The Association of Systemic Microvascular Changes with Lung Function and Lung Density: A Cross-Sectional Study

Smoking causes endothelial dysfunction and systemic microvascular disease with resultant end-organ damage in the kidneys, eyes and heart. Little is known about microvascular changes in smoking-related lung disease. We tested if microvascular changes in the retina, kidneys and heart were associated with obstructive spirometry and low lung density on computed tomography. The Multi-Ethnic Study of Atherosclerosis recruited participants age 45–84 years without clinical cardiovascular disease. Measures of microvascular function included retinal arteriolar and venular caliber, urine albumin-to-creatinine ratio and, in a subset, myocardial blood flow on magnetic resonance imaging. Spirometry was measured following ATS/ERS guidelines. Low attenuation areas (LAA) were measured on lung fields of cardiac computed tomograms. Regression models adjusted for pulmonary and cardiac risk factors, medications and body size. Among 3,397 participants, retinal venular caliber was inversely associated with forced expiratory volume in one second (FEV₁) (P<0.001) and FEV₁/forced vital capacity (FVC) ratio (P = 0.04). Albumin-to-creatinine ratio was inversely associated with FEV₁ (P = 0.002) but not FEV₁/FVC. Myocardial blood flow (n = 126) was associated with lower FEV₁ (P = 0.02), lower FEV₁/FVC (P = 0.001) and greater percentage LAA (P = 0.04). Associations were of greater magnitude among smokers. Low lung function was associated with microvascular changes in the retina, kidneys and heart, and low lung density was associated with impaired myocardial microvascular perfusion. These cross-sectional results suggest that microvascular damage with end-organ dysfunction in all circulations may pertain to the lung, that lung dysfunction may contribute to systemic microvascular disease, or that there may be a shared predisposition.     

Non-Disclosure of Violence among Female Sex Workers: Evidence from a Large Scale Cross-Sectional Survey in India

Objective

One of the indicators critical to the success of violence reduction programmes among female sex workers (FSWs) is the pattern of disclosure of violence. This study examines the rate of non-disclosure of violence among FSWs in India by perpetrators of violence and programme exposure.

Methods

Data were drawn from a cross-sectional study conducted among FSWs in 2009 across four states of India: Andhra Pradesh, Karnataka, Maharashtra and Tamil Nadu. The analytical sample included 1341 FSWs who experienced physical violence in past six months. Multilevel logistic regression stratified by state was conducted to examine predictors of non-disclosure.

Results

About 54% of FSWs did not disclose their experience of violence to anyone with considerable variations in the pattern of disclosure across states. Another 36% of FSWs shared the experience with NGO worker/peer. Compared to violence perpetrated by paying partners/stranger, that by non-paying partner were twice more likely to report non-disclosure (53% vs. 68%, Adjusted Odds Ratio [AOR]: 1.8, 95% Confidence Interval [CI]: 1.3–2.4). Similarly, FSWs who were not registered with an NGO/sex worker collective were 40% more likely to report non-disclosure of violence against those registered (58% vs. 53%, AOR: 1.4, 95% CI: 1.1–1.9).

Conclusions

Non-disclosure of physical violence is quite high among FSWs which can be a barrier to the success of violence reduction efforts. Immediate efforts are required to understand the reasons behind non-disclosure based on which interventions can be developed. Community collectivisation and designing gender-based interventions with the involvement of non-paying partners should be the way forward.     

Effects of Subchronic Aluminum Exposure on the Reproductive Function in Female Rats

The aim of this study was to investigate the effects of aluminum (Al) exposure on the reproductive function in female rats. Forty female Wistar (5 weeks old) rats, weighing 110–120 g, were divided randomly into four groups. They were orally administrated with 0, 64.18, 128.36, and 256.72 mg aluminum chloride (AlCl₃) per kilogram body weight in drinking water for 120 days. Levels of Al, estrogen (E₂), progestogen (P), testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in serum were measured at the end of experiment. The results showed that levels of E₂, P, FSH, and LH were significantly lower and Al concentration was significantly higher in all three Al-treated groups than those in the control group (GC). The level of T was significantly higher in the low- and medium-dose groups (GL and GM) (P < 0.05) but not in high-dose group (GH) compared with GC. The results suggest that the reproductive function of female rats is inhibited under long-term Al exposure in an Al dose-dependent manner.     

Long-Term Exposure to Primary Traffic Pollutants and Lung Function in Children: Cross-Sectional Study and Meta-Analysis

Background

There is widespread concern about the possible health effects of traffic-related air pollution. Nitrogen dioxide (NO₂) is a convenient marker of primary pollution. We investigated the associations between lung function and current residential exposure to a range of air pollutants (particularly NO₂, NO, NOx and particulate matter) in London children. Moreover, we placed the results for NO₂ in context with a meta-analysis of published estimates of the association.

Methods and Findings

Associations between primary traffic pollutants and lung function were investigated in 4884 children aged 9–10 years who participated in the Child Heart and Health Study in England (CHASE). A systematic literature search identified 13 studies eligible for inclusion in a meta-analysis. We combined results from the meta-analysis with the distribution of the values of FEV₁ in CHASE to estimate the prevalence of children with abnormal lung function (FEV₁<80% of predicted value) expected under different scenarios of NO₂ exposure. In CHASE, there were non-significant inverse associations between all pollutants except ozone and both FEV1 and FVC. In the meta-analysis, a 10 μg/m³ increase in NO₂ was associated with an 8 ml lower FEV₁ (95% CI: -14 to -1 ml; p: 0.016). The observed effect was not modified by a reported asthma diagnosis. On the basis of these results, a 10 μg/m³ increase in NO₂ level would translate into a 7% (95% CI: 4% to 12%) increase of the prevalence of children with abnormal lung function.

Conclusions

Exposure to traffic pollution may cause a small overall reduction in lung function and increase the prevalence of children with clinically relevant declines in lung function.     

Role of Community Group Exposure in Reducing Sexually Transmitted Infection-Related Risk among Female Sex Workers in India

Background

Empowering female sex workers (FSWs) to address structural barriers and forming community groups (CGs) through community mobilization are seen as essential components of HIV prevention programs in India. Taking the membership of a CG as an exposure intervention, we hypothesized whether participation in a CG lead to reduced sexually transmitted infections (STIs) and increased treatment-seeking behavior among FSWs in three selected states of India — Andhra Pradesh, Maharashtra and Tamil Nadu.

Methods and Findings

The propensity score matching (PSM) approach examined the effect of CG membership, as against no membership, on STI-related risk, described as selected outcome measures — presence of any STI, self-reported STI symptoms, and treatment-seeking behavior among FSWs. A cross sectional bio-behavioral survey was administered in 2009–2010 and covered 7,806 FSWs through two-stage probability-based conventional and time location cluster sampling in 23 administrative districts of Andhra Pradesh, Maharashtra and Tamil Nadu. Only 2,939 FSWs were reported to be members of a CG and among them 4.5% had any STIs. A majority of FSWs were aged above 24 years (86.4%), had ever been married (73%), operated from a public place for solicitation (81.5%), and had ever received HIV test results (75.6%). The average effect of CG exposure was reduction in STI prevalence by 4%, while self-reported STI symptom treatment-seeking behavior increased by 13.7%.

Conclusion

FSWs who were exposed to a CG were at a substantially lower risk of STIs than those who were unexposed. The FSWs exposed to a CG had a higher chance of seeking STI treatment from public and private health facilities. Collectivization related challenges must be overcome to provide access to tailored STI prevention and care services.     

The Impact of Syphilis Screening among Female Sex Workers in China: A Modelling Study

Background

In China, female sex workers (FSWs) are at high risk of syphilis infection, but are hard to reach for interventions. Point-of-care testing introduces opportunities for expanding syphilis control measures. Modelling is used to estimate the impact of using rapid tests to screen FSWs for syphilis. In other settings, modelling has predicted large rebounds in infectious syphilis following screening, which may undermine any impact achieved.

Methods

A deterministic syphilis transmission model among FSWs and clients was fitted to data from Yunnan Province (FSW syphilis prevalence = 7.5%), and used to estimate the impact of rapid syphilis testing and treatment for FSWs. Impact projections were compared for different model structures that included risk heterogeneity amongst FSWs, incoming syphilis infections amongst new FSWs and clients and re-infection from FSWs'' regular non-commercial partners. The rebound in syphilis prevalence after screening ceased was explored.

Results

All model structures suggest yearly syphilis screening could substantially reduce (by 72–88%) syphilis prevalence amongst FSWs in this setting over five years. However, incoming syphilis infections amongst new FSWs and clients or re-infections from regular non-commercial partners of FSWs can considerably reduce (>30%) the proportion of infections averted. Including heterogeneity in risk amongst FSWs had little effect upon the proportion of infections averted. In this setting, the rebound in syphilis prevalence after screening ceased is predicted to be slight, but it could be large in high prevalence settings.

Conclusions

Rapid test screening could dramatically reduce syphilis prevalence amongst hard-to-reach groups, but strategies to reduce re-infection from regular non-commercial partners are needed to maximise impact.     

The Association of Metallothionein-4 Gene Polymorphism and Renal Function in Long-Term Lead-Exposed Workers

The goal of this study is to investigate if metallothionein (MT) gene polymorphism affects the susceptibility to lead as well as renal function parameters and blood pressures (BP) in workers exposed to lead for extended period of time. By means of real-time polymerase chain reaction, the MT4-216 A/G genotypes classified as rs396230 in the single nucleotide polymorphism database of the National Center for Biotechnology Information (database) were analyzed on 113 workers of a lead battery-recycling factory. Workers with G (mutant) allele were more susceptible to the toxic effects of lead on their systolic BP and serum renal function parameters. Their BP was 10 mmHg higher than those with wild-type (AA type) allele. Among subjects with the 3-genome, the GG mutant type subjects appear to be more susceptible to lead. Regression models of serum creatinine and BUN showed significant differences between the GG and GA types compared to AA type subjects. This cross-sectional study shows that workers with different MT-4 genotypes have different lead-induced adverse health effects. Those with the G allele have the greater susceptibility to lead so their exposure should be reduced.     

Large-Scale Genome-Wide Association Studies and Meta-Analyses of Longitudinal Change in Adult Lung Function

Background

Genome-wide association studies (GWAS) have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function.

Methods

We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV₁) in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV₁ by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis.

Results

The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10^-7). In addition, meta-analysis using the five cohorts with ≥3 FEV₁ measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10^-8) at genome-wide significance. Neither locus was associated with FEV₁ decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV₁ decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively.

Conclusions

In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV₁ that harbor candidate genes with biologically plausible functional links to lung function.     

Determinants of Heterosexual Adolescents Having Sex with Female Sex Workers in Singapore

Objectives

We assessed the proportion of and socio-ecological factors associated with ever having had sex with female sex workers (FSWs) among heterosexual adolescents. We also described the characteristics of the adolescents who reported inconsistent condom use with FSWs.

Methods

This is a cross-sectional study (response rate: 73%) of 300 heterosexually active male adolescents of 16 to 19 years attending a national STI clinic in Singapore between 2009 and 2014. We assessed the ecological factors (individual, parental, peer, school and medial influences) and sexual risk behaviors using a self-reported questionnaire. Poisson regression was used to obtain the adjusted prevalence ratios (aPR) and confidence intervals (CI).

Results

The proportion of heterosexual male adolescents who had ever had sex with FSWs was 39%. Multivariate analysis showed that significant factors associated with ever having had sex with FSWs were sex initiation before 16 years old (aPR 1.79 CI: 1.30–2.46), never had a sexually active girlfriend (aPR 1.75 CI 1.28–2.38), reported lower self-esteem score (aPR 0.96 CI: 0.93–0.98), higher rebelliousness score (aPR 1.03 CI: 1.00–1.07) and more frequent viewing of pornography (aPR 1.47 CI: 1.04–2.09). Lifetime inconsistent condom use with FSWs was 30%.

Conclusions

A significant proportion of heterosexual male adolescents attending the public STI clinic had ever had sex with FSWs. A targeted intervention that addresses different levels of influence to this behavior is needed. This is even more so because a considerable proportion of adolescents reported inconsistent condom use with FSWs, who may serve as a bridge of STI transmission to the community. National surveys on adolescent health should include the assessment of frequency of commercial sex visits and condom use with FSWs for long-term monitoring and surveillance.     

Diagnostic Radiation Exposure of Injury Patients in the Emergency Department: A Cross-Sectional Large Scaled Study

In contrast to patients with underlying cancer or chronic disease, injury patients are relatively young, and can be expected to live their natural lifespan if injuries are appropriately treated. Multiple and repeated diagnostic scans might be performed in these patients during admission. Nevertheless, radiation exposure in injury patients has been overlooked and underestimated because of the emergent nature of such situations. Therefore, we tried to assess the cumulative effective dose (cED) of injury patients in the emergency department. We included patients who visited the emergency department (ED) of a single tertiary hospital due to injury between February 2010 and February 2011. The cED for each patient was calculated and compared across age, sex and injury mechanism. A total of 11,676 visits (mean age: 28.0 years, M:F = 6,677:4,999) were identified. Although CT consisted of only 7.8% of total radiologic examinations (n=78,025), it accounted for 87.1% of the total cED. The mean cED per visit was 2.6 mSv. A significant difference in the cED among injury mechanisms was seen (p<0.001) and patients with traffic accidents and fall down injuries showed relatively high cED values. Hence, to reduce the cED of injury patients, an age-, sex- and injury mechanism-specific dose reduction strategy should be considered.     

Left Ventricular Function during Acute High-Altitude Exposure in a Large Group of Healthy Young Chinese Men

Objective

The purpose of this study was to observe left ventricular function during acute high-altitude exposure in a large group of healthy young males.

Methods

A prospective trial was conducted in Szechwan and Tibet from June to August, 2012. By Doppler echocardiography, left ventricular function was examined in 139 healthy young Chinese men at sea level; within 24 hours after arrival in Lhasa, Tibet, at 3700 m; and on day 7 following an ascent to Yangbajing at 4400 m after 7 days of acclimatization at 3700 m. The resting oxygen saturation (SaO2), heart rate (HR) and blood pressure (BP) were also measured at the above mentioned three time points.

Results

Within 24 hours of arrival at 3700 m, the HR, ejection fraction (EF), fractional shortening (FS), stroke volume (SV), cardiac output (CO), and left ventricular (LV) Tei index were significantly increased, but the LV end-systolic dimension (ESD), end-systolic volume (ESV), SaO2, E/A ratio, and ejection time (ET) were significantly decreased compared to the baseline levels in all subjects. On day 7 at 4400 m, the SV and CO were significantly decreased; the EF and FS Tei were not decreased compared with the values at 3700 m; the HR was further elevated; and the SaO2, ESV, ESD, and ET were further reduced. Additionally, the E/A ratio was significantly increased on day 7 but was still lower than it was at low altitude.

Conclusion

Upon acute high-altitude exposure, left ventricular systolic function was elevated with increased stroke volume, but diastolic function was decreased in healthy young males. With higher altitude exposure and prolonged acclimatization, the left ventricular systolic function was preserved with reduced stroke volume and improved diastolic function.     

Long-Term Exposure to Silica Dust and Risk of Total and Cause-Specific Mortality in Chinese Workers: A Cohort Study

Background

Human exposure to silica dust is very common in both working and living environments. However, the potential long-term health effects have not been well established across different exposure situations.

Methods and Findings

We studied 74,040 workers who worked at 29 metal mines and pottery factories in China for 1 y or more between January 1, 1960, and December 31, 1974, with follow-up until December 31, 2003 (median follow-up of 33 y). We estimated the cumulative silica dust exposure (CDE) for each worker by linking work history to a job–exposure matrix. We calculated standardized mortality ratios for underlying causes of death based on Chinese national mortality rates. Hazard ratios (HRs) for selected causes of death associated with CDE were estimated using the Cox proportional hazards model. The population attributable risks were estimated based on the prevalence of workers with silica dust exposure and HRs. The number of deaths attributable to silica dust exposure among Chinese workers was then calculated using the population attributable risk and the national mortality rate. We observed 19,516 deaths during 2,306,428 person-years of follow-up. Mortality from all causes was higher among workers exposed to silica dust than among non-exposed workers (993 versus 551 per 100,000 person-years). We observed significant positive exposure–response relationships between CDE (measured in milligrams/cubic meter–years, i.e., the sum of silica dust concentrations multiplied by the years of silica exposure) and mortality from all causes (HR 1.026, 95% confidence interval 1.023–1.029), respiratory diseases (1.069, 1.064–1.074), respiratory tuberculosis (1.065, 1.059–1.071), and cardiovascular disease (1.031, 1.025–1.036). Significantly elevated standardized mortality ratios were observed for all causes (1.06, 95% confidence interval 1.01–1.11), ischemic heart disease (1.65, 1.35–1.99), and pneumoconiosis (11.01, 7.67–14.95) among workers exposed to respirable silica concentrations equal to or lower than 0.1 mg/m³. After adjustment for potential confounders, including smoking, silica dust exposure accounted for 15.2% of all deaths in this study. We estimated that 4.2% of deaths (231,104 cases) among Chinese workers were attributable to silica dust exposure. The limitations of this study included a lack of data on dietary patterns and leisure time physical activity, possible underestimation of silica dust exposure for individuals who worked at the mines/factories before 1950, and a small number of deaths (4.3%) where the cause of death was based on oral reports from relatives.

Conclusions

Long-term silica dust exposure was associated with substantially increased mortality among Chinese workers. The increased risk was observed not only for deaths due to respiratory diseases and lung cancer, but also for deaths due to cardiovascular disease. Please see later in the article for the Editors'' Summary     

MICB基因多态性与肺癌的易感关联性研究

目的:研究海南汉族人群MICB等位基因的多态性与肺癌易感性之间的关联性。方法:采用PCR-SSP(PCR sequence-specific primers)和PCR-SBT(PCR sequence-based typing)方法对样本MICB等位基因的多态性进行检测。结果:肺癌患者中检出14种MICB等位基因;和对照组相比较,MICB*00502等位基因在肺癌患者组分布频率较少(43.5%vs 57.8%),MICB*016等位基因在肺癌患者组分布较多(5.9%vs 0.6%);MICB*016等位基因可能对肺癌易感(OR=11.19,95%CI:2.59-48.24,Pc0.05);MICB*00502等位基因可能对肺癌不易感(MICB*00502:OR=0.56,95%CI:0.42-0.76,Pc0.05)。结论:MICB等位基因的多态性与肺癌的易感性之间存在关联性。     

A Dietary-Wide Association Study (DWAS) of Environmental Metal Exposure in US Children and Adults

Background

A growing body of evidence suggests that exposure to toxic metals occurs through diet but few studies have comprehensively examined dietary sources of exposure in US populations.

Purpose

Our goal was to perform a novel dietary-wide association study (DWAS) to identify specific dietary sources of lead, cadmium, mercury, and arsenic exposure in US children and adults.

Methods

We combined data from the National Health and Nutrition Examination Survey with data from the US Department of Agriculture''s Food Intakes Converted to Retail Commodities Database to examine associations between 49 different foods and environmental metal exposure. Using blood and urinary biomarkers for lead, cadmium, mercury, and arsenic, we compared sources of dietary exposure among children to that of adults.

Results

Diet accounted for more of the variation in mercury and arsenic than lead and cadmium. For instance we estimate 4.5% of the variation of mercury among children and 10.5% among adults is explained by diet. We identified a previously unrecognized association between rice consumption and mercury in a US study population – adjusted for other dietary sources such as seafood, an increase of 10 g/day of rice consumption was associated with a 4.8% (95% CI: 3.6, 5.2) increase in blood mercury concentration. Associations between diet and metal exposure were similar among children and adults, and we recapitulated other known dietary sources of exposure.

Conclusion

Utilizing this combination of data sources, this approach has the potential to identify and monitor dietary sources of metal exposure in the US population.     

Relationship between Exposure to Household Humidifier Disinfectants and Risk of Lung Injury: A Family-Based Study

BackgroundIn South Korea, a cluster of acute lung disease patients included lung injury disease suspected of being caused by the use of humidifier disinfectants. We examined the relationship between humidifier disinfectant exposure and clinically diagnosed humidifier disinfectant-associated lung injury (HDLI) in a family-based study.MethodsThis case-control study included 169 clinically confirmed HDLI cases and 303 family controls who lived with the HDLI patients. A range of information on exposure to humidifier disinfectants was obtained using a structured questionnaire and field investigations. Odds ratios (ORs) and confidence intervals (CIs) were estimated using unconditional logistic regression models that were adjusted for age, sex, presence of a factory within 1 km of residence, and the number of household chemical products used.ResultsHDLI risk increased approximately two-fold or more among the highest quartile compared with the lowest quartile in terms of the hours sleeping in a room with an operating humidifier treated with disinfectant (adjusted OR = 2.0, 95 % CI = 1.1-3.7), average hours of disinfectant-treated humidifier use per day (adjusted OR = 2.1, 95 % CI = 1.0-4.5), airborne disinfectant intensity (adjusted OR = 2.6, 95% CI = 1.2-5.3), and cumulative disinfectant inhalation level (adjusted OR = 2.0, 95% CI = 1.0-4.1). HDLI risk increased as the distance of the bed from humidifier gets shorter; compared with longer distance (> 1 m), the odds ratio was 2.7 for 0.5 to 1 m (95 % CI = 1.5-5.1) and 13.2 for <0.5 m (95 % CI = 2.4-73.0).ConclusionsThe use of household humidifier disinfectants was associated with HDLI risk in a dose-response manner.     

Association of Group B Streptococcus Colonization and Bovine Exposure: A Prospective Cross-Sectional Cohort Study

Background

While Group B Streptococcus (GBS) human colonization and infection has long been suspected as originating from cows, several investigators have suggested that ongoing interspecies GBS transmission is unlikely due to genotyping data demonstrating that human and bovine-derived GBS strains represent mostly distinct populations. The possibility of ongoing transmission between humans and their livestock has not been systematically examined.

Methodology/Principal Findings

To examine ongoing interspecies transmission, we conducted a prospective cross-sectional cohort study of 68 families and their livestock. Stool specimens were collected from 154 people and 115 livestock; GBS was detected in 19 (12.3%) humans and 2 (1.7%) animals (bovine and sheep). Application of multilocus sequence typing (MLST) identified 8 sequence types (STs or clones), with STs 1 and 23 predominating. There were 11 families in which two members submitted stools and at least one had GBS colonization. In 3 of these families, both members (consisting of couples) were colonized, yielding a co-colonization rate of 27% (95% CI: 7%–61%). Two of these couples had strains with identical MLST, capsule (cps) genotype, susceptibility, and RAPD profiles. One couple co-colonized with ST-1 (cps5) strains also had a bovine colonized with the identical strain type. On multivariate analysis of questionnaire data, cattle exposure was a predictor of GBS colonization, with each unit increase in days of cattle exposure increasing the odds of colonization by 20% (P = 0.02). These results support interspecies transmission with additional evidence for transmission provided by the epidemiological association with cattle exposure.

Conclusions/Significance

Although GBS uncommonly colonizes livestock stools, increased frequency of cattle exposure was significantly associated with human colonization and one couple shared the same GBS strains as their bovine suggesting intraspecies transmission. These results set the framework for GBS as a possible zoonotic infection, which has significant public health implications.     

Characterization of Lung Function Impairment in Adults with Bronchiectasis

Background

Characteristics of lung function impairment in bronchiectasis is not fully understood.

Objectives

To determine the factors associated with lung function impairment and to compare changes in spirometry during bronchiectasis exacerbation and convalescence (1 week following 14-day antibiotic therapy).

Methods

We recruited 142 patients with steady-state bronchiectasis, of whom 44 with acute exacerbations in the follow-up were included in subgroup analyses. Baseline measurements consisted of chest high-resolution computed tomography (HRCT), sputum volume, purulence and bacteriology, spirometry and diffusing capacity. Spirometry, but not diffusing capacity, was examined during acute exacerbations and convalescence.

Results

In the final multivariate models, having bronchiectasis symptoms for 10 years or greater (OR = 4.75, 95%CI: 1.46–15.43, P = 0.01), sputum culture positive for Pseudomonas aeruginosa (OR = 4.93, 95%CI: 1.52–15.94, P<0.01) and HRCT total score being 12 or greater (OR = 7.77, 95%CI: 3.21–18.79, P<0.01) were the major variables associated with FEV₁ being 50%pred or less; and the only variable associated with reduced D_LCO was 4 or more bronchiectatic lobes (OR = 5.91, 95%CI: 2.20–17.23, P<0.01). Overall differences in FVC and FEV₁ during exacerbations and convalescence were significant (P<0.05), whereas changes in other spirometric parameters were less notable. This applied even when stratified by the magnitude of FEV₁ and D_LCO reduction at baseline.

Conclusion

Significant lung function impairment should raise alert of chest HRCT abnormality and sputum culture positive for Pseudomonas aeruginosa, in patients with predominantly mild to moderate steady-state bronchiectasis. Acute exacerbations elicited reductions in FVC and FEV₁. Changes of other spirometric parameters were less significant during exacerbations.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01761214","term_id":"NCT01761214"}}NCT01761214     

A Qualitative Exploration of Barriers to Condom Use among Female Sex Workers in China

Background

Sex workers in China continue to engage in unprotected sex acts that put them at risk for contracting HIV (Human Immunodeficiency Virus) and other STIs (Sexually Transmitted Infections). The purpose of this study was to explore women’s work history, the context of sex work, condom use, HIV testing services, and potential barriers to condom use in a sample of FSWs (female sex workers) in Guangzhou, China.

Methodology/Principal Findings

In-depth, semi-structured, face-to-face interviews were conducted with 24 FSWs in Guangzhou, China. Informants were recruited using a purposive sampling technique. Qualitative data were coded and analyzed using NVivo 8.0. The majority of respondents were internal economic migrants who had entered the sex industry in pursuit of greater financial reward. Most women in the study were married or had steady boyfriends, and were young, with secondary education and limited knowledge about HIV and STIs. Most were not satisfied with their current living conditions and expressed a desire to leave the sex industry. Women reported that they were more likely to use condoms during sex acts with commercial partners than with non-commercial partners. The potential stigma of being seen as a sex worker prevented many from accessing HIV testing. Three key factors put these FSWs at risk for HIV and STIs: unreasonable trust toward clients, stereotypes and assumptions about customers, and financial incentives.

Conclusions/Significance

These findings suggest that social and economic factors play an important role in shaping sexual decision-making among female sex workers in Guangzhou. We argue that greater insight into and attention to these factors could enhance the success of HIV prevention efforts.     

A Novel Dual-Band Conformal Surface Plasmon Waveguide with Tunable Frequency Response in Large Scale

Plasmonics - A novel dual-band conformal surface plasmon (CSP) waveguide is designed and well studied in this paper. In earlier research studies, we have recognized that electromagnetic field of...