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Dongxing Zhao,1,2 Asghar Abbasi,1 Richard Casaburi,1 Alessandra Adami,3 Nicholas B Tiller,1 Wei Yuan,1,4 Christopher Yee,5 Nicholas G Jendzjowsky,1 David M MacDonald,6,7 Ken M Kunisaki,6,7 William W Stringer,1 Janos Porszasz,1 Barry J Make,8 Russell P Bowler,8 Harry B Rossiter1 On behalf of the COPDGene Investigators1Rehabilitation Clinical Trials Center, Division of Respiratory and Critical Care Physiology and Medicine, The Lundquist Institute for Biomedical Innovation at Harbor-UCLA Medical Center, Torrance, CA, USA; 2State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, 510120, People’s Republic of China; 3Department of Kinesiology, University of Rhode Island, Kingston, RI, USA; 4Respiratory Medicine Department, Beijing Friendship Hospital Affiliated of Capital Medical University, Beijing, 100050, People’s Republic of China; 5MemorialCare Long Beach Medical Center, Long Beach, CA, USA; 6Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Minnesota, Minneapolis, MN, USA; 7Minneapolis VA Health Care System, Minneapolis, MN, USA; 8National Jewish Health, Denver, CO, USACorrespondence: Harry B Rossiter Email hrossiter@ucla.eduBackground: Slow heart rate recovery (HRR) after exercise is associated with autonomic dysfunction and increased mortality. What HRR criterion at 1-minute after a 6-minute walk test (6MWT) best defines pulmonary impairment?.Study Design and Methods: A total of 5008 phase 2 COPDGene (NCT00608764) participants with smoking history were included. A total of 2127 had COPD and, of these, 385 were followed-up 5-years later. Lung surgery, transplant, bronchiectasis, atrial fibrillation, heart failure and pacemakers were exclusionary. HR was measured from pulse oximetry at end-walk and after 1-min seated recovery. A receiver operator characteristic (ROC) identified optimal HRR cut-off. Generalized linear regression determined HRR association with spirometry, chest CT, symptoms and exacerbations.Results: HRR after 6MWT (bt/min) was categorized in quintiles: ≤ 5 (23.0% of participants), 6– 10 (20.7%), 11– 15 (18.9%), 16– 22 (18.5%) and ≥ 23 (18.9%). Compared to HRR≤ 5, HRR≥ 11 was associated with (p< 0.001): lower pre-walk HR and 1-min post HR; greater end-walk HR; greater 6MWD; greater FEV1%pred; lower airway wall area and wall thickness. HRR was positively associated with FEV1%pred and negatively associated with airway wall thickness. An optimal HRR ≤ 10 bt/min yielded an area under the ROC curve of 0.62 (95% CI 0.58– 0.66) for identifying FEV1< 30%pred. HRR≥ 11 bt/min was the lowest HRR associated with consistently less impairment in 6MWT, spirometry and CT variables. In COPD, HRR≤ 10 bt/min was associated with (p< 0.001): ≥ 2 exacerbations in the previous year (OR=1.76[1.33– 2.34]); CAT≥ 10 (OR=1.42[1.18– 1.71]); mMRC≥ 2 (OR=1.42[1.19– 1.69]); GOLD 4 (OR=1.98[1.44– 2.73]) and GOLD D (OR=1.51[1.18– 1.95]). HRR≤ 10 bt/min was predicted COPD exacerbations at 5-year follow-up (RR=1.83[1.07– 3.12], P=0.027).Conclusion: HRR≤ 10 bt/min after 6MWT in COPD is associated with more severe expiratory flow limitation, airway wall thickening, worse dyspnoea and quality of life, and future exacerbations, suggesting that an abnormal HRR≤ 10 bt/min after a 6MWT may be used in a comprehensive assessment in COPD for risk of severity, symptoms and future exacerbations.Keywords: autonomic dysfunction, chest computed tomography, COPD exacerbation, exercise, spirometry

Although management of cancer pain is relatively easy to accomplish in most cases, patients in many developing and developed countries are deprived access to appropriate analgesic medications due to governmental, bureaucratic, and physician barriers, such as restrictions on quantity, type, and storage of drugs. Many of these governmental and bureaucratic barriers are discussed as arc steps being taken to overcome them in the different countries. [ABSTRACT FROM AUTHOR]

Rationale: Physical activity, lung function, and grip strength are associated with exacerbations, hospitalizations, and mortality in people with chronic obstructive pulmonary disease (COPD). We tested whether baseline inflammatory biomarkers were associated with longitudinal outcomes of these physiologic measurements., Methods: The COPD Activity: Serotonin Transporter, Cytokines, and Depression (CASCADE) study was a prospective observational study of individuals with COPD. A total of 14 inflammatory biomarkers were measured at baseline. Participants were followed for 2 years. We analyzed associations between baseline biomarkers and forced expiratory volume in 1 second (FEV 1 ), physical activity, and grip strength. We used a hierarchical hypothesis testing procedure to reduce type I error. We used Pearson correlations to test associations between baseline biomarkers and longitudinal changes in the outcomes of interest. We used Fisher's linear discriminant analysis to test if linear combinations of baseline biomarkers predict rapid FEV 1 decline. Finally, we used linear mixed modeling to test associations between baseline biomarkers and outcomes of interest at baseline, year 1, and year 2; models were adjusted for age, smoking status, baseline biomarkers, and FEV 1 ., Results: A total of 302 participants (age 67.5 ± 8.5 years, 19.5% female, 28.5% currently smoking) were included. Baseline biomarkers were not associated with longitudinal changes in grip strength, physical activity, or rapid FEV 1 decline. Higher interleukin-6 and C-reactive protein were associated with lower physical activity at baseline and these relationships persisted at year 1 and year 2., Conclusion: Baseline inflammatory biomarkers did not predict changes in lung function or physical activity, but higher inflammatory biomarkers were associated with persistently low levels of physical activity., (JCOPDF © 2024.)

Rationale: Pulmonary hypertension (PH) in COPD confers increased risk of exacerbations (ECOPD). Electrocardiogram (ECG) indicators of PH are prognostic both in PH and COPD. In the Beta-Blockers for the Prevention of Acute Exacerbations of COPD (BLOCK-COPD) trial, metoprolol increased risk of severe ECOPD through unclear mechanisms., Objective: We evaluated whether an ECG indicator of PH, P-pulmonale, would be associated with ECOPD and whether participants with P-pulmonale randomized to metoprolol were at higher risk of ECOPD and worsened respiratory symptoms given the potential detrimental effects of beta-blockers in PH., Methods: ECGs of 501 participants were analyzed for P-pulmonale (P wave enlargement in lead II). Cox proportional hazards models evaluated for associations between P-pulmonale and time to ECOPD (all and severe) for all participants and by treatment assignment (metoprolol vs. placebo). Linear mixed-effects models evaluated the association between treatment assignment and P-pulmonale on change in symptom scores (measured by CAT and SOBQ)., Results: We identified no association between P-pulmonale and risk of any ECOPD or severe ECOPD. However, in individuals with P-pulmonale, metoprolol was associated with increased risk for ECOPD (aHR 2.92, 95% CI: 1.45-5.85). There was no association between metoprolol and ECOPD in individuals without P-pulmonale (aHR 1.01, 95% CI: 0.77-1.31). Individuals with P-pulmonale assigned to metoprolol experienced worsening symptoms (mean increase of 3.95, 95% CI: 1.32-6.58) whereas those assigned to placebo experienced a mean improvement in CAT score of -2.45 (95% CI: -0.30- -4.61)., Conclusions: In individuals with P-pulmonale, metoprolol was associated with increased exacerbation risk and worsened symptoms. These findings may explain the findings observed in BLOCK-COPD., (© 2023. The Author(s).)

Rationale: The autonomic nervous system extensively innervates the lungs, but its role in chronic obstructive pulmonary disease (COPD) outcomes has not been well studied. Objective: We assessed relationships between cardiovascular autonomic nervous system measures (heart rate variability [HRV] and orthostatic hypotension [OH]) and incident COPD hospitalization in the multicenter ARIC (Atherosclerosis Risk In Communities) study. Methods: We used Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals between baseline (1987-1989) autonomic function measures (HRV measures from 2-minute electrocardiograms and OH variables) and incident COPD hospitalizations through 2019. Adjusted analyses included demographic data, smoking status, lung function, comorbidities, and physical activity. We also performed analyses stratified by baseline airflow obstruction. Results: Of the 11,625 participants, (mean age, 53.8 yr), 56.5% were female and 26.3% identified as Black. Baseline mean percentage predicted forced expiratory volume in 1 second was 94 ± 17% (standard deviation), and 2,599 participants (22.4%) had airflow obstruction. During a median follow-up time of 26.9 years, there were 2,406 incident COPD hospitalizations. Higher HRV (i.e., better autonomic function) was associated with a lower risk of incident COPD hospitalization. Markers of worse autonomic function (OH and greater orthostatic changes in systolic and diastolic blood pressure) were associated with a higher risk of incident COPD hospitalization (hazard ratio for the presence of OH, 1.5; 95% confidence interval, 1.25-1.92). In stratified analyses, results were more robust in participants without airflow obstruction at baseline. Conclusions: In this large multicenter prospective community cohort, better cardiovascular autonomic function at baseline was associated with a lower risk of subsequent hospitalization for COPD, particularly among participants without evidence of lung disease at baseline.

Background: Observational studies have shown an association between higher bilirubin levels and improved respiratory health outcomes. Targeting higher bilirubin levels has been proposed as a novel therapeutic strategy in COPD. However, bilirubin levels are influenced by multiple intrinsic and extrinsic factors, and these observational studies are prone to confounding. Genetic analyses are one approach to overcoming residual confounding in observational studies., Objectives: To test associations between a genetic determinant of bilirubin levels and respiratory health outcomes., Methods: COPDGene participants underwent genotyping at the baseline visit. We confirmed established associations between homozygosity for rs6742078 and higher bilirubin, and between higher bilirubin and decreased risk of acute respiratory events within this cohort. For our primary analysis, we used negative binomial regression to test associations between homozygosity for rs6742078 and rate of acute respiratory events., Results: 8,727 participants (n = 6,228 non-Hispanic white and 2,499 African American) were included. Higher bilirubin was associated with decreased rate of acute respiratory events [incidence rate ratio (IRR) 0.85, 95% CI 0.75 to 0.96 per SD increase in bilirubin intensity]. We did not find significant associations between homozygosity for rs6742078 and acute respiratory events (IRR 0.94, 95% CI 0.70 to 1.25 for non-Hispanic white and 1.09, 95% CI 0.91 to 1.31 for African American participants)., Conclusions: A genetic determinant of higher bilirubin levels was not associated with better respiratory health outcomes. These results do not support targeting higher bilirubin levels as a therapeutic strategy in COPD., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Chronic obstructive pulmonary disease (COPD) is among the leading causes of death worldwide and HIV is an independent risk factor for the development of COPD. However, the etiology of this increased risk and means to identify persons with HIV (PWH) at highest risk for COPD have remained elusive. Biomarkers may reveal etiologic pathways and allow better COPD risk stratification. We performed a matched case:control study of PWH in the Strategic Timing of Antiretoviral Treatment (START) pulmonary substudy. Cases had rapid lung function decline (> 40 mL/year FEV 1 decline) and controls had stable lung function (+ 20 to - 20 mL/year). The analysis was performed in two distinct groups: (1) those who were virally suppressed for at least 6 months and (2) those with untreated HIV (from the START deferred treatment arm). We used linear mixed effects models to test the relationship between case:control status and blood concentrations of pneumoproteins (surfactant protein-D and club cell secretory protein), and biomarkers of inflammation (IL-6 and hsCRP) and coagulation (d-dimer and fibrinogen); concentrations were measured within ± 6 months of first included spirometry. We included an interaction with treatment group (untreated HIV vs viral suppression) to test if associations varied by treatment group. This analysis included 77 matched case:control pairs in the virally suppressed batch, and 42 matched case:control pairs in the untreated HIV batch (n = 238 total) who were followed for a median of 3 years. Median (IQR) CD4 + count was lowest in the controls with untreated HIV at 674 (580, 838). We found no significant associations between case:control status and pneumoprotein or biomarker concentrations in either virally suppressed or untreated PWH. In this cohort of relatively young, recently diagnosed PWH, concentrations of pneumoproteins and biomarkers of inflammation and coagulation were not associated with subsequent rapid lung function decline.Trial registration: NCT00867048 and NCT01797367., (© 2023. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Rationale: The BLOCK COPD (β-Blockers for the Prevention of Acute Exacerbations of Chronic Obstructive Pulmonary Disease) study found that metoprolol was associated with a higher risk of severe exacerbation. Objectives: To determine the mechanism underlying these results, we compared changes in lung function over the course of the study between treatment groups and evaluated whether baseline bronchodilator response or early reduction in forced expiratory volume in 1 second (FEV 1 ) or forced vital capacity (FVC) was associated with exacerbation risk. Methods: We compared changes in lung function (FEV 1 and FVC) over the treatment period between treatment groups using linear mixed-effect models. Cox proportional hazards models were used to evaluate the association between baseline bronchodilator responsiveness (FEV 1 , FVC, and combined FEV 1 and FVC), early post-randomization (14 d) change in lung function, and the interaction between treatment assignment and these measures with risk of any or severe or very severe exacerbations. Negative binomial models were used to evaluate the relationship between bronchodilator responsiveness, the interaction between bronchodilator responsiveness and treatment assignment, and exacerbation rate. Results: Over the 336-day treatment period, individuals in the metoprolol group had a significantly greater decrease in logarithmic FEV 1 from baseline to visit on Day 28 than individuals in the placebo group. Individuals in the metoprolol group had a significantly greater decrease in FVC from baseline to visits on Days 14 and 28, and also a significantly greater decrease in logarithmic FVC from baseline to visits on Days 42 and 112 than individuals in the placebo group. There were no associations between early lung function reduction or interactions between lung function reduction and treatment assignment and time to any or severe or very severe exacerbations. There were no interactions between treatment arm and baseline bronchodilator responsiveness measures on risk or rate of exacerbations. However, those with baseline FVC bronchodilator responsiveness had a higher rate of severe or very severe exacerbations (adjusted rate ratio, 1.62; 95% confidence interval, 1.04-2.48). Conclusions: Metoprolol was associated with reduced lung function during the early part of the treatment period, but these effects were modest and did not persist. Early lung function reduction and baseline bronchodilator responsiveness did not interact with the treatment arm to predict exacerbations; however, baseline FVC bronchodilator responsiveness was associated with a 60% higher rate of severe or very severe exacerbations. Clinical trial registered with www.clinicaltrials.gov (NCT02587351).

Introduction: Autonomic dysfunction is common in chronic obstructive pulmonary disease (COPD), and worse autonomic function may be a marker of risk for acute exacerbations of COPD (AECOPD). Heart rate variability (HRV) is a measure of autonomic function. Our objective was to test whether lower (worse) HRV is a risk factor for AECOPD., Methods: We measured standard deviation of normal RR intervals (SDNN) and root mean square of successive RR interval differences (RMSSD) on 10-second electrocardiograms (ECGs) performed at screening and day 42 in participants in the Beta Blockers for the Prevention of Acute Exacerbations of COPD trial ( BLOCK-COPD), a placebo-controlled trial of metoprolol for prevention of AECOPD. We used Cox-proportional hazards models to test if these HRV measures were associated with risk of any AECOPD, and separately, hospitalized AECOPD. We tested associations using baseline HRV measures and incorporating HRV measures from day 42 as a time-varying covariate. We also tested for interactions with metoprolol assignment., Results: Of 532 trial participants, 529 (forced expiratory volume in 1 second [FEV 1 ]41 ± 16.3 % predicted) were included in this analysis. We did not find a significant association between HRV measures and risk of AECOPD when all participants were analyzed together. There was a significant interaction between RMSSD and assignment to metoprolol on time to first hospitalized AECOPD; in the placebo group greater RMSSD was associated with a lower risk of hospitalized AECOPD (adjusted hazard ratio0.71, 95% confidence interval: 0.52 to 0.96, per 10 ms increase) but there was no association in the metoprolol group., Conclusions: Autonomic dysfunction as measured by HRV may be a risk factor for AECOPD. Future studies should analyze longer HRV recordings and their performance in broader samples of people with COPD, including those on beta-blockers., (JCOPDF © 2022.)

Background: Lower heart rate (HR) increases during exercise and slower HR recovery (HRR) after exercise are markers of worse autonomic function that may be associated with risk of acute respiratory events (ARE)., Methods: Data from 6-min walk testing (6MWT) in COPDGene were used to calculate the chronotropic index (CI) [(HR immediately post 6MWT - resting HR)/((220 - age) - resting HR)] and HRR at 1 min after 6MWT completion. We used zero-inflated negative binomial regression to test associations of CI and HRR with rates of any ARE (requiring steroids and/or antibiotics) and severe ARE (requiring emergency department visit or hospitalization), among all participants and in spirometry subgroups (normal, chronic obstructive pulmonary disease [COPD], and preserved ratio with impaired spirometry)., Results: Among 4,484 participants, mean follow-up time was 4.1 years, and 1,966 had COPD. Among all participants, CI-6MWT was not associated with rate of any ARE [adjusted incidence rate ratio (aIRR) 0.98 (0.95-1.01)], but higher CI-6MWT was associated with lower rate of severe ARE [0.95 (0.92-0.99)]. Higher HRR was associated with a lower rate of both any ARE [0.97 (0.95-0.99)] and severe ARE [0.95 (0.92-0.98)]. Results were similar in the COPD spirometry subgroup., Conclusion: Heart rate measures derived from 6MWT tests may have utility in predicting risk of acute respiratory events and COPD exacerbations., (Published by Elsevier Ltd.)

HIV is an independent risk factor for lung disease, including chronic obstructive pulmonary disease (COPD) and emphysema. Angiotensin receptor blockers may be beneficial in COPD and emphysema through pathways that have been implicated in HIV-related lung disease. We performed a randomized comparison of the effects of losartan versus placebo on the plasma concentrations of the pneumoproteins, surfactant protein D (SPD) and club cell secretory protein (CCSP), in people living with HIV (PLWH). A total of 108 PLWH were included (52 assigned to losartan and 56 assigned to placebo). We found no difference in the change from baseline in log 2 concentrations of CCSP or SPD over 1 year of follow-up. For SPD, we found a strong interaction by CD4+ counts, where those with CD4+ counts >350 cells/mm 3 treated with losartan had more reduction (improvement) in SPD concentration than those treated with placebo ( p value for interaction <.001). In conclusion, we did not find a beneficial effect of losartan on pneumoprotein concentrations in PLWH, but PLWH with higher CD4+ counts may have improvement in SPD when treated with losartan.

Rationale: The chronotropic index quantifies the proportion of the expected heart rate increase that is attained during exercise. The relationship between the chronotropic index and acute exacerbations of chronic obstructive pulmonary disease (AECOPDs) has not been evaluated. Objectives: To determine whether a higher chronotropic index during a 6-minute walk (CI-6MW) is associated with lower risk of AECOPD and whether the CI-6MW is a marker of susceptibility to adverse effects of metoprolol in chronic obstructive pulmonary disease (COPD). Methods: We analyzed data from the BLOCK COPD (Beta-Blockers for the Prevention of AECOPDs) trial. We used Cox proportional hazards models to investigate the relationship between the CI-6MW and the time to AECOPDs. We also tested for interactions between study group assignment (metoprolol vs. placebo) and the CI-6MW on the time to AECOPDs. Results: Four hundred seventy-seven participants with exacerbation-prone COPD (mean forced expiratory volume in 1 second, 41% of predicted) were included in this analysis. A higher CI-6MW was independently associated with a decreased risk of AECOPDs of any severity (adjusted hazard ratio per 0.1 increase in CI-6MW of 0.88; 95% confidence interval, 0.80-0.96) but was not independently associated with AECOPDs requiring hospitalization (adjusted hazard ratio, 0.94; 95% confidence interval, 0.81-1.05). There was a significant interaction by treatment assignment, and in a stratified analysis, the protective effects of a higher CI-6MW on AECOPDs were negated by metoprolol use. Conclusions: A higher CI-6MW is associated with a decreased risk of AECOPDs and may be an indicator of susceptibility to the adverse effects of metoprolol.

Introduction: Universal Health Coverage is not only about access to health services but also about access to high-quality care, since poor experiences may deter patients from accessing care. Evidence shows that quality of care drives health outcomes, yet little is known about non-clinical dimensions of care, and patients' experience thereof relative to satisfaction with visits. This paper investigates the role of non-clinical dimensions of care in patient satisfaction., Methods: Our study describes the interactions of informed and non-informed patients with primary healthcare workers at 39 public healthcare facilities in two metropolitan centres in two South African provinces. Our analysis included 1357 interactions using standardised patients (for informed patients) and patients' exit interviews (for non-informed patients). The data were combined for three types of visits: contraception, hypertension and tuberculosis. We describe how satisfaction with care was related to patients' experiences of non-clinical dimensions., Results: We show that when real patients (RPs) reported being satisfied (vs dissatisfied) with a visit, it was associated with a 30% increase in the probability that a patient is greeted at the facilities. Likewise, when the RPs reported being satisfied (vs dissatisfied) with the visit, it was correlated with a 15% increase in the prospect that patients are pleased with healthcare workers' explanations of health conditions., Conclusion: Informed patients are better equipped to assess health-systems responsiveness in healthcare provision. Insights into responsiveness could guide broader efforts aimed at targeted education and empowerment of primary healthcare users to strengthen health systems and shape expectations for appropriate care and conduct., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Bilirubin is a potent antioxidant and higher serum bilirubin levels have been associated with improved COPD outcomes. We performed a systematic review to evaluate the association between serum bilirubin levels and lung function (FEV 1 ), prevalence/incidence of COPD, acute exacerbations of COPD, respiratory health status, and mortality., Methods: MEDLINE® and Embase were searched using Ovid® (search updated October 1st, 2019). We included studies that measured serum bilirubin levels and outcomes of interest in adults with or without underlying lung disease. We excluded studies of those with liver disease or drug-induced elevations in bilirubin. We used the Newcastle-Ottawa scale to assess individual study risk of bias (ROB) and the US Agency for Healthcare Research and Quality-Evidence Based Practice tool to assess overall strength of evidence (SOE). Two authors independently determined eligibility, performed data abstraction, assessed ROB, and determined SOE., Results: Thirteen studies (5 low risk of bias, 3 moderate and 5 high risk) were included. We found low strength of evidence for the association between higher bilirubin levels and lower risk of acute exacerbations of COPD (2 studies), mortality (3 studies), COPD diagnosis (4 studies), and lung function (FEV 1 ) (8 studies). We found insufficient evidence on the relationship between serum bilirubin and respiratory health status/exercise capacity (1 study) and airflow obstruction (FEV 1 /FVC ratio) (4 studies)., Conclusion: Higher bilirubin levels may be associated with lower mortality and improved COPD outcomes. Randomized trials are needed to evaluate the effect of medications that raise serum bilirubin on COPD outcomes. PROSPERO registration: CRD42019145747.

Purpose: Meaningful participation in research for both faculty and residents is generally viewed to be an essential component of residency training. To better understand best practices in residency research, the authors conducted a survey among Internal Medicine (IM) Residency Programs with experience in research., Methods: Phone interviews were conducted with a convenience sample of Residency Program Directors (PDs). Survey responses were analyzed across the following domains: size and makeup of the residency and research programs, resources for research, role of the PD/research director (RD), profile of trainees doing research, curriculum description, scope of research, role of mentors, career choices and determinants of success., Results: Fifteen programs were included in the study. Across these programs, approximately two-thirds of residents were involved in research during their training . Eighty percent of the programs required an application for residents to engage in research. Ninety-two percent of the programs had a RD but only 58% had a formal research curriculum. Clinical research projects were the most common types of research. On average, two-thirds of residents involved in research submitted abstracts to regional and/or national meetings. The factor most frequently associated with resident research success was an effective faculty research mentor., Conclusions: Research success during residency is multifactorial. The authors propose that having a robust structure for research that is led by a residency RD, and the presence of effective mentors and strong administrative support are critical for success., (Published by Elsevier Inc.)

Health holds an important position in maintaining economic development since it is both a prerequisite for and an outcome of economic development. This means that health contributes greatly to the attainment of sustainable development and health outcomes. The importance of health is demonstrated in the Millennium Development Goals (MDGs) where three of the eight goals are aimed at improving health outcomes. Despite progress made by other middle-income countries in achieving health-related MDGs, South Africa is still worse off in respect of health outcomes and experiences a challenge in attaining positive outcomes for these goals. This study's main focus was to identify the association between public health expenditure and health outcomes in South Africa's nine provinces from 2002 to 2016. The study implemented fixed effects and a random effects panel data estimation technique to control for time effects and individual provincial heterogeneity. This was followed by employing the Hausman specification test to identify the fixed effects model as the appropriate estimator for the study. The study also employed the seemingly unrelated regression (SUR) model and the least squares dummy variable (LSDV) model to examine the impact of public health expenditure on each province separately. The findings elucidated that the relationship between public health expenditure and health outcomes in South Africa varied across provinces depending on provincial management and infrastructure availability.

Objective: The aim of this study was to analyse the association of baseline biomarker data with cross-sectional lung function and subsequent decline in lung function in HIV-positive persons., Design: Lung function was modelled in all START pulmonary substudy participants who had baseline biomarker data and good-quality spirometry. In longitudinal analyses, we restricted to those participants with at least one good-quality follow-up spirometry test., Methods: We performed linear regression of baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC and their longitudinal slopes on log2-transformed baseline biomarkers with adjustment for age, sex, race, region, smoking status, baseline CD4+ T-cell counts and baseline HIV-RNA. Biomarkers included D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-27, serum amyloid A, soluble intercellular adhesion molecule (sICAM)-1, soluble vascular cell adhesion molecule (sVCAM)-1, albumin and total bilirubin., Results: Among 903 included participants, baseline median age was 36 years, CD4+ cell count was 647 cells/μl, and 28.5% were current smokers. In adjusted analyses, elevated markers of systemic inflammation (hsCRP, IL-6 and serum amyloid A) were associated with lower baseline FEV1 and FVC. Elevated D-dimer and IL-6 were associated with worse airflow obstruction (lower FEV1/FVC). Despite these cross-sectional associations at baseline, no associations were found between baseline biomarkers and subsequent longitudinal lung function decline over a median follow-up time of 3.9 years (3293 spirometry-years of follow-up)., Conclusion: Commonly available biomarkers, in particular markers of systemic inflammation, are associated with worse cross-sectional lung function, but do not associate with subsequent lung function decline among HIV-positive persons with early HIV infection and baseline CD4 T-cell counts more than 500 cells/μl.

Background: Chronic obstructive pulmonary disease (COPD) is a leading cause of death and disability globally. Both cigarette smoking and HIV have been identified as independent risk factors for COPD. We used data from the strategic timing of antiretroviral treatment (START) Pulmonary Substudy to quantify the impact of smoking on rate of lung function decline in HIV., Methods: We included START Pulmonary Substudy participants who contributed at least 2 good quality spirometry measures during the study. Slope of forced expiratory volume in 1 second (FEV1) was estimated using a repeated-measures model adjusted for the treatment group (immediate vs deferred treatment arm of START), age, sex, race, baseline COPD, and region., Results: Of 1026 START Pulmonary Substudy participants, 915 (89%) were included in this analysis. Median follow-up time was 3.9 years. Smokers and nonsmokers were similar in baseline age (median 36 years), but smokers were more likely to be white, male, and from Europe/Israel/Australia. Smokers had faster average FEV1 decline compared with nonsmokers [-38.3 mL/yr vs -25.1 mL/yr; difference of -13.2 mL/yr (95% confidence interval: -23.6 to -2.7); P = 0.013], were more likely to meet criteria for rapid FEV1 decline [7.2%-11.7% more likely (P = 0.09-P = 0.002), depending on the definition of rapid decline], and had borderline, but not statistically significant, higher incident COPD during follow-up (9.7% vs 5.8%, P = 0.06)., Conclusions: Compared to nonsmokers, HIV-positive smokers experience faster decline in lung function. These results underscore the need for a better understanding of how to best support smoking cessation among HIV-positive populations.

Background: The practice patterns for adjuvant therapies for stage I seminoma are rapidly evolving, and surveillance is currently preferred. How these recommendations have affected contemporary practice in an equal-access US population is unknown., Materials and Methods: A total of 436 men diagnosed with clinical stage IA-IB seminoma from 2001 to 2011 were identified in the Automated Central Tumor Registry (ACTUR). The ACTUR is the cancer registry system for the Department of Defense. Logistic regression models analyzed the association between patient characteristics and adjuvant therapy. Overall and recurrence-free survival were determined from Kaplan-Meier analysis., Results: The use of adjuvant radiotherapy in this population decreased significantly from 2001 to 2011. In 2001, 83.9% of patients received radiotherapy compared with only 24.0% in 2011. During that period, a concomitant increase occurred in the use of chemotherapy from 0% to 38.0%. A later year of diagnosis was significantly associated with a greater rate of receiving chemotherapy relative to radiotherapy (P < .001 for 2006-2011 vs. 2001-2005; relative rate ratio, 19.3; 95% confidence interval [CI], 8.04-46.13). A later year of diagnosis was not significantly associated with the receipt of surveillance (P = .412 for 2006-2011 vs. 2001-2005; odds ratio, 0.83; 95% CI, 0.54-1.29). Black race or age was not significantly associated with adjuvant therapy. With a median follow-up period of 4.7 years, the 5-year overall and recurrence-free survival rates were 98.0% and 77.0%, respectively., Conclusion: The use of adjuvant radiotherapy has been replaced by chemotherapy for clinical stage I testicular seminoma in an equal-access system. The lack of an increase in active surveillance in our cohort might represent overtreatment of the population., (Published by Elsevier Inc.)

Background: Hepatitis C treatment uptake in Australia is low. To increase access to hepatitis C virus treatment for people who inject drugs, we developed a community-based, nurse-led service that linked a viral hepatitis service in a tertiary hospital to primary care clinics, and resulted in hepatitis C treatment provision in the community., Methods: A retrospective cohort study of patients referred to the community hepatitis service was undertaken to determine the cascade of care. Logistic regression analyses were used to identify predictors of hepatitis C treatment uptake., Results: Four hundred and sixty-two patients were referred to the community hepatitis service; 344 attended. Among the 279 attendees with confirmed chronic hepatitis C, 257 (99%) reported ever injecting drugs, and 124 (48%) injected in the last month. Of 201 (72%) patients who had their fibrosis staged, 63 (31%) had F3-F4 fibrosis. Fifty-five patients commenced hepatitis C treatment; 26 (47%) were current injectors and 25 (45%) had F3-F4 fibrosis. Nineteen of the 27 (70%) genotype 1 patients and 14 of the 26 (54%) genotype 3 patients eligible for assessment achieved a sustained virologic response. Advanced fibrosis was a significant predictor of treatment uptake in adjusted analysis (AOR 2.56, CI 1.30-5.00, p = 0.006)., Conclusions: Our community hepatitis service produced relatively high rates of fibrosis assessment, hepatitis C treatment uptake and cure, among people who inject drugs. These findings highlight the potential benefits of providing community-based hepatitis C care to people who inject drugs in Australia-benefits that should be realised as direct-acting antiviral agents become available.

Understanding the structural organization of the prefrontal cortex (PFC) is an important step toward determining its functional organization. Here we investigated the organization of PFC using different neuronal tracers. We injected retrograde (Fluoro-Gold, 100 nl) and anterograde [Biotinylated dextran amine (BDA) or Fluoro-Ruby, 100 nl] tracers into sites within PFC subdivisions (prelimbic, ventral orbital, ventrolateral orbital, dorsolateral orbital) along a coronal axis within PFC. At each injection site one injection was made of the anterograde tracer and one injection was made of the retrograde tracer. The projection locations of retrogradely labeled neurons and anterogradely labeled axon terminals were then analyzed in the temporal cortex: area Te, entorhinal and perirhinal cortex. We found evidence for an ordering of both the anterograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) and retrograde (anterior-posterior, dorsal-ventral, and medial-lateral axes: p < 0.001) connections of PFC. We observed that anterograde and retrograde labeling in ipsilateral temporal cortex (i.e., PFC inputs and outputs) often occurred reciprocally (i.e., the same brain region, such as area 35d in perirhinal cortex, contained anterograde and retrograde labeling). However, often the same specific columnar temporal cortex regions contained only either labeling of retrograde or anterograde tracer, indicating that PFC inputs and outputs are frequently non-matched.

Peri-urban floodplains are an important interface between developed land and the aquatic environment and may act as a source or sink for contaminants moving from urban areas towards surface water courses. With increasing pressure from urban development the functioning of floodplains is coming under greater scrutiny. A number of peri-urban sites have been found to be populated with legacy landfills which could potentially cause pollution of adjacent river bodies. Here, a peri-urban floodplain adjoining the city of Oxford, UK, with the River Thames has been investigated over a period of three years through repeated sampling of groundwaters from existing and specially constructed piezometers. A nearby landfill has been found to have imprinted a strong signal on the groundwater with particularly high concentrations of ammonium and generally low concentrations of nitrate and dissolved oxygen. An intensive study of nitrogen dynamics through the use of N-species chemistry, nitrogen isotopes and dissolved nitrous oxide reveals that there is little or no denitrification in the majority of the main landfill plume, and neither is the ammonium significantly retarded by sorption to the aquifer sediments. A simple model has determined the flux of total nitrogen and ammonium from the landfill, through the floodplain and into the river. Over an 8 km reach of the river, which has a number of other legacy landfills, it is estimated that 27.5 tonnes of ammonium may be delivered to the river annually. Although this is a relatively small contribution to the total river nitrogen, it may represent up to 15% of the ammonium loading at the study site and over the length of the reach could increase in-stream concentrations by nearly 40%. Catchment management plans that encompass floodplains in the peri-urban environment need to take into account the likely risk to groundwater and surface water quality that these environments pose., (Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.)

The response to an avian influenza outbreak, especially highly pathogenic avian influenza (HPAI), should focus on four basic principles: 1) protect humans first, 2) protect animals 3) contain the virus, and 4) ensure that the outbreak remains a single event, by preparing response teams to work together effectively through advance training. The Stamping Out Pandemic and Avian Influenza (STOP AI) project is a U.S. Agency for International Development-funded global activity. STOP AI has designed and conducted practical, experiential training exercises that engage participants in simulated experiences that enhance their confidence and ability to apply these principles during a real HPAI outbreak. This article describes three specific exercises: 1) wearing and removing personal protective equipment (PPE) in a controlled environment, 2) site zoning, and 3) a planning and resource mapping exercise staged in Poultopia--a fictional region in a developing country. The PPE activity emphasizes the physical challenges of working in full PPE and the importance of proper equipment removal. In the zoning exercise, response teams focus on the areas and the tasks required by setting up a clean area, transit corridor, infected/culling area, and nontransit areas at a farm, village, or other location. In Poultopia, participants must determine where surveillance should occur, decide where roadblocks should be placed during an outbreak, choose which birds to cull first and determine how to dispose of them safely, ascertain the types of personnel and equipment needed, and assess timing issues. The Poultopia scenarios are adapted to the conditions of the region where the training takes place, thus adding to their realism and utility. The practical techniques described here have been taught successfully through STOP AI in more than 30 countries in Europe, Asia, and Africa.

Objective: Ovarian cancer is one of the most deadly human cancers, resulting in over 15,000 deaths in the US each year. A reliable method that could predict disease outcome would improve care of patients with this disease. The main aim of this study is to identify novel prognostic biomarkers for advanced ovarian cancer., Methods: We hypothesized that microRNAs (miRNAs) may predict outcome and have examined the prognostic value of these small RNA molecules on disease outcome prediction. miRNAs are a newly identified family of non-coding RNA genes, and recent studies have shown that miRNAs are extensively involved in the tumor development process. We have profiled the expression of miRNAs in advanced ovarian cancer using a novel PCR-based platform and correlated miRNA expression profiles with disease outcome., Results: By performing miRNA expression profiling analysis of 55 advanced ovarian tumors, we have shown that three miR-200 miRNAs (miR-200a, miR-200b and miR-429) in the miR-200b-429 cluster are significantly associated with cancer recurrence and overall survival. Further target analysis indicates that these miR-200 miRNAs target multiple genes that are involved in cancer development. In addition, we have also shown that overexpression of this miR-200 cluster inhibits ovarian cancer cell migration., Conclusions: miR-200b-429 may be used as a prognostic marker for ovarian cancer outcome, and low-level expression of miR-200 miRNAs in this cluster predicts poor survival. In addition, our study suggests that miR-200 miRNAs could play an important regulatory role in ovarian cancer.

Purpose: To describe a more aggressive treatment technique allowing dose escalation to positive para-aortic lymph nodes (PALN) in patients with cervical cancer, by means of positron emission tomography (PET)/computed tomography (CT)-guided intensity-modulated radiation therapy (IMRT). Here, we describe methods for simulation and planning of these treatments and provide objectives for target coverage as well as normal tissue sparing to guide treatment plan evaluation., Methods and Materials: Patients underwent simulation on a PET/CT scanner. Treatment plans were generated to deliver 60.0 Gy to the PET-positive PALN and 50.0 Gy to the PALN and pelvic lymph node beds. Treatment plans were optimized to deliver at least 95% of the prescribed doses to at least 95% of each target volume. Dose-volume histograms were calculated for normal structures., Results: The plans of 10 patients were reviewed. Target coverage goals were satisfied in all plans. Analysis of dose-volume histograms indicated that treatment plans involved irradiation of approximately 50% of the bowel volume to at least 25.0 Gy, with less than 10% receiving at least 50.0 Gy and less than 1% receiving at least 60.0. With regard to kidney sparing, approximately 50% of the kidney volume received at least 16.0 Gy, less than 5% received at least 50.0 Gy, and less than 1% received at least 60.0 Gy., Conclusions: We have provided treatment simulation and planning methods as well as guidelines for the evaluation of target coverage and normal tissue sparing that should facilitate the more aggressive treatment of cervical cancer.

Purpose: This treatment planning study compared pseudo-step-wedge intensity modulation (PSWIM), intensity-modulated radiation therapy (IMRT), and conventional external irradiation, all combined with brachytherapy, for treatment of patients with cervical cancer., Methods and Materials: This was a prospective study of 10 patients treated with PSWIM delivering 50.4 Gy to the pelvic lymph nodes and 20 Gy to the cervical tumor. This treatment was compared with a conventional treatment plan with a four-field box to 45 Gy and to an IMRT plan delivering 45 Gy. In each case, brachytherapy was prescribed to a total Point A low-dose-rate equivalent dose of 85 Gy. Total doses to Points A, Point P, the bladder point, and the rectal point were calculated. Acute toxicity and treatment response were prospectively recorded., Results: The mean PSWIM total low-dose-rate equivalent dose to Points A and P (97.3 Gy and 65.1 Gy, respectively) was significantly higher, the mean rectal dose was the same, and the mean bladder dose was higher than with IMRT or four-field box. No acute toxicity of greater Grade 2, as defined by the than Radiation Therapy Oncology Group, was experienced. The positron emission tomography-based treatment response compared favorably with our institutional experience., Conclusions: Use of PSWIM and brachytherapy delivers significantly more dose to the tumor and lymph nodes than do competing techniques. Rectal doses are comparable. Maximum bladder point doses are higher. Toxicity and tumor response are acceptable.

Infection with hepatitis B virus (HBV) has been detected in human populations throughout the world, as well as in a number of ape species (Pan troglodytes, Gorilla gorilla, gibbons [Nomascus and Hylobates species] and Pongo pygmaeus). To investigate the distribution of naturally occurring HBV infection in these species and other African Old World monkey species (Cercopithecidae), we screened 137 plasma samples from mainly wild caught animals by polymerase chain reaction (PCR) using several of highly conserved primers from the HB surface (HBs) gene, and for HBs antigen (HBsAg) by ELISA. None of the 93 Cercopithecidae screened (6 species) showed PCR or serology evidence for HBV infection; in contrast 2 from 8 chimpanzees and 5 from 22 gibbons were PCR-positive with each set of primers. Complete genome sequences from each of the positive apes were obtained and compared with all previously published complete and surface gene sequences. This extended phylogenetic analysis indicated that HBV variants from orangutans were interspersed by with HBV variants from southerly distributed gibbon species (H. agilis and H. moloch) occupying overlapping or adjacent habitat ranges with orangutans; in contrast, HBV variants from gibbon species in mainland Asia were phylogenetically distinct. A geographical rather than (sub)species association of HBV would account for the distribution of HBV variants in different subspecies of chimpanzees in Africa, and explain the inlier position of the previously described lowland gorilla sequence in the chimpanzee clade. These new findings have a number of implication for understanding the origins and epidemiology of HBV infection in non-human primates.

Background: Mixed-valent diruthenium tetracarboxylate complexes were shown to have slight antineoplastic activity against P388 leukemia cell lines. However these complexes suffered from poor water-solubility, which may have detrimentally affected their activity., Materials and Methods: Mixed-valent diruthenium tetracarboxylates of the type [Ru2(O2CR)4(L)2] (PF6) with L = imidazole, 1-methylimidazole and H2O when R = CH3, L = ethanol when R = Fc (ferrocenyl) or Fc-CH=CH- and of the type M3[Ru2(O2CR)4(H2O)2]4H2O, M = Na+ when R = m-C6H4SO3- and M = K+ when R = p-C6H4SO3-, were tested for cytotoxicity against HeLa and multidrug resistant CoLo 320DM human cancer cell lines. Cell survival was measured by means of the colorometric 3-(4,5dimethylthiazol-2-yl)-diphenyltetrazodium bromide assay., Results: The mean drug concentration from 3 experiments causing 50% cell killing, ie, IC50 values, varied between 120 and 950 micromol dm(-3)., Conclusion: The antineoplastic activity of the highly water-soluble m-sulpho derivative was the highest, while the poorly water-soluble imidazole derivatives did not exhibit any cytotoxic properties. The CoLo 320DM cancer cells were 5 times more prone to drug-induced cell death than the HeLa cells.

Parents of children who received blood or blood products between 1984 and 1990 were notified about the potential risk of hepatitis C virus (HCV) infection. Data were collected about knowledge, attitudes and intended behaviours to determine the acceptability of the notification process. Demographic variables that may predict responses to notification were also recorded and analysed. Recipients were sent couriered letters explaining HCV risk, and the survey questionnaire. Sera were screened for HCV antibody and reactive samples confirmed with a recombinant immunoblot assay (RIBA). Four letter recipients were RIBA positive for a prevalence of 1.1% (4/358) in the notification group. Thirty-two percent of respondents did not know their child had been transfused and 58% did not know about the potential risk of HCV infection. Although 90% (165/185) felt the notification was valuable, 65% reported emotional distress (fear, worry, anger, very depressed). Responders were similar to non-responders except for HCV testing rate (76.2% v. 59.8%, p < 0.0002). Parents of children at risk of transfusion-acquired HCV virus approved of notification programs, but experienced some emotional distress. Awareness of transfusion history or risk of HCV was not universal, indicating the need to address notification to individuals, rather than through public education campaigns alone.

The covalent attachment site of a substance P (SP) analogue containing the photoreactive amino acid p-benzoyl-l-phenylalanine (Bpa) in position 8 of the C-terminal portion of the peptide was identified previously as Met-181 on the neurokinin-1 (NK-1) receptor. In this study, a second photoreactive SP analogue, Bpa(4)-SP, in which the Bpa residue is located in the N-terminal portion of the peptide, was used to define further the peptide-receptor interface. The NK-1 receptor expressed in Chinese hamster ovary cells was specifically and efficiently photolabeled with a radioiodinated derivative of Bpa(4)-SP. Fragmentation analysis of the photolabeled receptor restricted the site of photoincorporation of Bpa(4)-SP to an amino acid within the sequence Thr-173 to Arg-177 located on the N-terminal side of the E2 loop. To identify the specific amino acid in this sequence that serves as the covalent attachment site for Bpa(4)-SP, a small photolabeled receptor fragment was generated by chemical cleavage with cyanogen bromide. Matrix-assisted laser desorption/ionization time of flight mass spectrometric analysis of the purified fragment identified a single protonated molecular ion with a molecular mass of 1801.3 +/- 1.8, indicating that upon irradiation, the bound photoligand covalently attaches to the terminal methyl group of a methionine residue. This result, taken together with the results of the peptide mapping studies, establishes that the site of Bpa(4)-SP covalent attachment to the NK-1 receptor is Met-174.

Infection with hepatitis B virus (HBV) was detected by serological testing for HBV surface antigen and by PCR assay for HBV DNA in serum samples from two common chimpanzees (Pan troglodytes subsp. verus) born in West Africa. The complete genome sequences obtained by nucleotide sequencing of overlapping DNA fragments amplified by PCR were compared with HBV variants recovered from other primates and with human genotypes A to F. Both chimpanzee sequences were 3, 182 nucleotides in length, and the surface gene sequence predicted the existence of a, d, and w serological determinants. Neither sequence contained stop codons in the precore region. On phylogenetic analysis, the HBV variants infecting the chimpanzees clustered together with a third chimpanzee HBV isolate independently obtained from an infected captive animal (A. J. Zuckerman, A. Thornton, C. R. Howard, K. N. Tsiquaye, D. M. Jones, and M. R. Brambell, Lancet ii:652-654, 1978), with an overall sequence similarity of >94%. This provides strong evidence for a chimpanzee-specific genotype of HBV which circulates in nature. These findings add to the recent evidence for infection in the wild of other Old and New World primates (gibbon, orangutan, and woolly monkey) with species-specific variants of HBV. There is no evidence for close phylogenetic clustering of variants found so far in primates with any of the established HBV genotypes from humans. With the new evidence for the widespread distribution of HBV in primates, hypotheses for the origins of human infection are reviewed.

Systemic corticosteroid therapy has been used to treat hemangiomas for 30 years; yet, there are no studies of possible complications. We reviewed the database of the Vascular Anomalies Center at the Boston Children's Hospital and gathered information on short- and long-term side effects in children who were given systemic corticosteroids for problematic hemangiomas. In addition, a questionnaire regarding early and late consequences was sent to the families of children who were treated with corticosteroids from 1983 to 1997. Of 300 patients with hemangiomas, 80 children were identified as having received a full course of systemic corticosteroids for problematic tumors. Complete data were collected on 62 of these children. The response rate to the questionnaire was 78 percent (n = 62 of 80). The initial dose of corticosteroid varied from 2 to 3 mg/kg/ day. Duration of therapy ranged from 2 to 21 months (mean, 7.9 months; median, 6.5 months). The follow-up interval from the cessation of therapy ranged from 6 months to 15 years (mean, 4 years; median, 3 years). Short-term complications included cushingoid facies (n = 44; 71 percent), personality changes (n = 18; 29 percent), gastric irritation (n = 13; 21 percent), fungal (oral or perineal) infection (n = 4; 6 percent), and diminished gain of height (n = 22; 35 percent) and weight (n = 26; 42 percent). A total of 91 percent of children who had diminished gain of height (n = 20) returned to their pretreatment growth curve for height by 24 months of age. One child, who was treated at another institution with a dose of 20 mg/kg/day for 6.5 months that was slowly tapered over 18 months, was petite 6 years after ending therapy. Another child treated with an initial dose of 2 mg/kg/day for 5 months was smaller than predicted at the age of 6 years, but she was born prematurely and was on ventilatory support for respiratory distress. Three children treated with the standard dose and duration were at a low percentile for weight 4, 5, and 10 years after the cessation of therapy. Statistical analysis showed a correlation between diminished gain of height with duration of therapy and age at initiation of treatment. One child had corticosteroid myopathy that resolved with cessation of therapy. We found no evidence for immunologic suppression, i.e., there was no increase in the number of bacterial infections during corticosteroid administration. In conclusion, systemic corticosteroids can be safely given to treat endangering hemangiomas in infants at doses of 2 to 3 mg/kg/day, which are slowly tapered and stopped before the age of 1 year. Short-term side effects were minor and transient, and no serious long-term complications occurred.

TT virus (TTV) is a newly discovered DNA virus originally classified as a member of the Parvoviridae. TTV is transmitted by blood transfusion where it has been reported to be associated with mild post-transfusion hepatitis. TTV can cause persistent infection, and is widely distributed geographically; we recently reported extremely high prevalences of viraemia in individuals living in tropical countries (e.g. 74% in Papua New Guinea, 83% in Gambia; Prescott & Simmonds, New England Journal of Medicine 339, 776, 1998). In the current study we have compared nucleotide sequences from the N22 region of TTV (222 bases) detected in eight widely dispersed human populations. Some variants of TTV, previously classified as genotypes 1a, 1b and 2, were widely distributed throughout the world, while others, such as a novel subtype of type 1 in Papua New Guinea, were confined to a single geographical area. Five of the 122 sequences obtained in this study (from Gambia, Nigeria, Papua New Guinea, Brazil and Ecuador) could not be classified as types 1, 2 or 3, with the variant from Brazil displaying only 46-50% nucleotide (32-35% amino acid) sequence similarity to other variants. This study provides an indication of the extreme sequence diversity of TTV, a characteristic which is untypical of parvoviruses.