Pharmacokinetics of isofraxidin in rat plasma after oral administration of the extract of acanthopanax senticosus using HPLC with solid phase extraction method

High-performance liquid chromatography coupled with solid phase extraction method was developed for determination of isofraxidin in rat plasma after oral administration of Acanthopanax senticosus extract (ASE), and pharmacokinetic parameters of isofraxidin either in ASE or pure compound were measured. The HPLC analysis was performed on a Dikma Diamonsil RP(18) column (4.6 mm x 150 mm, 5 microm) with the isocratic elution of solvent A (acetonitrile) and solvent B (0.1% aqueous phosphoric acid, v/v) (A : B = 22 : 78) and the detection wavelength was set at 343 nm. The calibration curve was linear over the range of 0.156-15.625 microg/ml. The limit of detection was 60 ng/ml. The intra-day precision was 5.8%, and the inter-day precision was 6.0%. The recovery was 87.30+/-1.73%. When the dosage of ASE is equal to pure compound caculated by the amount of isofraxidin, it has been found to have two maximum concentrations in plasma while the pure compound only showed one peak in the plasma concentration-time curve. The determined content of isofraxidin in plasma after oral administration of ASE is the total contents of free isofraxidin and its precursors in ASE in vitro. The pharmacokinetic characteristics of ASE showed the priority of the extract and the properities of traditional Chinese medicine.

Influence of osteocytes in the in vitro and in vivo β-tricalcium phosphate-stimulated osteogenesis

Osteocytes, known to act as the main regulators of bone homeostasis, have become a major focus in the field of bone research. Bioactive ceramics have been widely used for bone regeneration. However, there are few studies about the interaction of osteocytes with bioceramics. The effects of osteocytes on the in vitro and in vivo osteogenesis of bioceramics are also unclear. The aim of this study was to investigate the role of osteocytes on the b-tricalcium phosphate (b-TCP) stimulated osteogenesis. It was found that osteocytes responded to the b-TCP stimulation, leading to the release of Wnt (wingless-related MMTV integration site), which enhanced osteogenic differentiation of bone marrow stromal cells via Wnt signaling pathway. Receptor activator of nuclear factor kappa B ligand, an osteoclast inducer, was also upregulated, indicating that osteocytes would also participated in activation of osteoclasts, which played a major role in the degradation process of b-TCP and new bone remodeling. In vivo studies further demonstrated that when the material was completely embedded by newly formed bone, the only cell contacting with the material was osteocyte. However, the material would eventually be degraded and replaced by the new bone, requiring the participation of osteoclasts and osteoblasts, which were demonstrated by using immunostaining in this study. As the only cell contacting with the material, osteocytes probably acted in a regulatory role to regulate the surrounding osteoclasts and osteoblasts. Osteocytes were also found to participate in the maturation of osteoblasts and the mineralization process of biomaterials, by upregulating E11 (podoplanin) and dentin matrix protein 1 expression. These findings indicated that osteocytes involved in bone biomaterial-mediated osteogenesis and biomaterial degradation, providing valuable insights into the mechanism of material-stimulated osteogenesis, and a novel strategy to optimize the evaluating system for the biological properties of biomaterials.

Association study of calcitonin gene-related polypeptide-alpha (CALCA) gene polymorphism with migraine

Migraine is a neurological disorder that is associated with increased levels of calcitonin gene-related peptide (CGRP) in plasma. CGRP, being one of the mediators of neurogenic inflammation and a phenomenon implicated in the pathogenesis of migraine headache, is thus suggested to have an important role in migraine pathophysiology. Polymorphisms of the CALCA gene have been linked to Parkinson's disease, ovarian cancer and essential hypertension, suggesting a functional role for these polymorphisms. Given the strong evidence linking CGRP and migraine, it is hypothesised that polymorphisms in the CALCA gene may play a role in migraine pathogenesis. Seemingly non functional intronic polymorphisms are capable of disrupting normal RNA processing or introducing a splice site in the transcript. A 16 bp deletion in the first intron of the CALCA gene has been reported to be a good match for the binding site for a transcription factor expressed strongly in neural crest derived cells, AP-2. This deletion also eliminates an intron splicing enhancer (ISE) that may potentially cause exon skipping. This study investigated the role of the 16 bp intronic deletion in the CALCA gene in migraineurs and matched control individuals. Six hundred individuals were genotyped for the deletion by polymerase chain reaction followed by fragment analysis on the 3130 Genetic Analyser. The results of this study showed no significant association between the intronic 16 bp deletion in the CALCA gene and migraine in the tested Australian Caucasian population. However, given the evidence linking CGRP and migraine, further investigation of variants with this gene may be warranted.

The null allele of GSTM1 does not affect susceptibility to solar keratoses in the Australian white population

Solar keratoses (SKs) are induced by exposure to UV radiation and are capable of undergoing transformation to squamous cell carcinoma (SCC).1 The two main factors influencing the occurrence of SK are the sensitivity of the skin to sunlight and the total duration of solar exposure. These factors are responsible for the high incidence of SK in Australia. Although the influence of genetic factors is not defined, there is evidence that the gene encoding the enzyme, glutathione S-transferase, may be implicated in cancer predisposition and therefore SK. Glutathione S-transferase Mu-1 (GSTM1) is an isoenzyme involved in the detoxification of carcinogens. The GSTM1 protein is completely absent in approximately 50% of white persons. This absence is caused by a homozygous gene deletion on chromosome 1p resulting in a null genotype.2 Katoh3 showed that the frequency of the GSTM1 null genotype was significantly higher in 85 patients with urothelial cancer (61.2%; p < 0.05), suggesting that the null genotype may increase cancer susceptibility. This finding was supported by Lafuente et al.4 who found evidence that persons who lack the GSTM1 gene have approximately twice the chance of experiencing malignant melanoma. Further research in the United Kingdom found that patients with two or more skin tumors of different types, basal cell carcinoma (BCC) and SCC, had a significantly higher frequency of GSTM1 null genotypes than controls (71%; p = 0.033). However the GSTM1 genotype in patients with only SCC was not excessive in this population.5 Persons residing in northern Australia have the highest incidence of nonmelanoma skin cancer (SCC and BCC) in the world6 and receive far greater solar exposure than persons residing in the United Kingdom. It is possible that the GSTM1 null genotype may affect susceptibility to SK, which may act as SCC precursors, in Australians exposed to these high levels of solar radiation.

Osteocyte-induced angiogenesis via VEGF–MAPK-dependent pathways in endothelial cells

Recently, it has been suggested osteocytes control the activities of bone formation (osteoblasts) and resorption (osteoclast), indicating their important regulatory role in bone remodelling. However, to date, the role of osteocytes in controlling bone vascularisation remains unknown. Our aim was to investigate the interaction between endothelial cells and osteocytes and to explore the possible molecular mechanisms during angiogenesis. To model osteocyte/endothelial cell interactions, we co-cultured osteocyte cell line (MLOY4) with endothelial cell line (HUVECs). Co-cultures were performed in 1:1 mixture of osteocytes and endothelial cells or by using the conditioned media (CM) transfer method. Real-time cell migration of HUVECs was measured with the transwell migration assay and xCELLigence system. Expression levels of angiogenesis- related genes were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The effect of vascular endothelial growth factor (VEGF) and mitogen-activated phosphorylated kinase (MAPK) signaling were monitored by western blotting using relevant antibodies and inhibitors. During the bone formation, it was noted that osteocyte dendritic processes were closely connected to the blood vessels. The CM generated from MLOY4 cells-activated proliferation, migration, tube-like structure formation, and upregulation of angiogenic genes in endothelial cells suggesting that secretory factor(s) from osteocytes could be responsible for angiogenesis. Furthermore, we identified that VEGF secreted from MLOY4-activated VEGFR2–MAPK–ERK-signaling pathways in HUVECs. Inhibiting VEGF and/or MAPK–ERK pathways abrogated osteocyte-mediated angiogenesis in HUVEC cells. Our data suggest an important role of osteocytes in regulating angiogenesis.

Process and catalysts for the methanation of oxides of carbon

The present invention is directed to catalysts for the conversion of oxides of carbon to methane and/or other hydrocarbons and to precursors of such catalysts. The catalyst precursors include one or more refractory oxides selected from the group consisting of rare earth oxides and rare earth contg. perovskites, the precursor including nickel or nickel cations sufficient for a catalyst obtainable by reducing the precursor to be capable of at least partially reducing an oxide of carbon to a hydrocarbon product. Processes for the prepn. of such catalysts and catalyst precursors are also disclosed, as are processes for the conversion of oxides of carbon to methane and/or other hydrocarbons. [on SciFinder(R)]

Method of making metal oxides

A method for producing particles having at least regions of at least one metal oxide having nano-sized grains comprises providing particles of material having an initial, non-equiaxed particle shape, making a mixture of the particles of material and one or more precursors of the metal oxide, and treating the mixture such that the one or more precursors of the metal oxide react with the particles of material to thereby form at least regions of metal oxide on or within the particles, wherein atoms from the particles of material form part of a matrix of the at least one metal oxide and the at least one metal oxide has nano-sized grains and wherein at least some of the regions of metal oxide on or within the particles have a non-equiaxed grain shape.

Production of porous metal oxides

Porous complex oxides are produced by reacting metal oxide precursors in the presence of a pore-forming material to provide pore sizes in the range of 7-250 nm, followed by removal of the pore-forming material under conditions preserving the structure and compn. of the formed oxides. The pore-forming material are carbon black particles having a particle size of 10-100 nm. The carbon particles are removed from the formed oxide by heating at 100-300°. A surfactant can be added to the reaction mixt. [on SciFinder(R)]

Effect of dangling chains on the structure and physical properties of a tightly crosslinked poly(ethylene glycol) network

Major imperfections in crosslinked polymers include loose or dangling chain ends that lower the crosslink d., thereby reducing elastic recovery and increasing the solvent swelling. These imperfections are hard to detect, quantify and control when the network is initiated by free radical reactions. As an alternative approach, the sol-​gel synthesis of a model poly(ethylene glycol) (PEG-​2000) network is described using controlled amts. of bis- and mono-​triethoxy silyl Pr urethane PEG precursors to give silsesquioxane (SSQ, R-​SiO1.5) structures as crosslink junctions with a controlled no. of dangling chains. The effect of the no. of dangling chains on the structure and connectivity of the dried SSQ networks has been detd. by step-​crystn. differential scanning calorimetry. The role that micelle formation plays in controlling the sol-​gel PEG network connectivity has been studied by dynamic light scattering of the bis- and mono-​triethoxy silyl precursors and the networks have been characterized by 29Si solid state NMR, sol fraction and swelling measurements. These show that the dangling chains will increase the mesh size and water uptake. Compared to other end-​linked PEG hydrogels, the SSQ-​crosslinked networks show a low sol fraction and high connectivity, which reduces solvent swelling, degree of crystallinity and the crystal transition temp. The increased degree of freedom in segment movement on the addn. of dangling chains in the SSQ-​crosslinked network facilitates the packing process in crystn. of the dry network and, in the hydrogel, helps to accommodate more water mols. before reaching equil.

Aboriginality and the Northern Territory intervention

This thesis examines the construction of Aboriginality in recent public policy reasoning through identifying representations deployed by architects and supporters of the Commonwealth’s 2007 Northern Territory Emergency Response (the intervention). Debate about the Northern Territory intervention was explicitly situated in relation to a range of ideas about appropriate Government policy towards Indigenous people, and particularly about the nature, role, status, value and future of Aboriginality and of Aboriginal people and Torres Strait Islanders. This project involves analysis of constructions of Aboriginality deployed in texts created and circulated to explain and justify the policy program. The aim of the project is to identify the ideas about Aboriginality deployed by the intervention’s architects and supporters, and to examine the effects and implications of these discourses for political relationships between Indigenous people and settlers in Australia. This thesis will argue that advocates of the Northern Territory intervention construct Aboriginality in a range of important ways that reassert and reinforce the legitimacy of the settler colonial order and the project of Australian nationhood, and operate to limit Aboriginal claims. Specifically, it is argued that in linking Aboriginality to the abuse of Aboriginal children, the intervention’s advocates and supporters establish a political debate about the nature and future of Aboriginality within a discursive terrain in which the authority and perspectives of Indigenous people are problematised. Aboriginality is constructed in this process as both temporally and spatially separated from settler society, and in need of coercive integration into mainstream economic and political arrangements. Aboriginality is depicted by settler advocates of intervention as an anachronism, with Aboriginal people and cultures understood as primitive and/or savage precursors to settlers who are represented as modern and civilised. As such, the communities seen as the authentic home or location of Aboriginality represent a threat to Aboriginal children as well as to settlers. These constructions function to obscure the violence of the settler order, provide justification or moral rehabilitation for the colonising project, and reassert the sovereignty of the settler state. The resolution offered by the intervention’s advocates is a performance or enactment of settler sovereignty, representing a claim over and through both the territory of Aboriginal people and the discursive terrain of nationhood.

How international entrepreneurship characteristics influence Internet capabilities for the international business processes of the firm

This research explores the relationship between international entrepreneurship characteristics and the use of Internet capabilities for the international business processes of the firm. It has been suggested, that the accumulation of a firms Internet capability can assist international operations, especially when operating in fast changing dynamic Internet environments. However, international entrepreneurship characteristics which are seen as a precursor to leveraging Internet capabilities are still vague. Given this finding, eight case studies of small and medium sized travel and tourism firms were selected to investigate the influence of international entrepreneurship characteristics, and Internet capabilities for international business processes. Based on the eight in-depth case studies, the results signify that successful international entrepreneurial firms which encompass high levels of international innovativeness and proactiveness behaviour integrate Internet capabilities to a greater degree. Our findings also indicate that the prior international business experience, international risk-taking propensity and international networking characteristics are not necessarily precursors to successful integration of Internet capabilities for international business processes. On the contrary, international business experience and international networks actually lead to a reliance on traditional mechanisms of internationalisation and can dilute the development of Internet capabilities for international business processes.

High-temperature growth of graphene films on copper foils by ethanol chemical vapour deposition

Chemical vapor deposition (CVD) is widely utilized to synthesize graphene with controlled properties for many applications, especially when continuous films over large areas are required. Although hydrocarbons such as methane are quite efficient precursors for CVD at high temperature (∼1000 °C), finding less explosive and safer carbon sources is considered beneficial for the transition to large-scale production. In this work, we investigated the CVD growth of graphene using ethanol, which is a harmless and readily processable carbon feedstock that is expected to provide favorable kinetics. We tested a wide range of synthesis conditions (i.e., temperature, time, gas ratios), and on the basis of systematic analysis by Raman spectroscopy, we identified the optimal parameters for producing highly crystalline graphene with different numbers of layers. Our results demonstrate the importance of high temperature (1070 °C) for ethanol CVD and emphasize the significant effects that hydrogen and water vapor, coming from the thermal decomposition of ethanol, have on the crystal quality of the synthesized graphene.

Procaspase 8 overexpression in non-small-cell lung cancer promotes apoptosis induced by FLIP silencing

We found that procaspase 8 was overexpressed in non-small-cell lung cancers (NSCLCs) compared with matched normal tissues. The caspase 8 inhibitor FLICE-inhibitory protein (FLIP) was also overexpressed in the majority of NSCLCs. Silencing FLIP induced caspase 8 activation and apoptosis in NSCLC cell lines, but not in normal lung cell lines. Apoptosis induced by FLIP silencing was mediated by the TRAIL death receptors DR4 and DR5, but was not dependent on ligation of the receptors by TRAIL. Furthermore, the apoptosis induced by FLIP silencing was dependent on the overexpression of procaspase 8 in NSCLC cells. Moreover, in NSCLC cells, but not in normal cells, FLIP silencing induced co-localization of DR5 and ceramide, and disruption of this co-localization abrogated apoptosis. FLIP silencing supra-additively increased TRAIL-induced apoptosis of NSCLC cells; however, normal lung cells were resistant to TRAIL, even when FLIP was silenced. Importantly, FLIP silencing sensitized NSCLC cells but not normal cells to chemotherapy in vitro, and silencing FLIP in vivo retarded NSCLC xenograft growth and enhanced the anti-tumour effects of cisplatin. Collectively, our results suggest that due to frequent procaspase 8 overexpression, NSCLCs may be particularly sensitive to FLIP-targeted therapies.

Uric acid and xanthine oxidoreductase in wound healing

Chronic wounds are an important health problem because they are difficult to heal and treatment is often complicated, lengthy and expensive. For a majority of sufferers the most common outcomes are long-term immobility, infection and prolonged hospitalisation. There is therefore an urgent need for effective therapeutics that will enhance ulcer healing and patient quality of life, and will reduce healthcare costs. Studies in our laboratory have revealed elevated levels of purine catabolites in wound fluid from patients with venous leg ulcers. In particular, we have discovered that uric acid is elevated in wound fluid, with higher concentrations correlating with increased wound severity. We have also revealed a corresponding depletion in uric acid precursors, including adenosine. Further, we have revealed that xanthine oxidoreductase, the enzyme that catalyses the production of uric acid, is present at elevated levels in wound fluid. Taken together, these findings provide evidence that xanthine oxidoreductase may have a function in the formation or persistence of chronic wounds. Here we describe the potential function of xanthine oxidoreductase and uric acid accumulation in the wound site, and the effect of xanthine oxidoreductase in potentiating the inflammatory response.

Breast cancer cells induce osteolytic bone lesions in vivo through a reduction in osteoblast activity in mice

Bone metastases are severely debilitating and have a significant impact on the quality of life of women with metastatic breast cancer. Treatment options are limited and in order to develop more targeted therapies, improved understanding of the complex mechanisms that lead to bone lesion development are warranted. Interestingly, whilst prostate-derived bone metastases are characterised by mixed or osteoblastic lesions, breast-derived bone metastases are characterised by osteolytic lesions, suggesting unique regulatory patterns. This study aimed to measure the changes in bone formation and bone resorption activity at two time-points (18 and 36 days) during development of the bone lesion following intratibial injection of MDA-MB-231 human breast cancer cells into the left tibiae of Severely Combined Immuno-Deficient (SCID) mice. The contralateral tibia was used as a control. Tibiae were extracted and processed for undecalcified histomorphometric analysis. We provide evidence that the early bone loss observed following exposure to MDA-MB-231 cells was due to a significant reduction in mineral apposition rate, rather than increased levels of bone resorption. This suggests that osteoblast activity was impaired in the presence of breast cancer cells, contrary to previous reports of osteoclast-dependent bone loss. Furthermore mRNA expression of Dickkopf Homolog 1 (DKK-1) and Noggin were confirmed in the MDA-MB-231 cell line, both of which antagonise osteoblast regulatory pathways. The observed bone loss following injection of cancer cells was due to an overall thinning of the trabecular bone struts rather than perforation of the bone tissue matrix (as measured by trabecular width and trabecular separation, respectively), suggesting an opportunity to reverse the cancer-induced bone changes. These novel insights into the mechanisms through which osteolytic bone lesions develop may be important in the development of new treatment strategies for metastatic breast cancer patients.