SUMMARY: Three chamaeleon species including Chameleon Chamaeleo chamaeleon, Chameleon Chamaeleo africanus, and Chamaeleon vulgaris were collected and their tongue were dissected and examined morphologically and investigated using light and scanning electron microscopy. Both species showed similar histological manifestation of lingual papillae and tubular glands with dense mucous secretion especially in Chamaeleon vulgaris. There is no keratinization of lingual surfaces. Ultrastructurally, filliform represent the only pattern of lingual pappillae and take either cylindrical, conical and leaflet structure.Although the examined chalmaeleon species collected from different habitat, it shows almost similarities in their histological and ultrastructural structures.

ABSTRACT:The studied are explored the morphology and ultrastructure the shape variation of both jaws and pharyngeal teeth of four red sea fishes with different feeding habits. The teeth were investigated by light microscope and scanning electron microscopy to determine the surface teeth structure. Five adult live specimens of each type of fish are collected from the red sea at Hurghada. They are Sphyraena qenie Klunzinger, 1870, feed primarily on the fish (piscivorous); Scarus frenatus Lacepede,1802 feed primarily on algae; Cephalopholis oligosticta Randall and Ben-Tuvia,1982, feeding mainly on fish and crustaceans. Lethrinus mahsena, Forsskal,1775, the bulk of its food primarily consists of crabs, sea urchins, echinoderms and crustaceans. The study clarified that the teeth of the four species are different in their shape morphologically and ultrastructurally. The differences may be considered as adaptive modifications primarily related to the food preferences.

ABSTRACT:The present study is designed to investigate the accumulative effect of aging on the histological and immunohistochemical (IHC) changes of rabbit's cardiac muscle and the protective role of vitamin E on senescent animals. The study was carried out on male New Zealand rabbits. The animals were divided into three groups; group I served as adult rabbits (6 months of age, weighing 4 ± 0.5 kg), group II aged rabbits (24-months of age, weighing 7.5 ± 0.5 kg), and group III aged animals supplemented daily with the curative dose of vitamin E orally at 14 mg/kg b.w /day for 60 days. Histological study of the adult cardiac muscle revealed normal branched cardiomyocytes and normal striations with normal oval centrally located nuclei. The aged rabbits showed changes in the cardiac muscle structure represented by the disorganization of cardiomyocytes, pyknosis of nuclei, necrosis of various areas of degenerated muscle fibres, and congestion as well as dilatation of blood vessels. In IHC study, the cardiac muscle of adult rabbits expressed moderat e normal desmin immunostain in the intercalated discs and Z-lines of myofibers, and moderate normal vimentin immunostain in the connective tissue and periphery of blood vessels in endomysium between cardiomyocytes. The aged rabbit's cardiac muscle expressed an intense immunopositive reaction to both desmin and vimentin. Administration of vitamin E as antiaging medication, antagonize the deleterious effects of aging and improved the architecture of cardiac muscle that have been confirmed through the histolo gical and IHC investigations in the present study.