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Biomedical subjects

G H Warren

Publications and source records attributed to G H Warren.

At least 37 records · Page 2Linked to original sources
PubMed1982

Esophageal ulceration and bleeding after flexible fiberoptic esophageal vein sclerosis.

Three patients with portal hypertension and variceal hemorrhage were treated with flexible fiberoptic esophageal vein sclerosis by injection of sodium morrhuate. Each of these patients bled after sclerotherapy, and deep esophageal ulcers were found at the previous injection sites. Postsclerotherapy pathologic features are presented in 2 patients. It is suggested that the sclerotherapy caused esophageal ulceration and bleeding. Careful evaluation of the sclerosing technique and its histopathologic consequences is needed.

Adult↗
PubMed1980

Effect of cyclacillin and ampicillin on the gut flora of mice.

The oral administration of cyclacillin, a semisynthetic aminoalicyclic penicillin, results in the elimination of the lactobacilli from the gastrointestinal tract of mice. Although cyclacillin has a broad spectrum of activity similar to that of ampicillin, it does not, like ampicillin, affect the other flora of the gastrointestinal tract. Cyclacillin, unlike ampicillin, is rapidly absorbed from the stomach and upper small intestine, so that only small amounts reach the large bowel. Study of the dynamics of the lactobacillus population in the gut shows that in the mouse the prime site of localization and multiplication of lactobacilli is the stomach. The lactobacilli are transient in the small and large intestine, arriving there only after having been shed from the stomach.

Ampicillin↗
PubMed1979

Stimulation by a hydroxythiazolobenzimidazole of enhanced formation of antibodies to sheep erythrocytes in vitro and in vivo.

A hydroxythiazolobenzimidazole, a low molecular weight compound, was found to have an immunoenhancing effect on both the in vivo and in vitro antibody response of mouse spleen cells to an optimum immunizing dose of sheep red blood cells. At noncytotoxic concentrations the optimum range of 25 to 50 micrograms per 5 x 19(6) spleen cells was most effective in vitro. Concentrations greater than 100 micrograms per culture were toxic in vitro and reduced cell viability as well as antibody responsiveness. The compound enhanced to an even greater degree the antibody response of spleen cell cultures immunized with suboptimum doses of SRBC. The background PFC response, in the absence of SRBC, also was stimulated by the benzimidazole. These immunoenhancing responses were not related to mitogenic effects, since increased thymidine uptake did not occur when normal mouse spleen cells were incubated with graded doses of the compound. Therefore, the immunostimulatory properties of the compound, both in vivo and in vitro, were not due to mitogenic stimulation of lymphoid cells.

Animals↗
PubMed1979

Effect of disruption of the sebaceous layer of the sheep's skin on the incidence of fleece-rot.

It was postulated that integrity of the sebaceous layer on the skin is important in maintaining resistance to fleece-rot. This hypothesis was tested in an experimenta of a 2 x 2 factorial design in which sebaceous layer disruption and wetting were the 2 treatments. The sebaceous layer was disrupted by applying a light petroleum solvent to the skin of the sheep. Fleece-rot occurred in all sheep (20) that were both wetted and had the sebaceous layer disrupted while 9/19 of those wetted but without the sebaceous layer disrupted developed fleece-rot. The fleece-rot lesions observed were more severe in sheep in the disrupted wetted treatments than in the intact wetted treatment. Interpretation of these differences was complicated by a possible reaction of the skin to the solvent used. The differences were not due to an effect of treatment on fleece wettability. No fleece-rot developed in the sheep not wetted and application of the solvent alone did not induce fleece-rot.

Animals↗
PubMed1977

Cyclacillin-induced potentiation of Escherichia coli immunogenicity in vivo and in vitro.

The efficacy of cyclacillin as an antimicrobial agent against Escherichia coli was assessed in vivo in mice infected with low numbers of bacteria and compared to the relative effectiveness of the antibiotic against the same organisms in vitro. Treatment of mice with cyclacillin resulted in a rapid clearance of E. coli from the blood and their greater killing in the spleen and liver. Furthermore, a significantly higher antibody plaque response against E. coli developed in cyclacillin-treated mice than in untreated mice or in those given ampicillin. The increased immunogenicity of the E. coli in the antibiotic-treated mice appeared to be due to high levels of cyclacillin in the animals and rapid killing of the bacteria in vivo. In vitro experiments showed that injection of normal mouse peritoneal exudate macrophages which had been incubated with E. coli together with cyclacillin resulted in a greater immunogenicity of the bacteria than when the injection mixture was composed of E. coli which had been incubated alone or only with macrophages. These results suggest that the in vivo effectiveness of an antibiotic such as cyclacillin against a gram-negative organism such as E. coli may be due in part to an effect on the immunogenicity of the bacteria.

Ampicillin↗
PubMed1976

Cyclacillin: microbiological and pharmacological properties and use in chemotherapy of infection - a critical appraisal.

The pharmacological and microbiological properties of cyclacillin were discussed and its usefulness in the management of a variety of infections was reviewed. The antibacterial spectrum and clinical utility of this agent generally parallels that of ampicillin, but there are minor differences in specificity with regard to individual microorganisms. The in vitro activity of cyclacillin against gram-negative pathogens varies greatly, the results fluctuating in accordance with the composition of the assay medium of method. The drug has demonstrated excellent therapeutic effectiveness against experimental infections produced by both gram-positive and gram-negative pathogens, thus making questionable a prediction of therapeutic effectiveness from in vitro susceptibility tests alone. Cyclacillin is more resistant to beta-lactamase hydrolysis than ampicillin, is much better absorbed when given by mouth and, as a result, the levels reached in the blood and in the urine are considerably higher than those obtained with the same dose of ampicillin. Cyclacillin produces fewer and milder side-effects than ampicillin.

Ampicillin↗
PubMed1976

Amide Penicillin Wy-12,556: therapeutic activity in animals subjected to repeated bacterial infection.

Amide penicillin Wy-12,556 and DBED penicillin were studied for their antibacterial effect in CD-1 mice repeatedly infected with Streptococcus pyogenes C203 and/or Staphylococcus aureus Smith. Animals infected with S. aureus Smith failed to show a difference between the therapeutic activity of DBED penicillin and Wy-12,556. Wy-12,556 was significantly more effective than DBED penicillin in protecting the animals challenged repeatedly with S. pyogenes C203. Wy-12,556 provoked a positive transient chemotactic response in uninfected mice. 24 h after intraperitoneal challenge the exudate showed a high neutrophilic count.

Animals↗
PubMed1976

Nafcillin and oxacillin: comparative antistaphylococcal activity in mice.

The therapeutic properties of nafcillin, oxacillin and erythromycin were determined in mice infected with a strain (Evans) of Staphylococcus aureus shown to be tolerant to the bactericidal action of penicillinase-resistant derivatives of penicillin. The therapeutic activity of these agents was also correlated with the extent of colonization of kidneys by resistant clones of S. aureus Evans. The CD50 values or potency ratios proved that nafcillin was highly active against this organism, whereas oxacillin and erythromycin were capable of protecting the animals to a lesser degree. Of the agents studied, only nafcillin was capable of preventing or interfering with the colonization of the kidneys by S. aureus Evans. Although the exact interpretation and application of these data in the management of clinical problems remains to be determined, the observations suggest important differences between nafcillin and oxacillin in vivo and that it is difficult to predict the antibacterial efficacy of these drugs solely from MIC and MBC data.

Animals↗
PubMed1974

Cultivation and survival studies of Neisseria gonorrhoeae in a human diploid cell strain.

Neisseria gonorrhoeae was cultivated in a human diploid cell strain (WI-38). Eighty percent of the cultures contained viable gonococci for at least 4 m at 36°C, as evidenced by subculture to brain heart infusion broth. Monthly subcultures of bacteria could be made to fresh WI-38 cultures for at least 11 monthly passages with a 69% survival rate. The identity of gonococci was confirmed by morphology, gram staining, oxidase testing and fermentation reactions. Viability in brain heart infusion broth, minimum essential medium (Eagle), and WI-38 spent fluid was of much shorter duration. The organisms grown in WI-38 cultures appeared to orient largely in the vicinity of the WI-38 cells as well as within the cytoplasm of the cells.

Animals↗