Citations

ABSTRACTGenes that alter disease risk only in combination with certain environmental exposures may not be detected in genetic association analysis. By using methods accounting for gene‐environment (G × E) interaction, we aimed to identify novel genetic loci associated with breast cancer risk. Up to 34,475 cases and 34,786 controls of European ancestry from up to 23 studies in the Breast Cancer Association Consortium were included. Overall, 71,527 single nucleotide polymorphisms (SNPs), enriched for association with breast cancer, were tested for interaction with 10 environmental risk factors using three recently proposed hybrid methods and a joint test of association and interaction. Analyses were adjusted for age, study, population stratification, and confounding factors as applicable. Three SNPs in two independent loci showed statistically significant association: SNPs rs10483028 and rs2242714 in perfect linkage disequilibrium on chromosome 21 and rs12197388 in ARID1B on chromosome 6. While rs12197388 was identified using the joint test with parity and with age at menarche (P‐values = 3 × 10−07), the variants on chromosome 21 q22.12, which showed interaction with adult body mass index (BMI) in 8,891 postmenopausal women, were identified by all methods applied. SNP rs10483028 was associated with breast cancer in women with a BMI below 25 kg/m2 (OR = 1.26, 95% CI 1.15–1.38) but not in women with a BMI of 30 kg/m2 or higher (OR = 0.89, 95% CI 0.72–1.11, P for interaction = 3.2 × 10−05). Our findings confirm comparable power of the recent methods for detecting G × E interaction and the utility of using G × E interaction analyses to identify new susceptibility loci.

Abstract Part of the substantial unexplained familial aggregation of breast cancer may be due to interactions between common variants, but few studies have had adequate statistical power to detect interactions of realistic magnitude. We aimed to assess all two-way interactions in breast cancer susceptibility between 70 917 single nucleotide polymorphisms (SNPs) selected primarily based on prior evidence of a marginal effect. Thirty-eight international studies contributed data for 46 450 breast cancer cases and 42 461 controls of European origin as part of a multi-consortium project (COGS). First, SNPs were preselected based on evidence (P < 0.01) of a per-allele main effect, and all two-way combinations of those were evaluated by a per-allele (1 d.f.) test for interaction using logistic regression. Second, all 2.5 billion possible two-SNP combinations were evaluated using Boolean operation-based screening and testing, and SNP pairs with the strongest evidence of interaction (P < 10−4) were selected for more careful assessment by logistic regression. Under the first approach, 3277 SNPs were preselected, but an evaluation of all possible two-SNP combinations (1 d.f.) identified no interactions at P < 10−8. Results from the second analytic approach were consistent with those from the first (P > 10−10). In summary, we observed little evidence of two-way SNP interactions in breast cancer susceptibility, despite the large number of SNPs with potential marginal effects considered and the very large sample size. This finding may have important implications for risk prediction, simplifying the modelling required. Further comprehensive, large-scale genome-wide interaction studies may identify novel interacting loci if the inherent logistic and computational challenges can be overcome.

ABSTRACTClinical mutations in patients diagnosed with Type 2A von Willebrand disease (VWD) have been identified that break the single disulfide bond linking N‐ and C‐termini in the vWF A1 domain. We have modeled the effect of these mutations on the disulfide‐bonded structure of A1 by reducing and carboxy‐amidating these cysteines. Solution biophysical studies show that loss of this disulfide bond induces a molten globule conformational state lacking global tertiary structure but retaining residual secondary structure. The conformational dependence of platelet adhesion to these native and molten globule states of A1 is quantitatively compared using real‐time high‐speed video microscopy analysis of platelet translocation dynamics under shear flow in a parallel plate microfluidic flow chamber. While normal platelets translocating on surface‐captured native A1 domain retain the catch‐bond character of pause times that increase as a function of shear rate at low shear and decrease as a function of shear rate at high shear, platelets that interact with A1 lacking the disulfide bond remain stably attached and do not translocate. Based on these findings, we propose that the shear stress‐sensitive regulation of the A1‐GPIb interaction is due to folding the tertiary structure of this domain. Removal of the tertiary structure by disrupting the disulfide bond destroys this regulatory mechanism resulting in high‐strength interactions between platelets and vWF A1 that are dependent only on residual secondary structure elements present in the molten globule conformation. Proteins 2014; 82:867–878. © 2013 Wiley Periodicals, Inc.

The supraspinatus tendon consists morphologically of two sub‐regions, anterior and posterior. The anterior sub‐region is thick and tubular while the posterior is thin and strap‐like. The purpose of this study was to compare the structural and mechanical properties of the anterior and posterior sub‐regions of the supraspinatus tendon. The supraspinatus tendons from seven human cadaveric shoulders were morphologically divided into the anterior and posterior sub‐regions. Length, width, and thickness were measured. A servo‐hydraulic testing machine (MTS Systems Corporation, Minneapolis, MN) was used for tensile testing. The maximal load at failure, modulus of elasticity and ultimate tendon stress were calculated. Repeated measures were used for statistical comparisons. The mean anterior tendon cross‐sectional area was 47.3 mm2 and the posterior was 32.1 mm2. Failure occurred most often at the insertion site: anterior (5/7) and posterior (6/7). All parameters of the anterior sub‐region were significantly greater than those of the posterior sub‐region. The moduli of elasticity at the insertion site were 592.4 MPa in the anterior sub‐region and 217.7 MPa in the posterior (P = 0.01). The ultimate failure loads were 779.2 N in the anterior sub‐region and 335.6 N in the posterior (P = 0.003). The ultimate stresses were 22.1 MPa in the anterior sub‐region and 11.6 MPa in the posterior (P = 0.008). We recognized that the anterior and posterior sub‐regions of the SSP tendon have significantly different mechanical properties. In a future study, we need to evaluate how best to repair an SSP tendon considering these region‐specific properties. Clin. Anat. 27:702–706, 2014. © 2013 Wiley Periodicals, Inc.

Background:Neurokinin B (NKB) is a member of the tachykinin family of peptides. Inactivating mutations in the tachykinin 3 or tachykinin 3 receptor gene are associated with pubertal failure and congenital hypogonadotrophic hypogonadism in humans. This suggests that NKB may have a critical role in human reproduction. The effects of NKB administration have not been investigated previously in humans.Aim:The aim of this study was to determine the effects of iv administration of NKB on gonadotrophin secretion in healthy male and female volunteers.Methods:A total of 23 healthy men and 11 healthy women participated in the study. After an initial dose-finding study (study 1), men received a 4-hour infusion of vehicle (gelofusin) followed by a 4-hour infusion of NKB (2.56 or 5.12 nmol/kg/h) (study 2), and an 8-hour infusion of vehicle or NKB during different visits (study 3). Healthy women underwent a dose-finding study consisting of a 3-hour NKB administration during the follicular phase of the menstrual cycle, and the maximum dose of NKB was also tested during the preovulatory and midluteal phases of menstrual cycle (study 4).Results:Mean LH, FSH, and T secretion were not significantly altered during a 90-minute infusion of NKB (0.4–5.12 nmol/kg/h), or a 4-hour infusion of NKB (5.12 nmol/kg/h). No alterations in gonadotrophin secretion or LH pulsatility were observed during an 8-hour infusion of NKB when compared with vehicle. Doses of 0.64–5.12 nmol/kg/h NKB did not significantly alter LH, FSH, or estradiol secretion in healthy women during the follicular phase of the menstrual cycle. Finally, 5.12 nmol/kg/h did not significantly alter reproductive hormone secretion during the preovulatory or midluteal phases of the menstrual cycle.Conclusions:This is the first clinical study of NKB administration. None of the doses of NKB tested were associated with significant alterations in reproductive hormone secretion in healthy male or female volunteers. These novel data add to our understanding of the physiological actions of NKB in human reproduction.

Abstract The American Joint Committee on Cancer/Union Internationale Contre le Cancer ( AJCC / UICC ) TNM staging system provides the most reliable guidelines for the routine prognostication and treatment of colorectal carcinoma. This traditional tumour staging summarizes data on tumour burden (T), the presence of cancer cells in draining and regional lymph nodes (N) and evidence for distant metastases (M). However, it is now recognized that the clinical outcome can vary significantly among patients within the same stage. The current classification provides limited prognostic information and does not predict response to therapy. Multiple ways to classify cancer and to distinguish different subtypes of colorectal cancer have been proposed, including morphology, cell origin, molecular pathways, mutation status and gene expression‐based stratification. These parameters rely on tumour‐cell characteristics. Extensive literature has investigated the host immune response against cancer and demonstrated the prognostic impact of the in situ immune cell infiltrate in tumours. A methodology named ‘Immunoscore’ has been defined to quantify the in situ immune infiltrate. In colorectal cancer, the Immunoscore may add to the significance of the current AJCC / UICC TNM classification, since it has been demonstrated to be a prognostic factor superior to the AJCC / UICC TNM classification. An international consortium has been initiated to validate and promote the Immunoscore in routine clinical settings. The results of this international consortium may result in the implementation of the Immunoscore as a new component for the classification of cancer, designated TNM ‐I ( TNM ‐Immune). © 2013 The Authors. Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

The importance of portal insulin delivery in the regulation of postprandial carbohydrate metabolism is uncertain. To address this question, three groups of dogs were studied: one group in which pancreatic venous drainage was transected and reanastomosed (portal insulin delivery), one in which the pancreatic drainage was transected and anastomosed to the inferior vena cava (peripheral insulin delivery), and one that received only a sham operation. Plasma insulin was greater (P < 0.05) during peripheral insulin delivery than in either the portal or sham groups, respectively, before and after meal ingestion. On the other hand, C-peptide concentrations did not differ between groups, resulting in a higher (P < 0.001) insulin to C-peptide ratio in the peripheral group. This indicated that the hyperinsulinemia in the peripheral group was due to decreased insulin clearance rather than increased insulin secretion. Isotopically determined splanchnic uptake of ingested glucose, postprandial suppression of hepatic glucose release, incorporation of CO2 into glucose (a qualitative measure of gluconeogenesis), and total-body glucose uptake were virtually identical in all groups. Similarly, plasma lipid, β-hydroxybutyrate, and lactate concentrations did not differ between groups. Our data indicate that, despite differences in systemic insulin concentration, portal and peripheral insulin delivery comparably regulate hepatic and extrahepatic carbohydrate metabolism after meal ingestion.

Background: Kisspeptin is a critical hypothalamic regulator of reproductive function. Chronic kisspeptin administration causes profound tachyphylaxis in male monkeys and in women with functional hypothalamic amenorrhea. The pharmacological effects of chronic kisspeptin exposure in healthy women with normal menstrual cycles have not been studied previously. Aim: Our aim was to determine the effects of follicular-phase kisspeptin-54 treatment on menstrual cyclicity in healthy women. Methods: We performed a prospective, single-blinded, 1-way crossover study. Healthy women received twice-daily sc injections of kisspeptin (6.4 nmol/kg) or 0.9% saline during menstrual days 7–14 (n = 5 per treatment arm). Serial assessments of basal reproductive hormones, ultrasound parameters, LH pulsatility, and acute sensitivity to GnRH and kisspeptin-54 injection were performed. Results: Menstrual cyclicity persisted in all women after follicular-phase kisspeptin-54 treatment. Chronic exposure to kisspeptin-54 did not abolish acute stimulation of LH after injection of kisspeptin-54 or GnRH. In addition, kisspeptin-54 treatment was associated with a shorter mean length of the menstrual cycle (mean length of menstrual cycle was 28.6 ± 1.4 days with saline vs 26.8 ± 3.1 days with kisspeptin, P < .01), earlier onset of highest recorded serum LH (mean menstrual day of highest LH was 15.2 ± 1.3 with saline vs 13.0 ± 1.9 with kisspeptin, P < .05), and earlier onset of the luteal phase (mean menstrual day of progesterone increase was 18.0 ± 2.1 with saline vs 15.8 ± 0.9 with kisspeptin, P < .05). Conclusion: Our data suggest that 1 week of exogenous kisspeptin-54 does not abolish menstrual cyclicity in healthy women. Further work is needed to determine whether kisspeptin could be used to treat certain anovulatory disorders.