and then decreased . Orn levels before morning feeding were most similar to those after feeding.

Mikrobiol Z, 2001 Jan-Feb, 63(1), 56 - 61
{Deposition of microorganisms at patenting the invention and results for the inventor}; Pidhorskyi VS et al.; The standards of the patent legislation of Ukraine and other countries concerning the deposition of microorganisms at patenting of the invention and conditions for the availability of the deposited samples have been considered . The questions connected to practice of strains deposition in Ukraine which require the normative decision or specification in view of the tendency of development of patent legislation in the countries advanced in the sphere of the industrial property have been outlined.

Mikrobiol Z, 2001 Jan-Feb, 63(1), 41 - 50
{Invasion of microorganisms in bronchial mucosa of liquidators of the Chernobyl accident consequences}; Poliakova VA et al.; Bronchial bioptates of 97 liquidators of the Chernobyl accident consequences with chronic bronchitis and 23 patients of control nosological group as well as sputum (174 persons) and BAL (22 persons) of liquidators with chronic obstructive lung disease (COLD) were studied to define pathogenic role of automicroflora in the development of lung diseases . Such methods as electron microscopy, immunohistochemistry and microbiology were used . The revealed invasion of microorganisms occurred against the background of pathology of superficial bronchial epithelium with a decrease of HLA-DR and CD23 lymphocytes and increase of CD1c lymphocytes in lamina propria of bronchial mucosa of the liquidators . Verification of microorganisms characteristic of the upper respiratory tracts and atypical presence of Escherichia coli were found in the contents of the lower parts of broncho-pulmonary system of the liquidators . The obtained results testify to the activation of automicroflora and appearance of pathogenic microorganisms were caused by deterioration of specific and non-specific immune protection in liquidators with COLD.

Curr Microbiol, 2001 Aug, 43(2), 93 - 5
The Saccharomyces cerevisiae MLF6/YPL244C gene, which encodes a possible yeast homologue of mammalian UDP-galactose transporter, confers resistance to the immunosuppressive drug, leflunomide; Fujimura H; The immunosuppressant leflunomide (LFM) inhibits the growth of cytokine-stimulated proliferation of lymphoid cells in vitro and also inhibits the growth of eukaryotic microorganism, Saccharomyces cerevisiae . As a first step to elucidate the molecular mechanism of LFM action in human, yeast gene which suppresses the anti-proliferative effect when in increased copy number was cloned and designated MLF6 for multicopy suppressor of LFM sensitivity . DNA sequencing analysis revealed that the MLF6 gene is identical to the YPL244C gene which encodes a possible yeast homologue of human UDP-galactose transporter . The disruption of the MLF6 gene increased the sensitivity of yeast cells to the drug.

Protein Eng, 2001 Apr, 14(4), 245 - 53
Mutant barley (1-->3,1-->4)-beta-glucan endohydrolases with enhanced thermostability; Stewart RJ et al.; The similar three-dimensional structures of barley (1-->3)-beta-glucan endohydrolases and (1-->3,1-->4)-beta-glucan endohydrolases indicate that the enzymes are closely related in evolutionary terms . However, the (1-->3)-beta-glucanases hydrolyze polysaccharides of the type found in fungal cell walls and are members of the pathogenesis-related PR2 group of proteins, while the (1-->3,1-->4)-beta-glucanases function in plant cell wall metabolism . The (1-->3)-beta-glucanases have evolved to be significantly more stable than the (1-->3,1-->4)-beta-glucanases, probably as a consequence of the hostile environments imposed upon the plant by invading microorganisms . In attempts to define the molecular basis for the differences in stability, eight amino acid substitutions were introduced into a barley (1-->3,1-->4)-beta-glucanase using site-directed mutagenesis of a cDNA that encodes the enzyme . The amino acid substitutions chosen were based on structural comparisons of the barley (1-->3)- and (1-->3,1-->4)-beta-glucanases and of other higher plant (1-->3)-beta-glucanases . Three of the resulting mutant enzymes showed increased thermostability compared with the wild-type (1-->3,1-->4)-beta-glucanase . The largest increase in stability was observed when the histidine at position 300 was changed to a proline (mutant H300P), a mutation that was likely to decrease the entropy of the unfolded state of the enzyme . Furthermore, the three amino acid substitutions which increased the thermostability of barley (1-->3,1-->4)-beta-glucanase isoenzyme EII were all located in the COOH-terminal loop of the enzyme . Thus, this loop represents a particularly unstable region of the enzyme and could be involved in the initiation of unfolding of the (1-->3,1-->4)-beta-glucanase at elevated temperatures.

Proc Natl Acad Sci U S A, 2001 Jun 5, 98(12), 6842 - 7
Essential role for mammalian copper transporter Ctr1 in copper homeostasis and embryonic development; Lee J et al.; The trace metal copper (Cu) plays an essential role in biology as a cofactor for many enzymes that include Cu, Zn superoxide dismutase, cytochrome oxidase, ceruloplasmin, lysyl oxidase, and dopamine beta-hydroxylase . Consequently, Cu transport at the cell surface and the delivery of Cu to intracellular compartments are critical events for a wide variety of biological processes . The components that orchestrate intracellular Cu trafficking and their roles in Cu homeostasis have been elucidated by the studies of model microorganisms and by the characterizations of molecular basis of Cu-related genetic diseases, including Menkes disease and Wilson disease . However, little is known about the mechanisms for Cu uptake at the plasma membrane and the consequences of defects in this process in mammals . Here, we show that the mouse Ctr1 gene encodes a component of the Cu transport machinery and that mice heterozygous for Ctr1 exhibit tissue-specific defects in copper accumulation and in the activities of copper-dependent enzymes . Mice completely deficient for Ctr1 exhibit profound growth and developmental defects and die in utero in mid-gestation . These results demonstrate a crucial role for Cu acquisition through the Ctr1 transporter for mammalian Cu homeostasis and embryonic development.

Biosci Biotechnol Biochem, 2001 Apr, 65(4), 943 - 6
Microbial hydroxylation of (+/-)- and (-)-(2Z,4E)-5-(1',2'-epoxy-2',6',6'-trimethylcyclohexyl)-3-methyl-2,4-pentadienoic acid into (+/-)- and (-)-xanthoxin acid by Cunninghamella echinulata; Okazaki R et al.; Microbial hydroxylation of (+/-)-(2Z,4E)-5-(1',2'-epoxy-2',6',6'-trimethylcyclohexyl)-3-methyl-2,4-pentadienoic acid (3a) with Cercospora cruenta, a fungus producing (+)-abscisic acid, gave a four-stereoisomeric mixture consisting of (+)- and (-)-xanthoxin acid (4a), and (+)- and (-)-epi-xanthoxin acid (5a) by an HPLC analysis with a chiral column . Screening of the microorganisms capable of oxidizing (+/-)-3a showed that Cunninghamella echinulata stereoselectively oxidized (+/-)-3a to xanthoxin acid (4a) with the some degree of enantioselectivity as (-)-3a to (-)-4a.

Plant Cell Physiol, 2001 May, 42(5), 462 - 8
A large family of class III plant peroxidases; Hiraga S et al.; Class III plant peroxidase (POX), a plant-specific oxidoreductase, is one of the many types of peroxidases that are widely distributed in animals, plants and microorganisms . POXs exist as isoenzymes in individual plant species, and each isoenzyme has variable amino acid sequences and shows diverse expression profiles, suggesting their involvement in various physiological processes . Indeed, studies have provided evidence that POXs participate in lignification, suberization, auxin catabolism, wound healing and defense against pathogen infection . Little, however, is known about the signal transduction for inducing expression of the pox genes . Recent studies have provided information on the regulatory mechanisms of wound- and pathogen-induced expression of some pox genes . These studies suggest that pox genes are induced via different signal transduction pathways from those of other known defense-related genes.

Curr Microbiol, 2001 Jun, 42(6), 393 - 7
Phototrophic N2 fixation suppressed by activated sulfate reduction in anoxic rice soil slurries; Harada N et al.; Interactions between sulfate reduction (SR) and phototrophic nitrogenase activities were investigated in rice soil slurries mixed with rice straw . Activation of SR by adding exogenous sulfate suppressed acetylene-reducing activity (ARA) of the slurries, which was associated with phototrophic purple bacteria (PB) enumerated to 108-109 MPN g-1 dry weight (dw) soil . Adding 5 mm sodium molybdate, an inhibitor of SR, markedly increased ARA . However, in the slurries receiving both molybdate and exogenous sulfate, the effects declined simultaneously with partial recovery of SR . These results indicate outcompetition of sulfate-reducing bacteria (SRB) with PB in rice soil, when sulfate concentrations are high enough to support SR . The increasing effects of molybdate on ARA continued during the incubation in the sulfate-depleted condition, probably because of absence of SR and toxicity of molybdate to methanogenesis . Accordingly, stopping activities of the competitive microorganisms may be efficient to increase N2 fixation in rice soil.

Aliment Pharmacol Ther, 2001 Jun, 15(6), 813 - 20
Increased gastric acid secretion after Helicobacter pylori eradication may be a factor for developing reflux oesophagitis; Koike T et al.; BACKGROUND: The role of acid secretion in reflux oesophagitis which may develop after H . pylori eradication is not well known . AIM: To investigate the participation of altered gastric acid secretion and the presence of hiatal hernia in the development of reflux oesophagitis after eradication therapy for H . pylori . SUBJECTS AND METHODS: A total of 105 patients with H . pylori infection, but without reflux oesophagitis at the time of eradication therapy, were followed prospectively for 7 months after the clearance of this microorganism . Gastric acid secretion was assessed by endoscopic gastrin test, and the presence of hiatal hernia by endoscopy . RESULTS: Reflux oesophagitis developed in 11 out of 105 (10.5%) patients when examined at 7 months after the eradication therapy . The incidence was correlated significantly with the increase in gastric acid secretion after the eradication of H . pylori, and was significantly higher in the patients with hiatal hernia (20%) than in those without it (0%) . CONCLUSIONS: Increased acid secretion after H . pylori eradication is an important risk factor of reflux oesophagitis, especially in patients with hiatal hernia.

Trends Plant Sci, 2001 Jun, 6(6), 237 - 9
Antibiotic-free chloroplast genetic engineering - an environmentally friendly approach; Daniell H et al.; Chloroplast genetic engineering offers several advantages over nuclear genetic engineering, including gene containment and hyperexpression . However, introducing thousands of copies of transgenes into the chloroplast genome amplifies the antibiotic resistance genes . Two recent articles report different and novel strategies to either remove antibiotic resistance genes or select chloroplast transformants without using these genes . This should eliminate their potential transfer to microorganisms or plants and ease public concerns about genetically modified crops.

Minerva Anestesiol, 2001 Apr, 67(4), 292 - 7
Selective decontamination of the digestive tract as infection prevention in the critically ill . Does it lead to resistance?
Zandstra DF, van Saene HK.
Several meta-analysis showed the efficacy of selective decontamination of the digestive tract (SDD) in the reduction of infections in critically ill patients, particularly for ventilator associated pneumonia and bloodstream infections, thereby reducing mortality and morbidity . The principle of SDD is that by means of application of non-absorbable antibiotics in the intestinal canal and oropharyngeal cavity, potentially pathogenic microorganisms are eliminated, thereby reducing the incidence of organ site infections . The endogenous anaerobic flora is preserved as a factor contributing to defence against colonization . The potential induction of antibiotic resistance (AR) due to SDD is a major concern in ICU . This review evaluates the onset of clinically relevant AR after SDD . The results of a recent meta-analysis and of several studies, which confirmed the virtual absence of any reported AR with SDD and that did not find AR after stopping SDD, are presented . The eradication of the reservoir of abnormal bacteria located in the gut by topical non-absorbable antibiotics appears to significantly reduce morbidity, mortality and resistance . Using only systemic antibiotics in ICU may contribute to maintain an abnormal population of bacteria among which AR is encouraged.

Minerva Anestesiol, 2001 Apr, 67(4), 206 - 9
Pathophysiology and treatment of airway mucociliary clearance . A moving tale; Cole P; Airway hygiene depends largely on mucociliary clearance (MCC) which in turn depends upon the movement of viscoelastic mucus along the airway by the beating of the ciliary appendages of airway epithelial cells . Failure to keep the airways sterile by MCC results in a host inflammatory response to the persistent microorganisms which, if it becomes chronic, causes damage to the airway wall and upregulation of mucus production manifest clinically as bronchiectasis, sinusitis and otitis . There are three principal disorders of MCC . Firstly, primary ciliary dyskinesia (PCD), a rare genetic deficiency of the ultrastructural apparatus required to propel the cilium, in which nasal nitric oxide is very low due to a deficiency of inducible nitric oxide synthase . Secondly, secondary ciliary dyskinesia due principally to microbial toxin-induced dysfunction of the energy pathways required for ciliary beating . Thirdly, abnormalities in the physicochemical properties of mucus, including reduced salt content/osmolality which results in it being unsuitable in quality for cilia to move it . Methods of rectifying this defect promise to restore MCC to normal and interfere in the vicious circle of inflammatory lung damage.

Arch Insect Biochem Physiol, 2001 Jun, 47(2), 47 - 61
The origin and functions of the insect peritrophic membrane and peritrophic gel; Terra WR; There is a a fluid (peritrophic gel) or membranous (peritrophic membrane, PM) film surrounding the food bolus in most insects . The PM is composed of chitin and proteins, of which peritrophins are the most important . It is proposed here that, during evolution, midgut cells initially synthesized chitin and peritrophins derived from mucins by acquiring chitin-binding domains, thus permitting the formation of PM . Since PM compartmentalizes the midgut, new physiological roles were added to those of the ancestral mucus (protection against abrasion and microorganism invasion) . These new roles are reviewed in the light of data on PM permeability and on enzyme compartmentalization, fluid fluxes, and ultrastructure of the midgut . The importance of the new roles in relation to those of protection is evaluated from data obtained with insects having disrupted PM . Finally, there is growing evidence suggesting that a peritrophic gel occurs when a highly permeable peritrophic structure is necessary or when chitin-binding molecules or chitinase are present in food .

Appl Environ Microbiol, 2001 Jun, 67(6), 2775 - 80
Comparison of endotoxin exposure assessment by bioaerosol impinger and filter-sampling methods; Duchaine C et al.; Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers . Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay . In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filter sampling with IOM inhalable dust samplers . Analysis of variance for repeated measures showed that this association remained after controlling for other factors such as replicate, sawmill, sawmill operation, wood type, and interaction terms . Endotoxin concentrations in the swine barns were 10-fold higher on average than in sawmills . These samples demonstrated comparable endotoxin concentration estimates for impinger and filter methods although the variability was lower using the impinger method . In both occupational settings, side-by-side replicates were more uniform for the impinger samples than for the filter samples . This study demonstrates that impinger sampling is an acceptable method for quantitation of area endotoxin concentrations . Further, when sampling is performed with impingers for airborne microorganism quantitation, these same impinger solutions can yield valid endotoxin exposure estimates, negating the need for additional filter sampling.

Anesthesiology, 2001 Mar, 94(3), 407 - 14
Nosocomial infections and outcome of critically ill elderly patients after surgery; Stephan F et al.; BACKGROUND: The relation between older age and nosocomial infection and mortality in the intensive care unit (ICU) is still a controversial issue . METHODS: The authors prospectively studied 406 patients admitted to a surgical ICU, 106 of whom were more than 75 yr old . Information concerning ICU-acquired nosocomial infections, severity of illness, therapeutic activity, and hospital outcome was collected . A Cox proportional hazard analysis was used to evaluate potential risk factors for ICU-acquired nosocomial infections, ICU, and hospital death . RESULTS: During their ICU stay, 23 elderly patients experienced 40 nosocomial infections, 28 "young" patients (< 60 yr) experienced 54 nosocomial infections, and 52 "intermediate age" patients (60-75 yr) experienced 98 nosocomial infections . Incidence density of nosocomial infections was 4.9% patient days for elderly patients, 4.7% for young patients, and 6.0% for intermediate age patients (no significance) . The frequency distribution of the various microorganisms isolated was similar between the three groups . Compared with younger patients, elderly patients had a higher Acute Physiology and Chronic Health Evaluation II score and a higher ICU and hospital mortality rate . Despite a higher level of severity of illness, elderly patients had a reduction of therapeutic activity . However, Cox proportional hazard analysis showed that age more than 75 yr was not a risk factor for ICU-acquired nosocomial infection, ICU, or hospital death . CONCLUSIONS: In patients referred to a surgical ICU after a surgical procedure, age more than 75 yr by itself does not appear to be a significant predictor of ICU-acquired nosocomial infection or mortality rate during the ICU stay . However, it appears that patients more than 60 yr have a higher incidence of nosocomial infection in ICU.

Chemosphere, 2001 Jun, 43(8), 1119 - 26
Microbial PCB dechlorination in dredged sediments and the effect of moisture; Cho YC et al.; Evidence of reductive dechlorination of polychlorinated biphenyls (PCBs) in sediments was investigated in Hudson River sediments dredged and encapsulated in 1978 at Moreau, NY . The effect of different moisture contents in dredged sediments on dechlorination and dechlorinating microorganisms was also determined using PCB-spiked sediments in which the moisture level was adjusted by simulating a dewatering process . The congener pattern of PCBs indicated that the dechlorination in the dredged sediments was far less advanced than that in the river sediments collected from the general area of the dredged site (Ft . Edward site) . Dechlorination in encapsulated sediments at the Moreau site appeared to have stopped soon after dredging . When microorganisms eluted from the encapsulated sediments were inoculated in clean sediments spiked with Aroclor 1242, an extensive dechlorination was observed, indicating that the encapsulated sediments still harbored dechlorinating microorganisms . However, the same inoculum failed to further dechlorinate residual congeners in the dredged sediments . On the other hand, an inoculum obtained in 1990 from the dredged site in the Hudson River dechlorinated the residual congeners further . In simulated dredged sediments, the maximum level of dechlorination was lower at reduced moisture contents . The population size of dechlorinating microorganisms, as determined by the most probable number (MPN) technique, was also smaller at the lower moisture levels . There was a significant correlation between the maximum extent of dechlorination and the specific death rate of dechlorinating populations . These results indicate that the underlying mechanism of the moisture-dependent maximum dechlorination is the moisture-dependence of the death rate of dechlorinating microorganisms.

Common Factor . 1995 Apr;(no 10):1, 22.
"Yakugai" AIDS and the Yokohama Xth international AIDS conference; Haas GJ; AIDS: The Tenth International AIDS Conference focused on groups who often receive less attention: Asians, women, and persons with hemophilia . The conference revealed that there is a worldwide leveling of the male/female ratio of HIV infections, showing that transmission is now predominantly heterosexual and through IV drug use . Very little was discussed about women's health and treatment needs . Several men and adolescents with hemophilia/HIV infection from the Japanese hemophilia community shared their personal stories . A highlight of the conference was Yoshiaki Ishida's presentation, who described the conditions of HIV-infected persons with hemophilia living in Japan . While 1985 saw the first announced AIDS case in Japan, 40 percent of the hemophilia population were already infected . Because antihemophilic factor (AHF) concentrates were imported from the United States into Japan between 1972-85, several lawsuits have been initiated, citing Japanese law prohibiting the importation of any drugs which are or are likely to be contaminated by pathogenic microorganisms . The conference ended without addressing any important treatments or discussions about alternative therapies . A unifying theme did arise against the prevailing discriminatory travel restrictions for HIV-positive persons .

J Pediatr Orthop B, 2001 Apr, 10(2), 101 - 4
Subacute osteomyelitis in children; Gonzalez-Lopez JL et al.; Subacute osteomyelitis has a very anodyne symptomatology and is, therefore, difficult to diagnose . We studied 21 cases treated between 1984 and 1998 with subacute osteomyelitis of variable location and a mean diagnostic delay of 158.5 days . Of these, 10 cases could not be placed in the current classification . Diagnosis was radiologic in all cases, although in a few patients confirmation by isotopic bone scan and magnetic resonance imaging was required . Treatment was surgical in the first 11 cases to become, currently, predominantly conservative . The causal microorganism was only isolated in nine cases . Complete healing without sequelae was achieved in all but one case, which was of very tardy diagnosis and developed coxarthrosis.

Clin Infect Dis, 2001 Jun 15, 32(12), 1776 - 83 Epub 2001 May 21.
Venous access port--related bacteremia in patients with acquired immunodeficiency syndrome or cancer: the reservoir as a diagnostic and therapeutic tool; Longuet P et al.; To describe the rate of response to an antibiotic-lock technique (ALT) in the treatment of venous access port (VAP)--related bacteremia and to analyze the role of the reservoir in the persistence of infection, we reported the data from 12 human immunodeficiency virus--infected and 8 oncologic patients with VAP-related bacteremia . The ALT consisted of intracatheter delivery of antibiotics and was associated with a systemic antibiotic infusion . We monitored clinical manifestations and performed qualitative and quantitative blood cultures during and at the end of the treatment . Four patients had catheters removed before antibiotic treatment . Of the 16 patients who were treated with the ALT, 5 (31%) were cured, as determined by negative cultures of blood and of samples from the catheter; 2 (12.5%) were cured but had recurrent infection with another microorganism; and 9 (56%) had persistent positive cultures of blood and of samples from the tip, reservoir, or both of the VAP . Limited efficacy of the ALT might be explained by the presence of deposits of fibrin that include clusters of bacteria inside the reservoir of the port.

Thorax, 2001 Jun, 56(6), 477 - 81
Asthma and indoor environment in Nepal; Melsom T et al.; BACKGROUND: The development of asthma seems to be influenced by the adoption of a Western lifestyle . A study was undertaken to assess the importance of indoor environmental factors in Nepal where the lifestyle and home environment differ from that in the West . METHODS: The home environment of 121 schoolchildren with asthma and 126 controls aged 11-17 years was studied . The homes of all participants were investigated and the children and their mothers were interviewed using a standardised questionnaire . Cases and controls were identified from an ISAAC (International Study of Asthma and Allergy in Childhood) based population study of 2330 schoolchildren in Kathmandu, Nepal . RESULTS: Keeping cattle inside the house during the night was related to a lower risk for having asthma (adjusted odds ratio (OR) 0.2 (95% CI 0.1 to 0.5)) while there was no association between asthma and cattle kept outside . Asthma was associated with cigarette smoking by two or more family members (OR 1.9 (95% CI 1.0 to 3.9)) and with the domestic use of smoky fuels (OR 2.2 (95% CI 1.0 to 4.5)) . In analyses stratified by sex, passive smoking and the use of smoky fuels were significantly associated with asthma only in boys . CONCLUSIONS: The risk of asthma in Nepalese children was lower in subjects exposed to cattle kept inside the house and higher in subjects exposed to passive smoking and indoor use of smoky fuels . Childhood exposure to microorganisms or allergens from cattle may protect against the development of atopic disease.

Environ Microbiol, 2001 Apr, 3(4), 281 - 7
Anaerobic degradation of aromatic compounds coupled to Fe(III) reduction by Ferroglobus placidus; Tor JM et al.; Aromatic compounds are an important component of the organic matter in some of the anaerobic environments that hyperthermophilic microorganisms inhabit, but the potential for hyperthermophilic microorganisms to metabolize aromatic compounds has not been described previously . In this study, aromatic metabolism was investigated in the hyperthermophile Ferroglobus placidus . F . placidus grew at 85 degrees C in anaerobic medium with a variety of aromatic compounds as the sole electron donor and poorly crystalline Fe(III) oxide as the electron acceptor . Growth coincided with Fe(III) reduction . Aromatic compounds supporting growth included benzoate, phenol, 4-hydroxybenzoate, benzaldehyde, p-hydroxybenzaldehyde and t-cinnamic acid (3-phenyl-2-propenoic acid) . These aromatic compounds did not support growth when nitrate was provided as the electron acceptor, even though nitrate supports the growth of this organism with Fe(II) or H2 as the electron donor . The stoichiometry of benzoate and phenol uptake and Fe(III) reduction indicated that F . placidus completely oxidized these aromatic compounds to carbon dioxide, with Fe(III) serving as the sole electron acceptor . This is the first example of an Archaea that can anaerobically oxidize an aromatic compound . These results also demonstrate for the first time that hyperthermophilic microorganisms can anaerobically oxidize aromatic compounds and suggest that hyperthermophiles may metabolize aromatic compounds in hot environments such as the deep hot subsurface and in marine and terrestrial hydrothermal zones in which Fe(III) is available as an electron acceptor.

Environ Microbiol, 2001 Apr, 3(4), 237 - 45
Impact of surface thermodynamics on bacterial transport; Chen G et al.; Microbial surface thermodynamics correlated with bacterial transport in saturated porous media . The surface thermodynamics was characterized by contact-angle measurement and the wicking method, which was related to surface free energies of Lifshitz-van der Waals interaction, Lewis acid-base interaction, and electrostatic interaction between the bacteria and the medium matrix . Transport of three different strains of bacteria present at three physiological states was measured in columns of silica gel and sand from the Canadian River Alluvium (Norman, OK, USA) . Microorganisms in stationary state had the highest deposit on solid matrix, compared with logarithmic and decay states . The deposition correlated with the total surface free energy (DeltaG132TOT) and the differences in DeltaG132TOT were mainly controlled by the Lewis acid-base interaction . Infrared spectroscopy showed that the increased deposition correlated with an increase in the hydrogen-bonding functional groups on the cell surfaces.

Oral Microbiol Immunol, 2001 Jun, 16(3), 153 - 62
The effect of monoclonal antibody and route of immunization on the humoral immune response against Porphyromonas gingivalis; Van Tilburg ML et al.; Immunomodulation mediated by exogenous antibodies has been proposed as a vaccine strategy to improve immune protection against pathogenic microorganisms and suggested to contribute to protection following passive immunization . To test whether a monoclonal antibody directed against an adhesion epitope of the periodontal pathogen Porphyromonas gingivalis could influence the humoral immune response following mucosal immunization, BALB/c mice were immunized orally or intranasally with P . gingivalis alone or P . gingivalis coated with monoclonal antibody 61BG1.3 . Differences in antigenic specificity of anti- P . gingivalis serum immunoglobulin G (IgG) were demonstrated between groups of mice that received monoclonal antibody-coated P . gingivalis versus those that received P . gingivalis alone by either route of immunization . Binding of monoclonal antibody 61BG1.3 to P . gingivalis prior to immunization did not influence the serum IgG subclass distribution . However, minor differences in subclass distribution were observed between the various routes of mucosal immunization . These results support the hypothesis that specific monoclonal antibody bound to a bacterial vaccine can alter the quality of the humoral immune response to that organism.

Electrophoresis, 2001 Apr, 22(6), 1086 - 9
A two primers random amplified polymorphic DNA procedure to obtain polymerase chain reaction fingerprints of bacterial species; Rivas R et al.; Polymerase chain reation (PCR) fingerprints are used to characterize and recognize bacteria and are generally obtained using universal primers that generate an array of DNA amplicons, which can be separated by electrophoresis . Universal primers 8F and 1491 R have been used to amplify specifically 16S rDNA . We have used these primers at an annealing temperature of 50 degrees C . Agarose gel electrophoresis of PCR products revealed several bands . The band pattern of each bacterial species was different and the strains belonging to the same species shared an identical pattern . The patterns obtained did not show variations with plasmid DNA content or the growth stage of the bacteria . The peculiarity of the randomly amplified polymorphic DNA (RAPD) described in this work lies in the use of two large primers (proximately 20 nt) to obtain the pattern, since normally a only smaller primer is used, and in the new application for the primers used to amplify 16S rDNA . This new procedure, called two primers (TP)-RAPD fingerprinting, is thus rapid, sensitive, reliable, highly reproducible and suitable for experiments with a large number of microorganisms, and can be applied to bacterial taxonomy, ecological studies and for the detection of new bacterial species.

Int Immunopharmacol, 2001 Apr, 1(4), 625 - 35
Toll-like receptors; their physiological role and signal transduction system; Takeuchi O et al.; Drosophila Toll protein is a transmembrane receptor whose function is to recognize the invasion of microorganisms as well as to establish dorso-ventral polarity . Recently, mammalian homologues of Toll, designated as Toll-like receptors (TLRs) have been discovered . So far, six members (TLR1-6) have been reported and two of these, TLR2 and TLR4, have been shown to be essential for the recognition of distinct bacterial cell wall components . TLR2 discriminates peptidoglycan (PGN), lipoprotein, lipoarabinomannan (LAM) and zymosan, whereas TLR4 recognizes lipopolysaccharide (LPS), lipoteichoic acid (LTA) and Taxol . Bacterial components elicit the activation of an intracellular signaling cascade via TLR in a similar way to that occurs upon ligand binding to IL-1 receptor (IL-1R) . This signaling pathway leads to the activation of a transcription factor NF-kappaB and c-Jun N-terminal kinase (JNK), which initiate the transcription of proinflammatory cytokine genes . Particularly, analysis of knockout mice revealed a pivotal role for MyD88 in the signaling of the TLR/IL-1R family . Taken together, TLRs and the downstream signaling pathway play a key role in innate immune recognition and in subsequent activation of adaptive immunity.

Genetika, 2001 Mar, 37(3), 422 - 5
{Effect of the gene for bacterial hemoglobin vhb on the effectiveness of the process of Escherichia coli-Streptomyces interspecies conjugation and production of antibiotics in streptomycetes}; Tabakov VIu et al.; The bacterial hemoglobin vhb gene was cloned from sliding bacterium Vitreoscilla sp . as an element of the system ensuring survival of this microorganism in an environment that contains insufficient amount of oxygen . The vhb gene was transferred from Escherichia coli to some Streptomyces strains, producers of antibiotics, by the method of intergeneric conjugation using conjugative-integrative plasmid vectors pIH1 and pCH2 . The stability of plasmid DNA inheritance was analyzed in the genomes of exconjugants . A positive effect of the vhb gene on processes of conjugation and antibiotic production in a number of examined strains was shown.

Biofizika, 2001 Mar-Apr, 46(2), 251 - 5
{Mineral salt-dependent inhibition of light emission from the luminescent microorganism Escherichia coli Z9051}; Boiandin AN et al.; The influence of some mineral salts on the recombinant strain Escherichia coli Z9051 was investigated . It was shown that the composition (NaCl, Na2SO4, MgCl2 and MgSO4) and concentration (5 and 10%) of the salts substantially affect the expression of genes for the luminescence system of light-emitting bacteria cloned in the plasmid under the control of the lac-promoter . In some cases, the luminescence level of the microorganism in the presence of salts was similar to the luminescence level under catabolite repression by glucose, the more strong influence of the salts exceeding the effect of catabolite repression . The possibility of adaptation of the genetically modified microorganism to the salinity factor is discussed.

Pharmacol Rev, 2001 Jun, 53(2), 283 - 318
Long-circulating and target-specific nanoparticles: theory to practice; Moghimi SM et al.; The rapid recognition of intravenously injected colloidal carriers, such as liposomes and polymeric nanospheres from the blood by Kupffer cells, has initiated a surge of development for "Kupffer cell-evading" or long-circulating particles . Such carriers have applications in vascular drug delivery and release, site-specific targeting (passive as well as active targeting), as well as transfusion medicine . In this article we have critically reviewed and assessed the rational approaches in the design as well as the biological performance of such constructs . For engineering and design of long-circulating carriers, we have taken a lead from nature . Here, we have explored the surface mechanisms, which affords red blood cells long-circulatory lives and the ability of specific microorganisms to evade macrophage recognition . Our analysis is then centered where such strategies have been translated and fabricated to design a wide range of particulate carriers (e.g., nanospheres, liposomes, micelles, oil-in-water emulsions) with prolonged circulation and/or target specificity . With regard to the targeting issues, attention is particularly focused on the importance of physiological barriers and disease states.

Indian J Biochem Biophys, 2000 Dec, 37(6), 383 - 94
Carbon concentration mechanisms in photosynthetic microorganisms; Ghoshal D et al.; Unicellular green algae and cyanobacteria have mechanism to actively concentrate dissolved inorganic carbon into the cells, only if they are grown with air levels of CO2 . The carbon concentration mechanisms are commonly known as "CCM" or "DIC-pumps" . The DIC-pumps are environmental adaptation that function to actively transport and accumulate inorganic carbon (HCO3- and CO2; Ci) within the cell and then uses this Ci pool to actively increase the concentration of CO2 at the site of ribulose bisphosphate carboxylase-oxygenase (Rubisco), the primary CO2-fixing enzyme . The current working model for dissolved inorganic carbon concentration mechanism in unicellular green algae includes several isoforms of carbonic anhydrase (CA), and ATPase driven active transporters at the plasmalemma and at the inner chloroplast envelopes . In the past fifteen years, significant progress has been made in isolating and characterizing the various isoforms of carbonic anhydrase at the biochemical and molecular level . However, we have an inadequate understanding of active transporters that are located on the plasmalemma and at the chloroplast envelopes . In this mini-review we focus on certain aspects of the induction, function and significance of the dissolved inorganic carbon concentration mechanisms in aquatic photosynthetic microorganisms.

Oral Dis, 2000 Nov, 6(6), 351 - 65
Environmental cues and gene expression in Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans; Forng RY et al.; Microorganisms typically adapt to environmental cues by turning on and off the expression of virulence genes which, in turn, allows for optimal growth and survival within different environmental niches . This adaptation strategy includes sensing and responding to changes in nutrients, pH, temperature, oxygen tension, redox potential, microbial flora, and osmolarity . For a bacterium to adhere to, penetrate, replicate in, and colonize host cells, it is critical that virulence genes are expressed during certain periods of the infection process . Thus, throughout the different stages of an infection, different sets of virulence factors are turned on and off in response to different environmental signals, allowing the bacterium to effectively adapt to its varying niche . In this review, we focus on the regulation of virulence gene expression in two pathogens which have been implicated as major etiological agents in adult and juvenile periodontal diseases: Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans . Understanding the mechanisms of virulence gene expression in response to the local environment of the host will provide crucial information in the development of effective treatments targeted at eradication of these periodontal disease pathogensPublication Types:

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