Evaluation of antimicrobials combined with hyperbaric oxygen in a mouse model of clostridial myonecrosis.

The efficacy of hyperbaric oxygen (HBO) alone and in combination with several antimicrobial agents was evaluated in a lethal model of gas gangrene in mice. Intraperitoneal administration of penicillin, imipenem, clindamycin, or metronidazole immediately followed inoculation of > 10(9) CFU of Clostridium perfringens type A in mice. Mice treated with hyperbaric oxygen were exposed twice a day to 100% oxygen at 303 kilopascals (kPa) pressure for 90 minutes.

Hyperbaric hyperoxia enhances the lethal effects of amphotericin B in Leishmania braziliensis panamensis.

Leishmania braziliensis panamensis promastigotes were exposed in vitro to amphotericin B (AmB), menadione, or phenazine methosulfate under normoxic conditions. Promastigotes were also exposed to hyperoxia alone (100% O2 at total pressures of 101.3 or 253.

Hyperbaric oxygenation decreases blood flows in normal and septic rats.

The purpose of the study reported here was to characterize the effects of acute exposure to 100% oxygen at a pressure of 202.6 kPa on hemodynamics and organ blood flow in antibiotic-controlled bacterial sepsis. An abscess containing known numbers and strains of live Escherichia coli and Bacteroides fragilis was established in the peritoneal cavity of rats.

Hyperoxia prolongs the aminoglycoside-induced postantibiotic effect in Pseudomonas aeruginosa.

The objective of this study was to determine whether hyperoxia enhances aminoglycoside activity against Pseudomonas aeruginosa. The existence of tobramycin-oxygen synergy was determined by using the in vitro postantibiotic effect (PAE). P.

Pathophysiology of sea nettle (Chrysaora quinquecirrha), envenomation in a rat model and the effects of hyperbaric oxygen and verapamil treatment.

The effect of lethal sea nettle envenomation on the morphology and blood flow in various rat organs was characterized and the influence of two antidotes (hyperbaric oxygen and verapamil) was compared. Either antidote slightly prolonged survival, but the protective effects were not statistically significant. The venom caused no histologic alterations in brain, heart, or lungs but induced hepatic and renal necrosis.

Hyperoxia and the antimicrobial susceptibility of Escherichia coli and Pseudomonas aeruginosa.

We have tested the ability of hyperoxia (98% O2-2% CO2 at 2.8 atmospheres absolute [ca. 284.

Splanchnic blood flows in a rat model of antibiotic-controlled intra-abdominal abscess during normoxia and hyperoxia.

We have characterized splanchnic blood flows in a rat model of antibiotic-controlled, intra-abdominal abscess (ACIA) in normoxic and hyperoxic environments. Abscesses (1.5 ml average volume) were established by implanting a fecal-agar pellet containing known numbers and strains of live Escherichia coli and Bacteroides fragilis into the peritoneal cavity of rats via a midline incision.

Fatal Fusarium solani infections in baby sharks.

The occurrence of fatal fusariosis in baby bonnethead sharks (Sphyrna tiburo) born at the National Aquarium, Baltimore, Maryland, is reported. An atypical strain of Fusarium solani was cultured from the tissues of two of the infected sharks following postmortem examination. Histopathology revealed an apparent predilection of the fungus for hyaline cartilage.

Effect of hyperoxia on liver necrosis induced by hepatotoxins.

We have tested the effects of hyperbaric oxygen on necrosis of rat liver induced by the administration of several toxins. The extent of liver necrosis was determined 24 h after the administration of the toxins by measurement of serum levels of alanine and aspartate amino-transferases and by histologic and ultrastructural analyses. Treatment with hyperbaric oxygen decreases carbon tetrachloride (CCl4)-induced necrosis in a manner dependent upon duration and pressure of oxygen exposure.