Effect of trauma on the retina of the albino rat

This study has been carried out to elucidate the effect of trauma on the retina of 17 days and 8 weeks old rats. Fifty albino rats were used in this work 20 rats were used as a control to demonstrate the normal development of the retina in the albino rats 30 rats were exposed to a midline sagittal incision which made in one eye. The present study revealed that the trauma effect the same eye by retardation of growth and absence of some layers of it, also slight degenerative changes were noticed in some retinal cells. An increase in the growth of the retina and an increase in thickness of some retinal layers were observed in the opposite eye

Postnatal development of long bones [femour] in the albino rat

The postnatal development of long bones was demonstrated in the femur of albino rat at the level of the growing epiphyseal plates and middle of the diaphysis. This was achieved by using decalcified sections of the femur of few hours newborn rats, 4 weeks old rats, 8 weeks old rats and 12 weeks old rats. Growth of the long bones was found to pass into two directions, increase in length and increase in diameter. The results showed that the proliferation of the cartilage cells of the growing epiphyseal plate started in few hours newborn rat and gradually increased to be well marked in younger rat [4 weeks old]. In 8 weeks old rat's femur, the proliferation of the cartilage cells showed decreased activity. This finally ceased and was replaced by bone at the diaphyseal end of the cell columns, resulting in obliteration of the epiphyseal plate in 12 weeks old rats femur. Also, the growing trabeculae of the newborn rat's femur gradually progressed and developed till they reached their maximum development at the end of 8 weeks old rat Then they decreased in growth and changed into compact bone at the end of 1 2 weeks old rat's femur. In transverse sections, the diaphysis showed a thin layer of bone collar beneath the periosteum and bone trabeculae connected together forming marrow cavity in new born femur's rat. In 4 weeks old rat, the diaphysis of the femur became thicker and more developed having bone lamellae, primary osteons and bone trabeculae. The diaphysis of the femur became well developed and was differentiated into periosteum, outer circumferential lamellae, inner circumferential lamellae, interstitial lamellae, and mature Haversion system. So the increase in diameter of the long bone was the result of successive generation of osteoblasts which arose from osteogenic membrane beneath the periosteum forming the bone matrix

Effect of oxytetracycline on the developing retina of the chick embryo

In the present work fifty fresh fertile fayoumy eggs were used, 20 eggs were used as control and 30 eggs were injected with [1mg/embryo] of oxyteracycline on the 5 th day of incubation. The embryos were extracted on the 10 th, 12 th and 15 th days of incubation. Oxytetracyclines caused retatdation of grwth of the retina in 10 and 12 days treated chick embryos as evidenced by reduction of the size of the retina associated with disappearance of some layers of it the treated embryos showed signs of incomplete regeneration when examined on the 15 th day of incubation

Effect of noristerat on the development of the retina of the chick embryo

The present work was concerned with the development of the retina of the chick embryo and the effect of noristerat on its development, aiming for the explanation of the possible hazards of the drug which may occur to the fetus, if the pregnant mother is under the treatment with this drug. Morphological and histological studies were done on the retina of 10, 12 and 14-day old chick embryo treated on the 6th day of incubation by a dose of noristerat equivalent to the average human therapeutic dose [0.2 mg/embryo]. Retardation of growth of the retina was observed in all treated embryos as evidenced by reduction of the size of the retina, associated with disappearance of some layers of the retina