Further applications of blood gas analysis to gastric acidity determination.

It has been shown that the transient increase in total body bicarbonate that accompanies any acceleration of gastric acid secretion (the 'alkaline tide') is derivable from the associated changes in base excess in arterial blood and is precisely equivalent to the amount of acid secreted when the latter is simultaneously recovered. For the alkaline tide to qualify as a 'tubeless' measure of acid secretion, its equivalence to the latter has to be demonstrated without simultaneous aspiration of gastric juice. We therefore studied the course of the alkaline tide following pentagastrin injection and its relationship to pentagastrin-stimulated acid secretion as measured by aspiration on a separate occasion. In 12 duodenal ulcer patients, the sequential changes in base excess in arterial blood in response to pentagastrin invariably described coherent curves. Peak values occurred most frequently 45 min after injection. In 12 similar patients, alkaline tide 45 min after pentagastrin, as per analysis of arterialized venous blood, correlated well (r = 0.86) with 'peak acid output' (PAO) as measured by aspiration at another time. In 14 patients post vagotomy and pyloroplasty for duodenal ulcer, the 45-min alkaline tide was determined as above and PAO was predicted from the previously established regression-line: The 3 patients with recurrent duodenal ulceration had the highest predicted values for PAO, clearly discriminating them from the others. Measurement of alkaline tide holds promise as a valuable substitute for conventional gastric analysis. For the sake of accuracy, readings should be based on individually constructed time-curves of base excess, in preference to the raw data. Arterialized venous blood appears to be satisfactory substitute for arterial blood for studies of this type.

Treatment of duodenitis with cimetidine: a clinical, endoscopic, and histologic study.

We studied the effectiveness of cimetidine in the treatment of endoscopically diagnosed duodenitis. Sixty-nine patients with the solitary endoscopic finding of duodenitis (6% of 1,200 patients who underwent fiberoptic endoscopy of the upper gastrointestinal tract in our unit over 3 years) were studied retrospectively: a good clinical response was apparent in 45 of 69 patients treated with cimetidine (65%), and a fair response in another four (6%). In a controlled, randomized prospective study, we evaluated the effectiveness of cimetidine in duodenitis. Statistically significant improvement for the clinical and endoscopic scores was found in 10 patients treated with cimetidine (p less than 0.01). Improvement in the histologic score did not reach statistical significance. No such improvement was demonstrated in seven placebo-treated patients. We believe that duodenitis is a "peptic syndrome," has a good response to cimetidine treatment, and behaves much like duodenal ulcer disease.

Internal rectal prolapse: rubber-band ligation as treatment for a neglected disease.

Internal rectal prolapse was diagnosed in 21 patients with signs and symptoms consistent with this syndrome. They all underwent rubber-band ligation of the excess mucosa--2.2 procedures per patient on average. Eight patients became asymptomatic and 13 significantly improved clinically. Six patients, in spite of the clinical improvement, had rectoscopic evidence of recurrence. No side effects or complications were noted. Internal rectal prolapse has to be considered in the differential diagnosis of anorectal syndromes. Rubber-band ligation is a safe, simple procedure, leading to resolution of symptoms, and may prevent progression to total rectal prolapse.

Pentagastrin-stimulated gastric acid secretion: does desensitization exist?

The existence of tachyphylaxis to pentagastrin-stimulated gastric acid secretion in humans is controversial. To study this, we determined gastric acid output in 19 duodenal ulcer patients following the administration of two successive intramuscular injections of pentagastrin (6 micrograms/kg body weight). In 18 of 19 patients, the maximal acid output decreased by 33.73 +/- 3.25% (mean +/- SE) following the second pentagastrin administration when compared with the maximal acid output following the first injection. This study indicates the existence of tolerance to pentagastrin-induced gastric acid secretion in humans, which may be due to a receptor-mediated phenomenon of "down-regulation."

Torsion of leiomyosarcoma of Meckel's diverticulum.

A rare case report of leiomyosarcoma of Meckel's diverticulum, which caused torsion and strangulation of the diverticulum, is presented. The clinical picture was similar to acute appendicitis, which was the working diagnosis when the 42-yr-old Arab woman was sent to surgery. Although rare, leiomyosarcoma is the most common tumor of Meckel's diverticulum, and has to be considered in the differential diagnosis of right lower abdominal pain.