Prenatal and postnatal development of the lingual papillae in albino rat: light and scanning electron microscopic study

Adult albino rats of the Sprague- Dawley strain were caged together for 24 hours [every three estrous females with an adult male] and their resultant embryos and off springs were used in this study. The tongues of ten animals in each of the following prenatal age groups [16 and 20 days or E16- Group I and E20- Group 2 respectively] and another ten in each of the following postnatal age groups [7 and 21 days or P7- Group 3 and P21 - Group 4] were used. The lingual papillae in the tongues of the different age groups were studied using both light and scanning electron microscopy. In the prenatal group 1 [E16], the dorsal lingual epithelium was noticed to be stratified squamous epitheliumn with poorly developed vallate papillae. No evidence of keratinization, fungiform, or filiform papillae were visible a the dorsal surface of the tongue, while in group 2 [E20], few fungiform papillae and numerous rounded tips of filiform ones became visible. Also, a thin layer of keratin was clearly located at the tip of each, filiforin papilla. At later stages of development [P7 and P21], the filiformn papillae appeared longer, more slender with pointed tips, and the keratin layer increased in thickness. The primordia of the circumvallate papillae appeared as small rounded elevated areas on the dorsal surface of the tongue at E16. At E20 a solid epithelial downgrowth appeared on either side of the papilla in which future taste bud cells appeared. The glitter started to open at P7 and became well formed at P21. The taste buds were identified on both walls of the developing gutter, and they then gradually enlarged. Taste bud cells became differentiated into gustatory and supporting cells at P7 to P21 age groups

Protective effect of magnesium sulfate against radiation-induced heart damaged in albino rat

ability of Magnesium sulfate to reduce the severity of the late stage of radiation - induced heart disease [RIHD] was assessed in 40 white albino rats. Ten rats served as a control not exposed to radiation [cont.], another 10 rats were given only MgSo4 for 10 days as a negative control [-ve cont.]. The remaining rats were divided into two groups, group [A] ten animals exposed to a single dose of radiation [20 Gy]. Group [B] ten rats received MgSO4 [50 mg / kg intraperitoneally injected], 4 days prior to radiation, at the day of radiation and on the following 5 consecutive days. At 100 days post - radiation, the severity of the late state was determined by microscopic examination for myocardial fibrosis and by studying the ultrastructural changes. Irradiation found to have aggravated structured effect on the heart in the form of lysis and indistinct striation of muscle fibers, irregular pyknotic nuclei, depletion of glycogen granules and abnormal shaped mitochondiria. The adjacent cardiac muscle fibers were widely separated with marked congestion of the blood capillaries and interstitial cellular infiltration. Magnesium sulfate appeared to have protective effect in the form of reduction of myocardial of collagen content [fibrosis]. Suppression of the inflammation with preservation of the normal characters of most of the muscle fibers

genotoxic potential of nicotine in adult male albino rats with special reference to the protective role of alpha - tocopherol

The present study was under taken to reveal the toxic effects of nicotine - the main active principle in tobacco - on cell chromosomes and peripheral blood cells of adult male albino rats. Also to detect histological changes in bone marrow cells. Furthermore, the protective effect of the antioxidant vitamin E [alpha - tocopherol] in nicotine toxicity was studied. The study was carried out on one handered and twenty adult male albino rats divided into six numerically equal groups. The first group was the negative control group. The second was injected with distilled water, the solvent of nicotine, daily by intraperitoneal [IP] injected. The third group was given corn oil, the solvent of vitamin E, daily by gavage. The fourth group was given alpha - tocopherol daily by gavage. The fifth group was the nicotine group where it was injected intraperitoneally daily. Lastly the sixth group was given daily both nicotine by [IP] injections and alpha - tocopherol by gavage. The duration of the experiment was eight weeks. Twenty four hours after the end of the experiment each group was divided into two subgroups. Chromosomal study was carried out on the first subgroup bone marrow cells of rats. Five hundred cells in the mitotic stage were studied in each group. Any numerical or structural chromosomal abnormality was recorded. The 2nd subgroup was anaesthetized, blood samples were taken from each rat to study total and differential blood count. At the same time samples were taken from bone marrow of the femora and kept in preservative. Paraffin sections were prepared from bone marrow samples and stained either by haematoxylin and eosin of Feulgin stain to be studied by light microscope. For samples which were studied by electron microscope, ultrathin sections were stained by lead citrate and uranyl acetate. The results were statistically analysed. The study had revealed significant difference in the chromosomal structure and number in the nicotine group compared to the control groups. This was in the form of a significant increase in the number of cells with hyperdiploid or hypodiploid number of chromosomes and a significant increase in the rate of appearance of ring chromosome, break, fragments and gaps. Meanwhile, complete blood count revealed a significant decrease in total and differential blood count in the nicotine group, mainly as a decrease in the lymphocytic count. Furthermore, the light microscopic examination revealed a significant decrease in the number of bone marrow cells. Also a decrease in nuclear DNA content of the nucleated blood cell precursors was detected. As regard the electron microscopic examination most of the nucleated blood cell precursors showed disrupted cell membrane and nuclei were pyhnotic in the nicotine group. On the other hand, the nicotine and vitamin E combination group revealed a statistically significant improvement in the number and structure of the chromosomes and the total different blood cell count. At the same time the histological picture was improved both by light and electron microscopic examination where the DNA content of the cell was nearly normal and most of the cells appeared with intact cell membrane. The nuclei of the cells appeared as heterogenous structures with electron - dense and electron - lucent areas. This study has revealed the protective role of the antioxidant vitamin E [alpha - tocopherol] which proved the role of nicotine in forming free radicals that affect the cell. Moreover this study must be followed by other studies to prove the protective role of vitamin E in human smokers

Biochemical and histological study of the effect of methotrexate on the rat liver with special reference to the protective role of biotin

This study was conducted on 140 adult male albino rats who were divided into seven equal groups, each comprised 20 rats. The first group was the negative control group, the second and the third groups were positive control rats injected with saline and received biotin orally, respectively, the fourth and fifth groups were injected with methotrexate and the sixth and seventh groups were injected with methotrexate after biotin administration. At the end of the experimental period, the rats were sacrificed, blood was collected and the liver profile [serum hepatic transaminases, alkaline phosphatase, total serum proteins and serum albumin] was investigated and liver was exposed to histological and ultrastructural examination. The results showed a remarkable deterioration in the liver biochemical parameters as well as changes in its histological and ultrastructural appearance following methotrexate administration. The changes were more pronounced in rats received the drug treatment for a longer period. In addition, biotin had improved the liver function tests and decreased the histological and ultrastructural changes caused by methotrexate. The correlation between the functional and structural changes was discussed

Effect of cessation of cigarette smoking on semen quality and sperm morphology

Semen samples were collected from 42 male heavy cigarette smokers [ages 27-35 y] before and two years after successful abstinence from smoking. Semen samples were also obtained from ten healthy volunteers who never smoked. Those later served as negative control. All Selected subjects had no known cause that may alter the process of spermatogenesis The collected semen samples were evaluated for sperm density, motility and percentage of abnormal forms. Serum testosterone was assayed by RIA in control persons and in smokers before and after their successful quitting. Seminal fluids from all subjects were also examined by transmission electron microscope in an attempt to visualize accurately the morphologic characteristics of the sperms. All the investigated parameters of semen quality were significantly altered in smokers compared to nonsmokers testosterone level was significantly reduced in smokers and abnormal forms of sperms were encountered more. Two years after cessation of smoking, significant improvement was found in all the semen parameters together with a parallel rising up of the serum testosterone level. In spite of the marked improvement in semen quality and testosterone level after cessation of smoking, most of these parameters were still significantly different from the control the result of this work proved beyond doubt the harmful effects of smoking on potential male reproductive capacity evidenced by bad semen quality, abnormal hormonal profile and distorted ultrastructure of spermatozoa However, these effects were at least partially reversible and improved after prohibition of cigarette smoking for two years