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Biomedical subjects

C A Carson

Publications and source records attributed to C A Carson.

At least 73 records · Page 4Linked to original sources
PubMed1979

In vitro cultivation of Anaplasma marginale: growth pattern and morphologic appearance.

Anaplasma marginale propagated in vitro showed an increasing rate of replication in a sequence of three experiments. The changes in the percentage of parasitized erythrocytes and identification of the organism in culture were monitored by the Giemsa-staining and the direct fluorescent antibody techniques. The ultrastructure of the organism in culture also was determined. The percentage of parasitized erythrocytes increased more than three times in the first experiment during a period of 8 days, and about ten times in the second experiment during a period of 14 days. After 8 days of observation of the primary culture in the third experiment, the trend of growth was more rapid than in the first and second experiment. The viability of the organism was verified by inoculation of susceptible calves, using 13- and 33-day cultures of the first and the second experiments, respectively. The primary cultures were subcultured twice by dilution with normal bovine erythrocytes.

Anaplasma↗
PubMed1978

Platelet migration inhibtion as an indicator of immunologically mediated target cell injury in canine ehrlichiosis.

A platelet migration inhibition test was devised to determine the presence of antiplatelet activity in serum collected from experimentally produced and natural cases of canine ehrlichiosis. The maximum platelet migration inhibition effect was observed during the acute phase of the disease and before the appearance of specific humoral antibody, measured by the indirect fluorescent-antibody test. Platelet migration inhibition may be one of the earliest events leading to pancytopenia. In most cases, sera positive for humoral antibodies also were positive for platelet migration inhibition, although no direct correlation was evident between the serological titer and the degree of platelet migration inhibition. Inoculation of dogs with uninfected canine blood did not induce the production of inhibition factor or antibody activity, which precluded a histocompatibility response to the cellular elements in the inoculum. Scanning electron microscopy indicated that the platelet inhibition factor interfered with platelet migration by inhibiting pseudopod formation. Affected platelets became rounded and showed evidence of clumping and leakage.

Animals↗
PubMed1978

Growth of Babesia bovis in bovine erythrocyte cultures.

Babesia bovis was cultured in a suspension of bovine erythrocytes incubated at 37 degrees C in Medium 199 with 50% bovine serum. The cells in culture were kept in suspension by slow stirring in spinner flasks and the medium was replaced at 24-hour intervals. Persistent multiplication of the parasite in a short series of subcultures suggests the feasibility of this approach for continuous culture.

Animals↗
PubMed1978

Efficacy of attenuated Anaplasma marginale vaccine under laboratory and field conditions in Colombia.

Four-month-old Holstein-Friesian calves were inoculated with 3 different doses (1, 2, and 3 ml) of attenuated Anaplasma marginale vaccine. Vaccinated calves showed mild anaplasma parasitemia, slight decrease in packed cell volume, low serologic conversion, and no clinical illness. An artificial challenge exposure of vaccinated and unvaccinated calves with virulent Colombian A marginale showed that the vaccine provided protection against clinical signs of the disease, including parasitemia and anemia. The volume of the vaccinal dose did not alter the degree of protection provided. A 2nd group of 8- to 9-month-old Holstein-Friesian calves was then inoculated with 3 ml of anaplasma vaccine and premunized with both Babesia bigemina and Babesia argentina while being housed in an area free of these diseases. Calves were moved to an enzootic region heavily infested with various arthropods, including ticks, for natural field challenge exposure. Control calves, which were not given anaplasma vaccine, suffered clinical illness manifested by severe anemia and an average weight loss of 50.6 kg due to anaplasma field challenge exposure. In contrast, vaccinated calves did not show anemia and their weight loss was 3.9 kg.

Anaplasma↗
PubMed1977

Cell-mediated immune response to virulent and attenuated Anaplasma marginale administered to cattle in live and inactivated forms.

The leukocyte migration-inhibition test (LMIT) and lymphocyte transformation of blood leukocytes from cattle exposed to virulent, attenuated, and inactivated preparations of Anaplasma marginale served as indices of cell-mediated immunity in bovine anaplasmosis. The LMIT response increased markedly in cattle vaccinated with attenuated A marginale or injected with virulent A marginale. Cattle inoculated with inactivated anaplasma developed a transient, low-level LMIT response. The response to antigenic stimulation recorded in the lymphocyte transformation test of leukocytes collected from cattle which were given live anaplasma was less than the response elicited from leukocytes collected from cattle vaccinated with inactivated anaplasma in adjuvant.

Anaplasma↗
PubMed1977

Cell-mediated immunity related to challenge exposure of cattle inoculated with virulent and attenuated strains of Anaplasma marginale.

Cattle which were given virulent Anaplasma marginale as a premunization procedure or were vaccinated with live attenuated or killed anaplasma preparations were challenge inoculated with virulent A marginale. Exposure of cattle to virulent or attenuated A marginale, which induced a strong and lasting cell-mediated response as measured by the leukocyte migration-inhibition test, protected against the development of high parasitemia, anemia, and clinical signs of disease after challenge inoculation with virulent A marginale. Cattle which were vaccinated with killed anaplasma preparations that induced transient and low-level cell-mediated responses were not protected against the development of severe anemia after challenge inoculation, although postchallenge parasitemia seemed to be controlled.

Anaplasma↗
PubMed1977

Autologous lymphocyte-mediated cytotoxicity against monocytes in canine ehrlichiosis.

The 51Cr-release technique for detecting cytotoxicity had been adapted to immunologic studies of canine ehrlichiosis. Lymphocytes from dogs infected with Ehrlichia canis, cause of canine ehrlichiosis, were shown to be cytotoxic for autologous monocytes. The effect was dependent on the concentraton of lymphocytes, being optimal at 100:1 lymphocyte:monocyte ratio. Neither immune serum and complement, nor anti-canine globulin had any observable effect on cytotoxicity. The monocytotoxicity bore a temporal relationship to the thrombocytopenia. It is suggested that T lymphocyte activation accompanying ehrlichiosis contributes to pathogenesis of the disease and that the specific immune elimination of parasitized monocytes is antibody independent.

Animals↗
PubMed1976

Cutaneous hypersensitivity and isoantibody production in cattle injected with live or inactivated Anaplasma marginale in bovine and ovine erythrocytes.

Delayed cutaneous hypersensitivity and the production of isoagglutinins against normal bovine erythrocytes were measured in cattle inoculated with erythrocytic preparations containing live or inactivated Anaplasma marginale. The effect of blood group substances versus parasitic components on induction of delayed cutaneous hypersensitivity and isoimmunity was examined by using test antigens derived from normal and parasitized erythrocytes, virulent A marginale in bovine erythrocytes, and attenuated A marginale in ovine erythrocytes. The use of inactivated vaccine of bovine origin induced production of isoantibodies and cutaneous hypersensitivity to both bovine and ovine blood group factors, whereas a similar vaccine preparation of ovine origin stimulated antibodies and cutaneous reactivity only against ovine blood group factors.

Anaplasma↗
PubMed1975

A method for separation of bovine blood leukocytes for in vitro studies.

Various methods have been developed for separation of the cellular components of blood. Size and density differences in cellular blood elements of various animal species necessitate the use of specific separative procedures. This study describes a method which combines isopycnic density-gradient centrifugation with erythrocyte aggregation as a means of isolating leukocytes from bovine blood. The procedure yields a viable population of mixed leukocytes which has proven useful for cell culture and in vitro tests of cell-mediated immunity.

Animals↗
PubMed1972

Serologic response of turkeys to an agent associated with infectious enteritis (bluecomb).

The serologic response of turkey poults to an infectious enteritis (bluecomb disease) agent was analyzed. Serum samples collected from poults on post-inoculation days 3, 7, 14, and 21 were compared to serum from normal poults by electrophoresis and immunoelectrophoresis. Albumin concentrations were decreased whereas alpha and gamma globulins were increased during the disease. Qualitative and quantitative changes occurred in all migration zones.

Alpha-Globulins↗