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Biomedical subjects

B Postic

Publications and source records attributed to B Postic.

At least 37 records · Page 2Linked to original sources

Effect of ribavirin on murine cytomegalovirus infection.

Ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide), a new synthetic nucleoside, inhibited murine cytomegalovirus in cell culture. This was shown by the inhibition of viral cytopathic effect and plaque formation, as well as reduction in the yield of virus. Despite this in vitro antiviral effect, ribavirin did not protect mice from mortality produced by a high inoculum of cytomegalovirus. When a lower inoculum was used to initiate a chronic infection, the administration of ribavirin for 9 days had no effect on the titer of cytomegalovirus in the salivary gland, kidney, liver, and spleen. Thus, ribavirin was ineffective in the treatment of both acute and chronic murine cytomegalovirus infections.

Acute Disease

Delayed post-traumatic subdural empyema.

A case of subdural empyema is reported, treated through a frontal bone flap, with exenteration of the infected frontal sinus at operation, and subdural instillation of antibiotics for 48 hours postoperatively. Diagnostic findings are reviewed, and the likelihood of anaerobic infection this case and similar cases discussed.

Adult

Medium containing trypan blue and antibiotics for the detection of Cryptococcus neoformans in clinical samples.

A medium containing trypan blue, gentamicin, and chloramphenicol is introduced for the detection of Cryptococcus neoformans and Cryptococcus species from clinical samples. Ten recently isolated strains of Cryptococcus species as well as several clinical isolates of C. neoformans incorporated trypan blue and produced dark blue colonies on this mycological medium, whereas other common yeasts were light blue. The laboratory diagnosis of two cases of cryptococcosis was accomplished by the isolation of C. neoformans on the antibiotic-dye-containing medium. Compared to conventional media supporting large numbers of Pseudomonas aeruginosa and other gram-negative bacilli, the new medium was selective for yeasts. In one instance, the colonization of the respiratory tract by C. neoformans which led to fungemia was traced by the use of the antibiotic-dye medium. The antibiotic mixture, utilized herein, was more effective in suppressing bacteria contained in samples from patients than a medium containing cycloheximide and chloramphenicol.

Candida albicans

Interferon administered in the cerebrospinal space and its effect on rabies in rabbits.

Because combined administration of intramuscular and intravenous interferon has been partially successful in the incubationary treatment of rabies, the effect of direct interferon administration into the cerebrospinal fluid space was tested. After injecting 1,800 U of interferon into the cisterna magna or the lateral ventricle, periodic samples, obtained by cisternal taps, showed that 1 to 5% remained after 24 h, as opposed to the known clearance of interferon from the bloodstream to this level within minutes. The distributions of interferon and (131)I-labeled albumin were similar as demonstrated by kinetics of clearance monitored over 24 h. Beginning with and after experimental infection of rabbits, daily intraventricular injections of one million units of interferon were given for as long as 3 weeks. Interferon was prepared from cell culture fluids after pressure dialysis and chromatography on Sephadex G-100. This intensive treatment did not prevent encephalitis, but prolonged the length of the incubation period by one- to two-thirds. The outcome after intraventricular administration was not as favorable as when one million units equally divided between intramuscular and intravenous injections were given at the time of challenge. Interferon administered in the subarachnoid space in this fashion is apparently inadequate to protect the rabbit against rabies. Its role as an adjunct measure, or other methods of administration in the nervous system, remains to be examined.

Animals

Introduction of Pseudomonas aeruginosa into a hospital via vegetables.

Pseudomonas aeruginosa was isolated from tomatoes, radishes, celery, carrots, endive, cabbage, cucumbers, onions, and lettuce obtained from the kitchen of a general hospital, with tomatoes yielding both highest frequencies of isolation and highest counts. Presence of P. aeruginosa on the hands of kitchen personnel and cutting boards and knives which they used suggests acquisition of the organism through contact with these vegetables. It is estimated that a patient consuming an average portion of tomato salad might ingest as many as 5 x 10(3) colony-forming units of P. aeruginosa. Pyocine types of P. aeruginosa isolated from clinical specimens were frequently identical to those recovered from vegetables, thus implicating tomatoes and other vegetables as an important source and vehicle by which P. aeruginosa colonizes the intestinal tract of patients.

Bacteriocins

Effect of administered interferon on rabies in rabbits.

This study describes the effect of interferon on the survival of rabbits infected with a street strain of rabies virus. Interferon was prepared by collecting serum from rabbits injected with Newcastle disease virus and was characterized by biological and physicochemical methods. Rabbit serum interferon mixed and incubated with a suspension of rabies virus did not neutralize its infectivity. Rabbits were inoculated into the hind leg muscle with approximately 80 LD(50) of virus. Interferon was administered intravenously or intramuscularly, or by both methods, in the same or opposite leg as virus. Mortality due to rabies was significantly reduced by the concurrent administration of 8 x 10(5) units of interferon divided between the site of virus inoculation and intravenously. There was less protection if 3 hr elapsed between the inoculation of virus and interferon. Treatment given 24 hr after infection did not prevent death but prolonged the incubation period.

Animals

Effect of temperature on the induction of interferons by endotoxin and virus.

Postic, Bosko (University of Pittsburgh, Pittsburgh, Pa.), Catherine DeAngelis, Mary K. Breinig, and Monto Ho. Effect of temperature on the induction of interferons by endotoxin and virus. J. Bacteriol. 91:1277-1281. 1966.-The effect of ambient and body temperature on interferon formation in rabbits injected intravenously with virus differed from that seen after injection of endotoxin. Newcastle disease virus-induced interferon (VII) was elevated by increasing ambient temperature to 35 C, whereas cooling of the rabbit at 4 C resulted in low VII levels. Neither of these conditions affected the titers of endotoxin-induced interferon (EII). However, a significant enhancement of EII levels was found in sera of shorn rabbits, in which the body temperature was lower than in unshorn animals by 1.0 to 1.5 F and the pyrogenic response to endotoxin was less by about 2 F. This enhancement of EII by relatively low body temperatures was also in striking contrast to the reported enhancing effect of high body temperature of the rabbit on the lethal action of endotoxin. It is suggested that the temperature optimum for formation of EII is lower than for formation of VII.

Animals