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.

Aortic aneurysm associated with rheumatoid arthritis: a population-based cross-sectional study

Abstract: There is substantial evidence that aortic aneurysm (AA) may be a manifestation of several systemic rheumatic disorders. However, only several studies have assessed the association between rheumatoid arthritis (RA) and AA. The aim of this study was to evaluate the incidence of AA in RA patients in a case-control study. A retrospective case-control study was performed utilizing the database of Clalit Health Services (CHS), a large healthcare provider organization in Israel. Data available from the CHS database included age, sex, socioeconomic status (SES), and diagnoses of chronic diseases, including AA. Patients over the age of 20 years who were diagnosed with RA (“cases”) were compared with a sample of age- and gender-matched enrollees without RA (“controls”) regarding the prevalence of AA. Chi-square and t tests were used for univariate analysis, and a logistic regression model was used for multivariate analysis. The study included 11,782 RA patients and 57,973 age- and gender-matched controls. The proportion of AA was significantly higher in RA patients (0.72 %) compared to the control group 0.49 % (odds ratio (OR) 1.48, 95 %; confidence interval (CI) 1.15–1.88; p = 0.002). A multivariate analysis that evaluated covariates associated with AA revealed an independent association of AA and RA after adjustment for different factors including age, gender, SES, and smoking status (OR 1.406, 95 %; CI 1.094–1.789; p = 0.006). Our study has demonstrated that AA is more prevalent in patients with RA in comparison with general population. Future large randomized studies are important to identify cardiovascular- and disease-related risk factors for AA formation in RA patients.

Nonattendance in pediatric pulmonary clinics: an ambulatory survey

Abstract: Background Nonattendance for scheduled appointments disturbs the effective management of pediatric pulmonary clinics. We hypothesized that the reasons for non-attendance and the necessary solutions might be different in pediatric pulmonary medicine than in other pediatric fields. We therefore investigated the factors associated with nonattendance this field in order to devise a corrective strategy.

Low levels of calcium or vitamin D - which is more important in systemic lupus erythematosus patients? An extensive data analysis.

Abstract: OBJECTIVES Several reports have indicated an association between systemic lupus erythematosus (SLE) and low levels of vitamin D. We examined several blood work parameters in SLE patients and controls and performed an extensive data analysis in order to investigate the links between blood levels of calcium, vitamin D, and SLE disease. METHODS 4,278 SLE patients and 16,443 age and sex-matched controls were selected from a national health insurer database in Israel. Patients with no blood work results or having renal disease were excluded. Retrospective data from five consecutive years of routine blood work results were then analysed for mean serum calcium, albumin, albumin-corrected calcium, vitamin D levels, and the presence of a hypocalcaemic episode (Corrected Ca <8.5 mg/dL). RESULTS The mean levels of corrected serum calcium levels were slightly higher among SLE patients than controls (9.23±0.34 vs. 9.19±0.36 mg/dL p≤.001 respectively). In contrast to results of published studies, SLE patients had slightly higher levels of 25(OH)-vitamin D (SLE patients: 22.2±9.06 ng/ml, controls: 20.0±8.76 ng/ml, p≤.001). The most impressive finding entailing SLE patients was that they were twice as likely to experience episodes of hypocalcaemia in comparison to controls (SLE patients: 13.8%, controls: 6.4%, OR 2.34; 95% CI 2.33-2.83). CONCLUSIONS Calcium levels may play a significant role in the SLE disease process, more than originally thought, since SLE patients are at a higher risk for hypocalcaemic events. Specific changes in vitamin D and calcium homeostasis in SLE patients may be responsible for the severity of symptoms. Further research is required to determine the role of calcium supplementation.

Chronic hypnotic use at 10 years-does the brand matter?

Abstract: Chronic use of sedative-hypnotics is very common, although not guideline-endorsed. The incidence among new users is not well studied, and there are currently no recommendations favoring any specific agent. We quantified the risk for chronic use in first-time hypnotic users, and the association of the initial choice of hypnotic with later usage patterns. We used the computerized database of Israel’s largest healthcare provider. All 236,597 new users of sedative-hypnotics between the years 2000–2005 were followed for 10 years. Filled prescriptions in the second, fifth, and tenth years were recorded. The association of the first hypnotic choice (benzodiazepine/Z-drug) with chronic consumption was assessed using multivariate logistic regression. Average age on first use was 63.7 (SD ± 16.4) years. 58.6% were women. Benzodiazepines were initiated in 154,929 (65.5%) of the cases. Benzodiazepine users were older and of lower socioeconomic status, compared to Z-drug users (p < 0.001). On the tenth year, 103,912 (66.8%) of new users claimed ≤ 30 DDDs of hypnotics, 3,1724 (20.4%) were long-term users (≥ 180 DDD/year), and 828 (0.5%) used excessively (≥ 720 DDD/year). Z-drugs were associated with an increased risk of long-term use on the second year [17.3% vs. 12.4%, RR = 1.40 (1.37–1.43)] as well as on the fifth [21.9% vs. 13.9%, RR = 1.58 (1.55–1.61)] and tenth year [25.1% vs. 17.7%, RR = 1.42 (1.39–1.45)], p < 0.0001. Similar results were also observed for daily and excessive use (p < 0.001). One in five new users of sedative-hypnotics will become a long-term user, but only 0.5% will become excessive users. Z-drugs were associated with an increased risk of chronic use.

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.