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.

Pericarditis among giant cell arteritis patients: From myth to reality.

Abstract: BACKGROUND Giant cell arteritis (GCA) is an inflammatory disease of unknown etiology affecting adults age > 50 years. GCA (also known as temporal arteritis) is a vasculitis of large and medium-size vessels that involves the extracranial branches of the carotid artery. Common manifestations include constitutional symptoms, headache, jaw claudication, scalp tenderness, and vision loss. Cardiac involvement in GCA is considered to be as low as 5%, and < 30 cases of pericarditis among GCA patients have been reported in the literature. The aim of this study was to evaluate the association between GCA and pericarditis by conducting a cross-sectional study utilizing the database of the largest healthcare provider in Israel. HYPOTHESIS GCA is associated with pericarditis. METHODS The proportion of past documentation of pericarditis among patients diagnosed with GCA was compared with that of their age- and sex-matched controls. Univariate analysis was performed using the χ2 and t tests; multivariate analysis was performed using logistic regression. RESULTS The study included 4329 GCA patients and 21 611 controls. GCA patients had higher rates of cardiovascular risk factors. Pericarditis was observed in 53 GCA patients and 72 controls (1.22% vs 0.33%, respectively; P < 0.001), significantly higher among GCA patients in comparison with controls. A significant interaction was found between GCA, pericarditis, and young age (<70 years). CONCLUSIONS The study showed an independent association between GCA and pericarditis, especially among young patients. Proper screening should be applied whenever a suspicion arises as to the existence of comorbidity in patients with either disease.

Psoriasis and Dementia: A Cross-sectional Study of 121,801 Patients.

Abstract: Data regarding the association between psoriasis and dementia are inconclusive. The aim of this study was to evaluate this association in the database of Clalit Health Services, Israel. A comparative analysis for the association between psoriasis, dementia and its risk factors was performed for the entire study population and in the subgroup of patients with moderate-to-severe psoriasis. The study included 121,801 patients with psoriasis, of whom 16,947 were diagnosed with moderate-to-severe psoriasis, and 121,802 controls. Psoriasis was associated with a lower prevalence of dementia relative to control subjects (1.6% vs 1.8%; odds ratio (OR) 0.85; 95% confidence interval (95% CI) 0.80-0.91; p < 0.001). Multivariate analysis adjusting for demographic variables, cardiovascular-related risk factors, and healthcare utilization demonstrated a significant inverse association between psoriasis and dementia in the entire study population (adjusted OR 0.86; 95% CI 0.76-0.96; p = 0.009), but not in the subgroup of patients with moderate-to-severe psoriasis (adjusted OR 0.91; 95% CI 0.81-1.02; p = 0.113). In conclusion, these data support the hypothesis that psoriasis is inversely associated with dementia.

The Association Between Giant Cell Arteritis and Ischemic Heart Disease: A Population Based Cross-Sectional Study.

Abstract: BACKGROUND Patients with giant cell arteritis (GCA) suffer from inflammatory diseases often treated by large amounts of corticosteroids. Whether this inflammatory burden also carries an increased risk for cardiovascular morbidity, and especially ischemic heart disease, is not clearly established. OBJECTIVES To clarify the linkage between GCA and ischemic heart disease. METHODS In a cross-sectional study, we assessed the association between GCA and ischemic heart disease, adjusting for cardiovascular risk factors, among GCA patients and matched controls using the database of the largest healthcare provider in Israel. RESULTS The study group was comprised of 5659 GCA patients and 28,261 age and gender matched controls. The proportion of ischemic heart disease was higher in the GCA group (27.5% vs. 12.5% among controls, odds ratio 2.65). Diabetes mellitus, hypertension, hyperlipidemia and smoking were also found to have higher concurrency in GCA. After stratifying for those cardiovascular co-morbidities using logistic regression, GCA remained independently associated with ischemic heart disease with an odds ratio of 1.247 (1.146-1.357 P < 0.001). CONCLUSIONS GCA is associated with both cardiovascular risk factors and ischemic heart disease. Healthcare professionals should not overlook this aspect of the disease when managing GCA patients.

Venous thromboembolism events among RA patients.

Abstract: Background Rheumatoid arthritis (RA) is associated with an increased risk for venous thromboembolism. However, so far, relatively few and small size-based studies have been conducted. We aimed to investigate the link between RA and venous thromboembolism utilizing a large sample of subjects originating from a large data base. Materials and methods The study was performed utilizing the medical database of Clalit Health Services, the largest healthcare provider in Israel. We enrolled all patients with RA and age- and gender-matched controls. Chi-square and t-tests were used for univariate analysis and a logistic regression model was used for a multivariate analysis. RA patients were compared to controls regarding the proportion of venous thromboembolic events (defined as deep vein thrombosis, pulmonary embolism or both). Multivariate logistic regression was employed to assess factors associated with thromboembolic events. Results The study included 11,782 patients with RA and 57,973 age- and gender-matched controls. RA patients had a higher rate of venous thromboembolism events compared with controls (6.92% vs. 3.18%, respectively, p<0.001). RA and mean C-reactive protein levels were found to be independently associated with the proportion of thromboembolic events (OR 2.27 for RA and 1.07 for each 1 mg/dL increment of mean C-reactive protein, respectively). Conclusion RA and C-reactive protein levels are independently associated with venous thromboembolic events. Physicians should be aware of such findings and have a lower threshold for suspecting detecting such events in patients with RA, mainly those with mean high levels of C-reactive protein.

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.