43 research outputs found

    Growth assessments of Nicotianatabaccumcv.Xanthitransformed with Arabidopsis thalianaP5CS under salt stress

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    Proline plays important role in osmo-adjusment and prevention of osmotic stress in plants. In order to analyze osmotic stress resistance, germination and growth pattern in vitro and in vivo, the Arabidopsis thalianaδ-1-pyrroline-5-carboxylate synthetase (P5CS) which is the regulatory enzyme of proline biosynthesis, was reverse transcribed, amplified into double stranded cDNA, cloned and transformed into tobacco using Agrobacterium tumefaciens mediated transformation. Seeds of chimeric T0transgenic plants were grown; T1 and the succeeding T2 transgenic plants were obtained. Subsequently, wild type and binary vector transformed control plants along with T2 transgenic lines were exposed to salt concentrations from 0 to 250 mM during germination and growth stages. Results showed a significant difference (P < 0.0001) between T2 and control plants, while the control plants germinated in the presence of salt concentrations up to 50 mM and tolerated 100 mM salt during growth phase. Transgenic T2 lines were able to germinate in 200 mM NaCl and tolerated up to 250 mM salt during growth phase. Assessing proline contents, we observed 7.5 times more proline in T2 transgenic plantsthan control plants in normal condition which increased up to 3.3 folds in stress condition. This osmotic stress resistance was further assessed for T3 generation against drought and salt stresses in vivo. Results indicated osmotic stress resistance of T3 generation as well as stable expression of P5CS along with achievement of homozygous transgenic lines.Key words: δ-1-Pyrroline-5-carboxylate synthetase (P5CS), osmotic stress, transgenic plants, germination, growth phase

    High dose vitamin D supplementation can improve menstrual problems, dysmenorrhea and premenstrual syndrome in adolescents

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    Vitamin D has a crucial role in female reproduction, possibly through its effects on calcium homeostasis, cyclic sex steroid hormone fluctuations, or neurotransmitter function. We have assessed the effects of vitamin D supplementation on dysmenorrhea and premenstrual syndrome (PMS) in adolescents. In this study, 897 adolescent girls living in Mashhad and Sabzevar, Iran, received 9 high-dose vitamin D supplements (as 50000 IU/ week of cholecalciferol) and were followed up over 9 weeks. We evaluated the effect of vitamin D supplementation on individuals in 4 categories: those with only PMS; individuals with only dysmenorrhea; subjects with both PMS and dysmenorrhea and normal subjects. The prevalence of PMS after the intervention fell from 14.9% to 4.8% (P<0.001). Similar results were also found for the prevalence of subjects with dysmenorrhea (35.9% reduced to 32.4%), and in subjects with both PMS and dysmenorrhea (32.7% reduced 25.7%). Vitamin D supplementation was associated with a reduction in the incidence of several symptoms of PMS such as backache and tendency to cry easily as well decrement in pain severity of dysmenorrhea (P<0.05). High dose vitamin D supplementation can reduced the prevalence of PMS and dysmenorrhea as well has positive effects on the physical and psychological symptoms of PMS

    A genetic polymorphism in the CYP1B1 gene in patients with squamous cell carcinoma of the esophagus: an Iranian Mashhad cohort study recruited over 10 years

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    Background: Esophageal-cancer is the seventh most common-cause of cancer-related-deaths in men. Cytochrome-P450-family-1-subfamily-B-polypeptide-1 (CYP1B1) plays a role in the metabolism of xenobiotics, and is associated with several cancers. Here we investigated the association between a genetic-variant, CYP1B1-rs1056836, with the clinical-characteristics of patients with esophagus-squamous-cell-carcinoma (ESCC). Method: 117-patients with ESCC and 208 healthy-subjects were recruited. DNA was extracted and genotyped. Kaplan-Meier curves were utilized to assess overall and progression-free survival. The relationship between clinicopathological-data, disease-prognosis, and survival, were evaluated with the genotypes. Results: the genotypic frequency for GG, GC, and CC were 58.6%, 29.8%, 11.5% respectively in the healthy subjects and 51.8%, 36.14% and 12% in the ESCC group. An association between the GG genotype and stage of ESCC was found. Conclusion: Our findings suggest a relationship between the CYP1B1-rs1056836 genetic polymorphism and clinical features of ESCC, supporting further studies in larger-populations in different-ethnic groups, taking into account potentially important environmental-factors

    The role of mutations in core protein of hepatitis B virus in liver fibrosis

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    The core protein of hepatitis B virus encompasses B- and T-cell immunodominant epitopes and subdivided into two domains: the N-terminal and the functional C-terminal consisted phosphorylation sites. Mutations of the core gene may change the conformation of the core protein or cause alteration of important epitopes in the host immune response. In this study twenty nine men (mean age 40 ± 9 years old) with chronic hepatitis B were recruited for direct sequencing of the core gene. Serum ALT and HBV DNA level were measured at the time of liver biopsy. The effects of core protein mutations on patients' characteristics and subsequently mutations in B cell, T helper and cytotoxic T lymphocyte (CTL) epitopes and also C-terminal domain of core protein on the activity of liver disease was evaluated. Liver fibrosis was significantly increased in patients with core protein mutation (1.0 ± 0.8 vs 1.9 ± 1.4 for mean stage of fibrosis P = 0.05). Mutations in CTL epitopes and in phosphorylation sites of C-terminal domain of core protein also were associated with higher liver fibrosis (P = 0.003 and P = 0.04; Fisher's exact test for both). Patients with mutation in C-terminal domain had higher serum ALT (62 ± 17 vs 36 ± 12 IU/l, p = 0.02). Patients with mutations in B cell and T helper epitopes did not show significant difference in the clinical features. Our data suggests that core protein mutations in CTL epitopes and C-terminal domain accompanied with higher stage of liver fibrosis may be due to alterations in the function of core protein

    Qualitative analysis of Adenomatous Polyposis Coli promoter: Hypermethylation, engagement and effects on survival of patients with esophageal cancer in a high risk region of the world, a potential molecular marker

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    <p>Abstract</p> <p>Background</p> <p>Squamous cell carcinoma of esophagus (SCCE) occurs at a high incidence rate in certain parts of the world. This feature necessitates that different aspects of the disease and in particular genetic characteristics be investigated in such regions. In addition, such investigations might lead to achievement of molecular markers helpful for early detection, successful treatment and follow up of the disease. Adenomatous Polyposis Coli (<it>APC</it>) promoter hypermethylation has been shown to be a suitable marker for both serum and solid tumors of adenocarcinoma of esophagus. We investigated the status of <it>APC </it>promoter hypermethylation in Iranian patients, compared the results with the former studies, and evaluated its applicability as a candidate molecular marker by examining association between survival of SCCE patients and <it>APC </it>promoter methylation.</p> <p>Methods</p> <p>For evaluating the status of <it>APC </it>promoter hypermethylation and its association with SCCE, a qualitative methylation specific PCR (MSP) was used. DNA was extracted and digested with an appropriate restriction enzyme, treated with sodium bisulfite in agarose beads and amplified in two-step PCR reaction by applying either methylated or unmethylated promoter specific primers. Universally methylated DNA and methylase treated blood DNA of healthy donors were used as positive controls as well. Survival of patients was followed up for two years after treatment and survival rate of patients with methylated <it>APC </it>promoter was compared with that of unmethylated patients.</p> <p>Results</p> <p>Assessment of <it>APC </it>promoter methylation revealed that normal tissues were unmethylated, while twenty out of forty five (44.4%) tumor tissues were hypermethylated either in one or both alleles of <it>APC</it>. Among the tissues in which methylation was detected, seven were hypermethylated in both alleles while the other thirteen were hypermethylated in one of the two alleles of <it>APC</it>. Analyzing two-year survival rate of patients with respect to promoter hypermethylation showed a lower rate of survival for patients with methylated <it>APC </it>promoter following their treatment. Further investigation into the association between promoter hypermethylation and tumor differentiation status indicated that patients with well differentiated tumors were more likely to develop promoter hypermethylation.</p> <p>Conclusion</p> <p>Observing similar level of <it>APC </it>promoter hypermethylation in patients with SCCE in this high risk region and comparing it with other parts of the world could support the hypothesis that a common molecular mechanism might be involved in tumorigenesis of SCCE. In addition, the higher rate of two-year survival for patients with unmethylated <it>APC </it>promoter as well as its relationship with tumor differentiation would suggest that this tumor suppressor could be an appropriate candidate molecular marker for evaluating tumor malignancy and predicting survival of patients subsequent to treatment.</p

    Measurement and Evaluation of the Effectiveness Amount of Education System on Brain Dominance Using NedHerrmann Model

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    Nowadays, many researchers examine the causes of the gap of between university and industry. They want to find the effective factors on economic growth that they reach to entrepreneurship for economic growth. So entrepreneurship has a special position in industrious societies. It is introduces as one of the life quality factors in programs of Europe educational commission. This article reply to these questions: Does the difference exist between entrepreneurship management students with other management students? How is brain dominance between students of Tehran university in entrepreneurship management  field with Semnan university students in management field with using of Ned Herrmann ' s four brain quarter model. ? How amount does the teaching system of two universities effect on brain dominance? How is the potential of entrepreneurship in two universities? This research is using of Ned Herrmann ' s four brain quarter model .the results shows the wonderful influence of teaching on brain dominance an good potential on  entrepreneurship in both universities. Moreover, Semnan university students use from the two halves of the brain equally more than Teharn university students

    Source localization algorithms to find attention and memory circuits in the brain

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    Brain is a complex organ and many attempts have been done to know its functions. Studying attention and memory circuits can help to achieve much information about the brain. P300 is related to attention and memory operations, so its investigation will lead to better understanding of these mechanisms. In this study, EEG signals of thirty healthy subjects are analyzed. Each subject participates in three-segment experiment including start, penalty and last segments. Each segment contains the same number of visual and auditory tests including warning, attention, response and feedback phases. Data analysis is done by using conventional averaging techniques and P300 source localization is carried out with two localization algorithms including low-resolution and high-resolution algorithms. Using realistic head model to improve the accuracy of localization, our results demonstrate that the P300 component arises from a wide cerebral cortex network and localizing a definite generating cortical zone is impossible. This study shows that a combination of high-resolution and low-resolution algorithms can be a useful tool for physiologists to find the neural sources of primary circuits in the brain

    Effect of C-peptide on Cognitive Dysfunction and Neuronal Apoptosis Caused by beta amyloid 1-42 in Diabetic Rats

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    Background & Aim: Alzheimer disease is characterized by a progressive loss of memory. Its prevalence in diabetic patients is nearly twice in comparison of others. Recent findings suggest that C-peptide replacement in type 1 diabetes exerts beneficial effects on diabetic rats. We examined the effects of C-peptide on cognitive dysfunction and neuronal apoptosis caused by Aβ 1-42 on working memory in Streptozotocin induced diabetic rats. Methods: In the present experimental study which was carried out in 2009 at Shiraz University of Medical Sciences, 50 male Sprague Dawley rats (230-300 gr) were divided into five groups: control, type 1 diabetic, diabetic groups receiving C-peptide, diabetic group receiving beta amyloid, diabetic group receiving beta amyloid and c-peptide. The Neuronal apoptosis were assessed with tunnel staining. Diabetes was induced with IV injection of Streptozotocin (60 mg/kg). Twenty six days after the onset of diabetes, behavioral tests were conducted for three days. For data analysis, the Tukey and One way ANOVA tests were used. Results: In comparison to control group, in all diabetic groups working memory impairments was observed (P<0.05), but Aβ 1-42 caused severe deficits in the working memory (P<0.001) and C-peptide could significantly decrease the impairment (P<0.05). Only the diabetic beta amyloid group showed significant amount of tunnel positive neuron (P<0.05) and c-peptide replacement significantly decreased the amount of these cells (P<0.05). Conclusion: C-peptide could significantly decrease memory impairment and neuronal apoptosis among diabetic rats

    Internationalization of SMEs and Organizational Factors in Emerging Economies: High –Tech Industry of Iran

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    SMEs as an engine of growth play an important role in emerging economies for poverty reduction, the role which has attracted the attention of scholars in recent years. This study explores the effect of firm characteristics, resources and top management team (TMT) characteristics on the internationalization of SMEs. According to our conceptual model, we assumed that firm resources mediate the link between international performance of SMEs and characteristics of firms and of TMT. To test our model, we asked top managers of international SMEs in Iran ICT sector to fill in a questionnaire. The data was analyzed through structural equation modeling which leads us to codifying a causal model accordingly. The findings show a direct and indirect positive effect of TMT characteristics on internationalization of SMEs, however, it indicates that indirect effect of firm characteristics is not significant. Finally, a set of guidelines are proposed for internationalization of SMEs in emerging economies

    Risk factors and antimicrobial susceptibility in ventilator associated pneumonia: a brief report

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    Background: Ventilator associated pneumonia (VAP) is one of the serious complications of ventilatory support, occurring in ICUs. The aim of this study was to determine various risk factors associated with the acquisition of Acinetobacter infection and its antimicrobial susceptibility pattern.Methods: This cross-sectional study was performed in the ICUs of Rasoul-e-Akram Hospital in Tehran, Iran during the year 2011. A total of 51 endobronchial aspirates from intubated patients who had been clinically diagnosed to have VAP were studied bacteriologically. The in vitro susceptibility was determined by disk-diffusion and broth microdilution MIC methods.Results: Out of 51 patients with VAP, 35 (66.66%) had positive cultures for Acineto-bacter species. In vitro susceptibility test revealed that a high percentage of isolates were resistant to imipenem, piperacillin-tazobactam, third generation cephalosporines, and aminoglycosides.Conclusion: The antimicrobial resistance of gram negative bacteria, particularly Acine-tobacter species, is increasing and preventive measures need to be taken as a matter of urgency
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