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J W Boyd

Publications and source records attributed to J W Boyd.

At least 37 records · Page 2Linked to original sources
PubMed1971

Purification and properties of L-asparaginase from Serratia marcescens.

The purification and properties of a tumor inhibitory l-asparaginase from Serratia marcescens are described. The following properties of the enzyme were examined: kinetics of the enzyme reaction, catalytic activity as a function of pH, boundary sedimentation velocity, electrophoresis on polyacrylamide gel, immuno-electrophoresis against homologous and heterologous antisera, immunodiffusion, blood clearance rate in mice, and inhibition of the 6C3HED lymphoma in C3H mice. Complete regression of this tumor was obtained with a smaller dose of the enzyme from S. marcescens than with enzyme from Escherichia coli. The reason for this difference was not evident from a comparison of several properties of the two enzymes.

Acrylates↗
PubMed1971

Immunochemical comparison of L-asparaginases from Serratia marcescens and Escherichia coli.

Immunochemical properties of l-asparaginases from Serratia marcescens and Escherichia coli were compared by means of quantitative precipitin reactions and quantitative microcomplement-fixation reactions employing homologous and heterologous antisera. The enzyme preparations used in these tests produced one arc of precipitate upon immunoelectrophoresis. According to our results with the precipitin and micro-complement fixation reactions, both enzymes are related immunochemically. On the basis of these tests, distinct structural differences exist between the two enzymes. From results with the micro-complement fixation test, we estimated that the two enzymes could differ by 10 to 15 amino acid residues.

Ammonia↗
PubMedDate not supplied

Smoking and mental illness: A population-based prevalence study.

CONTEXT: Studies of selected groups of persons with mental illness, such as those who are institutionalized or seen in mental health clinics, have reported rates of smoking to be higher than in persons without mental illness. However, recent population-based, nationally representative data are lacking. OBJECTIVE: To assess rates of smoking and tobacco cessation in adults, with and without mental illness. DESIGN, SETTING, AND PARTICIPANTS: Analysis of data on 4411 respondents aged 15 to 54 years from the National Comorbidity Survey, a nationally representative multistage probability survey conducted from 1991 to 1992. MAIN OUTCOME MEASURES: Rates of smoking and tobacco cessation according to the number and type of psychiatric diagnoses, assessed by a modified version of the Composite International Diagnostic Interview. RESULTS: Current smoking rates for respondents with no mental illness, lifetime mental illness, and past-month mental illness were 22.5%, 34.8%, and 41.0%, respectively. Lifetime smoking rates were 39.1%, 55.3%, and 59.0%, respectively (P<.001 for all comparisons). Smokers with any history of mental illness had a self-reported quit rate of 37.1% (P =.04), and smokers with past-month mental illness had a self-reported quit rate of 30. 5% (P<.001) compared with smokers without mental illness (42.5%). Odds ratios for current and lifetime smoking in respondents with mental illness in the past month vs respondents without mental illness, adjusted for age, sex, and region of the country, were 2.7 (95% confidence interval [CI], 2.3-3.1) and 2.7 (95% CI, 2.4-3.2), respectively. Persons with a mental disorder in the past month consumed approximately 44.3% of cigarettes smoked by this nationally representative sample. CONCLUSIONS: Persons with mental illness are about twice as likely to smoke as other persons but have substantial quit rates. JAMA. 2000;284:2606-2610.

Adolescent↗
PubMedDate not supplied

Relationships between acid-base balance, serum composition and colostrum absorption in newborn calves.

Twenty-seven newborn Holstein bull calves were bottle-fed 2 litres of pooled colostrum which had been stored at -20 degrees C. Blood gas analysis before feeding showed a partially compensated respiratory acidosis in most of the calves, although they all appeared to be clinically normal. Mean venous blood pH was 7.346, carbon dioxide tension (PCO2) was 57.5 mmHg (7.6 kPa), bicarbonate was 30.6 mmol/l and base excess was 3.82 mmol/l. Mean serum IgG1 increased to 8.1 g/l after feeding colostrum. Several significant positive correlations were observed between post-absorptive serum protein, IgG1, IgM, gamma-glutamyltransferase (gamma GT) and D-xylose. Calves with either low serum albumin, high serum CK or low serum gamma GT before feeding tended to have less absorption of colostral protein. It was concluded that reduced absorption of IgG1 from colostrum is associated with hypercapnia in apparently healthy newborn calves.

Acid-Base Equilibrium↗