Is Umbilicocerebral Ratio better than Cerebroplacental Ratio for Predicting Adverse Pregnancy and Neonatal Outcomes?

Objective A secondary analysis of the trial of randomized umbilical and fetal flow in Europe suggested that the umbilicocerebral ratio (UCR) provides better differentiation of neurodevelopmental outcome in the abnormal range compared with that of the cerebroplacental ratio (CPR).1 However, the reported superiority of UCR is controversial.2 This study aimed to compare the CPR and the UCR for predicting operative delivery for presumed fetal compromise and prolonged neonatal unit (NNU) admission in term fetuses suspected to be small for gestational age (SGA). Study Design This study was a retrospective analysis of singleton pregnancies with estimated fetal weight less than the 10th centile (SGA) at 36 weeks’ gestation or beyond at St George’s Hospital in London between 1999 and 2015. CPR was calculated as the ratio of middle cerebral artery and umbilical artery pulsatility index, whereas UCR was calculated as the inverse of CPR. The outcomes were operative delivery for presumed fetal compromise and prolonged NNU admission (admission to the NNU for longer than 48 hours).3 Multiples of medians (MoMs) were calculated using the reference ranges reported by Acharya et al.4 The predictive accuracy was assessed using receiver operating characteristic curves. Results The analysis included 958 pregnancies. The incidence rates of operative delivery and prolonged NNU admission were 17.6% (169 of 958) and 4.7% (45 of 958), respectively. The CPR (median: 1.63 vs 1.51) and UCR (median: 0.61 vs 0.66) values were significantly different in fetuses who underwent operative delivery for presumed fetal compromise compared with those who did not (P=.015 for both). There were no statistically significant differences in either UCR or CPR between those with and without prolonged NNU admission (P=.230 for both). The number of outlier values without MoM correction was significantly more with UCR compared with CPR in those who did not have operative delivery for presumed fetal compromise (5.6%, 44 of 789, vs 1.6%,13 of 789; P<.001) and prolonged NNU admission (5.0%, 46 of 913, vs 1.5%, 14 of 913; P<.001). The area under the curve (AUC) values of UCR and CPR for predicting operative delivery for presumed fetal compromise (AUC, 0.56; 95% confidence interval [CI], 0.51–0.61) and prolonged NNU admission (AUC, 0.55; 95% CI, 0.46–0.64) were the same (Figure)

Cancer-testis gene expression is associated with the methylenetetrahydrofolate reductase 677 C\u3eT polymorphism in non-small cell lung carcinoma

BACKGROUND: Tumor-specific, coordinate expression of cancer-testis (CT) genes, mapping to the X chromosome, is observed in more than 60% of non-small cell lung cancer (NSCLC) patients. Although CT gene expression has been unequivocally related to DNA demethylation of promoter regions, the underlying mechanism leading to loss of promoter methylation remains elusive. Polymorphisms of enzymes within the 1-carbon pathway have been shown to affect S-adenosyl methionine (SAM) production, which is the sole methyl donor in the cell. Allelic variants of several enzymes within this pathway have been associated with altered SAM levels either directly, or indirectly as reflected by altered levels of SAH and Homocysteine levels, and altered levels of DNA methylation. We, therefore, asked whether the five most commonly occurring polymorphisms in four of the enzymes in the 1-carbon pathway associated with CT gene expression status in patients with NSCLC. METHODS: Fifty patients among a cohort of 763 with NSCLC were selected based on CT gene expression status and typed for five polymorphisms in four genes known to affect SAM generation by allele specific q-PCR and RFLP. RESULTS: We identified a significant association between CT gene expression and the MTHFR 677 CC genotype, as well as the C allele of the SNP, in this cohort of patients. Multivariate analysis revealed that the genotype and allele strongly associate with CT gene expression, independent of potential confounders. CONCLUSIONS: Although CT gene expression is associated with DNA demethylation, in NSCLC, our data suggests this is unlikely to be the result of decreased MTHFR function

Cancer-testis gene expression is associated with the methylenetetrahydrofolate reductase 677 C>T polymorphism in non-small cell lung carcinoma

Background: Tumor-specific, coordinate expression of cancer-testis (CT) genes, mapping to the X chromosome, is observed in more than 60% of non-small cell lung cancer (NSCLC) patients. Although CT gene expression has been unequivocally related to DNA demethylation of promoter regions, the underlying mechanism leading to loss of promoter methylation remains elusive. Polymorphisms of enzymes within the 1-carbon pathway have been shown to affect S-adenosyl methionine (SAM) production, which is the sole methyl donor in the cell. Allelic variants of several enzymes within this pathway have been associated with altered SAM levels either directly, or indirectly as reflected by altered levels of SAH and Homocysteine levels, and altered levels of DNA methylation. We, therefore, asked whether the five most commonly occurring polymorphisms in four of the enzymes in the 1-carbon pathway associated with CT gene expression status in patients with NSCLC.Publisher's Versio

Joint Prior Distributions for Variance Parameters in Bayesian Analysis of Normal Hierarchical Models

In random effect models, error variance (stage 1 variance) and scalar random effect variance components (stage 2 variances) are a priori modeled independently. Considering the intrinsic link between the stages 1 and 2 variance components and their interactive effect on the parameter draws in Gibbs sampling, we propose modeling the variances of the two stages a priori jointly in a multivariate fashion. We use random effects linear growth model for illustration and consider multivariate distributions to model the variance components jointly including the recently developed generalized multivariate log gamma (G-MVLG) distribution. We discuss these variance priors as well as the independent variance priors exercised in the literature in different aspects including noninformativeness and propriety of the associated posterior density. We show through an extensive simulation experiment that modeling the variance components of different stages multivariately results in better estimation properties for the response and random effect model parameters compared to independent modeling. We scrutinize the sensitivity of response model coefficient estimates to the parameters of considered noninformative variance priors and find that their full conditional expectations are insensitive to noninformative G-MVLG prior parameters. We apply independent and joint models for analysis of a real dataset and find that multivariate priors for variance components lead to better fitted hierarchical model than the univariate variance priors. (C) 2015 Elsevier Inc. All rights reserved.WoSScopu

A new multimodal and asymmetric bivariate circular distribution

Multimodal and asymmetric bivariate circular data arise in several different disciplines and fitting appropriate distribution plays an important role in the analysis of such data. In this paper, we propose a new bivariate circular distribution which can be used to model both asymmetric and multimodal bivariate circular data simultaneously. In fact the proposed density covers unimodality as well as multimodality, symmetry as well as asymmetry of circular bivariate data. A number of properties of the proposed density are presented. A Bayesian approach with MCMC scheme is employed for statistical inference. Three real datasets and a simulation study are provided to illustrate the performance of the proposed model in comparison with alternative models such as finite mixture Cosine model

Bayesian estimation of crop yield function: drought based wheat prediction model for tigem farms

Drought is one of the biggest threats that affects agriculture. Based on recent climatic observations and future projections, drought continues to increase its harmful impact on agricultural productivity especially in the arid areas of Turkey. Wheat farming in these arid and semi-arid areas such as Central Anatolia depends heavily on precipitation, thus monitoring for drought is needed. The timing of precipitation is also as important as its quantity. This study makes use of a crop and location specific model developed by FAO to simulate water related variables such as evapotranspiration, water deficiency and water satisfaction index to estimate the crop yield function for rain-fed wheat production in the arid regions of Turkey. A spatio-temporal yield model is estimated by Bayesian method known as Markov Chain Monte Carlo. By standardizing the simulated variables over normalized difference vegetation index (NDVI), impact of drought related variables on wheat yield is studied and two variables are found. Use of NDVI, as a numeraire, comes in handy in many ways. For actual evapotranspiration estimate, it strengthens separation between evaporation and transpiration and, for water deficiency, it better represents the drought properties of farms for the terrain chosen

Powerful Multilocus Tests of Genetic Association in the Presence of Gene-Gene and Gene-Environment Interactions

In modern genetic epidemiology studies, the association between the disease and a genomic region, such as a candidate gene, is often investigated using multiple SNPs. We propose a multilocus test of genetic association that can account for genetic effects that might be modified by variants in other genes or by environmental factors. We consider use of the venerable and parsimonious Tukey’s 1–degree-of-freedom model of interaction, which is natural when individual SNPs within a gene are associated with disease through a common biological mechanism; in contrast, many standard regression models are designed as if each SNP has unique functional significance. On the basis of Tukey’s model, we propose a novel but computationally simple generalized test of association that can simultaneously capture both the main effects of the variants within a genomic region and their interactions with the variants in another region or with an environmental exposure. We compared performance of our method with that of two standard tests of association, one ignoring gene-gene/gene-environment interactions and the other based on a saturated model of interactions. We demonstrate major power advantages of our method both in analysis of data from a case-control study of the association between colorectal adenoma and DNA variants in the NAT2 genomic region, which are well known to be related to a common biological phenotype, and under different models of gene-gene interactions with use of simulated data

Relationships Between Epidemiological Features and Tumor Characteristics of Breast Cancer

Objectives. Breast cancer is a histological, morphological and molecular heterogenous disease. Like clinical outcomes and prognoses of different subtypes, etiologies might also be different. Therefore, epidemiologic risk factors like sociologic, demographic, antropometric, reproductive, and menstrual factors can be considered as an entity reflected in tumor features. This study was planned to explore the relation between well known risk factors of breast cancer and histological and molecular features of the tumor. Materials and Methods. Epidemiologic data for 250 breast cancer patients followed-up by our clinic and 250 healthy individuals without any diagnosis of malignancy were obtained. The data displaying a relation to breast cancer are age, height, weight, body mass index (BMI), place of birth and province, educational level, menstrual status, age of menarche and menopause, number of births, age at first childbirth, family history of breast cancer, history of smoking and hormone treatment, mammographic screening, and presence of benign lesions. The tumor characteristics of patients in the breast cancer group were recorded. Results. Advanced age, nulliparity, low educational level, irregular mammographic screening, early menarche and late menopause, and high BMI in postmenopausal period were found to be related to increased breast cancer risk. Striking results in terms of the relation between epidemiological factors and tumor features were the early diagnosis of breast cancer in patients with regular mammographic screening. Tumor size was decreased with increased age and increased with increased BMI. Advanced age, prolonged lactation, increased number of births, and high education level were found to decrease axillary involvement. Conclusions. Multiparity still continues to be the strongest protective factor against breast cancer in our society. The decrease in menarche age may be an early sign of the increased breast cancer incidence. Women should be informed about the relation between postmenopausal obesity and breast cancer and encouraged to attend physical activity and exercise programmes. Regular physical examination and mammographic screening are protective against breast cancer

Impacts of salinity and fish-exuded kairomone on the survival and macromolecular profile of Daphnia pulex

Global warming is already causing salinization of freshwater ecosystems located in semi-arid regions, including Turkey. Daphnids, which are important grazers on phytoplankton and a major food source for fish and invertebrates, are sensitive to not only changes in salinity levels, but also presence of predators. In this study, the interactive effect of salinity toxicity (abiotic factor) with predation pressure mimicked by the fish-exuded kairomone (biotic factor) and the effect of salt acclimation on daphnids were investigated. Impacts of these stressors on daphnid survival, life history and molecular profile were observed. The presence of the kairomone antagonistically alters the effect of salinity, as observed from the 24- and 48-h LC50 values and survival results. Molecular findings provided solid evidence to this antagonism at even lower salt concentrations, for which antagonism was not evident with organismal data. Fish predation counterbalances the negative effect of salinity in terms of reserve energy density. Therefore, it is important to investigate multiple stressor effects in ecotoxicological bioassays complemented with molecular techniques. The single effect of increasing salinity resulted in increased mortality, decreased fecundity, and slower somatic growth in Daphnia, despite their acclimation to salinity. This insignificance of acclimation indicates that Daphnia do not have any physiological mechanisms to buffer the adverse effects of salinity, making it a very crucial factor. Salinity-induced reduction in population growth rate of freshwater keystone species Daphnia-despite acclimation-indicates that global warming-induced salinity may cascade through the food web and lead to dramatic environmental consequences in the structure of lake ecosystems

Effects of in utero cord blood collection on post-cesarean hemoglobin levels

Objective: To assess effects of in utero cord blood collection on postoperative hemoglobin, hematocrit levels