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At least 1,441 records · Page 80Linked to original sources
PubMed2006

Expression and function of TLR2, TLR4, and Nod2 in primary canine colonic epithelial cells.

The gut maintains a delicate balance between the downregulation of inflammatory reactions to commensal bacteria and the capacity to respond to pathogens with vigorous cellular and humoral immune responses. Intestinal epithelial cells, including colonic epithelial cells (CECs) possess many properties of cells of the innate immune system, in particular the ability to recognize and respond to microbial antigens. Recognition of microorganisms by CECs is based upon their recognition of signature molecules, called microbe-associated molecular patterns (MAMP), by pattern recognition receptors (PRR) including membrane toll-like receptors (TLR) and cytosolic Nod2, an intracellular counterpart of TLRs. The purpose of this study was to determine whether primary CECs from normal dogs express a functional TLR2, TLR4, and Nod2 and whether they are regulated by inflammatory mediators. We show that canine primary CECs express TLR2, TLR4, and Nod2 that can be modulated in response to their respective MAMPs, lipopolysaccharides (LPS) or peptidoglycans (PGN). Furthermore, we demonstrate that these receptors are functional as evidenced by the induction of cytokine gene expression in response to LPS or PGN.

Animals↗
PubMed1993

Analysis of intestinal flora of a patient with congenital absence of the portal vein.

A 14-year-old female patient, admitted for a closer examination of liver tumour (hepatocellular adenoma), was diagnosed as having a congenital absence of the portal vein. The blood ammonia level (approximately 120 micrograms dl-1) in the superior mesenteric vein was markedly low compared to the normal value of 300-350 micrograms dl-1 in the portal vein. The decreased ammonia concentration and urease activity of the patient's faeces were demonstrated. The dominant intestinal flora in the faeces of the patient, before operation, was Bifidobacterium sp., Bifidobacterium breve, Bifidobacterium lonqum, Lactobacillus plantarum, and after the operation Bacteroides vulgatus, Veillonella parvula, Peptococcus magnus Bifidobacterium longum. In contrast, Bifidobacterium bifidum, Bacteroides ureolyticus, Bacteroides ovatus and Bacteroides distasonis, B. ovatus, Bifidobacterium adolescentis were dominant flora in the faeces of two healthy volunteers, respectively. Among microorganisms isolated from the patient, Morganella morganii, Candida sp., Eubacterium aerofacience and Eubacterium rectale were strongly positive in urease activity in vitro; Streptococcus mitior, Staphylococcus intermedius, Micrococcus kristinae, Selenomonas ruminantum, Bacteroides ureolyticus and Lactobacillus casei ss. pseudoplantarum from the healthy volunteers. These results imply the homeostatic regulation system of faecal ammonia concentration by urease-producing microorganisms in the patient.

Adolescent↗
PubMed1989

Development of a nutrient medium to culture microorganisms of the genus Campylobacter.

The nutrient media developed in the USSR and CSR for the isolation of campylobacteria are multi-purpose as they enable the isolation of campylobacteria not only from material derived from patients with acute intestinal infection, but also from the internal organs of healthy and diseased animals and poultry as well as from a variety of objects in the environment.

Animals↗
PubMed1999

Interactions of viruses and microparticles with apical plasma membranes of M cells: implications for human immunodeficiency virus transmission.

In the rectal mucosa, specialized M cells of the lymphoid follicle-associated epithelium conduct vesicular transport of antigens from the mucosal surface into organized mucosal lymphoid tissues, where immune responses are induced. Bacteria and viruses may exploit this mechanism to initiate mucosal or systemic infection. Viral pathogens, including reovirus, poliovirus, and possibly human immunodeficiency virus (HIV), can enter the intestinal or rectal mucosa by adhering to apical membranes of M cells, but the membrane components involved in these interactions are unknown. Glycoprotein coats on the apical surfaces of epithelial cells act as diffusion barriers that limit access of particles and microorganisms to membrane glycolipids and to certain oligosaccharide epitopes of enterocytes but allow selective adherence to M cells. The accessibility of membrane glycolipids of M cells, along with their active endocytic activity, could promote entry of HIV into the rectal mucosa.

Animals↗
PubMed1986

Morphometric and cytochemical analysis of lysosomes in rat Peyer's patch follicle epithelium: their reduction in volume fraction and acid phosphatase content in M cells compared to adjacent enterocytes.

M cells are specialized epithelial cells over lymphoid follicles in Peyer's patches which take up viruses, bacteria, and antigenic macromolecules from the intestinal lumen. Unlike ordinary enterocytes which sequester pinocytosed material in lysosomes, M cells transport such material across the epithelium to antigen-processing areas in lymphoid follicle domes, suggesting a difference in lysosomal activity or a different route for movement of endocytic vesicles. Ileal Peyer's patches in rats were examined by electron microscopy to identify lysosomes by acid phosphatase activity. Acid phosphatase was found in dense bodies in enterocytes but not in M cells. Stereological analysis showed the volume fraction occupied by dense bodies in M cells to be 16 times less than in enterocytes (P less than .0005), even though the volume fractions of cytoplasm occupied by mitochondria in M cells and enterocytes were not significantly different. The small volume fraction of dense bodies and the absence of acid phosphatase activity in M cells thus correlate with absence of lysosomal degradation of luminal microorganisms during transport into lymphoid follicles by M cells and may provide not only a complete array of microbial antigens for initiation of immune responses, but also a route through the mucosal barrier for microorganisms which can evade local containment mechanisms.

Acid Phosphatase↗
PubMed1976

Immunoglobulins within human small-intestinal Paneth cells.

Human duodenal, jejunal, and ileal samples obtained at necropsy and by peroral and surgical biopsy, were studied by light microscopy using the unlabelled antibody enzyme method for imunocytochemical staining of lysozyme and immunoglobulins. Paneth cells contained IgA and IgG, but not IgD IgE, or IgM. Staining intensity indicated that IgA and IgG were present in amounts greater than in other epithelial cells. There was pronounced variation in the immunoglobulin content of Paneth cells. Rat Paneth cell containing IgA and lysozyme and are capable of the phagocytosis and degradation of microorganisms. These observations suggest that human Paneth cells may have similar functional capabilities.

Duodenum↗
PubMed1991

Bacterial translocation induces procoagulant activity in tissue macrophages. A potential mechanism for end-organ dysfunction.

The ability of bacterial translocation to induce cell-associated procoagulant activity was examined in a rodent model. Intestinal decontamination with streptomycin sulfate and bacitracin followed by oral feeding with a streptomycin-resistant strain of Escherichia coli produced monoassociation of the gastrointestinal tract with this microorganism. Using this model, the rate of bacterial translocation at day 3 increased from 6% (1 of 17) to 90% (28 of 31). Cell-associated procoagulant activity was measured in the mononuclear cell population of mesenteric lymph nodes as well as portal and systemic blood and also in hepatic nonparenchymal cells. In monoassociated animals, the procoagulant activity of mesenteric lymph node mononuclear cells was significantly greater than in control animals at day 3 (210% +/- 28% vs 100% +/- 6%) but not at days 1 or 6. Procoagulant activity of hepatic nonparenchymal cells was elevated in monoassociated animals at days 3 and 6 compared with control animals. Both control and monoassociated animals remained well throughout the experiment. The histologic features of the gastrointestinal tract, mesenteric nodes, and liver did not differ between groups. These studies provide evidence that bacterial translocation, in the absence of external stimuli, is able to induce cell activation at sites remote from the gastrointestinal tract and may therefore contribute to the pathogenesis of multiple organ failure.

Animals↗
PubMed1986

Clinical efficacy of ofloxacin in the treatment of otorhinolaryngological infections.

A multi-centered clinical study was carried out to evaluate the efficacy of ofloxacin in otorhinolaryngological infections in Japan. Ofloxacin was used at a dosage of 300 mg to 800 mg daily for three to 20 days in 206 cases of various infectious diseases in the otorhinolaryngological field such as otitis media, external otitis, paranasal sinusitis, tonsillitis and pharyngolaryngitis. Its efficacy rate was 79.9%. Minor side effects were seen in three cases (1.5%), gastro-intestinal disorders in two and headache in one. The antibacterial activity of ofloxacin was compared with the activity of pipemidic acid, nalidixic acid and norfloxacin against clinically isolated microorganisms. Ofloxacin was highly superior to pipemidic acid and nalidixic acid, and slightly more active than or equivalent to norfloxacin.

Anti-Infective Agents↗
PubMedDate not supplied

Long-term prophylaxis of infection by selective decontamination in leukopenia and in mechanical ventilation.

The autochthonous anaerobic bacterial flora in the mucosal layer of the gastrointestinal tract limits colonization by aerobic potential pathogens. This effect is called colonization resistance. Colonization of the digestive tract by potentially pathogenic microorganisms precedes infection in patients with leukopenia and in cases of mechanical ventilation and can be prevented by long-term administration of antimicrobial agents that spare the autochthonous anaerobic bacterial flora of the mucous membranes, a concept known as selective decontamination. Antimicrobial agents active against anaerobic flora reduce colonization resistance, permitting colonization by and overgrowth of potentially pathogenic microorganisms and possibly leading to infections with resistant microorganisms. A distinction can be made between antimicrobial agents that reduce colonization resistance and those that leave it intact by examining the effect of antimicrobial agents on aerobic intestinal flora of mice and humans.

Animals↗
PubMed2003

A genomic view of the human-Bacteroides thetaiotaomicron symbiosis.

The human gut is colonized with a vast community of indigenous microorganisms that help shape our biology. Here, we present the complete genome sequence of the Gram-negative anaerobe Bacteroides thetaiotaomicron, a dominant member of our normal distal intestinal microbiota. Its 4779-member proteome includes an elaborate apparatus for acquiring and hydrolyzing otherwise indigestible dietary polysaccharides and an associated environment-sensing system consisting of a large repertoire of extracytoplasmic function sigma factors and one- and two-component signal transduction systems. These and other expanded paralogous groups shed light on the molecular mechanisms underlying symbiotic host-bacterial relationships in our intestine.

Adult↗
PubMed2001

Changes in protein synthesis and morphology during acid adaptation of Propionibacterium freudenreichii.

Survival of bacteria in changing environments depends on their ability to adapt to abiotic stresses. Microorganisms used in food technology face acid stress during fermentation processes. Similarly, probiotic bacteria have to survive acid stress imposed within the stomach in order to reach the intestine and play a beneficial role. Propionibacteria are used both as cheese starters and as probiotics in human alimentation. Adaptation to low pH thus constitutes a limit to their efficacy. Acid stress adaptation in the probiotic SI41 strain of Propionibacterium freudenreichii was therefore investigated. The acid tolerance response (ATR) was evidenced in a chemically defined medium. Transient exposure to pH 5 afforded protection toward acid challenge at pH 2. Protein neosynthesis was shown to be required for optimal ATR, since chloramphenicol reduced the acquired acid tolerance. Important changes in genetic expression were observed with two-dimensional electrophoresis during adaptation. Among the up-regulated polypeptides, a biotin carboxyl carrier protein and enzymes involved in DNA synthesis and repair were identified during the early stress response, while the universal chaperonins GroEL and GroES corresponded to a later response. The beneficial effect of ATR was evident at both the physiological and morphological levels. This study constitutes a first step toward understanding the very efficient ATR described in P. freudenreichii.

Adaptation, Physiological↗
PubMed1980

Different actions of neomychin and metronidazole on breath hydrogen (H2) exhalation.

Purpose of this investigation was to characterize the effect of antibiotics as a possible limiting factor for the evaluation of hydrogen (H2) breath analysis tests which depend on bacterial carbohydrate fermentation. Breath H2-excretion following ingestion of the non-absorbable disaccharide lactulose was monitored in healthy subjects before and after pretreatment with the aminoglycoside neomycin or with metronidazole. Metronidazole decreased the amount of hydrogen exhaled by 39 % (p<0.05) and peak H2-excretion by 42.1 % (p<0.01), because it suppresses anaerobe H2 producing microorganisms. Neomycin intensified nonsignificantly the integrated (0-6 hours) breath hydrogen response to lactulose (+43 %) and the maximal H2-concentration by 29.8 %, probably because it interferes with intestinal bacteria which are important for H2-consumption.

Adult↗
PubMedDate not supplied

[Use of lactusan for the correction of microecological intestinal disturbances in children].

The study demonstrated that lactusan (lactulose) could be used as an effective remedy in dysbacteriosis. Twenty four sick children aged 1 month to 15 years were examined. Administration of lactusan to 21 patients resulted in perceptible improvement of clinical symptoms, mainly to the cessation of diarrhea. In 14 children an increase in the population level of bifidobacteria and lactic acid bacteria and a decrease in the number of opportunistic microorganisms were observed. Lactulose should be referred to prebiotics.

Adolescent↗
PubMed1998

Interactions between epithelial cells and immune cells in the intestine.

Not merely a passive barrier as previously assumed, epithelial cells act as sensitive indicators of infection that initiate defense responses. Noninvasive as well as invasive organisms have been demonstrated to elicit production of chemoattractants. That noninvasive organisms have this capacity suggests that receptor-mediated signaling pathways may be involved. Epithelial cells have been found to release both chemokines and cytokines in a precise mixture that varies according to the origin or maturity of the cell. Different microorganisms also elicit different response patterns. The information presented provides a basis for a new view of epithelial cell function in relation to host defense.

Animals↗
PubMed1984

Pharmacokinetics of sultamicillin in mice, rats, and dogs.

The irreversible beta-lactamase inhibitor sulbactam has been combined chemically via ester linkages with ampicillin to form sultamicillin . Upon oral absorption, sultamicillin is completely hydrolyzed to equimolar proportions of sulbactam and ampicillin, thereby acting as an efficient mutual prodrug. In rats, sultamicillin delivered 2 to 2.5 times greater total bioavailability for ampicillin and sulbactam than when each was used individually. Actual plasma or serum concentrations (measured in micrograms per milliliter) of ampicillin and sulbactam produced by sultamicillin were generally equivalent in rats, mice, and beagle dogs. Further studies also indicated that the components of sultamicillin were widely distributed in the various tissues of rats. These findings suggest that sultamicillin might be an effective agent against a variety of infections produced by both beta-lactamase-resistant and beta-lactamase-susceptible microorganisms.

Administration, Oral↗
PubMedDate not supplied

[Yeasts contaminating salmon roe].

Quantitative and species compositions of yeast contaminating eggs, fry and fingerlings of Salmo gairdneri Rich under artificial breeding have been studied. Prevalence of species of genera Candida, Rhodotorula, Cryptococcus and Debaryomyces is noted. Yeast isolated from perished eggs and sick fry do not possess pathogenic properties. Certain strains of yeast make stimulating effect on the studied microorganisms.

Animals↗
PubMed1994

Can microorganisms produce alcohol in body cavities of a living person?: a case report.

Unusual endogenous ethanol production in intraabdominal bloody fluid of an individual who was stabbed in the abdomen and who developed peritonitis after a peritoneotomy is discussed. In the intraabdominal bloody fluid, 2.45 mg/g ethanol and 0.079 mg/g n-propanol were detected. The level of ethanol in the heart blood was about 1 mg/g. The level of n-propanol indicates that a large quantity of ethanol was produced endogenously in the intraabdominal bloody fluid. In an animal experiment in which rats were injected with 20 mL of 10% glucose mixed 5:1 with a presumed volume of rat blood into the abdominal cavity after injury of the small intestine to allow enterobacteria to spread into the cavity, a significant quantity of ethanol was produced in the administered fluid while the animals were alive. The antemortem ethanol production in the intraabdominal bloody fluid of the victim might have been caused by the microorganisms responsible for the peritonitis after the operation.

Abdominal Injuries↗