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Biomedical subjects

A E Castro

Publications and source records attributed to A E Castro.

At least 55 records · Page 3Linked to original sources

Detection and control of rotavirus infections in zoo animals.

Fecal specimens from 15 exotic animal species, with and without diarrhea, were examined for the presence of rotavirus, bacterial enteropathogens, and intestinal parasites. A commercial enzyme-linked immunosorbent assay was used to detect antigens of rotavirus. Rotavirus was detected in the feces of 20 (57%) of 35 of the animals, which included addax (Addax nasomaculatus), nyala (Tragelaphus angasi), saiga (Saiga tatarica), white-tailed gnu (Connochaetus gnou), greater kudu (Tragelaphus strepsiceros), sitatunga (Tragelaphus spekei), Grant's gazelle (Gazella granti roosevelti), sable antelope (Hippotragus niger niger), kob (Kobus kob leucotis), pygmy marmoset (Callithrix pygmaea), bush dog (Speothos venaticus), grizzly bear (Ursus arctos horribilis), and red kangaroo (Megaleia rufa). Bacterial pathogens were found in 8 animals, 5 of which had concurrent rotavirus infections. Most (60%) of the animals with rotavirus infection were less than 2 weeks old; however, rotavirus also was detected in feces from adult animals. Although most of the cases of rotavirus infection were detected in nursery-reared animals, exhibit-reared animals also were infected with rotavirus.

Animals↗

Electron microscopic study of the African strain of malignant catarrhal fever virus in bovine cell cultures.

Malignant catarrhal fever (African strain) is a viral disease of ruminants which is considered an exotic disease in the United States. Viral isolates obtained from one clinically ill gaur (Bos gaurus) and a greater kudu (Tragelaphus strepsiceros) located in a zoologic park in Oklahoma, and from one heifer (Bos taurus) and a domestic white-tailed deer (Odocoileus virginianus) experimentally inoculated with the isolated and identified African strain of malignant catarrhal fever virus (MCFV), were each studied in bovine cell cultures by electron microscopy. Certain of the viral isolated were previously characterized as MCFV by serologic and morphologic examinations, their cytopathic effect in cell cultures, and their ability to reproduce disease in a ruminant host. The virions of MCFV (African) examined by electron microscopy were icosahedral similar to herpes-virus, were between 98 and 194 nm, developed in the nucleus and matured in the cytoplasm of the cell, and exhibited budding. The virus in infected cells passed through the nuclear and plasma membranes and also into cytoplasmic vesicles from which it acquired one or more envelopes. Virions of malignant catarrhal fever were closely associated with the cellular endoplasmic reticulum, and aberrant morphologic forms of MCFV were observed in virus-infected cells.

Animals↗

Malignant catarrhal fever in an Indian gaur and greater kudu: experimental transmission, isolation, and identification of a herpesvirus.

Herpesviruses were isolated in bovine cell cultures from buffy coat cells obtained from an Indian gaur (Bos gaurus) and a greater kudu (Tragelaphus strepsiceros) with clinical signs of the head and eye form of malignant catarrhal fever (MCF). Both animals were from herds housed in a zoologic park in Oklahoma. Serial transmission of the head and eye form of MCF was accomplished by using whole blood from the gaur into a Hereford-Angus heifer, then whole blood from the heifer into a Holstein calf, and finally, whole blood from the calf into a white-tailed deer (Odocoileus virginianus). A herpesvirus was isolated in bovine cell cultures inoculated with buffy coat cells from the heifer, and 2 deer inoculated with this herpesvirus developed the head and eye form of MCF. A deer inoculated with whole blood from the greater kudu also developed clinical signs of MCF, and a herpesvirus was subsequently recovered from the deer. Clinical signs of MCF included a mucopurulent catarrh, pyrexia (38.8 to 42.1 C), anorexia, and corneal opacity, and death occurred between postinoculation days 15 and 21.

Animals↗

Experimental malignant catarrhal fever (African form) in white-tailed deer.

White-tailed deer (Odocoileus virginianus) were experimentally infected with the African form of malignant catarrhal fever (AMCF) virus by inoculation of whole blood from experimentally infected cattle, from whole blood obtained from a greater kudu (Tragelaphus strepsiceros) and from virus isolated in cell culture. The incubation period from AMCF in experimentally infected deer ranged from 13 to 18 days. Clinical disease was characterized by lacrimation, an elevated body temperature, conjunctivitis and swelling of the external lymph nodes. Histologic lesions were primarily characterized by widespread vasculitis and lymphadenopathy. The organs most severely affected were liver, lymphoid tissue, brain and lungs. Successful recovery and identification of AMCF virus was accomplished from one experimentally infected deer.

Animals↗

Detection of bovine leukemia virus in B-lymphocytes by the syncytia induction assay.

Bovine peripheral blood lymphocytes (PBL's) from 3 cows and 1 steer infected with bovine leukemia virus (BLV) were separated by fractionation through nylon wool columns into nylon-adherent and nonadherent cell populations. Nylon-adherent cells were enriched in B-lymphocytes, as determined by the presence of surface membrane immunoglobulins (slg), whereas nylon-nonadherent cells or "non-B-lymphocytes" contained few slg-bearing cells. PBL's and separated B- and non-B-lymphocyte populations were assayed for the presence of BLV by the induction of syncytia in bovine embryonic spleen cells. PBL's and B-lymphocyte populations both produced many syncytia, whereas non-B-lymphocytes yielded few or no syncytia. The specificity of syncytia formation by anti-BLV serum. PBL's from 2 control animals were negative for syncytia induction. This study presents further evidence that B-lymphocytes are the target cells for BLV infection.

Animals↗

Lymphocyte antibody interaction in cytotoxicity against human transitional cell carcinoma.

The interaction of antibodies and lymphocytes in their immune reaction against human transitional cell carcinomas was studied using the in vitro microcytotoxicity assay. A non-complement dependent, IgG antibody was detected in the serum of occasional transitional cell carcinoma patients, which induced cytotoxicity against transitional cell carcinoma target cells by lymphocytes from donors with and without transitional cell carcinoma. The observation that lymphocytes from transitional cell carcinoma donors were more sensitive to activation by this anti-transitional cell carcinoma, lymphocyte dependent antibody is compatible with the hypothesis that the surface of lymphocytes from some transitional cell carcinoma donors is coated in vivo with an anti-transitional cell carcinoma lymphocyte dependent antibody and that this antibody may be a significant factor in immunity to transitional cell carcinomas of the urinary tract.

Adenocarcinoma↗

Isolation of RNA virus from papillary tumors of the human renal pelvis.

Virus particles were detected by electron microscopy in three papillary cancers of the human renal pelvis. Similar particles were seen in cells from all three tumors in primary culture. An RNA virus was isolated from these tumors. The serum of tumor patients contains neutralizing antibodies against virus isolated from two of the tumors. Initial studies suggest that this agent is not a known human RNA virus.

Adult↗