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Biomedical subjects

D O Castell

Publications and source records attributed to D O Castell.

At least 199 records · Page 11Linked to original sources
PubMed1991

Esophageal motility disorders and chest pain.

Motility abnormalities have long been recognized as a possible esophageal cause of chest pain; however, their exact role and prevalence remain largely unknown. Baseline manometry and the various provocative tests may suggest an esophageal origin, but their yield is low. The recent advent of prolonged ambulatory monitoring of intraesophageal pressure and the assessment of psychological factors are contributing to a clearer understanding of this complex problem.

Chest Pain↗
PubMed1991

Effect of intraperitoneal fluid volume changes on esophageal pressures: studies in patients on continuous ambulatory peritoneal dialysis.

Esophageal manometric studies were performed in 11 patients on continuous ambulatory peritoneal dialysis (CAPD) with the dialysis fluid in the peritoneal cavity, after emptying and again after reinfusion. No systematic changes were found in intragastric or lower esophageal sphincter (LES) pressures at any time. No differences in mean distal esophageal amplitude (DEA), duration, or velocity of peristalsis were noted. Although upper gastrointestinal problems are common in CAPD patients and were reported by eight of 11 patients, this study suggests that these symptoms cannot be explained by changes in gastric and esophageal pressures.

Adult↗
PubMed1991

Rationale for high-dose H2-receptor blockade in the treatment of gastro-oesophageal reflux disease.

Chronic gastro-oesophageal reflux disease is a common clinical problem. The underlying pathophysiology is considered to be acid injury to the oesophageal mucosa secondary to reflux of gastric contents across an incompetent lower oesophageal sphincter. Evidence suggests that gastro-oesophageal reflux disease is primarily a motility disorder, possibly the combined effect of decreased lower oesophageal sphincter pressure, abnormal oesophageal peristalsis, and, perhaps, delayed gastric emptying. The rationale for the use of acid-suppressing drugs in chronic gastro-oesophageal reflux disease is based on control of the known destructive role of acid and pepsin. Recent evidence indicates, however, that standard doses of H2-receptor blockers are often inadequate to control gastric acid-induced injury in many patients with chronic reflux. Long-term maintenance therapy with standard doses of these drugs has proved unsuccessful in approximately 50% of patients. More recent studies show that greater symptom relief and improved healing can be achieved with the use of larger doses of H2-receptor antagonists. This has been shown particularly with ranitidine at a dosage of 300 mg four times daily.

Animals↗
PubMed1991

Rationale and efficacy of conservative therapy for gastroesophageal reflux disease.

Major recent advances in the diagnosis and understanding of gastroesophageal reflux disease have afforded the practicing clinician a number of therapeutic options to treat the increasingly recognized affected patient population. With highly effective acid-suppressive therapies available, simple life-style modifications, such as selective food and medicine avoidance, weight loss, smoking cessation, elevation of the head of the bed, and the judicious use of antacids and alginate, have been relegated to a minor, if any, role in the management of these patients. The validity of these recommendations, however, remains consistent with our current understanding of the pathogenesis of gastroesophageal reflux disease. Although few well-designed placebo-controlled trials have been conducted, a review of the medical literature indicates an appreciable efficacy of these interventions, which are founded on well-studied physiologic determinants of gastroesophageal reflux. Most patients with gastroesophageal reflux disease can be managed by reassurance and simple life-style adjustments alone. The therapy for those with chronic or relapsing disease should always include the adjunctive reinforcement of these simple, efficacious, and cost-effective measures.

Alcohol Drinking↗
PubMed1991

Swallowing disorders in the elderly.

The classic symptoms of dysphagia, heartburn, and chest pain are the presenting manifestation of oropharyngeal and esophageal disorders in the elderly as well as the young. Several unique conditions, including Zenker's diverticulum and vascular compression of the esophagus, may occur in the elderly. Certain disorders, such as oropharyngeal dysphagia due to neurologic disorder, increase in frequency with age. Treatment approaches are similar in elderly and younger patients, but the potential for adverse drug effects and interaction is greater in the elderly than in the young.

Aged↗
PubMed1991

Diltiazem therapy for symptoms associated with nutcracker esophagus.

UNLABELLED: A randomized double-blind, cross-over prospective trial in 22 patients was designed to evaluate possible effect of an oral calcium channel blocker, diltiazem, on symptoms of chest pain and/or dysphagia in patients with nutcracker esophagus. We studied 22 consecutive patients referred to an esophageal diagnostic center for evaluation of noncardiac chest pain or dysphagia having high amplitude esophageal contractions, 14 of whom completed the study. Diltiazem (60-90 mg qid) was compared with placebo, each being administered for 8 wk. Patients were evaluated with esophageal motility pre- and posttreatment periods and with regular symptom assessment throughout each 8-wk treatment. Active diltiazem therapy resulted in significantly lower (p less than 0.05) mean distal esophageal peristaltic pressure (128 +/- 20 mm Hg; +/- SE) than placebo (158 +/- 16 mm Hg). Mean chest pains scores were significantly (p less than 0.05) lower with diltiazem therapy than with placebo. Only nine of the 14 patients fulfilled presently acceptable criteria for diagnosing nutcracker esophagus, and the diltiazem effect was similar, although not significant, because of the smaller sample. CONCLUSIONS: In this preliminary study involving 14 patients, the oral calcium channel blocker, diltiazem, appeared to improve noncardiac chest pain associated with strong esophageal contraction, the nutcracker esophagus. These improved symptoms were associated with significant decreases in contraction pressure.

Adult↗
PubMed1990

Gastroesophageal reflux in runners. Characteristics and treatment.

STUDY OBJECTIVE: To test the potential of distance running to induce reflux in healthy subjects and the ability of ranitidine to decrease esophageal acid exposure. DESIGN: A randomized, single-blind, crossover study. Objective assessment of reflux was done using an ambulatory intra-esophageal pH monitor during both a baseline hour and 1 hour of running on 2 days of testing. SUBJECTS: Fourteen normal volunteers (10 men, four women) between 22 and 37 years of age were studied. All volunteers ran regularly, completing an average of 20 miles weekly for at least 6 months. INTERVENTIONS: Ranitidine, 300 mg orally, or an identical placebo was administered after a low-fat breakfast just before the baseline hour of pH recording. SETTING: Esophageal motility and pH probe placement was done in the gastroenterology unit at Bowman Gray Medical Center. Running was done on local jogging trials. MEASUREMENTS AND MAIN RESULTS: There was more gastroesophageal reflux during running than during the baseline hour when reflux was measured at a pH threshold of 3.0, 4.0, or 5.0 (P less than 0.05). Reflux episodes were usually associated with belching. Ranitidine, 300 mg administered orally 1 hour before running, significantly (P less than 0.05) reduced the amount of esophageal acid exposure during running. CONCLUSIONS: Gastroesophageal reflux occurs during running in healthy volunteers. It is usually associated with belching. Acid suppression with ranitidine decreases intraesophageal acid exposure during running (P less than 0.05).

Adult↗
PubMed1990

Radiation-induced proctitis cystica profunda in the rat.

Therapeutic pelvic irradiation is notorious for the production of clinically significant sequela after a long latency. One of the rarest of these complications is proctitis cystica profunda (PCP). To study the histologic changes of chronic radiation proctitis, we evaluated 35 female Wistar rats that had received a single exposure of 22.5 Gy of radiation to the rectum and were then followed for one year. We identified PCP and its precursor lesions in 18 rats. The fully developed lesion consisted of a focal expansion of the submucosa by dilated cystic spaces lined by a single layer of benign epithelial cells. Usually, PCP evolved as glands herniated between small defects in the muscularis mucosae. Mitotic figures were not recognized in the cells lining the herniating glands. In two rats, the radiation had apparently caused large ulcers, which had subsequently reepithelialized, resulting in prominent submucosal glandular tissue. Although the number of goblet cells in the displaced epithelium was reduced, the cells had rather mature appearances ultrastructurally. Glands displaced into the submucosa were encased by an intact basal lamina but lacked in muscularis.

Animals↗
PubMed1990

Comparison of effects of upright versus supine body position and liquid versus solid bolus on esophageal pressures in normal humans.

New studies monitoring ambulatory esophageal pressures during food ingestion often compare results to normal values obtained from supine liquid swallows. We compared distal esophageal peristaltic and lower esophageal sphincter (LES) pressures in 15 normal subjects during six liquid swallows in the upright and supine positions, and six solid (small marshmallow) swallows in upright position. LES pressures were significantly (P less than 0.05) higher supine than upright but no differences were noted in LES pressure, relaxation, and duration of relaxation between upright solid and liquid swallows. Distal peristaltic wave velocities were faster upright than supine. Peristaltic wave amplitudes, durations, and DP/DT were significantly (P less than 0.05) greater in supine than in upright position. Atypical wave forms, defined as nontransmitted, simultaneous, and simultaneous/repetitive, increased in the upright position compared to supine (P less than 0.01), and during solid vs liquid swallows (P less than 0.05). These results indicate that body position substantially affects normal distal esophageal peristalsis and LES pressure and that "abnormal" wave forms occur more frequently during swallowing solids than liquids in the upright position. Conclusions regarding "abnormal" motility over prolonged periods and during food ingestion in patients should be tempered by these findings.

Adult↗
PubMed1990

Pharyngeal/upper esophageal sphincter pressure dynamics in humans. Effects of pharmacologic agents and thermal stimulation.

Extensive physiological studies of swallowing have been carried out in laboratory animals; however, similar studies in humans have been limited by available technology. In this study we describe the use of a solid-state circumferential sphincter transducer to define manometric characteristics of the human pharynx and upper esophageal sphincter (UES). Effects of pharmacologic agents and thermal stimulation are also described. We studied nine normal volunteers on three separate days. All studies were done in the upright position and consisted of a station pull-through of the UES and six wet swallows with the sphincter transducer in the most proximal segment of the UES and a posteriorly oriented single transducer 5 cm proximal in the pharynx. Baseline studies preceded all drug studies. Effects of bethanechol were studied on day 1, cold stimulation and benzonatate on day 2, edrophonium and atropine on day 3. The UES resting pressure showed large intrasubject day-to-day variations; however, mean values did not differ. There were no effects on UES relaxation or swallow coordination with any of the pharmacologic agents, although benzonatate produced multiple pharyngeal contractions.

Adult↗
PubMed1990

Edrophonium provocative test in noncardiac chest pain. Evaluation of testing techniques.

Edrophonium chloride is used frequently as a provocative agent in the assessment of noncardiac chest pain (NCCP). However, the optimum dose and most appropriate method of interpreting test results is controversial. We studied 150 consecutive NCCP patients and 50 age-matched controls who alternately received either 80 micrograms/kg or 10 mg intravenous bolus doses of edrophonium preceded by saline placebo injections. Distal esophageal pressures were measured before and after drug injection in response to ten 5-cc wet swallows. Following 10 mg of edrophonium, 33% of patients and 4% of controls reported chest pain, while 29% of patients and no controls receiving the 80 micrograms/kg dose complained of chest pain. Amplitude changes after either dose were not significantly different for all comparisons, but the duration of response did distinguish the two doses in patients with chest pain. A significantly greater (P = 0.01) increase in distal contraction duration occurred after 10 mg (74 +/- 12%; +/- SE) compared to 80 micrograms/kg dose (43 +/- 6%). However, individual responses to the two doses overlapped considerably. If a positive test is redefined to include both chest pain and manometric changes that are significantly different from controls, the positivity rate changes drastically; 33% to 9% in the 10-mg group and 30% to 3% in the 80-micrograms/kg group. Side effects were similar between doses, but there was a significant (P = 0.02) linear relationship between intensity of side effects and the edrophonium dose per kilogram of body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Weight↗
PubMed1990

Effects of body position and bolus consistency on the manometric parameters and coordination of the upper esophageal sphincter and pharynx.

The development of a solid-state intraluminal sphincter transducer has alleviated many of the problems associated with manometric studies of the upper esophageal sphincter (UES) and pharynx (P). We used this technology to study the effect of position (upright vs. supine) on resting UES pressures and the pressure dynamics of the UES/P complex during both wet and dry swallows in 11 normal volunteers and the effects of foods of different consistencies on the UES/P swallow dynamics in 10 normal volunteers. The UES/P coordination parameters were defined as the 15 time intervals that can be measured between any 2 of 6 pertinent points: the beginning, peak, and end of the pharyngeal contraction and the beginning, nadir, and end of the UES relaxation. Data from both the circumferential transducer used to measure sphincter pressures and a standard microtransducer used to measure pharyngeal pressures were collected on-line by an Apple IIe microcomputer and analyzed by programs written in our laboratory. Significant changes in swallow coordination were measured between upright and supine swallows of the same bolus size, between wet and dry swallows in the same position, and among foods of varying consistencies. Resting UES pressure was unchanged by position and pharyngeal contraction pressure was unchanged by bolus size or consistency.

Adult↗
PubMed1990

Scleroderma esophagus.

Scleroderma (systemic sclerosis) is a connective tissue disorder characterized by thickening and fibrosis of the skin and visceral involvement that may include the heart, lungs, kidneys, and gastrointestinal tract. At least 40-50% of patients with scleroderma experience esophageal symptoms such as heartburn and dysphagia, while up to 90% of patients have esophageal dysfunction on objective testing at some point in their disease. The disease results in smooth muscle dysfunction that causes esophageal aperistalsis and reduced lower esophageal sphincter pressures. Gastroesophageal reflux with poor acid clearance results with an increased incidence of complications such as peptic stricture and Barrett's esophagus. Aggressive medical therapy is necessary to prevent these and other complications of gastroesophageal reflux.

Esophageal Diseases↗
PubMed1990

Cerebral electrical potentials evoked by balloon distention of the human esophagus.

UNLABELLED: Cerebral evoked potentials provide a technique for evaluation of central nervous processing of information derived from a variety of sensory modalities. Evoked potentials associated with balloon distention of the smooth muscle esophagus were studied in 14 adult volunteers. Stimulation was applied via repeated inflation and deflation of a balloon attached to a pressure pump that cycled at 0.2 Hz. Cortical electrical responses were recorded from scalp electrodes at Cz, Cz', and Pz of the international 10-20 System for electroencephalographic recording. The recording electrodes were referenced to Fpz and averaged over a 1-s period for 100 repetitions. Latencies, amplitudes, and waveforms of the evoked potentials were compared with controls consisting of pump on/balloon detached, auditory masking, and conventional somatosensory posterior tibial nerve stimulation. Polyphasic evoked potentials were obtained in all subjects, and maximum positive deflections occurring with latencies of 202-396 ms. Maximal amplitudes ranged from 2.5-8.3 microV. Latencies and amplitudes of the evoked responses were highly reproducible in each subject with considerable variation among subjects. CONCLUSIONS: (a) Reproducible evoked potentials with distinctive waveforms can be recorded in response to esophageal balloon distention in humans; (2) long latency of the evoked potentials suggests involvement of nonmyelinated visceral afferent pathways; (3) the evoked potentials are probably specific to mechanical stimulation rather than being nonspecific arousal responses; and (4) the results support this as a promising new method for investigation of the neurobiology of gastrointestinal sensation in humans that may help clarify pathological conditions of the irritable esophagus syndrome and esophagus-related chest pain.

Adult↗
PubMed1990

Pharyngeal and upper esophageal sphincter manometry in humans.

Manometric studies of pharyngeal-upper esophageal sphincter (UES) coordination during swallowing have proven difficult. Asymmetry of the UES makes pressure measurements with a single, unoriented transducer suspect. Perfused systems lack the necessary response rate for measuring peak pharyngeal contraction pressures. Precise quantification of the coordination of pharyngeal contractions and UES relaxations during swallowing is difficult because of rapid pressure changes. We tested a modified solid-state transducer that measures pressures over 360 degrees. This transducer was placed in the proximal UES with a second, single transducer 5 cm proximal. Data were collected and analyzed with an Apple IIe microcomputer. A computer program was developed to measure nine timing sequences, UES resting pressure, nadir of UES relaxation, and pharyngeal contraction pressures. We studied 21 volunteers with six swallows each for dry, 5, 10, and 20 ml of water. Dry swallows differed significantly (P less than 0.05) from wet (5 ml). All timing sequences became progressively longer with increasing bolus size. Residual pressures were unchanged. Timing sequences were also measured for wet (5 ml) and dry swallows in seven volunteers using a Dent sleeve and single perfused orifice in the UES; no differences were seen.

Adult↗
PubMed1990

Cerebral potentials evoked by esophageal distension in human.

Recent studies have shown that cerebral evoked potentials (EPs) can be recorded after balloon distension of the human esophagus. The aim of this study was to evaluate the characteristics of these viscerosensory EPs and to investigate the relations between these EPs and perception of esophageal distension. Nineteen healthy volunteers (22-60 yr old) were studied. A balloon positioned 5 cm above the lower esophageal sphincter was inflated 10 times each minute. EPs recorded from four midline scalp electrodes were averaged for 50 and 100 inflation cycles. A clearly defined triphasic (negative-positive-negative) EP was recorded in all subjects and from all four recording sites when a volume leading to definite sensation and rapid balloon inflation (170 ml/s) was used. The latencies of the peaks were 231 +/- 7 (N1), 303 +/- 7 (P1), and 379 +/- 8 ms (N2). No significant correlation between stimulus perception and latency was found. The amplitude and quality of the EPs (scored by 3 blinded observers) increased significantly (P less than 0.01, ANOVA) with increasing sensation. Slow balloon inflation (30 ml/s) was significantly less effective in evoking EPs than rapid inflation (P less than 0.01). The EPs evoked by 100 inflations were not significantly clearer than those evoked by 50 inflations. It is concluded that the ability to record cerebral potentials evoked by esophageal balloon distension is related to the rate of balloon inflation and to the level of awareness of the stimulus.

Adult↗