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Biomedical subjects

L Alpert

Publications and source records attributed to L Alpert.

8 recordsLinked to original sources

Selection of the chimpanzee over the baboon as a model for Helicobacter pylori infection.

Baboons (Papio sp.) and chimpanzees (Pan troglodytes) were screened for the presence of Helicobacter pylori. The gastric mucosae of the baboons were colonized by large spiral bacteria. However, a group of adult chimpanzees were identified that were free of spiral gastric bacteria, with five animals being recruited into an H. pylori challenge study. These animals were inoculated orogastrically with one of four strains of H. pylori and followed for up to 26 weeks. H. pylori was established in one of these animals during a primary challenge and in two other animals on secondary challenge. It was shown that the chimpanzee can be infected with H. pylori and that the inflammatory response in these animals mimics that seen in humans. Infection was marked by an antibody response to H. pylori-specific antigens in two animals. It was observed that H. pylori antibody-negative chimpanzees had no apparent infection by H. pylori or related bacteria. Thus serological screening of chimpanzees can be used to identify candidate animals for further evaluation.

Animals

Calcium oxalate in breast lesions biopsied for calcification detected in screening mammography: incidence and clinical significance.

Two types of calcification have been reported in breast tissue: one appears as dark-blue deposits in routine histologic tissue sections and has been found to be composed mostly of calcium phosphate (CaP); the other is colorless and represents calcium oxalate (CaOx). CaP has been well characterized, but little is known about CaOx. The presence of CaOx was evaluated in 91 breast lesions (71 retrospective and 20 prospective cases) biopsied for the presence of calcification in screening mammography. CaOx was found in 36 cases (39%). CaOx is usually not clearly visible in routine histologic sections. CaOx is found as refractile, strongly birefringent crystals with characteristic morphology. CaOx was present only within benign lesions which frequently showed apocrine metaplasia. However, the breast tissue away from the areas with CaOx displayed a morphologic spectrum roughly similar to that in cases with CaP only. CaOx was clinically significant, i.e., actually represented the mammographic calcification, for which the biopsy was performed in 12% (11/91) of all cases studied and in 31% (11/36) of cases in which CaOx was found. In the cases where CaOx was not considered clinically significant, it was either not radiographically visible or, if visible, did not definitely represent the mammographic calcification for which the biopsy was performed. Since CaOx in breast biopsies is often clinically significant, and since CaOx is not clearly visible in routine sections, examination under polarized light is suggested for all breast biopsies removed for mammographic calcification, particularly when CaP deposits corresponding to the mammographic calcification are not apparent.

Adult

Long-term nonsteroidal antiinflammatory drug use and Helicobacter pylori infection.

This study investigates whether patients who take nonsteroidal antiinflammatory drugs are more likely to have Helicobacter pylori gastritis than age-matched individuals who do not take nonsteroidal antiinflammatory drugs, and whether patients who take nonsteroidal antiinflammatory drugs who are also infected with H. pylori are more likely to have dyspepsia, mucosal damage, or ulcers than those who are not infected. Two studies were performed, one serological and the other endoscopic, both in arthritis patients receiving nonsteroidal antiinflammatory drugs chronically. The presence of H. pylori was identified with a sensitive enzyme-linked immunosorbent assay test. One hundred eighty-three patients participated in the serological study and 75 patients in the endoscopic study. The frequency of H. pylori infection increased with age, independent of nonsteroidal antiinflammatory drug use; the age-adjusted frequency of H. pylori infection in arthritis patients paralleled that of 351 asymptomatic individuals without arthritis. The frequency of H. pylori infection increased from 30.7% in age group 21-30 years to 73.4% in age group 61-75 years. Nonsteroidal antiinflammatory drug-induced mucosal injury, either hemorrhages or erosions, was more frequent in those without H. pylori infection than with infection (61% vs. 32% for hemorrhages and 57% vs. 34% for erosions for those without and with H. pylori infection; only the difference in the frequency of hemorrhages was significant, P less than 0.05). No difference was observed in the presence of dyspeptic symptoms between those with and without H. pylori infection. These data suggest that nonsteroidal antiinflammatory drug-induced damage to the gastroduodenal mucosa does not increase the susceptibility to H. pylori infection.

Adult

Cholesteatoma of the renal pelvis: endoscopic management.

We report 2 cases of renal cholesteatoma, 1 of which was associated with inactive renal tuberculosis and the other with urinary stone disease. Both cases were managed by endourological techniques. The diagnosis of cholesteatoma was suspected at ureteroscopic examination of the renal pelvis and it was confirmed by histological examination of biopsy material in both cases. Treatment consisted of endoscopic extraction of the keratinous debris from the collecting system. In 1 case this was achieved with the ureteroscope and in the other case the nephroscope was used.

Adult

Captopril-induced liver dysfunction.

We have described a patient with captopril-induced cholestatic jaundice. Captopril was confirmed as the causative agent, because jaundice occurred after administration of captopril and resolved quickly after administration was stopped.

Captopril