Search PubMed⌕ Search

Biomedical subjects

J Pierce

Publications and source records attributed to J Pierce.

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

Smoking, alcohol, analgesics, and chronic duodenal ulcer. A controlled study of habits before first symptoms and before diagnosis.

The aim of the study was to investigate the role of smoking and alcohol and analgesic ingestion in the aetiology of chronic duodenal ulcer (DU). Exposure to these variables was studied during the lifetime and 1 year before the first ulcer symptom and 1 month before a diagnosis. The ulcer group of 100 patients was compared with 100 community controls matched for age, sex, and social grade. In men there was an increased risk of DU associated with smoking and alcohol ingestion both during the lifetime and 1 year before the first symptom. In women, there was an increased risk associated with smoking during the lifetime before the first symptom and with alcohol ingestion during the year before the first symptom. Analgesic ingestion was not a risk factor. In the month before diagnosis only smoking was commoner in the DU group. The data indicate that smoking and alcohol ingestion are risk factors for DU.

Age Factors↗
PubMed1981

Veterans Administration cooperative study on aphasia: a comparison of individual and group treatment.

Five Veterans Administration Medical Centers participated in an investigation designed to compare individual with group treatment for aphasic patients who had suffered a left hemisphere cerebral vascular accident. Patients who met selection criteria were assigned randomly to either traditional, individual, stimulus-response type treatment of specific language deficits or group therapy designed to improve communication through group interaction and discussion with no direct treatment of specific language deficits. All patients received eight hours of therapy each week beginning at four weeks postonset and continuing until 48 weeks postonset or until they dropped out of the study. A battery of language measures and a clinical neurologic evaluation were administered at intake and every 11 weeks a patient was in the study. Results show both individually and group-treated patients made significant improvement in language abilities. Individual treatment resulted in significantly better overall performance on the Porch Index of Communicative Ability; however, no significant differences were observed between groups on the other language measures. If the traditional belief is correct that significant spontaneous recovery is complete by three to six months postonset, significant improvement in both groups beyond 26 weeks postonset indicates both individual and group treatment are efficacious methods for managing aphasic patients.

Adult↗
PubMed1981

Metabolic labeling of lutropin with [35S]sulfate.

Chemical analyses have previously detected sulfate linked to the oligosaccharides of lutropin isolated from bovine and human pituitaries. To determine whether lutropin could be metabolically labeled with sulfate, isolated bovine and rat pituitaries were incubated with [35S]sulfate. In both species, two major labeled products were immunoprecipitated with antisera specific to lutropin subunits. Incorporation into the subunits occurred posttranslationally since it was not blocked by cycloheximide, which did, however, block the incorporation of radiolabeled methionine. Metabolic labeling with [35S]sulfate provides a valuable approach for examining the biosynthetic processing of lutropin and the physiological role of sulfate in this hormone.

Animals↗
PubMed1980

Interaction of ribulosebisphosphate carboxylase/oxygenase with transition-state analogues.

2-C-Carboxy-D-ribitol 1,5-bisphosphate and 2-C-carboxy-D-arabinitol 1,5-bisphosphate have been synthesized, purified, and characterized. In the presence of Mg2+, 2-C-carboxy-D-arabinitol 1,5-bisphosphate binds to ribulose-1,5-bisphosphate carboxylase/oxygenase by a two-step mechanism. The first, rapid step is similar to the binding of ribulose 1,5-bisphosphate or its structural analogues. The second step is a slower process (k = 0.04 s-1) and accounts for the tighter binding of 2-C-carboxy-D-arabinitol 1,5-bisphosphate (Kd less than or approximately to 10(-11) M) than of 2-C-carboxy-D-ribitol 1,5-bisphosphate (Kd = 1.5 X 10(6) M). Both carboxypentitol bisphosphates exhibit competitive inhibition with respect to ribulose 1,5-bisphosphate. 2-C-(Hydroxymethyl)-D-ribitol 1,5-bisphosphate and 2-C-(hydroxymethyl)-D-arabinitol 1,5-bisphosphate were also synthesized; both are competitive inhibitors with respect to ribulose 1,5-bisphosphate with Ki = 8.0 X 10(-5) M and Ki = 5.0 X 10(-6) M, respectively. Thus, the carboxyl group of 2-C-carboxy-D-arabinitol 1,5-bisphosphate is necessary for maximal interaction with the enzyme. Additionally, Mg2+ is essential for the tight binding of 2-C-carboxy-D-arabinitol 1,5-bisophsphate. A model for catalysis of ribulose 1,5-bisphosphate carboxylation is discussed which includes a functional role for Mg2+ in the stabilization of the intermediate 2-C-carboxy-3-keto-D-arabinitol 1,5-bisphosphate. Mechanistic implications that arise from the stereochemistry of this intermediate are also discussed.

Carboxy-Lyases↗
PubMed1980

Mass spectrometric analysis of the reactions of ribulosebisphosphate carboxylase/oxygenase.

The products of the reaction of D-[2-13C]ribulose 1,5-bisphosphate with molecular oxygen in the presence of D-ribulose 1,5-bisphosphate carboxylase/oxygenase were analyzed, after dephosphorylation, as the trimethylsilyl derivatives of glycolate and glycerate by mass spectrometry. The extent of isotopic incorporation into [1-13C]glycolate from [1-13C]glycolate 2-phosphate produced in the oxidation reaction demonstrates that at least 95% of the glycolate 2-phosphate produced arises from carbon atoms 1 and 2 of D-ribulose 1,5-bisphosphate. When D-[2-18O]ribulose 1,5-bisphosphate was used, a significant amount of [1-18O]glycolate 2-phosphate was formed, indicating that O-2 of D-ribulose 1,5-bisphosphate is retained in the carboxyl oxygens of glycolate 2-phosphate. In addition, analyses of the products of the reaction between D-[2-13C]ribulose 1,5-bisphosphate and [13C]O2 confirm and extend the conclusions of an earlier report (Müllhofer, G., and Rose, I. A. (1965) J. Biol. Chem. 240, 1341-1346) that cleavage of D-ribulose 1,5-bisphosphate occurs between carbon atoms 2 and 3 during its enzymatic carboxylation. The results eliminate possible mechanisms involving the obligatory loss of O-2 of D-ribulose 1,5-bisphosphate during its enzymatic oxidation and confirm the specificity of carbon--carbon bond cleavage in both the oxygenase and carboxylase reactions.

Carbon Isotopes↗
PubMed1979

Carbon-13-enriched carbohydrates: preparation of triose, tetrose, and pentose phosphates.

Three-, four-, and five-carbon aldononitrile phosphates were prepared, purified, and catalyticlly reduced with palladium--barium sulfate (5%) to the corresponding aldose phosphates in high yields at pH 1.7 +/- 0.1 and atmopsheric pressure. DL-Glyceraldehyde 3-phosphate and the tetrose 4-phosphates were prepared with carbon-13 enrichment at C-1, while the pentose 5-phosphates were prepared with enrichment at C-1 and C-2. Preparations of glycolaldehyde phosphate and d-glyceraldehyde 3-phosphate by lead tetra-acetate oxidation of glycerol phosphate and fructose 6-phosphate, respectively, are described. The proportions of cyclic hemiacetals and linear gem-diol forms of the two- to five-carbon aldose phosphates in aqueous solution are reported. Carbon-13 chemical shifts and carbon--phosphorus and carbon--hydrogen coupling constants for the furanose phosphate ring and linear gem-diol phosphates are reported and discussed. d-[2(-13)C]Ribulose 1,5-bisphosphate and L-[3,4(-13)C]sorbose 1,6-bisphosphate were prepared enzymatically from D-[2(-13)C]ribose 5-phosphate and dl-[1(-13)C]glyceraldehyde 3-phosphate, respectively.

Carbohydrate Epimerases↗
PubMed1979

Evaluation of paramedic programs using outcomes of prehospital resuscitation for cardiac arrest.

Two evaluation methods, one statistical and one comparative, were developed to assess the effectiveness of paramedic programs in King County, Washington. The outcome of hospital admission following prehospital cardiac arrest was used as a measure of effectiveness. In the statistical method, actual outcomes were compared with predicted outcomes. Predictive variables for admission were time from collapse to initiation of cardiopulmonary resuscitation and time from collapse to definitive care. Given knowledge of the predictive variables, the statistical evaluation enabled us to determine the probability of the outcome following cardiac arrest. In the comparative method, outcomes were compared with a standard in an adjacent community. Using this method, we identified program elements that could lead to improved outcome. Both evaluation methods are easily implemented.

Emergency Medical Services↗
PubMed1978

Control of intermittent positive pressure breathing (IPPB) by extracorporeal removal of carbon dioxide.

Five lambs were anaesthetized, paralysed, mechanically ventilated and connected to a membrane "lung" to permit removal of carbon dioxide. When part of the carbon dioxide was removed in this manner, the tidal volume was decreased to keep PaCO2 constant. For example, when 70% of carbon dioxide was removed by the membrane lung, total ventilation was reduced by 50%, peak inspiratory pressure was decreased by 45%, and PaO2 was kept constant by increasing the inspired oxygen fraction from 0.21 to 0.27%. The removal of carbon dioxide by a membrane during positive pressure breathing could decrease barotrauma, particularly in poorly compliant lungs. Technically, the extracorporeal removal of carbon dioxide is relatively simple procedure.

Animals↗
PubMed1976

Comparison of a private family practice and a university teaching practice.

In March 1972 a private family practice in Hamilton, Canada, became a teaching practice of McMaster University. Subsequently a before-and-after study was conducted to compare characteristics of the patients and the impact of the change on the practice. There was a 34 percent reduction in practice size. There was a shift to younger patients and a substantial drop in mean patient income. Utilization rates of health services rose, particularly hospitalization, even though the average length of stay decreased. Profiles of complaints and diagnoses remained very similar. Quality of care scores were comparable with those of community controls before and after the change. Gross income from clinical earnings dropped, but the amounts per person per year were very similar in the two periods. It is concluded that the "transplanted private practice" which becomes part of a school of medicine is a realistic teaching resource in primary care.

Family Practice↗