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Biomedical subjects

A R Moossa

Publications and source records attributed to A R Moossa.

At least 127 records · Page 7Linked to original sources
PubMed1981

Peritoneal malignant mesothelioma in a patient with recurrent peritonitis.

A patient is presented who developed a peritoneal malignant mesothelioma in association with severe persistent and recurrent diverticulitis. The case is unusual in that a spectrum of mesothelial proliferation was documented beginning initially as benign foci of mesothelial proliferation and passing through a stage of atypical proliferation before terminating as a malignant process. The possible role of the diverticular disease in the pathogenesis of the tumor is discussed.

Adult↗
PubMed1981

The diagnosis of "early" pancreatic cancer: the University of Chicago experience.

The results of a prospective study designed to investigate patients suspected of having pancreatic cancer are reported. One hundred and two of 238 patients investigated had pancreatic cancer. Ultrasonography, endoscopic retrograde cholangiopancreatography, and cytology were the most reliable tests for the diagnosis of resectable cancer. Computed tomography had a higher sensitivity for unresectable cancer. Factors responsible for delay in diagnosis are discussed. Cancer of the body and tail of the pancreas cannot be diagnosed early by investigating a symptomatic population. Factors influencing mortality in patients who survive over three years following pancreatic resection are discussed.

Adult↗
PubMed1981

Exogenous gastrin in rhesus monkeys. The effect of 50% distal small-bowel resection on its rate of disappearance.

The rate of disappearance from the circulation of exogenous heptadecapeptide gastrin was studied before and after 50% distal small-bowel resection in four rhesus monkeys. For each study, venous blood samples were drawn during, and at frequent intervals after, a one-hour peripheral venous infusion of synthetic human gastrin 1 given at a constant rate within the range of 0.4 to 2.4 microgram/hr/kg of body weight. The rate of disappearance of infused gastrin was not affected by small-bowel resection (mean half-time before operation, 2.50 minutes; mean half-time after operation, 2.47 minutes). These data indicate that in the rhesus monkey, the rate of catabolism of exogenous gastrin is not decreased after distal small-bowel resection, and indicate that other mechanisms are responsible for the hypergastrinemia and gastric acid hypersecretion observed in this animal model.

Animals↗
PubMed1981

Gastrointestinal hemorrhage from left-sided portal hypertension. An unappreciated complication of pancreatitis.

Eleven of 16 patients with splenic vein thrombosis subsequent to pancreatitis had variceal hemorrhage. variceal development tends to occur in the stomach, although esophageal varices may also occur, and is a result of left-sided or segmental portal hypertension. The antecedent pancreatitis may be quite mild and produce minimal symptoms. Angiography is required to establish the diagnosis as endoscopic detection of gastric varices is difficult and unreliable. Splenectomy is the definitive treatment, although transgastric ligation of varices must be added if active bleeding is taking place.

Adult↗
PubMed1981

Hemorrhage from ileal varices after total proctocolectomy.

We report two cases of hemorrhage from ileal varices developing after total proctocolectomy for chronic ulcerative colitis. Intermittent peristomal bleeding preceded life-threatening hemorrhage from tru ileal varices proximal to the stoma. Management by portacaval shunting was effective and has not resulted in encephalopathy.

Adult↗
PubMed1981

Hepatic metabolism of glucagon in the dog: contribution of the liver to overall metabolic disposal of glucagon.

The hepatic extraction (HE) of glucagon (G) and insulin (I) was measured in 27 dogs, using peripheral infusion of the hormones following elimination of endogenous secretion by pancreatectomy (Px) or somatostatin (S) infusion. HE(G) was 22.5 +/- 1.7%, and HE(I) was 45.1 +/- 3%. HE(G) in seven Px dogs was 27.9 +/- 4.2%, not significantly different from the value of 20.6 +/- 1.6% in 20 S-infused dogs, with corresponding values for HE(I) being 44.9 +/- 6 and 46.0 +/- 3.6%, respectively, suggesting that S does not affect HE of either hormone. HE of endogenous G (22.1 +/- 2.8%) was similar to that of exogenously infused G (19.1 +/- 1.9). HE(G) was nonsaturable in the physiologic and pathophysiologic range of plasma G levels, but there was evidence of saturability in the pharmacologic range. Comparison of simultaneously measured parameters of I and G metabolism indicated independence of the metabolic processes of these two islet hormones, despite distinct similarities in their overall patterns of metabolic disposal. Metabolic clearance rates (MCR) for G and I were 12.6 +/- 0.8 and 19.5 +/- 1.0 ml . kg-1 . min-1, while simultaneously measured hepatic HE rates were 4.2 +/- 0.3 and 8.1 +/- 0.6 ml . kg-1 . min-1, respectively. MCR(G) was independent of arterial G levels. Half-life of infused G and I was 5.5 +/- 0.5 and 4.1 +/- 0.3 min, respectively. The liver accounted for 34.7 +/- 2.4% of the MCR(G) and 42.0 +/- 2.9% of MCR(I). The liver is thus an important site for G removal. However, HE(G) varies widely in different animals, and it is therefore not possible to predict portal vein G concentrations or G secretion rates from G levels in peripheral vessels.

Animals↗
PubMed1980

Prospective evaluation of some candidate tumor markers in the diagnosis of pancreatic cancer.

As part of a prospective diagnostic protocol, patients suspected of having pancreatic cancer had systemic and portal venous blood samples assayed, in coded batches, for peptide hormones and enzymes thought to be of potential value as tumor markers. An average of 111 patients were tested for each candidate marker. Results were analyzed by dividing patients into three groups according to the definitive diagnoses. These were pancreatic cancer (32% of patients), other cancers (27%), and benign diseases (41%). Although elevated mean levels of fasting plasma glucose and serum alkaline phosphatase were found in the pancreatic cancer group, there were no significant differences in the mean levels of any of the candidate markers studied in the three groups. The diagnostic values of normal and elevated levels of each candidate marker studied have been calculated. None has proven to be as useful as the serum level of pancreatic oncofetal antigen, fasting plasma glucose, or serum alkaline phosphatase in the diagnosis or exclusion of pancreatic cancer.

Alkaline Phosphatase↗
PubMed1980

Sodium salicylate: effect on determinants of bile flow and cholesterol solubility in rhesus monkeys.

To study the mechanism of salicylate-induced choleresis in rhesus monkeys, we utilized animals with indwelling common bile duct catheters under phencyclidine anesthesia. Bile flow, [14C]erythritol clearance (an estimate of canalicular flow), and bile acid secretion were measured during baseline and for 1 1/2 hr during salicylate infusion. Bile flow increased from 91.2 +/- 7.3 ml/24 hr (SEM) to 180.1 +/- 8.0 ml/24 hr (P less than 0.001) with salicylate infusion and [14D]erythritol clearance from 114.5 +/- 8.9 ml/24 hr to 222.3 +/- 10.7 ml/24 hr (P less than 0.001), but bile acid secretion was unchanged, suggesting increased bile acid-independent canalicular bile flow. Salicylate concentration in bile averaged 1.48 +/- 0.08 mmol/liter, and salicylate concentration in extra bile produced by salicylate was unlikely to result in chloeresis of the magnitude observed. [3H]inulin bile-plasma ratios, measured in these same studies, were unchanged after salicylate administration, suggesting that permeability of the biliary tree was not altered. Bile lipid secretion, like bile acid secretion, was unchanged after salicylate administration, so no change occurred in the lithogenic index of the bile. These results demonstrate that salicylate is a potent choleretic in rhesus monkeys because of enhancement of bile acid-independent bile flow. Salicylate produced no change in the lithogenic index of the bile.

Animals↗
PubMed1980

Effect of 50 percent distal small bowel bypass on gastric secretory function in rhesus monkeys.

Six rhesus monkeys had basal acid output and histamine-stimulated maximal acid output measured before and at 10 weeks and 6 months after 50 percent distal small bowel bypass. At each stage fasting serum gastrin was measured in all animals and fasting serum gastric inhibitory polypeptide in two animals. No change in basal or maximal acid output occurred after a sham operation carried out in two of the animals. The mean preoperative basal acid output (0.17 +/- 0.02) increased to 0.49 +/- 0.04 at 10 weeks after bypass (p less than 0.001) and then decreased significantly to 0.33 +/- 0.03 mEq/kg/hour at 6 months (p less than 0.001). Preoperative maximal acid output (0.43 +/- 0.06) increased to 0.76 +/- 0.10 mEq/kg/hour at 10 weeks (p less than 0.001) and remained at that level at 6 months. Small bowel biopsy specimens at 6 months showed characteristic changes in both proximal and distal small bowel segments. Fasting gastrin and gastric inhibitory polypeptide levels did not change significantly during the study. A comparison of these results with those obtained after 50 percent distal small bowel resection in a previous study revealed a similar proportional increase in maximal acid output in both early (resection, 78 +/- 20 percent; bypass, 77 +/- 23 percent) and late postoperative studies (resection, 57 +/- 14 percent; bypass, 74 +/- 19 percent). However, the early increase in basal acid output after resection (370 +/- 50 percent) was sustained and was significantly greater (p less than 0.005) than the early ill-sustained increase (188 +/- 24 percent) after bypass.

Animals↗
PubMed1979

Value of new diagnostic aids in relation to the disease process in pancreatic cancer.

An assessment was made of the diagnostic value of six tests done on 28 patients who proved to have resectable and 45 patients who had non-resectable pancreatic cancer. Ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP) were the most sensitive tests for the diagnosis of resectable tumours. Ultrasonography was slightly, and cytology definitely, better for the diagnosis of resectable tumours than for the diagnosis of non-resectable tumours. Computerised tomography, angiography, and scintigraphy were not effective means of diagnosing resectable tumours. The differences in diagnostic sensitivities of the tests for resectable and non-resectable disease are probably due to variations in pathological features which influence not only the stage of presentation, but also the detectability of the tumour. As long as investigation is limited to patients with symptoms, a large proportion of tumours will not be diagnosed at a resectable stage. However, the results of this study suggest that the resectability rate may be maximised by the early use of ultrasonography in patients with symptoms suggesting cancer in the region of the head of the pancreas, and in patients with vague, non-specific complaints. A combination of ERCP and direct ductal aspiration for cytology is the best means of diagnosing resectable tumours.

Angiography↗
PubMed1979

Reoperation for pancreatic cancer.

Over an eight-year period, 24 patients were referred following laparotomy at various community hospitals where their conditions had been diagnosed as "incurable pancreatic cancer." Seventeen of these patients' conditions were reevaluated and they underwent exploratory surgery again. In two patients, no cancer was found in spite of multiple biopsies. Nine patients underwent total pancreatectomy with no operative deaths, and two of them had localized primary ampullary cancer. Eleven of these 17 patients have survived 1 1/2 to six years. We conclude that reoperation in selected cases in which the condition was diagnosed as "inoperable pancreatic cancer" can have an appreciable salvage rate. We suggest that pancreatic exploration with a view to resection should be performed only in specialty centers where there is interest and expertise in the problem.

Adult↗
PubMed1979

Ultrasonography and tumor-associated antigens. The concept of combining noninvasive tests in the screening for pancreatic cancer.

A total of 134 patients suspected of having pancreatic cancer were given preoperative ultrasonic examinations. A total of 54 cases had a final diagnosis of pancreatic cancer histologically confirmed. The diagnostic sensitivity and specificity of the ultrasonographies were 76% and 91% or 87% and 74%, depending on whether doubtful results were called abnormal or normal. "Doubtful" results were defined as those that stated that pancreatic cancer was "possible" or "could not be excluded." When these results were divided into abnormal and normal groups on the basis of the patients' preoperative serum carcinoembryonic antigen and pancreatic oncofetal antigen levels, the sensitivity and specificity of the combined tests may prove to be a more accurate means of screening patients for pancreatic cancer than ultrasonography alone.

Adenocarcinoma↗
PubMed1979

A reappraisal of the value of carcinoembryonic antigen in the management of patients with various neoplasms.

Eight hundred and eight patients with histologically proved malignant disease had carcinoembryonic antigen (CEA) estimations performed at the time of tissue diagnosis. An elevated level was found in 384 of 518 patients with gastrointestinal neoplasms (74 per cent) and in 162 of 290 patients with other neoplasms (56 per cent). No correlation was found between CEA elevations and tumour differentiation. There was a good correlation between tumour staging and CEA levels for patients with colorectal cancer; the more advanced the tumour, the higher the CEA. Several illustrative cases are presented and the role of CEA assay in the diagnosis and management of neoplasia is discussed. CEA assay is a poor screening test for neoplastic disease, but serial CEA monitoring is valuable in the detection of residual or recurrent cancer.

Adult↗
PubMed1979

Use of a glucose controlled insulin infusion system (artificial beta cell) to control diabetes during surgery.

An artificial beta cell has been used to achieve and maintain a preset plasma glucose concentration in five diabetic patients undergoing surgery. These subjects were compared to control groups of normal subjects receiving either saline or glucose, and diabetics receiving glucose intraoperatively. Hyperglycaemia during surgery was seen in normals (mean plasma glucose +/- SEM: 185 +/- 16 mg/dl) and, to a greater degree, diabetics (247 +/- 36 mg/dl) receiving glucose. Insulin and C-peptide levels did not increase during 2 hours of operation in any of the control groups, suggesting beta cell suppression during surgery. As C-peptide levels declined similarly in normal subjects whether they received saline or glucose, the hyperglycaemia seems to be due to an inability to use exogenous glucose. This is confirmed by a correlation of maximal plasma glucose to glucose infusion rate (r = 0.78, p less than 0.01). The artificial beta cell was able to achieve the same plasma glucose after 2 hours of operation (128 +/- 21 mg/dl) as normal subjects receiving saline (110 +/- 7 mg/dl). The artificial beta cell proved to be a safe, convenient and effective way of monitoring and controlling the hyperglycaemia seen in diabetic patients undergoing surgery.

Blood Glucose↗