Gulcin Abban

Stem cell support of oogenesis in the human

The possibility that women produce new oocytes post-natally as part of the normal physiological function of the ovary is currently under investigation. Post-natal production of oocyte-like cells has been detected under experimental conditions in the mouse. Although these cells have many characteristics of oocytes, their potential to mature to fertilization-competence was unproven. Zou et al. (Production of offspring from a germline stem cell line derived from neonatal ovaries. Nat Cell Biol 2009;11:631-636) made use of a striking cell isolation and culture strategy to establish cultures of proliferative germ cells from both newborn and adult ovaries. Their cells, referred to as female germline stem cells (FGSCs), proliferate long-term in culture and accept and maintain expression of a transgenic marker, green fluorescent protein. When delivered to the ovaries of conditioned mice, transgene-bearing FGSC engrafted, were enclosed within follicles, and when host females were mated, transgenic offspring were produced. That proliferative female germ cells capable of giving rise to offspring were detected in adult ovaries poses the question of whether they have a physiological role. Here, we discuss Zou et al.s data in terms of our current understanding of mouse ovarian physiology, and how this may relate to human reproductive biology and the treatment of ovarian dysfunction.

Effect of overdose zinc on mouse testis and its relation with sperm count and motility

The purpose of this study was to investigate the effects of excessive zinc intake on the testes and on sperm count and motility in mice. Thirty Balb c mice were divided randomly into 3 groups of 10 animals in each. Group I acted as controls; group II was supplied with drinking water containing 1.5 g/100 mL Zn, and group III was supplied with drinking water containing 2.5 g/100 mL Zn. The animals were sacrificed after 3 wk supplementation and the epididymis and testis were quickly excised. A negative correlation between Zn dose and sperm count and motility was found. The sperm count in group III was significantly lower than in groups II and I (p<0.05). The sperm motility in group III was significantly lower than in the controls (p<0.05). Degenerative changes, including spermatic arrest, degeneration of seminiferous tubules, and fibrosis in interstitial tissue, were observed in group III animals. These results show that high doses of zinc significantly alter sperm motility.

Effect of Vitamin E on Adriamycin- Induced Nephrotoxicity at the Ultrastructural Level in Guinea Pigs

It is known that Adriamycin, which is widely used in the treatment of various neoplastic conditions, exerts toxic effects in several organs. In this study, we have established that vitamin E has some beneficial effects on the kidney by protecting it from some of the toxcity induced by Adriamycin. A study was carried out which comprised one control group and two experimental groups of guinea pigs. In the experiment Adriamycin was administered either alone (group II) or together with vitamin E (group III). The results of groups II and III were compared with controls (group I). The kidneys were subsequently removed and examined by routine electron microscopic techniques. We found that vitamin E administered together with Adriamycin could reverse some of the degenerative changes caused by Adriamycin.

Preventive Effects of Vitamin E Against Oxidative Damage in Aged Diabetic Rat Bladders

OBJECTIVES To examine the effects of aging and/or diabetes mellitus on oxidative stress and the protective effect of vitamin E in the bladder. It was proposed that the balance between oxidant and antioxidant species is important regarding the aging process and prevention of diabetic complications. METHODS Young and aged rats were randomly allotted into six experimental groups: aged control, aged diabetic, aged diabetic and vitamin E-treated, young control, young diabetic, young diabetic and vitamin E-treated. Diabetes was induced by streptozotocin. Vitamin E was administered to the treated groups. Malondialdehyde and reduced glutathione levels were measured in all rat bladders, and histological changes were examined by electron microscopy. RESULTS We found increased malondialdehyde and decreased glutathione levels in the young and aged diabetic groups compared with the nondiabetic control groups. Elevated malondialdehyde and reduced glutathione levels were observed in the aged compared with the young control groups. There were no significant differences in the malondialdehyde and glutathione levels between young and aged diabetic vitamin E-treated groups compared with the related control groups. Degeneration was greatest in the aged diabetic group. The protective effects of vitamin E were seen in young and aged diabetic groups, especially in the young diabetic group. CONCLUSIONS Our results suggest that vitamin E supplementation prevents free radical damage in bladders of young and aged diabetic rats.

Transmission electron microscopy study of the effects of zinc overdose on mouse liver tissue

Thirty adult male mice were divided into three groups. The animals in group I were used as controls and drank only water during the entire period of experimentation. Group II animals drank water containing 1.5 g/100 mL zinc as ZnSO4, and group III animals received 2.5 g/100 mL zinc. After 3 wk supplementation with high doses of zinc, the animals were killed and the livers were removed and examined by electron microscopic techniques.After the supplementation period, the animals in groups II and II showed various degrees of degenerative changes in the hepatocytes, such as increased size and the presence of spaces and an abundance of lipid globules in the cytoplasm. The mitochondria showed a crystalline appearance, a diluted matrix, and dense aggregations. Some smooth endoplasmic reticulum tubules showed dilation and were filled with a dense substance. None of these changes were present in the group I control animals.

Transmission Electron Microscopy Study of the Effects of Cadmium and Copper on Fetal Rat Liver Tissue

During the entire period of their pregnancies, three groups of adult pregnant Wistar albino rats were provided with tap water (control; group I) or with tap water containing 10 mg/kg CdCl2 (group II) or 10 mg/kg CdCl2 plus 10 mg/kg CuSO4 (group III). At term, the animals were sacrificed and the fetal livers were removed and examined under electron microscopy. The liver tissue of the fetuses in maternal groups II and III showed degenerative changes to their hepatocytes. In group II, the smooth endoplasmic reticulum tubules showed dilatation, and the mitochondria showed a dense matrix. In group III, some mitochondrial degeneration was also seen, with a diluted matrix and mitochondrial dilatation. There were also more heterochromatic nuclei and an increased number of ribosomes. None of these histopathological changes were present in the fetal liver samples from the maternal group I control animals.