study on the prenatal development of the human sublingual salivary gland

In this study 30 human embryos from 8 weeks to full term were used. The prenatal development of the human sublingual gland was histologically and histochemically studied through sections stained with Haematoxylin and eosin, PAS and Alcian blue reactions. The gland started its development at the 8th week as a branched column of cells. This denoted the earliest indication of duct system formation. The primordia of the duct system were canalised at the 12th week and became differentiated into intralobular, interlobular and intercalated ducts by 20 weeks. At full term, the lining epithelium of the duct segments was simple columnar in the intralobular, pseudostratified columnar in the interlobular and flat in the intracalated ducts. The secretory unit developed later than the duct system, since the primordia of the acini appeared at 12 weeks. They showed cavitations at 18 weeks and became differentiated into mucous and serous acini by 20 weeks. The mucous acini were more numerous than serous ones, and some of them were capped with serous demilunes. A strong PAS reaction in the primordial cells appeared from the 8th week to full term. The duet cells showed progressive decrease in PAS reaction, while moderate PAS materials within the duct lumen were seen. AB reaction, however, was observed in the mucous acini for the first time at 12 weeks and increased at full term. The serous acini were negative at early stage, while at full term they showed faint reaction. The duct cells were unreactive to AB, though, their lumina showed rective materials from 12 weeks to full term

Effect of starvation and water depletion on the structure and function of the immunological system of albino rats

48 albino rats, 200-250 gm. body weight comprised the material for the present work. They were classified into 2 groups. The1st group was deprived from food while the 2nd groub was deprived from water as well. A third group of 6 animals used as control. The animals within the 1 st and 2nd groups were subdivided into 4 subgroups and used to study the effect od atarvation and stravation aasociated with dehydration for 3, 6, 9 and 12 days respectively on the structure and the function of the immunological system. It was found that atrophic changes inorm of lymphocytic epletion with absence of germinal centres occur in spleen, lymph nodes and tonsils after the first week. The atrophic changes were more marked in the group of starvation with dehydration. Also, efinite thymic involution was demonstrated from the start of the experiment in both groups. On the other hand relative increase in the gamma globulin occurred. At the same time decreased ymphocytic transformation reflecting an impairment of cell mediated immunity was demonstrated in the present study. The impact of these findings on existing public health and vaccination rograms are of importance and must be taken in consideration

Histochemical changes in pregnant rat's liver following repeated halothane exposure [1]

Eighteen adult white rats were divided into 3 groups, 6 rats each, 2 males. The first group was exposed to 1.5% halothane for 20 minutes, every other day, for 6 exposures. The rats mated and exposed for another 10 exposures. The second group was given 0. 1% phenobarbitone in milk, one week before and during the period of exposure, which similar to the first group. The third group was kept as a control. At the suspected date of delivery, the rats weresacrified and specimens were taken from the mother's liver for estimation of the activities of the enzymes succinate dehydrogenase, acid phosphatase and alkaline phosphatase. Repeated halothane exposure decreased the activity of the enzymes succinate dehydrogenase, acid phosphatase and alkaline phosphatase. Treatment with phenobarbitone has the same effect on succinate dehydrogenase, but partially spared the activities of acid and alkaline phosphatases

Histopathological changes in pregnant rat's liver following repeated halothane exposure [2]

Adulte white rats were divided into 3 groups, 6 rats each [2 and 4]. The first group was exposed to 1.5% halothane for 20 minutes every other day for 6 exposures. The rats were mated and exposed another 10 exposures. The second group was given 0.1% phenobarbitone in milk one week before, and during the period of exposure which was similar to the first group. The third group was kept as a control. At the suspected date of delivery, the rats were sacrified, and specimens were taken from the liver for haematoxylin and eosin stain, PAS reaction and Sudan black stain. Repeated exposure to halothane did not affect the pregnancy rate, but it resulted in hepatic focal and centrilobular necrosis with glycogen poverty and moderate lipid content. The portal spaces showed thick connective tissue and lymphocytic infiltration. Phenobarbitone reduced the pregnancy rate and resulted in 16.5% foetal mortality with more hepatic necrosis and increases in glycogen and lipid content