Parquet approximation for the 4x4 Hubbard cluster

We present a numerical solution of the parquet approximation, a conserving diagrammatic approach which is self-consistent at both the single-particle and the two-particle levels. The fully irreducible vertex is approximated by the bare interaction thus producing the simplest approximation that one can perform with the set of equations involved in the formalism. The method is applied to the Hubbard model on a half-filled 4x4 cluster. Results are compared to those obtained from determinant quantum Monte Carlo (DQMC), FLuctuation EXchange (FLEX), and self-consistent second-order approximation methods. This comparison shows a satisfactory agreement with DQMC and a significant improvement over the FLEX or the self-consistent second-order approximation.

Long-lasting infiltration anaesthesia by lidocaine-loaded biodegradable nanoparticles in hydrogel in rats

BACKGROUND

Infiltration of a long-lasting anaesthetic is helpful during the post-operative period. The recently developed local drug delivery system, biodegradable nanoparticles in a thermo-sensitive hydrogel (nanogel system), may possibly provide an extended duration of drugs. Therefore, we evaluated whether prolonged infiltration anaesthesia could be achieved by loading lidocaine into this delivery system.

METHODS

Thirty male rats were randomized into five groups of six rats each: saline; 2% hydrochloride lidocaine solution; lidocaine-loaded nanogel system and its compositing formulations, namely lido-nano gel; lido-nano; and lidogel. Durations of local anaesthesia with subcutaneously injected agents were measured by tail flick latency tests in a randomized, blind fashion.

RESULTS

Lido-nano gel produced effective anaesthesia for 360+/-113 min, compared with 150+/-33 min by lidogel, 180+/-37 min by lido-nano, and 110+/-45 min by lidocaine solution (P<0.001, means+/-SD), and elicited complete sensory blockade for 300+/-114 min, compared with 75+/-37 min by lidogel, 105+/-53 min by lido-nano, and 60+/-33 min by lidocaine solution (P<0.001, means+/-SD) without severe skin/systemic toxicity.

CONCLUSION

Lidocaine-loaded biodegradable nanoparticles in hydrogel produced prolonged infiltration anaesthesia in rats without severe toxicity, indicating a possible way to develop long-lasting local anaesthetics.

High pressure Raman investigations of multiferroic BiFeO(3)

We have reported a Raman scattering investigation of bismuth ferrite (BiFeO(3)) under high pressure up to 50 GPa. Distinct changes in the Raman spectra show evidence for three pressure-induced structural transitions. The abrupt frequency redshifts of the Raman modes near 300 cm(-1) at around 3 GPa are attributed to the modulation of the FeO(6) octahedral tilts. The disappearance of the modes below 250 cm(-1) at 8.6 GPa, together with the enhancement of the two modes in the range of 300-400 cm(-1), indicate the phase transition from the rhombohedral to orthorhombic symmetry. Afterward, the E-3 and E-4 modes disappear at 44.6 GPa, pointing to the occurrence of the orthorhombic-cubic phase transition, which is consistent with the previous postulate that an orthorhombic-cubic transition takes place across the metal-insulator transition at high pressures.

Effects of losartan on fibrinolytic parameters and von Willebrand factor in Chinese subjects with hypertension: a comparative study versus atenolol

To compare the effects of losartan and atenolol on plasma fibrinolytic parameters and von Willebrand factor (vWF), Chinese subjects with mild-to-moderate hypertension were randomized to receive losartan (50 mg/day; n = 30) or atenolol (50 mg/day; n = 30) for 8 weeks. If target blood pressure (< 140/90 mmHg) was not achieved at week 4, hydrochlorothiazide (12.5 mg/day) was also administered. Plasma levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and vWF were determined at baseline and after treatment. Between-group baseline characteristics and blood pressure decrease were comparable. Losartan significantly reduced plasma PAI-1 and vWF and PAI-1/tPA ratio. Atenolol significantly increased plasma tPA, but PAI-1, vWF and PAI-1/tPA ratio were unchanged. In conclusion, losartan, but not atenolol improved the fibrinolytic system and reduced plasma vWF levels in Chinese hypertensives.

Inhibition of autophagy induced by overexpression of mda-7/interleukin-24 strongly augments the antileukemia activity in vitro and in vivo

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a novel candidate of tumor suppressor that can selectively induce apoptosis experimentally in a spectrum of human cancer cells including leukemia cells. However, a recent study suggests that mda-7/IL-24 promotes the survival of chronic lymphocytic leukemia B-cells. In this study, we showed that mda-7/IL-24 was constitutively expressed in leukemia cell lines and primary acute myeloid leukemia samples. Using a conditionally replicating adenovirus expressing mda-7/IL-24 (ZD55-IL-24), we showed that enforced expression of mda-7/IL-24 in leukemia cells induced autophagy, which was triggered by the upregulation of Beclin-1. Immunofluorescence and coimmunoprecipitation studies suggested that mda-7/IL-24 protein interacts with Beclin-1. Class III PI3K/Beclin-1 complex was shown involved in the mda-7/IL-24-induced autophagy. Moreover, autophagy inhibition by phosphatidylinositol 3-kinase inhibitor, wortmannin, resulted in a reduced Beclin-1 expression and autophagosome formation associated with significantly enhanced cell death. Importantly, the combination of ZD55-IL-24 with wortmannin elicited a strongly enhanced antileukemia efficacy in established leukemia xenografts. These results suggest that mda-7/IL-24-induced autophagy in leukemia cells may provide survival advantage and mda-7/IL-24 combined with agents that disrupt autophagy is a promising new strategy for the treatment of leukemia.

Mechanism of cardiac preconditioning with volatile anaesthetics

In recent years, there has been increased interest in the mechanisms involved in anaesthetic-induced cardioprotection. It is not thoroughly understood how volatile anaesthetics protect the myocardium from ischaemia or reperfusion injury, but the overall mechanism is likely to be multifactorial. This review examines the recent experimental and clinical research underlying the cellular and molecular mechanisms involved in anaesthetic-induced preconditioning. A variety of intracellular signalling pathways have been implicated in the protective phenomenon. Ischaemic preconditioning and anaesthetic-induced preconditioning share similar molecular mechanisms, including activation of guanine nucleotide-binding proteins, triggering of second messenger pathways, activation of multiple kinases, mediation of nitric oxide formation and reactive oxygen species release, maintenance of intracellular and/or mitochondrial Ca2+ homeostasis and moderation of the opening of adenosine-triphosphate-sensitive potassium channels. A more thorough understanding of the multiple signalling steps and the ultimate cytoprotective mechanisms underlying anaesthetic-induced preconditioning may lead to improvements in the management of ischaemia and/or reperfusion injury.

Study on genes with altered expression in alpha-amanitin poisoned mice and evaluation on antagonistic effects of traditional Chinese medicines against toxicity of alpha-amanitin

The forward and reverse cDNA subtractive libraries before and after the toxic effect of alpha-amanitin were constructed by suppression subtractive hybridization and randomly selected clones from each subtractive library were screened by PCR and dot blot hybridization. A total of 85 genes with altered expression were finally identified, with 41 genes from the forward library and 44 from the reverse library. Subsequently, the antagonistic effects of candidate traditional Chinese medicines were evaluated based on the genetic transcription levels of the genes with significant altered expression, including Catnbeta, Flt3-L, IL-7r and Rpo2-4. The results indicated that Silybum marianum (L.) Gaert and Ganoderma lucidum had significant down-regulated effects on the transcription level of Catnbeta that was up-regulated by alpha-amanitin, and the two herbs also up-regulated the transcription levels of Flt3-L and Rpo2-4. Silybum marianum (L.) had significant up-regulated effects on the IL-7r that was down-regulated by alpha-amanitin. These preliminary studies suggested that Silybum marianum (L.) and Ganoderma lucidum were effective antagonists against the toxicity of alpha-amanitin.

K/pi Fluctuations at relativistic energies

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Classical aspects in above-threshold ionization with a midinfrared strong laser field

We present high resolution photoelectron energy spectra of noble gas atoms from high intensity above-threshold ionization (ATI) at midinfrared wavelengths. An unexpected structure at the very low-energy portion of the spectra, in striking contrast to the prediction of the simple-man theory, has been revealed. A semiclassical model calculation is able to reproduce the experimental feature and suggests the prominent role of the Coulomb interaction of the outgoing electron with the parent ion in producing the peculiar structure in long wavelength ATI spectra.

Lysophosphatidic acid-induced platelet shape change revealed through LPA(1-5) receptor-selective probes and albumin

Lysophosphatidic acid (LPA), a component of mildly-oxidized LDL and the lipid rich core of atherosclerotic plaques, elicits platelet activation. LPA is the ligand of G protein-coupled receptors (GPCR) of the EDG family (LPA(1-3)) and the newly identified LPA(4-7) subcluster. LPA(4), LPA(5) and LPA(7) increase cellular cAMP levels that would induce platelet inhibition rather than activation. In the present study we quantified the mRNA levels of the LPA(1-7) GPCR in human platelets and found a rank order LPA(4) = LPA(5) > LPA(7) > LPA(6) = LPA(2) >> LPA(1) > LPA(3). We examined platelet shape change using a panel of LPA receptor subtype-selective agonists and antagonists and compared them with their pharmacological profiles obtained in heterologous LPA(1-5) receptor expression systems. Responses to different natural acyl and alkyl species of LPA, and octyl phosphatidic acid analogs, alpha-substituted phosphonate analogs, N-palmitoyl-tyrosine phosphoric acid, N-palmitoyl-serine phosphoric acid were tested. All of these compounds elicited platelet activation and also inhibited LPA-induced platelet shape change after pre-incubation, suggesting that receptor desensitization is likely responsible for the inhibition of this response. Fatty acid free albumin (10 microM) lacking platelet activity completely inhibited platelet shape change induced by LPA with an IC(50) of 1.1 microM but had no effect on the activation of LPA(1,2,3,&5) expressed in endogenously non-LPA-responsive RH7777 cells. However, albumin reduced LPA(4) activation and shifted the dose-response curve to the right. LPA(5) transiently expressed in RH7777 cells showed preference to alkyl-LPA over acyl-LPA that is similar to that in platelets. LPA did not increase cAMP levels in platelets. In conclusion, our results with the pharmacological compounds and albumin demonstrate that LPA does not induce platelet shape change simply through activation of LPA(1-5), and the receptor(s) mediating LPA-induced platelet activation remains elusive.

Depression and low bone mineral density: a meta-analysis of epidemiologic studies

SUMMARY

The association between depression and loss of bone mineral density (BMD) has been reported inconsistently. This meta-analysis, which pooled results from 14 qualifying individual studies, found that depression was associated with a significantly decreased BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression.

INTRODUCTION

The reported association between depression and loss of BMD has been controversial. This meta-analysis was conducted to determine whether depression and BMD are associated and to identify the variation in some subgroups.

METHODS

English-language articles published before October 2008 were used as the data source. A total of six case-controlled and eight cross-sectional studies met prestated inclusion criteria (N = 10,523). Information on study design, participant characteristics, measurements of BMD and depression, and control for potential confounders was abstracted independently by two investigators using a standardized protocol.

RESULTS

Overall, depression was associated with a significant decrease in mean BMD of spine (-0.053 g/cm(2) [95% confidence interval {CI} -0.087 to -0.018 g/cm(2)]) and hip (-0.052 g/cm(2) [95% CI -0.083 to -0.022 g/cm(2)]). A substantially greater BMD decrease was observed in depressed women (-0.076 g/cm(2) in spine; -0.059 g/cm(2) in hip) and in cases of clinical depression (-0.074 g/cm(2) in spine; -0.080 g/cm(2) in hip).

CONCLUSION

Depression is associated with low BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression. Depression should be considered as an important risk factor for osteoporosis.

A +220 GATA motif mediates basal but not endotoxin-repressible expression of the von Willebrand factor promoter in Hprt-targeted transgenic mice

BACKGROUND

The von Willebrand factor (VWF) gene is a marker for spatial and temporal heterogeneity of the endothelium. A GATA motif at +220 has been implicated in basal VWF expression in vitro. Other studies have shown that GATA3 and VWF are transcriptionally downregulated in response to inflammatory mediators.

OBJECTIVES

Our goal was to determine the importance of the +220 GATA motif in mediating expression of VWF promoter in vivo, and to elucidate whether the GATA element plays a role in spatial and/or temporal regulation of VWF expression.

METHODS

ChIP and electrophoretic mobility shift assays were carried out in human umbilical vein endothelial cells (HUVEC). Reporter gene constructs containing 3.6 kb of the human VWF promoter with and without a mutation of the +220 GATA element were transfected into cultured endothelial cells or targeted to the Hprt locus of mice. The Hprt-targeted mice were subjected to endotoxemia.

RESULTS

In protein-DNA binding assays, the +220 GATA motif bound GATA-2, -3 and -6. Mutation of the GATA site resulted in reduced basal promoter activity in HUVEC. When targeted to the Hprt locus of mice, the GATA mutation resulted in a significant, proportionate reduction of promoter activity in LacZ expressing vascular beds. Systemic administration of lipopolysaccharide (LPS) resulted in a widespread reduction in VWF mRNA expression and promoter activity. LPS-mediated repression of the VWF promoter was unaffected by the GATA mutation.

CONCLUSIONS

A region of the VWF promoter between -2182 and the end of the first intron contains information for LPS-mediated gene repression. The +220 GATA motif is important for basal, but not LPS-repressible expression of the VWF gene.

Ultrastructural changes of nucleoli in common wheat induced by actinomycin DPeople's Republic of China

Common wheat root tip meristematic cells were treated with low concentrations of actinomycin D (ActD), then stained whole by silver nitrate. We showed by transmission electron microscopy that the typical nucleolar structure did not form, but a granular and fibrillar network was exhibited in the nucleolar region. Our results support a correlation between nucleolar organization/assembly and the activation of RNA Polymerase I transcription. Furthermore, we speculate that the fibrillar network present in the nucleolar region of ActD treated cells may represent the basic skeletal structure required to support the nucleolus.

Study of heat shock response of human umbilical vein endothelial cells (HUVECs) using cDNA microarray

Genetic response of human umbilical vein cells (HUVECs) to heat shock was studied using gene expression analysis. HUVECs were subjected to heat treatment at 44 degrees C and 55 degrees C for 1 h, respectively. Four hours after the treatment, gene expression of the treated cells and control cells (37 degrees C) were profiled using cDNA microarray. Data were analyzed using bioinformatics tools, and the results were verified by real-time quantitative PCR experiment. It has been shown that a large number of genes were regulated indicating global response to heat treatment at the genetic level.

Enhancing the prediction accuracy of bovine lameness models through transformations of limb movement variables

The issue of modeling bovine lameness was explored by testing the hypothesis that B-spline transformation of limb movement variables (LMV) employed in predictive models improved model accuracy. The objectives were to determine the effect of number of B-spline knots and the degree of the underlying polynomial approximation (degree of freedom) on model accuracy. Knot number used in B-spline transformation improved model accuracy by improving model specificity and to a lesser extent model sensitivity. Degree of polynomial approximation had no effect on model predictive accuracy from the data set of 261 cows. Model stability, defined as changes in predictive accuracy associated with the superimposition of perturbations (0.5 and 1.0%) in LMV on the measured data, was explored. Model specificity and to a lesser degree, sensitivity, increased with increased knot number across data set perturbations. Specificity and sensitivity increased by 43 and 11%, respectively, when knot number increased from 0 to 7 for a perturbation level of 0.5%. When the perturbation level was 1%, the corresponding increases in specificity and sensitivity were 32 and 4%, respectively. Nevertheless, different levels of LMV perturbation varied the optimal knot number associated with highest model accuracy. The optimal knot number for 0.5% perturbation was 8, whereas for 1% perturbation the optimal knot number was 7. The B-spline transformation improved specificity and sensitivity of predictive models for lameness, provided the appropriate number of knots was selected.

The experience of menopausal symptoms by Arabic women in Sydney

AIM

To investigate the menopausal experience of Arabic women living in Sydney and to explore the relationship between the psychosomatic symptoms and various sociodemographic factors.

METHOD

A cross-sectional survey was conducted among 197 Arabic women aged 45-65 years. The Menopause-specific Quality of Life (MENQOL) questionnaire was used to collect information on sociodemographic characteristics and menopausal symptoms.

RESULTS

The median age at menopause in the present study was 49 years (mean+/-standard deviation, 47.9+/-5.0 years). Out of 29 symptoms, the most frequent symptom reported was 'feeling tired or worn out' (86%), followed by 'aching in muscles and joints' (85%). Sixty-three percent of the subjects reported 'hot flushes' and 54% reported 'vaginal dryness during intercourse'. The least prevalent symptom was 'increased facial hair' (35%). Postmenopausal women suffered more vasomotor and sexual symptoms than pre- and perimenopausal women (p<0.05). Women from the sample who were better educated and had a lower body mass index reported fewer and less severe symptoms.

CONCLUSION

Menopause-related symptoms among these Arabic women in Sydney were more prevalent and severe than those reported in many other countries and their quality of life was negatively affected by these symptoms.

Mutations in the LDL receptor gene in four Chinese homozygous familial hypercholesterolemia phenotype patients

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused by mutations in the low-density lipoprotein receptor (LDL-R) gene, leading to elevated levels of cholesterol and an increased risk of coronary heart disease. In this article, from four homozygous FH phenotype probands we identified disease causing mutations and analyzed the relationship between genotype and phenotype.

METHODS AND RESULTS

DNA sequencing identified five LDL-R point mutations in four unrelated families. We found a novel homozygous mutation (C210R), a homozygous mutation at W462X, a compound heterozygous mutation of C122Y and T383I, and a G>A intron 3 splice site homozygous mutation. The functional alteration caused by the novel C210R mutation was confirmed by FACS analysis. Four probands have high low-density lipoprotein cholesterol (LDL-C) levels, ranging from 14.65 to 27.66 mmol/L. Their heterozygous parents had relatively low levels. B-mode ultrasound supplemented by Doppler was used to examine aortic/mitral valve structural alterations and carotid intima-media thickness (ITM) in all probands. The ITM values were between 1.2 and 2.3mm, much higher than the normal value of <0.8mm.

CONCLUSION

Our data demonstrated that all the probands were associated with severe hypercholesterolemia, thick carotid IMT and a low CFVR (coronary flow velocity reserve) value. The novel mutation (C120Y) is a disease causing mutation.