Prenatal developmental sequences of the esophageal epithelium in the New Zealand white rabbits: Light and electron microscopic analysis.

Several morphogenetic sequences occur during esophageal development and birth defects occur due to defects in foregut morphogenesis. This work aimed to record the cellular events in the morphogenesis of rabbits' esophageal epithelium. On the 16th day of gestation, the esophageal epithelium varied from stratified ciliated columnar to stratified squamous type. The surface epithelium presented mucous cells with mucigen granules of various sizes occupying their supranuclear cytoplasm. Cytoplasmic vacuolation was evident in all layers of the esophageal epithelium at this age. On the 18th gestational day, some light cells could be detected in the middle portion of the epithelium, while others occupied the whole epithelial length. On the 21st day, mucous cells are more frequently observed at the apical esophageal part as well as at the surface epithelium. Numerous elongated dark cells could be distinguished embedded between the basal cells. On the 24th gestational day the number of the mucous cells reached its peak. Reaching the 30th gestational day, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased. Collectively, detection of surface mucous and dark cells together with the non-cornified surface in some regions of the rabbit esophageal epithelium at the end of gestation ensure a postnatal development to reach the adult epithelium essential to sustain the passage of the harsh raw food. Future immunohistochemical studies are recommended to investigate the components of secretions in mucous cells and functional studies to highlight the dark cells significance. RESEARCH HIGHLIGHTS: Esophageal epithelium of fetal rabbit was analyzed by light and transmission microscopy. Surface epithelium presented mucous cells with mucigen granules of various sizes. They reached their maximum number on 24th day then decreased. On the 16th day, cytoplasmic vacuolation was evident in all epithelial layers. On the 21st day, numerous elongated dark cells could be distinguished embedded between the basal cells. Before birth, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased.

Ovary of Zebrafish during Spawning Season: Ultrastructure and Immunohistochemical Profiles of Sox9 and Myostatin.

This study sought to examine the ovarian cellular and stromal components of the zebrafish (Danio rerio) throughout the spawning season using light and electron microscopic tools. The ovaries of zebrafish showed oocytes in all stages of follicular development and degeneration (atresia). Six stages of oogenesis were demonstrated: oogonia, early oocytes, late oocytes, vacuolated follicles, the yolk globule stage (vitellogenesis), and mature follicles. The SOX9 protein was expressed in the ooplasm of the primary and previtellogenic oocytes and the theca cell layer of the mature follicles. Myostatin was expressed in the granulosa and theca cells. Many stem cells in the ovarian stroma expressed myostatin and SOX9. During the spawning season, the EM results indicated that the zona radiata increased in thickness and was crossed perpendicularly by pore canals that contained processes from both oocytes and zona granulosa. The granulosa cells contained many mitochondria, rER, sER, and vesicles. Meanwhile, the thecal layer consisted of fibroblast-like cells. Atretic follicles could be demonstrated that involved both oocytes and their follicular walls. Several types of cells were distinguished in the ovarian stroma, including mast cells, telocytes, lymphocytes, fibroblasts, endocrine cells, macrophages, adipocytes, dendritic cells, and steroidogenic (stromal) cells. The ovary of the zebrafish serves as a model to investigate follicular development.

In Vivo Wound-Healing Effect of Chemical and Green Synthesized Chitosan Nanoparticles Using Lawsonia inermis Ethanolic Extract.

Wounds can be a result of surgery, an accident, or other factors. There is still a challenge to find effective topical wound-healing agents. This study aims to investigate the wound-healing activity of chemical and green synthesized chitosan nanoparticles (Ch-NPs) using Lawsonia inermis leaves extract. The nanoparticles were morphologically and chemically characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (HRTEM). Forty-five adult female albino rats were randomly divided into three groups. The cutaneous surgical wounds were topically treated with 0.9% normal saline (control group), green Ch-NPs (second group), and chemical Ch-NPs gels (third group), respectively. The clinical picture of wounds and histopathological changes were assessed on the 3rd, 7th, 14th, and 21st days post-treatment. X-ray diffraction analysis revealed great crystallinity and purity of nanoparticles. The studied nanoparticles increased the wound contraction percent (WC%), reduced healing time and wound surface area (WSA), and these results were backed up by histological findings that indicated improved epithelialization, dermal differentiation, collagen deposition, and angiogenesis in treated rats compared with control rats (p < 0.05). We concluded that the wound-healing effects of the studied nanoparticles are encouraging, and further studies for complete assessment are still needed.

Catfish Epidermal Club Cell Morphologic and Immunologic Attributes: Heterogeneous S-100 Immunoreactivity and Possible Neuroendocrine Function.

The fish epidermis (EP) contains several cell types, and it has several functional roles, though the secretory role prevails. The alarm or epidermal club cells (ECCs) represent a voluminous immune cell secreting an alarm substance. Our work targeted the histochemical and immunologic attributes of the ECCs in catfish. Matrix metalloproteinase (MMP-9) immunostaining revealed strong immunoreactive signals in the cytoplasm of all ECCs, while S-100 protein immunoreactivity selectively marked the ECCs. Individual ECCs exhibit intense S-100 immunoreactivity compared to neighboring ECCs. The difference in the intensity of the S-100 immunostaining was associated with the difference in the ECC size. This was confirmed by the semithin results where several developmental stages of ECCs could be distinguished. Some eosinophilic granular cells with their characteristic metachromatic granules were recorded juxtaposing the ECCs. Moreover, some free electron-dense granules could be demonstrated in the intercellular spaces surrounding the ECCs. Collectively, these findings suggest several functional profiles for the catfish ECCs depending on their developmental stage. Most importantly, S-100 immunoreactivity in the ECCs suggests its neuroendocrine function. Moreover, the difference in the intensity and polar distribution of S-100 staining is a sign of its role in the differentiation of the ECCs.

Mapping the Distribution of Special Structured Pulmonary Vasculatures in the Dromedary Camel (Camelus dromedarius): Histological and Histochemical Study.

Dromedary camel (Camelus dromedarius) is adapted to survive the harsh environments. It has some key adaptation peculiarities in various organs. In this study, we aimed to map the distribution pattern of unique regulatory devices along the course of the pulmonary vessels using histological and histochemical analyses. Arteries with variable wall thickness and spirally oriented course were recorded within the adventitia of the main pulmonary artery. Throttle arteries and glomus bolsters were found within the wall of the lobar pulmonary artery. The bronchial artery was located within the wall of all bronchi reaching the subsegmental branches and it had elastic longitudinal muscular intima bolsters. Arteries with double muscular media were demonstrated in the pulmonary pleura. These bolsters are suggested to play a complicated role that allows for hemodynamic, humeral, and thermoregulatory activities. The lumen of some subsegmental pulmonary veins revealed occasional constrictions arising from the corresponding muscular pad-like protrusions of the tunica media. These veins may possess occlusive or constrictive mechanisms and their obstruction induces engorgement of the associated capillary bed in addition to restricting venous outflow. Collectively, these data strongly recommend a crucial role for the special regulatory devices in preserving the camel pulmonary function in the harsh desert environment.

Pulmonary Guardians and Special Regulatory Devices in the Lung of Nile Monitor Lizard (Varanus niloticus) with Special Attention to the Communication Between Telocyte, Pericyte, and Immune Cells.

Monitor lizards are acclimatized to a variety of environments. Most of the monitor species are terrestrial, although there are arboreal and semiaquatic monitors. Such accommodation requires unique cellular structure and regulatory devices in various organs, particularly their lungs. This study aimed to report the pulmonary guardians and special regulatory devices that may guard and promote the function of the lungs of the Nile monitor lizards (Varanus niloticus). Specially structured vessels were recorded in the pulmonary tissue involving atypical glomus vessels, vessels with variable wall thickness, and a venule with specialized internal elastic membrane. Moreover, numerous lung resident guardians could be identified including both alveolar and interstitial macrophages, dendritic cells, mast cells, and B- and T-lymphocytes. Pericytes were demonstrated surrounding the capillary endothelium with a characteristic direct hetero-cellular junction with telocytes. Telocytes established a microenvironment through an indirect hetero-cellular junction with the interstitial macrophage, dendritic cells, and pneumocyte type II. Collectively, these data indicate a significant role played by the specially structured vessels and the resident immune cells in guarding the pulmonary tissue of the Nile monitor lizards and promoting its function. Telocytes are suggested to play a key role in angiogenesis and cellular communication to promote the function of the immune cells.

Migrating and Nerve Fibers-Associated Eosinophilic Granule Cells in the Olfactory Organ of Catfish (Clarias garpienius): Light and Electron Microscopic Evidence.

Piscine mast cells or eosinophilic granule cells (EGCs) of fish are equivalent to the mammalian mast cells. Recently, a better understanding of EGCs functions is allowed because of the growing interest in fish models. Herein, we present a trial to furnish data regarding the distribution of the EGCs in the fish olfactory organ, an issue that has not been reported so far. Regarding their distribution, two kinds of EGCs had been identified. An intra-epithelial one was detected in the olfactory epithelium lining of the olfactory lamellae. The stromal one was identified in the connective tissue core of the olfactory lamellae and in the lamina propria underlying the olfactory epithelium. Some were detected in the capillary lumen. The cytoplasm of the EGCs reacted strongly with the MMP-9 antibody. Stimulating a migration perspective for the olfactory EGCs which was confirmed by their location in the blood capillaries. Several EGCs could be verified in close relation, some underneath the epineurium, with the nerve fiber. Mutually, this verifies the existence of intra-epithelial and stromal migrating EGCs in the catfish olfactory organ and their inclusion in the olfactory immune response. Additionally, this provides evidence for an immune­nervous interaction to influence both the immune reactions and the nervous scheme in catfish.

Tramadol Biological Effects: 4: Effective Therapeutic Efficacy of Lagenaria siceraria Preparation (Gamal & Aref1) and Melatonin on Cell Biological, Histochemical, and Histopathological Changes in the Kidney of Tramadol-Induced Male Mice.

Tramadol is used worldwide and is listed in many medical guidelines to treat both acute and chronic pains. There is a growing evidence of abuse of tramadol in some African and West Asian countries. Tramadol has some side effects. The present study designed to follow up the treatment of the cellular responses which might be induced in the kidney of tramadol mice. Treated mice received daily injection of tramadol dose (125 µg/100 g b.wt) for 20 and 40 days. Other mice received tramadol for 40 days and then were divided into three groups: the first received distilled water, the second received Lagenaria siceraria, and the third received melatonin daily for 40 days. Both the daily injection of tramadol for 20 and 40 days resulted in radical, extensive, and severe alterations in the normal histological architecture of the kidney. Treatment with Lagenaria siceraria or melatonin after tramadol administration for a long-term, markedly changed the collagen content and other chemical components, that may reach nearly normal levels. Such findings propose that although tramadol has many cytological and histopathological side effects on the kidneys of male mice, the treatments via Lagenaria siceraria and melatonin have effective therapeutic impacts on the tramadol side effects.