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Biomedical subjects

R L Squibb

Publications and source records attributed to R L Squibb.

At least 19 recordsLinked to original sources
PubMed1984

The effect of exercise and fasting on the myocardial protein and lipid metabolism in experimental bacterial myocarditis.

A generally nonlethal Salmonella typhimurium infection in weanling rats produced bacterial myocarditis and myocardial hyperplasia. Myocardial lesions were characterized by focal infiltrates of inflammatory cells (predominantly mononuclear), segmental myocyte necrosis, and incipient fibrosis. Although bacterial infections are infrequently associated with myocarditis, the S. typhimurium infection in young rats produced a new experimental model of diffuse myocardial inflammatory foci. Biochemical changes in the myocardium included great increases in total myocardial contents of protein (23%), RNA (39%) and DNA (43%) and several lipid fractions (35-55%) as well as in tissue activities of acid hydrolases, such as cathepsin D (124%) and beta-glucuronidase (135%), all of which contrasted with the relatively limited areas of histologic involvement (1.5%). To study the effects of additional stress in this model infection, some rats were exercised by forced running in wheels for 2 hours and others were fasted for 24 hours before samples were obtained. The short period of forced exercise in this infection caused an additional increase of myocardial protein content (47%) but with no additional change in histology. The expected fasting-induced degradation of protein as well as an infection-associated increase in myocardial lipids were each prevented when rats were fasted during ongoing acute infection. Protein degradation, as reflected by heightened acid hydrolase activities, seemed to occur at a similar rate regardless of other stresses, whereas the rate of myocardial protein synthesis appeared to be alterable.

Animals↗
PubMed1980

Effects of glucose and fructose loading on glycogenesis in chicks infected with avian tuberculosis.

The chick was used as a rapid metabolic model to determine the fate of ingested fructose vs. glucose in noninfected chicks and in those subjected to the stress of avian tuberculosis. The chicks were crop-loaded with either a 72% fructose or glucose solution 21 and 28 days post TB inoculation and killed 2 and 4 hr after loading. In noninfected chicks, both sugars were rapidly converted to glycogen, and there was an interaction with time and the amount of glycogen formed from each sugar. Infection depressed glycogen formation from both fructose and glucose. While the total amount of glycogen formed from glucose could be directly correlated to increased liver size in the TB chicks loaded with glucose, in the chicks loaded with fructose less glycogen was formed even though liver size was increased as a result of the TB infection. The depression in glycogen formation was not related to the severity of the infection since the TB involvement was not the same in the two experiments conducted; but in both cases chicks loaded with fructose showed a greater reduction in the capacity of the liver to synthesize glycogen.

Animals↗
PubMed1980

Effects of 1,3-butanediol-1,3-dioctanoate and corn oil on lipids of chick plasma, liver, and skin.

A synthetic energy source, 1,3-butanediol-1,3-dioctanoate (BDDO), and corn oil were fed at the 10% level in diets for chicks recovering from Newcastle disease virus at two levels of severity. There were little differences in plasma lipid concentrations between corn oil and BDDO groups. Liver lipid analyses showed significantly higher (P less than or equal to .01) triglyceride concentration for the BDDO group as compared with corn oil. In both trials, total liver lipid content was higher in all components for the BDDO group. Triglycerides and total lipids were notably lower (P less than or equal to .01) in skin of the BDDO group as compared with corn oil. Liver and skin lipid variations were attributed to different metabolic routes for BDDO and corn oil. The data suggest that BDDO tends to allow liver synthesis of triglycerides while suppressing lipid storage in the skin.

Animals↗
PubMed1979

The effect of vitamins A, E and K on experimentally induced histomoniasis in turkeys.

Vitamins A, E and K were incorporated into turkey starter rations at normal (1 x ), 5 x and 50 x the National Research Council recommended vitamin levels and evaluated for their effect on histomoniasis in turkeys. Infected as well as comparable unifected poults were included in all trials. Each vitamin was also evaluated at normal and 50 x the NRC level in combination with ipronidazole, a low-level antihistomonal agent. In addition to performance parameters, glutamate oxaloacetate transaminase (GOT) and lactate dehydrogenase (LDH) plasma enzyme levels were used to evaluate the vitamin effect. None of the vitamins tested alone were found to be effective in terms of reducing mortality and morbidity following a severe Histomonas meleagridis challenge, regardless of the vitamin dose. A significant improvement in performance was demonstrated with the vitamin E (50 X)--ipronidazole combination and a numerical improvement with the vitamin A (50 X)--ipronidazole combination over ipronidazole alone or the poults fed NRC recommended vitamin levels. The GOT and LDH plasma enzyme levels correlated well with the progressive pathological changes associated with the disease. At 11 days post-infection both enzymes were consistently and significantly elevated above those of the uninfected controls, irrespective of the vitamin levels provided. The presence of low ipronidazole in most instances delayed the onset of clinical symptoms and was associated with a delay in enzyme elevation, indicating the excellent correlation and sensitivity of the enzyme method in assessing liver damage.

Animals↗
PubMed1979

Effect of feeding 1,3-butanediol-1,3-dioctanoate as an energy source for chicks for catch-up growth during recovery from Newcastle disease virus.

1,3-Butanediol-1,3-dioctanoate (BDDO), a synthetic source of energy, has been shown to be equal to corn oil when fed to chicks recovering from moderate and severe Newcastle disease virus infections. Body weight increments of chicks fed diets containing 10% BDDO were equal to or greater than those of chicks fed 10% corn oil, both with restricted feeding regimens. Kilocalories of metabolizable energy required to produce 100 g of body weight increment over a basal group was used as a means of quantitating energy demand. BDDO was comparable to corn oil as an energy source with no adverse effects. Liver/body weight ratios were greater in the BDDO-fed chicks. Circadian rhythmicity of liver size and liver glycogen content was demonstrated. Chicks fed BDDO had total liver glycogen content threefold that of the corn oil controls, which was attributed to stimulation of insulin secretion. Catch-up growth in the chick following the growth depression of disease appears to be as well facilitated by a synthetic source as by a natural one.

Animals↗
PubMed1979

Effect of food toxicants on voluntary wheel running in rats.

Voluntary wheel running in rats in reaction to a dietary deficiency of iron or food toxicants of natural (dioscin) and environmental (cadmium) origins was used to develop a behavioral model by which rapid detection of food contaminants was accomplished following induction of spontaneous activity by techniques of feed restriction. High levels of voluntary wheel running in reference controls were followed by significant depressions in running activity in animals fed the dietary toxicants. Analyses of blood and liver tissues and depressions of testes size confirmed the presence of the insults to metabolism.

Animals↗
PubMed1979

Lysine deficiency and voluntary exercise in the albino rat.

The relationship between low dietary protein and voluntary wheel running was investigated by feeding weanling male white rats a natural diet deficient in lysine, by bioassay criterion. Lysine deficient rats ran more than those pair-fed or ad libitum fed the same diet with lysine added. Body composition of active and inactive rats on the three dietary regimens was compared. Of the carcass components, total and percent protein reduction correlated most strongly with running. Control animals matched in growth to the lysine deficient rats showed hyperactivity earlier, but to the same extent as the lysine deficient rats.

Animals↗
PubMed1979

Biochemical changes in avian tissues during infection.

Major sources of error in studies of diet--infectious disease interactions relate to failure 1) to define the stage of a disease cycle; and 2) to determine the extent of disease involvement at time of sampling. The former can be determined from clinical and biochemical observations from time of inoculation to recovery or mortality; the latter can be calculated from indexes obtained from histological preparations, changes in body temperatures, and other clinical symptoms, including weight loss and efficiencies of feed utilization. Other significant errors are derived from the normal 24-hour dynamics of particular tissue constituents, which include oscillations and circadian rhythms. Experimental designs and accuracy of data are always helped by prior knowledge of 24-hour patterns of these normal fluctuations. For example, such patterns will reveal that enzyme and hormonal changes are far more dynamic than body water changes. Studies of nutrition--disease interactions are extremely complex and the researcher must be aware of and eliminate as many sources of experimental error as possible to avoid confounding the data.

Amino Acids↗
PubMed1977

Effect of treadmill speeds and slopes on voluntary exercise in rats.

Male rats 87 days of age were given daily 90-minute sesions of voluntary exercise on self-operated treadmills pre-set to deliver speeds ranging from 6.1 to 73.2 m/minute and slopes of 0 to 27 degrees. Voluntary motivation to operate the treadmills was induced by maintaining the rats at constant body weights of 203 +/- 2 g. Under the conditions of the experiment, the rats selected 24.4 m/minute and 0 degree slope with running bursts averaging 21 to 24 seconds in duration as a preferred condition for greatest running. Since all activity was voluntary, the consistent patterns of running bursts at 24.4 m/minute are believed to be potentially capable of serving as reference baselines for detection of food contaminants, toxicants and other insults to normal metabolic processes.

Animal Nutritional Physiological Phenomena↗
PubMed1972

Quantitation of the bioenergetics of a tuberculosis infection in chicks.

Interaction of an avian tuberculosis infection with a known metabolizable energy yield of dietary corn oil in chicks was used to quantitate total host energy expenditure necessitated by the infectious process. Three trials in which two doses of inoculum were used resulted in mild and severe involvements. Trial 1 (mild) indicated that 6% and trials 2 and 3 (severe) that 96 and 93% of the energy supplied by known quantities of corn oil were utilized by the tuberculosis process. In the birds given the low level of inoculum, the degree of tuberculosis involvement, as measured by increased liver size, was correlated with increased total quantities of hepatic ribonucleic acid, monoglycerides, free fatty acids, free cholesterol, and glucose. All of these effects were observed prior to manifestations of clinical symptoms or failure of the chicks to consume all food offered.

Animal Feed↗
PubMed1971

Effect of Newcastle disease on serum copper, zinc, cholesterol, and carotenoid values in the chick.

Experimentally induced Newcastle disease virus infection of chicks, with a mortality index of 48%, was accompanied by increased concentrations in serum of copper and cholesterol and decreased concentrations of zinc and total carotenoids. These changes distorted, or were superimposed upon, the rhythmic variability in the normal serum concentrations of each of these moieties. Changing values for copper, zinc, and cholesterol became apparent before any overt signs of disease.

Analysis of Variance↗