Gastroenterology
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The deglutitive pharyngeal contraction was analyzed using simultaneous videofluoroscopic and manometric studies of eight volunteers. Anterior, posterior, and longitudinal movements of the pharyngeal surfaces, relative to the cervical vertebrae, were measured during swallows of 5 and 10 mL of liquid barium. Profound pharyngeal shortening during bolus transit through the pharynx eliminated access to the larynx and elevated the upper esophageal sphincter to within 1.5 cm of the retrolingual pharynx. ⋯ Prolonged upper sphincter opening with the larger-volume swallows resulted from a delayed onset rather than altered propagation of the horizontal pharyngeal contraction. It is concluded that the propagated pharyngeal contraction facilitates pharyngeal clearance but has a minimal role in the process of bolus propulsion during swallowing. The propagated contraction works in concert with profound pharyngeal shortening to minimize hypopharyngeal residue after a swallow.
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The quantitative impact of mesenteric vasoconstriction on the systemic hemodynamic response to cardiogenic shock induced by pericardial tamponade was evaluated. Graded increases in pericardial pressure produced corresponding decreases in cardiac output to 44% +/- 2% and arterial pressure to 64% +/- 3% of baseline and increases in total peripheral vascular resistance to 131% +/- 4% of baseline. Total mesenteric blood flow decreased disproportionately, to 28% +/- 3% of baseline, because of a disproportionate increase in mesenteric vascular resistance to 223% +/- 6% of baseline. ⋯ Prior blockade of the renin-angiotensin axis ablated this response and eliminated the mesenteric contribution to systemic vascular resistance, while confirmed blockade of the alpha-adrenergic system or vasopressin system had no effect. Without shock, central intravenous infusions of angiotensin II (but not norepinephrine or vasopressin) closely mimicked this selective vasoconstriction. Angiotensin-mediated selective mesenteric vasoconstriction accounts for more than 40% of the overall increase in systemic vascular resistance in cardiogenic shock.
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Gallstone pancreatitis is usually related to small stones, which may not be detected by conventional cholecystographic techniques. In the current study, it was hypothesized that some patients with acute pancreatitis of unknown cause could harbor occult microstones in the gallbladder. Therefore, evidence was sought prospectively of missed gallstones by biliary drainage and microscopic examination of centrifuged duodenal bile in 51 patients recovering from an attack of acute pancreatitis, including 24 patients with relapsing episodes. ⋯ This study provides firm evidence showing that in most patients with idiopathic acute pancreatitis, the disease is related to microscopic gallstones, as evidenced by the follow-up development of macroscopic stones or sludge and by the prevention of relapses with either cholecystectomy or a cholelitholytic bile acid. Occult gallstones should be strongly suspected when acute pancreatitis of unknown cause occurs in a relapsing manner and in aged patients and when it is associated with altered liver function test results. Biliary microscopy and/or follow-up ultrasonography of the gallbladder provide a simple means of uncovering them to institute appropriate therapy and prevent further attacks.
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Because of observations that patients with acute episodes of alcoholic pancreatitis had high serum lipase levels whereas patients with gall stone pancreatitis had high serum amylase levels, a prospective study was undertaken to determine whether the ratio of serum lipase to serum amylase, a newly computed ratio, would discriminate between acute episodes of alcoholic and nonalcoholic pancreatitis. In phase one, 30 consecutive patients with acute pancreatitis were entered into the study and divided into groups A and B. Patients with renal failure were excluded from the study. ⋯ Thirteen patients had a lipase/amylase ratio of greater than 2; in 11 of them, the etiology of the pancreatitis was alcohol. Eight patients had a lipase/amylase ratio of less than 2; of them, only 1 patient had an alcoholic etiology for the pancreatitis. These differences were statistically significant (P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)