ABSTRACT
No abstract available.
Subject(s)
Humans , Endothelial Cells , Hantaan virus , Umbilical VeinsABSTRACT
No abstract available.
ABSTRACT
No abstract available.
Subject(s)
Antibodies , Hepatitis B Surface Antigens , Hepatitis , PrevalenceABSTRACT
In 1933 Shope described an infectious papilloma of wild cattontail rabbits. Shope rabbit papilloma is a virus-induced epidermal neopIasm indigenous to western cottontail rabbits and readily transmissible to domestic rabbits by inocuiation with an cell-free extract of wild cottontail papilloma. Shope papilloma induced in the domestic rabbits may spoataneously, remain benign, or progress to carcinoma. Kidd et al. (1936) noted that the regression is not correlated with the titer of virus neutralizing antibody. The possibility that papilloma regression is brought about by a mechanism anaIogous to that operating in allograft rejection was suggested by kidd et al. (1938) with the view of the histological resemblance between papilloma regression and rejection of allografted tissue. That regression is mediated by an immune mechanism is strongly indicated by the findings of Evans et al.(1962) that the proportion of rabbits showing regression is substantially increased by vaccination of rabbits with their own papilloma tissue or with papilloma tissue from another rabbits. McMichael (1967) demonstrated that suppression of regression was achieved by use of large doses of corticosteroid. The effect of 5-fluorouracil on human warts was mentioned as being effective by Goldman et al. (1963). In Korea resinous extract from Paulownia coreana has long been used empirically in the treatment of human warts. In this investigation effects of dexamethasone administration on the development and the spontaneous regression of Shope papillomas in domestic rabbits were studied. At the same time, observations were made to evaluate the comparative effectiveness of topical application of 5% 5-fluorouracil ointment and resinous extract from Paulownia coreana on Shope papilloma in the domestic rabbit. The results are summarized as follows: l. Administration of dexamethasone significantly reduced the spontaneous regression of Shope papillomas in domestic rabbits by 12 weeks after virus inoculation. 2. Topical application of 5% 5-fluorouracil ointment on Shope papillomas cured the tumors by 4 weeks of drug application. However, similar treament with resinous extract from Paulownia coreana was without any demonstrable effects. 3. Marked losses of body weights became manifest in dexamethasone treated rabbits. 4. Reinoculation of Shope papilloma virus into 2 rabbits whose papillomas had regressed 3 months ago failed to produce papillomas.
Subject(s)
Humans , Rabbits , Allografts , Antibodies, Neutralizing , Body Weight , Cottontail rabbit papillomavirus , Dexamethasone , Fluorouracil , Korea , Papilloma , Tumor Virus Infections , Vaccination , WartsABSTRACT
In relation rto the size of viral inoculum, influenzal infection in ferrets caused by the inoculation of a mouse-adapted subline of PR 8 strain of type A influenza virus was studied. The results are summarized as follows; 1) When ferrets were inoculated with a highly diluted virus (10-7), a small proportion of them experienced inapparent infections and the rest of them escaped the infection. 2) With the increased size of viral inocula, there was a good correlation between the size of infecting does and the frequency of overt infections in ferrets. 3) Nasal tissues were the main locus of viral multiplication in ferrets at 72 hours after viral inoculation. Viral multiplication in nasal tissues was demonstrated only in a small proportion of ferrets which were inocu1ated with a 10-7 dilution of virus; however, when the size of vira1 inoculum was increased above this level, all ferrets had viral growth in their nasal tissues. 4) The involvement of pulmonary tissues, viral growth in those tissues and the development of gross lung lesions were significantly rare. There was no dear-cut relationship between the size of infecting doses and the frequency of such plumonary involvements in ferrets.
Subject(s)
Female , Animals , Carnivora , Influenza, Human/microbiology , OrthomyxoviridaeABSTRACT
Efforts have been made to accomplish a long term in vitro cultivation of mouse peritoneal macrophage as a host cell for growth of Mycobacterium lepraemurium. Following the inoculation with live or heat-killed Myco. lepraemuriuum of cultured macrophages either on a cover-slip in Leighton tube or in a small petri dish, microscopic observations of acid-fast (AF) stained slide preparation, and total counts of AF bacilli that were released by ultrasonic treatment from the macrophages in small petri dish have been followed in order to present microscopic and quantitative evidence of the actual multiplication of Myco. lepraemurium in cultured mouse peritoneal macrophage. The results are summarized and conclusions are as follows; 1. Successful long term in vitro cultivation of mouse peritoneal macrophage has been accomplished. The growth medium for tissue culture consisted of NCTC 109;50% heat-inactivated calf serum; 40% and beef embryo extract (diluted 1 : 5); 10% and the medium was renewed every 3 to 4 days. The incubation temperature was 37 degrees C; before and at 30 degrees C; after the inoculation with Myco. lepramurium. The CO2 content inside the CO2 humidity incubator for the cultivation of macrophage was kept at 5%. 2. In cultures of macrophage inoculated with live Myco. lepraemurium, clear features of increases in the number of AF bacilli inside individual cell, of elongation of bacill and of increased solidity in AF staining were observed. However, these features were absent in cultlires of macrophage inoculated with heat-killed Myco. lepraemurium. 3. The ultrasonic treatment of macrophage inoculated with 1ive Myco. lepraemurium, and the quantitative assessment of total number of AF bacilli through the course of 6 to 8 weeks after inoculation has provided partial but substantial evidence of actual multiplication of Myco. lepraemurium in cultured macrophages.