868 resultados para Human Fertilisation and Embryology Act 2008


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The primate temporal cortex has been demonstrated to play an important role in visual memory and pattern recognition. It is of particular interest to investigate whether activity-dependent modification of synaptic efficacy, a presumptive mechanism for learning and memory, is present in this cortical region. Here we address this issue by examining the induction of synaptic plasticity in surgically resected human inferior and middle temporal cortex. The results show that synaptic strength in the human temporal cortex could undergo bidirectional modifications, depending on the pattern of conditioning stimulation. High frequency stimulation (100 or 40 Hz) in layer IV induced long-term potentiation (LTP) of both intracellular excitatory postsynaptic potentials and evoked field potentials in layers II/III. The LTP induced by 100 Hz tetanus was blocked by 50-100 microM DL-2-amino-5-phosphonovaleric acid, suggesting that N-methyl-D-aspartate receptors were responsible for its induction. Long-term depression (LTD) was elicited by prolonged low frequency stimulation (1 Hz, 15 min). It was reduced, but not completely blocked, by DL-2-amino-5-phosphonovaleric acid, implying that some other mechanisms in addition to N-methyl-DL-aspartate receptors were involved in LTD induction. LTD was input-specific, i.e., low frequency stimulation of one pathway produced LTD of synaptic transmission in that pathway only. Finally, the LTP and LTD could reverse each other, suggesting that they can act cooperatively to modify the functional state of cortical network. These results suggest that LTP and LTD are possible mechanisms for the visual memory and pattern recognition functions performed in the human temporal cortex.

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"Remarks and references to literature": vol. 2, p. [459]-490.

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Title on inside leaf: Technical assistance guide for offender programs.

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Sulfonation is an important reaction in the metabolism of numerous xenobiotics, drugs, and endogenous compounds. A supergene family of enzymes called sulfotransferases (SULTs) catalyze this reaction. In most cases, the addition of a sulfonate moiety to a compound increases its water solubility and decreases its biological activity. However, many of these enzymes are also capable of bioactivating procarcinogens to reactive electrophiles. In humans three SULT families, SULT1, SULT2, and SULT4, have been identified that contain at least thirteen distinct members. SULTs have a wide tissue distribution and act as a major detoxification enzyme system in adult and the developing human fetus. Nine crystal structures of human cytosolic SULTs have now been determined, and together with site-directed mutagenesis experiments and molecular modeling, we are now beginning to understand the factors that govern distinct but overlapping substrate specificities. These studies have also provided insight into the enzyme kinetics and inhibition characteristics of these enzymes. The regulation of human SULTs remains as one of the least explored areas of research in the field, though there have been some recent advances on the molecular transcription mechanism controlling the individual SULT promoters. Interindividual variation in sulfonation capacity may be important in determining an individual's response to xenobiotics, and recent studies have begun to suggest roles for SULT polymorphism in disease susceptibility. This review aims to provide a summary of our present understanding of the function of human cytosolic sulfotransferases.

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Efforts to improve the efficiency and responsiveness of public services by harnessing the self-interest of professionals in state agencies have been widely debated in the recent literature on welfare state reform. In the context of social services, one way in which British policy-makers have sought to effect such changes has been through the "new community care" of the 1990 NHS and Community Care Act. Key to this is the concept of care management, in which the identification of needs and the provision of services are separated, purportedly with a view to improving advocacy, choice and quality for service users. This paper uses data from a wide-ranging qualitative study of access to social care for older people to examine the success of the policy in these terms, with specific reference to its attempts to harness the rational self-interest of professionals. While care management removes one potential conflict of interests by separating commissioning and provision, the responsibility of social care professionals to comply with organizational priorities conflicts with their role of advocacy for their clients, a tension rendered all the more problematic by the perceived inadequacy of funding. Moreover, the bureaucracy of the care management process itself further negates the approach's supposedly client-centred ethos. The definitive version is available at www.blackwell-synergy.com

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Cell-cell and cell-matrix interactions play a major role in tumor morphogenesis and cancer metastasis. Therefore, it is crucial to create a model with a biomimetic microenvironment that allows such interactions to fully represent the pathophysiology of a disease for an in vitro study. This is achievable by using three-dimensional (3D) models instead of conventional two-dimensional (2D) cultures with the aid of tissue engineering technology. We are now able to better address the complex intercellular interactions underlying prostate cancer (CaP) bone metastasis through such models. In this study, we assessed the interaction of CaP cells and human osteoblasts (hOBs) within a tissue engineered bone (TEB) construct. Consistent with other in vivo studies, our findings show that intercellular and CaP cell-bone matrix interactions lead to elevated levels of matrix metalloproteinases, steroidogenic enzymes and the CaP biomarker, prostate specific antigen (PSA); all associated with CaP metastasis. Hence, it highlights the physiological relevance of this model. We believe that this model will provide new insights for understanding of the previously poorly understood molecular mechanisms of bone metastasis, which will foster further translational studies, and ultimately offer a potential tool for drug screening. © 2010 Landes Bioscience.

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This paper examines the contribution of aspects of critical and referential realism to the “logic” of structural explanation through an analysis of Erik Olin Wright’s Classes and the debate surrounding this work. Wright’s Classes has been selected as a case study because it offers an opportunity to examine issues pertaining to “objective” and “subjective” determinations of class and related questions of agency and structure at the level of actual methodological strategies. A close examination of the structure of Wright’s inquiry reveals a number of places where Harre’s and Bhaskar’s approaches may contribute to the prescription of methodological strategies which could overcome some of the antinomies on which the debate on Classes is based. As a case study, the paper underlines the important “underlabourer” role of critical and referential realism and their contribution to questions of agency and structure in the context of actual stages involved in structural explanation