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Biomedical subjects

H W Ferguson

Publications and source records attributed to H W Ferguson.

At least 19 recordsLinked to original sources
PubMed1992

Rapid, simple and sensitive microassay for skeletal and cardiac muscle myoglobin and hemoglobin: use in various animals indicates functional role of myohemoproteins.

A novel, simple, rapid, sensitive and reproducible microassay is described for determination of myoglobin and hemoglobin content of myocardial and skeletal muscle biopsy specimens from various mammals, birds and fish. As little as 50 mg of tissue is needed and myoglobin concentrations lower than 1 mg% can be detected. Myoglobin and hemoglobin are separated at alkaline pH by ammonium sulfate extraction followed by ultrafiltration. Heme content is determined by absorption of the Soret band when the hemoprotein extract is visibly colored or more sensitively by its peroxidase activity when the extract has low color. The heme reacts with tertiary-butyl hydroperoxide and orthotolidine to generate a blue color. Hemoglobin content is correlated with myoglobin content and is related to aerobic capacity and blood flow to the tissue. Myoglobin content varied over 5 orders of magnitude up to 7 per cent of the weight of tissue, whereas hemoglobin content varied over 2 orders of magnitude up to 6 per cent of tissue weight. Myoglobin content is increased in species with high basal metabolic rate, high physical activity, prolonged diving capacity, fatigue resistance, and red muscle, whereas it is decreased in white muscle, iron-deficient animals, animals with sedentary lifestyles, and in animals and tissues with small fiber diameters such as avian or fish hearts.

Animals↗
PubMed1992

Responses of mucus-producing cells in gill disease of rainbow trout (Oncorhynchus mykiss).

This paper documents the responses of mucus-producing cells in the gills of rainbow trout (Oncorhynchus mykiss) throughout a naturally occurring outbreak of bacterial gill disease (BGD) and following exposure to experimentally induced high concentrations of ammonia and suspended solids. The responses were examined at three sites on the gill filament with three histochemical stains selected to identify the main types of mucous glycoproteins; these were periodic acid-Schiff (PAS), alcian blue pH 2.5 (AB2) and alcian blue pH 1.0 (AB1). In the BGD-infected fish, there was an increase in the numbers of PAS-positive and AB2-positive mucous cells and a corresponding decrease in AB1-positive cells. The greatest increase in mucus-producing cells occurred at the tips of the filaments, but the greatest relative change occurred at the mid-filamental (inter-lamellar) position. Fish exposed to high ammonia concentrations also had elevated numbers of mucus-producing cells, but there was no statistically significant change in fish exposed to high amounts of kaolin. The possible implications of these findings are discussed.

Ammonia↗
PubMed1991

Dietary excesses of leucine influence growth and body composition of rainbow trout.

This study examined the hypothesis that a diet containing excess leucine may promote protein deposition in the body of rainbow trout. Diets were formulated with wheat germ meal and crystalline amino acids as major nitrogen sources. In Experiment 1, diets containing 1.1, 1.5, 2.2, 2.7, 3.5, 4.5, 6.0 and 6.5% leucine in wheat germ meal-crystalline amino acid diets were fed to fingerling rainbow trout. Diets containing up to 6.5% leucine did not inhibit weight gain or food intake. Body protein concentration tended to decrease as dietary leucine increased. In Experiment 2, fish were fed similar diets containing 3.3, 6.2, 9.2 and 13.4% leucine. After 10-11 wk of feeding, gross lesions including scoliosis, deformed opercula, scale deformities, scale loss, spongiosis of epidermal cells and scale regeneration were observed in 20% of the fish fed diets containing 13.4% leucine. High dietary leucine did not depress plasma valine or isoleucine concentrations. Therefore, the gross lesions could be attributed to a toxic effect of excess dietary leucine. Polyamine concentrations, which were used as a metabolic indicator for growth, were not significantly different in the tissues of fish receiving different treatments, thus supporting the hypothesis that increasing dietary leucine did not increase body protein deposition.

Amino Acids, Branched-Chain↗
PubMed1991

Pharmacokinetic and tissue distribution study of oxytetracycline in rainbow trout following bolus intravenous administration.

Oxytetracycline pharmacokinetics and tissue distribution were studied in rainbow trout following bolus i.v. administration at 5 mg/kg. The mean serum (log) drug concentration data were plotted against time (linear). The decay curve was described by a three-component exponential decay function and a three-compartment model. The t1/2 of rapid distribution was 0.9 h, the t1/2 of the slow distribution was 5.9 h and the t1/2 elimination was 81.5 h. Clearance was 25.4 ml/kg/h and Vd(area) 2988 ml/kg. Regression analysis of the serum levels for the three intervals, 0.5-2.0 h, 6.0-18.0 h, and 24-96 h, indicated that the rates of decay for each interval were 0.6151 h-1, 0.0564 h-1 and 0.0088 h-1 respectively. Rates of equilibration between tissues and serum were determined. Kidney equilibrated the fastest with t1/2 to equilibration of 1.1 h for H (anterior) kidney and 1.98 h for P (posterior) kidney. The highest drug levels were found in the liver and the lowest were in the brain.

Animals↗
PubMed1990

Pathogenesis of skin and liver neoplasms in white suckers from industrially polluted areas in Lake Ontario.

Increased prevalences of epidermal and hepatobiliary neoplasms in white suckers (Catostomu commersoni) and brown bullheads (Ictalurus nebulosus) in the Western region of Lake Ontario have been associated with industrial pollution, but the identity and causative role of environmental carcinogens have not yet been established. Most epidermal tumors of lip and body skin are benign focal proliferations that occur in fish from the polluted Hamilton region, and also in fish from less polluted sites in the Great Lakes. These skin tumors in white suckers do not have consistent alterations in cellular glutathione S-transferases (GST), suggesting that growth of skin tumors is not promoted by chemicals normally detoxified by GST. However, elevated levels of glutathione peroxidase (GPO) and glutathione reductase (GR) in skin papillomas are indicative of promotional peroxidative tissue injury, either caused directly by xenobiotics or indirectly by chemical-induced inflammation. Liver tumors in white suckers from Lake Ontario include preneoplastic, benign, and malignant populations of hepatocellular and biliary cells, all of which are more prevalent in fish from polluted sites. These liver tumors are consistently associated with chronic cholangiohepatitis and segmental cholangiofibrosis, but these conditions also occur in white suckers in non-industrial locations. Thus, the natural occurrence of biliary disease, not attributable to industrial pollution, may have some influence on the development of liver tumors. Some preneoplastic lesions and the majority of neoplastic hepatocellular and biliary lesions in white suckers have low levels of total GST, indicating that these liver neoplasms are not promoted by xenobiotics normally detoxified by hepatic GSTs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

A field evaluation of an indirect fluorescent antibody-based broodstock screening test used to control the vertical transmission of Renibacterium salmoninarium in Chinook salmon (Oncorhynchus tshawytscha).

Ovarian fluid samples from erythromycin treated and untreated spawning three year old Chinook salmon were screened independently by two laboratories for the presence of Renibacterium salmoninarum using the indirect fluorescent antibody technique (IFAT). Agreement between the results of the two laboratories could be explained by chance when R. salmoninarum cell numbers as low as one per sample were considered sufficient to represent a positive result. If a positive result was considered to be the detection of larger numbers of R. salmoninarum cells (greater than 51 cells per sample), agreement increased and there was a statistically significant association between the results of the two laboratories. However, the level of agreement did not reach satisfactory levels for a population screening test. Furthermore, approximately 60% of the samples yielded false negative results when IFAT results were compared with positive culture results. These results led to the conclusion that the IFAT screening procedure, as carried out, was unsuitable for the purposes intended. Erythromycin injection of the spawning fish had no statistically significant effect on the results of the IFAT screening test.

Animals↗
PubMed1988

Degradation of extracellular thymidine by cultured hepatocytes from rainbow trout (Salmo gairdneri).

1. Trout hepatocytes cultured as attached monolayers had low rates of [3H]-thymidine ([3H]-TdR) incorporation during replicative or repair synthesis of DNA. 2. Within 2 hr, most [3H]-TdR was metabolized by trout hepatocytes to a major product that eluted in advance of intact [3H]-TdR on Sephacryl S-200 columns. 3. Metabolism of [3H]-TdR by trout hepatocytes rapidly destroyed its ability to label replicating indicator cultures of proliferating rat hepatocytes. 4. These studies demonstrate that [3H]-TdR tracer assays for DNA synthesis cannot be reliably used in cultured trout hepatocytes which catabolize thymidine much more rapidly than do rat hepatocytes.

Animals↗
PubMed1987

Epithelial and pillar cell replacement in gills of juvenile trout, Salmo gairdneri Richardson.

Young rainbow trout, Salmo gairdneri (Richardson) were injected intraperitoneally with tritiated thymidine, and killed at intervals between 2 hr and 16 days after inoculation. Labelled epithelial cells were first detected autoradiographically along the base of gill lamellae. Epithelial cells proliferated here and then migrated toward the tips of the lamellae. Uniform labelling along the length of the filaments at the base of lamellae indicated that cells were dividing at a constant rate. Transverse sections of filaments showed that epithelial proliferation was also uniform across the base of the lamellae. The interior of the lamellae often had labelled pillar cells, indicating that these cells also divide. The high intensity of the label in animals killed 16 days after inoculation with tritiated thymidine suggests that division probably occurs slowly, less than once every 16 days.

Animals↗
PubMed1986

Clinical pathology of myodegeneration (pancreas disease) in Atlantic salmon (Salmo salar).

The clinical pathology and histopathology of two groups of Atlantic salmon with severe degenerative myopathy (pancreas disease) is described and compared with a third healthy group. One affected group was anorexic and had low plasma protein and albumin levels while the other was feeding and had normal levels. Both diseased groups had plasma and tissue vitamin E and selenium levels lower than the healthy group. Similarly, creatine kinase values were raised in affected groups. If representative of the syndrome as a whole, the results suggest that the myopathy of pancreas disease has a basis in a vitamin E-selenium deficiency, but whether primary or induced is not clear. The results also demonstrate that the myopathy and pancreatic atrophy do not inevitably lead to anorexia or any other clinically obvious sign of disease, despite both cardiac and oesophageal involvement.

Animals↗
PubMed1985

Gastritis in Lake Tanganyika cichlids (Tropheus duboisii).

Necrotic and granulomatous gastritis is described in Lake Tanganyika cichlids. Clostridium hastiforme and flagellated protozoa were both associated with the reaction but the significance of either is unknown. Nevertheless, treatment of surviving fish with ampicillin was carried out and mortalities ceased. The possible involvement of an unsuitable diet as a predisposing factor is discussed.

Aeromonas↗
PubMed1979

Toxoplasmosis in a calf.

Gross post mortem and histopathological changes are described in a calf with toxoplasmosis. The major pathological changes were restricted to the lungs and kidneys and comprised interstitial pneumonia with multifocal necrosis, and glomerular necrosis. Many pseudocysts were present in both organs. The calf had been in close contact with young cats, one of which was killed and examined and shown to have a high antibody titre to Toxoplasma gondii, although there was little histological evidence of infection. No antibodies to toxoplasma were detected in serum from the dam of the calf, and accordingly, it is suggested that the cat was the source of infection for the calf.

Animals↗
PubMed1978

Antibodies to Leptospira in the sera of aborted bovine fetuses.

Antibodies to Leptospira serotypes were detected in sera from 15 (6.9 per cent) of 218 aborted fetuses, but were not detected in the sera from 196 non-aborted fetuses. Fourteen (6.4 per cent) sera from the aborted fetuses had antibodies to strains belonging to the Hebdomadis serogroup and 1 (0.5 per cent) had antibodies to a strain belonging to the Icterohaemorrhagiae serogroup. These antibodies were predominantly immunoglobulin M whereas in the dams, antibodies belonged to both immunoglobulin M and G classes.

Abortion, Veterinary↗