Mouse ovarian tissue vitrification on copper electron microscope grids versus slow freezing: a comparative ultrastructural study.

There are many reasons, including cancer therapy, for premature ovarian failure and infertility. Oocyte, embryo and ovarian cryopreservation are current options for fertility preservation. Ovarian tissue cryopreservation is essential in patients whose cancer therapy cannot be delayed, including prepubertal girls, and is mostly performed using slow freezing. In the present study, mouse ovarian tissues were vitrified on copper electron microscope grids (n=18) or conventionally slow frozen (n=18). Post-thaw tissues were examined histologically using light and electron microscopy and compared with the control group. According to light microscopy observations, antral follicles were found to be better preserved with the slow freezing technique rather than vitrification. Electron microscopy revealed swollen mitochondria in the oocyte cytoplasm, condensations in the zona pellucida, breakages in the junctions of granulosa cells and vacuolisation in the extracellular space in pathologic follicles, which were relatively more frequent, in the vitrification group after thawing. These results indicate that ovarian slow freezing is preferable than vitrification on copper electron microscope grids, especially for larger follicles. Conversely, vitrification of ovarian pieces using cooper grids is user-friendly and provided good protection for primordial follicles and stromal cells. There is a need for further studies into advanced tissue vitrification techniques and carriers.

Ionic high-osmolar contrast medium causes oxidant stress in kidney tissue: partial protective role of ascorbic acid.

It has been known that contrast medium may cause contrast-induced nephropathy in risk groups. This study sought to establish possible effects of ionic high-osmolar contrast medium administration with or without antecedent cisplatin treatment on oxidant/antioxidant status in rat kidney tissues, as well as to investigate a possible protective role of antioxidant ascorbic acid in this regard. Thirty-five female, 14-week-old Wistar-albino rats were used in this study. They were divided into five groups of seven rats (sham, contrast, contrast + ascorbic acid, contrast + cisplatin, and contrast + cisplatin + ascorbic acid). Ascorbic acid was given in a dose of 250 mg/kg/day orally throughout the study period, and cisplatin (10 mg/kg) as a single i.v. dose on the fourth day. Ionic high-osmolar contrast medium (3 gr/kg iodine as a single dose) was administered by i.v. route on the fifth day. After the animals were sacrificed on the sixth day, their kidney tissues were removed surgically to be used in the analyses. Malondialdehyde (MDA) level and activities of antioxidant (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px] and catalase [CAT]) and oxidant (xanthine oxidase [XO]) enzymes were measured in these samples. Serum urea and creatinine levels were measured to evaluate kidney functions. Histopathological investigation of the tissues was also performed. It was observed that contrast medium administration caused increases in MDA levels in the kidney tissues, either alone or together with antecedent cisplatin treatment. However, ascorbic acid prevented the increases in MDA levels in the kidney tissues. Histopathological findings revealed that ionic high-osmolar contrast medium administration alone led to mild acute structural damage, but contrast medium administration together with antecedent cisplatin usage caused severe tubular necrosis. Ascorbic acid supplementation prevented these changes, to a great extent. The results suggest that ionic high-osmolar contrast medium administration, either alone or together with antecedent cisplatin treatment, leads to accelerated oxidative reactions in rat kidney tissues, and ascorbic acid protects in part the kidney tissues against this oxidant stress.

The ultrastructural research of liver in experimental obstructive jaundice and effect of honey.

BACKGROUND: To examine the effects of honey on oxidative stress and apoptosis in experimental obstructive jaundice model. METHOD: Thirty rats were divided into 3 groups: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BDL followed by oral supplementation of honey 10 g/kg/d. Liver samples were examined under light microscope and transmission electron microscope. Hepatocyte apoptosis was quantitated using the terminal deoxy-nucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Plasma and blood malondialdehyde (MDA) and glutation activities were measured for determining the oxidative stress. RESULTS: The liver levels of MDA and GSH were significantly different between the honey and BDL groups (P = .006 and .001, respectively). However, there was no significant difference between the plasma MDA and GSH levels of these groups (P > .05). In group III, significant reductions in the size of enlarged hepatocytes and the edema were demonstrated. The dilatation of the bile canaliculi dramatically turned to original dimention. By TUNEL assay, it was shown that administration of honey decreased the number of apoptotic cells. CONCLUSIONS: In the present study, we found that honey diminished the negative effects of BDL on the hepatic ultrastructure. We conclude that this effect might be due to its antioxidant and anti-inflammatory activities.

New addition to the statin's effect.

BACKGROUND: Observations in humans and in animal models have shown that statins, besides reducing cholesterol levels and ischemic heart disease, might also reduce the risk of osteoporotic fractures. The purpose of this study was to investigate the effects of simvastatin on fracture healing in vivo. MATERIALS: Fifty-four rats were randomly assigned to one of three groups: the control group and the groups with two doses of 1 mg/d and 2 mg/d drug injected. We performed a closed fracture by digital manipulation on the distal leg of healthy rats under the ketamine anesthesia. Then, rats were injected one time per day on fracture day and by the following 4 days simvastatin to the fractured area into the subcutaneous tissue. On the 7th, 14th, and 21st days, rats from each group were first killed and then after the histologic observation the tibias were examined under light microscopy. Statistical analyses were performed using SPSS 11.5 package program. RESULTS: The simvastatin-injected group went through the stages of fracture faster than the control group did and the osteoid parameter was found to be significantly different (p = 0.001). There was no clear variation between different doses. CONCLUSION: Simvastatin treatment of the fractured bone showed a significant positive effect on fracture healing. In the simvastatin treatment group the formation and differentiation of osteoprogenitor cells were increased in number and were faster than in the control group. As the formation of new capillaries and calcification increased, the healing of the fracture accelerated.

Case report: mesenteric schwannoma.

Schwannomas are benign neurogenic tumors that arise from Schwann cells that line the sheaths of peripheral nerves. Schwannomas are commonly located in the soft tissues of the head and neck, extremities, mediastinum, retroperitoneum, and pelvis, but they are very rare in the mesentery. A 56-y-old man was admitted to the emergency service with nausea, vomiting, acute abdominal pain, and constipation. He reported weight loss and an intra-abdominal mass. On physical examination, the abdomen was distended, and a mass that was approximately 15 cm in diameter was palpated at the middle abdomen. Generalized abdominal tenderness and muscle spasm were noted. Air-fluid levels were seen on plain radiographs. Ultrasonography identified an intra-abdominal mass with intra-abdominal hemorrhage or perforation. Clinical signs and laboratory findings suggested an intra-abdominal mass, mechanical bowel obstruction, and an acute abdomen. The patient underwent surgery. The mass was completely excised and included a 4-cm-long intestinal segment that was densely adherent to the mass. Histopathologic and immunohistochemical examination revealed a mesenteric schwannoma. The patient was well 11 mo after surgery. Although schwannomas are very rare and generally asymptomatic, these tumors can become quite large and may cause acute abdominal problems such as mechanical bowel obstruction.

A new approach to the treatment of osteoporosis.

Osteoporosis remains a significant clinical problem despite the availability of effective therapies. The main therapy still needed is an anabolic agent for the treatment of osteoporosis. This study examined the in vivo effect of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor simvastatin, which controls the first step in the biosynthesis of cholesterol, on bone formation in rats. Histologic specimens were collected 7, 14, and 21 days after administration of 1 mg of simvastatin for 5 days and compared with control specimens for changes in bone tissue. The observed effects on the bone in a healthy animal model included advancement of the blood supply, acceleration of the proliferation and differentiation of osteoprogenitor cells, and formation of osteoid tissue.