Particulate matter,PM 10 & PM 2.5 levels,and airborne mutagenicity in Chiang Mai,Thailand

Daily levels of particulate matter (PM) in the ambient air (PM 2.5 and PM 10) were measured in a northern city of Thailand (Chiang Mai) from March 1998 to October 1999. Twenty-four-hour air particulate matter samples were collected each day with Airmetric Minivol portable air samplers. Monthly averages of PM 2.5 from four stations in Chiang Mai varied from 15.39 to 138.31microg/m(3) and 27.29 to 173.40 microg/m(3) for PM 10. The PM 2.5 annual average was 58.48 mg/m(3) and PM 10, 86.38 microg/m(3). Daily PM 2.5 (24h values) during the winter months in Chiang Mai frequently exceeded 200-300 microg/m(3). The maximum concentrations of PM 2.5 (24h average) in Chiang Mai air from December 1998 to April 1999 were 2.8-, 3.5-, 4.2-, 6.5- and 3.2-fold higher than the US Environmental Protection Agency (US EPA), PM 2.5, 24h standard of 65 microg/m(3). From May to October, the mean 24h levels of PM 2.5 and PM 10 were at acceptable levels. The data shows that during the winter season (December to March), levels of PM 2.5 and PM 10 in the Chiang Mai atmosphere are very high, and there may be significant health implications associated with these high concentrations. During the summer season, the fine particles were generally within the acceptable levels. To our knowledge, these are the first measurements of PM 2.5 to be reported for the city of Chiang Mai and they indicate considerable ambient fine particle exposures to the Chiang Mai population. In addition, dichloromethane extracts of airborne particulate matter PM 2.5 or PM 10 collected in the months of winter in the city of Chiang Mai were mutagenic to Salmonella typhimurium strain TA100 without metabolic activation. The mutagenicity appeared to track particle concentrations and increased in the presence of S9 mix.     

空气污染对信鸽比赛个体归巢速度的影响

空气污染作为一种有害的环境因素,对人类及动物的生理、心理均有影响。在鸟类中,信鸽(Columba livia)是研究空气污染影响的理想模型。为探究空气污染的行为学效应,通过收集并筛选2018和2019年成都市信鸽协会春秋两个季节举办的64场赛事共285羽参赛5场及以上的信鸽不同空距等级下的归巢速度,利用混合线性模型分析了6种大气污染物(CO、NO₂、O₃、PM_2.5、PM₁₀、SO₂)及气温、季节、天气等环境因子对信鸽归巢速度的影响。结果表明,PM₁₀、SO₂、NO₂、O₃浓度与归巢速度间有显著正相关关系,即这些空气污染物浓度越高,信鸽归巢速度越快;而CO浓度与归巢速度显著负相关,即CO浓度越高,信鸽归巢速度越慢。通过模型评估及比较,发现O3模型是归巢速度的最佳拟合模型,其次是NO2模型。本研究表明,信鸽的归巢速度的确受到空气污染的影响,但潜在的影响机制如归巢动机假说和嗅觉强化假说仍需进一步研究。     

The interaction of water molecules with purple membrane suspension using 2H double-quantum filter, 1H and 2H diffusion nuclear magnetic resonance

Bacteriorhodopsin is a membrane protein of the purple membrane (PM) of Halobacterium salinarum, which is isolated as sheets of highly organized two-dimensional hexagonal microcrystals and for which water molecules play a crucial role that affects its function as a proton pump. In this paper we used single- and double-quantum (2)H NMR as well as (1)H and (2)H diffusion NMR to characterize the interaction of water molecules with the PM in D(2)O suspensions. We found that, under the influence of a strong magnetic field on a concentrated PM sample (0.61 mM), the PM sheets affect the entire water population and a residual quadrupolar splitting (upsilon(q) approximately 5.5 Hz, 298 K, at 11.7 T) is observed for the D(2)O molecules. We found that the residual quadrupolar coupling, the creation time in which a maximal DQF signal was obtained (tau(max)), and the relative intensity of the (2)H DQF spectrum of the water molecules in the PM samples (referred to herein as NMR order parameters) are very sensitive to temperature, dilution, and chemical modifications of the PM. In concentrated PM samples in D(2)O, these NMR parameters seem to reflect the relative organization of the PM. Interestingly, we have observed that some of these parameters are sensitive to the efficiency of the trimer packing, as concluded from the apo-membrane behavior. The data for dionized blue membrane, partially delipidated sample, and detergent-treated PM show that these D(2)O NMR order parameters, which are magnetic field dependent, are sensitive to the structural integrity of the PM. In addition, we revealed that heating the PM sample inside or outside the NMR magnet has, after cooling, a different effect on the NMR characteristics of the water molecules in the concentrated PM suspensions. The difference in the D(2)O NMR order parameters for the PM samples, which were heated and cooled in the presence and in the absence of a strong magnetic field, corroborates the conclusions that the above D(2)O order parameters are indirect reflections of both microscopic and macroscopic order of the PM samples. In addition, (1)H NMR diffusion measurements showed that at least three distinct water populations could be identified, based on their diffusion coefficients. These water populations seem to correlate with different water populations previously reported for the PM system.     

环境污染物对巨噬细胞的影响及生物监测意义

随着工农业的发展,环境污染问题日趋严重。作为常见的环境污染物,二氧化硫经呼吸道转化为亚硫酸盐能引起多种呼吸系统疾病,并可能有促癌作用;重金属汞能引起中枢神经系统和多种器官损害,同时具有一定的免疫毒性,其危害已引起人们广泛关注。生物监测(bi0H10nitoring)是使用活     

NADPH oxidase-dependent hydrogen peroxide production, induced by salinity stress, may be involved in the regulation of total calcium in roots of wheat

Hydrogen peroxide (H(2)O(2)) is often generated by cells and tissues under environmental stress. In this work, we provide evidence that plasma membrane (PM) NADPH oxidase-dependent H(2)O(2) production might act as an intermediate step in the NaCl-induced elevation of calcium (Ca) in roots of wheat. Remarkable increases in the content of total Ca were observed not only in roots exposed to NaCl but also in roots of seedlings exposed to exogenous H(2)O(2). In roots, H(2)O(2) production increased upon exposure to salt stress. PM vesicles were isolated from roots, and NADPH oxidase activity was determined by measuring superoxide anion (O(2)(-)) production. NADPH oxidase-dependent O(2)(-) production was 11.6nmolmg(-1)proteinmin(-1) in control vesicles, but 19.6nmol after NaCl treatment (24h), indicating that salt stress resulted in the activation of the PM NADPH oxidase. Furthermore, the NaCl-induced increase in total Ca was partially abolished by the addition of 150U/mL catalase (CAT), a H(2)O(2) scavenger, and also by 10microM diphenylane iodonium (DPI), a NADPH oxidase inhibitor. This data suggest that NADPH oxidase-dependent H(2)O(2) production might be involved in the modulation of the Ca content in wheat roots. In conclusion, our results show that salinity stress increases the total Ca content of wheat roots, which is partly due to PM NADPH oxidase-dependent H(2)O(2) generation.     

在耐热性诱导中豌豆叶片过氧化氢和水杨酸含量与质膜ATP酶活性的变化及相互关系

在高温锻炼(37℃,2h)过程中,豌豆(Pisum sativum L.)叶片过氧化氢(H_2O_2)和游离态水杨酸(SA)含量与质膜ATP酶(H~ -ATPase)活性都有一个高峰,H_2O_2的迸发早于游离态SA的积累,而质膜H~ -ATPase活性高峰的出现则迟于SA高峰;活性氧清除剂、抗氧化剂、质膜NADPH氧化酶抑制剂和H_2O_2的淬灭剂预处理均可有效地阻止高温下H_2O_2和SA的积累以及质膜H~ -ATPase活性的增加。根据以上结果推测,H_2O_2、质膜H~ -ATPase和SA均参与耐热性诱导相关的信号传递,前者作用于SA的上游,而后者在SA下游起作用。     

Age-related alterations in superoxide anion generation in mouse peritoneal macrophages studied by repeated stimulations and heat shock treatment.

The ability of thioglycollate-elicited peritoneal macrophages (PM) from young and senescent mice to generate superoxide anions (O2-) under repeated stimulation or thermal stress was studied using either zymosan, opsonized zymosan (OZ), or phorbol myristate acetate (PMA). A diminished capacity to recover from repeated stimulation was found with aging. When stimulated for a second time 24 hours after the primary stimulation, PM from young animals generated 80% of the initial O2- responses to either zymosan, or OZ. Under the same conditions, PM from senescent mice generated 62% of the initial O2- produced in response to zymosan, and 45% in response to OZ. In both age groups the response to a second PMA stimulation comprised only 10% of the primary response. A considerably diminished capacity to generate O2- was also demonstrated in PM from senescent mice after recovery from exposure to thermal stress. Exposure to 42.5 degrees C for 20 minutes was found to be the threshold temperature for irreversible loss of activity in senescent PM, whereas at this temperature, PM from young animals recovered up to 70% of their O2- generating activity. Since NADPH oxidase and superoxide dismutase activities were only mildly affected by the hyperthermia in all age groups, they could not account for the age-related decline in the recovery from stress. Age-related alterations in signal transduction or receptor alterations could possibly play a primary role in this decline.     

ABA诱导玉米叶质外体H2O2积累的机制

通过组织化学染色和电镜观察并结合酶活性分析表明,ABA可通过诱导玉米（Zea mays L、）叶片质膜NADPH氧化酶、细胞壁POD及质外体PAO活性的升高,使其质外体产生H2O2;其中质膜NADPH氧化酶起主要作用。     

Effects of particulate air pollution on cardiovascular health: a population health risk assessment

Particulate matter (PM) air pollution is increasingly recognized as an important and modifiable risk factor for adverse health outcomes including cardiovascular disease (CVD). However, there are still gaps regarding large population risk assessment. Results from the nationwide Behavioral Risk Factor Surveillance System (BRFSS) were used along with air quality monitoring measurements to implement a systematic evaluation of PM-related CVD risks at the national and regional scales. CVD status and individual-level risk factors were collected from more than 500,000 BRFSS respondents across 2,231 contiguous U.S. counties for 2007 and 2009. Chronic exposures to PM pollutants were estimated with spatial modeling from measurement data. CVD outcomes attributable to PM pollutants were assessed by mixed-effects logistic regression and latent class regression (LCR), with adjustment for multicausality. There were positive associations between CVD and PM after accounting for competing risk factors: the multivariable-adjusted odds for the multiplicity of CVD outcomes increased by 1.32 (95% confidence interval: 1.23-1.43) and 1.15 (1.07-1.22) times per 10 μg/m(3) increase in PM(2.5) and PM(10) respectively in the LCR analyses. After controlling for spatial confounding, there were moderate estimated effects of PM exposure on multiple cardiovascular manifestations. These results suggest that chronic exposures to ambient particulates are important environmental risk factors for cardiovascular morbidity.     

Ambient Fine Particulate Matter Suppresses In Vivo Proliferation of Bone Marrow Stem Cells through Reactive Oxygen Species Formation

Aims

Some environmental insults, such as fine particulate matter (PM) exposure, significantly impair the function of stem cells. However, it is unknown if PM exposure could affect the population of bone marrow stem cells (BMSCs). The present study was to investigate the effects of PM on BMSCs population and related mechanism(s).

Main Metheods

PM was intranasally distilled into male C57BL/6 mice for one month. Flow cytometry with antibodies for BMSCs, Annexin V and BrdU ware used to determine the number of BMSCs and the levels of their apoptosis and proliferation in vivo. Phosphorylated Akt (P-Akt) level was determined in the BM cells with western blotting. Intracellular reactive oxygen species (ROS) formation was quantified using flow cytometry analysis. To determine the role of PM-induced ROS in BMSCs population, proliferation, and apotosis, experiments were repeated using N-acetylcysteine (NAC)-treated wild type mice or a triple transgenic mouse line with overexpression of antioxidant network (AON) composed of superoxide dismutase (SOD)1, SOD3, and glutathione peroxidase-1 with decreased in vivo ROS production.

Key Findings

PM treatment significantly reduced BMSCs population in association with increased ROS formation, decreased P-Akt level, and inhibition of proliferation of BMSCs without induction of apoptosis. NAC treatment or AON overexpression with reduced ROS formation effectively prevented PM-induced reduction of BMSCs population and proliferation with partial recovery of P-Akt level.

Significance

PM exposure significantly decreased the population of BMSCs due to diminished proliferation via ROS-mediated mechanism (could be partially via inhibition of Akt signaling).     

Lateral diffusion of the PH-20 protein on guinea pig sperm: evidence that barriers to diffusion maintain plasma membrane domains in mammalian sperm

PH-20 protein on the plasma membrane (PH-20PM) is restricted to the posterior head of acrosome-intact guinea pig sperm. During the exocytotic acrosome reaction the inner acrosomal membrane (IAM) becomes continuous with the posterior head plasma membrane, and PH-20PM migrates to the IAM. There it joins a second population of PH-20 protein localized to this region of the acrosomal membrane (PH-20AM) (Cowan, A.E., P. Primakoff, and D.G. Myles, 1986, J. Cell Biol. 103:1289-1297). To investigate how the localized distributions of PH-20 protein are maintained, the lateral mobility of PH-20 protein on these different membrane domains was determined using fluorescence redistribution after photobleaching. PH-20PM on the posterior head of acrosome-intact sperm was found to be mobile, with a diffusion coefficient and percent recovery typical of integral membrane proteins (D = 1.8 X 10(-10) cm2/s; %R = 73). This value of D was some 50-fold lower than that found for the lipid probe 1,1-ditetradecyl 3,3,3',3'-tetramethylindocarbocyanine perchlorate (C14diI) in the same region (D = 8.9 X 10(-9) cm2/s). After migration to the IAM of acrosome-reacted sperm, this same population of molecules (PH-20PM) exhibited a 30-fold increase in diffusion rate (D = 4.9 X 10(-9) cm2/s; %R = 78). This rate was similar to diffusion of the lipid probe C14diI in the IAM (D = 5.4 X 10(-9) cm2/s). The finding of free diffusion of PH-20PM in the IAM of acrosome-reacted sperm supports the proposal that PH-20 is maintained within the IAM by a barrier to diffusion at the domain boundary. The slower diffusion of PH-20PM on the posterior head of acrosome-intact sperm is also consistent with localization by barriers to diffusion, but does not rule out alternative mechanisms.     

An analysis of the pollution problem in Slavonski Brod (eastern Croatia)

H2S, PM2.5, O3, NO2, SO2 and meteorological parameters such as temperature, relative humidity, precipitation, wind speed and wind direction were measured simultaneously in an eastern Croatian town called Slavonski Brod during the season winter/spring 2010. Emissions from the nearby cross-border (Bosnia and Herzegovina) oil refinery were identified as sources of temporary elevated concentrations of H2S. The maximum daily averages of PM2.5 concentrations during the winter period were as high as 240 microg m(-3) which is a value 10 times greater than the threshold prescribed by the World Health Organization. It is considered that the heating season, dense traffic, intense industrial activities and temperature inversion during stable weather conditions are prevailing contributors to higher winter concentrations of PM2.5. The results of the principal component analysis technique (PCA) have shown that lower air temperature, lower wind speed and higher relative humidity play a significant role in the winter pollution episodes. From a public health point of view, implementation of measures aimed at reducing the levels of H2S and PM2.5 should be considered.     

Modulation of reactive oxygen species production during osmotic stress in Arabidopsis thaliana cultured cells: involvement of the plasma membrane Ca2+-ATPase and H+-ATPase

In Arabidopsis thaliana cells, hypoosmotic treatment initially stimulates Ca2+ influx and inhibits its efflux and, concurrently, promotes a large H2O2 accumulation in the external medium, representative of reactive oxygen species (ROS) production. After the first 10-15 min, Ca2+ influx rate is, however, lowered, and a large rise in Ca2+ efflux, concomitant with a rapid decline in H2O2 level, takes place. The drop of the H2O2 peak, as well as the efflux of Ca2+, are prevented by treatment with submicromolar concentrations of eosin yellow (EY), selectively inhibiting the Ca2+-ATPase of the plasma membrane (PM). Comparable changes of Ca2+ fluxes are also induced by hyperosmotic treatment. However, in this case, the H2O2 level does not rise, but declines below control levels when Ca2+ efflux is activated. Also K+ and H+ net fluxes across the PM and cytoplasmic pH (pH(cyt)) are very differently influenced by the two opposite stresses: strongly decreased by hypoosmotic stress and increased under hyperosmotic treatment. The H2O2 accumulation kinetics, followed as a function of the pH(cyt) changes imposed by modulation of the PM H+-ATPase activity or weak acid treatment, show a close correlation between pH(cyt) and H2O2 formed, a larger amount being produced for changes towards acidic pH values. Overall, these results confirm a relevant role for the PM Ca2+-ATPase in switching off the signal triggering ROS production, and propose a role for the PM H+-ATPase in modulating the development of the oxidative wave through the pH(cyt) changes following the changes of its activity induced by stress conditions.     

Sperm parameters on Iberian red deer: electroejaculation and post-mortem collection

Artificial reproductive technologies (ART) for cervids have improved, but a need remains for the collection of basic data. We studied two models of sperm collection in Iberian red deer, post-mortem (PM) in a wild population (179 samples) and by electroejaculation (EE) in a farmed population (37 samples), recording: testicular and epididymal weight, testicular diameter, sperm quantity, pH and osmolality and spermatozoa quality (motility by CASA, abnormal forms, cytoplasmic droplets, viability and acrosomal status). We tested the relationship of these parameters with stag age and compared the two models (PM and EE; medians showed). Genitalia parameters were linearly related to stag age (testicular diameter: 31.5-50.5mm for 2-9 years). Total number of spermatozoa collected were PM: 2.5x10(9) and EE: 3.6x10(9) (P>0.05), increasing with age only for PM. We found a positive relationship between testicular size and spermatozoa collected for PM. Osmolality and pH were PM: 6.28 and 378mOsm/kg; EE: 7.63 and 309mOsm/kg (P<0.05). The pH increased with age only for EE. Percentage of motile spermatozoa was similar for PM and EE, but motility quality was lower for PM. Abnormal forms, proximal and distal droplets were lower for EE (22%, 1.3%, 1.5% vs. PM: 23%, 4.3%, 83%). Viability was similar (74%) and intact acrosomes were higher for EE (97% vs. 89%). Both PM and EE samples could be used for germplasm banking. This study contributes with new data on red deer spermatology and for the development of ART in cervids.     

Risk of adult street vendor exposure to traffic-related air pollution in Bangkok,Thailand

Traffic-related air pollution (TRAP), including particulate matter (PM) in respirable coarse and fine size fractions (PM10 and PM2.5), is known to have exposure effects on human health and environment. Real-time PM10 and PM2.5 concentrations were collected from the study locations in Bangkok, Thailand, using TSI AM510 particle counters. Temperature and % relative humidity (%RH) were also collected. Data were compared to data from the closest station of the Pollution Control Department (PCD), Thailand. Real-time mean concentration varied from 86 to 1107 µg/m³ (PM10) and varied from 25 to 664 µg/m³ (PM2.5). In addition, real-time mean PM10 (223.1 µg/m³) was nearly four times greater than that measured by the PCD station, 60 µg/m³. Temperature and %RH from real-time air monitoring and PCD station were comparable. In each study location (five locations, two in morning and afternoon/evening), there were significant positive correlations between PM10 and PM2.5 concentrations and significant negative correlations between temperature and RH%. Results suggested that outdoor TRAP via measured real-time PM concentrations were more realistic exposure concentration estimates among street vendors as related to respiratory and other symptoms than data obtained from PCD station. Nevertheless, PM10 as measured by the PCD station might be a reasonable surrogate for estimated outdoor PM2.5 exposure.     

A Simple Synthetic Strategy toward Defect‐Rich Porous Monolayer NiFe‐Layered Double Hydroxide Nanosheets for Efficient Electrocatalytic Water Oxidation

In this work, porous monolayer nickel‐iron layered double hydroxide (PM‐LDH) nanosheets with a lateral size of ≈30 nm and a thickness of ≈0.8 nm are successfully synthesized by a facile one‐step strategy. Briefly, an aqueous solution containing Ni²⁺ and Fe³⁺ is added dropwise to an aqueous formamide solution at 80 °C and pH 10, with the PM‐LDH product formed within only 10 min. This fast synthetic strategy introduces an abundance of pores in the monolayer NiFe‐LDH nanosheets, resulting in PM‐LDH containing high concentration of oxygen and cation vacancies, as is confirmed by extended X‐ray absorption fine structure and electron spin resonance measurements. The oxygen and cation vacancies in PM‐LDH act synergistically to increase the electropositivity of the LDH nanosheets, while also enhancing H₂O adsorption and bonding strength of the OH* intermediate formed during water electrooxidation, endowing PM‐LDH with outstanding performance for the oxygen evolution reaction (OER). PM‐LDH offers a very low overpotential (230 mV) for OER at a current density of 10 mA cm^?2, with a Tafel slope of only 47 mV dec^?1, representing one of the best OER performance yet reported for a NiFe‐LDH system. The results encourage the wider utilization of porous monolayer LDH nanosheets in electrocatalysis, catalysis, and solar cells.     

Involvement of hydrogen peroxide and nitric oxide in salt resistance in the calluses from Populus euphratica

Nitric oxide (NO) and hydrogen peroxide (H2O2) function as signalling molecules in plants under abiotic and biotic stresses. Calluses from Populus euphratica, which show salt tolerance, were used to study the interaction of NO and H2O2 in plant adaptation to salt resistance. The nitric oxide synthase (NOS) activity was identified in the calluses, and this activity was induced under 150 mM NaCl treatment. Under 150 mM NaCl treatment, the sodium (Na) percentage decreased, but the potassium (K) percentage and the K/Na ratio increased in P. euphratica calluses. Application of glucose/glucose oxidase (G/GO, a H2O2 donor) and sodium nitroprusside (SNP, a NO donor) revealed that both H2O2 and NO resulted in increased K/Na ratio in a concentration-dependent manner. Diphenylene iodonium (DPI, an NADPH oxidase inhibitor) counteracted H2O2 and NO effect by increasing the Na percentage, decreasing the K percentage and K/Na ratio. NG-monomethyl-L-Arg monoacetate (NMMA, an NO synthase inhibitor) and 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxyde (PTIO, a specific NO scavenger) only reversed NO effect, but did not block H2O2 effect. The increased activity of plasma membrane (PM) H+ -ATPase caused by salt stress was reversed by treatment with DPI and NMMA. Exogenous H2O2 increased the activity of PM H+ -ATPase, but the effect could not be diminished by NMMA and PTIO. The NO-induced increase of PM H+ -ATPase can be reversed by NMMA and PTIO, but not by DPI. Western blot analysis demonstrated that NO and H2O2 stimulated the expression of PM H+ -ATPase in P. euphratica calluses. These results indicate that NO and H2O2 served as intermediate molecules in inducing salt resistance in the calluses from P. euphratica under slat stress by increasing the K/Na ratio, which was dependent on the increased PM H+ -ATPase activity.