Search

Introduction: The study was performed to investigate the dependency of the wedge factors (WF) ofa linac internal wedge with the depth and field size for 6MV photon beams. In addition, the currentstudy was performed in order to accurate determination of the WF to introduce an algorithm to beincorporated it in treatment planning to decrease the level of systematic error due to this factor inclinical applications.Materials An Elekta linac head structure with and without the internal wedge was precisely simulatedbased on the data provided by the manufacturer using MCNP 4C Monte Carlo code. The simulatedlinac was then benchmarked against the experimental measurement. Thereafter, a mini - phantom wassimulated using the same Monte Carlo code. Then, the relevant linac wedge factors due to the internalwedge were determined for different symmetric field sizes of 4, 5, 10, 15, and 20 cm2 at various depthsranged from 0.5 to 34cm, while the mini phantom was present in the fields. The wedge factors weredetermined based on the values, which are measured at 100cm SAD and 10 cm depth for each fieldsize. Linear trend lines were fitted on the set of depth dependent wedge factors for each of the fieldsizes. Then the trend lines’ constants were analyzed for investigating their field size dependency.Results: Results indicated that the wedge factor is dependent on the depth for each field size. Inaddition, it was noted that the level of the wedge factor dependency on the depth varies for differentfield sizes. For example the wedge factor calculated at a depth of 10 cm had a variation of %7.4 whenthe field size varied from 4 to 20 cm2 symmetric square fields.Conclusion: : In this study, a more accurate algorithm was determined that it can be used instead ofthe usual wedge factor look-up tables used for MU calculation in radiotherapy planning. The variationof the photon beam due to these circumstances can be determined accurately using Monte Carlomethod and the proposed algorithm. This algorithm enables us to reduce the level of possiblesystematic errors encountered in clinical practices.

Background & Objective: Using parametric models is common approach in survival analysis. In the recent years, artificial neural network (ANN) models have increasingly used in survival prediction. The aim of this study was to predict of survival rate of patients with gastric cancer by using a parametric regression and ANN models and compare these methods. Methods: We used the data of 436 gastric cancer patients from a cancer registry in Tehran between 2002-2007. All patients had a confirmed diagnosis. Data were randomly divided into two groups: training and testing (or validation) set. For analysis of data we used a parametric model (exponential, Weibull, normal, lognormal, logistic and log-logistic models) and a three layer ANN model. In order to compare of the prediction of two models, we used the area under receiver operating characteristic (AUROC) curve, classification table and concordance index. Results: The prediction accuracy of the ANN and the parametric (Weibull) models were 79.45% and 73.97% respectively. The AUROC for the ANN and the Weibull models were 0.815 and 0.748 respectively. Conclusions: The ANN had a better predictions than the Weibull model. Thus it is suggested to use of the ANN model survival prediction in field of cancer.

The present study was aimed at investigating the awareness level about warning signs of cancer and its determinants in an Iranian general population. This cross-sectional interview-based survey investigated 2,500 people aged 18 years and over, as a representative sample of Tehran population. Latent class regression was applied for analyzing data. A small (18.8%) proportion of the respondents had high level of knowledge, and 54.5% had moderate awareness, and 26.7% had low level of awareness. Most effective predictors for awareness were educational attainment, sex, and marital status. The findings suggest that the overall level of knowledge about warning signs of cancer among the public is low, particularly about some specific signs. Accordingly, educational and intervention programmes, with special attention placed on particular at-risk populations, to increase awareness about the disease leading to its early diagnosis are needed.

Allergic Rhinitis (AR) is a common global health problem with approximately one quarter of the world population affected. The Quality of Life (QOL) of sufferers with AR is significantly affected. The aim of this study was to evaluate the QOL of adults with AR. This study was designed for adults with AR above 18 years old. The study was conducted using a valid Rhinitis Quality of Life Questionnaires (RQLQ) which was completed for each patient during clinic visit and analyzed by applying statistical methods. One-hundred and ten AR patients participated in this study. Mean age of these patients was 32 years old and 62% were female. The correlation between severity of AR and QOL impairment was significant. Frequencies of mild persistent, moderate-severe persistent, mild intermittent and moderate- severe intermittent types of AR were 18%, 34.5%, 9% and 38%, respectively. Completed RQLQ indicated that about 55% of the cases were suffering from severe disturbances in their QOL. Furthermore, congestion (88%) was the most common symptom. The correlation between congestion and QOL reduction was significant. The correlation between congestion and sleep impairment was significant. AR was more common in young as well as female patients and their QOL was affected more than the others. The results showed a good relevancy between severity of symptoms and QOL scores. Consisting with ARIA classification, it was found that reduction in the quality of life is higher in patients with moderate-severe intermittent and persistent asthma. Nasal congestion was a bothersome and prevalent symptom in AR that was responsible for sleep problems. Therefore, nasal congestion was associated with sleep-disordered breathing, nocturnal sleep impairment, day time fatigue and somnolence which finally lead to QOL impairment.

Background: Asthma is the first cause of children hospitalization and need for emergency and impose high economic burden on the families and governments. We aimed to investigate the economic burden of pediatric asthma and its contribution to family health budget in Iran. Methods: Overall, 283 pediatric asthmatic patients, who referred to two tertiary pediatric referral centers in Tehran capital of Iran, included from 2010-2012. Direct and indirect asthma-related costs were recorded during one-year period. Data were statistically analyzed for finding association between the costs and factors that affect this cost (demographic variables, tobacco smoke exposure, control status of asthma and asthma concomitant diseases). Results: Ninety-two (32.5%) females and 191(67.5%) males with the age range of 1-16 yr old were included. We found the annual total pediatrics asthma related costs were 367.97±23.06 USD. The highest cost belonged to the medications (69%) and the lowest one to the emergency (2%). We noticed a significant increasing in boys’ total costs (P=0.011), and 7-11 yr old age group (P=0.018). In addition, we found significant association between total asthma costs and asthma control status (P=0.011). Conclusion: The presence of an asthmatic child can consume nearly half of the health budget of a family. Our results emphasis on improving asthma management programs, which leads to successful control status of the disease and reduction in economic burden of pediatric asthma.

Allergic sensitization to inhalant allergens could be considered as a predictor in allergic diseases. The objective of this study was to assess IgE-mediated sensitization to inhalant allergens in allergic and non-allergic adults as well as the evaluation of its association with allergic diseases. This cross-sectional study was conducted from 2013 to 2016 in 604 allergic and 102 non-allergic adults selected from blood donor volunteers in Tehran, Iran. After taking informed consent, a standard questionnaire was filled to determine asthma, allergic rhinitis and/or conjunctivitis and atopic dermatitis in participants. Specific IgE assay to common inhalant allergens was performed for all subjects. Logistic regression analysis was used to evaluate the impact of IgE sensitization on allergic diseases. A total of 371(61.4%) allergic subjects and 41(40.2%) non-allergic patients were males. The weeds (especially saltwort) and grasses (particularly meadow fescue and ryegrass) were identified as the most common inhalant allergens. The prevalence of IgE sensitization to trees, weeds, and grasses was higher in subjects with allergic rhino-conjunctivitis and trees sensitization was a significant factor in them [OR=2.32, 95% CI (1.58-3.41)]. IgE sensitization to any inhalant allergens could be a predictor for allergic rhinitis, conjunctivitis and rhino-conjunctivitis in adults [OR=2.20, 95% CI (1.54-3.15], [OR=1.81, 95% CI (1.28-2.54)] and [OR=2.55, 95% CI (1.72-3.78)], respectively. With an increase in the sum of specific IgE concentrations, the prevalence of allergic conjunctivitis and rhino-conjunctivitis also increased. Our results showed the association between positive specific IgE and its concentration with some allergic diseases which could help physicians to prevent such diseases by recognizing and treating them, particularly in individuals with a positive family history of allergic diseases.

Introduction: Colorectal cancer is the most common cancer of digestive system and also fourth cause fordeath of cancer around the world. Different studies indicate that survival of patients suffering fromcolorectal cancer has recently developed in some areas of the world. However, it is not clear which factorsinvolve in this improvement. This study aims at investigating some clinical and pathologic factors inprognosis of these patients with colon and rectum cancers separately.Material and Methods: Data recorded from 1194 patients with colorectal cancer in Cancer RecordCenter of Research Center for Gastroenterology and Liver Disease, Shahid Beheshti University of MedicalSciences (Tehran, Iran) was used in this study. Data analysis was performed using competing risks model.Software used for data analysis was STATA, 11 version, and significance level was regarded as 0.05.Results: Body mass index, alcohol consumption, tumor site, inflammatory bowel disease, metastasis tolymph nodes and metastasis to other organs had significant effect on death of colon cancer, while bodymass index, metastasis to other organs and kind of the first treatment had significant effect (P

Background & Aim: Need assessment for promotion reproductive health is important subject and development a questionnaire is essential. Thus the aim of this study was development of questionnaire of intention to use of oral contraception in withdrawal users based on construct of Theory of Planned Behavior (TPB). Methods & Materials : In-depth interviews were conducted to elicit the salient beliefs relevant to oral contraception among withdrawal users. Then a cross-sectional study carried out in Tehran, Iran for validate of questionnaire. Participants recruited from attending five family planning clinics of public health services in the Eastern district of Tehran, Iran. Validity and reliability was evaluated using concurrent, content validity and Cronbachchr('39')s alpha and test- retest respectively. Factor structure of the questionnaire was extracted by exploratory factor analysis (EFA). Confirmatory factor analysis (CFA) conducted to assess how well the EFA extracted model fits observed data. The SPSS version 16 and Lisrel programs were used to analyze the data. Results: Reliability and validity were confirmed. The principal component analysis revealed a three-factor structure for the questionnaire including attitude, subjective norm and perceive behavior control that explained 50.4 percent of the total of variance. Conclusion : In general, the findings suggest that questionnaire of intention to use of oral contraception in withdrawal users based on Theory of Planned Behavior is a reliable and valid measure.

Studies on HLA-G, a nonpolymorphic antigen of non-classical HLA class I, is of basic and clinical significance. In the present study, the expression of HLA-G proteins in the human skin tissue sections of normal and autoimmune pemphigus vulgaris (PV) individuals were investigated using monoclonal antibodies. The antibodies recognized both membrane-bound and soluble isoforms of HLA-G. RT-PCR was performed to assess the patterns of HLA-G mRNA transcripts in the epidermal cells of PV and normal subjects. HLA-G expression could only be detected at transcriptional level in normal skin tissues. However cells derived from PV subjects expressed detectable HLA-G molecules at both transcriptional and translational levels. In addition, the RT-PCR patterns of HLA-G amplification revealed a reduction in HLA-G2 and an increase in HLA-G1 transcripts in epidermal cells of PV patients as compared to normal cells. These observations further support suggestions in the literature regarding the role of HLA-G in induction of tolerance in autoimmune individuals.

"nBackground: To determine relationships between healths related quality of life and body mass index in children aged 9-11 years old."nMethods: This cross sectional study was conducted on 240 children 9-11 year olds who were selected via multi stage cluster sampling design from primary schools in the Shahre Qods of the Tehran, Iran in 2007. Pediatric Quality of Life inventory was completed by child self report with measured height and weight used to determine body mass index percentile/weight classification. Obesity was defined as body mass index (BMI) ≥95th percentile for age and gender and one way analyses of variance (ANOVA) was used for data analyses."nResults: Physical, social and school functioning was significantly lowered for obese when compared to normal weight children (P

Introduction: Chemotherapy after surgery is one of the adjuvant therapy components in breast cancerpatients. In the current study, Taxane-based and Anthracycline-based regimes were compared toCyclophosphamide, Methotrexate and 5-Fluorouracil (CMF) chemotherapy after modified radicalmastectomy (MRM) surgery in terms of disease-free survival (DFS).Materials and Methods: Sixty-two patients with confirmed breast cancer that underwent MRMsurgery at no metastasis stage (M0) enrolled. These patients were received one of the three types ofadjuvant chemotherapies that mentioned above and the relapse/metastasis in 8-year follow-up wasrecorded. In addition, some paraclinical and demographical factors were recorded and the efficacy of thedifferent chemotherapy regimes was compared using log-logistic survival model.Results: The mean age (SD) of patients was 49 (1.31). More than 40% of patients had tumors withgrade 3. The median time of follow-up was 20.0 months and the rate of 5-year DFS was 48%. Survivalanalysis indicated that type of chemotherapy (OR(Taxane/CMF) =3.676; OR (Anthracycline/CMF) =3.185),histological grade (OR=2.528), tumor size (OR=5.598) and number of lymph nodes (OR=1.112) affectthe DFS.Conclusion: The results of the current study indicated that the efficacy of Taxane-based andAnthracycline-based is more than CMF. This study also showed that early detection of tumor was animportant factor for a successful treatment in terms of DFS, and so, it declares the roll of screening andpublic education.

The purpose of the present study was to explore nurses' perception about spirituality and spiritual care. A qualitative content analysis approach was conducted on 20 registered nurses interviewed using unstructured strategy in 2009. Three themes emerged from the data analysis: 1) "meaning and purpose of work and life" including ‘spiritualistic view to profession', ‘commitment and professional responsibility', and ‘positive attitude'; 2) "religious attitude" including ‘God approval', ‘spiritual reward', ‘taking advice', ‘inner belief in the Supreme Being', ‘faith-based interactions and altruism'; 3) "transcendence-seeking" including ‘need for respect' and ‘personal-professional transcendence'. Therefore, the spirituality produces maintenance, harmony and balance in nurses in relation to God. Spiritual care focuses on respecting patients, friendly and sympathetic interactions, sharing in rituals and strengthening patients and nurses' inner energy. This type of spirituality gives a positive perspective to life and profession, peaceful interactions, a harmonious state of mind, and acts as a motivator among nurses to promote nursing care and spirituality.

Mannose-binding lectin (MBL) is a protein of innate immune system that is involved in opsonization and complement activation. MBL deficiency is associated with predisposition to infectious diseases; however subnormal levels are also seen in healthy subjects. The aim of this study was to investigate the prevalence and clinical manifestation of MBL deficiency in patients with increased susceptibility to infection. We studied the MBL serum concentration of 104 patients with a history of recurrent and/or severe infections referred to Immunology, Asthma and Allergy Research Institute (IAARI) in order to evaluate the primary immunodeficiency (PID). The distribution of MBL deficiency in these patients and 593 healthy subjects of previous study were analyzed. The frequency of individuals with MBL deficiency was significantly higher in patients with recurrent and/or severe infections (13.5% [14/104]) compared with healthy subjects (4.7% [28/593]; p=0.001; OR 3.1, 95% CI 1.5-6.1). However, in 10.9% (7/64) of patients with recurrent infections without any immunodeficiency background, the MBL deficiency was detected. On the whole, our findings indicate an association between MBL deficiency and increased susceptibility to infections.

Background & Objective: Mixed outcomes arise when, in a multivariate model, response variables measured on different scales such as binary and continuous. Artificial neural networks (ANN) can be used for modeling in situations where classic models have restricted application when some of their assumptions are not met. In this paper, we propose a method based on ANNs for modeling mixed binary and continuous outcomes. Methods: Univariate and bivariate models were evaluated based on two different sets of simulated data. The scaled conjugate gradient (SCG) algorithm was used for optimization. To end the algorithm and finding optimum number of iteration and learning coefficient, mean squared error (MSE) was computed. Predictive accuracy rate criterion was employed for selection of appropriate model. We also used our model in medical data for joint prediction of metabolic syndrome (binary) and HOMA-IR (continues) in Tehran Lipid and Glucose Study (TLGS). The codes were written in R 2.9.0 and MATLAB 7.6. Results: The predictive accuracy for univariate and bivariate models based on simulated dataset Ι, where two outcomes associated with a common covariate, were shown to be approximately similar. However, in simulated dataset ΙΙ in which two outcomes associated with different covariates, predictive accuracy in bivariate models were seen to be larger than that of univariate models. Conclusions: It is indicated that the predictive accuracy gain is higher in bivariate model, when the outcomes share a different set of covariates with higher level of correlation between the outcomes.

Mother's and infant exposure to cigarette smoke is one of the most important public health problems. There is no study in Iran evaluating the impact of cigarette smoke on infant growth and development. The purpose of this study was to determine the effects of cigarette. This prospective cohort study was conducted on 51 cigarette smoke-exposed infants (exposed group) and 51 non-exposed infants (non-exposed group). They were evaluated for weight, height and head circumference three times; five to seven days, two months and four months after birth. Urine samples were also collected in each turn. Exposure to secondhand smoke was assessed through questionnaires and urinary cotinine levels. The analysis was performed using an independent t-test, Mann-Whitney U test, chi-square and Fisher's exact and Kappa tests. Mean urinary cotinine level in the exposed group was 38.57±2.85 ng/mg creatinine at baseline, 86.95±1.16 at two months and 63.32±2.08 at four months of age. These indicated a gradual reduction of exposure from two to four months. The weight and height of the exposed group were significantly lower than the non-exposed group (P< 0.001) at two and four months after birth. The results of the present study showed that the exposure to secondhand smoke during infancy may lead to weight and height growth reduction in the first four months of life.

One of the main objectives of quantitative researches is assessment of models developed by qualitative studies. Models validation through their testing implies that the designed model is representative of the existed facts. Hence, this study was conducted to assess the clinical nurses' productivity model presented for Iranian nurses' productivity. The sample of the study consisted of 360 nurses of Tehran University of Medical Sciences. The research tool was a questionnaire for measuring the components of clinical nurses' productivity. After completing all steps of instrument psychometric and getting answers from the participants, the factors introduced in the questionnaire were named and then Lisrel Path Analysis tests were performed to analyze the components of the model. The results of the model test revealed there is an internal relationship among different components of the model. Regression Analysis showed that each increasing unit in components of the model was to be added to central variable of productivity model -human resource. Model components altogether explained 20 % of clinical nurses' productivity variance. This study found that the important component of productivity is human resources that are reciprocally related to other components of the model. Therefore, it can be stated that the managers can promote the productivity by using efficient strategies to correct human resource patterns.

Background The aim of the present study was to estimate the prevalence of mood disorders and examine a range of predictors for psychological well-being among Iranian women with polycystic ovary syndrome (PCOS). Methods A cross-sectional study was undertaken to ascertain the factors related to psychological distress in PCOS patients in Kashan, Iran. Psychological distress was measured using the Hospital Anxiety and Depression Scale (HADS). In addition we assessed quality of life using the Short Form Health Survey (SF-36). Socio-demographic details and clinical information of PCOS including obesity (body mass index), excessive body hair (hirsutism score), acne, menstrual cycle disturbances, infertility and endocrine profile also were recorded for each patient. Results In all 300 women with PCOS were entered into the study. Of these 32% (n =96) showed elevated HADS anxiety while depression was high in 5% (n =15). Quality of life was significantly impaired in women with anxiety (P Conclusions The high prevalence of depression and anxiety in this population suggests that initial evaluation of all women with PCOS should also include assessment of mental health disorders. The clinician should further pay attention to background of their patients especially in view of the factors influencing psychological well-being.