Search PubMed⌕ Search

Biomedical subjects

D O Castell

Publications and source records attributed to D O Castell.

At least 325 records · Page 18Linked to original sources
PubMed1982

Gastroesophageal reflux. Pathogenesis, diagnosis, and therapy.

In recent years, considerable new information has become available on the pathogenesis, diagnosis and therapy of gastroesophageal reflux. Gastric contents, mucosal resistance, esophageal acid clearance, and gastric emptying are now recognized, along with incompetency of the lower esophageal sphincter, as contributing factors to gastroesophageal reflux disease. The potential tests for reflux are reviewed and the diagnostic accuracy of each is evaluated. A diagnostic approach to the patient with reflux symptoms is outlined that considers the sensitivity and specificity of these various tests as well as their availability to the generalist and gastrointestinal specialist. Finally, an overview of the current therapy for reflux disease summarizes the controlled studies in the medical literature.

Alginates↗
PubMed1982

Verapamil--a potent inhibitor of esophageal contractions in the baboon.

Verapamil, a calcium channel blocking agent, has been shown to be a potent inhibitor of smooth muscle contraction. We studied the effects of verapamil on lower esophageal sphincter pressure and esophageal peristalsis in 5 awake baboons. An infusion of verapamil (80 micrograms/kg . min) decreased amplitude of peristalsis by 63% in the smooth muscle segments of the esophagus but had no effect on striated muscle. Duration of peristaltic waves in the smooth muscle portion of the esophagus was also shortened, but there was no effect on velocity of the contraction wave. Lower esophageal sphincter pressure decreased by 74% during verapamil infusion. These studies suggest that verapamil or other calcium channel blocking agents may be of potential use in the treatment of esophageal motility disorders associated with increased pressure.

Animals↗
PubMed1982

Pharyngoesophageal (Zenker's) diverticulum: a reappraisal.

Manometric evaluation of pharyngeal contraction and upper esophageal sphincter relaxation was performed in a group of patients with Zenker's diverticulum using a specially designed low compliance manometric recording system. The results were compared with those in normal controls. In all cases, the upper esophageal sphincter showed complete relaxation during swallowing and no incoordination between pharyngeal contraction and upper esophageal sphincter relaxation could be demonstrated compared to time intervals found in the control group. Resting upper esophageal sphincter pressures were significantly lower in diverticulum patients than in controls. It is concluded that symptomatic patients with Zenker's diverticulum have normal pharyngeal-upper esophageal sphincter coordination, exhibit complete upper esophageal sphincter relaxation on swallowing, and have low resting upper esophageal sphincter pressures. These results seriously question the previous concept of abnormalities of pharyngeal-upper esophageal sphincter coordination in patients with Zenker's diverticulum.

Aged↗
PubMed1981

Human esophageal response during chest pain induced by swallowing cold liquids.

Normal persons often note chest or back pain during rapid ingestion of cold liquids, commonly believed to result from cold-induced "spasm" of esophageal muscle. We studied the effects of swallowing cold liquids on esophageal function in five normal subjects, aged 20 to 44 years, by comparing their response to cold ice cream (-5 degrees C) and room temperature ice cream mix (20 degrees C). Decreased peristaltic amplitude was seen during cold ice cream ingestion, primarily in the midesophagus. When seven subjects rapidly ingested ice cream until chest pain was produced and maintained for at least 60 s, complete absence of motor activity in the distal esophagus occurred, with slow return to normal during the ensuing five minutes. Our studies indicate that ingestion of cold liquids significantly depresses peristaltic amplitudes and frequency of peristalsis in normal persons, and pain is associated with complete absence of motor activity in the body of the esophagus, rather than esophageal "spasm" as commonly believed.

Adult↗
PubMed1981

Abnormal gastric emptying response to pentagastrin in duodenal ulcer disease.

The effect of pentagastrin on gastric emptying in duodenal ulcer disease (DU) is unknown. The evaluation of this effect is complicated by the simultaneous action of the hormone on gastric secretion. We compared gastric emptying and net gastric output in 17 patients with active DU to that of 11 healthy controls. A dye-dilution technique was used to determine net acid output, fractional emptying rate, and acid emptying rate during a basal period and after pentagastrin (6 microgram/kg/hr, intravenously). Net basal acid output observed in controls (54 +/- 10 microEq/min; mean +/- SE) was used as the primary criterion for separating DU patients into 12 normosecretor (30 +/- 10 microEq/min) and 5 hypersecretor patient groups (163 +/- 40 microEq/min). The pentagastrin-stimulated net acid output was significantly greater in hypersecretor patients than in controls (P less than 0.01) but was normal in normosecretor patients. Basal fractional emptying and acid emptying rates were significantly greater in hypersecretors than in controls (P less than 0.05) but were normal in normosecretors. In contrast, both normo- and hypersecretor patients had significantly greater fractional emptying (P less than 0.01) and acid emptying rates than controls (P less than 0.05) during pentagastrin infusion. Thus, a greater load of acid transiently enters the duodenum in duodenal ulcer disease following pentagastrin stimulation, even in the absence of gastric hypersecretion.

Adult↗
PubMed1981

Effect of oral bethanechol on parameters of esophageal peristalsis.

It has been suggested that enhanced esophageal peristalsis may be an additional reason for the therapeutic effect of oral bethanechol (B) in reflux patients and for the improved acid clearing seen with B. This study was designed to determine the effect of oral B on various parameters of esophageal peristalsis. Healthy young adult males were studied with an intraesophageal transducer assembly. Amplitude, dp/dt, and velocity profiles for the smooth muscle portion of the esophagus were produced. Oral B, 25 mg, produced a significant increase (P less than 0.05) in amplitude in the distal esophagus from 15 to 45 min after drug administration. The effect on dp/dt was similar but not as marked. Oral bethanechol produced decreases in velocity at all points, reaching significance (P less than 0.05) at the most distal measuring site, 30 and 45 min after injection. Oral B produces a stronger but slower, perhaps more efficient, progression of the peristaltic wave in normal humans. Our findings may explain improved acid clearance found with this agent.

Adult↗
PubMed1981

Do prostaglandins cause gastrointestinal mucosal injury?

We have reviewed various examples of the injurious effects of prostaglandins on the gastrointestinal tract along with evidence that, in certain disease states, nonsteroidal antiinflammatory agents may have a prophylactic or therapeutic effect. The most important areas in which these drugs may be useful are in treatment or prevention of esophagitis, food intolerance symptoms, cholera, radiation-induced diarrhea, and ulcerative colitis. Although these two sets of facts appear to be contradictory, they may actually represent two distinct phenomena. The examples of deleterious effects of prostaglandins on gastrointestinal mucosa are all examples of inflammatory changes. Many changes occur in acute inflammation, including leukocytosis and chemotaxis of neutrophils to the area of inflammation. Release of many substances, including prostaglandins, histamine and bradykinin, occurs into the inflamed site. The prostaglandins involved in inflammation of the gastrointestinal mucosa may be quite different in source, type, and quantity from endogenous prostaglandins which play a role in cytoprotection. In addition, because other substances in addition to prostaglandins are involved in inflammation, and nonsteroidal antiinflammatory agents do not act exclusively by inhibition of prostaglandin synthesis, the therapeutic benefit of antiinflammatory agents in gastrointestinal mucosa may be due to several mechanisms. Therefore, in spite of the strong evidence indicting nonsteroidal antiinflammatory drugs as occasionally harmful to the gastric, duodenal, and intestinal mucosa, we should not lose sight of their important potential therapeutic role in other areas of the gastrointestinal tract.

Esophagus↗
PubMed1981

Beneficial effect of indomethacin on acid-induced esophagitis in cats.

Acid-induced esophageal injury in the cat, produced by infusion of 0.1 N HCl (1 ml/min for 30 min) on 4 consecutive days, has been shown previously to adversely affect lower esophageal sphincter (LES) pressure. We studied the role of prostaglandins in acid-induced esophagitis and the associated LES hypotension by simultaneous treatment of some animals with indomethacin (150 micrograms/kg intravenous), a specific inhibitor of prostaglandin synthesis, either during production of esophagitis or during recovery. LES pressures and esophageal histology were compared to control groups which received acid alone. Indomethacin treatment resulted in more rapid healing of the esophageal inflammation and prevented or promptly corrected the esophagitis-associated LES hypotension. These studies provide further evidence that prostaglandins play an important role in the pathogenesis of acid-induced esophagitis and LES hypotension and raise the possibility that indomethacin, a prostaglandin synthetase inhibitor, may be of benefit in prevention or therapy of esophagitis.

Animals↗
PubMed1981

Prostaglandin E1 effects on resting and cholinergically stimulated lower esophageal sphincter pressure in cats.

Intraluminal esophageal manometry with a sleeve catheter was used to compare the magnitude of decrease in lower esophageal sphincter (LES) pressure produced by an arterial or venous infusion of prostaglandin E1 in cats. Arterial PGE1 produced significantly lower LES pressures than venous PGE1 (p less than 0.05). Maximal decrease of 75% in basal LES pressure occurred with an associated 15% decrease in systolic blood pressure. The site of action of PGE1 in producing LES hypotension was studied by injection of either edrophonium, or bethanechol during the maximal PGE1 effect. Bethanechol, which acts directly on sphincteric smooth muscle, produced an increase in LES pressure during both saline and PGE1 infusion, while the increases in LES pressure seen with edrophonium during saline infusion were blocked during the PGE1 infusion. From these studies, we conclude that PGE1 produces LES hypotension in the cat by an inhibitory effect on the cholinergic pathway responsible for maintaining LES tone. These studies pharmacologically reproduce the LES pressure abnormality previously reported in the cat during acid-induced esophagitis and support the hypothesis that PGE1 may be involved in the pathogenesis of acute acid-induced lower esophageal sphincter abnormalities.

Animals↗
PubMed1981

Evaluation and management of diseases of the esophagus.

Current methods to evaluate patients with esophageal disease include barium swallow with fluoroscopy, which is useful in demonstrating structural defects. Disordered motility is better evaluated with a cine-esophagram. Recent application of radioisotopes has been useful in evaluation of esophageal reflux and the post-treatment of achalasia. Esophageal motility studies may evaluate lower esophageal sphincter and upper esophageal sphincter pressures and the response of the body of the esophagus to series of swallows. Since there is no "gold standard" for the evaluation of reflux esophagitis, some of the tests designed to evaluate reflux and the patient's reaction to acid in the esophagus include the acid infusion test, the standard acid reflux test, the acid clearance test, and 24-hour pH monitoring. Endoscopy with either the flexible or the rigid instrument is important for the diagnosis of obstruction or esophagitis and allows direct visualization of the esophagus. The treatment of reflux esophagitis is discussed. The differential diagnosis of dysphagia may include achalasia, diffuse esophageal spasm, and mechanical obstruction of the esophagus due to rings, webs, strictures, and benign or malignant tumors. The evaluation of dysphagia should include radiologic as well as endoscopic evaluation. Treatment of obstruction varies according to the nature of the lesion. The Mallory-Weiss syndrome or bleeding from the mucosal tears of the gastroesophageal junction and Boerhaave's syndrome, spontaneous esophageal perforation, are two disorders associated with vomiting. The Mallory-Weiss syndrome usually resolves without specific therapy, but a high index of suspicion is required for patients with chest pain after vomiting, as spontaneous perforation necessitates immediate surgery. Most diverticula need no treatment, but the Zenker diverticulum, if symptomatic, should probably be surgically repaired.

Deglutition Disorders↗
PubMed1981

Achalasia and Hodgkin's disease: a chance association?

We report a patient with a case of Hodgkin's disease, stage IIB, presenting as achalasia. Not only did careful evaluation fail to reveal tumor involvement of the esophagus, but therapy of the Hodgkin's disease failed to improve and, in fact, worsened the dysphagia. Pneumatic dilatation was required after completion of radiation therapy. We still need to evaluate dysphagia in patients with lymphoma by standard means, despite reports of "secondary" achalasia.

Barium↗
PubMed1981

Human esophageal response to rapid swallowing: muscle refractory period or neural inhibition?

The peristaltic response of the normal human esophagus to 10 repeated water swallows separated by varying time intervals (5, 10, 15, 20, and 30 s) between swallows was studied. Pressures measured during the shorter time intervals were of lower amplitude than those at 30-s swallowing intervals throughout the esophagus, with the distal esophagus showing the greatest effect. Frequency of peristalsis was decreased throughout the esophagus with rapid swallowing, especially distally at the 5- and 10-s time intervals. There was no significant change in wave velocity or duration at these time intervals. These data suggest that there is a refractory period in the distal (smooth muscle) esophagus. A series of paired swallows separated by 5 s resulted in a significant decrease in amplitude of the first swallow, and this was more marked in the distal esophagus. These data indicate that there is an inhibition of the progression of peristalsis by a subsequent swallow, probably through a neural mechanism. These studies show that repeated liquid swallows may effect peristalsis by two mechanisms: refractoriness of esophageal smooth muscle and a neural inhibitory discharge.

Adult↗
PubMed1981

Current approaches in the medical treatment of oesophageal reflux.

Gastro-oesophageal reflux and its complications are a common clinical management problem. Medical treatment revolves around the use of physical and mechanical methods in prevent reflux, dieting and drug restriction, acid reduction, mechanical foam barriers, and drugs to increase lower oesophageal sphincter (LES) pressure and improve acid clearance. It is recommended that patients elevate the head of their bed at night, eliminate alcohol and smoking, and avoid food known to decrease LES pressure or irritate the oesophageal mucosa. Antacids are effective in the control of reflux symptoms in most patients with mild to moderate reflux oesophagitis. 'Gaviscon' is also effective but no better than antacids. The histamine H2 receptor blocker, cimetidine, alleviates symptoms and may also improve endoscopic and histological oesophagitis. Cimetidine and drugs which augment sphincter pressure (bethanechol, metoclopramide, domperidone and prostaglandins) may be helpful in treating patients with severe reflux oesophagitis.

Diet↗
PubMed1981

Gastroesophageal reflux disease in the Zollinger-Ellison syndrome.

Gastroesophageal reflux has rarely been reported in the Zollinger-Ellison syndrome, presumably due to elevation in the lower esophageal sphincter pressure. We have evaluated 15 patients with the Zollinger-Ellison syndrome for evidence of esophageal disease. Five presented initially with esophageal disease: one, reflux symptoms; two, severe esophagitis; and two, strictures. Six of 15 had heartburn and nine of 15, objective evidence for reflux disease. Mean lower esophageal sphincter pressure was higher in the Zollinger-Ellison syndrome than in controls but was unrelated to serum gastrin levels. Zollinger-Ellison syndrome patients without heartburn had a higher mean sphincter pressure than did patients with heartburn (who had a mean sphincter pressure similar to that of controls but greater than that in patients with idiopathic gastroesophageal reflux). Four patients had biopsy evidence of esophagitis, one in association with Barrett's epithelium. Gastroesophageal reflux and its complications appear to be common in the Zollinger-Ellison syndrome.

Adult↗