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.

Theoretical determination of the blood's relative oxygen saturation in vivo

Abstract: The diffusion equations for randomly directed photons are applied to the problem of thein vivo determination of the oxygen relative saturation in blood. A model of the living tissue is presented. The transmitted and backscattered light fluxes are calculated for various skin properties, volume occupied by the blood and the blood relative oxygen saturation. Normalization functions are introduced and analyzed for sensitivities to changes in several parameters. The photodiffusion theoretical treatment is suggested for calculations which will lead to optimal normalization techniques and transducer design for thein vivo measurements of the oxygen relative saturation in the blood.

Helicobacter pylori infection is positively associated with an increased BMI, irrespective of socioeconomic status and other confounders: a cohort study.

Abstract: BACKGROUND Data on the association of Helicobacter pylori infection and BMI are conflicting. The fact that both H. pylori infection and BMI are associated with low socioeconomic status (SES) makes this relationship difficult to characterize. MATERIALS AND METHODS We aimed to evaluate the association between BMI and H. pylori infection after adjusting for multiple covariates. We analyzed a cohort of 235 107 individuals aged 18 years or older, who performed a C urease breath test (C-UBT), from 2007 to 2014. Data on BMI, age, sex, SES, ethnicity, and medications were extracted from a nationwide population-based database. BMIs were classified according to the WHO recommendations: underweight ( 35 kg/m). STUDY RESULTS The positivity rate for H. pylori among underweight, normal weight, overweight, and obese class I and class II or more was 55.6, 58.5, 63.0, 64.5, and 65.5%, respectively (P<0.001, Plinear trend 0.007). The association between BMI and H. pylori infection was significant across all SES, sex, ethnicity, and age categories. After adjusting for age, sex, ethnicity, and SES, being overweight and obese class I and class II or more were associated significantly with H. pylori positivity: odds ratio 1.13 [95% confidence interval (CI): 1.11-1.15], 1.14 (95% CI: 1.11-1.17), and 1.15 (95% CI: 1.11-1.19), respectively, P value less than 0.001 for all. CONCLUSION Among individuals who were referred to a C-UBT by primary care physician, after adjusting for multiple covariates including SES, we found a positive association between H. pylori infection and an increased BMI.

Biologics combined with conventional systemic agents or phototherapy for the treatment of psoriasis: real-life data from PSONET registries.

Abstract: Background Biologics have greatly improved psoriasis management. However, primary and secondary non-response to treatment requires innovative strategies to optimize outcomes. Objective To describe the use of combined treatment of biologics with conventional systemic agents or phototherapy in daily clinical practice. Methods We collected data on frequency of use, demographics, treatment characteristics and drug survival of biologics combined with conventional systemic agents or phototherapy in five PSONET registries. Results Of 9922 biologic treatment cycles, 982 (9.9%) were identified as combination treatment. 72.9% of treatment cycles concerned concomitant use of methotrexate, 25.3% concerned concomitant UVB therapy, acitretin or cyclosporin and 1.8% concerned combined treatment with PUVA, fumaric acids or a second biologic. Substantial variation was detected in type and frequency of combination treatments prescribed across registries. Patients initiated on combined treatment had generally severe disease and were affected with psoriasis for many years. The extent to which patients had been priory treated with biologic monotherapy and the proportion of patients affected with psoriatic arthritis differed between registries. Survival rates for etanercept, adalimumab, infliximab and ustekinumab with methotrexate ranged between 43-92%, 28-83%, 65-87% and 53-77% respectively across registries after one year with no consistent superior survival for a particular biologic. Longest survival on a biologic combined with methotrexate, acitretin or cyclosporin was 103, 78 and 34 months respectively. Conclusion Methotrexate was the most commonly used concomitant treatment for patients on a biologic. Wide geographical variations in treatment selection and persistence of combination treatment exist. Data derived from ongoing studies may help to determine whether combined treatment is superior to biologic monotherapy. This article is protected by copyright. All rights reserved.

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.