Infectious mononucleosis-like illness in an infant with measles.
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Biomedical subjects
Publications and source records attributed to I H Chu.
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Replication-competent molecular clones of feline immunodeficiency virus (FIV) were isolated directly from the DNA of bone marrow cells of a naturally FIV-infected cat. After transfection in a feline kidney cell line (CrFK) and subsequent cocultivation with peripheral blood mononuclear cells (PBMC), the viral progeny of the clones was infectious for PBMC but not for CrFK cells. PBMC infected with these clones showed syncytium formation, a decrease in cell viability, and gradual loss of CD4+ cells. The restriction maps of these clones differed from those obtained for previously described molecular clones of FIV derived from cats in the United States. The predicted amino acid sequence similarity of the envelope genes of the two clones was 99.3%, whereas the similarities of the sequences of the clones to those of two molecular clones from the United States, Petaluma and PPR, were 86 and 88%, respectively. Most of the differences between the amino acid sequences of the two clones and those of the clones from the United States were found in five different hypervariable (HV) regions, HV-1 through HV-5. The viral progeny of one of these clones was inoculated into two specific-pathogen-free cats. The animals seroconverted, and the virus could be reisolated from their PBMC.
To assess the value of feline immunodeficiency virus (FIV) infection as a model for human immunodeficiency virus (HIV) infection in man, we studied the impairment of certain immunological functions following natural or experimental FIV infection. Proliferative responses of peripheral blood mononuclear cells (PBMC) from symptomatic and asymptomatic cats after naturally or experimentally acquired FIV infection, induced by activation with the mitogens concanavalin A, pokeweed mitogen, or lipopolysaccharide or by stimulation with human interleukin-2 (IL-2), were significantly lower than the proliferative responses found with PBMC from noninfected control cats. Also IL-2 production levels of mitogen-activated PBMC from naturally infected symptomatic cats were significantly reduced. These data confirm that the pathogenesis of FIV infection in the cat, like HIV infection in man, is characterized by a serious malfunction of the immune system.
The paper reviews the present situation of brucellosis in Uganda and indicates that the infection is much more widespread than was hitherto considered. Positive agglutinin reactors among the unselected hospital patients in the zone of endemicity occupy 18-24%. The serology against bovine brucellosis in the newly established dairy farms and ranches shows 18.1% positive.
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The rabbit eye irritation test based on the Draize method is required for the hazard assessment of chemicals and products that may come into contact with the eye. Due to the potential for the suffering of animals and subjectivity of the test, many modifications of the method have been made that involved a reduction in the number of animals and a refinement of techniques. Additionally, there has been significant development of in vitro alternatives. This paper reviews recent advances in the in vivo test and in vitro alternatives, as well as regulatory requirements. While the refinement of in vivo protocols has resulted in a reduction in the number and discomfort on animals, the development of in vitro alternatives could lead to an eventual replacement of animal studies. In view of the inherent simplicity of many in vitro methods, some of which comprise cell cultures, further research into the relevance/mechanism of effects is required. Batteries of in vitro tests, when properly validated, may be considered as replacements for animal testing.