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1.  Au–Silica Nanowire Nanohybrid as a Hyperthermia Agent for Photothermal Therapy in the Near-Infrared Region 
Langmuir  2014;30(31):9514-9523.
Nanomaterial-based photothermal therapy has shown great potential for efficient cancer treatment. Here, we report a new hyperthermia agent, Au–silica nanowire nanohybrid (Au-SiNW nanohybrid) with tunable optical properties, for photothermal therapy. The unique feature of the synthetic method is no need of surface modification of SiNWs for the direct deposition of Au seeds, which can avoid complicated synthetic procedures and improve the reproducibility. The Au-SiNW nanohybrid can generate significant amount of heat upon irradiation in the near-infrared (NIR) region for inducing thermal cell death. Moreover, compared to reported hyperthermia nanomaterials, the new nanohybrid requires a much lower laser irradiation density of 0.3 W/cm2 for destroying cancer cells. A549 lung cancer cells were used for in vitro photothermal study. The nanohybrid showed excellent in vitro biocompatibility by using a 96-nonradioactive-cell proliferation assay. Even at a high concentration of 0.500 mg/mL nanohybrid, over 80% cells were alive. In contrast, almost all the cells were killed when NIR irradiation was applied at a concentration of 0.100 mg/mL nanohybrid. The Au-SiNW nanohybrid may become a promising hyperthermia agent.
PMCID: PMC4132849  PMID: 25029292
2.  Lyn cooperating with lipid rafts regulates inflammatory responses in Klebsiella pneumoniae infection through the p38/NF-κB pathway 
European journal of immunology  2013;44(3):763-773.
Klebsiella pneumoniae is one of the most common pathogens in nosocomial infections and is becoming increasingly multidrug-resistant. However, the underlying molecular pathogenesis of this bacterium remains elusive, limiting the therapeutic options. Understanding the mechanism of its pathogenesis may facilitate the development of antibacterial therapeutics. Here, we show that Lyn, a pleiotropic Src tyrosine kinase, is involved in host defense against K. pneumoniae (Kp) by regulating phagocytosis process and simultaneously downregulating inflammatory responses. Using acute infection mouse models, we observed that lyn−/− mice were more susceptible to Kp with increased mortality and severe lung injury compared with wild-type mice. Kp infected-lyn−/− mice exhibited elevated inflammatory cytokines (IL-6 and TNF-α), and increased superoxide in the lung and other organs. In addition, the phosphorylation of p38 and NF-κB p65 subunit increased markedly in response to Kp infection in lyn−/− mice. We also demonstrated that the translocation of p65 from cytoplasm to nuclei increased in cultured murine lung epithelial cells by Lyn siRNA knockdown. Furthermore, lipid rafts clustered with activated Lyn and accumulated in the site of Kp invasion. Taken together, these findings revealed that Lyn may participate in host defense against Kp infection through the negative modulation of inflammatory cytokines.
PMCID: PMC4103995  PMID: 24338528
Bacterial pathogenesis; Bioluminescence; Cytokinesis; In vivo imaging; Infectious diseases
3.  MicroRNA-302b augments host defense to bacteria by regulating inflammatory responses via feedback to TLR/IRAK4 circuits 
Nature communications  2014;5:3619.
MicroRNAs (miRNAs) have been implicated in a spectrum of physiological and pathological conditions, including immune responses. miR-302b has been implicated in stem cell differentiation but its role in immunity remains unknown. Here we show that miR-302b is induced by TLR2 and TLR4 through ERK-p38-NF-κB signaling upon Gram-negative bacterium Pseudomonas aeruginosa infection. Suppression of inflammatory responses to bacterial infection is mediated by targeting IRAK4, a protein required for the activation and nuclear translocation of NF-κB. Through negative feedback, enforced expression of miR-302b or IRAK4 siRNA silencing inhibits downstream NF-κB signaling and airway leukocyte infiltration, thereby alleviating lung injury and increasing survival in P. aeruginosa-infected mice. In contrast, miR-302b inhibitors exacerbate inflammatory responses and decrease survival in P. aeruginosa-infected mice and lung cells. These findings reveal that miR-302b is a novel inflammatory regulator of NF-κB activation in respiratory bacterial infections by providing negative feedback to TLRs-mediated immunity.
PMCID: PMC4011559  PMID: 24717937
4.  TOP2Ahigh is the phenotype of recurrence and metastasis whereas TOP2Aneg cells represent cancer stem cells in prostate cancer 
Oncotarget  2014;5(19):9498-9513.
Recurrence and metastasis are the main causes of death for prostate cancer patients and cancer stem cells (CSCs) are proposed to play important roles in cancer recurrence and metastasis. It is generally thought that genes upregulated in recurrent/metastatic disease are likely biomarkers of CSCs. Hence we analyzed multiple microarray datasets on prostate tumor tissues to identify upregulated genes associated with cancer recurrence/metastasis, and tried to explore whether those genes were true biomarkers of prostate CSCs. Our results indicated that TOP2A was the most highly upregulated gene in recurrent/metastatic prostate cancer, and its high expression was positively correlated with poor prognosis in patients. Using a promoter reporter system, we unexpectedly discovered enrichment of CSCs in TOP2Aneg cells. Compared to TOP2Ahigh cells, TOP2Aneg cells formed spheres and tumors more efficiently, and became enriched in the presence of stresses. Analysis of cell divisions by time lapse imaging indicated that more slow-cycling cells were observed in TOP2Aneg cells while the proportion of abnormal divisions was higher in TOP2Ahigh cells. Our studies demonstrate that TOP2Ahigh is the phenotype of recurrence/metastasis but TOP2Aneg cells show slow cycling and have CSCs properties in prostate cancer, which has significant implications for prostate cancer therapy.
PMCID: PMC4253449  PMID: 25237769
prostate cancer; cancer stem cells; TOP2A; recurrence; metastasis
5.  Soyasaponins Can Blunt Inflammation by Inhibiting the Reactive Oxygen Species-Mediated Activation of PI3K/Akt/NF-kB Pathway 
PLoS ONE  2014;9(9):e107655.
We and others have recently shown that soyasaponins abundant in soybeans can decrease inflammation by suppressing the nuclear factor kappa B (NF-kB)-mediated inflammation. However, the exact molecular mechanisms by which soyasaponins inhibit the NF-kB pathway have not been established. In this study in macrophages, soyasaponins (A1, A2 and I) inhibited the lipopolysaccharide (LPS)-induced release of inflammatory marker prostaglandin E2 (PGE2) to a similar extent as the NF-kB inhibitor (BAY117082). Soyasaponins (A1, A2 and I) also suppressed the LPS-induced expression of cyclooxygenase 2 (COX-2), another inflammatory marker, in a dose-dependent manner by inhibiting NF-kB activation. In defining the associated mechanisms, we found that soyasaponins (A1, A2 and I) blunted the LPS-induced IKKα/β phosphorylation, IkB phosphorylation and degradation, and NF-kB p65 phosphorylation and nuclear translocation. In studying the upstream targets of soyasaponins on the NF-kB pathway, we found that soyasaponins (A1, A2 and I) suppressed the LPS-induced activation of PI3K/Akt similarly as the PI3K inhibitor LY294002, which alone blocked the LPS-induced activation of NF-kB. Additionally, soyasaponins (A1, A2 and I) reduced the LPS-induced production of reactive oxygen species (ROS) to the same extent as the anti-oxidant N-acetyl-L-cysteine, which alone inhibited the LPS-induced phosphorylation of Akt, IKKα/β, IkBα, and p65, transactivity of NF-kB, PGE2 production, and malondialdehyde production. Finally, our results show that soyasaponins (A1, A2 and I) elevated SOD activity and the GSH/GSSG ratio. Together, these results show that soyasaponins (A1, A2 and I) can blunt inflammation by inhibiting the ROS-mediated activation of the PI3K/Akt/NF-kB pathway.
PMCID: PMC4169425  PMID: 25233217
6.  A Small Amount of Dietary Carbohydrate Can Promote the HFD-Induced Insulin Resistance to a Maximal Level 
PLoS ONE  2014;9(7):e100875.
Both dietary fat and carbohydrates (Carbs) may play important roles in the development of insulin resistance. The main goal of this study was to further define the roles for fat and dietary carbs in insulin resistance. C57BL/6 mice were fed normal chow diet (CD) or HFD containing 0.1–25.5% carbs for 5 weeks, followed by evaluations of calorie consumption, body weight and fat gains, insulin sensitivity, intratissue insulin signaling, ectopic fat, and oxidative stress in liver and skeletal muscle. The role of hepatic gluconeogenesis in the HFD-induced insulin resistance was determined in mice. The role of fat in insulin resistance was also examined in cultured cells. HFD with little carbs (0.1%) induced severe insulin resistance. Addition of 5% carbs to HFD dramatically elevated insulin resistance and 10% carbs in HFD was sufficient to induce a maximal level of insulin resistance. HFD with little carbs induced ectopic fat accumulation and oxidative stress in liver and skeletal muscle and addition of carbs to HFD dramatically enhanced ectopic fat and oxidative stress. HFD increased hepatic expression of key gluconeogenic genes and the increase was most dramatic by HFD with little carbs, and inhibition of hepatic gluconeogenesis prevented the HFD-induced insulin resistance. In cultured cells, development of insulin resistance induced by a pathological level of insulin was prevented in the absence of fat. Together, fat is essential for development of insulin resistance and dietary carb is not necessary for HFD-induced insulin resistance due to the presence of hepatic gluconeogenesis but a very small amount of it can promote HFD-induced insulin resistance to a maximal level.
PMCID: PMC4108306  PMID: 25055153
7.  Molecular mechanisms of master regulator VqsM mediating quorum-sensing and antibiotic resistance in Pseudomonas aeruginosa 
Nucleic Acids Research  2014;42(16):10307-10320.
The Pseudomonas aeruginosa quorum-sensing (QS) systems contribute to bacterial homeostasis and pathogenicity. Although the AraC-family transcription factor VqsM has been characterized to control the production of virulence factors and QS signaling molecules, its detailed regulatory mechanisms still remain elusive. Here, we report that VqsM directly binds to the lasI promoter region, and thus regulates its expression. To identify additional targets of VqsM in P. aeruginosa PAO1, we performed chromatin immunoprecipitation (ChIP) followed by high-throughput DNA sequencing (ChIP-seq) and detected 48 enriched loci harboring VqsM-binding peaks in the P. aeruginosa genome. The direct regulation of these genes by VqsM has been confirmed by electrophoretic mobility shift assays and quantitative real-time polymerase chain reactions. A VqsM-binding motif was identified by using the MEME suite and verified by footprint assays in vitro. In addition, VqsM directly bound to the promoter regions of the antibiotic resistance regulator NfxB and the master type III secretion system (T3SS) regulator ExsA. Notably, the vqsM mutant displayed more resistance to two types of antibiotics and promoted bacterial survival in a mouse model, compared to wild-type PAO1. Collectively, this work provides new cues to better understand the detailed regulatory networks of QS systems, T3SS, and antibiotic resistance.
PMCID: PMC4176358  PMID: 25034696
8.  HIV/AIDS-related stigmatizing and discriminatory attitudes and recent HIV testing among Beijing men who have sex with men 
AIDS and behavior  2012;16(3):499-507.
The study was to assess the correlates for recent HIV testing and HIV/AIDS-related stigmatizing and discriminatory attitudes among men who have sex with men (MSM) in Beijing, China. A cross-sectional study probed demographics, sexual and drug use behaviors, HIV testing, and prevention services. Of 500 participants, 39.3% recently received a test for HIV. Recent testing was independently associated with expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes, more male sex partners, no female sexual partners and knowing HIV status of their last male partner. Expressing lower levels of HIV/AIDS-related stigmatizing and discriminatory attitudes was independently associated with recent testing, younger age, and knowing HIV status of their last male partner. This study revealed that HIV/AIDS-related stigmatizing and discriminatory attitudes were common and inversely associated with recent HIV testing. Low levels of testing highlighted the urgent needs to reduce HIV/AIDS-related stigma and discrimination and expand HIV testing among Beijing MSM.
PMCID: PMC4048063  PMID: 22350831
HIV/AIDS; stigma; discrimination; testing; men who have sex with men
9.  Exposure to excess insulin (glargine) induces type 2 diabetes mellitus in mice fed on a chow diet 
The Journal of Endocrinology  2014;221(3):469-480.
We have previously shown that insulin plays an important role in the nutrient-induced insulin resistance. In this study, we tested the hypothesis that chronic exposure to excess long-acting insulin (glargine) can cause typical type 2 diabetes mellitus (T2DM) in normal mice fed on a chow diet. C57BL/6 mice were treated with glargine once a day for 8 weeks, followed by evaluations of food intake, body weight, blood levels of glucose, insulin, lipids, and cytokines, insulin signaling, histology of pancreas, ectopic fat accumulation, oxidative stress level, and cholesterol content in mitochondria in tissues. Cholesterol content in mitochondria and its association with oxidative stress in cultured hepatocytes and β-cells were also examined. Results show that chronic exposure to glargine caused insulin resistance, hyperinsulinemia, and relative insulin deficiency (T2DM). Treatment with excess glargine led to loss of pancreatic islets, ectopic fat accumulation in liver, oxidative stress in liver and pancreas, and increased cholesterol content in mitochondria of liver and pancreas. Prolonged exposure of cultured primary hepatocytes and HIT-TI5 β-cells to insulin induced oxidative stress in a cholesterol synthesis-dependent manner. Together, our results show that chronic exposure to excess insulin can induce typical T2DM in normal mice fed on a chow diet.
PMCID: PMC4045231  PMID: 24741073
insulin resistance; insulin; glargine; diabetes; cholesterol synthesis; T2DM
10.  Suitability of IS6110-RFLP and MIRU-VNTR for Differentiating Spoligotyped Drug-Resistant Mycobacterium tuberculosis Clinical Isolates from Sichuan in China 
BioMed Research International  2014;2014:763204.
Genotypes of Mycobacterium tuberculosis complex (MTBC) vary with the geographic origin of the patients and can affect tuberculosis (TB) transmission. This study was aimed to further differentiate spoligotype-defined clusters of drug-resistant MTBC clinical isolates split in Beijing (n = 190) versus non-Beijing isolates (n = 84) from Sichuan region, the second high-burden province in China, by IS6110-restriction fragment length polymorphism (RFLP) and 24-locus MIRU-VNTRs. Among 274 spoligotyped isolates, the clustering ratio of Beijing family was 5.3% by 24-locus MIRU-VNTRs versus 2.1% by IS6110-RFLP, while none of the non-Beijing isolates were clustered by 24-locus MIRU-VNTRs versus 9.5% by IS6110-RFLP. Hence, neither the 24-locus MIRU-VNTR was sufficient enough to fully discriminate the Beijing family, nor the IS6110-RFLP for the non-Beijing isolates. A region adjusted scheme combining 12 highly discriminatory VNTR loci with IS6110-RFLP was a better alternative for typing Beijing strains in Sichuan than 24-locus MIRU-VNTRs alone. IS6110-RFLP was for the first time introduced to systematically genotype MTBC in Sichuan and we conclude that the region-adjusted scheme of 12 highly discriminative VNTRs might be a suitable alternative to 24-locus MIRU-VNTR scheme for non-Beijing strains, while the clusters of the Beijing isolates should be further subtyped using IS6110-RFLP for optimal discrimination.
PMCID: PMC3958788  PMID: 24724099
11.  Changing the Landscape of the HIV Epidemic among MSM in China: Results from Three Consecutive Respondent-Driven Sampling Surveys from 2009 to 2011 
BioMed Research International  2014;2014:563517.
This study assessed the changes of HIV incidence and its predictors among Beijing's men who have sex with men (MSM). Three consecutive cross-sectional surveys were carried out using a consistent respondent-driven sampling (RDS) approach in 2009, 2010, and 2011, respectively. Structured-questionnaire based interviews were completed with computer-assisted self-administration. Incident infection was examined with BED capture enzyme immunoassay (BED-CEIA). The overall rate of HIV prevalence was 8.0% in the three years (95% confidence interval [CI]: 4.9%–11.2%). The overall rate of BED-CEIA incidence was 7.8/100 person years (PY) (95% CI: 5.5–10.1) with 6.8/100PY (95% CI: 3.4–10.2) in 2009, 11.2/100PY (95% CI: 6.2–16.3) in 2010, and 5.8/100PY (95% CI: 2.4–9.3) in 2011, respectively. Multivariable logistic regression analysis revealed that, compared with HIV-negative MSM, recently infected MSM were more likely to be bisexual (adjusted odds ratio [AOR] = 2.1, 95% CI: 1.1–4.1), live in Beijing ≤3 years (AOR = 2.1, 95% CI: 1.2–4.0), and have a negative attitude towards safe sex (AOR = 1.1 per scale point, 95% CI: 1.0–1.1). This study demonstrated a disturbing rise of HIV infections among Beijing's MSM. These findings underscored the urgency of scaling up effective and better-targeted intervention services to stop the rapid spread of the virus.
PMCID: PMC3918367  PMID: 24575408
12.  Pain reduction following vertebroplasty and kyphoplasty 
International Orthopaedics  2012;37(1):83-87.
To evaluate the clinical efficacy, especially the pain reduction, of vertebroplasty and balloon kyphoplasty in the treatment of osteoporotic vertebral compression fractures (OVCFs).
Eighty-six patients with OVCFs were treated with vertebroplasty or balloon kyphoplasty. All patients were followed up for seven–36 months. Visual analog scale (VAS), vertebral height, and local kyphotic angle were evaluated at pre-operation, postoperation, and final follow-up.
The VAS pain score decreased significantly after surgery in both kyphoplasty and vertebroplasty groups (p < 0.001), and the improvement of VAS score had no significant difference between the two groups (p = 0.826). There was a significant difference in the improvement of vertebral height (p < 0.001) and local kyphotic angle (p < 0.001) between the two groups. Improvement of VAS score had no correlation with improvement of vertebral height (vertebroplasty: r = −0.029, p = 0.869; kyphoplasty: r = 0.175, p = 0.219) or local kyphotic angle (vertebroplasty: r = 0.159, p = 0.361; kyphoplasty: r = 0.144, p = 0.312) in either group.
Vertebroplasty and kyphoplasty are effective procedures for the reduction of pain in OVCFs, and they have the same efficient effect on pain reduction. Correction of vertebral height and local kyphosis may have minimal effect on pain reduction.
PMCID: PMC3532655  PMID: 23142863
13.  Lumbar Intervertebral Disc Puncture under C-arm Fluoroscopy: a New Rat Model of Lumbar Intervertebral Disc Degeneration 
Experimental Animals  2014;63(2):227-234.
To establish a minimally invasive rat model of lumbar intervertebral disc degeneration (IDD) to better understand the pathophysiology of the human condition. The annulus fibrosus of lumbar level 4–5 (L4-5) and L5-6 discs were punctured by 27-gauge needles using the posterior approach under C-arm fluoroscopic guidance. Magnetic resonance imaging (MRI), histological examination by hematoxylin and eosin (H&E) staining, and reverse transcription polymerase chain reaction (RT-PCR) were performed at baseline and 2, 4, and 8 weeks after disc puncture surgery to determine the degree of degeneration. All sixty discs (thirty rats) were punctured successfully. Only two of thirty rats subjected to the procedure exhibited immediate neurological symptoms. The MRI results indicated a gradual increase in Pfirrmann grade from 4 to 8 weeks post-surgery (P<0.05), and H&E staining demonstrated a parallel increase in histological grade (P<0.05). Expression levels of aggrecan, type II collagen (Col2), and Sox9 mRNAs, which encode disc components, decreased gradually post-surgery. In contrast, mRNA expression of type I collagen (Col1), an indicator of fibrosis, increased (P<0.05). The procedure of annular puncture using a 27-gauge needle under C-arm fluoroscopic guidance had a high success rate. Histological, MRI, and RT-PCR results revealed that the rat model of disc degeneration is a progressive pathological process that is similar to human IDD.
PMCID: PMC4160990  PMID: 24770648
animal model; intervertebral disc degeneration; magnetic resonance imaging; nucleus pulposus
14.  Clinical significance of serum miR-21 in breast cancer compared with CA153 and CEA 
MicroRNA-21 (miR-21) has been shown to be a key regulator of carcinogenesis. There were few reports about the comparison of serum miR-21 with conventional tumor markers. This study aimed to explore the diagnostic value of circulating miR-21 as a tumor marker in breast cancer (BC) and compare it with CA153 and carcinoembryonic antigen (CEA).
Circulating miR-16 and miR-21 were amplified and quantitatively detected by real-time PCR in 89 BC patients and 55 healthy controls. The levels of CA153 and CEA were measured through electrochemiluminescence assays. Then the sensitivity in diagnosis of BC was compared among miR-21, CA153 and CEA.
The level of serum miR-21 was significantly higher in BC patients than controls (P<0.001). The sensitivity and specificity of miR-21 were 87.6% and 87.3%, respectively, whereas the sensitivities of CEA and CA153 were only 22.47% and 15.73%.
Compared with CEA and CA153, serum miR-21 has a higher sensitivity in diagnosis of BC. Although not correlated with the status of ER, PR and clinical stages, serum miR-21 may be a potential diagnostic indicator for BC, especially for the early stage.
PMCID: PMC3872537  PMID: 24385703
MicroRNA-21 (miR-21); breast cancer (BC); real-time polymerase chain reaction (real-time PCR)
15.  An Experimental Study on Fabricating an Inverted Mesa-Type Quartz Crystal Resonator Using a Cheap Wet Etching Process 
Sensors (Basel, Switzerland)  2013;13(9):12140-12148.
In this study, a miniaturized high fundamental frequency quartz crystal microbalance (QCM) is fabricated for sensor applications using a wet etching technique. The vibration area is reduced in the fabrication of the high frequency QCM with an inverted mesa structure. To reduce the complexity of the side wall profile that results from anisotropic quartz etching, a rectangular vibration area is used instead of the conventional circular structure. QCMs with high Q values exceeding 25,000 at 47 MHz, 27,000 at 60 MHz, 24,000 at 73 MHz and 25,000 at 84 MHz are fabricated on 4 × 4 mm2 chips with small vibration areas of 1.2 × 1.4 mm2. A PMMA-based flow cell is designed and manufactured to characterize the behavior of the fabricated QCM chip in a liquid. Q values as high as 1,006 at 47 MHz, 904 at 62 MHz, 867 at 71 MHz and 747 at 84 MHz are obtained when one side of the chip is exposed to pure water. These results show that fabricated QCM chips can be used for bio- and chemical sensor applications in liquids.
PMCID: PMC3821337  PMID: 24025559
quartz crystal microbalance; high fundamental frequency; wet etching process; rectangle; high Q value
16.  Sandwich ELISA for detecting urinary Survivin in bladder cancer 
Survivin as a tumor marker in the diagnosis of bladder cancer has not been completely confirmed yet and there are few reports about using Survivin enzyme-linked immunosorbent assay (ELISA) kit to detect the urine of bladder cancer patients. This study aimed to develop a Survivin ELISA and validate its value in the detection of bladder cancer.
Through square matrix titration, different combinations of coating antibody and detecting antibody, a Survivin ELISA was constructed. This assay was evaluated according to intra-assay precision, inter-assay precision and minimum detectable dose (MDD). Survivin levels were detected and analyzed in 102 bladder cancer patients and 102 healthy people by established ELISA. Then cutoff value was defined according to the analysis of receiver operating characteristic (ROC) curve. The sensitivity and specificity of detection were calculated on the basis of cutoff value to diagnose bladder cancer patients. Furthermore, the value of Survivin expression detected by ELISA among different clinicopathological characteristics of patients was also compared.
Through optimization of different conditions, intra-assay precision was 8.39%, inter-assay precision 8.57% and MDD 0.0625 ng/mL in this assay. When the optical density at 450 nm (OD450) was 0.09, it could get the optimized diagnostic cutoff value. According to this value, the sensitivity and specificity of diagnosis in bladder cancer patients were 70.6% and 89.2%, respectively. The associations between patients’ clinical variables and OD450 were not significant except tumor numbers in patients.
This experiment has preliminarily developed a Survivin ELISA and confirmed Survivin as a biomarker which owned a practical and significant value in the diagnosis of bladder cancer.
PMCID: PMC3752344  PMID: 23997523
Survivin; bladder cancer; enzyme-linked immunosorbent assay (ELISA); tumor marker; diagnosis
17.  Enantioselective Induction of a Glutathione-S-Transferase, a Glutathione Transporter and an ABC Transporter in Maize by Metolachlor and Its (S)-Isomer 
PLoS ONE  2012;7(10):e48085.
The metabolism of chiral herbicides in plants remains poorly understood. Glutathione conjugation reactions are one of the principal mechanisms that plants utilize to detoxify xenobiotics. The induction by rac- and S-metolachlor of the expression of three genes, ZmGST27, ZmGT1 and ZmMRP1, encoding respectively a glutathione-S-transferase, a glutathione transporter and an ATP-binding cassette (ABC) transporter was studied in maize. The results demonstrate that the inducing effect of rac- and S-metolachlor on the expression of ZmGST27 and ZmGT1 is comparable. However, the inducing effect of rac-metolachlor on ZmMRP1 expression is more pronounced than that of S-metolachlor. Furthermore, vanadate, an ABC transporter inhibitor, could greatly reduce the difference in herbicidal activity between rac- and S-metolachlor. These results suggest that the ABC transporters may preferentially transport conjugates of rac-metolachlor, leading to a faster metabolism of the latter. Through comparing the expression of ZmGST27, ZmMRP1 and ZmGT1 after treatment by rac- and S-metolachlor, we provide novel insights into the metabolic processes of chiral herbicides in plants.
PMCID: PMC3483294  PMID: 23144728
18.  Participation of HIV prevention programs among men who have sex with men in two cities of China—a mixed method study 
BMC Public Health  2012;12:847.
Although various HIV prevention programs targeting men who have sex with men (MSM) are operating in China, whether and how these programs are being utilized is unclear. This study explores participation of HIV prevention programs and influencing factors among MSM in two cities in China.
This is a mixed-method study conducted in Beijing and Chongqing. A qualitative study consisting of in-depth interviews with 54 MSM, 11 key informants, and 8 focus group discussions, a cross-sectional survey using respondent-driven sampling among 998 MSM were conducted in 2009 and 2010 respectively to elicit information on MSM’s perception and utilization of HIV prevention programs. Qualitative findings were integrated with quantitative multivariate factors to explain the quantitative findings.
Fifty-six percent of MSM in Chongqing and 75.1% in Beijing ever participated in at least one type of HIV prevention program (P=0.001). Factors related to participation in HIV prevention programs included age, ethnicity, income, HIV risk perception, living with boyfriend, living in urban area, size of MSM social network, having talked about HIV status with partners, and knowing someone who is HIV positive. Reasons why MSM did not participate in HIV prevention programs included logistical concerns like limited time for participation and distance to services; program content and delivery issues such as perceived low quality services and distrust of providers; and, cultural issues like HIV-related stigma and low risk perception.
The study shows that there is much room for improvement in reaching MSM in China. HIV prevention programs targeting MSM in China may need to be more comprehensive and incorporate the cultural, logistic and HIV-related needs of the population in order to effectively reach and affect this population’s risk for HIV.
PMCID: PMC3570394  PMID: 23039880
MSM; HIV prevention programs; Utilization; Participation; China
19.  Co-Induction of a Glutathione-S-transferase, a Glutathione Transporter and an ABC Transporter in Maize by Xenobiotics 
PLoS ONE  2012;7(7):e40712.
Glutathione conjugation reactions are one of the principal mechanisms that plants utilize to detoxify xenobiotics. The induction by four herbicides (2,4-D, atrazine, metolachlor and primisulfuron) and a herbicide safener (dichlormid) on the expression of three genes, ZmGST27, ZmGT1 and ZmMRP1, encoding respectively a glutathione-S-transferase, a glutathione transporter and an ATP-binding cassette (ABC) transporter was studied in maize. The results demonstrate that the inducing effect on gene expression varies with both chemicals and genes. The expression of ZmGST27 and ZmMRP1 was up-regulated by all five compounds, whereas that of ZmGT1 was increased by atrazine, metolachlor, primisulfuron and dichlormid, but not by 2,4-D. For all chemicals, the inducing effect was first detected on ZmGST27. The finding that ZmGT1 is activated alongside ZmGST27 and ZmMRP1 suggests that glutathione transporters are an important component in the xenobiotic detoxification system of plants.
PMCID: PMC3394700  PMID: 22792398
20.  Predictors of HIV and Syphilis among Men Who Have Sex with Men in a Chinese Metropolitan City: Comparison of Risks among Students and Non-Students 
PLoS ONE  2012;7(5):e37211.
Men who have sex with men (MSM) are at a substantial risk of HIV, given rising HIV prevalence in urban China. Adolescent and adult students often take HIV-related risk as part of sexual exploration. We compared the risks of HIV and syphilis infections and risky sexual behaviors between student and non-student among urban MSM.
Respondent driven sampling approach was used to recruit men who were self-identified as MSM in Chongqing Metropolitan City in southwestern China in 2009. Each participant completed a computer-assisted self-interview which collected demographic and behavioral data, and provided blood specimens for HIV and syphilis testing. Multivariable logistic regression analyses identified predictors for HIV and syphilis infections while comparing student and non-student MSM.
Among 503 MSM participants, 36.4% were students, of whom 84.2% were in college. The adjusted prevalence of HIV infection was 5.5% (95% confidence interval [CI]: 2.1%–10.2%) in students and 20.9% (95% CI: 13.7%–27.5%) in non-students; the adjusted prevalence of syphilis was 4.4% (95% CI: 0.7%–9.0%) in students and 7.9% (95% CI: 3.6%–12.9%) in non-students (P = 0.12). Two groups had similar risky sexual behaviors such as number of sexual partners and exchanging sex for money. Multivariate analysis showed that students had lower HIV prevalence than non-students (adjusted odds ratio [AOR]: 0.3; 95% CI: 0.1–0.8) adjusting for age, ethnicity and other variables.
Student MSM have lower HIV and similar syphilis prevalence compared with non-student MSM. However, due to a shorter duration of sexual experience and high prevalence of at-risk sexual behaviors among student MSM, HIV risk might be quite high in students as in non-students.
PMCID: PMC3356386  PMID: 22623994
21.  An Integrated Genetic and Cytogenetic Map of the Cucumber Genome 
PLoS ONE  2009;4(6):e5795.
The Cucurbitaceae includes important crops such as cucumber, melon, watermelon, squash and pumpkin. However, few genetic and genomic resources are available for plant improvement. Some cucurbit species such as cucumber have a narrow genetic base, which impedes construction of saturated molecular linkage maps. We report herein the development of highly polymorphic simple sequence repeat (SSR) markers originated from whole genome shotgun sequencing and the subsequent construction of a high-density genetic linkage map. This map includes 995 SSRs in seven linkage groups which spans in total 573 cM, and defines ∼680 recombination breakpoints with an average of 0.58 cM between two markers. These linkage groups were then assigned to seven corresponding chromosomes using fluorescent in situ hybridization (FISH). FISH assays also revealed a chromosomal inversion between Cucumis subspecies [C. sativus var. sativus L. and var. hardwickii (R.) Alef], which resulted in marker clustering on the genetic map. A quarter of the mapped markers showed relatively high polymorphism levels among 11 inbred lines of cucumber. Among the 995 markers, 49%, 26% and 22% were conserved in melon, watermelon and pumpkin, respectively. This map will facilitate whole genome sequencing, positional cloning, and molecular breeding in cucumber, and enable the integration of knowledge of gene and trait in cucurbits.
PMCID: PMC2685989  PMID: 19495411

Results 1-21 (21)