[Molecular epidemiology of Japanese encephalitis viruses isolated in Yunnan province, 1977-2010]

Objective: To understand the genetic and molecular epidemiologic characteristics of 63 strains of Japanese encephalitis virus (JEV) isolated in Yunnan province, China during 1977-2010. Methods: Suckling mice were inoculated with viruses continuously and the viral nucleic acid were extracted from the brain-grinding supernatants of the infected and moribund mice, then the gene fragments of E region were amplified by RT-PCR. Bioinformatics (Clustal X, DNAstar, Mega 5.0 and other software) was used to analyze the nucleotide and deduced amino acid sequences and phylogenetic trees. Results: Yunnan strains of JEV could cause illness and deaths in suckling mice. The results of virus nucleic acid detection and sequencing indicated that nucleotide sequences of E gene of the 63 virus strains were obtained. Phylogenetic tree and homology analyses based on E genomes showed that 47 strains of the experimental virus belonged to genotype 1 (G-1) and 16 strains belonged to genotype 3 (G-3). The 47 isolates of G-1 were divided into 2 clades, of them, the earliest isolates of G-1 (M28, 1977 and BN82215, 1982) in Yunnan of China and the early isolates of G-1 (U70416, 1982; DQ084229, the year is unknown) in Thailand were in one clade, and the isolates of G-1 from 2007-2010 in Yunnan could be divided into 2 subgroups. The 16 isolates of G-3 from Yunnan were divided into 3 clades, among them, the isolates from 1970-1990s in Yunnan were in two clades, and the isolates from 2004 in Yunnan were in one clade. In addition, their main amino acid sites of antigenicity, pathogenic, virulence of both G-1 and G-3 had no significant change. Conclusion: JEV G-1 and G-3 co-circulated in Yunnan, and G-1 was predominant. The JEV strains isolated in different years and areas in Yunnan had different molecular epidemiologic characteristics and genetic diversity. The results of this study suggested that JEV G-1 might originate from Yunnan of China and adjacent Southeast Asia region.

Dark plasmonic mode based perfect absorption and refractive index sensing

Dark plasmonic resonances in metallic nanostructures are essential for many potential applications such as refractive index sensing, single molecule detection, nanolasers etc. However, it is difficult to excite the dark modes in optical experiments and thus the practical applications are severely limited. Herein, we demonstrate a simple method to experimentally excite the quadrupolar and higher-order plasmonic modes with normal incident light. By directionally depositing silver films onto the sidewalls of metal-covered one-dimensional grating, we have experimentally observed a series of asymmetrical resonances at the plasmonic ranges of silver gratings. Interestingly, both of the reflection and transmission coefficients of high-order plasmonic modes are reduced to around zero, demonstrating the perfect absorption very well. The corresponding numerical simulations show that these resonances are the well-known dark modes. Different from the conventional dark modes in plasmonic dimers, here the dark modes are the electric oscillations (as standing waves) within the silver sidewalls that are excited by charge accumulation via the bright plasmonic resonance of the top silver strips. In addition to the simple realization of perfect absorption, the dark modes are found to be quite sensitive to the environmental changes. The experimentally measured reflective index sensitivity is around 458 nm per RIU (refractive index unit), which is much higher than the sensitivity of the metal-covered grating without silver sidewalls. This research shall pave new routes to practical applications of dark surface plasmons.

Chemotherapeutics-induced Oct4 expression contributes to drug resistance and tumor recurrence in bladder cancer

Cancer cells initially characterized as sensitive to chemotherapy may acquire resistance to chemotherapy and lead to tumor recurrence through the expansion of drug-resistant population. Acquisition of drug resistance to conventional chemotherapy is a major obstacle in the treatment of recurrent cancer. Here we investigated whether anticancer drugs induced Oct4 expression, thereby contributing to acquired drug resistance and tumor recurrence in bladder cancer. We identified a positive correlation of Oct4 expression with tumor recurrence in 122 clinical specimens of superficial high-grade (stages T1-2) bladder transitional cell carcinoma (TCC). Increased Oct4 levels in bladder tumors were associated with short recurrence-free intervals in the patients. Chemotherapy induced Oct4 expression in bladder cancer cells. Notably, treatment with cisplatin increased CD44-positive bladder cancer cells expressing Oct4, representing cancer stem-like cell subpopulation. Forced expression of Oct4 reduced, whereas knockdown of Oct4 enhanced, drug sensitivity in bladder cancer cells. Furthermore, tumor cells overexpressing Oct4 responded poorly to cisplatin in vivo. In regard to clinical relevance, inhibition of Oct4 by all-trans retinoic acid (ATRA) synergistically increased sensitivity to cisplatin in bladder cancer cells. Furthermore, the combination of cisplatin and ATRA was superior to cisplatin alone in suppressing tumor growth. Therefore, our results provide evidence that Oct4 increases drug resistance and implicate that inhibition of Oct4 may be a therapeutic strategy to circumvent drug resistance.

Hepcidin and iron metabolism associated with cardiometabolic risk factors in children: A case-control study

BACKGROUND AND AIMS

Iron metabolism plays a crucial role in the development of cardiometabolic disease; however, the association between cardiometabolic risk factors (CMRFs) and hepcidin as well as other iron parameters remains unclear in children. The aims of this study were to compare the circulating hepcidin levels and iron metabolism between children with and without CMRFs and to investigate the association between those iron parameters and CMRFs.

METHODS AND RESULTS

A case-control study was conducted among 1126 children aged 7-14 years in the case group (n = 563) with CMRFs and the healthy control group (n = 563). Iron parameters, lipids, and anthropometric characteristics were evaluated. The information on demographics, diet, and physical activities was either children reported or parent reported. Compared with the healthy controls, children with CMRFs had higher levels of hepcidin and lower levels of serum iron, transferrin, and soluble transferrin receptor (sTfR; P < 0.001). Besides, the odds ratios (ORs) for low levels of high-density lipoprotein (HDL) were 2.03, 0.21, and 0.33 in children with higher hepcidin, transferrin, and sTfR levels (P < 0.05). Furthermore, ORs for cardiometabolic risk were 0.50 (95% confidence interval (CI): 0.30-0.85, P < 0.05), 0.22 (95% CI: 0.12, 0.42, P < 0.01) and 0.19 (95% CI: 0.10, 0.36, P < 0.01) in children with higher serum iron, transferrin, and sTfR levels, respectively.

CONCLUSION

The levels of hepcidin were higher, while those of iron, transferrin, and sTfR were lower in children with CMRF. Hepcidin was positively associated with the risk of low HDL levels, whereas transferrin and sTfR levels negatively correlated with the risk of low HDL levels. In addition, serum iron, transferrin, and sTfR levels were negatively associated with cardiometabolic risk.

[The effect of phacoemulsification on intraocular pressure in eyes with primary angle closure glaucoma after trabeculectomy]

OBJECTIVE

To evaluate the effect of phacoemulsification on intraocular pressure (IOP) in filtered eyes with primary angle closure glaucoma (PACG).

METHODS

In this retrospective case series, 47 eyes from 47 PACG patients who previously had trabeculectomy were consecutively enrolled. All patients had visually significant cataracts and phacoemulsification was performed at least 3 months after trabeculectomy. The IOPs were recorded preoperatively, 1 day, 1 week, 2 weeks, 1 month, 3 months, 6 months, 12 months and 24 months after surgery. The best correct visual acuity (BCVA) , the number of glaucoma medications and the filtered bleb grade were recorded preoperatively and 24 months after phacoemulsification. IOP and BCVA before and after phacoemulsification were compared by student t test. The frequences of antiglaucoma medicine, bled grade and IOP control before and after phacoemulsification were compared by Mann-Whitney Test. Linear regression analysis, Pearson and Spearman were performed to assess the correlation between IOP change and other variants.

RESULTS

IOP was decreased significantly from (18.7±6.7) mmHg (1 mmHg=0.133 kPa) at baseline to 16.4±2.0 mmHg at final follow-up (t=2.54, P=0.015) . The median number of glaucoma medications was significantly decreased (P<0.01) at 2 years postoperatively. The magnitude of IOP reduction was significantly correlated with preoperative IOP (r=0.95, P<0.01). BCVA (LogMAR) was improved significantly at month 24 (t=5.62, P<0.01). Filtered bleb decreased insignificantly at 2 years postoperatively (P=0.113). Complete success, qualified success and failure rates in terms of IOP were 61.7%, 27.7% and 10.6% before surgery , 89.4%, 8.5%, 2.1% at 2 years postoperatively. In 29 patients with preoperative IOP≤21 mmHg, mean IOP increased insignificantly from (14.5±4.0) mmHg to (15.5 ± 2.3) (P=0.195) at 2 years. In the 18 patients with preoperative IOP> 21 mmHg, mean IOP decreased from (25.3 ± 4.4) mmHg preoperatively to (17.8 ± 2.4) mmHg (P<0.01).

CONCLUSIONS

Phacoemulsification reduces IOP and the number of glaucoma medications in previously filtered PACG eyes. The IOP remained normal in normal tension eyes after phacoemulsification in filtered PACG eyes but decreased significantly in hypertensive eyes.

Thrombin Activates Latent TGFβ1 via Integrin αvβ1 in Gingival Fibroblasts

Transforming growth factor β (TGFβ) regulates cell proliferation, differentiation, migration, apoptosis, and extracellular matrix production. It also plays a pivotal role in the pathogenesis of gingival overgrowth. Thrombin is a key player in tissue repair, remodeling, and fibrosis after an injury, and it exerts profibrotic effects by activating protease-activated receptors. Connective tissue growth factor (CTGF or CCN2) modulates cell adhesion, migration, proliferation, matrix production, and wound healing. It is overexpressed in many fibrotic disorders, including gingival overgrowth, and it is positively associated with the degree of fibrosis in gingival overgrowth. In human gingival fibroblasts, we previously found that TGFβ1 induced CCN2 protein synthesis through c-jun N-terminal kinase and Smad3 activation. Thrombin stimulates CCN2 synthesis through protease-activated receptor 1 and c-jun N-terminal kinase signaling. Curcumin inhibited TGFβ1- and thrombin-induced CCN2 synthesis. In this study, we demonstrated that thrombin and protease-activated receptor 1 agonist SFLLRN induced latent TGFβ1 activation and Smad3 phosphorylation in human gingival fibroblasts. Pretreatment with a TGFβ-neutralizing antibody, TGFβ type I receptor inhibitor SB431542, and Smad3 inhibitor SIS3 inhibited approximately 86%, 94%, and 100% of thrombin-induced CCN2 synthesis, respectively. Furthermore, blocking integrin subunits αv and β1 with antibodies effectively inhibited SFLLRN-induced Smad3 phosphorylation and CCN2 synthesis and increased activated TGFβ1 levels; however, similar effects were not observed for integrins αvβ3 and αvβ5. These results suggest that protease-activated receptor 1-induced CCN2 synthesis in human gingival fibroblasts is mediated through integrin αvβ1-induced latent TGFβ1 activation and subsequent TGFβ1 signaling. Moreover, curcumin dose dependently decreased thrombin-induced activated TGFβ1 levels. Curcumin-inhibited thrombin-induced CCN2 synthesis in human gingival fibroblasts is caused by the suppression of latent TGFβ1 activation.

Screening of highly informative and representative microsatellite markers for genotyping of major cultivated cotton varieties

We screened and assessed published cotton simple sequence repeat (SSR) primers to establish a set of core SSR markers suitable for cotton major cultivars in China and analyzed genetic diversity based on the core marker set. Using a stepwise screening strategy, 12 leading cultivars for preliminary screening and 96 cultivars for rescreening were evaluated. A total of 184 polymorphic SSR markers were initially screened from 3299 candidates, and a core set of 52 SSR markers with wide genome coverage (2 markers per chromosome) was obtained. Among 96 major cultivars, 273 amplification genotypes were generated using the core marker set. Polymorphism information content values ranged from 0.28-0.83, with an average value of 0.56. The core SSR marker set detected on denaturing polyacrylamide gel electrophoresis indicated that the band genotype was either a single or double band on conventional cultivars, while most were double bands (65.4%). Among 56 hybrids, the average heterozygosis rate was 35.8%, ranging from 7.1-55.4%. Eighteen of 96 cultivars had distinct band genotypes. The genetic diversity analyzed using the of NTSYS-pc V2.10 software indicated that the Yangtze River valley cotton region had the highest polymorphic level, followed by Xinjiang and then the Yellow River valley. The genetic basis of conventional cultivars was narrower than that of hybrids. The core marker set can be used for fingerprint construction, variety identification, and purity tests of major cotton cultivars in China.

Monocyte/macrophage β2-AR as a target of antisympathetic excitation-induced atherosclerotic progression

The aim of this study was to determine whether monocyte/macrophage β2-AR could act as the therapeutic target of antisympathetic excitation-induced atherosclerotic progression. Cultivated human THP-1 cells were divided into different groups and incubated with isoprenaline, metoprolol, propranolol or β2-AR blocker for 24 h, together with oxidized low-density lipoprotein (ox-LDL). Afterwards, each group was analyzed for C-C chemokine receptor type 2 (CCR2) expression, monocyte chemotactic protein 1 (MCP-1) release into medium and cell migration ability. In the isoprenaline group, CCR2 protein level was increased, as well as the secretion of MCP-1, and cell motility was enhanced, in a concentration-dependent manner. Propranolol and ICI 118,551 significantly reversed the stimulatory effect of isoprenaline on THP-1 cells induced by ox-LDL, but only high concentrations of metoprolol interfered significantly with the action of isoprenaline (P < 0.05). Isoprenaline or a β-AR blocker could mediate through β2-AR, affecting MCP-1 secretion, CCR2 protein expression and cell migration capacity of THP-1 cells. Therefore, monocyte-macrophage β2-AR may act as a target of antisympathetic excitation-induced atherosclerotic progression.