Arnon D. Cohen

Bio: Arnon D. Cohen is an academic researcher from Clalit Health Services. The author has contributed to research in topics: Population & Odds ratio. The author has an hindex of 41, co-authored 374 publications receiving 7913 citations. Previous affiliations of Arnon D. Cohen include University of Milan & University of Connecticut.

Hyperthyroidism association with SLE, lessons from real-life data--A case-control study

Abstract: Background: Despite the frequently encountered association between thyroid disease and systemic lupus erythematosus (SLE) is well known, it is of surprise that only several reports compromised of small population size support this observation. Objectives: To investigate the association of comorbid SLE and hyperthyroidism. Methods: Using the database of the largest health maintenance organization (HMO) in Israel, the Clalit Health Services, we searched for the co-existence of SLE and hyperthyroidism. Patients with SLE were compared with age- and sex-matched controls regarding the prevalence of hyperthyroidism in a case–control study. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for multivariate analysis. Results: The study included 5018 patients with SLE and 25 090 age- and sex- matched controls. The prevalence of hyperthyroidism in patients with SLE was increased compared with the prevalence in controls (2.59% and 0.91%, respectively, p < 0.001)...

Gradient-Type Algorithms for Partial Singular Value Decomposition

Abstract: It is often desirable to calculate only a few terms of the SVD expansion of a matrix, corresponding to the largest or smallest singular values. Two algorithms, based on gradient and conjugate gradient search, are proposed for this purpose. SVD is computed term by term in a decreasing or increasing order of singular values. The algorithms are simple to implement and are especially advantageous with large matrices.

Association between ischemic heart disease and systemic lupus erythematosus—a large case-control study

Abstract: Ischemic heart disease (IHD) is a well identified cause of mortality in systemic lupus erythematosus (SLE) patients due to an accelerated premature atherosclerosis. We investigated the proportion of comorbid IHD among SLE patients derived from a large, national real-life database. Using data from the largest HMO in Israel, the Clalit Health Services, we selected for patients with SLE. These patients were compared with age and sex matched controls with regards to the proportion of IHD in a case-control study. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The study included 5018 patients with SLE and 25090 age and sex-frequency matched controls. The prevalence of IHD in patients with SLE was increased in comparison to controls (11.3 and 3.1%, P < 0.001). In a multivariate analysis, SLE was associated with IHD (OR 3.77, 95% confidence interval 3.34–4.26). We have confirmed that SLE patients suffer a high prevalence of IHD. Our data supports that SLE is an independent risk factor for IHD. When evaluating by gender, the risk seems even more substantial in females. No significant difference was found in the risk of IHD in SLE among the difference socioeconomic strata.

New insights into associated co-morbidities in patients with cutaneous T-cell lymphoma (mycosis fungoides).

Abstract: Studies of associated cancer in patients with mycosis fungoides (MF) have focused primarily on secondary cancers in North American and European populations. This study investigated the association between MF and malignancies, anxiety and depression in the Israeli population. Data on Israeli patients with MF and age- and gender-matched controls were collected from a database of population- based cohort (683 patients; 1,700 controls) and an institution- based cohort (343 patients; 846 controls) and analysed by univariate and multivariate methods. MF was significantly associated with Hodgkin's lymphoma in both cohorts (multivariate odds ratio (OR) 7.83, univariate OR ∞, respectively); acute leukaemia (multivariate OR 10.1, first cohort) and lung cancer (multivariate OR 10.15, second cohort). MF was significantly associated with anxiety and depression (multivariate OR 1.59, OR 1.51, respectively in first cohort). The current study provides support to the associations between MF and other cancers: Hodgkin's lymphoma, acute leukaemia and lung cancer. The study also emphasizes the association between MF and anxiety and depression.

Intervention program to reduce waiting time of a dermatological visit: managed overbooking and service centralization as effective management tools.

Abstract: Background Long waiting times are an impediment of dermatological patient care world-wide, resulting in significant disruption of clinical care and frustration among carers and patients. Objective To reduce waiting times for dermatological appointments. Methods A focus group including dermatologists and management personnel reviewed the scheduling process, mapped potential problems and proposed a comprehensive intervention program. The two major approaches taken in the intervention program were revision of the scheduling process by managed overbooking of patient appointments and centralization of the dermatological service into a centralized dermatological clinic. Results Following the intervention program, the average waiting time for dermatological appointments decreased from 29.3 to 6.8 days. The number of scheduled appointments per 6 months rose from 17,007 to 20,433. Non-attendance proportion (no-show) decreased from 33% to 28%. Dermatologist work-hours were without significant change. Conclusions Waiting lists for dermatological consultations were substantially shortened by managed overbooking of patient appointments and centralization of the service.

Harrison's Principles of Internal Medicine

Abstract: The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

The Self-Organizing Map

Abstract: An overview of the self-organizing map algorithm, on which the papers in this issue are based, is presented in this article.

The Geometry of Algorithms with Orthogonality Constraints

Abstract: In this paper we develop new Newton and conjugate gradient algorithms on the Grassmann and Stiefel manifolds. These manifolds represent the constraints that arise in such areas as the symmetric eigenvalue problem, nonlinear eigenvalue problems, electronic structures computations, and signal processing. In addition to the new algorithms, we show how the geometrical framework gives penetrating new insights allowing us to create, understand, and compare algorithms. The theory proposed here provides a taxonomy for numerical linear algebra algorithms that provide a top level mathematical view of previously unrelated algorithms. It is our hope that developers of new algorithms and perturbation theories will benefit from the theory, methods, and examples in this paper.

Sarcoidosis

Abstract: 结节病易误诊,据王洪武等~([1])收集国内18篇关于此病误诊的文献,误诊率高达63.2%,当然有误诊就会有误治,如孙永昌等~([2])报道26例结节病在影像学检查诊断的第一印象中拟诊结核5例,其中就有2例完成规范的抗结核治疗,为此应引起临床对本病诊治的重视。

Type 2 diabetes mellitus.

Abstract: Type 2 diabetes mellitus (T2DM) is an expanding global health problem, closely linked to the epidemic of obesity. Individuals with T2DM are at high risk for both microvascular complications (including retinopathy, nephropathy and neuropathy) and macrovascular complications (such as cardiovascular comorbidities), owing to hyperglycaemia and individual components of the insulin resistance (metabolic) syndrome. Environmental factors (for example, obesity, an unhealthy diet and physical inactivity) and genetic factors contribute to the multiple pathophysiological disturbances that are responsible for impaired glucose homeostasis in T2DM. Insulin resistance and impaired insulin secretion remain the core defects in T2DM, but at least six other pathophysiological abnormalities contribute to the dysregulation of glucose metabolism. The multiple pathogenetic disturbances present in T2DM dictate that multiple antidiabetic agents, used in combination, will be required to maintain normoglycaemia. The treatment must not only be effective and safe but also improve the quality of life. Several novel medications are in development, but the greatest need is for agents that enhance insulin sensitivity, halt the progressive pancreatic β-cell failure that is characteristic of T2DM and prevent or reverse the microvascular complications. For an illustrated summary of this Primer, visit: http://go.nature.com/V2eGfN.