Effect of chronic nicotine administration on the anterior cingulate cortex [area 24a] of adult albino rats: a histological and immunohistochemical study

Nicotine is the principal active component in cigarettes and cigars. It was reported that tobacco smoking enhances the performance of cognitive processing. The anterior cingulate cortex plays an important role in attention and working memory performance. This study was conducted to demonstrate the effects of chronic administration of various nicotine doses on the structure of the ventral anterior cingulate cortex [area 24a] in adult rats, as well as study the effect of withdrawal of high doses of nicotine. A total of 48 adult male albino rats were used. They were divided into four groups. Group I [N=1 2] was considered the control group. Group II [n=12] rats were treated with 1 mg/kg nicotine subcutaneously for 2 months. Group III rats [n=24] were treated with 6 mg/kg nicotine subcutaneously for 2 months. Thereafter, half of the animals were sacrificed. Group IV [the recovered group] consisted of the remaining I 2 rats of group III that were kept for another 2 months without treatment and then sacrificed. Brains were processed to be studied using Einarson's gallocyanin stain, the Golgi-Cox method, transmission electron microscopy, and immunohistochemical study for glial fibrillary acidic protein [GFAP]. Further, the number of cells in the second and fifth layers of the cingulate cortex [area 24a] was measured and statistically analyzed for all the studied groups. Examination of the cingulate cortex [area 24a] in low-dose nicotine-treated rats [group II] revealed an increase in the branching of the dendrites of the pyramidal cells together with a relative increase in the density of the spines. An ultrastructural study showed the presence of numerous synaptic contacts between the nerve processes. In high-dose nicotine-treated rats [group III] the cells showed degenerative changes, which were more evident in pyramidal cells. These changes were associated with a marked reduction in the extension and branching of the dendrites. Dense GFAP immunostained fibers and cells could be seen particularly in layer I. In the recovered rats [group IV] most of the cells restored their normal appearance. Mild GFAP expression could be observed. An insignificant difference in the number of cells was also found in comparison with controls. The effect of nicotine on the organization of the anterior cingulate cortex [area 24a] was found to vary according to dose. Withdrawal of high doses of nicotine will result in a marked reduction in the structural impairment of neurons

Histological and immunohistochemical changes in placental chorionic villi of patients with poorly controlled gestational diabetes

Normal placental development is essential for normal fetal development. The placenta is a complex fetal organ that plays pleiotropic roles during fetal growth. It separates the maternal and the fetal circulation. The placenta is exposed to the regulatory influence of the hormones, cytokines, growth factors, and substrates present in the circulation, and thus may be affected by changes in any of these. Gestational diabetes is one of the most prevalent medical complications of pregnancy and may cause increased fetal wastage. To study the structural changes in the placental chorionic villi of women with poorly controlled gestational diabetes in comparison with metabolically normal pregnant women. The study was carried out on placentas from 22 full-term pregnant women. All the women delivered at 38-40 weeks of gestation. Ten placentas were from normal uncomplicated pregnancies [control group] and the other 12 were from gestational diabetic pregnancies [diabetic group]. The placentas were processed and examined using light and electron microscopy. An immunohistochemical study using S100 protein antibody was carried out. In comparison with the control group, the placentas of poorly controlled gestational diabetic mothers showed an increase in syncytial knots, partial shedding of trophoblastic microvilli, and thickening of the basement membrane of the trophoblast. Fibrinoid necrosis, villous fibrosis, and dilated congested fetal blood vessels were also observed. The frequent appearance of Hofbauer cells [placental macrophages] was observed in the diabetic placenta in comparison with the control placenta. Positive diabetic trophoblastic and stromal cells for S100 protein antibodies were observed. It is concluded that poor control of diabetes during gestation may result in structural changes in the placentas, which may contribute toward fetal complications. Further research in this field may help in finding a solution for the evaluation of the destructive changes in diabetic placenta in the initial stages of pregnancy

Possible teratogenic effects of antiepileptics in albino rats: comparative study between old and new generations: part I

All of the antiepileptic drugs [AEDs] are either known or suspected of being teratogenic. The possible mechanism of teratogenicity is likely to be multiple for the same drug. This is of major concern for all women with epilepsy using these drugs are delicately balanced between seizure control and the adverse effects the AEDs. The use of conventional AEDs eg. Carbamazepine control more than two thirds of the epileptic patients. In recent years, the number of commercially available AEDs has steadily increased eg. lamotrgine and levetiracetam.160 pregnant female albino rats were used in this study. Animals were classified randomly into eight groups; each group contained 20 pregnant female rats. Negative control group received nothing and positive control group received normal saline. Treated groups: each group received either the therapeutic dose or 1/4 LD50 of carbamazepine, lamotrigine or levetriacetam. The drugs were given by gastric tube from 6[th] day up to the 19[th] day of gestation. Teratological evaluation:the fetuses [both living and dead] in each group were weighted their crown rump length measured and morphological examination included: Head size and shape, orofacial development, vertebral column tail and abdomen, umbilicus and external genitalia Maternal findings showed high death rate in 1/4 LD50 of lamotrigine treated group; weight gain was dose dependant with highest effect in the lamotrigine treated groups. The fetal findings showed highest embrolethality and least litter siza in lamotrigine treated groups; while the fetal growth determined by weight gain and crown rumplength was retarded more in carbamazepine and lamotrigine treated groups than in levetiracetam treated groups. The morphological findings revealed that the highest percentage of congenital anomalies were in the dose of 1/4 LD50 of lamotrigine followed by carbamazepine and levetiracetam. The AEDs are potentially teratogenic and in utero exposure can increase the risk of adverse outcomes in off springs born epileptic mothers. The new AED lamotrigine caused gross fetal retardation even in therapeutic dose. Levetiracetam caused growth retardation in the therapeutic dose more than carbamazepine in the corresponding dose although it had the best effect on maternalparameters. As regard the congenital anomalies lamotrigine was the safest durg in the therapeutic dose

Effect of caffeine administration on the development of skeleton of albino rat

Caffeine, a naturally occurring central nervous system stimulant, is found in coffee and coca-based foods. Although caffeine passes readily through the placenta to the fetus, caffeine-containing products are still widely consumed during pregnancy. The present work was conducted to evaluate the effects of dietary caffeine intake during pregnancy and lactation on the skeleton of the developing rat. A total number of 20 pregnant albino rats were randomly chosen and divided into 2 groups: control group: 10 dams were given saline daily from the 10[th] day of gestation until delivery through a gastric tube, and an experimental group: 10 dams were given caffeine at a dose of 100 mg /kg/day dissolved in distilled water through a gastric tube for the same period of gestation. After normal delivery, some litters from both groups were sacrificed at postnatal day 1, and others were left for lactation and sacrificed at postnatal day 30. Samples from the lumbar region of the vertebral column, upper end of ulna and upper and lower ends of radius were taken from all groups, prepared for light microscopic examination and stained with haematoxylin and eosin and toluidine blue stains. Other samples from all groups were taken randomly and stained with alizarin red stain for gross skeletal examination. Caffeine treated groups showed delayed ossification in the developing bones including the skull, forelimb, hind limb and caudal vertebrae. Histological study of the growing ends of the long bones and vertebral bodies revealed cellular disorganization of chondrocytes especially in the hypertrophic zone, delayed ossification in between degenerating chondrocytes and less developed 2ry centers of ossification in treated animals. Also, degenerative changes were observed in the histological structure of the inter-vertebral disc in both newborn and one month old treated animals in the form of shrunken nucleus pulposus and disturbed lamellar arrangement of annulus fibrosus. These observed changes could be attributed to the direct effect of caffeine on the developing skeleton or due to some of its derivatives; theobromine or methylxanthine. The delay in the endochondral ossification may be attributed to zinc deficiency produced by the administration of caffeine