The impact of N-myc amplification on median survival in children with neuroblastoma

Background: Neuroblastoma is the most common extracranial malignant solid tumor in children under 5 years, and it is characterized by wide clinical and biological heterogeneity. N-myc oncogene amplification is considered to be one of the most important prognostic factors used to evaluate survival in these patients. Objectives: The aim of our study was to determine amplification of the N-myc oncogene using real-time quantitative polymerase chain reaction (PCR) and to show the influence of N-myc amplified tumors on the overall survival rate. Patients and Methods: This study is an analytical historical cohort study of forty children with neuroblastoma admitted to the Shafa Hospital, Iran from 1999 to 2010. Paraffined blocks of tumoral tissue were analyzed for N-myc amplification by a PCR. The degree of N-myc amplification was derived from the ratio of the N-myc oncogene and the single copy reference gene, NAGK. In the statistical analysis, a Kaplan-Meier survival analysis was used. Results: We found a variable degree of N-myc amplification, from 3 to 2 200, in 32 of the 40 neuroblastomas (80%). NMYC amplification was seen more frequently in patients older than 2.5 years (71.9%), stage 4 (65.6%) and female (53.1%). Median survival time in the males was significantly longer than in the females (P = 0.03). The overall median survival for N-myc amplified tumor patients was 20 months, and 30 months for the non amplified tumors. Conclusions: The N-myc amplified tumors may increase the probability of more aggressive behavior and rapid tumor progression, especially in advanced stages of neuroblastoma. This study confirmed the importance of obtaining correct measurements of oncogene amplification in the early evaluation of neuroblastomas in order to target more aggressive therapies in patients with a higher risk of cancer progression

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 (P0.05). 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. © 2016 Tehran University of Medical Sciences. All rights reserved.

Free transverse vibration analysis of laminated composite beams with arbitrary number of concentrated masses

In this study, a new closed-form solution for transverse free vibration analysis of laminated composite beams (LCBs) with arbitrary number of concentrated masses is developed. The LCB is modeled based on the Euler–Bernoulli beam theory and concentrated masses are simulated considering Dirac delta function. Obtained governing equations are, then, solved semianalytically, while the frequency equation and mode shapes are extracted for two different boundary conditions, i.e., clamped-free and simply supported. In order to verify the closed-form solution, the represented model is simplified for a beam without concentrated mass and outcomes are compared with available results in the literature. Finally, the effects of mass as well as location and number of concentrated masses on the free vibration response of the beam are investigated in detail. The results highlight that with increase in the value of point masses, the natural frequencies decrease. Also, it was revealed that the number of point masses influences on the vibration of cantilever beam more than the simply supported one. These outcomes would practically be used to minimize detrimental effects of vibrational noises, leading to increase in the structural components’ lifetime

Bond strength of resin cement to CO2 and Er:YAG laser-treated zirconia ceramic

Objectives It is difficult to achieve adhesion between resin cement and zirconia ceramics using routine surface preparation methods. The aim of this study was to evaluate the effects of CO2 and Er:YAG laser treatment on the bond strength of resin cement to zirconia ceramics. Materials and Methods In this in-vitro study 45 zirconia disks (6 mm in diameter and 2 mm in thickness) were assigned to 3 groups (n = 15). In control group (CNT) no laser treatment was used. In groups COL and EYL, CO2 and Er:YAG lasers were used for pretreatment of zirconia surface, respectively. Composite resin disks were cemented on zirconia disk using dual-curing resin cement. Shear bond strength tests were performed at a crosshead speed of 0.5 mm/min after 24 hr distilled water storage. Data were analyzed by one-way ANOVA and post hoc Tukey's HSD tests. Results The means and standard deviations of shear bond strength values in the EYL, COL and CNT groups were 8.65 ± 1.75, 12.12 ± 3.02, and 5.97 ± 1.14 MPa, respectively. Data showed that application of CO2 and Er:YAG lasers resulted in a significant higher shear bond strength of resin cement to zirconia ceramics (p < 0.0001). The highest bond strength was recorded in the COL group (p < 0.0001). In the CNT group all the failures were adhesive. However, in the laser groups, 80% of the failures were of the adhesive type. Conclusions Pretreatment of zirconia ceramic via CO2 and Er:YAG laser improves the bond strength of resin cement to zirconia ceramic, with higher bond strength values in the CO2 laser treated samples

Flexural Strength of Cold and Heat Cure Acrylic Resins Reinforced with Different Materials

Objectives: Heat-polymerized acrylic resin has been the most commonly used denture base material for over 60 years. However, the mechanical strength of acrylic resin is not adequate for long-term clinical performance of dentures. Consequently, fracture is a com- mon clinical occurrence, which often occurs in the midline of denture base.This study aimed to evaluate the efficacy of cold cure and heat cure acrylic resins, rein- forced with glass fibers, polyethylene fibers, and metal wire for denture base repair. Materials and Methods: Ninety specimens were prepared and allocated to nine groups. Ten specimens were included in the control group, and 80 were allocated to 8 experi- mental groups. In the experimental groups, the specimens were sectioned into two halves from the middle, and were then divided into two main groups: one group was repaired with heat cure acrylic resin, and the other with cold cure acrylic resin. Each group was di- vided into 4 subgroups: unreinforced, reinforced with glass fibers, polyethylene fibers, and metal wire. All specimens were then subjected to a 3-point bending test, and the flexural strength was calculated. Results: The group repaired with heat cure acrylic resin and reinforced with glass fiber showed the highest flexural strength; however, the group repaired with cold cure acrylic resin and reinforced with polyethylene fibers had the lowest flexural strength. There was no significant difference between the groups repaired with heat cure and cold cure acrylic resins without reinforcement. Conclusion: Repairing denture base with heat cure acrylic resin, reinforced with glass fi- bers increases the flexural strength of denture base

Tissue Doppler Echocardiographic Findings of Left Ventricle in Children with Sickle-Cell Anemia

Background: Sickle-cell disease (SCD) is an inherited hemoglobin childhood disorder, frequently complicated by pulmonary hypertension and cardiac involvement. Cardiovascular events and complications are the leading cause of mortality and morbidity in patients with SCD. Tissue Doppler imaging and the myocardial performance index (Tei index), are simple indices for the assessment of the cardiac function. The purpose of this study was to assess the left ventricular function in children with SCD. Methods: Sixty-four patients with SCD (mean age = 11.7 ± 5.5 years) were compared with 50 age matched healthy controls (mean age = 11.2 ± 5.20 years). Myocardial wall motion velocities at the lateral mitral annulus and the junction between the medial mitral annulus and the interventricular septum were assessed during systole (Sa), early diastole (Ea), and late diastole (Aa) through a four-chamber view using pulsed Doppler echocardiography. The ejection fraction and shortening fraction were estimated. The Tei index was estimated via tissue Doppler echocardiography. Results: The results showed that Ea and Aa velocity in the mitral annulus and interventricular septum had no difference between the patients and controls (p value > 0.05), and nor was there any difference between the two groups as regards the Tei index, Ea/Aa, ejection fraction, and shortening fraction (p value > 0.05). Sa difference between the two groups (p value < 0.038).wave velocity, however, had a significant Conclusion: The Tei index is a sensitive indicator for the cardiac function in chronic diseases and the right ventricular function in some disorders such as SCD

The effect of neck proprioception neuromuscular facilitation exercises program on dynamic balance and performance of female basketball players

Background and purpose:&nbsp;Basketball is a dynamic sport that keeping balance is an important factor to improve performance. Therefore, the purpose of this study was to investigate the effect of PNF neck exercises program on dynamic balance and sports performance (penalty throw) of female basketball players.Materials and methods: 30 basketball players were randomly divided into two intervention-control groups.&nbsp;Athletes in the intervention group participated in the 4-week scheduled program of PNF neck exercises. The control group performed only their daily routine exercises.Results:&nbsp;The results showed that dynamic balance indicators were decreased and free-throw basketball test in the intervention group was significantly increased after four weeks of PNF neck exercises that these changes were statistically significant in comparison with the control group and before performing exercise protocol (p&lt;0.05). Conclusion: According to the results, it seems that PNF neck exercises can be beneficial for enhancing dynamic balance and performance of female basketball players.</p

The characteristics of pre-diabetic patients associated with body composition and cardiovascular disease risk factors in the Iranian population

Background: Different populations have shown various patterns of association between impaired fasting glucose (IFG) and body composition parameters and risk factors of cardiovascular disease (CVD). The current study aimed at investigating the differences between persons with prediabetes and healthy people in terms of CVD risk factors including body composition parameters, blood pressure, and lipid profile in a sample of the Iranian population. Materials and Methods: In a case-control setting, a sample containing 386 (193 prediabetic subjects and 193 normal subjects) of the first-degree relatives of diabetic patients aged 35-55 years were investigated. Samples were assessed using glucose tolerance categories. Prediabetes was defined according to the American Diabetes Association (ADA) criteria. Body composition parameters, blood pressure, glucose parameters, and lipid profile were measured and compared between the two groups. Results: Prediabetic patients had higher body mass index (BMI), waist circumference (WC), and body fat (BF) in comparison to the control group (P < 0.05). In addition, prediabetic subject had a higher intake of energy, carbohydrate, protein, fat, and cholesterol and it seems that these patients had an unhealthy dietary intake (P < 0.05). Fasting blood glucose (FBG) (P < 0.001), total cholesterol (P = 0.007), low-density lipoprotein cholesterol (LDL-C), and triglyceride (P = 0.021) were higher in prediabetic patients (P < 0.05) than in the controls. Conclusion: Both the risk factors of CVD and body composition parameters were different between the prediabetic and normal groups; total cholesterol (TC), triglyceride (TG), and FBS were predictors of the risk of prediabetes