Associations between osteoprotegerin and femoral neck BMD in hemodialysis patients

Numerous humoral factors are involved in the development of renal osteodystrophy, causing perturbations in bone mineral density (BMD) in patients with end-stage renal disease (ESRD). The RANKL/OPG cytokine system appears to mediate the effects of many of these factors on bone turnover, contributing to the pathogenesis of renal bone disease. The aim of this study was to evaluate the clinical and biochemical correlations of BMD measurements in patients on chronic hemodialysis. Fifty-four hemodialysis patients underwent measurement of BMD at the proximal femur and the lumbar spine (L2–L4). Intact parathyroid hormone (PTH), osteoprotegerin (OPG), sRANKL, and main bone biochemical markers were also measured in serum samples of all patients. BMD of the femoral neck was negatively correlated with OPG levels (r = 0.333, P = 0.014). OPG levels were significantly different among normal, osteopenic, and osteoporotic tertiles defined according to BMD of the femoral neck. The highest OPG levels were measured in the lowest T-score (osteoporotic) tertile and were higher than in the osteopenic and normal tertiles (P < 0.05). A threshold level for OPG at 21.5 pmol/l enabled the detection of osteoporotic patients with 76.5% sensitivity and 62.2% specificity. BMD values of trabecular bone-rich sites of the skeleton such as lumbar spine (L2–L4), trochanter, and Ward’ s triangle were inversely correlated with total ALP levels (P < 0.05). Hemodialysis patients with low BMD of the femoral neck demonstrated higher OPG levels than patients with normal BMD. Those with lumbar spine (L2–L4), trochanteric, and Ward's triangle BMDs below the normal range presented higher total ALP levels. These results suggest that OPG and total ALP may be clinically useful markers in the detection of significant femoral neck and trabecular bone mineral deficit in hemodialysis patients, warranting further investigations.     

Laparoscopic bowel injury: role of the site and the instrument type: study with an animal model

Background  Unrecognized laparoscopic bowel injuries are complications that can occur during any laparoscopic procedure. These complications have variable morbidity and mortality rates, and their early clinical signs of inflammation are not typical. Therefore, a study was planned to predict the mechanical behavior of the injured bowel, taking into consideration two parameters: the size of the instrument and the site of the injury. Methods  For this study, 78 Wistar rats were divided into eight study groups and one control group with two subgroups. Bowel injury was created using different sizes of needles and electrocautery on two different bowel sites: the jejunum and the terminal ileum. The animals were killed 48 h after surgery, followed by harvesting of the injured part of the bowel and measurement of the intraluminal pressure at which the bowel ruptured. Results  The mean jejunum and terminal ileum rupture pressures on the injured bowel were significantly lower than on the intact bowel. The mean terminal ileum rupture pressures were significantly lower than those of the jejunum. Conclusions  The terminal ileum appears to be more fragile than the jejunum regardless of the size of the instrument that caused the injury. However, wider instrument tips cause more serious consequences.     

The mechanical performance and histomorphological structure of the descending aorta in hyperthyroidism

Thyroid hormones decrease systemic vascular resistance by directly affecting vascular smooth muscle relaxation. There is limited literature about their effect on the mechanical performance of the aortic wall. Therefore, the authors determined the influence of hyperthyroidism on the mechanical properties and histomorphological structure of the descending thoracic aorta in rats. Severe hyperthyroidism was induced in 20 male Wistar rats by administering L-thyroxine (T(4)) in their drinking water for 8 weeks; age-matched normal euthyroid rats acted as controls. Animals were sacrificed, and the mechanical and histomorphometrical characteristics of the descending thoracic aorta were studied. The aortic wall of hyperthyroid rats was stiffer than that of euthyroid animals at the upper physiologic levels of stress or strain (p < 0.05) but less stiff at the lower physiologic and lower levels (p < 0.05). The aorta of hyperthyroid animals compared with that of euthyroid ones showed an increase of the internal and external diameters (p < 0.05), the media area (p < 0.05), the number of smooth muscle cell nuclei (p < 0.05), and the collagen density (p < 0.05) and a decrease in the elastin laminae thickness (p < 0.001) and elastin density (p < 0.001). In hyperthyroid rats, the aortic wall was stiffer at the upper physiologic and higher levels of stress and strain. These changes correlated with microstructural changes of the aortic wall. The coexistence of hyperthyroidism with disease states or clinical conditions that predispose to increased arterial pressure may be associated with increased arterial stiffness and have undesirable consequences on the mechanical performance of the thoracic aorta and hemodynamic homeostasis. These changes could lead to an increased risk for developing vascular complications.     

Vasopressin and epinephrine in the treatment of cardiac arrest: an experimental study

Background

Epinephrine remains the drug of choice for cardiopulmonary resuscitation. The aim of the present study is to assess whether the combination of vasopressin and epinephrine, given their different mechanisms of action, provides better results than epinephrine alone in cardiopulmonary resuscitation.

Methods

Ventricular fibrillation was induced in 22 Landrace/Large-White piglets, which were left untreated for 8 minutes before attempted resuscitation with precordial compression, mechanical ventilation and electrical defibrillation. Animals were randomized into 2 groups during cardiopulmonary resuscitation: 11 animals who received saline as placebo (20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Epi group); and 11 animals who received vasopressin (0.4 IU/kg/20 ml dilution, bolus) + epinephrine (0.02 mg/kg) (Vaso-Epi group). Electrical defibrillation was attempted after 10 minutes of ventricular fibrillation.

Results

Ten of 11 animals in the Vaso-Epi group restored spontaneous circulation in comparison to only 4 of 11 in the Epi group (p = 0.02). Aortic diastolic pressure, as well as, coronary perfusion pressure were significantly increased (p < 0.05) during cardiopulmonary resuscitation in the Vaso-Epi group.

Conclusion

The administration of vasopressin in combination with epinephrine during cardiopulmonary resuscitation results in a drastic improvement in the hemodynamic parameters necessary for the return of spontaneous circulation.     

Project 2000 students' perceptions of their training

This paper reports on the findings of a study conducted into the perceptions of final year Project 2000 pre-registration students towards their pre-registration education programme The aim of the research was to discover how students perceive their training in terms of value, relevance, intellectual potency, teaching methods and organization Data were collected using the Hoste scale which has been developed for the evaluation of educational courses A convenience sample of students (n = 131) within one college of nursing were invited to participate Findings include a particularly high level of satisfaction with Project 2000 in terms of value, breadth and relevance Organization and liveliness of the course were perceived much less satisfactorily There was a trend for a statistically significant difference between the mean scores of the theoretical and practical components of the course The findings are discussed with particular reference to the perceptions of theory and practice within the educational programme     

Glibenclamide improves postprandial hypertriglyceridaemia in type 2 diabetic patients by reducing chylomicrons but not the very low-density lipoprotein subfraction levels.

AIM: There are scarce data dealing with the degree of postprandial lipaemia after sulphonylurea administration. The aim of this study was to examine the effect of acute glibenclamide administration on postprandial lipaemia in Type 2 diabetic patients. METHODS: Eight randomly selected Type 2 diabetic individuals, aged 43-65 years (mean, 54 years), who had never received any anti-diabetic drug, were included in the study. Each patient was given a 485 kcal mixed meal (45% fat, 40% carbohydrate and 15% protein) twice on separate days after an overnight fast: once with placebo and once with 5 mg glibenclamide, per os, in a random order. The two tests were performed with an interval of 7 days. Venous blood samples were drawn just before and 2 h, 4 h and 6 h after meal consumption. Total triglyceride levels in plasma, in chylomicrons (CM), in CM-deficient plasma, in very low-density lipoprotein (VLDL) subfractions (VLDL-1, VLDL-2) and in intermediate-density lipoprotein (IDL) were determined. Free fatty acid (FFA) and total cholesterol levels in plasma, as well as high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol levels in CM-deficient plasma, were also measured. Finally, serum glucose, insulin and C-peptide concentrations were measured in each sample. RESULTS: As expected there was a significant decrease in postprandial glycaemia after glibenclamide administration compared to placebo (mean area under the curve values: AUC = 53.3 +/- 18.2 and 69.1 +/- 21.6 mm/h, P = 0.00009). In addition, the mean AUC values of insulin and C-peptide were significantly greater after drug administration. The AUC values of total plasma triglyceride and of CM triglyceride following glibenclamide administration were significantly lower compared to placebo, while the AUC values of postprandial triglyceride in CM-deficient plasma and of postprandial triglyceride in VLDL-1, VLDL-2 and IDL were not different after drug administration compared to placebo. Finally, no significant differences were noted in the AUC values of total cholesterol, LDL cholesterol, HDL cholesterol and plasma FFA levels after glibenclamide administration. CONCLUSIONS: These results demonstrate that glibenclamide administration improves postprandial hypertriglyceridaemia acutely by reducing postprandial triglycerides of intestinal origin.     

Conceptualizing advanced nursing practice: curriculum issues to consider in the educational preparation of advanced practice nurses in the UK

The findings from a Florence Nightingale Scholarship to the USA and Canada, investigating the educational preparation of advanced practice nurses, are reported. The author considers a number of issues facing curriculum designers who might wish to develop clinically based advanced practice nurse programmes in the UK. Utilizing the experiential nature of personal visits, along with the available literature, the strategy adopted by some American and Canadian universities is highlighted to exemplify curriculum issues likely to be encountered in the UK. A definition of advanced nursing practice is provided as a foundation for discussion on curricular construction. This is followed by a discussion on advanced role nomenclature and components and characteristics of the 'nurse practitioner', 'clinical nurse specialist', 'nurse consultant' and 'nurse clinician', in order to clarify terminology and disentangle different advanced practice roles. The issues examined include the academic level of advanced practice nurse programmes; the determination of curricular content based on both a 'generalist' and 'specialist' model of practice; factors considered when exploring advanced practice competencies; and the resource implications for delivering opposing curriculum models. The paper suggests that there is a unique opportunity for advanced practice nursing to establish a key collaborative relationship in the delivery of health care, based on a nursing model, graduate study and the integration of key nursing and related concepts into clinical practice.