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PubMedDate not supplied

[How to test at once six cytokines in samples as small as 25 microl?].

Inflammatory and regulatory or anti-inflammatory cytokines (TNFalpha, IL-1beta, -6, -8, -10 and -12) regulate both the humoral and cellular immune responses. Cytokines have diverse peripheral and central functions. They are critical mediators of protective host responses, including defense against microbial invasion and tumorigenesis. However, the production of specific proinflammatory cytokines must be tightly regulated and compartmentalized to prevent the overexpression of these molecules that can end in chronic inflammation and tissue injury. Many diseases like autoimmune disease (rheumatoid arthritis, multiple sclerosis, arteriosclerosis, Crohn's disease), neurodegenerative disease (Alzheimer's and Parkinson's disease), tumor invasion and metastasis correlate with a deregulation in cytokine action. Thus, cytokines network provides an attractive and intensely competitive area of potential targets for therapeutic intervention. To monitor such secretion patterns in presence of putative drugs obtained by high throughput screening (HTS) some new techniques recently appeared on the market. We here compared results obtained by CBA (BD Cytometric Bead Array) to IC50 values obtained by classical sandwich Elisa. The complexity and cost of this new method is largely compensated by simultaneous testing of 6 cytokines in only 25 micro L of cell supernatant.

Flow Cytometry↗
PubMed2004

Correlation between cholestasis and infection.

This is an overview of cytokine-induced cholestasis, justified by the insufficient knowledge of this frequent type of cholestasis. In the presence of an infectious agent a systemic and intrahepatic production of proinflammatory cytokines results (TNF-alpha, IL-1beta, IL-6 etc.), stimulated by microbial lipopolysaccharides. In patients having systemic infections, the liver has several major functions: source of the inflammatory cytokines produced as a response to infection and a target of these inflammation mediators. The inflammatory cytokines interfere with the activity of both the sinusoidal and canalicular transporting systems. One of the potential consequences of this process is the appearance of cholestasis. An infection can lead to cholestasis despite the absence of direct invasion of the liver by the infectious agent. Particularly the cholestasis produced when the infection generating agent is not located in the liver (sepsis or extrahepatic infections) has been emphasized. The clinical aspect of the diseases associated with this type of cholestasis and the effects of anti-infectious therapy on cholestasis are presented. Cytokine-induced cholestasis represents a common pathogenic path for several diseases: hepatitides that present with an intrahepatic cholestatic pattern (viral, ethanol-induced, NSAID-induced), but also many other infections, which are sometimes overlooked because of the lack of clinical signs. When a preexistent liver disease is present, the cholestasis incidence is higher. In this latter condition, ignorance of this possible mechanism of cholestasis will lead to misdiagnosis and unnecessary tests, sometimes expensive and useless.

Bacterial Infections↗
PubMed1992

[The function of the small intestine based on hydrogen test data in men who have been exposed to small doses of ionizing radiation in the cleanup of the sequelae of the accident at the Chernobyl Atomic Electric Power Station].

Sixty-seven participants of the elimination of Chernobyl accident sequels were examined. Of these, 30 persons (44.8%) showed normal characteristics of the three small intestinal functions studied: activity of the intestinal enzyme beta-galactosidase, motility and microbial dissemination, 23 (34.3%) deficiency of the intestinal enzyme beta-galactosidase, and 24 (35.8%) bacterial dissemination of the small intestine. In 12 persons (17.9%), the deficiency of beta-galactosidase was associated with dysbiosis of the small intestine. The incidence of hypolactasia did not exceed the characteristic typical on the whole of the population of the Moscow region.

Accidents↗
PubMed1991

In vivo effects of recombinant human granulocyte colony-stimulating factor on normal neutrophil function and membrane effector molecule expression.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is now undergoing clinical trials. We investigated the effects of rhG-CSF on the function of neutrophils in vivo in healthy volunteers. rhG-CSF (0.5 micrograms/kg) was injected subcutaneously for 6 consecutive days. The number of neutrophils in peripheral blood decreased transiently within an hour, and thereafter increased 2-10-fold compared to the control 6 to 8 h after injection. The circulating neutrophils remaining during this early neutropenic period showed increases in such functions as random motility, chemotaxis, phagocytosis and superoxide anion production. On the other hand, the function of neutrophils which increased 6 to 8 h after rhG-CSF injection was normal. No decrease of neutrophil function was observed following the use of rhG-CSF. CD33-positive cells increased 3 days after rhG-CSF administration. CD11a (LFA-1) expression on the membranes circulating neutrophils decreased 6 h after rhG-CSF administration. This phenomenon suggested that neutrophils adhered to the reticuloendothelial system during neutropenia, and that there was an influx of CD11a-negative mature cells into the circulatory pool thereafter. All our findings suggest that rhG-CSF enhances the function of normal neutrophils in vivo, and that it is effective against microbial infection very soon after administration.

Adult↗
PubMed1991

Human lysosomal cathepsin G and granzyme B share a functionally conserved broad spectrum antibacterial peptide.

Human neutrophil lysosomal cathepsin G (cat G) exerts broad-spectrum antibacterial action in vitro against Gram-negative and -positive bacteria independent of its serine protease activity. We recently determined that an internal peptide of cat G (HPQYNQR), obtained after digestion of cat G with clostripain, possessed broad-spectrum antibacterial action in vitro, displaying an ED50 of 5 x 10(-5) M. In order to evaluate the structure-antibacterial properties of this peptide, synthetic variants with single alanine substitutions at each position were prepared and tested for antibacterial action. We found that alanine substitution for His-1 or Tyr-4, or certain modifications of the His-1 side chain, produced nonbactericidal peptides. A hexapeptide lacking the COOH-terminal Arg-7 but not a pentapeptide lacking both Gln-6 and Arg-7 possessed in vitro bactericidal activity. Interestingly, the cat G bactericidal peptide displays similarity to sequences within other serine proteases, notably the proposed cytotoxic granzymes present in the cytolytic granules of human and mouse cytotoxic T lymphocytes. We now report that an internal peptide of one human granzyme (granzyme B) with the sequence of HPAYNPK also displays bactericidal action in vitro. Our results suggest that an internal antibacterial domain among human serine proteases cat G and granzyme B has been functionally conserved through evolution perhaps for the purpose of host defense against microbial pathogens and targets of cytotoxic T lymphocyte killing.

Amino Acid Sequence↗
PubMed1988

Fate of genetically-engineered bacteria in activated sludge microcosms.

The conclusions that can be derived from this study regarding the fate of the GEMs and their ability to degrade added pollutants are as follows: 1. Both GEMs were able to survive in the microcoms. Because Pseudomonas sp. B13 has been cultured for a long time in the laboratory, it was not expected to survive well in the microcosm. Surprisingly, it and the derivative GEMs persisted at a high population level of approximately 10(5) bacteria/ml. Pure culture studies had demonstrated an ability of FR1(pFRC20P) to readily degrade simultaneous mixtures of 3CB and 4MB. In the microcosms, however, the GEM did not perform as well as expected, particularly when confronted with a shock load of a 3CB and 4MB mixture. Thus, the microcosm studies may be of potential help for making predictions concerning environmental applications of GEMs. 2. Pseudomonas sp. B13 derivative strains FR1 and FR1(pFRC20P) were able to degrade low concentrations of substituted benzoates within the complex ecosystem of the activated sludge microcosm. A good deal of information concerning the degradation pathway for aromatics by Pseudomonas sp. B13 was already known. This allowed for the construction of the stable, regulated pathways for the degradation of substituted aromatic compounds in both GEMs and indicates that the construction of similar GEMs for the degradation of environmental pollutants is a promising experimental strategy. 3. There was not any demonstrable, adverse effect of GEM addition to the microbial population level in the microcosm. The GEMs were even able to function in a protective manner for the indigenous populations by buffering them against the adverse effects of addition of substituted benzoates. In contrast, for microcosms lacking GEM addition, a wash-out of the bacterial population in the microcosm occurred (data not shown). 4. Lateral transfer of new genetic information (xylXYZLS) from the GEM chromosome to indigenous microorganisms was not detected, whereas transfer of the hybrid, mobilizable pFRC20P carrying the gene for lactone isomerase did apparently occur. In this particular case, transfer may have been beneficial for the community as a whole if it increased the ecosystem's ability to cope with the presence of toxic pollutants. As more GEMs are constructed for specific biotechnological applications the diversity and complexity of microcosms used to study their fate and function will increase. The ability of such studies to predict a priori the fate of these microorganisms will help to develop strategies both to decrease the risks associated with introducing GEMs into the environment and to increase and regulate the capacity of GEMs to degrade toxic pollutants.(ABSTRACT TRUNCATED AT 400 WORDS)

Bacteria↗
PubMed1987

Bacterial colonization of intestinal urinary conduit diversion: a morphologic and bacteriologic experimental study.

Cutaneous diversion of the urine through intestinal conduits results in bacteriuria with uropathogenic organisms in up to 80% of patients, many of whom suffer pyelonephritis. Analysis of the bacteriologic data from daily sampling at multiple sites and scanning and transmission electron microscopic studies of sequential loop and autopsy specimens in rabbits with functioning colonic conduits indicate that the pyelonephritis evolves in sequential stages of microbial colonization. Using these data on the natural progression of bacterial infection, we can rationally test the ability of strains of bacteria indigenous to the conduit of this animal model to prevent uropathogenic colonization of the conduit.

Animals↗
PubMed1986

[Remarks and recommendations on the definition and classification of eczematous diseases].

Numerous nomenclatures and classifications of eczemas have puzzled dermatologists for a long time. This confusion is due to the great number of external as well as internal noxious factors and/or agents causing eczemas being themselves a distinct and histologically well defined reaction of the papillary-epidermal compartment. Current classifications do not adequately reflect the complex causative conditions involved in the etiopathogenesis of eczematous disorders. I propose, therefore, to classify eczematous disorders according to the following three principal categories: "mainly endogenous" (or "atopic") eczemas, "mainly exogenous" (or "contact") eczemas, and "dysregulatory microbial" eczemas. The latter group comprises eczemas caused by various kinds of functional derangement of epidermal protective properties (e.g., venous stasis, exsiccation of horny layer, seborrhea/hyperhidrosis, epidermal atrophy), which in turn permit the resident and/or transient microflora of the horny layer to induce inflammatory responses of eczematous pattern. Since morphological, topical, and other clinical attributes may change in the course of the very same eczematous disease, they are inappropriate for basic classification of eczemas and should be only employed as minor criteria to characterize the predominant "type" or subset (i.e., clinical appearance) of the specific eczema. The possible combination of eczemas representing two (or even three) categories in one patient leads to intermediate forms entirely in keeping with the division into three principal groups. The classification proposed is aimed at eliminating the terminological confusion as well as enabling reliable documentation for compatible statistics, and should consequently improve the sematic communication between dermatologists and other physicians.

Dermatitis↗
PubMed1984

[Fermentative mechanisms of the psychrophilicity of Yersinia tuberculosis].

The specific activity of urease, nitrogenase, hialuronidase and neuraminidase in Y. pseudotuberculosis grown in different culture media and at different temperature has been studied. These enzymes have been found capable of functioning at both relatively low (2-8 degrees C) and high (37 degrees C) temperatures. The thermoadaptive properties of Y. pseudotuberculosis within a wide range of temperatures are ensured by the constant presence of isoenzymes, functioning only at low temperatures or only at high temperatures, in the microbial cells. Low temperature in combination with a definite culture medium triggers the activity of certain enzymatic systems, which explains, to some extent, the biochemical mechanisms of the psychrophilic properties of Y. pseudotuberculosis.

Cell Division↗
PubMed1996

[Motor, digestive and secretory processes of the forestomach and the abomasum--a short review].

This short review deals with some basic aspects concerning the physiology of the ruminant forestomachs and the abomasum. Following the discussion of the motoric activities, the major aspects of microbial carbohydrate and nitrogen metabolism within the reticulorumen are treated. Thereafter, some functions of the abomasum are presented in some more detail. These include the composition of abomasal contents, the mechanisms and regulation of hypochloric acid and enzyme secretion, and the mechanisms responsible for protection of the mucosa against digestion by gastric secretions.

Abomasum↗
PubMed2004

Requirement for a conserved Toll/interleukin-1 resistance domain protein in the Caenorhabditis elegans immune response.

The p38 mitogen-activated protein kinase pathway regulates innate immune responses in evolutionarily diverse species. We have previously shown that the Caenorhabditis elegans p38 mitogen-activated protein kinase, PMK-1, functions in an innate immune response pathway that mediates resistance to a variety of microbial pathogens. Here, we show that tir-1, a gene encoding a highly conserved Toll/IL-1 resistance (TIR) domain protein, is also required for C. elegans resistance to microbial pathogens. RNA interference inactivation of tir-1 resulted in enhanced susceptibility to killing by pathogens and correspondingly diminished PMK-1 phosphorylation. Unlike all known TIR-domain adapter proteins, overexpression of the human TIR-1 homologue, SARM, in mammalian cells was not sufficient to induce expression of NF-kappaB or IRF3-dependent reporter genes that are activated by Toll-like receptor signaling. These data reveal the involvement of a previously uncharacterized, evolutionarily conserved TIR domain protein in innate immunity that is functionally distinct from other known TIR domain signaling adapters.

Animals↗
PubMed2026

Probiotic potential of Parabacteroides johnsonii in mitigating age-related ovarian functional decline.

The gut microbiota is increasingly recognized as a regulator of reproductive health, yet its role in ovarian aging remains unclear. Here, we combine Mendelian randomization (MR) analysis with experimental validation to investigate the causal relationship between gut microbiota and ovarian aging. MR analysis identifies four microbial taxa significantly associated with age at natural menopause. In mouse models, germ-free mice exhibit accelerated ovarian functional decline, including reduced ovarian reserve and impaired folliculogenesis. Fecal microbiota transplantation (FMT) from young donors alleviates ovarian aging phenotypes, whereas FMT from aged donors exacerbates functional decline. Metagenomic analysis reveals species-level differences between young and ovarian-aging mice, with Parabacteroides johnsonii (P. johnsonii) enriched in young mice. Administration of P. johnsonii to middle-aged mice improves ovarian reserve, reduces follicular atresia, enhances granulosa cell proliferation, and decreases systemic inflammation. These findings highlight a causal role of the gut microbiota in ovarian aging and support microbiota-targeted interventions as a potential strategy to preserve ovarian function.

Female↗
PubMed2003

Beta-propellers: associated functions and their role in human diseases.

The beta-propeller fold appears as a very fascinating architecture based on four-stranded antiparallel and twisted beta-sheets, radially arranged around a central tunnel. Similar to the alpha/beta-barrel (TIM-barrel) fold, the beta-propeller has a wide range of different functions, and is gaining substantial attention. Some proteins containing beta-propeller domains have been implicated in the pathogenesis of a variety of diseases such as cancer, Alzheimer, Huntington, arthritis, familial hypercholesterolemia, retinitis pigmentosa, osteogenesis, hypertension, and microbial and viral infections. This article reviews some aspects of 3D structure, amino acids sequence regularities, and biological functions of the proteins containing beta-propeller domains. Major emphasis has been laid on beta-propellers whose functions are associated to human diseases. Recent research efforts reported in the fields of protein engineering, drug design, and protein structure-function relationship studies, concerning the beta-propeller architecture, have also been discussed.

Disease↗
PubMed2003

Targeting caveolae for vesicular drug transport.

Caveolae are morphologically evident as omega-shaped invaginations of the plasma membrane with a diameter of 50-100 nm. They may also exist in a variety of other forms including flattened domains indistinguishable from the plasma membrane itself. At least in some cell types caveolae undertake transport functions including that of the endocytic and transcytotic movement of macromolecules, and indeed microbes and microbial toxins. Opportunities exist for basic and applied investigators working within the pharmaceutical sciences to exploit caveolae membrane interactions with the aim to develop of novel cellular or transcellular drug delivery strategies. This overview article will provide: pertinent information on the biology of the caveolae membrane system; review the various caveolae isolation methods; highlight some of the literature evidence showing that caveolae are functional with regard to macromolecule transport; discuss the role that caveolae could fulfill in the pulmonary absorption of therapeutic proteins from alveolar airspace to capillary blood following inhalational drug delivery, and finally review some very recent work showing proof-of-principle that caveolae domains can be targeted in a tissue-specific manner with highly selective ligands.

Animals↗
PubMed2001

Probiotics in human disease.

Western civilization is facing a progressive increase in immune-mediated, gut-related health problems, such as allergies and autoimmune and inflammatory diseases, and genetic factors are an unlikely explanation for these rapid increases in disease incidence. Two environmental factors that relate to the modern lifestyle in Western societies are hygiene and nutrition. There has been a decline in the incidence of microbial stimulation by infectious diseases as a result of improved hygiene, vaccination, and antimicrobial medication. In the past, methods of food preservation involved either the natural fermentation or drying of foods; thus, the human diet once contained several thousand times more bacteria than it does today. The development of probiotic, functional foods aims to "kill two birds with one stone," which is accomplished by providing a microbial stimulus to the host immune system by means of beneficial live microorganism cultures that are characteristic of the healthy, human gut microflora, ie, probiotics. Probiotic bacteria were shown to reinforce the different lines of gut defense, which are immune exclusion, immune elimination, and immune regulation. They were also shown to stimulate nonspecific host resistance to microbial pathogens, thereby aiding in pathogen eradication. Consequently, the best documented clinical application of probiotics is in the treatment of acute diarrhea. In humans, documented effects were reported for the alleviation of intestinal inflammation, normalization of gut mucosal dysfunction, and down-regulation of hypersensitivity reactions. These data show that probiotics promote endogenous host defense mechanisms. Thus, modification of gut microflora by probiotic therapy may offer a therapeutic potential in clinical conditions associated with gut-barrier dysfunction and inflammatory response.

Diet↗
PubMed1996

Cloning of human adenosine kinase cDNA: sequence similarity to microbial ribokinases and fructokinases.

Adenosine kinase catalyzes the phosphorylation of adenosine to AMP and hence is a potentially important regulator of extracellular adenosine concentrations. Despite extensive characterization of the kinetic properties of the enzyme, its primary structure has never been elucidated. Full-length cDNA clones encoding catalytically active adenosine kinase were obtained from lymphocyte, placental, and liver cDNA libraries. Corresponding mRNA species of 1.3 and 1.8 kb were noted on Northern blots of all tissues examined and were attributable to alternative polyadenylylation sites at the 3' end of the gene. The encoding protein consists of 345 amino acids with a calculated molecular size of 38.7 kDa and does not contain any sequence similarities to other well-characterized mammalian nucleoside kinases, setting it apart from this family of structurally and functionally related proteins. In contrast, two regions were identified with significant sequence identity to microbial ribokinase and fructokinases and a bacterial inosine/guanosine kinase. Thus, adenosine kinase is a structurally distinct mammalian nucleoside kinase that appears to be akin to sugar kinases of microbial origin.

Adenosine Kinase↗

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