Towards a more place-sensitive nursing research: an invitation to medical and health geography

During recent years, nursing research has adopted and integrated perspectives and theoretical frameworks from a range of social science disciplines. I argue however, that a lack of attention has been paid in past research to the subdiscipline of medical geography. Although this may, in part, be attributed to a divergence between research priorities and foci, traditional 'scientific' geographical approaches may still be relevant to a wide range of nursing research. Furthermore, a recasting, redirecting and broadening of medical geography in the 1990s, towards what is termed health geography, has enhanced the discipline and provided a more cultural and expansive recognition of health, and a more comprehensive understanding of the dynamic relationship between people, health and place. Given the increasing range of places where health-care is provided and received, and some recent linkages made between nursing and place by nurse-theorists, these newer perspectives and concepts may be particularly useful for interpreting nurses' and patients' relationships both within and with a variety of healthcare settings and living spaces. Indeed, although a more place-sensitive nursing research is potentially a trans-disciplinary academic endeavor, a range of geographical approaches would be central to such a project.     

Rivastigmine in patients with Alzheimer's disease and concurrent hypertension

Rivastigmine has demonstrated significant benefits in patients with mild to moderate Alzheimer's disease (AD). We aimed to confirm whether rivastigmine was effective in patients with or without concurrent vascular risk factors (VRF), as previously suggested. We chose to stratify the 725 patients involved in an international dose-ranging study according to the presence of arterial hypertension (a marker of VRF) at baseline. Efficacy in each subgroup was assessed using the ADAS-cog, a measure of cognitive performance, the Progressive Deterioration Scale (PDS) and the Clinician's Interview-Based Impression of Change (CIBIC) with caregiver input. Patients receiving rivastigmine 6-12 mg/day showed better outcomes on the ADAS-cog than those receiving placebo, in both the hypertensive and non-hypertensive subgroups. Hypertensive patients receiving rivastigmine 6-12 mg/day also showed improvement over those receiving 1-4 mg/day (p = 0.023). Rivastigmine 6-12 mg/day also provided better outcomes than placebo on the PDS in the hypertensive (p = 0.031) and non-hypertensive (p = 0.035) subgroups. All patients receiving rivastigmine 6-12 mg/day had superior CIBIC-plus scores than those receiving placebo. There was a trend for lower incidences of nausea and vomiting in rivastigmine-treated patients with hypertension than in those without hypertension. No cardiac adverse events or drug-drug interactions were reported. Our data support the hypothesis that rivastigmine provides benefits to patients with or without hypertension, and contribute to the evidence that particular benefits may be observed in those with vascular risk factors.     

Fetal hematopoietic stem cell transplantation: a challenge for the twenty-first century

Successful in utero hematopoietic stem cell transplantation will likely represent a major step forward in the management of patients with congenital hematological, metabolic, and immunological disorders. We review the naturally occurring models of hematopoietic chimerism in animals and humans, as well as available experimental animal data and human clinical attempts of fetal transplantation. Data available from naturally occurring models and experimental models of fetal transplantation suggest that this technique should be translatable to the human fetus. However, to date, the success of human fetal hematopoietic stem cell therapy has been limited to fetuses with severe immunologic defects. Evaluation of successful attempts of human transplantation, the ontogeny of fetal immune development, and data available from animals provide insights into innovative approaches to fetal therapy that may bring the reality of successful fetal transplantation closer.     

Measuring nurse-sensitive patient outcomes across specialty units

In efforts to quantify the quality of care delivered to patients within their systems, nursing administrators are being called on to both privately and publicly report nursing-sensitive outcomes for their institutions. Accurate reporting with appropriate patient population or risk adjustment is essential if the reported outcomes are to provide meaningful data to consumers and providers. At present there are no effective mechanisms available that can sufficiently adjust nursing-sensitive outcomes to assure reliable reporting. This study suggests that specialty unit classification may be one method by which nursing-sensitive outcomes can be accurately reported.     

Bone mass response to discontinuation of long-term hormone replacement therapy: results from the Postmenopausal Estrogen/Progestin Interventions (PEPI) Safety Follow-up Study

BACKGROUND: Accelerated bone loss after stopping hormone therapy (HRT) is postulated to explain the lack of hip-fracture protection conferred by former HRT use. The abbreviation HRT (traditionally standing for "hormone replacement therapy") is used herein because of its wide recognition in the field. However, the pharmacological doses of estrogens and progestins used are not truly "replacement" in nature. OBJECTIVES: To determine whether women lose bone mineral density (BMD) after stopping HRT; to assess whether their rate of loss is significantly greater than that of women not undergoing HRT; and to determine whether long-term HRT is associated with continued gains in BMD. METHODS: A total of 495 women who were adherent to assigned treatment in the 3-year Postmenopausal Estrogen/Progestin Interventions randomized controlled trial (PEPI-RCT) and who had an additional BMD measurement during the PEPI Safety Follow-up Study were observed for an average of 3 years during and 4 years after the PEPI-RCT. RESULTS: Women who stopped HRT after 1 year during the PEPI-RCT had annual rates of BMD change of -0.54% (hip) and -0.81% (spine) during the following 2 years. Those who underwent HRT for 3 years during the PEPI-RCT and then discontinued it had annual changes of -1.01% (hip) and -1.04% (spine). Rates of BMD loss among women who stopped HRT during or after the PEPI-RCT did not differ significantly from those of women who did not undergo HRT, who lost bone at a rate of approximately 1% yearly during the first year of the PEPI-RCT and about half that rate afterward. Women who continued HRT after the PEPI-RCT did not show additional BMD gains. CONCLUSIONS: Our results do not support the hypothesis that bone is lost at an unusually fast rate after discontinuation of HRT, nor do they suggest that longer-term HRT leads to additional BMD gain beyond that evident after 3 years.     

Functional compartmentation of endothelial P2Y receptor signaling

The presence of multiple receptors for disparate nucleotides on endothelial cells makes it unclear how the endothelium differentiates among these signals. We propose that endothelial P2Y receptors are organized into cholesterol-rich signaling domains, such as caveolae and respond to nucleotide agonists by mobilizing intracellular calcium. Treatment of endothelial cells with 5 mmol/L beta-methyl-cyclodextrin prevents calcium release in response to the nucleotide receptor agonists 2-methylthio-ATP, ATP, ADP, and UTP, but not the kinin receptor agonist bradykinin, suggesting that depletion of membrane cholesterol disrupts signaling at P2Y receptors and that bradykinin receptors are not prelocalized to cholesterol microdomains in these cells. Direct measurement of cholesterol content after beta-methyl-cyclodextrin treatment of aortic rings reveals a concentration-dependent depletion of cholesterol that parallels functional antagonism of P2Y-mediated relaxation. Nucleotide- and bradykinin-mediated relaxation is disrupted by 5 to 15 mmol/L beta -methyl-cyclodextrin treatment or 1 to 10 microg/mL filipin III in a concentration-dependent fashion. Norepinephrine contracted aorta treated with A23187 relaxes in an endothelium-dependent fashion despite depletion of 84% of membrane-extractable cholesterol. These data indicate that in the basal state, P2Y receptors but not the kinin receptor may be compartmented to cholesterol-dependent signaling domains in guinea pig endothelium and that cholesterol-rich microdomains in these cells can respond to intracellular calcium in an agonist-specific manner. We suggest that the functional organization of cholesterol-rich signaling microdomains allows agonist-specific responses to increases in intracellular calcium and that this property may be a general phenomenon that permits cells to respond disparately to agonists that may signal through common calcium release pathways.