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Biomedical subjects

G A Valenzuela

Publications and source records attributed to G A Valenzuela.

10 recordsLinked to original sources

Objective and subjective results of a randomized, double-blind, placebo-controlled trial using cisapride to treat gastroparesis.

Cisapride, a relatively new gastrointestinal prokinetic agent, has been reported to increase gastric emptying and improve symptoms of gastroparesis. We investigated these effects of cisapride in patients with severe idiopathic and diabetic gastroparesis during an eight-week trial. The study design was a two-week single-blind placebo run in period to exclude placebo responders, followed by a six-week randomized, double-blind, placebo-controlled treatment phase. Delayed gastric emptying of solids on radionuclide scan and a minimum symptom intensity score were inclusion criteria. Forty-three patients were entered: four placebo responders and one other patient were excluded, leaving 19 patients randomized to cisapride (20 mg per os three times a day before meals), and 19 patients to placebo. Seven individual symptoms of gastroparesis were scored in a daily diary and reviewed at two-week visits. Sixteen patients in the cisapride group were able to complete the trial compared to 12 on placebo. The gastric emptying study was repeated at the end of treatment or at the time of withdrawal for those who dropped out. Cisapride significantly increased solid gastric emptying relative to baseline (P = 0.005) whereas placebo did not (P > 0.10). Cisapride did not significantly improve any symptom of gastroparesis relative to baseline or to placebo. We conclude that in a population of severe, refractory gastroparetic patients cisapride significantly accelerates gastric emptying of a solid meal without significantly reducing symptoms during a short-term treatment trial compared to placebo. Further trials of cisapride in less advanced and "end-stage" gastroparetics than studied here or combining cisapride with other prokinetic agents or antiemetics, are warranted.

Adolescent↗

Infective endocarditis due to Neisseria sicca and associated with intravenous drug abuse.

Intravenous drug abusers are subject to infective endocarditis from unusual pathogens, including the saprophytic species of Neisseria, sometimes transmitted by needles contaminated with oral secretions. We have recently encountered such a case, in which a 37-year-old man with vegetations on the anterior leaflet of the tricuspid valve had blood cultures positive for N sicca. A history of intravenous drug abuse using needles contaminated with oral secretions should alert clinicians to the possibility of infective endocarditis due to saprophytic Neisseria species.

Adult↗

A noninvasive scintigraphic assessment of the colonic transit of nondigestible solids in man.

A noninvasive, scintigraphic technique for quantifying large intestinal transit time that provides low radiation doses was developed. The scintigraphic large intestinal transit (SLIT) method uses a total of 100 microCi of 111In encapsulated in ten 2-cm nondigestible capsules, which are ingested after a 6-hr fast. Two hundred fifty microcuries of 99mTc-sulfur colloid were given to outline the gastrointestinal tract. Images were acquired at 4-hr intervals until all capsules were excreted. Normal volunteers (n = 10) consumed a standardized diet 2 days prior and during imaging. Segmental transit times were measured in the following: ascending, transverse, descending, recto-sigmoid colons; hepatic and splenic flexures. The radiation absorbed dose to the large intestine for the SLIT technique is less than half of that associated with other radiographic methods of colonic transit time measurement.

Adult↗

Pepsin fibrinolysis of artificial clots made from fibrinogen concentrate and bovine thrombin: the effect of pH and epsilon aminocaproic acid.

Artificial clots made from fibrin glue with and without an inhibitor of fibrinolysis can be used to treat gastrointestinal bleeding. We have been unable to find descriptions of the effects of acid and pepsin upon such artificial clots. Therefore, 10(-2) mol/l epsilon aminocaproic acid was added to fibrin glue in vitro at acid concentrations of pH 1.0 and pH 5.5. Pepsin was added at 9000 U/50 ml, the expected value for fasting human subjects. There was a highly significant reduction in clot survival at pH 1.0. At pH 5.5, clot weight was also significantly decreased with pepsin, compared to control. Thus pepsin and acidity greatly affect survival of artificial clots, but the addition of epsilon aminocaproic acid did not affect clot survival.

Aminocaproates↗

Endoscopic injection therapy for acute upper GI bleeding.

In summary, we have found this technique to be useful in patients in whom coagulation therapy is not possible or effective. It must still be considered a technique which is undergoing evaluation. Prospective randomized trials comparing this therapy with other currently available therapies such a electrocoagulation, laser and conservative management must be completed to firmly define its place in treatment strategy for acute upper GI bleeding.

Aged↗

Reversibility of gastric dysmotility in cortisol deficiency.

This case documents scintigraphically that gastric dysmotility associated with hypoadrenalism secondary to hypothalamic-pituitary dysfunction was reversed when the adrenal insufficiency was treated. The patient reported upon received almost immediate relief of symptoms after corticosteroid replacement therapy and improvement of gastric motility, as demonstrated by both liquid and solid phase 99mTc-labeled studies. This experience suggests that glucocorticoids are important permissive hormones for normal gastrointestinal motor function and may have a role in the pathophysiology of gastrointestinal tract disease.

Adrenal Insufficiency↗