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Biomedical subjects

R Wolfe

Publications and source records attributed to R Wolfe.

At least 91 records · Page 5Linked to original sources
PubMed1984

Effects of intravenous glucose on whole body leucine dynamics, studied with 1-13C-leucine, in healthy young and elderly adults.

We examined whole body leucine metabolism in healthy young and elderly adults while in the postabsorptive state and during an intravenous glucose administration at two rates. Leucine flux, incorporation into whole body protein, and oxidation were estimated from a continuous intravenous infusion of L-[1-13C]leucine and determination of 13C enrichment in plasma leucine and expired air. Per unit of body weight, leucine flux and rates of incorporation into protein were similar in young and old men. Old women showed lower rates compared with young women. Rates were similar for both age groups when expressed per unit of total body water and/or of muscle protein mass. Intravenous glucose infusion (4 mg . kg-1 . min-1) reduced plasma leucine levels and flux similarly in both age groups. Thus, age-related differences in muscle mass and sensitivity of peripheral tissues to insulin-mediated glucose uptake and metabolism are not paralleled by alterations in whole body leucine kinetics in the postabsorptive state.

Adult↗
PubMed1983

Autoantibodies to SS-A/Ro in infants with congenital heart block.

Antibodies to SS-A/Ro have been proposed to be a serologic marker for the neonatal lupus syndrome, which is characterized by congenital heart block or cutaneous lupus or both. The antibodies occur in the mother and are transiently found in the child's serum. We examined an unselected series of 12 children with idiopathic CHB, isolated in 10 children and with cutaneous lupus lesions in two. Six of these children and their mothers were studied during the child's neonatal period, and six were studied retrospectively. All six neonates had SS-A/Ro autoantibodies. Nine of 12 mothers had SS-A/Ro autoantibodies. Of the seropositive mothers, one had systemic lupus erythematosus, two had sicca syndrome, one had photosensitivity, one had arthralgias, and four were asymptomatic. We propose that congenital heart block may be related to transplacental passage of maternal SS-A/Ro antibodies and that neonatal lupus may be the most common cause.

Adult↗
PubMed1983

Self-monitoring and sex as moderator variables in the statistical explanation of self-reported marijuana and alcohol use.

Self-monitoring and sex are examined as likely moderators of some of the known effective predictors of self-reported use of marijuana and alcohol. The theory of self-monitoring implies that in comparisons between low and high self-monitors, dispositional predictors account for more of the variance in reported use among low self-monitors and environmental predictors account for more of the variance among high self-monitors. With the two classes of predictors established via principal-components analysis and with subgroups defined by scores on Snyder's Self-Monitoring Scale, data from 807 college students showed that self-monitoring does not affect the action of either dispositional or environmental predictors. Thus, the self-monitoring construct promises explanatory leverage that in these tests, the scale is not able to deliver. When subgroups are defined by sex, analyses of reported alcohol use yield small but significant moderator effects: Women's use is more predictable from environmental variables, whereas men's use is more predictable from dispositional variables. These effects are consistent with the conclusions of recent meta-analyses of results from studies of sex differences in conformity to group pressures.

Alcohol Drinking↗
PubMed1982

Effect of orally administered cimetidine on histamine- and antigen-induced bronchospasm in subjects with asthma.

Previous studies concerning the effect of cimetidine, a histamine H2 receptor antagonist, on histamine- or antigen-induced bronchoconstriction have yielded conflicting results. Therefore, we examined the effects of cimetidine on sensitivity to both histamine- and antigen-induced bronchospasm in 12 subjects with mild asthma (baseline FEV1 greater than 70% predicted). Bronchial challenges with inhaled histamine or antigen were performed 2 h after a single dose of 300 mg cimetidine or placebo orally administered in a random, double-blind manner on separate days. The provocative concentration of antigen or histamine that produced a 20% decline in FEV1 from the postdiluent control value (PC20) was determined and log transformed. Plasma cimetidine concentrations 2 h after oral administration (mean, 1.5 microgram/ml; range, 0.9 to 2.4 mirograms/ml) were above the minimal concentration required for suppression of gastric acid secretion. No difference was noted in FEV1, specific airway conductance, or partial expiratory flow rates after cimetidine compared with that after placebo, indicating the lack of any bronchospastic effect of cimetidine in the absence of histamine or antigen challenge. However, mean log PC20 of histamine (but not of antigen) was significantly less after cimetidine than after placebo (p less than 0.05), indicating that cimetidine augmented histamine-(but not antigen-) induced bronchospasm. Four of 12 subjects exhibited a significant (greater than or equal to fourfold) decline in PC20 for histamine after cimetidine compared with that after placebo but no subject demonstrated a significant (greater than or equal to tenfold) decline in PC20 of antigen. No relationship was apparent between baseline sensitivity to histamine and cimetidine effect on histamine sensitivity in individual subjects. We conclude that in subjects with mild asthma, cimetidine in the usual recommended orally administered dose can increase sensitivity to bronchospasm induced by histamine but not by antigen. These findings suggest that cimetidine in this dose has a blocking effect on H2 receptors in airway smooth muscle but that this effect is not sufficient to alter the net impact of immunologic release of mediators on the airways.

Adult↗
PubMed1980

Effects of a serum spreading factor on growth and morphology of cells in serum-free medium.

A heat-sensitive, trypsin-sensitive factor that promoted growth and spreading of cells in serum-free, hormone-supplemented medium was partially purified from human serum. The major portion of the proteins in these preparations migrated upon SDS-polyacrylamide gel electrophoresis with a mobility consistent with molecular weights between 60,000 and 90,000. The spreading activity, which we have termed serum spreading factor, stimulated growth and spreading of a wide variety of cell types. The serum spreading factor was similar to fibronectin in that it showed an affinity for the plastic cell culture substrate but was shown to be distinct from fibronectin by several criteria. This factor may prove useful in studies of cell attachment and spreading and in studies of the relationship of cell shape and cell proliferation.

Animals↗
PubMedDate not supplied

The emergency department management of near-hanging victims.

A 7-year retrospective review was performed to assess the complications of near-hangings injuries. Thirty-nine cases of near hanging were seen during this period. There were no hanging drops greater than 5 feet and no cervical spine fractures. One patient required intubation for soft tissue swelling. The adult respiratory distress syndrome (ARDS) occurred in three patients. All victims with field Glasgow Coma Scale levels >3, and three of eight with GCS = 3 survived to discharge with a normal mental status. We conclude that aggressive resuscitation and treatment of postanoxic brain injury is indicated even in patients without evident neurologic function in the field, as full recovery may still occur. Cervical spine fractures have not been reported in near-hanging victims and should only be considered if there is a possibility of a several foot drop or if a focal neurologic deficit is present. Injury to the anterior soft tissues of the neck may cause respiratory obstruction. Close attention to the development of pulmonary complications is required.

Accidents↗