ISSN:
1573-0832
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Granuloma formation in nude (nu/nu) mice and their heterozygous littermates (nu/+ mice) against Histoplasma capsulatum var. capsulatum infection was studied. A culture of H. capsulatum var. capsulatum, isolated from a granuloma in the nasal cavity of a Japanese patient, was used in this experiment. Sixteen specific-pathogen-free male nu/nu and 32 nu/+ mice were used in this study. The nu/+ mice were divided into two groups. Sixteen nu/+ mice in one group and 16 nu/nu mice were inoculated intraperitoneally with 106 yeast cells of the fungus, those in the other group of nu/+ mice were inoculated intravenously with the same number of the yeast cells. Two mice out of each group were sacrificed 2, 3, 7, 11, 14, 18, 25 and 30 days after inoculation, and each of their organs was examined histopathologically. In addition, pieces of these tissues were cultured on Sabouraud's dextrose agar slants. In the nu/+ mice inoculated intraperitoneally, although the fungus was recovered from the spleen, kidney and lymph nodes during the initial course of the infection, lesions were not detected in their histopathological sections. In the nu/+ mice inoculated intravenously, colonies were recovered from all of the organs examined, other than the brain and thymus, 7 days after inoculation. Histopathologically, a few microfoci consisting chiefly of mononuclear cells with or without yeast cells were found in the liver sections 4 days after inoculation. Seven and 11 days after inoculation the number of lesions had increased. They had large accumulations of mononuclear cells. From day 14 on, almost all of the yeast cells had lost most of their staining affinity or were destroyed in the granuloma. From day 25 on, the granulomatous lesions changed gradually to fibrous tissue. In the nu/nu mice the fungus was readily recovered from the spleen, liver, kidney and lymph nodes. Histopathologically, a few microfoci consisting of mononuclear cells were present in the liver sections 4 days after inoculation. That is to say, during the initial course of infection granulomas were formed. In the liver, from day 7 on, the lesions were large and their number increased. However, there was a definite difference between the nu/nu and nu/+ mice. In the former, the yeast cells were not killed, and they continued to multiply within the granulomas. These granulomas were never transformed into fibrous tissue.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00482808
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