Myron S. Cohen

Bio: Myron S. Cohen is an academic researcher from University of North Carolina at Chapel Hill. The author has contributed to research in topics: Population & Acquired immunodeficiency syndrome (AIDS). The author has an hindex of 103, co-authored 549 publications receiving 46021 citations. Previous affiliations of Myron S. Cohen include University of Massachusetts Medical School & Scripps Health.

Frequent detection of acute primary HIV infection in men in Malawi

Abstract: Acute (antibody-negative) HIV infection is associated with high transmission potential but is rarely recognized. Design: Cross-sectional study. We examined the prevalence and predictors of acute HIV infection among 1361 consecutive male outpatients attending sexually transmitted disease (STD; n = 929) and dermatology (n = 432) clinics in Lilongwe Malawi. Serum specimens negative for HIV antibodies were screened by HIV RNA PCR using a highly specific pooling/resolution testing algorithm. Five-hundred and fifty-three men (40.6%) were HIV antibody positive and 24 (1.8%) had acute HIV infection; 23 of 24 acutely infected men were from the STD clinic where they represented 4.5% of all HIV antibody-negative men and 5.0% of all HIV infections. HIV RNA levels for acutely infected men were significantly higher [median (interquartile range) 6.10 (5.19–6.54) log/10 HIV RNA copies/ml] than for 58 HIV antibody-positive men [4.42 (3.91–4.95) log/10 copies/ml; P < 0.0001]. The factor most strongly associated with acute HIV infection was STD clinic attendance: (odds ratio 15.2; 95% confidence interval 2.04–113.0). In multivariate analysis considering only STD patients factors associated with acute HIV infection included inguinal adenopathy genital ulceration and age 24–26 years the age stratum associated with peak incidence of HIV infection among Malawian men. Traditional HIV antibody tests alone are not sufficient to exclude HIV infection among men with acute STD in Malawi due to a surprising proportion of acute HIV infections in this population. Alternative screening methods are required for diagnosis of acute HIV infection; such screening could be important for research and for prevention of the sexual transmission of HIV in select populations. (authors)

Vitamin D metabolites change the phenotype of monoblastic U937 cells.

Abstract: U937 is a human-derived lymphoma cell line that has monoblastic properties and high-affinity receptors for 1 alpha,-dihydroxyvitamin D3. Incubation of these cells with the vitamin D metabolite at 10 nM for 5 days produced marked stimulation in adherence and ingestion of Staphylococcus aureus (645% of control) and of C3b receptor (CR1) expression (292% of control) and a slight increase in hexose monophosphate shunt activity without changing cell growth rates or Fc fragment receptor expression. The changes in cellular association of S. aureus and the CR1 were detected as early as 48 hr of incubation and peaked between 3 and 5 days. Similar changes in the CR1 were induced by 25-hydroxy- and 24,25-dihydroxyvitamin D3 at micromolar concentrations. Dexamethasone, hydrocortisone, and progesterone had no effect on CR1 expression. U937 cells incubated in the presence of vitamin D metabolites exhibited a change in their phenotype. These results suggest that vitamin D metabolites may contribute to monocyte/macrophage differentiation.

Human Experimentation with Neisseria gonorrhoeae: Rationale, Methods, and Implications for the Biology of Infection and Vaccine Development

Abstract: Neisseria gonorrhoeae infection is limited to the human host. Experimental urethral infection in male volunteers was used to study different aspects of the infection. Urethral installation of a variety of gonococcal variants (10(4)-10(6)) led to infection in 27 subjects, who developed pyuria and shed bacteria in urine before urethritis developed 1-6 days after gonococcal inoculation. The incubation period was affected by the inoculation procedure and size of the inoculum. Subjects were treated with intramuscular ceftriaxone (250 mg) if urethritis developed or at 6 days after inoculation. Urine cultures became negative within several hours of therapy, and symptoms resolved within 1 day of therapy. Infected patients suffered no major complications. Experimental male urethral gonococcal infection provides a unique opportunity to understand the biology and immunology of gonococcal infection and is an efficient method to test gonococcal vaccine candidates.

The development of CD4 binding site antibodies during HIV-1 infection.

Abstract: Broadly neutralizing antibodies to the CD4 binding site (CD4bs) of gp120 are generated by some HIV-1-infected individuals, but little is known about the prevalence and evolution of this antibody response during the course of HIV-1 infection. We analyzed the sera of 113 HIV-1 seroconverters from three cohorts for binding to a panel of gp120 core proteins and their corresponding CD4bs knockout mutants. Among sera collected between 99 and 258 weeks post-HIV-1 infection, 88% contained antibodies to the CD4bs and 47% contained antibodies to resurfaced stabilized core (RSC) probes that react preferentially with broadly neutralizing CD4bs antibodies (BNCD4), such as monoclonal antibodies (MAbs) VRC01 and VRC-CH31. Analysis of longitudinal serum samples from a subset of 18 subjects revealed that CD4bs antibodies to gp120 arose within the first 4 to 16 weeks of infection, while the development of RSC-reactive antibodies was more varied, occurring between 10 and 152 weeks post-HIV-1 infection. Despite the presence of these antibodies, serum neutralization mediated by RSC-reactive antibodies was detected in sera from only a few donors infected for more than 3 years. Thus, CD4bs antibodies that bind a VRC01-like epitope are often induced during HIV-1 infection, but the level and potency required to mediate serum neutralization may take years to develop. An improved understanding of the immunological factors associated with the development and maturation of neutralizing CD4bs antibodies during HIV-1 infection may provide insights into the requirements for eliciting this response by vaccination.

Prevention of HIV-1 Infection with Early Antiretroviral Therapy

Abstract: Background Antiretroviral therapy that reduces viral replication could limit the transmission of human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. Methods In nine countries, we...

Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the Management of Community-Acquired Pneumonia in Adults

Abstract: Lionel A. Mandell, Richard G. Wunderink, Antonio Anzueto, John G. Bartlett, G. Douglas Campbell, Nathan C. Dean, Scott F. Dowell, Thomas M. File, Jr. Daniel M. Musher, Michael S. Niederman, Antonio Torres, and Cynthia G. Whitney McMaster University Medical School, Hamilton, Ontario, Canada; Northwestern University Feinberg School of Medicine, Chicago, Illinois; University of Texas Health Science Center and South Texas Veterans Health Care System, San Antonio, and Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas; Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Pulmonary, Critical Care, and Sleep Medicine, University of Mississippi School of Medicine, Jackson; Division of Pulmonary and Critical Care Medicine, LDS Hospital, and University of Utah, Salt Lake City, Utah; Centers for Disease Control and Prevention, Atlanta, Georgia; Northeastern Ohio Universities College of Medicine, Rootstown, and Summa Health System, Akron, Ohio; State University of New York at Stony Brook, Stony Brook, and Department of Medicine, Winthrop University Hospital, Mineola, New York; and Cap de Servei de Pneumologia i Allergia Respiratoria, Institut Clinic del Torax, Hospital Clinic de Barcelona, Facultat de Medicina, Universitat de Barcelona, Institut d’Investigacions Biomediques August Pi i Sunyer, CIBER CB06/06/0028, Barcelona, Spain.

Role of free radicals and catalytic metal ions in human disease: an overview.

Abstract: Publisher Summary This chapter discusses the role of free radicals and catalytic metal ions in human disease. The importance of transition metal ions in mediating oxidant damage naturally leads to the question as to what forms of such ions might be available to catalyze radical reactions in vivo . The chapter discusses the metabolism of transition metals, such as iron and copper. It also discusses the chelation therapy that is an approach to site-specific antioxidant protection. The detection and measurement of lipid peroxidation is the evidence most frequently cited to support the involvement of free radical reactions in toxicology and in human disease. A wide range of techniques is available to measure the rate of this process, but none is applicable to all circumstances. The two most popular are the measurement of diene conjugation and the thiobarbituric acid (TBA) test, but they are both subject to pitfalls, especially when applied to human samples. The chapter also discusses the essential principles of the peroxidation process. When discussing lipid peroxidation, it is essential to use clear terminology for the sequence of events involved; an imprecise use of terms such as initiation has caused considerable confusion in the literature. In a completely peroxide-free lipid system, first chain initiation of a peroxidation sequence in a membrane or polyunsaturated fatty acid refers to the attack of any species that has sufficient reactivity to abstract a hydrogen atom from a methylene group.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

Abstract: 1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

Sexually transmitted diseases treatment guidelines.

Abstract: The MMWR series of publications is published by the Office of Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention (CDC), U.S. Department of Health and Human Services, Atlanta, GA 30333.