Publications

OBJECTIVES

We described frequency of secondhand smoke (SHS) exposure among young adults patronizing bars and associations between SHS exposure, attitudes, and smoking behavior.

METHODS

We collected cross-sectional surveys from randomized time-location samples of bar patrons aged 18 to 26 years in San Diego, California, and Oklahoma City and Tulsa, Oklahoma, in 2010 to 2011. Multivariate logistic regression evaluated associations between SHS exposure, attitudes about dangers of SHS, susceptibility to smoking initiation among nonsmokers, and quit attempts among current smokers.

RESULTS

More than 80% of respondents reported past 7-day exposure to any SHS, and more than 70% reported exposure at a bar. Current smokers reported more SHS exposure in cars and their own homes than did nonsmokers. Among nonsmokers, SHS exposure was associated with susceptibility to initiation, but those who believed that SHS exposure is harmful were less susceptible. Belief that SHS is dangerous was associated with quit attempts among smokers.

CONCLUSIONS

Smoke-free environments and education about the harms of SHS may decrease tobacco use among young adults who frequent bars, where they are heavily exposed to SHS.

In a survey of 1836 adult US smokers, when using a direct comparison measure, 22.1% reported snus was less harmful than were cigarettes. When asked indirectly (estimating the health risk of snus and cigarettes in 2 separate questions and comparing the answers to each other), 51.6% rated snus as less risky. The Food and Drug Administration should consider both direct and indirect measures when perceived risk data are presented as evidence for tobacco regulation.

OBJECTIVES

We explored the relationship between social isolation and mortality in a nationally representative US sample and compared the predictive power of social isolation with that of traditional clinical risk factors.

METHODS

We used data on 16,849 adults from the Third National Health and Nutrition Examination Survey and the National Death Index. Predictor variables were 4 social isolation factors and a composite index. Comparison predictors included smoking, obesity, elevated blood pressure, and high cholesterol. Unadjusted Kaplan-Meier tables and Cox proportional hazards regression models controlling for sociodemographic characteristics were used to predict mortality.

RESULTS

Socially isolated men and women had worse unadjusted survival curves than less socially isolated individuals. Cox models revealed that social isolation predicted mortality for both genders, as did smoking and high blood pressure. Among men, individual social predictors included being unmarried, participating infrequently in religious activities, and lacking club or organization affiliations; among women, significant predictors were being unmarried, infrequent social contact, and participating infrequently in religious activities.

CONCLUSIONS

The strength of social isolation as a predictor of mortality is similar to that of well-documented clinical risk factors. Our results suggest the importance of assessing patients' level of social isolation.

Solid organ transplantation in human immunodeficiency virus 1 (HIV)-infected individuals requiring the concomitant use of immunosuppressants (IS) [e.g. cyclosporine (CsA) or tacrolimus (TAC)] and antiretrovirals (ARVs) [e.g. protease inhibitors (PIs) and/or non-nucleoside reverse transcriptase inhibitors (NNRTIs)] is complicated by significant drug interactions. This paper describes the pharmacokinetics of CsA and TAC in 52 patients on both IS and NNRTIs, PIs or combined NNRTIs + PIs, in studies conducted at 2 weeks, 3, 6, 12 and 24 months after transplantation. Cyclosporine and TAC blood concentrations were measured by LC/MS/MS. This multisubject, varied ARV-IS drug combination, longitudinal observational patient study provided a unique opportunity to examine the effect of different ARV drugs on IS pharmacokinetics (PK) by comparing the ratios of parameters over time and between PK parameters. Subjects taking concomitant PIs exhibited increases in CsA and TAC exposure (AUC/dose) due to the increased apparent oral bioavailability and decreased apparent oral clearance. Those subjects taking CsA and concomitant efavirenz (EFV) showed time dependent increases in exposure due to ~30% increases in the apparent oral bioavailability over time as well as a decreased apparent oral clearance, while subjects on TAC and EFV showed time-dependent changes in all PK parameters. The increased bioavailability was not observed in patients on CsA and nevirapine (NVP). These differences between IS drugs and the changes in PK parameters are not easily predicted, illustrating the importance of continued therapeutic drug monitoring in patients on these complex medication regimens. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Sickle cell trait (HbAS) is the best-characterized genetic polymorphism known to protect against falciparum malaria. Although the protective effect of HbAS against malaria is well known, the mechanism(s) of protection remain unclear. A number of biochemical and immune-mediated mechanisms have been proposed, and it is likely that multiple complex mechanisms are responsible for the observed protection. Increased evidence for an immune component of protection as well as novel mechanisms, such as enhanced tolerance to disease mediated by HO-1 and reduced parasitic growth due to translocation of host micro-RNA into the parasite, have recently been described. A better understanding of relevant mechanisms will provide valuable insight into the host-parasite relationship, including the role of the host immune system in protection against malaria.

Next-generation sequencing was used for discovery and de novo assembly of a novel, highly divergent DNA virus at the interface between the Parvoviridae and Circoviridae. The virus, provisionally named parvovirus-like hybrid virus (PHV), is nearly identical by sequence to another DNA virus, NIH-CQV, previously detected in Chinese patients with seronegative (non-A-E) hepatitis. Although we initially detected PHV in a wide range of clinical samples, with all strains sharing ∼99% nucleotide and amino acid identity with each other and with NIH-CQV, the exact origin of the virus was eventually traced to contaminated silica-binding spin columns used for nucleic acid extraction. Definitive confirmation of the origin of PHV, and presumably NIH-CQV, was obtained by in-depth analyses of water eluted through contaminated spin columns. Analysis of environmental metagenome libraries detected PHV sequences in coastal marine waters of North America, suggesting that a potential association between PHV and diatoms (algae) that generate the silica matrix used in the spin columns may have resulted in inadvertent viral contamination during manufacture. The confirmation of PHV/NIH-CQV as laboratory reagent contaminants and not bona fide infectious agents of humans underscores the rigorous approach needed to establish the validity of new viral genomes discovered by next-generation sequencing.

Vitamin D receptors (VDR) are found in cells throughout the cardiovascular system. A variety of experimental studies indicate that the liganded VDR may play an important role in controlling cardiac hypertrophy and fibrosis, regulating blood pressure, and suppressing the development of atherosclerosis. Some, but not all, observational studies in humans provide support for these experimental findings, raising the possibility that vitamin D or its analogs might prove useful therapeutically in the prevention or treatment of cardiovascular disease.