New approaches for the assessment of vessel sizes in quantitative (cardio-)vascular X-ray analysis

This paper presents new approaches for the assessment of the arterial and reference diameters in (cardio-)vascular X-ray images, designed to overcome the problems experienced in conventional quantitative coronary and vascular angiography approaches. In single or “straight” vessel segments, the arterial and reference diameter directions were made independent of each other in order to be able to measure the minimal lumen diameter (MLD) more accurately, especially in curved vessel segments. For ostial segments, an extension of this approach was used, to allow measurement of ostial lesions in sidebranches more proximal than using conventional methods. Furthermore, two new bifurcation approaches were developed. The validation study shows that the straight segment approach results in significant smaller MLDs (on average 0.032 mm) and the ostial approach achieves on average an increase in %DS of 3.8% and an increase in lesion length of 0.59 mm due to loosening the directional constraint. The validation of our new bifurcation approaches in phantom data as well as clinical data shows only small differences between pre- and post-intervention measurements of the reference diameters outside the bifurcation core (errors smaller than 0.06 mm) and the bifurcation core area (errors smaller than 1.4% for phantom data). In summary, these new approaches have led to further improvements in the quantitative analyses of (cardio-)vascular X-ray angiographies

Exploring the impact of chronic obstructive pulmonary disease (COPD) on diabetes control in diabetes patients: a prospective observational study in general practice

Background:Little is known about the association between COPD and diabetes control parameters.Aims:To explore the association between comorbid COPD and longitudinal glycaemic control (HbA 1C) and systolic blood pressure (SBP) in a primary care cohort of diabetes patients.Methods:This is a prospective cohort study of type 2 diabetes patients in the Netherlands. In a mixed model analysis, we tested differences in the 5-year longitudinal development of HbA 1C and SBP according to COPD comorbidity (present/absent). We corrected for relevant covariates. In subgroup effect analyses, we tested whether potential differences between diabetes patients with/without COPD were modified by age, sex, socio-economic status (SES) and body mass index (BMI).Results:We analysed 610 diabetes patients. A total of 63 patients (10.3%) had comorbid COPD. The presence of COPD was not significantly associated with the longitudinal development of HbA 1C (P=0.54) or SBP (P=0.33), but subgroup effect analyses showed significant effect modification by SES (P<0.01) and BMI (P=0.03) on SBP. Diabetes patients without COPD had a flat SBP trend over time, with higher values in patients with a high BMI. For diabetes patients with COPD, SBP gradually increased over time in the middle-And high-SES groups, and it decreased over time in those in the low-SES group.Conclusions:The longitudinal development of HbA 1C was not significantly associated with comorbid COPD in diabetes patients. The course of SBP in diabetes patients with COPD is significantly associated with SES (not BMI) in contrast to those without COPD. Comorbid COPD was associated with longitudinal diabetes control parameters, but it has complex interactions with other patient characteristics. Further research is needed

The effect of comorbidity on glycemic control and systolic blood pressure in type 2 diabetes: A cohort study with 5 year follow-up in primary care

To explore the longitudinal effect of chronic comorbid diseases on glycemic control (HbA1C) and systolic blood pressure (SBP) in type 2 diabetes patients. Methods In a representative primary care cohort of patients with newly diagnosed type 2 diabetes in The Netherlands (n = 610), we tested differences in the five year trend of HbA1C and SBP according to comorbidity profiles. In a mixed model analysis technique we corrected for relevant covariates. Influence of comorbidity (a chronic disease already present when diabetes was diagnosed) was tested as total number of comorbid diseases, and as presence of specific disease groups, i.e. cardiovascular, mental, and musculoskeletal disease, malignancies, and COPD. In subgroup effect analyses we tested if potential differences were modified by age, sex, socioeconomic status, and BMI. Results The number of comorbid diseases significantly influenced the SBP trend, with highest values after five years for diabetes patients without comorbidity (p = 0.005). The number of diseases did not influence the HbA1C trend (p = 0.075). Comorbid musculoskeletal disease resulted in lower HbA1C at the time of diabetes diagnosis, but in higher values after five years (p = 0.044). Patients with cardiovascular diseases had sustained elevated levels of SBP (p = 0.014). Effect modification by socioeconomic status was observed in some comorbidity subgroups. Conclusions Presence of comorbidity in type 2 diabetes patients affected the long-term course of HbA1C and SBP in this primary care cohort. Numbers and types of comorbidity showed differential effects: not the simple sum of diseases, but specific types of comorbid disease had a negative influence on long-term diabetes control parameters. The complex interactions between comorbidity, diabetes control and effect modifiers require further investigation and may help to personalize treatment goals

Uptake and effectiveness of the Children's Fitness Tax Credit in Canada: the rich get richer

<p>Abstract</p> <p>Background</p> <p>The Government of Canada implemented a Children's Fitness Tax Credit (CFTC) in 2007 which allows a non-refundable tax credit of up to $500 to register a child in an eligible physical activity (PA) program. The purposes of this study were to assess whether the awareness, uptake, and perceived effectiveness of this tax credit varied by household income among Canadian parents.</p> <p>Methods</p> <p>An internet-based panel survey was conducted in March 2009 with a representative sample of 2135 Canadians. Of those, parents with children aged 2 to 18 years of age (<it>n </it>= 1004) were asked if their child was involved in organized PA programs (including dance and sports), the associated costs to register their child in these programs, awareness of the CFTC, if they had claimed the CFTC for the tax year 2007, and whether they planned to claim it in the upcoming year. Parents were also asked if they believed the CFTC has lead to their child being more involved in PA programs.</p> <p>Results</p> <p>Among parents, 54.4% stated their child was in organized PA and 55.5% were aware of the CFTC. Parents in the lowest income quartile were significantly less aware and less likely to claim the CFTC than other income groups. Among parents who had claimed the CFTC, few (15.6%) believed it had increased their child's participation in PA programs.</p> <p>Conclusions</p> <p>More than half of Canadian parents with children have claimed the CFTC. However, the tax credit appears to benefit the wealthier families in Canada.</p

The pathway of obstructed labour as perceived by communities in south-western Uganda: a grounded theory study

BACKGROUND: Obstructed labour is still a major cause of maternal and perinatal morbidity and mortality in Uganda, where many women give birth at home alone or assisted by non-skilled birth attendants. Little is known of how the community view obstructed labour, and what actions they take in cases where this complication occurs. OBJECTIVE: The objective of the study was to explore community members' understanding of and actions taken in cases of obstructed labour in south-western Uganda. DESIGN: Grounded theory (GT) was used to analyse data from 20 focus group discussions (FGDs), 10 with women and 10 with men, which were conducted in eight rural and two urban communities. RESULTS: A conceptual model based on the community members' understanding of obstructed labour and actions taken in response is presented as a pathway initiated by women's desire to 'protecting own integrity' (core category). The pathway consisted of six other categories closely linked to the core category, namely: (1) 'taking control of own birth process'; (2) 'reaching the limit - failing to give birth' (individual level); (3) 'exhausting traditional options'; (4) 'partner taking charge'; (5) 'facing challenging referral conditions' (community level); and finally (6) 'enduring a non-responsive healthcare system' (healthcare system level). CONCLUSIONS: There is a need to understand and acknowledge women's reluctance to involve others during childbirth. However, the healthcare system should provide acceptable care and a functional referral system closer to the community, thus supporting the community's ability to seek timely care as a response to obstructed labour. Easy access to mobile phones may improve referral systems. Upgrading of infrastructure in the region requires a multi-sectoral approach. Testing of the conceptual model through a quantitative questionnaire is recommended

Feller Processes: The Next Generation in Modeling. Brownian Motion, L\'evy Processes and Beyond

We present a simple construction method for Feller processes and a framework for the generation of sample paths of Feller processes. The construction is based on state space dependent mixing of L\'evy processes. Brownian Motion is one of the most frequently used continuous time Markov processes in applications. In recent years also L\'evy processes, of which Brownian Motion is a special case, have become increasingly popular. L\'evy processes are spatially homogeneous, but empirical data often suggest the use of spatially inhomogeneous processes. Thus it seems necessary to go to the next level of generalization: Feller processes. These include L\'evy processes and in particular Brownian motion as special cases but allow spatial inhomogeneities. Many properties of Feller processes are known, but proving the very existence is, in general, very technical. Moreover, an applicable framework for the generation of sample paths of a Feller process was missing. We explain, with practitioners in mind, how to overcome both of these obstacles. In particular our simulation technique allows to apply Monte Carlo methods to Feller processes.Comment: 22 pages, including 4 figures and 8 pages of source code for the generation of sample paths of Feller processe

Identification of a Common Gene Expression Response in Different Lung Inflammatory Diseases in Rodents and Macaques

To identify gene expression responses common to multiple pulmonary diseases we collected microarray data for acute lung inflammation models from 12 studies and used these in a meta-analysis. The data used include exposures to air pollutants; bacterial, viral, and parasitic infections; and allergic asthma models. Hierarchical clustering revealed a cluster of 383 up-regulated genes with a common response. This cluster contained five subsets, each characterized by more specific functions such as inflammatory response, interferon-induced genes, immune signaling, or cell proliferation. Of these subsets, the inflammatory response was common to all models, interferon-induced responses were more pronounced in bacterial and viral models, and a cell division response was more prominent in parasitic and allergic models. A common cluster containing 157 moderately down-regulated genes was associated with the effects of tissue damage. Responses to influenza in macaques were weaker than in mice, reflecting differences in the degree of lung inflammation and/or virus replication. The existence of a common cluster shows that in vivo lung inflammation in response to various pathogens or exposures proceeds through shared molecular mechanisms

Proximity to Sports Facilities and Sports Participation for Adolescents in Germany

Objectives - To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods - A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results - The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions - Improved proximity to gyms is likely to be more important for female adolescents living in rural areas

Approximation for Cooperative Interactions of a Spatially-Detailed Cardiac Sarcomere Model

We developed a novel ordinary differential equation (ODE) model, which produced results that correlated well with the Monte Carlo (MC) simulation when applied to a spatially-detailed model of the cardiac sarcomere. Configuration of the novel ODE model was based on the Ising model of myofilaments, with the “co-operative activation” effect introduced to incorporate nearest-neighbor interactions. First, a set of parameters was estimated using arbitrary Ca transient data to reproduce the combinational probability for the states of three consecutive regulatory units, using single unit probabilities for central and neighboring units in the MC simulation. The parameter set thus obtained enabled the calculation of the state transition of each unit using the ODE model with reference to the neighboring states. The present ODE model not only provided good agreement with the MC simulation results but was also capable of reproducing a wide range of experimental results under both steady-state and dynamic conditions including shortening twitch. The simulation results suggested that the nearest-neighbor interaction is a reasonable approximation of the cooperativity based on end-to-end interactions. Utilizing the modified ODE model resulted in a reduction in computational costs but maintained spatial integrity and co-operative effects, making it a powerful tool in cardiac modeling

Finite element analysis of the effect of cementing concepts on implant stability and cement fatigue failure

Background and purpose Two contradictory cementing techniques (using an undersized stem versus a canal-filling stem) can both lead to excellent survival rates, a phenomenon known as the “French paradox”. Furthermore, previous studies have indicated that the type of bone supporting the cement mantle may affect implant survival. To further evaluate the mechanical consequences of variations in cementing technique, we studied the effect of implant size and type of bone supporting the cement mantle on the mechanical performance of cemented total hip arthroplasty, using finite element analysis