---

Introduction: The acute response to renal ischemia-reperfusion injury involves attenuation of glomerular filtration rate, as well as reduced tubular function. The possible mediators involved in ischemia-reperfusion injury include vasoconstrictor agents including angiotensin II (Ang II). Inhibition of the angiotensin II receptor type 1 (AT1) diminishes the deleterious effects of ischemia-reperfusion on glomerular function. This study is done to investigate the effect of angiotensin II receptor type 1 antagonist on renal hemodynamic and tubular responses to ischemia-reperfusion injury in rat. Materials and Methods: In this experimental study, acute renal failure was induced by 30 minutes clamping of both renal arteries in male Sprague-Dawley rats. Renal hemodynamic and excretory function was followed for 120 minutes reperfusion, while saline or the selective AT1 receptor antagonist (Losartan) was infused. In plasma and urine samples, Cr level was measured. Also plasma and urine content of Sodium was measured. Data was analyzed using ANOVA and Duncan tests. Results: Renal ischemia for 30 minutes decreased glomerular filtration rate during reperfusion and increased urine flow and Sodium excretion up to three fold. Losartan (10 mg/kg i.v.) did not change glomerular filtration rate prior to ischemia but improved it during reperfusion and there were progressive increases in urine flow. Losartan caused a lowering of ischemia-induced rise in Sodium excretion. Conclusion: The ischemic challenge may cause release of angiotensin II, which acts on AT1 receptors to decrease perfusion.

---

Background: Pain is an unpleasant feeling which humans experience. It is a warning sign of the damaged tissue. Due to the awful sense of pain, scientists always attempt to relieve it. Retinoic acid (RT), an active metabolite of natural vitamin A has important roles in modulation of the inflammatory responses. The aim of the present study was to analyze the pain threshold of rats which had microinjections of RT, applying acute and chronic models. Methods and Materials: In this study, the tail flick and formalin tests were used to determine pain threshold. In each test, the acute and chronic pain thresholds of 252 Wistar male rats (275 ± 25 gr) were assayed. The druge were injected in the acute model one-dose30 minutes before behavioral testing and in chronic model two-dose for one or two-weeks. The rats of both models divided randomly into six groups (n=7). In four treatment groups retinoic acid (RT) intra cerebro ventricular (i.C.V) were injected as dosagc of 0.5, 3 and 6 (µg/kg) micrograms per kilogram. In control group, was microinjected by ACSF. In vehicle group injected RT solvent (DMSO+ Distil water). Results: The resuits Showed acute injection of RT did not change pain thresholds in the tail-flick methd, but the chronic administration of RT (0.5, 1, 3, 6 µg/kg) reduced tail-flick latencies of the rats (p<0.05) in compare to DMSO group. The threshold of pain in the first phase of formalin test was reduced after injection of 3µg/kg of RT for two weeks. Conclusion: It was concluded that chronic i.c.v. injections of RT can induce significant hyperalgesia in rat.

---

Background: Gastric cancer is a common and lethal disease throughout the world. This study was designed and carried out to determine the five-year survival rate of gastric cancer patients who had undergone surgical treatment at Taleghani Hospital of Tehran, and to assess its associated factors. Materials and Methods: In this historical-cohort study, information obtained from a total of 213 gastric cancer patients who underwent surgery at Taleghani Hospital of Tehran between 2003 and 2008 was included. In the analyses, Kaplan-Meier method, log-rank test, Cox proportional hazards model, and Lin-Ying additive hazards model were used. Results: The five-year survival rate and the median life expectancy in the studied patients were 14.6% and 29.6 months, respectively. Two covariates showed significant impacts on the gastric cancer patients’ data in both models: age at diagnosis and tumor size. We found that pathologic stage was significant under the Lin-Ying model (P=0.043) however, it was not significant under the Cox model (P=0.069). Other clinicopathological characteristics were not statistically significant (P>0.05). Conclusion: Since Cox and Lin-Ying models consider different aspects of the association between risk factors and the study outcome, it seems desirable to use both of them as complementary models but not as alternative models to obtain a more comprehensive understanding of data. This study showed that the early detection of patients in younger ages and in primary stages is important to decrease the risk of death in patients with gastric cancer and to increase the survival rate.

---

Background: Postpartum women are a population at risk for sedentary life. Previous studies have shown that self-efficacy is an important determinant of stage of change and exercise adherence. This study evaluates the relationship between self-efficacy and stage of change and physical activity (PA) behavior in Iranian mothers. Materials and Methods: In this cross-sectional study, 300 postpartum mothers were selected randomly from all health centers in Arak. The instruments used in this study included the 7-day PA recall, stages of exercise adoption tool, and self-efficacy for exercise scale. Data analysis was performed using SPSS software. Results: Ninety-one percent of the participants were in the pre-contemplation, contemplation, and preparation stages of change. Mean score for moderate PA was 38.94±40.5 minutes a week. Significant relationships were found between the stages of PA behavior change and METs of weekly energy expenditure from moderate activities (r=0.60, P<0.001). Also, statistically significant relationships were found between self-efficacy and the stages of PA behavior change (r=0.50, P<0.001) weekly energy expenditure from moderate activities (r=0.40, P<0.001), and pre-pregnancy PA behavior (r=0.39, P<0.001). Conclusion: The level of PA of the participants was less than the recommended minimum level for regular PA behavior (150 minutes of moderately intense PA per week). In this population, self-efficacy plays an important role in PA behavior and it should be taken into consideration in designing interventions for improving PA behavior.

---

Background: International AIDS questionnaire allows for making cross-cultural comparisons between individual’s levels of awareness and attitudes towards AIDS. This study assessed the reliability and validity of international AIDS questionnaire for Iranian student population. Materials and Methods: In this cross-sectional study, 448 students studying in non-medical sciences at universities in Qom were selected through convenience sampling. The participants completed the international AIDS questionnaire–Persian version (IAQ-P). Confirmatory and explanatory factor analysis, Pearson correlation, and Cronbach's Alpha were used in order to examine construct and concurrent validities, respectively. Independent t-test was run to compare the questionnaire scores between male and female participants. Results: The CFA supported the four-factor model, and the normative data showed patterns similar to previous research. Four dimensions of the questionnaire data were satisfactory (AGFI=0.91, GFI=0.93 and RMSEA=0.04, P<0.001). The total IAQ-P had a high internal consistency (Cronbach’s alpha=0.80). Cronbach’s alphas for the sub-scales were 0.78 (myths), 0.78 (attitudes), 0.79 (personal risk), and 0.60 (facts). After one month, test-retest study on a sub-sample of 41 students revealed Pearson correlation coefficient ranges from 0.36 to 0.75 (P<0.001). Conclusion: The IAQ-P was shown to be a valid and reliable instrument and the results of this study are similar to other versions of IAQ in other languages.

---

Background: Gastric cancer is the second leading cause of mortality due to cancer worldwide and it is the most common type of cancer in Iran. The aim of this study was to assess the effects of prognostic factors on the survival of patients with gastric cancer using the penalized spline in Cox model and compare it with Cox proportional hazards model. Materials and Methods: In this retrospective study, information obtained from a total of 216 gastric cancer patients who underwent surgery at Taleghani Hospital of Tehran between 2003 and 2008 years was included. Cox proportional hazards model and penalized spline in Cox model were used. R software was used for data analysis. The efficacy of these models was compared according to Akaike information criterion. Results: The five-year survival rate was 30% and the mean follow-up time was 16.60±15.28 months. Survival mean and median were 46 and 30 months, respectively. The analysis of Cox proportional hazards and penalized spline models resulted in age at diagnosis and tumor size as prognostic factors for survival time (P<0.05). Also, Akaike information criterion and survival curve for patients with a tumor size over 35 mm and age at diagnosis over 45 years were equal in both models. Conclusion: Cox proportional hazards and penalized spline models generated similar results thus, it is more appropriate to use Cox proportional hazards model because of its ease of interpretation and capability of modeling both continuous and discrete covariates. This study also showed if gastric cancer is diagnosed early, the relative risk of death will reduce.

---

Background: Height and weight growth failure are among the most important health disorders affecting children less than two in the developing countries. Failure to treat this disorder can lead to the development of serious conditions including increased mortality and types of disability. The aim of the present study is to investigate the factors affecting the height and weight growth of children less than two years old.

Materials and Methods: This historical cohort study was conducted on a sample of 2030 children less than two in Khorramabad who were selected using stratified and cluster sampling methods. Based on household records, data related to the height and weight were recorded as quantitative variables and finally were modeled using a longitudinal marginal model, identity link functions and the R software.

Results: Based on the marginal model, the effect of such variables as child's age, child's gender and mother's educational attainment were significantly related to the child's height and weight. Moreover the child's birth order had significant relationship with only the child's height. However, the variable of exclusive breastfeeding during the first six months was no significantly related to weight and height growth of the children.

Conclusion: Given the results, it seems that monitoring the growth of the children of the illiterate mothers, specially the girls and the children with first birth orders are the most important approaches to deal with growth disorders among this population.

---

Background: The Amyloid beta (Aβ) level increases in the brain of patients with Alzheimer's disease. The present study aimed to investigate the effects of eight weeks continuous training with low and high intensities on Aβ_1-42 levels in hippocampus of Alzheimer model rats.

Materials and Methods: Fifty male Wistar rats (12 weeks old and mean weight 219.82±13.10 g) were divided into five groups including: healthy control, Alzheimer’s control, Alzheimer's low-intensity training, Alzheimer's high-intensity training and sham. To induce Alzheimer's disease, homocysteine is infused into the rats cerebroventricular (dose of 0.6M). Low intensity groups trained with 20m/min (50-55% VO₂max) and high-intensity groups trained with 27m/min (75-80% VO₂max), 60min/day, and five days per week on the treadmill. For data analysis, one-way ANOVA and post hoc Tukey test were performed (p<0.05).

Results: The Aβ_1-42 levels in hippocampus of Alzheimer's control group was significantly higher than healthy control group (p=0.001) and in training groups with both low and high intensity was significantly lower than Alzheimer's control group (p=0.02). But no significant differences were found between two intensity (p=0.99).

Conclusion: It seems that continuous exercise training, through reducing the level of Aβ_1-42 in hippocampus, can be useful for Alzheimer’s disease model rats and continuous training can be studied as a complementary therapy in Alzheimer's disease.

---

Background:  Schizophrenia is a chronic debilitating psychiatric disorder affecting 1% of the population worldwide. As for key role of free radicals in the development of this disease and that Quince leaf is a natural source of antioxidant substances, this study was aimed to evaluate the protective effects of Quince leaf extract on locomotor activity and anxiety-like behaviors by an intraperitoneal injection of ketamine in male mice in a ketamine model of schizophrenia.

Materials and Methods: In the experimental research, male adult mice were divided into six groups including: control, Sham (received water orally and saline intraperitoneally), psychosis group (received 10 mg/kg/day ketamine i.p. for 10 days) and treated psychosis groups (received 50, 100 and 150 mg/kg/day). Treated groups received hydroalcoholic Quince leaf extract orally for 3 weeks before injection of ketamine. Extract gavages continue for 5 days after the last ketamine injection. Locomotor activity and anxiety-like behavioral changes were measured in the open-field test.

Results: The results showed that chronic administration of ketamine increases horizontal locomotor activity and anxiety like behaviors (p≤0.001) and pretreatment of Quince leaf extract effectively decreases horizontal locomotor activity (p<0.001) and increases duration that spends in middle area of Open field (p<0.01) and vertical ocomotor activity(p<0.001).

Conclusion: The results of this research showed that chronic administration of Quince leaf extract improves locomotor disorder and induced anxiety-like behaviors by having antioxidant properties in a ketamine model of schizophrenia.

---

---