Bone marrow lesions in hip osteoarthritis are characterized by increased bone turnover and enhanced angiogenesis.

OBJECTIVE: Bone marrow lesions (BML), previously denoted bone marrow edema, are detected as water signals by magnetic resonance imaging (MRI). Previous histologic studies were unable to demonstrate any edematous changes at the tissue level. Therefore, our aim was to investigate the underlying biological mechanisms of the water signal in MRI scans of bone affected by BML. METHODS: Tetracycline labeling in addition to water sensitive MRI scans of 30 patients planned for total hip replacement surgery was undertaken. Twenty-one femoral heads revealed BML on MRI, while nine were negative and used as controls (CON). Guided by the MRI images cylindrical biopsies were extracted from areas with BML in the femoral heads. Tissue sections from the biopsies were subjected to histomorphometric image analyses of the cancellous bone envelope. RESULTS: Patients with BML exhibited an average 40- and 18-fold increase of bone formation rate and mineralizing surface, respectively. Additionally, samples with BML demonstrated 2-fold reduction of marrow fat and 28-fold increase of woven bone. Immunohistochemical analysis showed a 4-fold increase of angiogenesis markers CD31 and von Willebrand Factor (vWF) in the BML-group compared to CON. CONCLUSION: This study indicates that BML are characterized by increased bone turnover, vascularity and angiogenesis in keeping with it being a reparatory process. Thus, the water signal, which is the hallmark of BML on MRI, is most probably reflecting increased tissue vascularity accompanying increased remodeling activity.

Order-preserving principles underlying genotype-phenotype maps ensure high additive proportions of genetic variance.

In quantitative genetics, the degree of resemblance between parents and offspring is described in terms of the additive variance (V(A)) relative to genetic (V(G)) and phenotypic (V(P)) variance. For populations with extreme allele frequencies, high V(A)/V(G) can be explained without considering properties of the genotype-phenotype (GP) map. We show that randomly generated GP maps in populations with intermediate allele frequencies generate far lower V(A)/V(G) values than empirically observed. The main reason is that order-breaking behaviour is ubiquitous in random GP maps. Rearrangement of genotypic values to introduce order-preservation for one or more loci causes a dramatic increase in V(A)/V(G). This suggests the existence of order-preserving design principles in the regulatory machinery underlying GP maps. We illustrate this feature by showing how the ubiquitously observed monotonicity of dose-response relationships gives much higher V(A)/V(G) values than a unimodal dose-response relationship in simple gene network models.

Summary: Canada's Food-borne Illness Outbreak Response Protocol.

BACKGROUND: The burden of illness due to food-borne pathogens each year in Canada is significant. Investigations of food-borne illness outbreaks, particularly those with cases in more than one jurisdiction, are complex. Accordingly, efficient outbreak response requires the coordination and collaboration of many investigative partners. OBJECTIVE: To highlight the Public Health Agency of Canada's Food-borne Illness Outbreak Response Protocol (FIORP), the primary guidance document for investigations of multi-jurisdictional food-borne illness outbreaks in Canada. APPROACH: The current version of the FIORP was developed in 2010 by the Public Health Agency of Canada following consultation with Health Canada, the Canadian Food Inspection Agency, and provincial and territorial stakeholders. RESULTS: The FIORP outlines guiding principles and operating procedures to enhance collaboration and coordination among multiple investigative partners in response to multi-jurisdictional food-borne illness outbreaks. It has provided guidance for the conduct of 22 such investigations led by the Public Health Agency of Canada's Centre for Food-borne, Environmental and Zoonotic Infectious Diseases between 2011 and 2013. Furthermore, it has also served as a guide for the development of provincial protocols. CONCLUSION: The timely and effective investigation of and response to multi-jurisdictional food-borne illness outbreaks in Canada is facilitated and enhanced by the FIORP.

Relationship between pedometer-registered activity, aerobic capacity and self-reported activity and fitness in patients with type 2 diabetes.

AIM: The aim of this study is to investigate the relationship between pedometer-registered activity, aerobic capacity (VO(2 max)) and self-reported activity and fitness in patients with type 2 diabetes before and after a 12-week exercise programme. METHODS: Twenty-nine men with type 2 diabetes (age=57.4 (7.8) years, BMI=31.7 (2.8) kg/m(2)) underwent exercise testing, registered pedometer activity and reported their physical fitness and activity in a questionnaire. Participants were randomly allocated to an exercise (EX) group (n=15) or a control (CO) group (n=14). Participants in EX group were offered supervised exercise twice a week for 12 weeks. At the end of the study, participants again underwent exercise testing, fasting blood tests and registration of pedometer activity. RESULTS: At baseline, pedometer activity correlated with VO(2 max) (r=0.43, p=0.02) and with perceived physical fitness (r=0.48, p=0.02). After, but not before, intervention, pedometer activity and VO(2 max) additionally correlated with perceived everyday activity (r=0.62, p<0.01 and r=0.49, p=0.03, respectively). Both EX and CO groups tended to increase pedometer activity. In EX group, weight decreased by 2.7% (p=0.01), VO(2 max) increased 10.6% (p=0.03) and HbA1c decreased by 5.2% from baseline (p=0.02). In EX group, an increase in pedometer activity correlated with a fall in HbA1c (r=0.84, p<0.01) and in diastolic blood pressure (r=0.77, p=0.025). CONCLUSIONS: Pedometer activity correlates with VO(2 max) in type-2 diabetic patients. Our exercise programme was well tolerated; it produced favourable effects on body weight, aerobic capacity and metabolic control. The use of pedometer may lead to more realistic assessment of perceived everyday physical activity.

Effect of physical training in children and adolescents with congenital heart disease.

In order to test the effect of systematic supervised physical training, we divided a total of 129 children and adolescents with congenital heart disease into a group undergoing intervention and a control group. All patients underwent exercise tests, measurements of physical activity, and a survey of psychosocial factors. An improvement in uptake of peak level of oxygen was observed after intervention. There was also an improvement in physical activity in both groups measured by a monitor, although this was significant only in those with intervention. The psychosocial scales measured by the Child Behavior Checklist showed a decrease in internalizing scores for those subjected to intervention. This was decreased due to decreased withdrawal and somatic complaints. In conclusion, we recommend systematic supervised training, including testing of routine follow-ups, in patients with congenital heart disease.