Tehran University Medical Journal

Background: Welding generates complex metal aerosols, inhalation of which is linked to adverse health effects among welders. Exposure to manganese (Mn) fume in welding processes can have a harmful effect on welders’ health. Long-term, high-level exposure to Mn is associated with impaired central nervous system (CNS) function. The present study aims to investigate relationship between exposure to manganese in welding fumes and incidence of migraine headache symptoms.
Methods: This cross-sectional analytic study was conducted in March 2017 in an Iron Smelting Industry. Forty welders were selected as the exposure group and thirty-five employees were selected from the administrative unit as the control group. Data related to symptoms of migraine headache were collected using with Ahvaz migraine questionnaire (AMQ). Air samples were collected on mixed cellulose ester membrane filters in personal air samplers and then analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES) (NIOSH Method 7300).
Results: The average concentration of welder’s exposure to manganese was 7.24±2.91 mg/m3, which is very higher (37 times) than the occupational exposure limit (Threshold limit value-time-weighted average). There was no significant difference between the mean age and work experience of the two groups (P<0.05). Comparison of the mean of migraine headache symptoms in the two groups of welders and office workers also showed that the frequency of these symptoms among welders was significantly higher than those reported by administrative staff (P<0.05). The correlation between the frequency of symptoms of migraine headache and the concentration of manganese in the air of the welders’ respiratory area was statistically significant (P<0.05).
Conclusion: Frequency of migraine headache symptoms was higher among welders compared to control group. Statistically the significant relationship was found between airborne Manganese concentration and occurrence of migraine headache; however, a conclusive conclusion is based on more comprehensive studies with larger sample size.

Considering the advancement of medical sciences, diagnostic tests have been developed to distinguish patients from healthy population. Therefore, Determining and evaluation of the diagnostic accuracy tests is of great importance. The accuracy of a test under evaluation is determined through the amount of agreement between its results with the results of the gold standard, and this test accuracy can be defined based on sensitivity, specificity, positive predictive value, negative predictive value and the area under the receiver operative characteristic curve (AUC). Gold standard is an accurate and error- free method to determine the presence or absence of disease of interest and classify patients, which is not available in some diseases and situations as this method is costly or invasive. In these cases, reference standard is a best available replacement method to be used by physicians to diagnostic disease. However, in some situation, the acceptable reference standard is invasive or costly and does not exist or unreliable. It can be imperfect and results of the reference standard method are not necessarily error- free and cannot be applied to everyone in the study; all these cases point to the conditions in which the gold standard is not available. The use of reference standard including error causes to incorrect separation of patients from healthy population and thus, it cannot be a comparing measure for other diagnostic tests and its results are inaccurate. Therefore, other alternatives methods are needed for evaluation and determine the diagnostic accuracy tests when the gold standard does not exist. Imputation method, correct imperfect reference standard method, the construct reference standard method, latent class models, differential verification, composite reference standard and discrepant analysis are of these alternative methods. Each of these methods, considering its features, advantages, and limitations can be used to evaluate the accuracy of diagnostic test in the absence of gold standard. The present study gave an overview of methods to evaluation of diagnostic accuracy tests when there is no gold standard and the focus of this study was on explain the concept of these solutions, review and compare them and their strengths and weaknesses.

Background: Staphylococcus aureus is a common pathogen in human that can be the cause of a wide range of infectious diseases including bacteremia, pneumonia, cellulitis, and osteomyelitis and skin and soft tissue infections. The coagulase enzyme is one of the most important virulence factors of this bacterium. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) Coa pattern is one of the molecular base typing methods. Molecular typing plays an important role in epidemiological studies of nosocomial infection, such as methicillin-resistant Staphylococcus aureus (MRSA) infection. The PCR-RFLP Coa gene technique provides a useful preliminary method to monitor variations in MRSA populations. We were done Coa-RFLP typing according to the method of Hookey et al., with some modifications.
Methods: In this cross-sectional study, one-hundred fifty isolates of S. aureus from urine and blood samples of patients that collected from educational hospitals of Imam Hossein and Al Zahra Isfahan University of Medical Sciences, Iran, from February 2018 to October 2018 were analyzed. After bacterial confirmation of isolates by Coa gene in polymerase chain reaction (PCR) technique, to perform coagulase gene typing, the repeated units encoding hypervariable regions of the coagulase gene of S. aureus were amplified by PCR. This was followed by AluI restriction enzyme digestion and analysis of restriction fragment length polymorphism (RFLP) patterns.
Results: Of 150 samples, 45 isolated of S. aureus were confirmed by biochemical methods. Of previous positive samples, 36 (80%) isolates carried Coa gene. Two different genotypes of Coa gene were obtained that include bp680 fragment in 20 specimens and bp750 fragment in 16 specimens. After enzymatic digestion by AluI restriction enzyme for RFLP, four different restriction patterns were obtained that including, the 280+400 pattern in 16 specimens (44.4%), 280+470 pattern in 7 specimens (19.4%), 340+340 pattern in 6 specimens (16.6%) and 750 patterns without digestion were in 7 specimens (19.6%).
Conclusion: Using the present experiments, it was determined that the PCR-RFLP pattern, 280+400, was the dominant pattern in the Staphylococcus aureus samples isolated in Isfahan.

Background: Infective endocarditis occurs due to the presence of microorganisms in the endocardium or the heart valves. Nowadays, infective endocarditis is still a major cause of death with an incidence rate of 5 to 7.9 per 100,000 populations. The aim of the study was to determine antibiotic resistance pattern of bacterial agents isolated from blood culture of patients with infective endocarditis.
Methods: In this retrospective study, infective endocarditis patients who were admitted to Sina and Ekbatan hospitals in Hamadan City, Iran, from March 2005 to February 2014, were enrolled. All demographic data, clinical manifestations, physical examinations and echocardiography reports of the patients were recorded in a check list. For all patients, blood cultures in Mueller Hinton agar and antimicrobial susceptibility testing for ceftriaxone, ceftazidime, oxacillin, cefazolin, vancomycin, imipenem, clindamycin, etc. were done by disk diffusion method. All data analyzed by SPSS statistical software, version 16 (IBM, Armonk, NY, USA).
Results: A total of 61 patients with definitive infective endocarditis were included in the study, 50 of them (82%) were males and 11 patients (18%) were females. The mean age of the patients was 37.45±14.79 (range 17-74) years and 37 (60.7%) of the patients lived in urban areas. The mean duration of admission was 20±13.59 days. In addition, 38 patients (62.3%) were injection drug users (IDUs) and 23 (37.7%) non-IDU. Meanwhile, 54 (88.5%) of them had normal valve endocarditis and 7 cases (11.5%) had a prosthetic valve endocarditis. Moreover, the most common underlying disease in the natural valve endocarditis was rheumatoid fever (6.6%). Blood cultures were positive in 44.3% of the patients. The most common isolated organism was staphylococcus aureus in 15 cases (55.55%), which had the highest resistance to oxacillin. Most patients were managed by antibiotic therapy, but 15 cases (24.6%) underwent cardiac surgery. In follow up patients between 3 months to 9 years, 19.7% of the patients had complete recovery and 8.2% of them died.
Conclusion: According to the findings, antibiotic resistance pattern of bacterial agents isolated from blood culture of patients with infective endocarditis was changed.

Background: Gestational diabetes mellitus (GDM) is one of the most common metabolic disorders in pregnancy, which is associated with serious complications. In the event of early diagnosis of this disease, some of the maternal and fetal complications can be prevented. The aim of this study was to early predict gestational diabetes mellitus by two statistical models including artificial neural network (ANN) and decision tree and also comparing these models in the diagnosis of GDM.
Methods: In this modeling study, among the cases of pregnant women who were monitored by health care centers of Kermanshah City, Iran, from 2010 to 2012, four hundred cases were selected, therefore the information in these cases was analyzed in this study. Demographic information, mother's maternal pregnancy rating, having diabetes at the beginning of pregnancy, fertility parameters and biochemical test results of mothers was collected from their records. Perceptron ANN and decision tree with CART algorithm models were fitted to the data and those performances were compared. According to the accuracy, sensitivity, specificity criteria and surface under the receiver operating characteristic (ROC) curve (AUC), the superior model was introduced.
Results: Following the fitting of an artificial neural network and decision tree models to data set, the following results were obtained. The accuracy, sensitivity, specificity and area under the ROC curve were calculated for both models. All of these values were more in the neural network model than the decision tree model. The accuracy criterion for these models was 0.83, 0.77, the sensitivity 0.62, 0.56 and specificity 0.95, 0.87, respectively. The surface under the ROC curve in ANN model was significantly higher than decision tree (0.79, 0.74, P=0.03).
Conclusion: In predicting and categorizing the presence and absence of gestational diabetes mellitus, the artificial neural network model had a higher accuracy, sensitivity, specificity, and surface under the receiver operating characteristic curve than the decision tree model. It can be concluded that the perceptron artificial neural network model has better predictions and closer to reality than the decision tree model.

Neurodegeneration with brain iron accumulation (NBIA) is a rare set of inherited neurodegenerative disorders with abnormal accumulation of iron in basal ganglia. It is a clinically and genetically heterogeneous disorder that is characterized by movement disorders, dystonia, dysarthria, Parkinsonism, intellectual disability, and spasticity. The age at onset varies from childhood to adulthood and the rate of progression is different among affected individuals. Although there is no information about the exact prevalence of NBIA in the world-wide, it is estimated less than 1/1,000,000 in population. NBIAs are inherited in autosomal recessive, autosomal dominant or X-linked fashions. Until now more than 10 genes have been identified for this group of disorders. Among these, only two genes encode proteins that directly involved in iron metabolism. Therefore, how iron contributes to the pathogenesis of NBIA remains unknown. The remaining NBIA-causing genes participate in lipid metabolism, lysosomal functions or autophagy process, and the roles of some of them remain unknown. NBIA is categorized based on the genetic cause of the disease. PKAN, PLAN, MPAN, and BPAN are the most common forms of the disease result from mutations in the PANK2, PLA2G6, C19orf12, and WDR45 genes, respectively. The diagnosis of NBIA is usually based on clinical features and a specific pattern of brain MRI which results from the abnormal accumulation of iron. For example, the pattern of “eye of the tiger” is observed in the brain MRI of PKAN cases. Since, clinical evaluations and neuroimaging have failed in the diagnosis of the disease in some NBIA cases, genetic testing will be helpful. Development of whole-exome sequencing (WES) has facilitated the identification of disease-causing genes but it seems some of NBIA-genes have remained unknown, yet. Identification of novel genes and molecular pathways will enable a deeper understanding of the underlying molecular bases and our knowledge about the pathogenesis of the disease. There is currently no comprehensive study about the NBIA in Iran, however, the latest discovered NBIA gene, GTPBP2, has been identified in an Iranian family.

Background: The Electronic Health Record contains personalized health care information. Several factors affect the quality of SEPAS (Iranian electronic health record) data, disregarding the types of hospital information system set-up in hospitals. The purpose of this study was to investigate users' views on the factors affecting the data quality of Iranian Electronic Health Record (SEPAS) in hospitals affiliated to Mashhad University of Medical Sciences.
Methods: This descriptive cross-sectional study was conducted in 2018. In this study, the views of supervisors of the SEPAS system, HIS chief officers, and head of health information technology departments of hospitals were evaluated through a valid and reliable researcher-made questionnaire. Content validity ratio and content validity index of the questionnaire were validated as 0.82 and 0.94, respectively. Furthermore, the internal questionnaire reliability was affirmed by Cronbach's alpha of 0.96. Data analysis was conducted using descriptive statistics in the SPSS v.16 software.

Background: coronavirus disease (COVID-19) as an emerging infectious disease started in China in 2019. By increasing the number of patients and spreading to all countries, it was considered a pandemic disease. COVID-19 became an international concern. Patients affected by coronavirus (SARS-Cov-2) reported different symptoms. Most signs and symptoms were related to the respiratory system. To our knowledge, the onset of Covid-19 with chronic hiccups was reported in two patients. The aim of this study was to assess the onset of symptoms of Covid-19 disease in patients in a hospital in Zabol, Iran.
Methods: This study is a retrospective descriptive cross-sectional study which was performed from March to June 2021. The study setting was a hospital affiliated with Zabol Medical University. The study population included all patients diagnosed with Covid-19. A total of 350 patients were selected by the census. For data gathering, we used Patient’s records including demographic information, clinical examination records, and para-clinical tests results. We used descriptive statistics and SPSS ver. 20 for data analysis and management.

Results: Out of 98 subjects, 24 (24.5%) had positive rectovaginal culture. Individuals treated with antibiotics based on positive culture results did not show a significant difference in terms of observed pregnancy outcomes compared with the control group. Conclusion: The prevalence of GBS colonization was significantly higher in patients with a history of vaginal discharge than in those without a history. Due to the small number of studies conducted in Iran, it is recommended to conduct studies with a larger sample size in order to explain a more appropriate protocol in terms of effectiveness and economics.

Results: In this study, from 144 patients with penetrating trauma in the upper extremities, 56 patients were suspected with nerve injuries and 50 patients were suspected with tendon injuries. After evaluation with an ultrasound probe, 21 out of 23 cases suspected of nerve injuries were confirmed by local exploration. Local exploration confirmed that 27 out of 28 cases were suspected of tendon injuries. The accuracy of ultrasound in the assessment of nerve damage was estimated at 99.64% and in tendon damage at 92%, and the sensitivity of ultrasound in the diagnosis of nerve damage was 91.30% and in the diagnosis of tendon damage was 96.42%. Conclusion: By the results of this research it can be concluded, that ultrasound leads to a faster diagnosis. It provides a wider field of view, can reduce possible secondary injuries and increases the accuracy of the diagnosis.

Background: Considering the frequency of MRSA strains in hospitals and medical centers as well as in different communities, it seems necessary and important to observe the use of appropriate drugs in order to reduce antibiotic resistance and reduce the economic costs of treatment. This study aimed to investigate the antibiotic resistance pattern of MRSA isolated from blood and wound samples of patients. The study patients were hospitalized in different departments in a number of Tehran University of Medical Sciences hospitals.
Methods: In this descriptive cross-sectional study from September 2021 to February 2022, the blood and wound samples of the patients were collected and referred to laboratory. Staphylococcus aureus had identified by phenotypic and biotypic tests. MRSA isolates were screened by showing resistance to Cefoxitin by disc diffusion method and finally confirmed by examining the mecA gene by PCR. The microbial resistance pattern of MRSA was also measured by disk diffusion method and resistance to Vancomycin was confirmed by E.test.

Results: 41 isolates from 87 Staphylococcus aureus samples were confirmed as MRSA by present the mecA gene. The mecA gene was detected in all MRSA by PCR method. The antibiotic resistance pattern showed the highest sensitivity to Vancomycin and Linezolid with 100% sensitivity and the highest resistance to three antibiotics Erythromycin, Ceftriaxone and Cloxacillin with 97.57%by disk diffusion method. The most MRSA strains were isolated from the ICU department with 13 cases and the least MRSA strains were isolated from the two NICU and pediatric departments with one case.The majority of the population infected with MRSA belonged to the age group of 40-65 years. Conclusion: The prevalence of microbial resistance with high dispersion was obtained among MRSA strains isolated from clinical samples; which indicates a significant increase in resistant strains and requires a quick and timely diagnosis to prescribe the appropriate antibiotic.

Results: Staphylococcus aureus diagnostic tests including gram staining on colonies, catalase, coagulase, DNase tests were performed and it was found that all strains were Staphylococcus aureus. In the next step, all samples were resistant to Cloxacillin by disc diffusion method, and the presence of mec A gene in them was confirmed by PCR method, thus the presence of MRSA strains was confirmed from the genotypic point of view. Of the 43 Staphylococcus aureus strains, 26 samples were identified as having the nor A gene by PCR and electrophoresis. Conclusion: The results of the present research have shown that the prevalence of Staphylococcus aureus bacteria in hospital samples is significant and resistance to methicillin and ciprofloxacin has increased in the strains of this bacteria.

Background: Infertility is defined as the inability to achieve conception after one year of unprotected intercourse. This study aimed to explore the factors associated with infertility in men referred to the infertility center at Imam Khomeini Hospital in Ahvaz.
Methods: This descriptive study utilized a cross-sectional questionnaire during March 2016 to September 2019, involving 800 infertile couples with complete records. We extracted demographic data, including age, occupation, duration of infertility, smoking habits, surgical history, semen analysis, and sperm condition and quality from the files of these men referred to the IVF department. The collected details were systematically entered into an information form. Quantitative results are presented as mean±standard deviation, with differences of p<0.05 between groups deemed statistically significant.

Results: In this study, the average age of the men referred for evaluation was 33.5 years. The analysis of semen quality revealed a mean semen volume of 2.34 mL, which falls within the acceptable range for normal ejaculate volume, typically defined as being greater than 1.4 mL. The average sperm count recorded was 16,365,000 per mL. Additionally, our study demonstrated that only 5.8% of the sperm exhibited normal morphology. Sperm motility, another key factor in male fertility, averaged at 9.24%, significantly lower than the normal standard. Regarding employment status, a significant majority of participants were employed (89%), while 11% were unemployed. The surgical history among the referred men primarily included varicocelectomy (n=108), hemorrhoid surgery (n=29), urinary tract procedures (n=28), testicular hernia repairs (n=23), and appendectomies (n=18). Additionally, 24% of the subjects reported drug use, with a notable distinction made between smoking and other forms of drug use. Conclusion: The findings from this study underscore significant concerns regarding male fertility among the referred men, particularly in terms of sperm count, motility, and morphology. These metrics suggest that many individuals may face challenges in achieving conception without medical intervention. Understanding these factors is crucial for developing effective treatment plans and improving reproductive outcomes for men facing infertility issues.