333 research outputs found

    Equity Impacts of Transit Fare Proposals: A Case Study of AC Transit

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    Faced with budget shortfalls, Oakland’s AC Transit proposed five alternative fare structures combining base fare hikes or reductions, eliminating free transfers, and discontinuing passes. Using onboard survey data, we analyzed impacts of proposals on groups of riders, evaluated equity impacts, and estimated potential fare revenues. Policies that eliminated passes or transfers produced dramatically unequal impacts on lower income riders, youth, and minorities. Flat fares were least equitable even with base fare reductions because less affluent riders made more frequent trips and transfers than the more affluent. The most equitable and profitable proposals adjusted existing fare structures

    Novel engineered CHO DG44 host cell line demonstrates lowered UPR, increased titers and superior quality of recombinant vaccines

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    The Chinese Hamster Ovary (CHO) DG44 platform is routinely used at the Vaccine Production Program (VPP) for manufacturing Vaccine Research Center (VRC) pipeline therapeutic proteins. Clonal cell lines have been generated that express broadly neutralizing monoclonal antibodies (bNmAbs) against HIV-1 with titers ranging between 1 and 5 g/L. In the analysis of data from high and low productivity clones across a range of projects, high-producing clones were found to display increased viable cell density (VCD) and viability at later days in fed-batch culture. With an objective to understand the underlying mechanism for the observed differences in titer, we investigated the Unfolded Protein Response (UPR) pathway and found that multiple genes were differentially regulated among high- and low-producing clones. UPR-induced apoptosis was observed to be significantly higher in lower-producing clones and significantly lower in higher-producing clones at late days in culture. Our initial analysis emphasized a need to generate a platform host cell with lowered UPR and more efficient protein secretion capacity to achieve maximum yields. Through the course of developing and characterizing a panel of cell lines expressing varying levels of human furin for use in a trimeric viral antigen project, a CHO DG44 clone expressing low levels of human furin was identified that had high VCD and viability in later days of fed-batch culture. Reduced UPR at late days in these cells, particularly the lowered expression of apoptotic genes, was seen to correlate to the late day increases in VCD and viability. When the low furin expressing host CHO DG44 cells were used for recombinant protein expression, the increases in VCD and viabilities were maintained compared to platform CHO DG44 host and we achieved a 3 X increase in viral antigen titers without any change in the existing upstream process. It is our goal to characterize the quality of recombinant proteins expressed in DG44- furin engineered clones. The extent of unfolded protein response in viral antigen expressing clones, furin level, and the influence of these factors on the quality of protein is currently under investigation. Our work describes a successful effort to rationally develop a superior host cell for increased and efficient yield of difficult-to-synthesize recombinant targets and points to a potential path forward for generating higher-producing clones for bNmAbs as well

    Injection drug use and patterns of highly active antiretroviral therapy use: an analysis of ALIVE, WIHS, and MACS cohorts

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    <p>Abstract</p> <p>Background</p> <p>Sustained use of antiretroviral therapy has been consistently shown to be one of the primary predictors of long-term effectiveness. Switching and discontinuation reflect patient and provider decisions that may limit future treatment options. In this study, we utilize data reported at semi-annual study visits from three prospective cohort studies, the AIDS Link to IntraVenous Exposure (ALIVE), the Women's Interagency HIV Study (WIHS), and the Multicenter AIDS Cohort Study (MACS), to investigate determinants of HAART modification with a particular focus on reported injection drug use (IDU).</p> <p>Methods</p> <p>Longitudinal data collected between 1996 and 2004 contributed from 2,266 participants (37% with a reported history of IDU) who reported initiating their first HAART regimen during follow-up were utilized. Separate proportional-hazards models were used to identify factors measured prior to HAART-initiation associated with the time to first HAART discontinuation and first switch of components of HAART among continuous HAART users.</p> <p>Results</p> <p>The use of PI- vs. NNRTI-based regimens among HAART users with and without any history of IDU was similar over follow-up. The median time to a first report of discontinuation of HAART was 1.1 years for individuals with a history of IDU but 2.5 years for those without a history of IDU and multivariate analyses confirmed overall that individuals with a history of IDU were at greater risk for HAART discontinuation (adj RH = 1.24, 95% CI: 1.03–1.48). However, when restricting to data contributed after 1999, there was no longer any significant increased risk (adj RH = 1.05, 95% CI: 0.81–1.36). After adjusting for pre-HAART health status and prior ARV exposure, individuals who were ethnic/racial minorities, reported an annual income < $10,000/year, and were not employed were at significantly greater risk for HAART discontinuation. The median time to a first change in HAART regimen was approximately 1.5 years after first HAART report and was not elevated among those with a history of IDU (adj RH = 1.09, 95% CI: 0.89–1.34).</p> <p>Conclusion</p> <p>Our analyses demonstrate that injection drug use by itself does not appear to be an independent risk factor for HAART switching or discontinuation in more recent years. However, as continued HAART use is of paramount importance for long-term control of HIV infection, efforts to improve maintenance to therapy among disadvantaged and minority populations remain greatly needed.</p

    Predicting the long-term impact of antiretroviral therapy scale-up on population incidence of tuberculosis.

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    OBJECTIVE: To investigate the impact of antiretroviral therapy (ART) on long-term population-level tuberculosis disease (TB) incidence in sub-Saharan Africa. METHODS: We used a mathematical model to consider the effect of different assumptions about life expectancy and TB risk during long-term ART under alternative scenarios for trends in population HIV incidence and ART coverage. RESULTS: All the scenarios we explored predicted that the widespread introduction of ART would initially reduce population-level TB incidence. However, many modelled scenarios projected a rebound in population-level TB incidence after around 20 years. This rebound was predicted to exceed the TB incidence present before ART scale-up if decreases in HIV incidence during the same period were not sufficiently rapid or if the protective effect of ART on TB was not sustained. Nevertheless, most scenarios predicted a reduction in the cumulative TB incidence when accompanied by a relative decline in HIV incidence of more than 10% each year. CONCLUSIONS: Despite short-term benefits of ART scale-up on population TB incidence in sub-Saharan Africa, longer-term projections raise the possibility of a rebound in TB incidence. This highlights the importance of sustaining good adherence and immunologic response to ART and, crucially, the need for effective HIV preventive interventions, including early widespread implementation of ART

    Serum lipid profiles among patients initiating ritonavir-boosted atazanavir versus efavirenz-based regimens

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    <p>Abstract</p> <p>Background</p> <p>Antiretrovirals used to treat HIV-infected patients have the potential to adversely affect serum lipid profiles and increase the risk of cardiovascular disease which is an emerging concern among HIV-infected patients. Since boosted atazanavir and efavirenz are both considered preferred antiretrovirals a head to head comparison of their effects on serum lipids is needed.</p> <p>Aim</p> <p>The primary objective of the study was to compare the effects of atazanavir (boosted and unboosted) and efavirenz based regimens on serum lipid profiles.</p> <p>Study Design</p> <p>Prospective cohort study nested within three ongoing cohorts of HIV-infected individuals.</p> <p>Study Population and Methods</p> <p>Participants initiating either atazanavir or efavirenz based regimens with documented pre- and post-initiation lipid values. Multivariate linear regression was conducted to estimate adjusted mean differences between treatment groups for high density lipoprotein cholesterol (HDL-c), non-HDL-c, and log total cholesterol (TC) to HDL-c ratio outcomes; log-linear regression models were used to estimate differences in prevalence of low HDL-c and desirable TC.</p> <p>Results</p> <p>The final study population was comprised of 380 efavirenz and 281 atazanavir initiators. Both atazanavir and efavirenz users had increases in serum HDL-c and decreases in TC/HDL ratio. In comparison to individuals initiating efavirenz, boosted atazanavir users on average had lower HDL-c (-4.12 mg/dl, p < 0.001) and non HDL-c (-5.75 mg/dl, p < 0.01), but similar declines in TC/HDL ratio.</p> <p>Conclusion</p> <p>Both efavirenz and atazanavir-based regimens (boosted and unboosted) resulted in similar beneficial declines in the TC/HDL ratio.</p

    Community-based active case-finding interventions for tuberculosis : a systematic review

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    This work was made possible through grants provided by the WHO Global TB Programme. RMB, ELC, and PM hold Wellcome fellowships: 203905/Z/16/Z (RMB), 200901/Z/16/Z (ELC), and 206575/Z/17/Z (PM). MR, LT, and HA are funded by part of the European and Developing Countries Clinical Trials Partnership 2 programme supported by the EU (grant number RIA2016S-1632-TREATS). AES is supported by a National Institutes of Health (NIH) grant K23AI140918.Background Community-based active case-finding interventions might identify and treat more people with tuberculosis disease than standard case detection. We aimed to assess whether active case-finding interventions can affect tuberculosis epidemiology in the wider community. Methods We did a systematic review by searching PubMed, Embase, Scopus, and Cochrane Library for studies that compared tuberculosis case notification rates, tuberculosis disease prevalence, or tuberculosis infection prevalence or incidence in children, between populations exposed and unexposed to active case-finding interventions. We included studies published in English between Jan 1, 1980, and April 13, 2020. Studies of active case-finding in the general population, in populations perceived to be at high risk for tuberculosis, and in closed settings were included, whereas studies of tuberculosis screening at health-care facilities, among household contacts, or among children only, and studies that screened fewer than 1000 people were excluded. To estimate effectiveness, we extracted or calculated case notification rates, prevalence of tuberculosis disease, and incidence or prevalence of tuberculosis infection in children, and compared ratios of these outcomes between groups that were exposed or not exposed to active case-finding interventions. Results 27 883 abstracts were screened and 988 articles underwent full text review. 28 studies contributed data for analysis of tuberculosis case notifications, nine for prevalence of tuberculosis disease, and two for incidence or prevalence of tuberculosis infection in children. In one cluster-randomised trial in South Africa and Zambia, an active case-finding intervention based on community mobilisation and sputum drop-off did not affect tuberculosis prevalence, whereas, in a cluster-randomised trial in Vietnam, an active case-finding intervention based on sputum tuberculosis tests for everyone reduced tuberculosis prevalence in the community. We found inconsistent, low-quality evidence that active case-finding might increase the number of cases of tuberculosis notified in populations with structural risk factors for tuberculosis. Interpretation Community-based active case-finding for tuberculosis might be effective in changing tuberculosis epidemiology and thereby improving population health if delivered with high coverage and intensity. If possible, active case-finding projects should incorporate a well designed, robust evaluation to contribute to the evidence base and help elucidate which delivery methods and diagnostic strategies are most effective. Funding WHO Global TB Programme.Peer reviewe
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