ABSTRACT
Background and Objective: Varicella zoster virus [VZV] can cause a moderate disease in children, but with high risk of serious disease or death in children with acute lymphoblastic leukemia [ALL] Vaccination from infection can be safe, immunogenic, and effective in children with leukemia. This study was done to evaluate the IgG and IgM antibodies against VZV in children with acute lymphoblastic leukemia
Methods: The descriptive-analytic study was performed on 66 children who were on chemotherapy in Dr Shigh hospital in Mashhad, Iran during 2012. Patients were receivied VZV vaccine. The title negative or positive serum sample for IgG-anti-VZV avidity was determined by using a test kit before and after injection of vaccines VZV for considering the efficacy of vaccines on pediatric patients
Results: Title serum sample IgG were positive in 32.6% patients, these children have history of chicken pox disease and to be safe against of VZV. 78.3% of the patients were negative for IgG antibody and sensitive against of VZV
Conclusion: Children with ALL receiving chemotherapy are sensitive to chicken pox disease according to negative IgG titer against VZV
Subject(s)
Humans , Male , Female , beta-Thalassemia/complications , Radiography, Thoracic , Echocardiography , HeartABSTRACT
NiTi rotary instruments have been extensively used in the preparation of curved root canals, due to their superelastic quality. These instruments are less susceptible to unexpected fracture as compared to their stainless steel counterparts. However, unexpected fracture of NiTi instruments under complex stress within curved canals can lead to serious problems. The aim of this investigation was to identify and evaluate the various failure mechanisms which can cause fracture of NiTi rotary instruments under clinical conditions. The causes of failure of two brands of Hero and Profile rotary files have been studied. A total of 1133 instruments that failed during clinical use were collected from several dental clinics. After inspection under a stereomicroscope, all instruments were classified as either plastically deformed or fractured. The fracture surfaces of all broken instruments were examined following ultrasonic cleaning in ethanol and acetone, 30 minutes each. The fracture surfaces of more than 70 broken instruments were subjected to fractographic analysis using a scanning electron microscope. More than 68% of the 1133 specimens were fractured. Stereomicroscopic inspection showed three failure mechanisms for the studied instruments: fracture, plastic deformation due to bending and torsion and a combination of both mechanisms. Based on fractographic observations, microvoid coalescence and cyclic stable crack growth by striation formation were identified. According to these results, excessive plastic deformation and fracture may be considered as the two main mechanisms responsible for the failure of NiTi rotary instruments