Publications

To achieve the benefits of the patient-centered medical home (PCMH) model, the American College of Physicians has issued a policy paper addressing the relationship between specialist and subspecialist physicians and PCMH practices. This paper represents a significant step toward improving care coordination and quality by demonstrating that this model is supported by numerous specialties and subspecialties, recognizing the importance of building a strong medical neighborhood, and providing a framework that will foster improvements in care at the interface of PCMHs and PCMH neighbors (PCMH-Ns). Construction of a well-functioning medical neighborhood will, however, require some refinements. First, the proposed interaction typology between PCMHs and PCMH-Ns must be expanded to include innovative forms of interaction that do not depend on traditional office visits, but for which there are clear incentives. Second, the recommended care coordination agreements must be better standardized for the sake of practicality. Finally, genuine dialogue between PCMH and PCMH-N practices needs to be realized.

Unlike some organs, the heart is unable to repair itself after injury. Human embryonic stem cells (hESCs) grow and divide indefinitely while maintaining the potential to develop into many tissues of the body. As such, they provide an unprecedented opportunity to treat human diseases characterized by tissue loss. We have identified early myocardial precursors derived from hESCs (hMPs) using an α-myosin heavy chain (αMHC)-GFP reporter line. We have demonstrated by immunocytochemistry and quantitative real-time PCR (qPCR) that reporter activation is restricted to hESC-derived cardiomyocytes (CMs) differentiated in vitro, and that hMPs give rise exclusively to muscle in an in vivo teratoma formation assay. We also demonstrate that the reporter does not interfere with hESC genomic stability. Importantly, we show that hMPs give rise to atrial, ventricular and specialized conduction CM subtypes by qPCR and microelectrode array analysis. Expression profiling of hMPs over the course of differentiation implicate Wnt and transforming growth factor-β signaling pathways in CM development. The identification of hMPs using this αMHC-GFP reporter line will provide important insight into the pathways regulating human myocardial development, and may provide a novel therapeutic reagent for the treatment of cardiac disease.

HIV infection can result in depletion of total CD4(+) T cells and naive CD8(+) T cells, and in the generation of dysfunctional effector CD8(+) T cells. In this study, we show that naive CD8(+) T cells in subjects with progressive HIV disease express low levels of CD8α and CD8β chains. Such naive CD8(low) T cells display broad signaling defects across the T-cell receptor complex, and their appearance correlates with generalized up-regulation of major histocompatibility complex class I (MHC-I) antigens on peripheral blood mononuclear cells (PBMCs). To explore a causal link between increased MHC-I up-regulation and the generation of naive CD8(low) T cells, we used the humanized SCID-hu Thy/Liv mouse model to show that HIV infection of the thymus and interferon α (IFNα) treatment alone result in MHC-I up-regulation and in the generation of dysfunctional CD3(high)CD8(+)CD4(-) single-positive 8 (SP8) thymocytes with low expression of CD8. We suggest that dysfunctional naive CD8(low) T cells are generated as a result of IFNα-mediated up-regulation of MHC-I on stromal cells in the thymus and antigen-presenting cells in the periphery, and that dysfunction in this naive compartment contributes to the immunodeficiency of HIV disease. This study is registered at www.clinicaltrials.gov as NCT00187512.

OBJECTIVE

To evaluate the association between treatment of HIV-tuberculosis (TB) coinfection and primary virologic failure among children initiating antiretroviral therapy in South Africa.

DESIGN

We performed a retrospective cohort study of 1029 children initiating antiretroviral therapy at two medical centers in KwaZulu Natal, South Africa, a region of very high TB incidence.

METHODS

Data were extracted from electronic medical records and charts and the impact of TB cotreatment on viral suppression at 6 and 12 months was assessed using logistic regression.

RESULTS

The overall rate of virologic suppression (<400 HIV RNA copies/ml) was 85% at 6 months and 87% at 12 months. Children who received concurrent treatment for TB had a significantly lower rate of virologic suppression at 6 months (79 vs. 88%; P = 0.003). Those who received nonnucleoside reverse transcriptase inhibitor-based HAART had similar rates of viral suppression regardless of whether they received concurrent TB therapy. In contrast, children who received protease inhibitor-based HAART had significantly lower viral suppression rates at both 6 and 12 months if treated concurrently for TB (P = 0.02 and 0.03). Multivariate logistic regression revealed that age at initiation, protease inhibitor therapy, and TB coinfection were each independently associated with primary virologic failure.

CONCLUSION

Concurrent treatment for TB is associated with lower rates of viral suppression among children receiving protease inhibitor-based HAART, but not among those receiving nonnucleoside reverse transcriptase inhibitor-based HAART. Guidelines for the care of young HIV-TB coinfected infants should be continually evaluated, as protease inhibitor-based antiviral therapy may not provide optimal viral suppression in this population.