Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 Isolation of Nontuberculous Mycobacteria Existing in Isfahan (Iran) Hospital Water Supplies by Phenotypic Method Isolation of Nontuberculous Mycobacteria Existing in Isfahan (Iran) Hospital Water Supplies by Phenotypic Method 2506 2512 13996 FA Davood Azadi MSc Student, Department of Microbiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Ramin Dibaj Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Abbas Daei Naser Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Hassan Shojaei Professor, Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2013 02 05 Background: Nontuberculous mycobacteria are of crucial importance in medicine due to their undisputable impact on human health. Among ecosystem factors, hospital water plays a major role as the inhabitant of mycobacteria and medium for transmission of opportunistic pathogens to a human. In addition, there is increasing evidence showing the correlation of mycobacteria in hospital water and nosocomial infection. Therefore, the aim of the current study was to assess the frequency of mycobacteria in hospital water and identify them according to Runyon classification. Methods: A total of 85 water samples were collected from hospital water resources in Isfahan, Iran. They were transferred to the research laboratory and subjected to filtration and decontamination. They were then subcultured to Lowenstein Jensen media and incubated at various temperatures and inspected weekly for the appearance of Mycobacterium-like colonies. A set of phenotypic tests were finally applied to identify the isolates based on Runyon classification. Findings: Out of 85 water samples, 76 were collected from tap waters and showers used in patient departments and the rest were collected from surface and underground water used in hospitals. Of 40 mycobacteria isolated, 15, 11, and 14 belonged to Runyon's groups of I, II and IV, respectively. Conclusion: The results of the current study showed that a noticeable rate of water resources in hospitals in Isfahan are contaminated with mycobacteria. This can be considered as a potential hazardous source of infection for patients with immunocompromised immune systems such as the elderly, children, and patients with immunodeficiency conditions. Keywords: Nontuberculous mycobacteria, Hospital water, Filtration Background: Nontuberculous mycobacteria are of crucial importance in medicine due to their undisputable impact on human health. Among ecosystem factors, hospital water plays a major role as the inhabitant of mycobacteria and medium for transmission of opportunistic pathogens to a human. In addition, there is increasing evidence showing the correlation of mycobacteria in hospital water and nosocomial infection. Therefore, the aim of the current study was to assess the frequency of mycobacteria in hospital water and identify them according to Runyon classification. Methods: A total of 85 water samples were collected from hospital water resources in Isfahan, Iran. They were transferred to the research laboratory and subjected to filtration and decontamination. They were then subcultured to Lowenstein Jensen media and incubated at various temperatures and inspected weekly for the appearance of Mycobacterium-like colonies. A set of phenotypic tests were finally applied to identify the isolates based on Runyon classification. Findings: Out of 85 water samples, 76 were collected from tap waters and showers used in patient departments and the rest were collected from surface and underground water used in hospitals. Of 40 mycobacteria isolated, 15, 11, and 14 belonged to Runyon's groups of I, II and IV, respectively. Conclusion: The results of the current study showed that a noticeable rate of water resources in hospitals in Isfahan are contaminated with mycobacteria. This can be considered as a potential hazardous source of infection for patients with immunocompromised immune systems such as the elderly, children, and patients with immunodeficiency conditions. Keywords: Nontuberculous mycobacteria, Hospital water, Filtration https://jims.mui.ac.ir/article_13996_e1c2e55cc575a2ccb30e7bbafc011b03.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 Comparative Evaluation of Disk Diffusion and E-Test in Determining the Susceptibility of Helicobacter Pylori to Metronidazole, Clarithromycin and Amoxicillin Comparative Evaluation of Disk Diffusion and E-Test in Determining the Susceptibility of Helicobacter Pylori to Metronidazole, Clarithromycin and Amoxicillin 2513 2519 13997 FA Farzad Khademi MSc Student, Department of Microbiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Jamshid Faghri Associate Professor, Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Farkhondeh Poursina Instructor, Department of Microbiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Masoumeh Madhi MSc Student, Department of Microbiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0002-7003-480X Peyman Adibi Professor, Department of Gastroenterology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0001-6411-5235 Hajieh Ghasemian Safaei Associate Professor, Department of Bacteriology and Virology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2013 01 16 Background: Increasing prevalence of antibiotic-resistant Helicobacter pylori strains have severe consequences. It is also the most important factor in determining the outcome of treatment with antibiotics. Therefore, using reliable, easy, fast, and inexpensive methods to determine of antibiotic susceptibility is crucial. Currently, there is no standard recommended for testing these fastidious organisms and interpretive criteria for determining the susceptibility or resistance of bacteria is not yet standardized. Among conventional methods to assess antibiotic susceptibility of bacteria are modified disk diffusion method (MDDM) and E-test. The aim of this study was to compare the results of MDDM and E-test in determining the susceptibility of Helicobacter pylori to metronidazole, clarithromycin, and amoxicillin. Methods: We collected 30 Helicobacter pylori isolates from biopsy specimens. MDDM and E-test were then used to detect the susceptibility of the isolates to metronidazole, clarithromycin, and amoxicillin. The results were compared according to the Clinical and Laboratory Standards Institute protocols. Findings: In both MDDM and E-test, Helicobacter pylori resistance to metronidazole, clarithromycin, and amoxicillin was 53.3%, 16.6%, and 10.0%, respectively. In addition, the minimum inhibitory concentration was determined for isolates resistant to three antibiotics. Conclusion: MDDM and E-test had similar results regarding the susceptibility of Helicobacter pylori to metronidazole, clarithromycin, and amoxicillin. Thus, for determination of antibiotic resistance of Helicobacter pylori isolates, disk diffusion method could be replaced with E-test. Keywords: Helicobacter pylori, Antibiotic resistance, Modified disk diffusion method, E-test Background: Increasing prevalence of antibiotic-resistant Helicobacter pylori strains have severe consequences. It is also the most important factor in determining the outcome of treatment with antibiotics. Therefore, using reliable, easy, fast, and inexpensive methods to determine of antibiotic susceptibility is crucial. Currently, there is no standard recommended for testing these fastidious organisms and interpretive criteria for determining the susceptibility or resistance of bacteria is not yet standardized. Among conventional methods to assess antibiotic susceptibility of bacteria are modified disk diffusion method (MDDM) and E-test. The aim of this study was to compare the results of MDDM and E-test in determining the susceptibility of Helicobacter pylori to metronidazole, clarithromycin, and amoxicillin. Methods: We collected 30 Helicobacter pylori isolates from biopsy specimens. MDDM and E-test were then used to detect the susceptibility of the isolates to metronidazole, clarithromycin, and amoxicillin. The results were compared according to the Clinical and Laboratory Standards Institute protocols. Findings: In both MDDM and E-test, Helicobacter pylori resistance to metronidazole, clarithromycin, and amoxicillin was 53.3%, 16.6%, and 10.0%, respectively. In addition, the minimum inhibitory concentration was determined for isolates resistant to three antibiotics. Conclusion: MDDM and E-test had similar results regarding the susceptibility of Helicobacter pylori to metronidazole, clarithromycin, and amoxicillin. Thus, for determination of antibiotic resistance of Helicobacter pylori isolates, disk diffusion method could be replaced with E-test. Keywords: Helicobacter pylori, Antibiotic resistance, Modified disk diffusion method, E-test https://jims.mui.ac.ir/article_13997_efe7beaa44d6e14c30432d43b2522ba2.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 Physicians and Nurses’ Awareness of Transmission and Prevention Methods of Congenital Cytomegalovirus Infection Physicians and Nurses’ Awareness of Transmission and Prevention Methods of Congenital Cytomegalovirus Infection 2520 2526 13998 FA Sharareh Moghim Assistant Professor, Department of Bacteriology and Virology, School of Medicine AND Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0002-7134-3145 Muhannad Zanouba Student of Medicine, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Behnoud Hedayatpour General Practitioner, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Bahram Nasr Esfahani Assistant Professor, Department of Bacteriology and Virology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0003-3264-3361 Hossein Fazeli Assistant Professor, Department of Bacteriology and Virology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2013 02 16 Background: Cytomegalovirus (CMV) is the most frequent cause of congenital virus infections. Considering limited treatment options, prevention methods and awareness of CMV are of utmost importance. Methods: This cross-sectional study was conducted in Alzahra Hospital (Isfahan, Iran) during 2010-11. It evaluated physicians and nurses’ awareness of congenital CMV infection. The participants’ age, sex, job and other demographic characteristics were collected using a questionnaire and analyzed with SPSS18. Findings: Of 400 participants, 98 (30 male, 68 female) were physicians and 302 (52 male, 250 female) were nurses. The mean ± SD of age was 36.7 ± 9.1 years. Among male physicians, weak, moderate, and favorable awareness was found in one, 18, and 11 subjects, respectively. While none of the female physicians had weak awareness, 11 had moderate awareness and others had favorable awareness (P = 0.01). In addition 31, 14, and seven male nurses had weak, moderate, and favorable awareness. No female nurse had weak awareness. Moderate and favorable awareness was detected in 83 and 39 female nurses, respectively (P = 0.04). Conclusion: According to results of this study, hospital staff need educations about congenital CMV and its transmission and prevention methods. Keywords: Congenital cytomegalovirus, Transmission methods, Awareness, Prevention methods Background: Cytomegalovirus (CMV) is the most frequent cause of congenital virus infections. Considering limited treatment options, prevention methods and awareness of CMV are of utmost importance. Methods: This cross-sectional study was conducted in Alzahra Hospital (Isfahan, Iran) during 2010-11. It evaluated physicians and nurses’ awareness of congenital CMV infection. The participants’ age, sex, job and other demographic characteristics were collected using a questionnaire and analyzed with SPSS18. Findings: Of 400 participants, 98 (30 male, 68 female) were physicians and 302 (52 male, 250 female) were nurses. The mean ± SD of age was 36.7 ± 9.1 years. Among male physicians, weak, moderate, and favorable awareness was found in one, 18, and 11 subjects, respectively. While none of the female physicians had weak awareness, 11 had moderate awareness and others had favorable awareness (P = 0.01). In addition 31, 14, and seven male nurses had weak, moderate, and favorable awareness. No female nurse had weak awareness. Moderate and favorable awareness was detected in 83 and 39 female nurses, respectively (P = 0.04). Conclusion: According to results of this study, hospital staff need educations about congenital CMV and its transmission and prevention methods. Keywords: Congenital cytomegalovirus, Transmission methods, Awareness, Prevention methods https://jims.mui.ac.ir/article_13998_63e6bc520edcbaa95446b5690d989f30.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 The Association between Metabolic Syndrome and Severity of Esophagitis Caused by Gastroesophageal Reflux Disease The Association between Metabolic Syndrome and Severity of Esophagitis Caused by Gastroesophageal Reflux Disease 2527 2536 13999 FA Ahmad Shavakhi Associate Professor, Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mohammad Minakari Assistant Professor, Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mahsa Khodadoostan Assistant Professor, Department of Internal Medicine, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0002-1499-5390 Leila Ghafouripour Student of Medicine, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2012 06 16 Background: The metabolic syndrome is one of the serious and unresolved public health problems in the world. It is a series of metabolic abnormalities including abdominal obesity, dyslipidemia, hypertension, and hyperglycemia. Using the Adult Treatment Panel (ATP III) definition, approximately 21.9% of Iranian adults living in central Iran have the metabolic syndrome. This syndrome increases the risk of cardiovascular diseases, stroke, type 2 diabetes, and renal complications. It is also known as a risk factor for several gastrointestinal diseases. The present study aimed to evaluate whether the metabolic syndrome and its components are risk factors for erosive esophagitis. Methods: This cross-sectional study included 151 people with heartburn or regurgitation. The patients underwent upper gastrointestinal tract endoscopy. Their blood pressure, blood markers (fasting glucose level and lipid profile), height, weight, and waist circumference were also measured. The relative frequency of metabolic syndrome in patients with and without endoscopic esophageal erosion caused by gastroesophageal reflux disease was then determined based on the obtained information and using SPSS. Findings: Of 151 patients, 36 (23.8%) had the metabolic syndrome [15 (18.3%) without esophageal erosions and 21 (30.4%) with esophageal erosions]. The prevalence of metabolic syndrome in the two groups had no significant difference (P = 0.08). According to Los Angeles (LA) classification, the metabolic syndrome was seen in 18.3% of patients without erosions and in 17.9%, 75%, and 100% of LAA, LAB, and LAC patients (P < 0.001). Conclusion: The metabolic syndrome and its components were associated with increased risk of severe reflux esophagitis. Therefore, patients with digestive discomfort should be evaluated in terms of the metabolic syndrome. Keywords: Metabolic syndrome, Endoscopic esophagitis, Esophageal erosion Background: The metabolic syndrome is one of the serious and unresolved public health problems in the world. It is a series of metabolic abnormalities including abdominal obesity, dyslipidemia, hypertension, and hyperglycemia. Using the Adult Treatment Panel (ATP III) definition, approximately 21.9% of Iranian adults living in central Iran have the metabolic syndrome. This syndrome increases the risk of cardiovascular diseases, stroke, type 2 diabetes, and renal complications. It is also known as a risk factor for several gastrointestinal diseases. The present study aimed to evaluate whether the metabolic syndrome and its components are risk factors for erosive esophagitis. Methods: This cross-sectional study included 151 people with heartburn or regurgitation. The patients underwent upper gastrointestinal tract endoscopy. Their blood pressure, blood markers (fasting glucose level and lipid profile), height, weight, and waist circumference were also measured. The relative frequency of metabolic syndrome in patients with and without endoscopic esophageal erosion caused by gastroesophageal reflux disease was then determined based on the obtained information and using SPSS. Findings: Of 151 patients, 36 (23.8%) had the metabolic syndrome [15 (18.3%) without esophageal erosions and 21 (30.4%) with esophageal erosions]. The prevalence of metabolic syndrome in the two groups had no significant difference (P = 0.08). According to Los Angeles (LA) classification, the metabolic syndrome was seen in 18.3% of patients without erosions and in 17.9%, 75%, and 100% of LAA, LAB, and LAC patients (P < 0.001). Conclusion: The metabolic syndrome and its components were associated with increased risk of severe reflux esophagitis. Therefore, patients with digestive discomfort should be evaluated in terms of the metabolic syndrome. Keywords: Metabolic syndrome, Endoscopic esophagitis, Esophageal erosion https://jims.mui.ac.ir/article_13999_1ad93267910df9c994eae8e51f527c7b.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 New Diagnostic Criteria for Inguinal Hernia Based on Ultrasound Examination New Diagnostic Criteria for Inguinal Hernia Based on Ultrasound Examination 2537 2544 14000 FA Mehdi Karami Assistant Professor, Department of Radiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mohsen Mahmoodieh Assistant Professor, Department of Surgery, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Masood Assarzadegan Resident, Department of Radiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Fatemeh Karami Resident, Department of Radiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Naziheh Assarzadegan General Practitioner, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran Marzieh Mansoori Resident, Department of Radiology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Elham Rabiei General Practitioner, School of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran Journal Article 2011 03 18 Background: According to increasing use of ultrasound in the diagnosis of inguinal herniation, this study was designed to evaluate the cross-sectional area of the inguinal canal in patients with inguinal herniation and its increase with Valsalva maneuver. We also compared the obtained values with those of normal population. Methods: a cross-sectional study, 52 normal persons and 35 cases with inguinal hernia were assessed. The cross-sectional area of the inguinal canal was measured in all subjects and data was analyzed using Student’s t-test and Pearson's correlation tests in SPSS. Receiver operator characteristic (ROC) curves were traced to define cut-off points. Findings: Valsalva maneuver caused significantly greater increase in the cross-sectional area of the inguinal canal among patients than in the normal group. The cut-off point of the cross-sectional area of inguinal canal was 63.5 mm2 in neutral state and 72.5 mm2 with Valsalva maneuver (increase rate: 34 mm2). In the absence of Valsalva maneuver, a cross-sectional area of the inguinal canal of greater than 63.5 mm2 is predictive of inguinal hernia (with 91% sensitivity and 98% specificity). Otherwise, values greater than 72.5 mm2 will be predictive of inguinal hernia (with 100% sensitivity and 98% specificity). Inguinal hernia will also be suspected if Valsalva maneuver increases the cross-sectional area of the inguinal canal by more than 34 mm2 (with 91% sensitivity and 100% specificity). Conclusion: The following diagnostic criteria are suggested for diagnosis of inguinal hernia through ultrasound examination: the presence of bowel loop within the inguinal canal, a cross-sectional area of the inguinal canal > 63.5 mm2 without Valsalva maneuver and > 72.5 mm2 with Valsalva maneuver, an increase of > 34 mm2 in the cross-sectional area of the inguinal canal with Valsalva maneuver, and a > 0.5 cm movement of the spermatic cord with Valsalva maneuver. Keywords: Ultrasound, Inguinal hernia, Inguinal canal Background: According to increasing use of ultrasound in the diagnosis of inguinal herniation, this study was designed to evaluate the cross-sectional area of the inguinal canal in patients with inguinal herniation and its increase with Valsalva maneuver. We also compared the obtained values with those of normal population. Methods: a cross-sectional study, 52 normal persons and 35 cases with inguinal hernia were assessed. The cross-sectional area of the inguinal canal was measured in all subjects and data was analyzed using Student’s t-test and Pearson's correlation tests in SPSS. Receiver operator characteristic (ROC) curves were traced to define cut-off points. Findings: Valsalva maneuver caused significantly greater increase in the cross-sectional area of the inguinal canal among patients than in the normal group. The cut-off point of the cross-sectional area of inguinal canal was 63.5 mm2 in neutral state and 72.5 mm2 with Valsalva maneuver (increase rate: 34 mm2). In the absence of Valsalva maneuver, a cross-sectional area of the inguinal canal of greater than 63.5 mm2 is predictive of inguinal hernia (with 91% sensitivity and 98% specificity). Otherwise, values greater than 72.5 mm2 will be predictive of inguinal hernia (with 100% sensitivity and 98% specificity). Inguinal hernia will also be suspected if Valsalva maneuver increases the cross-sectional area of the inguinal canal by more than 34 mm2 (with 91% sensitivity and 100% specificity). Conclusion: The following diagnostic criteria are suggested for diagnosis of inguinal hernia through ultrasound examination: the presence of bowel loop within the inguinal canal, a cross-sectional area of the inguinal canal > 63.5 mm2 without Valsalva maneuver and > 72.5 mm2 with Valsalva maneuver, an increase of > 34 mm2 in the cross-sectional area of the inguinal canal with Valsalva maneuver, and a > 0.5 cm movement of the spermatic cord with Valsalva maneuver. Keywords: Ultrasound, Inguinal hernia, Inguinal canal https://jims.mui.ac.ir/article_14000_5898493fbdf4a44a24084021b2215f85.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 Evaluating the Relationships between Body Mass Index, Weight, and Bone Mineral Density in Men Using Dual-Energy X-Ray Absorptiometry Evaluating the Relationships between Body Mass Index, Weight, and Bone Mineral Density in Men Using Dual-Energy X-Ray Absorptiometry 2545 2553 14001 FA Mohammad Reza Salamat Assistant Professor, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0002-8994-2541 Iraj Abedi PhD Student, Department of Medical Physics and Engineering, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0001-8094-0438 Amir Hosein Salamat Medical Engineer, University of Birmingham, Birmingham, United Kingdom Ghazal Babanoori Department of Radiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Journal Article 2013 01 28 Background: Body mass index (BMI) is used for the prediction and assessment of bone mineral density (BMD). BMD measurements are useful in the evaluation of the risk of osteoporotic fractures, diagnosis of osteoporosis, and efficient treatment. Methods: In this study, 230 men (age: 50-70 years old) who referred to Isfahan Osteoporosis Center and had BMD scans of hip and lumbar spine were evaluated using a dual-energy X-ray absorptiometry (DXA) system. Findings: Using Pearson's Correlation, we found significant direct relations between BMD of lumbar spine and weight (r = 0.301) and BMI (r = 0.314) and also between BMD of the hip and weight (r = 0.325) and BMI (r = 0.279). Conclusion: BMI and weight had significant direct correlations with BMD of the hip and the spine. Keywords: Body mass Index, Weight, Bone mineral density, Dual-energy X-ray absorptiometry Background: Body mass index (BMI) is used for the prediction and assessment of bone mineral density (BMD). BMD measurements are useful in the evaluation of the risk of osteoporotic fractures, diagnosis of osteoporosis, and efficient treatment. Methods: In this study, 230 men (age: 50-70 years old) who referred to Isfahan Osteoporosis Center and had BMD scans of hip and lumbar spine were evaluated using a dual-energy X-ray absorptiometry (DXA) system. Findings: Using Pearson's Correlation, we found significant direct relations between BMD of lumbar spine and weight (r = 0.301) and BMI (r = 0.314) and also between BMD of the hip and weight (r = 0.325) and BMI (r = 0.279). Conclusion: BMI and weight had significant direct correlations with BMD of the hip and the spine. Keywords: Body mass Index, Weight, Bone mineral density, Dual-energy X-ray absorptiometry https://jims.mui.ac.ir/article_14001_c47a3ba2c793b5b9e21260f903c37d4d.pdf

Isfahan University of Medical Sciences Journal of Isfahan Medical School 1027-7595 30 222 2013 02 19 The Role of Telomere in Cell; Telomere Dysfunction and Tumorigenesis The Role of Telomere in Cell; Telomere Dysfunction and Tumorigenesis 2554 2583 14002 FA Majid Kheirollahi Assistant Professor, Pediatric Inherited Diseases Research Center AND Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mahsa Kolahdouz MSc Student, Department of Genetics and Molecular Biology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Fatemeh Ahangari MSc Student, Department of Genetics and Molecular Biology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Leila Koulivand MSc Student, Department of Genetics and Molecular Biology, School of Medicine AND Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran Fariborz Khorvash Associate Professor, Department of Neurology, School of Medicine AND Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 0000-0002-3293-8891 Journal Article 2012 09 30 Telomeres consist of repetitive DNA sequences and a variety of non-nucleosomal proteins which are essential to survive chromosome. Telomeres protect the ends of chromosomes, but can also inhibit the expression of nearby genes, called telomere position effect. The telomeric cap is a dynamic structure between a fully capped closed and a partially uncapped or open conformation. The protection of chromosome termini from being sensed by the cell as broken DNA is an important function of the telomeres as the capping function. Functional telomeres have a special role in response to DNA damage. The presence of telomere and the length of telomere are two important determinants for binding of chromosomes to the nuclear envelope in meiosis. Future studies about the characteristics of epigenetic factors in telomere length will lead to a better understanding of telomere regulation and its role in human cancers. It seems that telomere dysfunction, rather than telomere length alone, may create insights not only into the pathogenesis, but could also have significant impact on the diagnosis of cancer. Keywords: Role, Telomere, Tumorigenesis, Telomere dysfunction Telomeres consist of repetitive DNA sequences and a variety of non-nucleosomal proteins which are essential to survive chromosome. Telomeres protect the ends of chromosomes, but can also inhibit the expression of nearby genes, called telomere position effect. The telomeric cap is a dynamic structure between a fully capped closed and a partially uncapped or open conformation. The protection of chromosome termini from being sensed by the cell as broken DNA is an important function of the telomeres as the capping function. Functional telomeres have a special role in response to DNA damage. The presence of telomere and the length of telomere are two important determinants for binding of chromosomes to the nuclear envelope in meiosis. Future studies about the characteristics of epigenetic factors in telomere length will lead to a better understanding of telomere regulation and its role in human cancers. It seems that telomere dysfunction, rather than telomere length alone, may create insights not only into the pathogenesis, but could also have significant impact on the diagnosis of cancer. Keywords: Role, Telomere, Tumorigenesis, Telomere dysfunction https://jims.mui.ac.ir/article_14002_86158a6b3924670a32dad65bbc41bd95.pdf