Publications

Little is known about the factors associated with delayed or incomplete adherence to recommendations for follow-up when breast abnormalities are seen in minority women. This study examines barriers to follow-up in a cohort of predominantly minority women, with input from providers, using quantitative and qualitative methods. We conducted telephone interviews with 535 women and inperson, unstructured interviews with 31 providers from three medical facilities in the Los Angeles area. Most patient respondents were <50 years old (59.6%), Latina (84.2%), and unmarried (60.9%); half (49.1%) had six or fewer years of education, and most were foreign-born (83.4%). Data from patient and provider groups identified race/ethnicity, country of birth, financial issues, fear of pain, and difficulty navigating the healthcare system as barriers to follow-up, though certain provider-identified barriers did predict adherence among women. System barriers, not individual patient characteristics, were more salient factors in the follow-up of breast abnormalities.

Preliminary studies suggest preemptive anti-HCV therapy in liver transplant recipients may enhance the rates of viral clearance, but the applicability and tolerability of preemptive therapy has not been evaluated in a contemporary cohort. In this randomized study, the safety and tolerability of preemptive standard (IFN) or pegylated (peg-IFN) interferon alfa-2b (3 MU thrice weekly or 1.5 microg/kg weekly), or IFN/peg-IFN plus ribavirin (600 mg increased to 1.0-1.2 g daily) was initiated 2-6 weeks post-transplantation and continued for a total of 48 weeks. Only 51 (41%) of 124 transplant recipients were eligible for preemptive treatment; eligible patients had lower model for end-stage liver disease (MELD) and Childs-Pugh scores pre-transplantation and were more frequently live donor transplant recipients than ineligible patients. Dose reductions and discontinuations were required in 85% and 37% of patients, respectively, and 27% experienced serious adverse events. Growth factor (GF) use (erythropoietin and GCSF) in the latter half of the study did not significantly affect the frequency of dose reductions. Only 15% of patients were able to achieve full-dose treatment during treatment. End-of-treatment and sustained virological responses were 13.6% and 9.1%, respectively, with most responders in the combination therapy group. We conclude that preemptive antiviral therapy is applicable to only a portion of transplant recipients, with 'sicker' patients less likely to be managed by this approach. Living donor liver transplant recipients were more frequently eligible for treatment than deceased donor recipients. Virological response rates are low, likely related to the poor tolerability of therapy and the lack of achievement of target drug doses. Future studies should focus on alternative dosing schedules with more aggressive use of adjuvant therapies, including GFs.

The three-dimensional structure of the antibiotic oxolide, (9S,11S)-11-amino-9-deoxo-11,12-deoxy-9,12-epoxyerythromycin, was determined in CD2Cl2 through constrained molecular mechanics with constraints derived from proton NMR. The calculations yielded a well-defined global minimum. Data acquired for oxolide in D2O, although not as complete, indicate that the antibiotic adopts the same conformation in water.

The Ebola filoviruses are aggressive pathogens that cause severe and often lethal hemorrhagic fever syndromes in humans and nonhuman primates. To date, no effective therapies have been identified. To analyze the entry and fusion properties of Ebola virus, we adapted a human immunodeficiency virus type 1 (HIV-1) virion-based fusion assay by substituting Ebola virus glycoprotein (GP) for the HIV-1 envelope. Fusion was detected by cleavage of the fluorogenic substrate CCF2 by beta-lactamase-Vpr incorporated into virions and released as a result of virion fusion. Entry and fusion induced by the Ebola virus GP occurred with much slower kinetics than with vesicular stomatitis virus G protein (VSV-G) and were blocked by depletion of membrane cholesterol and by inhibition of vesicular acidification with bafilomycin A1. These properties confirmed earlier studies and validated the assay for exploring other properties of Ebola virus GP-mediated entry and fusion. Entry and fusion of Ebola virus GP pseudotypes, but not VSV-G or HIV-1 Env pseudotypes, were impaired in the presence of the microtubule-disrupting agent nocodazole but were enhanced in the presence of the microtubule-stabilizing agent paclitaxel (Taxol). Agents that impaired microfilament function, including cytochalasin B, cytochalasin D, latrunculin A, and jasplakinolide, also inhibited Ebola virus GP-mediated entry and fusion. Together, these findings suggest that both microtubules and microfilaments may play a role in the effective trafficking of vesicles containing Ebola virions from the cell surface to the appropriate acidified vesicular compartment where fusion occurs. In terms of Ebola virus GP-mediated entry and fusion to various target cells, primary macrophages proved highly sensitive, while monocytes from the same donors displayed greatly reduced levels of entry and fusion. We further observed that tumor necrosis factor alpha, which is released by Ebola virus-infected monocytes/macrophages, enhanced Ebola virus GP-mediated entry and fusion to human umbilical vein endothelial cells. Thus, Ebola virus infection of one target cell may induce biological changes that facilitate infection of secondary target cells that play a key role in filovirus pathogenesis. Finally, these studies indicate that pseudotyping in the HIV-1 virion-based fusion assay may be a valuable approach to the study of entry and fusion properties mediated through the envelopes of other viral pathogens.

HM74 (GPR109B) and the highly homologous gene, HM74A (GPR109A) code for Gi-G protein-coupled orphan receptors that recently have been discovered to be involved in the metabolic effects of niacin. The B vitamin niacin is an important agent used in the treatment of dyslipidemias, but its use is limited by side effects. The novel role of the adjacent HM74 and HM74A genes in the metabolism of niacin may provide new targets for drug development. Human genetic variations in HM74 and HM74A have been reported but have not been studied in detail. These variations may play a role in the response to agents targeting receptors coded by these genes. Here we show that many of the nonsynonymous SNPs listed in public databases for HM74 and HM74A are artifacts resulting from extensive homology between these two genes. This may be representative of a neglected phenomenon in reporting sequences of highly homologous genes. We provide primer sequences that permit selective amplification of the complete coding regions of HM74 and HM74A. Using these primers, we show that subsequent sequencing of HM74 and HM74A reveals a novel and unique variation in the HM74A gene. Haplotype analysis suggests four SNPs can define the five major haplotypes that lie within a single haplotype block encompassing these two genes.

Autoimmunity is a complex process that likely results from the summation of multiple defective tolerance mechanisms. The NOD mouse strain is an excellent model of autoimmune disease and an important tool for dissecting tolerance mechanisms. The strength of this mouse strain is that it develops spontaneous autoimmune diabetes, which shares many similarities to autoimmune or type 1a diabetes (T1D) in human subjects, including the presence of pancreas-specific autoantibodies, autoreactive CD4+ and CD8+ T cells, and genetic linkage to disease syntenic to that found in humans. During the past ten years, investigators have used a wide variety of tools to study these mice, including immunological reagents and transgenic and knockout strains; these tools have tremendously enhanced the study of the fundamental disease mechanisms. In addition, investigators have recently developed a number of therapeutic interventions in this animal model that have now been translated into human therapies. In this review, we summarize many of the important features of disease development and progression in the NOD strain, emphasizing the role of central and peripheral tolerance mechanisms that affect diabetes in these mice. The information gained from this highly relevant model of human disease will lead to potential therapies that may alter the development of the disease and its progression in patients with T1D.