29 research outputs found

    Effective repair of articular cartilage using human pluripotent stem cell-derived tissue

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    In an effort to develop an effective source of clinically relevant cells and tissues for cartilage repair a directed differentiation method was used to generate articular chondrocytes and cartilage tissues from human embryonic stem cells (hESCs). It has previously been demonstrated that chondrocytes derived from hESCs retain a stable cartilage-forming phenotype following subcutaneous implantation in mice. In this report, the potential of hESC-derived articular-like cartilage to repair osteochondral defects created in the rat trochlea was evaluated. Articular cartilage-like tissues were generated from hESCs and implanted into the defects. After 6 and 12 weeks, the defects were evaluated histologically and immunohistochemically, and the quality of repair was assessed using a modified ICRS II scoring system. Following 6 and 12 weeks after implantation, hESC-derived cartilage tissues maintained their proteoglycan and type II collagen-rich matrix and scored significantly higher than control defects, which had been filled with fibrin glue alone. Implants were found to be well integrated with native host tissue at the basal and lateral surfaces, although implanted human cells and host cells remained regionally separated. A subset of implants underwent a process of remodeling similar to endochondral ossification, suggesting the potential for a single cartilaginous implant to promote the generation of new subchondral bone in addition to repair of the articular cartilage. The ability to create cartilage tissues with integrative and reparative properties from an unlimited and robust cell source represents a significant advance for cartilage repair that can be further developed in large animal models before clinicalsetting application

    Role of Matrix Metalloproteinases and Therapeutic Benefits of Their Inhibition in Spinal Cord Injury

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    This review will focus on matrix metalloproteinases (MMPs) and their inhibitors in the context of spinal cord injury (SCI). MMPs have a specific cellular and temporal pattern of expression in the injured spinal cord. Here we consider their diverse functions in the acutely injured cord and during wound healing. Excessive activity of MMPs, and in particular gelatinase B (MMP-9), in the acutely injured cord contributes to disruption of the blood-spinal cord barrier, and the influx of leukocytes into the injured cord, as well as apoptosis. MMP-9 and MMP-2 regulate inflammation and neuropathic pain after peripheral nerve injury and may contribute to SCI-induced pain. Early pharmacologic inhibition of MMPs or the gelatinases (MMP-2 and MMP-9) results in an improvement in long-term neurological recovery and is associated with reduced glial scarring and neuropathic pain. During wound healing, gelatinase A (MMP-2) plays a critical role in limiting the formation of an inhibitory glial scar, and mice that are genetically deficient in this protease showed impaired recovery. Together, these findings illustrate complex, temporally distinct roles of MMPs in SCIs. As early gelatinase activity is detrimental, there is an emerging interest in developing gelatinase-targeted therapeutics that would be specifically tailored to the acute injured spinal cord. Thus, we focus this review on the development of selective gelatinase inhibitors

    Leadership after virtue: MacIntyre’s critique of management reconsidered

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    MacIntyre argues that management embodies emotivism, and thus is inherently amoral and manipulative. His claim that management is necessarily Weberian is, at best, outdated, and the notion that management aims to be neutral and value free is incorrect. However, new forms of management, and in particular the increased emphasis on leadership which emerged after MacIntyre’s critique was published, tend to support his central charge. Indeed, charismatic and transformational forms of leadership seem to embody emotivism to a greater degree than do more Weberian, bureaucratic forms of management, so MacIntyre’s central contention about our emotivistic culture seems to be well-founded. Having criticised the details but defended the essence of MacIntyre’s critique of management, this paper sketches a MacIntyrean approach to management and leadership by highlighting the affinities between MacIntyre’s political philosophy and Greenleaf’s concept of servant leadership

    Exploring the diversity of virtues through the lens of moral imagination: A qualitative inquiry into organizational virtues in the Turkish context

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    The purpose of this article is to introduce a multidimensional framework based on the concept of moral imagination for analysing and capturing diverse virtues in contemporary Turkish organizations. Based on qualitative interviews with 58 managers in Turkey, this article develops an inventory of Turkish organizational virtues each of which can be associated with a different form of virtuous organizing. The inventory consists of nine forms of moral imagination, which map the multitude of virtues and moral emotions in organizations. Nine emergent forms of moral imagination are based on: integrity, affection, diligence, inspiration, wisdom, trust, gratefulness, justice, and harmony. The findings have made a contribution to the expanding literature on how Islamic organizations develop their business ethics through a repertoire of virtues. An empirical account of the range of virtues in organizational contexts that have emerged as a result of the hybridization of Islamic virtue/aesthetics and neoliberal capitalism in contemporary Turkey is provided. A theoretical contribution is made to business ethics literature through a phenomenology of virtues that provides unique insights on diverse forms of moral imagination in contemporary Turkey where Islam and neoliberal capitalism dynamically co-exist

    Reconciling Different Views on Responsible Leadership: A Rationality-Based Approach

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    Business leaders are increasingly responsible for the societal and environmental impacts of their actions. Yet conceptual views on responsible leadership differ in their definitions and theoretical foundations. This study attempts to reconcile these diverse views and uncover the phenomenon from a business leader's point of view. Based on rational egoism theory, this article proposes a formal mathematical model of responsible leadership that considers different types of incentives for stakeholder engagement. The analyses reveal that monetary and instrumental incentives are neither sufficient nor necessary for business leaders to consider societal and environmental stakeholder needs. Non-monetary and non-instrumental incentives, such as leaders' values and authenticity, as well as their planning horizons, counterbalance pure monetary and instrumental orientations. The model in this article complements the growing body of research on responsible leadership by reconciling its various conceptual views and providing a foundation for future theory development and testing
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