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 s