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Biomedical subjects

J Stevens

Publications and source records attributed to J Stevens.

At least 343 records · Page 19Linked to original sources
PubMed1979

Proximal femoral fractures in psychiatric patients.

During an 8-year period, 122 inpatients of a psychiatric hospital sustained fractures of the proximal part of the femur. They were treated by operative as well as by conservative methods and their subsequent mobility, morbidity and mortality have been reviewed. The results suggest that these patients are best managed within their familiar environment, that femoral head replacement arthroplasty is appropriate for high fractures and that the prevention of bedsores in conservatively treated patients is of great importance.

Aged↗
PubMed1979

Physicochemical differences between glucocorticoid-binding components from the corticoid-sensitive and -resistant strains of mouse lymphoma P1798.

The physicochemical properties of nuclear and cytosolic glucocorticoid-binding components from corticoid-sensitive (CS) and corticoid-resistant (CR) mouse lymphoma P1798 cells have been compared. Nuclei or cytosol fractions were prepared from lymphocytes that had been labeled at 37 or 4 degrees, respectively, with 30 nM [3H]triamcinolone acetonide ([3H]TA). [3H]TA was extracted with 0.6 M KCl, 10 mM spermidine, or 4.5 mM MgCl2 from CS nuclei and with 0.6 M KCl or 10 mM spermidine from CR nuclei. As reported previously, nuclear-associated [3H]TA in CR cells was resistant to extraction with mM concentrations of MgCl2. Loss of bound steroid during extraction with 0.6 M KCl was minimized by including the chymotrypsin inhibitor, carbobenzoxy-L-phenylalanine, in the extraction buffer. The inhibitor was not required during extraction with spermidine or MgCl2. Nuclear and cytosolic extracts were examined by analytical agarose gel filtration and glycerol density gradient centrifugation under high salt (0.6 M KCl) conditions. The glucocorticoid-binding component in KCl, spermidine, and MgCl2 extracts from CS nuclei was considerably larger and more asymmetrical [Stokes radius, 57 to 59 A; sedimentation coefficient, 3.64 to 3.70S; molecular weight, 90,000 daltons; frictional ratio, 1.8; axial ratio (prolate ellipsoid), 15] than the [3H]TA-macromolecular complex in KCl and spermidine extracts from CR nuclei[Stokes radius, 29 A; sedimentation coefficient, 3.23 to 3.30S; molecular weight, 40,000 daltons; frictional ratio, 1.25; axial ratio (prolate ellipsoid), 5]. Control experiments showed that the smaller size of the glucocorticoid-binding component in CR nuclei was probably not due to cleavage of a larger, CS-like complex during the extraction procedure. The larger size of the CS [3H]TA complex did not appear to result from aggregation of s a smaller species. No difference in physicochemical parameters of the binding component was observed if cells were labeled with [3H]dexamethasone instead of [3H]TA. However, [3H]dexamethasone complexes were less stable than those formed with [3H]TA as indicated by considerable dissociation of [3H]dexamethasone during gel filtration and gradient centrifugation. This may be due to the 3- to 5-fold lower relative binding affinity of [3H]dexamethasone. Analysis of [3H]TA-labeled cytosol by gel filtration and gradient centrifugation revealed the presence of a single binding component with physicochemical properties similar to those of nuclear [3H]TA complexes from the same strain of tumor. These results suggest that previously described differences in extractability of nuclear-associated [3H]TA between the CS and CR strains of mouse lymphoma P1798 and the lack of response of CR P1798 to glucocorticoid administration may be due, at least in part, to the presence of an altered glucocorticoid-binding component in the resistant tumor cells.

Adrenal Cortex Hormones↗
PubMed1978

The effect of drug concentration on the thermal (dark) degradation of promethazin hydrochloride in aqueous solution.

The thermal (dark) degradation of promethazine hydrochloride in aqueous solution presents a complex kinetic picture. The process is oxygen dependent and is modified by EDTA. In citrate buffer, pH 4.0, ionic strength 0.5M, containing 0.1% EDTA, the thermal degradation at 90 degrees can be fitted to first order rate plots at drug concentrations up to 1.56 x 10.27 (0.5%) and to zero order rate plots at drug concentrations greater than 9.35 x 10.2M (3.0%). At intermediate concentrations no simple equation can describe the data. These effects have been correlated with the formation of drug micelles and the rate date have been interpreted on the basis of a first order monomer process and a half order micellar process occurring simultaneously.

Chromatography, Gas↗
PubMed1978

Nuclear glucocorticoid binding in chronic lymphatic leukemia lymphocytes.

A reliable procedure is described for isolating 3H-triamcinolone acetonide (3H-TA) receptor complexes from purified chronic lymphatic leukemia (CLL) lymphocyte nuclei, based on the use of carbobenzoxy-L-phenylalanine (CBZ-L-phe) to prevent breakdown of hormone-receptor complexes during extraction of nuclei with 0.6M KCl. Using this method, specific nuclear glucocorticoid binding was demonstrated in 14/14 patients with untreated CLL. No correlation was found between levels of nuclear-associated 3H-TA and peripheral white blood cell count or rosetting ability of circulating lymphocytes.

Aged↗
PubMed1977

Cancer of the pancreas in blacks: a ten-year experience.

A ten-year retrospective study of cancer of the pancreas in black patients at Howard University Hospital is presented. A total of 68 patients was studied. The authors concluded that no form of treatment had significant effect in terms of survival in stages II, III, and IV disease.

Adult↗
PubMed1977

Evaluation of computer-aided monitoring of patients after heart surgery.

The medical and economic benefits of a computer-aided monitoring system were evaluated in a prospective, randomized study of 810 patients after open-heart surgery. The design of the study separated benefits of systematized postoperative care from benefits unique to the computer system and established measurable criteria by which computer-aided monitoring systems could be objectively evaluated. Criteria for comparison included the rapidity, safety, and smoothness of convalescence and time spent for various nursing activities. The study showed that the computer-aided monitoring system did not provide discernible medical benefits nor favorably affect nursing activities. Downtime of the system averaged 1 day per week. Reliability and accuracy of the system were inadequate and the benefit/cost ratio was low. Future development of computer-aided monitoring systems for open cardiac surgery should stress reliability, accuracy and relevance of the monitored measurements.

Cardiac Surgical Procedures↗