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Biomedical subjects

H Meshkinpour

Publications and source records attributed to H Meshkinpour.

At least 37 records · Page 2Linked to original sources
PubMed1988

Effect of gastric bubble as a weight reduction device: a controlled, crossover study.

In spite of the widespread use of the Garren-Edwards gastric bubble as an adjuvant device in weight reduction, its efficacy has not been established. Therefore, our purpose was to conduct a randomized, double-blind, crossover study of this device in the management of exogenous obesity. The study group consisted of 23 patients, 21 women and 2 men, ranging in age from 21 to 53 yr. Patients were 25%-111% above their ideal body weight. They were studied for 24 wk, consisting of two separate 12-wk evaluation periods. Patients were randomly assigned either to receive the gastric bubble or to have a sham procedure. After the first 12-wk evaluation period, the gastric bubble and sham were administered in crossover fashion, so that those who had received the gastric bubble initially received the sham later and vice versa. The study coordinator remained blind to the kind of treatment, weighed each patient biweekly, enforced dietary counseling, and provided behavior modification. Those who had passed or were found to have a deflated bubble at the end of the treatment period were excluded from the study. Mean weight reduction in the two evaluation periods did not differ significantly. Patients lost 5.4 +/- 1.7 kg (mean +/- SE) during the gastric bubble period and 5.20 +/- 0.8 kg during the sham period. The order of administration of the gastric bubble and sham did not significantly affect the result. The time-course of mean biweekly values, however, revealed that with the gastric bubble, weight loss was significantly greater only during first (p less than 0.005) and second (p less than 0.025) 2-wk evaluation periods. This difference, however, disappeared after the initial 4 wk of treatment. These observations suggest that although gastric bubble implantation reduced weight significantly more than the sham procedure initially, the mean weight loss during 12 wk of evaluation was not different between the two periods. In our opinion, the gastric bubble is of no value as an adjuvant device in weight reduction.

Adult↗
PubMed1987

Impact of neodecortication on colon motor response to a meal in the rat.

The colon motor response to a meal consisting of 100 mM of sodium oleate was assessed before and after neodecortication in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low-compliance perfusion system. A motility index took into account the amplitude, duration, and frequency of contractions. Neodecortication increased the motility index of the distal colon in the fasting state. However, removal of the cerebral cortex did not affect significantly the colon motor response to a meal. Meal stimulation increased the motility index before and after neodecortication. These findings suggest that resting colonic motor activity is increased after neodecortication, probably through the loss of an inhibitory influence of the central nervous system; and the cerebral cortex is not required for the colon response to a meal in the rat.

Animals↗
PubMed1986

The neurovisceral and electrodiagnostic evaluation of patients with thoracic spinal cord injury.

We studied nine patients with complete thoracic spinal cord injury in order to investigate distal electrophysiologic and end organ function. Studies included motor and sensory nerve conduction velocities, spinal and cortical somatosensory evoked responses, bulbocavernosus reflex responses, cystometry and colonic compliance, motor and myoelectrical activity. These studies confirmed an intact peripheral nervous system, as well as normal nerve root, cauda equina, conus medullaris and distal spinal cord function. Cystometry demonstrated decreased bladder capacity and inability to suppress detrusor contractions. Colonic compliance was greatly reduced, compared to control subjects. While basal colonic motor and myoelectrical activity was normal, these spinal cord injury patients failed to demonstrate the postprandial increase in colonic motor and myoelectric activity seen in normal subjects. These tests allow the clinician to define and document the extent of neuronal injury distal to a transverse myelopathy and to evaluate visceral end organ function.

Adult↗
PubMed1986

The renin-angiotensin system in hypothyroidism of short duration.

In six hypothyroid patients (2 male, 4 females, ages 22 through 59 years), plasma renin activity (PRA) and aldosterone (Aldo) were measured when the patients were euthyroid on levothyroxine therapy and one month after the therapy was stopped. Colonic mucosal potential differences were measured during the hypothyroid and euthyroid stages, and catecholamine sensitivity was determined by the blood pressure response to infused norepinephrine. Significant differences were observed in the PRA and aldosterone concentrations which were 4.1 +/- 2.5 ng/ml/h and 9.4 +/- 5.9 ng/dl, respectively in the hypothyroid stage and 6.9 +/- 2.3 ng/ml/h and 15.2 +/- 7.3 ng/dl, respectively when the patients were made euthyroid. The colonic mucosal potential differences (which reflect increased endogenous mineralocorticoid activity), became more electronegative after correction of hypothyroidism (-16.8 +/- 7.5 mV vs -32 +/- 18.2 mV; P less than 0.04) concentrations. Statistically significant decreases in norepinephrine pressor effects were observed in hypothyroid patients when compared to the euthyroid state (7.4 +/- 2.3 vs 10.9 +/- 1.9 micrograms/ng/min; P less than 0.01). It is concluded that patients with hypothyroidism have a hormonal pattern reminiscent of "low renin hypertension", and exhibit decreased sensitivity to catecholamines. Such changes are corrected when the patients become euthyroid on levothyroxine therapy.

Adult↗
PubMed1985

Modified acid reflux test. A benefit and cost analysis.

Although the standard acid reflux test is often used to diagnose gastroesophageal reflux (GER), the cost and benefit of this diagnostic test has never been evaluated. In this study, 184 consecutive referrals with esophageal symptoms were interviewed and had an esophagram, an esophageal manometry, and a modified acid reflux test (MART). The results were analyzed to determine how frequently MART altered the clinical diagnosis and to assess the cost of the new information. Patients with typical symptoms of GER (heartburn or regurgitation) were compared to those with atypical presentation (chest pain or dysphagia). Previously unsuspected GER was demonstrated in 63% of the atypical group, whereas no altered diagnosis was made in the typical group. There was no statistically significant difference between the two groups when mean lower esophageal sphincter pressures and mean pH scores were compared. MART was cost effective only in the atypical group, in which the cost of an altered diagnosis was $633.00.

Adolescent↗
PubMed1985

Colonic absorption of 1,2-dimethyl hydrazine (DMH) in the rat.

1,2-Dimethyl hydrazine (DMH) is absorbed in the colon by passive diffusion in the 0.1-5.0 mM concentration range. Absorption of DMH is enhanced by both conjugated and unconjugated bile acids. The presence of hydroxy-fatty acids in the colon markedly increased DMH absorption while fatty acids of different chain length did not influence absorption.

1,2-Dimethylhydrazine↗
PubMed1985

Effects of thoracic spinal cord transection on colonic motor activity in rats.

The resting colonic motor activity before and consecutively after spinal cord transection was recorded in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low compliance perfusion system. A motility index took into account the amplitude, duration and frequency of contractions. Following a baseline recording animals were subjected either to spinal cord transection at T4 level or a sham operation. The recording sessions continued regularly on alternate days for the observation period of 3 weeks. Transection of the thoracic spinal cord markedly reduced the motility index of the distal colon on the first postoperative day. However, the motor activity gradually returned to pre-operative values after 7 days. Sham surgery did not influence the motor activity. These findings suggest that colonic motor activity is influenced by spinal shock and probably by different neural mechanisms mediating proximal and distal activities of the colon in rats.

Animals↗
PubMed1984

Colonic absorption of acetylsalicylic acid in the rat.

Aspirin is absorbed in the colon by passive diffusion to a significant degree in spite of the alkaline pH of the colonic lumen. Aspirin absorption by the colon is enhanced by increasing the hydrogen ion concentration. Butyric acid, by markedly reducing the absorption rate of aspirin, may be partially responsible for the unpredictable absorption of rectally administered aspirin. The addition of glycerol to aspirin preparations does not hinder the absorption of aspirin by the colon.

Animals↗
PubMed1984

Bile duct dyskinesia. Clinical and manometric study.

Unexplained right upper quadrant symptoms have often been attributed to bile duct dyskinesia. In this study we evaluated the pressure profile of the sphincter of Oddi in 10 patients with recurrent episodes of right upper quadrant pain, intermittent mild transaminasemia, and a normal pancreatobiliary tract. Nine healthy volunteers served as control. A triple-lumen catheter with an external diameter of 1.7 mm and recording sites at 2-mm intervals was introduced into the papilla through the endoscope. Ductal pressure, basal sphincter of Oddi pressure, and the amplitude and propagation direction of the phasic contractions of the sphincter were determined in patients and subjects. All measurements were performed relative to duodenal pressure, which was taken as zero. There was no significant difference between patients and subjects in the amplitude and frequency of phasic contractions of sphincter of Oddi. In contrast, the patients demonstrated a higher sphincter of Oddi pressure (p less than 0.005) and increased proportion of retrograde propagation direction of phasic contractions (p less than 0.01). It is concluded that a subpopulation of patients with unexplained abdominal pain demonstrated abnormal pressure profile of the sphincter of Oddi.

Adult↗
PubMed1984

Colonic dysfunction in patients with thoracic spinal cord injury.

Severe constipation is a debilitating concomitant of complete traumatic thoracic spinal cord injury. In order to investigate the pathophysiology of this symptom, we studied colonic compliance, as well as motor and myoelectrical activity, in the fasting and postprandial states and after neostigmine stimulation in 9 patients with clinically and electrophysiologically documented complete thoracic spinal cord injury. Electrophysiologic studies, including nerve conduction velocities, cortical and spinal somatosensory-evoked responses, and bulbocavernosus reflex responses, as well as urinary bladder cystometry, documented normal peripheral somatosensory function, integrity of the distal spinal cord, conus medullaris and cauda equina, and interruption of the somatosensory and descending spinal pathways proximal to the cauda equina. These 9 patients with spinal cord injury demonstrated a decrease in colonic compliance compared with a control group (p less than 0.01). They failed to demonstrate the postprandial increase in colonic motor and myoelectrical activity observed in a control group (p less than 0.01), but did respond to neostigmine with an increase in both motor and myoelectrical activity (p less than 0.02), suggesting an intact myogenic component. In these patients, decreased colonic compliance and absent postprandial colonic motor and myoelectrical activity may be mediated by ablation of outflow from higher centers to the lower spinal cord and may be correlates of visceral neuropathy and severe constipation.

Adult↗
PubMed1983

Work in progress. Gastrointestinal ulcerations: detection using a technetium-99m-labeled ulcer-avid agent.

Technetium-99m-labeled sucralfate, an ulcer-avid material, was shown in preliminary animal and human studies to be stable in vivo with good sensitivity. Eight experimentally produced discrete gastric ulcers in three rabbits were visualized using this material. Of seven human studies, four studies were true-positive and three were true-negative. It is suggested that Tc-99m-labeled sucralfate may prove to have significant clinical advantages for the evaluation of gastrointestinal ulcer disease and other diseases that are associated with loss of mucosal integrity. The method for labeling sucralfate with Tc-99m was developed by the authors.

Aluminum↗
PubMed1983

Colonic compliance in patients with spinal cord injury.

While numerous communications have focused on urinary bladder dysfunction in the course of spinal cord injury, gastrointestinal disorders have received little attention. Abnormal bladder response to distention (automatic bladder) has been widely encountered among patients with complete thoracic spinal cord injury. To examine the similar concept in the colon, intracolonic pressure changes were measured in response to variable volumes of water introduced into the organ. Eight patients with complete spinal cord injury at the thoracic region (T6-T10) and 10 healthy volunteers were studied. Water was infused into the colon and intracolonic pressure was recorded using a rectilinear dynograph. The procedure was continued until the pressure reached 40mmHg or 2500ml of water had been administered. In spinal cord injury patients, the intracolonic pressure increased rapidly to a mean value of 35mmHg with as little as 300ml of water, whereas in normal controls this pressure was achieved only after 2200ml of water had been introduced into the colon. These findings indicate that the colon in patients with complete spinal cord injury of the thoracic region demonstrates an abnormal stretch response similar to that described in the bladder. This phenomenon could explain the frequent colonic symptoms experienced by these patients.

Adolescent↗
PubMed1982

Esophageal manometry: a benefit and cost analysis.

Esophageal manometric study has gained tremendous popularity over the past decade. However, the contribution of this diagnostic technology has not been critically evaluated. The purpose of this report is, therefore, to determine how frequently esophageal manometry alters the clinical diagnosis and treatment and to assess the cost of new information. The patients reviewed in this report consisted of 363 consecutive referrals. Each completed a questionnaire, had an esophagogram, and underwent an esophageal manometric study for the evaluation of dysphagia, heartburn, and/or chest pain of unexplained etiology. To determine the clinical contribution of manometry, diagnoses before and after the study were compared. On the basis of symptoms and radiologic data, specific clinical entities were diagnosed in 36 patients. Manometric study did not confirm the diagnosis of achalasia in four of the 27 patients referred with this diagnosis and resulted in 19 additional specific diagnoses. Manometry changed the course of treatment in 14 cases, eight additional patients with achalasia received treatment, and four false-positive patients were spared inappropriate treatment. Moreover, two patients with simultaneous esophageal motor disorder and chest pain were spared further investigation. It is concluded that esophageal manometry altered the clinical diagnosis in 6% and changed the course of treatment in 4% of the population studied. Esophageal manometry is beneficial in patients with chest pain, dysphagia, and those in whom diagnosis of achalasia is suspected, but is of little benefit in patients with chronic heartburn. Assuming the cost per study to be +250, the cost of the study was +3945 per alteration of diagnosis and +6482 per alteration of treatment.

Cost-Benefit Analysis↗
PubMed1982

Attenuation of hypertension by conjugation estrogens.

An unusual case of hypertension in a female that was normalized by the administration of conjugated estrogens is reported. During the period when no estrogens were administered, marked sodium retention was noted with an associated increase in sensitivity to the vasopressive effect of infused catecholamines and an increase in the electronegativity of the colonic mucosal potential difference. These findings suggested the presence of a mineralocorticoid influence that was reversed by estrogen therapy. The increase in arteriolar sensitivity occurred despite normal serum concentrations of aldosterone, deoxycorticosterone and 18-hydroxy 11-deoxycorticosterone and paralleled the sodium-retaining state. All the abnormalities were corrected with estrogen administration.

Estrogens, Conjugated (USP)↗
PubMed1982

Pseudo-Cushing's syndrome: the role of alcohol.

The mechanisms responsible for the genesis of pseudo-Cushing's syndrome are poorly understood. We studied the effect of acute ethanol administration on the hypothalamic-pituitary-adrenal axis in five chronic alcoholic patients and three normal volunteers. Ethanol was administered alone and together with beta 1-24 ACTH given intravenously. Baseline plasma ACTH and cortisol concentrations were significantly higher in the patients than in normal controls (p less than 0.05). Acute ethanol administration produced no significant change in the mean plasma ACTH concentration, failed to augment the effect of exogenous ACTH on the adrenal gland, and produced similar changes in the serum cortisol and aldosterone concentration in both the normal controls and the alcoholic patients. We speculate that pseudo-Cushing's syndrome may represent a state of stress-induced hypercortisolemia secondary to multiple episodes of subacute withdrawal from ethanol.

Adrenocorticotropic Hormone↗