Biomedical subjects
Publications and source records attributed to H A Gallichio.
The results of single radial immunodiffusion assays of influenza virus hemagglutinin were found to be greatly altered by small antigenic differences between test and reference strains. When such differences were present, the precise specificity of the antiserum used had a critical effect on the measured hemagglutinin antigen content obtained.
Studies were undertaken in adult groups aged 17-24 years, 25-64 years and 66-100 years to determine the haemagglutination-inhibiting antibody responses to sub-unit influenza containing A/USSR/90/77 (H1N1). Antibody responses to A/USSR/90/77 were low in all groups. The young adult group (17-24 years) produced a primary response to A/USSR/90/77 and showed a significant response to a second dose of vaccine, whereas their responses to the A/Texas/1/77 (H3N2) and B/Hong Kong/8/73 components were of the anamnestic type and showed no significant increase to a second dose. The adult (25-64 years) and aged (66-100 years) groups responded anamnestically to all three vaccine components. There was no impairment of the antibody response in the aged group in comparison with the response in the adult group. A comparative assay in microtitre trays and WHO plates showed two- to four-fold differences in antibody titre to A/USSR/90/77 in these systems.
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Tissue culture monolayers of seven human intracranial tumours comprising 2 astrocytomas, 3 meningiomas, 1 secondary squamous cell carcinoma and 1 secondary adenocarcinoma were examined by a double immunofluorescent staining technique to demonstrate Concanavalin A (Con A) surface receptors and cytoplasmic actin in the same cell. Tumour cells, treated with fluoresceinisothiocyanate-labelled Con A (FITC-Con A) showed staining in cell margins or in a random distribution over the cell surface. Incubating the cells with FITC-Con A at 37 degrees for increasing periods of time resulted first in staining of clusters and later of perinuclear globules. Cells, pretreated with 4% paraformaldehyde at 4 degrees for 10 min or with cytochalasin B at 37 degrees for 30 min showed staining restricted to cell margins. In the cytochalasin B-treated cells, the peripheral staining was in the form of coarse clusters. Double fluorochrome studies showed that the anti-actin antibody (AAA) staining occurred in sites closely related to those stained by FITC-Con A both in untreated as well as in cytochalasin B-treated cells. The findings suggest that Con A receptors, as an example of a stable cell membrane determinant in human tumour cells, are associated with actin and that their mobility on the cell surface is dependent on an intact cytoplasmic actin system.
Twenty adult rabbits were killed two to 12 weeks after antibodies to Encephalitozoon cuniculi were first detected in their sera. Specimens of urine were examined for E cuniculi and sections of kidneys and brains were examined both for organisms and lesions consistent with encephalitozoonosis. Organisms were observed in the kidneys from two weeks after the appearance of antibodies, and histological lesions in the kidneys were observed after five weeks. However, organisms were rarely seen in the brain and lesions in this organ were infrequent and, generally, not present until at least eight weeks after the first detectable antibody. The results indicate the course of natural infection of encephalitozoonosis in rabbits and show that serology is the most sensitive procedure for its early diagnosis.
Serologic screening of a rabbit breeding colony over a 9-month period showed that all 9-week-old rabbits with Encephalitozoon cuniculi infection were born of E cuniculi-infected does. This observation, obtained from studies on 395 young rabbits, suggested that transmission of infection is either transplacental or the result of close contact soon after birth. On this basis, 16 young healthy rabbits, seronegative to E cuniculi, were isolated and tested at 2-week intervals for antibodies to E cuniculi. In the first 2 months, seven rabbits showed indications of developing antibodies to E cuniculi and were immediately removed from the colony. The remaining rabbits along with their 52 offspring were tested for serum antibodies for a further 16 months and no rabbit became seropositive. Eight months after establishment of the colony, three does, one buck and six 12-week-old rabbits were killed. Macroscopic and extensive histologic and immunofluorescence examinations failed to reveal any evidence of infection with E cuniculi. These results showed that serological screening for E cuniculi infection by immunofluorescence is a simple yet adequate procedure for establishing a rabbit colony free of encephalitozoonosis.
An indirect immunofluorescence test for serum antibodies to Nosema cuniculi was evaluated in rabbits by comparison with established histopathological methods of diagnosis. Cell-culture isolation procedures and immunofluorescence and histological techniques designed to detect the parasite in urine or tissues were used to confirm the diagnosis. The serological diagnosis showed excellent correlation with presence of brain lesions characteristic of nosematosis, and N cuniculi were detected in 63 per cent of seropositive rabbits but in no seronegatives. Serum cross-reactivity tests between N cuniculi and Toxoplasma gondii showed that these two protozoa are antigenically distinct. The technique offers a simple, sensitive and reliable procedure for diagnosis of nosematosis in a living animal.
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