Publications

Cardiovascular disease is the leading cause of mortality for women in the United States. Coronary heart disease, which includes coronary atherosclerotic disease, myocardial infarction, acute coronary syndromes, and angina, is the largest subset of this mortality, with >240,000 women dying annually from the disease. Atherosclerotic coronary artery disease (CAD) is the focus of this consensus statement. Research continues to report underrecognition and underdiagnosis of CAD as contributory to high mortality rates in women. Timely and accurate diagnosis can significantly reduce CAD mortality for women; indeed, once the diagnosis is made, it does appear that current treatments are equally effective at reducing risk in both women and men. As such, noninvasive diagnostic and prognostic testing offers the potential to identify women at increased CAD risk as the basis for instituting preventive and therapeutic interventions. Nevertheless, the recent evidence-based practice program report from the Agency for Healthcare Research and Quality noted the paucity of women enrolled in diagnostic research studies. Consequently, much of the evidence supporting contemporary recommendations for noninvasive diagnostic studies in women is extrapolated from studies conducted predominantly in cohorts of middle-aged men. The majority of diagnostic and prognostic evidence in cardiac imaging in women and men has been derived from observational registries and referral populations that are affected by selection and other biases. Thus, a better understanding of the potential impact of sex differences on noninvasive cardiac testing in women may greatly improve clinical decision making. This consensus statement provides a synopsis of available evidence on the role of the exercise ECG and cardiac imaging modalities, both those in common use as well as developing technologies that may add clinical value to the diagnosis and risk assessment of the symptomatic and asymptomatic woman with suspected CAD.

The NIMH Healthy Living Project (HLP), a randomized behavioral intervention trial for people living with HIV, enrolled 943 individuals, including women, heterosexual men, injection drug users, and men who have sex with men from Los Angeles, Milwaukee, New York, and San Francisco. The intervention, which is based on qualitative formative research and Ewart's Social Action Theory, addresses three interrelated aspects of living with HIV: stress and coping, transmission risk behavior, and medication adherence. Fifteen 90-minute structured sessions, divided into 3 modules of five sessions each, are delivered to individuals. Sessions are tailored to individuals within a structure that uses role-plays, problem solving, and goal setting techniques. A 'Life Project'--or overarching goal related to personal striving-provides continuity throughout sessions. Because this is an ongoing project with efficacy yet to be established, we do not report intervention outcomes. However, the intervention was designed to be useful for prevention case management, settings where repeated one-on-one contact is possible, and where a structured but highly individualized intervention approach is desired.

Adverse effects from antiretroviral therapy (ARV) for HIV are associated with medication nonadherence. The purposes of this study were to explore group differences in the reporting of adverse effects, identify individual adverse effects that are linked to nonadherence, and to explore the role of coping in the relationship between adverse effects and adherence. Cross-sectional interviews of 2,765 HIV-positive adults on ARV therapies in four U.S. cities were performed using a computerized assessment of self-reported adverse effects, coping self-efficacy, and adherence. There were no gender differences in the rate or severity of adverse effects reported. Latino respondents reported more adverse effects than either White or African Americans. Those taking a protease inhibitor (PI) reported a higher rate and greater severity of adverse effects. Older participants reported fewer adverse effects despite being more likely to be on a regimen containing a PI. Respondents with less than 90% adherence reported greater numbers and severity of adverse effects overall. In multivariate analyses, nausea, skin problems, vomiting, and memory adverse effects were independently related to less than 90% adherence over the prior three days. Coping moderated the relationship between nausea and adherence such that individuals who reported lower coping self-efficacy and experienced nausea were at increased risk for nonadherence, regardless of the length of time on the current ARV regimen. Women and men are similar in their overall reports of adverse effects, and Latinos report more adverse effects to ARVs than White or African American patients. Specific adverse effects (skin problems, memory problems, vomiting, and nausea) are more likely than others to be associated with missing ARV medications. Increasing adaptive coping self-efficacy among patients experiencing nausea may be a particularly effective strategy in increasing medication adherence.

Human immunodeficiency virus type 1 (HIV-1) in the male genital tract may comprise virus produced locally in addition to virus transported from the circulation. Virus produced in the male genital tract may be genetically distinct, due to tissue-specific cellular characteristics and immunological pressures. HIV-1 env sequences derived from paired blood and semen samples from the Los Alamos HIV Sequence Database were analyzed to ascertain a male genital tract-specific viral signature. Machine learning algorithms could predict seminal tropism based on env sequences with accuracies exceeding 90%, suggesting that a strong genetic signature does exist for virus replicating in the male genital tract. Additionally, semen-derived viral populations exhibited constrained diversity (P < 0.05), decreased levels of positive selection (P < 0.025), decreased CXCR4 coreceptor utilization, and altered glycosylation patterns. Our analysis suggests that the male genital tract represents a distinct selective environment that contributes to the apparent genetic bottlenecks associated with the sexual transmission of HIV-1.

Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) is a significant cause of morbidity. The requirements for HIV adaptation to the CNS for neuropathogenesis and the value of CSF virus as a surrogate for virus activity in brain parenchyma are not well established. We studied 18 HIV-infected subjects, most with advanced immunodeficiency and some neurocognitive impairment but none with evidence of opportunistic infection or malignancy of the CNS. Clonal sequences of C2-V3 env and population sequences of pol from HIV RNA in cerebrospinal fluid (CSF) and plasma were correlated with clinical and virologic variables. Most (14 of 18) subjects had partitioning of C2-V3 sequences according to compartment, and 9 of 13 subjects with drug resistance exhibited discordant resistance patterns between the two compartments. Regression analyses identified three to seven positions in C2-V3 that discriminated CSF from plasma HIV. The presence of compartmental differences at one or more of the identified positions in C2-V3 was highly associated with the presence of discordant resistance (P = 0.007), reflecting the autonomous replication of HIV and the independent evolution of drug resistance in the CNS. Discordance of resistance was associated with severity of neurocognitive deficits (P = 0.07), while low nadir CD4 counts were linked both to the severity of neurocognitive deficits and to discordant resistance patterns (P = 0.05 and 0.09, respectively). These observations support the study of CSF HIV as an accessible surrogate for HIV virions in the brain, confirm the high frequency of discordant resistance in subjects with advanced disease in the absence of opportunistic infection or malignancy of the CNS, and begin to identify genetic patterns in HIV env associated with adaptation to the CNS.

Candida albicans is the most common human fungal pathogen and causes significant morbidity and mortality worldwide. Nevertheless, the basic principles of C. albicans pathogenesis remain poorly understood. Of central importance to the study of this organism is the ability to generate homozygous knockout mutants and to analyze them in a mammalian model of pathogenesis. C. albicans is diploid, and current strategies for gene deletion typically involve repeated use of the URA3 selectable marker. These procedures are often time-consuming and inefficient. Moreover, URA3 expression levels-which are susceptible to chromosome position effects-can themselves affect virulence, thereby complicating analysis of strains constructed with URA3 as a selectable marker. Here, we describe a set of newly developed reference strains (leu2Delta/leu2Delta, his1Delta/his1Delta; arg4Delta/arg4Delta, his1Delta/his1Delta; and arg4Delta/arg4Delta, leu2Delta/leu2Delta, his1Delta/his1Delta) that exhibit wild-type or nearly wild-type virulence in a mouse model. We also describe new disruption marker cassettes and a fusion PCR protocol that permit rapid and highly efficient generation of homozygous knockout mutations in the new C. albicans strains. We demonstrate these procedures for two well-studied genes, TUP1 and EFG1, as well as a novel gene, RBD1. These tools should permit large-scale genetic analysis of this important human pathogen.

After infection with human immunodeficiency virus (HIV), progression toward immunodeficiency is governed by a complex interplay of viral and host determinants. The viral accessory protein Nef is a key factor for the development of AIDS. Strains of HIV and simian immunodeficiency virus that lack functional nef genes either do not induce AIDS or do so only after a significant delay. The validity of a transgenic-small-animal model for de novo infection by HIV will depend on its ability to recapitulate the actions of critical factors of viral pathogenicity, such as Nef. We assessed the ability of rat, mouse, and hamster cells to support key effector functions of Nef. In cell lines from rodents, the subcellular distribution of wild-type HIV type 1 strain SF2 Nef and mutants was comparable to that in human cells. Nef downregulated human CD4 from the cell surface, was associated with p21-activated kinase activity, and enhanced the infectivity of HIV-1 virions. Importantly, these Nef-induced effects, as well as the downregulation of rat CD4 and major histocompatibility complex class I molecules, could also be demonstrated in primary T lymphocytes and macrophages from human CD4-transgenic rats. Thus, HIV-1 Nef exerts key functions in rodent cells. In line with our ongoing efforts to establish a transgenic-rat model of HIV disease, these results indicate that important aspects of viral pathogenesis could be addressed in a transgenic-rodent model permissive for de novo infection and that such a model would be valuable for evaluating the function of Nef in vivo.

Human immune cells possess a built-in mechanism that could potentially block the replication of retroviruses such as HIV-1. This protective mechanism centers on apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G (APOBEC3G), a DNA-editing enzyme produced by host cells infected by certain retroviruses that is then incorporated into virions. Due to its cytidine deaminase activity, APOBEC3G is able to mutate the minus-strand DNA formed during reverse transcription. These events ultimately halt completion of the HIV life cycle. Unfortunately, HIV-1 encodes a protein termed virion infectivity factor (Vif) that specifically suppresses the activity of APOBEC3G. Vif achieves this effect by depleting the intracellular stores of APOBEC3G, thus making this antiviral enzyme unavailable for incorporation into budding virions. APOBEC3G depletion involves the recruitment of a specific E3 ligase complex by Vif leading to the polyubiquitylation and proteasome-mediated degradation of this enzyme. The potent activity of APOBEC3G has led to considerable interest in the identification of small molecules that interrupt the Vif-induced degradative process.

Since the introduction of HIV protease inhibitors (PIs), disorders of glucose and lipid metabolism have emerged. In dissecting out the direct effect on lipid and glucose metabolism, it has become apparent that individual PIs have different effects on metabolism. Some PIs such as indinavir acutely induce insulin resistance. PIs have also been shown to cause other disorders of glucose metabolism, including impairment of insulin secretion and increased endogenous glucose production. Individual PIs also have different effects on lipid metabolism. Ritonavir predominantly increases triglyceride and very low-density lipoprotein cholesterol levels. Limited studies in HIV-negative volunteers suggest that several of the PIs do not increase low-density lipoprotein cholesterol levels. This review examines the direct effects of PIs on glucose and lipid metabolism by assessing prospective studies of HIV-infected and healthy normal volunteers, and in vitro studies.

Comparisons of body composition and metabolic changes among antiretroviral-naive patients randomly assigned to didanosine and stavudine- (ddI+d4T) vs. abacavir and lamivudine- (ABC+3TC) containing regimens were assessed in a nested substudy of an ongoing multicenter randomized trial. At baseline and every 4 months, body cell mass and total body fat were calculated, anthropometric measurements were performed, and fasting metabolic parameters were obtained. The rates of change (unit/mo) estimated using the slopes of regression lines and overall mean changes from baseline were compared by study assignment. Among 96 patients enrolled, 46 received ddI+d4T- and 50 received ABC+3TC-containing regimens with a median follow-up of 32.4 months. For both study arms, an overall increase in the rates of change was seen for body cell mass. For ddI+d4T, after an initial increase, the rates of change declined for regional fat and total body fat compared with an increase for ABC+3TC, with the 2 arms being significantly different (P<0.05). For high-density lipoprotein cholesterol rates of change, ddI+d4T decreased, while ABC+3TC increased. For both arms, low-density lipoprotein cholesterol decreased, while triglycerides increased. Early and sustained increases in insulin and insulin resistance were seen only for ddI+d4T. In this prospective study, metabolic and body composition changes varied according to whether subjects received ddI+d4T or ABC+3TC.