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Biomedical subjects

I Wiener

Publications and source records attributed to I Wiener.

At least 55 records · Page 3Linked to original sources
PubMed1985

Effect of divalent cations on gastrointestinal hormone release and exocrine pancreatic secretion in dogs.

The purpose of this study was to examine the effect of three common divalent cations (Ca2+, Mg2+, and Zn2+) on the release of cholecystokinin (CCK-33), pancreatic polypeptide (PP), and gastrin. Five dogs with pancreatic and gastric fistulas were given 1-h intraduodenal infusions of calcium (5 mmol X kg-1 X h-1), magnesium (4 mmol X kg-1 X h-1), or zinc (1 mmol X kg-1h-1). At another time the same dogs were given an intravenous bolus followed immediately by a 1-h infusion of calcium (0.36 mmol/kg [bolus], 0.36 mmol X kg-1 X h-1), magnesium (0.25 mmol/kg [bolus], 0.25 mmol X kg-1 X h-1), or zinc (0.03 mmol/kg [bolus], 0.03 mmol X kg-1 X h-1). Intraduodenal infusions of calcium, magnesium, and zinc significantly stimulated CCK-33, PP, and gastrin release. Intravenous calcium stimulated CCK-33, PP, and gastrin release to 245, 193, and 155% of basal levels, respectively. Intravenous magnesium increased CCK-33 to 123% of basal levels but did not stimulate PP and gastrin levels. Intravenous zinc stimulated release of CCK-33, PP, and gastrin to 126, 185, and 124%, respectively. This study shows that calcium, magnesium, and zinc can stimulate release of CCK-33, PP, and gastrin in much the same manner. We suggest that these cations may have a nonspecific electrical action that results in an alteration of membrane permeability, which leads to release of gastrointestinal hormones.

Animals↗
PubMed1985

Correlation of in vitro measurements of contractility of the gallbladder with in vivo ultrasonographic findings in patients with gallstones.

The objective of this study was to examine the in vitro responsiveness to cholecystokinin-8 of gallbladder muscle strips from patients with gallstones and to correlate the findings with preoperative ultrasonographic studies of gallbladder contractility. The response of gallbladder muscle strips to cholecystokinin-8 of patients with noncontracting gallbladders was significantly reduced in comparison to that of patients with gallstones whose gallbladders contracted in response to fat.

Cholelithiasis↗
PubMed1985

Influence of different anesthetic agents on the release of cholecystokinin in dogs.

The purpose of this study was to investigate the effect of pentobarbital, halothane, and chloralose anesthesia on the endogenous release of cholecystokinin-33 (CCK-33) in dogs prepared with duodenal fistulas. Release of CCK-33 was induced by intraduodenal infusion of a medium-chain triglyceride (corn oil, 1 gm/kg/hr). Plasma CCK-33 concentrations were measured by means of a specific radioimmunoassay. Pentobarbital and chloralose were administered intravenously, and halothane was administered by a vaporizer (semiclosed technique), with O2 and N2O used as carriers. No incidence of hypotension was found with the use of these anesthetic agents. Basal concentrations of plasma CCK-33 were elevated, although not significantly, during pentobarbital or chloralose anesthesia. In conscious dogs (control study), peak plasma CCK-33 concentrations of 529 +/- 53 pg/ml were measured 30 minutes after intraduodenal infusion of fat. Under pentobarbital anesthesia, peak plasma CCK-33 concentrations of 452 +/- 264 pg/ml were found 80 minutes after infusion of fat. Under halothane anesthesia, fat-induced release of CCK-33 was abolished, whereas chloralose anesthesia did not influence fat-induced release of CCK-33. These findings may have implications for the design of future studies of gastrointestinal physiology. In CCK-33 studies that require anesthesia, chloralose appears to be an appropriate anesthetic agent.

Anesthesia, General↗
PubMed1985

Effect of aging on gallbladder contraction and release of cholecystokinin-33 in humans.

The objective of this study was to examine the effect of aging on gallbladder contraction and cholecystokinin (CCK) release, as well as on the correlation between the two in humans who are free of gallbladder disease. Twenty-nine human volunteers were divided into a young group of 14 individuals (ages 22 to 42 years, median age 32 years) and an older group of 15 individuals (ages 60 to 84 years, median age 66 years). In the study each person in both groups was given corn oil (Lipomul), 1.5 ml/kg, by mouth after an overnight fast. Blood was collected for measurement of CCK-33 by radioimmunoassay before and at intervals after ingestion of Lipomul. Simultaneous measurements of gallbladder volume were obtained by real-time varian ultrasonography. Both fasting and fat-stimulated concentrations of CCK in plasma were significantly higher in the older individuals than in the younger volunteers. The 60-minute integrated measurement of CCK release was significantly increased in the older people as compared with the young. Both fasting and maximally contracted gallbladder volumes were equal in the older and younger groups. The rate of emptying of the gallbladder was equal in both age groups, but the gallbladders of older people appeared to show an earlier initiation of contraction. The highly significant correlation of gallbladder contraction with levels of CCK was similar in both age groups, but the sensitivity of the gallbladder to CCK in the older people was significantly decreased. In conclusion, both fasting and fat-stimulated plasma levels of CCK increase with aging. The sensitivity of the gallbladder muscle to stimulation by CCK is diminished with age, but this appears, teleologically, to be matched by the increased release of CCK, so the kinetics of gallbladder emptying are little different in the aged.

Adult↗
PubMed1984

Fragmented endocardial electrical activity in patients with ventricular tachycardia: a new guide to surgical therapy.

Eight patients with ventricular aneurysms and ventricular tachycardia refractory to drugs were studied. Each patient underwent intraoperative epicardial and endocardial mapping during stable sinus rhythm. After aneurysmectomy, areas of the endocardial border zone which demonstrated fragmented activity were excised. Mapping was then repeated to ensure that major areas of fragmentation did not remain. Mapping was completed in less than 20 minutes in each patient. One patient died of pump failure before hospital discharge and a second patient, who was arrhythmia-free, died of pump failure 12 months postoperatively. Six patients are alive and free of ventricular tachycardia 5 to 25 months (mean 11.5) postoperatively. We conclude that excision of areas of fragmented electrical activity in the endocardial border zone of ventricular aneurysms is a useful approach to surgical therapy for ventricular tachycardia. This approach allows an excision directed to arrhythmogenic areas without the need for tachycardia induction in the operating room.

Adult↗
PubMed1984

Endocardial activation in patients with coronary artery disease: effects of regional contraction abnormalities.

Endocardial mapping was performed on 16 patients undergoing coronary artery bypass surgery, and the results were correlated with ventriculography. Bipolar electrograms were recorded from 25 to 30 left ventricular (LV) endocardial sites by a specially designed probe which was inserted through the LV vent. Electrograms were evaluated for timing and presence of fragmentation. Five patients had normally contracting ventricles, four had areas of hypokinesis, six had areas of akinesis, and one had an area of dyskinesis. In each patient earliest endocardial activation was in the septum, most often the middle portion. Latest activation was in the lateral basal area in 13 patients and in the lateral apical area in three patients. Fragmented electrograms were not found in any normal or hypokinetic zones but were found in three of six akinetic segments, and in the one dyskinetic segment. These findings describe endocardial activation of the LV and the changes seen with regional contraction abnormalities.

Adult↗
PubMed1984

Traumatic false aneurysm of the vertebral artery.

A case of an enlarging asymptomatic pseudoaneurysm of the left vertebral artery, resulting from a gunshot wound, illustrates the dilemma of proper treatment selection. This case was treated by ligation of the involved third portion of the vertebral artery.

Adult↗
PubMed1984

Amiodarone for refractory automatic atrial tachycardia: observations on the electrophysiological actions of amiodarone.

A patient with automatic atrial tachycardia refractory to all conventional therapies is described. Amiodarone controlled the tachycardia by causing a progressive decrease in the rate of discharge from the atrial focus. We conclude that 1) amiodarone was effective therapy for automatic atrial tachycardia, avoiding the need for nonmedical therapy; and 2) amiodarone appeared to act by decreasing spontaneous automaticity.

Amiodarone↗
PubMed1984

Detrimental effects of verapamil in patients with primary pulmonary hypertension.

Calcium channel blockade provides a logical approach to the treatment of pulmonary hypertension because these drugs exert direct vasodilator effects in the highly constricted pulmonary circulation. To determine the effectiveness of verapamil in the treatment of primary pulmonary hypertension the haemodynamic effects of the drug were evaluated in seven patients with this disorder; 10 mg was given intravenously to six patients and 120 mg orally to one patient. Verapamil produced a 20% decline in pulmonary vascular resistance and a 27% decrease in mean pulmonary arterial pressure without significant changes in systemic vascular resistance. One patient who received verapamil 480 mg orally daily for three months showed sustained haemodynamic and clinical improvement. Concomitant with its beneficial effects on the pulmonary circulation, however, verapamil produced a pronounced decrease in right ventricular stroke work index (42%) and increase in right ventricular filling pressure (50%), indicating a direct depressant effect of the drug on right ventricular function. In one patient these cardiodepressant effects were sufficiently pronounced to produce severe hypotension and cardiac arrest. In conclusion, although verapamil appears to exert preferential vasodilator effects on the pulmonary circulation, its negative inotropic effects may be particularly detrimental to patients with primary pulmonary hypertension who have pre-existing right ventricular dysfunction; hence, treatment with verapamil is not recommended in such cases.

Adult↗
PubMed1984

Release of cholecystokinin in response to food and intraduodenal fat in pigs, dogs and man.

The present study was done to compare endogenous cholecystokinin-33 release in response to physiologic stimuli (meal, fat) in pigs, dogs and man. Plasma levels of cholecystokinin-33 were monitored using a radioimmunoassay for cholecystokinin which detects only cholecystokinin-33 and cholecystokinin-39. Ingestion of a meal caused release of cholecystokinin-33 within five, 20 and 120 minutes in man, pigs and dogs, respectively. Intraduodenal administration of corn oil resulted in a significant release of cholecystokinin-33 within 20 minutes in dogs, pigs and man.

Adult↗
PubMed1984

Comparison of cholecystokinin release and gallbladder emptying in men and in women at estrogen and progesterone phases of the menstrual cycle.

Why are gallstones more common in women than in men? To investigate this, we measured gallbladder emptying (by ultrasonography) and release of endogenous cholecystokinin (CCK) (by specific radioimmunoassay) in eight men and nine women in response to ingestion of corn oil (1 gm/kg). Each woman was studied on the fourteenth and twenty-first day of her menstrual cycle, estimated to be the estrogen (women [E] ) and progesterone (women [P] ) peaks, respectively. Fasting plasma concentrations of CCK were significantly higher in women (E) (135 +/- 7 pg/ml) than in men (99 +/- 13 pg/ml) but not significantly higher than in women (P) (113 +/- 11 pg/ml). The peak increase in CCK concentration over basal concentration and the integrated release of CCK were not significantly different from one group to another. Men had a larger fasting gallbladder volume (GBV) (21.4 +/- 3.2 ml) than did women (E) (12.4 +/- 2.1 ml) and women (P) (14.2 +/- 2.1 ml) and emptied more GBV in response to fat than did the women. The residual GBV and fractional emptying after ingestion of corn oil were not different among the three groups. Measurements of plasma CCK and GBV during the contraction phase were highly correlated in all groups. It appears, from these data, that the increased prevalence of gallstones in women relative to men cannot be explained on the basis of significant differences either in release of CCK or in gallbladder motility. Linear regression lines that were developed indicated that the mean change in GBV relative to a given change in plasma CCK was significantly higher in men than in women. Differences between men and women in this hormonal-motility relationship may contribute to the incidence of gallstones in premenopausal women.

Adult↗
PubMed1983

Determinants of ventricular tachycardia in patients with coronary artery disease and ventricular aneurysm. Clinical, hemodynamic, and angiographic factors.

Many patients with coronary artery disease (CAD) in whom ventricular tachycardia (VT) develops have transmural scars or frank aneurysms. However, only a minority of patients with ventricular aneurysms go on to develop VT. To determine which factors are associated with the development of VT in patients with aneurysms, we retrospectively reviewed the records of 154 patients with CAD and segments of akinesia or dyskinesia, or both, on left ventriculography. Of the 154 patients, 85 had 24-hour Holter monitoring or 48 consecutive hours of continuous electrocardiographic monitoring in an intensive care unit within 6 months of catheterization. VT occurring at least 10 days after myocardial infarction (MI) or in the chronic phase was recorded in 19 patients (Group I); the remaining 66 patients did not have VT (Group II). The clinical, hemodynamic, and angiographic characteristics of these 2 groups showed no significant difference with respect to age, time from first transmural MI to catheterization, congestive heart failure (CHF), ejection fraction, or presence of dyskinesia. Patients with VT had significantly larger aneurysms and a higher prevalence of septal akinesia or dyskinesia. However, stepwise discriminant analysis revealed septal akinesia or dyskinesia to be the only independently significant variable distinguishing the 2 groups. Thus, septal involvement appears to be a major determinant of VT in patients with CAD and ventricular aneurysm.

Adult↗
PubMed1983

Correlation between gallbladder size and release of cholecystokinin after oral magnesium sulfate in man.

In order to determine the effect of oral magnesium sulfate on gallbladder contraction and release of cholecystokinin (CCK) in man, magnesium sulfate (25 g in 100 ml distilled water) was given by mouth to five fasting adult male volunteers. Plasma samples were collected for measurement of CCK by a specific radioimmunoassay. Gallbladder volumes were determined from sonograms obtained from a phased-array real-time ultrasound scanner. Basal concentrations of CCK (82.2 +/- 10.1 pg/ml) increased significantly at 20 minutes after oral magnesium sulfate (113.8 +/- 7.1 pg/ml), and reached a maximal value at 50 minutes (150.0 +/- 42.0 pg/ml). The mean basal volume of the gallbladder was 30.8 +/- 5.3 cm(3) and maximum reduction of gallbladder volume (to one third of original) was achieved at 50 minutes after ingestion of magnesium sulfate. Linear regression analysis showed a close correlation (r = -0.9337) between plasma concentrations of CCK and gallbladder size in response to magnesium sulfate. Oral magnesium sulfate also caused a significant increase in serum gastrin (from basal of 51.4 +/- 9.9 pg/ml to 69.8 +/- 15.5 pg/ml at 5 min); there was no significant correlation between gastrin release and gallbladder contraction. This study provides direct evidence that the mechanism of magnesium sulfate-stimulated gallbladder contraction occurs through the release of CCK, and shows a close correlation between CCK release and contraction of the gallbladder.

Adult↗
PubMed1983

The role of surgery in the Zollinger-Ellison syndrome.

When the Zollinger-Ellison syndrome was first identified, total gastrectomy was proposed as the most effective treatment for the secretory manifestations of the syndrome. Recently, however, great enthusiasm has developed for medical treatment by means of H2-receptor antagonists. The authors have cared for 27 patients with the Zollinger-Ellison syndrome at The University of Texas Medical Branch in the past 12 years and have been pleased with the results of total gastrectomy, which was performed in 23 of the 27 patients (one patient refused operation and three patients had lesser gastric operations). Twenty-three patients underwent total gastrectomy with Roux-en-Y esophagojejunostomy. There were no operative deaths. Primary tumors were found in 17 patients, seven of whom also had metastatic tumors. No tumors were found in nine patients. Nine patients are dead; the actuarial survival rate for all patients was 75% at 5 years and 52% at 10 years. Eleven of the 27 patients had the multiple endocrine neoplasia I syndrome. Of the 18 survivors, only three have normal serum gastrin levels, and all three had extrapancreatic gastrinomas, one in peripancreatic lymph nodes, one in the liver, and one in a cystic tumor attached to the stomach. Nutritional results were good to excellent, with a mean postoperative weight loss of 14.7% (mean follow-up period was 45 months). The authors conclude that treatment of the hypersecretory problems of the Zollinger-Ellison syndrome by total gastrectomy is safe and dependable. Results compare well with those of long-term medical management, whose success is dependent upon serial favorable responses to a lifetime of repeated challenges.

Adolescent↗