Effect of cyclic versus continous hormonal replacement therapy on the structure of dentate gyrus of ovarictomized adult albino rats: a histological and immunohistochemical study

Hormonal replacement has been implicated as a possible therapeutic agent for ameliorating age-related cognitive decline in postmenopausal women. Estrogen in particular enhanced learning and memory in many women by improving the function of hippocampus after menopause. However, there is lack of studies concerning the most effective way of replacement therapy. The aim of the study was to investigate the effect of hormonal replacement on the structure of dentate gyrus and to assess the most effective therapy regimen. Thirty six adult female albino rats were used in the study and were divided into four groups: the control group, the ovariectomized group, the ovariectomy and continuous estrogen+progesterone group, and the ovariectomy and cyclic estrogen+progesterone group. All rats were sacrificed after 5 months from the beginning of therapy. Coronal brain specimens were obtained, processed into paraffin blocks, and subjected to histological, immunohistochemical, histomorphometric, and statistical studies. Ovariectomy resulted in neurodegenerative changes in the dentate gyrus. These changes were partially reversed by continuous hormonal therapy; however, cyclic method of therapy was more effective. Cyclic hormonal therapy was proven to be more effective than continuous method after ovariectomy. Hence, it is recommended to use the cyclic method of hormonal therapy for after menopause

Effect of atorvastatin on phenytoin-induced osteoporosis in adult albino rats: a pharmacological and light and electron microscopic study

Phenytoin, an antiepileptic drug [AED], might affect bone structure and mineralization. Epileptic patients who take AEDs are at increased risk for falls and fractures. Therefore, there is a need for a new approach to increase bone health in these patients. This study was conducted to assess the efficacy of statins in preventing bone loss associated with AEDs. Thirty male adult albino rats were divided into five equal groups. The animals, which received daily treatment by gastric gavage for 5 weeks, were classified into: group I [the control group]; group II, in which the rats were given phenytoin 20 mg/kg bw; group III, in which rats received phenytoin as in group II with atorvastatin 5 mg/kg bw; group IV, in which rats were given phenytoin along with atorvastatin 10 mg/kg bw; and group V, in which they were given phenytoin along with atorvastatin 20 mg/kg bw. Biochemical assays, assessment of bone mineral density, light [LM] and scanning electron microscopic studies [SME], as well as morphometric and statistical studies were carried out. The present work demonstrated that atorvastatin in a dose-dependent manner significantly [P<0.001] prevented the decrease in serum and bone calcium and phosphorus and bone-specific alkaline phosphatase due to phenytoin administration. There was also a graded improvement in osteocalcin [a marker for osteoblastic activity] and TRAP [a marker for osteoclastic activity] levels. Moreover, atorvastatin significantly inhibited the loss in bone weight, volume, and density. On LM and SEM examination, atorvastatin showed a gradual improvement of the tibia bone with higher doses as there was a significant increase [P<0.05] in trabecular and cortical bone thickness and a significant decrease [P<0.05] in osteoclast numbers per area of bone surface in the metaphysis; compared with the phenytoin-only-treated group, an improvement was seen in the growth of the epiphyseal plate. Atorvastatin could be considered a beneficial drug for treatment of osteoporosis in epileptic patients on phenytoin

possible protective role of aminoguanidine in gentamicin-induced ototoxicity in guinea pig: a histological and immunohistochemical study

Introduction: Gentamicin is an ototoxic drug affecting both auditory and vestibular cells. Reactive oxygen species might play important role in the molecular pathway of this ototoxicity. Aminoguanidine is one of the guanidine derivatives and is considered as an antioxidant therapy

Aim of the work: to investigate the possible protective effect of aminoguanidine on ototoxicity induced by gentamicin in guinea pig

Materials and methods: Twenty one adult male guinea pigs were used. They were divided into three groups, seven animals each. Group I: served as a control group. Group II: I.M. injection of gentamicin [80 mg/kg/day] was used for 14 days. Group III: animals received gentamicin in the same way as group II and then followed by aminoguanidine [100 mg/kg/ day] administration using a gastric tube for 14 days. At the end of experiment, the cochlea was excised and prepared for light [LM] and scanning electron microscope [SME] examination. Immunohistochemichal technique was done to detect iNOS. Morphometric and statistical studies were also done

Results: By LM and SME examination, the present study showed that aminoguanidine protected the structure of organ of Corti in the cochlea by decreasing the degeneration of hair cells and other supporting cells. It also showed a significant decrease in the iNOS immune-reactivity in organ of Corti, stria vascularis and bipolar cells in spiral ganglia compared to group II

Conclusion: Aminoguanidine is a promising and successful antioxidant therapy for ototoxicity

Effect of alloxan-induced diabetes on implantation sites of pregnant rats with special emphasis on angiogenesis

Diabetes is relatively common worldwide. According to the reports of the WHO, more than 150 million people suffer from diabetes across the world. A primary negative effect of a diabetic environment on the developing embryo is impaired vascularization of the yolk sac. Angiogenesis at the sites of blastocyst implantation is associated with increased vascular permeability. The present study aimed to investigate the effect of diabetes on the implantation site and intersite in albino rats during the early period of pregnancy with special emphasis on angiogenesis, by studying vascular endothelial growth factor expression. Forty adult female albino rats aged 4-6 months were used in this study. Rats were divided into two groups [20 rats each]. Group I constituted the control group and group II constituted the alloxan-induced diabetic group. Diabetes was induced in rats by intravenous injection of alloxan monohydrate dissolved in normal saline into the dorsal tail vein at a dose of 40mg/kg body weight. Vaginal smears were collected from each animal; the presence of sperm in the smear was designated as day 1 of pregnancy. Pregnant rats from the control and diabetic groups were sacrificed at days 4, 5, 6 and 7 of pregnancy [n=5]. Examination of the uterine horn sections showed occurrence of implantation on day 6 in the control group, whereas implantation in the diabetic group occurred only on day 7. Granulated metrial glandular cells were clearly seen in the control group, whereas lymphocytic infiltration was obvious in the diabetic group. The expression of vascular endothelial growth factor was stronger in the diabetic group

Scanning electron microscope: a new approach of an old issue

With a power that reaches more than 100000 times the naked eye, the scanning electron microscope [SEM] has emerged during the past 2 decades as a novel technique for visualizing the ultrastructures of tissues and cells, providing a different point of view for many medical applications. Several techniques have been developed throughout the years to prepare the specimens for examination by the SEM, ranging between maceration, cracking, and resin-corrosion cast techniques. It is clear that the problem is not in the methods of the techniques themselves, but involves the application of them, which is implicated by human error and bias. Their outcoming results, when interpreted as it should, will direct the attention of the researchers to more vast discoveries. It has been shown throughout the past years that the SEM is and will stay a valuable tool for approaching new research results, but only if the suitable technique is properly applied

Histological study on the effect of pyrrolidine dithiocarbamate on hepatic and small intestinal injury induced by ischemia reperfusion in rats

Restoration of the blood flow and reintroduction of oxygen after deprivation accelerate tissue injury. The insult of intestinal ischemia reperfusion [PR] is not necessarily limited to the intestine itself, but involves the severe destruction of the other tissues because of the reperfused oxygenated blood. Many reports indicated that I/R is an important inciting event in the pathogenesis of multiple organ system failure, which is the leading cause of death in critically ill patients. So, the aim of this study was to evaluate the possible protective role of pyrrolidine dithiocarbamate [PDTC] on liver and small intestinal injury following mesenteric ischemia reperfusion. The study was performed on forty adult male albino rats weighting 200-250 gm that were divided into three groups. Group I: Control animals which divided into untreated and sham operated [10 animals each]. Group II: Intestinal ischemia reperfusion animals, which were underwent one hour ischemia and two hours reperfusion. Group Ill: Animals received 200 mg/kg PDTC intraperitoneally one hour before intestinal ischemia reperfusion procedure. Parts were taken from the liver and jejunum were processed for histological examination and other jejunal parts for scanning electron microscopic examinations [SEM]. Immunohistochemical expression of NF-ka B factor in the liver was investigated. A variety of changes were observed in the jejunal ranging from epithelial separation and loss of the brush border to cellular lysis, destruction of villi, cellular infiltrations, hemorrhages and basal glandular ulcerations. The liver showed areas of edema fluid, hemorrhages, mononuclear cellular infiltration and increased expression of INF-ka B factor. Treatment with PDTC resulted in improvement in most of the histological changes induced by intestinal ischemia-reperfusion in the jejunum and liver. Therefore, PDTC can be considered as an effective protecting agent during intestinal ischemia reperfusion and can be used clinically in such instances