C R Weinberg

..These interesting biological observations prompt a statistical question regarding how to distinguish the synchronized genes from genes that are systematically lagged in phase/peak expression time across two tissues...

..The objective of this study is to determine if multiple systemic autoimmune diseases (SAID) share gene expression pathways that could provide insights into pathogenic mechanisms common to these disorders...

..Conditioning on both the grandparents' and the affected grandchild's genotypes, a third log-linear model captures the remaining information, in an independent LRT for maternal effects...

..In settings where high assay costs constrain the number of people an investigator can afford to study, specimen pooling can make it possible to study more people and hence improve the study's statistical power with no increase in cost...

..The investigator must also consider certain practical issues, such as the availability of parents or sibling controls...

....

..Simulations based on an admixed population demonstrate good operating characteristics for these procedures, under diverse scenarios...

..Information from siblings also can be incorporated to further improve the statistical power when genetic data from parents or probands are missing...

..When a single allele is under study, the proposed method can yield powerful tests for detection of linkage disequilibrium and is applicable to a broader array of causal scenarios than is the TDT...

..Benefits are even more marked if, as is typical, information on genotype is missing for some individuals...

..Results suggest that non-Hodgkin's lymphoma classification based on the t(14;18) translocation is of value in etiologic research...

..We use simulations based on a population with admixture to compare our method to a popular non-parametric family-based association test (FBAT), testing the null of no association in the presence of linkage...

..We illustrate the methods by application to two prospective fertility studies. Published in 2000 by John Wiley & Sons, Ltd...

..Under the same assumptions, empirical confidence interval coverage is consistent with the nominal 95%...

..Through genotyping of parents of population-based controls and assuming Mendelian transmission, power is markedly enhanced. One can also estimate main effects for exposures and now flexibly assess models for joint effects...

..Methods are illustrated with birth weight and gestational length, two quantitative outcomes for which data were collected in a Montreal, Canada, study of intrauterine growth restriction between May 1998 and June 2000...

..Published in 2001 by John Wiley & Sons, Ltd...

..Thus, the results of studies relating the timing of intercourse to the probability of conception should be interpreted cautiously...

..002). CONCLUSIONS Although limited by small numbers and infrequent exposures, our analyses suggest that a woman's exposures both early in life and at the time of pregnancy may influence early development of the conceptus...

..Because the needed assumptions likely hold in many situations, the likelihood-based approach should be broadly applicable for diseases in which probands commonly have living parents...

....

..quot; However, a pregnancy cannot be detected before the blastocyst implants. Due to natural variability in the timing of ovulation, implantation does not necessarily occur before the expected onset of next menses...

....

..Therefore the aim of this study was to describe the average profile of hCG and its variability during the 7 days following estimated implantation in a population of naturally conceived pregnancies...

..We find that the possibility of late ovulation produces a persistent risk of pregnancy even into the sixth week of the cycle. Post-coital contraceptives may be indicated even when intercourse has occurred late in the cycle...

..We illustrate by applying the method to a recent study of in vitro fertilization carried out in North Carolina. The number of cells at transfer is evidently a marker for embryo viability...

..Menstrual discomfort is common among women of reproductive age and can be debilitating. The accuracy of self-report of menstrual discomfort is unknown...

..Examples are given, some of which depend on scale and some of which do not. An example illustrates possible biologic implications for such an effect modification DAG...

..Despite strong evidence for genetic causes of oral facial clefts and the protective effects of maternal vitamins, we found no convincing indication that polymorphisms in these vitamin metabolism genes play an etiologic role...

..Hypertensive disorders of pregnancy, including pregnancy-induced hypertension (PIH) and preeclampsia (PE), complicate 2-8% of pregnancies. Few studies have examined environmental risk factors in relation to these conditions...

..Delineating the functional importance of an abrupt progesterone rise at the time of implantation may provide new strategies for promoting successful implantation in assisted reproduction...

..As an illustration, we reanalyze data from a previously reported orofacial cleft study, to now investigate both fetal and maternal effects of the IRF6 gene...

..If such rare factors underlie the association of birth weight with mortality, it would have broad implications for the study of fetal growth restriction and birth weight, and for the prevention of infant mortality...

..Bias was greatest when the magnitude of error for pregnancies at higher risk was much larger than that for pregnancies at lower risk...

..This practice has increased in recent decades, but its net effect on fetal and infant survival has not been assessed...

..In this example, our method was able to identify several biologically interesting genes that previous analyses failed to reveal...

..Studies that rely on self-reported cycle length could be prone to artifactual findings because of systematic covariate effects on reporting...

..To assess possible seasonal patterns in the onset of polymyositis (PM) and dermatomyositis (DM)...

..While results were consistent with the estimates from studies of miners, this study provides no evidence of an increased risk for lung cancer at the exposure levels observed...

..In addition, missing parental genotype data can be accommodated through an expectation-maximization (EM) algorithm approach. The EM approach allows recovery of most of the lost power due to incomplete trios...

..Such coordination has not been established in humans. We explored this possibility by examining patterns of sexual intercourse in relation to ovulation...

..Very early pregnancy losses do not appear to influence subsequent menstrual cycles to the same degree as spontaneous miscarriages...

..Both designs offer important advantages over the commonly applied case-mother/control-mother design...

..We sought to identify characteristics associated with follicular phase length...

..These findings support the use of stored urine specimens collected during the relevant stage of human pregnancy to investigate the influence of phthalate exposures on later outcomes...

..To illustrate, we reanalyze data from a study of orofacial clefts to investigate a 9-SNP candidate haplotype of the IRF6 gene...

..Our proposed methodology is illustrated by applying it to a HeLa cell-cycle gene-expression data...

..We apply the method to a set of rat sperm tracks representative of both normal and abnormal motion characteristics...

..Pregnancy loss before 6 weeks' gestation is common, but little has been reported about the associated bleeding. We compared women's bleeding following a pregnancy loss before 6 weeks' gestation with their typical menstruation...

..The characterization of additional molecular factors that contribute to static and dynamic obstruction may help predict response to pharmacotherapy and serve to identify novel drug targets for the clinical management of BPH...

..To evaluate whether seasonal early environmental exposures might influence later development of autoimmune disease, by assessing distributions of birth dates in groups of patients with idiopathic inflammatory myopathies (IIMs)...

..Studies of couple fertility have produced conflicting results. We evaluate how changes in the availability and use of effective contraception and induced abortion might bias the direct study of time trends in couple fertility...

..CONCLUSIONS: Cigarette smoking was not clearly associated with t(14;18)-positive NHL. Family history may be a marker for factors that act specifically through t(14;18)-negative pathogenic mechanisms...

..As an extension to our earlier work, we systematically examine the sensitivity, reproducibility and stability of gene selection/sample classification to the choice of parameters of the algorithm...

..The earliest symptoms do not begin until after key stages of embryogenesis, reinforcing the need for women to initiate sound health behaviors before pregnancy is apparent. Published by Elsevier Science Inc...

..Our aims were to evaluate the stability of BPA in specimens after 22-24 years of storage and to measure within-person temporal variability in urinary BPA...

..Epidemiologic studies have suggested an association between exposure to mixed anesthetic gases and impaired fertility. We investigated the effects of occupational exposure to nitrous oxide on the fertility of female dental assistants...

..We propose a procedure that uses case-parent triad data and, though not fully robust, resists bias from population structure...

..The model permits estimation of and hypothesis testing about biologically meaningful parameters that characterize cycling genes...

..30, 4.69). The authors found that a long TTP was associated with preeclampsia, supporting the hypothesis that some factors delaying clinically recognized conception may also be in a causal pathway for preeclampsia...

....

..Little is known about the role of xenobiotic-metabolizing gene variants as risk factors for small-for-gestational-age (SGA) births or as modifiers for the effects of exposures such as maternal smoking...

..Affected newborns also inherited the prothrombin G20210A variant significantly less often than expected. These results suggest that these three genes exhibit segregation distortion or reduce gestational survival...

..In addition, the power of the pent-1 approach is comparable with that of the approach based on data using all four grandparents...

..This study benefited from two large samples, involving independent populations, that provided substantial power and a framework for future studies that could identify a susceptible population for preventive health care...

..Detecting and monitoring early pregnancy depend on the measurement of HCG. Little is known about how production of various forms of HCG may evolve over the earliest weeks of pregnancy, particularly in naturally conceived pregnancies...

..Women with recurrent pre-eclampsia or pre-eclampsia early in pregnancy reportedly have an increased long-term risk of CVD. Short stature is a risk factor for CVD but has rarely been examined in relation to pre-eclampsia...

..When CLR is invalid, WCPR continues to have good operating characteristics. For illustration, we apply both WCPR and CLR to a periodontal data set where there is heterogeneity in response to exposure across clusters...