Publications

BACKGROUND AND PURPOSE

Raloxifene, a selective estrogen receptor modulator, reduces risk of invasive breast cancer and osteoporosis, but the effect on risk for stroke and venous thromboembolism in different patient subgroups is not established. The purpose of this analysis was to evaluate the effect of raloxifene on the incidence of all strokes, stroke deaths, and venous thromboembolic events according to participant subgroups.

METHODS

This was a secondary end point analysis of an international, randomized, placebo-controlled clinical trial of 10 101 postmenopausal women with or at increased risk of coronary heart disease followed a median of 5.6 years. Strokes, venous thromboembolic events, and deaths were adjudicated by expert centralized committees. Strokes were categorized as ischemic, hemorrhagic, or undetermined and venous thromboembolic events were subclassified.

RESULTS

The incidences of all strokes did not differ between raloxifene (incidence rate per 100 woman-years=0.95) and placebo (incidence rate=0.86) treatment groups (P=0.30). In women assigned raloxifene versus placebo, there was a higher incidence of fatal strokes (incidence rates=0.22 and 0.15, respectively, P=0.0499) and venous thromboembolic events (incidence rates=0.39 and 0.27, respectively, P=0.02). No significant subgroup interactions were found except that there was a higher incidence of stroke associated with raloxifene use among current smokers.

CONCLUSIONS

In postmenopausal women at increased risk for coronary events, the incidences of venous thromboembolism and fatal stroke but not all strokes were higher in those assigned raloxifene versus placebo. Raloxifene's effect did not differ across subgroups, except that the risk of stroke differed by smoking status. Treatment decisions about raloxifene should be based on a balance of projected absolute risks and benefits.

Diabetes mellitus (DM) and chronic kidney disease (CKD) are common in patients with chronic heart failure (HF) and are associated with poor outcomes. However, the impact of multimorbidity due to DM and CKD on outcomes, relative to co-morbidity due to DM alone, has not been well studied in these patients. Of the 7,788 patients with chronic HF in the Digitalis Investigation Group trial, 2,218 had DM. We categorized these patients into those with DM alone (DM-only n = 1,123) and those with both DM and CKD (DM-CKD n = 1,095). Propensity scores for DM-CKD, calculated for each of the 2,218 patients, were used to match 699 pairs of patients with DM-only or DM-CKD. Matched Cox regression models were used to estimate associations between DM-CKD and outcomes. All-cause mortality occurred in 44% (rate 1,648/10,000 person-years) of patients with DM-CKD and 39% (rate 1,349/10,000 person-years of follow-up) of patients with DM-only (hazard ratio when DM-CKD was compared with DM-only 1.34, 95% confidence interval [CI] 1.11 to 1.62, p = 0.003). All-cause hospitalization occurred in 76% (rate 5,799/10,000 person-years) and 73% (rate 4,909/10,000 person-years) of patients with DM-CKD and DM-only, respectively (hazard ratio 1.16, 95% CI 0.99 to 1.36, p = 0.064). Respective hazard ratios for other outcomes were cardiovascular mortality 1.33 (95% CI 1.07 to 1.66, p = 0.010), HF mortality 1.41 (95% CI 1.02 to 1.96, p = 0.040), cardiovascular hospitalization 1.17 (95% CI 0.99 to 1.39, p = 0.064), and HF hospitalization 1.26 (95% CI 1.03 to 1.55, p = 0.026). In conclusion, compared with co-morbidity due to DM alone, the presence of multimorbidity due to DM and CKD was associated with increased mortality and morbidity in patients with chronic HF.

Human semen contains peptides capable of forming amyloid fibrils termed semen-derived enhancer of viral infection (SEVI) that can greatly increase human immunodeficiency virus (HIV) infection. While SEVI appears to enhance virion attachment to target cells, its underlying mechanism of action is unknown. We now demonstrate that the intrinsic positive charges of SEVI (pI = 10.21) facilitate virion attachment to and fusion with target cells. A mutant form of SEVI in which lysines and arginines are replaced with alanines retains the ability to form amyloid fibrils but is defective in binding virions and enhancing infection. In addition, the interaction of wild-type SEVI with virions and the ability of these fibrils to increase infection are abrogated in the presence of various polyanionic compounds. These anionic polymers also decrease the enhancement of HIV infection mediated by semen. These findings suggest that SEVI enhances viral infection by serving as a polycationic bridge that neutralizes the negative charge repulsion that exists between HIV virions and target cells. Combinations of agents that neutrale SEVI action and produce HIV virucidal effects are an attractive future direction for microbicide development.

High-throughput short-read technologies have revolutionized DNA sequencing by drastically reducing the cost per base of sequencing information. Despite producing gigabases of sequence per run, these technologies still present obstacles in resequencing and de novo assembly applications due to biased or insufficient target sequence coverage. We present here a simple sample preparation method termed the "long march" that increases both contig lengths and target sequence coverage using high-throughput short-read technologies. By incorporating a Type IIS restriction enzyme recognition motif into the sequencing primer adapter, successive rounds of restriction enzyme cleavage and adapter ligation produce a set of nested sub-libraries from the initial amplicon library. Sequence reads from these sub-libraries are offset from each other with enough overlap to aid assembly and contig extension. We demonstrate the utility of the long march in resequencing of the Plasmodium falciparum transcriptome, where the number of genomic bases covered was increased by 39%, as well as in metagenomic analysis of a serum sample from a patient with hepatitis B virus (HBV)-related acute liver failure, where the number of HBV bases covered was increased by 42%. We also offer a theoretical optimization of the long march for de novo sequence assembly.

A subset of antiretroviral-untreated, human immunodeficiency virus (HIV)-infected individuals are able to maintain undetectable plasma HIV RNA levels in the absence of antiretroviral therapy. These "elite" controllers are of high interest as they may provide novel insights regarding host mechanisms of virus control. The degree to which these individuals have residual plasma viremia has not been well defined. We performed a longitudinal study of 46 elite controllers, defined as HIV-seropositive, antiretroviral-untreated individuals with plasma HIV RNA levels of <50 to 75 copies/ml. The median duration of HIV diagnosis was 13 years, the median baseline CD4(+) T-cell count was 753 cells/mm(3), and the median duration of follow-up was 16 months. Plasma and cellular HIV RNA levels were measured using the transcription-mediated amplification (TMA) assay (estimated limit of detection of <3.5 copies RNA/ml). A total of 1,117 TMA assays were performed (median of five time points/subject and four replicates/time point). All but one subject had detectable plasma HIV RNA on at least one time point, and 15 (33%) subjects had detectable RNA at all time points. The majority of controllers also had detectable cell-associated RNA and proviral DNA. A mixed-effect linear model showed no strong evidence of change in plasma RNA levels over time. In conclusion, the vast majority (98%) of elite controllers had measurable plasma HIV RNA, often at levels higher than that observed in antiretroviral-treated patients. This confirms the failure to eradicate the virus, even in these unique individuals who are able to reduce plasma viremia to very low levels without antiretroviral therapy.