Trifocal diffractive intraocular lens implantation in patients after previous corneal refractive laser surgery for myopia.

BACKGROUND: With the difficulties in IOL power calculation and the potential side effects occurring postoperatively, multifocal IOL implantation after previous corneal refractive surgery are rarely reported especially for the trifocal IOL. Herein we report the clinical observation of trifocal IOL implantation in patients with previous myopia excimer laser correction. In this study, a multi-formula average method was performed for the IOLs power calculation to improve the accuracy. Visual and refractive outcomes were analyzed, and the subjective quality of patients' life was evaluated by questionnaires survey. METHODS: This retrospective case series included patients with previous myopia excimer laser correction who underwent femtosecond laser assisted phacoemulsification and trifocal IOL (AT LISA tri 839 MP) implantation. Follow-up was done at 1-day, 1-month and 3-month to assess the visual outcomes. Outcome measures were uncorrected distance, intermediate and near visual acuity (UDVA, UIVA, UNVA), manifest refraction, defocus curve, and subjective quality of vision. RESULTS: Twenty-one Eyes from sixteen patients (14 eyes with previous laser in situ keratomileusis and 7 eyes with previous photorefractive keratectomy) were included. Mean postoperative spherical equivalent (SE) at 3-month was - 0.56 D ± 0.49 SD, wherein, 10 eyes (47.6%) were within ±0.50 D of the desired emmetropia and 19 eyes (90.5%) were within ±1.0 D. Mean monocular UDVA, UIVA and UNVA (logMAR) at last visit were 0.02 ± 0.07, 0.10 ± 0.10, and 0.15 ± 0.11 respectively. Three patients (19%) reported halos and glare in postoperative 3 months, two of them needed to use spectacles to improve the intermediate visual acuity. Fifteen patients (94%) reported a satisfaction score of ≥3.5 out of 4.0, without any difficulty in daily activity. Thirteen patients (81%) did not need spectacles at all distances, while the other 3 patients (19%) used spectacles for near-distance related visual activity. Mean composite score of the VF-14 questionnaire was 95.00 ± 7.29 out of 100. CONCLUSIONS: Trifocal IOL implantation after myopia excimer laser correction could restore good distance, intermediate visual acuity and acceptable near visual acuity, and provide accurate refractive outcomes as well as high spectacles independence rate.

Development of a reference dose for BDE-47, 99, and 209 using benchmark dose methods.

Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA's benchmark dose software (BMDS) for calculation of a benchmark dose (BMD) and a benchmark dose low (BMDL). After assessing 91 endpoints across the nine studies, a total of 23 of these endpoints were identified for BMD modeling, and BMDL estimates corresponding to various dose-response models were compiled for these separate endpoints. Thyroid, neurobehavior and reproductive endpoints for BDE-47, -99, -209 were quantitatively evaluated. According to methods and feature of each study, different uncertainty factor (UF) value was decided and subsequently reference doses (RfDs) were proposed. Consistent with USEPA, the lowest BMDLs of 2.10, 81.77, and 1698 µg/kg were used to develop RfDs for BDE-47, -99, and -209, respectively. RfDs for BDE-99 and BDE-209 were comparable to EPA results, and however, RfD of BDE-47 was much lower than that of EPA, which may result from that reproductive/developmental proves to be more sensitive than neurobehavior for BDE-47 and the principal study uses very-low-dose exposure.

Application of statistical distribution of PM10 concentration in air quality management in 5 representative cities of China.

OBJECTIVE: To estimate the frequency of daily average PM10 concentrations exceeding the air quality standard (AQS) and the reduction of particulate matter emission to meet the AQS from the statistical properties (probability density functions) of air pollutant concentration. METHODS: The daily PM10 average concentration in Beijing, Shanghai, Guangzhou, Wuhan, and Xi'an was measured from 1 January 2004 to 31 December 2008. The PM10 concentration distribution was simulated by using the lognormal, Weibull and Gamma distributions and the best statistical distribution of PM10 concentration in the 5 cities was detected using to the maximum likelihood method. RESULTS: The daily PM10 average concentration in the 5 cities was fitted using the lognormal distribution. The exceeding duration was predicted, and the estimated PM10 emission source reductions in the 5 cities need to be 56.58%, 93.40%, 80.17%, 82.40%, and 79.80%, respectively to meet the AQS. CONCLUSION: Air pollutant concentration can be predicted by using the PM10 concentration distribution, which can be further applied in air quality management and related policy making.

[The establishment and application of Shanghai air quality health index].

OBJECTIVE: This work aimed to construct Shanghai air quality health index (SAQHI) and to grade the air quality in Shanghai. METHODS: Daily average concentrations of particulate matter with aerodynamic diameter less than 10 micrometer (PM(10)), SO(2) and NO(2) from 2001 to 2008 in the central urban areas of Shanghai were collected from Shanghai Environmental Monitoring Center. Contemporaneous data of daily average temperature and relative humidity were obtained from Shanghai Meteorological Bureau. Contemporaneous daily non-accidental mortality of registered residents in central urban areas of Shanghai were obtained from Shanghai Municipal CDC, respectively. Time-series analysis was conducted to estimate the association between air pollution and daily non-accidental mortality in the central urban areas of Shanghai. SAQHI was then established and applied to grade the air quality in Shanghai. RESULTS: On average, there were 122 non-accidental daily deaths in the central urban areas of Shanghai from 2001 to 2008. The contemporaneous daily average concentrations of PM(10), SO(2) and NO(2) for the same period were (97.3 ± 59.5), (50.1 ± 27.8) and (64.7 ± 23.9) µg/m(3), respectively. Daily average temperature was (17.7 ± 8.8)°C, and daily average relative humidity was (71.4 ± 11.8)%. Based on results of time series analysis, formula for SAQHI was SAQHI = 10/17× (exp (0.000 153×PM(10))-1+exp (0.000 662×NO(2))-1)×100. Air quality in Shanghai was graded according to SAQHI values as low health risk (SAQHI: 0 ∼ 3), moderate health risk (SAQHI: 4-6), high health risk (SAQHI: 7-10) and very high health risk (SAQHI: > 10). CONCLUSION: SAQHI could be applied in grading air quality in Shanghai, and reflect the effects of the overall air quality on health.

[Application of disability adjusted life years in evaluating health effects due to particulate air pollution in Chinese cities].

OBJECTIVE: To evaluate the loss of disability adjusted life years (DALYs) due to particulate air pollution in Chinese urban residents. METHODS: DALYs was applied to evaluate the health effects due to particulate air pollution in the residents of 656 Chinese cities, and the data of annual average concentrations of inhalable particle (PM(10)) in 2006 were collected from the state-owned air quality monitoring network. RESULTS: Particulate air pollution in Chinese urban areas in 2006, could cause (506.6 +/- 95.2) thousand premature deaths, (156.6 +/- 41.2) thousand new cases of chronic bronchitis, (12.6 +/- 5.2) million outpatient visits for internal medicine, (99.9 +/- 50.4) thousand and (72.0 +/- 8.2) thousand hospital admissions for cardiovascular diseases and respiratory diseases respectively. The attributable DALYs loss in urban residents amounted up to (5.26 +/- 0.99) million person years in 2006, of which, 96.26% (506.55/526.22) were caused by premature deaths. The attributable loss of DALYs increased with more seriously PM-polluted atmosphere and larger urban population. CONCLUSION: Substantial adverse health effects due to outdoor particulate air pollution were observed in China urban areas, thus strengthening air pollution control still remains an imperative and urgent matter in public health perspective.

Impact of ambient air pollution on public health under various traffic policies in Shanghai, China.

OBJECTIVE: To investigate the potential impact of ambient air pollution on public health under various traffic policies in Shanghai. METHODS: The exposure level of Shanghai residents to air pollution under various planned traffic scenarios was estimated, and the public health impact was assessed using concentration-response functions derived from available epidemiological studies. RESULTS: Our results showed that ambient air pollution in relation to traffic scenarios had a significant impact on the future health status of Shanghai residents. Compared with the base case scenario, implementation of various traffic scenarios could prevent 759-1574, 1885-2420, and 2277-2650 PM10-related avoidable deaths (mean-value) in 2010, 2015, and 2020, respectively. It could also decrease the incidence of several relevant diseases. CONCLUSION: Our findings emphasize the need to consider air pollution-related health effects as an important impact of traffic policy in Shanghai.

A time series analysis of outdoor air pollution and preterm birth in Shanghai, China.

OBJECTIVE: To investigate the relation between air pollution exposure and preterm birth in Shanghai, China. METHODS: We examined the effect of ambient air pollution on preterm birth using time-series approach in Shanghai in 2004. This method can eliminate potential confounding by individual risk factors that do not change over a short period of time. Daily numbers of preterm births were obtained from the live birth database maintained by Shanghai Municipal Center of Disease Control and Prevention. We used the generalized additive model (GAM) with penalized splines to analyze the relation between preterm birth, air pollution, and covariates. RESULTS: We observed a significant effect of outdoor air pollution only with 8-week exposure before preterm births. An increase of 10 microg/m3 of 8-week average PM10, SO2, NO2, and O3 corresponded to 4.42% (95%CI 1.60%, 7.25%), 11.89% (95%CI 6.69%, 17.09%), 5.43% (95%CI 1.78%, 9.08%), and 4.63% (95%CI 0.35%, 8.91%) increase of preterm birth. We did not find any significant acute effect of outdoor air pollution on preterm birth in the week before birth. CONCLUSION: Ambient air pollution may contribute to the risk of preterm birth in Shanghai. Our analyses also strengthen the rationale for further limiting air pollution level in the city.

Interaction between ambient particles and ozone and its effect on daily mortality.

OBJECTIVE: To examine the effect of particulate matter (PM) less than 10 microns in diameter (PM10) and ozone (O3) on daily mortality in Shanghai, China. METHODS: A generalized additive model with penalized spline function was used to observe the acute effect of PM10 and O3 on daily mortality. RESULTS: Higher PM10 significantly increased the effect of O3 on total mortality, and O3 also increased the effect of PM10 although the estimated increment was statistically insignificant. CONCLUSION: Our findings provide further evidence for the effect of PM10 and O3 on daily mortality.

Phthalate exposure and human semen quality in Shanghai: a cross-sectional study.

OBJECTIVE: To monitor the level of phthalates in human semen samples and to analyze the relationship between phthalate levels and semen parameters. METHODS: Concentrations of three kinds of commonly used phthalates (di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP) were measured using reversed-phase HPLC. Semen parameters were measured by computer aided sperm analysis (CASA). RESULTS: The three phthalates were detected in most of the biological samples, with median levels of 0.30 mg/L (0.08-1.32 mg/L) in semen specimens. There was a significant positive association between liquefied time of semen and phthalate concentrations of semen. The correlation coefficient was 0.456 for DEP, 0.475 for DBP, and 0.457 for DEHP, respectively. There was no significant difference between phthalate concentrations of semen and sperm density or livability, though the correlation coefficients were negative. CONCLUSION: These results suggest that people who reside in Shanghai are exposed to phthalates, especially to DBP and DEHP. Although the level of phthalates is relatively mild, an association of phthalate levels and reduced quality of human semen has been shown in the present study.

Application of DALYs in measuring health effect of ambient air pollution: a case study in Shanghai, China.

OBJECTIVE: To investigate the effect of ambient air pollution on human health and the subsequent disability-adjusted life years (DALYs) lost in Shanghai. METHODS: We used epidemiology-based exposure-response functions to calculate the attributable number of cases due to air pollution in Shanghai in 2000, and then we estimated the corresponding DALYs lost in Shanghai based on unit DALYs values of the health consequences. RESULTS: Ambient air pollution caused 103,064 DALYs lost in Shanghai in 2000. Among all the health endpoints, premature deaths and chronic bronchitis predominated in the value of total DALYs lost. CONCLUSION: The air pollution levels have an adverse effect on the general population health and strengthen the rationale for limiting the levels of air pollution in outdoor air in Shanghai.

Establishment of exposure-response functions of air particulate matter and adverse health outcomes in China and worldwide.

OBJECTIVE: To obtain the exposure-response functions that could be used in health-based risk assessment of particulate air pollution in China. METHODS: Meta analysis was conducted on the literatures on air particulate matter and its adverse health outcomes in China and worldwide. RESULTS: For each health outcome from morbidity to mortality changes, the relative risks were estimated when the concentration of air particulate matter increased to some certain units. CONCLUSION: The exposure-response functions recommended here can be further applied to health risk assessment of air particulate matter in China.

Relationship between ambient air pollution and daily mortality of SARS in Beijing.

OBJECTIVE: To study the relationship between ambient air pollution and daily mortality of SARS in Beijing. METHODS: The approach of time-series Poisson regression was used to assess the relationship between daily SARS mortality, ambient air pollution, and other factors from April 25 to May 31, 2003 in Beijing. RESULTS: An increase of each 10 microg/m3 over a 5-day moving average of PM10, SO2 and NO2 corresponded to 1.06 (1.00-1.12), 0.74 (0.48-1.13) and 1.22 (1.01-1.48) relative risks (RRs) of daily SARS mortality, respectively. The relative risks (RRs) values depended largely on the selection of lag days. CONCLUSION: The daily mortality of SARS might be associated with certain air pollutants in Beijing.

Statistical distributions of ambient air pollutants in Shanghai, China.

OBJECTIVE: To determine the best statistical distribution of concentration data of major air pollutants in Shanghai. METHODS: Four types of theoretic distributions (lognormal, gamma, Pearson V and extreme value) were chosen to fit daily average concentration data of PM10, SO2 and NO2 from June 1, 2000 to May 31, 2003 in Shanghai by using the maximum likelihood method. The fit results were evaluated by Chi-square test. RESULTS: The best-fit distributions for PM10, SO2 and NO2 concentrations in Shanghai were lognormal, Pearson V, and extreme value distributions, respectively. CONCLUSION: The results can be further applied to local air pollution prediction and control, e.g., the probabilities exceeding the air quality standard and emission source reduction of air pollutant concentration to meet the standard.

Impact of long-term exposure to air particulate matter on life expectancy and survival rate of Shanghai residents.

OBJECTIVE: To evaluate the impact of long-term air particulate matter exposure on the life expectancy and survival rate of Shanghai residents. METHODS: Epidemiology--based exposure-response function was used for the calculation of attributable deaths to air particulate matter in Shanghai, and the effect of long-term exposure to particulate matter on life expectancy and survival rate was estimated using the life table of Shanghai residents in 1999. RESULTS: It was shown that in 1999, the long-term air particulate matter exposure caused 1.34-1.69 years reduction of life expectancy and a decrease of survival rate for each age group of Shanghai residents. CONCLUSION: The effect of long-term exposure to air particulate matter on life expectancy is substantial in Shanghai.

Temperature and daily mortality in Shanghai: a time-series study.

OBJECTIVE: To investigate the association between temperature and daily mortality in Shanghai from June 1, 2000 to December 31, 2001. METHODS: Time-series approach was used to estimate the effect of temperature on daily total and cause-specific mortality. We fitted generalized additive Poisson regression using non-parametric smooth functions to control for long-term time trend, season and other variables. We also controlled for day of the week. RESULTS: A gently sloping V-like relationship between total mortality and temperature was found, with an optimum temperature (e.g. temperature with lowest mortality risk) value of 26.7 degrees C in Shanghai. For temperatures above the optimum value, total mortality increased by 0.73% for each degree Celsius increase; while for temperature below the optimum value, total mortality decreased by 1.21% for each degree Celsius increase. CONCLUSIONS: Our findings indicate that temperature has an effect on daily mortality in Shanghai, and the time-series approach is a useful tool for studying the temperature-mortality association.

[Reversibility of adverse effects of di-n-butyl phthalate on F1 generation rat testes].

OBJECTIVE: To study the reversibility of di-n-butyl phthalate (DBP) effects on F(1) generation rat testes. METHODS: Pregnant rats were treated with different dose of DBP (0, 50, 250 and 500 mg per kg per day) by gavage from GD1 to PND21. The adverse effects of DBP on testes of F(1) male rats in different developmental period (PND14, 21 and 70) were observed by anatomy and pathological methods. RESULTS: There was no difference in rat testis weight and testis/body weight between DBP-treated group and the control. From the results of pathology and sertoli cell counting, comparing with the control, thinner seminiferous epithelium, decreased cell number and vacuole cells were observed in PND14 male DBP-treated rats. In PND21 rats, the number and form of sertoli cells were recovered and few exfoliated spermatogenic cells were found. When maturing to PND70, few rats were found irreversible damages such as seminiferous tubule degeneration, seminiferous epithelium atrophy, etc. CONCLUSION: These results suggest that adverse effects of DBP on young rat testes should be reversibility.

[Copper treatment alters the barrier functions of human intestinal Caco-2 cells].

OBJECTIVE: To investigate the effects of copper on permeability and P-glycoprotein (P-gp) of Caco-2 cell monolayers. METHODS: The differentiated Caco-2 cell model was used in this study. Permeability of cell monolayers was reflected by monitoring transepithelial electrical resistance (TEER); distribution of tight junctional protein ZO-1 was measured by immunofluorescent staining; F actin was measured by fluorescence staining; and Activity of P-gp was reflected by changes of transcellular transport and accumulation of Rho-123 in Caco-2 cells. RESULTS: Apical treatment with copper (30 - 100 micromol/L, Hanks' buffered salt solution, up to 3 hours) induced a time- and concentration-dependent increase in permeability reflected by progressive decrease of TEER of Caco-2 cell monolayers, accompanied by deorganization of F actin, but without significant effects on tight junctional protein ZO-1; at a dose without any adverse effects on viability and permeability of Caco-2 monolayers, copper treatment (300 micromol/L, complete medium, 24 hours) decreased Papp(BL-->AP) from 7.37 +/- 0.20 x 10(-6) cm/s (controls) to (6.43 +/- 0.27) x 10(-6) cm/s, the increased Papp(AP-->BL) from (1.23 +/- 0.05) x 10(-7) cm/s (controls) to (3.41 +/- 0.08) x 10(-7) cm/s, and enhanced the intracellular Rho-123 from (0.31 +/- 0.01) nmol/filter (controls) to (0.50 +/- 0.03) nmol/filter. CONCLUSION: Copper might alter the barrier functions of Caco-2 cells through increasing the permeability and inhibiting P-gp of Caco-2 cells.

[Study on the level of phthalates in human biological samples].

OBJECTIVE: To monitor the level of phthalates in human biological samples. METHODS: The concentrations of three commonly-used phthalate (di-ethyl phthalate, DEP; di-n-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP) in the human biological samples were measured by using reversed-phase HPLC. The blood serum samples were collected from 52 women and 8 men, semen specimens from 36 men, and fat samples from 6 women and 5 men. All these people were randomly selected, from 23 to 50 years of age and residing in Shanghai. We also measured hormone levels of serum and conventional indices of semen specimens. RESULTS: The three phthalates were detected in most of the biological samples, with median levels of 5.71 mg/L (ND-37.91 mg/L) in blood serum, 0.30 mg/L (0.08 -1.32 mg/L) in semen specimens, and 0.72 mg/kg (ND-2.19 mg/kg) in fat samples. The spearman correlation coefficients between concentrations of phthalates and levels of hormone in serum were 0.442 for DBP and E(2), and -0.486 for DEP and testosterone. There was a positive association between liquefied time of semen and semen concentrations of phthalates. The correlation coefficients were 0.456 for DEP, 0.475 for DBP, and 0.457 for DEHP, respectively. There was no significant difference between semen concentrations of phthalates and sperm density. CONCLUSION: These results suggest that people residing in Shanghai area are exposed to phthalates (particularly to DBP and DEHP) though the level is still relatively low.

[Study on the application of benchmark dose and biological monitoring indexes of fluorides in drinking water].

OBJECTIVE: By using Benchmark Dose (BMD) approach to explore the relations among drinking water fluoride, urine fluoride, serum fluoride and dental fluorosis; and to evaluate the significance of urine fluoride and serum fluoride in control and prevention of endemic fluorosis. METHODS: 512 children (290 in Xinhuai Village, 222 in Wamiao Village) aged 8-13 years were recruited in the study. Epidemiological methods were used to investigate the prevalence of dental fluorosis, and the levels of urine fluoride, serum fluoride, and drinking water fluoride in superficial well. The children were divided into six subgroups by the concentration of fluoride in drinking water: < 0.5 mg/L, 0.5-mg/L, 1.0-mg/L, 2.0-mg/L, 3.0-mg/L and > or = 4.0 mg/L. RESULTS: There was significant dose-response relationship between the drinking water fluoride and the prevalence of dental fluorosis or the prevalence of defect dental fluorosis. The BMDLs (Benchmark Dose Lower Bound) were 1.01 and 1.30 mg/L, respectively. Urine fluoride and serum fluoride also had significant dose-response relationship to the prevalence of dental fluorosis or defect dental fluorosis. The correlation coefficient between drinking water fluoride and urine fluoride was 0.717, and it was 0.855 between drinking water fluoride and serum fluoride, and 0.617 between urine fluoride and serum fluoride. CONCLUSIONS: The currently national standard of fluoride in drinking water in China is safe and reasonable. As a biological monitoring index, the levels of fluoride in serum may be more useful than that in urine in the control and prevention of endemic fluorosis.

Exposure levels of environmental endocrine disruptors in mother-newborn pairs in China and their placental transfer characteristics.

There is a growing concern about the potential health effects of exposure to various environmental chemicals during pregnancy and infancy. The placenta is expected to be an effective barrier protecting the developing embryo against some endocrine disruptors (EDs) circulating in maternal blood. The current study was designed to assess in utero exposure levels of non-persistent organic pollutants (non-POPs) and persistent organic pollutants (POPs) in Chinese newborns and potential role of placenta barrier against fetal exposure to these commonly-used environmental endocrine disruptors. A total of 230 newborn-mother pairs were enrolled during 2010-2011, 201 pairs of which were recruited from Shanghai, and the other 29 pairs came from Wenzhou. Maternal blood, cord blood, and meconium specimens were collected in the subject population from Shanghai and analyzed for non-POPs, including mono-2-ethylhexyl phthalate (MEHP), octylphenol (OP) and 4-nonylphenol (4-NP). A total of 19 polybrominated diphenyl ethers (PBDEs) congeners, which belong to POPs, were detected in maternal and cord blood specimens from the other 29 pairs. Fetal-maternal ratios (F-M ratios) and regression coefficients were presented to assess potential function of placenta on barricading the mother/fetal transfer of these EDs. Concentrations of the detected non-POPs in cord blood samples were approximately 20% lower than those in maternal blood, and regression coefficients of which were all over 0.80. In contrast, PBDEs levels in cord blood samples were significantly higher than those in maternal blood. MEHP levels in meconium were much higher than those in cord blood samples, and highly correlated. Therefore, observations demonstrated that the placental barrier slightly decreased the fetal exposure to most non-POPs, while PBDEs seemed to be totally transferred across the placenta and finally reached the fetus. For in utero exposure assessment of Di-2-ethylhexyl phthalate (DEHP), MEHP level in meconium may be a useful biomarker.