393 research outputs found
Structural, item, and test generalizability of the psychopathology checklist - revised to offenders with intellectual disabilities
No full textThe Psychopathy Checklist–Revised (PCL-R) is the most widely used measure of psychopathy in forensic clinical practice, but the generalizability of the measure to offenders with intellectual disabilities (ID) has not been clearly established. This study examined the structural equivalence and scalar equivalence of the PCL-R in a sample of 185 male offenders with ID in forensic mental health settings, as compared with a sample of 1,212 male prisoners without ID. Three models of the PCL-R’s factor structure were evaluated with confirmatory factor analysis. The 3-factor hierarchical model of psychopathy was found to be a good fit to the ID PCL-R data, whereas neither the 4-factor model nor the traditional 2-factor model fitted. There were no cross-group differences in the factor structure, providing evidence of structural equivalence. However, item response theory analyses indicated metric differences in the ratings of psychopathy symptoms between the ID group and the comparison prisoner group. This finding has potential implications for the interpretation of PCL-R scores obtained with people with ID in forensic psychiatric settings
Is T-cell memory maintained by crossreactive stimulation?
No full textWhether or not T- and B-cell memory is antigen driven remains unresolved. Recent studies indicate that, in humans, naive and memory T cells can be distinguished by their expression of different CD45 isoforms. Extensive phenotypic analysis of naive and memory T cells shows that the latter express greater amounts of several adhesion molecules as well as low levels of several antigens indicative of activation. These features suggest to Peter Beverley that memory T cells may be more readily activated and that memory may be maintained by crossreactive restimulation. © 1990
Interferon, β-2-microglobulin and immunoselection in the pathway to malignancy. A blinkered view from Nag's Head Yard
No full textRecent clinical studies suggest that benign tumour cells express MHC class-I antigens while malignant cells with the same tissue origin do not. Interferons induce normal cells to increase the expression of class-I antigens but Arnold Sanderson and Peter Beverley argue here that malignant cells may not respond in this way. As a result, they may lack the antigens that would make them vulnerable to immune mechanisms dependent on T cells which recognize class-I self-MHC antigens. © 1983
Effect of PCL and Compatibility Contents on the Morphology, Crystallization and Mechanical Properties of PLA/PCL Blends
No full textAbstractThis study focused on the effect of PCL on crystalline morphology, isothermally crystallization of PLA in PLA/PCL blends using POM on investigation. The blend with Pluronic used as a plasticizer was also studied. The blends were prepared by melt blending in an internal mixer. The contents of PCL incorporated were varied from 0-30% by weight. The content of Pluronic used in this study was at 2.5, 5 and 7.5 phr. The blends were characterized for their morphology, crystallization and mechanical properties. Melt strength of the blends was also investigated. The morphology of the blends confirmed immiscibility of two polymer phases. Scanning electron microscope (SEM) of PLA/PCL blends indicated larger particle size of PCL dispersed in PLA with the increase of PCL contents. Tg of PLA in the blend could not be observed on Differential Scanning Calorimetry (DSC) traces. This was due to the overlapping with Tm of PCL. The presence of Pluronic in PLA/PCL blends resulted in Tms shifting to slightly lower temperatures. The crystallinity of PLA was also decreased. The spherulitic growth of PLA in blends was followed by polarized optical microscope using isothermal condition at 141°C. The spherulite structure was found affected by the presence of Pluronic hence effect on crystallization of PLA. Tensile properties of PLA/PCL blend were suffered with PCL content except for elongation at break which seems to be enhanced. It was found that the presence of pluronic in PLA/PCL blend increased ductility of the blends. At Plurunic of 2.5 phr and PCL content of 10-20% by weight, tensile strength of these blends was increased. This was explained by the fine dispersed PCL particles facilitated orientation of PLA chain after proportional limit and hence increased tensile strength. With higher content both PCL and Pluronic, large PCL particle size was disadvantaged for tensile properties
Production and immobilization of lipase PCL and its application in synthesis of α‐linolenic acid‐rich diacylglycerol
No full textα‐Linolenic acid‐rich diacylglycerol has been demonstrated with promising health promotion functions. This study examined the production, immobilization of lipase PCL, and its application in the synthesis of diacylglycerol by esterification of α‐linolenic acid with glycerol. The resin ECR8806 was selected as an effective support for the immobilization of lipase PCL. Fourier transform infrared and Laser scanning confocal microscope analysis proved that the lipase was successfully immobilized on the resin. Compared with the free PCL, the immobilized one exhibited higher temperature tolerance. Under optimized reaction conditions, a DAG content of 54.49% were obtained. After further purified by molecular distillation, the purity of DAG was up to 99.28%. During esterification, the immobilized PCL was quite stable and retained more than 91.60% of its initial activity after 10 cycles. These new findings on the immobilized PCL will make it to be a prospective enzyme in oils and fats industry.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi
Development of PCL/Ibuprofen Tubes for Peripheral Nerve Regeneration
No full textAbstractPolymeric bioabsorbable tubes can be used as drug delivery systems and guides for cellular growth in peripheral nerve regeneration. In this study polycaprolactone/ibuprofen tubes manufactured by melt extrusion technique were investigated under different screw speeds and processing temperatures. To assess the structure and properties of PCL/ibuprofen tubes, analysis was performed using scanning electron microscopy, X-ray diffraction, infrared spectroscopy, flexural tests and dynamic mechanical analysis (DMA). The drug delivery profile was obtained by determining the in vitro release of ibuprofen. Tubes of PCL/ibuprofen were prepared by vertical extrusion. The average values for the diameter and wall thickness of the PCL/ibuprofen tubes were 1.5mm and 250μm, respectively. The crystallinity values for the PCL/ibuprofen tubes were lower than those for the pure PCL tubes, probably due to the interaction of the drug with the polymer chains. The value for the flexural modulus of the PCL/ibuprofen tubes increased with the processing temperature and screw speed, which is probably due to better drug dispersion at higher temperature and higher shear rates. The preparation of the tubes using faster screw speeds led to higher values being obtained for the storage modulus in the DMA, indicating that the shear rate also affects the mechanical properties. The PCL/ibuprofen tubes had lower glass transition temperatures compared with pure PCL tubes, also suggesting interaction between ibuprofen and the PCL matrix. The results suggest that the PCL/ibuprofen tubes prepared by vertical extrusion using a screw speed of 17rpm and processing temperature of 140 ̊C were the most suitable for peripheral nerve regeneration offering appropriate dimensions and mechanical properties and an acceptable drug release profile
PCL/Ibuprofen Implants Fabricated by Selective Laser Sintering for Orbital Repair
No full textAbstractThis paper describes the properties of porous polycaprolactone/ibuprofen implants fabricated by SLS for orbital floor repair. The specimens prepared showed homogeneous morphology and pore interconnectivity. PCL/ibuprofen specimens presented a higher degree of sintering than pure PCL specimens. The PCL/ibuprofen specimen sintered under the highest laser power showed the lowest crystallinity value due to a fast cooling rate resulting from the strong laser absorption presented by the PCL/ibuprofen mixture. The specimens showed a significant increase in the flexural modulus when the laser energy density used in the manufacturing was increased. The DMA tests indicated that solubilization and the formation of secondary chemical interactions between the drug and the PCL did not occur. The PCL/ibuprofen specimens showed the occurrence of non-linear drug release with respect to time, suggesting Fickian release kinetics via a diffusion mechanism. The release profile for porous plates of PCL/ibuprofen prepared by selective laser sintering indicated that these devices could be applied for bone regeneration and the control of the inflammatory process soon after implantation
Intra-Tumoral Delivery of Functional ID4 Protein via PCL/ Maltodextrin Nano-Particle Inhibits Prostate Cancer Growth
No full textID4, a helix loop helix transcriptional regulator has emerged as a tumor suppressor in prostate cancer. Epigenetic silencing of ID4 promotes prostate cancer whereas ectopic expression in prostate cancer cell lines blocks cancer phenotype. To directly investigate the anti-tumor property, full length human recombinant ID4 encapsulated in biodegradable Polycaprolactone/Maltodextrin (PCL-MD) nano-carrier was delivered to LNCaP cells in which the native ID4 was stably silenced (LNCaP(-)ID4). The cellular uptake of ID4 resulted in increased apoptosis, decreased proliferation and colony formation. Intratumoral delivery of PCL-MD ID4 into growing LNCaP(-)ID4 tumors in SCID mice significantly reduced the tumor volume compared to the tumors treated with chemotherapeutic Docetaxel. The study supports the feasibility of using nanocarrier encapsulated ID4 protein as a therapeutic. Mechanistically, ID4 may assimilate multiple regulatory pathways for example epigenetic re-programming, integration of multiple AR co-regulators or signaling pathways resulting in tumor suppressor activity of ID4
Immunological intervention with monoclonal antibodies
No full textA recent workshop held in the Bavarian alps considered the possibilities for immunological intervention with monoclonal antibodies. While at present the benefits of most attempts to use monoclonal antibodies in vivo in man are uncertain, in-vitro and animal experiments have yielded enough positive results to encourage further efforts. Immediate dramatic effects are not to be expected because as one participant noted, we are still at an early stage in the use of monoclonal antibodies as therapeutic agents. © 1987
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