Social networks and forecasting the spread of HIV infection

This study is an initial effort to use network data to forecast the spread of HIV in a large U.S. city. Data were collected from a sample of drug users and sociodemographically matched nonusers in low-income areas of Houston, Texas. Two sample-based HIV prevalence models and two sociological models were combined with three published biological models to yield forecasts of the growth of HIV seroprevalence. The forecasts predict a compounded annual growth in HIV of between 2.4% and 16.5% among low-income residents of Houston's inner city. These results suggest that forecasts are most sensitive to the nature of the sociological model used. A random mixing model showed about a threefold overestimate of 20-year projected seroprevalence compared with the empiric network data. Thus, the collection of additional social network data is probably the most important requirement for more accurate projections.     

New frontiers and challenges in HIV research among older minority populations

Older racial and ethnic minorities are a rapidly growing segment of the population. HIV infection disproportionately affects minorities of all ages, presenting new challenges in research, prevention, and treatment of HIV infection. Cultural characteristics coupled with changing values and age-related beliefs can present some atypical challenges to HIV researchers and clinicians. Family relationships, language barriers, and the psychology of aging complicate these challenges even further. Older minorities also experience certain stigmas that the added burden of HIV infection only exacerbates. Effective research, prevention, and treatment must begin with sensitivity to the varied characteristics of older minorities.     

Distortion-product otoacoustic emissions study of the noise-induced toughening effect in rats

OBJECTIVE: To compare the toughening effects in rats induced by pure tones and a broadband noise (BBN). MATERIAL AND METHODS: Sprague-Dawley female albino rats (n = 148; 8-10 weeks old) were used. Three experimental groups were established as follows. Toughening only: 38 rats, divided into 3 subgroups, were exposed to different conditioning sounds (2 and 4 kHz and a BBN of 0.25-6 kHz, respectively) at 75-85 dB sound pressure limit (SPL) for 8 h/day for 10 days. Acoustic trauma only: 54 rats, divided into 3 subgroups, were exposed to different conditioning sounds as above for 24 h at 100-110 dB SPL. Toughening plus acoustic trauma: 56 rats, divided into 3 subgroups, were exposed to different conditioning sounds as above, followed 8 h later by traumatic exposure to the conditioning sound at 110 dB SPL for 24 h. 2f1-f2 distortion-product (DP) otoacoustic emission measurements were obtained from the right ear of each animal pre-exposure, immediately post-exposure and after 8 h of the traumatic or conditioning exposure. RESULTS: In our control DPgram response, the maximum amplitude occurred at the highest frequencies (2, 3, 4, 5 and 6 kHz). No statistical differences between the control DPgram and the DP toughening (2 and 4 kHz and BBN)responses were found. Only 2 and 4 kHz frequencies induced a protective effect against traumatic sound exposures to the same frequencies, and this finding was statistically significant. CONCLUSION: The toughening phenomenon induced using 2 and 4 kHz pure tones and BBN in rats does not modify the DPgram response. Nevertheless, only 2 and 4 kHz frequencies induce a protective effect against traumatic sound exposures to the same frequencies.     

Cost-Effectiveness of Switching to Exemestane after 2 to 3 Years of Therapy with Tamoxifen in Postmenopausal Women with Early-Stage Breast Cancer

OBJECTIVES: Data from the Intergroup Exemestane Study (IES) suggest that switching to the aromatase inhibitor, exemestane, after 2 to 3 years of tamoxifen therapy prolongs disease-free survival versus continuing on tamoxifen therapy. We sought to evaluate the cost-effectiveness of this management strategy. METHODS: A Markov model was developed to predict patients' transitions across various health states based on treatment strategy (continuing tamoxifen vs. switching to exemestane), breast cancer status (no recurrence, local or distant recurrence, contralateral breast cancer), and other related health events (osteoporosis, endometrial cancer, death). Rates of disease-related events (recurrence and contralateral breast cancer) were estimated using data from the IES. Survival and lifetime medical-care costs by type of disease-related event were estimated using SEER-Medicare data. The model was used to estimate direct costs (in 2004 US dollars), life expectancy, quality-adjusted life-years (QALYs), and incremental cost-effectiveness. RESULTS: Switching to exemestane versus continuing tamoxifen therapy was associated with increased disease-free survival (181 vs. 172 months), QALYs (12.21 vs. 11.89), and net discounted lifetime costs of cancer care ($12,124 vs. $7724 per patient). The incremental cost-effectiveness ratio of exemestane was $20,100 per QALY gained (95% confidence interval: $12,100, $59,000). Sensitivity analyses showed that results were robust to plausible variations in recurrence rates, costs, and utilities. CONCLUSIONS: Switching postmenopausal early-stage breast cancer patients to exemestane after 2 to 3 years of tamoxifen appears to be a cost-effective treatment strategy versus completing a 5-year course of tamoxifen.     

Chlamydia trachomatis in the conjunctiva of children living in three rural areas in Mexico.

OBJECTIVES: Chlamydia trachomatis infections, in the context of extreme poverty, may trigger trachoma. Because the levels of C. trachomatis eye infections in Mexico are unknown, this study sought to determine if C. trachomatis was present in the conjunctiva of children living in three poor, rural areas of the country. METHODS: Clinical diagnosis of conjunctival follicles in children was conducted during the 2004 visual acuity assessment campaigns in rural areas of the states of Chiapas, Oaxaca, and Zacatecas. C. trachomatis detection was carried out by sampling the children with follicles and examining the specimens after Giemsa or microimmunofluorescence (MIF) staining. RESULTS: A total of 941 children from 6 to 12 years of age were examined in 2004. Of the 484 in Chiapas, 30% were found to have follicles; of the 181 in Zacatecas, 22%; and of the 276 in Oaxaca, 42%. C. trachomatis was detected at levels ranging between 2% and 5%; positive by Giemsa in 4.5% of the children with follicles, and by MIF in 15.5%. CONCLUSIONS: Considering that the chlamydiae sampling procedures and detection methods used in this study were not the most sensitive, the results underestimate the chlamydial eye infections and represent a conservative assessment of a potential risk for preventable visual impairment. Because C. trachomatis was detected here at levels similar to those reported for low-endemic trachoma areas, health authorities should be prepared to implement appropriate measures should it be confirmed that the visual health of Mexico's children is at risk.     

A 12-year follow-up of a methadone medical maintenance program

Methadone Medical Maintenance (MDM) is an alternative for treatment of stable methadone maintained individuals. It involves a monthly physician's visit, at which methadone take-home doses are dispensed to last until the next appointment. The safety and efficacy of this treatment modality is currently under investigation. The purpose of this study was to evaluate the long-term safety and efficacy of MDM in a methadone program in Baltimore. A sample of 21 patients was enrolled in the study and followed for 12 years. They were evaluated once a month by a primary care physician affiliated with a methadone clinic who collected urine toxicology samples and dispensed the monthly methadone dose. The results showed that only 6 (28.6%) patients dropped out during the 12 years of the study. Twelve (0.5%) of 2,290 urine samples collected were positive for drugs. No methadone overdose or diversion was observed. Participants reported significant improvement in their quality of life. The results of this study support the safety and efficacy of medical maintenance of stable methadone maintained individuals.     

Engaging hospitalized heroin-dependent patients into substance abuse treatment.

The purpose of this study was to evaluate a 6-month outpatient program developed to improve abstinence and other health and social problems of heroin-addicted persons hospitalized in an urban academic medical center's medical or surgical unit and referred from the Substance Abuse Consult Service. Treatment intervention consisted of methadone therapy, daily group therapy, individual case management, medical and psychiatric consultation, and social services. The first 67 patients referred were followed for 6 months. Outcome measures were retention in treatment, urine drug screens, and health and social indicators. Patients averaged 19 weeks in treatment, with 52% of patients completing the 6-month program. Urine toxicology screens showed a reduction of illicit drug use. Patients improved deficits in health and social indicators by obtaining medical coverage, keeping outpatient medical appointments, and improving their housing conditions. Findings suggest that this combination of intensive psychosocial treatment with opioid substitution following an acute illness substantially impacts treatment outcomes. Implications for service delivery and health-care economics are discussed.     

Multivariate discriminant analysis of risk factors for operative mortality following isolated coronary artery bypass graft. Loyola University Medical Center experience, 1970 to 1984

The Loyola Open-Heart Registry is a fully operational database that contains detailed data on approximately 9,000 patients who have undergone coronary bypass or cardiac valve replacement from January 1970 to December 1984. We analyzed the registry data using multivariate discriminant analysis to identify and quantitate those factors that might predict operative mortality (OM) for patients undergoing coronary artery bypass grafts at Loyola University Medical Center: Operative mortality was defined as death within 30 days following surgery. A total of 50 clinical and angiographic variables were analyzed for possible univariate association with operative mortality. Twenty-two variables were found to have significant univariate association with OM, and these 22 variables were subjected to multivariate discriminant analysis. For patients undergoing isolated, elective coronary artery bypass, the factors found to be predictive of OM are age (greater than 70) (F = 11.57), severe (more than six stenoses) coronary artery disease (F = 5.81), diffuse disease (F = 5.54), positive family history (F = 5.17), and number of coronary arteries bypassed (F = 4.78).     

Intertrigo-like eruption caused by pegylated liposomal doxorubicin (PLD)

Pegylated liposomal doxorubicin (PLD) is a drug whose use is increasingly common. It has been associated with a lower rate of haematologic and cardiac side effects than its nonencapsulated form. However, mucocutaneous toxicity is quite frequent and can be severe. Here we provide a case report of a patient who developed an intertrigolike eruption during treatment with PLD.     

Early myocardial revascularization for postinfarction angina

In 1983 and 1984, coronary artery bypass grafting (CABG) was performed on 107 consecutive patients for postinfarction angina. In each instance, CABG was done within 30 days of infarction. Sixty-three patients (59%) required intravenous administration of nitroglycerin and/or the intraaortic balloon pump (IABP) for relief of angina. Oral medications relieved angina in the remaining 44 patients. Thirty-eight patients underwent CABG 7 days or less after the infarction (Group 1), 25 received it between 8 and 15 days later (Group 2), and 44 had CABG between 16 and 30 days later (Group 3). There were 9 in-hospital deaths: 4 in Group 1, 2 in Group 2, and 3 in Group 3. Thirteen patients needed the IABP for hemodynamic stability as well as relief of angina. Even when the patient was stable hemodynamically, death was more likely to occur among these 13 patients if CABG was conducted within 7 days of infarction. Follow-up was 94% complete at 29.4 months. Eighty-six percent of patients were asymptomatic or in New York Heart Association Functional Class I, and 6% were in Class II. There were 2 late deaths. CABG for angina can be accomplished within 30 days of an acute infarction with good results. The exception to this rule is the patient in whom shock develops after a myocardial infarction and who, despite stabilization, receives CABG within 7 days of the infarction.