Anatomical Sciences Journal
Volume:16 Issue: 1, Winter Spring 2019

Despite the significant advances in regenerative medicine, wound healing has remained a challenging clinical problem. Skin is the largest human organ with many vital functions; therefore, any damage to its normal structure should be treated as soon as possible. Easy access to skin stem cells has created a lot of excitement in therapeutic applications. “Cell therapy” is considered a novel method in regenerative medicine, especially when conventional treatments fail. Candidate cell populations for therapeutic applications include embryonic, induced pluripotent, adult mesenchymal, and hair follicle stem cells. It is possible to differentiate stem cells separated from the bulge area of hair follicle into neurons, melanocytes, keratinocytes, glia and smooth muscle cells that are negative for the keratinocyte marker kr15. This review discusses the plasticity of skin stem cells, especially stem cells located in the hair follicle and their involvement in wound healing, gene expression profile in wound healing, hair follicle stem cells, and their surrounding epidermis. Moreover, the ability of hair follicle stem cells for treating wounds and regenerative medicine is going to be discussed. Eventually we suggest the hair follicle as an ideal source of stem cells for cell therapy and regenerative medicine because they are abundant with easy access and great differentiation ability.

Prior qualitative and quantitative studies have reported morphological changes that occur in nerve fibers and non-neuronal cells of peripheral nerve during the lifetime of the rats. Previous studies suggest that Aloe Vera has some beneficial and therapeutic effects such as anti-oxidant effects. In the current study, we have evaluated histological and histomorphometric changes of Sciatic nerve in aged rats treated with Aloe Vera gel extract.

Sixty healthy male albino Sprague-Dawley rats weighing 200-250 g were randomly divided into two groups: control (normal diet), and experimental group (normal diet+Aloe Vera extract). Rats of the experimental group received 400 mg/kg Aloe Vera extract daily. Within 16, 20 and 24 months, animals were anesthetized with sodium thiopental (40 mg/kg) via IP injection. After removal of Sciatic nerve on the left side, nerve dissected and fixed in 4% glutaraldehyde, post fixed in osmium tetroxide 1%, dehydrated and then embedded in TAAB resin. Thin sections (1 μm) were stained with toluidine blue stain and ten slides were obtained from each animal and got examined on light microscope. Masson’s trichrome stain was used to evaluate the development of fibrosis. Histomorphometric and histologic criteria on Sciatic nerve were determined and data were recorded. Data were analyzed using SPSS software. 

Results of the current study confirmed accumulation of collagen in the perineurium by aging. Our data suggested that aging caused a decrease in diameter of nerve trunk and nerve fibers, thickness of myelin and nerve fiber area. The nerve fascicle diameter decreased in the control group, only. The numbers of myelinated fibers with enfolding into the axoplasm and out folding, irregularity of nerve fibers, myelin sheath with unclear boundaries and alteration in myelin compaction were also increased. Treatment with Aloe Vera gel prevented nerve trunk, as well as fiber and myelin thickness changes.

In the current study, we observed some alterations in sciatic nerve caused by aging, such as accumulation of collagen in perineurieum and endoneurieum. Also, a significant decrease was seen in nerve fibers,nerve trunks diameter and myelin thickness which were highly evident in rats of the 24 months age group. Treatment with Aloe vera gel extract improved histological changes and retarded neuropathy signs, significantly.

Mesenchymal Stem Cells (MSCs) are multipotent cells capable of duplication and auto-recovery and distinction from various cells including chondrocytes, adipocytes, chondroblasts, fibroblasts, and osteoblasts. Human stem cells are always subject to local and external mechanical loads. External loads are caused by physical activity in external environment loading to infliction of static and dynamic loads on the body and internal loads are typically caused due to body physiological function. Mechanical factors can affect different parameters such as morphology, proliferation, migration, metabolism and death as well as chemical changes in cells and lead to chemical changes in extracellular matrix and intracellular environment, besides distinction of cells. 

MSCs were isolated from rat’s bone marrow, then cultured in microgravity conditions. Morphologic changes of cells were analyzed by taking pictures at different times.

Results indicated a reduction in cell area and an increase in cell aspect ratio, in microgravity conditions. No significant difference was observed in cell angle of rotation at different time measurements. Also, in measuring viability of these cells using MTT test it was found that microgravity reduces viability of stem cells, considerably. 

Microgravity conditions have a considerable impact on morphology of MSCs. Furthermore, viability of MSCs decreased signi ficantly after 48 h, under microgravity conditions.

Leptin is a critical metabolic signal linking nutrition and reproductive functions. Leptin receptors are expressed in germ cells, Sertoli and Leydig cells. Oxidative stress increases sperm DNA damages. Nitric oxide is a free radical, produced by most cells via Nitric Oxide (NO) synthase and plays stimulatory and inhibitory roles on cells. Physiological concentrations of NO are essential for the biology and physiology systems. However, a low level of NO has a detrimental effect on cells. This study aimed to determine the correlation between seminal and serum leptin and NO in asthenoteratozoospermic men.

Semen and blood samples were obtained from (n=52) males referring to the Arak Infertility Clinic, in Arak City, Iran. We examined each patient for serum hormones (LH, testosterone) by chemiluminescence. Serum and seminal leptin were measured by ELISA and seminal NO was measured by Griess reaction. 

There were differences in serum leptin levels, and total testosterone, LH, and NO concentrations among the 2 groups. Asthenoteratozoospermic groups showed higher testosterone and LH levels than the normozoospermic group. Serum leptin levels of asthenoteratozoospermic men significantly increased in comparison with normozoospermic men. Seminal leptin levels of asthenoteratozoospermic men significantly decreased compared to normozoospermic men. NO levels in asthenoteratozoospermic men significantly decreased in comparison with normozoospermic cases. There were no significant correlations between serum and seminal leptin and seminal plasma NO.

Our results do not support the hypothesis that in vivo serum and seminal leptin affect NO synthesis. Also, our results revealed that nitrite in the seminal plasma is not able to entirely indicate in vivo NO synthesis.

Many previous studies have proved that the anatomical features of cervix can affect the success of artificial insemination. These characteristics differ in sheep breeds. This study aimed to describe the anatomical features of cervix in Zell ewes; the only tailed sheep in Iran.

Eighty nonpregnant and clinically healthy reproductive tracts of adult Zel sheep were collected from a slaughter house. Based on the estrous cycle, the specimens were divided into follicular or luteal phase. Then, the morphology of the vaginal protrusion of cervix was classified as slit, papilla, duckbill, flap or rose. The cervices were sectioned longitudinally, and the length, number of cervical rings and the arrangement of the rings were recorded. 

The results showed the duckbill type was more common in vaginal protrusion of cervix. The mean length of cervix was 61.25±2.88 mm during follicular phase and 63.27±2.56 mm in luteal phase. The mean number of cervical ridges was 7.4 and cervices with a series of complete aligned cervical rings lying across the opened lumen were predominant. However, incomplete ridges and closed cervical canal were observed in some specimens. In 42.85% of cervices, the distance between first and second ridge were significantly more than the distance between other ridges.

The results showed that the anatomical characteristics of cervix in Zel sheep may lower the fertility chance through the Transcervical Artificial Insemination. However, the long distance between first and second cervical fold that has been observed in many cases may be suitable for intracervical insemination.

The morphogenic and histogenetic events of an organ and their time sequencing are basic required information to study factors involved in cells differentiation and evaluating the influence of different agents during the critical period of organ formation. The birds are noted as models in experimental embryologic studies, more than other animals. The present study described the morphogenetic events of pheasant (as a native bird of Iran) esophagus, as a unique investigation. 

We analyzed the pheasant embryos from fifth-24th days of incubation period. After meeting the routine methods of histology laboratory, the slides were stained with Hematoxylin-Eosin, Periodic Acid-Schiff, Alcian Blue, and Van Gieson staining methods. Then, the formation of four layers of primordial esophagus, its epithelial cell differentiation, the separation of lamina propria and submucosa, time of glands formation, their secretion activities and the shape of lumen of gland were studied by a light microscope. 

The data of this study indicated that the most esophageal developmental events of the pheasant occur in the first 2-thirds of the incubation period. The esophageal primordium was noted for the first time on the fifth day of incubation period. The mesenchymal boundary of the esophagus was distinguishable during seventh to eighth days of incubation period. They differentiated the lamina propria and muscular layers during the next 10 days. The epithelial layer of esophagus was gradually differentiated from pseudostratified columnar epithelium (ninth day) into the 2 layered cuboidal (9-10), simple cuboidal (10-12), and the stratified squamous (13th day onward). The esophageal glands were the only structures that began to form in the second half of the incubation period on the 15th day and completed their development on the 21th day. In the present work, the most developmental events were observed in the thoracic esophagus earlier than cervical region.

The comparison of the obtained data with other studied birds shows a general pattern of the esophagus formation among them. However, some differences can be detected in the developmental details and in the time sequencing of the layers. Some of these variations can be related to the differences in the duration of the incubation period among different species.

To attach the fetus to the endometrial epithelium, the endometrium should be affected and allowed by the steroid hormones secreted from the ovary. Thus, the endometrium is then subject to several structural and biochemical changes. Implantation involves the embedment, adhesion and invasion steps that specific receptors are engaged in that. The role of membrane receptors in uterine epithelium is important. Most of these receptors are glycoprotein and among which integrins are of importance. In menstrual period, the uterus undergoes structural changes, so that endometrium is provided for the placenta and the embryo in addition to extracellular matrix, especially fibronectin. 

The animals were anesthetized with ketamine and xylacin intraperitoneally, to perform surgery. After opening the abdomen, the ovaries were removed from both sides. After 72 hours, and observing the vaginal plaque, animals received high doses of ketamine and xylazine. The left uterine horn was removed and placed in fixative solutions and prepared for cutting during the tissue processing of the molds. The slices were stained with PAS to determine the glycoprotein layer thickness. 

There is a statistically significant difference in the increased luminal membrane thickness of glycoprotein layer of endometrial epithelium cells between the Gonal-F receptor groups with hCG, compared to other groups at the same time. 

The study results indicated that Gonal-F and hCG can increase the amount of glycoprotein expression without damaging the endometrial wall.