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Biomedical subjects

L Recher

Publications and source records attributed to L Recher.

At least 19 recordsLinked to original sources

Oral hairy leukoplakia: a light microscopic and immunohistochemical study.

We compared the light microscopic features and immunoperoxidase staining for human papillomavirus antigen of oral hairy leukoplakia (OHL) and flat condylomatous lesions of the cervix. Our findings support the conclusion that OHL and flat condylomatous lesions of the cervix are not similar morphologically or etiologically. Therefore the term koilocyte seems inappropriate to describe the swollen epithelial cells in OHL. The various diagnostic criteria for a diagnosis of OHL were reviewed. On the basis of the review of our cases of OHL and our review of the literature, we conclude that a definitive diagnosis of OHL requires either the biochemical evidence of Epstein-Barr virus or the ultrastructural demonstration of herpesviruses in suspected lesions.

Antigens, Viral, Tumor↗

Intestinal permeability changes in rodents: a possible mechanism for degraded carrageenan-induced colitis.

Rats and guinea-pigs were treated with degraded carrageenan (50 g/litre in the drinking-water) and their intestinal permeability was studied at weekly intervals over the last 4 wk of the test period by determining the recovery of orally administered tracer doses of [3H]polyethylene glycol (PEG-900) or D-[3H]mannitol in 16-hr urine collections. A freely diffusible dye, Azure A, was administered simultaneously to compensate for non-intestinal factors that could modify renal excretion. Animals were killed after a total treatment period of 5 months for rats and 6 wk for guinea-pigs. After 3 wk of carrageenan treatment, excretion of PEG-900 (expressed as a ratio of the Azure A excretion) in guinea-pigs showed a statistically significant increase over that in the control group. At autopsy, the caeca showed numerous macroscopically visible erosions of the entire mucosal surface and histological examination showed ulcerations largely in the mucosa with abscesses in the crypts. Although no such histological changes were seen in the intestines of the treated rats, even after 5 months, a statistically significant increase in PEG-900 excretion was again found compared with the control group. This increase did not occur when deoxycholate was administered with the carrageenan solution. No effect of carrageenan treatment on mucosal permeability to D-[3H]mannitol was demonstrated in either species. The results suggest that degraded carrageenan-induced colitis could be a result of increased intestinal permeability, since ingestion of this polysaccharide by rats increased PEG-900 absorption without causing mucosal damage.

Animals↗

Solitary osteochondroma with spinal cord compression.

Osteochondromas are unusual in the spine, and they are very rarely present with compression of the spinal cord. Two cases are reported with delineation of the tumor by metrizamide myelography and computed tomography.

Adult↗

A cytochemical and radioautographic study of human tissue culture cell nucleoli.

Fine structural aspects of human tissue culture cell nucleoli were studied by cytochemical and radioautographic methods. Ribonuclease and pepsin digestions were carried out on glutaraldehyde-fixed cells that, in some instances, were labeled with thymidine-(3)H prior to digestion. Double digestion by ribonuclease and pepsin revealed a fine fibrillar reticulum that appears to be the supportive structure of nucleolonemal threads. The nature of the reticulum remains to be determined. The question of whether it may represent a dispersed form of chromatin was raised. Structural findings suggested such an hypothesis but the results of radioautographic studies do not support it. The reticulum showed a striking absence of radioactive labeling following a 3 hr incorporation of thymidine-(3)H. Only few silver grains were observed occasionally in the fibrillar nucleolonema that may or may not be significant. The radioautographic results are believed to be inconclusive for the various reasons discussed. The possibility that the reticulum is composed of proteins has to be considered. It appears that basic proteins can resist pepsin digestion in aldehyde-fixed cells. Individual chromatin fibrils were found to be associated with the nucleolar reticulum. It is possible that these alone represent the dispersed genetically active chromatin of nucleoli.

Adenocarcinoma↗