Ovarian hormone loss induces bioenergetic deficits and mitochondrial β-amyloid

Previously, we demonstrated that reproductive senescence was associated with mitochondrial deficits comparable to those of female triple-transgenic Alzheimer's mice (3xTgAD). Herein, we investigated the impact of chronic ovarian hormone deprivation and 17β-estradiol (E2) replacement on mitochondrial function in nontransgenic (nonTg) and 3xTgAD female mouse brain. Depletion of ovarian hormones by ovariectomy (OVX) in nontransgenic mice significantly decreased brain bioenergetics, and induced mitochondrial dysfunction and oxidative stress. In 3xTgAD mice, OVX significantly exacerbated mitochondrial dysfunction and induced mitochondrial β-amyloid and β-amyloid (Aβ)-binding-alcohol-dehydrogenase (ABAD) expression. Treatment with E2 at OVX prevented OVX-induced mitochondrial deficits, sustained mitochondrial bioenergetic function, decreased oxidative stress, and prevented mitochondrial β-amyloid and ABAD accumulation. In vitro, E2 increased maximal mitochondrial respiration in neurons and basal and maximal respiration in glia. Collectively, these data demonstrate that ovarian hormone loss induced a mitochondrial phenotype comparable to a transgenic female model of Alzheimer's disease (AD), which was prevented by E2. These findings provide a plausible mechanism for increased risk of Alzheimer's disease in premenopausally oophorectomized women while also suggesting a therapeutic strategy for prevention.

SU-E-T-308: Dosimetry of a New Minimally Invasive Episcleral Brachytherapy Device

PURPOSE

Describe the dosimetry of an episcleral brachytherapy device.

METHODS

The SMD-I device is designed to treat exudative age-related macular degeneration (AMD) and employs a Sr-90/Y-90 source encapsulated in a stainless steel cylinder. The source is welded to a flexible wire allowing it to travel from a shielded vault in the SMD-I handle to the distal end of a curved cannula to deliver a therapeutic dose of radiation through the sclera to the neovascular target in the subchoroidal space. The SMD-I handle and vault are comprised of Ultem, a lightweight radiation tolerant plastic, which shields the surgeon. Dose calculations were performed using the MCNPX radiation transport code. The absolute dose rate was determined using radiochromic film (GAFChromatic© MD-55) at a point in solid water 2.0mm from the source center perpendicular to the cannula. Dose rates at several depths were measured using Kodak EDR2 film in water equivalent phantoms to compare with the absolute dose rate measurement and MCNPX calculations. The surgeon's hand dose received while manipulating the device with the source in the vault was measured using standard TL (thermoluminescence) finger ring dosimeters, TL ChipstratesTM, and calculated with MCNPX.

RESULTS

The absolute dose rate 2.0mm from the source center is 0.45 Gy/min/mCi. The EDR2 film results agree with the absolute dose measurement and the MCNPX calculations. The dose rate decreases rapidly with depth so that the dose at the target depth (3mm) is approximately 8 times less than at 1mm depth (sclera). The dose distribution is sensitive to the angle between the cannula and the neovascular plane. Both TL methods yield a maximum dose rate of 6 μSv/min mCi to the surgeon's fingers consistent with the MCNPX calculation.

CONCLUSIONS

The SMD-I device permits accurate delivery of a therapeutic radiation dose for the treatment of exudative AMD. Russell J. Hamilton is a founder and currently serves on the Scientific Advisory Board of Salutaris Medical Devices, Inc. Wendell Lutz and Thomas Cetas serve on the Scientific Advisory Board of Salutaris Medical Devices, Inc. All authors have received financial support from Salutaris Medical Devices, Inc.

Extending the clinical research network approach to all of healthcare

The development of Clinical Research Networks (CRN) has been central to the work conducted by Health Departments and research funders to promote and support clinical research within the NHS in the UK. In England, the National Institute for Health Research has supported the delivery of clinical research within the NHS primarily through CRN. CRN provide the essential infrastructure within the NHS for the set up and delivery of clinical research within a high-quality peer-reviewed portfolio of studies. The success of the National Cancer Research Network is summarized in Chapter 5. In this chapter progress in five other topics, and more recently in primary care and comprehensively across the NHS, is summarized. In each of the 'topic-specific' networks (Dementias and Neurodegenerative Diseases, Diabetes, Medicines for Children, Mental Health, Stroke) there has been a rapid and substantial increase in portfolios and in the recruitment of patients into studies in these portfolios. The processes and the key success factors are described. The CRN have worked to support research supported by pharmaceutical, biotechnology and medical device companies and there has been substantial progress in improving the speed, cost and delivery of these 'industry' studies. In particular, work to support the increased speed of set up and delivery of industry studies, and to embed this firmly in the NHS, was explored in the North West of England in an Exemplar Programme which showed substantial reductions in study set-up times and improved recruitment into studies and showed how healthcare (NHS) organizations can overcome delays in set up times when they actively manage the process. Seven out of 20 international studies reported that the first patient to be entered anywhere in the world was from the UK. In addition, the CRN have supported research management and governance, workforce development and clinical trials unit collaboration and coordination. International peer reviews of all of the CRN have been positive and resulted in the continuation of the system for a further 5 years in all cases.

Research-intensive cancer care in the NHS in the UK

In the late 1990 s, in response to poor national cancer survival figures, government monies were invested to enhance recruitment to clinical cancer research. Commencing with England in 2001 and then rolling out across all four countries, a network of clinical cancer research infrastructure was created, the new staff being linked to existing clinical care structures including multi-disciplinary teams. In parallel, a UK-wide co-ordination of cancer research funders driven by the 'virtual' National Cancer Research Institute, combined to create a 'whole-system approach' linking research funders, researchers and NHS clinicians all working to the same ends. Over the next 10 years, recruitment to clinical trials and other well-designed studies, increased 4-fold, reaching 17% of the incident cancer population, the highest national rate world-wide. The additional resources led to more studies opened, and more patients recruited across the country, for all types of cancers and irrespective of additional clinical research staff in some hospitals. In 2006, a co-ordinated decision was made to increasingly focus on randomized trials, leading to increased recruitment, without any fall-off in accrual to non-randomized and observational studies. The National Cancer Research Network has supported large successful trials which are changing clinical practice in many cancers.

Effect of colleague and coworker abuse on family physicians in Canada

OBJECTIVE

To assess the effects of physician-colleague and coworker abuse on family physicians in Canada.

DESIGN

A mixed-methods, bilingual study that included surveys and telephone interviews.

SETTING

Canada.

PARTICIPANTS

Family physicians in active practice who were members of the College of Family Physicians of Canada in 2009.

METHODS

Surveys were mailed to a random sample of family physicians (N = 3802), and 37 family physicians who had been abused in the past year participated in telephone interviews.

MAIN FINDINGS

A total of 770 surveys (20%) were completed. A small number of respondents reported having been subjected to abuse by physician colleagues (9%) or coworkers (6%) in the previous month. Many of the respondents reported that the same physician colleagues or coworkers were repeat abusers. More than three-quarters (77%) of the physician-colleague abusers were men, whereas more than three-quarters (77%) of the other coworker abusers were women. Interviewed family physicians described feeling humiliated and unappreciated, and developed symptoms of anxiety or depression. As a result of the abuse, some family physicians terminated their employment or refused to work in certain environments. The most striking effect of this abuse was that respondents reported losing confidence in their professional abilities and skills.

CONCLUSION

Although only a small number of family physicians experience abuse by physician colleagues and other coworkers, the effects can be considerable. Victims reported a loss of confidence in their clinical abilities and some subsequently were faced with mental health issues.

Oscillatory shear stress induces mitochondrial superoxide production: implication of NADPH oxidase and c-Jun NH2-terminal kinase signaling

Fluid shear stress is intimately linked with vascular oxidative stress and atherosclerosis. We posited that atherogenic oscillatory shear stress (OSS) induced mitochondrial superoxide (mtO2•-) production via NADPH oxidase and c-Jun NH(2)-terminal kinase (JNK-1 and JNK-2) signaling. In bovine aortic endothelial cells, OSS (±3 dyn/cm2) induced JNK activation, which peaked at 1 h, accompanied by an increase in fluorescein isothiocyanate-conjugated JNK fluorescent and MitoSOX Red (specific for mtO2•- production) intensities. Pretreatment with apocynin (NADPH oxidase inhibitor) or N-acetyl cysteine (antioxidant) significantly attenuated OSS-induced JNK activation. Apocynin further reduced OSS-mediated dihydroethidium and MitoSOX Red intensities specific for cytosolic O2•- and mtO2•- production, respectively. As a corollary, transfecting bovine aortic endothelial cells with JNK siRNA (siJNK) and pretreating with SP600125 (JNK inhibitor) significantly attenuated OSS-mediated mtO2•- production. Immunohistochemistry on explants of human coronary arteries further revealed prominent phosphorylated JNK staining in OSS-exposed regions. These findings indicate that OSS induces mtO2•- production via NADPH oxidase and JNK activation relevant for vascular oxidative stress.

Using a positive self-talk intervention to enhance coping skills in breast cancer survivors: lessons from a community-based group delivery model

PURPOSE

Cancer survivorship is a distinct phase of the cancer continuum, and it can have myriad associated stresses and challenges. The purpose of the present study was to evaluate the effectiveness of a positive self-talk (pst) intervention in enhancing the coping skills and improving the psychological well-being of breast cancer survivors.

METHODS

Participants (n = 38) were recruited from 5 support groups in a small eastern Canadian province. Support groups were randomly assigned to either a control (n = 18) or an intervention (n = 20) condition. Intervention participants were pre-tested, received a 2-hour pst in-person group workshop and a 10-minute "booster" session by telephone, and completed post-test questionnaires 1 month later.

RESULTS

Intervention participants reviewed the workshop favourably. Nearly all participants used the intervention in everyday life, were able to accurately describe how pst works, and found that pst had a considerable impact on their ability to cope with cancer and related sequelae. However, the descriptive findings from the workshop evaluation did not translate into significant differences between the intervention and control groups on the psychometric measures.

CONCLUSIONS

The pst intervention, delivered in a community group model, was positively received and effective in teaching participants about pst and how pst can be used to enhance coping skills for breast cancer patients. However, the intervention did not promote significantly greater levels of change in anxiety, depression, mood disturbance, or coping ability for intervention participants. The unique challenges of community-level psychological intervention are explored.