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2.  Spatiotemporal Transmission and Determinants of Typhoid and Paratyphoid Fever in Hongta District, Yunnan Province, China 
Background
Typhoid and paratyphoid fever are endemic in Hongta District and their prevalence, at 113 per 100,000 individuals, remains the highest in China. However, the exact sources of the disease and its main epidemiological characteristics have not yet been clearly identified.
Methods and Findings
Numbers of typhoid and paratyphoid cases per day during the period 2006 to 2010 were obtained from the Chinese Center of Disease Control (CDC). A number of suspected disease determinants (or their proxies), were considered for use in spatiotemporal analysis: these included locations of discharge canals and food markets, as well as socio-economic and environmental factors. Results showed that disease prevalence was spatially clustered with clusters decreasing with increasing distance from markets and discharge canals. More than half of the spatial variance could be explained by a combination of economic conditions and availability of health facilities. Temporal prevalence fluctuations were positively associated with the monthly precipitation series. Polluted hospital and residential wastewater was being discharged into rainwater canals. Salmonella bacteria were found in canal water, on farmland and on vegetables sold in markets.
Conclusion
Disease transmission in Hongta district is driven principally by two spatiotemporally coupled cycles: one involving seasonal variations and the other the distribution of polluted farmland (where vegetables are grown and sold in markets). Disease transmission was exacerbated by the fact that rainwater canals were being used for disposal of polluted waste from hospitals and residential areas. Social factors and their interactions also played a significant role in disease transmission.
Author Summary
Typhoid and paratyphoid epidemics are serious events in low-income countries; these diseases are notorious for their high infection rate, long duration, and heavy health burden. In China, typhoid and paratyphoid are considered to be under control, although the situation varies considerably from place to place. During 2010 the disease incidence was 1.2 per 100,000 at the national level. The highest incidence, 113 per 100,000, occurred in the Hongta District of Yunnan province, in southwestern China. We used quantitative spatiotemporal analysis to explore the relationship between the incidence of these diseases and a number of factors suspected of influencing their occurrence. We found that cases tended to occur near discharge canals and polluted farmland where vegetables are grown for sale in local markets. The spatial characteristics of disease transmission were associated with the seasonal variations common to all intestinal infectious diseases. The findings of this work could inform local public health planners and the health directorate and help to improve public health intervention programs in regions with the highest incidence of these diseases.
doi:10.1371/journal.pntd.0002112
PMCID: PMC3597484
3.  N-Substituted Benzyl Matrinic Acid Derivatives Inhibit Hepatitis C Virus (HCV) Replication through Down-Regulating Host Heat-Stress Cognate 70 (Hsc70) Expression 
PLoS ONE  2013;8(3):e58675.
Heat-stress cognate 70 (Hsc70) is a host factor that helps hepatitis C virus (HCV) to complete its life cycle in infected hepatocytes. Using Hsc70 as a target for HCV inhibition, a series of novel N-substituted benzyl matrinic/sophoridinic acid derivatives was synthesized and evaluated for their anti-HCV activity in vitro. Among these analogues, compound 7c possessing N-p-methylbenzyl afforded an appealing ability to inhibit HCV replication with SI value over 53. Furthermore, it showed a good oral pharmacokinetic profile with area-under-curve (AUC) of 13.4 µM·h, and a considerably good safety in oral administration in mice (LD50>1000 mg/kg). As 7c suppresses HCV replication via an action mode distinctly different from that of the marketed anti-HCV drugs, it has been selected as a new mechanism anti-HCV candidate for further investigation, with an advantage of no or decreased chance to induce drug-resistant mutations.
doi:10.1371/journal.pone.0058675
PMCID: PMC3597726
4.  Assessing the nutritional status of elderly Chinese lung cancer patients using the Mini-Nutritional Assessment (MNA®) tool 
Purpose
This study assessed the nutritional status of elderly Chinese lung cancer inpatients using a revised version of the Mini-Nutritional Assessment (MNA®) tool.
Patients and methods:
The revised version of the MNA tool was used to assess the nutritional status of 180 elderly Chinese lung cancer inpatients prior to their scheduled surgery between June 2010 and July 2011. Patients’ demographic data, anthropometric parameters, and biochemical markers were collected and analyzed.
Results
Among the 180 inpatients who underwent the MNA, 9% were malnourished (MNA score < 19), 33% were at risk of malnutrition (MNA score 19–23), and 58% were well nourished (MNA score ≥ 24). There was significant correlation between the MNA scores of patients who were malnourished, at risk of malnutrition, and well nourished (P < 0.001), as well as between total MNA score and most MNA questions. The three patient groups with different nutritional statuses differed significantly in their responses to anthropometrics and global, diet, and subjective assessments.
Conclusion
Incidence rates of malnutrition prior to surgery are high among elderly Chinese lung cancer inpatients. The revised MNA is a valid and reliable tool that can be used to assess and prevent malnutrition among these inpatients.
doi:10.2147/CIA.S41941
PMCID: PMC3592510  PMID: 23487488
malnutrition; MNA-SF; nutrition; inpatients; diet
5.  Novel germline PALB2 truncating mutations in African-American breast cancer patients 
Cancer  2011;118(5):1362-1370.
Background
It has been demonstrated that PALB2 acts as a bridging molecule between the BRCA1 and BRCA2 proteins and is responsible for facilitating BRCA2-mediated DNA repair. Truncating mutations in the PALB2 gene have been reported to be enriched in Fanconi anemia and breast cancer patients in various populations.
Methods
We evaluated the contribution of PALB2 germline mutations in 279 African-American breast cancer patients including 29 patients with a strong family history, 29 patients with a moderate family history, 75 patients with a weak family history, and 146 non-familial or sporadic breast cancer cases.
Results
After direct sequencing of all the coding exons, exon/intron boundaries, 5′UTR and 3′UTR of PALB2, three (1.08%; 3 in 279) novel monoallelic truncating mutations were identified: c.758dupT (exon4), c.1479delC (exon4) and c.3048delT (exon 10); together with 50 sequence variants, 27 of which are novel. None of the truncating mutations were found in 262 controls from the same population.
Conclusions
PALB2 mutations are present in both familial and non-familial breast cancer among African-Americans. Rare PALB2 mutations account for a small but substantial proportion of breast cancer patients.
doi:10.1002/cncr.26388
PMCID: PMC3244533  PMID: 21932393
Breast cancer; PALB2; Mutation; African-American; Sequencing
6.  Mouse miRNA-709 directly regulates miRNA-15a/16-1 biogenesis at the posttranscriptional level in the nucleus: evidence for a microRNA hierarchy system 
Cell Research  2011;22(3):504-515.
MicroRNAs (miRNAs) are endogenous noncoding RNAs (∼22 nt) that regulate target gene expression at the post-transcriptional level in the cytoplasm. Recent discoveries of the presence of miRNAs and miRNA function-required argonaute family proteins in the cell nucleus have prompted us to hypothesize that miRNAs may also have regulatory functions in the cell nucleus. In this study, we demonstrate that mouse miR-709 is predominantly located in the nucleus of various cell types and that its nuclear localization pattern rapidly changes upon apoptotic stimuli. In the cell nucleus, miR-709 directly binds to a 19-nt miR-709 recognition element on pri-miR-15a/16-1 and prevents its processing into pre-miR-15a/16-1, leading to a suppression of miR-15a/16-1 maturation. Furthermore, nuclear miR-709 participates in the regulation of cell apoptosis through the miR-15a/16-1 pathway. In summary, the present study provides the first evidence that one miRNA can control the biogenesis of other miRNAs by directly targeting their primary transcripts in the nucleus.
doi:10.1038/cr.2011.137
PMCID: PMC3292299  PMID: 21862971
microRNA; nucleus; apoptosis
7.  Genetic Susceptibility to Type 2 Diabetes and Breast Cancer Risk in Women of European and African Ancestry 
Background
Epidemiologic studies have reported a positive association between type 2 diabetes (T2D) and breast cancer risk, independent of body weight.
Methods
We investigated 40 genetic variants known to be associated with T2D in relation to breast cancer risk among 2651 breast cancer cases and 2520 controls of African or European ancestry that were pooled from seven studies.
Results
We found that two T2D risk alleles in Caucasian women (rs5945326-G, rs12518099-C) and one in women of African ancestry (rs7578597-T) were positively associated with breast cancer risk at a nominal significance level of 0.05, whereas two T2D risk alleles were inversely associated with breast cancer risk in Caucasian women (rs1111875-C, rs10923931-T). The composite T2D susceptibility score (the number of risk allele) was not significantly associated with breast cancer risk.
Conclusion
The association between established T2D genetic susceptibility variants and breast cancer risk in women of African or European ancestry is likely weak, if it does exist.
Impact
The pleiotropic effects of known T2D risk alleles cannot explain the association between T2D and breast cancer risk.
doi:10.1158/1055-9965.EPI-11-0979
PMCID: PMC3297695  PMID: 22237986
8.  Ginsenoside Rg1 Attenuates Oligomeric Aβ1-42-Induced Mitochondrial Dysfunction 
Current Alzheimer Research  2012;9(3):388-395.
Mitochondrial dysfunction is one of the major pathological changes seen in Alzheimer's disease (AD). Amyloid beta-peptide (Aβ), a neurotoxic peptide, accumulates in the brain of AD subjects and mediates mitochondrial and neuronal stress. Therefore, protecting mitochondrion from Aβ-induced toxicity holds potential benefits for halting and treating and perhaps preventing AD. Here, we report that administration of ginsenoside Rg1, a known neuroprotective drug, to primary cultured cortical neurons, rescues Aβ-mediated mitochondrial dysfunction as shown by increases in mitochondrial membrane potential, ATP levels, activity of cytochrome c oxidase (a key enzyme associated with mitochondrial respiratory function), and decreases in cytochrome c release. The protective effects of Rg1 on mitochondrial dysfunction correlate to neuronal injury in the presence of Aβ. This finding suggests that ginsenoside Rg1 may attenuate Aβ-induced neuronal death through the suppression of intracellular mitochondrial oxidative stress and may rescue neurons in AD.
PMCID: PMC3381883  PMID: 22381145
Alzheimer's disease; oligomeric beta-amyloid peptide1-42; mitochondria; ginsenoside Rg1
9.  HCV IRES-Mediated Core Expression in Zebrafish 
PLoS ONE  2013;8(3):e56985.
The lack of small animal models for hepatitis C virus has impeded the discovery and development of anti-HCV drugs. HCV-IRES plays an important role in HCV gene expression, and is an attractive target for antiviral therapy. In this study, we report a zebrafish model with a biscistron expression construct that can co-transcribe GFP and HCV-core genes by human hepatic lipase promoter and zebrafish liver fatty acid binding protein enhancer. HCV core translation was designed mediated by HCV-IRES sequence and gfp was by a canonical cap-dependent mechanism. Results of fluorescence image and in situ hybridization indicate that expression of HCV core and GFP is liver-specific; RT-PCR and Western blotting show that both core and gfp expression are elevated in a time-dependent manner for both transcription and translation. It means that the HCV-IRES exerted its role in this zebrafish model. Furthermore, the liver-pathological impact associated with HCV-infection was detected by examination of gene markers and some of them were elevated, such as adiponectin receptor, heparanase, TGF-β, PDGF-α, etc. The model was used to evaluate three clinical drugs, ribavirin, IFNα-2b and vitamin B12. The results show that vitamin B12 inhibited core expression in mRNA and protein levels in dose-dependent manner, but failed to impact gfp expression. Also VB12 down-regulated some gene transcriptions involved in fat liver, liver fibrosis and HCV-associated pathological process in the larvae. It reveals that HCV-IRES responds to vitamin B12 sensitively in the zebrafish model. Ribavirin did not disturb core expression, hinting that HCV-IRES is not a target site of ribavirin. IFNα-2b was not active, which maybe resulted from its degradation in vivo for the long time. These findings demonstrate the feasibility of the zebrafish model for screening of anti-HCV drugs targeting to HCV-IRES. The zebrafish system provides a novel evidence of using zebrafish as a HCV model organism.
doi:10.1371/journal.pone.0056985
PMCID: PMC3585870  PMID: 23469178
10.  γ-Tocotrienol Induces Paraptosis-Like Cell Death in Human Colon Carcinoma SW620 Cells 
PLoS ONE  2013;8(2):e57779.
Colorectal cancer is one of the most serious illnesses among diagnosed cancer. As a new type of anti-cancer composition from tocotrienol-rich fraction of palm oil, γ-tocotrienol is widely used in anti-cancer research. The objectives of this study were to investigate the effects of γ-tocotrienol on human colon cancer SW620 and HCT-8 cells. We showed that treatment with different concentrations of γ-tocotrienol resulted in a dose dependent inhibition of cell growth. Cell death induced by γ-tocotrienol was mediated by a paraptosis-like cell death in SW620 and HCT-8 cells. Real-time RT-PCR and western blot analyses showed that γ-tocotrienol inhibited the expression level of β-catenin, cyclin D1 and c-jun. These data suggest that a paraptosis-like cell death induced by γ-tocotrienol in SW620 cells is associated with the suppression of the Wnt signaling pathway, which offers a novel tool for treating apoptosis-resistance colon cancer.
doi:10.1371/journal.pone.0057779
PMCID: PMC3585143  PMID: 23469066
11.  Primary Analysis of the Expressed Sequence Tags in a Pentastomid Nymph cDNA Library 
PLoS ONE  2013;8(2):e56511.
Background
Pentastomiasis is a rare zoonotic disease caused by pentastomids. Despite their worm-like appearance, they are commonly placed into a separate sub-class of the subphylum Crustacea, phylum Arthropoda. However, until now, the systematic classification of the pentastomids and the diagnosis of pentastomiasis are immature, and genetic information about pentastomid nylum is almost nonexistent. The objective of this study was to obtain information on pentastomid nymph genes and identify the gene homologues related to host-parasite interactions or stage-specific antigens.
Methodology/Principal Findings
Total pentastomid nymph RNA was used to construct a cDNA library and 500 colonies were sequenced. Analysis shows one hundred and ninety-seven unigenes were identified. In which, 147 genes were annotated, and 75 unigenes (53.19%) were mapped to 82 KEGG pathways, including 29 metabolism pathways, 29 genetic information processing pathways, 4 environmental information processing pathways, 7 cell motility pathways and 5 organismal systems pathways. Additionally, two host-parasite interaction-related gene homologues, a putative Kunitz inhibitor and a putative cysteine protease.
Conclusion/Significance
We first successfully constructed a cDNA library and gained a number of expressed sequence tags (EST) from pentastomid nymphs, which will lay the foundation for the further study on pentastomids and pentastomiasis.
doi:10.1371/journal.pone.0056511
PMCID: PMC3577888  PMID: 23437150
12.  Overexpression of p65 attenuates celecoxib-induced cell death in MDA-MB-231 human breast cancer cell line 
Background
Celecoxib is a selective cyclooxygenase (COX)-2 inhibitor that has been reported to reduce the risk of breast cancer. In our previous study, celecoxib induced apoptosis and caused cell cycle arrest at the G0/G1 phase in the breast cancer cell line MDA-MB-231, and its effects were mediated by downregulation of NF-κB signaling. The NF-κB p65/RelA subunit may play a role in cell death through the activation of anti-apoptotic target genes including the inhibitor of apoptosis (IAP) and Bcl-2 families, and inhibition of protein kinase B/Akt. The aim of the present study was to investigate p65 as the potential target of celecoxib treatment and determine whether p65 overexpression can override the inhibitory effect of celecoxib on NF-κB activity and affect cell survival.
Methods
The effects of p65 overexpression on celecoxib-inhibited NF-κB transcriptional activity were examined by western blotting, electrophoretic mobility shift assay (EMSA) and luciferase reporter gene assay. Cell viability and cell death were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay, and the levels of cleaved poly(ADP-ribose) polymerase (PARP) and caspase. Anti-apoptotic NF-κB target genes and cell cycle regulators were examined by western blotting to screen for the expression of target genes under direct regulation by p65.
Results
Overexpression of p65 increased NF-κB transcriptional activity and interfered with celecoxib-mediated apoptosis as assessed by MTT assay and caspase-3, caspase-9, and PARP expressions. Exogenously overexpressed p65 upregulated NF-κB-responsive genes, including anti-apoptotic genes such as survivin and XIAP, and the cell cycle regulatory gene cyclin D1. However, p65 overexpression did not affect celecoxib-induced p-Akt inactivation, suggesting that celecoxib might have separate molecular mechanisms for regulating Akt signaling independently of its inhibition of NF-κB transcriptional activity.
Conclusions
p65 is a pivotal anti-apoptotic factor that can reverse celecoxib-induced growth inhibition in MDA-MB-231 cells.
doi:10.1186/1475-2867-13-14
PMCID: PMC3586361  PMID: 23402310
Breast cancer; p65; Celecoxib; Apoptosis
13.  New Insight into Ki67 Expression at the Invasive Front in Breast Cancer 
PLoS ONE  2013;8(1):e54912.
Purpose
To investigate the distribution of Ki67+ cells in breast cancer in relation to clinical-pathological parameters and prognosis.
Materials and Methods
Ki67 expression status was detected in 1,086 breast cancer specimens using immunohistochemistry staining and examining the relationship between the Ki67+ cells' location. Subsequently, clinical-pathological parameters and prognosis were determined.
Results
In total, Ki67 protein expression was found in 781 (71.92%) of the 1,086 breast cancer specimens. Among the 781 Ki67+ cases, 461 were defined as diffuse type and 320 were defined as borderline type. After universal correlation analysis, significant differences were observed in age, histological grade, metastatic nodes, postoperative distant metastasis, and molecular subtype between Ki67+ and Ki67− cases (P = 0.01, 0.001, 0.001, 0.001, and 0.001, respectively). After subgroup analysis, the borderline cases were found to be characterized by a high distant metastasis rate compared to the diffuse cases as well as the Ki67− cases (P = 0.001). No differences were observed between diffuse type or Ki67− cases (P = 0.105). Multivariate analysis showed that age, tumor size, histological grade, lymph node metastasis, molecular subtype, and the Ki67 distribution pattern were observed to be related to postoperative distant metastasis (all P<0.05). Furthermore, borderline type was shown to attain a significantly more distant bone and liver metastasis and worse disease-specific survival than the other types (P = 0.001). In the Cox regression test, the Ki67 distribution pattern was detected as an independent prognostic factor (P = 0.001).
Conclusion
The distribution pattern of Ki67 may be a new independent prognostic factor for breast cancer.
doi:10.1371/journal.pone.0054912
PMCID: PMC3561452  PMID: 23382998
14.  Characterization and Expression Patterns of microRNAs Involved in Rice Grain Filling 
PLoS ONE  2013;8(1):e54148.
MicroRNAs (miRNAs) are upstream gene regulators of plant development and hormone homeostasis through their directed cleavage or translational repression of the target mRNAs, which may play crucial roles in rice grain filling and determining the final grain weight and yield. In this study, high-throughput sequencing was performed to survey the dynamic expressions of miRNAs and their corresponding target genes at five distinct developmental stages of grain filling. In total, 445 known miRNAs and 45 novel miRNAs were detected with most of them expressed in a developmental stage dependent manner, and the majority of known miRNAs, which increased gradually with rice grain filling, showed negatively related to the grain filling rate. Detailed expressional comparisons revealed a clear negative correlation between most miRNAs and their target genes. It was found that specific miRNA cohorts are expressed in a developmental stage dependent manner during grain filling and the known functions of these miRNAs are involved in plant hormone homeostasis and starch accumulation, indicating that the expression dynamics of these miRNAs might play key roles in regulating rice grain filling.
doi:10.1371/journal.pone.0054148
PMCID: PMC3554753  PMID: 23365650
15.  Molecular Analysis of Colorectal Tumors within a Diverse Patient Cohort at a Single Institution 
Clinical Cancer Research  2011;18(2):350-359.
Purpose
African American colorectal cancer (CRC) patients have worse survival outcomes than Caucasian patients. To determine if differences exist in the molecular mechanisms driving CRC between African Americans and Caucasians, we characterized patient tumors from a single institution by assessing genetic alterations involved in CRC progression and response to treatment.
Experimental Design
We retrospectively examined 448 African Americans and Caucasians diagnosed with CRC at The University of Chicago Medical Center between 1992 and 2002. Microsatellite instability (MSI) status was determined by genotyping the BAT25, BAT26, BAT40, D5S346, and BAX loci. Mutations in KRAS codons 12 and 13 and BRAF codon 600 were identified by direct sequencing. MSI and detected mutations were correlated with clinicopathological features.
Results
Overall, no difference existed in MSI or BRAF mutation frequencies between African Americans and Caucasians. However, African Americans with microsatellite stable (MSS)/MSI-low (MSI-L) tumors had a higher proportion of KRAS mutations than Caucasians (34% v. 23%, p=0.048) that was isolated to proximal colon cancers and primarily driven by mutations in codon 13. There was no racial/ethnic difference in receipt of chemotherapy, but African Americans with MSS/MSI-L tumors had a 73% increased risk of death over Caucasians that could not be explained by known prognostic factors.
Conclusions
The significantly higher risk of death among African Americans with MSS/MSI-L tumors may be related to differences in the distribution of factors influencing response to standard therapies. These data underscore the need for further research into the molecular mechanisms driving CRC progression in underserved and understudied populations.
doi:10.1158/1078-0432.CCR-11-1397
PMCID: PMC3272273  PMID: 22114137
colorectal cancer; microsatellite instability; KRAS; BRAF; African Americans
16.  The Identification of CD163 Expressing Phagocytic Chondrocytes in Joint Cartilage and Its Novel Scavenger Role in Cartilage Degradation 
PLoS ONE  2013;8(1):e53312.
Background
Cartilage degradation is a typical characteristic of arthritis. This study examined whether there was a subset of phagocytic chondrocytes that expressed the specific macrophage marker, CD163, and investigated their role in cartilage degradation.
Methods
Cartilage from the knee and temporomandibular joints of Sprague-Dawley rats was harvested. Cartilage degradation was experimentally-induced in rat temporomandibular joints, using published biomechanical dental methods. The expression levels of CD163 and inflammatory factors within cartilage, and the ability of CD163+ chondrocytes to conduct phagocytosis were investigated. Cartilage from the knees of patients with osteoarthritis and normal cartilage from knee amputations was also investigated.
Results
In the experimentally-induced degrading cartilage from temporomandibular joints, phagocytes were capable of engulfing neighboring apoptotic and necrotic cells, and the levels of CD163, TNF-α and MMPs were all increased (P<0.05). However, the levels of ACP-1, NO and ROS, which relate to cellular digestion capability were unchanged (P>0.05). CD163+ chondrocytes were found in the cartilage mid-zone of temporomandibular joints and knee from healthy, three-week old rats. Furthermore, an increased number of CD163+ chondrocytes with enhanced phagocytic activity were present in Col-II+ chondrocytes isolated from the degraded cartilage of temporomandibular joints in the eight-week experimental group compared with their age-matched controls. Increased number with enhanced phagocytic activity of CD163+ chondrocytes were also found in isolated Col-II+ chondrocytes stimulated with TNF-α (P<0.05). Mid-zone distribution of CD163+ cells accompanied with increased expression of CD163 and TNF-α were further confirmed in the isolated Col-II+ chondrocytes from the knee cartilage of human patients with osteoarthritis, in contrast to the controls (both P<0.05).
Conclusions
An increased number of CD163+ chondrocytes with enhanced phagocytic activity were discovered within degraded joint cartilage, indicating a role in eliminating degraded tissues. Targeting these cells provides a new strategy for the treatment of arthritis.
doi:10.1371/journal.pone.0053312
PMCID: PMC3543453  PMID: 23326413
17.  Ferromagnetism in sphalerite and wurtzite CdS nanostructures 
Room-temperature ferromagnetism is observed in undoped sphalerite and wurtzite CdS nanostructures which are synthesized by hydrothermal methods. Scanning electron microscopy and transmission electron microscopy results indicate that the sphalerite CdS samples show a spherical-like shape and the wurtzite CdS ones show a flower-like shape, both of which are aggregated by lots of smaller particles. The impurity of the samples has been ruled out by the results of X-ray diffraction, selected-area electron diffraction, and X-ray photoelectron spectroscopy. Magnetization measurements indicate that all the samples exhibit room-temperature ferromagnetism and the saturation magnetization decreases with the increased crystal sizes, revealing that the observed ferromagnetism is defect-related, which is also confirmed by the post-annealing processes. This finding in CdS should be the focus of future electronic and spintronic devices.
doi:10.1186/1556-276X-8-17
PMCID: PMC3577620  PMID: 23294671
CdS nanostructures; Hydrothermal methods; Room-temperature ferromagnetism; Sulfur vacancies
18.  Prospective cohort study of HIV incidence and molecular characteristics of HIV among men who have sex with men(MSM) in Yunnan Province, China 
Background
Yunnan has the largest number of reported HIV/AIDS cases among all Chinese provinces, the reported prevalence of HIV among Yunnan men who have sex with men (MSM) passed 10%, while HIV incidence epidemic and molecular characteristics of new infected Yunnan MSM were not evaluated before.
Methods
An 18 months prospective followed up with a frequency of 3 month per visit were conducted among HIV seronegative MSM in Kunming cityduring 2009–2011. Interviewer-administrated questionnaires were carried out. Blood specimens were obtained to test for syphilis and HIV, in which HIV were evaluated by standard HIV enzyme immunoassay (EIA) and HIV nucleic acid amplification testing (NAAT). Near full-length regions of the HIV-1 were evaluated for subtyping, primary drug resistance mutations.
Results
During the follow-up 70.1% of the recruited 378 MSM retained in the cohort. Eleven MSM seroconverted to HIV and fifteen MSM seroconverted to syphilis. The HIV incidence and syphilis incidence was 3.5 (95% CI 1.8-6.2) cases /100 person year(PY) and 5.3 (95% CI 3.0-8.7) cases/100 PY, respectively. Multivariate analysis showed that baseline syphilis infection (aHR, 17.7), occupation (students vs. others [aHR, 5.7], retirees vs. others [aHR, 4.1]), bleeding experience after receptive anal intercourse (aHR,7.6), and minority ethnic(vs. Han) [aHR, 5.7] were independent risk factors for HIV seroconversion(each P<0.05). Among the 7/11 successfully amplified near full-length sequences, 71.4% (5/7) were CRF01_AE, and 28.6% (2/7) were CRF07_BC. Two HIV transmission pairs were detected among seroconverted minority ethnic MSM.
Conclusions
HIV incidence was moderately high among Yunnan MSM. Yunnan province need to strengthen both HIV and syphilis screening among MSM population. Some subpopulations of MSM, such as students, retirees and minority ethnic groups require more HIV epidemic surveillance and strengthened behavior interventions. HIV subtypes and primary drug resistance should be continually monitored to track cross-group transmission of HIV strains.
doi:10.1186/1471-2334-13-3
PMCID: PMC3599414  PMID: 23286213
Men who have sex with men (MSM); HIV; Incidence; Prospective cohort study; HIV subtypes; Molecular characteristics
19.  Oxidative and Endoplasmic Reticulum Stresses Mediate Apoptosis Induced by Modified LDL in Human Retinal Müller Cells 
Purpose.
We previously showed that extravasated, modified LDL is implicated in pericyte loss in diabetic retinopathy (DR). Here, we investigate whether modified LDL induces apoptosis in retinal Müller glial cells.
Methods.
Cultured human retinal Müller cells (MIO-M1) were treated with highly oxidized glycated LDL (HOG-LDL, 200 mg protein/L) or native LDL (N-LDL, 200 mg protein/L) for up to 24 hours with or without pretreatment with N-acetyl-cysteine (NAC, a blocker of oxidative stress) and 4-phenylbutyrate (4-PBA, a blocker of endoplasmic reticulum [ER] stress). Effects of HOG-LDL on cell viability, apoptosis, oxidative stress, and ER stress were assessed by cell viability, TUNEL, and Western blot assays. In separate experiments, Müller cells were treated with 7-ketocholesterol (7-KC, 5–20 μM) or 4-hydroxynonenal (4-HNE, 5–40 μM) for up to 24 hours. The same markers were measured.
Results.
HOG-LDL induced apoptosis (decreased cell viability, increased TUNEL staining, increased expression of cleaved PARP, cleaved caspase-3, and BAX; decreased Bcl-2), oxidative stress (increased NOX4 and antioxidant enzymes, catalase, and superoxide dismutase 2), and ER stress (increased phospho-eIF2α, KDEL, ATF6, and CHOP). Pretreatment with NAC or 4-PBA partially attenuated apoptosis. In addition. NAC attenuated activation of ER stress. Similar to HOG-LDL, 7KC, and 4HNE also induced apoptosis, oxidative stress, and ER stress.
Conclusions.
Our data suggest that extravasated, modified lipoproteins may be implicated in apoptotic Müller cell death, acting at least partially via enhanced levels of oxidative and ER stresses. They support our main hypothesis that, in addition to hyperglycemia, extravasated and oxidized LDL is an important insult to the diabetic retina.
Our new data indicate that, in addition to hyperglycemia, extravasated and oxidized LDL is an important insult to Müller cells, thus potentially promoting the development of diabetic retinopathy.
doi:10.1167/iovs.12-9910
PMCID: PMC3394695  PMID: 22678501
20.  The HECTD3 E3 Ubiquitin Ligase Suppresses Cisplatin-Induced Apoptosis via Stabilizing MALT11 2 
Neoplasia (New York, N.Y.)  2013;15(1):39-48.
Homologous to the E6-associated protein carboxyl terminus domain containing 3 (HECTD3) is an E3 ubiquitin ligase with unknown functions. Here, we show that HECTD3 confers cancer cell resistance to cisplatin. To understand the molecular mechanisms, we performed a yeast two-hybrid analysis and identified mucosa-associated lymphoid tissue 1 (MALT1) as an HECTD3-interacting protein. HECTD3 promotes MALT1 ubiquitination with nondegradative polyubiquitin chains by direct interacting with the MALT1 through its N-terminal destruction of cyclin domain. HECTD3 does not target MALT1 for degradation but stabilize it. HECTD3 depletion dramatically decreases the levels of MALT1 in MCF7 and HeLa cells treated with cisplatin, which is correlated to an increase in apoptosis. Knockdown of MALT1 likewise increases cisplatin-induced apoptosis in these cancer cells. However, HECTD3 over-expression leads to a decreased cisplatin-induced apoptosis, whereas overexpression of MALT1 partially rescues HECTD3 depletion-induced apoptosis. These findings suggest that HECTD3 promotes cell survival through stabilizing MALT1. Our data have important implications in cancer therapy by providing novel molecular targets.
PMCID: PMC3556937  PMID: 23358872
21.  Making Sense of Oxidative Stress in Obstructive Sleep Apnea: Mediator or Distracter? 
Obstructive sleep apnea is increasingly recognized as an important contributor to cognitive impairment, metabolic derangements, and cardiovascular disease and mortality. Identifying the mechanisms by which this prevalent disorder influences health outcomes is now of utmost importance. As the prevalence of this disorder steadily increases, therapies are needed to prevent or reverse sleep apnea morbidities now more than ever before. Oxidative stress is implicated in cardiovascular morbidities of sleep apnea. What role oxidative stress plays in neural injury and cognitive impairments has been difficult to understand without readily accessible tissue to biopsy in persons with and without sleep apnea. An improved understanding of the role oxidative stress plays in neural injury in sleep apnea may be developed by integrating information gained examining neural tissue in animal models of sleep apnea with key features of redox biochemistry and clinical sleep apnea studies where extra-neuronal oxidative stress characterizations have been performed. Collectively, this information sets the stage for developing and testing novel therapeutic approaches to treat and prevent, not only central nervous system injury and dysfunction in sleep apnea, but also the cardiovascular and potentially metabolic conditions associated with this prevalent, disabling disorder.
doi:10.3389/fneur.2012.00179
PMCID: PMC3530694  PMID: 23293626
neurons; obstructive sleep apnea; superoxide; redox regulation; carbonylation; cardiovascular diseases; intermittent hypoxia
22.  Patients' Attitudes towards the Surplus Frozen Embryos in China 
BioMed Research International  2012;2013:934567.
Background. Assisted reproductive techniques have been used in China for more than 20 years. This study investigates the attitudes of surplus embryo holders towards embryos storage and donation for medical research. Methods. A total of 363 couples who had completed in vitro fertilization (IVF) treatment and had already had biological children but who still had frozen embryos in storage were invited to participate. Interviews were conducted by clinics in a narrative style. Results. Family size was the major reason for participants' (dis)continuation of embryo storage; moreover, the moral status of embryos was an important factor for couples choosing embryo storage, while the storage fee was an important factor for couples choosing embryo disposal. Most couples discontinued the storage of their embryos once their children were older than 3 years. In our study, 58.8% of the couples preferred to dispose of surplus embryos rather than donate them to research, citing a lack of information and distrust in science as significant reasons for their decision. Conclusions. Interviews regarding frozen embryos, including patients' expectations for embryo storage and information to assist them with decisions regarding embryo disposal, are beneficial for policies addressing embryo disposition and embryo donation in China.
doi:10.1155/2013/934567
PMCID: PMC3591130
23.  Downregulation of DLC-1 Gene by Promoter Methylation during Primary Colorectal Cancer Progression 
BioMed Research International  2012;2013:181384.
Purpose. DLC-1 is a tumor suppressor gene frequently silenced in human cancers. However, the pathogenicity of DLC-1 epigenetic silencing in the mucosa-adenoma-carcinoma transformation process of colorectal cancer (CRC) has not been studied. Methods. Promoter methylation status of DLC-1 was evaluated in 4 human CRC cell lines, 48 normal mucosa, 57 adenomas, and 80 CRC tissues with methylation-sensitive high-resolution melting analysis (MS-HRMA), while the mRNA expression was examined by qPCR. HRMA was utilized to detect the KRAS codon 12, 13 and BRAF V600Emutations. Results. Partial (1%–10%) and extensive (10%–100%) DLC-1 promoter methylations were observed in 10% and 0% of normal mucosa, 46% and 14% of adenomas, and 60% and 36% of CRCs, respectively. The promoter methylation of DLC-1 was related with the reduction of gene expression and the advanced Duke's stages (Stage C and D). DLC-1 promoter methylation and KRAS mutations are common concurrent pathological alternations. Conclusions. Epigenetic alternation plays a key role in the transcriptional silencing of DLC-1. It is also an independent risk factor related to the carcinogenesis of colorectal tumors and spans over its pathogenesis process. Therefore, DLC-1 promoter methylation quantitation may have a promising significance in the evaluation and management of CRC patients.
doi:10.1155/2013/181384
PMCID: PMC3591122
24.  Neutral Fragment Filtering for Rapid Identification of New Diester-Diterpenoid Alkaloids in Roots of Aconitum carmichaeli by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Mass Spectrometry 
PLoS ONE  2012;7(12):e52352.
A rapid and effective method was developed for separation and identification of diester-diterpenoid alkaloids (DDA) in the roots of Aconitum carmichaeli by ultra-high-pressure liquid chromatography coupled with high resolution LTQ-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MSn). According to accurate mass measurement and the characteristic neutral loss filtering strategy, a total of 42 diester-diterpenoid alkaloids (DDA) were rapidly detected and characterized or tentatively identified. Meanwhile, the proposed fragmentation pathways and the major diagnostic fragment ions of aconitine, mesaconitine and hypaconitine were investigated to trace DDA derivatives in crude plant extracts. 23 potential new compounds were successfully screened and characterized in Aconitum carmichaeli, including 16 short chain fatty acyls DDA, 4 N-dealkyl DDA and several isomers of aconitine, mesaconitine and hypaconitine.
doi:10.1371/journal.pone.0052352
PMCID: PMC3528760  PMID: 23285005
25.  Taenia taeniaeformis in Rat Favors Protracted Skin Lesions Caused by Sporothrix schenckii Infection: Dectin-1 and IL-17 Are Dispensable for Clearance of This Fungus 
PLoS ONE  2012;7(12):e52514.
We occasionally found that cestode Taenia taeniaeformis in rats favored Sporothrix schenckii infection and survival, causing protracted cutaneous lesions. In this study, we compared the pathology and cytokines profile of rats co-infected with the two pathogens and infected with S. schenckii alone to explore underlying mechanisms. In the co-infection group, there was high expression of β-glucan receptor Dectin-1 in the cutaneous lesions and no multinucleated giant cells, but in the S. schenckii infection group the opposite was observed. Cytokines profiles demonstrated an expected finding that IL-4, commonly expressed in helminth and fungus infection, is undetectable in the two infection groups. In the single fungal infection group, cytokines IFN-γ, IL-10 and IL-17 kept increasing in the first few weeks of infection to a peak which was followed by gradual decrease. This study showed that Dectin-1 and IL-17, which were believed to be the major anti-fungus mechanisms, are Th2 independent and dispensable for clearance of S. schenckii infection, suggesting that S. schenckii has a different molecular recognition pattern and evokes anti-infection mechanisms other than Dectin-1 and IL-17.
doi:10.1371/journal.pone.0052514
PMCID: PMC3527553  PMID: 23285072

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