[Depressive symptoms and influencing factors in employees from thirteen enterprises]

OBJECTIVE

To explore depressive symptoms and influencing factors in employees from 13 enterprises.

METHODS

A total of 6711 workers from 13 enterprises were investigated by cluster sampling, and data were collected anonymously between November 2008 and June 2009. Job satisfaction, occupational stressors, strains, coping strategy, and social support were measured using occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire.

RESULTS

Median and P25~P75 values of depression score were 14 and 9~21, respectively. The depression score of male workers (16.31 ± 10.12) was significantly higher than that of female workers(14.50 ± 9.08) (Z=4.09, P<0.01). The depression score of managers was lowest (12.89 ± 8.70), and the front-line workers scored highest (16.02 ± 9.94), with a significant difference between the two groups (χ² =9.90, P<0.01). The depression score of shift workers (16.79 ± 9.974) was significantly higher than that of non-shift workers (14.81 ± 9.63) (Z=53.43, P<0.01). The depression scores of workers with weekly job times of ≤ 40 h, ~50 h, ~59 h, and ≥ 60 h were (14.70 ± 9.94), (15.76 ± 9.84), (15.46 ± 9.91), and (19.70 ± 10.67), respectively (χ² = 31.79, P <0.01). Correlation analysis revealed that depression score was negatively correlated with the scores of job control (r=-0.236, P <0.01), reward (r=-0.443, P<0.01), job satisfaction (r=-0.418, P<0.01), positive affectivity (r=-0.307, P <0.01), superior support (r=-0.287, P<0.01), colleague support (r=-0.235, P<0.01), and coping strategy (r=-0.208, P<0.01), but positively correlated with the scores of external effort (r=0.225, P<0.01), inherent effort (r=0.248, P<0.01), psychological demands (r = 0.246, P <0.01), physical demands (r=0.246, P<0.01), and negative affectivity (r=0.525, P<0.01). Multivariate logistic regression analysis revealed that the risk of depressive symptoms in workers with high negative affectivity was about four times as high as that in workers with low negative affectivity. The risks of depressive symptoms in workers with low reward, having disease in the past six months, and with high inherent effort were 1.62, 1.50, and 1.48 times, respectively, as high as those for their counterparts.

CONCLUSION

Occupational stress, individual factors, health status, and shift work affect the depressive symptoms of workers. Reducing negative affectivity and increasing rewards are main measures to relieve depressive symptoms.

Real-time in vivo imaging reveals the ability of neutrophils to remove Cryptococcus neoformans directly from the brain vasculature

Although neutrophils are typically the first immune cells attracted to an infection site, little is known about how neutrophils dynamically interact with invading pathogens in vivo. Here, with the use of intravital microscopy, we demonstrate that neutrophils migrate to the arrested Cryptococcus neoformans, a leading agent to cause meningoencephalitis, in the brain microvasculature. Following interactions with C. neoformans, neutrophils were seen to internalize the organism and then circulate back into the bloodstream, resulting in a direct removal of the organism from the endothelial surface before its transmigration into the brain parenchyma. C. neoformans infection led to enhanced expression of adhesion molecules macrophage 1 antigen on neutrophils and ICAM-1 on brain endothelial cells. Depletion of neutrophils enhanced the brain fungal burden. Complement C3 was critically involved in the recognition of C. neoformans by neutrophils and subsequent clearance of the organism from the brain. Together, our finding of the direct removal of C. neoformans by neutrophils from its arrested site may represent a novel mechanism of host defense in the brain, in addition to the known, direct killing of microorganisms at the infection sites. These data are the first to characterize directly the dynamic interactions of leukocytes with a microbe in the brain of a living animal.

DEC1 regulates breast cancer cell proliferation by stabilizing cyclin E protein and delays the progression of cell cycle S phase

Breast cancer that is accompanied by a high level of cyclin E expression usually exhibits poor prognosis and clinical outcome. Several factors are known to regulate the level of cyclin E during the cell cycle progression. The transcription factor DEC1 (also known as STRA13 and SHARP2) plays an important role in cell proliferation and apoptosis. Nevertheless, the mechanism of its role in cell proliferation is poorly understood. In this study, using the breast cancer cell lines MCF-7 and T47D, we showed that DEC1 could inhibit the cell cycle progression of breast cancer cells independently of its transcriptional activity. The cell cycle-dependent timing of DEC1 overexpression could affect the progression of the cell cycle through regulating the level of cyclin E protein. DEC1 stabilized cyclin E at the protein level by interacting with cyclin E. Overexpression of DEC1 repressed the interaction between cyclin E and its E3 ligase Fbw7α, consequently reducing the level of polyunbiquitinated cyclin E and increased the accumulation of non-ubiquitinated cyclin E. Furthermore, DEC1 also promoted the nuclear accumulation of Cdk2 and the formation of cyclin E/Cdk2 complex, as well as upregulating the activity of the cyclin E/Cdk2 complex, which inhibited the subsequent association of cyclin A with Cdk2. This had the effect of prolonging the S phase and suppressing the growth of breast cancers in a mouse xenograft model. These events probably constitute the essential steps in DEC1-regulated cell proliferation, thus opening up the possibility of a protein-based molecular strategy for eliminating cancer cells that manifest a high-level expression of cyclin E.

A new small molecule inhibits Streptococcus mutans biofilms in vitro and in vivo

AIMS

The aim of this study was to identify new small molecules that can inhibit Streptococcus mutans biofilms by in vitro and in vivo model.

METHODS AND RESULTS

We evaluated the effect of a small molecule 2-amino-imidazole/triazole conjugate (2-AI/T) on the formation of Strep. mutans biofilms by culturing in 96-well plates. Toxicity was assessed through cell culture and intragastrically administering to mice. The anti-biofilm and anti-caries effects were investigated in vivo. The inhibitive mechanism was detected by isobaric tag for relative and absolute quantification (itraq) and RT-QPCR. In vitro and in vivo study revealed that 2-AI/T significantly inhibited biofilm formation of Strep. mutans and is more so than inhibiting planktonic cells without toxicity. The ribosome and histidine metabolism pathways of Strep. mutans were significantly regulated by this compound.

CONCLUSIONS

These results suggest that the 2-AI/T conjugate is a potent inhibitor that can be potentially developed into a new drug to treat and prevent dental caries.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first study to use small molecule from marine natural products, to protect from dental caries in vivo. It has potential broad range application in clinical caries prevention, or as a bioactive ingredient for food applications.

Expression Patterns of Circular RNAs from Primary Kinase Transcripts in the Mammary Glands of Lactating Rats

Purpose

Circular RNAs (circRNAs), a novel class of RNAs, perform important functions in biological processes. However, the role of circRNAs in the mammary gland remains unknown. The present study is aimed at identifying and characterizing the circRNAs expressed in the mammary gland of lactating rats.

Methods

Deep sequencing of RNase R-enriched rat lactating mammary gland samples was performed and circRNAs were predicted using a previously reported computational pipeline. Gene ontology terms of circRNA-producing genes were also analyzed.

Results

A total of 6,824 and 4,523 circRNAs were identified from rat mammary glands at two different lactation stages. Numerous circRNAs were specifically expressed at different lactation stages, and only 1,314 circRNAs were detected at both lactation stages. The majority of the candidate circRNAs map to noncoding intronic and intergenic regions. The results demonstrate a circular preference or specificity of some genes. DAVID analysis revealed an enrichment of protein kinases and related proteins among the set of genes encoding circRNAs. Interestingly, four protein-coding genes (Rev3l, IGSF11, MAML2, and LPP) that also transcribe high levels of circRNAs have been reported to be involved in cancer.

Conclusion

Our findings provide the basis for comparison between breast cancer profiles and for selecting representative circRNA candidates for future functional characterization in breast development and breast cancer.

Suppressed phase transition and giant ionic conductivity in La2Mo2O9 nanowires

Improving the ionic conductivity of solid electrolytes at low temperatures represents a major challenge and an opportunity for enabling a variety of solid-state ionic devices for energy conversion and storage, as well as for environmental protection. Here we report a giant ionic conductivity of 0.20 Scm(-1), achieved at 500 °C, in the La2Mo2O9 nanowires with a bamboo-wire morphology, corresponding to a 1000-fold enhancement in conductivity over conventional bulk material. Stabilization of the high-temperature phase is observed to account for about a 10-fold increase in the conductivity. We further demonstrate that fast surface conduction in ∼3 nm thick, partially ordered, surface 'amorphous' films, under strain on the curved surfaces of the nanowires (as a non-autonomous surface phase or complexion), contributes to an enhancement of the conductivity by another two orders of magnitude. Exemplified here by the study of the La2Mo2O9 nanowires, new possibilities for improvement of conductivity and for miniaturization of solid-state ionic devices by the careful use of one-dimensional nanomaterials can be envisioned.

Viral Restriction Activity of Feline BST2 Is Independent of Its N-Glycosylation and Induction of NF-κB Activation

BST2 (CD317, tetherin, HM1.24) is an interferon-inducible transmembrane protein which can directly inhibit the release of enveloped virus particles from infected cells, and its anti-viral activity is reported to be related to the specific topological arrangement of its four structural domains. The N-terminal cytoplasmic tail of feline BST2 (fBST2) is characterized by a shorter N-terminal region compared to those of other known homologs. In this study, we investigated the functional impact of modifying the cytoplasmic tail region of fBST2 and its molecular mechanism. The fBST2 protein with the addition of a peptide at the N-terminus retained anti-release activity against human immunodeficiency virus type-1 and pseudovirus based on feline immunodeficiency virus at a weaker level compared with the wild-type fBST2. However, the fBST2 protein with addition of a peptide internally in the ectodomain proximal to the GPI anchor still retained its anti-viral activity well. Notably, the N-glycosylation state and the cell surface level of the N-terminally modified variants were unlike those of the wild-type protein, while no difference was observed in their intracellular localizations. However, in contrast to human BST2, the wild-type fBST2 did not show the ability to activate NF-κB. Consistent with previous reports, our findings showed that adding a peptide in the cytoplasmic tail region of fBST2 may influence its anti-viral activity. The shorter N-terminal cytoplasmic region of fBST2 compared with human BST2 did not apparently affect its anti-viral activity, which is independent of its N-glycosylation and ability to activate NF-κB.

Genetic associations of leptin-related polymorphisms with systemic lupus erythematosus

Leptin is abnormally elevated in the plasma of patients with systemic lupus erythematosus (SLE), where it is thought to promote and/or sustain pro-inflammatory responses. Whether this association could reflect an increased genetic susceptibility to develop SLE is not known, and studies of genetic associations with leptin-related polymorphisms in SLE patients have been so far inconclusive. Here we genotyped DNA samples from 15,706 SLE patients and healthy matched controls from four different ancestral groups, to correlate polymorphisms of genes of the leptin pathway to risk for SLE. It was found that although several SNPs showed weak associations, those associations did not remain significant after correction for multiple testing. These data do not support associations between defined leptin-related polymorphisms and increased susceptibility to develop SLE.

Combination of early and delayed ischemic postconditioning enhances brain-derived neurotrophic factor production by upregulating the ERK-CREB pathway in rats with focal ischemia

Ischemic postconditioning, including early and delayed ischemic postconditioning, has been recognized as a simple and promising strategy in the treatment of stroke. However, the effects of the combination of early and delayed ischemic postconditioning, and the mechanisms underlying these effects, remain unclear. The aim of the present study was to determine whether the combination of early and delayed ischemic postconditioning offers greater protection against stroke, and enhances the production of brain‑derived neurotrophic factor (BDNF). A combination of early and delayed ischemic postconditioning was established by repeated, transient occlusion and reperfusion of the ipsilateral common carotid artery in a rat model of middle cerebral artery occlusion. Infarct size, motor function, cerebral blood flow and brain edema were then evaluated, in order to confirm the effects of combinative ischemic postconditioning. TUNEL staining was used to analyze the rate of apoptosis of cells in the penumbral area. BDNF, extracellular signal‑regulated kinases 1/2 (ERK1/2) and cAMP response element‑binding protein (CREB) expression was detected using immunofluorescence staining and western blot analysis. The results of the present study indicated that the combination of early and delayed ischemic postconditioning further reduced the infarct volume, stabilized cerebral blood disturbance and attenuated neuronal apoptosis, compared with either alone. However, combinative postconditioning exerted the same effect on neurological function and brain edema, compared with early or delayed ischemic postconditioning alone. Further investigation indicated that combinative ischemic postconditioning increased the expression of BDNF, and a significantly higher number of BDNF‑positive cells was observed in neurons and astrocytes from the combined group than in the early or delayed groups. Combinative ischemic postconditioning also induced the phosphorylation of ERK1/2 and CREB in the cortex, following focal ischemia. The results of the present study suggest that the combination of early and delayed ischemic postconditioning may further reduce brain ischemic reperfusion injury following focal ischemia, compared with either treatment alone. In addition, it induces the production of BDNF in neurons and astrocytes. Furthermore, the effects of combinative ischemic postconditioning may be mediated by the activation of ERK1/2 and CREB.

Norovirus P particle: an excellent vaccine platform for antibody production against Alzheimer's disease

Active vaccination against amyloid β (Aβ42) is considered a potential therapeutic approach for Alzheimer's disease (AD). However, immunization with synthetic human Aβ1-42 has resulted in meningoencephalitis in 6% of patients and generated only low-titer anti-Aβ42 antibodies. In order to develop a safe and effective vaccine against Alzheimer's disease, the Aβ1-6 peptide was used as the novel immunogen and Norovirus P particles as the vaccine platform in this study. By inserting and presenting Aβ1-6 on the outermost surface of the P particle, we showed that the chimeric P particle-based AD protein vaccine could elicit a strong immune response, inducing highly specific antibody titers against Aβ42 without causing T-cell activation. Furthermore, antibodies induced by the AD protein vaccines were demonstrated to be effective at the cellular level. In addition, we also compared the immunogenicity of the chimeric P particles with different insertional loci in the loop structure domain and demonstrated that insertion of the antigen into all three loops of the P particle at the same time could significantly improve immune responses to the vaccine. In conclusion, the Norovirus P particle is an excellent vaccine platform for stimulating Aβ42 antibody production, and chimeric P particles may be developed as an effective therapy for AD.

[Application of xenograft for alveolar ridge preservation in posterior sites: a randomized controlled clinical trial]

OBJECTIVE

To investigate the effect of ridge preservation with Bio-Oss Collagen and Bio-Gide in posterior sites.

METHODS

From May 2010 to July 2013, 16 patients with bilateral posterior teeth planned to be extracted and replaced by implants were enrolled. One of the sockets was randomly selected and presserved with Bio-Oss Collagen and Bio-Gide (intervention group). The contralateral socket was left to heal spontaneously (control group). Cone-beam (CBCT) scans were performed immediately after the extraction and 6 month later. The bone cores were collected during the implant placement surgery and analyzed by micro-computed tomography.

RESULTS

After 6 month healing, the vertical and horizontal dimensional alteration of the treatment group were (0.55 ± 1.05) mm and (-0.99 ± 0.94) mm respectively, while the vertical and horizontal change of control group were (-0.71 ± 1.41) mm and (-2.26 ± 1.29) mm respectively. The micro-computed tomography results showed that there was no significant difference in new bone volume between control and intervention groups.

CONCLUSIONS

Applying Bio-Oss Collagen and Bio-Gide for ridge preservation in posterior sites resulted in less vertical and horizontal bone resorption of sockets following extraction.

State-to-State Quantum Dynamics of Reactions O((3)P) + HD (v = 0-1, j = 0) → OH+D and OD+H: Reaction Mechanism and Vibrational Excitation

Time-dependent quantum wave packet dynamics calculations have been performed in order to characterize the dynamics and mechanism of O((3)P) + HD (v = 0-1, j = 0) → OH+D and OD+H reactive collisions using the adiabatic potential energy surface by Rogers et al. [J. Phys. Chem. A 2000, 104, 2308] Special attention has been paid to the calculations and discussion of the state resolved integral and differential cross sections and the product state distributions. In addition, the intramolecular isotopic branching ratio has been determined. The results revealed that the OD + H is the favored product channel and the product OH has the same quantum number v as the reactant HD. For low collision energy, the product angular distributions concentrate in the backward region being consistent with a rebounding mechanism. In the case of higher collision energy, the stripping collisions with larger impact parameters tend to produce sideways and forward scatterings, especially for the HD vibrationally excited state. The cross section and intramolecular isotopic branching ratio are in agreement with the previous theoretical results. A cartoon depiction collision model is built and works well for our calculation results.

Theory of Half-Space Light Absorption Enhancement for Leaky Mode Resonant Nanowires

Semiconductor nanowires supporting leaky mode resonances have been used to increase light absorption in optoelectronic applications from solar cell to photodetector and sensor. The light conventionally illuminates these devices with a wide range of different incident angles from half space. Currently, most of the investigated nanowires have centrosymmetric geometry cross section, such as circle, hexagon, and rectangle. Here we show that the absorption capability of these symmetrical nanowires has an upper limit under the half-space illumination. Based on the temporal coupled-mode equation, we develop a reciprocity theory for leaky mode resonances in order to connect the angle-dependent absorption cross section and the radiation pattern. We show that in order to exceed such a half-space limit the radiation pattern should be noncentrosymmetric and dominate in the direction reciprocal to the illumination. As an example, we design a metal trough structure to achieve the desired radiation pattern for an embedded nanowire. In comparison to a single nanowire case the trough structure indeed overcomes the half-space limit and leads to 39% and 64% absorption enhancement in TM and TE polarizations, respectively. Also the trough structure enables the enhancement over a broad wavelength range.

Expression, purification and characterization of heterotrimeric forms of sTRAIL using a polycistronic expression vector

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), which is capable of selectively inducing apoptosis of cancer cells, is a potential targeted drug for cancer therapy. The TRAIL protein induces apoptosis only in trimeric form. However, the recombinant soluble TRAIL (sTRAIL) trimer has low stability and a short half-life, which is a major obstacle for its advancement into clinical trials. Moreover, a percentage of engineered sTRAIL proteins are produced as dimers which may be toxic to normal human hepatocytes. In this study, we inserted three copies of the same subunit fragment of sTRAIL with a His tag into a polycistronic expression vector (pST39) to explore whether it would increase the proportion of trimers. We also constructed a heterozygous vector containing three subunit fragments of sTRAIL each with a different tag (His, HA, and Cmyc). Hybrid sTRAIL proteins (P-dTags) mainly as heterologous trimers were obtained by elution with a low concentration of imidazole based on different binding affinities of His with a nickel column. Functional analysis demonstrated that heterotrimeric forms of sTRAIL showed more stable activity compared to the P-3H at 4°C but not at 37°C without alteration in the native killing capacity. In addition, the heterologous trimers showed decreased toxicity to hepatocytes. These results suggest that the polycistronic expression system may be useful for expression of recombinant sTRAIL and improving its potential in cancer therapeutic applications.