Patients with severe COVID-19 have reduced circulating levels of angiotensin-(1-7): A cohort study.

Background and Aims: Angiotensin-converting enzyme 2 (ACE2) acts as a functional receptor for the entry of severe acute respiratory syndrome coronavirus 2 into host cells. Angiotensin (1-7) (Ang (1-7)) obtained from the function of ACE2 improves heart and lung function. We investigated the relationship between Ang (1-7) level and disease severity in patients with coronavirus disease 2019 (COVID-19). Methods: This cohort study was carried out at Masih Daneshvari Hospital in Tehran, Iran from September 2020 to October 2020. To do so, the Ang (1-7) levels of 331 hospitalized COVID-19 patients with and without underlying disease were measured by ELISA kit. The need for oxygen, intubation, and mechanical ventilation were recorded for all the patients. Results: Results showed a significant inverse relationship between the levels of Ang 1-7 and the severity of the disease (needed oxygen, intubation, and mechanical ventilation). According to the results, median (interquartile range) of Ang (1-7) levels was significantly lower in patients who needed oxygen versus those who needed no oxygen (44.50 (91) vs. 82.25 (68), p = 0.002), patients who needed intubation and mechanical ventilation versus those who did not (9.80 (62) vs. 68.70 (102), p < 0.000) and patients hospitalized in an intensive care unit (ICU) than people hospitalized in other wards. We also found that the older patients were more in need of ICU and mechanical ventilation than younger patients. Conclusions: Higher levels of Ang (1-7) have been associated with decreased disease severity. Besides this, we perceived that synthetic Ang 1-7 peptides may be useful to treat and reduce the complications of COVID-19.

COVID-19 Pandemic and Tuberculosis Control: A Narrative Review.

Background: The world is currently struggling with the COVID-19pandemic. Measures to control the COVID-19 pandemic have affected other health problems and diseases, including tuberculosis (TB) and its control. The present narrative review aimed at reviewing published literature on the impact of the COVID-19 pandemic on TB control. Materials and Methods: English language databases, including PubMed, ISI, Scopus, and Google Scholar, were searched using the keywords "Tuberculosis, COVID-19, and Coronavirus" to find relevant articles. Results: Problems and limitations in financial and human resources, as well as medical and laboratory services caused by the COVID-19 pandemic, contribute to the reduction in the number of newly diagnosed patients with TB. More effort in identifying patients with TB is of great importance, and if the global number of newly diagnosed patients with TB decreases by 25% for three consecutive months due to the COVID-19 pandemic, the TB mortality rate will increase by 13%. An increase in the TB mortality rate means the failure of TB control programs to reach the targets of the Global End TB Strategy. Conclusion: According to the latest statistics released by the Ministry of Health, the incidence of TB in Iran has not yet reached fewer than 100 cases per million population. On the other hand, being a neighbor with countries with a high risk of TB is a serious threat to Iran. Therefore, further effort to control TB during the COVID-19 pandemic is particularly important.

Frequency of Pulmonary Anthracosis and its Related Factors in Autopsy Specimens in Guilan, Iran, in 2019.

Background: Anthracosis is caused by several factors and is a risk factor for cancer and tuberculosis. This study investigated the prevalence of anthracosis and the associated factors in autopsy specimens from the Guilan Office of the Iranian Legal Medicine Organization. Materials and Methods: This retrospective study examined the medical records of autopsy specimens (>18 years) in the Guilan Office of the Iranian Legal Medicine Organization in 2019 for pulmonary anthracosis. Data were extracted from the autopsy findings, and demographic characteristics, occupational information, tuberculosis or pulmonary cancer history, and anthracosis were recorded in a checklist. SPSS version 16 was used to analyze the collected data. Results: The study included 190 autopsy specimens with a 32.1% anthracosis prevalence. Forty-five (23.7%) subjects had anthracofibrosis. Individuals with agricultural carriers or who worked in tobacco fields had the highest prevalence of anthracosis. The frequency of pulmonary cancer and tuberculosis was significantly higher in the specimens with anthracosis (anthracosis group) than in the non-anthracosis group (P<0.05). The use of traditional cooking and heating methods, as well as exposure to carbon and smoke in the workplace, were significantly higher in the anthracosis group than in the non-anthracosis group (P<0.05). Conclusion: The results of the current study revealed that occupational exposure, tuberculosis, pulmonary cancer, and traditional indoor cooking and heating methods were all associated with anthracosis.

Stress and burnout in health care workers during COVID-19 pandemic: validation of a questionnaire.

Aim: To validate a questionnaire to assess stress and burnout in healthcare workers during COVID-19 pandemic. Subjects and methods: In this study, content validity, Cronbach's alpha, and test-retest reliability method were utilized among 60 HCWs to evaluate the validity, internal consistency, and reliability of the questionnaire respectively. The final questionnaire was composed of four parts asking for the background information, questions about the stress caused by the COVID-19, the Depression, Anxiety and Stress Scale - 21 (DASS-21), and six questions from the Copenhagen Burnout Inventory (CBI). Results: The CVR of 46 questions was equal to 1, making them acceptably valid (CVR > 0.78), so that the items could be arranged into a final questionnaire. Moreover, all items could successfully attain CVI values above 0.79, confirming the content validity of the questionnaire. The Cronbach's alpha was between 0.80-0.95 for different sections of questionaire, confirming the stable reliability and high repeatability of the questionnaire. Conclusion: The results of this study showed that the DASS-21 offers adequate levels of validity and reliability for assessing the stress, anxiety, and depression among the HCWs engaged with the COVID-19 pandemic. Moreover, the six items adapted from the Copenhagen burnout inventory (CBI) were found to provide a good instrument for investigating the job burnout among the HCWs at Masih Daneshvari Hospital during the outbreak of the COVID-19 epidemic.

Challenges in Longitudinal Spirometry Data in Occupational Medicine: Spirometry Indices during Five Consecutive Years and its Causative Factors.

Background: Respiratory illnesses caused by occupational exposure have the most negative effects on the workers' health status in workplaces. In occupations with a high likelihood of labor-induced pulmonary diseases, a periodic spirometry test is usually used to monitor occupational lung function and prevent occupational respiratory diseases. Monitoring workers exposed to occupational pulmonary diseases is widely done using forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) for early diagnosis of obstructive pulmonary and lung diseases. We assessed the usefulness of longitudinal data of periodic spirometry tests in a sulfate production industry. Materials and Methods: In this longitudinal study, 212 individuals working in a sulfate production industry near Tehran were examined. Demographic data and information, such as FEV1, FVC, FEV1%, FVC%, and FEV1 / FVC ratio were obtained from 2009 to 2013. Data were analyzed using the SPSS software version 21. The one-way analysis of variance (ANOVA) and repeated measures ANOVA for data analysis. Results: The results showed that the variation of the spirometry parameters over 5 years was significant. The factors studied not only decreased in some years but also increased in comparison with the previous year. Also, the average FEV1 and FVC and also FEV1 / FVC significantly was different at different time points [F(2.864, 590.029)= 27.269, P < .0001], [F(2.910, 599.546)= 38.239, P < .0001], and [F(3.257, 671.019)= 13.351, P < .0001]. Conclusion: The best spirometry tests, not only acceptable tests, are important in longitudinal spirometry evaluations. There is no systematic supervision on spirometry tests in Iran and the results of this study reflect a serious need for such supervision.

Sleep Disorders and Mental Health in Menopausal Women in Tehran.

BACKGROUND: Sleep complaints are common problems in the general population and insomnia and sleep disorders place significant economic and social burdens on the community. Postmenopausal women are 2.6 to 3.5 times more likely to develop obstructive sleep apnea (OSA) compared to non-menopausal women. In this study, we evaluated sleep disorders and mental health in postmenopausal women. MATERIALS AND METHODS: This study was a descriptive cross-sectional study and the samples were selected from postmenopausal women above 50 years who had participated in a survey entitled, "Evaluation of Sleep Disorders among Adults in Tehran" in 2017. Cluster sampling method was applied with proportional allocation. A total of 4021 samples were collected, 2075 of which belonged to women. In addition, 174 out of 2075 samples were related to postmenopausal women over the age of 50. The data were analyzed using the statistical package IBM SPSS version 22.0. P-values less than 0.05 were considered significant. RESULTS: In this study, 118 (67.8%) women had insomnia for less than three months, and 23 (13.2%) women had insomnia for more than three months. The prevalence of STOPBANG parameters in this group of postmenopausal women was 37% and significantly related to Body mass index (BMI) and neck circumference at P < 0.001 and 0.006, respectively. There was no significant relationship between social dysfunction and insomnia. However, anxiety in General Health Questionnaire (GHQ) was significantly associated with insomnia, sleepiness, sadness, and irritability. CONCLUSION: Our results indicate that the impact of insomnia symptoms, OSA comorbidity and mental disorders could extend far beyond. The use of urgent health care and quality of life issues is essential for long-term mental and physical well-being; if there is no treatment in the menopause population, there will be serious mental and physical complications.

Cigarettes Smoking and Skin: A Comparison Study of the Biophysical Properties of Skin in Smokers and Non-Smokers.

BACKGROUND: Tobacco smoke is toxic for cells and could be a damaging factor to skin. The purpose of this study was to compare the biophysical properties of skin in smokers and non-smokers. MATERIALS AND METHODS: The study population consisted of 28 current smokers and 24 non-smokers. The hydration of the stratum corneum, trans epidermal water loss, pH, erythema, melanin content, sebum, friction and elasticity parameters (R0, R2, R5) of skin, epidermis and dermis thickness and echo-density were measured on middle forehead, right cheek and right inner arm of participants. Also volume, surface area and depth of right nasolabial folds were measured. The mean of these values in smokers were compared with non-smokers by independent sample T- test. RESULTS: Gross elasticity was significantly lower in smokers on forehead (p= 0.048). Thickness of epidermis was higher in smokers in all measured sites but the differences were not statistically significant. Thickness of dermis was higher in smokers in all measured sites too, but only the difference on cheek was statistically significant (p= 0.009). Density of epidermis was lower in smokers in all measured sites, but only the difference on forehead was statistically significant (p= 0.019). Density of dermis was lower in smokers in all measured sites, but only the difference on arm was statistically significant (p= 0.028). Volume and area of nasolabial folds were higher in smokers, but only the difference of area was statistically significant (p = 0.031). CONCLUSION: Tobacco smoking could affect the biophysical parameters of skin, especially thickness and density of dermis and epidermis and nasolabial folds.

Investigating air quality status and air pollutant trends over the Metropolitan Area of Tehran, Iran over the past decade between 2005 and 2014.

Studies on the trend of air pollution in Tehran, Iran, as one of the most polluted metropolis in the world are scant, and today Tehran is known for its high levels of air pollutants. In this study, the trend of air pollution concentration was evaluated over the past 10 years (2004-2015). The data were collected from 22 stations of the Air Quality Control Company. Daily concentrations of CO, NO2, SO2, O3, PM10 were analyzed using SPSS 16 based on the statistical method, repeated measures, and intra-group test to determine the pattern of each pollutant changes. As a result of the 22 air pollution monitoring stations, NO2 and SO2 concentrations have been increasing over the period of 10 years. The highest anomaly is related to SO2. The CO concentrations represent a descending pattern over the period, although there was a slight increase in 2013 and 2014. The O3 concentrations declined in the following years. The average concentration of PM10 has been rising during the period. Also we evaluated changes of each pollutant in different months and calculated the number of clean, healthy, unhealthy days for sensitive, unhealthy, very unhealthy, and dangerous groups. The study findings illustrated the necessity for larger investment in air pollution abatement. Overall, trends have been progressed to worsening, the number of healthy days has been declined and the number of unhealthy days has been increased in recent years.

A Novel Questionnaire to Ergonomically Assess Respirators among Health Care Staff: Development and Validation.

BACKGROUND: Health care workers are at a high risk of exposure to infectious diseases spread by airborne transmission. N95 respirators are the most common respirators used in the health care system and negligence in using them may cause health problems. Hence, more emphasis should be on ergonomic aspects of this mask. This study aimed to develop a tool for ergonomic evaluation of these respirators. MATERIALS AND METHODS: After reviewing previous studies and employees' problems in the use of the N95 respirators, 50 questionnaires were designed and their validity was assessed. Then, the questionnaire was completed by 290 staff members of Masih Daneshvari Hospital and its internal consistency and reproducibility were investigated using Cronbach's alpha coefficient and test-retest method, respectively. Confirmatory factor analysis was used to assess its consistency and internal consistency (construct validity). RESULTS: With the confirmation of the face and content validities, internal consistency (0.89) calculated by the Cronbach's alpha coefficient and reproducibility of the questionnaire (0.997; p<0.001) assessed by using the ICC Index, were approved. Following examining internal consistency and stability, the questionnaire convergent construct validity was also confirmed using confirmatory factor analysis. CONCLUSION: The questionnaire contained 42 items and it is beneficial to use it in the health care system to evaluate the ergonomic problems of the respirators and to have optimal choice in this respect. Also, it can be used in the promotion of the staffs' behavior in wearing these respirators when necessary.

Relationship of aerobic fitness with cardiovascular risk factors in firefighters.

BACKGROUND: Epidemiological studies on the general population have shown that increased physical activity and aerobic fitness (AF) significantly decrease the risk of coronary artery disease. Finding ways to decrease such risk factors can promote the health of firefighters. METHODS: This study was conducted in a large industrial facility in Tehran. AF assessment and submaximal aerobic fitness testing of participants were performed according to the guidelines of the American College of Sports Medicine (ACSM). AF was determined using a bicycle ergometer. Other information was collected using a specifically designed questionnaire, physical examination and blood test. Data were analyzed using SPSS. Level of significance was set at P < 0.05. RESULTS: A total of 157 male firefighters were evaluated in an industrial facility. The results of logistic regression analysis revealed that AF was significantly correlated with age, body mass index (BMI), cigarette smoking, physical activity, hemoglobin level, low-density lipoprotein (LDL) level, high-density lipoprotein (HDL) level, resting systolic blood pressure (RSBP), diastolic blood pressure (RDBP) and heart rate (RHR) (P < 0.05). CONCLUSIONS: Firefighters with greater AF had lower cardiovascular disease (CVD) risk factors. Longitudinal studies are required to further confirm this finding. Increasing the AF may decrease CVD risk factors in firefighters.

Effect of General Health Status on Chronicity of Low Back Pain in Industrial Workers.

Recognizing patients at a higher risk of developing chronic low back pain (LBP) is important in industrial medicine. This study aimed to assess the power and quality of General Health Questionnaire (GHQ) for prediction of the odds of chronicity of acute LBP. This study was conducted on industrial workers. All subjects with acute LBP who met the inclusion criteria were enrolled. Demographic characteristics, occupational, physical, and mental parameters and the general health status of subjects were evaluated;  they were followed up for developing chronic LBP for one year. Cigarette smoking, high body mass index, job stress, physical load and high GHQ scores were found to be the risk factors for the progression of acute LBP to chronic LBP (P<0.05). Standing position while working, age, work experience, exercise, level of education, weekly work hours and shift work were not the risk factors for chronic LBP (P>0.05). High GHQ score can be a risk factor for progression of acute LBP to chronic LBP. The GHQ in combination with the Job Content Questionnaire can be used as a quick and simple screening tool for detection of subjects at high risk of chronic LBP when evaluating acute LBP in an occupational setting.

Prevalence of snoring and the risk of sleep apnea in hospital staff.

BACKGROUND: Untreated Obstructive sleep apnea syndrome (OSAS) as a common breathing sleep disorder results in impaired work performance. The economic burden of untreated OSAS accounts for billions of dollars per year. OBJECTIVE: The aim of this study was to evaluate the prevalence of snoring and the risk of OSAS in healthcare system staff. METHODS: This cross-sectional study was performed on 715 staff of Dr. Masih Daneshvari Hospital in 2012. The Berlin questionnaire was used to identify the prevalence of snoring and the risk of sleep apnea. Additional information, including demographic characteristics, night work, night sleep less than 4 hours, smoking, underlying disease, and quality of sleep were evaluated as well. The information was analyzed using SPSS 15. RESULTS: 12.6% reported snoring. 6.9% and 93.1% were categorized into the high and low risk groups for OSAS respectively. There was an association between the risk of OSAS and age group (P-value = 0.007), gender (P-value = 0.028), marital status (P-value = 0.008), educational level (P-value = 0.035), chronic disease (P-value = 0.008), night sleep less than 4 hours (P-value = 0.001), difficulty in staying asleep (P-value = 0.000) and waking up too early (P-value = 0.006). Even logistic regression analysis demonstrated the relationship between the risk of OSAS and night sleep less than 4 hours (P-value = 0.019) and difficulty in staying asleep (P-value = 0.009). CONCLUSIONS: The results showed that the risk of OSAS is significant in healthcare system staff. Hope to provide a special screening program for OSAS in a regular occupational examination.

The Intricate Expression of CC Chemokines in Glial Tumors: Evidence for Involvement of CCL2 and CCL5 but Not CCL11.

Chemokines are biologically active peptides involved in the pathogenesis of various pathologies including brain malignancies. They are amongst primitive regulators of the development of immune responses against malignant glial tumors. The present study aimed to examine the expression of CC chemokines in anaplastic astrocytoma and glioblastoma multiform patients at both mRNA and protein levels. Blood specimens in parallel with stereotactic biopsy specimens were obtained from 123 patients suffering from glial tumors and 100 healthy participants as a control. The serum levels of CCL2, CCL5, and CCL11 were measured by ELISA and stereotactic samples subjected to western and northern blotting methods for protein and mRNA, respectively. Demographic characteristics were also collected by a researcher-designed questionnaire. Results of the present study indicated that, however,CCL2 and CCL5 are elevated in serum and tumor tissues of patients suffering from a glial tumor at both mRNA and protein levels, the CCL11 was almost undetectable. According to the findings of the present investigation, it could presumably be reasonable to conclude that chemokines are good predictive molecules for expecting disease severity, metastasis, and response to treatment.

Association between Occupational Accidents and Sleep Apnea in Hospital Staff.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is a common disorder in which instability of the upper airways leads to a reduction or cessation of airflow during sleep. Sleep disorders such as OSAS increase the risk of occupational accidents and impaired work performance. Sleep deprivation during shift increases the risk of occupational accidents among health care employees. The purpose of this study was to determine the association between occupational injuries in hospital staff and the risk of sleep apnea. MATERIALS AND METHODS: This cross-sectional study was conducted on hospital staff of Masih Daneshvari Hospital in 2012. In this study, the hospital staff's (715) response to the Berlin questionnaire plus additional information including a history of an occupational accident, night shifts, less than four hours of night sleep, history of smoking, chronic disease and quality of sleep were assessed. Information obtained was analyzed using SPSS 15. RESULTS: In general, 27.6% reported a history of occupational accidents. The incidence of occupational accidents in the high-risk group for sleep apnea was significantly higher than the low-risk group (OR=2.736, CI=1.522-4.917, P=0.001). The results of logistic regression analysis also showed a statistically significant association between occupational accidents and risk of sleep apnea (OR = 2.247, CI = 1.194-4.231, P= 0.012). CONCLUSION: This study showed that the incidence of occupational accidents in the hospital employees is strongly related to the probability of OSA. Therefore, special attention should be directed to respiratory sleep disorders in order to reduce occupational injuries at hospitals.

Relationship of occupational and non-occupational stress with smoking in automotive industry workers.

BACKGROUND: Tobacco use is the second cause of death and first cause of preventable mortality worldwide. Smoking in the workplace is particularly concerning. Smoking-free workplaces decrease the risk of exposure of non-smoking personnel to cigarette smoke. Recent studies have mostly focused on the effect of daily or non-occupational stressors (in comparison with occupational stress) on prevalence of smoking. Occupational stress is often evaluated in workplaces for smoking cessation or control programs, but the role of non-occupational stressors is often disregarded in this respect. MATERIALS AND METHODS: This cross-sectional study was conducted in an automobile manufacturing company. The response of automotive industry workers to parts of the validated, reliable, Farsi version of Musculoskeletal Intervention Center (MUSIC)-Norrtalje questionnaire was evaluated. A total of 3,536 factory workers participated in this study. Data were analyzed using SPSS and P<0.05 was considered statistically significant. RESULTS: The correlation of smoking with demographic factors, occupational stressors and life events was evaluated. The results of logistic regression analysis showed that even after adjusting for the confounding factors, cigarette smoking was significantly correlated with age, sex, level of education, job control and life events (P<0.05). CONCLUSION: The results showed that of occupational and non-occupational stressors, only job control was correlated with cigarette smoking. Non-occupational stressors had greater effect on cigarette smoking. Consideration of both non-occupational and occupational stressors can enhance the success of smoking control programs. On the other hand, a combination of smoking control and stress (occupational and non-occupational) control programs can be more effective than smoking cessation interventions alone.

Asthma and body mass index in occupational setting.

BACKGROUND: Asthma is the most common respiratory disease with an increasing prevalence. On the other hand, obesity is also a challenging disease compromising health in human communities. This study sought to assess the correlation of asthma and body mass index (BMI) in occupational setting. METHODS: This study was conducted in a cable manufacturing company in 2012. A total of 551 workers from the production (exposed group) and non-production (unexposed group) units were studied. A questionnaire specifically designed for this purpose was filled out for study subjects and then all workers with respiratory symptoms suggestive of asthma thoroughly examined by a physician and medical history was taken from them. Complementary diagnostic tests were also carried out. RESULTS: A total of 11.6% of our understudy subjects had asthma. The prevalence of asthma in exposed subjects with BMI≥25 kg/m(2) was found to be significantly higher than in exposed workers with BMI<25 kg/m(2) (p<0.01). However, no significant differences existed in prevalence of asthma between the two subgroups of BMI≥25 kg/m(2) and BMI<25 kg/m(2) in the unexposed group (p>0.05). After adjusting for confounding factors significant associations were observed between BMI and asthma at cut points of 30 kg/m(2) and 25 kg/m(2) (OR: 8.53 and 2.41, respectively). CONCLUSION: Our study results showed that prevalence of asthma might be higher in workers with higher BMI who are exposed to occupational asthmogens. This finding highlights the necessity of offering weight loss recommendations in periodic examinations to workers with exposure to occupational asthmogens.

Silicoproteino-tuberculosis: Three distinct entities or a unique entity: A case report and review of the literature.

Silicosis is considered to be among the occupational lung diseases and associated with sandblasting, mining, quarrying and tunneling. Acute silicosis is usually progressive diseaseand despite treatment with corticosteroids it leads to cardio-respiratory failure and death. Alveolar silicoproteinosis is one of it's acute presentations due to exposure to silica dust and lungs filling with proteinaceous material. Here, we have presented a 29 year old male sandblaster with the three conditions of acute silicosis, secondary alveolar proteinosis and pulmonary tuberculosis on four anti tuberculous medications who presented with respiratory distress.

Assessment of the relationship between physical working conditions and different levels of work ability.

Early leaving of workplace by work forces is one of the fundamental problems worldwide. Maintenance and enhancement of employees work ability are important for raising productivity. This study investigated the relationship between work ability index and physical working conditions and was carried out in 2013 on 641 workers at a manufacturing plant in Tehran. Work ability was assessed by the questionnaire of work ability index and the participants were classified into four work ability groups of poor, moderate, good, and excellent. Physical working conditions were evaluated by the MUSIC-Norrtalje questionnaire and the participants were classified into two groups with proper and poor physical working conditions. The mean score of work ability questionnaire was 42.40; and 2.5% (16 persons), 9.2% (59 persons), 38.2% (245 persons), and 50.1% (321 persons) of the participants were in poor, moderate, good, and excellent work ability groups, respectively. The mean score of physical working conditions questionnaire was 20.06. The results of logistic regression analysis showed that even after adjusting the confounding variables, a significant correlation existed between work ability and physical working conditions (p < 0.05). According to the results of this study, there may be a correlation between physical working conditions such as awkward postures, repetitive movements, load lifting, exposure to whole body vibration and so on with work ability. Therefore it seems that enhancement of the quality of physical working conditions may increase work ability.

Menstrual disturbances and hormonal changes in women workers exposed to a mixture of organic solvents in a pharmaceutical company.

BACKGROUND: Chemicals are among risk factors that can affect women's reproductive system. This study is aimed to investigate the association of occupational exposure to a mixture of organic solvents with menstruation disturbances and hormonal changes among female workers. METHODS: Female workers of a pharmaceutical company were divided into three groups of non-exposed, lowexposed and highly-exposed to a mixture of organic solvents (formaldehyde, phenol, N-hexane, and chloroform) based on workplace measurements. Menstrual disturbances (in terms of short cycles, long cycles, irregular cycles, and bleeding or spotting between periods) and mean of hormone levels (including follicle stimulating hormone, luteinizing hormone, thyroid stimulating hormone, prolactin, estrogen and progesterone levels) were compared between these three groups. For investigating associations, logistic regression was performed. RESULTS: Our study showed that mean length of cycles, duration of bleeding, and amount of flow and also prevalence of long cycles, irregular cycles, and bleeding or spotting between periods were higher in exposed groups (p≤0.05). Odds ratio for prevalence of menstrual disturbances in the low exposure group and high exposure group were 9.69 (p=0.001) and 3.40 (p=0.002) respectively compared to the reference group. Estrogen and progesterone levels were not affected (p> 0.05), but other hormones levels were significantly disturbed in the exposed groups compared with the non-exposed group (p=0.001). CONCLUSION: Occupational exposure to the mixture of organic solvents may be associated with the increase of menstrual disorders and hormonal changes in female workers. Based on our findings, periodic evaluation of reproductive system of female workers in pharmaceutical companies is recommended.

Qualification study of two genomic DNA extraction methods in different clinical samples.

INTRODUCTION: The purity of genomic DNA (gDNA) extracted from different clinical specimens optimizes sensitivity of polymerase chain reaction (PCR) assays. This study attempted to compare two different DNA extraction techniques namely salting-out and classic phenol-chloroform. MATERIALS AND METHODS: Qualification of two different DNA extraction techniques for 634 clinical specimens highly suspected of having mycobacterial infection was performed. Genomic DNA was extracted from 330 clinical samples using phenol-chloroform and 304 by non-toxic salting-out. Qualification of obtained gDNA was done through amplification of internal controls, ß-actin and ß-globin. RESULTS: ß-actin-positive was detected in 279/330 (84%) and 272/304 (89%) samples by phenol-chloroform technique and salting-out, respectively. PCR inhibitor was found for the gDNA of 13/304 (4%) patient samples were negative by ß-actin and ß-globin tests via salting-out technique in comparison with gDNAs from 27/330 (8.5%) samples extracted by phenol-chloroform procedure. No statistically significant difference was found between phenol-chloroform technique and salting-out for 385 sputum, 29 bronchoalveolar lavage (BAL), 105 gastric washing, and 38 body fluid (P=0.04) samples. This illustrates that both techniques have the same quality for extracting gDNA. CONCLUSION: This study discloses salting-out as a non-toxic DNA extraction procedure with a superior time-efficiency and cost-effectiveness in comparison with phenol-chloroform and it can be routinely used in resource-limited laboratory settings.