Genetic diversity and structure of Oncomelania hupensis hupensis in two eco-epidemiological settings as revealed by the mitochondrial COX1 gene sequences.

BACKGROUND: Oncomelania hupensis hupensis is the only intermediate host of Schistosoma japonicum, the causative agent of schistosomiasis in China and is therefore of significant medical and veterinary health importance. Although tremendous progress has been achieved, there remains an understudied area of approximately 2.06 billion m2 of potential snail habitats. This area could be further increased by annual flooding. Therefore, an understanding of population genetics of snails in these areas may be useful for future monitoring and control activities. METHODS AND RESULTS: We sampled snails from Hexian (HX), Zongyang (ZY) and Shitai (ST) in Anhui (schistosomiasis transmission control), and from Hengtang (HT), Taicang (TC), Dongsan (DS) and Xisan (XS) in Jiangsu (schistosomiasis transmission interrupted), downstream of Anhui. ST, DS and XS are classified as hilly and mountainous areas, and HX, ZY, TC and HT as lake and marshland areas. The mitochondrial cytochrome c oxidase subunit I gene were sequenced. Out of 115 snails analyzed, 29 haplotypes were identified. We observed 56 (8.72%) polymorphic sites consisting of 51 transitions, four transversions and one multiple mutational change. The overall haplotype and nucleotide diversity were 0.899 and 0.01569, respectively. Snail populations in Anhui had higher genetic diversity than in Jiangsu. 73.32% of total variation was distributed among sites and 26.68% within sites. Snails were significantly separated according to eco-epidemiological settings in both network and phylogenetic analyses. CONCLUSION: Our results could provide important guidance towards assessing coevolutionary interactions of snails with S. japonicum, as well as for future molluscan host monitoring and control activities.

Effects of environmental chemicals on the proliferation and differentiation of neural stem cells.

The objective of the present study was to explore the effects of environmental chemicals, such as methyl mercury, paraquat, and bisphenol A, on cell proliferation and apoptosis, as well as the expression levels of neuronal differentiation-related genes in neural stem cells (NSCs). NSCs originated from human umbilical cord blood (HUCB-NSCs) were used as cell models in the current study. CCK-8 and flow cytometry experiments were performed to assess the effects of methyl mercury, paraquat, and bisphenol A on the proliferation and apoptosis of HUCB-NSCs at different processes, including proliferation and differentiation stages. The expressions of neuronal differentiation-related genes were determined by reverse transcription-polymerase chain reaction and western blot analysis. The results showed that methyl mercury, paraquat, and bisphenol A treatments significantly inhibited cell proliferation and induced cell apoptosis in HUCB-NSCs, as well as decreased the expressions of Oct4, Gdf3, and Sox1, whereas increased Pax6 and Ngn1 expressions at both mRNA and protein levels. In conclusion, this study demonstrates that environmental chemicals can impair the proliferation and differentiation of NSCs, which may cause abnormal development of the nervous system.

Assessment of chlorpyrifos exposure and absorbed daily doses among infants living in an agricultural area of the Province of Jiangsu, China.

PURPOSE: Chlorpyrifos (CPF) is one of the most widely used organophosphorous pesticides in China. However, few reports on CPF pesticide exposure and body burden of infants at 2 years of age in China are available. The aim of this study was to assess the exposure level and the absorbed daily dose (ADD) of CPF among infants from an agricultural area of Jiangsu, China, and determine whether the infants' estimated dose exceeds the recommended reference dose (RfD) and the population adjusted dose (PAD) set by U.S. Environmental Protection Agency (EPA). METHODS: In our study, 364 infants at 2 years of age who lived in the agricultural area of Jiangsu Province (China) were enrolled into the biomonitoring study from June 2011 to January 2012. CPF exposure was estimated based on both questionnaire survey and measured results of urinary metabolite 3,5,6-trichloro-2-pyridinol (TCPy) of CPF by high-performance liquid chromatography. Furthermore, the ADD of CPF among infants was also evaluated and compared with the RfD and the PAD values issued by EPA. RESULTS: Urinary TCPy was detected in more than 70 % of the urine samples among 364 infants. The unadjusted and creatinine-adjusted geometric means in these subjects for TCPy were 1.33 µg/L and 6.73 µg/g Cre., respectively. Infants lived nearby (100 m distance) plantations or green parks present significantly higher levels of urinary TCPy than those lived far away (p = 0.045). Urinary TCPy levels were also significantly higher in infants who had frequent hand-to-mouth activities than those with less frequency (p = 0.037). Urinary TCPy concentrations in the infants at 2 years of age in Jiangsu were lower than those in the children at 2-6 years of age in the USA. The median estimated ADD of CPF in this study (0.07 µg/kg/day) was much lower than the acute and chronic RfDs (5 and 0.3 µg/kg/day, respectively) announced by EPA, but higher than the chronic PAD (cPAD) (0.03 µg/kg/day) for children. Additionally, the 75th percentile of the estimated ADD in our study was 2.5 times as much as the cPAD from EPA, even assuming only half of the TCPy amount from CPF exposure. CONCLUSIONS: Our findings revealed that infants at 2 years of age in Jiangsu of China were widely exposed to CPF pesticide. The estimated ADD probably suggested that about 25 % of the enrolled infants were at potential risk of pesticide exposure, which warned of urgency to eliminate the potential exposure risk to infants living in agricultural areas of China.

[Intervention of pyrrolidine dithiocarbamate on expressions of connective tissue growth factor, type I collagen, and type III collage in acute paraquat poisoned rats].

OBJECTIVE: To observe the changes in the expression of connective tissue growth factor (CTGF), type I collagen (Col I), and type III collagen (Col III) among the rats with acute paraquat (PQ) poisoning and the intervention effect of pyrrolidine dithiocarbamate (PDTC) on their expression, and to investigate the mechanism of PQ-induced pulmonary fibrosis and the intervention effect of PDTC on the disease. METHODS: Sprague-Dawley rats were randomly divided into control group (n = 6), PQ group (n = 36), and PQ + PDTC group (n = 36). The PQ group and PQ + PDTC group were given a single dose of saline-diluted PQ (80 mg/kg) by gavage; 2 h later, the PQ + PDTC group was intraperitoneally injected with a single dose of PDTC (100 mg/kg), and the PQ group was intraperitoneally injected with the same amount of saline. The control group was given saline (1 ml/kg) by gavage and was intraperitoneally injected with the same amount of saline 2h later. At 1, 3, 7, 14, 25, and 56 days after operation, the protein expression of CTGF was evaluated by Western blot; the mRNA expression of CTGF, Col I, and Col III was analyzed by real-time quantitative PCR; the content of hydroxyproline in lung tissue was measured, and the pathological changes of lung tissue of the poisoned rats were observed. RESULTS: The protein expression of CTGF in the PQ group increased as the time went on, slowly from the 3rd to the 14th day and rapidly from the 28th to the 56th day, significantly higher than that in the control group at each time point (P < 0.05 or P < 0.01). The mRNA expression of CTGF in the PQ group began to rise markedly on the 1st day, increased rapidly from the 3rd to the 14th day, and remained at a relatively high level from the 28th to the 56th day, significantly higher than that in the control group at each time point (P < 0.01). The mRNA expression of Col I in the PQ group changed little on the 1st and 3rd day, increased slightly on the 7th day, and increased greatly from the 14th to the 56th day, significantly higher than that in the control group from the 7th to the 56th day (P < 0.05 or P < 0.01). The mRNA expression of Col III in the PQ group began to rise on the 1st day, reached the peak level on the 7th day, and then declined, significantly higher than that in the control group at each time point (P < 0.05 or P < 0.01). Masson staining showed that fibroblasts proliferated from the 14th to the 28th day, and collagen fibers increased gradually. Compared with the PQ group, the PQ + PDTC group showed significantly decreased protein expression of CTGF as well as mRNA expression of CTGF, Col I, and Col III (P < 0.05 or P < 0.01). CONCLUSION: In PQ-induced pulmonary fibrosis, the expression of CTGF keeps rising, and the collagen secretion and matrix synthesis are increased probably by upregulating the transcriptional levels of Col I and Col III; CTGF plays an important role in PQ-induced pulmonary fibrosis. PDTC can inhibit the expression of CTGF, thus reducing the lung injury in rats with PQ poisoning.

[Paraquat involves differentiation of human neural stem cells via Notch signaling].

OBJECTIVE: To investigate effects of paraquat on the mRNA expression of key elements of Notch signaling (Notch1, Jagged1 and DTX1) during differentiation process of human neural stem cells (hNSCs). METHODS: hNSCs exposed to PQ at the concentrations 0.10, 1.00, 10.00 M. Cell proliferation ability was assessed using MTT assay and mRNA expressions of Notch1, Jagged1 and DTX1 were detected by Real-time RT-PCR at 2, 4, 8, 12 d of differentiation. RESULTS: Compared with control group, NOTCH1, JAG1 mRNA expression levels exposed to PQ at the concentration of 0.10 M significantly reduced at 2, 4, 8 d and significantly went up at 12d (P < 0.01). Compared with control group, NOTCH1, JAG1 and DTX1 mRNA expression levels exposed to PQ at the concentration of 10.00 M significantly reduced at 2, 8, 12 d (P < 0.01). PQ could down-regulate Notch1, Jagged1 and DTX1 mRNA expressions at the early stage of differentiation, then up-regulate Notch1 mRNA expression, and down-regulate Notch1, Jagged1 and DTX1 mRNA expressions at the end of differentiation. CONCLUSION: Notch signaling pathway may be involved in differentiation of neural stem cell exposed to PQ.

[Effects of pyrrolidine dithiocarbamate on expressions of α-smooth muscle actin, integrin α5 and fibronectin in acute paraquat poisoned rats].

OBJECTIVE: To observe the expressions of α-SMA, integrin α5 and fibronectin (Fn) in acute paraquat poisoned rats and the effect of PDTC. To investigate the mechanism of paraquat-induced pulmonary fibrosis. METHODS: Sprague-Dawley rats were randomly divided into three experimental groups: Control group (6 rats), PQ group (36 rats) and PQ+PDTC group (36 rats). On the 1st, 3rd, the 7th, the 14th, the 28th and the 56th day after exposure, the protein expression of α smooth muscle actin (α-SMA) was evaluated by western blot. The mRNA levels of integrin α5 and fibronectin (Fn) were analyzed with real-time quantitative PCR (RT-PCR). Meanwhile, the lung pathological changes were observed and semi-quantified. RESULTS: T With the time passing, the expression of α-SMA in PQ group increased gradually compared with control group (P < 0.05 or P < 0.01). The increasing extent was gently on the 3 rd, the 7 th day. While increasing extent was rapidly from the 28 th to the 56 th day. RT-PCR showed PQ significantly increased Fn mRNA level on all time points and increased integrin α5 mRNA level from the 7 rd to 56 th day compared with control group (P < 0.05 or P < 0.01). PDTC treatment significantly deceased α-SMA, Fn, and integrin α5 levels compared with PQ group in corresponding time points (P < 0.05 or P < 0.01) Noteworthy, in PQ+PDTC group, the occurrence of pathological changes were drastically attenuated and pathologic score significantly decreased (P < 0.05 or P < 0.01). CONCLUSIONS: α-SMA, integrin α5 and fibronectin could play an important role in the development of pulmonary fibrosis caused by paraquat poisoning. PDTC, asa strong NF-κB inhibitor, may inhibit NF-κB activity and further significantly decreased expressions of α-SMA, integrin α5 and fibronectin which were important part of ECM, leading to drastically attenuated pulmonary fibrosis. However, the mechanisms of PDTC intervention still remains to be explored.

[Determination of1-bromopropane in the workplace air by GC-FID].

OBJECTIVE: To establish a method for determination 1-bromopropane (1-BP) in workplace air by gas chromatography-flame ionization detector (GC-FID). METHOD: 1-bromopropane in workplace air was collected with activated charcoal tube, then desorbed by carbon disulfide and determined by GC-FID. 1-bromopropane was quantitatively measured using retention time and peak area. RESULTS: Linear regression formula was Y = 3353.4x-10064 in a range of 2.50 ∼ 500.00 µg/ml with regression coefficient R = 0.9998. Detection limit was 0.25 µg/ml and the lowest detection concentration of 1-brmopropane in air was 0.14 mg/m(3) (at air volume 1.8L). The mean recoveries of 1-BP were between 96.8% and 102.6%, and relative standard deviation of inter and intra-assay was less than 10%. The average desorption efficiencies were between 93.2% and 104.4%. The samples in activated charcoal tube could be stably stored for 5 days at room temperature. CONCLUSION: The method could be feasible to determine 1-bromopropane in workplace air.

Phylogeography and Genetic Structure of the Bush Cricket Decma fissa (Orthoptera, Tettigoniidae) in Southern China.

Decma fissa is the most widely distributed species of the genus Decma occuring in southern China. This study presents the first phylogeographic work of D. fissa based on COI, Cytb and ITS sequence. We examined genetic diversity with ITS and mitochondrial sequence respectively, and phylogenetic work was based on the mitochondrial data. A high-level genetic diversity was revealed based on mitochondrial data but a low-level diversity was shown with ITS sequence. For the mitochondrial data, divergence time analysis displayed five lineages. Based on the Mantel test, geographic and genetic distances among D. fissa populations revealed a significant positive correlation. Bayesian skyline plot (BSP) analyses implied that none of three major lineages of D. fissa was seemingly affected by the last glacial maximum (LGM, 0.015-0.025 Mya). Ecological niche modeling was used to predict the distribution of D. fissa in four periods (LGM, Mid-Holocene, current and 2070) in China. Analysis of the ancestral area reconstruction indicated that D. fissa occurred in the South China area.

Crop rotations increased soil ecosystem multifunctionality by improving keystone taxa and soil properties in potatoes.

Continuous cropping of the same crop leads to soil degradation and a decline in crop production, and these impacts could be mitigated through rotation cropping. Although crop rotation enhances soil fertility, microbial community diversity, and potato yield, its effects on the soil ecosystem multifunctionality (EMF) remain unclear. In the present research, we comparatively examined the effects of potato continuous cropping (PP) and rotation cropping [potato-oat rotation (PO) and potato-forage maize rotation (PFM)] on the soil EMF as well as the roles of keystone taxa, microbes abundance, and chemical properties in EMF improvement. It was demonstrated that soil EMF is increased in rotation cropping (PO and PFM) than PP. Soil pH was higher in rotation cropping (PO and PFM) than in PP, while total phosphorus (TP) and available phosphorus (AP) were significantly decreased than that in PP. Rotation cropping (PO and PFM) markedly changed the bacterial and fungal community compositions, and improved the potential plant-beneficial fungi, e.g., Schizothecium and Chaetomium, while reducing the abundances of the potentially phytopathogenic fungi, e.g., Alternaria, Fusarium, Verticillium dahiae, Gibberella, Plectosphaerella, Colletotrichum, Phoma, and Lectera in comparison with PP. Also, co-occurrence patterns for bacteria and fungi were impacted by crop rotation, and keystone taxa, e.g., Nitrospira.1, Lysinibacillus, Microlunatus.1, Sphingomonas.3, Bryobacter.1, Micromonospora, and Schizothecium, were enriched in PO and PFM than PP. The structural equation model (SEM) further demonstrated that cropping systems increased soil ecosystem multifunctionality through regulating SOM and keystone taxa (Schizothecium1), and keystone taxa were mediated by soil pH. This study suggested that rotation cropping might contribute to the improvement of soil ecosystem multifunctionality as well as the development of disease-suppressive soils in comparison with potato continuous cropping.

Comparative genomics of widespread and narrow-range white-bellied rats in the Niviventer niviventer species complex sheds light on invasive rodent success.

Widespread species that inhabit diverse environments possess large population sizes and exhibit a high capacity for environmental adaptation, thus enabling range expansion. In contrast, narrow-range species are confined to restricted geographical areas and are ecologically adapted to narrow environmental conditions, thus limiting their ability to expand into novel environments. However, the genomic mechanisms underlying the differentiation between closely related species with varying distribution ranges remain poorly understood. The Niviventer niviventer species complex (NNSC), consisting of highly abundant wild rats in Southeast Asia and China, offers an excellent opportunity to investigate these questions due to the presence of both widespread and narrow-range species that are phylogenetically closely related. In the present study, we combined ecological niche modeling with phylogenetic analysis, which suggested that sister species cannot be both widespread and dominant within the same geographical region. Moreover, by assessing heterozygosity, linkage disequilibrium decay, and Tajima's D analysis, we found that widespread species exhibited higher genetic diversity than narrow-range species. In addition, by exploring the "genomic islands of speciation", we identified 13 genes in highly divergent regions that were shared by the two widespread species, distinguishing them from their narrow-range counterparts. Functional annotation analysis indicated that these genes are involved in nervous system development and regulation. The adaptive evolution of these genes likely played an important role in the speciation of these widespread species.

Complete mitochondrial genome of Locusta migratoria migratoria (Orthoptera: Oedipodidae): three tRNA-like sequences on the N-strand.

The complete 16053 bp mitochondrial genome (mitogenome) sequence of Locusta migratoria migratoria has been determined. This mitogenome contains the base compositional biases and codon usage typical of metazoans, and the RSCU values indicate a negative correlation with the C and G contents in codon. The orientation and gene order of the L. migratoria migratoria is identical to Locusta migratoria migratoiodes. An unusual feature of the L. migratoria migratoria mitogenome is the presence of three tRNA-like structures on the N-strand: one tRNA(Ile)-like and two tRNA(Leu(CUN))-like sequences. The tRNA-like sequences have proper folding structures and anticodons sequences. Two repeated DNA sequences, Rpt I and Rpt II, were found in the A+T-rich region of the L. migratoria migratoria mitogenome. Both repeated sequences have various features. In the 5' region of Rpt I, a 51 bp fragment is localized in the srRNA gene; and there are two tandemly sub-repeated DNA sequences (sub-Rpts), Rpt 1-4, within Rpt I and Rpt II. One stem-loop structure on the N-strand that may be involved in the N-strand replication initiation was found in the A+T-rich region.

Paraquat mediates BV-2 microglia activation by raising intracellular ROS and inhibiting Akt1 phosphorylation.

Microglia is the innate immune cell in central nervous system (CNS) and plays an important role in neuroinflammation. Microglia mediated neuroinflammation is the key factor affecting the development of neurodegenerative diseases. Although there was evidence that paraquat (PQ) could induce inflammatory response, its mechanism was not clear. The present study investigated the mechanisms of PQ-induced inflammatory responses in BV-2 microglia cells, and tried to reveal the role of ROS/Akt1 pathway. The results showed that the cell activation markers (iNOS and CD206) of BV-2 cells were increased after PQ treatment, suggesting that BV-2 microglia were activated. PQ induced the reactive oxygen species (ROS) and inhibited the AKT1 phosphorylation in BV-2 cells. Besides, the M1 markers expression (IL-6, TNF-α and IL-1ß) were significantly increased after PQ treatment, which suggested that PQ induced the increase of M1 phenotype of BV-2 microglia. Pre-treated with NAC (ROS scavenger), the M1 phenotype was decreased while the p-Akt1 was restored compared to PQ stimulation. Furthermore, we built an Akt1(S473E)-overexpression BV-2 cell line. The Akt1 (S473E) partially attenuated the PQ induced increase in M1 phenotype, while ROS did not significantly change. These results indicated that PQ induced BV-2 microglia activation by increased ROS mediated Akt1 activation inhibition, leading to neuroinflammation.

A flexible electrode array for determining regions of motor function activated by epidural spinal cord stimulation in rats with spinal cord injury.

Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury. The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation. To activate lower-limb muscles precisely by epidural spinal cord stimulation, we proposed a high-density, flexible electrode array. We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord, which was established by a transection method. For evaluating the effect of stimulation, the evoked potentials were recorded from bilateral lower-limb muscles, including the vastus lateralis, semitendinosus, tibialis anterior, and medial gastrocnemius. To determine the appropriate stimulation sites and parameters of the lower muscles, the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation. In the vastus lateralis and medial gastrocnemius, these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment, respectively. The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles. The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius. Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array. They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury. This study was approved by the Animal Research Committee of Southeast University, China (approval No. 20190720001) on July 20, 2019.

Potent Anti-SARS-CoV-2 Efficacy of COVID-19 Hyperimmune Globulin from Vaccine-Immunized Plasma.

Coronavirus disease 2019 (COVID-19) remains a global public health threat. Hence, more effective and specific antivirals are urgently needed. Here, COVID-19 hyperimmune globulin (COVID-HIG), a passive immunotherapy, is prepared from the plasma of healthy donors vaccinated with BBIBP-CorV (Sinopharm COVID-19 vaccine). COVID-HIG shows high-affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, the receptor-binding domain (RBD), the N-terminal domain of the S protein, and the nucleocapsid protein; and blocks RBD binding to human angiotensin-converting enzyme 2 (hACE2). Pseudotyped and authentic virus-based assays show that COVID-HIG displays broad-spectrum neutralization effects on a wide variety of SARS-CoV-2 variants, including D614G, Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Kappa (B.1.617.1), Delta (B.1.617.2), and Omicron (B.1.1.529) in vitro. However, a significant reduction in the neutralization titer is detected against Beta, Delta, and Omicron variants. Additionally, assessments of the prophylactic and treatment efficacy of COVID-HIG in an Adv5-hACE2-transduced IFNAR-/- mouse model of SARS-CoV-2 infection show significantly reduced weight loss, lung viral loads, and lung pathological injury. Moreover, COVID-HIG exhibits neutralization potency similar to that of anti-SARS-CoV-2 hyperimmune globulin from pooled convalescent plasma. Overall, the results demonstrate the potential of COVID-HIG against SARS-CoV-2 infection and provide reference for subsequent clinical trials.

[Genetic differentiation among different geographic populations of Gampsocleis sedakovii].

The mitochondrial cytochrome oxidase I (mtDNA-COI) gene was used to investigate the intraspecific genetic subdivision among 12 geographical populations of Gampsocleis sedakovii distributed in Jilin, Liaoning, Inner Mongolia, Hebei, and Sichuan provinces, China. As for the 626 bp mtDNA-COI sequences of 36 individuals, 29 haplotypes and 71 (11.3%) polymorphic sites were detected, including 37 parsimony informative and 34 singleton variable sites. The results of the analysis of molecular variance (AMOVA) showed that the percentage of variation within populations (37.23%) was less than that among populations. The Fst value was 0.62770 (P< 0.001), and the genetic divergence among populations was significant. Maximum parsimony (MP) analysis revealed two clearly differentiated branch (Ⅰ and Ⅱ) with high bootstrap support (100%). However, these two branches did not correspond in the subspecies distinction based on morphological character. Based on the habitats analysis, we preliminary inferred that morphological divergence between Gampsocleis se-dakovii sedakovii and Gampsocleis sedakovii obscura was the result of habitat dissimilarity. The majority of the G. se-dakovii individuals collected in NTL (Tongliao, Inner Mongolia) were identified as the members of branch Ⅱ, but one individual (NTL-3) belonged to branch Ⅰ. Thus, at least this locality was occupied by two phylogenetically independent individuals. Haplotypes (H10) were shared by three localities, NTL, NEWK (Ewenke, Inner Mongolia) and JJL (Jilin, Jilin), indicated that they shared a common ancestor. We approved that Northeastern China (Manchuria China) was the center of G. sedakovii genetic differentiation, but disapproved the subspecies distinction based on morphological character.

[Detecting the concentrations of bisphenol A (BPA) in air of workplaces with HPLC].

OBJECTIVE: To establish the method of detecting the concentrations of bisphenol A (BPA)in air of workplaces with high performance liquid chromatographic (HPLC). METHODS: According to standards of methods for determining the chemical substances in workplace air, BPA in the air was collected by glass fiber filter, then dissolved by acetonitrile and determined by high performance liquid chromatography with FLD. RESULTS: There was a linear relationship within the range of 0.01-10.0 pg /ml, and the detection limit was 0.005 pg/ml. The lowest detected concentration was 3.3x10-5 mg/m3. The relative standard deviation was 2.5-5.5%. The dissolution efficiencies were 95.0%-101.9% and the sampling efficiencies were 99.6%. The samples in glass fiber filter membrane could be stored for 7 days at room temperature. CONCLUSION: The present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of BPA in workplace air.

[Involvement of excitatory amino acid system in astrocytes activation caused by dimethoate].

OBJECTIVE: To study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate. METHODS: Pure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10(-6),10(-5),10(-4) mol/L dimethoate for 48 h, 50 micromol/L and 100 micromol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10(-4) mol/L dimethoate. HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100beta mRNA, and immunofluorescence staining method was applied to measure the expression levels of GFAP and S100beta proteins. RESULTS: The expression levels of GLAST mRNA in all exposure groups were 67.8%, 68.6% and 76.2% of control level, respectively, which were significantly lower than that of control group (P < 0.05); The concentrations of EAA significantly decreased in 10(-4) mol/L dimethoate group, as compared with control group (P < 0.01); the expression levels of GFAP mRNA in 10(-4) mol/L dimethoate group, of S100beta mRNA in 10(-5) mol/L dimethoate group, of GFAP protein in 10(-4) mol/L and 10(-5) mol/L dimethoate groups and S100beta protein in 10(-4) mol/L dimethoate group were significantly higher than those in control group (P < 0.01). The expression levels of GLT-1 and GLAST mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01), the expression levels of NR2B mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with control group (P < 0.05 or P < 0.01); the concentration of Glu in 10(-4) mol/L dimethoate plus 100 micromol/L MK801 group increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01); the expression levels of GFAP mRNA and protein in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups decreased significantly (P < 0.01); S100beta protein expression level in 50 micromol/L MK801 intervention group was significantly higher than thatl in control group (P < 0.01). CONCLUSION: Excitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.

Computed tomography-identified phenotypes of small airway obstructions in chronic obstructive pulmonary disease.

ABSTRACT: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characteristic of small airway inflammation, obstruction, and emphysema. It is well known that spirometry alone cannot differentiate each separate component. Computed tomography (CT) is widely used to determine the extent of emphysema and small airway involvement in COPD. Compared with the pulmonary function test, small airway CT phenotypes can accurately reflect disease severity in patients with COPD, which is conducive to improving the prognosis of this disease. CT measurement of central airway morphology has been applied in clinical, epidemiologic, and genetic investigations as an inference of the presence and severity of small airway disease. This review will focus on presenting the current knowledge and methodologies in chest CT that aid in identifying discrete COPD phenotypes.

Phylogeography and genetic diversity of the widespread katydid Ducetia japonica (Thunberg, 1815) across China.

Habitat fragmentation can lower migration rates and genetic connectivity among remaining populations of native species. Ducetia japonica is one of the most widespread katydids in China, but little is known about its genetic structure and phylogeographic distribution. We combined the five-prime region of cytochrome c oxidase subunit I (COI-5P), 11 newly developed microsatellite loci coupled with an ecological niche model (ENM) to examine the genetic diversity and population structure of D. japonica in China and beyond to Laos and Singapore. Both Bayesian inference (BI) and haplotype network methods revealed six mitochondrial COI-5P lineages. The distribution of COI-5P haplotypes may not demonstrate significant phylogeographic structure (N ST > G ST, p > .05). The STRUCTURE analysis based on microsatellite data also revealed six genetic clusters, but discordant with those obtained from COI-5P haplotypes. For both COI-5P and microsatellite data, Mantel tests revealed a significant positive correlation between geographic and genetic distances in mainland China. Bayesian skyline plot (BSP) analyses indicated that the population size of D. japonica's three major mitochondrial COI-5P lineages were seemingly not affected by last glacial maximum (LGM, 0.015-0.025 Mya). The ecological niche models showed that the current distribution of D. japonica was similar to the species' distribution during the LGM period and only slightly extended in northern China. Further phylogeographic studies based on more extensive sampling are needed to identify specific locations of glacial refugia in northern China.

[Effects of controlling specific dangerous pesticides on prevention of acute pesticide poisoning in rural area].

OBJECTIVE: To investigate the effects of controlling the specific dangerous pesticides on prevention of acute pesticide poisoning in rural area. METHODS: The data of reported cases of pesticide poisoning were analyzed to find out the specific dangerous pesticide in acute pesticide poisoning. Then the occurrence of occupational pesticide poisoning and fatality of non-occupational pesticide poisoning were estimated under the hypothesis of removing the specific dangerous pesticides. RESULTS: The data indicated that parathion (including methyl parathion) was the specific dangerous pesticide inducing occupational pesticide poisoning. After removing the use of parathion, the hazard of pesticides which caused occupational pesticide poisoning would be significantly decreased (P < 0.01). Parathion was also the most dangerous pesticide which caused non-occupational pesticide poisoning, with its fatality up to 15.8%. If parathion was well controlled, the fatality of non-occupational pesticide poisoning would be declined from 9.4% to 7.4%. The analyses of related literatures also revealed the similar results. CONCLUSION: The occurrence of occupational pesticide poisoning and fatality of non-occupational pesticide poisoning may decrease if the most dangerous pesticides are well supervised.