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Biomedical subjects

D O Castell

Publications and source records attributed to D O Castell.

At least 397 records · Page 22Linked to original sources
PubMed1975

Effect of dry swallows and wet swallows of different volumes on esophageal peristalsis.

The effect of dry swallows and wet swallows of various volumes on esophageal function was studied in normal subjects. An intraesophageal transducer assembly was used to measure the dynamics of esophageal peristalsis. The strength of esophageal contraction (amplitude) following a 1-ml liquid bolus was similar to that following a dry swallow but was significantly less than that following a wet swallow of a larger volume. There was no difference in strength of esophageal squeeze following swallows ranging from 2 to 20 ml. In addition, a wet swallow was associated with slower wave speed, greater duration of the contraction wave, and later time of appearance of the peristaltic wave in the distal esophagus than a dry swallow. Futhermore, the incidence of peristalsis was greater with a wet swallow than a dry swallow. The results of our studies indicate that although the act of swallowing alone in man initiates peristalsis, afferent information contributes to the regulation of primary peristalsis.

Adult↗
PubMed1975

The lower esophageal sphincter. Physiologic and clinical aspects.

Current concepts in physiology and pathophysiology of lower esophageal sphincteric mechanism are reviewed. With recent advances in manometric method for more accurate in-vivo human studies combined with in-vivo and in-vitro studies in animal models, there is much information regarding function of this sphincter. Three components of sphincter control have been identified: specialized circular smooth muscle at esophagogastric junction, autonomic nervous system, and probable physiology effects of gastrointestinal hormones, particularly gastrin. Clinical syndromes of sphincteric dysfunction have been identified relative to these three controlling elements. Foods and drugs that adversely effect sphincter pressure have been identified and indicate that anticholinergic agents, fatty foods, chocolate, alcohol, and cigarette smoking may have a harmful effect on a patient with heartburn. Drugs that increase the antireflux sphincter barrier have been studied. Clinical effectiveness of antacids and bethanechol in therapy of heartburn is supported by controlled treatment trials. Research continues on other medications producing increases in sphincter pressure.

Anemia, Pernicious↗
PubMed1975

Experimental esophagitis in cats impairs lower esophageal sphincter pressure.

We studied the effect of esophageal inflammation on lower esophageal sphincter (LES) pressure in cats by measuring LES pressure and taking mucosal biopsies before and after the development of experimental esophagitis, as well as after a 3 1/2-week recovery period. Perfusion of the esophagus with 0.1 N HCl for either 1 hr or 1/2 hr per day for 4 days produced inflammatory changes by mucosal biopsy and was associated with a marked decline in LES pressure. Upon resolution of the inflammation, LES pressure returned to normal. Biopsies were normal in control groups which underwent either esophageal perfusion with distilled water or intragastric perfusion with acid, 1 hr per day for 4 days, and LES pressures in these groups remained unchanged from pre-perfusion values. These studies indicate that lower esophageal inflammation per se adversely affects LES pressure in cats, and that experimental esophagitis may be a useful model for the study of LES function and its relation to esophageal inflammation.

Animals↗
PubMed1975

Evaluation of the effect of fundoplication on the incompetent lower esophageal sphincter.

The increase in tension of the gastroesophageal high pressure zone after fundoplication and hiatal hernia repair could represent either a mechanical effect or enhanced smooth muscle tone of the lower esophageal sphincter. Determination of the response of this high pressure zone to cholinergic stimulation, a protein meal and deglutition before and after Belsey Mark IV fundoplasty in seven patients with intractable reflux indicates the latter. Fundoplication resulted in a resting tension of the high pressure zone significantly greater than that found preoperatively but similar to that of controls. This normotensive postoperative high pressure zone had properties of a physiologic lower esophageal sphincter, that is, normal relaxation to deglutition, a response to a protein meal and a response to cholinergic stimulation with edrophonium. In response to edrophonium, evidence of a partial improvement in lower esophageal sphincter smooth muscle function was found postoperatively when compared with the response of controls and in patients preoperatively. The response to a protein meal postoperatively remained similar to that noted preoperatively, which was significantly less than the response of controls. Therefore, the increase in tension of the high pressure zone after fundoplication and hiatal hernia repair appears to result from improved function of the lower esophageal sphincteric smooth muscle.

Adult↗