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Biomedical subjects

J C Williams

Publications and source records attributed to J C Williams.

At least 361 records · Page 20Linked to original sources
PubMed1981

Anthelmintic efficacy of albendazole against inhibited larvae of Ostertagia ostertagi.

Albendazole was evaluated for its efficacy against inhibited early 4th-stage larvae of Ostertagia ostertagi for the 3rd consecutive year (April 1979) in naturally infected yearling beef cattle. Mean numbers of O ostertagi developmental stages in 10 nontreated controls were: adults, 11,485; developing 4th-stage larvae, 1,370; and early 4th-stage larvae, 51,500. The mean proportion of inhibited early 4th-stage larvae was 76.8%. Small numbers of Haemonchus sp and Trichostrongylus axei were uniformly present in the controls. At a dosage level of 7.5 mg/kg of body weight in a group of 10 cattle, the percentage of reduction in comparison with controls was: O ostertagi adults, 93.5; developing 4th-stage larvae, 53.4; developing 4th-stage larvae, 30.8. Percentage of reduction against Haemonchus sp and T axei adults was 94.5 and 100.0, respectively. At the larger dosage of 10.0 mg/kg in 10 cattle, percentage of reduction was: O ostertagi adults, 94.8; developing 4th-stage larvae, 18.6. Percentage of reduction against Haemonchus sp and T axei adults was 100.0 for both species. Considerable variability of efficacy against inhibited larvae, as well as developing 4th-stage larvae in half of the animals of each treatment group, was responsible for the poor reductions. Clinical signs of toxicosis were not observed after administration of albendazole.

Albendazole↗
PubMed1981

Sickle cell crisis as evaluated from measurements of hydroxybutyrate dehydrogenase and myoglobin in plasma.

Data on plasma hydroxybutyrate dehydrogenase activity (I) and myoglobin concentration were used to evaluate painful sickle cell crises. I was increased during non-crisis steady state in patients with sickle cell disease as compared to normal values (232, SD 79.7 vs 85, SD 33 Sigma units/mL). During crisis, the mean value for I increased further to 379 (SD 139) Sigma units/mL. For 12 patients evaluated both during steady state and crisis, there was a mean increase in plasma I of 131% (SD 76%). Repeated determinations of I in sickle cell disease patients during several months while they were in steady state showed that baseline I varied by no more than 20% from the mean. Plasma myoglobin in patients with sickle cell disease was not above normal, but during crisis 21 of 39 patients tested had increased plasma myoglobin concentrations. Our data suggest that I may be a useful indicator of sickle cell crisis when the patient's own baseline value is available for comparison. Plasma myoglobin measurements give evidence of muscle damage during crisis with high specificity but low sensitivity.

Anemia, Sickle Cell↗
PubMed1980

Adenine nucleotide degradation by the obligate intracellular bacterium Rickettsia typhi.

Adenosine 5'-triphosphate (ATP) was catabolized by whole cells and cell-free extracts of Rickettsia typhi to adenosine 5'-diphosphate (ADP) and then to adenosine 5'-monophosphate (AMP), the end product of ATP catabolism under the experimental conditions used. The only intermediate of the pathway from ATP to AMP which was identified by thin-layer chromatography and quantitated by the (14)C content was ADP, whereas products such as adenine, adenosine, hypoxanthine, inosine, and inosine 5'-monophosphate were not detected. The enzymes which could be theoretically responsible for the catabolism or the anabolism of AMP were not detected by standard assay procedures. Most importantly, 5'-nucleotidase or nonspecific phosphatase and AMP nucleosidase activities were undetectable under a variety of experimental conditions. Although these two enzymes remove AMP from the adenylate pool in other cells, they are apparently nonfunctional in R. typhi. The biosynthesis of ATP was initiated by adenylate kinase because no adenine phosphoribosyltransferase or adenosine kinase could be detected. Furthermore, AMP was transported intact without prior dephosphorylation. These observations suggest that for R. typhi the in vivo activity of adenine nucleotide interconversion was limited to the nucleotides, with AMP being the end product of ATP catabolism, and that the salvage of purine bases and nucleosides was not an essential feature of purine metabolism. These results elucidate the findings of a previous study which showed that in the absence of glutamate as a source of energy, the adenylate energy charge of resting cells of R. typhi is drastically lowered by the high proportion of AMP.

ATP Synthetase Complexes↗
PubMed1979

Hyperlipoproteinemia and multifocal neurologic dysfunction in systemic lupus erythematosus.

Two patients with systemic lupus erythematosus, including one with neuropathologic findings, had recurrent multifocal neurologic dysfunction and hyperlipoproteinemia. The lipoprotein disturbances were complex and variable over time. Deficient lipoprotein lipase was found in both patients and appeared to be related temporally to neurologic deterioration. One of these patients had neurologic disease and lipoprotein abnormalities 2 1/2 years before SLE could be documented serologically. These studies suggest that lipoprotein lipase deficiency may be a marker for the endothelial disorder causing cerebral vasculopathy in SLE.

Adolescent↗
PubMed1979

Activity of fenbendazole against inhibited early fourth-stage larvae of Ostertagia ostertagi.

The efficacy of fenbendazole (Panacur, Hoechst-Roussel) against inhibited early fourth-stage larvae of Ostertagia ostertagi and other nematodes of the abomasum and intestinal tract was investigated in naturally infected, yearling cattle in April 1978. The time when peak levels of inhibited larvae occurred was determined by epizootiologic study which began in November 1977. All animals were removed from pasture and maintained free from further helminth infection until slaughter (19 to 21 days). The fenbendazole liquid suspension was administered as an oral drench at dose level of 10 mg/kg to 10 animals and then at dose level of 15 mg/kg to an additional 10 animals at 10 days after removal from pasture. Eleven animals were maintained as untreated controls. In cattle given the dose of 10 mg/kg, the following reductions were observed: O ostertagi adults--100%, developing stages--80%, and inhibited larvae--97%; other worm genera in the abomasum and nematodes of the intestinal tract--100%. In the cattle given the larger dose, the following reductions were observed: O ostertagi adults--100%, developing stages--98%, and inhibited larvae--99%; other worm genera in the abomasum and nematodes of the intestinal tract--100%.

Animals↗
PubMed1978

Carbohydrate composition of purified serum glycoproteins in mucolipidosis II and mucolipidosis III.

Mucolipidosis II (I-cell disease) and Mucolipidosis III (ML III) are inherited disorders in which the molecular defect may involve an abnormality in a common post-translational modification step (possibly glycosylation) shared by lysosomal hydrolases. We tested whether such an alteration might be a generalized defect in glycoprotein biosynthesis and, thus, be reflected in an abnormal carbohydrate composition of non-lysosomal glycoproteins. The apoprotein of low density lipoprotein (apo-LDL) and immunoglobulin G (IgG) were purified to apparent homogeneity. Gas liquid chromatographic (glc) analysis of the carbohydrate content of these glycoproteins from ML II, ML III and normal sera revealed no differences in the relative ratios and total amounts of mannose, galactose, N-acetylglucosamine and sialic acid. These results suggest that if the postulated post-translational defect in these disorders involves changes in carbohydrate composition, it is not a general defect in glycosylation and may be specific for lysosomal hydrolases.

Ammonium Sulfate↗
PubMed1978

Improved radioisotopic assay for cytidine 5'-triphosphate synthetase (EC 6.3.4.2).

An improved radioassay for cytidine 5-triphosphate synthetase is reported which employs thin-layer chromatographic methods and provides a number of advantages over previously available techniques. (i) The method resolves the nucleotides and the degradation products generated during the time course of the enzymatic reaction by ascending chromatography employing polyethyleneimine cellulose plastic-backed sheets. (ii) Determinations of CTP formed and all nucleotide pairs generated during kinetic analysis of CTP synthetase are greatly simplified, further facilitating the detection of extraneous enzymatic activities. (iii) The sensitivity of the assay is enhanced and as little as 50 pmol of product formed was readily detected in supernatant fluids. This was made possible, in part, by the addition of NaF and phosphoenolpyruvate which together maintain the nucleotide triphosphates in the reaction mixture. (iv) A large number of samples can be handled at one time with highly reproducible results. The synthesis of CTP from UTP by enzyme preparations from rat liver, hepatomas, and Salmonella typhimurium LT2 was quantitated with this method.

Animals↗