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Biomedical subjects

R Lev

Publications and source records attributed to R Lev.

At least 55 records · Page 3Linked to original sources
PubMed1980

Segmental tuberculosis of the colon mimicking carcinoma.

Tuberculosis of the distal colon occurring in the absence of ileocecal or pulmonary involvement is often mistaken for neoplasm or Crohn's disease. In spite of various studies, including colonoscopy and brushings with biopsy, the diagnosis might still be in doubt at the time of operation. The combined approach of surgery and chemotherapy appears to be the treatment of choice, especially in those patients who have bleeding and/or obstruction in whom the diagnosis cannot be made by other modalities.

Adult↗
PubMed1980

Pathological and histomorphometric study of the effects of alcohol on the human duodenum.

Duodenal biopsies from 47 alcoholic patients and 21 nonalcoholics were examined histologically and the number of chronic inflammatory (mononuclear) cells in the lamina propria and of villus goblet cells was calculated using a cell-counting technique. The number of mononuclear cells was the same in both groups. Goblet cell hyperplasia, gastric metaplasia and changes in the villi and epithelium were found almost exclusively in the alcoholics. Mononuclear cell counts were higher in patients from both groups showing concomitant chronic gastritis. Goblet cells were more numerous in older patients; mononuclear cells in nonalcoholics showed a slight increase with age. Correlation between endoscopy and histology gave equivocal results.

Adolescent↗
PubMed1979

The biochemical and histochemical demonstration of lactase induction in fetal rat intestine by intra-amniotic injection of lactose.

A single dose of 20 mg beta-D-lactose injected into the amniotic sac of rats on day 17 of pregnancy induced an increase in lactase activity in fetal jejunum. This effect was first noted two days after injection and lasted for at least two additional days. Histoenzymatic investigation indicated that this enzyme was located on the surface of the absorptive cells lining the villi and thus corresponds to the "dietary" form of beta-galactosidase. A much smaller increase, based presumably on progressive increase in fetal size (age) was found in control fetuses which had received glucose or no injections. Peak lactase values in fetuses receiving lactose were substantially higher than peak values in control fetuses. In both lactose-injected and non-injected rats which were allowed to deliver, there was a sharp drop in lactase values coincident with birth.

Amnion↗
PubMed1979

Histologic and morphometric study of chronic gastritis in alcoholic patients.

The effect of chronic alcohol ingestion on the gastric mucosa was determined in 96 patients in whom gastroscopy was performed because of upper gastrointestinal symptoms. Seventy-two patients were classified as alcoholics and 24 patients as nonalcoholics. In all cases biopsy specimens were taken from the fundus and antrum. The diagnoses of chronic superficial and atrophic gastritis were based on conventional histologic criteria and a morphometric technique utilizing quantitation of the chronic inflammatory cells in the lamina propria. Alcoholic patients were found to have a higher incidence of chronic gastritis of the antrum than nonalcoholics (p less than 0.001). Fundic involvement was also more common, probably accounting for the decreased gastric acid output described in chronic alcoholic patients. Finally, gastritis was more severe in the alcoholics; below 45 years of age chronic atrophic gastritis was seen only in alcoholics. We conclude that chronic gastritis develops more frequently in alcoholic patients and evolves into chronic atrophic gastritis at an earlier age than in nonalcoholic subjects.

Acute Disease↗
PubMed1978

Pathogenesis of rat colon carcinomas induced by N-methyl-N-nitrosourea.

Colon specimens were obtained from 45 young male and female inbred CDF rats between 11 and 42 weeks after they began to receive intrarectal injections of the carcinogen N-methyl-N-nitrosourea (MNU) 43--108 mg, total dose); specimens were also obtained from 26 control rats. Well-developed tumors from rats receiving MNU generally presented grossly as polyps; histologically, as invasive adenocarcinomas that had not metastasized. These tumors resembled their human counterparts. Focal epithelial atypias were found in grossly normal mucosa both from rats that had not yet developed tumors and from tumor-bearing rats. Such foci typically consisted of low columnar cells with enlarged nuclei, increased number of mitoses, cytoplasmic basophilia, and reduced cytoplasmic mucus. Serial section studies of minute foci of atypia indicated that some of them arose from normal deep crypt cells. Transitions were frequently found between atypical foci and in situ or invasive carcinomas. Less commonly, adenomatous epithelium was identified in the early lesions or within the frank adenocarcinomas. It was concluded that most invasive carcinomas in this rat model originate in foci of epithelial atypia, which are found with increasing frequency in the flat mucosa during treatment with MNU, but that some carcinomas also arise from adenomatous epithelium.

Adenocarcinoma↗
PubMed1977

Simple method for the preparation of single cell suspensions from normal and tumorous rat colonic mucosa.

Viable single cell suspensions from rat colonic epithelium were obtained by using phosphate buffered saline containing 0-2 M mannitol. The method, which requires no prior enzyme treatment, provides undamaged cells in high yield within one hour. The procedure was also applied to neoplastic rat colonic tissue, which was induced by repeated intrarectal infusion of N-methyl-N-nitrosourea. Comparison between normal and neoplastic cells has shown that the latter have a higher nucleus: cytoplasm ratio and a higher metabolic activity.

Animals↗
PubMed1977

An electron microscopic study of intraepithelial lymphocytes in human fetal small intestine.

Human small intestine was obtained from fetuses at 8 to 20 weeks of gestation. The tissues were examined by electron microscopy. Lymphocytes were present as isolated cells in the mucosal mesenchyme as early as the 8th week of intrauterine life and were found, in increasing numbers, in the epithelium of specimens obtained from 11- to 20-week-old fetuses. All intraepithelial lymphocytes were located in the lateral spaces between contiguous columnar cells. Some displayed cytoplasmic pseudopods and were thought to migrate within the extracellular spaces of the epithelial layer. Surface invaginations and cytoplasmic vesicles in fetal lymphocytes suggested that these cells were capable of pinocytotic activity. The possibile origin and function of lymphocytes in fetal small intestine are discussed.

Cell Nucleus↗
PubMed1976

Substrate-induced acceleration of lactase synthesis in fetal rat intestine.

Twenty milligrams of lactose were injected into the amniotic sacs of fetuses in one uterine horn and 20 mg glucose were injected into the amniotic sacs of fetuses in the opposite uterine horn of six rats on days 17-19 of pregnancy. Two or 3 days later the pregnant animals were killed and segments of jejunum obtained from their fetuses were homogenized in water. Assays for lactase and protein determinations were performed on these homogenates. Lactase values were significantly higher in the lactose-injected group than in fetuses receiving glucose (Table 2), P less than 0.0005. Thus, fetal intestinal lactase activity can be increased by exposure to the substrate lactose during late fetal life.

Amnion↗
PubMed1976

Morphological features and healing of stress ulcers induced by alcohol and restraint.

Gastric mucosal damage was produced in 130 mice by forced ingestion of alcohol, followed by restraint in the cold. Animals were killed at intervals from six hours to 27 days following the stress. Linear hemorrhagic erosions and diffuse hemorrhagic patches were found grossly, predominantly in the glandular portion of the stomach, in about 75% of the animals 6 to 24 hours after stress. At later time intervals, the linear mucosal depressions persisted; these became progressively less prominent with time but substantial numbers were still readily discernible three weeks after injury. Microscopical examination of the fresh lesions showed a variable amount of mucosal necrosis and acute inflammation. Epithelial regeneration became prominent after three days and persisted for several weeks. The first regenerating epithelial cells were primitive, cuboidal elements followed by mucous cells, parietal cells, and zymogen cells, in that order. The morphological features and evolution of the lesions were similar to that described in human stress ulcers.

Animals↗
PubMed1975

Acute fatty liver of pregnancy. Complication by disseminated intravascular coagulation.

A 31-year-old white woman had idiopathic acute fatty liver of pregnancy. Shortly after admission to the hospital, it became apparent that she was also suffering from disseminated intravascular coagulation. This was treated with heparin sodium, resulting in cessation of overt bleeding and laboratory evidence of moderate abatement of her coagulation abnormalities. Nevertheless, both patient and fetus died. This case report reemphasizes the need for recognition and therapy for the nonhepatic complications of this syndrome.

Acute Disease↗
PubMed1975

Fetal monkey absorption of 55Fe from amniotic fluid.

A single dose of 0.5 mCi radioiron (55Fe) was injected directly into the amniotic cavity of each of four pregnant monkeys near term. At 6 or 24 hours after 55Fe adminstration, samples of fetal jejunum, ileum, blood, spleen, liver, lung and fetal membranes were taken for radioautography and scintillation counts. Counts were also made on corresponding maternal tissues. Intestinal radioiron levels and localization indicated that fetuses swallowed and absorbed 55Fe within 6 to 24 hours after injection. Silver grains over the meconium bodies of fetal ileum suggested that intestinal epithelium retained at least some of the absorbed radioiron. However, elevated 55Fe levels in fetal blood and hematopoietic organs indicated that transport of radioiron to the circulation had occurred, presumably through fetal intestine, extraembryonic membranes and/or fetal lungs. Transfer of 55Fe across the placenta from fetus to mother occurred at a slow rate, i.e., samples of maternal organs obtained at 24 hours gave low counts.

Amniotic Fluid↗