Biomedical subjects
K W Cochran
Publications and source records attributed to K W Cochran.
Acceleration of scrapie in mice by target-organ treatment with interferon inducers.
Interferon inducers were used in the target-organ treatment of scrapie in mice. Intracerebral treatments began 24 hr prior to intracerebral inoculation of 10(4.8) LD50 of the Chandler strain of scrapie agent. The treatments included 30 and 0.3 microgram poly(I:C) given weekly 9 times, 45 microgram statolon given biweekly 7 times, or 1.5 HA units of Sendai virus given biweekly 6 times. All treatments except the lower dose of poly(I:C) accelerated death in scrapie-affected mice. Compared to saline-treated control groups, 30 microgram poly(I:C), given weekly, shortened the mean survival time 13.5 days. Groups treated with statolon or Sendai virus had their mean survival times shortened 18.5 and 21.7 days, respectively. Infected mice were also evaluated for signs of disease at approximately weekly intervals using a numerical scoring method. Acceleration was also apparent using this parameter of disease. When treatment occurred only once, Sendai virus was the only inducer to significantly shorten the survival of mice.
Effect of diethylpyrocarbonate on the antiviral and interferon-inducing activities of viral and nonviral agents.
Diethylpyrocarbonate (DEPC) treatment of interferon (IF) inducers was studied both in vitro and in vivo. DEPC did not affect the antiviral activity of poly(I.C), statolon, or reovirus in cultured chicken embryo fibroblast cells, but the activities of poly(I.C), statolon, and MU9 replicative form in cultured mouse embryo cells were markedly reduced by the treatment. Target-organ treatment of Swiss Webster mice with DEPC-treated poly(I.C) produced higher levels of serum IF than did the same procedure with untreated poly(I.C), but the animals were not protected against vaccinial encephalitis. In contrast, DEPC-treated statolon protected the animals, although the peak serum IF level was significantly lower than in those treated with intact statolon. Nevertheless, the antiviral activity of statolon was also found to be mediated by IF, since no activity was seen in Vero cells. DEPC-treated single-stranded ribonucleic acid viruses failed to stimulate IF production, indicating that some viral factor(s) susceptible to DEPC is required for the stimulation observed with untreated viruses.
Airborne coliphages from wastewater treatment facilities.
The emission (from wastewater treatment plants) of airborne coliphages that form plaques on two strains of Escherichia coli was investigated. Two activated-sludge and two trickling-filter plants were studied. Field sampling procedures used large-volume air samplers with recirculation devices. Coliphages were enumerated by a most-probable-number (MPN) procedure. Temperature, relative humidity, windspeed, and presence of sunlight were monitored. Concurrent samples of sewage were taken during each air-sampling run. Average coliphage levels in the airborne emissions of trickling-filter beds and activated-sludge units were 2.84 X 10(-1) and 3.02 X 10(-1) MPN/m3, respectively, for all positive observations, and sewage liquor concentrations from the sources were 4.48 X 10(5) and 2.94 X 10(6) plaque-forming units/liter, respectively, depending upon the E. coli host used for assay. This work establishes minimal airborne-coliphage concentrations from the plants studied. The procedures employed will be useful in evaluating the animal virus levels in these emissions.
Target-organ treatment of neurotropic virus disease with interferon inducers.
Interferon inducers were used against vaccinial encephalitis to study the target-organ treatment of neurotropic disease and to correlate interferon levels and the antiviral state following such treatment. A 45-mug amount of statolon, 30 mug of polyribinosinic-polyribocytidylic acid complex (poly I.poly C), or 0.0154 HA unit of Sendai virus given intracerebrally protected 100% of mice challenged the next day with 1,000 median lethal doses (LD(50)) of vaccinia virus. Significant protection against 1,000 LD(50) of vaccinia virus persisted for 1, 4, or 3 weeks after poly I.poly C, statolon, or Sendai virus (154 HA units), respectively. These doses of poly I.poly C and statolon were also used to study postinfection treatment. Mice challenged with 1, 10, 100, or 1,000 LD(50) were treated intracerebrally with poly I.poly C or statolon 24 or 48 hr later. Significant increases in survival time were seen in mice challenged with 1 to 100 LD(50) of vaccinia virus and treated 24 hr later. At challenges of 10 or 100 LD(50), statolon was more effective than poly I.poly C in increasing survival times. When treatment was delayed until 48 hr after infection, significant increases in survival time occurred only when the challenges were in the range of 1 to 10 LD(50), with poly I.poly C and statolon being equally effective. Interferon was measured by Finter's dye-uptake method, with L-929 cells and Semliki Forest virus. Poly I.poly C, statolon, or Sendai virus, given intracerebrally to mice, produced serum interferon peaks of 5,120 units/ml at 2 hr, 2,560 units/ml at 12 hr, or 320 units/ml at 18 hr, respectively. Corresponding brain interferon peaks were 640 units/g at 2 hr, 640 units/g at 4 to 24 hr, and 960 units/g at 72 hr.
Symposium on pertussis immunization, in honor of Dr. Pearl L. Kendrick in her eightieth year: introduction.
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Effects of reovirus type 1 on the developing mouse embryo.
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Studies on the antiviral activity of amantadine hydrochloride.
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Effect of caffeic acid on mouse and ferret lung infected with influenza A virus.
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Clitocybe clavipes: antabuse-like reaction to alcohol.
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