Synergistic effects of beta-aescin and 5-fluorouracil in human hepatocellular carcinoma SMMC-7721 cells

The effects and mechanisms of action of beta-aescin and 5-fluorouracil (5-FU), alone and in combination, were studied in human hepatocellular carcinoma SMMC-7721 cells. Growth inhibition, cell cycle distribution, apoptosis, Bcl-2 expression and caspase activity were assessed. The Isobole-method/interaction-index analysis was applied to evaluate the synergy, additivity or antagonism of these agents. The results indicate that mixtures of beta-aescin and 5-FU showed a synergistic effect on the 50% inhibitory effect when their ratio was 4:1 when compared with either agent alone. The mechanism of action could be through the synergistic arrest of the cell cycle, induction of apoptosis, activation of caspases-3, 8 and 9, and down-regulation Bcl-2 expression. The results suggest that mixtures of these two agents had a synergistic inhibitory effect on SMMC-7721 cells, an observation which might be useful for the further development of anti-cancer drugs.

Search for Randall-Sundrum gravitons in the dielectron and diphoton final states with 5.4 fb(-1) of data from pp collisions at square root(s) = 1.96 TeV

Using 5.4  fb(-1) of integrated luminosity from pp collisions at square root(s)=1.96  TeV collected by the D0 detector at the Fermilab Tevatron Collider, we search for decays of the lightest Kaluza-Klein mode of the graviton in the Randall-Sundrum model to ee and γγ. We set 95% C.L. lower limits on the mass of the lightest graviton between 560 and 1050 GeV for values of the coupling k/M(Pl) between 0.01 and 0.1.

Genomic polymorphisms within alpha 7 nicotinic acetylcholine receptor and severe sepsis in Chinese Han population

Alpha 7 nicotinic acetylcholine receptor, a kind of ligand-gated ion channel mainly expressed in macrophages, plays a crucial role in improving survival in sepsis via suppressing proinflammatory cytokines. The predisposition of genomic polymorphisms within alpha 7 nicotinic acetylcholine receptor gene (CHRNA7) to sepsis has not been investigated. The current association study was performed to analyse six common genetic variations within 5'-upstream region of CHRNA7 gene in 229 patients with severe sepsis and 267 controls. Neither allelic frequencies nor genotype distributions were significantly different between patients and controls, as well as between surviving and nonsurviving patients. The frequencies of estimated haplotypes were also comparable between above defined groups. The present study suggests that genomic polymorphisms in the 5'-upstream region of CHRNA7 gene may not be a major risk factor for severe sepsis in Chinese Han population.

Histone deacetylase 1 and 2 differentially regulate apoptosis by opposing effects on extracellular signal-regulated kinase 1/2

Histone deacetylases (HDACs) are epigenetic regulators that are important for the control of various pathophysiological events. We found that HDAC inhibitors completely abolished transforming growth factor-β1 (TGF-β1)-induced apoptosis in AML-12 and primary mouse hepatocytes. Expression of a dominant-negative mutant of HDAC1 or downregulation of HDAC1 by RNAi both suppressed TGF-β1-induced apoptosis. In addition, overexpression of HDAC1 enhanced TGF-β1-induced apoptosis, and the rescue of HDAC1 expression in HDAC1 RNAi cells restored the apoptotic response of cells to TGF-β1. These data indicate that HDAC1 functions as a proapoptotic factor in TGF-β1-induced apoptosis. In contrast, downregulation of HDAC2 by RNAi increased spontaneous apoptosis and markedly enhanced TGF-β1-induced apoptosis, suggesting that HDAC2 has a reciprocal role in controlling cell survival. Furthermore, inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) by MEK1 inhibitor PD98059 or expression of a kinase-dead mutant of MEK1 restored the apoptotic response to TGF-β1 in HDAC1 RNAi cells. Strikingly, HDAC2 RNAi caused an inhibition of ERK1/2, and the spontaneous apoptosis can be abolished by reactivation of ERK1/2. Taken together, our data demonstrate that HDAC1 and 2 reciprocally affect cell viability by differential regulation of ERK1/2; these observations provide insight into the roles and potential mechanisms of HDAC1 and 2 in apoptosis.

HEXIM1 modulates vascular endothelial growth factor expression and function in breast epithelial cells and mammary gland

Recently, we found that mutation of the C-terminus of transcription factor Hexamethylene bisacetamide inducible protein 1 (HEXIM1) in mice leads to abnormalities in cardiovascular development due to aberrant vascular endothelial growth factor (VEGF) expression. HEXIM1 regulation of some genes has also been shown to be positive transcription elongation factor b (P-TEFb)-dependent. However, it is not known whether HEXIM1 regulates VEGF in the mammary gland. We demonstrate that HEXIM1 regulates estrogen-induced VEGF transcription via inhibition of Estrogen Receptor alpha recruitment to the VEGF promoter in a P-TEFb-independent manner in MCF-7 cells. Under hypoxic conditions, HEXIM1 inhibits estrogen-induced Hypoxia-inducible factor-1 alpha (HIF-1α) protein expression and recruitment of HIF-1α to the hypoxia response element in the VEGF promoter. In the mouse mammary gland, increased HEXIM1 expression decreased estrogen-driven VEGF and HIF-1α expression. Conversely, a mutation in the C-terminus of HEXIM1 (HEXIM1_1-312) led to increased VEGF and HIF-1α expression and vascularization in mammary glands of heterozygous HEXIM1_1-312 mice when compared to their wild-type littermates. Additionally, HEXIM1_1-312 mice have a higher incidence of carcinogen-induced mammary tumors with increased vascularization, suggesting an inhibitory role for HEXIM1 during angiogenesis. Taken together, our data provide evidence to suggest a novel role for HEXIM1 in cancer progression.

Influence of 1-methylcyclopropene (1-MCP) on the production of bacterial cellulose biosynthesized by Acetobacter xylinum under the agitated culture

AIMS

Bacterial cellulose is an extracellular polysaccharide secreted by Acetobacter xylinum, which has become a novel material increasingly used in food and medical industries. However, its broad application is limited by its low yield and high cost. 1-Methylcyclopropene (1-MCP) is a potent inhibitor to either exogenous or endogenous ethylene during the biological senescence of plants, which has been broadly applied in commercial preservation of fruits and vegetables. The purpose of this study was to investigate the effects of 1-MCP on both the growth of Acet. xylinum and its cellulose production to demonstrate the potential enhancement of bacterial cellulose yield.

METHODS AND RESULTS

Three groups of samples were fermented under agitated culture with 125 rev min(-1) rotational speed. To the culture media, 0.14 mg of 1-MCP contained in 100 mg dextrose powder was added on assigned days or on the first culture day only. Results from the measurement of bacterial cell concentration and bacterial cellulose yield at the end of a 12-day culture demonstrated that cultures excluding 1-MCP displayed a higher cell concentration and a lower cellulose production, while cultures containing 1-MCP produced 15.6% more cellulose (1-MCP added on day 1) and 25.4% (1-MCP added on each assigned day) with less biomass.

CONCLUSIONS

1-MCP was able to affect the growth of Acet. xylinum cells and resulted in increasing bacterial cellulose yield up to 25.4% over controls, which did not contain 1-MCP.

SIGNIFICANCE AND IMPACT OF THE STUDY

This was the first study to use the growth inhibitor of plants to investigate its effects on bacterial growth and production. It also demonstrated a significant enhancement of bacterial cellulose yield by the addition of 1-MCP during the common agitated culture of Acet. xylinum.

A study on using texture analysis methods for identifying lobar fissure regions in isotropic CT images

The major hurdle for segmenting lung lobes in computed tomographic (CT) images is to identify fissure regions, which encase lobar fissures. Accurate identification of these regions is difficult due to the variable shape and appearance of the fissures, along with the low contrast and high noise associated with CT images. This paper studies the effectiveness of two texture analysis methods - the gray level co-occurrence matrix (GLCM) and the gray level run length matrix (GLRLM) - in identifying fissure regions from isotropic CT image stacks. To classify GLCM and GLRLM texture features, we applied a feed-forward back-propagation neural network and achieved the best classification accuracy utilizing 16 quantized levels for computing the GLCM and GLRLM texture features and 64 neurons in the input/hidden layers of the neural network. Tested on isotropic CT image stacks of 24 patients with the pathologic lungs, we obtained accuracies of 86% and 87% for identifying fissure regions using the GLCM and GLRLM methods, respectively. These accuracies compare favorably with surgeons/radiologists' accuracy of 80% for identifying fissure regions in clinical settings. This shows promising potential for segmenting lung lobes using the GLCM and GLRLM methods.

Search for the associated production of a b quark and a neutral supersymmetric Higgs boson that decays into tau pairs

We report results from a search for production of a neutral Higgs boson in association with a b quark. We search for Higgs decays to tau pairs with one tau subsequently decaying to a muon and the other to hadrons. The data correspond to 2.7 fb(-1) of pp collisions recorded by the D0 detector at square root(s)=1.96 TeV. The data are found to be consistent with background predictions. The result allows us to exclude a significant region of parameter space of the minimal supersymmetric model.

The development and validation of a new coeliac disease quality of life survey (CD-QOL)

BACKGROUND

Previous studies on coeliac disease (CD)-related quality of life (QOL) have been limited by their use of a 'generic' rather than coeliac disease-specific assessment instruments.

AIM

To develop and psychometrically validate a new coeliac disease-specific instrument, the CD-QOL.

METHODS

Through a series of focus groups, we elicited items from patients that related to the specific nature of their disease and its impact on their basic needs. Through expert review, cognitive debriefing with patients and pilot testing, a scale was developed, refined and administered to 387 patients on a gluten-free diet from both community-based support groups and a tertiary care referral centre. Finally, a formal validation study was conducted to assess the psychometric properties of the CD-QOL.

RESULTS

The final CD-QOL has 20 items across four clinically relevant subscales (Limitations, Dysphoria, Health Concerns, and Inadequate Treatment). The CD-QOL has high internal consistency, reliability, and psychometric validation indicates both convergent and discriminate validity.

CONCLUSIONS

The CD-QOL is a reliable and valid measure of coeliac disease related QOL. As a new disease-specific instrument, it is likely to be a useful tool for evaluating patients with this disorder.

Fabrication of guided-mode resonance elements by nanoimprint lithography

This paper addresses utilization of nanoimprint lithography for fabrication of nanopatterned resonant photonic elements. These compact periodic films resonate sharply when illuminated with light. The attendant spectral and angular signatures are useful in design of photonic devices for various applications. It is of interest to design and optimize resonant leaky-mode elements with prescribed filtering, polarization, and security attributes. Applying nanoimprint lithography techniques, we fabricate prototype devices using polymer materials produced by Dymax Corporation. The initial prototypes are designed for use in the near-IR and telecommunications spectral regions. We apply holographic surface-relief gratings as master templates. With these templates, we have formed submasters in PDMS (polydimethylsiloxane) to function as imprint stamps for the soft lithography steps. Using these submasters, we fabricate periodic surfaces in UV-curable polymers with resonant films deposited on the surface by sputtering. Several example devices possessing resonance efficiencies exceeding 90% are presented along with their spectral and angular characteristics.

Search for the standard model higgs Boson in the ZH-->nunubb channel in 5.2 fb{-1} of pp collisions at sqrt[s]=1.96 TeV

A search is performed for the standard model Higgs boson in 5.2 fb{-1} of pp collisions at sqrt[s]=1.96 TeV, collected with the D0 detector at the Fermilab Tevatron Collider. The final state considered is a pair of b jets and large missing transverse energy, as expected from pp-->ZH-->nunubb production. The search is also sensitive to the WH-->lnubb channel when the charged lepton is not identified. For a Higgs boson mass of 115 GeV, a limit is set at the 95% C.L. on the cross section multiplied by branching fraction for [pp-->(Z/W)H](H-->bb) that is a factor of 3.7 larger than the standard model value, consistent with the factor of 4.6 expected.

Search for a resonance decaying into WZ boson pairs in pp collisions

We present the first search for an electrically charged resonance W' decaying to a WZ boson pair using 4.1 fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp collider. The WZ pairs are reconstructed through their decays into three charged leptons (l=e, mu). A total of 9 data events is observed in good agreement with the background prediction. We set 95% C.L. limits on the W'WZ coupling and on the W' production cross section multiplied by the branching fractions. We also exclude W' masses between 188 and 520 GeV within a simple extension of the standard model and set the most restrictive limits to date on low-scale technicolor models.