39 2228-7043 Iran University of Medical Sciences 2151 Biostatistics Application of the generalized additive model in determination of the retinopathy risk factors relation types for Tehran diabetic patients Salehi Masood b Vazirinasab Habibeh c Khoshgam Masoomeh d Rafati Nasrin e b Tehran University of Medical Sciences c Tehran University of Medical Sciences d Tehran University of Medical Sciences e Shahid Beheshti University of Medical Sciences 1 7 2012 19 97 1 9 18 07 2012   Background : One of the most important complications of diabetes, is diabetic retinopathy that causes the blindness of 10,000 people every year. Different researches have been done on retinopathy risk factors in diabetic patients. This study was carried out to check the type of relationship between retinopathy risk factors and the condition of temptation it with generalized additive models. The study attempts to increase the quality of predicting the response variable and to reveal the non-linear and non-monotonic relationships between the response and the set of explanatory variables with generalized additive models.   Methods: This cross-sectional study has been done on 367 diabetic patients who take part in assessment recall of retinopathy in Tehran. Entrants have been checked to determine their particulars, medical conditions and medicines. Finally has been used a data complex for fitting generalized additive models and binary logistic regression, including six continues explanatory variables: age, duration of diabetes, Body Mass index (BMI ), hemoglobin A1C, cholesterol, systolic blood pressure and response variable, to the presence of retinopathy Fitting model has been done with mgcvR software.   Results: In this study 120 cases (33%) were retinopathy patient and 247 cases (67%) were not. Results of the generalized additive model were denoting that following factors have affected on retinopathy: duration of diabetes, hemoglobin and systolic blood pressure. Moreover, it has been mentioned that duration of diabetes with linear function, hemoglobin with function of degree four and systolic blood pressure with quadratic function was related to retinopathy.   Conclusion: In addition to determination of retinopathy risk factors, it has been shown that generalized additive model can identify nonlinear relationship between variables. Therefore this model increases the quality of predicting response variable, with more information of the data relationships.
2152 Mycology Evaluation of Antifungal activity of new derivatives of Imidazole using Colorimetric method Lotfali Ensieh f Falahati Mehraban g Foroumadi Alireza h Emami Saied i f Tehran University of Medical Sciences g Tehran University of Medical Sciences h Tehran University of Medical Sciences i Mazandaran University of Medical Sciences 1 7 2012 19 97 10 16 18 07 2012   Background : The incidence of invasive fungal infections has been increasing for two decades. Amatter of concern in the treatment of fungal infections is the limited number of efficacious antifungal drugs. Many available drugs lead to the development of resistance, In order to seek new antifungal agents we assessed the antifungal activity of newly synthesized Imidazol compounds by a colorometric method .   Methods: In this experimental study antifungal activity of the new Imidazol compounds against Candida albicans, Saccharomyces cervisiae, Aspergillus niger, Microsporum gypseom was investigated by colorometric method and results were compared to microdilution ones.   Results: 2-hydroxyphenacyl-azole and 2- hydroxyphenacyl-azolium compounds have been identified as a new class of azole antifungal agents with a good spectrum of activity . The colorimetric method is a simple microtiter method for determining the susceptibility of species of fungal against antifungal agents.   Conclusion: Most derivatives showed significant in vitro antifungal activities against tested fungi with low MIC (minimum inhibitory concentration) values included in the range of 0.25-32 µg/mL comparable to the reference drug Fluconazole. 2150 Anesthesiology Fiberoptic intubation Hassani Valiollah j Faiz Seyed Hamidreza k Rahimzadeh Poopak l Sharifian Mahshid m j Tehran University of Medical Sciences k Tehran University of Medical Sciences l Tehran University of Medical Sciences m Tehran University of Medical Sciences 1 7 2012 19 97 17 28 18 07 2012   Airway management is the most important duty of an anesthetist, so more attention should be paid on different educational approaches in tackling difficult airway. Having problems in airway control leads to terrible consequences such as hypoxia and aspiration. Intubation with fiberoptic is a useful method for a safe airway management.   When neck movement is not possible due to cervical spine injury or when direct laryngoscopy and vocal cord vision is not possible, awake oral or nasal fiberoptic intubation or under general anesthesia is very useful. This study’s aim is to introduce a useful scopic device for intubation. 2153 Public Health Investigation of substance use prevalence and the interrelated factors involved through third-year high school students in Nazarabad city from January 2008 to June 2008. Ghavidel Nooshin n Samadi Maryam o Kharmanbiz Amirhossein p Asadi Ali Feyzi Alireza Ahmadi Roghiyeh Abedini Mojtaba Hosseini Fatemeh n Rafsanjan University of Medical Sciences o Kashan University p Ghazvin university of Medical Sciences Tehran University Zahedan University of Medical Sciences Tehran University of Medical Sciences Isfahan university of Medical Sciences Tehran University 1 7 2012 19 97 29 37 18 07 2012   Background : Opioids are one of the most prevalent hygienic difficulties of the country and are causes of prevalence of some dangerous diseases such as AIDS and Hepatitis. Studies show relatively more prevalence of substance use in 15-35 years old students in the country. The purpose of the present study is investigation prevalence of substance use and the interrelated factors involved with third-year high school students in Nazarabad city.   Methods: This is a cross sectional study done on 400 students including 204 female and 196 male of third-year of high school in Nazarabad city by random sampling.   Research instruments were questionnaire Investigating substance use in young students and MMPI test. The methods of data analysis, were descriptive statistics methods, Pearson and Chi-Square tests, in the format of software program of SPSS 11/5.   Results: The findings of the study reveal that 24/5% students were users of substances such as: cigarette, alcohol, opium, psychoactive substances, heroin, heroin crack, LSD, cannabis and cocaine. Prevalence of substance use was expressively more in males ( % 69/7) than females ( % 26/2) and the most important cause of use was amusement ( % 42/5) and curiosity ( % 29/9). Prevalence of substance use in suburban boys’ high schools is more than urban boys’ high schools. Prevalence of psychological disease was similar to usual individuals but some disease such as psychotic disorders, hysteric, adjustment disorders and OCD in substance users was more than usual students.   Conclusion: The prevalence of substance use in teenagers is high and the most cause of use is entertainment and curiosity, Therefore some steps should be taken to resolve this problem. 2154 Ophthalmology Posterior corneal elevation changes after photorefractive keratectomy Damanpak Vahid Ghasemi Mohammad Sadegh Nasiri Nader Doostdar Asgar Tehran University of Medical Sciences Tehran University of Medical Sciences Shahid Beheshti University of Medical Sciences Tehran University of Medical Sciences 1 7 2012 19 97 38 44 18 07 2012   Background : Posterior corneal elevation changes are keys to early diagnosis of corneal ectasia after keratorefractive surgery, so it is important to use an accurate method for measuring posterior corneal elevation. The purpose of this study is investigating posterior corneal elevation changes with Pentacam(HR) on patients underwent photorefractive keratectomy.   Methods: In this clinical trial and prospective study, Pentacam was used to evaluate changes in posterior corneal elevation before and after photorefractive keratectomy in 32 eyes of 16 patients. Posterior corneal elevation defined by maximum elevation before and after surgery and posterior corneal displacement defined by maximum difference in posterior elevation before and after surgery in the central 4mm zone. SPSS for windows ) version 17) was used for data analysis and Paired T test was used for statistical analysis.   Results: The mean age of patients was 25.17±7.11 years and the mean of equivalent sphere was -3.75±1.14 diopters. After photorefractive keratectomy, mean posterior corneal displacement was -0.84±3.53 micrometers and mean posterior corneal elevation before and after surgery was 5.38±4.12 and 4.31±5.05 micrometers respectively (p=0.108) .   Conclusion: There was no statistically significant difference in posterior corneal elevation values between before and after photorefractive keratectomy and no case of corneal ectasia with Pentacam, that was contrary to results obtained with Orbscan in previous studies . Our study suggests that Pentacam can show more accurate values of posterior corneal elevation in comparison to Orbscan. More studies must be performed to verify our conclusion. 2155 Biophysics Possibility Analysis of using radioisotope neutron sources at Boron neutron capture therapy Abdullahzade Masood Ghasemi Abbas Salehi Rohollah Taheri Mohammad University of Imam Hossein Islamic Azad University University of Imam Hossein University of Imam Hossein 1 7 2012 19 97 45 53 18 07 2012   Background : Performing successful BNCT experiments needs a suitable neutron source. Important factors of the neutron beam are flux and energy that are very important in the selection of neutron source. In most centers that use this method for treatment, reactor is a neutron source, which according to characteristics of the reactor appropriated neutrons are very high. High cost of constructing a BNCT center with using of reactor caused seeking other sources such as accelerator indirectly and radioisotope source directly that each has their own advantage and disadvantages. In this paper we created neutron beam by analysis Am-Be neutron source, using neutron filter technique and suitable moderators. The advantages of Am-Be neutron source are being inexpensive, easy portability, small size and well-designed shields. Therefore, by analyzing radioisotope neutron sourcesand Am-Be neutron source specially, we can prepare possible analysis radioisotope neutron source at boron neutron capture therapy. We hope to achieve suitable results by more studies.   Methods: Neutron beam in 1keV energy created with using Am-Be neutron source and designed suitable neutron filter with using neutron absorbent materials that it will be used in testing BNCT. By studying and Identifying various materials such as oxides Alumina, graphite and beryllium as a moderator and materials such as boron, cadmium and titanium as absorbent materials to a cylindrical crust in filter has been used. Neutron Filter has been designed in the investigation of two parts. The first is consisting of a moderator with high scattering and very low percent and it is caused the fast Neutron servant brought back his spectrum Am-Be source in this without mono-energetic to the low energy transferred spectrum. Part II filter is consisting of the elements of boron, cadmium and titanium that are absorbent neutron with various energy, therefore they can exchange these neutrons in certain energy to mono-energetic. More analysis, study and designing suitable neutron conductors for increase neutron flux is recommended.   Results: Neutron filter passes neutron with energy 1keV that can be used in the BNCT experiments. According to data obtained from the implementation MCNP4C code, a peak is obtained in energy 1keV that indicate area under the flux 2.22E-05 n/cm2.s with error 0.0065 for a neutron. Flux obtained can be multiplied at the Am-Be source of power that is equal 108n/cm2.s until the total flux to be achieved. The total flux is obtained 2.22E+03n/cm2.s at 1 cm2. We must multiply total intensity at total area to achieve total neutron flux, Since the flux required for the BNCT experiments is 5*108n/cm2.s with using different ways and designing suitable reflectors and conductors, this neutron flux will be provided.   Conclusion: This paper analyzed possible use of radioisotope neutron source by simulation Am-Be neutron source. We can solve many problems that exist for reactor source paying attention to characteristics of radioisotope sources such as being inexpensive, easy portability and small size also more studies are present in this base. Of course, with completing this simulation, we can be hopeful for practicality and remedy of patients in Iran.