Femoral neck trabecular microstructure in ovariectomized ewes treated with calcitonin: MRI microscopic evaluation.

Ovariectomy induces deterioration of the trabecular structure in the femoral neck of ewes, as depicted by MR microscopic imaging. This structural deterioration is prevented by salmon calcitonin treatment. INTRODUCTION: This study evaluated the trabecular (Tb) microarchitecture of an ovariectomy (OVX)-induced osteoporotic model in ewes and determined the effects of salmon calcitonin (sCT), an osteoclast inhibitor, on the Tb structure. This is the first report of OVX-induced changes in the Tb structure in the femoral neck in the ewes and effect of sCT on the microarchitecture. MATERIALS AND METHODS: Ewes (5-8 years old, n = 28) were equally allocated into sham (Sham), OVX injected with vehicle, or OVX injected with sCT at 50 or 100 IU, three injections per week. They were killed 6 months after OVX. The femoral neck was examined with an MR imager at 9.4 T in axial, coronal, and sagittal planes. An internal calibration procedure as a means of standardizing image analysis was used to adjust the segmentation threshold. Data from all three planes were averaged. RESULTS AND CONCLUSIONS: Compared with Sham, OVX induced significant changes (p < 0.0125) in the MRI-derived femoral neck Tb structure: Tb bone volume fraction (BV/TV), -18%; Tb number, -20%; Tb separation, +23%; number of free ends, +28%; number of nodes, -39%; number of Tb branches, -23%; mean length of Tb branches, -19%. Compared with OVX, treatment of sCT at 100 IU significantly improved all the Tb structural parameters to the Sham level (p < 0.0001 approximately p = 0.0281), whereas 50 IU significantly increased the Tb number and the mean length of the Tb branches. BV/TV explained 74% of the variation of compressive stress of the trabecular cylinder cores of the femoral neck. Combining all structural parameters in a multivariate regression analysis significantly improved the explanation to 84%, and adding BMD further improved the predictive ability of the model to 92%. We conclude that OVX induces deterioration of the MRI-derived Tb microstructure in the femoral neck of ewes. sCT treatment prevents OVX-induced changes. The femoral neck microarchitecture significantly correlates with its biomechanical properties. Combining microstructural parameters with BMD further improves the prediction of bone biomechanical properties. The effects of sCT on OVX ewes may help explain reduced fracture risk in postmenopausal osteoporotic women treated with sCT.     

The effect of systemic arterial hypertension on blood-to-tissue transport in experimental gliomas

Systemic arterial hypertension was induced with epinephrine in 15 rats with 39 transplanted RG-2 brain tumors in an attempt to increase blood-to-tissue transport of a water-soluble compound. In 4 rats, hypertension was induced acutely (< 5 sec), and in 11 hypertension was induced more slowly (over 5 min). Regional values of the unidirectional blood-to-tissue transfer constant (K) of alpha aminoisobutyric acid were measured with quantitative autoradiography. Mean arterial blood pressure (BP) over the experimental period increased from 117 ± 17 mmHg (SD) to 168 ± 18 mmHg in the rats with slowly induced hypertension, and from 124 ± 4 to 142 ± 5 mmHg in the acute hypertension group. Peak BP was 208 ± 16 in the first group and 216 ± 13 mmHg in the second. Intracerebral hemorrhage occurred in 10/15 animals, and there was disruption of BBB in tumor-free brain in 10/15 animals. Averaged mean whole tumor K of AIB in all hypertensive rats was 0.052 ± 0.022 ml/g/min, compared to 0.037 ± 0.015 ml/g/min in normotensive controls; there was no difference in mean tumor K between the two hypertensive groups. However, in intraparenchymal tumors without hemorrhage, K was only 0.039 ± 0.013 ml/g/min. Although the mean K of AIB was higher in brain tumors of the hypertensive rats, the increase is unlikely to be meaningful in terms of augmented delivery of watersoluble drugs to brain tumors, and the high incidence of intracerebral hemorrhage countermands any clinical use of this approach.     

Hormesis as a Pro-Healthy Aging Intervention in Human Beings?

Hormesis is a phenomenon in which adaptive responses to low doses of otherwise harmful factors (also called mild stressors) make cells and organisms more robust. Aging is a complex and poorly understood process. This review explores the positive effects of hormesis on aging in animal models and human cell cultures, and discusses whether it might apply to humans. As an example, repeated mild heat stress confers anti-aging benefits to normal human cells in culture. Calorie restriction and xenohormetic compounds such as resveratrol, in large part via activation of sirtuins, decrease risk of common age-related conditions, such as cancer, cardiovascular disease, type 2 diabetes, and neurological diseases, so lengthening lifespan. Mild stressors and xenohormetic dietary components have diverse molecular targets and affect many pathways. Despite experimental advances in aging research, findings in humans are still quite limited. Moderate-intensity exercise, weight management and healthy diet ameliorate diseases of aging to increase lifespan and this could involve hormesis.     

History of family dysfunction and perpetration of dating violence by adolescent boys: a longitudinal study.

PURPOSE: To examine whether there is a direct or a mediated association between dysfunctional parental behavior in later childhood and involvement in dating violence in a sample of low socioeconomic-status boys during mid-adolescence. METHODS: Subjects were 717 boys who participated in a longitudinal study. Data collected at six time periods, beginning at age 10 years and covering a span of 8 years, were analyzed. Dysfunctional parental behavior patterns were defined as perceived harsh parenting practices, laxness of monitoring, and interparental conflict witnessed by the subject. Perpetrated psychological and physical abuse in dating, measured at ages 16 and 17 years, and delinquency, measured at age 15 years, served as dependent measures. All instruments were self-report questionnaires. Multiple regression analysis was used in data analysis. RESULTS: Only two variables contributed independently to dating violence. Boys who perceived laxness of monitoring from their parents in their late childhood and reported antisocial behavior at age 15 years, such as delinquency and substance abuse, were at risk of becoming involved in violent dating relationships at age 16 years. Harsh parenting practices from ages 10 to 12 years were also predictors of dating violence. CONCLUSIONS: A direct relationship was found between harsh parenting and antisocial behavior and later dating violence. No support was found for the mediation hypothesis of antisocial behavior, but an indirect influence was noted in association with monitoring.     

Interferon alpha/beta and interleukin 12 responses to viral infections: pathways regulating dendritic cell cytokine expression in vivo

Interferon (IFN)-alpha/beta and interleukin (IL)-12 are cytokines critical in defense against viruses, but their cellular sources and mechanisms of regulation for in vivo expression remain poorly characterized. The studies presented here identified a novel subset of dendritic cells (DCs) as major producers of the cytokines during murine cytomegalovirus (MCMV) but not lymphocytic choriomeningitis virus (LCMV) infections. These DCs differed from those activated by Toxoplasma antigen but were related to plasmacytoid cells, as assessed by their CD8alpha(+)Ly6G/C(+)CD11b(-) phenotype. Another DC subset (CD8alpha(2)Ly6G/C(-)CD11b(+)) also contributed to IL-12 production in MCMV-infected immunocompetent mice, modestly. However, it dramatically increased IL-12 expression in the absence of IFN-alpha/beta functions. Conversely, IFN-alpha/beta production was greatly reduced under these conditions. Thus, a cross-regulation of DC subset cytokine responses was defined, whereby secretion of type I IFNs by CD8alpha(+) DCs resulted in responses limiting IL-12 expression by CD11b(+) DCs but enhancing overall IFN-alpha/beta production. Taken together, these data indicate that CD8alpha(+)Ly6G/C(+)CD11b(-) DCs play important roles in limiting viral replication and regulating immune responses, through cytokine production, in some but not all viral infections. They also illustrate the plasticity of cellular sources for innate cytokines in vivo and provide new insights into the roles of IFNs in shaping immune responses to viruses.     

Effects of a Relationship-Enhancing Program of Care on Outcomes

Purpose: To examine the effects of a relationship-enhancing program of care (REPC) on resident and care provider outcomes.
Design and Methods: A quasi-experimental, repeated measures design, with intervention and comparison groups. Questionnaires were distributed to 50 residents, and observations were conducted of 40 residents and 34 nursing staff at baseline and 3 months after the intervention, on two Canadian nursing home units. An investigator-designed educational program based on Winnicott's theory of relationships and the empirical literature, was provided to care providers and their supervisors on the intervention unit. Repeated measures analysis of variance (RM-ANOVA) was used to compare the intervention and comparison groups in regard to changes in the outcomes over time.
Findings: The REPC had statistically significant effects on (a) residents' perceptions of care providers' relational care, (b) care providers' relational behaviors, and (c) continuity of care.
Conclusions: Evidence showed that these care providers were taught how to enhance their relational skills with residents living in long-term care facilities without added staff. Recommendations for practice and research are discussed.     

Partnership in research: a tandem of opportunities and constraints

Partnership is a term that is occurring more and more frequently in the research lexicon, an approach that is gradually becoming a sine qua non in the field of health and healthcare research in Canada. The purpose of this article is to share thoughts and experiences regarding research carried out in partnership. The relevance and necessity of partnerships in strategic health research will be examined, and the contribution of partnerships to the development and "re-centring" of intra- and interdisciplinary knowledge and knowledge transfer will be discussed. Based on the nursing and related-fields literature, the key elements of partnership, and the advantages and disadvantages of this strategy to pursuing research projects will be presented. An important issue in a professional discipline such as nursing will be discussed, i.e. the intra-disciplinary partnership between researchers and clinicians. Strategies that could enhance this particular type of partnership and avenues for catalyzing the synergy that must perforce develop, over the coming years, will be proposed.     

Caregivers of elderly people with loss of autonomy in Lebanon: what is the context of their health care?

The primary objective of this pan Lebanese study was to describe the health care context of family caregivers cohabiting with an elderly relative with loss of autonomy while the secondary objective consisted in the qualitative documentation of their positive and negative perceptions as to the role of the caregivers. The study uses a theoretical framework of stress. The results indicate that the caregivers (N = 319) take care of relatives (40% with memory troubles) having a moderate level of loss of autonomy and who present more depressive behaviors than "disturbing" behaviors. The caregivers are particularly affected by the behaviors of their relatives. They accomplish several health care tasks and very few receive formal services to support them. Their neighborhood offers them more emotional support than instrumental support. More caregivers perceive positive aspects than negative aspects in their role. Recommendations are formulated to guide the elaboration of a national policy of support to caregivers and the development of innovative community care practices.