Assessing the contributions of an urban population health initiative to shift political priority towards cardiovascular health: three case studies from Brazil, Mongolia and Senegal.

BACKGROUND: The urban population health initiative was designed as a multidisciplinary, multisector programme to address cardiovascular (CV) disease, specifically hypertension and its underlying causes in the cities of Ulaanbaatar, Mongolia; Dakar, Senegal; and São Paulo, Brazil. This article aims to provide an overview of the history and dynamics of CV disease policy making in the three countries, to present the policy reform contributions of the initiative and its role in the policy agenda-setting framework/process in each country and to identify the enablers and challenges to the initiative for doing so. METHODS: A qualitative case study was conducted for each setting from November 2020 to January 2021, comprised of a document review, semi-structured in-depth interviews and unstructured interviews with stakeholders involved in the initiative. The literature review included documents from the initiative and the peer-reviewed and grey literature with a total of 188 documents screened. Interviews were conducted with 21 stakeholders. Data collection and thematic analysis was guided by (i) the Kingdon multiple streams conceptual framework with the main themes being CV disease problems, policy, politics and the role of policy entrepreneurs; and (ii) the study question inquiring on the role of the urban population health initiative at the CV disease policy level and enabling and challenging factors to advancing CV disease policy. Data were thematically analysed using the Framework Method. RESULTS: Each setting was characterized by a high hypertension and CV disease burden combined with an aware and proactive political environment. Policy outcomes attributed to the initiative were updating the guidelines and/or algorithms of care for hypertension and including revised physical and nutritional education in school curricula, in each city. Overall, the urban health initiative's effects in the policy arena, were most prominent in Mongolia and Senegal, where the team effectively acted as policy entrepreneur, promoting the solutions/policies in alignment with the most pressing local problems and in strong involvement with the political actors. The initiative was also involved in improving access to CV disease drugs at primary health levels. Its success was influenced by the local governance structures, the proximity of the initiative to the policy makers and the local needs. In Brazil, needs were expressed predominantly in the clinical practice. CONCLUSIONS: This multi-country experience shows that, although the policy and political environment plays its role in shaping initiatives, often the local priority needs are the driving force behind wider change.

Population health impact and economic evaluation of the CARDIO4Cities approach to improve urban hypertension management.

Cardiovascular disease (CVD) is the leading cause of mortality worldwide, with 80% of that mortality occurring in low- and middle-income countries. Hypertension, its primary risk factor, can be effectively addressed through multisectoral, multi-intervention initiatives. However, evidence for the population-level impact on cardiovascular (CV) event rates and mortality, and the cost-effectiveness of such initiatives is scarce as long-term longitudinal data is often lacking. Here, we model the long-term population health impact and cost-effectiveness of a multisectoral urban population health initiative designed to reduce hypertension, conducted in Ulaanbaatar (Mongolia), Dakar (Senegal), and in the district of Itaquera in São Paulo (Brazil) in collaboration with the local governments. We based our analysis on cohort-level data among hypertensive patients on treatment and control rates from a real-world effectiveness study of the CARDIO4Cities approach (built on quality of care, early access, policy reform, data and digital, Intersectoral collaboration, and local ownership). We built a decision tree model to estimate the CV event rates during implementation (1-2 years) and a Markov model to project health outcomes over 10 years. We estimated the number of CV events averted and quality-adjusted life-years gained (QALYs through the initiative and assessed its cost-effectiveness based on the costs reported by the funder using the incremental cost effectiveness ratio (ICER) and published thresholds. A one-way sensitivity analysis was performed to assess the robustness of the results. The modelled patient cohorts included 10,075 patients treated for hypertension in Ulaanbaatar, 5,236 in Dakar, and 5,844 in São Paulo. We estimated that 3.3-12.8% of strokes and 3.0-12.0% of coronary heart disease (CHD) events were averted during 1-2 years of implementation in the three cities. We estimated that over the subsequent 10 years, 3.6-9.9% of strokes, 2.8-7.8% of CHD events, and 2.7-7.9% of premature deaths would be averted. The estimated ICER was USD 748 QALY gained in Ulaanbaatar, USD 3091 in Dakar, and USD 784 in São Paulo. With that, the intervention was estimated to be cost-effective in Ulaanbaatar and São Paulo. For Dakar, cost-effectiveness was met under WHO-CHOICE standards, but not under more conservative standards adjusted for purchasing power parity (PPP) and opportunity costs. The findings were robust to the sensitivity analysis. Our results provide evidence that the favorable impact of multisector systemic interventions designed to reduce the hypertension burden extend to long-term population-level CV health outcomes and are likely cost-effective. The CARDIO4Cities approach is predicted to be a cost-effective solution to alleviate the growing CVD burden in cities across the world.

Emerging anti-HDV drugs and HBV cure strategies with anti-HDV activity.

Hepatitis delta virus (HDV) is a satellite RNA virus that requires the presence of hepatitis B virus (HBV) for its replication. HDV/HBV co-infection is often associated with a faster disease progression of chronic hepatitis in comparison to HBV mono-infection. Therefore, the development of novel antiviral therapies targeting HDV represents a high priority and an urgent medical need. In this review, we summarize the ongoing efforts to evaluate promising HDV-specific drugs, such as lonafarnib (LNF), pegylated interferon lambda (PEG-IFN-λ) and their use as a combination therapy. Furthermore, we review the most recent developments in the area of anti-HBV drugs with potential effects against HDV, including therapeutic agents targeting hepatitis B surface antigen (HBsAg) expression, secretion and function. Finally, we consider the important insights that have emerged from the development of these potential antiviral strategies, as well as the intriguing questions that remain to be elucidated in this rapidly changing field.

Comparison of Three Diagnostic Definitions of Metabolic Syndrome and Estimation of Its Prevalence in Mongolia.

We sought to estimate the prevalence of metabolic syndrome (MS) in the urban population of Mongolia and suggest a preferred definition. This cross-sectional study comprised 2076 representative samples, which were randomly selected to provide blood samples. MS was defined by the National Cholesterol Education Program's Adults Treatment Panel III (NCEP ATP III), the International Diabetes Federation (IDF), and the Joint Interim Statement (JIS). The Cohen's kappa coefficient (κ) was analyzed to determine the agreement between the individual MS components using the three definitions. The prevalence of MS in the 2076 samples was 19.4% by NCEP ATP III, 23.6% by IDF, and 25.4% by JIS criteria. For men, moderate agreement was found between the NCEP ATP III and waist circumference (WC) (κ = 0.42), and between the JIS and fasting blood glucose (FBG) (κ = 0.44) and triglycerides (TG) (κ = 0.46). For women, moderate agreement was found between the NCEP ATP III and high-density lipoprotein cholesterol (HDL-C) (κ = 0.43), and between the JIS and HDL-C (κ = 0.43). MS is highly prevalent in the Mongolian urban population. The JIS definition is recommended as the provisional definition.

Peripheral B cells from patients with hepatitis C virus-associated lymphoma exhibit clonal expansion and an anergic-like transcriptional profile.

Chronic HCV infection remains a global health concern due to its involvement in hepatic and extrahepatic diseases, including B cell non-Hodgkin lymphoma (BNHL). Clinical and epidemiological evidence support a causal role for HCV in BNHL development, although mechanistic insight is lacking. We performed RNA-sequencing on peripheral B cells from patients with HCV alone, BNHL alone, and HCV-associated BNHL to identify unique and shared transcriptional profiles associated with transformation. In patients with HCV-associated BNHL, we observed the enrichment of an anergic-like gene signature and evidence of clonal expansion that was correlated with the expression of epigenetic regulatory genes. Our data support a role for viral-mediated clonal expansion of anergic-like B cells in HCV-associated BNHL development and suggest epigenetic dysregulation as a potential mechanism driving expansion. We propose epigenetic mechanisms may be involved in both HCV-associated lymphoma and regulation of B cell anergy, representing an attractive target for clinical interventions.

Implementing a multisector public-private partnership to improve urban hypertension management in low-and middle- income countries.

BACKGROUND: Cardiovascular disease presents an increasing health burden to low- and middle-income countries. Although ample therapeutic options and care improvement frameworks exist to address its prime risk factor, hypertension, blood pressure control rates remain poor. We describe the results of an effectiveness study of a multisector urban population health initiative that targets hypertension in a real-world implementation setting in cities across three continents. The initiative followed the "CARDIO4Cities" approach (quality of Care, early Access, policy Reform, Data and digital technology, Intersectoral collaboration, and local Ownership). METHOD: The approach was applied in Ulaanbaatar in Mongolia, Dakar in Senegal, and São Paulo in Brazil. In each city, a portfolio of evidence-based practices was implemented, tailored to local priorities and available data. Outcomes were measured by extracting hypertension diagnosis, treatment and control rates from primary health records. Data from 18,997 patients with hypertension in primary health facilities were analyzed. RESULTS: Over one to two years of implementation, blood pressure control rates among enrolled patients receiving medication tripled in São Paulo (from 12·3% to 31·2%) and Dakar (from 6·7% to 19·4%) and increased six-fold in Ulaanbaatar (from 3·1% to 19·7%). CONCLUSIONS: This study provides first evidence that a multisectoral population health approach to implement known best-practices, supported by data and digital technologies, and relying on local buy-in and ownership, can improve hypertension control in high-burden urban primary care settings in low-and middle-income countries.

Design of an observational multi-country cohort study to assess immunogenicity of multiple vaccine platforms (InVITE).

In response to the COVID-19 pandemic, COVID-19 vaccines have been developed, and the World Health Oraganization (WHO) has granted emergency use listing to multiple vaccines. Studies of vaccine immunogenicity data from implementing COVID-19 vaccines by national immunization programs in single studies spanning multiple countries and continents are limited but critically needed to answer public health questions on vaccines, such as comparing immune responses to different vaccines and among different populations.

Immune imprinting, breadth of variant recognition, and germinal center response in human SARS-CoV-2 infection and vaccination.

During the SARS-CoV-2 pandemic, novel and traditional vaccine strategies have been deployed globally. We investigated whether antibodies stimulated by mRNA vaccination (BNT162b2), including third-dose boosting, differ from those generated by infection or adenoviral (ChAdOx1-S and Gam-COVID-Vac) or inactivated viral (BBIBP-CorV) vaccines. We analyzed human lymph nodes after infection or mRNA vaccination for correlates of serological differences. Antibody breadth against viral variants is lower after infection compared with all vaccines evaluated but improves over several months. Viral variant infection elicits variant-specific antibodies, but prior mRNA vaccination imprints serological responses toward Wuhan-Hu-1 rather than variant antigens. In contrast to disrupted germinal centers (GCs) in lymph nodes during infection, mRNA vaccination stimulates robust GCs containing vaccine mRNA and spike antigen up to 8 weeks postvaccination in some cases. SARS-CoV-2 antibody specificity, breadth, and maturation are affected by imprinting from exposure history and distinct histological and antigenic contexts in infection compared with vaccination.

Direct comparison of antibody responses to four SARS-CoV-2 vaccines in Mongolia.

Different SARS-CoV-2 vaccines are approved in various countries, but few direct comparisons of the antibody responses they stimulate have been reported. We collected plasma specimens in July 2021 from 196 Mongolian participants fully vaccinated with one of four COVID-19 vaccines: Pfizer/BioNTech, AstraZeneca, Sputnik V, and Sinopharm. Functional antibody testing with a panel of nine SARS-CoV-2 viral variant receptor binding domain (RBD) proteins revealed marked differences in vaccine responses, with low antibody levels and RBD-ACE2 blocking activity stimulated by the Sinopharm and Sputnik V vaccines in comparison to the AstraZeneca or Pfizer/BioNTech vaccines. The Alpha variant caused 97% of infections in Mongolia in June and early July 2021. Individuals who recover from SARS-CoV-2 infection after vaccination achieve high antibody titers in most cases. These data suggest that public health interventions such as vaccine boosting, potentially with more potent vaccine types, may be needed to control COVID-19 in Mongolia and worldwide.

High Prevalence of Chronic Viral Hepatitis and Liver Fibrosis Among Mongols in Southern California.

BACKGROUND: Mongolia is a highly endemic region for chronic hepatitis B (HBV), hepatitis delta (HDV), and hepatitis C (HCV) infections. Aim of this study was to comprehensively characterize chronic viral hepatitis among Mongols living in Southern California. METHODS: Three screening events were conducted between August and November 2018, with 528 adult Mongols tested for HBV and HCV. HBsAg (+) individuals (CHB) underwent additional testing for HDV RNA and anti-HDV. Liver tests, platelet count, and FibroScan™ were performed on CHB and chronic HCV (CHC) individuals. RESULTS: Fifty-one out of 534 were HBsAg reactive (9.7%), and all were foreign-born. Mean age of CHB individuals was 37.8 (range 18-69) years. Forty-six out of 51 were HBeAg (-). HBV genotypes were exclusively D2 or A1. Twenty-one out of 51 (41.2%) were anti-HDV (+) and 17/51 (33.3%) were HDV RNA (+). HDV RNA (+) individuals had significantly higher ALT, fibrosis-4 score, and liver stiffness compared to HDV RNA (-) individuals. Incidence of advanced fibrosis was higher in HDV RNA (+) individuals (57% vs. 13%, p = 0.013). Forty-eight (9.1%) individuals were anti-HCV (+) and 19 (3.6%) were HCV RNA (+). Mean age of CHC individuals was 40.2 (range 28-71) years. Prevalence of anti-HCV (+) was higher among those born between 1945 and 1965 versus those born after 1965 (18.8% vs. 7.9%, p = 0.025). Genotype 1b was predominant. Incidence of cirrhosis was 7% among all participants. CONCLUSIONS: Mongols living in the USA are at high risk for CHB and CHC infections. One-third of CHB individuals had CHD superinfection with advanced fibrosis. Universal screening for viral hepatitis in Mongols in the USA is mandatory.

Improvement of long-term risks of cardiovascular events associated with community-based disease management in Chinese patients of the Xinjiang autonomous region of China.

BACKGROUND: A recent community-based disease management (CBDM) pilot study reported a 20.5% prevalence of hypertension and a 0.5 and 3.6% prevalence of stroke and coronary heart disease (CHD), respectively, in an elderly population (mean age 65 years) in the Xin Jiang autonomous region of China. The CBDM was initiated in 2013 as an essential public health service; however, the potential long-term impact of CBDM on cardiovascular (CV: CHD and stroke) events is unknown. The objective of the study was to understand the long-term impact of CBDM interventions on CV risk factors using disease-model simulation based on a single-arm experimental study. METHODS: A discrete event simulation was developed to evaluate the impact of CBDM on the long-term CV risk among patients with hypertension, in China's Xin Jiang autonomous region. The model generated pairs of identical patients; one receives CBDM and one does not (control group). Their clinical courses were simulated based on time to CV events (CHD and strokes), which are estimated using published risk equations. The impact of CBDM was incorporated as improvement in systolic blood pressure (SBP) based on observations from the CBDM study. The simulation estimated the number of CV events over patients' lifetimes. RESULTS: During a 2-year follow up, the CBDM led to an average reduction of 8.73 mmHg in SBP from baseline, and a 42% reduction in smoking. The discrete event simulation showed that, in the control group, the model estimated incidence rates of 276, 1789, and 616 per 100,000 individuals for lifetime CHD, stroke, and CV-related death, respectively. The impact of CBDM on SBP translated into reductions of 8, 28, and 23% in CHD, stroke, and CV-related deaths, respectively. Taking into account CBDM's reduction of both SBP and smoking, deaths from CHD, stroke, and CV-related deaths were reduced by 12, 30, and 26%, respectively. CONCLUSIONS: The implementation of CBDM in China's Xinjiang autonomous region is expected to significantly reduce incidences of CHD, strokes, and CV-related deaths.

Sensitivity and specificity of commercially available rapid diagnostic tests for viral hepatitis B and C screening in serum samples.

Early diagnosis of chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections is pivotal for optimal disease management. Sensitivity and specificity of 19 rapid diagnostic test (RDT) kits by different manufacturers (ABON, CTK Biotech, Cypress Diagnostics, Green Gross, Human Diagnostic, Humasis, InTec, OraSure, SD Bioline, Wondfo) were assessed on serum samples of 270 Mongolians (90 seropositive for hepatitis B surface antigen (HBsAg), 90 seropositive for hepatitis C antibody (HCV-Ab), 90 healthy subjects). All tested RDTs for detection of HBsAg performed with average sensitivities and specificities of 100% and 99%, respectively. Albeit, overall sensitivity and specificity of RDTs for detection of HCV-Ab was somewhat lower compared to that of HBsAg RDTs (average sensitivity 98.9%, average specificity 96.7%). Specificity of RDTs for detection of HCV-Ab was dramatically lower among HBsAg positive individuals, who were 10.2 times more likely to show false positive test results. The results of our prospective study demonstrate that inexpensive, easy to handle RDTs are a promising tool in effective HBV- and HCV-screening especially in resource-limited settings.

Hypertension prevalence and control in Ulaanbaatar, Mongolia.

This study examines the prevalence, awareness, treatment, and control of hypertension in Ulaanbaatar, Mongolia, using both the American Heart Association and conventional thresholds (130/80 and 140/90 mm Hg, respectively). In this randomized cross-sectional study, two-stage cluster sampling was used to obtain a sample of 4515 individuals aged ≥20 years. Hypertension was defined by the use of antihypertensives in the last 2 weeks or a blood pressure at or above the thresholds of 140/90 and 130/80 mm Hg. The mean age of the participants was 41.1 ± 14.0 years and 54.5% were women. Hypertension prevalence was 25.6% (using 140/90 mm Hg) and 46.5% (using 130/80 mm Hg). Prevalence increased with age and below 50 years men were consistently more likely to be hypertensive. Among hypertensive participants, the rates of awareness, treatment, and control were 69.7%, 46.8%, and 24.0% (using 140/90 mm Hg) and 49.1%, 25.8%, and 6.4% (using 130/80 mm Hg, respectively). Men had lower rates of awareness, treatment, and control compared with women, with the most pronounced differences at younger ages. This study shows that awareness, treatment, and control rates in Ulaanbaatar are better than in most low- and middle-income countries but are still suboptimal. The largest "care gap" was in young men where a regulatory requirement for annual workplace blood pressure screening has the potential to enhance care. A major hypertension control program has just been initiated in Ulaanbaatar.

Hypertension knowledge, attitudes, and practices of nurses and physicians in primary care in Ulaanbaatar Mongolia.

Increased blood pressure is a leading risk for death globally, and interventions to enhance hypertension control have become a high priority. An important aspect of clinical interventions is understanding the knowledge, attitudes, and practices (KAP) of differing primary healthcare practitioners. We examined KAP surveys from 803 primary care practitioners in Ulaanbaatar, Mongolia (response rate 80%), using a comprehensive KAP survey developed by the World Hypertension League (WHL). The WHL KAP survey uniquely includes an assessment of key World Health Organization recommended interventions to enhance hypertension control. There were few substantive differences between healthcare professional disciplines. Primary care practitioners mostly had a positive attitude toward hypertension management. However, confidence and practice in performing specific tasks to control hypertension were suboptimal. A low proportion indicated they systematically screened adults for hypertension and many were not aware of the need to or were confident in prescribing more than two antihypertensive medications. It was the practice of a high proportion of doctors to not pharmacologically treat most people with hypertension who were at high cardiovascular risk. There was a reluctance by physicians to task share hypertension diagnosis, drug prescribing and assessing cardiovascular risk to nurses. The minority of health care professions use a hypertension management algorithm, and few have patient registries with performance reporting functions. There were few substantive differences based on the age, gender, and years of clinical practice of the practitioners. The study findings support the need for standardized education and training of primary care practitioners in Ulaanbaatar to enhance hypertension control.

Hypertension, knowledge, attitudes, and practices of primary care physicians in Ulaanbaatar, Mongolia.

We examined the knowledge, attitudes, and practices of primary care doctors in Ulaanbaatar, Mongolia using a recently developed World Hypertension League survey. The survey was administered as part of a quality assurance initiative to enhance hypertension control. A total of 577 surveys were distributed and 467 were completed (81% response rate). The respondents had an average age of 35 years and 90.1% were female. Knowledge of hypertension epidemiology was low (13.5% of questions answered correctly); 31% of clinical practice questions had correct answers and confidence in performing specific tasks to improve hypertension control had 63.2% "desirable/correct" answers. Primary care doctors mostly had a positive attitude toward hypertension management (76.5% desirable/correct answers) and highly prioritized hypertension management activities (85.7% desirable/correct answers). Some important highlights included the majority (> 80%) overestimating hypertension awareness, treatment, and control rates; 78.2% used aneroid blood pressure manometers; 15% systematically screened adults for hypertension in their clinics; 21.8% reported 2 or more drugs were required to control hypertension in most people; and 16.1% reported most people could be controlled by lifestyle changes alone. 55% of respondents were not comfortable prescribing more than 1 or 2 antihypertensive drugs in a patient and the percentage of desirable/correct responses to treating various high-risk patients was low. Most (53%-74%) supported task shifting to nonphysician health care providers except for drug prescribing, which only 13.9% supported. A hypertension clinical education program is currently being designed based on the specific needs identified in the survey.

Clinical and virological heterogeneity of hepatitis delta in different regions world-wide: The Hepatitis Delta International Network (HDIN).

BACKGROUND & AIMS: Chronic hepatitis D (delta) is a major global health burden. Clinical and virological characteristics of patients with hepatitis D virus (HDV) infection and treatment approaches in different regions world-wide are poorly defined. METHODS: The Hepatitis Delta International Network (HDIN) registry was established in 2011 with centres in Europe, Asia, North- and South America. Here, we report on clinical/ virological characteristics of the first 1576 patients with ongoing or past HDV infection included in the database until October 2016 and performed a retrospective outcome analysis. The primary aim was to investigate if the region of origin was associated with HDV replication and clinical outcome. RESULTS: The majority of patients was male (n = 979, 62%) and the mean age was 36.7 years (range 1-79, with 9% of patients younger than 20 years). Most patients were HBeAg-negative (77%) and HDV-RNA positive (85%). Cirrhosis was reported in 48.7% of cases which included 13% of patients with previous or ongoing liver decompensation. Hepatocellular carcinoma (HCC) developed in 30 patients (2.5%) and 44 (3.6%) underwent liver transplantation. Regions of origin were independently associated with clinical endpoints and detectability of HDV RNA. Antiviral therapy was administered to 356 patients with different treatment uptakes in different regions. Of these, 264 patients were treated with interferon-a and 92 were treated with HBV-Nucs only. CONCLUSIONS: The HDIN registry confirms the severity of hepatitis delta but also highlights the heterogeneity of patient characteristics and clinical outcomes in different regions. There is an urgent need for novel treatment options for HDV infection.

Assessing healthcare professional knowledge, attitudes, and practices on hypertension management. Announcing a new World Hypertension League resource.

To assist hypertension control programs and specifically the development of training and education programs on hypertension for healthcare professionals, the World Hypertension League has developed a resource to assess knowledge, attitudes, and practices on hypertension management. The resource assesses: (1) the importance of hypertension as a clinical and public health risk; (2) education in national or international hypertension recommendations; (3) lifestyle causes of hypertension; (4) measurement of blood pressure, screening, and diagnosis of hypertension; (5) lifestyle therapy counseling; (6) cardiovascular risk assessment; (7) antihypertensive drug therapy; and (8) adherence to therapy. In addition, the resource assesses the attitudes and practices of healthcare professionals for task sharing/shifting, use of care algorithms, and use of registries with performance reporting functions. The resource is designed to help support the Global Hearts Alliance to provide standardized and enhanced hypertension control globally.

A novel quantitative microarray antibody capture assay identifies an extremely high hepatitis delta virus prevalence among hepatitis B virus-infected mongolians.

Hepatitis delta virus (HDV) causes the most severe form of human viral hepatitis. HDV requires a hepatitis B virus (HBV) coinfection to provide HDV with HBV surface antigen envelope proteins. The net effect of HDV is to make the underlying HBV disease worse, including higher rates of hepatocellular carcinoma. Accurate assessments of current HDV prevalence have been hampered by the lack of readily available and reliable quantitative assays, combined with the absence of a Food and Drug Administration-approved therapy. We sought to develop a convenient assay for accurately screening populations and to use this assay to determine HDV prevalence in a population with abnormally high rates of hepatocellular carcinoma. We developed a high-throughput quantitative microarray antibody capture assay for anti-HDV immunoglobulin G wherein recombinant HDV delta antigen is printed by microarray on slides coated with a noncontinuous, nanostructured plasmonic gold film, enabling quantitative fluorescent detection of anti-HDV antibody in small aliquots of patient serum. This assay was then used to screen all HBV-infected patients identified in a large randomly selected cohort designed to represent the Mongolian population. We identified two quantitative thresholds of captured antibody that were 100% predictive of the sample either being positive on standard western blot or harboring HDV RNA detectable by real-time quantitative PCR. Subsequent screening of the HBV+ cohort revealed that a remarkable 57% were RNA+ and an additional 4% were positive on western blot alone. CONCLUSION: The quantitative microarray antibody capture assay's unique performance characteristics make it ideal for population screening; its application to the Mongolian HBV surface antigen-positive population reveals an apparent ∼60% prevalence of HDV coinfection among these HBV-infected Mongolian subjects, which may help explain the extraordinarily high rate of hepatocellular carcinoma in Mongolia. (Hepatology 2017;66:1739-1749).

Effects of subanesthetic dose of nitrous oxide on cerebral blood flow and metabolism: a multimodal magnetic resonance imaging study in healthy volunteers.

BACKGROUND: Nitrous oxide, in a concentration of 50% or more, is a known cerebral vasodilator. This study investigated whether a lower dose (30%) of nitrous oxide would also increase cerebral blood flow. In addition, the authors wished to study whether the increase in cerebral blood flow was accompanied by an increase in cerebral metabolism. METHODS: Multimodal Magnetic Resonance Imaging at 3T was performed, and data were obtained in 17 healthy volunteers during three inhalation conditions: medical air, oxygen-enriched medical air (40% oxygen), and 30% nitrous oxide with oxygen-enriched medical air (40% oxygen). Arterial spin labeling was used to derive the primary tissue specific hemodynamic outcomes: cerebral blood flow, arterial blood volume and arterial transit times. Magnetic Resonance Susceptometry and proton Magnetic Resonance Spectroscopy were used for secondary metabolic outcomes: venous oxygenation, oxygen extraction fraction, cerebral metabolic oxygen rate and prefrontal metabolites. RESULTS: Nitrous oxide in 40% oxygen, but not 40% oxygen alone, significantly increased gray matter cerebral blood flow (22%; P < 0.05) and arterial blood volume (41%; P < 0.05). Venous oxygenation increased in both oxygen and nitrous oxide conditions. Compared with medical air inhalation, nitrous oxide condition caused a significantly larger decrease in oxygen extraction fraction than 40% oxygen alone (mean [SD] 11.3 [5.6]% vs. 8.3 [5.9]% P < 0.05), while global cerebral metabolic rate and prefrontal metabolites remained unchanged. CONCLUSIONS: This study demonstrates that 30% nitrous oxide in oxygen-enriched air (40% oxygen) significantly increases cerebral perfusion, and reduces oxygen extraction fraction, reflecting a strong arterial vasodilatory effect without associated increases in metabolism.