8 research outputs found
A Pilot Study of Abnormal Growth in Autism Spectrum Disorders and Other Childhood Psychiatric Disorders
The aims of the current study were to examine whether early growth abnormalities are (a) comparable in autism spectrum disorders (ASD) and other childhood psychiatric disorders, and (b) specific to the brain or generalized to the whole body. Head circumference, height, and weight were measured during the first 19 months of life in 129 children with ASD and 59 children with non-ASD psychiatric disorders. Both groups showed comparable abnormal patterns of growth compared to population norms, especially regarding height and head circumference in relation to height. Thus abnormal growth appears to be related to psychiatric disorders in general and is mainly expressed as an accelerated growth of height not matched by an increase in weight or head circumference
Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk
BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat
An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers
Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe
Theory and research in strategic management: Swings of a pendulum
The development of the field of strategic management within the last two decades has been dramatic. While its roots have been in a more applied area, often referred to as business policy, the current field of strategic management is strongly theory based, with substantial empirical research, and is eclectic in nature. This review of the development of the field and its current position examines the field’s early development and the primary theoretical and methodological bases through its history. Early developments include Chandler’s (1962) Strategy and Structure and Ansoff’s (1965) Corporate Strategy. These early works took on a contingency perspective (fit between strategy and structure) and a resource-based framework emphasizing internal strengths and weaknesses. Perhaps, one of the more significant contributions to the development of strategic management came from industrial organization (IO) economics, specifically the work of Michael Porter. The structure-conduct-performance framework and the notion of strategic groups, as well as providing a foundation for research on competitive dynamics, are flourishing currently. The IO paradigm also brought econometric tools to the research on strategic management. Building on the IO economics framework, the organizational economics perspective contributed transaction costs economics and agency theory to strategic management. More recent theoretical contributions focus on the resource-based view of the firm. While it has its roots in Edith Penrose’s work in the late 1950s, the resource-based view was largely introduced to the field of strategic management in the 1980s and became a dominant framework in the 1990s. Based on the resource-based view or developing concurrently were research on strategic leadership, strategic decision theory (process research) and knowledge-based view of the firm. The research methodologies are becoming increasingly sophisticated and now frequently combine both quantitative and qualitative approaches and unique and new statistical tools. Finally, this review examines the future directions, both in terms of theory and methodologies, as the study of strategic management evolves.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline