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Biomedical subjects

J Isaacs

Publications and source records attributed to J Isaacs.

44 records · Page 3Linked to original sources
PubMed1977

Glutathione dependent control of protein disulfide-sulfhydryl content by subcellular fractions of hepatic tissue.

The disulfide-sulfhydryl (SS/SH) ratios of subcellular fractions of rat hepatic tissue were found to vary diurnally with the ratio lowest in the early morning and highest in the early evening. These changes were found in the nuclear, microsomal and cytosol fractions. The primary reaction is the reversible formation of mixed disulfides of glutathione with proteins. This formation is controlled by the activity of thiol transferase and the level of oxidized glutathione (GSSG) as substrate. Several enzymes including mitochondrial and microsomal oxidases, glutathione reductase and peroxidase and glucose-6-phosphate dehydrogenase were found to control the levels of GSSG. An NADPH-dependent microsomal oxidase system, inhibited by GSSG, was found to produce activated oxygen which served as substrate for flutathione peroxidase. Evidence is presented for the concept that the formation of mixed disulfides of proteins with glutathione is a mechanism for maintenance of a disulfide-sulfhydryl ratio such that the integrity of particulate membranes is maintaine during oxidative and reductive stresses on the hepatic cells.

Animals↗
PubMed1976

Postresectional anemia. A preventable complication of total gastrectomy.

The incidence of anemia after total gastrectomy has not received sufficient clinical emphasis. During a follow-up period averaging 32 months, postresectional anemia developed in seven of ten patients without evidence of malignant neoplasm; all but one of these patients had received parenterally administered cyanocobalamin. Despite low levels of circulating erythrocytes and proportionately increased erythropoietin levels, reticulocytosis was not evident. This observation suggests an uncharacterized failure of marrow erythyroid precursors. Multiple deficits in intake of constituents necessary for the production of erythrocytes were demonstrated. With the possible exception of iron, malabsorption of these constituents is not an important factor in the production of anemia. Postresectional anemia is multicausal, but is primarily nutritional. As total gastrectomy becomes more commonly employed in the treatment of nonmalignant conditions, recognition of the frequency and causes of postresectional anemia should assist both diagnostic anticipation and therapy.

Adult↗
PubMed1975

Nutritional consequences of total gastrectomy.

Nutritional status was investigated in 10 patients who had previously undergone total gastrectomy without evidence of malignancy. The ability of these patients to ingest and absorb adequate amounts of nutrients was examined. Metabolic balance studies were also performed to discover how effectively these patients could accumulate and use the absorbed nutrients. In the controlled hospital situation, the amount of food ingested was greater than the amount required for maintenance of Ideal Body Weight. Although mild malabsorption of fat and nitrogen was documented, weight gain and positive nitrogen balance occurred. In direct contrast, food intake significantly decreased when the patients returned to their home environment. While severe malabsorption may contribute to malnutrition in the individual patient, the most common mechanism responsible for postoperative malnutrition was inadequate intake. In the occasional patient with severe malabsorption, the universal demonstration of jejunal anaerobic bacterial overgrowth offers important therapeutic implications. The relative importance of pancreatico-biliary insufficiency in promoting malabsorption remains to be determined. Construction of a Hunt-Lawrence jejunal pouch was not found to favorably affect caloric intake, weight gain, degree of malabsorption, or dumping symptoms. Although some degree of malnutrition does result from total gastric resection, in most cases it is mild and potentially correctable. Avoidance of indicated total gastrectomy due to fears of progressive postoperative malnutrition is unwarranted.

Adult↗
PubMedDate not supplied

Dynamic ankle ultrasonography. A new imaging technique for acute ankle ligament injuries.

We have developed a noninvasive ultrasound technique that may be used to differentiate complete and incomplete acute tears of the anterior talofibular ligament. Direct visualization of the ligament will demonstrate the lesion in most cases and can be supplemented by an anterior drawer test with the ligament under direct vision. Seventeen athletes involved in sports and work that put high-demand pressure on their ankles underwent ultrasonic examination of their acute lateral ankle ligament injuries before surgical exploration. Fourteen scans demonstrating a complete lesion of the anterior talofibular ligament were confirmed at operation. Three scans were equivocal; two of these patients had incomplete lesions of their anterior talofibular ligaments and one patient had a complete tear that was not detected. We have found that the dynamic ultrasound test is a simple and reliable examination. We suggest that this technique is indicated where the extent of an acute lateral ligament injury requires further definition. Ankle ultrasonography may reduce the need for ankle arthrography.

Adolescent↗