Search tips
Search criteria

Results 1-25 (353)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Bad Marriage, Broken Heart? Age and Gender Differences in the Link between Marital Quality and Cardiovascular Risks among Older Adults 
Working from a life course perspective, we develop hypotheses about age and gender differences in the link between marital quality and cardiovascular risk and test them using data from the first two waves of the National Social Life, Health, and Aging Project. The analytic sample includes 459 married women and 739 married men (aged 57–85 in the first wave) who were interviewed in both waves. We apply Heckman-type corrections for selection bias due to mortality and marriage. Cardiovascular risk is measured as hypertension, rapid heart rate, C-reactive protein, and general cardiovascular events. Results suggest that changes in marital quality and cardiovascular risk are more closely related for older married people than for their younger counterparts; and that the link between marital quality and cardiovascular risk is more pronounced among women than among men at older ages. These findings fit with the gendered life course perspective and cumulative disadvantage framework.
PMCID: PMC4325990  PMID: 25413802
2.  Anti-Human α-Synuclein N-Terminal Peptide Antibody Protects against Dopaminergic Cell Death and Ameliorates Behavioral Deficits in an AAV-α-Synuclein Rat Model of Parkinson’s Disease 
PLoS ONE  2015;10(2):e0116841.
The protein α-synuclein (α-Syn) has a central role in the pathogenesis of Parkinson’s disease (PD) and immunotherapeutic approaches targeting this molecule have shown promising results. In this study, novel antibodies were generated against specific peptides from full length human α-Syn and evaluated for effectiveness in ameliorating α-Syn-induced cell death and behavioral deficits in an AAV-α-Syn expressing rat model of PD. Fisher 344 rats were injected with rAAV vector into the right substantia nigra (SN), while control rats received an AAV vector expressing green fluorescent protein (GFP). Beginning one week after injection of the AAV-α-Syn vectors, rats were treated intraperitoneally with either control IgG or antibodies against the N-terminal (AB1), or central region (AB2) of α-Syn. An unbiased stereological estimation of TH+, NeuN+, and OX6 (MHC-II) immunostaining revealed that the α-Syn peptide antibodies (AB1 and AB2) significantly inhibited α-Syn-induced dopaminergic cell (DA) and NeuN+ cell loss (one-way ANOVA (F (3, 30) = 5.8, p = 0.002 and (F (3, 29) = 7.92, p = 0.002 respectively), as well as decreasing the number of activated microglia in the ipsilateral SN (one-way ANOVA F = 14.09; p = 0.0003). Antibody treated animals also had lower levels of α-Syn in the ipsilateral SN (one-way ANOVA F (7, 37) = 9.786; p = 0.0001) and demonstrated a partial intermediate improvement of the behavioral deficits. Our data suggest that, in particular, an α-Syn peptide antibody against the N-terminal region of the protein can protect against DA neuron loss and, to some extent behavioral deficits. As such, these results may be a potential therapeutic strategy for halting the progression of PD.
PMCID: PMC4319932  PMID: 25658425
3.  In vivo monitoring of dihydroartemisinin-piperaquine sensitivity in Plasmodium falciparum along the China-Myanmar border of Yunnan Province, China from 2007 to 2013 
Malaria Journal  2015;14:47.
Artemisinin-based combination therapy (ACT) is the recommended first-line treatment of falciparum malaria in all endemic countries. Artemisinin resistance in Plasmodium falciparum has been confirmed in the Greater Mekong subregion (GMS). Dihydroartemisinin-piperaquine (DAPQ) is the most commonly used ACT in China. To understand the DAPQ sensitivity of P. falciparum, DAPQ resistance was monitored in vivo along the China-Myanmar border from 2007 to 2013.
Eligible patients with mono-infections of P. falciparum were recruited to this study after obtaining full informed consent. DAPQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 42 days. Polymerase chain reaction (PCR) was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome was assessed according to the WHO recommended standards.
243 patients were completed valid follow-up. The fever clearance time (FCT) and asexual parasite clearance times (APCT) were, respectively, 36.5 ± 10.9 and 43.5 ± 11.8 hours, and there was an increasing trend of both FCT (F = 268.41, P < 0.0001) and APCT (F = 88.6, P < 0.0001) from 2007 to 2013. Eight (3.3%, 95% confidence interval, 1.4–6.4%) patients present parasitaemia on day three after medication; however they were spontaneous cure on day four. 241 (99.2%; 95% CI, 97.1–99.9%) of the patients were adequate clinical and parasitological response (ACPR) and the proportions of ACPR had not changed significantly from 2007 to 2013 (X2 = 2.81, P = 0.7288).
In terms of efficacy, DAPQ is still an effective treatment for falciparum malaria. DAPQ sensitivity in P. falciparum had not significantly changed along the China-Myanmar border of Yunnan Province, China. However more attentions should be given to becoming slower fever and parasite clearance.
PMCID: PMC4333884  PMID: 25652213
Plasmodium falciparum; Dihydroartemisinin-piperaquine; In vivo test; Resistance; China-Myanmar border
4.  Hydroxymethylation at Gene Regulatory Regions Directs Stem/Early Progenitor Cell Commitment during Erythropoiesis 
Cell reports  2013;6(1):231-244.
Hematopoietic stem cell differentiation involves the silencing of self-renewal genes and induction of a specific transcriptional program. Identification of multiple covalent cytosine modifications raises the question of how these derivatized bases influence stem cell commitment. Using a replicative primary human hematopoietic stem/progenitor cell differentiation system, we demonstrate dynamic changes of 5-hydroxymethylcytosine (5-hmC) during stem cell commitment and differentiation to the erythroid line-age. Genomic loci that maintain or gain 5-hmC density throughout erythroid differentiation contain binding sites for erythroid transcription factors and several factors not previously recognized as erythroid-specific factors. The functional importance of 5-hmC was demonstrated by impaired erythroid differentiation, with augmentation of myeloid potential, and disrupted 5-hmC patterning in leukemia patient-derived CD34+ stem/early progenitor cells with TET methylcytosine dioxygenase 2 (TET2) mutations. Thus, chemical conjugation and affinity purification of 5-hmC-enriched sequences followed by sequencing serve as resources for deciphering functional implications for gene expression during stem cell commitment and differentiation along a particular lineage.
PMCID: PMC3976649  PMID: 24373966
5.  A Re-evaluation of CD22 Expression by Human Lung Cancer 
Cancer research  2014;74(1):263-271.
CD22 is a transmembrane glycoprotein expressed by mature B cells. It inhibits signal transduction by the B cell receptor and its co-receptor CD19. Recently it was reported that most human lung cancer cells and cell lines express CD22 making it an important new lung cancer therapeutic target (Can Res 72:5556, 2012). The objective of our studies was to independently validate these results with the goal of testing the efficacy of our CD22 immunotoxins on lung cancer cell lines. As determined by qRT-PCR analysis, we found that levels of CD22 mRNA in a panel of human lung cancer cell lines were 200–60,000- fold lower than those observed in the human CD22+ Burkitt’s lymphoma cells, Daudi. Using flow cytometry with a panel of CD22 monoclonal antibodies and Western blot analyses, we could not detect surface or intracellular expression of CD22 protein in a panel of lung cancer cell lines. In addition, the in vitro proliferation of the lung tumor cell lines was not affected by CD22 antibodies or our highly potent anti-CD22 immunotoxin. By contrast, CD22+ Daudi cells expressed high levels of CD22 mRNA and protein and were sensitive to our CD22 immunotoxin. Importantly, primary non-small cell lung cancers from over 250 patient specimens did not express detectable levels of CD22 protein as assessed by immunohistochemistry. We conclude that CD22 is not expressed at measurable levels on the surface of lung cancer cells and that these cells can not be killed by anti-CD22 immunotoxins.
PMCID: PMC3903042  PMID: 24395821
lung cancer; CD22 expression
6.  Epigenetic and metabolic regulation of breast cancer stem cells*  
Breast cancer has a relatively high mortality rate in women due to recurrence and metastasis. Increasing evidence has identified a rare population of cells with stem cell-like properties in breast cancer. These cells, termed cancer stem cells (CSCs), which have the capacity for self-renewal and differentiation, contribute significantly to tumor progression, recurrence, drug resistance and metastasis. Clarifying the mechanisms regulating breast CSCs has important implications for our understanding of breast cancer progression and therapeutics. A strong connection has been found between breast CSCs and epithelial mesenchymal transition (EMT). In addition, recent studies suggest that the maintenance of the breast CSC phenotype is associated with epigenetic and metabolic regulation. In this review, we focus on recent discoveries about the connection between EMT and CSC, and advances made in understanding the roles and mechanisms of epigenetic and metabolic reprogramming in controlling breast CSC properties.
PMCID: PMC4288940  PMID: 25559951
Cancer stem cells (CSCs); Epithelial mesenchymal transition (EMT); Epigenetic modification; Metabolic reprogramming; Breast cancer
7.  Peripheral Blood Mononuclear Cell Traffic Plays a Crucial Role in Mother-to-Infant Transmission of Hepatitis B Virus 
The role of peripheral blood mononuclear cells (PBMCs) in HBV intrauterine infection is not fully defined. Particularly the origin of PBMCs in HBV-infected neonates remains to be addressed. We carried out a population-based nested case-control study by enrolling 312 HBsAg-positive mothers and their babies. PBMC HBV DNA as well as serum HBsAg and HBV DNA was tested in cohort entry samples. Totally, 45.5% (142/312) of the newborns were found to be infected with HBV in perinatal transmission. 119 mother-infant pairs were identified to be different in the genetic profile of maternal and fetal PBMCs by AS-PCR and hemi-nested PCR. Among them, 57.1% (68/119) of the maternal PBMCs in index cases were positive for HBV DNA while 83.8% (57/68) of the HBV DNA positive maternal PBMCs passed the placental barrier and entered the fetus. Furthermore, maternal PBMC HBV infection was significantly associated with newborn infants HBV infection. PBMC traffic from mother to fetus resulted in a 9.5-fold increased risk of HBV infection in PBMC HBV DNA positive newborn infants. These data indicate that maternal PBMCs infected with HBV contribute to HBV intrauterine infection of newborn infants via PBMC traffic from mother to fetus.
PMCID: PMC4323366
Hepatitis B virus; mother-to-infant transmission; peripheral blood mononuclear cell; fetomaternal cellular traffic.
8.  APOC3 may not be a predictor of risk of ischemic vascular disease in the Chinese population 
F1000Research  2014;3:270.
The genetic background of ischemic vascular disease is actively being explored. Several studies have shown that inhibition of APOC3 significantly reduces plasma levels of apolipoprotein C3 and triglycerides. Recently, the TG and HDL Working Group and Jørgensen et al. reported that loss-of-function mutations in APOC3 are associated with decreased triglyceride levels and a reduced risk of ischemic vascular disease in European and African individuals. We performed a replication study in 4470 Chinese participants. The coding regions of APOC3 were amplified and re-sequenced. However, only synonymous and intronic variants with no functional consequences were identified. None of the loss-of-function mutations reported in European and African individuals were observed. Therefore, APOC3 may not be an ideal predictor for risk of ischemic vascular disease in the Chinese population.
PMCID: PMC4304213  PMID: 25653838
ischemic vascular disease; risk prediction; APOC3
9.  Osteoblast inhibition by chemokine cytokine ligand3 in myeloma-induced bone disease 
Cancer Cell International  2014;14(1):132.
Multiple myeloma is a hematologic malignancy characterized by the accumulation of monoclonal plasma cells in the bone marrow. A common manifestation of the disease is myeloma bone disease (MBD), which is caused by increased osteoclastic bone resorption and decreased bone formation. The chemokine cytokine ligand 3 (CCL3) is a pro-inflammatory protein and chemokine that stimulates osteoclasts in MBD. However, little is known about the effect of CCL3 on osteoblasts (OB).
The OBs are induced from patients with MBD and healthy donors, cultured in vitro, and identified by histochemistry. The effects of CCL3 and CCL3 antibody on the OBs in vitro are observed. The CCL3 receptor (CCR1), osteocalcin (OCN), runt-related transcription factor 2 (Runx2), and osterix (Osx) are detected using flow cytometry, enzyme-linked immunosorbent assay, and real-time PCR.
Proliferation and osteogenic potential of the OB in patients with MBD are suppressed. Moreover, the CCR1 expression is significantly higher in patients with MBD than in normal controls. The OCN level, quantity of calcium nodules, and Runx2 and Osx levels decrease after CCL3 stimulation, which indicates that CCL3 inhibits OB function. Furthermore, CCL3 antibody partially restores OB activity through the upregulation of the OCN, Runx2, and Osx.
CCL3 contributes to the OB/OC imbalance by inhibiting OB differentiation and function in MBD.
PMCID: PMC4268854  PMID: 25520585
Chemokine cytokine ligand 3; Myeloma bone disease; Osteoblast; Runx2; Osterix
10.  Reduction of facial pigmentation of melasma by topical lignin peroxidase: A novel fast-acting skin-lightening agent 
The aim of the present study was to evaluate the efficacy and safety of lignin peroxidase (LIP) as a skin-lightening agent in patients with melasma. A self-controlled clinical study was performed in 31 women who had melasma on both sides of the face. This study involved 8 weeks of a full-face product treatment. The skin color was measured at days 0, 7, 28 and 56 using a chromameter on the forehead and cheeks. Standardized digital photographic images of each side of the face of all subjects were captured by a complexion analysis system. Clinical scores of the pigmentation were determined by two dermatologists. After using the LIP whitening lotion for 7 days, the luminance (L*) values of the melasma and the normal skin were significantly increased from baseline. The L* values continued to increase at days 28 and 56. The melasma area severity index (MASI) score was statistically decreased after 28 days of treatment. No treatment-related adverse events were observed. LIP whitening lotion was able to eliminate the skin pigmentation after 7 days of treatment, and provides a completely innovative approach to rapid skin lightening. The LIP whitening lotion exhibited good compatibility and was well tolerated.
PMCID: PMC4280934  PMID: 25574195
lignin peroxidase; melanin; melasma; skin lightening; emulsions; statistics
11.  Nosocomial Infection in Adult Admissions with Hematological Malignancies Originating from Different Lineages: A Prospective Observational Study 
PLoS ONE  2014;9(11):e113506.
Nosocomial infection (NI) causes prolonged hospital stays, increased healthcare costs, and higher mortality among patients with hematological malignancies (HM). However, few studies have compared the incidence of NI according to the HM lineage.
To compare the incidence of NI according to the type of HM lineage, and identify the risk factors for NI.
This prospective observational study monitored adult patients with HM admitted for >48 hours to the General Hospital of the People's Liberation Army during 2010–2013. Attack rates and incidences of NI were compared, and multivariable logistic regression was used to control for confounding effects.
This study included 6,613 admissions from 1,922 patients. During these admissions, 1,023 acquired 1,136 NI episodes, with an attack rate of 15.47% and incidence of 9.6‰ (95% CI: 9.1–10.2). Higher rates and densities of NIs were observed among myeloid neoplasm (MN) admissions, compared to lymphoid neoplasm (LN) admissions (28.42% vs. 11.00%, P<0.001 and 11.4% vs. 8.4‰, P<0.001). NI attack rates in acute myeloid leukemia (AML) and myelodysplastic/myeloproliferative neoplasm (MDS/MPN) were higher than those in MDS (30.69% vs. 20.19%, P<0.001; 38.89% vs. 20.19%, P = 0.003). Attack rates in T/NK-cell neoplasm and B-cell neoplasm were higher than those in Hodgkin lymphoma (15.04% vs. 3.65%; 10.94% vs. 3.65%, P<0.001). Multivariable regression analysis indicated prolonged hospitalization, presence of central venous catheterization, neutropenia, current stem cell transplant, infection on admission, and old age were independently associated with higher NI incidence. After adjusting for these factors, MN admissions still had a higher risk of infection (odds ratio 1.34, 95% CI: 1.13–1.59, P<0.001).
Different NI attack rates were observed for HM from different lineages, with MN lineages having a higher attack rate and incidence than LN lineages. Special attention should be paid to MN admissions, especially AML and MDS/MPN admissions, to control NI incidence.
PMCID: PMC4240653  PMID: 25415334
12.  A rare case of extra-adrenal pheochromocytoma localized to the ovary and detected via abdominal computed tomography angiography 
Oncology Letters  2014;9(2):774-776.
Extra-adrenal pheochromocytomas are rare tumors that originate from the chromaffin tissue of the sympathetic nervous system. Ovarian extra-adrenal pheochromocytoma is even more rare. The present study reports a rare case of an extra-adrenal pheochromocytoma that was localized to the right ovary, but was gynecologically asymptomatic. Computed tomography angiography (CTA) detected the tumor and indicated that it was well defined, highly vascularized and obtained its blood supply from the right ovarian artery. This is the second case of ovarian extra-adrenal pheochromocytoma reported in the literature, and the first description of the CTA manifestations in the ovary. Gynecologists and radiologists should consider the possibility that an ovarian mass could be an extra-adrenal pheochromocytoma, which would allow time to prepare appropriately for the surgical removal of the mass.
PMCID: PMC4301517  PMID: 25621050
pheochromocytoma; paraganglioma; extra-adrenal; ovary; computed tomography angiography
13.  Suppression of histone deacetylation promotes the differentiation of human pluripotent stem cells towards neural progenitor cells 
BMC Biology  2014;12(1):95.
Emerging studies of human pluripotent stem cells (hPSCs) raise new prospects for neurodegenerative disease modeling and cell replacement therapies. Therefore, understanding the mechanisms underlying the commitment of neural progenitor cells (NPCs) is important for the application of hPSCs in neurodegenerative disease therapies. It has been reported that epigenetic modifications of histones play important roles in neural differentiation, but the exact mechanisms in regulating hPSC differentiation towards NPCs are not fully elucidated.
We demonstrated that suppression of histone deacetylases (HDACs) promoted the differentiation of hPSCs towards NPCs. Application of HDAC inhibitors (HDACi) increased the expression of neuroectodermal markers and enhanced the neuroectodermal specification once neural differentiation was initiated, thereby leading to more NPC generation. Similarly, the transcriptome analysis showed that HDACi increased the expression levels of ectodermal markers and triggered the NPC differentiation related pathways, while decreasing the expression levels of endodermal and mesodermal markers. Furthermore, we documented that HDAC3 but not HDAC1 or HDAC2 was the critical regulator participating in NPC differentiation, and knockdown of HDAC3′s cofactor SMRT exhibited a similar effect as HDAC3 on NPC generation.
Our study reveals that HDACs, especially HDAC3, negatively regulate the differentiation of hPSCs towards NPCs at an earlier stage of neural differentiation. Moreover, HDAC3 might function by forming a repressor complex with its cofactor SMRT during this process. Thus, our findings uncover an important epigenetic mechanism of HDAC3 in the differentiation of hPSCs towards NPCs.
Electronic supplementary material
The online version of this article (doi:10.1186/s12915-014-0095-z) contains supplementary material, which is available to authorized users.
PMCID: PMC4254204  PMID: 25406762
Histone deacetylation; Histone deacetylase inhibitors; Neuroectodermal specification; Neural progenitor cells; Human pluripotent stem cells
14.  Planar integrated metasurfaces for highly-collimated terahertz quantum cascade lasers 
Scientific Reports  2014;4:7083.
We report planar integration of tapered terahertz (THz) frequency quantum cascade lasers (QCLs) with metasurface waveguides that are designed to be spoof surface plasmon (SSP) out-couplers by introducing periodically arranged SSP scatterers. The resulting surface-emitting THz beam profile is highly collimated with a divergence as narrow as ~4° × 10°, which indicates a good waveguiding property of the metasurface waveguide. In addition, the low background THz power implies a high coupling efficiency for the THz radiation from the laser cavity to the metasurface structure. Furthermore, since all the structures are in-plane, this scheme provides a promising platform where well-established surface plasmon/metasurface techniques can be employed to engineer the emitted beam of THz QCLs controllably and flexibly. More importantly, an integrated active THz photonic circuit for sensing and communication applications could be constructed by incorporating other optoelectronic devices such as Schottky diode THz mixers, and graphene modulators and photodetectors.
PMCID: PMC4235285  PMID: 25403796
15.  APOC3 may not be a predictor of risk of ischemic vascular disease in the Chinese population 
F1000Research  2014;3:270.
The genetic background of ischemic vascular disease is actively being explored. Several studies have shown that inhibition of APOC3 significantly reduces plasma levels of apolipoprotein C3 and triglycerides. Recently, the TG and HDL Working Group and Jørgensen et al. reported that loss-of-function mutations in APOC3 are associated with decreased triglyceride levels and a reduced risk of ischemic vascular disease in European and African individuals. We performed a replication study in 4470 Chinese participants. The coding regions of APOC3 were amplified and re-sequenced. However, only synonymous and intronic variants with no functional consequences were identified. None of the loss-of-function mutations reported in European and African individuals were observed. Therefore, APOC3 may not be an ideal predictor for risk of ischemic vascular disease in the Chinese population.
PMCID: PMC4304213  PMID: 25653838
ischemic vascular disease; risk prediction; APOC3
16.  Long-term efficacy and safety of E/C/F/TDF vs EFV/FTC/TDF and ATV+RTV+FTC/TDF in HIV-1-infected treatment-naïve subjects ≥50 years 
Journal of the International AIDS Society  2014;17(4Suppl 3):19767.
In high-income countries, ≥30% of HIV-infected patients are ≥50 years (yrs) old (UNAIDS 2013). In two phases, three clinical trials (Studies 102 and 103) elvitegravir/cobicistat/emtricitabine/tenofovir DF (E/C/F/TDF; STB) had non-inferior efficacy and favourable safety vs efavirenz/emtricitabine/tenofovir DF (EFV/FTC/TDF; ATR) or ritonavir-boosted atazanavir (ATV+RTV)+FTC/TDF (TVD) in HIV-infected, treatment-naïve subjects at Week 144. The efficacy and safety of STB in subjects < or ≥50 yrs is described.
Materials and Methods
Post hoc analysis of efficacy, tolerability and safety in subjects < or ≥50 yrs at Week 144.
Subjects ≥50 yrs in Study 102: STB: 14% (49/348), ATR: 16% (56/352); in Study 103: STB: 14% (48/353), ATV+RTV+TVD: 14% (48/355). Efficacy, safety and tolerability by age and study endpoint are shown in Table 1. Regardless of age, STB had robust efficacy at Week 144 with similar virologic outcomes vs ATR or ATV+RTV+TVD. Discontinuations (DC) due to AE on STB were similar to the comparators, most occurred by Week 48. Median changes in eGFR on STB were similar by age; DC with renal PRT was rare [STB: 4 (0.6%); ATV: 3 (0.8%); ATR: 0], 2 and 1 in ≥50 yrs old strata, respectively.
STB compared to ATR or ATV+RTV+TVD, is an efficacious, well-tolerated and safe regimen for HIV-1-infected, treatment-naïve subjects
PMCID: PMC4225383  PMID: 25397511
BioMed Research International  2014;2014:319351.
Conventional methods to determine the efficacy of bacteriophage (phage) for biocontrol of E. coli require several days, due to the need to culture bacteria. Furthermore, cell surface-attached phage particles may lyse bacterial cells during experiments, leading to an overestimation of phage activity. DNA-based real-time quantitative polymerase chain reaction (qPCR) is a fast, sensitive, and highly specific means of enumerating pathogens. However, qPCR may underestimate phage activity due to its inability to distinguish viable from nonviable cells. In this study, we evaluated the suitability of propidium monoazide (PMA), a microbial membrane-impermeable dye that inhibits amplification of extracellular DNA and DNA within dead or membrane-compromised cells as a means of using qPCR to identify only intact E. coli cells that survive phage exposure. Escherichia coli O157:H7 strain R508N and 4 phages (T5-like, T1-like, T4-like, and O1-like) were studied. Results compared PMA-qPCR and direct plating and confirmed that PMA could successfully inhibit amplification of DNA from compromised/damaged cells E. coli O157:H7. Compared to PMA-qPCR, direct plating overestimated (P < 0.01) phage efficacy as cell surface-attached phage particles lysed E. coli O157:H7 during the plating process. Treatment of samples with PMA in combination with qPCR can therefore be considered beneficial when assessing the efficacy of bacteriophage for biocontrol of E. coli O157:H7.
PMCID: PMC4233675  PMID: 25530959
Rice false smut caused by Villosiclava virens is an economically important disease of grains worldwide. The genetic diversity of 153 isolates from six fields located in Wuhan (WH), Yichang Wangjia (YCW), Yichang Yaohe (YCY), Huanggang (HG), Yangxin (YX), and Jingzhou (JZ) in Hubei province of China were phylogenetically analyzed to evaluate the influence of environments and rice cultivars on the V. virens populations. Isolates (43) from Wuhan were from two rice cultivars, Wanxian 98 and Huajing 952, while most of the other isolates from fields YCW, YCY, HG, YX, and JZ originated from different rice cultivars with different genetic backgrounds. Genetic diversity of isolates was analyzed using random amplified polymorphic DNA (RAPD) and single-nucleotide polymorphisms (SNP). The isolates from the same cultivars in Wuhan tended to group together, indicating that the cultivars had an important impact on the fungal population. The 110 isolates from individual fields tended to cluster according to geographical origin. The values of Nei's gene diversity (H) and Shannon's information index (I) showed that the genetic diversity among isolates was higher between than within geographical populations. Furthermore, mean genetic distance between groups (0.006) was higher than mean genetic distance within groups (0.0048) according to MEGA 5.2. The pairwise population fixation index (FST) values also showed significant genetic differentiation between most populations. Higher genetic similarity of isolates from individual fields but different rice cultivars suggested that the geographical factor played a more important role in the selection of V. virens isolates than rice cultivars. This information could be used to improve the management strategy for rice false smut by adjusting the cultivation measures, such as controlling fertilizer, water, and planting density, in the rice field to change the microenvironment.
PMCID: PMC3993286  PMID: 24584249
Neurobiology of aging  2013;34(11):2647-2658.
Mcl-1 is an anti-apoptotic member of the Bcl-2 family that modulates apoptosis-related signaling pathways and promotes cell survival. We have previously demonstrated a reduction of Mcl-1 expression in aging cochleae. To investigate whether restoring Mcl-1 expression would reduce aging-related cochlear degeneration, we developed a rat model of Mcl-1 overexpression. A plasmid encoding human Mcl-1/enhanced green fluorescent protein was applied to the round window of the cochlea. This in vivo treatment transfected both the sensory and supporting cells of the cochlear sensory epithelium and enhanced Mcl-1 expression at both the mRNA and the protein level. The upregulation of Mcl-1 expression reduced the progression of age-related cochlear dysfunction and sensory cell death. Furthermore, the transfection of Mcl-1 exerted its protective effect by suppressing cochlear apoptosis at the mitochondrial level. This study demonstrates that the genetic modulation of Mcl-1 expression reduces the progression of age-related cochlear degeneration.
PMCID: PMC3742618  PMID: 23790646
Mcl-1; gene delivery; cochlea; aging; intervention; hair cells; rat
Recurrent metastatic melanoma provides a unique opportunity to analyze disease evolution in metastatic cancer. Here, we followed 8 patients with an unusually prolonged history of metastatic melanoma, who developed a total of 26 recurrences over several years. Cell lines derived from each metastasis were analyzed by comparative genomic hybridization and global transcript analysis. We observed that conserved, patient-specific characteristics remain stable in recurrent metastatic melanoma even after years and several recurrences. Differences among individual patients exceeded within-patient lesion variability, both at the DNA copy number (p<0.001) and RNA gene expression level (p<0.001). Conserved patient-specific traits included expression of several cancer/testis antigens and the c-kit proto-oncogene throughout multiple recurrences. Interestingly, subsequent recurrences of different patients did not display consistent or convergent changes toward a more aggressive disease phenotype. Finally, sequential recurrences of the same patient did not descend progressively from each other, as irreversible mutations, such as homozygous deletions were frequently not inherited from previous metastases. This study suggests that the late evolution of metastatic melanoma, which dramatically turns an indolent disease into a lethal phase, is prone to preserve case-specific traits over multiple recurrences and occurs through a series of random events that do not follow a consistent step-wise process.
PMCID: PMC3989423  PMID: 24270663
Scientific Reports  2014;4:6847.
This work presents a method for synthesis of high-yield, uniform and band gap tunable Zn2SnO4 nanocubes. These nanocubes can be further self-assembled into a series of novel nanofilms with tunable optical band gaps from 3.54 to 3.18 eV by simply increasing the heat treatment temperature. The Zn2SnO4 nanocube-nanofilm based device has been successfully fabricated and presents obviously higher photocurrent, larger photocurrent to dark current ratio than the previously reported individual nanostructure-based UV-light photodetectors, and could be used in high performance photodetectors, solar cells, and electrode materials for Li-ion battery.
PMCID: PMC4213775  PMID: 25355096
Nature Communications  2014;5:5110.
Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology.
Cassava is a major source of food in tropical and subtropical regions. Here the authors sequence the genomes of wild and domesticated cassava varieties and identify genes that have been selected for and against during the evolution and domestication of this economically important crop.
PMCID: PMC4214410  PMID: 25300236
PLoS ONE  2014;9(10):e110825.
Exposure to electromagnetic field (EMF) emitted by mobile phone and other machineries concerns half the world’s population and raises the problem of their impact on human health. The present study aims to explore the effects of electromagnetic field exposures on sleep quality and sleep duration among workers from electric power plant.
A cross-sectional study was conducted in an electric power plant of Zhejiang Province, China. A total of 854 participants were included in the final analysis. The detailed information of participants was obtained by trained investigators using a structured questionnaire, which including socio-demographic characteristics, lifestyle variables, sleep variables and electromagnetic exposures. Physical examination and venous blood collection were also carried out for every study subject.
After grouping daily occupational electromagnetic exposure into three categories, subjects with long daily exposure time had a significantly higher risk of poor sleep quality in comparison to those with short daily exposure time. The adjusted odds ratios were 1.68 (95%CI: 1.18, 2.39) and 1.57 (95%CI: 1.10, 2.24) across tertiles. Additionally, among the subjects with long-term occupational exposure, the longer daily occupational exposure time apparently increased the risk of poor sleep quality (OR (95%CI): 2.12 (1.23∼3.66) in the second tertile; 1.83 (1.07∼3.15) in the third tertile). There was no significant association of long-term occupational exposure duration, monthly electric fee or years of mobile-phone use with sleep quality or sleep duration.
The findings showed that daily occupational EMF exposure was positively associated with poor sleep quality. It implies EMF exposure may damage human sleep quality rather than sleep duration.
PMCID: PMC4207748  PMID: 25340654
PLoS ONE  2014;9(10):e111045.
Esophageal squamous cell carcinoma (ESCC) is a common cancer with poor prognosis. In order to identify useful biomarkers for accurately classifying prognostic risks for ESCC patients, we examined the expression of six proteins by immunohistochemistry (IHC) in 590 paraffin-embedded ESCC samples. The candidate proteins include p53, EGFR, c-KIT, TIMP1 and PI3K-p110α reported to be altered in ESCC tissues as well as another important component of PI3K, PI3K-p85α. Of the six proteins tested, p53, EGFR, c-KIT, TIMP1 and PI3K-p85α were detected with high expression in 43.0%, 36.6%, 55.9%, 70.7% and 57.1% of tumors, respectively. Significant associations were found between high expression of PI3K-p85α, EGFR and p53 and poor prognosis (P = 0.00111; 0.00001; 0.00426). Applying these three proteins as an IHC panel could divide patients into different subgroups (P<0.000001). Multivariate cox regression analysis indicated that the three-protein panel was an independent prognostic factor with very high statistical significance (HR = 2.090, 95% CI: 1.621–2.696, P = 0.00000001). The data suggest that the three-protein panel of PI3K-p85α, EGFR and p53 is an important candidate biomarker for the prognosis of patients with ESCC.
PMCID: PMC4206450  PMID: 25337715
Materials  2014;7(1):1-15.
Recently, gradient performance and fidelity has become of increasing interest, as the fidelity of the magnetic resonance (MR) image is somewhat dependent on the fidelity of the gradient system. In particular, for high fidelity non-Cartesian imaging, due to non-fidelity of the gradient system, it becomes necessary to know the actual k-space trajectory as opposed to the requested trajectory. In this work we show that, by considering the gradient system as a linear time-invariant system, the gradient impulse response function (GIRF) can be reliably measured to a relatively high degree of accuracy with a simple setup, using a small phantom and a series of simple experiments. It is shown experimentally that the resulting GIRF is able to predict actual gradient performance with a high degree of accuracy. The method captures not only the frequency response but also gradient timing errors and artifacts due to mechanical vibrations of the gradient system. Some discussion is provided comparing the method presented here with other analogous methods, along with limitations of these methods.
PMCID: PMC4204731  PMID: 25343017
magnetic resonance imaging (MRI); gradients; impulse response function

Results 1-25 (353)