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Biomedical subjects

H Gaafar

Publications and source records attributed to H Gaafar.

29 records · Page 2Linked to original sources

Scanning electron microscopy of the endolymphatic sac epithelium.

In this study, scanning electron micrographs of the dog endolymphatic sac surface epithelium are presented. According to our morphological findings, three portions were recognized, the proximal, intermediate and distal part. The intermediate or 'rugose' portion was found the most differentiated where two types of cells were identified. These cells were seen to have many of the criteria for fluid absorption and phagocytosis. In man, alteration in the ability of these cells may lead to endolymphatic hydrops.

Animals↗

Rhinoscleroma: a scanning electron-microscopic study.

Nasal biopsies from 6 patients with rhinoscleroma were studied by scanning electron microscopy. Numerous bacilli of different sizes were found on the epithelial surface. Few bacilli with thin spiral terminal cilia were seen over the surface of large protruding non-epithelial cells. These cells appeared to be the Mikulicz cells migrating from the tunica propria to the epithelial surface through small ulcerations. In the tunica propria, Mikulicz cells containing numerous bacilli were observed. In 4 patients, round bodies and long tubular structures were found on the epithelial surface. These bodies were suggested to be fungi, yet their exact nature and their relation to Klebsiella rhinoscleromatitis bacilli need further investigation.

Adult↗

The effect of ammonia on olfactory epithelium and vomeronasal organ neuroepithelium of rabbits. A histological and histochemical study.

In recent studies, the vomeronasal organ (VNO), although vestigial and with unknown function in humans, was reported to be present in almost every person examined. In rabbits, it is a well-developed organ, one lying on each side of the nasal septum. Histologically it was found to contain neuroepithelium which is considered an accessory olfactory system taking charge of an olfactory discrimination different from that of olfactory epithelium. Experimental removal of the VNO in male animals reduces reproductive performance and aggression. In this study, the effects of prolonged exposure to ammonia vapor on the histological pattern and enzymatic activity of the olfactory epithelium and the VNO neuroepithelium of 30 adult male rabbits were investigated and compared with a control group. In the exposed animals, the supporting cells in both types of epithelia showed hyperplasia which was more marked in the olfactory epithelium. Manifestations of cytotoxicity were found more in the bipolar cells of the olfactory epithelium than in the VNO neuroepithelium. The enzymatic activity in the exposed group supported the histological results. The presence of the VNO neuroepithelium of the rabbit in a narrow duct with a minute nasal orifice could have some protective effects on the cells.

Alkaline Phosphatase↗

The tunica propria in rhinoscleroma. An electron microscopic study.

The ultrastructure in 15 cases of scleroma was studied. The vacuoles of the Mikulicz cells had a definite limiting membrane containing two types of granular material, "A" considered to be antibody, and "B" considered antigenic. Inside the vacuoles infrequent beaded filamentous crystalloid structures were seen, probably of a proteinaceous nature. An enzymatic etiology causing disruption of the limiting vacuolar membrane was considered. New ultrastructural characteristics of the 'early' Mikulicz cell are described. The capillaries occasionally showed subendothelial amyloid deposition. The seromucinous glands were infrequent but of normal character.

Adolescent↗