Differential utilization of vitamin B12-dependent and independent pathways for propionate metabolism across human cells.

Propionic acid links the oxidation of branched-chain amino acids and odd-chain fatty acids to the TCA cycle. Gut microbes ferment complex fiber remnants, generating high concentrations of short chain fatty acids, acetate, propionate and butyrate, which are shared with the host as fuel sources. Analysis of vitamin B12-dependent propionate utilization in skin biopsy samples has been used to characterize and diagnose underlying inborn errors of cobalamin (or B12) metabolism. In these cells, the B12-dependent enzyme, methylmalonyl-CoA mutase (MMUT), plays a central role in funneling propionate to the TCA cycle intermediate, succinate. Our understanding of the fate of propionate in other cell types, specifically, the involvement of the ß-oxidation-like and methylcitrate pathways, is limited. In this study, we have used [14C]-propionate tracing in combination with genetic ablation or inhibition of MMUT, to reveal the differential utilization of the B12-dependent and independent pathways for propionate metabolism in fibroblast versus colon cell lines. We demonstrate that itaconate can be used as a tool to investigate MMUT-dependent propionate metabolism in cultured cell lines. While MMUT gates the entry of propionate carbons into the TCA cycle in fibroblasts, colon-derived cell lines exhibit a quantitatively significant or exclusive reliance on the ß-oxidation-like pathway. Lipidomics and metabolomics analyses reveal that propionate elicits pleiotropic changes, including an increase in odd-chain glycerophospholipids, and perturbations in the purine nucleotide cycle and arginine/nitric oxide metabolism. The metabolic rationale and the regulatory mechanisms underlying the differential reliance on propionate utilization pathways at a cellular, and possibly tissue level, warrant further elucidation.

Growth requirement for methionine in human melanoma-derived cell lines with different levels of MMACHC expression and methylation.

Methionine dependence, the inability to grow in culture when methionine in the medium is replaced by its metabolic precursor homocysteine, occurs in many tumor cell lines. In most affected lines, the cause of methionine dependence is not known. An exception is the melanoma-derived cell line MeWo-LC1, in which hypermethylation of the MMACHC gene is associated with decreased MMACHC expression. Decreased expression results in decreased provision of the methylcobalamin cofactor required for activity of methionine synthase and thus decreased conversion of homocysteine to methionine. Analysis of data in the Cancer Cell Line Encyclopedia Archive demonstrated that MMACHC hypermethylation and decreased MMACHC expression occurred more frequently in melanoma cell lines when compared to other tumor cell lines. We further investigated methionine dependence and aspects of MMACHC function in a panel of six melanoma lines, including both melanoma lines with known methionine dependence status (MeWo, which is methionine independent, and A375, which is methionine dependent). We found that the previously unclassified melanoma lines HMCB, Colo829 and SH-4 were methionine dependent, while SK-Mel-28 was methionine independent. However, despite varying levels of MMACHC methylation and expression, none of the tested lines had decreased methylcobalamin and adenosylcobalamin synthesis as seen in MeWo-LC1, and the functions of both cobalamin-dependent enzymes methionine synthase and methylmalonyl-CoA mutase were intact. Thus, while melanoma lines were characterized by relatively high levels of MMACHC methylation and low expression, the defect in metabolism observed in MeWo-LC1 was unique, and decreased MMACHC expression was not a cause of methionine dependence in the other melanoma lines.

The MMACHC variant c.158T>C: Mild clinical and biochemical phenotypes and marked hydroxocobalamin response in cblC patients.

Mutations in MMACHC cause cobalamin C disease (cblC, OMIM 277400), the commonest inborn error of vitamin B12 metabolism. In cblC, deficient activation of cobalamin results in methylcobalamin and adenosylcobalamin deficiency, elevating methylmalonic acid (MMA) and total plasma homocysteine (tHcy). We retrospectively reviewed the medical files of seven cblC patients: three compound heterozygotes for the MMACHC (NM_015506.3) missense variant c.158T>C p.(Leu53Pro) in trans with the common pathogenic mutation c.271dupA (p.(Arg91Lysfs*14), "compounds"), and four c.271dupA homozygotes ("homozygotes"). Compounds receiving hydroxocobalamin intramuscular injection monotherapy had age-appropriate psychomotor performance and normal ophthalmological examinations. In contrast, c.271dupA homozygotes showed marked psychomotor retardation, retinopathy and feeding problems despite penta-therapy (hydroxocobalamin, betaine, folinic acid, l-carnitine and acetylsalicylic acid). Pretreatment levels of plasma and urine MMA and tHcy were higher in c.271dupA homozygotes than in compounds. Under treatment, levels of the compounds approached or entered the reference range but not those of c.271dupA homozygotes (tHcy: compounds 9.8-32.9 µM, homozygotes 41.6-106.8 (normal (N) < 14); plasma MMA: compounds 0.14-0.81 µM, homozygotes, 10.4-61 (N < 0.4); urine MMA: compounds 1.75-48 mmol/mol creatinine, homozygotes 143-493 (N < 10)). Patient skin fibroblasts all had low cobalamin uptake, but this was milder in compound cells. Also, the distribution pattern of cobalamin species was qualitatively different between cells from compounds and from homozygotes. Compared to the classic cblC phenotype presented by c.271dupA homozygous patients, c.[158T>C];[271dupA] compounds had mild clinical and biochemical phenotypes and responded strikingly to hydroxocobalamin monotherapy.

Effectiveness of conservation messages to reduce households' GHG emissions: A serious-gaming experiment.

Households play a critical role in reducing greenhouse gas emissions. However, there have been few studies of household conservation from the perspective of the nexus of food, energy, and water (FEW) consumption. This study's objective is to understand the effects of different types of intervention messages for inducing conservation of FEW resources and reducing carbon emissions at the household level in the U.S. Employing a serious-gaming approach, we developed the HomeRUN (Home Role-play for Understanding the Nexus) game, which allows players to act as homeowners and take behavioral and technological upgrade actions in a computer-simulation setting. The types of messages tested include social comparisons and resource-reduction measures across FEW sectors as well as information about the health, economic, and environmental impacts of FEW consumption. A game experiment with U.S. university students finds that social-comparison messages on food and energy consumption, but not on water, lead to significant reductions in household carbon emissions. In addition, messages associated with each type of FEW resource tend to lead to an immediate action corresponding to the particular FEW domain. These insights support a prioritization of intervention messaging for coordinated FEW conservation efforts at a household level.

Outcomes and care quality metrics for people living with rheumatic heart disease and atrial fibrillation in Uganda.

Background: Atrial fibrillation (AF) is a common complication of rheumatic heart disease (RHD) and is challenging to treat in lower-resourced settings in which RHD remains endemic. Objective: We characterized demographics, treatment outcomes, and factors leading to care retention for participants with RHD and AF in Uganda. Methods: We conducted a retrospective analysis of the Uganda national RHD registry between June 2009 and May 2018. Participants with AF or atrial flutter were included. Demographics, survival, and care metrics were compared with participants without AF. Multivariable logistic regression was used to identify factors associated with retention in care among participants with AF. Results: A total of 1530 participants with RHD were analyzed and 293 (19%) had AF. The median age was 24 (interquartile range 14-38) years. Mortality was similar in both groups (adjusted hazard ratio 1.183, P = .77) over a median follow-up of 203 (interquartile range 98-275) days. A total of 79% of AF participants were prescribed anticoagulation, and 43% were aware of their target international normalized ratio. Retention in care was higher in participants with AF (18% vs 12%, P < .01). Factors associated with decreased retention in care include New York Heart Association functional class III/IV (adjusted odds ratio [OR] 0.48, 95% confidence interval [CI] 0.30-0.76) and distance to nearest health center (adjusted OR 0.94, 95% CI 0.90-0.99). Anticoagulation prescription was associated with enhanced care retention (adjusted OR 1.86, 95% CI 1.24-2.79). Conclusion: Participants with RHD and AF in Uganda do not experience higher mortality than those without AF. Anticoagulation prescription rates are high. Although retention in care is poor among RHD participants, those with concurrent AF are more likely to be retained.

User-Centered Design to Develop Automated Short Message Service Messaging for Patient Support of Rheumatic Heart Disease Secondary Antibiotic Prophylaxis.

BACKGROUND: The Active Community Case Management Platform is a cloud-based technology developed to facilitate rheumatic heart disease case management by health care providers. This study aimed to design and pilot an automated short message service (SMS) intervention to support secondary prophylaxis adherence. METHODS AND RESULTS: We developed a concise library of messages to support secondary antibiotic prophylaxis. The SMS intervention used TextIT, an interface that enables users to send out interactive SMS messages at scale. The message bank was piloted in a cohort of 50 patients with rheumatic heart disease randomized into 2 groups. Group 1 received standard support (nurse-led/Active Community Case Management Platform). Group 2 received standard support plus SMS intervention for 2 months in the Lira and Gulu districts of Northern Uganda. We collected qualitative data on participants' experiences and assessed treatment adherence. Using a sequential user-centered process consisting of 4 phases (phases 1-4), we developed a message bank (n=43) deployed during our pilot study. There were no between-group differences in treatment adherence or acceptance. Interviews of participants indicated that the intervention was viewed positively. A total of 75% of SMS recipients responded to the messages, and 25% called the study staff to acknowledge receipt of text messages. CONCLUSIONS: This study has successfully developed a bank of SMS messages to support secondary antibiotic prophylaxis adherence. We have demonstrated the feasibility and acceptability of SMS technology in rheumatic heart disease care management. Future work will include integrating automated SMS into the Active Community Case Management Platform and a larger study of integrated SMS to reduce health care worker burden for patient support and improve adherence to secondary antibiotic prophylaxis.

Service readiness for the management of non-communicable diseases in publicly financed facilities in Malawi: findings from the 2019 Harmonised Health Facility Assessment census survey.

INTRODUCTION: Non-communicable diseases (NCDs) are rising in low-income and middle-income countries, including Malawi. To inform policy-makers and planners on the preparedness of the Malawian healthcare system to respond to NCDs, we estimated NCD service readiness in publicly financed healthcare facilities in Malawi. METHODS: We analysed data from 564 facilities surveyed in the 2019 Harmonised Health Facility Assessment, including 512 primary healthcare (PHC) and 52 secondary and tertiary care (STC) facilities. To characterise service readiness, applying the law of minimum, we estimated the percentage of facilities with functional equipment and unexpired medicines required to provide NCD services. Further, we estimated permanently unavailable items to identify service readiness bottlenecks. RESULTS: Fewer than 40% of PHC facilities were ready to deliver services for each of the 14 NCDs analysed. Insulin and beclomethasone inhalers had the lowest stock levels at PHC facilities (6% and 8%, respectively). Only 17% of rural and community hospitals (RCHs) have liver and kidney diagnostics. STC facilities had varying service readiness, ranging from 27% for managing acute diabetes complications to 94% for chronic type 2 diabetes management. Only 38% of STC facilities were ready to manage chronic heart failure. Oral pain medicines were widely available at all levels of health facilities; however, only 22% of RCHs and 29% of STCs had injectable morphine or pethidine. Beclomethasone was never available at 74% of PHC and 29% of STC facilities. CONCLUSION: Publicly financed facilities in Malawi are generally unprepared to provide NCD services, especially at the PHC level. Targeted investments in PHC can substantially improve service readiness for chronic NCD conditions in local communities and enable STC to respond to acute NCD complications and more complex NCD cases.

The economic costs of orthopaedic services: a health system cost analysis of tertiary hospitals in a low-income country.

BACKGROUND: Traumatic injuries are rising globally, disproportionately affecting low- and middle-income countries, constituting 88% of the burden of surgically treatable conditions. While contributing to the highest burden, LMICs also have the least availability of resources to address this growing burden effectively. Studies on the cost-of-service provision in these settings have concentrated on the most common traumatic injuries, leaving an evidence gap on other traumatic injuries. This study aimed to address the gap in understanding the cost of orthopaedic services in low-income settings by conducting a comprehensive costing analysis in two tertiary-level hospitals in Malawi. METHODS: We used a mixed costing methodology, utilising both Top-Down and Time-Driven Activity-Based Costing approaches. Data on resource utilisation, personnel costs, medicines, supplies, capital costs, laboratory costs, radiology service costs, and overhead costs were collected for one year, from July 2021 to June 2022. We conducted a retrospective review of all the available patient files for the period under review. Assumptions on the intensity of service use were based on utilisation patterns observed in patient records. All costs were expressed in 2021 United States Dollars. RESULTS: We conducted a review of 2,372 patient files, 72% of which were male. The median length of stay for all patients was 9.5 days (8-11). The mean weighted cost of treatment across the entire pathway varied, ranging from $195 ($136-$235) for Supracondylar Fractures to $711 ($389-$931) for Proximal Ulna Fractures. The main cost components were personnel (30%) and medicines and supplies (23%). Within diagnosis-specific costs, the length of stay was the most significant cost driver, contributing to the substantial disparity in treatment costs between the two hospitals. CONCLUSION: This study underscores the critical role of orthopaedic care in LMICs and the need for context-specific cost data. It highlights the variation in cost drivers and resource utilisation patterns between hospitals, emphasising the importance of tailored healthcare planning and resource allocation approaches. Understanding the costs of surgical interventions in LMICs can inform policy decisions and improve access to essential orthopaedic services, potentially reducing the disease burden associated with trauma-related injuries. We recommend that future studies focus on evaluating the cost-effectiveness of orthopaedic interventions, particularly those that have not been analysed within the existing literature.

Health and economic burden of insufficient physical activity in Saudi Arabia.

BACKGROUND: Insufficient physical activity (PA) was estimated to cause 4.8% of deaths and 2.6% of disability-adjusted life-years (DALYs) due to noncommunicable diseases in Saudi Arabia in 2019. While Saudi Arabia is already achieving great improvements, we predict the health and economic burden of insufficient PA up to 2040 to present a case for policy makers to invest more in the uptake of PA. METHODS: Using a population health model to estimate avoidable health loss, we identified four causes of health loss related to low PA (cardiovascular diseases, diabetes, breast cancer, and colorectal cancer) and estimated the deaths and DALYs from these causes. We projected the expected disease burden until 2040 under alternative assumptions about future PA levels and trends by using three health scenarios: baseline (no change in 2019 PA levels), intervention (81% of the population achieving sufficient PA levels), and ideal (65% of population: moderate PA, 30%: high PA, and 5%: inactive). We applied an "intrinsic value" approach to estimate the economic impact of each scenario. RESULTS: Overall, we estimate that between 2023 and 2040, about 80,000 to 110,000 deaths from all causes and 2.0 million to 2.9 million DALYs could be avoided by increasing PA levels in Saudi Arabia. The average annual economic loss from insufficient PA is valued at 0.49% to 0.68% of the current gross domestic product, with an average of US$5.4 billion to US$7.6 billion annually till 2040. The most avoidable disease burden and economic losses are expected among males and because of ischemic heart disease. CONCLUSIONS: This study highlights that low PA levels will have considerable health and economic impacts in Saudi Arabia if people remain inactive and do not start following interventions. There is an urgent need to develop innovative programs and policies to encourage PA among all age and sex groups.

Scaling-up and scaling-out the Systems Analysis and Improvement Approach to optimize the hypertension diagnosis and care cascade for HIV infected individuals (SCALE SAIA-HTN): a stepped-wedge cluster randomized trial.

BACKGROUND: Undiagnosed and untreated hypertension is a main driver of cardiovascular disease and disproportionately affects persons living with HIV (PLHIV) in low- and middle-income countries. Across sub-Saharan Africa, guideline application to screen and manage hypertension among PLHIV is inconsistent due to poor service readiness, low health worker motivation, and limited integration of hypertension screening and management within HIV care services. In Mozambique, where the adult HIV prevalence is over 13%, an estimated 39% of adults have hypertension. As the only scaled chronic care service in the county, the HIV treatment platform presents an opportunity to standardize and scale hypertension care services. Low-cost, multi-component systems-level strategies such as the Systems Analysis and Improvement Approach (SAIA) have been found effective at integrating hypertension and HIV services to improve the effectiveness of hypertension care delivery for PLHIV, reduce drop-offs in care, and improve service quality. To build off lessons learned from a recently completed cluster randomized trial (SAIA-HTN) and establish a robust evidence base on the effectiveness of SAIA at scale, we evaluated a scaled-delivery model of SAIA (SCALE SAIA-HTN) using existing district health management structures to facilitate SAIA across six districts of Maputo Province, Mozambique. METHODS: This study employs a stepped-wedge design with randomization at the district level. The SAIA strategy will be "scaled up" with delivery by district health supervisors (rather than research staff) and will be "scaled out" via expansion to Southern Mozambique, to 18 facilities across six districts in Maputo Province. SCALE SAIA-HTN will be introduced over three, 9-month waves of intensive intervention, where technical support will be provided to facilities and district managers by study team members from the Mozambican National Institute of Health. Our evaluation of SCALE SAIA-HTN will be guided by the RE-AIM framework and will seek to estimate the budget impact from the payer's perspective. DISCUSSION: SAIA packages user-friendly systems engineering tools to support decision-making by frontline health workers and to identify low-cost, contextually relevant improvement strategies. By integrating SAIA delivery into routine management structures, this pragmatic trial will determine an effective strategy for national scale-up and inform program planning. TRIAL REGISTRATION: ClinicalTrials.gov NCT05002322 (registered 02/15/2023).

Global Assessment of Palliative Care Need: Serious Health-Related Suffering Measurement Methodology.

CONTEXT: Inequities and gaps in palliative care access are a serious impediment to health systems especially in low- and middle-income countries and the accurate measurement of need across health conditions is a critical step to understanding and addressing the issue. Serious Health-related Suffering (SHS) is a novel methodology to measure the palliative care need and was originally developed by The Lancet Commission on Global Access to Palliative Care and Pain Relief. In 2015, the first iteration - SHS 1.0 - was estimated at over 61 million people worldwide experiencing at least 6 billion days of SHS annually as a result of life-limiting and life-threatening conditions. OBJECTIVES: In this paper, an updated methodology - SHS 2.0 - is presented building on the work of the Lancet Commission and detailing calculations, data requirements, limitations, and assumptions. METHODS AND RESULTS: The updates to the original methodology focus on measuring the number of people who die with (decedents) or live with (non-decedents) SHS in a given year to assess the number of people in need of palliative care across health conditions and populations. Detail on the methodology for measuring the number of days of SHS that was pioneered by the Lancet Commission, is also shared, as this second measure is essential for determining the health system responses that are necessary to address palliative care need and must be a priority for future methodological work on SHS. CONCLUSIONS: The methodology encompasses opportunities for applying SHS to future policy making assessment of future research priorities particularly in light of the dearth of data from low- and middle-income countries, and sharing of directions for future work to develop SHS 3.0.

Circulating microRNA Analysis in a Prospective Co-clinical Trial Identifies MIR652-3p as a Response Biomarker and Driver of Regorafenib Resistance Mechanisms in Colorectal Cancer.

PURPOSE: The multi-kinase inhibitor (mKi) regorafenib has demonstrated efficacy in chemorefractory patients with metastatic colorectal cancer (mCRC). However, lack of predictive biomarkers and concerns over significant toxicities hamper the use of regorafenib in clinical practice. EXPERIMENTAL DESIGN: Serial liquid biopsies were obtained at baseline and monthly until disease progression in chemorefractory patients with mCRC treated with regorafenib in a phase II clinical trial (PROSPECT-R n = 40; NCT03010722) and in a multicentric validation cohort (n = 241). Tissue biopsies collected at baseline, after 2 months and at progression in the PROSPECT-R trial were used to establish patient-derived organoids (PDO) and for molecular analyses. MicroRNA profiling was performed on baseline bloods using the NanoString nCounter platform and results were validated by digital-droplet PCR and/or ISH in paired liquid and tissue biopsies. PDOs co-cultures and PDO-xenotransplants were generated for functional analyses. RESULTS: Large-scale microRNA expression analysis in longitudinal matched liquid and tissue biopsies from the PROSPECT-R trial identified MIR652-3p as a biomarker of clinical benefit to regorafenib. These findings were confirmed in an independent validation cohort and in a "control" group of 100 patients treated with lonsurf. Using ex vivo co-culture assays paired with single-cell RNA-sequencing of PDO established pre- and post-treatment, we modeled regorafenib response observed in vivo and in patients, and showed that MIR652-3p controls resistance to regorafenib by impairing regorafenib-induced lethal autophagy and by orchestrating the switch from neo-angiogenesis to vessel co-option. CONCLUSIONS: Our results identify MIR652-3p as a potential biomarker and as a driver of cell and non-cell-autonomous mechanisms of resistance to regorafenib.

Building the health-economic case for scaling up the WHO-HEARTS hypertension control package in low- and middle-income countries / Argumentos de la economía de la salud para ampliar las medidas de control de la hipertensión de la iniciativa HEARTS de la OMS en los países de ingresos medianos y bajos / Ampliação do pacote de controle da hipertensão OMS-HEARTS em países de baixa e média renda: argumentos a partir da perspectiva da economia em saúde

ABSTRACT Generally, hypertension control programs are cost-effective, including in low- and middle-income countries, but country governments and civil society are not likely to support hypertension control programs unless value is demonstrated in terms of public health benefits, budget impact, and value-for-investment for the individual country context. The World Health Organization (WHO) and the Pan American Health Organization (PAHO) established a standard, simplified Global HEARTS approach to hypertension control, including preferred antihypertensive medicines and blood pressure measurement devices. The objective of this study is to report on health economic studies of HEARTS hypertension control package cost (especially medication costs), cost-effectiveness, and budget impact and describe mathematical models designed to translate hypertension control program data into the optimal approach to hypertension care service delivery and financing, especially in low- and middle-income countries. Early results suggest that HEARTS hypertension control interventions are either cost-saving or cost-effective, that the HEARTS package is affordable at between US$ 18-44 per person treated per year, and that antihypertensive medicines could be priced low enough to reach a global standard of an average <US$ 5 per patient per year in the public sector. This health economic evidence will make a compelling case for government ownership and financial support for national scale hypertension control programs.

RESUMEN En general, los programas de control de la hipertensión son costo-eficaces, incluso en los países de ingresos bajos y medios. Aun así, es poco probable que los gobiernos nacionales y la sociedad civil apoyen los programas de control de la hipertensión a menos que se demuestre su valor en términos de beneficios para la salud pública, impacto presupuestario y valor de la inversión para el contexto individual del país. La Organización Mundial de la Salud (OMS) y la Organización Panamericana de la Salud (OPS) implementaron la iniciativa HEARTS, un enfoque mundial estandarizado y simplificado para el control de la hipertensión, que incluye los medicamentos antihipertensivos y los dispositivos de medición de la presión arterial de preferencia. El objetivo de este estudio es informar sobre los estudios en el ámbito de la economía de la salud relativos al costo de las medidas de control de la hipertensión previstas en HEARTS (especialmente, de los medicamentos), la costo-efectividad y el impacto presupuestario, así como describir los modelos matemáticos diseñados para traducir los datos de este programa en un enfoque óptimo para la prestación y el financiamiento de los servicios de atención de la hipertensión, especialmente en países de ingresos medianos y bajos. Los primeros resultados indican que las intervenciones de HEARTS para el control de la hipertensión son de bajo costo o costo-eficaces, que el conjunto de medidas HEARTS es asequible, a un precio que oscila entre US$ 18 y US$ 44 al año por paciente tratado, y que los medicamentos antihipertensivos podrían tener un precio lo suficientemente bajo como para alcanzar un estándar medio mundial de <US$ 5 por paciente al año en el sector público. Estos datos del ámbito de la economía de la salud serán argumentos convincentes para que los gobiernos se involucren en los programas de control de la hipertensión a escala nacional y les brinden apoyo financiero.

RESUMO Geralmente, os programas de controle de hipertensão são custo-efetivos, inclusive em países de baixa e média renda, mas os governos dos países e a sociedade civil provavelmente não apoiarão tais programas a menos que demonstrem valor em termos de benefícios à saúde pública, impacto orçamentário e retorno sobre o investimento no contexto individual do país. A Organização Mundial da Saúde (OMS) e a Organização Pan-Americana da Saúde (OPAS) criaram a Global HEARTS, uma abordagem padrão e simplificada ao controle da hipertensão arterial, que inclui medicamentos anti-hipertensivos preferidos e dispositivos para aferição da pressão arterial preferidos. O objetivo deste estudo é relatar os estudos de economia em saúde que analisaram o custo (especialmente custos de medicamentos), custo-benefício e impacto orçamentário do pacote HEARTS para controle da hipertensão e descrever modelos matemáticos elaborados para traduzir os dados do programa de controle de hipertensão em uma abordagem ideal para a prestação e financiamento de serviços de atenção às pessoas com hipertensão, especialmente em países de baixa e média renda. Os primeiros resultados sugerem que as intervenções HEARTS para controle da hipertensão são de baixo custo ou custo-efetivas, que o pacote HEARTS é acessível (custando de US$ 18 a 44 por pessoa tratada por ano) e que o preço dos medicamentos anti-hipertensivos poderia ser baixo o suficiente para atingir uma média global de <US$ 18 por paciente por ano no setor público. Estas evidências do campo da economia em saúde serão um argumento convincente para que os governos se responsabilizem por programas de controle de hipertensão em escala nacional e os dotem de recursos financeiros.

Acute HIV infection with rapid progression to AIDS

Acute HIV infection is rarely recognized as the signs and symptoms are normally unspecific and can persist for days or weeks. The normal HIV course is characterized by a progressive loss of CD4+ cells, which normally leads to severe immunodeficiency after a variable time interval. The mean time from initial infection to development of clinical AIDS is approximately 8-10 years, but it is variable among individuals and depends on a complex interaction between virus and host. Here we describe an extraordinary case of a man who developed Pneumocisits jiroveci pneumonia within one month after sexual exposure to HIV-1, and then presented with 3 consecutive CD4 counts bellow 200 cells/mm³ within 3 months, with no other opportunistic disease. Although antiretroviral therapy (AZT+3TC+ATZ/r) was started, with full adherence of the patient, and genotyping indicating no primary antiretroviral resistance mutations, he required more than six months to have a CD4 restoration to levels above 200 cells/mm³ and 10 months to HIV-RNA to become undetectable.

Is an HIV vaccine possible?

The road to the discovery of a vaccine for HIV has been arduous and will continue to be difficult over the ensuing twenty years. Most vaccines are developed by inducing neutralizing antibodies against the target pathogen or by using attenuated strains of the particular pathogen to engender a variety of protective immune responses. Unfortunately, simple methods of generating anti-HIV antibodies have already failed in a phase III clinical trial. While attenuated SIV variants work well against homologous challenges in non-human primates, the potential for reversion to a more pathogenic virus and recombination with challenge viruses will preclude the use of attenuated HIV in the field. It has been exceedingly frustrating to vaccinate for HIV-specific neutralizing antibodies given the enormous diversity of the Envelope (Env) glycoprotein and its well-developed glycan shield. However, there are several antibodies that will neutralize many different strains of HIV and inducing these types of antibodies in vaccinees remains the goal of a vigorous effort to develop a vaccine for HIV based on neutralizing antibodies. Given the difficulty in generating broadly reactive neutralizing antibodies, the HIV vaccine field has turned its attention to inducing T cell responses against the virus using a variety of vectors. Unfortunately, the results from Merck's phase IIb STEP trial proved to be disappointing. Vaccinees received Adenovirus type 5 (Ad5) expressing Gag, Pol, and Nef of HIV. This vaccine regimen failed to either prevent infection or reduce the level of HIV replication after challenge. These results mirrored those in non-human primate testing of Ad5 using rigorous SIV challenge models. This review will focus on recent developments in HIV vaccine development. We will deal largely with attempts to develop a T cell-based vaccine using the non-human primate SIV challenge model.

The hope for an HIV vaccine based on induction of CD8+ T lymphocytes: a review

The only long-term and cost-effective solution to the human immunodeficiency virus (HIV) epidemic in the developing world is a vaccine that prevents individuals from becoming infected or, once infected, from passing the virus on to others. There is currently little hope for an AIDS vaccine. Conventional attempts to induce protective antibody and CD8+ lymphocyte responses against HIV and simian immunodeficiency virus (SIV) have failed. The enormous diversity of the virus has only recently been appreciated by vaccinologists, and our assays to determine CD8+ lymphocyte antiviral efficacy are inadequate. The central hypothesis of a CTL-based vaccine is that particularly effective CD8+ lymphocytes directed against at least five epitopes that are derived from regions under functional and structural constraints will control replication of pathogenic SIV. This would be somewhat analogous to control of virus replication by triple drug therapy or neutralizing antibodies.

Identification and characterization of previously described epitopes in HIV-1 subtypes B, C, F and BF in Brazil

Genetic analysis of HIV-1 is essential to improve treatment strategies and select epitopes for vaccine programs. The objective of this study was to determine whether known CD4+ and CD8+ epitopes were present in Brazilian HIV-1 strains. We used previously described CD8+ and CD4+ epitopes from the Los Alamos laboratory to search for these epitopes in the Brazilian sequences using the HIVbase program and we compared the frequency results with the analyses using physical-chemical profile tools from Network Protein Sequence Analysis (NPSA), and the SYFPEITHI program. Furthermore, this analysis was carried out with the Prosite tool using the GeneDoc program and ds/dn analyses using the Synonymous Nonsynonymous Analysis Program (SNAP). The HIVbase epitope mapping demonstrated that 30 CD8+ and 6 CD4+ epitopes were present in the Brazilian sequences at a high frequency. Only two of these epitopes were heavily glycosylated. Interestingly, ds/dn analyses showed evidence of purifying selective pressure. These types of analyses could be useful for the assessment of possible vaccine efficiency in populations.