869 research outputs found

    Human phosphodiesterase 4D7 (PDE4D7) expression is increased in TMPRSS2-ERG positive primary prostate cancer and independently adds to a reduced risk of post-surgical disease progression

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    background: There is an acute need to uncover biomarkers that reflect the molecular pathologies, underpinning prostate cancer progression and poor patient outcome. We have previously demonstrated that in prostate cancer cell lines PDE4D7 is downregulated in advanced cases of the disease. To investigate further the prognostic power of PDE4D7 expression during prostate cancer progression and assess how downregulation of this PDE isoform may affect disease outcome, we have examined PDE4D7 expression in physiologically relevant primary human samples. methods: About 1405 patient samples across 8 publically available qPCR, Affymetrix Exon 1.0 ST arrays and RNA sequencing data sets were screened for PDE4D7 expression. The TMPRSS2-ERG gene rearrangement status of patient samples was determined by transformation of the exon array and RNA seq expression data to robust z-scores followed by the application of a threshold >3 to define a positive TMPRSS2-ERG gene fusion event in a tumour sample. results: We demonstrate that PDE4D7 expression positively correlates with primary tumour development. We also show a positive association with the highly prostate cancer-specific gene rearrangement between TMPRSS2 and the ETS transcription factor family member ERG. In addition, we find that in primary TMPRSS2-ERG-positive tumours PDE4D7 expression is significantly positively correlated with low-grade disease and a reduced likelihood of progression after primary treatment. Conversely, PDE4D7 transcript levels become significantly decreased in castration resistant prostate cancer (CRPC). conclusions: We further characterise and add physiological relevance to PDE4D7 as a novel marker that is associated with the development and progression of prostate tumours. We propose that the assessment of PDE4D7 levels may provide a novel, independent predictor of post-surgical disease progression

    Exploring the impact of social network change:Experiences of older adults ageing in place

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    Social networks are sources of support and contribute to the well-being of older adults who are ageing in place. As social networks change, especially when accompanied by health decline, older adults' sources of support change and their well-being is challenged. Previous studies predominantly used quantitative measures to examine how older adults' social networks change. Alternatively, this study explores the impact of changing social networks on older adults' lives by examining their personal experiences. We held four focus groups, two with a total of 14 older adults who are ageing in place and receiving home care and two with a total of 20 home-care nurses from different regions and organisations in the Netherlands. Subsequently, an expert team of home-care professionals and managers discussed and verified the results. Procedures for grounded theory building were used for analysis. We revealed four themes of high-impact experiences: (a) struggling with illness/death of the spouse; (b) working out a changing relationship with (grand)children; (c) regretting the loss of people they have known for so long and (d) feeling dependent and stressed when helpers enter the network. Also, network dynamics were found to follow three consecutive stages: (a) awareness of social network change; (b) surprise when social network change actually occurs and (c) acceptance and adjusting to new circumstances. Together, the four themes of experiences and three stages of network change form an integrative model of the role of social network dynamics for older adults' lives when ageing in place

    A novel doxorubicin-glucuronide prodrug DOX-GA3 for tumour-selective chemotherapy: distribution and efficacy in experimental human ovarian cancer

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    The doxorubicin (DOX) prodrug N -[4-doxorubicin- N -carbonyl (oxymethyl) phenyl] O -β-glucuronyl carbamate (DOX-GA3) was synthesised for specific activation by human β-glucuronidase, which is released in necrotic areas of tumour lesions. This novel prodrug was completely activated to the parent drug by human β-glucuronidase with V max= 25.0 μmol min–1mg–1and K m= 1100 μM. The pharmacokinetics and distribution of DOX-GA3 in nude mice bearing human ovarian cancer xenografts (OVCAR-3) were determined and compared with DOX. Administration of DOX at 8 mg kg–1i.v. (maximum tolerated dose, MTD) to OVCAR-3-bearing mice resulted in a peak plasma concentration of the drug of 16.4 μM (t = 1 min). A 7.6-times lower peak plasma concentration of DOX was measured after injection of DOX-GA3 at 250 mg kg–1i.v. (50% of MTD). In normal tissues the prodrug showed peak DOX concentrations that were up to 5-fold (heart) lower than those found after DOX administration. DOX-GA3 activation by β-glucuronidase in the tumour yielded an almost 5-fold higher DOX peak concentration of 9.57 nmol g–1(P< 0.05) than the peak concentration of only 2.14 nmol g–1observed after DOX. As a consequence, the area under the curve of DOX calculated in tumour tissue after DOX-GA3 (13.1 μmol min–1g–1) was 10-fold higher than after DOX (1.31 μmol min–1g–1). The anti-tumour effects of DOX-GA3 and DOX were compared at equitoxic doses in OVCAR-3 xenografts at a mean tumour size of 125 mm3. The prodrug given i.v. at 500 mg kg–1weekly × 2 resulted in a maximum tumour growth inhibition of 87%, while the standard treatment with DOX at a dose of 8 mg kg–1i.v. weekly × 2 resulted in a maximum tumour growth inhibition of only 56%. Treatment with DOX-GA3 was also given to mice with larger tumours containing more necrosis. For tumours with a mean size of 400 mm3the specific growth delay by DOX-GA3 increased from 2.7 to 3.9. Our data indicate that DOX-GA3 is more effective than DOX and suggest that the prodrug will be specifically advantageous for treatment of advanced disease. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Striatal glucose metabolism and dopamine D2 receptor binding in asymptomatic gene carriers and patients with Huntington's disease

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    We used PET scans with the tracers [18F]fluorodeoxyglucose (FDG) and [11C]raclopride (RACLO) to study glucose metabolism and dopamine D2 receptor binding in the caudate nucleus and putamen of 18 carriers of the Huntington's disease gene mutation (10 asymptomatic subjects and eight untreated symptomatic Huntington's disease patients in an early disease stage). We also performed MR1 scans and measured the bicaudate ratio (BCR) in the same subjects. Data were compared with those from nine mutation-negative members of Huntington's disease families and separate groups of age matched controls. The PET scans were repeated 1.5-3 years later in six of the asymptomatic gene carriers. Symptomatic Huntington's disease patients showed a marked reduction of FDG and RACLO uptake in the caudate nucleus and putamen and a significant increase of BCR. Asymptomatic mutation carriers revealed significant hypometabolism in the caudate nucleus and putamen. The RACLO binding was significantly decreased in the putamen. Decrements of caudate nucleus tracer uptake, particularly RACLO, correlated significantly with BCR increases in both symptomatic and asymptomatic gene carriers. In asymptomatic carriers, metabolic and receptor binding decreases were also significantly associated with the CAG repeat number but not with the individual's age. Discriminant function analysis correctly classified clinical and genetic status in 24 of 27 subjects on the basis of their striatal PET values (83% sensitivity and 100% specificity). Three asymptomatic mutation carriers were classified/grouped together with mutation-negative subjects, indicating that these individuals had normal striatal RACLO and FDG uptake. Follow-up PET data from gene-positive subjects showed a significant reduction in the mean striatal RACLO binding of 6.3% per year. Striatal glucose metabolism revealed an overall non significant 2.3% decrease per year These data indicate that asymptomatic Huntington's disease mutation carriers may show normal neuronal function for a long period of life. These findings also suggest that it may be possible to predict when an asymptomatic gene carrier will develop clinical symptoms from serial PET measurements of striatal functio

    Human phosphodiesterase 4D7 (PDE4D7) expression is increased in TMPRSS2-ERG-positive primary prostate cancer and independently adds to a reduced risk of post-surgical disease progression

    Get PDF
    Background:There is an acute need to uncover biomarkers that reflect the molecular pathologies, underpinning prostate cancer progression and poor patient outcome. We have previously demonstrated that in prostate cancer cell lines PDE4D7 is downregulated in advanced cases of the disease. To investigate further the prognostic power of PDE4D7 expression during prostate cancer progression and assess how downregulation of this PDE isoform may affect disease outcome, we have examined PDE4D7 expression in physiologically relevant primary human samples.Methods:About 1405 patient samples across 8 publically available qPCR, Affymetrix Exon 1.0 ST arrays and RNA sequencing data sets were screened for PDE4D7 expression. The TMPRSS2-ERG gene rearrangement status of patient samples was determined by transformation of the exon array and RNA seq expression data to robust z-scores followed by the application of a threshold >3 to define a positive TMPRSS2-ERG gene fusion event in a tumour sample.Results:We demonstrate that PDE4D7 expression positively correlates with primary tumour development. We also show a positive association with the highly prostate cancer-specific gene rearrangement between TMPRSS2 and the ETS transcription factor family member ERG. In addition, we find that in primary TMPRSS2-ERG-positive tumours PDE4D7 expression is significantly positively correlated with low-grade disease and a reduced likelihood of progression after primary treatment. Conversely, PDE4D7 transcript levels become significantly decreased in castration resistant prostate cancer (CRPC).Conclusions:We further characterise and add physiological relevance to PDE4D7 as a novel marker that is associated with the development and progression of prostate tumours. We propose that the assessment of PDE4D7 levels may provide a novel, independent predictor of post-surgical disease progression

    Effect of H-Bonding on Order Amplification in the Growth of a Supramolecular Polymer in Water

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    While a great deal of knowledge on the roles of hydrogen bonding and hydrophobicity in proteins has resulted in the creation of rationally designed and functional peptidic structures, the roles of these forces on purely synthetic supramolecular architectures in water have proven difficult to ascertain. Focusing on a 1,3,5-benzenetricarboxamide (BTA)-based supramolecular polymer, we have designed a molecular modeling strategy to dissect the energetic contributions involved in the self-assembly (electrostatic, hydrophobic, etc.) upon growth of both ordered BTA stacks and random BTA aggregates. Utilizing this set of simulations, we have unraveled the cooperative mechanism for polymer growth, where a critical size must be reached in the aggregates before emergence and amplification of order into the experimentally observed fibers. Furthermore, we have found that the formation of ordered fibers is favored over disordered aggregates solely on the basis of electrostatic interactions. Detailed analysis of the simulation data suggests that H-bonding is a major source of this stabilization energy. Experimental and computational comparison with a newly synthesized 1,3,5-benzenetricarboxyester (BTE) derivative, lacking the ability to form the H-bonding network, demonstrated that this BTE variant is also capable of fiber formation, albeit at a reduced persistence length. This work provides unambiguous evidence for the key 1D driving force of hydrogen bonding in enhancing the persistency of monomer stacking and amplifying the level of order into the growing supramolecular polymer in water. Our computational approach provides an important relationship directly linking the structure of the monomer to the structure and properties of the supramolecular polymer

    The Citation Field of Evolutionary Economics

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    Evolutionary economics has developed into an academic field of its own, institutionalized around, amongst others, the Journal of Evolutionary Economics (JEE). This paper analyzes the way and extent to which evolutionary economics has become an interdisciplinary journal, as its aim was: a journal that is indispensable in the exchange of expert knowledge on topics and using approaches that relate naturally with it. Analyzing citation data for the relevant academic field for the Journal of Evolutionary Economics, we use insights from scientometrics and social network analysis to find that, indeed, the JEE is a central player in this interdisciplinary field aiming mostly at understanding technological and regional dynamics. It does not, however, link firmly with the natural sciences (including biology) nor to management sciences, entrepreneurship, and organization studies. Another journal that could be perceived to have evolutionary acumen, the Journal of Economic Issues, does relate to heterodox economics journals and is relatively more involved in discussing issues of firm and industry organization. The JEE seems most keen to develop theoretical insights

    In Vivo Imaging of Vesicular Monoamine Transporters in Human Brain Using [ 11 C]Tetrabenazine and Positron Emission Tomography

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    The pharmacokinetics of [ 11 CJtetrabenazine, a high-affinity radioligand for the monoamine vesicular transporter, were determined in living human brain using in vivo imaging by positron emission tomography (PET). The radiotracer showed high brain uptake and rapid washout from all brain regions with relatively slower clearance from regions of highest concentrations of monoamine vesicular transporters (striatum), resulting in clear differential visualization of these structures at short intervals after injection (10–20 min). As the first human PET imaging study of a vesicular neurotransmitter transporter, these experiments demonstrate that external imaging of vesicular transporters forms a new and valuable approach to the in vivo quantification of monoaminergic neurons, with potential application to the in vivo study of neurodegenerative disorders such as Parkinson's disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65743/1/j.1471-4159.1993.tb03521.x.pd
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