Immunohistochemical study on the effect of soft diet and omega 3-fortified soft diet on neurogenesis in the rat dentate gyrus and the subventricular zone

Adult brain neurogenesis persists in the subventricular zone [SVZ] and in the subgranular zone [SGZ] of the dentate gyrus. Modulation of neurogenesis by diet is a mechanism by which nutrition affects memory, learning, and mood. To study the effect of the soft diet with or without omega 3 fatty acids on neurogenesis. Thirty weaned male albino rats [3 weeks] were divided into three groups. Group 1 [control group] were fed on hard diets, group 2 were fed on soft diets, and group 3 were fed on soft diets plus omega 3 fatty acids for 3 months. Nerve cell proliferation in the SVZ and the SGZ was detected immunohistochemically using thymidine analog bromodeoxyuridine [BrdU]. The results were statistically analyzed. In the dentate gyrus, there was a significant increase in the number of BrdU-positive cells in groups 1 and 3 compared with group 2. Meanwhile in the SVZ, there was a significant increase in the number of BrdU-positive cells in group 3 compared with group 1. In group 1, the newly formed cells in the SGZ reached the granular cell layer of the dentate gyrus. The newly formed cells in the SVZ reached the olfactory bulb [OB] after 2 weeks but failed to survive for 4 weeks in the OB. In group 2, few newly formed cells reached the granular cell layer of the dentate gyrus, but they failed to reach the OB. In group 3, the newly formed cells reached their destination in the granular cell layer of the dentate gyrus and the OB. In the OB, the cells succeeded to survive for 4 weeks and were incorporated among the granular cells of OB. Hard diet and omega 3-fortified soft diet had a stimulatory effect on the process of neurogenesis in the dentate gyrus. Meanwhile in the SVZ, fortified soft diet had more stimulatory effect on proliferation and improvement of the survival rate of the newly formed cells than the hard diet

Development of uteroplacental vasuclature, granulated metrial gland cells and trophoblasts in the uterine wall of the mouse during pregnancy

The development of the uteroplacental vasculature was studied by Indian ink injection method. The non-pregnant [estrus] endometrium was supplied by radial and terminal arteries. On day 5 of pregnancy the radial arteries became spiral arteries. All these changes appeared as an indication for the increased uterine blood volume. In this early five days interval of rapid development prior to blastocyst attachment, the endometrium underwent a decidual reaction by transforming its fusiform stromal cells into large polyhedral cells [decidual cells]. Ultrastructurally, their processes appeared to penetrate the basement membranes of the uterine epithelial cells and might aid in its disintegration. In the subsequent stages [days 6-8 of pregnancy] during the initial stages of invasion of the endometrial stroma by the embryo, most trophoblastic cells surrounding the blastocyst were flat [or roughly low cuboidal]. As pregnancy proceeded [on day 8], the area occupied by the trophoblasts became larger and some of these cells became giant. This was associated with an activation of the giant cells and their aquistion of invasive behavior, to complete the process of implantation previously experienced by decidual cells. From day 8 to day 14, the products of conception continued to enlarge at the expence of th surrounding endometrium. On day 8 erosion of endometrial blood vessels became more extensive. The outward growth of the trophoblasts from the trophoblastic shell forming primary villi. When the latter villi were invaded by mesenchymal connective tissue and branches of the umbilical arteries, they were termed chorionic villi. This was the anatomical bases for the achievement of the labyrinthine hemochorial placenta which increases in size in the subsequent stages [11-14 days]. It was considered the first step towards establishing the uteroplacental circulation on which the growth of the embryo will later depend. Numerous GMG cells characterized by their PAS positive cytoplasmic granules were found to differentiate in the deciduas basalis and metrial glands of the uterine wall during the first half of pregnancy [till day 8]. By day 8 and the subsequent stages of pregnancy some of the GMG cells were lying adjacent to the labyrinthine placenta

Effect of experimentaly induced diabetes on the rat's heart: influence of tocopherol as antioxidant [a morphological and a morphometric study]

The present work aimed to study the effect of vitamin E supplementation on diabetic cardiomyopathy. This was achieved by comparing the normal control group [group I], alloxan induced diabetic group [group II] versus vitamin E-treated diabetic group III. This was clarified by studying these groups as regards cardiomyocytes, connective tissue matrix and blood vessels [coronary arteries and capillaries] in an attempt to find out if this vitamin could protect against diabetic cardiomyopathy. The following parameters were measured for all groups: non fasting blood glucose levels; plasma tocopherol concentrations, body and heart weight. For histological study of the myocardium, all animals were subjected to the following techniques: morphometric study for the myofiber diameters and the numerical densities of blood capillaries/ mm[2] of the examined tissues, paraffin sections stained with HX and E, Masson's trichrome and PAS, cryostate sections stained with succinic dehydrogenase, and alkaline phosphatase, and ultrastructural study. There was a significant increase in non fasting blood glucose levels [370 +/- 55mg/dL] in group II animals if compared with that [100 +/- 20 mg/dL] of group 1 healthy animals. While in alloxan diabetic /vitamin E treated group III the non fasting blood glucose levels were [180 +/- 30 mg/dl] not too higher than that in group I. Plasma tocopherol concentrations for group III animals [12.7 +/- 0.5 mg/dl] were significantly increased of about 66 +/- 0.14 percent more than that [8.4 +/- 0.4 mg/dl] in the control group I. This means that the concentration of Eocopherol in the plasma was significantly influenced by feeding the animals a vitamin E-enriched diet for 16 weeks starting soon after inducing diabetes. This vitamin E- enriched diet used for group III animals nearly preserved both body and heart weights, which were significantly reduced in diabetic animals fed on the standard diet. Morphometric study showed a significant decrease in myofiber diameter observed in focal areas of the myocardium of alloxan diabetic rats. The cause of this result could be attributed to focal structural alterations affecting the cardiomyocytes. These structural changes included disorganization of the myofibrils at the Z lines, transverse tearing and distortion of intercalated discs and presence of contraction bands. There were also deterioration and fragmentation of myofilaments leading to loss of cross and longitudinal striations, crestolysis of mitochondria and cytoplasmic vacuolation. The intramural coronary arteries had thickened basement membranes and thickened walls due to deposition of more collagen fibers in their adventitia, and these changes might impair their elasticity and elastic recoil. These stressed blood vessels often lead to myocardial ischemia due to impairment of blood flow. The interstitial blood capillaries in the myocardium of diabetic group II showed an increase in their numerical densities /mm[2][CD[s]]. This increase was about 5 +/- 0.06 percent more than that in the control group I. This increase in CDs could be owed to the need to maintain good microvascularity, even in diabetic state, to protect the myocardium from ischemic damage. Many, not all of these capillaries appeared partially collapsed with thickened basement membranes. This was due to increase in the amount of connective tissue fibers especially collagen in the precapillary locations. These collapsed capillaries were observed to retain blood in their lumena, and this indicated that these capillaries impeded the influx of blood. The endothelial cells lining these capillaries appeared swollen and rich in biosynthetic organelles e.g. rER, ribosomes, mitochondria and Golgi bodies with the associated vesicles. This explains the effort exerted by these cells to synthesize new fibers added to their basement membranes in an attempt to compensate the degenerative changes associated with diabetes. Tocopherol acetate-enriched diet used instead of the standard diet to feed diabetic animals of group III was cardio protective and largely prevented severe alterations of myocardial structure typically observed after an alloxan diabetes duration of 16 weeks [group II]. Deterioration and fragmentation of myofilaments were seen less, the areas of degeneration and of contraction bands were clearly reduced, the abundant collagen fiber deposits especially at precapillary locations and in the wall of coronaries were significantly reduced. It could be concluded that the oxidative stress plays a significant role in the disturbances of cardiac structure in diabetes. Antioxidants such as alpha tocopherol are able to prevent these adverse effects despite the elevated blood glucose levels. It seems likely that adjuvant treatment with antioxidants is needed to maintain a healthy balance in diabetic patients with multiple complications. Therefore it would seem wise to supplement all diabetics with vitamin E either from natural or medicinal sources to retard or even prevent the occurrence of complications especially cardiomyopathy

Structural changes of lung alveoli and alveolar macrophages of the albino rat following invivo and invitro exposure to sodium fluoride

In this work both the effect of ingestion of sodium fluoride [NaF] for three months on the ultrastructure of lung alveoli and, the effect of NaF on macrophages isolated from the lung and cultured invitro were studied. The results revealed that ingestion of NaF led to distortion of alveolar epithelia, thickening of the blood air barrier and interstitial edema due to transudation of fluid from the dilated blood capillaries into the interstitial spaces. Also, Pneumocyte type II [P2] were degenerated and their secretory granules showing amellar structure [lamellar bodies] were decreased. This was an indication of increased surfactant secretion without a corresponding increase in the rate of synthesis. There was increase of pulmonary alveolar macrophages [PAM] and most of them showed heterogeneity of their cytoplasmic inclusions mainly in the form of heterophagic vacuoles, Most of PAM showed apoptotic changes [in the form of nuclear pyknosis or even fragmentation of the nuclei] after NaF ingestion and after invitro culture with NaF, From this work it could be concluded that NaF ingestion caused damage of the lung alveoli. Also, NaF particles acted as a stimulating factor for the proliferation of macrophages to engulf these foreign particles. Eventually the toxicity of fluoride leads to apoptosis of macrophages. So it could be concluded that NaF acts as an environmental toxicant that carries the risk of occurance of pulmonary dysfunction

Dendritic reticulum cells of lymph nodes in the rat using zinc iodide - osmium technique

Ten adult Sprague - Dawly rats of both sexes, weighing between 180 - 220 g were used in this study. They were maintained under convential laboratory conditions with free access to water and commercial rat food. The morphological architecture of dendritic reticulum cells [DRCs] in the rat lymph nodes was studied by light and electron microscopy after tissue impregnation and staining by zinc iodide-osmium [ZIO] method. DRCs represented the main stromal cell population. These cells were located both in the cortex and in the medulla and exhibited various configurations. In the cortex they appeared elongated and fusiform in shape with slender and long dendritic processes that ramify in a complex fashion. They were observed in the lymphoid follicles [especially in the germinal centre], lymphatic sinuses and the deep cortex, the DRCs were detected in close association with the subcapsular sinus, they might be located just underneath the sinus endothelium or directly share in forming the sinus lining. In the medulla, the DRCs appeared irregular in shape with coarse or delicate cytoplasmic processes forming an extensive cellular reticulum. This cellular reticulum spanned the region between the sinuses and the blood vessels such as capillaries and / or high endothelial venules [HEVs]. In this instance they were organized in a discontinuous sheath - like fashion around the vessel wall. By light and electron microscopy, DRCs have been observed to come in close spatial relationship with each other and with various other cell types including small, medium sized and large lymphocytes, lymphoblasts, plasma cells, interdigitating cells, sinus endothelial cells, the endothelium of HEVs and capillaries. These microanatomical features were consitent with the proposal that DRCs might be involved in the communicative networks between the different lymph node compartments. In particular, DRCs were thought to provide efficient anatomical arrangements which influence the lymphocyte traffic patterns and might be involved in the transport of molecules from the sinus compartment to the HEVs or to the distinct cell populations in the lymphoid parenchyma. From the previous data, it was suggested that the DRCs serve as accessory cells for the development of immune responses. Further studies should be performed to clarify the role of these cells in the regulation of lymphocyte mediated immunity