Publications by authors named "Jose Luis Sebastian"

We conducted a cluster-randomized trial to estimate effects of directly observed combination antiretroviral therapy (DOT-cART) on retention with viral suppression among HIV-positive adults in Peru. We randomly allocated facilities to receive the 12-month intervention plus the standard of care, including adherence support provided through accompaniment. In the intervention arm, health workers supervised doses, twice daily, and accompanied patients to appointments.

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Among tuberculosis patients, timely diagnosis of human immunodeficiency virus (HIV) co-infection and early antiretroviral treatment are crucial, but are hampered by a myriad of individual and structural barriers. Community-based models to provide counseling and rapid HIV testing are few but offer promise. During November 2009-April 2010, community health workers offered and performed HIV counseling and testing by using the OraQuick Rapid HIV-1/2 Antibody Test to new tuberculosis cases in 22 Ministry of Health establishments and their household contacts (n = 130) in Lima, Peru.

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Objective: To analyze the evolution of published scientific articles on HIV/AIDS in Peru.

Methods: A bibliometric analysis of papers on HIV/AIDS published in journals indexed in MEDLINE, SciELO and LILACS until October 2010. We selected research papers fully developed in Peru, and multicenter studies with participating Peruvian sites.

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We use the Maxwell stress tensor to calculate the dielectrophoretic force and electrorotational torque acting on a realistic four-shelled model of the yeast Saccharomyces cerevisiae in a nonuniform rotating electric field generated by four coplanar square electrodes. The comparison of these results with numerical calculations of the dipolar and quadrupolar contributions obtained from an integral equation for the polarization charge density shows the effect of the quadrupole contribution in the proximity of the electrode plane. We also show that under typical experimental conditions the substitution of the multilayered cell by an equivalent cell with homogeneous permittivity underestimates the quadrupole contribution to the force and torque by 1 order of magnitude.

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HIV and poor mental health are intricately related. In settings of poverty, both are often rooted in structural factors related to material and social deprivation. We performed a qualitative analysis to understand factors contributing to poor emotional health and its impact among impoverished Peruvian HIV-infected individuals.

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From December 2005 through August 2008, we provided community-based accompaniment with supervised antiretroviral therapy (CASA) to impoverished individuals starting highly active antiretroviral therapy. Adherence support was provided for 18 months by a community-based team comprised of several nurses and two types of community health workers: field supervisors and directly observed therapy (DOT) volunteers. To complement our quantitative data collection in 2008 using purposive sampling, we conducted two gender-mixed focus group discussions with 13 CASA patient participants and 13 DOT volunteers from Lima, Peru to identify the mediating mechanisms by which CASA improved well-being, and to understand the benefits of the intervention, as perceived by these individuals.

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We examined the relationship between food insufficiency and antiretroviral therapy (ART) adherence. A cohort of HIV-infected adults in urban Peru was followed for a two-year period after ART initiation. ART adherence was measured using a 30-day self-report tool and classified as suboptimal if <95% adherence was reported.

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From December 2005 to April 2007, we enrolled 60 adults starting antiretroviral therapy (ART) in Lima, Peru to receive community-based accompaniment with supervised antiretrovirals (CASA), consisting of 12 months of DOT-HAART, as well as microfinance assistance and/or psychosocial support group according to individuals' need. We matched 60 controls from a neighboring district, and assessed final clinical and psychosocial outcomes at 24 months. CASA support was associated with higher rates of virologic suppression and lower mortality.

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We predict the complex polarizability of a realistic model of a red blood cell (RBC), with an inhomogeneous dispersive and anisotropic membrane. In this model, the frequency-dependent complex electrical parameters of the individual cell layers are described by the Debye equation while the dielectric anisotropy of the cell membrane is taken into account by the different permittivities along directions normal and tangential to the membrane surface. The realistic shape of the RBC is described in terms of the Jacobi elliptic functions.

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The aim of this study is to analyze the electromagnetic energy stored in stomatocyte, erythrocyte and echinocyte cells exposed to a linearly polarized electromagnetic plane wave at 900, 1800 and 2450MHz radiofrequency signals. This analysis can provide a better understanding of the order of appearance of altered shapes of erythrocytes (RBC) in the stomatocyte-echinocyte transition under radiofrequency exposure in terms of the deposited electromagnetic energy. For this purpose we use a realistic geometrical cell model based on parametric equations that allow for continuous transformations between normal erythrocytes and three stomatocyte subclasses with different degree of invagination and also between normal erythrocytes and echinocytes with an arbitrary number of spicules.

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From December 2005 to April 2007, we enrolled 60 adults starting antiretroviral therapy (ART) in a health district of Lima, Peru to receive community-based accompaniment with supervised antiretroviral (CASA). Paid community health workers performed twice-daily home visits to directly observe ART and offered additional medical, social and economic support to CASA participants. We matched 60 controls from a neighboring district by age, CD4 and primary referral criteria (TB status, female, neither).

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We show that within the dipole approximation the complex polarizability of shelled particles of arbitrary shape can be written as the volume of the particle times a weighted average of the electric field in the particle, with weights determined by the differences in permittivities between the shells and the external, possibly lossy media. To calculate the electric field we use an adaptive-mesh finite-element method which is very effective in handling the irregular domains, material inhomogeneities, and complex boundary conditions usually found in biophysical applications. After extensive tests with exactly solvable models, we apply the method to four types of hematic cells: platelets, T-lymphocytes, erythrocytes, and stomatocytes.

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The purpose of this study was to validate the Spanish version of the Berger HIV Stigma Scale in an urban Spanish-speaking population in Peru and create a valid and reliable abridged version of the scale. Participants were HIV-infected adults enrolled in an observational study to examine the effectiveness of a community-based antiretroviral therapy adherence intervention. Approximately half of participants were female, and the median age at enrollment was 30.

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Objective: Tuberculosis and HIV coinfection poses unique clinical and psychosocial complexities that can impact nonadherence to highly active antiretroviral treatment (HAART).

Methods: This was a prospective case series to identify risk factors for HAART nonadherence among 43 patients with HIV and tuberculosis (TB) in Lima, Peru. Nonadherence was defined by patient self-report.

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Many countries with financial support for HIV treatment experience delays in scale-up because of bureaucratic, operational, and technical obstacles. The authors describe the Peruvian National HIV Program's response to such challenges. A team of consultants experienced in the scale-up of the Peruvian national program to treat multidrug-resistant tuberculosis worked with the national HIV program to identify and address key factors contributing to slow enrollment of HIV patients into the antiretroviral treatment program.

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We study the influence of an external electromagnetic field of 1.8 GHz in the formation or disaggregation of long rouleau of identical erythrocyte cells. In particular we calculate the variation of the transmembrane potential of an individual erythrocyte illuminated by the external field due to the presence of the neighboring erythrocytes in the rouleau, and compare the total electric energy of isolated cells with the total electric energy of the rouleau.

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