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Biomedical subjects

R S Wright

Publications and source records attributed to R S Wright.

54 records · Page 3Linked to original sources
PubMed1978

A radio-gas chromatographic method for the determination of 11-oxotestosterone in fish plasma: its use in confirming estimations by radioimmunoassay.

A radio-gas chromatographic method has been devised for the estimation of 11-oxotestosterone (17beta-hydroxyandrost-4-ene-3, 11-dione) in fish plasma samples which provides an independent means of validating the radioimmunoassay described earlier. Estimates of the concentration of 11-oxotestosterone in a sample of male rainbow trout plasma by radio-gas chromatography using peak height and peak weight measurements were 6.9 microgram/100 ml and 7.4 microgram/100 ml respectively, in good agreement with that of 7.1 microgram/100 ml determined by radioimmunoassay.

Animals↗
PubMed1977

A radioimmunoassay for 11-oxotestosterone: its application in the measurement of levels in blood serum of rainbow trout (S. Gairdneri).

17beta-Hydroxyandrost-4-ene-3,11-dione was linked via its 3-(O-carboxymethyl) oxime to bovine serum albumin to give a conjugate which was used to generate antiserum in rabbits. The antiserum, at an overall dilution of 1 in 16,000, together with [1,2-3H] 17beta-hydroxyandrost-4-ene-3,11-dione synthesized from [1,2-3H] cortisone have been used to develop a radioimmunoassay for the parent steroid. The assay incorporates a purification step in which serum or plasma extracts are chromatographed on silica gel layers bound to plastic or aluminum sheets and the steroid containing zones cut out and eluted directly with assay buffer. The cross-reactivities of several steroids with the antiserum and the specificity, sensitivity, accuracy and precision of the assay are described. Blood sera from immature male rainbow trout contain ca 0.2-0.4 mature, serum levels rise sharply to reach values of 2 to greater than 9 microng/100 ml of 17beta-hydroxyandrost-4-ene-3,11 dione. As male fish mature, serum levels rise sharply to reach values of 2 to greater than 9 microng/100 ml. Levels in immature females rarely exceeded the assay sensitivity but serum from three ripe females showed low but detectable levels (ca 0.2 microng/100 ml) of steroid. The assay has found application in sexing live fish for experimental purposes.

Age Factors↗
PubMed1976

Tibial and peroneal bypass in severe occlusive disease of the lower extremities.

Symptomatic arteriosclerotic occlusive disease involving the femoral and proximal popliteal arteries is currently best treated by reversed autogenous saphenous vein bypass graft. Severe occlusive disease frequently includes the popliteal and/or origin of the trifurcation vessels with reconstitution of one or more of the vessels in the lower leg. We have used distal bypass 97 times in 90 patients during the past decade. There was only one postoperative death in the series in spite of the advanced age and concurrent disease in the majority of the patients. Our indications for operation continue to be relief of pain or salvage of an extremity. We rely on high quality preoperative angiograms for selection of vessels to receive the bypass. The posterior tibial artery was used in 63 of the cases, while the anterior tibial and peroneal were used in 24 and 10 cases, respectively. There were 11 immediate inhospital failures in this series of 97 cases requiring amputation in five. Three additional patients had amputations during the ensuing several months. Of the 85 grafts functioning at the time of discharge from the hospital, 16 or (18.8%) failed during the first years. Grafts that remained patent for one year have a high incidence of long term patency which is in keeping with other reported series.

Adult↗
PubMed1975

Conservative surgical treatment of reflux esophagitis and esophageal stricture.

During a recent 3-year period, 17 consecutive patients were seen with advanced fibrotic esophageal strictures secondary to alkaline-acid-pepsin reflux. From detailed preoperative evaluations alone it was impossible to determine whether therapy should consist of excisional surgery, esophagogastroplasty or intra-operative dilatation with correction of reflux. Only at operation could the length, extent, degree and severity of the stricture be fully determined. Each of the 17 patients was treated by controlled dilatation, coupled with an antireflux procedure. This simplified approach proved successful on strictures thought preoperatively to be undilatable. It appears that this conservative approach is applicable to many advanced strictures and excisional and plastic procedures should be reserved for those cases that prove unyielding to intraoperative dilatation. The true appraisal of a reflux stricture and the choice of surgical procedure is best determined at the operating table.

Aged↗
PubMedDate not supplied

Annual recertification program for audit standards used in the EPA PM2.5 Performance Evaluation Program.

This paper describes procedures used to perform 152 annual recertifications of temperature, pressure, and flow rate audit standards. It discusses the metrology laboratories and the uncertainty of their recertifications. It describes the data base for the standards that tracks their recertifications and shipments. Finally, it presents some illustrative recertification results and describes what these results reveal about the audit standards and the recertifications.

Air Pollution, Indoor↗