Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
J Environ Sci (China) ; 130: 37-51, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37032041

RESUMEN

This study analyzes the impact of circulation types (CTs) on ozone (O3) pollution in Beijing. The easterly high-pressure (SWW) circulation occurred most frequently (30%; 276 day), followed by northwesterly high-pressure (AN) circulation (24.3%; 224 day). The SWW type had the highest O3 anomaly of +17.28 µg/m3, which was caused by excellent photochemical reactions, poor diffusion ability and regional transport. Due to the higher humidity and precipitation in the low-pressure type (C), the O3 increase (+8.02 µg/m3) was less than that in the SWW type. Good diffusion/wet deposition and weak formation ability contributed to O3 decrease in AN (-12.54 µg/m3) and northerly high-pressure (ESN) CTs (-12.26 µg/m3). The intra-area transport of O3 was significant in polluted circulations (SWW- and C-CTs). In addition, higher temperature, radiation and less rainfall also contributed to higher O3 in northern Beijing under the SWW type. For the clean CTs (AN and ESN CTs), precursor amount and intra-area transport played a dominant role in O3 distribution. Under the northeasterly low-pressure CT, better formation conditions and higher precursor amount combined with the intra-area southerly transport to cause higher O3 values in the south than in the north. The higher O3 in the northwestern area under the northeasterly high-pressure type was influenced by weaker titration loss and high O3 concentration in previous day. Annual variation in the CTs contributed up to 86.1% of the annual variation in O3. About 78%-83% of the diurnal variation in O3 resulted from local meteorological factors.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Ozono , Ozono/análisis , Beijing , Contaminantes Atmosféricos/análisis , Estaciones del Año , Monitoreo del Ambiente , China , Contaminación del Aire/análisis
2.
J Proteomics ; 276: 104841, 2023 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-36796721

RESUMEN

PURPOSE: Henoch-Schönlein purpura (HSP) is diagnosed based on characteristic skin changes. This study aimed to identify the serum biomarkers of HSP in children. EXPERIMENTAL DESIGN: We performed proteomic analysis of serum samples from 38 paired pre- and posttherapy HSP patients and 22 healthy controls using a combination of magnetic bead-based weak cation exchange and MALDI-TOF MS. ClinProTools was used to screen the differential peaks. Then, LC-ESI-MS/MS was performed to identify the proteins. ELISA was used to verify the expression of whole protein in the serum of 92 HSP patients, 14 peptic ulcer disease (PUD) patients and 38 healthy controls, which were prospectively collected. Finally, logistic regression analysis was performed to analyze the diagnostic value of the above predictors and existing clinical indicators. RESULTS: Seven potential HSP serum biomarker peaks (m/z:1228.95, m/z:1781.22, m/z:1468.43, m/z:1619.53, m/z:1868.41, m/z:1694.05, m/z:1743.25) with higher expression in the pretherapy group and one peak (m/z:1947.41) with lower expression in the pretherapy group were all identified as peptide regions of albumin (ALB), complement C4-A precursor (C4A), tubulin beta chain (TUBB), isoform 1 of fibrinogen alpha chain (FGA), and ezrin (EZR). The expression of identified proteins was validated by ELISA. Multivariate logistic regression analysis showed that serum C4A EZR and ALB were independent risk factors for HSP, serum C4A and lgA were independent risk factors for HSPN, and serum D-dimer was an independent risk factor for abdominal HSP. CONCLUSIONS AND CLINICAL RELEVANCE: These findings revealed the specific etiology of HSP from the perspective of serum proteomics. The identified proteins might serve as potential biomarkers for HSP and HSPN diagnoses. SIGNIFICANCE: Henoch-Schönlein purpura (HSP) is the most common systemic vasculitis in children, and its diagnosis depends primarily on characteristic skin changes. Early diagnosis of non-rash patients is difficult, especially for abdominal and renal types (Henoch-Schönlein purpura nephritis, HSPN). HSPN has poor outcomes, is diagnosed based on urinary protein and/or haematuria, and cannot be detected early in HSP. Patients with an earlier diagnosis of HSPN appear to have better renal outcomes. Our plasma proteomic analysis of HSP in children revealed that HSP patients could be distinguished from healthy controls and peptic ulcer disease patients using complement C4-A precursor (C4A), ezrin, and albumin. C4A and IgA could distinguish HSPN from HSP in the early stages, and D-dimer was a sensitive index used to distinguish abdominal HSP; identifying these biomarkers could promote the early diagnosis of HSP, especially pediatric HSPN and abdominal HSP, thereby improving precision therapy.


Asunto(s)
Vasculitis por IgA , Nefritis , Humanos , Niño , Vasculitis por IgA/complicaciones , Vasculitis por IgA/diagnóstico , Proteoma , Pueblos del Este de Asia , Proteómica , Espectrometría de Masas en Tándem , Nefritis/etiología , Biomarcadores , Complemento C4 , Albúminas
3.
Br J Cancer ; 128(5): 766-782, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36526675

RESUMEN

BACKGROUND: Deregulation of either RNA polymerase I (Pol I)-directed transcription or expression of signal transducer and activator of transcription 3 (STAT3) correlates closely with tumorigenesis. However, the connection between STAT3 and Pol I-directed transcription hasn't been investigated. METHODS: The role of STAT3 in Pol I-directed transcription was determined using combined techniques. The regulation of tumor cell growth mediated by STAT3 and Pol I products was analyzed in vitro and in vivo. RNAseq, ChIP assays and rescue assays were used to uncover the mechanism of Pol I transcription mediated by STAT3. RESULTS: STAT3 expression positively correlates with Pol I product levels and cancer cell growth. The inhibition of STAT3 or Pol I products suppresses cell growth. Mechanistically, STAT3 activates Pol I-directed transcription by enhancing the recruitment of the Pol I transcription machinery to the rDNA promoter. STAT3 directly activates Rpa34 gene transcription by binding to the RPA34 promoter, which enhances the occupancies of the Pol II transcription machinery factors at this promoter. Cancer patients with RPA34 high expression lead to poor survival probability and short survival time. CONCLUSION: STAT3 potentiates Pol I-dependent transcription and tumor cell growth by activating RPA34 in vitro and in vivo.


Asunto(s)
ARN Polimerasa I , Factor de Transcripción STAT3 , Transcripción Genética , Humanos , Regiones Promotoras Genéticas , ARN Polimerasa I/genética , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Factor de Transcripción STAT3/metabolismo
4.
Front Cell Infect Microbiol ; 13: 1351814, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38304460

RESUMEN

Introduction: Respiratory viral infection (RVI) is of very concern after the outbreak of COVID-19, especially in pediatric departments. Learning pathogen spectrum of RVI in children previous the epidemic of COVID-19 could provide another perspective for understanding RVI under current situation and help to prepare for the post COVID-19 infection control. Methods: A nucleic acid sequence-based amplification (NASBA) assay, with 19 pairs of primers targeting various respiratory viruses, was used for multi-pathogen screening of viral infections in children presenting influenza-like illness (ILI) symptoms. Children with ILI at the outpatient department of Beijing Tsinghua Changgung Hospital during the influenza epidemic from 12/2018 to 01/2019 were included. Throat swabs were obtained for both the influenza rapid diagnostic test (IRDT) based on the colloidal gold immunochromatographic assay and the NASBA assay, targeting various respiratory viruses with an integrated chip technology. Results and discussion: Of 519 patients, 430 (82.9%) were positive in the NASBA assay. The predominant viral pathogens were influenza A H1N1 pdm1/2009 (pH1N1) (48.4%) and influenza A (H3N2) (18.1%), followed by human metapneumovirus (hMPV) (8.8%) and respiratory syncytial virus (RSV) (6.1%). Of the 320 cases identified with influenza A by NASBA, only 128 (40.0%) were positive in the IRDT. The IRDT missed pH1N1 significantly more frequently than A (H3N2) (P<0.01). Influenza A pH1N1 and A (H3N2) were the major pathogens in <6 years and 6-15 years old individuals respectively (P<0.05). In summary, influenza viruses were the major pathogens in children with ILI during the 2018-2019 winter influenza epidemic, while hMPV and RSV were non-negligible. The coexistence of multiple pathogen leading to respiratory infections is the normalcy in winter ILI cases.


Asunto(s)
COVID-19 , Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Virosis , Niño , Humanos , Lactante , Gripe Humana/diagnóstico , Gripe Humana/epidemiología , Subtipo H3N2 del Virus de la Influenza A , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/epidemiología
5.
J Biol Chem ; 298(3): 101581, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35038452

RESUMEN

RNA polymerase III (pol III) products play fundamental roles in a variety of cellular processes, including protein synthesis and cancer cell proliferation. In addition, dysregulation of pol III-directed transcription closely correlates with tumorigenesis. It is therefore of interest to identify novel pathways or factors governing pol III-directed transcription. Here, we show that transcription factor (TF) GATA binding protein 4 (GATA4) expression in SaOS2 cells was stimulated by the silencing of filamin A (FLNA), a repressor of pol III-directed transcription, suggesting that GATA4 is potentially associated with the regulation of pol III-directed transcription. Indeed, we show that GATA4 expression positively correlates with pol III-mediated transcription and tumor cell proliferation. Mechanistically, we found that GATA4 depletion inhibits the occupancies of the pol III transcription machinery factors at the loci of pol III target genes by reducing expression of both TFIIIB subunit TFIIB-related factor 1 and TFIIIC subunit general transcription factor 3C subunit 2 (GTF3C2). GATA4 has been shown to activate specificity factor 1 (Sp1) gene transcription by binding to the Sp1 gene promoter, and Sp1 has been confirmed to activate pol III gene transcription by directly binding to both Brf1 and Gtf3c2 gene promoters. Thus, the findings from this study suggest that GATA4 links FLNA and Sp1 signaling to form an FLNA/GATA4/Sp1 axis to modulate pol III-directed transcription and transformed cell proliferation. Taken together, these results provide novel insights into the regulatory mechanism of pol III-directed transcription.


Asunto(s)
Filaminas , Factor de Transcripción GATA4 , Proteínas Quinasas , ARN Polimerasa III , Proliferación Celular , Filaminas/genética , Filaminas/metabolismo , Factor de Transcripción GATA4/genética , Factor de Transcripción GATA4/metabolismo , Proteínas Quinasas/metabolismo , ARN Polimerasa III/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Transcripción Genética
6.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(9): 877-881, 2021.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-34535200

RESUMEN

OBJECTIVES: To study the efficacy of Huaiqihuang granules as adjuvant therapy for bronchial asthma in children. METHODS: A multicenter, prospective, and registered real-world study was performed for the children, aged 2-5 years, who had a confirmed diagnosis of bronchial asthma in the outpatient service of 21 hospitals in China. Among these children, the children treated with medications for long-term asthma control (inhaled corticosteroid and/or leukotriene receptor antagonist) without Huaiqihuang granules were enrolled as the control treatment group, and those treated with medications for long-term asthma control combined with Huaiqihuang granules were enrolled as the combined treatment group. The medical data of all children were collected. Outpatient or telephone follow-up was performed at weeks 4, 8, 12, 20, 28, and 36 after treatment, including asthma attacks and rhinitis symptoms. A statistical analysis was performed for the changes in these indices. RESULTS: There was no significant difference in the frequency of asthma attacks or rhinitis attacks between the two groups before treatment (P>0.05). After treatment, the combined treatment group had significantly lower frequencies of asthma attacks, severe asthma attacks, and rhinitis attacks compared with the control treatment group (P<0.05). There was no signification difference in the incidence rate of adverse reactions between the two groups (P=0.667). CONCLUSIONS: Huaiqihuang granules in addition to medications for long-term asthma control can alleviate the symptoms of bronchial asthma and rhinitis and improve the level of asthma control in children with bronchial asthma, with good safety and little adverse effect. Citation.


Asunto(s)
Asma , Medicamentos Herbarios Chinos , Asma/tratamiento farmacológico , Niño , Medicamentos Herbarios Chinos/uso terapéutico , Humanos , Estudios Prospectivos , Calidad de Vida
7.
Front Med (Lausanne) ; 8: 617393, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34012969

RESUMEN

Acute lung injury (ALI), which is induced by renal ischemia-reperfusion (IR), is one of the leading causes of acute renal IR-related death. Obesity raises the frequency and severity of acute kidney injury (AKI) and ALI. Tanshinone IIA (TIIA) combined with cyclosporine A (CsA) was employed to lessen the lung apoptosis led by renal IR and to evaluate whether TIIA combined with CsA could alleviate lung apoptosis by regulating mitochondrial function through the PI3K/Akt/Bad pathway in obese rats. Hematoxylin-eosin (HE) staining was used to assess the histology of the lung injury. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) was used to assess apoptosis of the lung. Electron microscopy was used to assess mitochondrial morphology in lung cells. Arterial blood gas and pulmonary function were used to assess the external respiratory function. Mitochondrial function was used to assess the internal respiratory function and mitochondrial dynamics and biogenesis. Western blot (WB) was used to examine the PI3K/Akt/Bad pathway-related proteins. TIIA combined with CsA can alleviate lung apoptosis by regulating mitochondrial function through the PI3K/Akt/Bad pathway in obese rats.

8.
Biochem Biophys Res Commun ; 560: 112-118, 2021 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-33984768

RESUMEN

RNA polymerase I (Pol I) is responsible for the synthesis of the majority of ribosomal RNA molecules in eukaryotes. Pol I subunit 12 (RPA12) is involved in the transcriptional termination and lipid metabolism in yeast. However, its role in human cells hasn't been investigated so far. Here, we show that RPA12 is present in the nucleolus and nucleoplasm of HeLa cells. RPA12 can act as a positive factor to regulate Pol I-mediated transcription and the proliferation of 293T and HeLa cells. Unexpectedly, RPA12 can repress HeLa cell migration, indicating that RPA12 plays opposite roles in cell proliferation and migration. This study provides a novel insight into the role of RPA12 in human cells.


Asunto(s)
Movimiento Celular , Proliferación Celular , Proteínas de Unión al ADN/fisiología , Nucléolo Celular/química , Núcleo Celular/química , Proteínas de Unión al ADN/análisis , Regulación de la Expresión Génica , Células HEK293 , Células HeLa , Humanos , ARN Polimerasa I/metabolismo , Transcripción Genética
9.
Sci Rep ; 11(1): 10454, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-34001951

RESUMEN

Site-directed mutagenesis for large plasmids is a difficult task that cannot easily be solved by the conventional methods used in many laboratories. In this study, we developed an effective method for Site-directed Mutagenesis for Large Plasmids (SMLP) based on a PCR technique. The SMLP method combines several effective approaches, including a high-efficiency DNA polymerase for the large DNA amplification, two independent PCR reactions and a fast recombinational ligation. Using this method, we have achieved a variety of mutants for the filamin A gene (7.9 kb) cloned in the pcDNA (5.4 kb) or the pLV-U6-CMV-EGFP (9.4 kb) plasmids, indicating that this method can be applied to site-directed mutagenesis for the plasmids up to 17.3 kb. We show that the SMLP method has a greater advantage than the conventional methods tested in this study, and this method can be applied to substitution, deletion, and insertion mutations for both large and small plasmids as well as the assembly of three fragments from PCR reactions. Altogether, the SMLP method is simple, effective, and beneficial to the laboratories that require completing the mutagenesis of large plasmids.


Asunto(s)
ADN/genética , Mutagénesis Sitio-Dirigida/métodos , Plásmidos/genética , Reacción en Cadena de la Polimerasa/métodos , Clonación Molecular , Recombinación Genética
10.
Huan Jing Ke Xue ; 42(5): 2110-2120, 2021 May 08.
Artículo en Chino | MEDLINE | ID: mdl-33884780

RESUMEN

The characteristics of meteorological conditions and pollutant concentrations were analyzed based on two pollution episodes before and after city heating in Beijing during February to March of 2019. The backward trajectory and WRF-CAMx models were used to analyze the evolution of pollutants before and after city heating, and the influences of meteorological conditions, regional transport, and secondary transformation on the episodes were discussed. There was little difference in the average ρ(PM2.5) between February 21-24 (episode 1) and March 18-20 (episode 2), with concentrations of 100.1 µg·m-3 and 97.2 µg·m-3, respectively. However, compared with that of episode 2, in episode 1 the average peak value was higher with two peak stages, the diurnal variation was clearer, and the process developed much more rapidly. Moreover, episode 1 was regional pollution, while episode 2 was more related to local pollution in Beijing. The SO2 concentrations in both episodes were not higher than 16 µg·m-3, thereby indicating the effectiveness of coal-burning treatment and other measures. In addition, two peaks occurred in the diurnal fluctuation of SO2 in episode 1, whereas only one peak occurred for episode 2. In episode 1, the CO concentration was high and the ratio of ρ(CO)/ρ(SO2) increased around February 22-23 (phase 1); moreover, the pollutant concentrations in the central and southern areas of the Beijing-Tianjin-Hebei region and those in the background sites located in the southern part of the Beijing plain were higher than those in the urban area, thereby indicating that the diffusion conditions of episode 1 were unfavorable and the first PM2.5 peak was mainly affected by regional transport. A high ratio of ρ(PM2.5)/ρ(CO) in episode 2 suggested a slightly larger proportion of secondary generation for PM2.5, whereas higher ratios of ρ(NO2)/ρ(CO), ρ(SO2)/ρ(CO), and ρ(SO42-)/ρ(PM2.5) in episode 2 and the similar SOR value to that of episode 1 demonstrated that episode 1 was more advantageous for gas phase transformation and episode 2 was more affected by the coal industry. Phased analysis of episode 1 showed that the indicators of second generation for PM2.5 in phase 2 (around February 23-24) of episode 1 and episode 2 were similar, and both were higher than that in phase 1 of episode 1, which implied that the second PM2.5 peaks of episode 1 and episode 2 were mainly related to local emissions and chemical conversion. Both WRF-CAMx with and without assimilation experiments could better reproduce the temporal variation in pollutants, and the correlation between the simulation and observations increased but with lower values after assimilation. The model performance for the PM2.5 trend simulation significantly increased with data assimilation, and the simulated lower NO2 in February and higher NO2 in March as well as the overestimated SO2 were also improved. In addition, the pollutant concentration simulation in Beijing was more sensitive to that of Hebei in episode 1, which suggested that episode 1 was more affected by regional transport. The simulation ability for the rapid growth of pollutants needs to be promoted, and the response of pollutant types to emission reduction and the feedback related to the atmospheric oxidant and aerosol properties may be important for the simulation effect, which all require further study.

11.
Huan Jing Ke Xue ; 41(11): 4844-4854, 2020 Nov 08.
Artículo en Chino | MEDLINE | ID: mdl-33124228

RESUMEN

In this study, the hourly meteorological factors and PM2.5 concentrations during 2014-2019 in Beijing were analyzed, in order to explore the characteristics of the prevailing wind direction of pollution, and the corresponding long-term tendency. During the study period, 67% of pollution in Beijing occurred under the influence of southerly and easterly wind, and pollution was most likely to occur in winter, followed by spring and autumn. The average pollution probability of winter, spring, autumn and summer was 45.2%, 34.1%, 32.1%, and 26.1% and 47.0%, 45.8%, 39.7%, and 29.6% for southerly and easterly wind, respectively. In Beijing, the southerly wind appeared more frequently, but the pollution occurrence probability was higher under the control of easterly wind, with the maximum difference of 11.7% (2.8%-18.6%) in spring and the minimum difference of 1.8% (-7.6%-13.9%) in winter. During the past six years, the pollution probability decreased at a rate of 4.6%-8.0% and 5.5%-7.9% per year under the southerly and easterly wind influence, respectively. This was clearly reflected in reduced moderate and above levels of pollution. An analysis of both the pollution and meteorological factors under the two wind directions indicates that the visibility, mixing layer height, wind speed, and the frequency of hourly wind speed greater than 3 m·s-1 were higher, and the relative humidity and dew point temperature were lower, when pollution occurred under the southerly wind, while the PM2.5 concentration of pollution was higher in winter and significantly lower in other seasons compared to that of the easterly wind. These findings show that when pollution occurred under the southerly wind, the carrying capacity and diffusion capacity of pollutants in the atmosphere was slightly better than that of the easterly wind, and the increased atmospheric water content under the easterly wind was more conducive to the maintenance and aggravation of pollution. Moreover, under the background of original emission levels, when adding urban heating in winter, the air mass transported by the southerly wind may be more conducive to increased PM2.5 concentration. Furthermore, pollution in Beijing tended to be an "easterly wind type" in spring, summer and autumn, but remained a "southerly wind type" in winter.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Beijing , China , Monitoreo del Ambiente , Material Particulado/análisis , Estaciones del Año , Viento
12.
RSC Adv ; 10(50): 29712-29722, 2020 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-35518216

RESUMEN

An efficient and convenient iridium(iii) catalyzed ortho-C-H bond amidation of weakly coordinating benzamides treated with readily available sulfonyl azides as the amino source has been described. In this transformation, ionic liquids represents an ideal reaction medium, giving rise to a broad range of amidation products under mild conditions in the open air. This protocol offers moderate to excellent chemical yields, exclusive regioselectivities, and good functional group tolerance.

13.
Acta Trop ; 202: 105285, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31786108

RESUMEN

Dipstick Dye Immunoassay (DDIA) and Indirect Haemagglutination Assay (IHA), are two commercially available kits which have been widely used for screening Schistosoma japonicum in P.R. China. Whether they can be used for screening of Schistosoma haematobium are not clear. In order to evaluate the diagnostic efficiency of DDIA and IHA for screening Schistosoma haematobium, serum samples were collected from pupils in endemic areas in Zambia, Southern Africa, and tested by DDIA and IHA by single-blind manner. Meanwhile, the pupils were microscopically examined by infection with Schistosoma and soil-transmitted helminths, visually observed for parasite eggs. Of the enrolled 148 pupils, 61% tested positive for S. haematobium infection, while 31% and 36% of pupils were infected with hookworm and Ascaris respectively. Regarding the parasitological tests as reference standard, for the diagnosis of S. haematobium infection, IHA performed higher sensitivity (74%, 95% CI: 65%-83%) than that of DDIA (60%, 95%CI: 49%-70%). The sensitivities of IHA and DDIA are significant higher in 10-14 years old students than those of 7-9 years old group. The specificity of DDIA and IHA were 61% (95%CI: 49%-74%) and 72% (95%CI: 60%-84%), respectively. The co-infection with STHs decreased the specificity of DDIA but had no impact on that of IHA. Our study indicated that IHA has more potential as an alternative diagnostic tool for identifying schistosomiasis haematobium but need further improvement.


Asunto(s)
Anticuerpos Antihelmínticos/sangre , Schistosoma haematobium/inmunología , Schistosoma japonicum/inmunología , Esquistosomiasis Urinaria/diagnóstico , Esquistosomiasis Japónica/diagnóstico , Adolescente , Animales , Niño , Coinfección , Femenino , Pruebas de Hemaglutinación , Humanos , Inmunoensayo , Masculino , Tamizaje Masivo , Esquistosomiasis Urinaria/sangre , Esquistosomiasis Urinaria/inmunología , Esquistosomiasis Japónica/epidemiología , Sensibilidad y Especificidad , Método Simple Ciego , Zambia
14.
Environ Health Perspect ; 127(6): 67007, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31170008

RESUMEN

BACKGROUND: Studies found approximately linear short-term associations between particulate matter (PM) and mortality in Western communities. However, in China, where the urban PM levels are typically considerably higher than in Western communities, some studies suggest nonlinearity in this association. Health impact assessments (HIA) of PM in China have generally not incorporated nonlinearity in the concentration-response (C-R) association, which could result in large discrepancies in estimates of excess deaths if the true association is nonlinear. OBJECTIVES: We investigated nonlinearity in the C-R associations between with PM with aerodynamic diameter [Formula: see text] ([Formula: see text]) and mortality in Beijing, China, and the sensitivity of HIA to linearity assumptions. METHODS: We modeled the C-R association between [Formula: see text] and cause-specific mortality in Beijing, China (2009-2012), using generalized linear models (GLM). [Formula: see text] was included through either linear, piecewise-linear, or spline functions to investigate evidence of nonlinearity. To determine the sensitivity of HIA to linearity assumptions, we estimated [Formula: see text]-attributable deaths using both linear- and nonlinear-based C-R associations between [Formula: see text] and mortality. RESULTS: We found some evidence that, for nonaccidental and circulatory mortality, the shape of the C-R association was relatively flat at lower concentrations of [Formula: see text], but then had a positive slope at higher concentrations, indicating nonlinearity. Conversely, the shape for respiratory mortality was positive and linear at lower concentrations of [Formula: see text], but then leveled off at the higher concentrations. Estimates of excess deaths attributable to short-term [Formula: see text] exposure were, in some cases, very sensitive to the linearity assumption in the association, but in other cases robust to this assumption. CONCLUSIONS: Our results demonstrate some evidence of nonlinearity in [Formula: see text]-mortality associations and that an assumption of linearity in this association can influence HIAs, highlighting the importance of understanding potential nonlinearity in the [Formula: see text]-mortality association at the high concentrations of [Formula: see text] in developing megacities like Beijing. https://doi.org/10.1289/EHP4464.


Asunto(s)
Evaluación del Impacto en la Salud/métodos , Mortalidad , Material Particulado/efectos adversos , Contaminantes Atmosféricos/efectos adversos , Beijing/epidemiología , Enfermedades Cardiovasculares/mortalidad , Exposición a Riesgos Ambientales/efectos adversos , Humanos , Modelos Lineales , Tamaño de la Partícula , Enfermedades Respiratorias/mortalidad
15.
Huan Jing Ke Xue ; 40(3): 1011-1023, 2019 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-31087947

RESUMEN

During 2014-2017, the number of haze days and air pollution days declined year by year obviously in Beijing. The average mass concentrations of PM2.5, PM10, SO2, and NO2 also decreased with the alleviated pollution level. These decreases were more obvious during the heating period, especially in November and December. In order to analyze the reasons for the improvement of air quality, changes of the meteorological factors and emission-reduction have been discussed and quantified in this study. This work was based on the numerical simulation model WRF-CHEM and the large data mining technologies of k-nearest neighbor (KNN) and support vector machines (SVM). Meteorological observations indicated that the mean wind speed of 2017 increased by 7.9% compared with the last three years. The frequency of hourly wind speed higher than 3.4 m·s-1 was the highest (10.6%), and frequency of daily relative humidity higher than 70% was lowest (25.1%), in 2017. Meanwhile, the number of low wind days (daily wind speed lower than 2 m·s-1), environmental capacity, ventilation index, and height of the boundary layer showed that the diffusion conditions were better in the heating period of 2017 than those of 2014~2016, especially in November and December. The accumulated precipitation during the non-heating period was 558.3 mm in 2017, which is conducive to pollutant removal and wet deposition. Inter-annual changes of meteorological conditions are important to the air quality. A simulation for December 1~19 by WRF-CHEM during 2014-2017 was performed, and the results demonstrated that changes of meteorological conditions led to a reduction of the PM2.5 concentration of 2017 by 5%, 38%, and 25% compared with that of 2014-2016, respectively. However, it was not possible to quantify the specific contributions of meteorology conditions because of the lack of real emission reduction options. The KNN and SVM models are applied in this study based on the observed meteorology factors, haze days, and pollution days, and it was found that for the reduced haze days and heavy pollution days in 2017, 65.0% could be attributed to emission reduction and 35.0% was caused by improvement of the meteorological conditions.

16.
Acta Trop ; 149: 19-26, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25976412

RESUMEN

Although co-infection of tuberculosis (TB) and intestinal parasites, including protozoa and helminths, in humans has been widely studied globally, very little of this phenomenon is known in China. Therefore, a cross-sectional study was conducted in a rural county of China to investigate such co-infections. Patients with pulmonary TB (PTB) undergoing anti-Mycobacterium tuberculosis (anti-MTB) treatment were surveyed by questionnaires, and their feces and blood specimens were collected for detection of intestinal protozoa and helminths, routine blood examination and HIV detection. The χ(2) test and multivariate logistic regression model were used to identify risk factors. A total of 369 patients with PTB were included and all of them were HIV negative. Overall, only 7.3% of participants were infected with intestinal protozoa, among which prevalence of Blastocystis hominis, Entamoeba spp. and Trichomonas hominis were 6.0%, 1.1% and 0.3%, respectively; 7.0% were infected with intestinal helminths, among which prevalence of hookworm, Trichuris trichiura, Ascaris lumbricoides and Clonorchis sinensis were 4.3%, 1.9%, 0.5% and 0.3%, respectively; and 0.5% were simultaneously infected with intestinal protozoa and helminths. Among patients with PTB, body mass index (BMI)≤18 (OR=3.30, 95% CI=1.44-7.54) and raised poultry or livestock (e.g., chicken, duck, pig) (OR=3.96, 95% CI=1.32-11.89) were significantly associated with harboring intestinal protozoan infection, while BMI≤18 (OR=3.32, 95% CI=1.39-7.91), anemia (OR=3.40, 95% CI=1.44-8.02) and laboring barefoot in farmlands (OR=4.54, 95% CI=1.88-10.92) were significantly associated with having intestinal helminth infection. Additionally, there was no significant relationship between duration of anti-MTB treatment and infection rates of intestinal parasites including protozoa and helminths. Therefore, preventing malnutrition, avoiding unprotected contact with reservoirs of protozoa, and improving health education for good hygiene habits, particularly wearing shoes while outdoors, are beneficial in the prevention of intestinal protozoan and helminth infection among patients with PTB.


Asunto(s)
Anemia/epidemiología , Helmintiasis/epidemiología , Parasitosis Intestinales/epidemiología , Exposición Profesional/estadística & datos numéricos , Infecciones por Protozoos/epidemiología , Delgadez/epidemiología , Tuberculosis Pulmonar/epidemiología , Anciano , Agricultura , Animales , Ascariasis/epidemiología , Ascaris lumbricoides , Infecciones por Blastocystis/epidemiología , Blastocystis hominis , China/epidemiología , Clonorquiasis/epidemiología , Coinfección/epidemiología , Estudios Transversales , Entamoeba , Entamebiasis/epidemiología , Heces/parasitología , Femenino , Helmintos , Humanos , Higiene , Ganado , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , Prevalencia , Factores de Riesgo , Población Rural/estadística & datos numéricos , Encuestas y Cuestionarios , Tricomoniasis/epidemiología , Tricuriasis/epidemiología , Trichuris
17.
Artículo en Chino | MEDLINE | ID: mdl-26767262

RESUMEN

OBJECTIVE: To understand the epidemic situation of schistosomiasis in 27 counties (cities, districts) that reached the criteria of schistosomiasis infection controlled in Anhui Province. METHODS: According to the requirement of The National Assessment Scheme of Schistosomiasis, 81 administrative villages where the schistosomiasis epidemic situation was relatively heaver in above-mentioned 27 counties (1 village per town, 3 towns per county) were sampled and investigated. RESULTS: From 2012 to 2014, 81 villages were investigated, and 34,293 residents received the serum examinations, and 1,086 were positive with a positive rate of 3.17% (0.65%-9.58%), and the positives received stool examinations and the average stool positive rate was 0.37% (0-4.0%). The calculated prevalence of human infection was 0.01%. A total of 3 057 domestic animals were investigated including 438 cattle, 2,550 sheep, and 69 other animals, and no infections were detected. A total of 11,261 living Oncomelania hupensis snails were collected and detected, but no schistosome infected snails were found. Before this investigation, no infected snails were detected for more than 2 years [average 2.3 (2-6) years], and no acute schistosome infection cases were found for more than 2 years [average 4.9 (2-9) years]. CONCLUSION: The infection rates of schistosomiasis in residents and domestic animals are relatively low, and no schistosome infected snails are found in the regions.


Asunto(s)
Enfermedades Endémicas/estadística & datos numéricos , Esquistosomiasis/epidemiología , Adolescente , Adulto , Anciano , Animales , Niño , China/epidemiología , Humanos , Persona de Mediana Edad , Esquistosomiasis/prevención & control , Caracoles/parasitología
18.
Acta Biochim Biophys Sin (Shanghai) ; 46(7): 582-9, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24829401

RESUMEN

Pyrrolidine dithiocarbamate (PDTC) can lower the blood glucose level and improve the insulin sensitivity in diabetic rats. However, the mechanisms underlying this effect of PDTC treatment in diabetic rats remained uncertain. In this study, we evaluated the mechanisms by which PDTC conferred protection against oxidative damage to pancreatic islet ß-cells in rats with experimental type 2 diabetes mellitus (DM). DM in the rats was elicited by long-term high-fat diet accompanied with a single intraperitoneal (i.p.) injection of a low dose of streptozotocin. After a 7-day administration of PDTC (50 mg/kg/day i.p.), blood glucose levels were measured and pancreatic tissues were collected for the determination of various biochemical and enzymatic activities using immunohistochemistry, immunofluorescence, and western blot techniques. The percentage of apoptotic pancreatic islet ß-cells was detected by flow cytometry. The results showed that diabetic rats had elevated blood glucose levels and insulin resistance, accompanied with an increase in malondialdehyde content, nitrotyrosine production, and inducible nitric oxide synthase expression. A decrease in superoxide dismutase and glutathione peroxidase activities was also observed in DM rats, culminating with elevated ß-cell apoptosis. PDTC treatment significantly reduced the oxidative damage and the ß-cell apoptosis, and also increased the insulin production through down-regulating FoxO1 acetylation and up-regulating nuclear PDX-1 level. These data suggested that PDTC can protect islet ß-cells from oxidative damage and improve insulin production through regulation of PDX-1 and FoxO1 in a DM rat model.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Factores de Transcripción Forkhead/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Proteínas del Tejido Nervioso/metabolismo , Estrés Oxidativo/efectos de los fármacos , Pirrolidinas/farmacología , Tiocarbamatos/farmacología , Animales , Antioxidantes/farmacología , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/patología , Glutatión Peroxidasa/metabolismo , Insulina/biosíntesis , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Masculino , Malondialdehído/metabolismo , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
19.
Am J Trop Med Hyg ; 90(1): 106-13, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24166044

RESUMEN

Epidemiologic studies of co-infection with tuberculosis (TB) and intestinal parasites in humans have not been extensively investigated in China. A cross-section study was conducted in a rural county of Henan Province, China. Pulmonary TB (PTB) case-patients receiving treatment for infection with Mycobacterium tuberculosis and healthy controls matched for geographic area, age, and sex were surveyed by using questionnaires. Fecal and blood specimens were collected for detection of intestinal parasites, routine blood examination, and infection with human immunodeficiency virus. The chi-square test was used for univariate analysis and multivariate logistic regression models were used to adjust for potential confounding factors. A total of 369 persons with PTB and 366 healthy controls were included; all participants were negative for human immunodeficiency virus. The overall prevalence of intestinal parasites in persons with PTB was 14.9%, including intestinal protozoa (7.9%) and helminthes (7.6%). The infection spectrum of intestinal parasites was Entamoeba spp. (1.4%), Blastocystis hominis (6.2%), Trichomonas hominis (0.3%), Clonorchis sinensis (0.3%), Ascaris lumbricoides (0.5%), Trichuris trichiura (2.2%), and hookworm (4.6%). The prevalence of intestinal parasites showed no significant difference between persons with PTB and healthy controls after adjusting for potential confounding factors. There was no factor that affected infection rates for intestinal parasites between the two groups. Infection with intestinal parasites of persons with PTB was associated with female sex (adjusted odds ratio [AOR] = 2.05, 95% confidence interval [CI] = 1.01-4.17), body mass index ≤ 19 (AOR = 3.02, 95% CI = 1.47-6.20), and anemia (AOR = 2.43, 95% CI = 1.17-5.03). Infection of healthy controls was only associated with an annual labor time in farmlands > 2 months (AOR = 4.50, 95% CI = 2.03-10.00). In addition, there was no significant trend between rates of infection with intestinal parasites and duration of receiving treatment for infection with M. tuberculosis in persons with PTB. The prevalence of intestinal parasites was not higher in persons with PTB, and there was no evidence that PTB increased susceptibility to intestinal parasites in this study. However, for patients with PTB, women and patients with comorbidities were more likely to be infected with intestinal parasites.


Asunto(s)
Infecciones por VIH/epidemiología , Enfermedades Parasitarias/complicaciones , Tuberculosis Pulmonar/complicaciones , Anciano , Antituberculosos/uso terapéutico , China/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Parasitarias/epidemiología , Factores de Riesgo , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología
20.
Infect Dis Poverty ; 2(1): 18, 2013 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-23971713

RESUMEN

BACKGROUND: Parasite infections often result in a switch of the human body's predominant immune reaction from T-helper 1 (Th1)-type to Th2-type. Hence, parasite infections are widely expected to accelerate the progression of human immunodeficiency virus (HIV) infections to acquired immunodeficiency syndrome (AIDS). In the People's Republic of China, both parasitic diseases and AIDS are epidemic in certain rural areas, and co-infections are relatively common. However, no population-based studies have yet investigated the frequency of HIV and parasite co-infections, and its effects on immune responses. We studied (1) the immune status of an HIV-infected population, and (2) the effect of co-infection of HIV and intestinal parasites on selected parameters of the human immune system. METHODS: A total of 309 HIV-infected individuals were recruited and compared to an age-matched and sex-matched control group of 315 local HIV-negative individuals. Questionnaires were administered to all participants to obtain information on sociodemographic characteristics, sanitation habits, family income, and recent clinical manifestations. Two consecutive stool samples and 10 ml samples of venous blood were also collected from each individual for the diagnosis of parasite infections and quantitative measurements of selected cytokines and CD4+ T-lymphocytes, respectively. RESULTS: During the study period, 79 HIV-infected individuals were not under highly active antiretroviral therapy (HAART) and were thus included in our analysis; the prevalence of intestinal helminth infections was 6.3% and that of protozoa was 22.8%. The most common protozoan infections were Blastocystis hominis (B. hominis) (13.9%) and Cryptosporidium spp. (10.1%). The prevalence of Cryptosporidium spp. in HIV-infected individuals was significantly higher than that in HIV negative individuals (P < 0.05). Compared to the non-co-infected population, no significant difference was found for any of the measured immunological indicators (P > 0.05). However, the following trends were observed: IFN-γ levels were lower, but the IL-4 level was higher, in the population co-infected with HIV and helminths. In the population co-infected with HIV and B. hominis, the IL-2 level was higher. The population co-infected with HIV and Cryptosporidium spp. had markedly lower CD4+ T-lymphocyte counts. CONCLUSION: According to the immunologic profile, co-infection with helminths is disadvantageous to HIV-infected individuals. It was associated with a shift in the Th1/Th2 balance in the same direction as that caused by the virus itself, which might indicate an acceleration of the progress from an HIV infection to AIDS. Co-infection with Cryptosporidium spp. was not associated with a significant change in immune factors but co-infection with Cryptosporidium spp. was associated with a reduced level of CD4 + T-lymphocytes, confirming the opportunistic nature of such infections. Co-infection with B. hominis, on the other hand, was associated with an antagonistic shift in the immunological profile compared to an HIV infection.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...