Effect of 70-nm silica particles on the toxicity of acetaminophen, tetracycline, trazodone, and 5-aminosalicylic acid in mice

Exposure to nano-sized particles is increasing because they are used in a wide variety of industrial products, cosmetics, and pharmaceuticals. Some animal studies indicate that such nanomaterials may have some toxicity, but their synergistic actions on the adverse effects of drugs are not well understood. In this study, we investigated whether 70-nm silica particles (nSP70), which are widely used in cosmetics and drug delivery, affect the toxicity of a drug for inflammatory bowel disease (5-aminosalicylic acid), an antibiotic drug (tetracycline), an antidepressant drug (trazodone), and an antipyretic drug (acetaminophen) in mice. Co-administration of nSP70 with trazodone did not increase a biochemical marker of liver injury. In contrast, co-administration increased the hepatotoxicity of the other drugs. Co-administration of nSP70 and tetracycline was lethal. These findings indicate that evaluation of synergistic adverse effects is important for the application of nano-sized materials.

Genotypic resistance profile of hepatitis B virus (HBV) in a large cohort of nucleos(t)ide analogue-experienced Chinese patients with chronic HBV infection

The study investigated the hepatitis B virus (HBV) genotypic resistance profile in 1803 nucleos(t)ide analogue (NA)-experienced Chinese patients with chronic HBV infection. Serum HBV DNA was extracted, and the reverse transcriptase region was analysed by a high-sensitive direct PCR sequencing and verified by clonal sequencing if necessary. Drug-resistant mutations were detected in 560 of the 1803 patients, including 214 of 490 patients who received lamivudine (LAM), 35 of 428 patients who received adefovir (ADV), five of 18 patients who received telbivudine and 306 of 794 patients who received various sequential/combined NA therapies. ADV-resistant mutations were detected in 36 of 381 patients who received LAM and then switched-to ADV in contrast to one of 82 patients who received ADV add-on LAM. Entecavir (ETV)-resistant mutations were detected not only in LAM- and ETV-treated patients but also in LAM-treated ETV-naïve patients. Double mutations rtM204I and rtL180M were detected more frequently in genotype C than in genotype B virus, and patients infected with this mutant had higher alanine transaminase levels than those infected with mutant containing the rtM204I substitution alone. Multidrug-resistant HBV strains were identified in eight patients, including two novel strains with mutational patterns rtL180M + A181V + S202G + M204V + N236T and rtL180M + S202G + M204V + N236T. The results provide new information on HBV genotypic resistance profiles in a large cohort of Chinese patients with chronic HBV infection and may have important clinical implication for HBV drug resistance management in China.

Time reversal microwave breast imaging for contrast-enhanced tumor classification

This paper studies the decomposition of the time reversal operator (DORT, by the French acronym) technique for microwave breast lesion classification. We apply the finitedifference time-domain (FDTD) method to a realistic numerical breast phantom where lesion-like targets are artificially introduced, and obtain the multistatic data matrix (MDM) for a particular antenna array configuration. Then, the singular value decomposition (SVD) of this matrix is derived for different targets, which represent malignant and benign lesions. We show that the singular value spectrum can assist in classifying these targets as malignant or benign, especially in the case where contrast-enhanced agents can be employed to allow the analysis of differential backscatter data.

Alterations in the proteome of the NHERF2 knockout mouse jejunal brush border membrane vesicles

To identify additional potential functions for the multi-PDZ domain containing protein Na+/H+ exchanger regulatory factor 2 (NHERF2), which is present in the apical domain of intestinal epithelial cells, proteomic studies of mouse jejunal villus epithelial cell brush border membrane vesicles compared wild-type to homozygous NHERF2 knockout FVB mice by a two-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS)-iTRAQ approach. Jejunal architecture appeared normal in NHERF2 null in terms of villus length and crypt depth, Paneth cell number, and microvillus structure by electron microscopy. There was also no change in proliferative activity based on BrdU labeling. Four brush border membrane vesicles (BBMV) preparations from wild-type mouse jejunum were compared with four preparations from NHERF2 knockout mice. LC-MS/MS identified 450 proteins in both matched wild-type and NHERF2 null BBMV; 13 proteins were changed in two or more separate BBMV preparations (9 increased and 4 decreased in NHERF2 null mice), while an additional 92 proteins were changed in a single BBMV preparation (68 increased and 24 decreased in NHERF2 null mice). These proteins were categorized as 1) transport proteins (one increased and two decreased in NHERF2 null); 2) signaling molecules (2 increased in NHERF2 null); 3) cytoskeleton/junctional proteins (4 upregulated and 1 downregulated in NHERF2 null); and 4) metabolic proteins/intrinsic BB proteins) (2 upregulated and 1 downregulated in NHERF2 null). Immunoblotting of BBMV was used to validate or extend the findings, demonstrating increase in BBMV of NHERF2 null of MCT1, coronin 3, and ezrin. The proteome of the NHERF2 null mouse small intestinal BB demonstrates up- and downregulation of multiple transport proteins, signaling molecules, cytoskeletal proteins, tight junctional and adherens junction proteins, and proteins involved in metabolism, suggesting involvement of NHERF2 in multiple apical regulatory processes and interactions with luminal contents.

Glycogen synthase kinase-3β is a functional modulator of serotonin-1B receptors

Glycogen synthase kinase-3 (GSK3) is a constitutively active protein kinase that is involved in neuronal regulation and is a potential pharmacological target of neurological disorders. We found previously that GSK3β selectively interacts with 5-hydroxytryptamine-1B receptors (5-HT1BR) that have important functions in serotonin neurotransmission and behavior. In this study, we provide new information supporting the importance of GSK3β in 5-HT1BR-regulated signaling, physiological function, and behaviors. Using molecular, biochemical, pharmacological, and behavioral approaches, we tested 5-HT1BR's interaction with G(i)α(2) and β-arrestin2 and 5-HT1BR-regulated signaling in cells, serotonin release in mouse cerebral cortical slices, and behaviors in wild-type and β-arrestin2 knockout mice. Molecular ablation of GSK3β and GSK3 inhibitors abolished serotonin-induced change of 5-HT1BR coupling to G(i)α(2) and associated signaling but had no effect on serotonin-induced recruitment of β-arrestin2 to 5-HT1BR. This effect is specific for 5-HT1BR because GSK3 inhibitors did not change the interaction between serotonin 1A receptors and G(i)α(2). Two GSK3 inhibitors, N-(4-methoxybenzyl)-N'-(5-nitro-1,3-thiazol-2-yl)urea (AR-A014418) and 3-(5-bromo-1-methyl-1H-indol-3-yl)-4-(benzofuran-3-yl)pyrrole-2,5-dione (BIP-135), efficiently abolished the inhibitory effect of the 5-HT1BR agonist anpirtoline on serotonin release in mouse cerebral cortical slices. GSK3 inhibitors also facilitated the 5-HT1BR agonist anpirtoline-induced behavioral effect in the tail suspension test but spared anpirtoline-induced locomotor activity. These results suggest that GSK3β is a functional selective modulator of 5-HT1BR-regulated signaling, and GSK3 inhibitors fine-tune the physiological and behavioral actions of 5-HT1BR. Future studies may elucidate the significant roles of GSK3 in serotonin neurotransmission and implications of GSK3 inhibitors as functional selective modulators of 5-HT1BR.

Effects on condom use of an HIV prevention programme 36 months postintervention: a cluster randomized controlled trial among Bahamian youth

Data are lacking on long-term effects of HIV behavioural intervention programmes. In this study, we report intervention effects 36 months postintervention on condom use and relevant outcome variables from the theory-based programme 'Focus on Youth in the Caribbean' (FOYC). Participants (1360 sixth-grade youth) were randomized by school into: (1) FOYC, plus one of two brief parent interventions or (2) the control condition 'Wondrous Wetlands', plus a brief parent intervention. Mixed effect analysis demonstrated significant programme effects, including enhanced HIV/AIDS knowledge (effect size D = 0.44, 95% confidence interval [CI]: 0.43, 0.46), increased self-efficacy of (D = 0.42, 95% CI: 0.30, 0.54), skills for (D = 0.62, 95% CI: 0.56, 0.64) and intention to use a condom (D = 0.20, 95% CI: 0.03, 0.37). Youth who received FOYC plus the parental monitoring intervention had higher condom use rates (odds ratio = 1.49, 95% CI: 0.97, 2.28). Feedback effects from key variables were also detected, supporting the sustained effect.

Rheological Properties of Neat and Calcium Carbonate Particles Filled Polypropylene Blends under Axial Vibration Force Field

Structures, working mechanism, data collecting and processing methods of the self-made multifunctional all-electronic rheometer for polymer composites were introduced in detail. The validity of this equipment was proved by deriving the apparent shear viscosity expression under axial vibration condition and comparing the results obtained from both this self-made rheometer and Rosand Rh7D capillary rheometer at steady state. With this equipment, the effects of calcium carbonate weight fraction, particle size and vibration parameters on apparent shear viscosity of calcium carbonate filled propylene composites were investigated. The results show that: the apparent shear viscosity of the composites increases with the filled particle concentration. However, it is seldom affected by particle size within certain a range of shear rate. While the apparent shear viscosity increases with the decrease of particle size at moderate shear rate. Besides, the apparent shear viscosity declines rapidly with the increasing vibration amplitude. However it exhibits a cosinoidal or sinusoidal trend as vibration frequency increases and peaks at the resonant frequency of the composites.

Electrohydrodynamic deposition of nanotitanium doped hydroxyapatite coating for medical and dental applications

Nano-sized titanium containing hydroxyaptite has been prepared, the particle size of nanoTiHA was shown to be 12-20 nm in width and 30-40 nm in length, smaller than that of nanoHA. X-ray diffraction analysis revealed the phase purity of nanoTiHA produced. Antimicrobical assays demonstrated that nanoTiHA has excellent growth inhibitory properties, and is able to inhibit the growth of all bacterial strains tested, both Gram-negative and Gram-positive species, including multi-antibiotic resistant EMRSA 15 and EMRSA 16 'superbugs'. Biocidal activity against all four Staphylococcus spp was also shown at the concentration tested. Nanostuctured TiHA coating was successfully deposited onto Ti surfaces using EHDA spraying under optimized processing conditions with the thickness of the coating being further controlled by the spraying time. All of the nanoTiHA coated Ti surfaces were able to support human osteoblast (HOB) cell attachment and growth. The coating thickness did not significantly influence the proliferation of HOB cells on nanoTiHA coatings, while the ability of nanoTiHA coating to support HOB cell differentiation was demonstrated from the alkaline phosphatase activity. Our study showed that nanoTiHA has excellent anti-bacterial properties and the thin nanoTiHA coating was also able to support the attachment, growth and differentiation of HOB cells. Therefore, nanoTiHA coating could pave the way for the development of the next generation of dental and orthopedic implants by offering anti-infection potential in addition to osteoconductivity.

Disruption of the cyclic AMP phosphodiesterase-4 (PDE4)-HSP20 complex attenuates the β-agonist induced hypertrophic response in cardiac myocytes

The small heat shock protein HSP20 is known to be cardioprotective during times of stress and the mechanism underlying its protective abilities depends on its phosphorylation on Ser16 by PKA (protein kinase A). Although the external stimuli that trigger Ser16 phosphorylation have been well studied, the events that modulate spatial and temporal control of this modification remain to be clarified. Here, we report that inhibition of cAMP phosphodiesterase-4 (PDE4) induces the phosphorylation of HSP20 in resting cardiac myocytes and augments its phosphorylation by PKA following β-adrenergic stimulation. Moreover, using peptide array technology, in vitro binding studies, co-immunoprecipitation techniques and immunocytochemistry, we show that HSP20 binds directly to PDE4 within a region of the conserved catalytic domain. We also show that FRET-based, genetically-encoded cAMP reporters anchored to HSP20 exhibit a larger response to PDE4 inhibition compared to free cytosolic cAMP reporters, suggesting that the interaction with PDE4 is crucial in modulating the highly localised pool of cAMP to which HSP20 is exposed. Using information gleaned from peptide array analyses, we developed a cell-permeable peptide that serves to inhibit the interaction of PDE4 with HSP20. Disruption of the HSP20-PDE4 complex, using this peptide, suffices to induce phosphorylation of HSP20 by PKA and to protect against the hypertrophic response measured in neonatal cardiac myocytes following chronic β-adrenergic stimulation.

Novel Endothelial Biomarkers: Implications for Periodontal Disease and CVD

Endothelial cells are actively involved in various aspects of vascular biology and different stages of atherosclerosis. Endothelial function is increasingly used as an important outcome measure in cardiovascular research. Endothelial progenitor cells (EPCs) are closely linked to endothelial function, and their biomarkers have received much attention. EPCs may not only serve as a pool of progenitor cells and possess the capacity to repair the damaged vasculature, but also act as potent effectors in systemic inflammation, suggesting that EPCs may play a critical role in maintaining endothelial function and the progression of cardiovascular disease (CVD). Emerging evidence shows an association of periodontal infections (gingivitis and periodontitis) with endothelial dysfunction, while the relevant mechanisms remain unknown. Our recent finding of the association of periodontitis with EPCs warrants their utilization as additional biomarkers in future studies on periodontal medicine. This review starts with a brief account on the current understanding of the nature of periodontal infections and their link with systemic inflammation and endothelial dysfunction. The paper also provides an update on endothelial biology and function as well as the novel biomarkers of EPCs and concludes with clinical studies on periodontal diseases and CVD.

Cross section and parity-violating spin asymmetries of W± boson production in polarized p + p collisions at sqrt[s] = 500 GeV

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = -0.86(-0.14) (+0.30) and A(L)(e-) = 0.88(-0.71) (+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p+p collisions at a center-of-mass energy of sqrt[s] = 500 GeV with the PHENIX detector at RHIC. These e± come mainly from the decay of W± and Z0 bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W± to the light quarks. The observed electron and positron yields were used to estimate W± boson production cross sections for the e± channels of σ(pp → W+ X) × BR(W+ → e+ ν(e)) = 144.1 ± 21.2(stat)(-10.3) (+3.4) (syst) ± 21.6(norm)  pb, and σ(pp → W- X) × BR(W- → e- ν[over ¯](e)) = 31.7 ± 12.1(stat)(-8.2) (+10.1) (syst) ± 4.8(norm)  pb.

Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

Site-Selective Photoluminescence Excitation and Photoluminescence Spectroscopy of Er-Implanted Wurtzite GaN

Site-selective photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy have been carried out at 6K on the ∼1540 nm 4I15/2 → 4I15/2 emissions of Er3+ in Er-implanted GaN. The PLE spectra exhibit several broad, below-gap, defect- or impurity-related absorption bands which excite three distinct site-selective Er + PL spectra. The near-band edge spectral position and lineshape of the PLE spectrum of one of the site-selective PL bands suggest that this Er site forms a trap level within the band gap and an exciton bound at this trap is involved in the excitation mechanism. In addition, high resolution PLE spectra obtained with a tunable laser in the 810 nm spectral range reveal a set of sharp PLE peaks due to the 4I15/2 → 4I9/2 internal Er+ ƒ-band absorption superimposed on the broad defect PLE band. The site-selective PL spectrum excited by the sharp line ∼810 nm Er+ intra-ƒ shell PLE bands is characteristic of a fourth distinct Er+ site. The simple structure of the site-selective PL and PLE spectra associated with direct intra-ƒ shell absorption suggests that the optically active Er site responsible for these spectra is of high symmetry in wurtzite GaN and that it could be attributed to a single Er atom on a Ga site.

Correlation between imaging features and epithelial cell proliferation in keratocystic odontogenic tumour

OBJECTIVES

this study was undertaken to investigate the relationship between radiographic appearance and epithelial cell proliferations in keratocystic odontogenic tumours (KCOTs).

METHODS

a retrospective radiographic analysis was performed on 284 cases of KCOT to gain insight into the radiographic characteristics. Expression of Ki-67 in 30 of the 284 cases was detected by the labelled streptavidin-biotin (LSAB) method and evaluated by an image analysis system.

RESULTS

the radiographic presentation of KCOT was divided into four types: unilocular, multilocular, multiple and naevoid basal cell carcinoma syndrome (NBCCS). The expression of Ki-67 in NBCCS was significantly different from the solitary and multiple KCOTs (P = 0.018, 0.002). In multilocular KCOTs it was also significantly different from the unilocular and syndrome-associated lesions (P = 0.000). In contrast, no significant differences were observed between the solitary and multiple lesions (P = 0.220).

CONCLUSIONS

a high correlation exists in KCOT between its biological behaviour and imaging features. The solitary KCOT seems less biologically aggressive and it should be classified as a cyst rather than a tumour. This means that more than half of KCOTs manifest themselves as ordinary cysts.

Clinicopathologic and genetic features of Chinese hereditary nonpolyposis colorectal cancer (HNPCC)

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Background: Hereditary non-polyposis colorectal cancer (HNPCC) is the most common hereditary colorectal cancer (CRC). At least five mismatch repair genes, majorly hMLH1and hMSH2 gene mutations, are associated with this syndrome. Given the geographical and racial differences, Chinese HNPCC patients have some special characteristics compared with patients in West countries. Based on our former studies, we developed a criteria, the Fudan Criteria, for clinical diagnosis of Chinese HNPCC. The aim of this study is (1) to understand the relationship between genotype and phenotype in Chinese HNPCC; and (2) to investigate the clinical value of Fudan Criteria.

Methods: 116 unrelated probands of HNPCC or suspected HNPCC families from the Fudan Colorectal Registry were studied. 32 families fulfilled the Amsterdam criteria (AC group), 28 families fulfilled the Fudan Criteria (FD group). 56 families met the revised Bethesda guideline (BG Group). Direct DNA sequencing of all exons of hMSH2 and hMLH1 genes were performed. Mutation and clinicalpathological features were compared between the groups.

Results: 32 pathological germline mutations were identified. 16/32 mutations were located at hMLH1 and 16/32 located at hMSH2. The sensitivity of Amsterdam Criteria was 50%, specificity was 81% and Youden's index was 31%. The sensitivity of Fudan Criteria was 75%, specificity was 58% and Youden's index was 33%. In AC group, there were no significant clinicopathological differences in patients with or without mutation. However, families with hMSH2 mutation had a higher ratio of synchronous and metachronous CRC than families with hMLH1 mutation (33% vs. 6%; P=0.04). Families in AC group share the same clinicopathological features with families in FD group, except multiple relative tumors (21.6% vs.6%; P=0.001).

Conclusions: There seems no close relation between genotype and phenotype, except patients with hMSH2 mutation more frequently harbor synchronous and metachronous CRC. Fudan Criteria had a little higher sensitivity and accuracy than Amsterdam Criteria for identification of Chinese HNPCC.

No significant financial relationships to disclose.