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Biomedical subjects

R Calzada

Publications and source records attributed to R Calzada.

8 recordsLinked to original sources
PubMed1991

Neutrophil chemotaxis in gastric mucosa. A signal-to-response comparison.

This prospective study compares levels of neutrophil chemotactic activity (NCA) in gastric juice to the neutrophil count in gastric biopsies. Sixty-three male patients enrolled in the study and had antral biopsies following collection of gastric juice during esophagogastroduodenoscopy. Biopsies were examined for the magnitude of gastritis, tissue PMN count, and presence of Helicobacter pylori. Secretions were assayed for neutrophil chemotactic activity. Results show an increase in NCA and in tissue PMN counts with increasing severity of gastritis. H. pylori-positive patients had higher levels of NCA and PMN than H. pylori-negative patients. Wide variability in NCA levels preclude a direct correlation between NCA and PMN counts.

Biopsy↗
PubMed1991

Differential activation of ornithine decarboxylase and tyrosine kinase in the rectal mucosa of patients with hyperplastic and adenomatous polyps.

Hyperplastic polyps are considered to be benign colonic lesions with almost no potential for malignant transformation. Recent reports have shown an increased association of hyperplastic polyps with adenomatous polyps and have advocated a full colonoscopy in patients who harbor hyperplastic polyps. Hyperproliferative mucosa is known to be associated with adenomatous polyps, but its relationship to hyperplastic polyps is unknown. In the present pilot study, it is determined whether a change in mucosal proliferative patterns is observed in patients who harbor only hyperplastic polyps or a history of hyperplastic polyps relative to those who harbor both hyperplastic polyps and adenomatous polyps by measuring ornithine decarboxylase and tyrosine kinase activity in macroscopically normal rectal mucosa. Fifteen patients had either adenomatous polyps proximally or harbored adenomatous polyps and hyperplastic polyps. Seven patients had hyperplastic polyps and 15 patients had a prior history of hyperplastic polyps with no polyps found during the current examination. The ornithine decarboxylase activity of the rectal mucosa with proximal adenomatous polyps or both polyp types was significantly higher than that of hyperplastic polyps, the history of hyperplastic polyps, or controls, and values for hyperplastic polyps and the history of hyperplastic polyps were similar to controls. On the other hand, tyrosine kinase activity in the rectal mucosa of patients with both or either polyp type was elevated without any significant difference between hyperplastic and adenomatous polyps. Thus, it is concluded that although increased ornithine decarboxylase activity in rectal mucosa suggests the presence of adenomatous polyps or a combination of adenomatous with hyperplastic polyps, increased tyrosine kinase activity suggests the presence of any type of polyp.

Colonic Polyps↗
PubMed1991

Splenic trauma during colonoscopy.

A case of splenic rupture following therapeutic colonoscopy is described, and previously reported cases are reviewed. The occurrence of this event and the associated circumstances are often unpredictable. A high index of suspicion is the key to the diagnosis of this rare but potentially lethal complication.

Aged↗
PubMed1989

Persistence of gastric ulcers caused by plain aspirin or nonsteroidal antiinflammatory agents in patients treated with a combination of cimetidine, antacids, and enteric-coated aspirin.

Twenty-three patients chronically ingesting plain aspirin or nonsteroidal antiinflammatory drugs, who had endoscopically proven solitary or multiple gastric ulcers, were treated for eight weeks with cimetidine and antacids. Plain aspirin and nonsteroidal antiinflammatory drugs were discontinued in all patients. Seven patients received enteric-coated aspirin throughout the treatment phase and continuously for the entire study period (2.5-12 months). The remainder of patients (N = 16) did not receive enteric-coated aspirin. An endoscopy was performed to assess ulcer healing. None of seven patients receiving enteric-coated aspirin had complete healing of their ulcer(s) while 15 of 16 patients not receiving enteric-coated aspirin demonstrated complete healing of their ulcer(s) (P less than 0.001). An eight-week course of cimetidine and antacids is ineffective in completely healing gastric ulcers caused by plain aspirin or nonsteroidal antiinflammatory drugs while enteric-coated aspirin is continued.

Antacids↗
PubMed1988

Life after colectomy.

Animal and epidemiologic studies have raised hopes that effective chemoprevention of colorectal cancer in very high-risk patients may be possible in the future, but at present, the only established effective way to prevent colorectal cancer in very high-risk patients is colectomy. Advances in surgical techniques, improvements in stomal appliances, and medical advances in dealing with complications of colorectal surgery (such as impotence) have contributed to substantial improvements in the quality of life of patients who have had prophylactic colectomies.

Colectomy↗