First experimental demonstration of faster-than-Nyquist PDM-16QAM transmission over standard single mode fiber

We demonstrate faster-than-Nyquist (FTN) transmission with a novel mitigation scheme of intercarrier interference. To the best of our knowledge, it is the first experimental demonstration of FTN PDM-16QAM transmission over standard single mode fiber (SSMF). Due to the use of maximum likelihood sequence detection and multi-input multi-output processing for severely overlapped Nyquist-PDM-16QAM carriers, 5.4-dB optical signal-to-noise ratio improvement is experimentally observed under the scenario of 2×16-GBd PDM-16QAM back-to-back transmission with a carrier spacing of 15 GHz. A net spectral efficiency up to 7.68 b/s/Hz is achieved by transmission of a 15-GHz spaced dual-carrier superchannel over 960-km SSMF, with hard decision forward error correction taken into account. Furthermore, FTN superchannel transmission with carrier spacings of 14 and 15 GHz are successfully realized over 960- and 1920-km SSMFs, respectively.

Manifesto on small airway involvement and management in asthma and chronic obstructive pulmonary disease: an Interasma (Global Asthma Association - GAA) and World Allergy Organization (WAO) document endorsed by Allergic Rhinitis and its Impact on Asthma (ARIA) and Global Allergy and Asthma European Network (GA2LEN)

Evidence that enables us to identify, assess, and access the small airways in asthma and chronic obstructive pulmonary disease (COPD) has led INTERASMA (Global Asthma Association) and WAO to take a position on the role of the small airways in these diseases.

Starting from an extensive literature review, both organizations developed, discussed, and approved the manifesto, which was subsequently approved and endorsed by the chairs of ARIA and GA²LEN. The manifesto describes the evidence gathered to date and defines and proposes issues on small airway involvement and management in asthma and COPD with the aim of challenging assumptions, fostering commitment, and bringing about change.

The small airways (defined as those with an internal diameter <2 mm) are involved in the pathogenesis of asthma and COPD and are the major determinant of airflow obstruction in these diseases. Various tests are available for the assessment of the small airways, and their results must be integrated to confirm a diagnosis of small airway dysfunction.

In asthma and COPD, the small airways play a key role in attempts to achieve disease control and better outcomes. Small-particle inhaled formulations (defined as those that, owing to their size [usually <2 μm], ensure more extensive deposition in the lung periphery than large molecules) have proved beneficial in patients with asthma and COPD, especially those in whom small airway involvement is predominant.

Functional and biological tools capable of accurately assessing the lung periphery and more intensive use of currently available tools are necessary. In patients with suspected COPD or asthma, small airway involvement must be assessed using currently available tools. In patients with subotpimal disease control and/or functional or biological signs of disease activity, the role of small airway involvement should be assessed and treatment tailored. Therefore, the choice between large- and small-particle inhaled formulations must reflect the physician’s considerations of disease features, phenotype, and response to previous therapy. This article is being co-published in Asthma Research and Practice and the World Allergy Organization Journal.

[Antimicrobial applications and toxicity of nano-silver in the medical field]

With the rapid development of modern science and technology, the application of nanomaterial is ubiquitous in our daily life and medical field, in which the application related to nano-silver is more extensive. On one hand, it can make positive effects, such as anti-bacteria, anti-virus, anti-fungi, anti-parasitic infection and anti-tumor. In particular, its anti-bacterial activity in some acute or chronic treatment of infected wounds is more prominent. The application in diseases of gynecology, orthopedics, cardiovascular system, oral cavity, and ophthalmology is increasing. On the other hand, it can induce negative impacts and potential toxicity. It can be harmful to skin, gastrointestinal tract, respiratory tract, cardiovascular system, and so on. This article summarizes the antimicrobial application of nano-silver on treatment of diseases, its potential toxic effects on some organs or systems, and the possible toxic mechanism, as well as makes prospects of the research trends of nano-silver in future.

Serum troponin I concentrations assessed 18-24 hours after coronary artery bypass grafting are significant predictors of early patient prognosis

OBJECTIVE

Coronary heart disease (CHD) is a frequent medical condition in developed countries and is one of the most serious diseases threatening patients' lives. Perioperative myocardial infarction is the major cause of perioperative cardiac death and cardiac arrest, but is difficult to be precisely identified by observing clinical symptoms or assessing cardiac enzyme levels or by ECG examination. Therefore, assessment of patient prognosis requires reliable predictors. In this regard, we tested the prognostic value of serum troponin I (TnI) concentrations.

PATIENTS AND METHODS

98 patients undergoing elective simple off-pump coronary artery bypass grafting were recruited. Venous blood samples were collected within 3-5 hours, 18-24 hours, and 36-48 hours post-operation, and associations of TnI concentrations with early outcomes measures (duration of assisted ventilation, length of stay in the ICU, length of postoperative stay, administration of antihypotensive medications, use of intra-aortic balloon pump, and ECG abnormalities) were evaluated. Correlations of postoperative TnI concentrations with the outcomes measures were analyzed by using median TnI concentrations as the cut-off value.

RESULTS

TnI concentrations assessed within 18-24 hours post-operation showed significant associations with most tested outcome measures (p < 0.05 for four out of five comparisons). Furthermore, after building ROC curves, the highest AUC values (> 0.9) were also observed for TnI1 concentrations assessed within this time frame. The optimal cutoff value for TnI concentration was 1.78 ng/ml.

CONCLUSIONS

TnI concentrations assessed within 18-24 hours after elective off-pump coronary artery bypass grafting can effectively predict early patient prognosis.

Associations of serotonin receptor gene HTR3A, HTR3B, and HTR3A haplotypes with bipolar disorder in Chinese patients

Single nucleotide polymorphisms (SNPs) in HTR3A and HTR3B have been reported to be associated with bipolar disorder in European and Japanese populations. We explored the roles of 21 tag SNPs in HTR3A and HTR3B in susceptibility to bipolar disorder in a Chinese cohort. Twenty-one Tag SNPs were genotyped in a study consisting of 130 patients with bipolar disorder, who visited Shandong Mental Health Center between June 2013 and May 2014, and 109 healthy individuals as controls. All of the tag SNPs were genotyped using Sequenom MassArray matrix-assisted laser desorption/ionization time of flight spectrometry. Plink 1.07, Haploview 4.2, and SPSS 20.0 were used for the analysis of the genotypes and the associations of the haplotypes with bipolar disorder. Association analyses of tag SNPs detected significant associations with the A allele in HTR3A rs1176719 (P = 0.030) and the C allele in HTR3A rs1176713 (P = 0.048). Haplotype-based association analyses indicated a statistically significant (P = 0.035) five-SNP haplotype (rs1062613:C, rs11604247:C, rs1176722:G, rs2276302:A, rs1176719:G) of linkage disequilibrium in block 3. Analysis of our small Chinese sample revealed a significant association of HTR3A with bipolar disorder, but yielded no evidence of an association between HTR3B and bipolar disorder. Furthermore, evidence for an association was found for a haplotype of HTR3A. Studies with larger Chinese samples are needed to verify our findings.

The role of apoptosis inducing factor in the apoptosis of retinal pigment epithelium cells induced by oxidative stress

To explore the role of apoptosis inducing factor (AIF) in the apoptosis of retinal pigment epithelium (RPE) cells induced by oxidative stress. RPE cell apoptotic models were constructed by H2O2, Annexin V/PI flow cytometry and MTT assay were used to determine the changes of RPE cell apoptosis and proliferation. The production of reactive oxygen species (ROS) and mitochondrial membrane potential were observed. QRT-PCR and western blot were used to determine the expression of AIF to evaluate whether AIF-mediated non caspase pathway participated in the RPE cell apoptosis induced by H2O2. After adding melatonin, the production of ROS, RPE apoptotic rate and the changes of AIF expression were also detected. The production of ROS and apoptotic rate of RPE cells increased with the increase of H2O2 concentration and treating time. The expression of AIF increased evidently in cytoplasm, while not in mitochondria. After intervention with melatonin, the production of ROS was inhibited and the apoptotic rate decreased. However, the expression of AIF was not inhibited correspondingly. AIF may participate in but not be dominant in the process of RPE cell apoptosis induced by oxidative stress.

Effect of cardiopulmonary bypass on leukocyte activation: changes in membrane-bound elastase on neutrophils

Background: Neutrophil elastase is known to be released from the activated leukocytes as a result of cardiopulmonary bypass (CPB). However, its biological effect on organ injury is questionable because it is quickly bound by natural proteinase inhibitors (PIs). Recently, membrane-bound elastase (MBE) was found to be able to resist the PIs’ process and, thus, is biologically more active. This paper studies the effect of CPB on the kinetic change of MBE and its possible link to postoperative inflammation and organ function.

Method: Ten consecutive patients undergoing elective coronary artery bypass grafting (CABG) surgery with CPB were recruited into the study. Blood samples were taken before sternotomy, after aortic declamping, at the end of CPB, three and six hours after CPB and on the first postoperative day. MBE was determined by substrate assay from isolated neutrophils. Inflammation and organ function markers were determined according to routine laboratory methods.

Results: MBE slightly increased after aortic declamping, while it significantly increased and reached its peak at the end of CPB; it returned to its preoperative level on the first postoperative day. In contrast to lung sequestration of neutrophils, there was no transpulmonary gradient of MBE between left and right atria after aortic declamping. Neither MBE nor total MBE activity was positively correlated with postoperative inflammation markers such as blood lactate and C-reactive protein and organ function markers such as creatine phosphokinase and alanine aminotransferase.

Conclusions: CPB induces increased MBE expression on neutrophils with its peak at the end of CPB. Lack of association between neutrophil MBE and clinical markers suggests that multiple systems might be involved in the post-CPB inflammatory reaction and organ dysfunction.

Extracorporeal hepatic resection and autotransplantation for primary gastrointestinal stromal tumor of the liver

We report a case of primary gastrointestinal stromal tumor of the liver. A 60-year-old woman with a large mass in the liver was asymptomatic with no hepatic virus infection and negative tumor markers. Because the tumor was unresectable by conventional means, we used extracorporeal hepatic resection and autotransplantation (ECHRA) for operation. The pathology showed a gastrointestinal stromal tumor that was diagnosed based on positive immunostaining for c-kit and CD34. Mutation analysis revealed an acquired mutation in exon 11 of c-kit. As we know, this is the eighth case of a primary hepatic extragastrointestinal stromal tumor reported previously in English, and the first case of which that was treated with ECHRA.

High-energy dissipative solitons generation from a large normal dispersion Er-fiber laser

We report on a passively mode-locked erbium-doped fiber laser featuring a large normal dispersion and emitting high-energy dissipative solitons. Mode-locking is stabilized by the combined actions of a high nonlinearity amplitude modulator and a narrow band spectral filter. The laser routinely delivers highly chirped pulses with more than 38 nJ energy that can be compressed down to 700 fs duration using bulk gratings. Numerical simulations confirm the experimental results and reveal the self-similar pulse evolution along the normal dispersion fibers included inside the cavity.

Association Between Smoking and p53 Mutation in Oesophageal Squamous Cell Carcinoma: A Meta-analysis

AIMS

Several studies have evaluated the association between smoking and p53 mutation in oesophageal squamous cell carcinoma (ESCC), but the conclusions are inconsistent. The aim of the present study was to carry out a meta-analysis evaluating the relationship between smoking and p53 mutation in patients with ESCC.

MATERIALS AND METHODS

Eligible studies were identified through searches in PubMed and EMBASE. The odds ratio with 95% confidence interval was used to assess the association. In total, 20 studies were identified that met the selection criteria; these studies were analysed using STATA 12.0 software.

RESULTS

The 20 studies identified comprised 1524 ESCC patients, of whom 72.97% were smokers and 27.03% were non-smokers. The pooled odds ratio of p53 mutation in ESCC for any cigarette smoking versus no smoking was 1.28 (95% confidence interval=0.88-1.88). The estimated odds ratios were 1.06 (95% confidence interval=0.56-2.00, based on five studies, 129 light smokers and 70 non-smokers) for light smoking and 2.01 (95% confidence interval=1.12-3.60, based on five studies, 223 heavy smokers and 73 non-smokers) for heavy smoking.

CONCLUSION

The results of our meta-analysis indicate an overall positive relationship between heavy smoking and p53 mutation in ESCC. Heavy smokers with ESCC have a higher risk for p53 mutation than non-smokers. Large-scale clinical studies are still needed to draw a more precise conclusion.

Chronic stress causes neuroendocrine-immune disturbances without affecting renal vitamin D metabolism in rats

INTRODUCTION

Vitamin D (VD) insufficiency has been repeatedly observed in the medical conditions associated with inflammation, such as cardiovascular disease, diabetes and depression. However, contrasting to the observational evidence, randomized trials of VD supplementation failed to demonstrate such link. Given the recent evidence that the inflammatory process can in turn alter VD metabolism, it has been hypothesized that the insufficient VD status could be the result rather than the cause of chronic inflammation involved in the onset of depression and other disease conditions.

MATERIALS AND METHODS

Chronic mild stress (CMS) is a valid animal model of depression that accompanied with neuroendocrine-immune disturbances. In the present research, we assessed serum VD concentrations and renal expression of the cytochromes P450 enzymes involved in VD activation (CYP27B1) and catabolism (CYP24A1) of rats following 8-week exposure to CMS.

RESULTS

While CMS induced the rats to a depression-like state and increased serum levels of the proinflammatory cytokines and corticosterone, and the antidepressant, sertraline, mitigated depression-like behaviors and neuroendocrine-immune disturbances, neither the stress regimen nor sertraline significantly affected endocrine metabolism of VD.

CONCLUSION

Our data suggest that the stress-induced neuroendocrine-immune disturbances may account for the development of depression, but are not responsible for the insufficient VD status that frequently observed in depressed patients.

The LIM protein fhlA is essential for heart chamber development in zebrafish embryos

Four-and-a-half LIM proteins FHL1-3 play important roles in cardiovascular pathophysiology. However, their roles in heart development remain unclear. Here, we report that fhlA, the zebrafish homolog of human FHL1, was found to be expressed around the 22-somite stage. After 24 hpf, expression was restricted to the heart. fhlA knockdown caused an enlarged cardiac chamber phenotype with up-regulated expression of the cardiac markers, but fhlA overexpression reduced the sizes of the cardiac chambers and down-regulated expression of the markers. The morphology associated with the cmlc2, amhc, and vmhc expression patterns at the 22 somite and 24 hpf stages included a broadened domain in embryos lacking fhlA and a smaller domain in embryos overexpressing fhlA. The changes in the sizes of the chambers were attributed to the changes in the number of ventricular and atrial cells. Loss of fhlA caused a longer heart period and pause between heartbeats in M-modes than in controls, but fhlA overexpression caused shorter systolic and diastolic intervals. Abnormal cardiac chambers and physiological function were found to be largely rescued. We also showed the expression of fhlA in the heart to be increased by retinoic acid (RA) and decreased by the RA synthase inhibitor DEAB. Both fhlA and RA signaling caused a phenotype characterized by the morphological alterations in the chamber sizes, suggesting that the role of fhlA in heart development is probably regulated by RA signaling. Taken together, these results showed that fhlA regulates the size of the heart chamber by reducing the number of cardiac cells.

Activation of β-catenin stimulated by mechanical strain and estrogen requires estrogen receptor in mesenchymal stem cells (MSCs)

BACKGROUND AND OBJECTIVES

Mechanical stimulation and hormones act via interconnected signaling pathways to influence the function of bone cells. Estrogen receptor (ER) and β-catenin play important role in bone formation and have implicated in mechanotransduction in bone cells. To investigate the interaction between mechanotransduction and estrogenic signaling in mesenchymal stem cells (MSCs), this study examined the effect of mechanical strain and estrogen on activation of β-catenin in MSCs, and the role of ER in response to mechanical strain and estrogen in MSCs.

MATERIALS AND METHODS

MSCs were exposed to mechanical strain (2%, 1 Hz) and estrogen (100 nM). The ER inhibitor, ICI182,780 was used to assess the role of ER in activation of β-catenin stimulated by mechanical strain and estrogen. Changes of activated β-catenin in the nuclei were determined by immunoflourescent test. The expression of β-catenin was detected by western blotting.

RESULTS

Mechanical strain and estrogen augment, respectively, activation of β-catenin and accumulation of activated β-catenin in the nuclei of MSCs. Combined treatment with estrogen and mechanical strain had higher levels of activated β-catenin than the cells exposed to mechanical strain or estrogen. After MSCs were pre-treated by ICI182,780, the level of activated β-catenin expression induced by mechanical strain or estrogen was depressed. Meanwhile, ICI182,780 blocked effect of combined stimulation on activation of β-catenin in MSCs.

CONCLUSIONS

Our study demonstrates that mechanical strain and estrogen both promote the levels of activated β-catenin in MSCs. Estrogen receptor implicates in activation of β-catenin stimulation by mechanical strain and estrogen in MSCs.

Neuropilin-1 is overexpressed in osteosarcoma and contributes to tumor progression and poor prognosis

AIM

Neuropilin (NRP)-1, a co-receptor for vascular endothelial growth factor (VEGF), plays an important role in angiogenesis and malignant progression of many cancers. However, the involvement of NRP-1 in osteosarcoma is not completely understood. The aim of this study was to investigate the expression pattern and clinical significance of NRP-1 in human osteosarcoma.

METHODS

NRP-1 mRNA and protein expression levels were detected by RT-PCR and Western blot assays, respectively, using 166 pairs of osteosarcoma and noncancerous bone tissues. Then, the association of NRP-1 expression with clinicopathological factors or survival of osteosarcoma patients was further evaluated.

RESULTS

RT-PCR and Western blot assays revealed that NRP-1 expression in osteosarcoma tissues was significantly higher than that in corresponding noncancerous bone tissues at both mRNA and protein levels (both P < 0.001). In addition, high NRP-1 expression more frequently occurred in osteosarcoma tissues with advanced clinical stage (P = 0.006), positive distant metastasis (P = 0.01) and poor response to chemotherapy (P = 0.006). Moreover, osteosarcoma patients with high NRP-1 expression had significantly shorter overall survival and disease-free survival (both P < 0.001) when compared with patients with the low expression of NRP-1. On Cox multivariate analysis, NRP-1 overexpression was an independent and significant prognostic factor to predict poor overall survival and disease-free survival (both P = 0.001).

CONCLUSION

This is the first study to reveal that NRP-1 overexpression may be related to the prediction of metastasis potency, response to chemotherapy and poor prognosis for osteosarcoma patients, suggesting that NRP-1 may serve as a prognostic marker for the optimization of clinical treatments.

Role of mechanical strain and estrogen in modulating osteogenic differentiation of mesenchymal stem cells (MSCs) from normal and ovariectomized rats

Bone's adaptability to loading depends upon the process of bone remodeling. This adaptive mechanism is restricted in postmenopausal osteoporosis. Differentiation of mesenchymal stem cells (MSCs) is crucial to bone remodeling and regeneration. It is well accepted that mechanical loading influences the fate of MSC differentiation. The aim of this study was to explore the possible restricted mechanism in osteoporotic condition, through investigating response of MSCs from both sham-operated and ovariectomized rats. MSCs were exposed to estrogen and mechanical strain (2%, 1Hz, 6h/day) for 3 days. Osteogenic differentiation and β-catenin protein in MSCs were examined. Exposure to estrogen and mechanical strain alone enhanced expression of Runx2 (Cbfα1), type I collagen (ColI) and activated β-catenin protein in MSCs from both sham-operated and OVX rats. MSCs from both sham-operated and OVX rats stimulated with both mechanical strain and estrogen had higher expression of osteogenic genes and activated β-catenin protein than these cells exposed to estrogen and mechanical strain alone. Osteoporotic MSCs had lower expression of osteogenic genes and protein in the absence and presence of stimulation than did MSCs from sham-operated rats. Cumulatively, our results indicate that mechanical strain and estrogen in vitro enhance osteogenic potential and activation of β-catenin in MSCs from both sham-operated and OVX rats. Estrogen augments strain-induced osteogenic potential and activity of β-catenin in MSCs.

Anti-tumour necrosis factor therapy enhances mucosal healing through down-regulation of interleukin-21 expression and T helper type 17 cell infiltration in Crohn's disease

Anti-tumour necrosis factor (TNF) monoclonal antibody (mAb) (infliximab, IFX) has been shown to be highly effective in the management of Crohn's disease (CD). Herein we investigated the potential role of IFX in inducing clinical remission and regulating interleukin (IL)-21 expression and T helper type 17 (Th17) cell infiltration in the intestinal mucosa of CD patients. Twenty-six CD patients were treated with IFX at weeks 0, 2 and 6. Clinical response, mucosal healing, serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were evaluated at week 10 after IFX administration. Expression of IL-21, IL-17A and retinoic acid-related orphan receptor C (RORC) in intestinal mucosa were analysed by quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. Peripheral blood and lamina propria CD4(+) T cells were stimulated with anti-CD3 and anti-CD28 mAbs in the presence of IFX. Cytokine profiles and RORC were determined with enzyme-linked immunosorbent assay (ELISA) and real-time PCR. IL-21 and Th17 cells were found to be expressed highly in inflamed mucosa of active CD patients compared with healthy controls. Ten weeks after IFX infusion, CD activity index, ESR, CRP and intestinal mucosal healing were improved markedly in CD patients, and IL-21 expression and Th17 cell infiltration were decreased significantly compared with those before IFX therapy. In-vitro study demonstrated that IFX treatment could suppress IL-21, IL-17A and RORC expression in cultured CD biopsies. Moreover, IFX was also observed to down-regulate markedly IL-17A, IL-21 and RORC expression by CD CD4(+) T cells. IFX is highly effective in inducing clinical remission and promoting intestinal mucosal healing in CD patients through down-regulation of IL-21 expression and Th17 cell infiltration in intestinal mucosa.

Enhancement of chitosanase production by cell immobilization of Gongronella sp. JG

Chitosanase production of Gongronella sp. JG cells immobilized in calcium alginate gel and polyurethane foam was compared with that of the free cells, there was a 60% increase in the enzyme yield (2429 U/L) compared to the highest yield obtained from free cells (1513 U/L). The optimal immobilization parameters (concentrations of sodium alginate, calcium chloride, bead inoculums, bead diameter, etc) for the enhanced production of chitosanase were determined as: sodium alginate 2% (w/v), 0.1 M calcium chloride, inoculum 10 mL beads to 100 mL production media and 2.7 mm bead diameter. Maximum chitosanase production was achieved with initial pH of 5.5 and temperature of 30 °C. The alginate beads had well stability, retained 85% ability of enzyme production even after 7 cycles of repeated batch fermentation. These results showed the immobilization technique was a feasible and economical method for chitosansase production by Gongronella sp. JG.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Altered white matter integrity in adolescents with prelingual deafness: a high-resolution tract-based spatial statistics imaging study

BACKGROUND AND PURPOSE

Prelingual deafness is a hearing loss that occurs before language is acquired and may result in brain structural alterations. We studied microstructural WM alterations in prelingually deaf adolescents by using DTI. We hypothesized that any morphologic alterations are mainly located in the auditory association areas. Furthermore, considering that the developing brain is both more vulnerable to deprivation and more plastic than the adult brain, we speculated that the affected areas should be larger than those previously reported in adult deafness.

MATERIALS AND METHODS

Diffusion tensor images were obtained from 16 prelingually deaf adolescents (age range, 10-18 years) and 16 healthy control adolescents matched for age and sex. Both groups were compared in fractional anisotropy and radial diffusivity by tract-based spatial statistics. In addition, we examined the correlation between the structural data (FA, RD) differences and the duration of sign language use and hearing aid experience.

RESULTS

Prelingually deaf adolescents had significantly lower FA and increased RD in the bilateral superior temporal gyri, Heschl gyrus, planum polare, and the splenium of the corpus callosum. Only RD values in the right superior temporal gyrus correlated significantly and negatively (r = -0.518; P = .040) with duration of sign language use. These alterations were larger than those previously reported in adult deafness.

CONCLUSIONS

As expected, we found severe morphologic changes of decreased FA and increased RD in multiple auditory association areas and in the corpus callosum. These changes are signs of development impairments in prelingually deaf adolescents, possibly reflecting axonal loss or lack of myelination.

Increased expression of CD24 is associated with tumor progression and prognosis in patients suffering osteosarcoma

OBJECTIVE

As a small heavily glycosylated mucin-like glycosyl-phosphatidylinositol-anchored cell surface protein, CD24 plays an important role in carcinogenesis of various human malignancies. However, its involvement in osteosarcoma is still unclear. The aim of this study was to investigate the expression pattern and the clinical significance of CD24 in human osteosarcoma.

METHODS

CD24 mRNA and protein expression levels were, respectively, detected by RT-PCR and Western blot assays using 30 pairs of osteosarcoma and noncancerous bone tissues. Then, immunohistochemistry was performed to analyze the association of CD24 expression in 166 osteosarcoma tissues with clinicopathological factors or survival of patients.

RESULTS

CD24 expression at mRNA and protein levels were both significantly higher in osteosarcoma tissues than those in corresponding noncancerous bone tissues (both P < 0.001). In addition, CD24 protein was positively expressed in 129 of 166 (77.7 %) osteosarcoma specimens with a cytoplasmic and membraneous staining, and also increased in the osteosarcoma specimens with advanced clinical stage (P = 0.01) and positive distant metastasis (P = 0.005). The univariate and multivariate analyses showed that osteosarcoma patients with high CD24 expression had poorer overall and disease-free survival, and high CD24 expression was an independent prognostic factor for both overall and disease-free survival.

CONCLUSION

The aforementioned findings offer convincing evidence for the first time that the increased expression of CD24 is correlated with tumor aggressiveness and tumor metastasis of osteosarcoma, and this molecule is an independent prognostic marker for osteosarcoma patients.

Microbial community structure in the rhizosphere of Sophora viciifolia grown at a lead and zinc mine of northwest China

Understanding the effects of heavy metal contamination on microbial activity is important for developing strategies to reclaim sites disturbed by industrial activities. In this study, we investigated arbuscular mycorrhizal (AM) fungi and bacteria associated with Sophora viciifolia growing at a lead and zinc mine in Qinling Mountain, China. Specifically, we measured the extent of AM fungal root colonization, examined microbial community structure by PCR-denaturing gradient gel electrophoresis (PCR-DGGE), and identified the dominant microorganisms. We also measured the amount of glomalin-related soil protein (GRSP) and the association of GRSP with heavy metal ions. We found that AM root colonization decreased, but total GRSP increased with the increase of the lead concentration in soil. The Shannon-Wiener Index (H') of the AM fungal community showed a significant negative correlation with the available lead concentration (r=0.92, P=0.009). Bacterial community H' was also negatively correlated with the total and available lead concentrations in the soil (r=0.97, P=0.007 and r=0.92, P=0.025 for total and available lead, respectively). Both, AM fungal and bacterial community structures differed significantly between sites along the pollution gradient. The specific distributions of the two kinds of organisms indicated their differing tolerances to heavy metal. The dominant AM fungi were identified as Glomeraceae, whereas the dominant bacteria belonged to Proteobacteria. The amount of lead bound to GRSP varied from 3.3 to 172.5 mg kg(-1), which positively correlated with total and available soil lead concentration (r=0.99, P<0.000 and r=0.93, P=0.020 for total soil lead and available soil lead concentration, respectively), thus reducing the bioavailability of heavy metal ions.

Human embryonic stem cell encapsulation in alginate microbeads in macroporous calcium phosphate cement for bone tissue engineering

Human embryonic stem cells (hESC) are promising for use in regenerative medicine applications because of their strong proliferative ability and multilineage differentiation capability. To date there have been no reports on hESC seeding with calcium phosphate cement (CPC). The objective of this study was to investigate hESC-derived mesenchymal stem cell (hESCd-MSC) encapsulation in hydrogel microbeads in macroporous CPC for bone tissue engineering. hESC were cultured to form embryoid bodies (EB), and the MSC were then migrated out of the EB. hESCd-MSC had surface markers characteristic of MSC, with positive alkaline phosphatase (ALP) staining when cultured in osteogenic medium. hESCd-MSC were encapsulated in alginate at a density of 1millioncellsml(-1), with an average microbead size of 207μm. CPC contained mannitol porogen to create a porosity of 64% and 218-μm macropores, with 20% absorbable fibers for additional porosity when the fibers degrade. hESCd-MSC encapsulated in microbeads in CPC had good viability from 1 to 21days. ALP gene expression at 21days was 25-fold that at 1day. Osteocalcin (OC) at 21days was two orders of magnitude of that at 1day. ALP activity in colorimetric p-nitrophenyl phosphate assay at 21days was fivefold that at 1day. Mineral synthesis by the encapsulated hESCd-MSC at 21days was sevenfold that at 1day. Potential benefits of the CPC-stem cell paste include injectability, intimate adaptation to complex-shaped bone defects, ease in contouring to achieve esthetics in maxillofacial repairs, and in situ setting ability. In conclusion, hESCd-MSC were encapsulated in alginate microbeads in macroporous CPC, showing good cell viability, osteogenic differentiation and mineral synthesis for the first time. The hESCd-MSC-encapsulating macroporous CPC construct is promising for bone regeneration in a wide range of orthopedic and maxillofacial applications.

Role of antisite disorder on preamorphization swelling in titanate pyrochlores

Ion irradiation experiments and atomistic simulations were used to demonstrate that irradiation-induced lattice swelling in a complex oxide, Lu2Ti2O7, is due initially to the formation of cation antisite defects. X-ray diffraction revealed that cation antisite formation correlates directly with lattice swelling and indicates that the volume per antisite pair is approximately 12  Å3. First principles calculations revealed that lattice swelling is best explained by cation antisite defects. Temperature accelerated dynamics simulations indicate that cation Frenkel defects are metastable and decay to form antisite defects.