Exon structure requirements for yeast tRNA ligase

Different nucleotides were introduced into nucleotides 32, 37 and 38 of yeast tRNA(Phe) precursors via oligonucleotide directed mutations. Pre-tRNAs were prepared using T7-transcription in vitro and spliced with the purified yeast tRNA endonuclease and tRNA ligase. It is demonstrated that tRNA ligase activities will be inhibited by the 5'-double-stranded end of 3'-halves.

CYP11A1 Is a Predictor of Mammographic Breast Density

Mammographic density (MD) is a strong predictor of breast cancer risk and is highly correlated with the hormone exposure profiles of women. It is also a highly heritable risk factor (heritable component ∼67%). As such, many efforts have been made to identify underlying genetic determinants of MD within pathways related to steroid hormone biosynthesis and metabolism. Several associations with genetic polymorphisms in genes involved in estrogen metabolism have been previously described (e.g. COMT and HSD3B1). Still, there is controversy among the conclusions of these studies. In addition, only a few candidate genes have been interrogated at a time. In this study, we assess associations of genetic variants with MD using the most extensive estrogen metabolic pathway coverage to date.Materials and methods:Cases were 891 Swedish-born women who were 50-74 years of age at diagnosis and diagnosed with breast cancer between October 1993 and March 1995. 840 controls were population and frequency matched to the expected age distribution of the cases.MD was measured using a computer-assisted technique (Cumulus, University of Toronto, Canada) and evaluated by comparing the dense area by the total breast area.Genotyping was performed on a total of 239 SNPs in 34 estrogen metabolic genes using the Sequenom (San Diego, California) primer extension-based assay. SNPs with a call rate <85%, minor allele frequency <1% or out of Hardy-Weinberg Equilibrium (p<0.05/239) were excluded from further analysis.The Cochran-Armitage trend test was carried out for all SNPs with adjustments for age, body mass index, menopausal status and hormone replacement therapy usage.Results:We report a novel association finding between MD and the gene CYP11A1. 5 out of 6 SNPs within the gene were found to be significant after adjustment. The average increase in MD attributed to these SNPs is 5.4%. Other genes with significant associations include HSD17B3, STS, and NQO1.Discussion:A high level of endogenous estrogen is well-known to be correlated with an increased risk of breast cancer. CYP11A1 encodes a member of the cytochrome P450 superfamily of enzymes and is of interest as it represents is the first as well as a rate-limiting step in steroid hormone biosynthesis.In addition, a role for CYP11A1 in the metabolism of vitamin D3 has been reported recently. High vitamin D levels have been associated with a decrease in both breast cancer risk and MD. Although the active compound most commonly implicated is 1,25-dihydroxyvitamin D3 derived from a more extensively studied pathway, new studies have shown that a by-product of CYP11A1 exhibits similar functions in the regulation of cell proliferation and differentiation.Although CYP11A1 has been previously reported to be associated with breast cancer, it has never been studied in relation to MD. This novel finding suggests that CYP11A1 exerts an influence on MD through two different pathways linked to breast cancer and affirms MD as an intermediate phenotype for the disease.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5161.

Cerebrospinal Fluid Cytology and Clinical Analysis of 34 Cases with Leptomeningeal Carcinomatosis

The clinical characteristics and cerebrospinal fluid (CSF) cytological features of 34 hospitalized patients with leptomeningeal carcinomatosis (LC) were studied. Most patients presented with signs of meningeal irritation (19 cases) and intra-cranial hypertension (23 cases). Computed tomography (CT) and/or magnetic resonance imaging (MRI) revealed brain parenchymal lesions, hydrocephalus and leptomeningeal enhancement (nine, six and eight cases, respectively). The CSF changes included high opening pressure (21 cases), increased white blood cell count (23 cases), elevated protein levels (25 cases) and low glucose levels (17 cases). Malignant cells were found in all CSF specimens and 32 cases had malignant cells in their initial CSF examinations. High serum levels of carcinoembryonic antigen (CEA) occurred in 11 patients. Signs of meningeal irritation and intra-cranial hypertension were common. It is concluded that serum CEA measurement along with CT and MRI scanning are helpful in the diagnosis of LC. Crucially, however, CSF cytology could be the most important technique for the diagnosis of LC.

Electron attachment and electron ionization of acetic acid clusters embedded in helium nanodroplets

The effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic products ejected into the gas phase are detected by mass spectrometry. The cation chemistry (induced by electron ionization at 100 eV) is dominated by production of protonated acetic acid (Ac) clusters, Ac(n)H(+), although some fragmentation is also observed. In the case of anion production (at 2.8 eV electron energy) there is a clear distinction between the monomer and the clusters. For the monomer the dominant product is the dehydrogenated species, [Ac-H](-), whereas for the clusters both the parent anion, Ac(n)(-), and the dehydrogenated species, [Ac(n)-H](-), have similar abundances. A particularly intriguing contrast between the monomer and cluster anions is that helium atoms are seen attached to the latter whereas no evidence of helium atom attachment is found for the monomer. This surprising observation is attributed to the formation of acyclic (head-to-tail) acetic acid clusters in helium nanodroplets, which have more favourable electronic properties for binding helium atoms. The acyclic clusters represent a local minimum on the potential energy surface and in the case of the dimer this is distinct from the cyclic isomer (the global minimum) identified in gas phase experiments.

Genome sequence, comparative analysis, and population genetics of the domestic horse

We report a high-quality draft sequence of the genome of the horse (Equus caballus). The genome is relatively repetitive but has little segmental duplication. Chromosomes appear to have undergone few historical rearrangements: 53% of equine chromosomes show conserved synteny to a single human chromosome. Equine chromosome 11 is shown to have an evolutionary new centromere devoid of centromeric satellite DNA, suggesting that centromeric function may arise before satellite repeat accumulation. Linkage disequilibrium, showing the influences of early domestication of large herds of female horses, is intermediate in length between dog and human, and there is long-range haplotype sharing among breeds.

Hepatitis B virus protein preS2 potentially promotes HCC development via its transcriptional activation of hTERT

BACKGROUNDS AND AIMS

Telomerase is significantly reactivated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC). Our previous studies showed that the transactivation unit of HBV surface (S) gene, preS2, could upregulate human telomerase reverse transcriptase (hTERT) expression and telomerase activity of HepG2 cells. Here, we aim to explore the functions, and the underlying mechanisms, of this preS2-mediated hTERT upregulation during HCC development.

METHODS

An antisense blocking assay was performed on HBV-integrated HepG2.2.15 cells. The expression of hTERT was examined in clinical samples to test the role of the preS2-mediated hTERT upregulation in HCC development in vivo. In order to explore the mechanisms of preS2-mediated hTERT upregulation, co-transfection, reporter assays and electrophoretic mobility shift assays (EMSA) were performed.

RESULTS

Blocking preS2 expression reduced hTERT expression, telomerase activity, cell proliferation and tumorigenicity of HepG2.2.15. A region located between -349 and -329 bp upstream of the transcription initiation site of hTERT was identified as responsible for the preS2-mediated effect. preS2 interacted with the preS2-responsible region (PRR) and activated the hTERT promoter. Importantly, hTERT was also highly expressed in preS2-positive human HCC samples. All these findings strongly suggest that preS2 may promote HCC development via hTERT activation.

CONCLUSIONS

HBV protein preS2 upregulates hTERT via the PRR element in promoting HCC development.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

Use of short echo time two-dimensional 1H-magnetic resonance spectroscopy in temporal lobe epilepsy with negative magnetic resonance imaging findings

We evaluated short echo time two-dimensional 1H magnetic resonance spectroscopy (2D-1HMRS) with the point-resolved spatial selection (PRESS) protocol in temporal lobe epilepsy (TLE) patients with negative magnetic resonance imaging (MRI) findings and described the characteristics of 2D-(1)HMRS in the epileptic focus. Thirty-eight TLE patients with negative conventional MRI findings and 10 healthy controls were studied by 2D-1HMRS. A 128-channel prolonged video-electroencephalographic (EEG) method was used as the standard for epileptogenic focus localization to evaluate N-acetyl aspartate/(choline + creatine + phosphocreatine) (NAA/[Cho + Cr-PCr]), glutamate + glutamine/creatine (Glx/Cr-PCr) and myo-inositol/Cr-PCr ratios in patients with negative MRI findings. The 2D-1HMRS showed that 32/38 patients and all healthy controls had stable baselines and good signal-to-noise ratios. Compared with the healthy controls, 32 patients showed abnormal NAA/(Cho + Cr-PCr) ratios in the hippocampus and, in 25 of these patients, focus lateralization agreed with the EEG. It is concluded that short echo time 2D-1HMRS with the PRESS protocol can help find abnormalities in lateralization of temporal epilepsy in patients with negative MRI findings.

The relationship between Chinese construction workers' HIV/AIDS-related knowledge, attitudes and behaviour: a structural equation model

This study explored the relationship between human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS)-related knowledge, attitudes and behaviour in migrant urban construction workers using structural equation modelling (SEM). A cross-sectional study was conducted among 428 male subjects on three building sites in Shenyang City. The SEM model of HIV/AIDS-related knowledge, attitudes and behaviour was built using LISREL version 8.5 and it fitted the data well, as shown by an adjusted goodness of fit index of 0.82 and a root mean square error of approximation of 0.094. Knowledge of HIV/AIDS was closely correlated with attitudes and behaviour. Age was an important factor affecting HIV/AIDS-related knowledge, attitudes and behaviour. These findings suggest that increasing HIV/AIDS-related knowledge could improve the attitude and behaviour of migrant urban construction workers, enabling them to avoid high-risk behaviour that increases the spread of HIV/AIDS. Any intervention used will need to take the important factor of age into consideration.

Reliability and validity testing of the SF-36 questionnaire for the evaluation of the quality of life of Chinese urban construction workers

The quality of life (QOL) of the Chinese 'floating' migrant population is of growing concern. Urban construction workers are the main migrant population in China, but there is little published research on their QOL. The reliability and validity of the 36-Item Short Form Health Survey (SF-36) questionnaire were assessed by conducting a population-based study of migrant construction workers in Shenyang, China. Two construction sites were randomly selected from each of the five districts of Shenyang City and 1200 copies of the questionnaire were distributed to rurally-registered, non-Shenyang workers aged > or = 16 years at these sites. A total of 1125 questionnaires were evaluated. The overall Cronbach's alpha coefficient of the SF-36 questionnaire was 0.821 while the respective Cronbach's alpha coefficient for each dimension was > 0.70. Results showed that the SF-36 questionnaire demonstrated good reliability and validity, and that it can be used to measure QOL among Chinese migrant urban construction workers.

Cytokines and angiogenic factors in patients with metastatic renal cell carcinoma treated with interferon-alpha: association of pretreatment serum levels with survival

BACKGROUND

To correlate serum cytokine and angiogenic factor (CAF) levels with overall survival (OS) in metastatic renal cell carcinoma (mRCC) treated with interferon-alpha (IFN-alpha).

PATIENTS AND METHODS

Serum CAF levels were measured in 103 patients treated on a randomized trial with IFN-alpha 0.5 million units (MU) twice daily or 5 MU daily. Concentrations of 17 analytes were determined by multiplex bead immunoassays [vascular endothelial growth factor A (VEGF(A)) and several cytokines] or enzyme-linked immunosorbent assay (basic fibroblast growth factor). We used proportional hazards models to evaluate the effect of CAF levels and clinical factors on OS.

RESULTS

Pretreatment serum interleukin (IL) 5, IL-12 p40, VEGF(A), and IL-6 levels and Memorial Sloan-Kettering Cancer Center risk grouping independently correlated with OS, with hazard ratios of 2.33, 2.00, 2.07, 1.82, and 0.39, respectively (concordance index = 0.69 for the combined model versus 0.60 for the CAF model versus 0.52 for the clinical model). Based on an index derived from these five risk factors (RFs), patients with 0-2 RF had a median OS time of 32 months versus 9 months for patients with 3-5 RF (P < 0.0001).

CONCLUSIONS

Serum CAF profiling contributes to prognostic evaluation in mRCC and helps to identify a subset of patients with 20% 5-year OS.

Fibronectin adsorption studied using neutron reflectometry and complementary techniques

In implantology it is known that fibronectin affects cell-substrate adhesion, consequently, the structure and composition of the initially adsorbed fibronectin layer to a large extent determines the biological response to a biomaterial implanted into the body. In this study we have used neutron reflectometry and quartz-crystal microbalance with dissipation to investigate the amount of fibronectin adsorbed, the layer density, thickness and structure of films adsorbed to polished silicon oxide surfaces. We have cultured MG63 osteoblast-like cells on surfaces coated and uncoated with fibronectin and monitored the cellular response to these surfaces. The results show that at fibronectin concentrations in the range 0.01 to 0.1 mg/ml a single highly hydrated layer of fibronectin approximately 40-50 Å in thickness adsorbs to a polished silicon oxide surface and is likely to correspond to one diffuse monolayer of fibronectin arranged side-on. Cells cultured on this fibronectin layer have dramatically different morphology and growth to those grown on bare surfaces. Using a model silicon oxide surface has enabled us to study the substrate/protein interface, together with the impact of a fibronectin layer on the cellular response using consistent experimental conditions across a unique set of experimental techniques.

Cornelia de Lange syndrome, cohesin, and beyond

Cornelia de Lange syndrome (CdLS) (OMIM #122470, #300590 and #610759) is a dominant genetic disorder with multiple organ system abnormalities which is classically characterized by typical facial features, growth and mental retardation, upper limb defects, hirsutism, gastrointestinal and other visceral system involvement. Mutations in three cohesin proteins, a key regulator of cohesin, NIPBL, and two structural components of the cohesin ring SMC1A and SMC3, etiologically account for about 65% of individuals with CdLS. Cohesin controls faithful chromosome segregation during the mitotic and meiotic cell cycles. Multiple proteins in the cohesin pathway are also involved in additional fundamental biological events such as double-strand DNA break repair and long-range regulation of transcription. Moreover, chromosome instability was recently associated with defective sister chromatid cohesion in several cancer studies, and an increasing number of human developmental disorders is being reported to result from disruption of this pathway. Here, we will discuss the human disorders caused by alterations of cohesin function (termed 'cohesinopathies'), with an emphasis on the clinical manifestations of CdLS and mechanistic studies of the CdLS-related proteins.

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.