Search PubMed⌕ Search

Biomedical subjects

Z Cohen

Publications and source records attributed to Z Cohen.

At least 253 records · Page 14Linked to original sources
PubMed1981

Reevaluation of nitrate and nitrite levels in the human intestine.

Analyses of human fecal and ileostomy samples by a method that is insensitive and free from interferences indicate that nitrate and nitrite levels in the intestine are lower than reported previously. Fecal nitrate and nitrite concentrations ranged from 0 to 14 mumol/kg (0 to 0.9 ppm) and 5 to 19 mumol/kg (0.3 to 0.9 ppm), respectively. Ileostomy samples contained from 0 to 7 mumol/kg (0 to 0.4 ppm) and 0 to 15 mumol/kg (0 to 0.7 ppm) for nitrate and nitrite, respectively. We also showed that, when deliberately added to feces samples, nitrate and nitrite were destroyed during a two-hr incubation period in a reaction that depended on the presence of microorganisms. The results suggest that conditions in the lower gastrointestinal tract favor denitrification, not nitrification as had been proposed previously.

Adolescent↗
PubMed1981

Iodinated starch particles: new contrast material for computed tomography of the liver.

An iodinated starch suspension was used as a model particulate hepatic contrast agent for computed tomography (CT). The material, synthesized from starch and triiodobenzoic acid, formed a stable concentrated suspension, containing particles smaller than 4 micrometer. Following intravenous administration of 0.16 gI/kg to rabbits, approximately 85% of the injected dose was present in the liver, resulting in a 180 to 200 Hounsfield unit (1,000 scale) increase in liver CT value. The material produced marked and sustained normal liver opacification but no hepatic tumor enhancement. Lesions as small as 2 mm in diameter were detected. The approximate LD50 of the suspension in mice was 0.9 g I/kg. There were no signs of toxicity at sublethal doses. This suspension produces greater, more sustained, and more selective liver opacification than conventional biliary and urographic contrast materials.

Animals↗
PubMed1980

Ileal excretion and bacterial modification of bile acids and cholesterol in patients with continent ileostomy.

Bile acid (acidic sterol) and neutral steroid excretion were determined in 15 patients, five with conventional ileostomy, five with continent ileostomy, and five with continent ileostomy and an ileal resection. Acidic sterol losses were normal in conventional ileostomy patients and not significantly increased in those with continent ileostomy alone. Bile acid excretion rates were significantly increased in patients with a continent ileostomy and an ileal resection. Neutral steroid excretion was similar in all groups and not different from normal. Deoxycholic acid was not detected in ileal effluent of patients with conventional ileostomy and less than 2% of neutral steroid excreted was in the form of bacterial metabolites of cholesterol. The same was true of six of the 10 patients with continent ileostomies; in the other four patients at least 10% of acidic or neutral steroids were excreted as secondary bile acids or as a coprostanol. Modification of steroids was not related to ileal resection. Continent ileostomy was associated with a significant increase in percentage water content and a reduction in the pH of ileal effluent.

Adult↗
PubMed1980

Continent reservoir ileostomy: 1. Early experience and evolution of the surgical technique.

A continent Kock ileostomy was constructed in 17 patients with histologically proven ulcerative colitis; in 11 a conventional ileostomy was converted to a Kock ileostomy and in 4 the Kock ileostomy was carried out in conjunction with proctocolectomy. There were no operative deaths. All patients are completely continent with regard to flatus and stool. No patient requires an external appliance and all agree that the quality of their lives has greatly improved. However, 10 patients (59%) required at least one additional surgical procedure for early or late complications, the most frequent of which were intestinal obstruction and valve slipping. In an attempt to reduce morbidity, several technical modifications were made. The preliminary results of the modified techniques used in 17 patients are described. The benefits of the continent ileostomy are substantial despite the high initial morbidity. The authors recommend the use of the continent ileostomy in selected patients.

Adult↗
PubMed1979

Highly selective vagotomy and truncal vagotomy and pyloroplasty for duodenal ulcer: a clinical review.

A review was conducted of the operations of highly selective vagotomy (HSV) and truncal vagotomy and pyloroplasty (TVP) performed for peptic ulcer disease. Gastric acid output was reduced equally after both procedures: basal acid output was reduced by 80% and maximal acid output by 50% to 60%. Not surprisingly, therefore, the recurrence rates were similar (6.6% after HSV compared to 5.6% after TVP). However, the mortality following HSV was 0% compared with 0.7% after TVP. The incidence of all side effects was lower following HSV, so that the results in 86% of patients who underwent this operation were considered excellent or very good (Visick grades I and II). The authors conclude that HSV should be considered the primary conservative procedure in the surgical management of peptic ulcer disease.

Duodenal Ulcer↗
PubMed1976

Canine small bowel transplantation. A study of the immunological responses.

A canine small bowel allograft model was used to determine the effects of radiation to the graft in modifying the immunological effects of the passenger leukocytes. When untreated allografts were transplanted, death of the recipient animals occurred at a mean of nine days. The allograft was well-preserved and showed no signs of rejection. The reasons for attributing death to graft-versus-host (GVH) disease are discussed. When allografts were treated with 150 rads prior to transplantation, allograft rejection occurred, with death of the recipient animals at a mean of 9.2 days. This was the only group in which cell-mediated immunity developed. When allografts were treated with 50 rads, prolonged survival of the recipients to a mean of 28 days was noted. It is postulated that in this group a balance was struck between the allograft rejection reaction and GVH disease, with prolongation of allograft survival.

Animals↗
PubMed1976

Surgical treatment of hydatid disease of the liver.

Hydatid disease in southern Ontario is becoming more frequent because of infection in the large immigrant population. Review of 25 cases of hydatid disease of the liver has clarified the clinical features, diagnostic approach and methods of treatment. The commonest presenting symptoms were pain, mass or hepatomegaly, and jaundice. Diagnosis was confirmed, and cysts were localized, by Casoni skin testing, hepatic scanning and angiography. Surgical treatment consisted either of resection, excision or enucleation, and evacuation of the cyst. Two patients were treated by left lateral segmental resection, 6 by either wedge excision of the cyst or enucleation, and 14 by evacuation of cyst contents with or without drainage with the aid of a technique designed to prevent spillage of cyst contents at operation. None of the 14 treated by means of this technique developed recurrent disease, but in 4 of the patients treated by wedge excision or enucleation the cyst contents spilled at operation, resulting in recurrent disease in 2. Controlled cyst evacuation, with tube drainage for infected cavities and those communicating with the biliary tract is the recommended form of treatment in the management of hepatic hydatid disease.

Canada↗
PubMedDate not supplied

Urolithiasis risk factors in continent reservoir ileostomy patients.

Conventional ileostomy patients are at an increased risk to urinary stone formation compared to normal controls. This study was designed to evaluate any further risk factors to urinary stone formation in patients with Kock ileostomies. Nine Kock ileostomy patients were matched for age, sex, and body weight with nine conventional ileostomy patients and nine controls. Two 24-hour urine samples from each patient were analyzed for volume, pH, Na+/K+ ratio, oxalate, and uric acid concentration. Both ileostomy groups demonstrated reduced urinary volume and Na+/K+ ratio as compared to the control groups (P less than 0.05). The Kock ileostomy group had the lowest urinary volume. There was no significant reduction in urinary pH or elevation in urine uric acid concentration in the Kock ileostomy group. The results suggest that there is no significantly added risk to uric acid stone formation in Kock ileostomy patients.

Calcium↗