فصلنامه ابن سینا
سال پانزدهم شماره 1 (پیاپی 42، بهار 1392)

Noise-induced hearing loss (NIHL) is a complex disease caused by interaction of genetic and environmental factors. Airport environment، as a source of noise، imposes loud noise on its staff and adjacent inhabitants. The aim of this study was to determine frequency of NIHL in staff of Yazd (Shahid Sadoughi) Airport in 20I0-2011. In this descriptive study، 106 subjects were collected by consecutive sampling from different parts of the airport. Three types of classification were applied، on the basis of workplace noise intensity، employment years، and daily work hours. Auditory status was assessed by pure tone audiometry. Workplace noise levels were also measured in flight and non-flight situations. The airport noise was intermittent and its intensity exceeded 85 dB in some situations. Among flight situations highest intensities were recorded respectively at the time of «on the runway»، «ready to fly»، descent «and» ascent «Among non-flight situations،» electricity generator «،» siren of ground security «and» flight guidance consul«had intensities higher than flight situations. (Respectively 109،103، and 94. 4 dB) Regarding pure tone audiometry، significant decrease of hearing threshold was more frequent at 4، 6 and 8 kHz (i. e. 8. 7%، 14. 6% and 18. 4% respectively in right ear، and 13. 2%، 21% and 16. 2% respectively in left ear). Thirty three percent of staff had NIHL. NIHL rate was higher in exposed subjects than non-exposed ones (42. 1% vs. 28. 9%; P-value=0. 039). Although، employment years had a significant impact on NIHL (p<0/001)، daily work hours had no effect. Airport environment noise caused hearing loss among airport staff، although it exceeded non-hazardous level only in few conditions.

The cardiovascular disease (CVD) is one of the main causes of morbidity and mortality worldwide. The aim of present study was to determine prevalence of cardiovascular risk factors and metabolic syndrome among military parachutists in Iran. In a cross-sectional study on 96 military parachutists، arterial blood pressure، weight، height، body mass index، waist circumference، hip circumference، fasting blood glucose، and lipid profile were assessed and then the rate of metabolic syndrome was evaluated. Mean age was 37. 4 years. Totally، 24 (25%) parachutists fulfilled the criteria of hypertension، while 36 (37. 5%) exhibited blood pressure in the range of pre-hypertension. Five (5. 2%) cases suffered from diabetes mellitus and 4 (4. 2%) were pre-diabetics. Hypertriglyceridemia and hypercholesterolemia was seen in 23 (24%) and 46 (47%) participants، respectively. The rate of metabolic syndrome based on ATP III and IDF criteria was 5. 2% (5 cases) and 13. 5% (13 cases)، respectively. Although war-related stressors and high intensity physical activities are associated with both acute cardiac events and cardiac risk factors، our data is in favor of lower frequency of cardiovascular risk factors among military parachutists. However، routine monitoring of military parachutists is necessary to find the cardiovascular risk factors.

Aviation can be a stressful environment for human. The pilots can suffer from great anxiety during military air travels. Apart from stress، microgravity، cosmic radiations and low oxygen pressure in high altitude، can affect the physiological systems of human body، especially the immune system. The purpose of this study is to investigate different parts of the immune system in the air force pilots. In a case-control study، twenty pilots were compared with control group cellular surface markers CD3، CD4، CD8 and CD56 using flow cytometry technique. IgM and IgG levels against herpes simplex virus 1، 2 (HSV-1،2)، Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) were also analyzed by ELISA method. The results of this study showed that peripheral blood neutrophil cells percentage، cytotoxic T cells (and natural killer cells (were significantly higher in the pilots compared to the control group (p<0. 05). In contrary، total peripheral blood lymphocytes percentage and helper T cells (were significantly lower in the pilots (p<0. 05). The results indicated that aviation can change pilots'' immune system، especially their cellular immunity.

Physical fitness is one of the most important causes of superiority in the battle fields so determining and ability to predict fitness is always an important goal for all armed forces universally. In this project the authors try to measure physical f itness of Iranian army personnel and simultaneously measure some of the physiologic indices to investigate their relationship with physical fitness indices. 200 personnel of Iranian Army aged 22 to 59 years old enrolled in the study. First the subjects filled a questionnaire about their history of previous illnesses then physical examination was performed by a sport medicine specialist، followed by Anthropometric and flexibility measurements and the body composition estimation using Bioelectric Impedance Analyzer. The cardio-respiratory fitness of subjects was measured. Fasting serum total cholesterol، Triglyceride، LDL، HDL and FBS and Hemoglobin concentration were also measured. The data were analyzed using Enter and Backward Linear Regression and the best model for predicting physical fitness indices determined. The mean average and maximal force of subjects were 48. 52±13. 7 and 77±18. 6. The mean flexibility measured using Sit & Reach test was 42. 44±9. 92. We could find statistically significant relations between Fitness indices and physiologic Biomarkers but only two models could predict the variation of Stress test time and distance (R2=0. 746، P Value<0. 001). Estimation of cardio-respiratory fitness using measured biomarkers is possiblei it is highly suggested to measure indices and physiologic biomarkers in operational personnel of army.

The high incidence of lower limb overuse and acute injuries that occur in military populations suggests that fatigue may contribute to altered neuromuscular control of the ankle and knee joints. Moreover، deficits in ankle and knee joint position senses (JPSs) were seen in subjects with history of lower limb musculoskeletal injuries. The aim of this study was to evaluate if military exercises could alter the ankle JPS and to examine the possible relation of JPS to further lower limb musculoskeletal injuries in military service. 50 male conscripts from a unique base with same military training were recruited. Subjects were asked to recognize pre-determined position of the dominant ankle (21 degree of plantar flexion) before and after military exercises by continuous passive motion device (CPM). The average of the absolute error (AE) of three trials was recorded as scores for both conditions and results were compared. The subjects were followed for 8 weeks for any musculoskeletal injuries and the relationship between the incidence of lower limbinjury and JPS were determined by paired t-test. There was significant decrease in subject''s ability to recognize passive and active repositioning of their ankle joint after a session of military protocol (p<0. 001). There was a strong correlation between lower JPS acuity and occurrence of injury (r= 0. 86، p<0. 001). The acuity of the ankle JPS is reduced subsequent to military exercises. Decreasing JPS accuracy was associated with growing incidence of lower limb musculoskeletal injuries.

The initial treatment of patients with gun shot trauma، before reaching proper care، can be effective in patient’s morbidity and mortality. The aim of this study was to evaluate the trauma system in the pre-hospital approaches for patients with bullet trauma. In this study، the bullet trauma patients presenting in four major hospitals in Mashhad between 2010 and 2011 were studied. A total of 66 patients admitted to our hospitals (51 with directly admission and 15 were referred from other centers). The most common anatomic site of injury was extremities (60. 6%) and the highest mortality rate was seen in patients with more than one site injury (e. g. chest and abdomen). The length of stay in hospital had no significant difference in these groups (P = 0. 188). Also، the length of stay in hospital was similar between patients who were transferred with ambulance and others who were transferred with other vehicles (P = 0. 553). Similarity in the length of stay in hospital between emergency ambulance and other vehicles transmitted patients reflects the need for more strengthening the manpower and equipments in the health care in emergency services.

Neurofeedback is a new technique recently used in various fields such as mental، physical، educational and military with favorable results in improving brain function. This paper is a brief overview of the principles and concepts of neurofeedback and it effectiveness and the ways to use it in military training، especially in the area of aviation and pilot training. A search through the contents of the internal and external Web sites and psychiatric textbooks was performed. In this study of neurofeedback applications are described and the methods and systems for military training are provided، with emphasis on pilots’ training and their mental performance enhancement. Since the neurofeedback had effects on improving brain function in several studies and also used in developing countries in different areas، it can be helpful for pilot training to increase efficiency and reduce errors.