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R Escola

Publications and source records attributed to R Escola.

18 recordsLinked to original sources
PubMed1990

Ablation of submandibular salivary glands in rats provokes a decrease in plasma luteinizing hormone levels correlated with morphological changes in Leydig cells.

This work was designed to determine whether changes in plasma and hypophyseal levels of LH are the source of the previously reported atrophy of testicular interstitial tissue following ablation of submandibular salivary glands. The plasma and hypophyseal levels of LH were assayed, and testicular sections examined by electron microscopy in rats, weighing 230-260 g, whose submandibular glands had been removed. Twenty days after sialectomy, the rats were killed, and the pituitary glands removed, homogenized and frozen until used in LH-RIA like the blood samples. Testes were removed and fixed in osmic acid. There was a significant decrease in plasma LH levels in operated animals when compared with sham-operated controls (47.28 +/- 7 ng/ml versus 70.42 +/- 8; p less than 0.02), but the hypophyseal LH content was not significantly modified. Electron microscopy mainly showed important changes in the morphology of the Leydig cells, with a distinct reduction in the number of mitochondria and elements of the smooth endoplasmic reticulum. These findings suggest a physiological involvement of submandibular glands in a possible endocrinological link with the gonadotropic axis.

Animals↗
PubMed1989

[Demonstration of PGE2 by immunofluorescence in the wall of radicular cysts].

The present study gives the first evidence, through immunofluorescence, of the prostaglandins PGE2 in radicular cysts. The results are in agreement with literature. In addition, the immunofluorescence technique has also demonstrated the localization of prostaglandins inside the cyst cavity. In opposition to previous data, the present study also shows that epithelial cells seem to synthesize more PGE2 than fibroblasts and mononuclear components of the external connective tissue.

Dinoprostone↗
PubMed1986

Effect of submandibular salivary gland removal on body weight, plasmatic testosterone levels, testicular weight and spermatogenesis in rats.

In this work we report the effect of the removal of submandibular salivary glands (S.S.G.) on plasmatic testosterone levels and other aspects of testicular function and on body weight in rats. Our results were obtained with 72 male rats weighing 230-260 g whose S.S.G. were removed. At only twenty days after removal a slight but significant decrease (p less than 0.05) of testicular absolute weight (3.431 +/- 75 mg vs 3.612 +/- 53 mg) was detected. This decrease was probably due to atrophy of interstitial tissue, as revealed by histological examination. In contrast, neither plasmatic testosterone (T) levels nor spermatogenesis (S.P.G.) were altered. The effect on testicular weight at twenty days was not closely associated with the effect on body weight. Changes in this latter parameter were observed twenty days after extirpation of S.M.G. (107 +/- 5.5 vs 124 +/- 4.3 g; p less than 0.02) and up until forty days (175.6 +/- 4.1 g vs 202.8 +/- 5.5; p less than 0.05) after S.S.G. removal. Difference in gain of body weight is not influenced by nutritional lack, as shown by the fact that nutritional absorption is not modified in the operated animals controlled in wire bottom cages. These data suggest that S.S.G. right play a trophic regulatory role, separately, on testes and body without the mediation of T. The direct involvement of biological peptides contained in S.S.G. is discussed.

Animals↗
PubMed1977

[The gingival fluid].

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Gingival Crevicular Fluid↗
PubMed1976

Relationship between Hassall's corpuscles and thymocytes fate in guinea-pig foetus.

The development and structure of the Hassall's corpuscles are studied with the light and electron microscope in 53 guinea-pig foetuses from 30 to 58 days gestation. The different stages of their life cycle are described. Prior to the appearance of Hassall's corpuscles, no medullary lymphocytes can be found in the early medulla. Hassall's corpuscles are seen initially between 35-42 days gestation. They are surrounded by large and medium-size lymphocytes, while medullary lymphocytes are in close contact with the "external cells" which exhibit cytoplasmic characteristics of a secretory function. The data reported in this paper suggest that Hassall's corpuscles are not the only sites of lymphoid cells destruction but are also "privileged" areas for maturation of medullary lymphocytes at least for the guinea-pig.

Animals↗