[Clinical diagnosis and treatment of hereditary thrombocytopenia and purpura: a report of five cases and literature review].

Objective: To report the clinical manifestations and laboratory features of five patients with congenital thrombotic thrombocytopenic purpura (cTTP) and explore its standardized clinical diagnosis and treatment along with a review of literature. Methods: Clinical data of patients, such as age of onset, disease manifestation, personal history, family history, and misdiagnosed disease, were collected. Treatment outcomes, therapeutic effects of plasma infusion, and organ function evaluation were observed. The relationship among the clinical manifestations, treatment outcomes, and ADAMTS13 gene mutation of patients with cTTP was analyzed. Additionally, detection of ADAMTS13 activity and analysis of ADAMTS13 gene mutation were explored. Results: The age of onset of cTTP was either in childhood or adulthood except in one case, which was at the age of 1. The primary manifestations were obvious thrombocytopenia, anemia, and different degrees of nervous system involvement. Most of the patients were initially suspected of having immune thrombocytopenia. Acute cTTP was induced by pregnancy and infection in two and one case, respectively. ADAMTS13 gene mutation was detected in all cases, and there was an inherent relationship between the mutation site, clinical manifestations, and degree of organ injury. Therapeutic or prophylactic plasma transfusion was effective for treating cTTP. Conclusions: The clinical manifestations of cTTP vary among individuals, resulting in frequent misdiagnosis that delays treatment. ADAMTS13 activity detection in plasma and ADAMTS13 gene mutation analysis are important bases to diagnose cTTP. Prophylactic plasma transfusion is vital to prevent the onset of the disease.

[Clinical and prognostic significance of ABO promotor methylation level in adult leukemia and myelodydysplastic syndrome].

Objective: To investigate the clinical and prognostic significance of ABO promotor methylation level in adult patients with leukemia and myelodydysplastic syndrome(MDS). Methods: ABO promoter methylation level of 182 malignant hematological disease patients and 68 normal controls were detected by bisulfite sequencing PCR.Then clinical features and outcome were compared between hypermethylation group and hypomethylation group. Results: The median methylation rate of ABO promoter in newly diagnosed acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) were 46.98% and 11.01% respectively, which were both higher than that in controls (2.30%, P<0.05). The methylation rates in remission AML and ALL were 1.58% and 2.30% respectively, which were comparable with that in normal group (P>0.05). As to relapse AML and ALL, methylation rates were 41.26% and 17.50% respectively, also significantly higher than that in controls (P<0.05).In patients with chronic myeloid leukemia (CML) chronic phase, the median methylation rate was 1.00%, which was similar to normal group. But a CML patient who transformed to ALL hadextremely high methylation rate 92.56%. The median methylation rate in patients with MDS significantly elevated as 5.81% compared with that in controls (P<0.05). The median overall survival (OS) of ALL and AML (non-M3) patients with hypermethylation were 12.5 months and 15.3 months, which were significantly shorter than those with hypomethylation (24.0 months and 20.0 months)(P<0.05).The median disease-free survival (DFS) of ALL and AML (non-M3) patients with hypermethylation were 9.9 months and 12.0 months, which were significantly shorter than those with hypomethylation (22.3 months and 18.5 months), (P<0.05). Multivariable analysis suggested that ABO promoter methylation level was an independent predictive factor of OS and DFS in ALL and AML (non-M(3)) patients. Conclusion: ABO promoter hypermethylation is closely related to genesis, development and prognosis of leukemia and MDS. Hypermethylationis related to a clinical poor prognosis compare with hypomethylation.

Causes of ozone pollution in summer in Wuhan, Central China.

In August 2016, continuous measurements of volatile organic compounds (VOCs) and trace gases were conducted at an urban site in Wuhan. Four high-ozone (O3) days and twenty-seven non-high-O3 days were identified according to the China's National Standard Level II (∼100 ppbv). The occurrence of high-O3 days was accompanied by tropical cyclones. Much higher concentrations of VOCs and carbon monoxide (CO) were observed on the high-O3 days (p < 0.01). Model simulations revealed that vehicle exhausts were the dominant sources of VOCs, contributing 45.4 ±â€¯5.2% and 37.3 ±â€¯2.9% during high-O3 and non-high-O3 days, respectively. Both vehicle exhausts and stationary combustion made significantly larger contributions to O3 production on high-O3 days (p < 0.01). Analysis using a chemical transport model found that local photochemical formation accounted for 74.7 ±â€¯5.8% of the daytime O3, around twice the regional transport (32.2 ±â€¯5.4%), while the nighttime O3 was mainly attributable to regional transport (59.1 ±â€¯9.9%). The local O3 formation was generally limited by VOCs in urban Wuhan. To effectively control O3 pollution, the reduction ratio of VOCs to NOx concentrations should not be lower than 0.73, and the most efficient O3 abatement could be achieved by reducing VOCs from vehicle exhausts. This study contributes to the worldwide database of O3-VOC-NOx sensitivity research. Its findings will be helpful in formulating and implementing emission control strategies for dealing with O3 pollution in Wuhan.

New particle formation and growth at a suburban site and a background site in Hong Kong.

Atmospheric nanoparticles have great impacts on human health and global climate change. The number concentrations and size distributions of nanoparticles in the size range of 5.5-350.4 nm were detected at a background site and a suburban site in Hong Kong from summer to winter in 2011 and in autumn of 2013, respectively. Significantly higher particle number concentrations in all modes were observed at the suburban site (p < 0.05) during the sampling periods, possibly due to stronger primary emissions/regional transport and more intensive new particle formation (NPF). Particle number concentrations were much enhanced under northerly winds at both sites, resulting from regional transport of Aitken and accumulation mode particles, enhanced local NPF and occasionally low condensation sink. NPF was mainly limited by the precursors of condensable vapors and oxidative capacity of the atmosphere at the background site and the suburban site, respectively. In most cases, the formation rate of 5.5 nm particles was a function of sulfuric acid vapor to the power of 1.32 ± 0.34 at the background site and 0.81 ± 0.31 at the suburban site, abiding by the cluster activation theory. However, ozonolysis of monoterpenes (particularly α-pinene) might also drive NPF, particularly in the afternoon. These reactions also contributed to the growth of nucleation mode particles, which was largely explained by sulfuric acid vapor (73.6 ± 10% at the background site and 60.4 ± 9.8% at the suburban site). In contrast, the oxidations of isoprene, ß-pinene and aromatics (particularly xylenes and trimethylbenzenes) were found to participate in the growth of Aitken mode particles.

Observation of SOA tracers at a mountainous site in Hong Kong: Chemical characteristics, origins and implication on particle growth.

Secondary organic aerosol (SOA) is an important constituent of airborne fine particles. PM2.5 (particles with aerodynamic diameters≤2.5µm) samples were collected at a mountainous site in Hong Kong in autumn of 2010, and analyzed for SOA tracers. Results indicated that the concentrations of isoprene SOA tracers (54.7±22.7ng/m3) and aromatics SOA tracers (2.1±1.6ng/m3) were on relatively high levels in Hong Kong. Secondary organic carbon (SOC) derived from isoprene, monoterpenes, sesquiterpenes and aromatics was estimated with the SOA tracer based approach, which constituted 0.35±0.15µg/m3 (40.6±5.7%), 0.20±0.03µg/m3 (30.4±5.5%), 0.05±0.02µg/m3 (5.6±1.7%) and 0.26±0.20µg/m3 (21.3±8.2%) of the total estimated SOC. Biogenic SOC (0.60±0.18µg/m3) dominated over anthropogenic SOC (0.26±0.20µg/m3) at this site. In addition to the total estimated SOC (17.8±4.6% of organic carbon (OC) in PM2.5), primary organic carbon (POC) emitted from biomass burning also accounted for a considerable proportion of OC (11.6±3.2%). Insight into the OC origins found that regional transport significantly (p<0.05) elevated SOC from 0.37±0.17 to 1.04±0.39µg/m3. Besides, SOC load could also increase significantly if there was influence from local ship emission. Biomass burning related POC in regional air masses (0.81±0.24µg/m3) was also higher (p<0.05) than that in samples affected by local air (0.29±0.35µg/m3). Evidences indicated that SOA formation was closely related to new particle formation and the growth of nucleation mode particles, while biomass burning was responsible for some particle burst events in Hong Kong. This is the first SOA study in afforested areas of Hong Kong.

Tropospheric volatile organic compounds in China.

Photochemical smog, characterized by high concentrations of ozone (O3) and fine particles (PM2.5) in the atmosphere, has become one of the top environmental concerns in China. Volatile organic compounds (VOCs), one of the key precursors of O3 and secondary organic aerosol (SOA) (an important component of PM2.5), have a critical influence on atmospheric chemistry and subsequently affect regional and global climate. Thus, VOCs have been extensively studied in many cities and regions in China, especially in the North China Plain, the Yangtze River Delta and the Pearl River Delta regions where photochemical smog pollution has become increasingly worse over recent decades. This paper reviews the main studies conducted in China on the characteristics and sources of VOCs, their relationship with O3 and SOA, and their removal technology. This paper also provides an integrated literature review on the formulation and implementation of effective control strategies of VOCs and photochemical smog, as well as suggestions for future directions of VOCs study in China.

Evaluation of the effectiveness of air pollution control measures in Hong Kong.

From 2005 to 2013, volatile organic compounds (VOCs) and other trace gases were continuously measured at a suburban site in Hong Kong. The measurement data showed that the concentrations of most air pollutants decreased during these years. However, ozone (O3) and total non-methane hydrocarbon levels increased with the rate of 0.23 ± 0.03 and 0.34 ± 0.02 ppbv/year, respectively, pointing to the increasing severity of photochemical pollution in Hong Kong. The Hong Kong government has ongoing programs to improve air quality in Hong Kong, including a solvent program implemented during 2007-2011, and a diesel commercial vehicle (DCV) program since 2007. From before to after the solvent program, the sum of toluene, ethylbenzene and xylene isomers decreased continuously with an average rate of -99.1 ± 6.9 pptv/year, whereas the sum of ethene and propene increased by 48.2 ± 2.0 pptv/year from before to during the DCV program. Despite this, source apportionment results showed that VOCs emitted from diesel exhaust decreased at a rate of -304.5 ± 17.7 pptv/year, while solvent related VOCs decreased at a rate of -204.7 ± 39.7 pptv/year. The gasoline and liquefied petroleum gas vehicle emissions elevated by 1086 ± 34 pptv/year, and were responsible for the increases of ethene and propene. Overall, the simulated O3 rate of increase was lowered from 0.39 ± 0.03 to 0.16 ± 0.05 ppbv/year by the solvent and DCV programs, because O3 produced by solvent usage and diesel exhaust related VOCs decreased (p < 0.05) by 0.16 ± 0.01 and 0.05 ± 0.01 ppbv/year between 2005 and 2013, respectively. However, enhanced VOC emissions from gasoline and LPG vehicles accounted for most of the O3 increment (0.09 ± 0.01 out of 0.16 ± 0.05 ppbv/year) in these years. To maintain a zero O3 increment in 2020 relative to 2010, the lowest reduction ratio of VOCs/NOx was ∼1.5 under the NOx reduction of 20-30% which was based on the emission reduction plan for Pearl River Delta region in 2020.

[Effects of DNA methylation on ABO gene expression in leukemia].

Objective: To investigate the impact of promoter CpG island methylation on ABO mRNA expression in leukemia. Methods: 25 cases of leukemia and 20 cases of normal control were studied, and the leukemia cell lines K562、HL-60 and Jurkat were treated with different concentrations of decitabine. PCR-SSP was used to identify ABO genotype, RQ-PCR for ABO mRNA expression and bisulfite sequencing PCR for DNA methylation status. Results: ① The methylation of ABO promoter in acute myeloid leukemia patients (10 cases) and acute lymphoblastic leukemia patients (10 cases) were 53.85% and 18.22% respectively, which were obviously higher than those in control (20 cases, 2.33%) and chronic myeloid leukemia patients (5 cases, 2.12% ). ② ABO genotype of K562 was O1O1, which has changed little before and after decitabine treatment. ABO genotype of HL-60 and Jurkat could not been identify before treatment, but showed as O1A1 and A1O2 after treatment. ③ABO mRNA expression of K562 was 1 275.67 ± 35.86, which was obviously higher than that in HL-60 (0.54 ± 0.07, P<0.05) and Jurkat (0.82±0.16, P<0.05). ④The methylation of ABO promoter in K562, HL-60 and Jurkat were 0, 58.14%, and 96.74%. As concentration of decitabine increased, the methylation of ABO promoter were decreased and the expressions of ABO mRNA were increased in HL-60 and Jurkat, which had significant differences compared with that before treatment (P<0.05). Conclusion: The methylation of ABO promoter shows a negative correlation with ABO mRNA expression. DNA methylation was an important aspect of ABO antigens decrease in acute leukemia.

Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China.

To evaluate the impact of emission control measures on the air quality in the Pearl River Delta (PRD) region of South China, statistic data including atmospheric observations, emissions and energy consumptions during 2006-2014 were analyzed, and a Weather Research and Forecasting - Community Multi-scale Air Quality (WRF-CMAQ) model was used for various scenario simulations. Although energy consumption doubled from 2004 to 2014 and vehicle number significantly increased from 2006 to 2014, ambient SO2, NO2 and PM10 were reduced by 66%, 20% and 24%, respectively, mainly due to emissions control efforts. In contrast, O3 increased by 19%. Model simulations of three emission control scenarios, including a baseline (a case in 2010), a CAP (a case in 2020 assuming control strength followed past control tendency) and a REF (a case in 2020 referring to the strict control measures based on recent policy/plans) were conducted to investigate the variations of air pollutants to the changes in NOx, VOCs and NH3 emissions. Although the area mean concentrations of NOx, nitrate and PM2.5 decreased under both NOx CAP (reduced by 1.8%, 0.7% and 0.2%, respectively) and NOx REF (reduced by 7.2%, 1.8% and 0.3%, respectively), a rising of PM2.5 was found in certain areas as reducing NOx emissions elevated the atmospheric oxidizability. Furthermore, scenarios with NH3 emission reductions showed that nitrate was sensitive to NH3 emissions, with decreasing percentages of 0-10.6% and 0-48% under CAP and REF, respectively. Controlling emissions of VOCs reduced PM2.5 in the southwestern PRD where severe photochemical pollution frequently occurred. It was also found that O3 formation in PRD was generally VOCs-limited while turned to be NOx-limited in the afternoon (13:00-17:00), suggesting that cutting VOCs emissions would reduce the overall O3 concentrations while mitigating NOx emissions in the afternoon could reduce the peak O3 levels.

Spatiotemporal variation of ozone precursors and ozone formation in Hong Kong: Grid field measurement and modelling study.

Grid field measurements of volatile organic compounds (VOCs) covering the entire territory of Hong Kong were simultaneously carried out twice daily on 27 September 2013 and 24 September 2014, respectively, to advance our understanding on the spatiotemporal variations of VOCs and ozone (O3) formation, the factors controlling O3 formation and the efficacy of a control measure in Hong Kong. From before to after the control measure on liquefied petroleum gas (LPG) fueled vehicles, the VOCs originated from LPG vehicle exhaust deceased from 41.3±1.2µg/m(3) (49.7±1.5%) to 32.8±1.4µg/m(3) (38.8±1.7%) (p<0.05). In contrast, the contribution to VOCs made by gasoline and diesel vehicle exhaust and solvent usage increased (p<0.05). VOCs and nitric oxide (NO) in LPG source experienced the highest reductions at the roadside sites, while the variations were not significant at the urban and new town sites (p>0.05). For O3 production, LPG vehicle exhaust generally made a negative contribution (-0.17±0.06 ppbv) at the roadside sites, however it turned to a slightly positive contribution (0.004±0.038 ppbv) after the control measure. At the urban sites, although the reductions of VOCs and NO were minor (p>0.05), O3 produced by LPG vehicle significantly reduced from 4.19±1.92 ppbv to 0.95±0.38 ppbv (p<0.05). Meanwhile, O3 produced by LPG at the new town sites remained stable. The analysis of O3-precursor relationships revealed that alkenes and aromatics were the main species limiting roadside O3 formation, while aromatics were the most predominant controlling factor at urban and new town sites. In contrast, isoprene and sometimes NOx limited the O3 formation in rural environment.

Ambient volatile organic compounds and their effect on ozone production in Wuhan, central China.

Ambient volatile organic compounds (VOCs) were continuously measured from February 2013 to October 2014 at an urban site in Wuhan. The characteristics and sources of VOCs and their effect on ozone (O3) formation were studied for the first time. The total VOC levels in Wuhan were relatively low, and of all VOCs, ethane (5.2 ± 0.2 ppbv) was the species with the highest levels. Six sources, i.e., vehicular exhausts, coal burning, liquefied petroleum gas (LPG) usage, the petrochemical industry, solvent usage in dry cleaning/degreasing, and solvent usage in coating/paints were identified, and their contributions to the total VOCs were 27.8 ± 0.9%, 21.8 ± 0.8%, 19.8 ± 0.9%, 14.4 ± 0.9%, 8.5 ± 0.5%, and 7.7 ± 0.4%, respectively. Model simulation of a photochemical box model incorporating the Master Chemical Mechanism (PBM-MCM) indicated that the contribution to O3 formation of the above sources was 23.4 ± 1.3%, 22.2 ± 1.2%, 23.1 ± 1.7%, 11.8 ± 0.9%, 5.2 ± 0.4%, and 14.2 ± 1.1%, respectively. LPG and solvent usage in coating/paints were the sources that showed higher contributions to O3 formation, compared to their contributions to VOCs. The relative incremental reactivity (RIR) analysis revealed that the O3 formation in Wuhan was generally VOC-limited, and ethene and toluene were the primary species contributing to O3 production, accounting for 34.3% and 31.5% of the total RIR-weighted concentration, respectively. In addition, the contribution of CO to the O3 formation was remarkable. The C4 alkanes and alkenes from the LPG usage also significantly contributed to the O3 formation. The results can assist local governments in formulating and implementing control strategies for photochemical pollution.