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1.  Association of MICA gene polymorphisms with liver fibrosis in schistosomiasis patients in the Dongting Lake region 
Major histocompatibility complex class I chain-related A (MICA) is a highly polymorphic gene located within the MHC class I region of the human genome. Expressed as a cell surface glycoprotein, MICA modulates immune surveillance by binding to its cognate receptor on natural killer cells, NKG2D, and its genetic polymorphisms have been recently associated with susceptibility to some infectious diseases. We determined whether MICA polymorphisms were associated with the high rate of Schistosoma parasitic worm infection or severity of disease outcome in the Dongting Lake region of Hunan Province, China. Polymerase chain reaction-sequence specific priming (PCR-SSP) and sequencing-based typing (SBT) were applied for high-resolution allele typing of schistosomiasis cases (N = 103, age range = 36.2-80.5 years, 64 males and 39 females) and healthy controls (N = 141, age range = 28.6-73.3 years, 73 males and 68 females). Fourteen MICA alleles and five short-tandem repeat (STR) alleles were identified among the two populations. Three (MICA*012:01/02, MICA*017 and MICA*027) showed a higher frequency in healthy controls than in schistosomiasis patients, but the difference was not significantly correlated with susceptibility to S. japonicum infection (Pc > 0.05). In contrast, higher MICA*A5 allele frequency was significantly correlated with advanced liver fibrosis (Pc < 0.05). Furthermore, the distribution profile of MICA alleles in this Hunan Han population was significantly different from those published for Korean, Thai, American-Caucasian, and Afro-American populations (P < 0.01), but similar to other Han populations within China (P > 0.05). This study provides the initial evidence that MICA genetic polymorphisms may underlie the severity of liver fibrosis occurring in schistosomiasis patients from the Dongting Lake region.
PMCID: PMC3854198  PMID: 22370708
Schistosoma japonicum; MICA; NKG2D; Gene polymorphism; Liver fibrosis
2.  A Small Physiological Electric Field Mediated Responses of Extravillous Trophoblasts Derived from HTR8/SVneo Cells: Involvement of Activation of Focal Adhesion Kinase Signaling 
PLoS ONE  2014;9(3):e92252.
Moderate invasion of trophoblast cells into endometrium is essential for the placental development and normal pregnancy. Electric field (EF)-induced effects on cellular behaviors have been observed in many cell types. This study was to investigate the effect of physiological direct current EF (dc EF) on cellular responses such as elongation, orientation and motility of trophoblast cells. Immortalized first trimester extravillous trophoblast cells (HTR-8/SVneo) were exposed to the dc EF at physiological magnitude. Cell images were recorded and analyzed by image analyzer. Cell lysates were used to detect protein expression by Western blot. Cultured in the dc EFs the cells showed elongation, orientation and enhanced migration rate compared with non-EF stimulated cells at field strengths of 100 mV/mm to 200 mV/mm. EF exposure increased focal adhesion kinase (FAK) phosphorylation in a time-dependent manner and increased expression levels of MMP-2. Pharmacological inhibition of FAK impaired the EF-induced responses including motility and abrogated the elevation of MMP-2 expression. However, the expression levels of integrins like integrin α1, α5, αV and β1 were not affected by EF stimulation. Our results demonstrate the importance of FAK activation in migration/motility of trophobalst cells driven by EFs. In addition, it raises the feasibility of using applied EFs to promote placentation through effects on trophoblast cells.
PMCID: PMC3958492  PMID: 24643246
3.  Characterization of Maltocin P28, a Novel Phage Tail-Like Bacteriocin from Stenotrophomonas maltophilia 
Applied and Environmental Microbiology  2013;79(18):5593-5600.
Stenotrophomonas maltophilia is an important global opportunistic pathogen for which limited therapeutics are available because of the emergence of multidrug-resistant strains. A novel bacteriocin, maltocin P28, which is produced by S. maltophilia strain P28, may be the first identified phage tail-like bacteriocin from S. maltophilia. Maltocin P28 resembles a contractile but nonflexible phage tail structure based on electron microscopy, and it is sensitive to trypsin, proteinase K, and heat. SDS-PAGE analysis of maltocin P28 revealed two major protein bands of approximately 43 and 20 kDa. The N-terminal amino acid residues of these two major subunits were sequenced, and the maltocin P28 gene cluster was located on the S. maltophilia P28 chromosome. Our sequence analysis results indicate that this maltocin gene cluster consists of 23 open reading frames (ORFs), and that its gene organization is similar to that of the P2 phage genome and R2 pyocin gene cluster. ORF17 and ORF18 encode the two major structural proteins, which correspond to gpFI (tail sheath) and gpFII (tail tube) of P2 phage, respectively. We found that maltocin P28 had bactericidal activity against 38 of 81 tested S. maltophilia strains. Therefore, maltocin P28 is a promising therapeutic substitute for antibiotics for S. maltophilia infections.
PMCID: PMC3754179  PMID: 23835182
4.  Influenza Virus Drug Resistance: A Time-Sampled Population Genetics Perspective 
PLoS Genetics  2014;10(2):e1004185.
The challenge of distinguishing genetic drift from selection remains a central focus of population genetics. Time-sampled data may provide a powerful tool for distinguishing these processes, and we here propose approximate Bayesian, maximum likelihood, and analytical methods for the inference of demography and selection from time course data. Utilizing these novel statistical and computational tools, we evaluate whole-genome datasets of an influenza A H1N1 strain in the presence and absence of oseltamivir (an inhibitor of neuraminidase) collected at thirteen time points. Results reveal a striking consistency amongst the three estimation procedures developed, showing strongly increased selection pressure in the presence of drug treatment. Importantly, these approaches re-identify the known oseltamivir resistance site, successfully validating the approaches used. Enticingly, a number of previously unknown variants have also been identified as being positively selected. Results are interpreted in the light of Fisher's Geometric Model, allowing for a quantification of the increased distance to optimum exerted by the presence of drug, and theoretical predictions regarding the distribution of beneficial fitness effects of contending mutations are empirically tested. Further, given the fit to expectations of the Geometric Model, results suggest the ability to predict certain aspects of viral evolution in response to changing host environments and novel selective pressures.
Author Summary
In recent years, considerable attention has been given to the evolution of drug resistance in the influenza A H1N1 strain. As a major annual cause of morbidity and mortality, combined with the rapid global spread of drug resistance, influenza remains as one of the most important global health concerns. Our work here focuses on a novel multi-faceted population-genetic approach utilizing unique whole-genome multi-time point experimental datasets in both the presence and absence of drug treatment. In addition, we present novel theoretical results and two newly developed and widely applicable statistical methodologies for utilizing time-sampled data – with a focus on distinguishing the relative contribution of genetic drift from that of positive and purifying selection. Results illustrate the available mutational paths to drug resistance, and offer important insights in to the mode and tempo of adaptation in a viral population.
PMCID: PMC3937227  PMID: 24586206
5.  Mesenteric Lymph Drainage Alleviates Acute Kidney Injury Induced by Hemorrhagic Shock without Resuscitation 
The Scientific World Journal  2014;2014:720836.
This study aimed to investigate the effect of mesenteric lymph drainage on the acute kidney injury induced by hemorrhagic shock without resuscitation. Eighteen male Wistar rats were randomly divided into sham, shock, and drainage groups. The hemorrhagic shock model (40 mmHg, 3 h) was established in shock and drainage groups; mesenteric lymph drainage was performed from 1 h to 3 h of hypotension in the drainage group. The results showed that renal tissue damage occurred; the levels of urea, creatinine, and trypsin in the plasma as well as intercellular adhesion molecule-1 (ICAM-1), receptor of advanced glycation end-products (RAGE), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), lactic acid (LA), and 2,3-DPG in the renal tissue were increased in the shock group after 3 h of hypotension. Mesenteric lymph drainage lessened the following: renal tissue damage; urea and trypsin concentrations in the plasma; ICAM-1, RAGE, TNF-α, MDA, and LA levels in the renal tissue. By contrast, mesenteric lymph drainage increased the 2,3-DPG level in the renal tissue. These findings indicated that mesenteric lymph drainage could relieve kidney injury caused by sustained hypotension, and its mechanisms involve the decrease in trypsin activity, suppression of inflammation, alleviation of free radical injury, and improvement of energy metabolism.
PMCID: PMC3956641  PMID: 24723822
6.  Molecular Evidence of RNA Editing in Bombyx Chemosensory Protein Family 
PLoS ONE  2014;9(2):e86932.
Chemosensory proteins (CSPs) are small scavenger proteins that are mainly known as transporters of pheromone/odor molecules at the periphery of sensory neurons in the insect antennae and in the producing cells from the moth female pheromone gland.
Sequencing cDNAs of RNA encoding CSPs in the antennae, legs, head, pheromone gland and wings from five single individual adult females of the silkworm moth Bombyx mori showed that they differed from genomic sequences by subtle nucleotide replacement (RDD). Both intronless and intronic CSP genes expressed RDDs, although in different rates. Most interestingly, in our study the degree of RDDs in CSP genes were found to be tissue-specific. The proportion of CSP-RDDs was found to be significantly much higher in the pheromone gland. In addition, Western blot analysis of proteins in different tissues showed existence of multiple CSP protein variant chains particularly found in the pheromone gland. Peptide sequencing demonstrated the occurrence of a pleiad of protein variants for most of all BmorCSPs from the pheromone gland. Our findings show that RNA editing is an important feature in the expression of CSPs and that a high variety of RDDs is found to expand drastically thus altering the repertoire of CSP proteins in a tissue-specific manner.
PMCID: PMC3923736  PMID: 24551045
7.  Unusual chromatin structure associated with monoparalogous transcription of the Babesia bovis ves multigene family 
Rapid antigenic variation in Babesia bovis involves the variant erythrocyte surface antigen-1 (VESA1), a heterodimeric protein with subunits encoded by two branches of the ves multigene family. The ves1α and ves1β gene pair encoding VESA1a and 1b, respectively, are transcribed in a monoparalogous manner from a single locus of active ves transcription (LAT), just one of many quasi-palindromic ves loci. To determine whether this organization plays a role in transcriptional regulation, chromatin structure was first assessed. Limited treatment of isolated nuclei with micrococcal nuclease to assay nucleosomal patterning revealed a periodicity of 156–159 bp in both bulk chromatin and specific gene coding regions. This pattern also was maintained in the intergenic regions (IGr) of non-transcribed ves genes. In contrast, the LAT IGr adopts a unique pattern, yielding an apparent cluster of five closely-spaced hypersensitive sites flanked by regions of reduced nucleosomal occupancy. ves loci fall into three patterns of overall sensitivity to micrococcal nuclease or DNase I digestion, with only the LAT being consistently very sensitive. Non-transcribed ves genes are inconsistent in their sensitivity to the two enzymatic probes. Nonlinear DNA structure in chromatin was investigated to determine whether unique structure arising as a result of the quasi-palindromic nature of the LAT may effect transcriptional control. The in vitro capacity of ves IGr sequences to adopt stable higher-order DNA structure is demonstrated here, but the presence of such structure in vivo was not supported. Based upon these results a working model is proposed for the chromatin structural remodeling responsible for the sequential expression of ves multigene family members from divergently-organized loci.
PMCID: PMC3563878  PMID: 23178996
Antigenic variation; Babesia bovis; Chromatin remodeling; Chromatin structure; Nucleosome remodeling; Promoter structure; Transcription
8.  Suggestion of GLYAT gene underlying variation of bone size and body lean mass as revealed by a bivariate genome-wide association study 
Human genetics  2012;132(2):189-199.
Bone and muscle, two major tissue types of musculoskeletal system, have strong genetic determination. Abnormality in bone and/or muscle may cause musculoskeletal diseases such as osteoporosis and sarcopenia. Bone size phenotypes (BSPs), such as hip bone size (HBS), appendicular bone size (ABS), are genetically correlated with body lean mass (mainly muscle mass). However, the specific genes shared by these phenotypes are largely unknown. In this study, we aimed to identify the specific genes with pleiotropic effects on BSPs and appendicular lean mass (ALM).
We performed a bivariate genome-wide association study (GWAS) by analyzing ~690,000 SNPs in 1,627 unrelated Han Chinese adults (802 males and 825 females) followed by a replication study in 2,286 unrelated US Caucasians (558 males and 1728 females).
We identified 14 interesting single nucleotide polymorphisms (SNPs) that may contribute to variation of both BSPs and ALM, with p values <10−6 in discovery stage. Among them, the association of three SNPs (rs2507838, rs7116722, and rs11826261) in/near GLYAT (glycine-N-acyltransferase) gene was replicated in US Caucasians, with p values ranging from 1.89×10−3 to 3.71×10−4 for ALM-ABS, from 5.14×10−3 to 1.11×10−2 for ALM-HBS, respectively. Meta-analyses yielded stronger association signals for rs2507838, rs7116722, and rs11826261, with pooled p values of 1.68×10−8, 7.94×10−8, 6.80×10−8 for ALB-ABS and 1.22×10−4, 9.85×10−5, 3.96×10−4 for ALM-HBS, respectively. Haplotype allele ATA based on these three SNPs were also associated with ALM-HBS and ALM-ABS in both discovery and replication samples. Interestingly, GLYAT was previously found to be essential to glucose metabolism and energy metabolism, suggesting the gene’s dual role in both bone development and muscle growth.
Our findings, together with the prior biological evidence, suggest the importance of GLYAT gene in co-regulation of bone phenotypes and body lean mass.
PMCID: PMC3682481  PMID: 23108985
Bivariate GWAS; Bone size; Lean mass; GLYAT
9.  Steatocystoma multiplex as initial impression of non-small cell lung cancer with complete response to gefitinib 
Cutaneous metastases are rare and seldom present at the time of first diagnosis of cancer. Data from various studies show that 1-12% of lung cancer patients experience tumor spread to the skin. The scalp, chest, and abdomen are favored sites of skin metastases from lung cancers, but metastases to multiple skin sites in a single patient are rarely reported. We describe a 56-year-old lung adenocarcinoma patient, initially diagnosed with steatocystoma multiplex who responded well to gefitinib treatment. The efficacy of conventional chemotherapy for cutaneous metastases has been limited because of the relatively poor blood supply to the skin. It has been demonstrated that tyrosine kinase inhibitor (TKI), gefitinib, has significant clinical benefit in lung cancer patients with epidermal growth factor receptor (EGFR) mutation even in metastases to the brain. However, the therapeutic response to gefitinib in patients with skin metastases is seldom mentioned in the literature. We report one case of lung adenocarcinoma with multiple skin metastases that were successfully treated with gefitinib.
PMCID: PMC3937749  PMID: 24653640
Steatocystoma multiplex; lung cancer; adenocarcinoma; gefitinib
10.  Exercise Training Attenuates Hypertension and Cardiac Hypertrophy by Modulating Neurotransmitters and Cytokines in Hypothalamic Paraventricular Nucleus 
PLoS ONE  2014;9(1):e85481.
Regular exercise as an effective non-pharmacological antihypertensive therapy is beneficial for prevention and control of hypertension, but the central mechanisms are unclear. In this study, we hypothesized that chronic exercise training (ExT) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs) and restoring the neurotransmitters balance in the hypothalamic paraventricular nucleus (PVN) in young spontaneously hypertensive rats (SHR). In addition, we also investigated the involvement of nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in exercise-induced effects.
Methods and results
Moderate-intensity ExT was administrated to young normotensive Wistar-Kyoto (WKY) and SHR rats for 16 weeks. SHR rats had a significant increase in mean arterial pressure and cardiac hypertrophy. SHR rats also had higher levels of glutamate, norepinephrine (NE), phosphorylated IKKβ, NF-κB p65 activity, NAD(P)H oxidase subunit gp91phox, PICs and the monocyte chemokine protein-1 (MCP-1), and lower levels of gamma-aminobutyric acid (GABA) and interleukin-10 (IL-10) in the PVN. These SHR rats also exhibited higher renal sympathetic nerve activity (RSNA), and higher plasma levels of PICs, and lower plasma IL-10. However, ExT ameliorates all these changes in SHR rats.
These findings suggest that there are the imbalances between excitatory and inhibitory neurotransmitters and between pro- and anti-inflammatory cytokines in the PVN of SHR rats, which at least partly contributing to sympathoexcitation, hypertension and cardiac hypertrophy; chronic exercise training attenuates hypertension and cardiac hypertrophy by restoring the balances between excitatory and inhibitory neurotransmitters and between pro- and anti-inflammatory cytokines in the PVN; NF-κB and oxidative stress in the PVN may be involved in these exercise-induced effects.
PMCID: PMC3901693  PMID: 24482680
11.  The Prevalence of Nonalcoholic Fatty Liver Disease and Relationship with Serum Uric Acid Level in Uyghur Population 
The Scientific World Journal  2014;2014:393628.
Objective. To investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and the association of serum uric acid level with NAFLD in Uygur people, Xinjiang. Methods. A total of 2241 Uyghur persons (1214 males and 1027 females) were interviewed for physical checkups from 2011 to 2012. The clinical data of questionnaire survey, body mass index (BMI), abdominal circumference, blood pressure, blood sugar, blood lipid, and serum uric acid level were collected for analysis. Results. The prevalence rates of NAFLD determined by abdominal ultrasound examination and hyperuricemia were 43.9% and 8.4%, respectively. The persons with NAFLD had significantly higher serum uric acid levels than those without NAFLD (320 ± 88 versus 254 ± 80 μmol/L; P < 0.001). The prevalence rate of NAFLD was significantly higher in subjects with hyperuricemia than that in those without hyperuricemia (78.19% versus 40.83%; P < 0.001), and the prevalence rate increased with progressively higher serum uric acid levels (P < 0.001). Multiple regression analysis showed that hyperuricemia was associated with an increased risk of NAFLD (odds ratio (OR): 2.628, 95% confidence interval (CI): 1.608–4.294, and P < 0.001). Conclusion. Serum uric acid level was significantly associated with NAFLD, and the prevalence rate of NAFLD increased with progressively higher serum uric acid levels.
PMCID: PMC3910275  PMID: 24516367
12.  Norepinephrine inhibition in juvenile male zebra finches modulates adult song quality 
Brain research bulletin  2012;90:132-136.
During development, male zebra finches learn a song that they eventually use in courtship and defense of nest sites. Norepinephrine (NE) is important for learning and memory in vertebrates, and this neuromodulator and its receptors are present throughout the brain regions that control song learning and production. The present study used the neurotoxin N-(2-Chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP4) to reduce brain levels of NE in juvenile males. This manipulation inhibited the development of quality songs, with some birds producing syllables that were unusually long and/or contained frequencies that were predominantly higher than normal. These results suggest that NE is important for the acquisition of typical song.
PMCID: PMC3527669  PMID: 23160069
Songbird; development; DSP4; catecholamine
13.  Structure and spectroscopy of a bidentate bis-homocitrate dioxo-molybdenum(VI) complex: Insights relevant to the structure and properties of the FeMo-cofactor in nitrogenase 
Direct reaction of potassium molybdate (with natural abundance Mo or enriched with 92Mo or 100Mo) with excess hydrolyzed homocitric acid-γ-lactone in acidic solution resulted in the isolation of a cis-dioxo bis-homocitrato molybdenum(VI) complex, K2[*MoO2(R,S-H2homocit)2]·2H2O (1) (*Mo = Mo, 1; 92Mo, 2; 100Mo, 3; H4homocit = homocitric acid-γ-lactone·H2O) and K2[MoO2(18O-R,S-H2homocit)2]·2H2O (4). The complex has been characterized by elemental analysis, FT-IR, solid and solution 13C NMR, and single crystal x-ray diffraction analysis. The molybdenum atom in (1) is quasi-octahedrally coordinated by two cis oxo groups and two bidentate homocitrate ligands. The latter coordinates via its α-alkoxy and α-carboxy groups, while the β- and γ-carboxylic acid groups remain uncomplexed, similar to the coordination mode of homocitrate in the Mo-cofactor of nitrogenase. In the IR spectra, the Mo=O stretching modes near 900 cm-1 show 2-3 cm-1 red- and blue-shifts for the 92Mo-complex (2) and 100Mo-complex (3) respectively compared with the natural abundance version (1). At lower frequencies, bands at 553 and 540 cm-1 are assigned to νMo–O vibrations involving the alkoxide ligand. At higher frequencies, bands in the 1700-1730 cm-1 region are assigned to stretching modes of protonated carboxylates. In addition, a band at 1675 cm-1 was observed that may be analogous to a band seen at 1677 cm-1 in nitrogenase photolysis studies. The solution behavior of (1) in D2O was probed with 1H and 13C NMR spectra. An obvious dissociation of homocitrate was found, even though bound to the high valent Mo(VI). This suggests the likely lability of coordinated homocitrate in the FeMo-cofactor with its lower valence Mo(IV).
PMCID: PMC3596267  PMID: 23147649
Homocitric acid-γ-lactone; Homocitrate; FeMo-cofactor; Nitrogenase; FT-IR; Nitrogenase; NMR; Crystal structure
14.  Atrazine Molecular Imprinted Polymers: Comparative Analysis by Far-Infrared and Ultraviolet Induced Polymerization 
Atrazine molecular imprinted polymers (MIPs) were comparatively synthesized using identical polymer formulation by far-infrared (FIR) radiation and ultraviolet (UV)-induced polymerization, respectively. Equilibrium binding experiments were carried out with the prepared MIPs; the results showed that MIPuv possessed specific binding to atrazine compared with their MIPFIR radiation counterparts. Scatchard plot’s of both MIPs indicated that the affinities of the binding sites in MIPs are heterogeneous and can be approximated by two dissociation-constants corresponding to the high-and low-affinity binding sites. Moreover, several common pesticides including atrazine, cyromazine, metamitron, simazine, ametryn, terbutryn were tested to determine their specificity, similar imprinting factor (IF) and different selectivity index (SI) for both MIPs. Physical characterization of the polymers revealed that the different polymerization methods led to slight differences in polymer structures and performance by scanning electron microscope (SEM), Fourier transform infrared absorption (FT-IR), and mercury analyzer (MA). Finally, both MIPs were used as selective sorbents for solid phase extraction (SPE) of atrazine from lake water, followed by high performance liquid chromatography (HPLC) analysis. Compared with commercial C18 SPE sorbent (86.4%–94.8%), higher recoveries of atrazine in spiked lake water were obtained in the range of 90.1%–97.1% and 94.4%–101.9%, for both MIPs, respectively.
PMCID: PMC3907826  PMID: 24398982
atrazine; molecular imprinted polymers; far-infrared induced; ultraviolet induced
15.  Restoration of femoral offset, rotation centers, limbs length equality of Chinese total hip arthroplasty patients 
Objective: To explore the restoration of femoral offset, rotation centers, limbs length equality of Chinese total hip arthroplasty patients with careful preoperative surgical planning, the appropriate prosthesis and skillful manipulation combined with a variety of verification tests during the operation.
Methods: There were 92 hips (from 92 patients) surgery was performed by the same surgeon using the posterlateral approach by careful preoperative surgical planning. Appropriate prosthesis was chosen determining the reasonable femur osteotomy location, skillful manipulation and paying attention to every detail combined with a variety of verification tests and preoperative measurements during the operation. We evaluated the offset and rotation centers of the healthy (not performed) side and the operated side, the preoperative and postoperative limbs length discrepancy and analyzed the change of femoral offset, rotation centers and limbs length discrepancy of THA patients by self-control.
Results: We found that the preoperative and postoperative femoral offset was basically not changed, the postoperative rotation centers had a tendency to the medial and inferior of the original rotation centers, the limbs length discrepancy and Harris Hip Score (HHS) were improved much more than before.
Conclusions: Careful preoperative surgical planning, the appropriate prosthesis and skillful manipulation combined with a variety of verification tests during the operation is significantly correlated to the remarkable radiological and clinical results of THA patients.
PMCID: PMC3955554  PMID: 24639843
Femoral offset; Limbs length; Rotation centers; Total hip arthoplasty
16.  Optimal Duration of Fluorouracil-Based Adjuvant Chemotherapy for Patients with Resectable Gastric Cancer 
PLoS ONE  2013;8(12):e83196.
Although several clinical trials have suggested that postoperative adjuvant chemotherapy can improve survival of patients with gastric cancer, the optimal treatment duration has not been studied. This retrospective analysis evaluated the outcomes of patients with gastric cancer treated with six cycles of fluorouracil-based treatment compared with a cohort treated with four or eight cycles.
We retrospectively identified 237 patients with stage IB–IIIC gastric cancer who received four, six, or eight cycles of fluorouracil-based adjuvant chemotherapy administered every 3 weeks after radical gastrectomy. The endpoint was overall survival (OS). Factors associated with prognosis were also analyzed.
The estimated 3-year OS rates for the four-, six-, and eight-cycle cohorts were 54.4%, 76.1%, and 68.9%, respectively; and the estimated 5-year OS rates were 41.2%, 74.0%, and 65.8%, respectively. Patients who received six cycles were more likely to have a better OS than those who received four cycles (P = 0.002). Eight cycles failed to show an additional survival benefit (P = 0.454). In the multivariate analysis, the number of chemotherapy cycles was associated with OS independent of clinical covariates (P<0.05). Subgroup analysis suggested that among patients in all age groups examined, male patients, and subgroups of fluorouracil plus oxaliplatin combined chemotherapy, stage III, poor differentiation, and gastrectomy with D2 lymphadenectomy, six cycles of adjuvant chemotherapy were associated with a statistically significant benefit of OS compared with four cycles (P<0.05).
Six cycles of adjuvant chemotherapy might lead to a favorable outcome for patients with gastric cancer, and two further cycles could not provide an additional clinical benefit.
PMCID: PMC3873471  PMID: 24386161
17.  Lactuside B decreases aquaporin-4 and caspase-3 mRNA expression in the hippocampus and striatum following cerebral ischaemia-reperfusion injury in rats 
This study aimed to investigate the effects of lactuside B (LB) on aquaporin-4 (AQP4) and caspase-3 mRNA expression in the hippocampus and the striatum following cerebral ischaemia-reperfusion (I/R) injury in rats. Cerebral I/R injury was established in Sprague-Dawley rats by occluding the middle cerebral artery for 2 h and then inducing reperfusion. Rats in the I/R + LB groups were treated with various doses of LB following reperfusion. Neurological deficit scores and brain water content were obtained to determine the pharmacodynamics of LB. Reverse transcription polymerase chain reaction was performed to determine the expression levels of AQP4 and caspase-3 mRNA in the hippocampus and the striatum. The results of the present study indicate that LB decreased the neurological deficit scores and the brain water content. In the hippocampus, AQP4 and caspase-3 mRNA expression levels were significantly downregulated in the I/R + LB groups at 24 and 72 h following drug administration, compared with those in the I/R group (P<0.05). In the striatum, LB was also shown to significantly reduce AQP4 and caspase-3 mRNA expression levels at 24 and 72 h following drug administration, compared with those in the I/R group (P<0.05). The effects became stronger as the LB dose was increased. The most significant reductions in AQP4 and caspase-3 mRNA expression were noted in the I/R + LB 25 mg/kg and I/R + LB 50 mg/kg groups at 72 h following drug administration. The results of the present study show that LB is capable of significantly downregulating AQP4 and caspase-3 mRNA expression in the hippocampus and striatum following cerebral I/R injury in rats. The mechanism by which LB improved ischaemic brain injury may be associated with changes in AQP4 and caspase-3 mRNA expression in the hippocampus and the striatum.
PMCID: PMC3919888  PMID: 24520266
lactuside B; cerebral I/R injury; brain edema; AQP4; caspase-3; apoptosis; hippocampus; striatum
18.  Dual-band Fourier domain optical coherence tomography with depth-related compensations 
Biomedical Optics Express  2013;5(1):167-182.
Dual-band Fourier domain optical coherence tomography (FD-OCT) provides depth-resolved spectroscopic imaging that enhances tissue contrast and reduces image speckle. However, previous dual-band FD-OCT systems could not correctly give the tissue spectroscopic contrast due to depth-related discrepancy in the imaging method and attenuation in biological tissue samples. We designed a new dual-band full-range FD-OCT imaging system and developed an algorithm to compensate depth-related fall-off and light attenuation. In our imaging system, the images from two wavelength bands were intrinsically overlapped and their intensities were balanced. The processing time of dual-band OCT image reconstruction and depth-related compensations were minimized by using multiple threads that execute in parallel. Using the newly developed system, we studied tissue phantoms and human cancer xenografts and muscle tissues dissected from severely compromised immune deficient mice. Improved spectroscopic contrast and sensitivity were achieved, benefiting from the depth-related compensations.
PMCID: PMC3891330  PMID: 24466485
(110.4500) Optical coherence tomography; (170.3880) Medical and biological imaging
19.  Primary adenosquamous carcinoma of the esophagus 
AIM: To investigate the clinical characteristics, diagnosis, treatment, and prognosis of primary adenosquamous carcinoma (ASC) of the esophagus.
METHODS: A total of 4015 patients with esophageal carcinoma underwent surgical resection between January 1995 and June 2012 at the Cancer Hospital of Shantou University Medical College. In 37 cases, the histological diagnosis was primary ASC. Clinical data were retrospectively analyzed from these 37 patients, who underwent transthoracic esophagectomy with lymphadenectomy. The χ2 or Fisher’s exact test was used to compare the clinicopathological features between patients with ASC and those with squamous cell carcinoma (SCC). The Kaplan-Meier and Log-Rank methods were used to estimate and compare survival rates. A Cox proportional hazard regression model was used to identify independent prognostic factors.
RESULTS: Primary esophageal ASC accounted for 0.92% of all primary esophageal carcinoma cases (37/4015). The clinical manifestations were identical to those of other types of esophageal cancer. All of the 24 patients who underwent preoperative endoscopic biopsy were misdiagnosed with SCC. The median survival time (MST) was 21.0 mo (95%CI: 12.6-29.4), and the 1-, 3-, and 5-year overall survival rates were 67.5%, 29.4%, and 22.9%, respectively. In multivariate analysis, only adjuvant radiotherapy (HR = 0.317, 95%CI: 0.114-0.885, P = 0.028) was found to be an independent prognostic factor. The MST for ASC patients was significantly lower than that for SCC patients [21.0 mo (95%CI: 12.6-29.4) vs 46.0 mo (95%CI: 40.8-51.2), P = 0.001]. In subgroup analyses, the MST for ASC patients was similar to that for poorly differentiated SCC patients.
CONCLUSION: Primary esophageal ASC is a rare disease that is prone to be misdiagnosed by endoscopic biopsy. The prognosis is poorer than esophageal SCC but similar to that for poorly differentiated SCC patients.
PMCID: PMC3857463  PMID: 24363531
Adenosquamous carcinoma; Diagnosis; Esophagus; Prognosis; Treatment
20.  Upregulation of Endocan by Epstein-Barr Virus Latent Membrane Protein 1 and Its Clinical Significance in Nasopharyngeal Carcinoma 
PLoS ONE  2013;8(12):e82254.
Endocan (or called Esm-1) has been shown to have tumorigenic activities and its expression is associated with poor prognosis in various cancers. Latent membrane protein 1 (LMP1) is an Epstein-Barr virus (EBV)-encoded oncoprotein and has been shown to play an important role in the pathogenesis of EBV-associated nasopharyngeal carcinoma (NPC). To further understand the role of LMP1 in the pathogenesis of NPC, microarray analysis of LMP1-regulated genes in epithelial cells was performed. We found that endocan was one of the major cellular genes upregulated by LMP1. This induction of endocan by LMP1 was confirmed in several epithelial cell lines including an NPC cell line. Upregulation of endocan by LMP1 was found to be mediated through the CTAR1 and CTAR2 domains of LMP1 and through the LMP1-activated NF-κB, MEK-ERK and JNK signaling pathways. To study whether endocan was expressed in NPC and whether endocan expression was associated with LMP1 expression in NPC, the expression of endocan and LMP1 in tumor tissues from 42 NPC patients was evaluated by immunohistochemistry. Expression of endocan was found in 52% of NPC specimens. Significant correlation between LMP1 and endocan expression was observed (p<0.0001). Moreover, NPC patients with endocan expression were found to have a shorter survival than NPC patients without endocan expression (p=0.0104, log-rank test). Univariate and Multivariate analyses revealed that endocan was a potential prognostic factor for NPC. Finally, we demonstrated that endocan could stimulate the migration and invasion ability of endothelial cells and this activity of endocan was dependent on the glycan moiety and the phenylalanine-rich region of endocan. Together, these studies not only identify a new molecular marker that may predict the survival of NPC patients but also provide a new insight to the pathogenesis of NPC.
PMCID: PMC3855342  PMID: 24340011
21.  Phase III Trials of Standard Chemotherapy with or without Bevacizumab for Ovarian Cancer: A Meta-Analysis 
PLoS ONE  2013;8(12):e81858.
Platinum-based standard chemotherapy improves survival of ovarian cancer (OC), but the five-year survival rate remains below 50%. Antiangiogenic agents (7.5 or 15 mg/kg Bevacizumab, Bev) plus to standard chemotherapy improve progression-free survival (PFS) not overall survival (OS) in completed randomized controlled trials (RCTs). The efficacy and safety of two doses of Bev + standard chemotherapy remain controversial.
MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane databases and were searched. The outcomes of eligible RCTs included PFS, OS and toxicities. Hazard ratio (HR) and relative risk (RR) were used for the meta-analysis and were expressed with 95% confidence intervals (CIs).
Bev + chemotherapy improved PFS (HR, 0.82; 95% CI, 0.75 to 0.89; P = .000) and OS (HR, 0.87; 95% CI, 0.77 to 0.99; P = .026) in newly diagnosed OC (2 trials, 2776 patients), and PFS (HR, 0.48; 95% CI, 0.41 to 0.57; P = .000) in recurrent OC (2 trials, 845 patients). Bev + chemotherapy increased non-CNS bleeding (RR, 3.63; 95% CI, 1.81 to 7.29; P = .000), hypertension grade ≥ 2 (RR, 4.90; 95% CI, 3.83 to 6.25; P = .000), arterial thromboembolism (RR, 2.29; 95% CI, 1.33 to 3.94; P = .003), gastrointestinal perforation (RR, 2.90; 95% CI, 1.44 to 5.82; P = .003), and proteinuria grade ≥ 3 (RR, 6.63; 95% CI 3.17 to 13.88; P = .000). No difference was observed between the two Bev doses in PFS (HR, 1.04; 95% CI, 0.88 to 1.24) or OS (HR, 1.15, 95% CI, 0.88 to 1.50), but 15 mg/kg Bev increased toxicities.
Bev + standard chemotherapy delayed progression for newly diagnosed and recurrent OC, and improved survival for newly diagnosed OC. The 7.5 mg/kg dose appeared to be optimal for newly diagnosed OC patients with high risk for progression.
PMCID: PMC3853655  PMID: 24324725
22.  Ovarian cancer stem-like cells with induced translineage-differentiation capacity and are suppressed by alkaline phosphatase inhibitor 
Oncotarget  2013;4(12):2366-2382.
Spheroid formation is one property of stem cells—such as embryo-derived or neural stem cells—that has been used for the enrichment of cancer stem-like cells (CSLCs). However, it is unclear whether CSLC-derived spheroids are heterogeneous or whether they share common embryonic stemness properties. Understanding these features might lead to novel therapeutic approaches. Ovarian carcinoma is a deadly disease of women. We identified two types of spheroids (SR1 and SR2) from ovarian cancer cell lines and patients' specimens according to their morphology. Both types expressed stemness markers and could self-renew and initiate tumors when a low number of cells were used. Only SR1 could differentiate into multiple-lineage cell types under specific induction conditions. SR1 spheroids could differentiate to SR2 spheroids through epithelial–mesenchymal transition. Alkaline phosphatase (ALP) was highly expressed in SR1 spheroids, decreased in SR2 spheroids, and was absent in differentiated progenies in accordance with the loss of stemness properties. We verified that ALP can be a marker for ovarian CSLCs, and patients with greater ALP expression is related to advanced clinical stages and have a higher risk of recurrence and lower survival rate. The ALP inhibitor, levamisole, disrupted the self-renewal of ovarian CSLCs in vitro and tumor growth in vivo. In summary, this research provides a plastic ovarian cancer stem cell model and a new understanding of the cross-link between stem cells and cancers. This results show that ovarian CSLCs can be suppressed by levamisole. Our findings demonstrated that some ovarian CSLCs may restore ALP activity, and this suggests that inhibition of ALP activity may present a new opportunity for treatment of ovarian cancer.
PMCID: PMC3926833  PMID: 24280306
alkaline phosphatase; cancer stem-like cells; epithelial-mesenchymal transition; epithelial ovarian cancer; levamisole; trans-lineage differentiation
23.  Investigation of the Material Basis Underlying the Correlation between Presbycusis and Kidney Deficiency in Traditional Chinese Medicine via GC/MS Metabolomics 
Objective. To investigate the correlation between presbycusis and kidney deficiency as defined by traditional Chinese medicine (TCM) and its material basis from the perspective of metabolism. Methods. Pure-tone audiometry was used to test auditory function. A kidney deficiency symptom scoring table was used to measure the kidney deficiency accumulated scores of the research subjects. Gas chromatography/mass spectrometry (GC/MS) was used to measure the metabolites in the urine samples from 11 presbycusis patients and 9 elderly people with normal hearing. Results. Hearing loss in the elderly was positively correlated with kidney deficiency score in TCM. There were significant differences in urine metabolite profile between the presbycusis patients and the controls. A total of 23 differentially expressed metabolites were found. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that these metabolites were related to glutathione metabolism, amino acid metabolism, glucose metabolism, the N-methyl-D-aspartic acid (NMDA) receptor pathway, and the γ-aminobutyric acid (GABA) receptor pathway. Conclusion. Glutathione metabolism, amino acid metabolism, glucose metabolism, NMDA receptors, and GABA receptors may be related to the pathogenesis of presbycusis and may be the material basis underlying the correlation between presbycusis and kidney deficiency in TCM.
PMCID: PMC3858872  PMID: 24371466
24.  Adaptive Evolution of Multiple Traits Through Multiple Mutations at a Single Gene 
Science (New York, N.Y.)  2013;339(6125):10.1126/science.1233213.
The identification of precise mutations is required for a complete understanding of the underlying molecular and evolutionary mechanisms driving adaptive phenotypic change. Using plasticine models in the field, we show that the light coat color of deer mice that recently colonized the light-colored soil of the Nebraska Sand Hills provides a strong selective advantage against visually hunting predators. Color variation in an admixed population suggests that this light Sand Hills phenotype is composed of multiple traits. We identified distinct regions within the Agouti locus associated with each color trait and found that only haplotypes associated with light trait values have evidence of selection. Thus, local adaptation is the result of independent selection on many mutations within a single locus, each with a specific effect on an adaptive phenotype, thereby minimizing pleiotropic consequences.
PMCID: PMC3836219  PMID: 23493712
25.  The impact of equilibrium assumptions on tests of selection 
Frontiers in Genetics  2013;4:235.
With the increasing availability and quality of whole genome population data, various methodologies of population genetic inference are being utilized in order to identify and quantify recent population-level selective events. Though there has been a great proliferation of such methodology, the type-I and type-II error rates of many proposed statistics have not been well-described. Moreover, the performance of these statistics is often not evaluated for different biologically relevant scenarios (e.g., population size change, population structure), nor for the effect of differing data sizes (i.e., genomic vs. sub-genomic). The absence of the above information makes it difficult to evaluate newly available statistics relative to one another, and thus, difficult to choose the proper toolset for a given empirical analysis. Thus, we here describe and compare the performance of four widely used tests of selection: SweepFinder, SweeD, OmegaPlus, and iHS. In order to consider the above questions, we utilize simulated data spanning a variety of selection coefficients and beneficial mutation rates. We demonstrate that the LD-based OmegaPlus performs best in terms of power to reject the neutral model under both equilibrium and non-equilibrium conditions—an important result regarding the relative effectiveness of linkage disequilibrium relative to site frequency spectrum based statics. The results presented here ought to serve as a useful guide for future empirical studies, and provides a guide for statistical choice depending on the history of the population under consideration. Moreover, the parameter space investigated and the Type-I and Type-II error rates calculated, represent a natural benchmark by which future statistics may be assessed.
PMCID: PMC3822286  PMID: 24273554
population genetics; statistical inference; positive selection; demography; simulation

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