Part 5. Public health and air pollution in Asia (PAPA): a combined analysis of four studies of air pollution and mortality

BACKGROUND

In recent years, Asia has experienced rapid economic growth and a deteriorating environment caused by the increasing use of fossil fuels. Although the deleterious effects of air pollution from fossil-fuel combustion have been demonstrated in many Western nations, few comparable studies have been conducted in Asia. Time-series studies of daily mortality in Asian cities can contribute important new information to the existing body of knowledge about air pollution and health. Not only can these studies verify important health effects of air pollution in local regions in Asia, they can also help determine the relevance of existing air pollution studies to mortality and morbidity for policymaking and environmental controls. In addition, the studies can help identify factors that might modify associations between air pollution and health effects in various populations and environmental conditions. Collaborative multicity studies in Asia-especially when designed, conducted, and analyzed using a common protocol-will provide more robust air pollution effect estimates for the region as well as relevant, supportable estimates of local adverse health effects needed by environmental and public-health policymakers.

SPECIFIC OBJECTIVES

The Public Health and Air Pollution in Asia (PAPA*) project, sponsored by the Health Effects Institute, consisted of four studies designed to assess the effects of air pollution on mortality in four large Asian cities, namely Bangkok, in Thailand, and Hong Kong, Shanghai, and Wuhan, in China. In the PAPA project, a Common Protocol was developed based on methods developed and tested in NMMAPS, APHEA, and time-series studies in the literature to help ensure that the four studies could be compared with each other and with previous studies by following an established protocol. The Common Protocol (found at the end of this volume) is a set of prescriptive instructions developed for the studies and used by the investigators in each city. It is flexible enough to allow for adjustments in methods to optimize the fit of health-effects models to each city's data set. It provides the basis for generating reproducible results in each city and for meta-estimates from combined data. By establishing a common methodology, factors that might influence the differences in results from previous studies can more easily be explored. Administrative support was provided to ensure that the highest quality data were used in the analysis. It is anticipated that the PAPA results will contribute to the international scientific discussion of how to conduct and interpret time-series studies of air pollution and will stimulate the development of high-quality routine systems for recording daily deaths and hospital admissions for time-series analysis.

METHODS

Mortality data were retrieved from routine databases with underlying causes of death coded using the World Health Organization (WHO) International Classification of Diseases, 9th revision or 10th revision (ICD-9, ICD-10). Air quality measurements included nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter with aerodynamic diameter < or = 10 microm (PM10), and ozone (O3) and were obtained from several fixed-site air monitoring stations that were located throughout the metropolitan areas of the four cities and that met the standards of procedures for quality assurance and quality control carried out by local government units in each city. Using the Common Protocol, an optimized core model was established for each city to assess the effects of each of the four air pollutants on daily mortality using generalized linear modeling with adjustments for time trend, seasonality, and other time-varying covariates by means of a natural-spline smoothing function. The models were adjusted to suit local situations by correcting for influenza activity, autocorrelation, and special weather conditions. Researchers in Hong Kong, for example, used influenza activity based on frequency of respiratory mortality; researchers in Hong Kong and Shanghai used autoregressive terms for daily outcomes at lag days; and researchers in Wuhan used additional smoothing for periods with extreme weather conditions.

RESULTS AND DISCUSSION

For mortality due to all natural (nonaccidental) causes at all ages, the effects of air pollutants per 10-microg/m3 increase in concentration was found to be higher in Bangkok than in the three Chinese cities, with the exception of the effect of NO2 in Wuhan. The magnitude of the effects for cardiovascular and respiratory mortality were generally higher than for all natural mortality at all ages. In addition, the effects associated with PM10 and O3 in all natural, cardiovascular; and respiratory mortality were found to be higher in Bangkok than in the three Chinese cities. The explanation for these three findings might be related to consistently higher daily mean temperatures in Bangkok, variations in average time spent outdoors by the susceptible populations, and the fact that less air conditioning is available and used in Bangkok than in the other cities. However, when pollutant concentrations were incorporated into the excess risk estimates through the use of interquartile range (IQR), the excess risk was more comparable across the four cities. We found that the increases in effects among older age groups were greater in Bangkok than in the other three cities. After excluding data on extremely high concentrations of PM10 in Bangkok, the effect estimate associated with PM10 concentrations decreased in Bangkok (suggesting a convex relationship between risk and PM10, where risk levels off at high concentrations) instead of increasing, as it did in the other cities. This leveling off of effect estimates at high concentrations might be related to differences in vulnerability and exposure of the population to air pollution as well as to the sources of the air pollutant. IMPLICATIONS OF THE STUDY: The PAPA project is the first coordinated Asian multicity air pollution study ever published; this signifies the beginning of an era of cooperation and collaboration in Asia, with the development of a common protocol for coordination, data management, and analysis. The results of the study demonstrated that air pollution in Asia is a significant public health burden, especially given the high concentrations of pollutants and high-density populations in major cities. When compared with the effect estimates reported in the research literature of North America and Western Europe, the study's effect estimates for PM10 were generally similar and the effect estimates for gaseous pollutants were relatively higher. In Bangkok, however, a tropical city where total exposures to outdoor pollution might be higher than in most other cities, the observed effects were greater than those reported in the previous (i.e., Western) studies. In general, the results suggested that, even though social and environmental conditions across Asia might vary, it is still generally appropriate to apply to Asia the effect estimates for other health outcomes from previous studies in the West. The results also strongly support the adoption of the global air quality guidelines recently announced by WHO.

Effect of pregnancy and progesterone concentration on expression of genes encoding for transporters or secreted proteins in the bovine endometrium

The objective of this study was to determine the temporal and spatial expression patterns of genes encoding transporters, as well as selected secreted proteins that may be regulated by progesterone (P4) and/or the presence of the conceptus in the bovine endometrium. Estrus-synchronized beef heifers were randomly assigned to either: 1) pregnant, high P4; 2) pregnant, normal P4; 3) cyclic, high P4; or 4) cyclic, normal P4. Uteri were collected on days 5, 7, 13, and 16 of the estrous cycle or pregnancy. Localization of mRNAs for ANPEP, CTGF, LPL, LTF, and SLC5A1 in the uteri was determined by radioactive in situ hybridization, and expression quantified in the endometria by quantitative real-time PCR. ANPEP localized to luminal (LE) and superficial glandular (sGE) epithelia of all heifers on days 5 and 7 only. SLC5A1 mRNA was detected in the LE and sGE on days 13 and 16 in all heifers, and expression increased on day 16 in pregnant groups. CTGF localized weakly to the LE and GE on days 5 and 7 but increased on days 13 and 16 with an increase ( P < 0.05) in CTGF expression in high P4 ( day 7) and pregnant heifers ( day 16). Both LPL and LTF localized to the GE only on days 5 and 7. In conclusion we have characterized the temporal expression pattern of these genes and modulation of their transcript abundance by P4 ( CTGF, LPL) and/or the conceptus ( CTGF, SLC5A1) likely modifies the uterine microenvironment, enhancing histotroph composition and contributing to advanced conceptus elongation.

Association of p53 with Bid induces cell death in response to etoposide treatment in hepatocellular carcinoma

Appropriate subcellular localization of proteins is crucial for regulating their functions. Both p53 and the BH3-only Bid play roles in the development and the treatment of hepatocellular carcinoma (HCC). They both participate in the cross talk of cell cycle arrest and apoptosis in response to DNA damage. However, some important issues related to their pathways are not yet resolved. Bid genomic loci contain p53-binding DNA response elements and Bid can mediate p53-dependent transactivation. Here, we showed that etoposide-induced DNA damage could significantly induce p53 and Bid nuclear export. When cells were stimulated by etoposide, p53 could, through the association with Bid, cause translocation of Bid from the nucleus to the cytoplasm and on to its ultimate location in the mitochondria. p53 was physically associated with Bid, and both p53 and Bid cooperatively promoted cell death induced by etoposide. Knockdown of Bid expression notably attenuated cell death induced by etoposide and also released p53 from the mitochondria. These findings reveal a novel mechanism by which p53 is associated with Bid in the nucleus to facilitate exportation of Bid to the mitochondria and induce apoptosis in response to etoposide-induced DNA damage in HCC.

Artemisia fukudo essential oil attenuates LPS-induced inflammation by suppressing NF-kappaB and MAPK activation in RAW 264.7 macrophages

In the present study, the chemical constituents of Artemisia fukudo essential oil (AFE) were investigated using GC-MS. The major constituents were alpha-thujone (48.28%), beta-thujone (12.69%), camphor (6.95%) and caryophyllene (6.01%). We also examined the effects of AFE on the production of nitric oxide (NO), prostaglandin E(2) (PGE(2)), tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6, in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Western blotting and RT-PCR tests indicated that AFE has potent dose-dependent inhibitory effects on pro-inflammatory cytokines and mediators. We investigated the mechanism by which AFE inhibits NO and PGE(2) by examining the level of nuclear factor-kappaB (NF-kappaB) activation within the mitogen-activated protein kinase (MAPK) pathway, which is an inflammation-induced signal pathway in RAW 264.7 cells. AFE inhibited LPS-induced ERK, JNK, and p38 phosphorylation. Furthermore, AFE inhibited the LPS-induced phosphorylation and degradation of Ikappa-B-alpha, which is required for the nuclear translocations of the p50 and p65 NF-kappaB subunits in RAW 264.7 cells. Our results suggest that AFE might exert an anti-inflammatory effect by inhibiting the expression of pro-inflammatory cytokines. Such an effect is mediated by a blocking of NF-kappaB activation which consequently inhibits the generation of inflammatory mediators in RAW264.7 cells. AFE may be useful for treating inflammatory diseases.

Increased expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in rat cardiac allografts

This study was designed to investigate the role of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) during chronic cardiac allograft rejection. Wistar rats were used as donors, and SD rats as recipients heterotopic cardiac transplants. Recipients pretreated with inoculation of donor splenocytes (SPC) followed by cyclophosphamide (CP) were divided into 4 groups: (A) untreated group (n = 18) without immunosuppression; (B) SPC plus CP-treated group (n = 18) that were euthanized at 15-120 days posttransplantation; (C) CsA-treated group (n = 18) euthanized at 2-3 months posttransplantation; and (D) tolerance group (n = 18) treated with SPC plus CP and monitored for at least 1 year posttransplantation. Cardiac allografts were harvested at various times for immunohistochemical studies performed to evaluate the expression of ICAM-1 and VCAM-1. Pretreatment of animals with SPC and CP induced long-term cardiac allograft survival. Immunohistochemical staining demonstrated a low level of ICAM-1 and VCAM-1 expression in cardiac allograft muscle and coronary arteries among Groups B and D. In contrast, the expressions of ICAM-1 and VCAM-1 in cardiac allografts of Groups A and C were significantly higher than those in Groups B and D. Our results suggested that the expression of ICAM-1 and VCAM-1 plays an important role during the development of chronic cardiac allograft rejection.

A Mobile Sensor Network System for Monitoring of Unfriendly Environments

Observing microclimate changes is one of the most popular applications of wireless sensor networks. However, some target environments are often too dangerous or inaccessible to humans or large robots and there are many challenges for deploying and maintaining wireless sensor networks in those unfriendly environments. This paper presents a mobile sensor network system for solving this problem. The system architecture, the mobile node design, the basic behaviors and advanced network capabilities have been investigated respectively. A wheel-based robotic node architecture is proposed here that can add controlled mobility to wireless sensor networks. A testbed including some prototype nodes has also been created for validating the basic functions of the proposed mobile sensor network system. Motion performance tests have been done to get the positioning errors and power consumption model of the mobile nodes. Results of the autonomous deployment experiment show that the mobile nodes can be distributed evenly into the previously unknown environments. It provides powerful support for network deployment and maintenance and can ensure that the sensor network will work properly in unfriendly environments.

The experimental study of cardiac allograft vasculopathy and myocardial fibrosis in rats

We sought to analyze the development of myocardial fibrosis and cardiac allograft vasculopathy (CAV) as a theoretical basis for the prevention and treatment of rejection. Heterotopic cardiac transplantation was performed from Wistar rats to Sprague-Dawley rats. The recipients pretreated with donor splenocyte (SPC) infusion followed by cyclophosphamide (CP) were divided into 3 groups: Control animals without immunosuppression (Group 1; n = 10); Group 2, CsA treatment (n = 10) with euthanasia 2-3 months posttransplantation; and Group 3 (n = 20), CP plus SPC treatment with 10 recipients euthanized at 2 weeks posttransplantation and 10 animals monitored for at least 1 year posttransplantation. Histological studies were performed to evaluate myocardial fibrosis and CAV; 2-3 days after transplantation, there was abundant infiltration of collagenous fibers in the adventitia and intima of the coronary arteries in Group 1 allografts. Group 2 allografts demonstrated abundant infiltration of collagenous fibers in the adventitia and intima of arteries and arterioles resulting in significant luminal stenosis. In contrast, pretreatment of animals with SPC and CP induced long-term allograft survival; myocardial fibrosis and CAV were dramatically reduced in Group 3 compared with Groups 1 and 2. The infiltration of collagenous fibers in coronary arteries was one of the major causes of CAV. Preconditioning of recipients with SPC followed by CP not only induced immune tolerance but also alleviated myocardial fibrosis and CAV in allografts.

A novel c.545-546insG mutation in the loricrin gene correlates with a heterogeneous phenotype of loricrin keratoderma

BACKGROUND

Loricrin keratoderma (LK) is a group of congenital skin abnormalities characterized by the common features of honeycomb palmoplantar keratoderma and diffused ichthyosiform dermatosis. Earlier studies have shown that LK is associated with genetic defects of the loricrin gene.

OBJECTIVES

To determine the correlation between a loricrin mutation and a heterogeneous phenotype of loricrin keratoderma.

METHODS

We obtained DNA samples from a large family in which affected members showed more severe hyperkeratosis on the dorsal parts of their hands, mild palmoplantar keratoderma with no honeycomb-like manifestations and generalized ichthyosis. Screening of the loricrin gene was performed by direct sequencing of the entire coding region. Plasmids encoding the green fluorescent protein-tagged human loricrin were constructed and transferred to 293A cells for subcellular localization analyses.

RESULTS

Molecular analyses of the loricrin gene identified a novel insertion mutation c.545-546insG that resulted in a frameshift after codon 182. This mutation was predicted to produce a mutant protein with a frameshift of its C-terminal sequence of amino acids that embeds a newly generated nuclear localization signal (NLS), and to be 22 amino acids longer than the wild-type protein due to a delayed termination codon. The NLSs appear to result in an accumulation of mutant loricrin within nuclei.

CONCLUSIONS

Our results extend the repertoire of loricrin mutations underlying LK, provide further evidence that heterogeneous phenotypes of LK may be the result of genetic heterogeneity of loricrin mutations, and demonstrate that nuclear accumulation of mutant loricrin is due to the nuclear targeting sequences in the mutant C-terminus.

Surface coating of carbon nanofibers/nanotubes by electrodeposition for multifunctionalization

Carbon nanomaterials in the form of paper sheets have been used as platforms to achieve multifunctionality. Combined with electrochemical deposition, room temperature synthesis of magnetic Ni coatings on individual carbon nanofibers (CNF) and/or carbon nanotubes (CNT) has been realized through solution penetration and ion diffusion. In addition to significant electrical conductivity improvement, the magnetic responses of the Ni coated carbon nanopaper sheets can be tuned within large ranges in terms of saturation magnetic field, remnant magnetization and coercivity. After being re-suspended in liquids, the magnetized CNFs/CNTs can be aligned with small external magnetic fields.

Differential Expression of Cathepsins and Cystatin C in Ovine Uteroplacental Tissues

Cathepsins (CTSs) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of pro-hormones. Cystatin C (CST3) is a secreted inhibitor of lysosomal cysteine proteases cathepsin B (CTSB) and CTSL. Our working hypothesis is that cathepsins and cystatins play important roles in implantation and placentation in sheep. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, CTSZ, and CST3 mRNAs was detected in ovine uteroplacental tissues with distinct temporal and/or spatial expression patterns between Days 40 and 120 of pregnancy. Of particular note, CTSB, CTSD, and CTSZ mRNAs were predominantly detected in the chorion of the placenta and were more abundant in the placentomes than the intercaruncular endometria. CTSL and CST3 mRNAs were abundant in the endometrial epithelia and chorion, whereas CTSK, CTSS and CTSH mRNAs were most abundant in the stratum compactum stroma of the intercaruncular endometrium. Consistent with localisation of mRNAs, immunoreactive CTSL and CST3 proteins were mainly observed in the intercaruncular endometrial glands and intercotyledonary placenta during later pregnancy. These results support the working hypothesis that CTS and CST3 in uteroplacental tissues are involved in endometrial remodelling and placentation in sheep.

Seroprevalence of hepatitis C in intravenous opioid users presenting in the early phase of injecting drug use in Singapore

INTRODUCTION

All over the world, Hepatitis C virus (HCV) accounts for an estimated 130 million chronic infections. Injection drug use has become one of the most important risk factors for HCV, and within the injection drug user population, the prevalence of HCV antibody ranges from 70 to 95 percent depending on an individual's length of use and the prevalence of infection in the community. This study was undertaken to determine the prevalence of and the risk factors for Hepatitis C antibodies in injecting drug users presenting to the Community Addictions Management Programme (CAMP) in Singapore.

METHODS

Eligibility criteria for inclusion in this study were all intravenous buprenorphine users presenting to CAMP. 106 subjects, who consented to the study, completed an interviewer-administered questionnaire, and underwent a urine and blood analysis.

RESULTS

The prevalence rate for HCV was 42.5 percent among the subjects included in our study. The odds of seroprevalence in those sharing needles were 5.6 times that of those who were not, and the odds of seroprevalence among those using with others (peers or partners) were 6.3 times, as compared to among those who were individual users. Racial differences were also seen, but these could be accounted for by the sharing of needles.

CONCLUSION

This study provides important local data at the onset of an early buprenorphine-injecting epidemic in Singapore. This data is useful for disease prevention and healthcare planning.

Contaminants-induced oxidative damage on the carp Cyprinus carpio collected from the upper Yellow River, China

The Yellow River, the second largest river in China, is the most important resource of water supply in North China. In the last 40 years, even in the upper Yellow River, with the development of industry and agriculture, more and more contaminants have been discharged into this river and greatly polluted the water. Although a routine chemical component analysis has been performed, little is known about the real toxic effects of the polluted water on organisms at environmental level. To explore whether the pollutants induced oxidative stress and damage to aquatic organisms, malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in hepatopancreas, kidney and intestine of the field-collected carp Cyprinus carpio from a mixed polluted (Lanzhou Region, LZR) and a relatively unpolluted (Liujiaxia Region, LJXR) sites of the upper Yellow River were measured. The results showed that when the values of LZR compared with those of LJXR, SOD and GST activities increased and GPx activity decreased significantly in all the three organs (P < 0.05-0.01); CAT activity decreased but MDA level increased significantly (P < 0.05-0.01) only in kidney and intestine. In conclusion, the results of this study suggest that the pollutants can induce obvious oxidative damage in the carp, and the SOD, GST and GPx might be better indicators for the oxidative damage in aquatic organisms.