Citations

Background Intracranial aneurysms ( IAs ), abdominal aortic aneurysms ( AAAs ), and thoracic aortic aneurysms ( TAAs ) all have a familial predisposition. Given that aneurysm types are known to co‐occur, we hypothesized that there may be shared genetic risk factors for IAs , AAAs, and TAAs . Methods and Results We performed a mega‐analysis of 1000 Genomes Project‐imputed genome‐wide association study ( GWAS ) data of 4 previously published aneurysm cohorts: 2 IA cohorts (in total 1516 cases, 4305 controls), 1 AAA cohort (818 cases, 3004 controls), and 1 TAA cohort (760 cases, 2212 controls), and observed associations of 4 known IA , AAA , and/or TAA risk loci (9p21, 18q11, 15q21, and 2q33) with consistent effect directions in all 4 cohorts. We calculated polygenic scores based on IA ‐, AAA ‐, and TAA ‐associated SNP s and tested these scores for association to case‐control status in the other aneurysm cohorts; this revealed no shared polygenic effects. Similarly, linkage disequilibrium–score regression analyses did not show significant correlations between any pair of aneurysm subtypes. Last, we evaluated the evidence for 14 previously published aneurysm risk single‐nucleotide polymorphisms through collaboration in extended aneurysm cohorts, with a total of 6548 cases and 16 843 controls ( IA ) and 4391 cases and 37 904 controls ( AAA ), and found nominally significant associations for IA risk locus 18q11 near RBBP 8 to AAA (odds ratio [ OR ]=1.11; P =4.1×10 −5 ) and for TAA risk locus 15q21 near FBN 1 to AAA ( OR =1.07; P =1.1×10 −3 ). Conclusions Although there was no evidence for polygenic overlap between IAs , AAAs , and TAAs , we found nominally significant effects of two established risk loci for IAs and TAAs in AAAs . These two loci will require further replication.

OBJECTIVE Standardized, reproducible, and feasible quantification of β-cell function (BCF) is necessary for the evaluation of interventions to improve insulin secretion and important for comparison across studies. We therefore characterized the responses to, and reproducibility of, standardized methods of in vivo BCF across different glucose tolerance states. RESEARCH DESIGN AND METHODS Participants classified as having normal glucose tolerance (NGT; n = 23), prediabetes (PDM; n = 17), and type 2 diabetes mellitus (T2DM; n = 22) underwent two standardized mixed-meal tolerance tests (MMTT) and two standardized arginine stimulation tests (AST) in a test-retest paradigm and one frequently sampled intravenous glucose tolerance test (FSIGT). RESULTS From the MMTT, insulin secretion in T2DM was >86% lower compared with NGT or PDM (P < 0.001). Insulin sensitivity (Si) decreased from NGT to PDM (∼50%) to T2DM (93% lower [P < 0.001]). In the AST, insulin secretory response to arginine at basal glucose and during hyperglycemia was lower in T2DM compared with NGT and PDM (>58%; all P < 0.001). FSIGT showed decreases in both insulin secretion and Si across populations (P < 0.001), although Si did not differ significantly between PDM and T2DM populations. Reproducibility was generally good for the MMTT, with intraclass correlation coefficients (ICCs) ranging from ∼0.3 to ∼0.8 depending on population and variable. Reproducibility for the AST was very good, with ICC values >0.8 across all variables and populations. CONCLUSIONS Standardized MMTT and AST provide reproducible and complementary measures of BCF with characteristics favorable for longitudinal interventional trials use.

Summary: Soft tissue wounds overlying the dorsum of the foot and ankle are difficult to treat, and historically have been treated with free tissue transfer. Advances in surgical technique have expanded the use of pedicle perforator flaps to avoid free tissue transfer in certain situations. The authors describe a technique for using an extensor digitorum brevis flap to provide soft tissue coverage for wounds of the ankle and foot. In the senior authors’ experience, the use of this flap has achieved wound coverage in 100% of patients with smaller wounds (≤45 cm2) of the ankle.

AbstractThe increased use of genomic sequencing in clinical diagnostics and therapeutics makes imperative the development of guidelines and policies about how to handle secondary findings. For reasons both practical and ethical, the creation of these guidelines must take into consideration the informed opinions of the lay public. As part of a larger Clinical Sequencing Exploratory Research (CSER) consortium project, we organized a deliberative democracy (DD) session that engaged 66 participants in dialogue about the benefits and risks associated with the return of secondary findings from clinical genomic sequencing. Participants were educated about the scientific and ethical aspects of the disclosure of secondary findings by experts in medical genetics and bioethics, and then engaged in facilitated discussion of policy options for the disclosure of three types of secondary findings: 1) medically actionable results; 2) adult onset disorders found in children; and 3) carrier status. Participants’ opinions were collected via surveys administered one month before, immediately following, and one month after the DD session. Post DD session, participants were significantly more willing to support policies that do not allow access to secondary findings related to adult onset conditions in children (Χ2 (2, N = 62) = 13.300, p = 0.001) or carrier status (Χ2 (2, N = 60) = 11.375, p = 0.003). After one month, the level of support for the policy denying access to secondary findings regarding adult‐onset conditions remained significantly higher than the pre‐DD level, although less than immediately post‐DD (Χ2 (1, N = 60) = 2.465, p = 0.041). Our findings suggest that education and deliberation enhance public appreciation of the scientific and ethical complexities of genome sequencing.

Background Light chain amyloidosis (AL) is associated with high mortality, especially in patients with advanced cardiovascular involvement. It is caused by toxicity of misfolded light chain proteins ( LC ) in vascular, cardiac, and other tissues. There is no treatment to reverse LC tissue toxicity. We tested the hypothesis that nanoliposomes composed of monosialoganglioside, phosphatidylcholine, and cholesterol (GM1 ganglioside–containing nanoliposomes [ NLGM 1]) can protect against LC ‐induced human microvascular dysfunction and assess mechanisms behind the protective effect. Methods and Results The dilator responses of ex vivo abdominal adipose arterioles from human participants without AL to acetylcholine and papaverine were measured before and after exposure to LC (20 μg/mL) with or without NLGM 1 (1:10 ratio for LC : NLGM 1 mass). Human umbilical vein endothelial cells were exposed for 18 to 20 hours to vehicle, LC with or without NLGM 1, or NLGM 1 and compared for oxidative and nitrative stress response and cellular viability. LC impaired arteriole dilator response to acetylcholine, which was restored by co‐treatment with NLGM 1. LC decreased endothelial cell nitric oxide production and cell viability while increasing superoxide and peroxynitrite; these adverse effects were reversed by NLGM 1. NLGM 1 increased endothelial cell protein expression of antioxidant enzymes heme oxygenase 1 and NAD (P)H quinone dehydrogenase 1 and increased nuclear factor, erythroid 2 like 2 (Nrf‐2) protein. Nrf‐2 gene knockdown reduced antioxidant stress response and reversed the protective effects of NLGM 1. Conclusions NLGM1 protects against LC ‐induced human microvascular endothelial dysfunction through increased nitric oxide bioavailability and reduced oxidative and nitrative stress mediated by Nrf‐2–dependent antioxidant stress response. These findings point to a potential novel therapeutic approach for light chain amyloidosis.

Abstract Background: Germline mutations in the BRCA1 and BRCA2 genes lead to hereditary breast cancers that are defective in homologous recombination (HR) repair and sensitive to DNA damaging agents. HR deficiency (HRD) also occurs in sporadic breast cancers, but its incidence and etiology are unclear. Genomic signatures of HRD recently were employed as biomarkers in clinical trials with modest success. We posited that sporadic breast cancers displaying functional HR deficiency would harbor genetic alterations affecting HR DNA repair genes. To test this hypothesis, we applied a functional assay to define lack of competent HR DNA repair and sequenced the exomes of consecutive sporadic breast cancers. Methods: We developed an assay to assess the ability of cancer cells to localize RAD51 into sub nuclear foci in response to ex-vivo irradiation (IR) in fresh sporadic breast cancer tissue specimens from 60 patients. RAD51 focus formation was compared between mock and IR conditions to determine relative fold induction. Twenty-nine tumors with sufficient DNA underwent whole-exome sequencing. Structural genomic signatures of HRD (i.e. large state transitions (LST), telomeric imbalance (NtAI), loss-of-heterozygositiy (LOH)) and a previously reported mutational signature related to BRCA1/2 hereditary breast cancers were assessed. HR deficient tumors were defined as those with both RAD51 foci defects and a genomic signature of HR deficiency (LST>15 or presence of a BRCA mutational signature). Somatic, germ-line, and copy number changes in HR genes were investigated. BRCA1 methylation status was determined. Results: Seventeen of 60 (28%) tumors displayed defective RAD51 recruitment following ex-vivo IR (RAD51-DEF). RAD51-DEF was seen in all breast cancer subtypes , including 7 of 33 (21%) ER+/HER2-, 4 of 14 (29%) HER2+, and 6 of 13 (48%) triple-negative cases. Of the 29 sequenced tumors, 13 (45%) were RAD51-DEF and 16 (55%) were competent for inducing RAD51 foci. LST was elevated in 10 tumors (LST >15) and associated with RAD51-DEF (p=0.02), whereas NtAI (p=0.10) and LOH (p=0.052) did not show a significant association with RAD51-DEF. The BRCA1/2 mutational signature was evident in 4 tumors, all were RAD51-DEF (p=0.03) and 2 were BRCA2 mutated. Nine of 29 (31%) sequenced tumors were determined to have HRD by the RAD51 assay and presence of a genomic scar. Eight of these 9 (88%) cases with HRD had a genetic alteration of both alleles of a bona fide HR gene due to a pathogenic mutation (somatic or germline) coupled with loss of heterozygosity or a homozygous deletion compared to 1 (5%) tumor without HRD (p<0.001). Both alleles of a gene were affected for BRCA2 (n=4), FAAP100 (n=2), CHEK2 (n=1), TP53BP1 (n=1) and BRCA1 (n=1). BRCA1 gene promoter methylation was found not to be significantly associated with HRD. Conclusion: Combined functional and genomic analyses of breast tumors demonstrated that genetic loss of an HR gene may underpin HRD in sporadic breast cancers. Our findings warrant further comprehensive genetic assessment (somatic, germline, and copy number) of HR genes as potential biomarker for HR-directed therapies. Citation Format: Powell SN, Riaz N, Mutter RW, Ng CKY, Delsite R, Piscuoglio S, King TA, Martelotto L, Sakr R, Brogi E, Edelweiss M, Lim R, Higginson D, Weigelt B, Lee W, Reis-Filho JS. A functional assay for homologous recombination (HR) DNA repair and whole exome sequencing reveal that HR-defective sporadic breast cancers are enriched for genetic alterations in DNA repair genes. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S4-03.

AbstractKidney transplant (KT) programs have extended recipient eligibility to those who were previously excluded due to advanced age. We aimed to determine the outcomes of the patients ≥70 years undergoing KT and investigate factors predicting survival. Two thousand six hundred and twenty‐four KT patients between 2003 and 2013 at two institutions were divided into two groups; those ≥70 years (n=300) and those <70 years (n=2324) at the time of KT. Patient survival at 1, 3, and 5 years was 95%, 86%, and 77% in ≥70 years of age group and 98%, 95%, and 90% in the <70 years group (P<.001). When graft loss due to death was censored, graft survival was not significantly different between the two groups (P=.18). On multivariable analysis, the significant predictors of inferior survival in patients ≥70 years included: body mass index (BMI)>30 kg/m2 (hazard ratio [HR] 1.07; P=.01), panel reactive antibody (PRA)>20% (HR 2.38; P=.01), previous coronary artery bypass grafting (CABG; HR 1.95; P=.03) and peripheral vascular disease (PVD; HR 2.60; P=.04). Acceptable outcomes can be achieved in KT recipients ≥70 years. Caution should be used when listing these patients if they have BMI>30 kg/m2, PRA>20%, CABG or PVD.