2,027 research outputs found

    BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

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    Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear. Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk. Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives. Conclusion: These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found

    The Third wave in globalization theory

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    This essay examines a proposition made in the literature that there are three waves in globalization theory—the globalist, skeptical, and postskeptical or transformational waves—and argues that this division requires a new look. The essay is a critique of the third of these waves and its relationship with the second wave. Contributors to the third wave not only defend the idea of globalization from criticism by the skeptics but also try to construct a more complex and qualified theory of globalization than provided by first-wave accounts. The argument made here is that third-wave authors come to conclusions that try to defend globalization yet include qualifications that in practice reaffirm skeptical claims. This feature of the literature has been overlooked in debates and the aim of this essay is to revisit the literature and identify as well as discuss this problem. Such a presentation has political implications. Third wavers propose globalist cosmopolitan democracy when the substance of their arguments does more in practice to bolster the skeptical view of politics based on inequality and conflict, nation-states and regional blocs, and alliances of common interest or ideology rather than cosmopolitan global structures

    Association of atrial fibrillation and obstructive sleep apnea.

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    BACKGROUND: Obstructive sleep apnea (OSA) is associated with recurrent atrial fibrillation (AF) after electrocardioversion. OSA is highly prevalent in patients who are male, obese, and/or hypertensive, but its prevalence in patients with AF is unknown. METHODS AND RESULTS: We prospectively studied consecutive patients undergoing electrocardioversion for AF (n=151) and consecutive patients without past or current AF referred to a general cardiology practice (n=312). OSA was diagnosed with the Berlin questionnaire, which is validated to identify patients with OSA. We also assessed its accuracy compared with polysomnography in a sample of the study population. Groups were compared with the 2-tailed t, Wilcoxon, and chi2 tests. Logistic regression modeled the association of AF and OSA after adjustment for relevant covariates. Patients in each group had similar age, gender, body mass index, and rates of diabetes, hypertension, and congestive heart failure. The questionnaire performed with 0.86 sensitivity, 0.89 specificity, and 0.97 positive predictive value in our sample. The proportion of patients with OSA was significantly higher in the AF group than in the general cardiology group (49% versus 32%, P=0.0004). The adjusted odds ratio for the association between AF and OSA was 2.19 (95% CI 1.40 to 3.42, P=0.0006). CONCLUSIONS: The novel finding of this study is that a strong association exists between OSA and AF, such that OSA is strikingly more prevalent in patients with AF than in high-risk patients with multiple other cardiovascular diseases. The coinciding epidemics of obesity and AF underscore the clinical importance of these results

    Hamiltonian 2-forms in Kahler geometry, III Extremal metrics and stability

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    This paper concerns the explicit construction of extremal Kaehler metrics on total spaces of projective bundles, which have been studied in many places. We present a unified approach, motivated by the theory of hamiltonian 2-forms (as introduced and studied in previous papers in the series) but this paper is largely independent of that theory. We obtain a characterization, on a large family of projective bundles, of those `admissible' Kaehler classes (i.e., the ones compatible with the bundle structure in a way we make precise) which contain an extremal Kaehler metric. In many cases, such as on geometrically ruled surfaces, every Kaehler class is admissible. In particular, our results complete the classification of extremal Kaehler metrics on geometrically ruled surfaces, answering several long-standing questions. We also find that our characterization agrees with a notion of K-stability for admissible Kaehler classes. Our examples and nonexistence results therefore provide a fertile testing ground for the rapidly developing theory of stability for projective varieties, and we discuss some of the ramifications. In particular we obtain examples of projective varieties which are destabilized by a non-algebraic degeneration.Comment: 40 pages, sequel to math.DG/0401320 and math.DG/0202280, but largely self-contained; partially replaces and extends math.DG/050151

    Learning a Factor Model via Regularized PCA

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    We consider the problem of learning a linear factor model. We propose a regularized form of principal component analysis (PCA) and demonstrate through experiments with synthetic and real data the superiority of resulting estimates to those produced by pre-existing factor analysis approaches. We also establish theoretical results that explain how our algorithm corrects the biases induced by conventional approaches. An important feature of our algorithm is that its computational requirements are similar to those of PCA, which enjoys wide use in large part due to its efficiency

    Biometric Risk Factors for Angle Closure Progression After Laser Peripheral Iridotomy

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    IMPORTANCE: Laser peripheral iridotomy (LPI) is the most common primary treatment for primary angle closure disease (PACD). However, there are sparse data guiding the longitudinal care of PAC suspect (PACS) eyes after LPI. OBJECTIVE: To elucidate the anatomic effects of LPI that are associated with a protective outcome against progression from PACS to PAC and acute angle closure (AAC) and to identify biometric factors that predict progression after LPI. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective analysis of data from the Zhongshan Angle Closure Prevention (ZAP) trial, a study of mainland Chinese people aged 50 to 70 years with bilateral PACS who received LPI in 1 randomly selected eye. Gonioscopy and anterior-segment optical coherence tomography (AS-OCT) imaging were performed 2 weeks after LPI. Progression was defined as the development of PAC or an acute angle closure (AAC) attack. Cohort A included a random mix of treated and untreated eyes, and cohort B included only eyes treated with LPI. Univariable and multivariable Cox regression models were developed to assess biometric risk factors for progression in cohorts A and B. Data were analyzed from January 4 to December 22, 2022. MAIN OUTCOME AND MEASURE: Six-year progression to PAC or AAC. RESULTS: Cohort A included 878 eyes from 878 participants (mean [SD] age, 58.9 [5.0] years; 726 female [82.7%]) of whom 44 experienced progressive disease. In a multivariable analysis, treatment (hazard ratio [HR], 0.67; 95% CI, 0.34-1.33; P = .25) was no longer associated with progression after adjusting for age and trabecular iris space area at 500 μm (TISA at 500 μm) at the 2-week visit. Cohort B included 869 treated eyes from 869 participants (mean [SD] age, 58.9 [5.0] years; 717 female [82.5%]) of whom 19 experienced progressive disease. In multivariable analysis, TISA at 500 μm (HR, 1.33 per 0.01 mm2 smaller; 95% CI, 1.12-1.56; P = .001) and cumulative gonioscopy score (HR, 1.25 per grade smaller; 95% CI, 1.03-1.52; P = .02) at the 2-week visit were associated with progression. Persistent angle narrowing on AS-OCT (TISA at 500 μm ≤0.05 mm2; HR, 9.41; 95% CI, 3.39-26.08; P <.001) or gonioscopy (cumulative score ≤6; HR, 2.80; 95% CI, 1.13-6.93; P =.04) conferred higher risk of progression. CONCLUSIONS AND RELEVANCE: Study results suggest that persistent angle narrowing detected by AS-OCT or cumulative gonioscopy score was predictive of disease progression in PACS eyes after LPI. These findings suggest that AS-OCT and gonioscopy may be performed to identify patients at high risk of developing angle closure who may benefit from closer monitoring despite patent LPI
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