Dosimetric characteristics of the <Superscript>192</Superscript>Ir high-dose-rate afterloading brachytherapy source

Purpose  

For the treatment of some cancerous tumors using brachytherapy, an American Association of Physicists in Medicine (AAPM) Task Group No. 43U1 report recommends that the dosimetric parameters of a new brachytherapy source must be determined in two experimental and Monte Carlo theoretical methods before using each new source clinically. This study presents the results of Monte Carlo calculations of the dosimetric parameters for a Ir2.A85-2 brachytherapy source design.     

High Frequency of Genes’ Promoter Methylation, but Lack of BRAF V600E Mutation among Iranian Colorectal Cancer Patients

Gene silencing due to DNA hypermethylation is a major mechanism for loss of tumor suppressor genes function in colorectal cancer. Activating V600E mutation in BRAF gene has been linked with widespread methylation of CpG islands in sporadic colorectal cancers. The aim of the present study was to evaluate the methylation status of three cancer-related genes, APC2, p14ARF, and ECAD in colorectal carcinogenesis and their association with the mutational status of BRAF and KRAS among Iranian colorectal cancer patients. DNA from 110 unselected series of sporadic colorectal cancer patients was examined for BRAF V600E mutation by PCR-RFLP. Promoter methylation of genes in tumors was determined by methylation specific PCR. The frequency of APC2, E-CAD, and p14 methylation was 92.6%, 40.4% and 16.7%, respectively. But, no V600E mutation was identified in the BRAF gene in any sample. No association was found in cases showing epigenetic APC, ECAD, and p14 abnormality with the clinicopathological parameters under study. The association between KRAS mutations and the so called methylator phenotype was previously reported. Therefore, we also analyzed the association between the hot spot KRAS gene mutations in codons of 12 and 13 with genes' promoter hypermethylation in a subset of this group of patients. Out of 86 tumors, KRAS was mutated in 24 (28%) of tumors, the majority occurring in codon 12. KRAS mutations were not associated with genes' methylation in this tumor series. These findings suggest a distinct molecular pathway for methylation of APC2, p14, and ECAD genes from those previously described for colorectal cancers with BRAF or KRAS mutations.     

Systematic review of modulators of benzodiazepine receptors in irritable bowel syndrome： Is there hope？

Several drugs are used in the treatment of irritable bowel syndrome(IBS) but all have side effects and variable efficacy.Considering the role of the gut-brain axis,immune,neural,and endocrine pathways in the pathogenesis of IBS and possible beneficial effects of benzodiazepines(BZD) in this axis,the present systematic review focuses on the efficacy of BZD receptor modulators in human IBS.For the years 1966 to February 2011,all literature was searched for any articles on the use of BZD receptor modulators an...     

The association of parental obesity with physical activity and sedentary behaviors of their children: the CASPIAN-V study

Objective

Low physical activity and sedentary behaviors, two important determinants of childhood obesity, may be influenced by parental lifestyle and weight status. This study aims to determine the association of parental weight status with children's physical activity and screen time.

A systematic review of the impact of n-3 fatty acids in bone health and osteoporosis.

Osteoporosis, especially in postmenopausal women, delineates a major health and economic problem in the world. Regarding the pathogenesis of osteoporosis and the interaction between various cells and mediators, many studies have been conducted to evaluate the benefit of different therapeutic options. Over the past several years evidence has been growing on the effects of dietary fatty acids on bone health. The objective of this paper was to provide a review of the current knowledge of dietary fatty acids and osteoporosis. Medline/Index Medicus and EMBASE/Excerpta Medica were searched for relevant papers regarding the effects of n-3 fatty acids on osteoporosis between 1963 and 2007 using the key words: osteoporosis, bone health, n-3 fatty acids, and PUFA. Bone mineral density and bone markers have been used in several animal studies to evaluate the beneficial effect of n-3 fatty acids on bone health and the prevention of osteoporosis. Generally, animal studies support the beneficial effects of n-3 fatty acids on bone health and osteoporosis; however, the dissimilar lipid metabolism in human and animals, the various study designs, and controversies over the human study outcomes make it difficult to draw a definite conclusion. The authors believe that conclusive findings in humans are still lacking in this area and it needs to be further investigated.     

Fetal pulse oximetry: correlation between oxygen desaturation,duration, and frequency and neonatal outcomes

OBJECTIVE: The purpose of this study was to identify the threshold of fetal arterial oxyhemoglobin saturation that predicts neonatal acidosis and adverse outcomes. STUDY DESIGN: Fetal oxygen saturation data from a published randomized controlled trial of fetal pulse oximetry were evaluated in relation to the number and duration of low fetal oxygen saturation episodes and neonatal outcomes. Fetal oxygen saturation episodes (epochs) of at least 10-second duration were categorized into the following groups: (1). <30% and >or=25%, (2). <25% and >or=20%, (3). <20%, and (control) randomly selected control subjects >30%. RESULTS: One hundred seventy-four fetal heart rate tracings were identified. An analysis of mean umbilical artery pH revealed a significant difference between groups 1 and 3 compared with the control subjects. The incidence of adverse neonatal outcome was significantly greater when the number of epochs exceeded 10. An analysis of the duration of fetal oxygen saturation of <30%, as correlated with neonatal compromise, was not significant. CONCLUSION: This study confirms previous findings that fetal oxygen saturation of <30% is associated with declining fetal arterial pH. There appears to be an association between adverse neonatal outcomes and >10 epochs of <30%.