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Background: Vasomotor disorders are one of the most painful menopausal complications that negatively affect the quality of life in menopausal women. This study investigated the effects of omega3 fatty acid on vasomotor disorders in menopausal women. Materials and Methods: This randomized, double-blind, placebo-controlled clinical trial study was done on 83 menopausal women aged 45-60 years that had met the inclusion criteria. The participants were randomly assigned to omega3 or placebo groups. Fish oil capsules (containing 300 mg of omega3) or placebo capsules were prescribed to the participants one capsule a day for 8 weeks. Of the 83 patients enrolled, 68 completed the study (omega3 supplement, n=34 placebo n=34). Data collection was done through demographic questionnaire, daily self report, and food frequency questionnaire (FFQ). Data were analyzed by t-test, Chi square, Fiedman, and Mann-Whitney tests using SPSS software version 18. Results: After 8 weeks of intervention, there was a significant difference in HF frequency (p=0.003) and nightsweats frequency (p=0.001) between the two groups. There was no significant difference in HF intensity between the two groups (p=0.2) but reduction of nightsweats intensity was significant between the two groups (p=0.003). Conclusion: Omega3 affected the reduction of HF frequency and nightsweats frequency and intensity but it did not have a significant effect on the severity of HF.

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Background: TEM, PER, and VEB are extended-spectrum betalactamase (ESBL) enzymes that are capable of hydrolyzing penicillins, cephalosporins, and aztreonam. The aim of this study was to determine the prevalence of ESBL producing E.coli and molecular evaluation of TEM, PER, and VEB β-lactamases among E.coli strains. Materials and Methods: A total of 200 clinical strains of E.coli were isolated from clinical specimens and their antibiotic susceptibility was determined by disk diffusion method. ESBL production was determined using the combined disk method with CAZ and CTX with clavulanic acid and alone. Minimum concentration inhibition (MIC) for CAZ and CTX with clavulanic acid and alone was determined by agar dilution method. Finally, PCR with specific primers was used for determining the presence of blaTEM, blaPER, and blaVEB genes. Results: Combined disk method confirmed 94 strains (47%) to be ESBL producing E.coli. Of the 94 ESBL producing strains, 36 samples had MIC=16, 44 samples had MIC between 32-256, and 10 samples had MIC≥512 for ceftazidime, whereas 8 samples had MIC=16, 68 samples had MIC between 32-256, and 21 samples had MIC≥512 for cefotaxime. The frequency of TEM was 44% however, blaPER and blaVEB genes were not detected by PCR among ESBL producing isolates. Conclusion:The results indicated that the high percentage of ESBL producing E.coli is 47% and PCR method showed a high frequency of TEM enzyme, but PER and VEB betalactamase were not found among them.

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Background: H. pylori infection is common worldwide involving 50% of the general population. The aim of this study was to compare the effect of two sequential regimen therapies on the eradication of H. pylori. Materials and Methods: In this clinical trial, 150 patients were allocated to two groups of 75 each: group A and group B. The eradication of H. pylori in groups A and B was based on azithromycin and ofloxacin sequential regimens, respectively, and the results were compared between the groups. The data were analyzed by t-test, Chi-square test, and Fisher’s exact test using SPSS software version 16. Results: Mean of the patients’ age was 39.3± 1.2 within the age range of 18 to 85 years. There were not significant differences between the two groups considering the type of peptic ulcer. In group A, Urea Breath Test (UBT) was negative in 67 (89.3%) patients while in group B, it was only positive in 8 (10.7%) patients. In group B, there were 64 (85.3%) negative and 11 (14.7%) positive UBT test results. There were no significant differences in H. pylori eradication rates between the two groups (P=0.31). Conclusion: Noticing the absence of a significant difference between the two groups in terms of H. pylori eradication, it can be concluded that ofloxacin-based drug regimens have no superiority over azithromycine-based regimens and each regimen can be prescribed considering drug complication rates in different patients.

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Background: Enterococcus is known as an important pathogen in Iran like all around the world. The increasing use of vancomycin makes vancomycin-resistant enterococci (VRE) an important nosocomial pathogen. Vancomycin in combination with an aminoglycoside can provide effective treatment for severe enterococcus infections, while resistance to vancomycin antibiotic is increasing in enterococci. In this study, the pattern of antibiotic resistance and prevalence of vancomycin resistance enterococci have been explored. Materials and Methods: In this experimental study, after isolating and identifying 150 strains of enterococci from clinical specimens, the antibiotic resistance pattern of these strains to erythromycin, teicoplanin, vancomycin, ciprofloxacin, tetracycline, gentamicin, co-trimoxazole and linezolid was examined. The MIC test by using micro dilution broth method was performed for the vancomycin resistance enterococci specimens with the vancomycin and teicoplanin antibiotics. Results: Antibiotic susceptibility test showed 14% and 5.3% of the samples were resistant to vancomycin and teicoplanin respectively. Resistant to erythromycin, co-trimoxazole, ciprofloxacin, tetracycline, linezolid and gentamicin were 64, 40, 38.6, 6.6, 0, 38.76 percent respectively. Fourteen samples had high resistance to vancomycin which MIC were ≥ 256 µg/ml. Conclusion: Based on the results of present study, there are vancomycin-resistant enterococci in Arak as well as other parts of the world. The percentage of vancomycin resistance enterococci is high in Arak and appropriate treatment of infections caused by enterococcus is essential

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Background: Diabetes mellitus is one of the most important health problems in the world. B-cells are susceptible to damage by free radicals. Noticing the mechanism of cupping, this study was carried out to evaluate the effect of cupping together with drug therapy on biochemical factors and oxidative stress. Materials and Methods: In this clinical trial, 5ml of intravenous blood was obtained from diabetic patients in beginning and late stages of this disease who referred to a diabetes center. In addition to receiving metformin and glibenclamide, the patients underwent cupping after one month and were analyzed one month later. Blood samples obtained one month before and after the treatment were compared in terms of diabetes and oxidative stress indicators. To evaluate lipid peroxidation, TBA method was used and FRAPS method was employed to measure total serum antioxidants and blood factors by Pars Azmon kit. Results: Hemoglobin A1C, fasting blood sugar, blood sugar 2 hours after fasting, triglycerides, cholesterol, and low-density lipoprotein as well as high-density lipoprotein showed significant increases. Aspartate transferase in diabetic patients significantly decreased after phlebotomy (p<0.05). Conclusion: Cupping improves blood factors in diabetic patients and it is recommended to be used as a complementary treatment in patients with diabetes type II.

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Background: Epidemiological studies have shown the relationship between incidence of asthma symptoms and environmental factors, such as sedentary lifestyle and metabolic and cardiovascular diseases. However, the role of exercise rehabilitation protocols on lung function in obese adult patients with chronic asthma is a controversial issue. The aim of the present study is to evaluate the impact of aerobic exercise on lung function in obese middle-aged men with chronic asthma. Materials and Methods: This semi-experimental study was conducted on 39 obese middle-aged males with mild and moderate asthma. The experimental group (n=19) with regard to the safe range 15≥ RPE>9 followed the sub-maximal rehabilitation exercise program (50 to 80% HRmax intensity) for 3 months. Then, they underwent one month of detraining. The control group (n=20) did not have any form of aerobic exercise. Spirometric parameters in base, three months of training, and one month of detraining were measured by standard methods. Results: Indicators of lung function, including FVC, FEV1/FVC, PEF, FEF%75, and MVV significantly decreased. The pattern of changes in FEV1, FEV1/FVC, and MVV remained stable even after a month of detraining (p<0.05). However, no significant changes occurred in the dependent variables of the control group (p>0.05). Conclusion: It seems that the incidence of physiological adaptations of aerobic exercise, as a non-pharmacologic clinical factor, after the one-month detraining period affected the spirometric parameters in obese asthmatic patients

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Background: Nowadays, the elderly population is growing all over the world. Diseases and conditions resulting from this evolutionary process can severely affect the quality of life of the elderly. Therefore, the aim of this study was to determine the effect of educational programs of healthy lifestyle on the quality of life of the elderly in Arak city.

Materials and Methods: This quasi-experimental was carried out on 60 elderly subjects in Arak city. The subjects participated in classes on nutrition, exercise, sleep hygiene, and life skills for a month and they were followed for three months after intervention. Data were collected by the short form quality of life (SF-36) in elderly.

Results: The mean score of quality of life was 61.06±7.42. The highest mean was associated with social health (74.5±15) while the lowest mean was for physical health (46±17). In terms of quality of life indicators before educational intervention, four categories emerged: poor (13.3%), medium (30%), good (41.7%), and high (15%). After intervention, the majority of the samples fell in the good (38.3%) and high (45%) categories. There was a significant difference before and after the educational intervention (p<0.001).

Conclusion: Education to elderly about the healthy lifestyle practices can prevent a lot of problems and help them to improve their quality of life. Therefore, classroom education is fruitful for this group that is often neglected.

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Background: Load lifting is the most stressful activity of the Manual Material Handling and can trigger of work-related musculoskeletal disorders of workers. Purposes of this study are determining the prevalence of musculoskeletal disorders, assessment lifting tasks by NIOSH lifting equation method, ergonomic design and assessment of its effectiveness.

Materials and Methods: This analytical and interventional study was performed on 30 workers in a Porcelain Health Manufacturing industry in Hamadan. Assessment of lifting tasks by NIOSH lifting equation and determining the prevalence of musculoskeletal disorders by Nordic questionnaire was conducted. Then, construction steps and determination of the effectiveness of ergonomic design was conducted.

Results: The results showed that the most frequent musculoskeletal disorders related to back. Results of the lifting index (LI) showed that the risk of lifting load in before intervention is high (greater than 3). This value after the conducting of ergonomic intervention (load-carrying cart) decreased to moderate level (between 1 to 3). The relationship of risk average amount before and after interventions were significant (p<0.001).

Conclusion: Load-carrying cart designed with shelves capable of moving vertically up and down has considerable role in safe making of lifting tasks and probability of reduce the prevalence of musculoskeletal disorders and lumbar injuries will bring in the near future.

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Background: Factor XIII deficiency is an extremely rare, autosomal recessive coagulation disorder with estimated prevalence of 1/2000000 worldwide. This disorder represents with different clinical manifestations including, umbilical cord bleeding, recurrent abortion and CNS bleeding. CNS bleeding is a common but life threating complication of disease. The aim of this study was to evaluate the effect of a common polymorphism of thrombin activatable fibrinolysis inhibitor (TAFI) occurrence of CNS bleeding in patients with severe factor XIII deficiency.

Materials and Methods: This case control study was performed on 34 patients with factor XIII deficiency and history of CNS bleeding and 36 patients with factor XIII deficiency but without CNS bleeding as control group. Initially all patients were molecularly analyzed for factor XIII deficiency, then both groups were assessed for common TAFI Thr325Ile polymorphism. Finally obtained data was analyzed by SPSS software.

Results: Molecular analysis of TAFI Thr325Ile polymorphism revealed that almost all patients with CNS bleeding (89%) had this mutation that in 67% of patients was homozygote. There is a significant relationship between Thr325Ile polymorphism in homozygote manner with incidence of CNS bleeding in factor XIII deficient (OR 18.9, 95% CI 3.8 to 95.1).

Conclusion: It seems that Thr325Ile polymorphism is a suitable prognostic factor in patients with severe factor XIII deficiency and this probably polymorphism increases risk of CNS bleeding about 20 fold.

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Background: According to the studies, Iran’s per capita antibiotic consumption is remarkable. Since the emergence of Antibiotic Resistant Organisms (AROs) is considered a global problem in the community and hospitals, this study aimed to investigate the pattern of antibiotic resistance in Gram-negative bacteria isolated from patients in an academic and a non-academic hospital in Arak, Iran.

Materials and Methods: This descriptive cross-sectional study included all specimens referred to the microbiology laboratory at Amir Al-Momenin Hospital (academic hospital) and Imam Khomeini Hospital (non-academic hospital) in a one-year period from June 2012 to June 2013. The susceptibility of the isolated Gram-negative bacteria against the important antibiotics used in clinical practice was determined using the disk diffusion method.

Results: A total of 846 specimens were collected from patients in the two hospitals where 520 (61.5%) were Gram-negative bacteria, of which 63.3% were E. coli. The prevalence of Gram-negative organisms in the academic and the non-academic hospital was measured 79.8% and 20.2%, respectively (p=0.097). It was also determined that there is a significant difference between the two hospitals in the prevalence of ESBL (Extended-Spectrum Beta-Lactamase) Gram-negative bacteria (p=0.003).

Conclusion: There was a significant difference between the two hospitals in the prevalence of ESBL Gram-negative bacteria. Therefore, conducting regional surveillance programs to examine the patterns of antibiotic resistance is recommended.

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Background: Allergy is regarded as a multifactorial condition that its onset and severity are influenced by both genetic and environmental factors. Hence, identification of genetic factors involved in allergic rhinitis development and its related phenotypes is a major task in understanding the genetic background of allergic rhinitis. This study was designed to examine the association between IL-18 -607 A/C promoter polymorphism on chromosome 11q22 and allergic rhinitis.

Materials and Methods: In this analytic study, genomic DNA was obtained from the blood samples of 293 patients with allergic rhinitis and 218 healthy controls by standard phenol chloroform method. The IL-18/-607 A/C polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. To analyze the association between genotypes and alleles and the disease in the case group compared with the control group, X2 test was used.

Results: The frequency of the AC genotype of the IL-18/-607 A/C gene polymorphism was significantly greater in allergic rhinitis patients than in controls (p<0.05). By comparing the frequency of AA genotype with other genotypes, OR was calculated as 2.03.

Conclusion: The results suggest that IL-18/-607 A/C polymorphism gene may be one of the factors participating in the pathogenesis of AR or its intermediary phenotypes.

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Background: Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children. Currently, chemotherapy is the most effective method of leukemia cancer treatmentwhich has many side effects. New strategies in cancer therapy utilizecompounds that specifically target aberrant signaling pathways in order to reduce toxic sideeffects Indole-3-carbinl (I3C) found in vegetables has multiple anti-cancer properties because of its ability to modulate multiple cellular signaling pathways. In this study the molecular mechanism of the action of indole-3-carbinol on pre- B ALL cells was investigated.

Materials and Methods: In current study, NALM-6 cells were treated with different concentrations of I3C at specific times. Analysis of cellular DNA content was performed by flow cytometry for evaluation of cell cycle status. The protein expression of p21, p53 as well as c-Myc proteins was determined by Western blot in I3C-treated cells.

Results: Cell cycle histogram analysis showed that I3C significantly increased the percentage of G1 cells compared with non-treated cells (control)(p<0.05). The western blot analysis also indicated I3C significantly up regulated p21, p53 expression and down regulated c-Myc expression (p<0.05).

Conclusion: The G1 arrest induced by I3C is associated with down-regulation of c-Myc and up-regulation of p53 and its downstream target p21.

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Background: This study aimed to examine the antibacterial effect of Polyamidoamine-G4 dendrimer on Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus.

Materials and Methods: In this experimental study, the antibacterial effects of Polyamidoamine-G4 dendrimer were studied by disc diffusion and micro-dilution method. Different concentrations of Polyamidoamine-G4 inoculated onto blank disks and were placed in Mueller-Hinton agar media. Zone of inhibition was investigated by bacterial inoculation according to the McFarland standard 0.5. Minimum inhibitory concentration and minimum bactericidal concentration of Polyamidoamine-G4 dendrimer were determined by micro-dilution method in nutrient broth culture.

Results: Zone of inhibition in concentration 500 &mug/ml of Polyamidoamine-G4 dendrimers for Escherichia coli, Enterobacter cloacae, Bacillus subtilis and Staphylococcus aureus were 14, 0, 35 and 29mm, respectively. Concerning the Zone of inhibition in gram negative bacteria with gram positive ones was p<0.05 and had significant difference. The minimum inhibitory concentration of Polyamidoamine-G4 dendrimer for Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 1250, 2.5, and 1 &mug/ml, respectively. The minimum bactericidal concentration of Polyamidoamine-G4 dendrimer belonged to Escherichia coli, Bacillus subtilis and Staphylococcus aureus were 2500, 5 and 5 &mug/ml, respectively. Polyamidoamine-G4 dendrimer had not bacteriostatic and bactericidal effects on Enterobacter cloacae.

Conclusion: According to the results, Polyamidoamine-G4 dendrimer can eliminate Escherichia coli, Staphylococcus aureus and Bacillus subtilis effectively. It is suggested in the rest of this study that the probable toxicity of nanostructured compounds examined in drinking water and, economic studies is done for synthesis and their applications in case of prevention of using.

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Background: Heat shock proteins (HSP) can act as a cellular protection by facilitating reconstruction of denatured proteins. The aim of this study is evaluation of protective effects of glutamine consumption on HSP70 and cortisol response.

Materials and Methods: In this experimental study, 28 soccer players divided into 4 groups: control (n=7), supplement (n=7), exercise (n=7) and exercise supplement (n=7). Supplements (glutamine) and placebo (Dextrin) to a 0.5 gram per kg of body weight and volume of 5 ml per kg of body weight one hour prior to the exercise protocol was used. exercise protocol include a 3-stage 20-minute run at 80% of maximum heart rate and rest 5 minutes. Blood samples of basal (after 12-14 hour overnight fasting), post exercise, and 90 minutes after exercise were gathered and HSP70 of serum and cortisol were measured with Elisa and RIA respectively. Data were analyzed with multivariate repeated measures (MANOVA) at p&le0.05 level.

Results: There was significant difference in HSP70 amounts between supplement group and exercise supplement group compared to the control group (p&le0.09, p&le0.019) and also supplement group with exercise supplement group (p&le0.032). Also there was significant difference Between post exercise and 90 min after exercise stages compared to basal stage (p&le0.08, p&le0.06) and between post exercise and 90 min after exercise (p&le0.030). In cortisol amounts between basal and 90 min after exercise stages (p&le0.026) there was significant difference.

Conclusion: Glutamine sitimulate of HSP70 induction and combination of supplement with exercise has a great HSP70 response thus athletes who wish to compete or have intense exercise, glutamine consumption is recommended.

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Background: The outbreaks of new antigenic variants of influenza viruses in human populations have increased necessity the improvement of controlling programs. Influenza vaccines are formulated with adjuvant to enhance and direct the host immune responses. Currently, much effort is devoted to designing molecular adjutants. Hemokinin-1 (HK-1) activates T and B cells for proliferation, survival, differentiation into plasma cells, and antibody production. In this study, the effect of HK-1 as a molecular adjuvant for inducing humoral immune response against influenza virus was investigated.

Materials and Methods: The HK-1 coding sequence was cloned into pcDNA3.1 vector and used as adjuvant. Groups of mice were immunized with an inactivated influenza vaccine formulated with HK-1. The sera of vaccinated mice were collected prior to priming and boosting injections and at defined weeks, and analyzed with serological assays.

Results: The results showed that HK-1 was able to increase antibody titer against virus vaccine. The mice immunized with the adjuvanted vaccine produced higher antibody titers against influenza comparing to vaccine alone immunized group. Number of boosting had no effect on the enhancing of antibody titer.

Conclusion: These data revealed that HK-1 as a molecular adjuvant induces stronger humoral and memory responses against influenza immunization.

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Background: Doxorubicin is a chemotherapeutic agent still in widespread use in hematologic malignancies. A side effect of anthracyclines such as doxorubicin is the activation of nuclear factor-&kappaB (NF-&kappaB), a potent inducer of antiapoptotic genes, which may blunt the therapeutic efficacy of the drugs. In this study, the effect of indole -3-carbinol (I3C) on the activation NF-&kappaB and the anti-apoptotic genes whose expression is regulated by NF-&kappaB was assessed in NALM-6 cells.

Materials and Methods: NALM-6 cells were preincubated with various concentrations of I3C and then treated with doxorubicin. Cellular DNA content assay and Annexin V-FITC staining were performed by flowcytometry for evaluation of apoptosis. For assessing the effect of I3C on the expression of XIAP, survivin, and nuclear p65 proteins, NALM-6 cells were pretreated with I3C and then incubated with doxorubicin. Whole-cell and nuclear extracts were prepared for Western blot analysis. A paired t-test was conducted to evaluate the results.

Results: DNA histogram analysis of NALM-6 cells indicates a combination of I3C with doxorubicin significantly escalated the percentages of sub-G1 population cells compared with doxorubicin - only treated group (p<0.05). Annexin V-FITC staining also showed that cotreatment of NALM-6 cells with I3C and doxorubicin significantly increased the proportion of Annexin-V positive cells in comparison with the doxorubicin treated cells (p<0.05). The western blot analysis indicated I3C significantly inhibits both doxorubicin -induced nuclear translocation of p65 and the expression of doxorubicin-induced NF-&kappaB target.

Conclusion: Our results indicated that using natural non-toxic inhibitors of NF-&kappaB such as I3C in combination with anthracyclines might be a rational combination therapy for BCP-ALL cells in which NF-&kappaB is constitutively active.

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Background: Unpleasant side effect of awareness within general anesthesia is potentially an important concern in patients. The patient may sleep during anesthesia and feels the pain due to loss of pain suppression of sensory perception of pain during surgery. The aim of this study is to determine the effect of BIS monitoring on level of awareness during anesthesia in women undergoing elective caesarean section.

Materials and Methods: In this double-blind, randomized clinical trial, 214 ASAI–II patients, over 15 years of age, candidate for elective cesarean section were included in the study. Patients randomly divided to two groups of anesthesia with and without BIS monitoring. Patients were assessed for awareness within anesthesia immediately, 24 hours, and 3-6 days after operation.

Results: From 107 patients without BIS monitoring, 8 patients (7.4%) suffered from awareness during anesthesia and their awareness score was two and greater than two. While none of the patients in the BIS group experienced awareness during anesthesia. Level of awareness during anesthesia in the control group was significantly more than the BIS group (p<0.0000).

Conclusion: The incidence of awareness during anesthesia is significantly lower in BIS monitored group than the control group.

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Background: Allergic rhinitis, a chronic inflammatory disease of the respiratory tract, includes an IgE-mediated inflammatory response in the mucosal region of the aerial tubles. Since IL-8 plays a role in increasing the amount of immunoglobulin E and serves as an effective factor in the prevalence of this disease, so this study aims to investing at that whether IL-8 genotypes of 133 C/G polymorphism is associated with the amount of immunoglobulin E in serum in patients with allergic rhinitis.

Materials and Methods: In this analytical and descriptive study, by investigating 130 patients with AR and 62 healthy control volunteers in Chahar Mahalo Bakhtiari province, total level of IgE in serum was determined by ELISA method and then its association with 133 C/G polymorphism was investigated. T-test and chi-square statistical analyzes were performed using SPSS software for statistical analyses.

Results: the total serum IgE level of the patients with GC genotype of 133 C/G SNP were significantly higher regarding normal individuals (p<0.05).

Conclusion: The sigmificant relationship between 133 C/G genotype in IL-8 P gene promoter and increased serum IgE level confirms tht it plays a role in the prevalence of AR.

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Background: Atrial fibrillation (AF) is the most common complication after coronary artery bypass graft surgery (CABG). This complication causes an increase in morbidity and mortality after CABG and also increases the length of ICU stay and hospitalization. The aim of this study is to evaluate the prophylactic effect of amiodarone in reducing the incidence of post CABG atrial fibrillation.

Materials and Methods: In this clinical trial study, 204 patients, candidate for elective CABG, entered the study according to inclusion and exclusion criteria, and randomly divided into two equal groups. The case group received 300 mg of intravenous amiodarone before anesthesia induction and the control group received normal saline. Incidence of AF was recorded until 24 hours after CABG.

Results: The incidence of post CABG AF was 16 patients in the case group and 35 patients in the control group. Comparison of the frequency of AF between groups by Chi square analyses showed a significant difference (p=0.037) and the incidence of AF was significantly lower in the amiodarone group.

Conclusion: In total, amiodarone could significantly prevent the incidence of atrial fibrillation after coronary artery bypass surgery. In this study, patients took this medication only in the first 24 hours, while in some studies, this drug has been prescribed for even 14 days.

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        Background: Dendrimers are a subset of branched structures that have certain structural order. The aim of this study was to investigate the performance of Polypropylenimine-G2 (PPI-G2) dendrimers in removal of Escherichia coli, Proteus mirabilis, Bacillus subtilis and Staphylococcus aureus from aqueous solution .

        Materials and Methods: In this experimental study , initially dilution of 10³ CFU/ml was prepared from each strain of bacteria . Then , different concentrations of dendrimers (0.5, 5, 50 and 500 µg/ml) was added to water . In order to determine the efficiency of dendrimers in removal of bacteria, samples were taken at different times (0, 10, 20, 30, 40, 50 and 60 min) and were cultured on nutrient agar medium . Samples were incubated for 24 hours at 37 ° C and then the number of colonies was counted .

       Results: By the increasment of dendrimer concentration and contact time , the number of bacteria in aqueous solution decreased. In times of 40 , 50 and 60 minutes, and the concentrations of 50 and 500 µg/ml, all kinds of bacteria in aqueous solution were removed . 0.5 µg/ml of dendrimer concentration had not effect in reducing the number of Escherichia coli and Proteus mirabilis . The effect of dendrimer on gram-negative bacteria was weaker than gram-positive bacteria.

       Conclusion: Results of this study indicated that PP I -G2 dendrimer is able to remove Escherichia coli , Proteus mirabilis , Staphylococcus aureus and Bacillus subtilis in aqueous solution. However, using dendrimers can be considered as a new approach for drinking water disinfection but it requires further wide range studies.