Biomedical subjects

B Roberts

Publications and source records attributed to B Roberts.

At least 199 records · Page 11Linked to original sources

PubMed1975

Operative management of renovascular hypertension.

From 1966 to 1975, 38 patients underwent 42 procedures for renovascular hypertension; 35 operations were aortorenal bypasses and 7 were nephrectomies. Forty-five per cent of the patients were cured, 43% were improved and 12% were unimproved. There were no operative deaths and only three late deaths. Two grafts occluded and 2 became stenotic, giving a graft complication rate of 12%. Curability was best correlated with a short history of hypertension and a pathologic diagnosis of fibromuscular hyperplasia, but not with patient age. Most patients selected for surgery had elevated renal venous renin ratios, and of these 95% were cured or improved. Of those with normal renin ratios, 85% were still cured or improved. Postoperative aortography and peripheral renin measurements offered valuable information in predicting the ultimate response to surgery. Preservation of renal function was a principal indication for surgery in 11 patients. In 8, azotemia was documented preoperatively. Hypertension was cured or improved in every case and 5 patients demonstrated a 10-50% reduction in BUN and creatinine following revascularization.

Aorta↗

PubMed1975

Glutamate dehydrogenase specific activity and cephalosporin C synthesis in the M8650 series of Cephalosporium acremonium mutants.

Conditions for the accurate measure of glutamic dehydrogenase (GDH) from Cephalosporium acremonium were determined. K(m) values for alpha-ketoglutarate and ammonium ion were 7 and 15 mM, respectively. The half-saturation for reduced nicotinamide adenine dinucleotide phosphate was 5 muM. Reduced nicotinamide adenine dinucleotide did not serve as a cofactor for the enzyme. The specific activity of GDH was measured in six mutants of C. acremonium which varied in their ability to synthesize cephalosporin C. The mutants represented two separately derived lines, A and B. The four mutants in line B were characterized by a derepression of the GDH upon entry into stationary phase. The two mutants in line A were characterized by repressed levels of GDH during the same period. Both lines exhibited high GDH activity early in their fermentations, but activity decreased during the period of active cell growth. Cytochrome c concentrations followed the same pattern as total soluble intracellular protein. Line A mutants were low in cephalosporin C productivity and line B encompassed low, intermediate, and high productivity mutants. The relative frequency of yield improvements in line A and B indicate that the altered regulation pattern for GDH in line B may have removed a nitrogen limitation for cephalosporin C synthesis.

Acremonium↗

PubMed1975

Effect of elevated triglycerides on the diffusing capacity of man.

In view of the decreased diffusing capacity recently reported in man during lipid infusion, studies have now been made on the effects of hyperlipidemia on the diffusing capacity for carbon monoxide (DLco). In normal volunteers and patients with hyperlipidemias, DLco and plasma triglyceride concentrations were determined during fat tolerance tests and while the patients were on diets that increased or decreased triglyceride concentrations. During the fat tolerance tests, the largest triglyceride and DLco changes were from 346 mg per 100 ml with a DLco of 18.8 ml per min per mm Hg to 1,545 mg per 100 ml with a DLco of 23.4 ml per min per mm Hg. While patients were on speical diets, the largest triglyceride and DLco changes were from 5,102 mg per 100 ml and 29.0 ml per min per mm Hg to 492 mg per 100 ml and 26.4 ml per min per mm Hg, respectively. Sta tistical tests showed no significant change of DLco with change in triglyceride concentration. The data suggest that there is normally no association between change in triglyceride concentration and change in DLco, and that triglycerides normally transported in plasma, even when present in extreme amounts as chylomicrons or very-low-density lipoprotein, do not affect the DLco.

Adult↗

PubMed1975

Operative management of renovascular hypertension.

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Adult↗

PubMed1975

Twenty-one years' experience with ruptured abdominal aortic aneurysms.

The surgical experience with 107 ruptured abdominal aortic aneurysms at this hospital during the years 1953 to 1975 has been reviewed. The operative mortality rate during the first ten years of this study was 86 per cent, but since 1966, it has fallen to 40 per cent. These improved mortality statistics are related primarily to improved techniques for controlling operative blood loss and minimizing the time of aortic cross clamping. The use of an intra-aortic balloon has been useful in this regard. Twenty-four additional patients died from ruptured aneurysms without undergoing operation, all before 1966. Only seven had a correct diagnosis prior to death, and these seven serve to emphasize the importance of being alert to the diagnosis of ruptured aneurysm which often masquerades as urologic or orthopedic problems because of the frequent symptoms of back, abdominal, flank or groin pain. Since the operative mortality rate for elective resection of the aneurysm has been less than 1 per cent at this institution during the last eight years, we believe we are justified in encouraging prompt resection of aneurysms on an elective basis to eliminate the high mortality rate that still accompanies rupture of the aneurysm.

Adult↗

PubMed1975