HIV and HCV health beliefs in an inner-city community.

Chronic infection with the hepatitis C virus (HCV) is more prevalent than human immunodeficiency virus (HIV) infection, but more public health resources are allocated to HIV than to HCV. Given shared risk factors and epidemiology, we compared accuracy of health beliefs about HIV and HCV in an at-risk community. Between 2002 and 2003, we surveyed a random patient sample at a primary care clinic in New York. The survey was organized as domains of Common Sense Model of Self-Regulation: causes ('sharing needles'), timeline/consequences ('remains in body for life', 'causes cancer') and controllability ('I can avoid this illness', 'medications may cure this illness'). We compared differences in accuracy of beliefs about HIV and HCV and used multivariable linear regression to identify factors associated with relative accuracy of beliefs. One hundred and twenty-two subjects completed the survey (response rate 42%). Mean overall health belief accuracy was 12/15 questions (80%) for HIV vs 9/15 (60%) for HCV (P < 0.001). Belief accuracy was significantly different across all domains. Within the causes domain, 60% accurately believed sharing needles a risk factor for HCV compared to 92% for HIV (P < 0.001). Within the timeline/consequences domain, 42% accurately believed HCV results in lifelong infection compared to 89% for HIV (P < 0.001). Within the controllability domain, 25% accurately believed that there is a potential cure for HCV. Multivariable linear regression revealed female gender as significantly associated with greater health belief accuracy for HIV. Thus, study participants had significantly less accurate health beliefs about HCV than about HIV. Targeting inaccuracies might improve public health interventions to foster healthier behaviours and better hepatitis C outcomes.

Ethylene-regulated expression of a tomato fruit ripening gene encoding a proteinase inhibitor I with a glutamic residue at the reactive site.

We report the isolation from tomato (Lycopersicon esculentum) of an ethylene-responsive member of the proteinase inhibitor gene family. DNA sequence analysis of a full-length cDNA clone indicates that the ethylene-responsive gene is distantly related to the tomato proteinase inhibitor I gene, having 53% sequence identity. The predicted amino acid sequence reveals 47% and 45% sequence identity with the tomato and potato proteinase inhibitor I polypeptides, respectively. Additionally, the ethylene-responsive inhibitor has evolved a completely different pattern of gene expression and inhibitory specificity than other members of the inhibitor I family. Gel blot hybridization experiments show that, unlike the tomato proteinase inhibitor I gene, it is not induced in wounded leaves. In contrast, it is activated by the plant hormone ethylene in leaves and during fruit ripening. Furthermore, the ethylene-responsive inhibitor exhibits a novel reactive site, having glutamic acid as the P1 residue. This suggests that the ethylene-responsive proteinase inhibitor does not react with chymotrypsin, as does proteinase inhibitor I, but that it reacts with proteolytic enzymes that cleave at glutamic residues, such as the Staphylococcus aureus V8 proteinase, for which no inhibitors are known. Finally, isolation and analysis of a genomic clone reveals that the ethylene-responsive proteinase inhibitor gene is tightly linked to another, yet unidentified, coordinately expressed gene. We discuss these results with regard to the function and evolution of proteinase inhibitor genes in tomato.

Recombinant Gq alpha. Mutational activation and coupling to receptors and phospholipase C.

Gq mediates hormonal stimulation of phosphoinositide-specific phospholipase C (PI-PLC). We mutated the alpha subunit of Gq (alpha q) to replace arginine 183 with cysteine. Mutations that substitute cysteine for the corresponding arginine residues of alpha s and alpha i2 constitutively activate their respective effector pathways, creating the gsp and gip2 oncogenes. Transient expression of alpha q-R183C in COS-7 and HEK-293 cells constitutively activates PI-PLC, but wild type (WT) alpha q does not. This suggests that the mutated arginines in alpha s, alpha i2, and alpha q share a common function in regulating the active state of these proteins and that the alpha q gene may serve as a target for oncogenic mutations in human tumors. In an attempt to develop an assay for receptor stimulation of recombinant alpha q, we co-expressed receptors with alpha q-WT. We found that the alpha 2-adrenoceptor stimulates PI-PLC activation in HEK-293 cells in a fashion that depends completely on co-expression of alpha q-WT. These findings create an experimental model, similar to that provided for alpha s by S49 cyc- cells, that should make it possible to analyze receptor and effector coupling by mutant alpha q against a null background.

Supplemental insurance and use of effective cardiovascular drugs among elderly medicare beneficiaries with coronary heart disease.

CONTEXT: Cost-sharing in US prescription drug coverage plans for elderly persons varies widely. Evaluation of prescription drug use among elderly persons by type of health insurance could provide useful information for designing a Medicare drug program. OBJECTIVE: To determine use of effective cardiovascular drugs among elderly persons with coronary heart disease (CHD) by type of health insurance. DESIGN, SETTING, AND PATIENTS: Cross-sectional evaluation of 1908 community-dwelling adults, aged 66 years or older, with a history of CHD or myocardial infarction from the 1997 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries. MAIN OUTCOME MEASURES: Use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), beta-blockers, and nitrates, and out-of-pocket expenditures for prescription drugs, stratified by type of health insurance: Medicare without drug coverage (Medicare only or self-purchased supplemental insurance) or with drug coverage (Medicaid, other public program, Medigap, health maintenance organization, or employer-sponsored plan). RESULTS: Statin use ranged from 4.1% in Medicare patients with no drug coverage to 27.4% in patients with employer-sponsored drug coverage (P<.001). Less variation between these 2 types occurred for beta-blockers (20.7% vs 36.1%; P =.003) and nitrates (20.4% vs 38.0%; P =.005). In multivariate analyses, statin use remained significantly lower for patients with Medicare only (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.05-0.49) and beta-blocker use was lower for Medicaid patients (OR, 0.55; 95% CI, 0.34-0.88) vs those with employer-sponsored coverage. Nitrate use occurred less frequently in persons lacking drug coverage (patients with Medicare only, P =.049; patients with supplemental insurance without drug coverage, P =.03). Patients with Medicare only spent a much larger fraction of income on prescription drugs compared with those with employer-sponsored drug coverage (7.9% vs 1.7%; adjusted P<.001). CONCLUSION: Elderly Medicare beneficiaries with CHD who lack drug coverage have disproportionately large drug expenditures and lower use rates of statins, a class of relatively expensive drugs that improve survival.

Hormonal stimulation of adenylyl cyclase through Gi-protein beta gamma subunits.

Agonist-bound receptors activate heterotrimeric (alpha beta gamma) G proteins by catalysing replacement by GTP of GDP bound to the alpha subunit, resulting in dissociation of alpha-GTP from the beta gamma subunits. In most cases, alpha-GTP carries the signal to effectors, as in hormonal stimulation and inhibition of adenylyl cyclase by alpha s and alpha i respectively. By contrast, genetic evidence in yeast and studies in mammalian cells suggest that beta gamma subunits of G proteins may also regulate effector pathways. Indeed, of the four recombinant mammalian adenylyl cyclases available for study, two, adenylyl cyclases II and IV, are stimulated by beta gamma. This effect of beta gamma requires costimulation by alpha s-GTP. This conditional pattern of effector responsiveness led to the prediction that receptors coupled to many G proteins will mediate elevation of cellular cyclic AMP, provided that Gs is also active. We now confirm this prediction. Coexpression of mutationally active alpha s with adenylyl cyclase II converted agonists that act through 'inhibitory' receptors (coupled to Gi) into stimulators of cAMP synthesis. Experiments using pertussis toxin and a putative scavenger of beta gamma, the alpha subunit of transducin, suggest that beta gamma subunits of the Gi proteins mediated this stimulation. These findings assign a new signalling function to beta gamma subunits of Gi proteins, the conditional stimulation of cAMP synthesis by adenylyl cyclase II.

Intention to discontinue care among primary care patients: influence of physician behavior and process of care.

BACKGROUND: Specific elements of health care process and physician behavior have been shown to influence disenrollment decisions in HMOs, but not in outpatient settings caring for patients with diverse types of insurance coverage. OBJECTIVE: To examine whether physician behavior and process of care affect patients' intention to return to their usual health care practice. DESIGN: Cross-sectional patient survey and medical record review. SETTING: Eleven academically affiliated primary care medicine practices in the Boston area. PATIENTS: 2,782 patients with at least one visit in the preceding year. MEASUREMENT: Unwillingness to return to the usual health care practice. RESULTS: Of the 2,782 patients interviewed, 160 (5.8%) indicated they would not be willing to return. Two variables correlated significantly with unwillingness to return after adjustment for demographics, health status, health care utilization, satisfaction with physician's technical skill, site of care, and clustering of patients by provider: dissatisfaction with visit duration (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4 to 7.4) and patient reports that the physician did not listen to what the patient had to say (OR, 8.8; 95% CI, 2.5 to 30.7). In subgroup analysis, patients who were prescribed medications at their last visit but who did not receive an explanation of the purpose of the medication were more likely to be unwilling to return (OR, 4.9; 95% CI, 1.8 to 13.3). CONCLUSION: Failure of physicians to acknowledge patient concerns, provide explanations of care, and spend sufficient time with patients may contribute to patients' decisions to discontinue care at their usual site of care.