Energy relations of positron-electron pairs emitted from surfaces

The impact of a primary positron onto a surface may lead to the emission of a correlated positron-electron pair. By means of a lab-based positron beam we studied this pair emission from various surfaces. We analyzed the energy spectra in a symmetric emission geometry. We found that the available energy is shared in an unequal manner among the partners. On average the positron carries a larger fraction of the available energy. The unequal energy sharing is a consequence of positron and electron being distinguishable particles. We provide a model which explains the experimental findings.

Role of cathepsin B in regulating migration and invasion of fibroblast-like synoviocytes into inflamed tissue from patients with rheumatoid arthritis

Cathepsin B (CB), an important proteinase that participates in joint destruction in rheumatoid arthritis (RA), exhibits higher expression in fibroblast-like synoviocyte (FLS) of abnormal proliferative synovial tissues. Whether and how it affects the biological behaviours of RA-FLS, such as migration and invasion, are poorly understood. In the present study, CB expression in synovial tissues of patients with RA and ostearthritis (OA) were measured by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC), respectively. Stable depletion of endogenous CB was achieved by small interfering RNA (siRNA) transfection, and decrease of CB activity was acquired by using its specific inhibitor (CA074Me). The effects of CA074Me and RNA interference (RNAi) treatments on proliferation, migration, invasion, matrix metalloproteinase (MMP)-2/-9 expression, focal adhesion kinase (FAK) activation, and mitogen-activated protein kinases (MAPKs) phosphorylation of FLS were analysed. In RA synovial tissues, CB was expressed at elevated levels compared with OA synovial tissues. CA074Me could inhibit invasion of FLS obtained from RA patients in an ex-vivo invasion model. CA074Me and siRNA treatments suppressed the migration and invasion of FLS, reduced the activity, expression and mRNA level of MMP-2, restrained the activation of FAK and reduced the expression of F-actin. Moreover, CA074Me decreased the phosphorylation of P38 MAPK and c-Jun N-terminal kinase (JNK) in FLS, while siCB treatment reduced the phosphorylation of P38 but not JNK. CB substantially contributes to the invasive phenotype of FLS that leads to joint destruction in RA. This proteinase may show promise as a therapeutic target in inflammatory arthritis.

Nuclear factor erythroid 2-related factor 2 rescues the oxidative stress induced by di-N-butylphthalate in testicular Leydig cells

Aim:

This study aimed to determine whether nuclear factor erythroid 2-related factor 2 antagonized the oxidative stress induced by di- N-butylphthalate (DBP) in testicular Leydig cells.

Methods:

Mouse TM3 testicular Leydig cells were treated with Nrf2 knockdown (KD) or overexpression in the presence and absence of DBP. Oxidative profiles were examined. Nrf2 target antioxidant genes were studied, and the effects of Nrf2 inducer sulphoraphane (SFN) were tested.

Results:

DBP induced intracellular oxidative stress to a similar extent with Nrf2 KD. Expression and protein levels of Nrf2 were increased together with its target genes, namely heme oxygenase 1, nicotinamide adenine dinucleotide phosphate quinone oxidoreductase 1 and peroxiredoxin 6, following DBP stimulation. Use of SFN not only restored the intracellular oxidative toxicity but also cell proliferation and testosterone secretion in response to DBP.

Conclusion:

Increased Nrf2 activity, for example, by SFN can effectively antagonize the oxidative stress in testicular Leydig cells caused by DBP.

Default network connectivity as a vulnerability marker for obsessive compulsive disorder

BACKGROUND

Aberrant functional connectivity within the default network is generally assumed to be involved in the pathophysiology of obsessive compulsive disorder (OCD); however, the genetic risk of default network connectivity in OCD remains largely unknown.

METHOD

Here, we systematically investigated default network connectivity in 15 OCD patients, 15 paired unaffected siblings and 28 healthy controls. We sought to examine the profiles of default network connectivity in OCD patients and their siblings, exploring the correlation between abnormal default network connectivity and genetic risk for this population.

RESULTS

Compared with healthy controls, OCD patients exhibited reduced strength of default network functional connectivity with the posterior cingulate cortex (PCC), and increased functional connectivity in the right inferior frontal lobe, insula, superior parietal cortex and superior temporal cortex, while their unaffected first-degree siblings only showed reduced local connectivity in the PCC.

CONCLUSIONS

These findings suggest that the disruptions of default network functional connectivity might be associated with family history of OCD. The decreased default network connectivity in both OCD patients and their unaffected siblings may serve as a potential marker of OCD.

Common characteristics shared by different differential phase contrast imaging methods

There are many variations of differential phase contrast imaging methods. Although these imaging methods are different in configuration, they are alike in imaging by extracting differential phase information through the evaluation of the refraction angles. In this paper, we investigate common characteristics shared by various different differential phase contrast imaging methods.

The expression and significance of TIPE2 in peripheral blood mononuclear cells from asthmatic children

Tumour necrosis factor-α-induced protein-8 like-2 (TIPE2) is a newly identified immune negative regulator. The abnormal expression of TIPE2 has been found in several human inflammatory diseases. However, the expression level and clinical significance of TIPE2 in childhood asthma remain unclear. In this study, we detected TIPE2 expression in peripheral blood mononuclear cells (PBMC) from 42 children with asthma and 39 healthy controls by RT-PCR, qRT-PCR and Western blot. We also detected the levels of serum total immunoglobulin E (IgE), eosinophil (EO), interleukin-4 (IL-4) and interferon-γ (IFN-γ) and analysed the correlations of TIPE2 expression with IgE, EO, IL-4 and IFN-γ. The results showed that TIPE2 mRNA and protein expression were decreased in children with asthma compared with healthy controls. The levels of IgE, EO and IL-4 in the children with asthma were obviously higher than those in normal controls, while the level of IFN-γ in patients with asthma was significantly lower than that in healthy subjects. Furthermore, the expression level of TIPE2 mRNA was negatively correlated with IgE, EO and IL-4. However, no statistically significant correlation was found between TIPE2 mRNA expression and serum IFN-γ level. In conclusion, our data suggest that reduced TIPE2 expression may contribute to the pathogenesis of childhood asthma.

Chain-growth polycondensation of perylene diimide-based copolymers: a new route to regio-regular perylene diimide-based acceptors for all-polymer solar cells and n-type transistors

Chain-growth tin-free room temperature polymerization is reported which leads to perylene diimide-based n-type polymers suitable for solar cell and transistor applications.

Prevalence of latent tuberculosis infection among healthcare workers in China as detected by two interferon-gamma release assays

Healthcare workers in China have a high risk of tuberculosis infection. This study measured the prevalence of latent tuberculosis infection in 210 healthcare workers in a chest hospital in Harbin using two interferon-gamma release assays (IGRAs) [QuantiFERON(®)-TB Gold In-Tube (QFT-GIT) and A.TB] and the tuberculin skin test. Results from the IGRAs had moderate agreement with positivity rates of 76.5% (QFT-GIT) and 65.7% (A.TB) but <50% of subjects returned for tuberculin skin test readings. Risk of infection increased with patient exposure. IGRAs may be more useful than tuberculin skin test in monitoring tuberculosis infections in high risk environments.

Expression profiles analysis of pancreatic cancer

BACKGROUND

[Corrected] Pancreatic cancer is the fourth most common cause of cancer-related deaths across the globe and has a poor prognosis.

AIM

To investigate the characteristics of genomic expression profiles of pancreatic cancer and screen differentially expressed genes.

MATERIALS AND METHODS

Using GSE16515 dataset downloaded from GEO (Gene Expression Omnibus) database, we first screened the differentially expressed genes (DEGs) in pancreatic cancer by packages in R language. The key functions of DEGs were investigated by GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis. The potential functionally important SNP (Single Nucleotide Polymorphism) was selected from the dbSNP database.

RESULTS

A total of 1270 DEGs were identified. Most of them were predicted to be involved in pancreatic cancer development by sequence variant. Six genes (CDC42, STAT1, RALA, BCL2L1, TGFA, and EGF) were enriched in the known pancreatic cancer pathway. All these six genes had SNP, usually mutation at A/G and C/T point.

CONCLUSIONS

Our results provide some underlying biomarkers for early diagnosis of pancreatic cancer.

Functional single nucleotide polymorphism in C20orf54 modifies susceptibility to esophageal squamous cell carcinoma

The aim of this study was to explore the association of C20orf54 functional single nucleotide polymorphism (SNP) with the susceptibility to esophageal squamous cell carcinoma (ESCC) in a northern China population. The C20orf54 SNP was genotyped by direct sequencing in 240 cancer patients and 198 controls in northern China. The results showed that drinking status, family history of ESCC, and body mass index have great influence on the risk of developing ESCC. The overall genotype frequencies of C20orf54 in ESCC patients have a significant difference with healthy controls (χ(2)  = 8.06, P = 0.018). By using C/C genotype as the reference, the C/T genotype showed a significantly decreased risk to the development of ESCC. Thus, compared with the C/C genotype, smokers, drinkers with C/T genotype significantly decreased the risk of developing ESCC. A positive family history of ESCC with C/T and T/T genotype both increased the risk of developing ESCC. Body mass index between 18.5 and 24 with C/T genotype significantly decreased the risk of developing ESCC. The present study suggests that the C20orf54 functional SNP might be associated with a risk of development in ESCC.

55 STUDY ON THE INTERSPECIFIC NUCLEAR TRANSFER OF PRZEWALSKI'S GAZELLES AND BOVINES

Przewalski’s gazelle (Procapra przewalskii), also known as Platts antelope, is an endangered species only found in China. It belongs to the Artiodactyla order, Bovidae family, antelope subfamily, and Gazella genus. In this study, 5 experiments were designed to examine the developmental potential of Przewalski’s gazelle somatic cells transplanted into bovine enucleated oocytes. Enucleation was conducted by Hoechst 33342 staining of the oocytes and guided by a fluorescent microscope to ensure the removal of the nuclei. The gazelle cells were then transferred to the enucleated oocytes and electrically fused to reconstructed embryos. The study resulted in 5 major findings. (1) When gazelle-bovine reconstructed embryos were treated with the deacetylase inhibitor valproic acid (VPA), at different concentrations and for different times, treatment of the cloned embryos with VPA at 0.5 mM for 24 h significantly increased the 8- to 16-cell-stage embryo development [61.9% (96/155) v. 33.8% (46/136) control]. However, the morula [1.3% (2/155) v. 1.5% (2/155); P > 0.05] and blastocyst (0.7% v. 1.5%; P > 0.05) development were similar to that of the control. In the intraspecific (bovine-bovine) control group, the cleavage, morula and blastocyst development of 3 cloned embryos were 72.6% (127/175), 28.0% (49/175), and 23.4% (41/175). (2) Octamer-binding transcription factor 4 (Oct-4), as a developmental potential and expression marker, was transfected to gazelle cells. When Oct-4-eGFP-confected cells were transferred, the cloned embryo development did not improve either with or without VPA treatment. (3) When the gazelle-bovine embryos were treated with the deacetylase inhibitor trichostatin A (TSA) for 24 h at 10 ng mL–1, blastocyst development was significantly higher than in the control group [3.6% (6/168) v. 0.8% (1/125); P < 0.05]. (4) When a reverse NT protocol, in which the oocyte nucleus was removed after the cell nucleus was fused to the oocyte, was used for NT, the cloned embryo development did not improve. (5) The gazelle-bovine and bovine-bovine cloned embryos at 8- to 16-cell stages, gazelle cells, bovine cells, and bovine oocytes transcriptomes were analyzed by Affymetrix microarray (Affymetrix Microarray Inc., Santa Clara, CA, USA) and repeated twice. A total of 643 genes were activated in gazelle-cattle embryos compared with oocytes, whereas 1527 genes were activated in bovine-bovine clones. A total of 1010 genes that were exclusively expressed in gazelle somatic cells were still expressed in the interspecies cloned embryos. In conclusion, TSA treatment of Przewalski’s gazelle somatic cells transferred into enucleated bovine oocytes improved development of cloned embryos to the blastocyst stage, although still with low efficiency. Data from microarray analyses of the gazelle-cattle embryos showed that over 1000 gazelle-specific genes were still expressed in the interspecific cloned embryos. This work was supported by the National Basic Research Program of China (no. 2012CB22306).

45 EFFECT OF DEACETYLASE INHIBITOR VALPROIC ACID ON BOVINE CULTURED SOMATIC CELLS

Normal development depends on a precise sequence of changes in the configuration of chromatin. Epigenetic modifications, such as histone acetylation and methylation and DNA methylation, control the precise tissue-specific gene expressions. Valproic acid (VPA) is an aliphatic acid compound and a deacetylase inhibitor that influences cellular proliferation, differentiation, apoptosis, and migration. Several studies have shown that treatment of fused, cloned embryos with VPA improved embryo development. However, whether the treatment of donor cells with VPA affected cloned embryo development was not clear. In the present study, bovine fibroblast cells were treated with VPA at 0, 0.25, 0.5, 1.0, 2.0, and 4.0 mM concentrations for 24 and 48 h, respectively. The cell growth, cell cycle, diploid composition, and histone modifications were examined. The results showed that (1) when the cells were treated with VPA at and over 2.0 mM concentrations for 24 or 48 h, cell growth was significantly inhibited; (2) VPA treatment resulted in a decrease in cell diploid composition; (3) VPA induced the arrestment of cells at the G0/G1 stages; (4) VPA treatment increased early cell apoptosis; (5) VPA at a 4.0 mM concentration and treatment of cells for 24 h improved H3K9 acetylation; however, treatment of cells with VPA decreased H3K9 methylation in all experimental groups; and (6) when the cells treated with VPA at 0, 0.25, 0.5, 1.0, and 2.0 mM concentrations for 24 h were used as donor cells for NT, the cleavage rates were 83.2, 80.0, 82.1, 80.5, and 65.5%, respectively, and the percentages of blastocyst development were 30.5, 29.6, 29.2, 25.0, and 15.5%, respectively. When the cells were treated with VPA at 4.0 mM concentration, the cleavage (65.5%, 76/116) and blastocyst development (15.5%, 18/116) significantly decreased as compared with the control [83.2% (158/190) and 30.5% (58/190), respectively]. The cell numbers of the blastocysts derived from VPA treatment at 0, 0.25, 0.5, 1.0, and 2.0 mM concentrations were 89.6, 88.6, 87.6, 75.0, and 71.3, respectively, which decreased with the increase in VPA concentration. In conclusion, VPA affected cell growth and histone modifications in a concentration-dependent manner. The VPA-treated cells did not improve the cloned embryo development and even decreased blastocyst when VPA was at a high concentration. This work was supported by the National Basic Research Program of China (no. 2012CB22306).

Whole blood genome-wide gene expression profile in males after prolonged wakefulness and sleep recovery

Although the specific functions of sleep have not been completely elucidated, the literature has suggested that sleep is essential for proper homeostasis. Sleep loss is associated with changes in behavioral, neurochemical, cellular, and metabolic function as well as impaired immune response. Using high-resolution microarrays we evaluated the gene expression profiles of healthy male volunteers who underwent 60 h of prolonged wakefulness (PW) followed by 12 h of sleep recovery (SR). Peripheral whole blood was collected at 8 am in the morning before the initiation of PW (Baseline), after the second night of PW, and one night after SR. We identified over 500 genes that were differentially expressed. Notably, these genes were related to DNA damage and repair and stress response, as well as diverse immune system responses, such as natural killer pathways including killer cell lectin-like receptors family, as well as granzymes and T-cell receptors, which play important roles in host defense. These results support the idea that sleep loss can lead to alterations in molecular processes that result in perturbation of cellular immunity, induction of inflammatory responses, and homeostatic imbalance. Moreover, expression of multiple genes was downregulated following PW and upregulated after SR compared with PW, suggesting an attempt of the body to re-establish internal homeostasis. In silico validation of alterations in the expression of CETN3, DNAJC, and CEACAM genes confirmed previous findings related to the molecular effects of sleep deprivation. Thus, the present findings confirm that the effects of sleep loss are not restricted to the brain and can occur intensely in peripheral tissues.