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Biomedical subjects

M J Cooper

Publications and source records attributed to M J Cooper.

At least 163 records · Page 9Linked to original sources
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

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

Choleresis and cholestasis produced by infusion of taurocholic acid or taurodehydrocholic acid combined with BSP in the rhesus monkey.

To study the determinants of BSP Tm in rhesus monkeys, animals with indwelling silastic catheters were infused with sufficient BSP to produce a rising plasma concentration and normal saline or taurocholic acid 3.5 mumol/min, 7.0 mumol/min, or 10.5 mumol/min. BSP Tm was 3.84 +/- 0.11 mg/kg/10 min during normal saline infusion, 5.52 +/- 0.53 mg/kg/10 min during taurocholic acid 3.5 mumol/min, despite greater bile flow with the latter compound. Higher infusion rates of taurocholic acid inhibited BSP Tm and the proportion of conjugated BSP secreted into bile, as well as bile flow and bile acid secretion. Taurodehydrocholic acid 7.0 mumol/min produced similar but less marked effects. These results indicate that bile flow does not explain the effects of bile acids on BSP Tm and suggests that bile acids exert varying effects on BSP transport or binding in micelles. The cholestasis observed with combined BSP and higher bile acid infusion rates is probably due to inhibition of liver cell intermediary metabolism or to liver cell toxicity.

Animals↗
PubMed1979

Atropine-induced ventricular fibrillation: case report and review of the literature.

A bradycardic and mildly hypotensive acute myocardial infarction patient developed sinus tachycardia, ventricular tachycardia, flutter, and fibrillation following intravenous atropine. Previous case reports are reviewed and the literature regarding the advisability of this mode of therapy is discussed. In the light of conflicting opinion as to the necessity of atropine in the mildly hypotensive and bradycardic acute myocardial infarction patient, and in view of its potentially deliterious effects on ischemic myocardium, a cautious and selective application of this drug is advised.

Atropine↗
PubMed1979

A relaxation technique in the management of hypercholesterolemia.

Chronic sympathetic nervous system overactivity has been implicated as a factor capable of elevating and maintaining high serum cholesterol levels independent of dietary measures. We conducted a controlled trial to determine the effect of a relaxation technique. Transcendental Meditation, on serum cholesterol levels in hypercholesterolemic subjects. Serum cholesterol levels were measured at beginning and end of an 11-month period in 12 hypercholesterolemic subjects who regularly practiced meditation. Eleven hypercholesterolemic controls who did not practice the technique were similarly followed up for 13 months. Paired comparisons showed a significant (p less than 0.005) reduction in fasting serum cholesterol levels of those subjects who practiced meditation. These results suggest that the regular practice of a relaxation technique may contribute, most likely through a reduction in adrenergic activity, to the amelioration of hypercholesterolemia in certain subjects.

Adult↗
PubMed1979

Prospective evaluation of angiography in the diagnosis and management of patients suspected of having pancreatic cancer.

One hundred three patients suspected of having pancreatic cancer underwent celiac and superior mesenteric arteriography which was reported 'blind.' Final diagnosis, operative findings, and resectability of pancreatic cancers were correlated with angiography reports. Forty patients had pancreatic cancer. Thirty-seven of these underwent laparotomy, and 14 (37%) had resectable lesions. Sensitivity and specificity of arteriogrphy for pancreatic cancer were 72% (29/40) and 71% (45/63) respectively. Resectability was unrelated to the angiographic diagnosis. Nonresectability was related to an angiographic finding of definite tumor vessel (4/4), large-vessel encasement (14/7), and major venous pathology (8/11). Only the first of these was unique to pancreatic cancer. Hepatic metastases were detected in only six of 13 patients. Small-artery encasement, arterial occlusion, vessel displacement, and gallbladder distention were not indicators of diagnosis or extent of disease. Major anatomic anomaly of foregut vasulature was revealed in 25% of angiographic studies. Prior knowledge of such anomalies has important bearing on the operative approach to pancreatic resection. We conclude that angiography should be performed prior to laparotomy whenever a resectable pancreatic cancer is suspected from other investigations. When used prospectively, angiography is not a reliable diagnostic or prognostic tool for pancreatic cancer.

Adolescent↗
PubMed1979

Comparison of Bungarus caeruleus venom with the venom from which a putative cholinergic ionophore marker was isolated.

Comparisons are described between Bungarus caeruleus venom and the actual venom from which a putative marker for the cholinergic ionophore, called ceruleotoxin, was isolated. The venoms are shown to be different by two procedures for ion exchange chromatography and by isoelectric focusing on polyacrylamide gel. The activities of the purified "ceruleotoxin" as an inhibitor of acetylcholine receptor-mediated ion flux and as a phospholipase have been reported (Bon & Changeux, 1977b). The results reported herein suggest that this toxin is from an unknown origin.

Bungarotoxins↗
PubMed1979

Non-operative differentiation between pancreatic cancer and chronic pancreatitis.

Eighty-five of 186 patients investigated for suspected pancreatic cancer had an unequivocal final diagnosis of either pancreatic cancer (58 patients) or chronic pancreatitis (27 patients). They had been studied prospectively using ultrasonography, computerized tomography, radionuclide scanning, endoscopic retrograde cholangiopancreatography (ERCP), selective celiac and superior mesenteric angiography, duodenal drainage studies, cytologic studies, serum carcinoembryonic antigen assay, and pancreatic oncofetal antigen assay, The results were compared to determine which test would most frequently and reliably differentiate between pancreatic cancer and pancreatitis in a patient believed to have one or other disease. Criteria for interpreting results, first for highest rate of correct diagnoses, and second for highest accuracy were derived. Applying these criteria, ultrasonography achieved the highest rate of correct diagnoses (97% of patients diagnosed with 84% accuracy). ERCP, duodenal drainage studies, and cytology were the most accurate tests ((86% accuracy each test) but, with this accuracy, ERCP most frequently gave a diagnosis (diagnosis rate: ERCP--70%, duodenal drainage--32%, cytology--35%). The results suggest that ultrasonography is the best noninvasive test, and that a combination of ERCP, pancreatic juice assay and cytology in a single procedure may prove to be the best discriminating investigation.

Adult↗
PubMed1978

Prospective evaluation of gray scale ultrasonography in the diagnosis of pancreas cancer.

One hundred thirty-four patients suspected of having pancreas cancer successfully underwent gray scale ultrasound examination of the pancreas. The prospective ultrasound findings were correlated with the final diagnoses, laparotomy findings, and pathology findings. Fifty-four patients had pancreas cancer, confirmed by resection or biopsy in all cases. On ultrasonography, the pancreas was correctly reported to have abnormalities in sixty-one of seventy-eight patients (78 per cent) and correctly reported to have no abnornalities in thirty-eight of fifty-six patients (68 per cent). A correct ultrasound diagnosis of pancreas cancer was made for forty-four of fifty-six patients (81 per cent), and there were thirteen false-positive reports. Ninety-four percent of cancers confined to the head of the pancreas and 70 per cent of cancers at other locations within the gland were detected by ultrasound examination. The correct ultrasound diagnosis was given for fifteen of seventeen patients with resectable pancreas cancer, the degree of associated pancreatitis ranging from minimal to severe. Analysis of the predictive values of positive and negative ultrasound examinations suggests that this test could be used to screen a population of patients with symptoms mildly suggestive of pancreas cancer. The importance of preselecting the level of confidence of a positive test result, a,ove which further investigation is indicated, is emphasized.

Diagnosis, Differential↗
PubMed1978

Prospective evaluation of endoscopic retrograde cholangiopancreatography in the diagnosis of periampullary cancers.

In a prospective study of 112 patients suspected of periampullary cancer endoscopic retrograde cholangiopancreatography (ERCP) was successfully performed in 87 patients (78%). Technical failures were due to gastric outlet obstruction in four patients and inability to cannulate the ampulla of Vater in 21 patients. Successfully performed ERCP had both a high sensitivity (92%) and specificity (90%) for periampullary cancer. The few errors in pancreatogram interpretation were due to juxta-ductal cancers and difficulty in differentiating duct changes of cancer from those of chronic pancreatitis. Pancreatic cytology, performed in 21 patients, was reliable, diagnosed two pancreatic cancers when the pancreatogram failed and, if used routinely, assists interpretation of the pancreatogram. Retrograde cholangiography provided a correct diagnosis in six jaundiced patients with normal pancreatograms. Three complications of ERCP occurred in this series.

Ampulla of Vater↗