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Biomedical subjects

Bingheng Chen

Publications and source records attributed to Bingheng Chen.

At least 19 recordsLinked to original sources
PubMed2007

Differentiating the effects of fine and coarse particles on daily mortality in Shanghai, China.

The findings on health effects of ambient fine particles (PM2.5) and coarse particles (PM10-2.5) remain inconsistent. In China, PM2.5 and PM10-2.5 are not the criteria air pollutants, and their monitoring data are scarce. There have been no epidemiological studies of health effects of PM2.5 and PM10-2.5 simultaneously in China. We conducted a time series study to examine the acute effects of PM2.5 and PM10-2.5 on daily mortality in Shanghai, China from Mar. 4, 2004 to Dec. 31, 2005. We used the generalized additive model (GAM) with penalized splines to analyze the mortality, air pollution and covariate data. The average concentrations of PM2.5 and PM10-2.5 were 56.4 microg/m3 and 52.3 microg/m3 in our study period, and PM2.5 constituted around 53.0% of the PM10 mass. Compared with the Global Air Quality Guidelines set by World Health Organization (10 microg/m3 for annual mean) and U.S. National Ambient Air Quality Standards (15 microg/m3 for annual mean), the PM2.5 level in Shanghai was much higher. We found that PM2.5 was associated with the death rates from all causes and from cardiorespiratory diseases in Shanghai. We did not find a significant effect of PM10-2.5 on mortality outcomes. A10 microg/m3 increase in the 2-day moving average (lag01) concentration of PM2.5 corresponded to 0.36% (95% CI 0.11%, 0.61%), 0.41% (95% CI 0.01%, 0.82%) and 0.95% (95% CI 0.16%, 1.73%) increase of total, cardiovascular and respiratory mortality. For PM10-2.5, the effects were attenuated and less precise. Our analyses provide the first statistically significant evidence in China that PM2.5 has an adverse effect on population health and strengthen the rationale for further limiting levels of PM2.5 in outdoor air in Shanghai.

Air Pollutants↗
PubMed2007

Low-carbon energy policy and ambient air pollution in Shanghai, China: a health-based economic assessment.

Energy and related health issues are of growing concern worldwide today. To investigate the potential public health and economic impact of ambient air pollution under various low-carbon energy scenarios in Shanghai, we estimated the exposure level of Shanghai residents to air pollution under various planned scenarios, and assessed the public health impact using concentration-response functions derived from available epidemiologic studies. We then estimated the corresponding economic values of the health effects based on unit values for each health outcome. Our results show that ambient air pollution in relation to low-carbon energy scenarios could have a significant impact on the future health status of Shanghai residents, both in physical and monetary terms. Compared with the base case scenario, implementation of various low-carbon energy scenarios could prevent 2804-8249 and 9870-23,100 PM10-related avoidable deaths (mid-value) in 2010 and 2020, respectively. It could also decrease incidence of several relevant diseases. The corresponding economic benefits could reach 507.31-1492.33 and 2642.45-6192.11 million U.S. dollars (mid-value) in 2010 and 2020, respectively. These findings illustrate that a low-carbon energy policy will not only decrease the emission of greenhouse gases, but also play an active role in the reduction of air pollutant emissions, improvement of air quality, and promotion of public health. Our estimates can provide useful information to local decision-makers for further cost-benefit analysis.

Air Pollutants↗
PubMed2006

Ozone and daily mortality in Shanghai, China.

BACKGROUND: Controversy remains regarding the relationship between ambient ozone and mortality worldwide. In mainland China, the largest developing country, there has been no prior study investigating the acute effect of O3 on death risk. Given the changes in types of air pollution from conventional coal combustion to the mixed coal combustion/motor vehicle emissions in China's large cities, it is worthwhile to investigate the acute effect of O3 on mortality outcomes in the country. OBJECTIVES: We conducted a time-series study to investigate the relation between O3 and daily mortality in Shanghai using 4 years of daily data (2001-2004). METHODS: We used the generalized additive model with penalized splines to analyze mortality, O3 pollution, and covariate data in warm and cold seasons. We considered daily counts of all-cause mortality and several cause-specific subcategories (respiratory and cardiovascular). We also examined these associations among several subpopulations based on age and sex. RESULTS: O3 was significantly associated with total and cardiovascular mortality in the cold season but not in the warm season. In the whole-year analysis, an increase of 10 microg/m3 of 2-day average (lag01) O3 corresponds to 0.45% [95% confidence interval (CI) , 0.16-0.73%], 0.53% (95% CI, 0.10-0.96%), and 0.35% (95% CI, -0.40 to 1.09%) increase of total nonaccidental, cardiovascular, and respiratory mortality, respectively. In the cold season, the estimates increased to 1.38% (95% CI, 0.68-2.07%), 1.53% (95% CI, 0.54-2.52%), and 0.95% (95% CI, -0.71 to 2.60%), respectively. In the warm season, we did not observe significant associations for both total and cause-specific mortality. The results were generally insensitive to model specifications such as lag structure of O3 concentrations and degree of freedom for time trend. Multipollutant models indicate that the effect of O3 was not confounded by particulate matter<or=10 microm in diameter (PM10) or by sulfur dioxide; however, after adding nitrogen dioxide into the model, the association of O3 with total and cardiovascular mortality became statistically insignificant. CONCLUSIONS: O3 pollution has stronger health effects in the cold than in the warm season in Shanghai. Our analyses also strengthen the rationale for further limiting levels of O3 pollution in outdoor air in the city.

Adolescent↗
PubMed2005

An initial investigation of the association between the SARS outbreak and weather: with the view of the environmental temperature and its variation.

OBJECTIVE: To understand the association between the SARS outbreak and the environmental temperature, and to provide a scientific basis for prevention and control measures against it. METHODS: The daily numbers of the probable SARS patients and the daily meteorological factors during the SARS outbreak period in Hong Kong, Guangzhou, Beijing, and Taiyuan were used in the data analysis. Ecological analysis was conducted to explore the association between the daily numbers of probable SARS patients and the environmental temperature and its variations. RESULTS: There was a significant correlation between the SARS cases and the environmental temperature seven days before the onset and the seven day time lag corresponds well with the known incubation period for SARS. The optimum environmental temperature associated with the SARS cases was between 16 degrees C to 28 degrees C, which may encourage virus growth. A sharp rise or decrease in the environmental temperature related to the cold spell led to an increase of the SARS cases because of the possible influence of the weather on the human immune system. This study provided some evidence that there is a higher possibility for SARS to reoccur in spring than that in autumn and winter. CONCLUSION: Current knowledge based on case studies of the SARS outbreak in the four cities suggested that the SARS outbreaks were significantly associated with the temperature and its variations. However, because the fallacy and the uncontrolled confounding effects might have biased the results, the possibility of other meteorological factors having an affect on the SARS outbreaks deserves further investigation.

China↗
PubMed2004

Exposures and health outcomes from outdoor air pollutants in China.

China's economy has developed rapidly in the recent two decades. Economic development is usually linked with increase in energy consumption and consumption emissions, which in turn leads to worsening of air quality. Due to the adoption of various control measures, the ambient air quality in a number of large cities in China has actually improved. The ambient air TSP and SO(2) levels in China have been decreasing in the last decade. However, ambient air NO(x) level has been increasing due to the increased number of motor vehicles. Coal has been and is still the major source of energy in China. Ambient air pollution in large cities has changed from the conventional coal combustion type to the mixed coal combustion/motor vehicle emission type. A series of epidemiological studies on air pollution and health effects ranging from mortality, morbidity to functional changes have been conducted in China. The results showed that ambient air pollution had acute and chronic effects on mortality, morbidity, hospital admissions, clinical symptoms, lung function changes, etc. The exposure-response relationship between air pollutants and daily mortality, morbidity, hospital admissions, and lung function has been established accordingly.

Adult↗
PubMed2004

Particulate air pollution in urban areas of Shanghai, China: health-based economic assessment.

Urban air quality is becoming a serious public health concern in China. To obtain the quantitative result of the impact of particulate air pollution on human health and the subsequent economic costs in Shanghai, we used epidemiology-based exposure-response functions to calculate the attributable number of cases due to particulate air pollution in urban areas of Shanghai in 2001, and then we estimated the corresponding economic costs of the health damage based on unit values of the health outcomes. It was estimated that the total economic cost of health impacts due to particulate air pollution in urban areas of Shanghai in 2001 was approximately 625.40 million US dollars, accounting for 1.03% of gross domestic product of the city. The results suggest that the impact of particulate air pollution on human health could be substantial in urban Shanghai, whether in physical and economic terms.

Adolescent↗
PubMed2004

Reproductive and developmental toxicity in F1 Sprague-Dawley male rats exposed to di-n-butyl phthalate in utero and during lactation and determination of its NOAEL.

Di-n-butyl phthalate (DBP) is one of the commonly used plasticizers in China. DBP can enter the environment and organisms through various routes and then affect reproductive and developmental processes of the organism and its descendants (mainly affecting male offspring). It is known that animals are sensitive to exposure of DBP in utero and during lactation. In the present study, pregnant rats were treated with different doses of DBP (0, 50, 250, and 500 mg/kg body weight/day) by daily gavage from GD1 to PND21. The developmental condition of F1 rats and the reproductive system of mature F1 male rats were monitored. DBP had no obvious effect on pregnant rats; however, it reduced several parameters including birth weight, number of live pups per litter, body weight gain and male anogenital distance. Severe damage to the reproductive system of mature F1 male rats included testicular atrophy, underdeveloped or absent epididymis, undescended testes, obvious decline of epididymal sperm parameters, total sperm heads per g testis, decrease of organ/body weight ratio of epididymis and prostate, and was observed in the group treated with 250 mg/kg BW/day and higher. These results showed that the male reproductive system was the main target organ of DBP exposure. The NOAEL (no observable adverse effect level) for developmental toxicity of DBP was established based on pup body weight and male reproductive lesions at 50 mg/kg BW/day. Accordingly, the RfD for human exposure to DBP through oral intake was recommended as 500 mg/kg BW/day.

Abnormalities, Drug-Induced↗
PubMed2004

Copper treatment alters the barrier functions of human intestinal Caco-2 cells: involving tight junctions and P-glycoprotein.

This study investigated the effects of copper on paracellular permeability and P-glycoprotein (P-gp) in Caco-2 cells. Apical treatment with 100-300 microM CuSO4 in Hanks' balanced salt solution (HBSS, up to 3 hours) induced a time- and concentration-dependent increase in permeability of Caco-2 cell monolayers monitored by transepithelial electrical resistance (TEER). Copper treatment also induced a concentration-dependent reduction of F-actin stain, but not of tight junctional protein ZO-1. In addition, without any adverse effects on TEER, apical treatment with 300 microM CuSO4 in complete medium (for 24 hours) could reduce basolateral-to-apical transport, and increase apical-to-basolateral transport of rhodamine-123 (Rho-123) and accumulation of Rho-123 in Caco-2 cells. Treatment with 10-100 microM CuSO4 in HBSS (up to 3 hours) also induced a time- and concentration-dependent increase in accumulation of Rho-123 in Caco-2 cells. The results indicated that copper treatment increased the paracellular permeability probably by perturbing F-actin skeleton, and inhibited P-gp, thus altering the barrier functions of Caco-2 cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

[Reproductive and developmental toxicity of F1 male rats treated with DBP in utero and during lactation].

OBJECTIVE: To observe the effects of Di-n-butyl phthalate (DBP) on the developmental condition of F1 rats and on the reproductive system of mature F1 male rats and to establish the NOAEL of DBP. METHODS: In this study, pregnant rats were treated with different dose of DBP (0, 50, 250 and 500 mg per kg per day) by gavage in utero and during lactation (from GD1 to PND21). The effects of DBP on F1 rats were observed. RESULTS: DBP had no obvious effect on pregnant rats but could decline pups' born weight, live pups per litter, body weight gain and male pups' anogenital distance obviously. Severe damages on the reproductive system of mature F1 male rats (testicular atrophy, underdevelopmental epididymis, absent of epididymis, undescended testes, obvious decline of epididymal sperm parameters, total sperm heads per g testis, decrease of organ/body weight ratio of epididymis, liver, kidney and prostate, etc.) were observed in the group of 250 mg per kg per day and higher. CONCLUSION: These results showed that male reproductive system was the target organ of DBP and the damages on pups were partly irreversible. According to these results, the NOAEL of DBP, which was not available in the current database, was established based on the outcomes of this study, i.e., 50 mg per kg per day. Accordingly, the RfD for human exposure to DBP through oral intake was recommended as 500 micrograms per kg per day.

Abnormalities, Drug-Induced↗
PubMed2004

[A time-series study on the association of stroke mortality and air pollution in Zhabei District, Shanghai].

OBJECTIVE: To assess the association between air pollution and daily stroke mortality. METHODS: All death records of the decreased who lived in one urban district of Shanghai and died from stroke from January 1 to December 31, 2001 were collected. We used a time series approach to study the acute effects of air pollution on stroke mortality after controlling for long-term trends, weather variables, and day of the week. RESULTS: An increase of 10 micrograms/m3 of PM10, SO2 and NO2 corresponds to 1.008 (95% CI 1.000-1.016), 1.017 (95% CI 0.998-1.036), and 1.029 (95% CI 1.001-1.057) relative risk of stroke mortality, respectively in Shanghai. CONCLUSION: Our findings provide new evidence for the association between air pollution and acute stroke mortality risk.

Air Pollutants↗
PubMed2004

[Toxicological effects of copper on human intestinal Caco-2 cells].

OBJECTIVE: To study the toxicological effects of copper on human intestinal Caco-2 cells. METHODS: The effects of copper on human intestinal Caco-2 cells were evaluated by MTT conversion, intra-cellular production of reactive oxygen species (ROS), cloning efficiency and changes of P-glycoprotein (P-gp) activities in Caco-2 cells. In addition, Caco-2 cells and Salmonella enteritidis served as the models to examine the effect of copper on the host-parasite interaction. RESULTS: Copper induced a dose-dependent decrease of cell viability measured by MTT assay; by using the fluorescent probe 2, 7-dichlorofluorescin diacetate, a significant increase of ROS production in Cu-treated cells was detected; the significant time- and dose-dependent decrease of P-gp activities in Cu-treated cells was demonstrated by increased accumulation of rhodamine 123 in cells. Copper treatment also increased the efficiency of the bacterial invasion, but decreased the number of bacteria surviving in the intracellular environment. CONCLUSION: Copper induced a variety of toxicological endpoints which might be caused by oxidative damage, but the effect of copper on cell-bacteria interaction needs to be further investigated.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

The association of daily diabetes mortality and outdoor air pollution in Shanghai, China.

The objective of the study reported here was to assess the association between air pollution and daily diabetes mortality in Shanghai. Death records were collected for all individuals who lived in the Zhabei district of Shanghai and died from diabetes from January 1, 2001, to December 31, 2002. The authors used a time-series approach to study the acute effects of air pollution on diabetes mortality after controlling for long-term trends, weather variables, and day of the week. Each increase of 10 microg/m3 in PM10, SO2, or NO2 was found to correspond, respectively, to a 1.006 (95 percent CI: 1.000-1.012), 1.011 (95 percent CI: 0.990-1.032), or 1.013 (95 percent CI: 1.000-1.026) relative risk of diabetes mortality in Shanghai. The air pollutants also were observed to have a greater effect on diabetics than on nondiabetics. These findings provide new evidence for the association between air pollution and diabetes mortality risk, and suggest that diabetics are more susceptible to air pollution than are nondiabetics.

Air Pollutants↗
PubMed2004

[Caco-2 cell monolayers and it's application in toxicological research].

Caco-2 cells derived from a human colon adenocarcinoma, spontaneously differentiate after reaching confluence in culture, exhibiting several morphological and functional characteristics of mature enterocytes. Caco-2 cell monolayers represents a well-established model for the study of intestinal transport of nutrients and xenobiotics, and is wildly used in pharmacology and toxicology. In this review the cell culture conditions, characteristics and functional parameters of model were introduced. The application of Caco-2 cell monolayers in studying mechanism, uptake, transport and gastrointestinal toxicity of xenobiotics were also explained.

Biological Transport↗
PubMed2003

Confirmation of an acute no-observed-adverse-effect and low-observed-adverse-effect level for copper in bottled drinking water in a multi-site international study.

In a double blind, 3x3 factorial (volumexdose) study, 70 adult females (18-60 years of age) at four different international sites (total pooled n=269) were given 100, 150, or 200ml of bottled drinking water with 0.4, 0.8, or 1.2mg of copper (Cu) as the sulfate salt once each week. Two additional doses (0 and 1.6mg Cu) were added at the 200ml volume to determine a dose-response relationship and corroborate previously reported results. All subjects completed a questionnaire at 0, 0.25, and 1h post-dosing that screened for positive gastrointestinal (GI) effects (nausea, vomiting, abdominal pain, and diarrhea). Nausea was the most prevalent symptom reported and was generally reported within the first 15min (water volume, p<0.032; copper dose, p<0.0001; and water volumexcopper interaction, p<0.97). As volume increased, the effect of Cu-induced nausea decreased; as Cu dose increased, the incidence of nausea increased. At 200ml, a significant increase in reported incidence of nausea at 0.25h occurred at 1.2 mg Cu (6mg Cu/L), indicating a NOAEL of 0.8mg Cu (4mg Cu/L) for adult females. These data confirm a previously determined human acute NOAEL for Cu added to distilled water, and provide additional, controlled human data for determining safe concentrations of Cu in drinking water.

Administration, Oral↗
PubMed2003

A case-crossover analysis of air pollution and daily mortality in Shanghai.

We used a case-crossover approach to assess the association between air pollution and daily mortality in Shanghai from June 2000 to December 2001. By design, this method can avoid some common concerns about the time-series approach, which was most frequently used to assess the short-term effects of air pollution. Different control periods (unidirectional and bi-directional control samplings) were used for the analysis. With a bi-directional six control sampling approach, the results from a conditional logistic regression model controlling for weather conditions showed that each 10 microg/m3 increase over a 48-h moving average of PM10, SO2 and NO2 corresponds to 1.003 (95%CI 1.001-1.005), 1.016 (95%CI 1.011-1.021), and 1.020 (95%CI 1.012-1.027) relative risk of non-accident mortality, respectively. The association between air pollution and mortality for chronic obstructive pulmonary diseases (COPD) and cardiovascular causes was found to be closer than that for all causes. The results confirmed the deleterious role of the current air pollution level on human health in Shanghai, and provided information on the applicability of case-crossover design in studying the acute health effects of air pollution.

Air Pollutants↗
PubMed2003

[A new toxicological concept-acute reference dose].

Acute reference dose (ARfD) is a new concept in toxicology and risk assessment, and mainly used for assessing health effect from short-time exposure to environmental chemicals. The ARfD of a chemical was defined as "an estimate of a substance in food or drinking water, expressed on a body weight basis, that can be ingested over a short period of time, usually during one meal or one day, without appreciable health risk to the consumer on the basis of all the known facts at the time of the evaluation. It is usually expressed in milligrams per kilogram of body weight." ARfD is different from ADI and reference dose. In this review the principles and methods in establishing ARfD were explained.

Dose-Response Relationship, Drug↗