Temporospatial dynamics of the morphogenesis of the rabbit retina from prenatal to postnatal life: Light and electron microscopic study.

The retina consists of various cell types arranged in eight cell layers and two membranes that originate from the neuroectodermal cells. In this study, the timing of differentiation and distribution of the cellular components and the layers of the rabbit retina are investigated using light and electron microscopy and immunohistochemical techniques. There were 32 rabbit embryos and 12 rabbits used. The rabbit retina begins its prenatal development on the 10th day of gestation in the form of optic cup. The process of neuro- and gliogenesis occurs in several stages: In the first stage, the ganglionic cells are differentiated at the 15th day. The second stage includes the differentiation of Muller, amacrine, and cone cells on the 23rd day. The differentiation of bipolar, horizontal, and rod cells and formation of the inner segments of the photoreceptors consider the late stage that occurs by the 27th and 30th day of gestation. On the first week of age postnatally, the outer segments of the photoreceptors are developed. S100 protein is expressed by the Muller cells and its processes that traverse the retina from the outer to the inner limiting membranes. Calretinin is intensely labeled within the amacrine and displaced amacrine cells. Ganglionic cells exhibited moderate immunoreactivity for calretinin confined to their cytoplasm and dendrites. In conclusion, all stages of neuro- and gliogenesis of the rabbit retina occur during the embryonic period. Then, the retina continues its development postnatally by formation of the photoreceptor outer segments and all layers of the retina become established. RESEARCH HIGHLIGHTS: The aim of this study is to investigate the morphogenesis of the rabbit retina during pre- and postnatal life. The primordia of the retina could be observed in the form of the optic cup. The ganglionic cells are the first cells to differentiate, while the photoreceptor cells are the last. S100 protein is expressed by the Muller cells and its processes. Calretinin is intensely labeled in the amacrine and displaced amacrine cells and moderately expressed in the cytoplasm and dendrites of ganglionic cells.

Morphogenetic events influencing corneal maturation, development, and transparency: Light and electron microscopic study.

The development of the cornea is a fascinating process. Its dual origin involves the differentiation of surface ectoderm cells and the migration of mesenchymal cells of neural crest origin. This research aimed to demonstrate the morphogenesis of the rabbit cornea from fetal to postnatal life using light- and electron microscopy, and immunohistochemical analysis. There were 27 rabbit embryos and nine rabbits used. The rabbit cornea begins its prenatal development on the twelfth day of gestation. The surface ectoderm differentiates into the corneal epithelium on day 13. Intriguingly, telocytes were visible within the epithelium. The secondary stroma develops on the sixteenth day of gestation by differentiation of keratocytes. At the age of 2 weeks, the lamellae of collagenous fibers become highly organized, and the stroma becomes avascular, indicating that the cornea has become transparent. Bowman's membrane appears on day 23 of pregnancy and disappears on day 30. The Descemet's membrane appears at this time and continues to thicken postnatally. The corneal endothelium appears on the twentieth gestational day as double layer of flattened cells and becomes a single layer of cuboidal cells on day 30. The spaces between the endothelial cells resemble craters. VEGF immunohistochemical expression increases over the course of development, reaching its peak in the first week after birth before decreasing in all corneal layers and becoming negative in the stroma. In conclusion, numerous morphogenetic events contribute to corneal maturation and transparency, allowing the cornea to perform its vital functions.

Effect of cultured white soft cheese on the histopathological changes in the kidneys and liver of albino rats.

Three different types of lactic acid bacteria (Lactobacillus helveticus, Lactobacillus rhamnosus and Streptococcus thermophilus S3855) were used to manufacture white soft cheese. The resultant white soft cheeses were pickled for 28 days at refrigerator temperatures and were fed to the experimental rats. The chemical and microbiological analyses of white soft cheese were conducted at different storage periods (fresh, 7 days, 14 days, 21 days, and 28 days). The pH values and protein content of white soft cheese gradually decreased during the storage peroid. Conversely, the moisture content, titratable acidity, and fat/DM % of white soft cheese were found to increase with of the increase in pickling periods of up to 28 days. Microbiologically, the total viable count of bacteria in the control samples was lower than that in the other treatments. Furthermore, the treatments containing the L. helveticus and L. rhamnosus strains had the highest lactoacilli counts whereas the treatment containing the S. thermophilus strain had the highest streptococci counts. Twenty-five male Albino rats were used for experiemntal technique. Rats were fed with 70% basal diet with addition of 30% white soft cheese. Several pathological findings were present in all experimental groups apart from the control rats, and the kidney samples exhibited renal vascular congestion especially in the cortical area. The changes of the glomeruli comprise atrophy, distortion, hypocellularity of the glomerular tuft, and focal lymphoid cell reactions. The renal tubular epithelium showed a series of degenerative changes ranging up to necrosis. The liver samples showed variable hepatic injury in the form of thickening in the Glisson capsule, as well as dissociation and disorganization of hepatic cords. Hepatocellular vacuolar degeneration, presence of focal areas of nodular hyperplasia, the hyperplastic cells mixed with lymphocytic infiltration, congestion in the portal vein, periportal fibrosis and edema with the presence of newly formed nonfunctional bile ductulus. Based on the histopathology scores, the severity of renal and hepatic changes was significantly increased (P ≤ 0.05) in all of the experimental groups compared with the control group. Generally, the chemical composition, microbiological analysis and vital organs were significantly affected by using cultured white soft cheese.

Histological, histochemical, immunohistochemical and ultrastructural characterization of the testes of the dove.

Avian testes have been used in the study of germ cell transfer, importantly for understanding the preservation and control of birds. For this purpose, we use light microscopy, electron microscopy and immunohistochemistry to understand the reproductive efficiency of dove testes. The tunica albuginea was thin and septula testes were not observed. The testicular parenchyma was formed mainly of closely packed convoluted seminiferous tubules with little interstitial area. Three types of spermatogonia were distinguished. The primary spermatocyte appeared as the largest spermatogenic cell and was identified at different stages of meiosis. Different morphological stages of the spermatid were categorized. Various cellular associations were described within the seminiferous epithelium. The cytoplasm of Sertoli cells was pale and ill defined due to its close relationship to the germinal epithelium. The spermatid attached to the luminal border of Sertoli cells and germ cells were closely associated. A single layer of myoid cells surrounded the seminiferous tubule. Testicular telocytes of doves were located in the peritubular region and near the blood vessels. Telopods appeared as long cytoplasmic processes arising from the cell body. Leydig cells were distributed singly or in small groups and cords. The intensity of androgen receptor (AR) immunostaining in the testes of the dove was established for the first time and is described in this paper.

Distribution of estrogen receptor in the rabbit cervix during pregnancy with special reference to stromal elements: an immunohistochemical study.

The estrogen plays a critical role during pregnancy through their receptors. Although the rabbit is one of the most important lab animal estrogen receptor alpha (ERA) localization on basic cells, newly discovered cells including telocyte and neuroendocrine cells, vascular compartments and interstitium during pregnancy not been described. At 0 day pregnancy, the most prominent immunoreactivity was moderate to ERA and observed on the ciliated cells, secretory cells, blood plasma, and interstitium. The smooth muscles and the endothelial cells showed mild immunoreactivity to ERA. Lymphocytes only exhibited strong immunoreactivity to ERA. At 7 days pregnancy moderate immunoreactivity to ERA observed on ciliated cells, secretory cells, smooth muscles, interstitium, and lymphocytes. Strong immunoreactivity to ERA detected on endothelial cells and blood plasma. At 14 days of pregnancy, the most prominent immunoreactivity was strong and detected on ciliated cells, smooth muscles, lymphocytes, and interstitium. Moderate immunoreactivity detected on endothelial cells and blood plasma. Secretory cells only exhibited mild immunoreactivity to ERA. At 21 days of pregnancy, the immunoreactivity to ERA ranged between mild on ciliated cells, smooth muscles, blood plasma and interstitium and negative on secretory cells, endothelial cells and lymphocytes. Our results indicated that the frequency and intensity of ERA immunostaining in the rabbit cervix varied on different structural compartments of the cervix during different pregnancy stages.