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Biomedical subjects

L G Young

Publications and source records attributed to L G Young.

At least 73 records · Page 4Linked to original sources
PubMed1977

Studies on vitamin E and selenium deficiency in young pigs. I. Hematological and biochemical changes.

Pigs which were deficient in vitamin E and/or selenium had the following parameters weekly determined from six to 13 weeks of age: Packed cell volume, hemoglobin concentration, red cell and white cell counts, red cell indices, reticulocyte count, serum iron, serum total iron binding capacity, myeloid: erythroid ratio, serum glutamic-oxaloacetic transaminase and creatine phosphokinase activities and body weight. Except for the myeloid:erythroid ratio and serum creatine phosphokinase activity, these parameters were not found to be significantly affected by either vitamin E deficiency, selenium deficiency or deficiency of both. The myeloid:erythroid ratio was increased (p less than 0.01) in association with selenium deficiency, which tends to indicate decreased erythropoiesis but was not reflected in the peripheral red cell picture. Evidence of dyserythropoiesis was not found to be a significant feature in serial bone marrow aspiration biopsies of vitamin E and/or selenium deficient pigs. Even if the serum glutamic-oxaloacetic transaminase activities were not found to be significantly affected by either vitamin E deficiency, selenium deficiency or deficiency in both as compared to replete animals, a few animals, especially in the group deficient in both vitamin E and selenium, presented quite marked transient increases of serum glutamic-oxaloacetic transaminase activity which was interpreted to reflect the occurrence of acute episodes of hepatosis dietetica. Serum creatine phosphokinase activities were found to be increased in association with vitamin E deficiency (p less than 0.01), selenium deficiency (less than 0.05) and the interaction was also significant (p less than 0.01). It was concluded that the serum creatine phosphokinase activity increases reflect the occurrence of subclinical muscular dystrophy and that vitamin E and selenium deficiencies have marked additive effects in the induction of skeletal muscular dystrophy.

Animals↗
PubMed1977

Studies on vitamin E and selenium deficiency in young pigs. III. Effect on kinetics of erythrocyte production and destruction.

The effect of vitamin E and/or selenium deficiency on the kinetics of erythrocyte production and destruction has been investigated in swine. The plasma iron turnover rate, 59Fe incorporation into newly formed red cells as well as the 51Cr apparent red cell half-life, were not found to be significantly affected by either vitamin E deficiency, selenium deficiency or deficiency of both, as compared to replete animals. The results of this study suggest that vitamin E is not a limiting factor for normal erythropoiesis in young growing pigs. Erythropoiesis appeared, however, to be slightly decreased in selenium deficient pigs and will need to be further investigated.

Animals↗
PubMed1977

Studies on vitamin E and selenium deficiency in young pigs. IV. Effect on coagulation system.

An evaluation of the coagulation system has been conducted in vitamin E and/or selenium deficient swine. The partial thromboplastin time, plasma fibrinogen concentration, platelet lipid peroxides, as well as the fibrinogen/fibrin degradation products were not found to be significantly affected by either vitamin E deficiency, selenium deficiency, or deficiency of both. With selenium deficiency, the prothrombin time was shortened (p less than 0.05). The platelet count and platelet turnover were greatly decreased by both vitamin E (p less than 0.001) and selenium deficiency (p less than 0.005). Further-more, the survival of platelets labelled with 75Se-selenomethionine and the per cent isotope incorporated into platelets were reduced (p less than 0.05 and p less than 0.005) in association with vitamin E deficiency, but not with selenium deficiency. These results were interpreted as evidence of a platelet production defect and possibly a platelet function defect in vitamin E deficient animals. Selenium deficiency were also associated with decreased (p less than 0.05) survival of fibrinogen labelled with 75Se-selenomethionine and increased (p less than 0.05) turnover of fibrinogen. From these fibrinogen kinetic findings, it was considered that chronic low grade disseminated intravascular coagulation possibly occurs in selenium deficient animals, probably in relation to the development of hepatosis dietetica or widespread microvascular damage. However, other possibilities such as increased fibrinogenolysis in relation with hepatosis dietetica or an intrinsic fibrinogen defect due to selenium deficiency also need to be taken into consideration and have not been ruled out in the present study.

Animals↗
PubMed1976

A model for reinforcing mental health facilities: a student's view.

Present mental health care facilities are not reinforcing either to work in or to utilize. A new approach to agency design, in order to provide client self-respect and situational relief, to increase availability and accessibility of services, and to attract highly skilled staff should be adopted. The criteria for a reinforcing agency should be based on a client, staff, and community needs. Changes can be implemented by building new facilities or modifying old ones. The resulting facilities would enhance the treatment process, reinforce behavioral change, and reinforce productivity.

Community Mental Health Services↗
PubMed1976

Infleuce of dietary levels of vitamin E and selenium on tissue and blood parameters in pigs.

Eighteen barrows approximately three weeks of age were used in a 3 X 3 factorial arrangement to investigate the effect of level of supplemental vitamin E and selenium on tissue and blood parameters. Tissue selenium concentrations increased in a quadratic manner with increased selenium intake with kidney tissue containing considerably greater concentrations than liver, heart or muscle. Supplementation of the diet caused a three-fold increase in serum selenium within the first week with a slight tendency to further increases in subsequent weeks. Serum vitamin E of unsupplemented pigs declined by fifty percent during the experiment, whereas supplemental vitamin E resulted in increased serum vitamin E. There was a considerable viration in percent peroxide hemolysis. Correlation of -0.63 between percent peroxide hemolysis and vitamin E intake and -0.85 between percent peroxide hemolysis and serum vitamin E were observed.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Purification and properties of rat liver adenine phosphoribosyltransferase.

The adenine phosphoribosyltransferase (AMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.7) of rat liver was purified to a specific activity of 1.1 mumol of AMP formed per min per mg. The enzyme activity is associated with an apparently homogenous protein as shown by isoelectrofocusing, acrylamide gel electrophoresis, and N-terminal amino acids analysis (phenylalanine). The molecular weight of the enzyme was estimated to be approx. 20 000 by acrylamide gel electrophoresis in the presence of sodium dodecylsulfate and by sucrose density gradient zone sedimentation. The rat liver enzyme exhibited initial burst synthesis of AMP when 1-pyrophosphorylribose 5-phosphate was added. The 1-pyrophosphorylribose 5-phosphate initial-burst activity copurifies with the adenine phosphoribosyltransferase activity. A PH optimum of 10.0 was demonstrable for the adenine phosphoribosyltransferase. The initial-burst and steady-state phases of AMP synthesis catalyzed by highly purified rat liver adenine phosphoribosyltransferase have been partially characterized by the use of ligands which bind to sulfhydryl groups. Studies utilizing p-chloromercuribenzoate and HgCl2 as inhibitors of AMP sulfhydryl during the initial-burst and steady-state phases have revealed that sulfhydryl groups with different rates of ligand binding are present in the enzyme. The initial-burst phase was thereby delineated from the steady-state phase by use of these mercurial ligands. This delineation was also accomplished by titration with the Mg-2+ chelator, EDTA. The inhibitory effects of mercurials and EDTA were reversed by beta-mercaptoethanol and excess Mg-2+, respectively. Quantitative binding studies with 5,5'-dithiobis(2-nitrobenzoic acid) and p-chloromercuribenzoate yielded values of 3.65 and 3.6 mol of sulfhydryl per mol of enzyme, respectively. 3.3 mol of cysteic acid per mol of performic acid-oxidized enzyme were found by amino acid analysis.

Adenine Phosphoribosyltransferase↗
PubMed1975

Characterization of the ATP-phosphohydrolase activity of bovine spermatozoa flagellar extracts.

The ATP-phosphohydrolase activity of extracts prepared from bovine spermatozoa flagella (BSFE), was characterized with respect to enzyme, substrate, activator ion and salt concentration, temperature dependence and time stability. BSFE required the presence of a divalent cation for activity: Mg++ or Ca++ could function as activator; Mn++, Zn++ and Cd++ could not. EDTA, but not EGTA, was inhibitory to enzymatic activity. Ca++ inhibited the Mg++ stimulated activity. ATP was dephosphorylated more rapidly than GTP greater than CTP greater than ITP, and ADP was dephosphorylated at 40% of the rate of ATP. The magnesium activated ATPase was stimulated by potassium and inhibited by sodium ions. Activation of BSFE ATP-phosphohydrolase was maximal in the presence of Mg++ and ATP in equimolar concentrations and K+ (0.05-0.3 M) at 30 degrees C. Although the enzymatic activity of the extract was found to decrease rapidly with time, it could be maintained for up to three days by the addition of 2-beta-mercaptoethanol to the bovine spermatozoa flagellar extracts.

Adenosine Triphosphatases↗
PubMed1972

Dietary induction of mulberry heart disease and hepatosis dietetica in pigs. I. Nutritional aspects.

Two trials were conducted, involving 48 Yorkshire specific pathogen-free pigs, three to four weeks old, to investigate diets which would result in a high incidence of deaths from mulberry heart disease and hepatosis dietetica in pigs. Diets based on ground corn with torula yeast resulted in a high incidence of death. Protein supplements of dried skim milk or soybean meal with corn did not induce a high incidence of death. Diets supplemented with torula yeast had the lowest selenium concentration and highest (alpha-)tocopherol concentration of the diets investigated and resulted in lower liver selenium concentrations. A higher frequency of hepatosis dietetica, mulberry heart disease, skeletal muscle degeneration and exudative diathesis was observed in pigs fed the low level selenium diets containing torula yeast.

Animal Feed↗
PubMed1972

Effect of supplemental vitamin E and selenium in high moisture corn diets on the incidence of mulberry heart disease and hepatosis dietetica in pigs.

Forty-eight intact male pigs were used to investigate the influence of source of protein supplement, corn moisture content, and supplemental vitamin E-selenium survived the cidence of mulberry heart disease, hepatosis dietetica and associated lesions. Pigs fed soybean meal-high moisture corn diets survived fewer days than pigs fed the other diets. None of the pigs fed torula yeast-dry corn or soybean meal-high moisture corn without supplemental vitamin E-selenium survived the 13 week trial. Supplemental vitamin E-selenium increased survival of pigs. A higher incidence of hepatosis dietetica, myocardial degeneration, skeletal muscle degeneration, and exudative diathesis was observed in pigs fed torula yeast-dry corn or soybean meal-high moisture corn than pigs fed soybean meal-dry corn. Supplemental vitamin E-selenium resulted in a reduction in the incidence of the above lesions by approximately 50% with the exception of hepatosis dietetica. Tissue selenium concentration did not appear to be related to the incidence of the various lesions.

Animal Feed↗