Endothelium-dependent effect of sesame seed feeding on vascular reactivity of streptozotocin-diabetic rats: underlying mechanisms

Cardiovascular disorders continue to constitute major causes of morbidity and mortality in diabetic patients. In this study, the effect of chronic administration of sesame [Sesamum indicum L] seed feeding was studied on aortic reactivity of streptozotocin [STZ]-diabetic rats. Male diabetic rats received sesame seed-mixed food at weight ratios of 3% and 6% for 7 weeks, one week after diabetes induction. Contractile responses to KCl and phenylephrine [PE] and relaxation response to acetylcholine [ACh] and sodium nitroprusside [SNP] were obtained from aortic rings. Maximum contractile response of endothelium-intact rings to PE was significantly lower in sesame-treated diabetic rats [at a ratio of 6%] relative to untreated diabetics and endothelium removal abolished this difference. Endothelium-dependent relaxation to ACh was also significantly higher in sesame-treated diabetic rats [at a ratio of 6%] as compared to diabetic rats and pretreatment of rings with nitric oxide synthase inhibitor, N[G]-nitro-l-arginine methyl ester [L-NAME] significantly attenuated the observed response. Two-month diabetes also resulted in an elevation of malondialdehyde [MDA] and decreased superoxide dismutase [SOD] activity and sesame treatment significantly reversed the increased MDA content and restored activity of SOD. We thus conclude that chronic treatment of diabetic rats with sesame seed could in a dose- manner prevent some abnormal changes in vascular reactivity through nitric oxide and via attenuation of oxidative stress in aortic tissue and endothelium integrity is necessary for this beneficial effect

Nitric oxide-induced polycystic ovaries in the wistar rat

Nitric oxide [NO] involves in polycystic ovary syndrome [PCOS], a cause of infertility in women during the reproductive age. The PCOS is now categorized as an inflammatory phenomenon. The aim of this study was to evaluate the role of NO, a proinflammatory agent, in this syndrome at histological and biochemical levels. In this experimental study, animals were female Wistar rats [weighing 200-250 g] kept under standard conditions. L-Arginine [50-200 mg/kg], a precursor of NO, was injected intra-peritoneally [i.p.] through a period ranging from 9 to14 days/ once a day. The rats' estrous cycle was studied using Papanicolaou test; those showing phase of Diestrous were grouped into experimental and control groups. The control group solely received saline [1 ml/kg, i.p.] throughout all experiments. To evaluate the inflammatory effect of NO, the rats were treated an anti-inflammatory agent, naloxone hydrochloride [0.4 mg/kg, i.p.], prior to L-arginine. At the end of the treatment period all animals' ovaries were assessed for histopathological and histochemical investigations. Also, activation of NO synthase [NOS] in the experiments was studied using NADPH-diaphorase technique. The ovaries of rats treated with L-arginine showed polycystic characteristics in contrast to those collected from control or naloxone pretreated groups, based on image analysis. A difference in enzyme activation was also shown in the sections that belonged to the groups that received L-arginine when compared with the pre-naloxone and control groups. Based on these results, we believe that NO may play a major role in the pathophysiology of PCOS

Difference in epidemiology and antibiotic susceptibility of methicillin resistant and methicillin susceptible Staphylococcus aureus isolates

Antimicrobial resistance of Staphylococcus aureus especially methicillin resistant S. aureus [MRSA] continues to be a problem for clinicians worldwide. Although difference in epidemiology and antibiotic susceptibility of methicillin resistant S. aureus [MRSA] and methicillin susceptible S. aureus [MSSA] isolates has been proposed by investigators, few data have been reported to now. Disk diffusion method was used for determination of in vitro susceptibility of S. aureus isolates to 15 antibiotics. Susceptibility pattern of 192 non-duplicates S. aureus isolated from clinical specimens in four university hospitals in Tehran, from November 2007 to August 2008, were compared. In addition, distribution of MRSA and MSSA isolates were investigated in different specimens, on various wards, and in different age groups. MRSA isolates were constituted 49% of all isolates. While only 1.7% of the MSSA isolates were multidrug resistant, all of MRSA were shown resistance to at least five antibiotics. Majority of isolates from patients >/= 65 years old were MRSA and prevalence of methicillin resistance was highest among S. aureus isolated from respiratory specimens. Also, MRSA appeared to be more prevalent in intensive care units and operation wards than in other departments. This study has shown a relationship between methicillin resistance and resistance to other antibiotics in S. aureus isolates. Also, considerable differences were observed in epidemiology of MRSA and MSSA isolates

Expression of MDM2 gene in primary breast cancer and it's, relationship with prognostic factors

The breast cancer is the most common malignancy in women. MDM2 expression is determined in some carcinomas, sarcomas, leukemias,and breast cancer. The purpose of this study was to determine the expression of MDM2 gene in primary breast cancer and it's relationship with grade, stage and axillary lymph node involvement. the study was the cross-sectional one, that was performed on 75 samples of patients with breast cancer admitted in Mostafa Khomeini hospital Tehran, Iran [2000-05]. After preparing the samples, a tissue section from each samples was obtained. One of the tumoral sections and one of the lymph node sections were stained by H and E. We determined the type of the tumor, the number of lymph nodes, the stage and the grade of the tumor. We studied MDM2 with polyclonal antibody by IHC. The mean +/- SD of patients were 54 +/- 12.5 years old. 69.3% of patients had lymphoid involvement. 32% of samples were positive for MDM2. 58.7% of samples were in stage II and the most of patients [42.7%] were in grade III. In this study, there was not any relationship between MDM2 and tumor grade, but there was a relationship between stage of tumor and lymph node involvement with MDM2 gene [P < 0.05]. This study showed that MDM2 gene is a prognostic factor in breast cancer