Genetic ancestry, self-reported race and ethnicity in African Americans and European Americans in the PCaP cohort

Background

Family history and African-American race are important risk factors for both prostate cancer (CaP) incidence and aggressiveness. When studying complex diseases such as CaP that have a heritable component, chances of finding true disease susceptibility alleles can be increased by accounting for genetic ancestry within the population investigated. Race, ethnicity and ancestry were studied in a geographically diverse cohort of men with newly diagnosed CaP.

Methods

Individual ancestry (IA) was estimated in the population-based North Carolina and Louisiana Prostate Cancer Project (PCaP), a cohort of 2,106 incident CaP cases (2063 with complete ethnicity information) comprising roughly equal numbers of research subjects reporting as Black/African American (AA) or European American/Caucasian/Caucasian American/White (EA) from North Carolina or Louisiana. Mean genome wide individual ancestry estimates of percent African, European and Asian were obtained and tested for differences by state and ethnicity (Cajun and/or Creole and Hispanic/Latino) using multivariate analysis of variance models. Principal components (PC) were compared to assess differences in genetic composition by self-reported race and ethnicity between and within states.

Results

Mean individual ancestries differed by state for self-reporting AA (p = 0.03) and EA (p = 0.001). This geographic difference attenuated for AAs who answered “no” to all ethnicity membership questions (non-ethnic research subjects; p = 0.78) but not EA research subjects, p = 0.002. Mean ancestry estimates of self-identified AA Louisiana research subjects for each ethnic group; Cajun only, Creole only and both Cajun and Creole differed significantly from self-identified non-ethnic AA Louisiana research subjects. These ethnicity differences were not seen in those who self-identified as EA.

Conclusions

Mean IA differed by race between states, elucidating a potential contributing factor to these differences in AA research participants: self-reported ethnicity. Accurately accounting for genetic admixture in this cohort is essential for future analyses of the genetic and environmental contributions to CaP.     

Identification of marker-trait associations in the German winter barley breeding gene pool (Hordeum vulgare L.)

A genome-wide association mapping approach for grain yield and traits of high agronomic relevance was carried out on basis of a set of 61 six-rowed and 48 two-rowed German winter barley (Hordeum vulgare L.) cultivars representing breeding progress in the period 1959?C2003. Extensive phenotyping was conducted in field trials carried out at 12 locations in 3?years. Heritability was estimated at between 0.45 for grain yield and 0.94 for grains per spike. By using the Illumina Golden Gate Bead Array technology, 833 single nucleotide polymorphisms with an allele frequency higher than 5% were obtained. Linkage disequilibrium on the whole genome extends to 7.35?cM. Based on a mixed linear model approach taking into account the population structure estimated on the basis of 72 simple sequence repeat markers covering the whole barley genome, 91 significant marker-trait associations were detected, corresponding to 48 different genomic regions.     

Advanced material modelling in numerical simulation of primary acetabular press-fit cup stability

Primary stability of artificial acetabular cups, used for total hip arthroplasty, is required for the subsequent osteointegration and good long-term clinical results of the implant. Although closed-cell polymer foams represent an adequate bone substitute in experimental studies investigating primary stability, correct numerical modelling of this material depends on the parameter selection. Material parameters necessary for crushable foam plasticity behaviour were originated from numerical simulations matched with experimental tests of the polymethacrylimide raw material. Experimental primary stability tests of acetabular press-fit cups consisting of static shell assembly with consecutively pull-out and lever-out testing were subsequently simulated using finite element analysis. Identified and optimised parameters allowed the accurate numerical reproduction of the raw material tests. Correlation between experimental tests and the numerical simulation of primary implant stability depended on the value of interference fit. However, the validated material model provides the opportunity for subsequent parametric numerical studies.     

Day-to-day alteration of 24-hour sleep pattern immediately before and after giving birth

Sleep and Biological Rhythms - The current literature suggests that nighttime sleep is compromised during late pregnancy and early postpartum periods, but little is known about the 24-hour sleep...     

Automated behavioral phenotyping reveals presymptomatic alterations in a SCA3 genetrap mouse model

Characterization of disease models of neurodegenerative disorders requires a systematic and comprehensive phenotyping in a highly standardized manner.Therefore,automated high-resolution behavior test systems such as the homecage based LabMaster system are of particular interest.We demonstrate the power of the automated LabMaster system by discovering previously unrecognized features of a recently characterized atxn3 mutant mouse model.This model provided neurological symptoms including gait ataxia,tremor,weight loss and premature death at the age of 12 months usually detectable just 2 weeks before the mice died.Moreover,using the LabMaster system we were able to detect hypoactivity in presymptomatic mutant mice in the dark as well as light phase.Additionally,we analyzed inflammation,immunological and hematological parameters,which indicated a reduced immune defense in phenotypic mice.Here we demonstrate that a detailed characterization even of organ systems that are usually not affected in SCA3 is important for further studies of pathogenesis and required for the preclinical therapeutic studies.     

Expression of the transcription factor Zfp191 during embryonic development in the mouse

The human zinc finger protein 191 (ZNF191) is a Krüppel-like protein and can specifically interact with the widespread TCAT motif which constitutes the HUMTH01 microsatellite in the tyrosine hydroxylase (TH) gene (encoding the rate-limiting enzyme in the synthesis of catecholamines). Allelic variations of HUMTH01 are known to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. This factor has been isolated from bone marrow and promyelocytic leukemia cell lines indicating that ZNF191 also plays a role in hematopoiesis. Thus, ZNF191 could participate in the regulation of several genes implicated in different functions. Moreover, mice that are deficient in Zfp191, the murine homologue of ZNF191, have been shown to be severely retarded in development and to die approximately at embryonic day 7.5. In order to gain further insight into its biological functions, we have analysed the localisation of Zfp191 throughout mouse development. Expression was detected early during embryogenesis in ectodermal, endodermal, mesodermal and extra-embryonic tissues. In particular, Zfp191 was observed in the developing central nervous system. Interestingly, its expression levels were prominent in areas of proliferation such as the subventricular zone. Zfp191 expression pattern during development can account for the phenotypic features of Zfp191(-/-) embryos.     

Detection of 2-hydroxyethidium in cellular systems: a unique marker product of superoxide and hydroethidine

Various detection methods of the specific product of reaction of superoxide (O(2)(*-)) with hydroethidine (HE), namely 2-hydroxyethidium (2-OH-E(+)), and with its mitochondria-targeted analog are described. The detailed protocol for quantification of 2-OH-E(+), the unique product of HE/O(2)(*-) in cellular systems, is presented. The procedure includes cell lysis, protein precipitation using acidified methanol and HPLC analysis of the lysate. Using this protocol, we determined the intracellular levels of 2-OH-E(+) and E(+) in the range of 10 and 100 pmol per mg protein in unstimulated macrophage-like RAW 264.7 cells. In addition to HE, 2-OH-E(+) and E(+), we detected several dimeric products of HE oxidation in cell lysates. As several oxidation products of HE are formed, the superoxide-specific product, 2-OH-E(+) needs to be separated from other HE-derived products for unequivocal quantification.     

Artificial enzymes, “Chemzymes”: current state and perspectives

Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successfully perform Michaelis–Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called “Chemzymes”, based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well as chemzymes that catalyze conjugate additions, cycloadditions, and self-replicating processes. The focus will be mainly on cyclodextrin-based chemzymes since they have shown to be good candidate structures to base an enzyme model skeleton on. In addition hereto, other molecules that encompass binding properties will also be presented.