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Biomedical subjects

C A Carson

Publications and source records attributed to C A Carson.

At least 55 records · Page 3Linked to original sources
PubMed1992

Apparent elevation of serum CK-MB not due to acute myocardial infarction.

An increased serum level of the MB isoenzyme of creatine kinase (CK-MB) is a useful marker for acute myocardial infarction. Although described extensively in clinical chemistry literature, there is little information in standard medical references about false positives for this test. We report two cases where high levels of measured CK-MB activity were in fact due to another form of CK, associated with internal malignancy.

Aged↗
PubMed1990

Babesia bovis: evidence for selection of subpopulations during attenuation.

DNA probes were used to detect variation in subpopulations of virulent and serially passaged Babesia bovis. Two distinct patterns were evident after hybridization to genomic DNA; the first was a basic profile typical of virulent B. bovis and the second, a more variable array, was characteristic of B. bovis after various stages of attenuation. Tick transmission of avirulent B. bovis causes reversion to the virulent genomic pattern, suggesting that selective enrichment of a small residual subpopulation caused reversion to a virulent profile of subpopulations. Certain genomic fragments, predominant in either virulent or avirulent parasite forms, are putative "markers" or actual elements responsible for these biological characteristics.

Animals↗
PubMed1990

Calcium-dependent protein phosphorylation in Babesia bovis and its role in growth regulation.

Intracellular growth of protozoan parasite Babesia bovis has been followed to study the effect of some chemical agents on growth regulation. Using an in vitro parasite culture system we present evidence that the normal growth of the parasite is dependent upon available calcium and a Ca2(+)-binding protein, calmodulin, because sequestration of either of these 2 components from the culture medium causes inhibition of parasitic growth. Further studies demonstrate that the parasite contains a protein kinase that can phosphorylate a 40-kDa parasitic protein and its activity is regulated by calcium and calmodulin. Both the enzyme and its substrate are present in the membrane of the parasite. In addition, the parasite also contains a highly active protein kinase C activity that is documented by phosphorylating histone, a known substrate for protein kinase C. These findings suggest a possible correlation between the growth of parasite and calcium/calmodulin-dependent protein phosphorylation activity.

Animals↗
PubMed1986

Babesia bovis: purification and concentration of merozoites and infected bovine erythrocytes.

Babesia bovis merozoites, externalized by removal of infected erythrocytes from ordinary culture conditions, were completely separated from red blood cells and stroma by centrifugation in a Percoll gradient. A merozoite band formed at a point corresponding to about 1.087 g/ml specific density. Infected red blood cells were concentrated approximately fourfold to obtain greater than 49.0% parasitemia after centrifugation in Percoll. Most highly enriched fractions positioned between 1.121 and 1.123 g/ml specific density. Full parasite viability was retained.

Animals↗
PubMed1986

Cloning of in vitro propagated Babesia bigemina.

The original Babesia bigemina culture conditions were modified with regard to infected bovine erythrocyte concentration and atmospheric environment. A procedure was designed which would yield a homogeneous parasite population, beginning with a single infected erythrocyte. Calculated dilutions were made in 96-well tissue culture plates to approach one infected erythrocyte per four wells. Growth of parasites in wells was detected between 16 and 28 days after cultures were initiated. Clones were transferred to 24-well tissue culture plates for regular maintenance. Three primary clones were selected for additional recloning. The probability that the parasites detected in one well are the progeny of a single infected erythrocyte approaches 0.99 for tertiary clones.

Animals↗
PubMed1986

Enzymatic characterization of Babesia bovis.

Agarose gel electrophoresis was used to identify metabolic enzymes in Babesia bovis and B. bigemina. Glutamate dehydrogenase, lactate dehydrogenase, glucose phosphate isomerase, and hexokinase were identified in B. bovis- and B. bigemina-infected erythrocytes and B. bovis merozoite preparations. A specific electrophoretic mobility was observed for each enzyme. Malate dehydrogenase, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and adenylate kinase were only detected in normal erythrocyte preparations. Inter-species, but not intra-species, variation was noted when comparing electrophoretograms of both species. Kinin-activating activity was not detected in B. bovis-infected erythrocyte or merozoite preparations at pH 4.2 or 7.6.

Adenylate Kinase↗
PubMed1986

Concentration and enzyme content of in vitro-cultured Babesia bigemina-infected erythrocytes.

Clones of in vitro-cultured Babesia bigemina-infected erythrocytes were concentrated by several density gradient procedures. The density range of infected erythrocytes containing pairs of parasites was 1.077 to 1.089 g/ml, whereas the density range of infected erythrocytes containing single parasites was 1.092 to 1.100 g/ml. Three enzymes--lactate dehydrogenase, glucose-phosphate isomerase, and glutamate dehydrogenase--were found associated with infected erythrocytes. The parasite-specific enzyme and/or isoenzymes were shown to have different mobility patterns in starch gel electrophoresis from those found in the normal bovine erythrocytes. The enzyme 6-phosphogluconate dehydrogenase was not detected as a parasite-specific enzyme in B. bigemina-infected erythrocytes.

Animals↗
PubMed1985

In vitro cultivation of Babesia bigemina.

A strain of Babesia bigemina was isolated from an infected calf and propagated in vitro. Culture conditions included washing of infected and normal bovine erythrocytes in a special solution, and the use of a 5% to 10% (v/v) erythrocyte suspension in medium 199 (with 20% to 50% fresh normal bovine serum) at a depth of 4 mm in a 5% CO2, 2% O2, 93% N2 atmosphere. After 36 days in vitro and 9 subcultures, the cultured organism was inoculated into a susceptible calf. This calf developed clinical signs of disease and recovered when treated with 1% trypan blue solution. The strain was also reisolated from the second calf. The original isolate had been maintained in continuous in vitro cultivation for more than 99 days.

Animals↗
PubMed1985

Cryopreservation of Babesia bigemina for in vitro cultivation.

Babesia bigemina-infected RBC and merozoites were cryopreserved and used to initiate in vitro cultures in normal bovine RBC; the cryoprotectant was a final 10% polyvinylpyrrolidone in Vega y Martinez solution. A cooling rate of 20 C/min until -80 C and then rapid transfer to liquid N2 storage was satisfactory. Samples for culture initiation were rapidly thawed at 37 C, washed in Vega y Martinez solution and resuspended in complete culture media containing 10% normal bovine RBC. The optimum culture conditions to reestablish cultures were a 24-well plate (16 mm ID), 5 mm in depth, and an atmosphere of 2% to 5% O2, 5% CO2, and 93% to 90% N2.

Animals↗
PubMed1983

Cloning of Babesia bovis by in vitro cultivation.

A procedure for cloning Babesia bovis was developed. The procedure was used to establish and cultivate homogeneous populations of parasites and to isolate B. bovis from carrier animals. Three different clone lines of B. bovis based on in vitro growth rates were established.

Animals↗
PubMed1982

Cryopreservation of Babesia bovis for in vitro cultivation.

The most efficient procedure for cryopreserving viable Babesia bovis organisms for in vitro cultivation consists of freezing extracellular parasites in a solution of 10% (w/v) polyvinylpyrrolidone (PVP) using a cooling rate of 20 degrees C/min. Although cultures can be established from thawed infected erythrocytes, the plating efficiency is relatively low. Freezing extracellular parasites resulted in plating efficiency up to 25%, when thawed and placed in culture. Glycerin or dimethyl sulphoxide (Me2SO) can be used successfully in the cryopreservation of B. bovis but apparent toxic effects greatly decrease their efficiency. B. bovis parasites have been kept to -196 degrees C for 60 days with no appreciable reduction in plating efficiency.

Animals↗
PubMed1980

Cell-mediated and humoral immune responses of German Shepherd Dogs and Beagles to experimental infection with Ehrlichia canis.

The cell-mediated and the humoral immune responses of 12 German Shepherd Dogs and 5 Beagles inoculated with Ehrlichia canis were evaluated. Results indicated that specific and nonspecific immunosuppression due to E canis occurred in the German Shepherd Dogs. Canine leukocyte migration-inhibition factor was successfully isolated and shown to be physically and functionally similar to human and guinea pig migration inhibition factor. Of the German Shepherd Dogs, 58% developed positive cell-mediated responses; 80% of the Beagles became positive. German Shepherd Dogs that developed severe chronic ehrlichiosis did not respond to as great a degree as did the German Shepherd Dogs and Beagles with mild chronic disease. The cell-mediated responses decreased with time and disappeared by 147 days after inoculation. Humoral antibody titers in all inoculated dogs increased with time and remained at increased concentrations. Treatment of four inoculated dogs with antilymphocyte serum did not modify the course of the disease. The findings indicated that cell-mediated immunity may have a significant role in determining the course of disease in dogs infected with E canis.

Animals↗
PubMed1980

Comparison of three methods of immunization against bovine anaplasmosis: an examination of postvaccinal effects.

Normandy calves ranging in age from 7 to 11 months were immunized against bovine anaplasmosis, using a diluted virulent Anaplasma marginale stabilate of Colombian origin, diluted bovine blood containing an apparently mild strain of A marginale isolated in Colombia, or an attenuated A marginale vaccine of ovine origin from the United States. Calves given the stabilate generally showed a moderate degree of parasitemia and reduction in packed cell volume (PCV). Calves given the apparently mild Colombian isolate of A marginale developed a moderate parasitemia, a reduction in PCV, and in some instances, required treatment to moderate the premunization procedure. Calves given the attenuated vaccine showed minimal evidence of parasitemia and PCV reduction. Most of the immunized calves became seropositive in the complement-fixation test for anaplasmosis and all calves sampled showed evidence of a cell-mediated response, using the leukocyte migration-inhibition test.

Anaplasma↗
PubMed1980

Comparison of three methods of immunization against bovine anaplasmosis: evaluation of protection afforded against field challenge exposure.

The efficacy of three immunization methods for bovine anaplasmosis was tested on 88 yearling Normandy cattle which were challenge-exposed under field conditions in an enzootic zone in Colombia, South American. A total of 30 cattle were immunized (premunized) with a presumed mild Colombian isolate of Anaplasma marginale; 29 calves were vaccinated with an attenuated A marginale of ovine origin; and 29 were exposed to a virulent A marginale stabilate of Colombian origin. Twenty-nine nonvaccinated cattle served as controls. Parasitemia, packed cell volume, body weight, and complement-fixation antibody response were monitored to determine host response to challenge exposure. The calves experienced a Babesia challenge exposure following arrival in the enzootic zone, after which a transient increase in Anaplasma parasitemia, accompanied by a decrease in packed cell volume, occurred in most of the vaccinated calves. However, neither clinical anaplasmosis nor mortality due to the disease occurred in the immunized cattle. Twenty-seven of the nonvaccinated calves had signs of clinical anaplasmosis and five (17%) died of the disease.

Anaplasmosis↗
PubMed1979

Mortality, weight loss and anaemia in Bos taurus calves exposed to Boophilus microplus ticks in the tropics of Colombia.

One hundred and sixteen pure-bred Normandy calves previously immunised against babesiosis and anaplasmosis were transported to the Caribbean Coast of Colombia where they divided into 2 equal groups and placed in separate pastures. One group sustained heavy infestation with Boophilus microplus ticks. The second group became lightly infested. The heavily infested calves suffered average losses in body weight of 38 kg and a 48% decrease in mean packed cell volume. Twenty-three (40%) died 16 to 39 days following arrival from severe ixodiasis and babesiosis. Mortality did not occur nor were significant weight losses observed in the group of lightly infested calves.

Anemia↗