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Biomedical subjects

J Pierce

Publications and source records attributed to J Pierce.

At least 109 records · Page 6Linked to original sources
PubMed1975

Purification of alpha1-antitrypsin from plasma through thiol-disulfide interchange.

1. Monomeric nu-chains were conjugated with CNBr-activated Sepharose 4B. The C-terminal cysteine of the conjugated nu-chain was converted to a mixed disulfide with 3-carboxy-4-nitro-benzenethiol (Nbs) and used to separate plasma proteins with reactive thiol groups. The plasma proteins, alpha1-antitrypsin and prealbumin have the greatest affinity for the interchange reaction with mixed disulfides. The disulfide link between alpha1-antitrypsin and nu-chain is sensitive to excess Nbs, and is selectively cleaved in the presence of 5,5'-dithiobis(2-nitrobenzoate) (Nbs2) which accepts the sulfhydryl group of alpha1-antitrypsin. 2. A Simple method developed for the isolation of human alpha1-antitrypsin was equally effective for the various inherited phenotypes and for alpha1-antitrypsin from the dog, baboon, and monkey, Glutathione-Sepharose was also used successfully, but the nu-chain conjugate yielded alpha1-antitrypsin less contaminated with mercaptalbumin and prealbumin. 3. The alpha1-antitrypsin is harvested from this procedure as a mixed disulfide with Nbs. The negative charge of Nbs at pH 8.1 causes an increased electrophoretic mobility of the alpha1-antitrypsin derivative. Mild reduction liberates Nbs and electrophoretic mobility of alpha1-antitrypsin returns to normal. The method described can increase the alpha1-antitrypsin content of a plasma fraction from 5% of the total protein to 95% within one day with a yield of about 50%. This purification procedure does not exert any detectable effect on microheterogeneity.

Animals↗
PubMed1975

Secretion of alpha and beta subunits of TSH by the anterior pituitary.

We have attempted to determine whether blood concentrations of the alpha chains of TSH arise by direct pituitary secretion of alpha chain or by degradation of the intact hormone after secretion. Highly purified human TSH was administered by infusion to euthyroid volunteers; blood TSH concentrations were raised to 36 muu/ml. After TSH infusion, circulating blood alpha chain concentrations did not change. The same volunteers received an infusion of TRH which stimulated pituitary secretion of TSH, raising blood concentrations to 15 muu/ml in one series of subjects and to 23 muu/ml in a second series. After TRH, blood concentrations of alpha chain increased from undetectable to over 400 pg/ml. We conclude that alpha subunits of TSH are directly secreted by the pituitary gland and are not formed by degradation of intact TSH in the peripheral circulation.

Humans↗
PubMedDate not supplied

National age and sex differences in quitting smoking.

The 1986 Adult Use of Tobacco Survey conducted by the Office on Smoking and Health of the Centers for Disease Control asked detailed questions on smoking behavior from a representative sample of 13,031 Americans. Using a smoking continuum developed from that survey as an index, it was postulated that a hard-core group of smokers would be overrepresented in some categories of this continuum in certain groups of the population. In this survey, more women than men who had quit in the preceding year had relapsed to smoking by the time of the survey. However, the fact that similar proportions of men and women had quit smoking for between one and five years suggested that the difference might not have involved the proportion who relapsed but only the timing of that relapse. Smokers over the age of 65 are more likely both to attempt to quit and to continue abstaining than those between ages 25 and 64. Results from this survey do not indicate a major group of smokers who either resist change or who feel unable to quit successfully.

Adolescent↗
PubMedDate not supplied

Low-frequency positive pressure ventilation with extracorporeal carbon dioxide removal (LFPPV-ECCO2R): an experimental study.

We describe a new form of mechanical pulmonary ventilation, low-frequency positive pressure ventilation with extracorporeal CO2 removal (LEPPV-ECCO2R). In a series of animal studies the rate of mechanical ventilation was 0.66, 1, 2, and 4 min-1 at a tidal volume of 3, 10, and 15 ml kg-1. We were able to maintain normal blood gases and normal lung volumes and lung mechanics even at the lowest ventilator rate with tidal volumes of 10 or 15 ml kg-1. Each experiment lasted 7 hours. Our data suggest a possible new dimension in the management of a difficult patient on mechanical pulmonary ventilation.

Animals↗