Altered cell interactions of subchondral bone osteoblasts and articular chondrocytes in osteoarthritis is through the mediation of ERK1/2 phosphorylation

Introduction: Osteoarthritis (OA) is the most common musculoskeletal disorder and represents a major health burden to society. In the course of the pathological development of OA, articular cartilage chondrocytes (ACCs) undergo a typical phenotype changes characterized by the expression of hypertrophic differentiation markers. Also, the adjacent subchondral bone shows signs of abnormal mineral density and enhanced production of bone turnover markers, indicative of osteoblast dysfunction. However, the mechanism(s) by which these changes occur during the OA development are not completely understood. Materials and Methods: ACCs and subchondral bone osteoblasts (SBOs) were harvested from OA and healthy patients for the cross-talk studies between normal and OA ACCs and SBOs. The involvement of mitogen activated protein kinase (MAPK) signalling pathway during the cell-cell interactions was analysed by zymography, ELISA and western blotting methods. Results: The direct and in-direct co-culture studies showed that OA (ACCs and SBOs) cells induced osteoarthritic changes of normal (ACC and SBOs) cells. This altered cell interaction induced by OA cells significantly aggravated the proteolytic activity, which resulted cartilage degeneration. The altered cell interaction appeared to significantly activate ERK 1/2 phosphorylation and inhibition of MAPK-ERK 1/2 pathway reversed the osteoarthrtitic phenotypic changes. Discussion and Conclusion: Our study has demonstrated that the altered bi-directional communication of SBOs and ACCs are critical for initiation and progression of OA related changes and that this process is mediated by MAPK signalling pathways. Targeting these altered interactions by the use of MAPK inhibitors may provide the scientific rationale for the development of novel therapeutic strategies in the treatment and management of OA related disorders.

Change-induced stressors and effective coping strategies in nursing

This study seeks to examine the causality of non-nursing and nursing stressors on the job satisfaction of nurses and how coping strategies have a mediating influence on this relationship in the context of sector-wide reform. To conceptualize the relationships, a mediation path model was developed. Data were collected at two time points using a self-completed online survey over a six monthly interval. During time 1, 306 Australian nurses completed the online survey. In the first wave (time 1), 306 Australian nurses completed the survey. In the second wave (time 2), matched survey data were collected from 119 nurses. The analysis showed a significant causal relationship between time 1 administrative and role stressors and an increase in nursing stress in time 2. A significant relationship was also identified between job specific context stressors and the adoption of effective coping strategies to deal with increased level of change-induced stress and strain and the likelihood of reporting higher level of job satisfaction in time 2. This study contributes by providing an integrated theoretical perspective on how stress affects retention that has so far been elusive. This is useful to researchers wanting to examine this phenomenon further and practitioners responsible for implementing change programs.

Equity management strategies in the Australian private sector

This paper outlines the methods and outcomes of a study into equity management strategies in Australian private sector organisations reporting to the Equal Opportunity for Women in the Workplace Agency. Reports from 1976 organisations indicate eleven key factors characterising equity management in Australia. The study highlights differences within previously identified social structural policies, temperamental and opportunity policies and identifies a further policy type, categorised as “support policies”. Differences have also been identified in relation to distribution structures, suggesting that gender is not the sole consideration in determining equity management strategies. The principle of distribution also figures strongly in equity management implementation.