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Biomedical subjects

E Ayala

Publications and source records attributed to E Ayala.

14 recordsLinked to original sources
PubMed1994

Cytomegalovirus in upper gastrointestinal ulcers.

Cytomegalovirus (CMV), an important cause of severe infections in immunocompromised patients, can cause ulcerations anywhere in the gastrointestinal tract, most commonly stomach and colon. Only a few cases of CMV inclusions in gastrointestinal ulcers have been reported in normal hosts. We undertook a prospective study of the incidence of CMV in gastroduodenal ulcerations in immunocompetent patients. Thirty-eight patients who were referred for evaluation of dyspepsia, hematemesis, melena, guaiac-positive stools, or iron deficiency anemia and who had gastric or duodenal ulcerations without stigmata of recent hemorrhage or visible vessel were enrolled in the study. Six biopsies obtained from the ulcer base and margin were submitted for histologic examination, shell-vial viral cultures, and monoclonal antibody testing. Thirty-two patients had gastric ulcer and six had duodenal bulbar ulcer ranging in size from 8 to 20 mm in diameter. Forty-four percent of patients had been taking aspirin or nonsteroidal antiinflammatory drugs (NSAIDs) within 10 days of ulcer discovery. Evaluation of all biopsies in 38 patients failed to document any evidence of CMV by light microscopy, viral cultures, or monoclonal antibody testing. CMV infection is uncommon in the gastrointestinal tract of immunocompetent patients with gastroduodenal ulcers. Even within areas of previous mucosal injury induced by nonsteroidal drugs, no evidence of CMV "superinfection" was found. We conclude that CMV infection is not a significant factor in routine peptic or NSAID-induced ulcer disease, and the discovery of CMV inclusions in gastroduodenal ulcerations should lead to a search for an immunocompromised state.

Adult↗
PubMed1989

Effect of L-lysine monohydrochloride on cutaneous herpes simplex virus in the guinea pig.

The effect of topical applications of crystalline lysine therapy on cutaneous herpes simplex virus (HSV) inoculations and subsequent dorsal root ganglia (DRG) infection was studied in male Hartley guinea pigs. Although HSV-I was recovered from the inoculated sites from all animals, the L-lysine-treated skin remained clinically normal, whereas untreated controls manifested clinical symptoms up to 3 days postinoculation (p.i.). However, cocultivation of DRG (C1-S1) indicated a selective tropism of infective particles to specific DRG in the groups treated with amino acids. In lysine-treated animals, HSV was recovered from a few DRG (T-12, T-13, and L-1) at 3 days p.i. and from DRG T-10 in leucine-treated controls; yet no HSV was recovered from DRG of untreated controls. These results suggest an immunomodulatory effect of L-lysine on inoculation site infections and the possible potentiation of subsequent DRG manifestation in amino-acid-treated animals.

Administration, Topical↗
PubMed1988

Production of pili on Vibrio parahaemolyticus.

Electron microscopic examination showed that all strains of Vibrio parahaemolyticus examined had pili on their surface when the organism was grown on marine agar at 28 degrees C for 6-12 h. The pili were morphologically stable on heat treatment at 60 degrees C for 10 min, but both the lateral and polar flagella possessed by this organism were labile. No immunological cross-reactivity between pili of enterotoxigenic Escherichia coli and Vibrio cholerae non-01 and those of V. parahaemolyticus was observed.

Agglutination Tests↗
PubMed1986

Effects of exposure to high potassium concentration on the longitudinal muscle-myenteric plexus preparation from guinea-pig.

The effect of potassium on the longitudinal muscle-myenteric plexus (LM-MP) preparation from guinea-pig was studied. The strips were exposed to elevated K+ (30 mM, 60 mM, 90 mM, 120 mM or 150 mM). A phasic contraction of the LM-MP was caused by 10 mM K+ or 15 mM K+ followed by an increase of the contractile activity probably due to the increase in acetylcholine release. A higher molarity of K+ produces more marked depolarization in the LM-MP and above 22 mM K+ tetanizing effects were observed. We attempted to demonstrate that opiate-like material could be released when the tissue was exposed to more than 30 mM K+ even though several different neurotransmitters could be liberated by elevated K+ molarities.

Animals↗
PubMed1986

Active and passive immunization with Pseudomonas aeruginosa ribosomal vaccines and antisera in the burned rat model.

Pseudomonas aeruginosa ribosomal vaccines were tested for their ability to protect rats subjected to a 20% total body surface burn against the lethal effects of infection with homologous organisms. When administered prior to burning, the vaccines provided 100% protection. When administered postburning, the vaccine from one strain also provided 100% protection when the time interval between vaccination and infection was 3 days. When this time interval was reduced to 1 or 2 days, approximately 50% protection was obtained with the same vaccine. The vaccine from a second strain tested provided about 50% protection with a 3-day time interval. In addition, passive immunization using antiserum to a ribosomal vaccine was also demonstrated to be effective in protecting burned and infected rats, especially when multiple doses of antiserum were used. In this case, 80% protection was obtained (with no protection observed using multiple doses of normal serum). Finally, a comparison of ribosomal and lipopolysaccharide vaccines and antisera was also performed.

Animals↗
PubMed1977

Effects of pneumococcal infection on rat liver microsomal enzymes and lipogenesis by isolated hepatocytes.

Modification in the enzymatic complement and lipogenic functions of rat liver endoplasmic reticulum (ER) were shown to occur during pneumococcal sepsis. Glucose-6-phosphatase, 5'nucleotidase, esterase, and NADPH cytochrome C reductase decreased in activity by as much as 50% with respect to controls. Hydroxymethylglutaryl-CoA and NADH cytochrome C reductases were increased 6-and 2-fold, respectively. Alkaline phosphatase and inosine-5'-diphosphatase did not differ with respect to fasted controls. The lipogenic capacity of the ER was shown to be enhanced. In vitro [14C]acetate incorporation into cholesterol and other lipids by hepatocytes isolated from infected rats was increased 2-to 10-fold. It is concluded that the flow of acetyl-CoA in liver cell of Streptococcus pneumoniae-infected rats is toward lipogenesis rather than ketogenesis.

Animals↗
PubMed1975

Phagocytosis of Francisella tularensis by Rhesus monkey peripheral leukocytes.

Phagocytosis of Francisella tularensis by rhesus monkey peripheral neutrophils (PMN, was assessed by autoradiography, electron microscopy, and biochemical techniques. PMN, in contrast to mononuclear phagocytes, were unable to phagocytize F. tularensis in vitro in the absence of immune serum. It is postulated that in the nonimmune host the innate inability of PMN to phagocytize F. tularensis deletes one of the possible mechanisms of host defense to bacterial infection and thus permits the early dissemination of F. tularensis to intracellular sites of specific target tissues.

Animals↗
PubMed1975

Aminoisobutyric acid transport in primary cultures of normal adult rat hepatocytes.

In contrast to suspensions of freshly isolated hepatic parenchymal cells (HPC), short-term monolayer cultures of HPC displayed properties of active transport for the amino acid analog aminoisobutyric acid (AIB). The uptake of AIB was inhibited by KCN and iodoacetate, failed to occur at 4 degrees, and was stimulated by glucagon. The apparent Km for AIB uptake by cultured HPC was approximately 19 mM. Glucagon did not alter the apparent Km but did increase V.

Aminoisobutyric Acids↗