In vitro study on influence of a discrete nano-hydroxyapatite on leukemia P388 cell behavior

Influence of a discrete nano-hydroxyapatite crystal (nano-HAp) on lymphatic leukemia P388 cell behavior was investigated by an in vitro technique using an MTT test and FITC analysis. The discrete nano-HAp was prepared by decanting upside clear layer of the nano-HAp suspension which was synthesized by a wet method using calcium hydroxide suspension and phosphoric acid solutions. The nano-HAp was identified as hydroxyapatite by the X-ray powder diffraction pattern and an infrared spectroscopy. The nano-HAp with concentrations of 8-40 microg/ml was dispersed into PRMI 1640 media with leukemia cells derived from BALB/C mice. The survival ratio of the cells decreased with the amounts of the nano-HAp increasing. Apoptosis rates of leukemia P388 cells on co-culturing with the nano-HAp of 35 microg/ml for 24, 48 h were 14.5% and 45.8%, respectively, and higher than those of 10.4% and 34% in controls. The G0/G1 peak values in leukemia P388 cell cycle were declined to reduce and the S peak values increased with extension time of co-culture. These results proved that the discrete nano-HAp can cause apoptosis of the leukemia P388 cells, and selectively act on G1 phase and arrest the G1 phase in cell cycle of the leukemia P388.

The Expression of von Willebrand Factor, Soluble Thrombomodulin, and Soluble P-Selectin During Orthotopic Liver Transplantation

BACKGROUND

We evaluated von Willebrand factor (vWF), soluble thrombomodulin (sTM), and soluble P-selectin (sP-selectin) levels in ischemia/reperfusion injury during orthotopic liver transplantation (OLT).

METHODS

The vWF, sTM, and sP-selectin were analyzed in 20 patients who underwent liver transplantation. Blood samples were drawn from the radial artery at serial times during surgery. Plasma levels of sTM and sP-selectin were detected by enzyme-linked immunosorbent assay (ELISA). The wWF activity was measured using the immuno-turbidimetric method. Plasma aspartate transaminase (AST) and alanine transaminase (ALT) were assayed by routine clinical chemistry testing.

RESULTS

Marked elevation levels of plasma AST and ALT were released during the 15 minutes after reperfusion phase, with a peak on the first postoperative day (P < .01). The sTM level remained unchanged from preoperative to anhepatic phase (P > .05). In contrast, a mean 2.5-fold increase of sTM was observed during the 15-minute reperfusion stage compared with the preoperative value (P < .01). The vWF activity only showed significant increase during the 60-minute reperfusion stage compared with the preoperative value (P < .05). No significant increase occurred in sP-seletin levels during the reperfusion phase. Platelet count showed significant decrease during the entire observation period compared with the preoperative value (P < .01).

CONCLUSION

The endothelial reperfusion injury after OLT is characterized by increased vWF and sTM but not by sP-selectin in peripheral blood.

Measurements of the continuum R(uds) and R values in e(+)e(-) annihilation in the energy region between 3.650 and 3.872 GeV

We report measurements of the continuum R(uds) near the center-of-mass energy of 3.70 GeV, the R[uds(c)+psi(3770)](s) and the R(had)(s) values in e(+)e(-) annihilation at 68 energy points in the energy region between 3.650 and 3.872 GeV with the BES-II detector at the BEPC Collider. We obtain the R(uds) for the continuum light hadron (containing u, d, and s quarks) production near the DD threshold to be R(uds)=2.141+/-0.025+/-0.085.

Determination of in-vivo articular cartilage contact areas of human talocrural joint under weightbearing conditions

OBJECTIVE

The knowledge of in-vivo cartilage contact biomechanics is important to the understanding of the pathogenesis of joint diseases such as osteoarthritis. This study investigated the in-vivo contact areas of human talocrural joint under weightbearing conditions that simulated the stance phase of walking using a combined magnetic resonance (MR) and dual-orthogonal fluoroscopic imaging technique.

DESIGN

Nine healthy ankles of living subjects were recruited for this study. The in-vivo talocrural joint positions were recorded using the dual-orthogonal fluoroscopic images at three ankle positions that simulated those occurring during the stance phase of walking: heel strike, mid-stance, and toe off. Three-dimensional (3D) models of the talocrural joints were created from MR images and used to reproduce the in-vivo ankle positions recorded on the fluoroscopic images. The talocrural cartilage contact area was defined as the overlap area of the distal tibial and the proximal talar cartilage surfaces. The method was validated using an in-vitro experimental setup to evaluate its accuracy in determination of cartilage contact area.

RESULTS

The validation study demonstrated that the articular cartilage contact area of the talocrural joint determined using the imaging technique was approximately 4% lower than that of the experimental measurement. In the nine living ankles, the average cartilage coverage area was 964.9+/-156.1 mm(2) on the distal tibia and 1304.8+/-208.4 mm(2) on the proximal talus. The average talocrural cartilage contact areas were 272.7+/-61.1 mm(2) at heel strike, 416.8+/-51.7 mm(2) at mid-stance, and 335.7+/-64.5 mm(2) at toe off. The contact area at mid-stance was significantly larger than those at heel strike and toe off, while the contact area at toe off was significantly larger than that at heel strike.

CONCLUSION

The combined dual fluoroscopic and MR imaging technique was shown to be capable of determining in-vivo talocrural cartilage contact areas. During the simulated stance phase of walking, the contact areas were less than 44% and 31% of the cartilage coverage areas of the distal tibia and the proximal talus, respectively. These data may be useful for understanding in-vivo biomechanical function of the cartilage as well as the etiology of osteoarthritis.

Valproate protects dopaminergic neurons in midbrain neuron/glia cultures by stimulating the release of neurotrophic factors from astrocytes

Valproate (VPA), one of the mood stabilizers and antiepileptic drugs, was recently found to inhibit histone deacetylases (HDAC). Increasing reports demonstrate that VPA has neurotrophic effects in diverse cell types including midbrain dopaminergic (DA) neurons. However, the origin and nature of the mediator of the neurotrophic effects are unclear. We have previously demonstrated that VPA prolongs the survival of midbrain DA neurons in lipopolysaccharide (LPS)-treated neuron-glia cultures through the inhibition of the release of pro-inflammatory factors from microglia. In this study, we report that VPA upregulates the expression of neurotrophic factors, including glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) from astrocytes and these effects may play a major role in mediating VPA-induced neurotrophic effects on DA neurons. Moreover, VPA pretreatment protects midbrain DA neurons from LPS or 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity. Our study identifies astrocyte as a novel target for VPA to induce neurotrophic and neuroprotective actions in rat midbrain and shows a potential new role of cellular interactions between DA neurons and astrocytes. The neurotrophic and neuroprotective effects of VPA also suggest a utility of this drug for treating neurodegenerative disorders including Parkinson's disease. Moreover, the neurotrophic effects of VPA may contribute to the therapeutic action of this drug in treating bipolar mood disorder that involves a loss of neurons and glia in discrete brain areas.

Search for invisible decays of eta and eta' in J/psi --> phi eta and phi eta'

Using a data sample of 58 x 10(6) J/psi decays collected with the Beijing Spectrometer II detector at the Beijing Electron Positron Collider, searches for invisible decays of eta and eta' in J/psi to phi eta and phi eta' are performed. The phi signals, which are reconstructed in K+K- final states, are used to tag the eta and eta' decays. No signals are found for the invisible decays of either eta or eta', and upper limits at the 90% confidence level are determined to be 1.65 x 10(-3) for the ratio B(eta-->invisible)/B(eta --> gamma gamma) and 6.69 x 10(-2) for B(eta' --> invisible)/B(eta' --> gammagamma). These are the first searches for eta and eta' decays into invisible final states.

Activation of extracellular signal-regulated kinase by TGF-beta1 via TbetaRII and Smad7 dependent mechanisms in human bronchial epithelial BEP2D cells

Transforming growth factor-beta1 (TGF-beta1) can activate mitogen-activated protein kinases (MAPKs) in many types of cells. The mechanism of this activation is not well elucidated. Here, we explore the role of TGF-beta/Smads signaling compounds in TGF-beta1-mediated activation of extracellular signal-regulated kinase (ERK) MAPK in human papillomavirus (HPV)-18 immortalized human bronchial epithelial cell line BEP2D and the role of TGF-beta1-induced phosphorylation of ERK in proliferation and apoptosis of BEP2D. The cell models of siRNA-mediated silencing of TGF-beta receptor type II (TbetaRII), Smad2, Smad3, Smad4, and Smad7 were employed in this study. Our results demonstrate that TGF-beta1 activates ERK in a time-dependent manner with a maximum effect at 60 min; overexpression of Smad7 increased this TGF-beta1-mediated phosphorylation of the ERK; and siRNA-mediated silencing of TbetaRII, Smad3, Smad4, and Smad7 abrogated this effect. Moreover, we observed that overexpression of Smad7 restored TGF-beta1-mediated ERK phosphorylation in Smad4 knockdown cells but not in TbetaRII knockdown cells. In BEP2D cells, TGF-beta1 treatment effectively inhibited cells' proliferation and induced their apoptosis. Pretreatment with U0126, an inhibitor of ERK1/2, significantly enhanced the TGF-beta1-mediated antiproliferative and apoptosis induction effects in BEP2D cells. These data revealed that TbetaRII and Smad7 play the critical roles in TGF-beta1-mediated activation of ERK; Smad3 and Smad4 can play an indirect role through up-regulating Smad7 expression; and TGF-beta1-induced phosphorylation of ERK may participate in BEP2D cell proliferation and apoptosis regulation.

Observation of a broad 1-- resonant structure around 1.5 GeV/c2 in the K+K- mass spectrum in J/psi-->K+K-pi0

A broad peak is observed at low K+K- invariant mass in J/psi-->K+K-pi(0) decays found in a sample of 5.8x10(7) J/psi events collected with the BESII detector. The statistical significance of the broad resonance is much larger than 5sigma. A partial wave analysis shows that the J;{PC} of this structure is 1--. Its pole position is determined to be [1576(-55)(+49)(stat)-91+98(syst)] MeV/c(2)-i/2[818(-23)(+22)(stat)-133+64(syst)] MeV/c(2). These parameters are not compatible with any known meson resonances.

Pseudomonas aeruginosa autoinducer modulates host cell responses through calcium signalling

The opportunistic pathogen Pseudomonas aeruginosa utilizes a cell density-dependent signalling phenomenon known as quorum sensing (QS) to regulate several virulence factors needed for infection. Acylated homoserine lactones, or autoinducers, are the primary signal molecules that mediate QS in P. aeruginosa. The autoinducer N-3O-dodecanoyl-homoserine lactone (3O-C12) exerts effects on mammalian cells, including upregulation of pro-inflammatory mediators and induction of apoptosis. However, the mechanism(s) by which 3O-C12 affects mammalian cell responses is unknown. Here we report that 3O-C12 induces apoptosis and modulates the expression of immune mediators in murine fibroblasts and human vascular endothelial cells (HUVEC). The effects of 3O-C12 were accompanied by increases in cytosolic calcium levels that were mobilized from intracellular stores in the endoplasmic reticulum (ER). Calcium release was blocked by an inhibitor of phospholipase C, suggesting that release occurred through inositol triphosphate (IP3) receptors in the ER. Apoptosis, but not immunodulatory gene activation, was blocked when 3O-C12-exposed cells were co-incubated with inhibitors of calcium signalling. This study indicates that 3O-C12 can activate at least two independent signal transduction pathways in mammalian cells, one that involves increases in intracellular calcium levels and leads to apoptosis, and a second pathway that results in modulation of the inflammatory response.

Measurements of the branching fractions for psi(3770)-->D(0)D[over ](0), D+D-, DD[over ], and the resonance parameters of psi(3770) and psi(2S)

We measure the branching fractions for psi(3770)-->D(0)D[over ](0), D+D-, DD[over ], and non-DD[over ] to be (46.7+/-4.7+/-2.3)%, (36.9+/-3.7+/-2.8)%, (83.6+/-7.3+/-4.2)%, and (16.4+/-7.3+/-4.2)%, respectively. The resonance parameters of psi(3770) and psi(2S) are measured to be M_(psi(3770))=3772.2+/-0.7+/-0.3 MeV, Gamma_(psi(3770))(tot)=26.9+/-2.4+/-0.3 MeV, and Gamma_(psi(3770))(ee)=251+/-26+/-11 eV; M_(psi(2S))=3685.5+/-0.0+/-0.3 MeV, Gamma_(psi(2S))(tot)=331+/-58+/-2 keV, and Gamma_(psi(2S))(ee)=2.330+/-0.036+/-0.110 keV. We also measure the light hadron R value to be R(uds)=2.262+/-0.054+/-0.109 in the energy region from 3.660 to 3.872 GeV.

GLUT1 and p63 expression in endometrial intraepithelial and uterine serous papillary carcinoma

AIMS

To analyse the expression patterns of GLUT1, p63 and p53 and the possible correlation between these markers in uterine serous papillary carcinoma (USPC) and endometrial intraepithelial carcinoma (EIC).

METHODS AND RESULTS

Fourteen cases of USPC, 12 of which also showed EIC, were examined for GLUT1, p63 and p53 immunoreactivity. Four-micrometre sections from formalin-fixed paraffin-embedded tissue were immunostained using commercially available primary antibodies and Dako Envision Plus reagents for visualization. Membranous GLUT1 immunoreactivity was observed in all cases, including all 14 invasive tumours (100%) and 11 of 12 associated EICs (92%), and was confined to neoplastic cells. In USPC, staining tended to be strongest in superficial antistromal regions. p63 positivity was found in 8/14 (57%) USPCs and 9/12 (75%) associated EICs. In 11 cases p53 was overexpressed in both invasive USPC (11/14; 79%) and EIC (11/12; 92%). p53+ USPCs tended to be positive for p63, whereas p53- USPCs were also negative for p63.

CONCLUSIONS

GLUT1 is expressed in the vast majority of USPC and EIC, suggesting a biological role during the early steps of carcinogenesis in endometrial serous neoplasms. GLUT1 expression may be induced by hypoxia-related as well as other mechanisms.

The visfatin gene is associated with glucose and lipid metabolism in a Chinese population

AIMS

Visfatin is a newly discovered adipokine found in abundance in visceral fat. It lowers plasma glucose in humans and mice. In this study, we explored the relationships between the plasma level of visfatin and genetic single nucleotide polymorphisms (SNPs) and Type 2 diabetes mellitus (T2DM) and anthropometric and metabolic parameters in Chinese subjects.

METHODS

Oral glucose tolerance tests (OGTT) and biochemical assays for plasma insulin, lipid profiles and serum visfatin were performed in 241 newly diagnosed T2DM patients, subjects with impaired glucose regulation (IGR), and normal glucose tolerant subjects more than 40 years of age. Genotyping for three SNP loci: -1535C/T, rs2058539 and rs10953502 were performed using the allele-specific real-time PCR method.

RESULTS

Visfatin levels were similar in T2DM patients, IGR and normal glucose tolerant subjects. However, visfatin levels were significantly lower in obese than normal-weight subjects (13.66 +/- 0.87 vs. 15.46 +/- 0.47 ng/ml, P = 0.03). There was suggestively significant correlation between visfatin level and body mass index (r = -0.17 P = 0.07) and waist-hip ratio (r = 0.16 P = 0.08) in male subjects, but not in female subjects. Allele and common haplotype frequencies of the three SNP loci were similar in T2DM patients, IGR and normal glucose tolerant subjects. However, significant associations were found between these three SNP loci and plasma glucose concentration at 0 and 120 min during OGTT, the area under the response curve for plasma glucose, and triglyceride and total cholesterol levels.

CONCLUSIONS

Serum visfatin levels may be related to visceral obesity in men, and the visfatin gene may account for variation of glucose and lipid parameters in Chinese subjects.

The prediction of stress-relaxation of ligaments and tendons using the quasi-linear viscoelastic model

Recent studies have questioned the ability of the quasi-linear viscoelastic (QLV) model to predict stresses and strains in response to loading conditions other than those used to fit the model. The objective of this study was to evaluate the ability of several models in the literature to predict the elastic stress response of ligament and tendon at strain levels higher than the levels used to fit the model. The constitutive models were then used to evaluate the ability of the QLV model to predict the overall stress response during stress relaxation. The models expressing stress as an exponential function of strain significantly overestimated stress when used at higher strain levels. The polynomial formulation of the Mooney-Rivlin model more accurately predicted the stress-strain behavior of ligament and tendon. The results demonstrate that the ability of the QLV model to accurately predict the stress-relaxation response is dependent in part on the accuracy of the function used to model the elastic response of the soft tissue.

Discovery and preliminary structure-activity relationship studies of novel benzotriazine based compounds as Src inhibitors

We report the discovery and preliminary SAR studies of a series of structurally novel benzotriazine core based small molecules as inhibitors of Src kinase. To the best of our knowledge, benzotriazine template based compounds have not been reported as kinase inhibitors. The 3-(2-(1-pyrrolidinyl)ethoxy)phenyl analogue (43) was identified as one of the most potent inhibitors of Src kinase.

Prevalence and genetic diversity of coronaviruses in bats from China

Coronaviruses can infect a variety of animals including poultry, livestock, and humans and are currently classified into three groups. The interspecies transmissions of coronaviruses between different hosts form a complex ecosystem of which little is known. The outbreak of severe acute respiratory syndrome (SARS) and the recent identification of new coronaviruses have highlighted the necessity for further investigation of coronavirus ecology, in particular the role of bats and other wild animals. In this study, we sampled bat populations in 15 provinces of China and reveal that approximately 6.5% of the bats, from diverse species distributed throughout the region, harbor coronaviruses. Full genomes of four coronavirues from bats were sequenced and analyzed. Phylogenetic analyses of the spike, envelope, membrane, and nucleoprotein structural proteins and the two conserved replicase domains, putative RNA-dependent RNA polymerase and RNA helicase, revealed that bat coronaviruses cluster in three different groups: group 1, another group that includes all SARS and SARS-like coronaviruses (putative group 4), and an independent bat coronavirus group (putative group 5). Further genetic analyses showed that different species of bats maintain coronaviruses from different groups and that a single bat species from different geographic locations supports similar coronaviruses. Thus, the findings of this study suggest that bats may play an integral role in the ecology and evolution of coronaviruses.

Observation of two new N* peaks in J/psi-->ppi-n and ppi+n decays

The decay J/psi-->NNpi provides an effective isospin 1/2 filter for the piN system due to isospin conservation. Using 58x10(6) J/psi decays collected with the Beijing Electromagnetic Spectrometer at the Beijing Electron Positron Collider, more than 100 thousand J/psi-->ppi-n+c.c. events are obtained. Besides the two well-known N* peaks at around 1500 MeV/c2 and 1670 MeV/c2, there are two new, clear N* peaks in the ppi invariant mass spectrum around 1360 MeV/c2 and 2030 MeV/c2 with statistical significance of 11sigma and 13sigma, respectively. We identify these as the first direct observation of the N*(1440) peak and a long-sought missing N* peak above 2 GeV/c2 in the piN invariant mass spectrum.