Static and dynamic compressive strains influence nitric oxide production and chondrocyte bioactivity when encapsulated in PEG hydrogels of different crosslinking densities

OBJECTIVE: Mechanical loading is an important regulator of chondrocytes; however, many of the mechanisms involved in chondrocyte mechanotransduction still remain unclear. Here, poly(ethylene glycol) (PEG) hydrogels are proposed as a model system to elucidate chondrocyte response due to cell deformation, which is controlled by gel crosslinking (rho(x)). METHODS: Bovine articular chondrocytes (50 x 10(6)cells/mL) were encapsulated in gels with three rho(x)s and subjected to static (15% strain) or dynamic (0.3 Hz or 1 Hz, 15% amplitude strain) loading for 48 h. Cell deformation was examined by confocal microscopy. Cell response was assessed by total nitric oxide (NO) production, proteoglycan (PG) synthesis ((35)SO(4)(2-)-incorporation) and cell proliferation (CP) ([(3)H]-thymidine incorporation). Oxygen consumption was assessed using an oxygen biosensor. RESULTS: An increase in rho(x) led to lower water contents, higher compressive moduli, and higher cell deformations. Chondrocyte response was dependent on both loading regime and rho(x). For example, under a static strain, NO was not affected, while CP and PG synthesis were inhibited in low rho(x) and stimulated in high rho(x). Dynamic loading resulted in either no effect or an inhibitory effect on NO, CP, and PG synthesis. Overall, our results showed correlations between NO and CP and/or PG synthesis under static and dynamic (0.3 Hz) loading. This finding was attributed to the hypoxic environment that resulted from the high cell-seeding density. CONCLUSION: This study demonstrates gel rho(x) and loading condition influence NO, CP, and PG synthesis. Under a hypoxic environment and certain loading conditions, NO appears to have a positive effect on chondrocyte bioactivity.     

Encouraging smoking cessation among disadvantaged groups: a qualitative study of the financial aspects of cessation

Introduction and Aims. This study aimed to explore perceptions about financial aspects of smoking cessation among a group of disadvantaged welfare agency clients and their carers. Design and Methods. Qualitative focus groups and in‐depth interviews were supplemented with participant exit surveys about preferred smoking cessation strategies. Each discussion was audiotaped, transcribed and analysed using a thematic analysis. The setting was six non‐government community welfare service organisations operating in New South Wales, Australia. Eleven social services offered by these organisations participated. Thirty two clients participated in six client focus groups, 35 staff participated in six staff focus groups and eight manager telephone interviews were conducted. Results. Clients indicated that the cost of nicotine replacement therapy was a barrier to its use and that financial incentives were acceptable. Of the 16 possible strategies listed in the exit survey, the three selected as the most preferred by clients incorporated financial or non‐financial assistance. By contrast, staff and managers selected financial and non‐financial incentives as the least preferred and least feasible strategies. Discussion and Conclusions. The study found high acceptance of incentives as a smoking cessation strategy among a disadvantaged group of non‐government welfare service clients. The comparatively low level of desirability and feasibility from the perspective of service staff and managers suggests implementation of such an approach within the community service setting requires careful further testing.[Bonevski B, Bryant J, Paul C. Encouraging smoking cessation among disadvantaged groups: A qualitative study of the financial aspects of cessation. Drug Alcohol Rev 2011;30:411–418]     

Reduction of hypoxia-induced angiogenesis in ovarian cancer cells by inhibition of HIF-1 alpha gene expression

Purpose  

The goal of this study was to investigate the effects of silencing HIF-1 alpha gene expression with specific small interfering RNA (siRNA) on VEGF production and angiogenesis in epithelial ovarian cancer (EOC) cells.     

Voluntary certification and the uniform guidelines on selection procedures: a potential problem for personnel managers

Employers in health care sometimes rely upon various standardized testing procedures in selecting, promoting, and training personnel. Within the health professions, voluntary certification programs have developed to permit individuals to demonstrate competence and become recognized as qualified practitioners. This article addresses the problems which can occur, but are not widely recognized, when employers use voluntary certification examinations in the selection process. The impact of the federal government's "Uniform Guidelines on Employee Selection Procedures" upon voluntary certification activities is uncertain at best, and frightening, at worst. While the Guidelines require employers to use only validated examinations where adverse impact upon protected minority groups exists, they do not effectively address the use of professional certifying examinations and fail to provide guidance for either certifying agencies or employers. This leaves great potential for conflict, since circumstances in which employment is terminated, an employee denied promotion, or even denied opportunities for entry into positions based on an employer's use of voluntary certifying examinations, are increasing daily. How does an employer validate a national certifying examination that he does not administer? How does the certifying agency protect itself from allegations of discrimination or anti-trust violations based on actions of an employer with whom the agency has no contact? This article offers no answers to these troublesome questions. However, it may help eliminate another problem noted by the author--widespread ignorance of the seriousness of these circumstances for employers and certifying agencies. From first-hand experience and research into the development of the Uniform Guidelines, the author points out many of the difficulties which await those who rely on non-validated examinations or choose to ignore the government's edict that examinations used in selection must have a demonstrated relationship to the job. Finally, the article proposes solutions to the dilemma faced by certifying organizations and suggests that, by becoming more aware of the Uniform Guidelines, employers and testing groups have the opportunity to protect themselves before a problem occurs.     

Treatment of military-related post-traumatic stress disorder: challenges,innovations, and the way forward

Abstract

Post-traumatic stress disorder (PTSD) is one of the common mental disorders in military and veteran populations. Considerable research and clinical opinion has been focused on understanding the relationship between PTSD and military service and the implications for prevention, treatment, and management. This paper examines factors associated with the development of PTSD in this population, considers issues relating to engagement in treatment, and discusses the empirical support for best practice evidence-based treatment. The paper goes on to explore the challenges in those areas, with particular reference to treatment engagement and barriers to care, as well as treatment non-response. The final section addresses innovative solutions to these challenges through improvements in agreed terminology and definitions, strategies to increase engagement, early identification approaches, understanding predictors of treatment outcome, and innovations in treatment. Treatment innovations include enhancing existing treatments, emerging non-trauma-focused interventions, novel pharmacotherapy, personalized medicine approaches, advancing functional outcomes, family intervention and support, and attention to physical health.     

Role of frequency and mechanical index in ultrasonic-enhanced chemotherapy in rats

Purpose  The therapeutic effect of ultrasound and micellar-encapsulated doxorubicin was studied in vivo using a tumor-bearing rat model with emphasis on how tumor growth rate is affected by ultrasonic parameters such as frequency and intensity. Methods  This study employed ultrasound of two different frequencies (20, 476 kHz) and two pulse intensities, but identical mechanical indices and temporal average intensities. Ultrasound was applied weekly for 15 min to one of two bilateral leg tumors (DHD/K12/TRb colorectal epithelial cell line) in the rat model immediately after intravenous injection of micelle-encapsulated doxorubicin. This therapy was applied weekly for 6 weeks. Results  Results showed that tumors treated with drug and ultrasound displayed, on average, slower growth rates than non-insonated tumors (P = 0.0047). However, comparison between tumors that received 20 or 476-kHz ultrasound treatments showed no statistical difference (P = 0.9275) in tumor growth rate. Conclusion  Application of ultrasound in combination with drug therapy was effective in reducing tumor growth rate, irrespective of which frequency was employed.     

Developing youth capacity for community-based research: the Sarasota County demonstration project.

Although youth involvement in health promotion efforts is not a new concept, projects that actively involve youths in planning research, collecting data, and making research design decisions are rare. This article describes the evaluation process and outcomes for a youth-directed data collection initiative. Eleven youth researchers conducted 112 personal in-depth interviews and 22 focus groups involving 206 youths in 5th through 12th grade. Youth researchers felt confident they could conduct focus groups and in-depth interviews and staff ratings of youths' effectiveness in moderating focus groups indicated they were successful in carrying out the qualitative research.     

Attitudes to Vaginal/Urethral Touching and Device Placement in Women with Urinary Incontinence

Because of recent development of a number of intravaginal and urethral occlusive devices for the treatment of urinary incontinence, we aimed to develop a linear analog scale that measured women’s attitudes to becoming familiar with their genital anatomy and to placing devices into or upon the vagina or urethral orifices. We also investigated whether such attitudes were affected by previous tampon or diaphragm use, or were age dependent. After pilot studies, a 10-item questionnaire was given to 104 consecutive incontinent women, only 30% of whom were quite comfortable about the concept of touching their genitalia: this attitude was age dependent. Only 21% were quite willing to insert a continence device into their vagina: this attitude varied weakly with age but was significantly affected by previous tampon or diaphragm usage. Only 15% felt very comfortable about placing a continence device on to their urethra, but the likelihood of a positive response to this concept was not at all affected by age and was only slightly more common in previous tampon users. Thus older women are less likely to understand the anatomy of their genitalia or to be comfortable about the idea of exploring it, but age is no barrier to willingness to employ urethral or vaginal continence devices per se. We suggest that such a linear analog questionnaire may help gynecologists determine which patients might respond well to the use of vaginal or urethral continence devices.