Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2007
OBJECTIVE
To assess baseline factors associated with having ever drunk alcohol, smoked, and having had sex two years later among a sample of Latino adolescents.
DESIGN
In a prospective cohort study, Latino adolescents completed telephone surveys assessing demographic information and health-enhancing and -compromising behaviors, administered 3 times (baseline, T2, and T3) during a two-year period.
SETTING
Students were recruited between 1997 and 1998, from four middle schools within three Los Angeles school districts.
PARTICIPANTS
Latino adolescents in 7th and 8th grade, from any of the four middle schools, whose parents provided written permission for them to participate in a telephone health behavior survey.
MAIN OUTCOME MEASURES
Self-report of ever drank alcohol, ever smoked cigarettes, ever had sex by T3.
RESULTS
Being more acculturated, engaging in risky behaviors, valuing independence, and having friends who had ever smoked at baseline were positively associated with having ever drunk alcohol and having ever smoked by T3. Parents' negative reactions to risky and unhealthy behaviors were protective against drinking and smoking. Working at a paid job and having parents with a high school education or higher were associated with drinking alcohol by T3. Older age at baseline was positively associated with having sex, while receiving good grades and valuing religion were protective against having sex.
CONCLUSIONS
Findings reveal that both parents and peers are important influences on adolescent risk behaviors and suggest that interventions for adolescents to prevent such behaviors should involve peers and parents.
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In California, 641 Chinese and 629 Vietnamese age 12-17 participated in a longitudinal telephone study from 1999 to 2001. Four attitude scales were constructed: acceptance of smokers, addictive nature of smoking, psychosocial reasons to smoke, and gender roles and smoking. Vietnamese American adolescents had more pro-smoking attitudes than Chinese American adolescents. Male gender, having friends who smoked, and baseline smoking were associated with smoking susceptibility at follow-up. Those factors, U.S. birthplace, and the acceptance and psychosocial scales were associated with smoking. Smoking prevention efforts targeting Chinese and Vietnamese American adolescents should focus on gender, birthplace, peer smoking, and attitudes.
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The natural history of ductal carcinoma in situ (DCIS) is largely unknown, and its optimal treatment remains controversial. Using semi-structured interviews, this study compared 18 White and 16 Latina women's understanding of their DCIS diagnosis, treatment decision-making processes, and satisfaction with care. Ethnic differences were observed in cognitive and emotional responses to DCIS, with White women generally reporting a better understanding of their diagnosis and treatment, and Latinas reporting more distress. Regardless of ethnicity, women with DCIS preferred that physicians discuss treatment options and attend to their informational and emotional needs. Satisfaction was associated with adequate information, expediency of care, and physicians' sensitivity to patients' emotional needs.
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Prior studies have indicated that dehydroepiandrosterone (DHEA) may have immunomodulatory properties as well as positive effects on mood, quality of life, and body composition. Preliminary data suggest that DHEA inhibits expression of human immunodeficiency virus 1 (HIV) in latently infected cells; thus, it might be a potential adjunct to currently available antiretroviral therapy. The objective was to determine DHEA's impact on latent HIV infection, persistent viral replication, immunity, and nonimmune aspects of health restoration. A randomized, double-blind, placebo-controlled 24-week outpatient intervention included 40 subjects with suppressed HIV viremia on a stable antiretroviral regimen. Participants were randomized with equal probability to receive either DHEA or placebo for 12 weeks, followed by open-label DHEA for an additional 12 weeks. Intensive virologic monitoring included plasma viral load assays (lower limits of detection 50 copies/ml and 2.5 copies/ml) and quantitative cultures of replication-competent virus reservoirs in blood cells. A full battery of immunologic measurements was performed. Measurements of hormones, body weight, and body composition were obtained. Quality of life was assessed using validated questionnaires. DHEA was bioavailable as ascertained by increased levels of DHEA, DHEA(S), and androstenedione in recipients' plasma compared to the control group. The titers of infectious HIV culturable from blood trended upward in the DHEA arm although there was no significant change in plasma HIV RNA level. No significant immune effects were observed with DHEA. There appeared to be no benefit with regard to lean muscle mass or bone density in the DHEA recipients. DHEA treatment had a positive impact on overall quality of life. DHEA supplementation in fully suppressed HIV patients was associated with an improvement in quality of life but appeared to have no beneficial antiviral, immunomodulatory, hormonal, or body composition effects, suggesting that it not be routinely used as an adjunctive therapy in this population.
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The American Heart Association (AHA) and the American Diabetes Association (ADA) have each published guidelines for cardiovascular disease prevention: the ADA has issued separate recommendations for each of the cardiovascular risk factors in patients with diabetes, and the AHA has shaped primary and secondary guidelines that extend to patients with diabetes. This statement will attempt to harmonize the recommendations of both organizations where possible but will recognize areas in which AHA and ADA recommendations differ.
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As the volume, complexity, and cost of new medical technology increase, the need for evaluating benefits and risks becomes increasingly important. Once the formal requirements for Food and Drug Administration approval and insurance coverage are met, however, few systematic criteria are applied to ensure patient benefit. A more systematic policy approach regarding new technologies is needed, with input from balanced groups reviewing evidence of clinical outcomes data to determine patient benefit. This paper examines cardiac computed tomography angiography as a case study; it proposes procedures designed to ensure that the benefits of new technologies justify their costs.
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Candida albicans is a species of fungus that typically resides in the gastrointestinal tracts of humans and other warm-blooded animals. It is also the most common human fungal pathogen, causing a variety of skin and soft tissue infections in healthy people and more virulent invasive and disseminated diseases in patients with compromised immune systems. How this microorganism manages to persist in healthy hosts but also to cause a spectrum of disease states in the immunocompromised host are questions of significant biological interest as well as major clinical and economic importance. In this review, we describe recent developments in population genetics, the mating process, and gene disruption technology that are providing much needed experimental insights into the biology of C. albicans.
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In the prevailing model of HIV-1 trans-infection, dendritic cells (DCs) capture and internalize intact virions and transfer these virions to interacting T cells at the virological synapse. Here, we show that HIV-1 virions transmitted in trans from in vitro derived DCs to T cells principally originate from the surface of DCs. Selective neutralization of surface-bound virions abrogated trans-infection by monocyte-derived DCs and CD34-derived Langerhans cells. Under conditions mimicking antigen recognition by the interacting T cells, most transferred virions still derived from the cell surface, although a few were transferred from an internal compartment. Our findings suggest that attachment inhibitors could neutralize trans-infection of T cells by DCs in vivo.
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PLS3 (phospholipid scramblase-3) is a new member of the family of phospholipid scramblases and transports CL (cardiolipin) from the inner to the outer mitochondrial membrane. In the present paper we examined whether changing the levels of functional PLS3 in HeLa cells altered de novo CL biosynthesis and its resynthesis. HeLa cells overexpressing PLS3 or expressing a disrupted PLS3 (F258V) or control were incubated with [1,3-3H]glycerol and radioactivity incorporated into CL was determined. CL biosynthesis from [1,3-3H]glycerol was increased 1.8-fold in PLS3 cells and 2.1-fold in F258V cells compared with control. This was due to a 64% (P<0.05) and 2.6-fold (P<0.05) elevation in CL synthase activity in PLS3 and F258V cells respectively, compared with control, and not due to changes in phosphatidylglycerolphosphate synthase activity. The increase in CL synthase activity in these cells was due to an increase in its mRNA expression. In contrast, resynthesis of CL from [1-14C]linoleic acid was reduced 52% (P<0.05) in PLS3 and 45% (P<0.05) in F258V cells compared with control and this was due to a reduction in mitochondrial monolysocardiolipin acyltransferase activity. Although protein levels of mitochondrial monolysocardiolipin acyltransferase were unaltered, activity and mRNA expression of endoplasmic reticulum monolysocardiolipin acyltransferase was upregulated in PLS3 and F258V cells compared with controls. These data indicate that the CL resynthesis in HeLa cells is sensitive to the mitochondrial localization of CL and not the level of the reacylating enzymes. Alterations in functional PLS3 levels in PLS3 or F258V cells did not affect the mitochondrial decarboxylation of phosphatidylserine to phosphatidylethanolamine indicating that the biosynthetic changes to CL were specific for this mitochondrial phospholipid. We hypothesize that the cardiolipin resynthesis machinery in the cell 'senses' altered levels of CL on mitochondrial membranes and that de novo CL biosynthesis is up-regulated in HeLa cells as a compensatory mechanism in response to altered movement of mitochondrial CL. The results identify PLS3 as a novel regulator of CL de novo biosynthesis and its resynthesis.
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