19 research outputs found
The impact of sleep deprivation on sexual behaviors and FAAH expression in the prefrontal cortex of male rats
Sleep deprivation (SD) causes alterations in the function of the endocannabinoid (EC) system and also results in alteration in many behaviors such as increased anxiety, deteriorated alertness, memory deficits, as well as sexual behaviors. Controversial data about the effects of SD on sexual response are provided. Fatty acid amide hydrolase (FAAH), the enzymes involved in the degradation of the EC system play an important role in the function of the EC system. This study aimed to investigate the effect of REM SD (RSD) and total SD (TSD) on the sexual behaviors and FAAH expression in the prefrontal cortex (PFC) of male rats. RSD was carried out through the flower pot technique for 24 h and 48 h, and TSD also was induced by keeping awake the rats by gentle handling for 6 h. Immediately after RSD and TSD, sexual behaviors were recorded for 45 min. Sexual behaviors were reduced by both types of RSD and TSD. The deleterious effects of 24 h RSD were more severe compared with 6 h of TSD. Serum testosterone concentration was significantly higher after TSD but not RSD compared to the normal sleep (NS) group. FAAH expression in the PFC was significantly reduced after both RSD and TSD compared to the NS group. Given that the function of the EC system has been previously shown to change different behaviors such as sexual activity, our results could suggest that behavioral effects of both types of SD on sexual behavior may partially result from activation of this signaling pathway by the reduction of FAAH in the PFC
Predictors of Transition in Different Stages of Smoking: A Longitudinal Study
Abstract
We investigated longitudinally the prevalence of smoking according to three stages of smoking (never smoking, experimenting the smoking, and regular smoking), the rates of transition from one stage to another one, and determinant predictors of transition through these stages of smoking.
Of all 10th grade students in Tabriz, 1785 students were randomly selected and assessed twice, with a 12-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the 10th grade. Logistic regression and principal component analysis were used to analysis data at grade 11.
Of 1785 students, 14.3% (CI 95%: 12.3-16.4) and 2.8% (CI 95%: 2.0-4.0) of the never smokers became experimenters and regular smokers, respectively and 16.5% (CI 95%: 12.4-21.7) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR = 1.24), having smoker friends (OR = 1.85) and a positive attitude towards smoking (OR = 1.22) predicted experimentation; and participating in smokers groups (OR = 1.35) and a lower socioeconomic class (OR = 0.36) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR = 2.56) and participating in smoker groups (OR = 2.58) were distinguished as those who progressed to regular smoking in follow-up.
Programs aimed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages, and targeting participation in smoker groups
Predictors of Transition in Different Stages of Smoking: A Longitudinal Study
AbstractBackground: We investigated longitudinally the prevalence of smoking according to three stages of smoking (never smoking, experimenting the smoking, and regular smoking), the rates of transition from one stage to another one, and determinant predictors of transition through these stages of smoking.Methods: Of all 10th grade students in Tabriz, 1785 students were randomly selected and assessed twice, with a 12-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the 10th grade. Logistic regression and principal component analysis were used to analysis data at grade 11.Findings: Of 1785 students, 14.3% (CI 95%: 12.3-16.4) and 2.8% (CI 95%: 2.0-4.0) of the never smokers became experimenters and regular smokers, respectively and 16.5% (CI 95%: 12.4-21.7) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR = 1.24), having smoker friends (OR = 1.85) and a positive attitude towards smoking (OR = 1.22) predicted experimentation; and participating in smokers groups (OR = 1.35) and a lower socioeconomic class (OR = 0.36) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR = 2.56) and participating in smoker groups (OR = 2.58) were distinguished as those who progressed to regular smoking in follow-up.Conclusion:Programs aimed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages, and targeting participation in smoker groups.Keyword: Smoking, Students, Risk-Taking, Longitudinal Studies, Peer Group, Epidemiology, Prevalence, Risk factor
Comparison of bone regeneration using three demineralized freeze-dried bone allografts: A histological and histomorphometric study in rabbit calvaria
Background: It has been stated that the bone allografts from different tissue banks may lead to various amount of bone induction, so the aim of this study was to evaluate bone regeneration of three demineralized allografts both histologically and histomorphometrically in rabbits calvaria bone defects.
Materials and Methods: In this double-blind randomized experimental animal study, 32 critical size defects (11-mm diameter) in the calvaria of 16 male New Zealand white rabbits were randomly filled with three demineralized freeze-dried bone allografts (DBM, CENOBONE, DEMBONE), while the nongrafted defect was regarded as control group. After 6 and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation and remained graft particles. The data were analyzed by one-way ANOVA with Tukey′s ad-hoc test and t-test. (P < 0.05 was considered to be statistically significant).
Results: Mean percentage of bone formation increased between two healing time, but it was not statistically significant in all groups except DBM which the bone formation significantly decreased (P = 0.04). There were not statistically significant differences between three allografts in remained particles and bone formation in both healing times and they could not induce significantly more bone formation than control group.
Conclusion: Both test and control groups resulted in successful new bone formation. No difference was noted in bone formation and remained particles between three commercial bone allografts. Further studies in this issue may be needed
Cash Effective Tax Rate as a Criterion of Tax avoidance or Earnings Management
The purpose of this paper is to examine whether cash effective tax rate is a suitable criterion for measuring tax avoidance? The sample includes 102 firms (including 714 firm-year observations) with positive pre-tax income and listed in Tehran Stock Exchange (TSE) for the period from 2005 to 2912.
To test hypotheses, panel data method is used. Results suggest that the cash effective tax rate is not a suitable criterion to measure tax avoidance; because, this rate reflects two distinct effects of tax avoidance and upward earnings management at the same time. This is due to the pre-tax income in denominator which can be affected by activities designed to manage pre-tax income. Using this rate for measuring tax avoidance in researches affected also by earnings management, may distort the results
Physical measures for certain class of non-uniformly hyperbolic endomorphisms on the solid torus
Evaluation and comparing the tooth discoloration induced by cold ceramic and MTA Angelus as endodontic cements
Background and Aims: The aim of this study was to investigate the tooth discoloration caused by cold ceramic compared to MTA Angelus in contact with the washing solutions such as sodium hypochlorite (NaOCl) and normal saline.
Materials and Methods: 50 samples of extracted human maxillary anterior teeth were selected. After preparing the access cavity, they were divided into 4 experimental groups and 1 control group (10 in each group). The access cavities of teeth in groups 2 and 4 were rinsed with 5.25% sodium hypochlorite and those in groups 1 and 3 were rinsed with normal saline. Then, after drying, 3 mm thickness of cold ceramic (groups 1 and 2) and MTA Angelus (groups 3 and 4) were placed in the access cavities of the teeth. After setting of the materials, all specimens were restored with a resin modified glass ionomer. Based on the CIE Lab system, each sample’s total color change (∆E) was obtained before, one, and 90 days after application. Data were statistically analyzed using the Wilcoxon test.
Results: According to the results, there was no statistically significant difference in the average tooth discoloration between the groups filled with cold ceramic and in different time periods (P>0.05). While, in the groups filled with MTA Angelus, the difference in the average tooth discoloration in 90 days after application was significantly higher than one day (P<0.05).
Conclusion: The results of this study showed that compared to MTA Angelus, cold ceramic causes less tooth discoloration over time and therefore, it can be suggested as a more suitable alternative endodontic cement than MTA Angelus
Narcotic Alkaloids of Four Papaver Species from Iran
Four native Papaver species of Iran, i. e. P. glaucum, P. tenuifolium, P. dubium and P. fugax, were collected from their natural habitat and subjected to HPLC analysis for determination of their morphine, codeine and thebaine content. P. dubium and P. glaucum contained all of the three mentioned narcotic alkaloids, while morphine was not found in P. fugax, and P. tenuifolium was free from codeine
Factors Related to Marital Satisfaction in Women with Major Depressive Disorder
Objective: Major depressive disorder (MDD) is one of the most common psychiatric disorders which affects married couples frequently.The present study aims to explain the role of family processes, social support and demographic factors in marital satisfaction of women with Major Depressive Disorder (MDD).Method: In this cross-sectional study, 188 women with MDD were randomly selected among the patients who visited Bozorgmehr Clinic of Tabriz University of Medical Sciences. The sample selection was carried out through structured psychiatric interviews based on DSM-TV-TR criteria. Data were collected using Index of Marital Satisfaction (IMS), Family Process Scale (FPS) and Norbeck Social Support Questionnaire (NSSQ).The Mann Whitney U, Multivariate and ANOVA tests were used to analyze the data.Results: No relationship was observed between age, educational level, age difference of couples and number of children with family processes and marital satisfaction (p≥0.05). The patients with low educational level reported less social support (p≥0.05).Marital satisfaction and family coherence were lower when the husband had a psychiatric disorder (P≤0.01). The family processes (family coherence, problem-solving skills, communication skills and religious beliefs) and social support positively predicted marital satisfaction, while the husband's psychiatric disorders negatively predicted marital satisfaction.Conclusion: The findings highlight the significance of family processes, social support and husband's psychiatric disorders in marital satisfaction of women with MDD
The chemokine receptor CXCR4 is associated with the staging of gastric cancer
Background: CXCR4 is a cognitive receptor for stromal-derived factor-1 (SDF-1) and has been previously shown to be associated with tumor growth and invasion of many cancers. However, its expression and function in gastric cancer has not been well clarified.
Materials and Methods: Herein, we studied the expression of CXCR4 on gastric samples from patients with gastric adenocarcinoma in comparison with precancerous lesions by employing qRT-PCR.
Results: Our qRT-PCR data show that CXCR4 is highly expressed in tissue samples from patients with gastric cancer than precancerous lesions (2.4 times higher, P value < 0.05). When we correlated the level of CXCR4 with clinicopathological findings, we observed that CXCR4 level is associated with staging of the disease and lymphatic invasion.
In conclusion: We present evidence that CXCR4 level is significantly elevated in later stages of gastric cancer. Thus, CXCR4 may play a crucial role in gastric cancer progression