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1.  Characterization of Self-Assembled Virus-Like Particles of Merkel Cell Polyomavirus 
PLoS ONE  2015;10(2):e0115646.
In our recombinant baculovirus system, VP1 protein of merkel cell polyomavirus (MCPyV), which is implicated as a causative agent in Merkel cell carcinoma, was self-assembled into MCPyV-like particles (MCPyV-LP) with two different sizes in insect cells, followed by being released into the culture medium. DNA molecules of 1.5- to 5-kb, which were derived from host insect cells, were packaged in large, ~50-nm spherical particles but not in small, ~25-nm particles. Structure reconstruction using cryo-electron microscopy showed that large MCPyV-LPs are composed of 72 pentameric capsomeres arranged in a T = 7 icosahedral surface lattice and are 48 nm in diameter. The MCPyV-LPs did not share antigenic determinants with BK- and JC viruses (BKPyV and JCPyV). The VLP-based enzyme immunoassay was applied to investigate age-specific prevalence of MCPyV infection in the general Japanese population aged 1–70 years. While seroprevalence of MCPyV increased with age in children and young individuals, its seropositivity in each age group was lower compared with BKPyV and JCPyV.
doi:10.1371/journal.pone.0115646
PMCID: PMC4324643  PMID: 25671590
2.  Protective immunity induced by peptides of AMA1, RON2 and RON4 containing T-and B-cell epitopes via an intranasal route against toxoplasmosis in mice 
Parasites & Vectors  2015;8:15.
Background
Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis. Apical membrane antigen-1 (AMA1) and rhoptry neck protein (RON2, RON4) are involved in the invasion of T. gondii.
Methods
This study chemically synthesized peptides of TgAMA1, TgRON2 and TgRON4 that contained the T- and B-cell epitopes predicted by bioinformatics analysis. We evaluated the systemic response by proliferation, cytokine and antibody measurements as well as the mucosal response by examining the levels of antigen-specific secretory IgA (SIgA) in the nasal, vesical and intestinal washes obtained from mice after nasal immunization with single (AMA1, RON2, RON4) or mixtures of peptides (A1 + R2, A1 + R4, R2 + R4, A1 + R2 + R4). We also assessed the parasite burdens in the liver and brain as well as the survival of mice challenged with a virulent strain.
Results
The results showed that the mice immunized with single or mixed peptides produced effective mucosal and systemic immune responses with a high level of specific antibody responses, a strong lymphoproliferative response and significant levels of gamma interferon (IFN-γ), interleukin-2 (IL-2) and IL-4 production. These mice also elicited partial protection against acute and chronic T. gondii infection. Moreover, our study indicated that mixtures of peptides, especially the A1 + R2 mixture, were more powerful and efficient than any other single peptides.
Conclusions
These results demonstrated that intranasal immunisation with peptides of AMA1, RON2 and RON4 containing T- and B-cell epitopes can partly protect mice against toxoplasmosis, and a combination of peptides as a mucosal vaccine strategy is essential for future Toxoplasma vaccine development.
doi:10.1186/s13071-015-0636-5
PMCID: PMC4297402  PMID: 25582167
Toxoplasma gondii; AMA1; RON2; RON4; Peptide epitope; Mucosal vaccine
3.  The influence of astragalus polysaccharide and β-elemene on LX-2 cell growth, apoptosis and activation 
BMC Gastroenterology  2014;14(1):224.
Background
Activated hepatic stellate cells are the main source of excessive collagen deposition in liver fibrosis. Here we report the inhibitory effects of the combinational treatment of two natural products, astragalus polysaccharide (APS) and β-elemene (ELE) on the activation of human liver hepatic stellate cell line LX-2 cells.
Methods
Cultured LX-2 cells were treated with different concentrations of APS or ELE for 24 or 48 hours. Cell viability/apoptosis was measured by MTT assay and Annexin V/PI staining , activation related genes including α-SMA and CD44 expressions were measured by real-time PCR and western blot respectively.
Results
The majority of LX-2 cells showed morphological change in the presence of APS or ELE for 24 hours. Treatment with APS + ELE for 24 or 48 hours significantly inhabited the cell proliferation compared with APS or ELE treatment alone on LX-2 cells. APS + ELE may block the up-regulation of α-SMA and CD44 both in mRNA and protein levels through TGF-β pathway in LX-2 cells.
Conclusion
APS or ELE treatment alone on LX-2 cells could inhibit cell proliferation and induce apoptosis. The combinational treatment using APS + ELE significantly increased the killing efficiency on LX-2 cells. α-SMA and CD44 expressions was inhibited upon APS + ELE treatment through TGF-β pathway in LX-2 cells. The results indicated a novel treatment using natural products for liver diseases with anti-fibrotic effect.
doi:10.1186/s12876-014-0224-8
PMCID: PMC4297370  PMID: 25551689
Astragalus polysaccharide; β-elemene; Hepatic stellate cells
4.  Epidemiological Characterization and Risk Factors of Allergic Rhinitis in the General Population in Guangzhou City in China 
PLoS ONE  2014;9(12):e114950.
The prevalence of allergic rhinitis (AR) in China has increased with an apparent geographic variation. The current study aims to investigate the AR prevalence/classification, diagnosis/treatment conditions, trigger factors, and risk factors in the general population of Guangzhou, the third biggest city in China. A cross-sectional survey was performed in the citizens in Guangzhou from December 2009 to March 2010 by using a stratified multistage cluster sampling method. All subjects were asked to complete a comprehensive questionnaire via a face to face interview. A total of 9,899 questionnaires were valid. The prevalence rate of AR in the general population of Guangzhou was 6.24%, with a significant higher prevalence in urban area (8.32%) versus rural area (3.43%). Among the AR subjects, most (87%) were diagnosed with intermittent AR and 87% suffered from moderate-severe symptoms. High percentages of the AR patients did not have previously physician-based diagnosis (34%) or specific medical treatment (55%). Morning time, winter season, and cold air were the most common trigger factors of AR. Family history of AR, current living place, living place during babyhood, smoking, home renovation, and pet ownership were the significant risk factors associated with AR prevalence in the population. The study demonstrated comprehensive epidemiological and clinical information about the AR in Guangzhou population. Change of living environment and lifestyles had strong impacts on the prevalence of AR. Public health policies should help the patients benefit from a proper diagnosis/treatment and specifically target the local risk factors, in order to control the AR incidence.
doi:10.1371/journal.pone.0114950
PMCID: PMC4267734  PMID: 25514026
5.  VATS right upper lobectomy 
Journal of Thoracic Disease  2014;6(12):1853-1854.
A 56-year-old male patient was admitted due to one small pulmonary nodule in the apicoposterior segment of the right upper lobe, which was found on his health screening one month ago. Preoperative examinations showed no distant metastasis, and his heart and lung functions could tolerate the lobectomy. Chest computed tomography (CT) showed one small pulmonary nodules on the apicoposterior segment of the right upper lobe, which was considered to be malignant lesions. No remarkably swollen lymph node was visible in the mediastinum. Therefore, VATS right upper lobectomy was performed and intraoperative frozen section confirmed the diagnosis of adenocarcinoma.
doi:10.3978/j.issn.2072-1439.2014.12.15
PMCID: PMC4283350  PMID: 25589990
VATS; right upper lobectomy; sequential dissection
6.  Effect of Continuous Cropping Generations on Each Component Biomass of Poplar Seedlings during Different Growth Periods 
The Scientific World Journal  2014;2014:618421.
In order to investigate the change rules and response characteristics of growth status on each component of poplar seedling followed by continuous cropping generations and growth period, we clear the biomass distribution pattern of poplar seedling, adapt continuous cropping, and provide theoretical foundation and technical reference on cultivation management of poplar seedling, the first generation, second generation, and third generation continuous cropping poplar seedlings were taken as study objects, and the whole poplar seedling was harvested to measure and analyze the change of each component biomass on different growth period poplar leaves, newly emerging branches, trunks and root system, and so forth. The results showed that the whole biomass of poplar seedling decreased significantly with the leaf area and its ratio increased, and the growth was inhibited obviously. The biomass aboveground was more than that underground. The ratios of leaf biomass and newly emerging branches biomass of first continuous cropping poplar seedling were relatively high. With the continuous cropping generations and growth cycle increasing, poplar seedling had a growth strategy to improve the ratio of root-shoot and root-leaf to adapt the limited soil nutrient of continuous cropping.
doi:10.1155/2014/618421
PMCID: PMC4225849  PMID: 25401150
7.  Partial Protective Effect of Intranasal Immunization with Recombinant Toxoplasma gondii Rhoptry Protein 17 against Toxoplasmosis in Mice 
PLoS ONE  2014;9(9):e108377.
Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects a variety of mammals, including humans. An effective vaccine for this parasite is therefore needed. In this study, RH strain T. gondii rhoptry protein 17 was expressed in bacteria as a fusion with glutathione S-transferase (GST) and the recombinant proteins (rTgROP17) were purified via GST-affinity chromatography. BALB/c mice were nasally immunised with rTgROP17, and induction of immune responses and protection against chronic and lethal T. gondii infections were investigated. The results revealed that mice immunised with rTgROP17 produced high levels of specific anti-rTgROP17 IgGs and a mixed IgG1/IgG2a response of IgG2a predominance. The systemic immune response was associated with increased production of Th1 (IFN-γand IL-2) and Th2 (IL-4) cytokines, and enhanced lymphoproliferation (stimulation index, SI) in the mice immunised with rTgROP17. Strong mucosal immune responses with increased secretion of TgROP17-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes were also observed in these mice. The vaccinated mice displayed apparent protection against chronic RH strain infection as evidenced by their lower liver and brain parasite burdens (59.17% and 49.08%, respectively) than those of the controls. The vaccinated mice also exhibited significant protection against lethal infection of the virulent RH strain (survival increased by 50%) compared to the controls. Our data demonstrate that rTgROP17 can trigger strong systemic and mucosal immune responses against T. gondii and that ROP17 is a promising candidate vaccine for toxoplasmosis.
doi:10.1371/journal.pone.0108377
PMCID: PMC4177930  PMID: 25255141
8.  A novel P20R mutation in the alpha-B crystallin gene causes autosomal dominant congenital posterior polar cataracts in a Chinese family 
BMC Ophthalmology  2014;14(1):108.
Background
To identify the genetic defects and investigate the possible mechanism of cataract genesis in a five-generation family with autosomal dominant congenital posterior polar cataracts.
Methods
Clinical data were collected, and the lens phenotypes of the affected members in this family were recorded by slit lamp photography. Genomic DNA was isolated from peripheral blood using QIAamp DNA Blood Mini Kits. Twenty-three mutational hot spots associated with autosomal dominant congenital posterior polar cataracts were screened by PCR-based DNA sequencing. Properties and structural models of wild-type and mutant alpha-B (αB)-crystallin (CRYAB) were generated and analyzed using SWISS-MODEL.
Results
All affected individuals in this family started to exhibit poor vision at the age of 8–10 years. The lens opacity consisted of a single, well-defined plaque, 0.5–3 mm in diameter, which was confined to the posterior pole of the lens. DNA sequencing analysis of the affected members showed a novel, heterozygous missense mutation c.59C > G (P20R) in exon 1 of the CRYAB gene. This mutation was not found in 10 unaffected family members, or in 200 unaffected and unrelated individuals, thereby excluding the possibility that it is a rare polymorphism. Data generated using the ProtScale and PyMOL programs revealed that the mutation altered the stability and solubility of the αB-crystallin protein.
Conclusions
This study reported a novel c.59C > G (P20R) missense mutation in CRYAB in a five-generation Chinese family with posterior polar cataract.
Electronic supplementary material
The online version of this article (doi:10.1186/1471-2415-14-108) contains supplementary material, which is available to authorized users.
doi:10.1186/1471-2415-14-108
PMCID: PMC4169818  PMID: 25195561
Congenital posterior polar cataract; Alpha-B crystallin gene; P20R mutation
9.  Anti-RAGE antibody ameliorates severe thermal injury in rats through regulating cellular immune function 
Acta Pharmacologica Sinica  2014;35(9):1167-1176.
Aim:
The receptor of advanced glycation end products (RAGE) participates in a variety of pathophysiological processes and inflammatory responses. The aim of this study was to investigate the therapeutic potential of an anti-RAGE neutralizing antibody for severe thermal injury in rats, and to determine whether the treatment worked via modulating cellular immune function.
Methods:
Full-thickness scald injury was induced in Wistar rats, which were treated with the anti-RAGE antibody (1 mg/kg, iv) at 6 h and 24 h after the injury. The rats were sacrificed on d 1, 3, 5, and 7. Blood and spleen samples were harvested to monitor organ function and to analyze dendritic cell (DC) and T cell cytokine profiles. The survival rate was analyzed up to d 7 after the injury.
Results:
Administration of the antibody significantly increased the 7 d survival rate in thermally injured rats (6.67% in the model group; 33.33% in anti-RAGE group). Treatment with the antibody also attenuated the multiple organ dysfunction syndrome (MODS) following the thermal injury, as shown by significant decreases in the organ dysfunction markers, including serum ALT, AST, blood urea nitrogen, creatinine and CK-MB. Moreover, treatment with the antibody significantly promoted DC maturation and T cell activation in the spleens of thermally injured rats.
Conclusion:
Blockade of the RAGE axis by the antibody effectively ameliorated MODS and improved the survival rate in thermally injured rats, which may be due to modulation of cellular immune function.
doi:10.1038/aps.2014.56
PMCID: PMC4155528  PMID: 25152026
RAGE; anti-RAGE antibody; burns; thermal injury; multiple organ dysfunction syndrome; cytokine; inflammation; immune response; dendritic cell; T cell
10.  Clinical, molecular and cytogenetic analysis of 46, XX testicular disorder of sex development with SRY-positive 
BMC Urology  2014;14:70.
Background
To review the possible mechanisms proposed to explain the etiology of 46, XX sex reversal by investigating the clinical characteristics and their relationships with chromosomal karyotype and the SRY(sex-determining region Y)gene.
Methods
Five untreated 46, XX patients with SRY-positive were referred for infertility. Clinical data were collected, and Karyotype analysis of G-banding in lymphocytes and Fluorescence in situ hybridization (FISH) were performed. Genomic DNA from peripheral blood of the patients using QIAamp DNA Blood Kits was extracted. The three discrete regions, AZFa, AZFb and AZFc, located on the long arm of the Y chromosome, were performed by multiplex PCRs(Polymerase Chain Reaction) amplification. The set of PCR primers for the diagnosis of microdeletion of the AZFa, AZFb and AZFc region included: sY84, sY86, sY127, sY134, sY254, sY255, SRY and ZFX/ZFY.
Results
Our five patients had a lower body height. Physical examination revealed that their testes were small in volume, soft in texture and normal penis. Semen analyses showed azoospermia. All patients had a higher follicle-stimulating hormone(FSH), Luteinizing Hormone(LH) level, lower free testosterone, testosterone level and normal Estradiol, Prolactin level. Karyotype analysis of all patients confirmed 46, XX karyotype, and FISH analysis showed that SRY gene were positive and translocated to Xp. Molecular analysis revealed that the SRY gene were present, and the AZFa, AZFb and AZFc region were absent.
Conclusions
This study adds cases on the five new 46, XX male individuals with SRY-positive and further verifies the view that the presence of SRY gene and the absence of major regions in Y chromosome should lead to the expectance of a completely masculinised phenotype, abnormal hormone levels and infertility.
doi:10.1186/1471-2490-14-70
PMCID: PMC4149805  PMID: 25169080
46; XX testicular disorder of sex development (DSD); SRY-positive; Sexual hormone
11.  Expression of Wheat High Molecular Weight Glutenin Subunit 1Bx Is Affected by Large Insertions and Deletions Located in the Upstream Flanking Sequences 
PLoS ONE  2014;9(8):e105363.
To better understand the transcriptional regulation of high molecular weight glutenin subunit (HMW-GS) expression, we isolated four Glu-1Bx promoters from six wheat cultivars exhibiting diverse protein expression levels. The activities of the diverse Glu-1Bx promoters were tested and compared with β-glucuronidase (GUS) reporter fusions. Although all the full-length Glu-1Bx promoters showed endosperm-specific activities, the strongest GUS activity was observed with the 1Bx7OE promoter in both transient expression assays and stable transgenic rice lines. A 43 bp insertion in the 1Bx7OE promoter, which is absent in the 1Bx7 promoter, led to enhanced expression. Analysis of promoter deletion constructs confirmed that a 185 bp MITE (miniature inverted-repeat transposable element) in the 1Bx14 promoter had a weak positive effect on Glu-1Bx expression, and a 54 bp deletion in the 1Bx13 promoter reduced endosperm-specific activity. To investigate the effect of the 43 bp insertion in the 1Bx7OE promoter, a functional marker was developed to screen 505 Chinese varieties and 160 European varieties, and only 1Bx7-type varieties harboring the 43 bp insertion in their promoters showed similar overexpression patterns. Hence, the 1Bx7OE promoter should be important tool in crop genetic engineering as well as in molecular assisted breeding.
doi:10.1371/journal.pone.0105363
PMCID: PMC4136844  PMID: 25133580
12.  Polymorphisms in estrogen receptors predict the risk of male infertility: a meta-analysis 
Background
Estrogen receptors play an important role in mediating estrogen action on target tissues, and the estrogen is relevant to male infertility. Single nucleotide polymorphisms (SNPs) in estrogen receptors may be associated with the risk of male infertility. A variety of case control studies have been published evaluating this association. However, the accumulated studies have shown inconsistent conclusions.
Methods
To further determine the potential association between the four common SNPs (rs2234693, rs9340799, rs1256049 and rs4986938) in estrogen receptors gene and male infertility, this meta-analysis was performed according to the 10 published case control studies. The odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the strength of the associations.
Results
It was revealed that the sub-group analysis by the ethnicity, for the rs2234693, a significant association in the comparison of CC vs. TT (OR = 0.61, 95% CI: 0.40-0.93), CT vs. TT (OR = 0.67, 95% CI: 0.49-0.93) and CC + CT vs. TT (OR = 0.66, 95% CI: 0.49-0.89) in the Asian population with male infertility. For rs9340799 polymorphism, increased risks were observed for the comparison of AA vs. GG (OR = 1.75, 95% CI: 1.15-2.68) and AA vs. GA + GG (OR = 1.38, 95% CI: 1.02-1.88). For rs1256049 polymorphism, the comparison of the GA vs. GG (OR = 1.52, 95% CI: 1.00-2.31) and AA + GA vs. GG (OR = 1.74, 95% CI: 1.03-2.94), also increased risks present in Asian and Caucasian population, respectively.
Conclusions
The rs2234693C allele was associated with the decreased risk for male infertility; however, the rs9340799AA genotype and the rs1256049GA genotype were associated with an increased risk for male infertility.
Electronic supplementary material
The online version of this article (doi:10.1186/1477-7827-12-79) contains supplementary material, which is available to authorized users.
doi:10.1186/1477-7827-12-79
PMCID: PMC4141121  PMID: 25128001
Male infertility; Polymorphisms; Estrogen receptors
13.  A novel COL4A1 gene mutation results in autosomal dominant non-syndromic congenital cataract in a Chinese family 
BMC Medical Genetics  2014;15:97.
Background
Almost one-third of congenital cataracts are primarily autosomal dominant disorders, which are also called autosomal dominant congenital cataract, resulting in blindness and clouding of the lens. The purpose of this study was to identify the disease-causing mutation in a Chinese family affected by bilateral, autosomal dominant congenital cataract.
Methods
The detection of candidate gene mutation and the linkage analysis of microsatellite markers were performed for the known candidate genes. Molecular mapping and cloning of candidate genes were used in all affected family members to screen for potential genetic mutations and the mutation was confirmed by single enzyme digestion.
Results
The proband was diagnosed with isolated, congenital cataract without the typical clinical manifestations of cataract, which include diabetes, porencephaly, sporadic intracerebral hemorrhage, and glomerulopathy. A novel mutation, c.2345 G > C (Gly782Ala), in exon 31 of the collagen type IV αlpha1 (COL4A1) gene, which encodes the collagen alpha-1(IV) chain, was found to be associated with autosomal dominant congenital cataract in a Chinese family. This mutation was not found in unaffected family members or in 200 unrelated controls. Sequence analysis confirmed that the Gly782 amino acid residue is highly conserved.
Conclusions
The novel mutation (c.2345 G > C) of the COL4A1 gene is the first report of a non-syndromic, autosomal dominant congenital cataract, thereby highlighting the important role of type IV collagen in the physiological and optical properties of the lens.
doi:10.1186/s12881-014-0097-2
PMCID: PMC4236509  PMID: 25124159
Type IV collagen; COL4A1; Non-syndromic congenital cataract
14.  Comparison of the clinical features and outcomes in two age-groups of elderly patients with atrial fibrillation 
Background
Atrial fibrillation (AF) disproportionately affects older adults. However, direct comparison of clinical features, medical therapy, and outcomes in AF patients aged 65–74 and ≥75 years is rare. The objective of the present study was to evaluate the differences in clinical characteristics and prognosis in these two age-groups of geriatric patients with AF.
Materials and methods
A total of 1,336 individuals aged ≥65 years from a Chinese AF registry were assessed in the present study: 570 were in the 65- to 74-year group, and 766 were in the ≥75-year group. Multivariable Cox hazards regression was performed to analyze the major adverse cardiac events (MACEs) between groups.
Results
In our population, the older group were more likely to have coronary artery disease, hypertension, previous stroke, cognitive disorder, or chronic obstructive pulmonary disease, and the 65- to 74-year group were more likely to have valvular heart disease, left ventricular systolic dysfunction, or sleep apnea. The older patients had 1.2-fold higher mean CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes, stroke) scores, but less probability of being prescribed drugs. Compared with those aged 65–74 years, the older group had a higher risk of death (hazard ratio 2.881, 95% confidence interval 1.981–4.189; P<0.001) or MACE (hazard ratio 2.202, 95% confidence interval 1.646–2.945; P<0.001) at the 1-year follow-up. In multivariable Cox analyses, secondary AF diagnosis, a history of chronic obstructive pulmonary disease, and left ventricular systolic dysfunction were independent predictors of MACE in the older group.
Conclusion
Patients aged ≥75 years had a worse prognosis than those aged 65–74 years, and were associated with a higher risk of both death and MACE.
doi:10.2147/CIA.S67123
PMCID: PMC4136954  PMID: 25143720
atrial fibrillation; geriatric patients; mortality; major adverse cardiac events (MACE)
15.  Effects of Salt-Drought Stress on Growth and Physiobiochemical Characteristics of Tamarix chinensis Seedlings 
The Scientific World Journal  2014;2014:765840.
The present study was designed to clarify the effects of salinity and water intercross stresses on the growth and physiobiochemical characteristics of Tamarix chinensis seedlings by pots culture under the artificial simulated conditions. The growth, activities of SOD, POD, and contents of MDA and osmotic adjusting substances of three years old seedlings of T. chinensis were studied under different salt-drought intercross stress. Results showed that the influence of salt stress on growth was greater than drought stress, the oxidation resistance of SOD and POD weakened gradually with salt and drought stresses intensified, and the content of MDA was higher under severe drought and mild and moderate salt stresses. The proline contents increased with the stress intensified but only significantly higher than control under the intercross stresses of severe salt-severe drought. It implied that T. chinensis could improve its stress resistance by adjusted self-growth and physiobiochemical characteristics, and the intercross compatibility of T. chinensis to salt and drought stresses can enhance the salt resistance under appropriate drought stress, but the dominant factors influencing the physiological biochemical characteristics of T. chinensis were various with the changing of salt-drought intercross stresses gradients.
doi:10.1155/2014/765840
PMCID: PMC4130323  PMID: 25140348
16.  Shear Modulus Estimation on Vastus Intermedius of Elderly and Young Females over the Entire Range of Isometric Contraction 
PLoS ONE  2014;9(7):e101769.
Elderly people often suffer from sarcopenia in their lower extremities, which gives rise to the increased susceptibility of fall. Comparing the mechanical properties of the knee extensor/flexors on elderly and young subjects is helpful in understanding the underlying mechanisms of the muscle aging process. However, although the stiffness of skeletal muscle has been proved to be positively correlated to its non-fatiguing contraction intensity by some existing methods, this conclusion has not been verified above 50% maximum voluntary contraction (MVC) due to the limitation of their measurement range. In this study, a vibro-ultrasound system was set up to achieve a considerably larger measurement range on muscle stiffness estimation. Its feasibility was verified on self-made silicone phantoms by comparing with the mechanical indentation method. The system was then used to assess the stiffness of vastus intermedius (VI), one of the knee extensors, on 10 healthy elderly female subjects (56.7±4.9 yr) and 10 healthy young female subjects (27.6±5.0 yr). The VI stiffness in its action direction was confirmed to be positively correlated to the % MVC level (R2 = 0.999) over the entire range of isometric contraction, i.e. from 0% MVC (relaxed state) to 100% MVC. Furthermore, it was shown that there was no significant difference between the mean VI shear modulus of the elderly and young subjects in a relaxed state (p>0.1). However, when performing step isometric contraction, the VI stiffness of young female subjects was found to be larger than that of elderly participants (p<0.001), especially at the relatively higher contraction levels. The results expanded our knowledge on the mechanical property of the elderly’s skeletal muscle and its relationship with intensity of active contraction. Furthermore, the vibro-ultrasound system has a potential to become a powerful tool for investigating the elderly’s muscle diseases.
doi:10.1371/journal.pone.0101769
PMCID: PMC4081795  PMID: 24991890
17.  Effects of a Disrupted Blood-Brain Barrier on Cholesterol Homeostasis in the Brain* 
The Journal of Biological Chemistry  2014;289(34):23712-23722.
Background: The role of the blood-brain barrier for cholesterol homeostasis in the brain is not known.
Results: Significant influx of cholesterol into the brain and increased efflux of 24(S)-hydroxycholesterol were observed in mice with a defect blood-brain barrier.
Conclusion: A defect blood-brain barrier increases permeability for steroid flux in both directions.
Significance: Elucidation of the role of the blood-brain barrier for brain cholesterol turnover.
The presence of the blood-brain barrier (BBB) is critical for cholesterol metabolism in the brain, preventing uptake of lipoprotein-bound cholesterol from the circulation. The metabolic consequences of a leaking BBB for cholesterol metabolism have not been studied previously. Here we used a pericyte-deficient mouse model, Pdgfbret/ret, shown to have increased permeability of the BBB to a range of low-molecular mass and high-molecular mass tracers. There was a significant accumulation of plant sterols in the brains of the Pdgfbret/ret mice. By dietary treatment with 0.3% deuterium-labeled cholesterol, we could demonstrate a significant flux of cholesterol from the circulation into the brains of the mutant mice roughly corresponding to about half of the measured turnover of cholesterol in the brain. We expected the cholesterol flux into the brain to cause a down-regulation of cholesterol synthesis. Instead, cholesterol synthesis was increased by about 60%. The levels of 24(S)-hydroxycholesterol (24S-OHC) were significantly reduced in the brains of the pericyte-deficient mice but increased in the circulation. After treatment with 1% cholesterol in diet, the difference in cholesterol synthesis between mutants and controls disappeared. The findings are consistent with increased leakage of 24S-OHC from the brain into the circulation in the pericyte-deficient mice. This oxysterol is an efficient suppressor of cholesterol synthesis, and the results are consistent with a regulatory role of 24S-OHC in the brain. To our knowledge, this is the first demonstration that a defective BBB may lead to increased flux of a lipophilic compound out from the brain. The relevance of the findings for the human situation is discussed.
doi:10.1074/jbc.M114.556159
PMCID: PMC4156098  PMID: 24973215
Brain Metabolism; Cholesterol Regulation; Hydroxylase; Neurodegeneration; Sterol
18.  A Novel p. Gly630Ser Mutation of COL2A1 in a Chinese Family with Presentations of Legg–Calvé–Perthes Disease or Avascular Necrosis of the Femoral Head 
PLoS ONE  2014;9(6):e100505.
Objective
Mutations in the type II collagen gene are associated with certain human disorders, collectively termed type II collagenopathies. They include Legg–Calvé–Perthes disease (LCPD) and avascular necrosis of the femoral head (ANFH). These two diseases are skeletal dysplasias, inherited in an autosomal dominant fashion, characterized by groin pain, dislocation of the hip and diminished joint mobility. Coxa vara and elevation of the greater trochanter of the femur comprise the typical phenotype of LCPD, but do not occur in ANFH. Lack of synthesis of type II collagen and structural defects are responsible for the major clinical outcomes, because collagen is the essential matrix protein of all connective tissues. Type II collagen, encoded by the COL2A1 gene, contains N- and C- terminal regions that are cleaved after secretion into the extracellular matrix, and the core area is composed of a triple helical (Gly–X–Y) domain. If the Gly in this specific region is replaced by other amino acids, the structure of type II collagen will be destroyed.
Method
Forty-five members of a four-generation family were recruited and investigated. Diagnosis was made by independent orthopedic surgeons and radiologists. A mutation of the COL2A1 gene was detected.
Result
In our research, we identify a heterozygous mutation (c.1888 G>A, p. Gly630Ser) in exon 29 of COL2A1 in the Gly–X–Y domain, in a Chinese family affected by LCPD and ANFH. Our findings provide significant clues to the phenotype–genotype relationships in these syndromes and may be helpful in clinical diagnosis. Furthermore, these results should assist further studies of the mechanisms underlying collagen diseases.
Conclusion
Our data add new variants to the repertoire of COL2A1 mutation resulting in related collagenopathies.
doi:10.1371/journal.pone.0100505
PMCID: PMC4065060  PMID: 24949742
19.  Pulmonary benign metastasizing leiomyoma: a case report and literature review 
Journal of Thoracic Disease  2014;6(6):E92-E98.
Benign metastasizing leiomyoma (BML) is a rare condition that occurs in all age groups and that is particularly prevalent among women of late childbearing age. All patients have a history of uterine leiomyoma and/or myomectomy, often associated with distant metastases from the uterus, which commonly occurs in the lung. We report the case of a 32-year-old young woman suffering from chest stuffiness, labored respiration and weakness after a myomectomy performed one month earlier. The chest CT showed a diffuse miliary shadow in both sides of her lungs, but serum tumor markers such as CA125, CA199, carcinoembryonic antigen (CEA), neuron specific enolase (NSE), and CYFRA21-1 were normal. The patient underwent a lung biopsy by thoracoscopic surgery after four weeks of anti-TB treatment; there were no significant changes in the chest CT. H&E staining showed that the tumor cells had characteristics of smooth muscle cell differentiation. Immunohistochemical staining showed a low tumor cell proliferation index, which indicated that the likelihood of a malignancy was not high. There was no expression of CD10, indicating a diagnosis of pulmonary benign metastasizing leiomyoma (PBML). Smooth muscle actin (SMA) and desmin as specific markers of smooth muscle and the estrogen receptor (ER) and progesterone receptor (PR) were all strongly positive, which is characteristic of PBML. The patient was given the anti-estrogen tamoxifen for 3 months. With no radiological evidence of disease development and further distant metastasis, the patient will continue to be followed.
doi:10.3978/j.issn.2072-1439.2014.04.37
PMCID: PMC4073417  PMID: 24977035
Benign metastasizing leiomyoma (BML); myomectomy; pulmonary metastases; lung biopsy; immunohistochemistry
20.  HIV Incidence and Risk Factors in Chinese Young Men Who Have Sex with Men—A Prospective Cohort Study 
PLoS ONE  2014;9(5):e97527.
Objectives
To assess HIV incidence and its associated risk factors among young men who have sex with men (YMSM) in urban areas, China.
Design
The study used a prospective cohort study design and standard diagnostic tests.
Methods
A twelve-month prospective cohort study was conducted among YMSM (18–25 years old) in 8 large cities in China. The participants were recruited via snowball sampling. A total of 1102 HIV-negative YMSM completed baseline assessment, 878 YMSM participants completed 6-month follow-up, and 902 completed 12-month follow-up. HIV was screened by an enzyme-linked immunosorbent assay and confirmed with Western Blot. Syphilis was screened via rapid plasma reagent and confirmed by treponema pallidum particle agglutination assay.
Results
78 HIV seroconversions were identified within 1168.4 person-year observations yielding an incidence rate of 6.7 per 100 person-years. HIV seroconversion was associated with non-student status (RR = 2.61, 90% CI = 1.3–5.26), low HIV transmission knowledge (RR = 8.87, 90% CI = 2.16–36.43), and syphilis infection (RR = 5.04, 90% CI = 2.57–9.90).
Conclusions
Incidence of HIV among YMSM is high in urban areas of China. Interventions measures are required to contain the HIV epidemic within this population.
doi:10.1371/journal.pone.0097527
PMCID: PMC4039446  PMID: 24878586
21.  MicroRNA-27a Modulates HCV Infection in Differentiated Hepatocyte-Like Cells from Adipose Tissue-Derived Mesenchymal Stem Cells 
PLoS ONE  2014;9(5):e91958.
Background and Aims
Despite the discovery of hepatitis C virus (HCV) entry factor, the mechanism by which it is regulated by miRNAs remains unclear. Adipose tissue-derived human mesenchymal stem cells (AT-hMSCs) have been widely used for differentiated hepatocyte-like cells (DHCs). Here, we established an in vitro HCV infection model using DHCs from AT-hMSCs and identified miRNAs that modulate HCV infectivity.
Methods
AT-hMSCs were differentiated into DHCs using the conditional media, and evaluated for hepatocyte characteristics using RT-PCR, immunocytochemistry, periodic acid-Schiff staining, and a urea synthesis assay. The expression of HCV candidate receptors was also verified using immunocytochemistry. The levels of candidate miRNAs targeting HCV receptors were then determined by relative quantitative RT-PCR (rqRT-PCR). Finally, DHCs were infected using HCVcc and serum from HCV-infected patients, and infectivity of the virus was measured by rqRT-PCR and transmission electron microscopy (TEM).
Results
The expected changes in morphology, function and hepatic gene expression were observed during hepatic differentiation. Moreover, the expression of candidate HCV entry factors and miR-27a were altered during hepatic differentiation. The infection and replication of HCV occurred efficiently in DHCs treated with HCVcc or infected with serum from HCV-infected patients. In addition, HCV infectivity was suppressed in miR-27a-transfected DHCs, due to the inhibition of LDLR expression by miR-27a.
Conclusions
Our results demonstrate that AT-hMSCs are a good source of DHCs, which are suitable for in vitro cultivation of HCV. Furthermore, these results suggest that miR-27a modulates HCV infectivity by regulating LDLR expression.
doi:10.1371/journal.pone.0091958
PMCID: PMC4019502  PMID: 24824429
22.  Homologous haplotypes, expression, genetic effects and geographic distribution of the wheat yield gene TaGW2 
BMC Plant Biology  2014;14:107.
Background
TaGW2-6A, cloned in earlier research, strongly influences wheat grain width and TKW. Here, we mainly analyzed haplotypes of TaGW2-6B and their effects on TKW and interaction with haplotypes at TaGW2-6A.
Results
About 2.9 kb of the promoter sequences of TaGW2-6B and TaGW2-6D were cloned in 34 bread wheat cultivars. Eleven SNPs were detected in the promoter region of TaGW2-6B, forming 4 haplotypes, but no divergence was detected in the TaGW2-6D promoter or coding region. Three molecular markers including CAPS, dCAPS and ACAS, were developed to distinguish the TaGW2-6B haplotypes. Haplotype association analysis indicated that TaGW2-6B has a stronger influence than TaGW2-6A on TKW, and Hap-6B-1 was a favored haplotype increasing grain width and weight that had undergone strong positive selection in global wheat breeding. However, clear geographic distribution differences for TaGW2-6A haplotypes were found; Hap-6A-A was favored in Chinese, Australian and Russian cultivars, whereas Hap-6A-G was preferred in European, American and CIMMYT cultivars. This difference might be caused by a flowering and maturity time difference between the two haplotypes. Hap-6A-A is the earlier type. Haplotype interaction analysis between TaGW2-6A and TaGW2-6B showed additive effects between the favored haplotypes. Hap-6A-A/Hap-6B-1 was the best combination to increase TKW. Relative expression analysis of the three TaGW2 homoeologous genes in 22 cultivars revealed that TaGW2-6A underwent the highest expression. TaGW2-6D was the least expressed during grain development and TaGW2-6B was intermediate. Diversity of the three genes was negatively correlated with their effect on TKW.
Conclusions
Genetic effects, expression patterns and historic changes of haplotypes at three homoeologous genes of TaGW2 influencing yield were dissected in wheat cultivars. Strong and constant selection to favored haplotypes has been found in global wheat breeding during the past century. This research also provides a valuable case for understanding interaction of genes that control complex traits in polyploid species.
doi:10.1186/1471-2229-14-107
PMCID: PMC4021350  PMID: 24766773
Triticum aestivum; TaGW2; Grain weight; Gene expression; Haplotype interaction
23.  Open conformation of hERG channel turrets revealed by a specific scorpion toxin BmKKx2 
Cell & Bioscience  2014;4:18.
Background
The human ether-a-go-go-related gene potassium channel (hERG) has an unusual long turret, whose role in recognizing scorpion toxins remains controversial. Here, BmKKx2, the first specific blocker of hERG channel derived from scorpion Mesobuthus martensii, was identified and the turret role of hERG channel was re-investigated using BmKKx2 as a molecular probe.
Results
BmKKx2 was found to block hERG channel with an IC50 of 6.7 ± 1.7 nM and share similar functional surface with the known hERG channel inhibitor BeKm-1. The alanine-scanning mutagenesis data indicate that different residue substitutions on hERG channel by alanine decreased the affinities of toxin BmKKx2 by about 10-fold compared with that of wild-type hERG channel, which reveals that channel turrets play a secondary role in toxin binding. Different from channel turret, the pore region of hERG channel was found to exert the conserved and essential function for toxin binding because the mutant hERG-S631A channel remarkably decreased toxin BmKKx2 affinity by about 104-fold.
Conclusions
Our results not only revealed that channel turrets of hERG channel formed an open conformation in scorpion toxin binding, but also enriched the diversity of structure-function relationships among the different potassium channel turrets.
doi:10.1186/2045-3701-4-18
PMCID: PMC4108063  PMID: 24725272
Scorpion toxin; BmKKx2; hERG channel; Turret; Pore region; Molecular mechanism
24.  Complete Genome of Hepatitis E Virus from Laboratory Ferrets 
Emerging Infectious Diseases  2014;20(4):709-712.
The complete genome of hepatitis E virus (HEV) from laboratory ferrets imported from the United States was identified. This virus shared only 82.4%–82.5% nt sequence identities with strains from the Netherlands, which indicated that the ferret HEV genome is genetically diverse. Some laboratory ferrets were contaminated with HEV.
doi:10.3201/eid2004.131815
PMCID: PMC3966362  PMID: 24655541
hepatitis E virus; HEV; viruses; ferrets; laboratory ferrets; imported infection; complete genome; sequencing; zoonoses
25.  Oleuropein prevents the progression of steatohepatitis to hepatic fibrosis induced by a high-fat diet in mice 
Nonalcoholic steatohepatitis (NASH) is characterized by hepatocyte injury and inflammatory cell infiltration, which has been linked to peripheral insulin resistance and increased levels of triglycerides in the liver. The purposes of this study were to establish a mouse model of NASH by feeding mice a 60% high-fat diet (HFD) and to demonstrate the anti-fibrotic effects of oleuropein, which has been shown to have anti-oxidant and anti-inflammatory properties, in this HFD-induced mouse model of NASH. C57BL/6 mice were divided into three groups: a regular diet group (Chow), a HFD group and an oleuropein-supplemented HFD group (OSD), which was fed a 0.05% OSD for 6 months. The effects of oleuropein in this model were evaluated using biochemical, histological and molecular markers. The expression levels of alpha-smooth muscle actin (α-SMA)and collagen type I in the HFD and OSD groups were evaluated using real-time PCR and western blotting. The body weight, biochemical marker levels, nonalcoholic fatty liver disease activity score, homeostasis model of assessment-insulin resistance (HOMA-IR) and leptin levels observed in the HFD group at 9 and 12 months were higher than those observed in the Chow group. The HOMA-IR and leptin levels in the OSD group were decreased compared with the HFD group. In addition, α-SMA and collagen type I expression were decreased by oleuropein treatment. We established a NASH model induced by HFD and demonstrated that this model exhibits the histopathological features of NASH progressing to fibrosis. Our results suggest that oleuropein may be pharmacologically useful in preventing the progression of steatohepatitis and fibrosis and may be a promising agent for the treatment of NASH in humans.
doi:10.1038/emm.2014.10
PMCID: PMC3972787  PMID: 24763197
fibrosis; nonalcoholic steatohepatitis; oleuropein

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