Développement d'une technique laparoscopique de biopsie intestinale chez le cheval debout

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Cutting the Gordian knot of futility : a case for law reform on unilateral withholding and withdrawal of potentially life-sustaining treatment

In this paper, we propose law reform with respect to the unilateral withholding or withdrawal of potentially life-sustaining treatment in Australia and New Zealand. That is, where a doctor withholds or withdraws potentially life-sustaining treatment without consent from a patient or a patient’s substitute decision-maker (where the patient lacks capacity), or authorisation from a court or tribunal, or by operation of a statute or justifiable government or institutional policy. Our proposal is grounded in the core values that do (or should) underpin a regulatory framework on an issue such as this; these values are drawn from existing commitments made by Australia and New Zealand through legislation, the common law, and conventions and treaties. It is also grounded in a critical review of the law on unilateral withholding and withdrawal as well as the legal context within which this issue sits in Australasia. We argue that the current law is inconsistent with the core values and develop a proposal for a legal response to this issue that more closely aligns with the core values it is supposed to serve.

Adults who lack capacity : substitute decision-making

• Mechanisms to facilitate consent to healthcare for adults who lack capacity are necessary to ensure that these adults can lawfully receive appropriate medical treatment when needed. • In Australia, the common law plays only a limited role in this context, through its recognition of advance directives and through the parens patriae jurisdiction of superior courts. • Substitute decision-making for adults who lack capacity is facilitated primarily by guardianship and other related legislation. This legislation, which has been enacted in all Australian States and Territories, permits a range of decision-makers to make different types of healthcare decisions. • Substitute decision-makers can be appointed by the adult or by a guardianship or other tribunal. Where there is no appointed decision-maker, legislation generally empowers those close to the adult to make the relevant decision. Most Australian jurisdictions have also provided for statutory advance directives. • For the most serious of decisions, such as non-therapeutic sterilisations, consent can only be provided by a Tribunal. Other decisions can generally be made by a range of substitute decision-makers. Some treatment, such as very minor treatment or that which is needed in an emergency, can be provided without consent. • Guardianship legislation generally establishes a set of principles and/or other criteria to guide healthcare decisions. Mechanisms to resolve disputes as to who is the appropriate decision-maker and how a decision should be made have also been established.

Fabrication of a corneal-limbal tissue substitute using silk fibroin

Fibroin extracted from silkworm cocoon silk provides an intriguing and potentially important biomaterial for corneal reconstruction. In the present chapter we outline our methods for producing a composite of two fibroin-based materials that supports the co-cultivation of human limbal epithelial (HLE) cells and human limbal stromal (HLS) cells. The resulting tissue substitute consists of a stratified epithelium overlying a three-dimensional arrangement of extracellular matrix components (principally ‘degummed’ fibroin fibers) and mesenchymal stromal cells. This tissue substitute is currently being evaluated as a tool for reconstructing the corneal limbus and corneal epithelium.

Enduring powers of attorney : promoting attorneys' accountability as substitute decision makers

Aim The misuse and abuse of Enduring Powers of Attorney (EPAs) by attorneys, particularly in relation to financial decision-making, is a growing concern. This paper explores the opportunities to enhance accountability of attorneys at the time of the execution of the document in Queensland. Method A four stage multi-method design comprised a critical reference group; semi-structured interviews with 32 principals or potential principals, attorneys and witnesses; two focus groups with service providers and a state wide survey of 76 principals, attorneys and witnesses. Results Across all methods and user groups, understanding the role and obligations of the attorney in an EPA was consistently identified as problematic. Conclusions Promoting accountability and understanding can be addressed by greater attention to the role of the attorney in the forms/ guidelines and in the structure and witnessing of the forms, increased direction about record keeping and access to appropriate advice and support.

Adults who lack capacity : substitute decision-making

• Mechanisms to facilitate consent to healthcare for adults who lack capacity are necessary to ensure that these adults can lawfully receive appropriate medical treatment when needed. • In Australia, the common law plays only a limited role in this context, through its recognition of advance directives and through the parens patriae jurisdiction of superior courts. • Substitute decision-making for adults who lack capacity is facilitated primarily by guardianship and other related legislation. This legislation, which has been enacted in all Australian States and Territories, permits a range of decision-makers to make different types of healthcare decisions. • Substitute decision-makers can be appointed by the adult or by a guardianship or other tribunal. Where there is no appointed decision-maker, legislation generally empowers those close to the adult to make the relevant decision. Most Australian jurisdictions have also provided for statutory advance directives. • For the most serious of decisions, such as non-therapeutic sterilisations, consent can only be provided by a tribunal. Other decisions can generally be made by a range of substitute decision-makers. Some treatment, such as very minor treatment or that which is needed in an emergency, can be provided without consent. • Guardianship legislation generally establishes a set of principles and/or other criteria to guide healthcare decisions. Mechanisms have also been established to resolve disputes as to who is the appropriate decision-maker and how a decision should be made.

A Bruch’s membrane substitute fabricated from silk fibroin supports the function of retinal pigment epithelial cells in vitro

Silk fibroin provides a promising biomaterial for ocular tissue reconstruction including the damaged outer blood-retinal barrier of patients afflicted with age-related macular degeneration (AMD). The aim of the present study was to evaluate the function of retinal pigment epithelial (RPE) cells in vitro, when grown on fibroin membranes manufactured to a similar thickness as Bruch’s membrane (3 μm). Confluent cultures of RPE cells (ARPE-19) were established on fibroin membranes and maintained under conditions designed to promote maturation over 4 months. Control cultures were grown on polyester cell culture well inserts (Transwell). Cultures established on either material developed a cobblestoned morphology with partial pigmentation within 12 weeks. Immunocytochemistry at 16 weeks revealed a similar distribution pattern between cultures for F-actin, ZO-1, ezrin, cytokeratin pair 8/18, RPE-65 and Na+/K+-ATPase. Electron microscopy revealed that cultures grown on fibroin displayed a rounder apical surface with a more dense distribution of microvilli. Both cultures avidly ingested fluorescent microspheres coated with vitronectin and bovine serum albumin (BSA), but not controls coated with BSA alone. VEGF and PEDF were detected in the conditioned medium collected from above and below both membrane types. Levels of PEDF were significantly higher than for VEGF on both membranes and a trend was observed towards larger amounts of PEDF in apical compartments. These findings demonstrate that RPE cell functions on fibroin membranes are equivalent to those observed for standard test materials (polyester membranes). As such, these studies support advancement to studies of RPE cell implantation on fibroin membranes in a preclinical model.

Development of a cultured tissue substitute to repair the ageing retina

This project provides a foundation for the use of silk membranes in a tissue engineered therapy for the treatment of devastating retinal diseases such as age-related macular degeneration. The three-dimensional tissue model described in this thesis has great potential for use in basic research of retinal pathologies, and the potential to be implemented into clinical approaches after appropriate refinement.