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K R DUMBELL

Publications and source records attributed to K R DUMBELL.

17 recordsLinked to original sources
PubMed1962

The chemotherapy of variola major infection.

In view of earlier work which suggested that certain derivatives of isatin beta-thiosemicarbazone might be of possible clinical use in smallpox infections, several such derivatives have been tested for antiviral effect in infant mice inoculated intracerebrally with up to 10(3) LD(50) (up to 10(6.5) pock-forming units) of the Harvey strain of variola major virus.Survival of 100% was obtained in mice treated twice daily with N-methylisatin beta-thiosemicarbazone in a dose level of 10 mg/kg, isatin beta-thiosemicarbazone in a dose level of 25 mg/kg and 7-methylisation beta-thiosemicarbazone at 10 mg/kg, the treatment beginning immediately after infection. No evidence of toxicity was observed at these dose levels. At lower dose levels of these and other related compounds complete protection was not obtained, but a chemotherapeutic effect was demonstrated by a prolongation of the mean survival time. Mice which had survived variola infection after treatment with an adequate dose of chemotherapeutic agent were immune when challenged with 10(5) pock-forming units of rabbitpox virus.

Animals↗
PubMed1961

The laboratory differentiation between variola major and variola minor.

Three methods have been used to differentiate between the viruses of variola major and variola minor in the laboratory. In this paper these three methods are compared directly, using the international reference strains of the two viruses. Results emphasize the great importance of temperature in determining the growth and spread of these viruses in the chick embryo. On the basis of the results described and of previous experience a simple diagnostic test, applicable to infective material obtained directly from the patient, is recommended. This test will enable a differential diagnosis to be made within two days of the receipt of suitable specimens. It is based on the fact that variola major virus will produce pocks on the chick chorio-allantois in eggs incubated at 38.25 degrees C, whereas variola minor will fail so to do.

Animals↗
PubMed1958

An infectious cutaneous fibroma of the Virginia whitetailed deer (Odocoileus virginianus).

A naturally occurring cutaneous fibroma of deer has proven to be experimentally transmissible in deer. The causative agent is a virus that is readily alterable through Berkefeld N candles and that survives in fibroma tissue for at least as long as 27 months in glycerol-saline at -20 degrees C. The experimentally produced deer fibroma has an incubation period of about 7 weeks, a very slow rate of growth, and a high regression rate.

Animals↗
PubMed1957

Laboratory and vaccination studies with dried smallpox vaccines.

In a vaccination and laboratory study, two dried smallpox vaccines (designated P and Q) were tested at intervals of 4, 8, 16, and 32 weeks after storage at both 37 degrees C and 45 degrees C. Vaccine P was also tested after 64 weeks at these temperatures and gave 100% successful vaccination rates after all periods of storage at both temperatures. Vaccine Q deteriorated within four weeks, rapidly at 45 degrees C and less rapidly, but very substantially, at 37 degrees C. There was no clear evidence of the cause of this deterioration, but there was a suggestion of denaturation of some of the samples stored at the higher temperature. So far as could be ascertained, the laboratory results-rabbit skin scarification tests and chorio-allantoic membrane pock counts-ran parallel with the vaccination success rates. The pock count was found to be the more accurate method of laboratory titration. Vaccine P as used in the trial was not an exceptional batch.Vaccines which give a pock count of 10(8) infective units per ml will give the highest possible rate of successful primary vaccinations.A statistical note on the trials is given in an annex.

Animals↗
PubMed1956

Pox viruses.

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Humans↗