Selina Aksak

Effects of diabetes and ovariectomy on rat hippocampus (A biochemical and stereological study)

Oxidative stress is one of the main reasons of both menopause and diabetes. So, it plays crucial role in the pathogeneses of that condition and disease. Therefore, the objective of the present study was to investigate the effects of menopause and diabetes upon the hippocampus using a rat model. Adult female Sprague Dawley rats (n = 24) were allocated randomly as follows; control (C group) ovariectomized (O group), diabetic (D group) and ovariectomy plus diabetic groups (DO group) (n = 6; in each group), respectively. For evaluating the results, tissue biochemistry and stereological analysis were made. Biochemistry results (lipid peroxidase (LPO); catalase (CAT); superoxide dismutase (SOD); total glutatyon (GSH); and myeloperoxidase (MPO) values) in Group C-DO were determined as 12.27, 21.88, 23.08 and 29.90 nmol/gr tissue; 59.3, 70.06, 69.7 and 78.1 mmol/min/mg tissue; 174.2, 156.4, 159.7 and 154.6 mmol/min/mg tissue; 3.63, 3.61, 4.21 and 3.97 nmol/mg tissue; and 5.05, 5.68, 5.58 and 6.19 µmol/min/mg tissue, respectively. Moreover, both menopause and diabetes led to change of lipid profiles. There were significant differences between the control and other groups (Group C and D-DO) (p < 0.01) and among experimental groups (p < 0.01) in terms of neuron number. When the volumes of the hippocampus were compared, there were no significant differences between the all groups (P > 0.05). At this point, we suggested that diabetes could aggravate deleterious effects of ovariectomy.

A Stereological Assessment Method for Estimating the Surface Area of Cycloids

OBJECTIVE In this study, we sought to determine differences in estimations of surface area made by classical vertical uniform random (VUR) section series and vertical section series obtained perpendicular to a fixed horizontal plane. MATERIALS AND METHODS One volunteer subject (male, 25 years of age) with no neurological deficit was chosen at random from a bank of controls in the magnetic resonance (MR) image data library of the Department of Radiology. First, a soccer ball with known geometrical features (radius: 9.75 cm) was imaged using a T1-weighted MR scanner at 5-mm thickness (total 40 sections) to test the validity and reliability of surface area and volume measurements obtained via stereological methods. Second, T1-weighted MR section profiles were obtained from a volunteer individual. Surface area and volume estimation procedures were carried out using the Stereo Investigator 6, MicroBright-Field, Inc., USA. CONCLUSIONS We determined that there are no differences in either surface area or volume estimations made using VUR sections and direct vertical sections. We have performed an exhaustive series analysis with a variety of objects.

Peripheral 5-HT7 receptors as a new target for prevention of lung injury and mortality in septic rats.

Sepsis is a complex pathophysiological event involving metabolic acidosis, systemic inflammatory response syndrome, tissue damage and multiple organ dysfunction syndrome. Although many new mechanisms are being investigated to enlighten the pathophysiology of sepsis, there is no effective treatment protocol yet. Presence of 5-HT7 receptors in immune tissues prompted us to hypothesize that these receptors have roles in inflammation and sepsis. We investigated the effects of 5-HT7 receptor agonists and antagonists on serum cytokine levels, lung oxidative stress, lung histopathology, nuclear factor κB (NF-κB) positivity and lung 5-HT7 receptor density in cecal ligation and puncture (CLP) induced sepsis model of rats. Agonist administration to septic rats increased survival time; decreased serum cytokine response against CLP; decreased oxidative stress and increased antioxidant system in lungs; decreased the tissue NF-κB immunopositivity, which is high in septic rats; and decreased the sepsis-induced lung injury. In septic rats, as a result of high inflammatory response, 5-HT7 receptor expression in lungs increased significantly and agonist administration, which decreased inflammatory response and related mortality, decreased the 5-HT7 receptor expression. In conclusion, all these data suggest that stimulation of 5-HT7 receptors may be a new therapeutic target for prevention of impaired inflammatory response related lung injury and mortality.

Comparative study of three angiotensin II type 1 receptor antagonists in preventing liver fibrosis in diabetic rats: stereology, histopathology, and electron microscopy

The presence of liver disease in patients with progressively worsening insulin resistance may not be recognized until patients develop manifestations of the metabolic syndrome such as diabetes, hypertension, hyperlipidemia, and vascular disease. It was aimed to investigate whether three angiotensin II type 1 receptor antagonists (ARBs) (olmesartan, losartan, and valsartan) had preventive effect against hepatic fibrosis and this was a common characteristic among ARBs. In current study, 25 adult male rats were used and divided into five groups: the non-diabetic healthy group, alloxan induced diabetic (AID) control group, AID losartan group, AID valsartan group and AID olmesartan group. According to numerical density of hepatocytes, significant difference was found between the non-diabetic healthy group and diabetic control group. All treatments groups were significant when compared to diabetic control group. In diabetic control group it was examined swelling, irregular cristae arrangement in some of mitochondria. It was also determined mitochondria membrane degeneration in some areas of section profiles. In diabetic rats treated with losartan group, there were necrotic hepatocytes. In diabetic rats treated with valsartan group, predominantly, findings were similar to losartan group. In diabetic rats treated with olmesertan group, plates of hepatocytes were quite regular. There were hardly necrotic cells. Not only other organelles such as RER, SER and lysosom but also mitochondrial structures had normal appearance. In the diabetic control group electron microscopy revealed edema in both the cytoplasm and perinuclear area and the nuclear membranes appeared damaged. In conclusion, it was established that the most protective ARB the liver in diabetic rats was olmesartan, followed by losartan.

Effects of intraocular rifampicin on retinal ganglion cell structure: a stereological and histopathological study

AIM To determine the histopathological changes of rifampicin applied intravitreally on retinal ganglion cells by means of stereological and histopathological methods. METHODS For this study twenty-four New Zealand adult rabbits were divided into four groups (n=6 for each group). 50µg/0.1mL (group 1), 100µg/0.1mL (group 2), 150µg/0.1mL (group 3) and 200µg/0.1mL (group 4), rifampicin were injected into the vitreous of the right eyes of animals, their left eyes were used as control (group 5). After the 28(th) day of application, animals were anesthetised with xylazine (8mg/kg, IM) and then their eyes were enucleated immediately. Patterns were taken away and eyes were prepared for both stereological and electromicroscopic observation. RESULTS Depending on the high dose of rifampicin, some histopathological changes such as cytoplasmic dilatation and damaged membrane were observed on the electromicroscopic level. Using quantitative examination, which was done at the light microscopic level, it was shown that the number of neurons decreased linearly as rifampicin dose increased when compared with the control group. CONCLUSION Based on these findings, low-dose rifampicin (50µg/0.1mL) may be useful for treatment of the ocular diseases.

Östrojen hormonu ve menopoz

RonnekleInsanoglunun en onemli saglik problemleri arasinda olan over yaslanmasi ve menopozla birlikte disi hormon sisteminde duzensizlikler bas gostermektedir. Ostrojen hormonu azalmakta ve buna bagli olarak osteoporoz, kardiyovaskuler rahatsizliklar, Alzheimer hastaligi, artrit, katarakt, over ve kolon kanserleri, diyabet, dis ve cene bozukluklari gibi patolojilerin gorulme sikliginda artis saptanmaktadir. Bu derlemede ostrojen hormonununtemel etki mekanizmalari, hucresel duzeydeki yansimalari ve organizma uzerindeki etkileri hakkinda detayli bilgiyeulasilmasi amaclanmistir. Estrogen hormone and menopause Overian aging and menopause, the most important health problems for human being, cause with these problems a lot of irregulations in female hormone system. The estrogen is decreased and parallel with this situation, some pathologies such as osteoporosis, cardiovascular diseases, Alzheimer’s disease, arthritis, cataract, ovarian and colon cancers, diabetes, teeth and jaw disorders may be seen.This review paper presents detailed information about estrogen’s basic effect mechanisms, its reflection on cellular level and effects on organisms. J. Exp. Clin. Med., 2012; 29:252-256