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

Gene therapy, science fiction or science fact?

The term gene therapy is commonly understood to be the use of DNA as a pharmaceutical agent to treat diseases. This may be done by replacing defective or absent genes or to counteract those that are overexpressed. This would have been a science fiction story only a few years ago. Currently, gene therapy has attracted considerable attention and has become a hot topic for investigation. Gene therapy aims to repair the cause of the problem and not merely suppress symptoms, provides long-term cure, and does not require repeated applications or clinic visits

Bone marrow stem cells as a potential treatment of experimentally induced cartilage defects in the knee joint of adult male albino rats

Spontaneous proper healing of articular cartilage trauma in adults is rare and osteoarthritis might develop as a result. Cultured bone marrow mesenchymal stem cells [BM-MSCs] could differentiate into chondrocytes, and might thus be a good choice for treating such trauma. To assess the efficacy of an intraarticular injection of BM-MSCs derived from young albino rats in the repair of an induced chondral defect in the knee joints of adult albino rats. Six young male albino rats were used as a source of BM-MSCs. In addition, 30 adult male albino rats were divided into four groups. Group I served as a control. Group II served as a model of a chondral defect. Group III was subdivided into subgroups IIIa and IIIb, in which a cartilage defect was induced and sacrificed after 4 and 8 weeks, respectively. Group IV was subdivided into subgroups IVa and IVb, in which a cartilage defect was induced and injected intraarticularly by BM-MSCs suspended in hyaluronic acid [HA] in the right knees and HA alone into their left knees and then sacrificed after 4 and 8 weeks, respectively. Histological, immunohistochemical, and statistical studies were performed. Group III showed healing of the defect by fibrous tissue. However, BM-MSCs- injected knees healed by hyaline-like cartilage, whereas the HA injection induced healing by fibrocartilage. Intraarticular injections of BM-MSCs suspended in HA promoted healing of an articular cartilage defect by hyaline cartilage. Thus, it is recommended to treat a traumatic articular cartilage injury by BM-MSCs

Effect of omega-3 versus omega-6 fatty acids on induced ulcerative colitis in male albino rat. Light and electron microscopic study

Ulcerative colitis [UC] is an inflammatory bowel disease [IBD] well known by its exacerbated immune response. At present, a specific causal treatment for IBD is not available. The drugs currently used for management of IBD unfortunately are not devoid of potentially serious side effects. Polyunsaturated fatty acids [PUFAS] as omega-3 and omega-6 were reported to have immunomodulatory activities. Hence, may be of benefit in treating UC. The goal of this study was to illustrate the effect of omega-3 and omega-6 fatty acids on ulcerative colitis induced in male albino rat. Thirty adult male albino rats were used in the study. They were divided into four groups; Group I served as a control group. Group II was used as a model of ulcerative colitis. Rats of this group were subjected to intracolonic enema injection of 1 ml of 2% acetic acid for three consecutive days. Group III and group IV were subjected to colitis induction and on the fourth day, daily oral administration of omega-3 and omega-6 was done respectively for 14 days. All rats were sacrificed on day 17 from the beginning of the experiment. Colon specimens were collected and processed for light microscopic, scanning and transmission electron microscopic examination. Ulcerative colitis induction showed mucosal injury. There were patchy areas with loss of crypt architecture, inflammatory cell infiltrate and ulcerated mucosa. Scanning electron microscopic study revealed areas of ulceration, whereas other areas showed alteration of the columnar absorptive cells. Transmission electron microscopic study revealed loss of apical microvilli of enterocytes with signs of degeneration. Administration of omega-3 completely treated the colonic structure, while omega-6 was by far less efficient in treating induced ulcerative colitis. Omega-6 fatty acids partially improved the colon against ulcer induction. Meanwhile, omega-3 fatty acid proved to be a more effective dietary management of ulcerative colitis without the adverse effects of either surgery or medications

Histological and immunohistochemical study on the effect of hypo and hypercaloric diet on the structure of hippocampus of male albino rat

Caloric restriction remains the major, non genetic intervention that extends the life span of the short and long -lived mammalian species. This nutritional intervention also delays the onset, or slows the progression of many age-related disease processes. The present study investigated the effect of hypocaloric diet, in comparison to the hypercaloric and the balanced diet feeding on the structure of hippocampus. The study was conveyed on young and aged male albino rats for eight weeks. Showed that the aged control rats manifested many degenerative changes in the hippocampus. These changes were in the form of degenerated pyramidal cells with pyknotic nuclei and Karyolysis of some cells. A significant decrease in the pyramidal cell number was detected with a significant compensatory increase in the number of the astrocytes. Shrinkage of some pyramidal cells and swelling of others could be observed. Hypercaloric diet feeding resulted in exaggeration of these age -related changes that started to be noticed in the young rats. On the other hand hypocaloric diet feeding attenuated the age-related hippocampal changes. This was evidenced by histological, immunohistochemical, and statistical studies. These results direct our attention to limit the caloric intake in our food, to maintain a healthy life style for safe aging