Laser Synthesis of Iron Nitride Nanoparticles from Pyrolysis of Fe(CO)5-NH3 System

By vapor-phase pyrolysis of Fe(CO) 5 and NH3 induced by CW CO2 laser, γ'-Fe4N and ε- Fe3N nanoparticles(≤35nm) were prepared in Ar and N2 atmospheres. In Ar, γ'-Fe4N accompanied by a little α-Fe was formed at low temperatures below 650°C, while higher temperatures favored the formation of γ-Fe. In N2 atmospheres, a mixture of Fe4N and Fe3N nanoparticles were obtained at high temperatures. In addition, the influences of synthesis parameters on the structure, morphology and magnetic properties of the nanoparticles were discussed.

High dose human insulin and insulin glargine promote T24 bladder cancer cell proliferation via PI3K-independent activation of Akt

BACKGROUND

This study was to investigate the effects of human insulin and insulin glargine on proliferation of T24 human bladder cancer cells and the implication of the PI3K/Akt and MEK/ERK1/2 pathways.

METHODS

After exposure to insulin or glargine at the indicated concentrations for certain time courses, in the absence or presence of inhibitor for MEK (PD98059) or PI3K (LY294002), T24 cell proliferation was evaluated by CCK-8 assay. Phosphorylation of Akt and ERK1/2 was analyzed by Western blot.

RESULTS

Insulin and glargine similarly induced phosphorylation of Akt and slight increases in T24 cell proliferation at 10-100IU/L. LY294002 remarkably reduced T24 cell proliferation in all groups. However, in the presence of LY294002, cell growth was still promoted by insulin and glargine relative to LY294002-treated group. Accordingly, LY294002 profoundly reduced protein levels of pAkt, while insulin and glargine increased pAkt in T24 cells pretreated with LY294002 as compared with cells treated with LY294002 alone. PD98059 reduced pERK while enhanced T24 cell proliferation. Insulin and glargine increased pERK at 15, 30, 60 min, not at 24h.

CONCLUSIONS

High dose human insulin and insulin glargine similarly promoted T24 bladder cancer cell proliferation via PI3K-independent activation of Akt.

Algal-derived organic matter as precursors of disinfection by-products and mutagens upon chlorination

Algal-derived organic materials (including algal cells, hydrophilic and hydrophobic proteins) from Chlamydomonas sp. (a common green alga in local reservoirs), were chlorinated in the laboratory (20 °C, pH 7, Cl(2)/DOC ratio of 20 mg Cl(2) mg(-1)). Levels of disinfection by-products and mutagenicity (via Salmonella T100 mutation assay, -S9) over 2 h of chlorination time were determined. The hydrophilic proteins were more effective precursors of chloroform (35.9 μmol L(-1) at 120 min), 35 times greater than that from the hydrophobic proteins; whereas the hydrophobic proteins were more potent precursors of direct-acting mutagens (maximum level of 50.1 rev μL(-1) at 30 s) than the hydrophilic proteins (maximum level of 3.38 rev μL(-1) at 60 min). The mutagenicity of the chlorinated solutions generally reached a peak level shortly after chlorination and then declined afterwards, a pattern different from that of chloroform generation. The results indicate that algal hydrophilic proteins, containing low aromaticity and difficult to be removed via coagulation/flocculation, are important chloroform precursors. It is also suggested that hydrophobic organic intermediates with low molecular weight formed during chlorination may serve as the direct-acting mutagens.

Adenosine 2A receptor is protective against renal injury in MRL/lpr mice

OBJECTIVE

Adenosine is considered as a potent endogenous anti-inflammatory and immunosuppressive molecule. We examined the roles of A2A-adenosine receptor (A(2A)R) in the progression of lupus nephritis.

METHODS

MRL/lpr mice were given a selective A(2A)R agonist, CGS21680 (0.4 mg/kg per day, i.p.) while control mice received saline only. After 8 weeks of treatment, mice were sacrificed for assessment of functional and histological parameters as well as inflammatory infiltration in the kidneys. MCP-1, IFN-γ, MHC-II and A(2A)R mRNA expression was evaluated by RT-PCR. Expression of A(2A)R and nuclear NFκB p65 protein was determined by Western blot analysis. Levels of anti-dsDNA antibody and IFN-γ were measured by ELISA.

RESULTS

CGS21680 treatment resulted in significant decrease in proteinuria, blood urea and creatinine as well as improvement in renal histology. Renal macrophage and T-cell infiltration were significantly attenuated in association with suppressed expression of MCP-1, IFN-γ and MHC-II. CGS21680 treatment reduced the level of serum anti-dsDNA and renal immune complex deposition. CGS21680 inhibited the activation of NFκB and suppressed the expression of IFN-γ, MCP-1 and MHC-II in MRL/lpr splenocytes.

CONCLUSIONS

A(2A)R activation suppressed inflammation in the kidneys of MRL/lpr mice and can be considered as a novel therapeutic approach for human lupus nephritis.

Proteomic analysis of human serum for finding pathogenic factors and potential biomarkers in preeclampsia

OBJECTIVE(S)

To apply a novel proteomic method to discover potential pathogenic factors and biomarkers of preeclampsia.

STUDY DESIGN

Sera from five patients complicated with preeclampsia and five healthy pregnant controls were separately pooled. Each pool was treated with peptide ligand library beads (PLLBs) to remove high abundance proteins by affinity and thus enrich low abundance proteins. The proteins from the eluate were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expression levels were quantified using spectral counts and the extracted ion current.

RESULTS

1172 unique proteins in preeclampsia and 1149 in healthy controls were identified in the present study. 51 proteins were differentially expressed between preeclampsia and healthy pregnant women including chorionic somatommammptropin hormone (CSH) and fibulin-1. 31 proteins identified were up-regulated and 20 were down-regulated.

CONCLUSIONS

The results demonstrate that peptide ligand library combining with 1D gel-LC-MS/MS analysis is an efficient method to identify differentially expressed proteins in sera and two biological processes of complement and coagulation activations and lipid metabolism were involved in the pathogenesis of preeclampsia.

Pentachlorophenol induced physiological-biochemical changes in Chlorella pyrenoidosa culture

Present study investigated physiological and biochemical changes in a green alga culture (Chlorella pyrenoidosa) upon exposure to varied concentrations of pentachlorophenol (PCP) (0, 0.4 mgL(-1), 2.5 mgL(-1) and 10 mgL(-1)). The results revealed that with the increase of PCP concentration, a decrease of the algal biomass, levels of photosynthetic pigments (chlorophyll a, b and carotenoid), soluble protein and an increase of nitrate reductase (NR) activity were observed. This suggests that the PCP may serve as an uncoupler, causing low ATP level within the algal cells and led most of the NR molecules to be in the dephosphoration state (i.e. active from). Moreover, it shows that photosynthetic pigments especially carotenoid were more sensitive indicators to indicate PCP toxicity as compared to the other parameters.

Superiority of visipaque (iodixanol)-controlled density gradient over Ficoll-400 in adult porcine islet purification

OBJECTIVE

Sufficient and favorable biological functions of islets are major problems hindering xenotransplantation. The aim of the present study was to evaluate the effects on harvesting, purity, viability, and function of using improved Visipaque (iodixanol) and Ficoll-400 for adult porcine islet purification.

METHODS

Twelve adult porcine pancreata were randomly divided into an Iodixanol-University of Wisconsin (UW) group and a Ficoll-400-UW group according to the purification method. Porcine pancreata were isolated by collagenase digestion. After isolation and purification, the islet yield and purity were evaluated by dithizone staining, and islet function assessed by in vitro insulin release assays and in vivo islet xenotransplantation.

RESULTS

There were no marked differences in the islet yield before purification (5254.67 +/- 189.44 IEQ/g vs 5092.67 +/- 178.94 IEQ/g, P > .05). After purification, there were significantly more islets harvested in Iodixanol-UW group than in the Ficoll-400-UW group: 4222.00 +/- 228.84 IEQ/g vs 3036.83 +/- 79.60 IEQ/g (P < .05). Islets from the two groups showed satisfactory insulin secretory ability. There were no significant differences in islet survival times between the two groups in diabetic rats: 8.2 +/- 1.619 days vs 6.9 +/- 1.197 days (P > .05).

CONCLUSION

The improved iodixanol-UW density gradient method was superior to Ficoll-400 method to improve the number, viability, and insulin secret of purified adult porcine islets although the benefits did not improve in vivo survival.

Neoclassical toroidal plasma viscosity torque in collisionless regimes in tokamaks

Bumpiness in a magnetic field enhances the magnitude of the plasma viscosity and increases the rate of the plasma flow damping. A general solution of the neoclassical toroidal plasma viscosity (NTV) torque induced by nonaxisymmetric magnetic perturbation (NAMP) in the collisionless regimes in tokamaks is obtained in this Letter. The plasma angular momentum can be strongly changed, when there is a small deviation of the toroidal symmetry caused by a NAMP of the order of 0.1% of the toroidal field strength.

Probing quark-gluon interactions with transverse polarized scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

The antiapoptotic protein, FLIP, is regulated by heterogeneous nuclear ribonucleoprotein K and correlates with poor overall survival of nasopharyngeal carcinoma patients

Heterogeneous nuclear ribonucleoprotein K (hnRNP K) mediates antiapoptotic activity in part by inducing downstream antiapoptotic genes. To systematically identify hnRNP K targets in nasopharyngeal carcinoma (NPC), affymetrix chips were used to identify genes that were both overexpressed in primary NPC and downregulated by hnRNP K knockdown in NPC-TW02 cells. The resulting gene set included the antiapoptotic gene, FLIP, which was selected for further study. In cells treated with hnRNP K siRNA, TRAIL-induced apoptosis was enhanced and the FLIP protein level was reduced. Promoter, DNA pull-down and chromatin-immunoprecipitation assays revealed that hnRNP K directly interacts with the poly(C) element on the FLIP promoter, resulting in transcriptional activation. Through iTRAQ-mass spectrometric identification of proteins differentially associated with the poly(C) element or its mutant, nucleolin was determined to be a cofactor of hnRNP K for FLIP activation. Furthermore, FLIP was highly expressed in tumor cells, and this high-level expression was significantly correlated with high-level hnRNP K expression (P=0.002) and poor overall survival (P=0.015) as examined in 67 NPC tissues. A multivariate analysis confirmed that FLIP was an independent prognostic factor for NPC. Taken together, these findings indicate that FLIP expression is transcriptionally regulated by hnRNP K and nucleolin, and may be a potential prognostic and therapeutic marker for NPC.

Multiresonance effect in type-I edge-localized mode control with low n fields on JET

Multiple resonances in the edge-localized mode (ELM) frequency (f(ELM)) as a function of the edge safety factor q(95) have been observed for the first time with an applied low n (=1,2) field on the JET tokamak. Without an n=1 field applied, f(ELM) increases slightly from 20 to 30 Hz by varying the q(95) from 4 to 5 in a type-I ELMy H-mode plasma. However, with an n=1 field applied, a strong increase in f(ELM) by a factor of 4-5 has been observed with resonant q(95) values, while the f(ELM) increased only by a factor of 2 for nonresonant values. A model, which assumes that the ELM width is determined by a localized relaxation triggered by an unstable ideal external peeling mode, can qualitatively predict the observed resonances when low n fields are applied.

Toll-like receptors regulate B cell cytokine production in patients with diabetes

AIMS/HYPOTHESIS

Understanding cellular and molecular events in diabetes mellitus will identify new approaches for therapy. Immune system cells are important modulators of chronic inflammation in diabetes mellitus, but the role of B cells is not adequately studied. The aim of this work was to define the function of B cells in diabetes mellitus patients through focus on B cell responses to pattern recognition receptors.

METHODS

We measured expression and function of Toll-like receptors (TLRs) on peripheral blood B cells from diabetes mellitus patients by flow cytometry and multiplexed cytokine analysis. We similarly analysed B cells from non-diabetic donors and periodontal disease patients as comparative cohorts.

RESULTS

B cells from diabetes mellitus patients secrete multiple pro-inflammatory cytokines, and IL-8 production is significantly elevated in B cells from diabetic patients compared with those from non-diabetic individuals. These data, plus modest elevation of TLR surface expression, suggest B cell IL-8 hyperproduction is a cytokine-specific outcome of altered TLR function in B cells from diabetes mellitus patients. Altered TLR function is further evidenced by demonstration of an unexpected, albeit modest 'anti-inflammatory' function for TLR4. Importantly, B cells from diabetes mellitus patients fail to secrete IL-10, an anti-inflammatory cytokine implicated in inflammatory disease resolution, under a variety of TLR-stimulating conditions. Comparative analyses of B cells from patients with a second chronic inflammatory disease, periodontal disease, indicated that some alterations in B cell TLR function associate specifically with diabetes mellitus.

CONCLUSIONS/INTERPRETATION

Altered TLR function in B cells from diabetes mellitus patients increases inflammation by two mechanisms: elevation of pro-inflammatory IL-8 and lack of anti-inflammatory/protective IL-10 production.

Jak/STAT signaling is involved in the inflammatory infiltration of the kidneys in MRL/lpr mice

Cytokines are known to play an important role in the pathogenesis of lupus nephritis (LN) and the Jak/STAT (Janus kinase-signal transducer and activator of transcription factor) pathway is important in mediating signal transduction of cytokines. This study examined the pathogenic role of Jak/STAT signaling in LN. MRL/lpr mice were either treated with a selective Jak2 inhibitor tyrphostin AG490 or with vehicle alone from 12 weeks of age until being sacrificed at week 20. AG490 significantly inhibited the phosphorylation of Jak2 and STAT1 (p < 0.05). Compared with the vehicle-treated mice, AG490 treatment significantly reduced proteinuria, improved renal function and suppressed histological lesions of the kidneys and salivary glands (p < 0.05). AG490 treatment significantly inhibited the renal expression of monocyte chemotactic protein (MCP)-1, interferon (IFN)-gamma and class II MHC, which was accompanied by reduced renal infiltration of T cells and macrophages (p < 0.05). In addition, AG490 treatment resulted in a decrease in serum anti-double-stranded DNA (anti-dsDNA) antibody and attenuated the deposition of IgG and C3 in the kidneys (p < 0.05). This study demonstrated that Jak/STAT pathway is implicated in the progression of renal inflammation in MRL/lpr mice and targeting this pathway may provide a potential therapeutic approach for LN.