Mediastinitis after coronary artery bypass grafting increases the incidence of left internal mammary artery obstruction

Mediastinitis after coronary artery bypass grafting (CABG) gives a longstanding chronic inflammation and has a detrimental negative effect on long‐term survival. For this reason, we aimed to study the effect of mediastinitis on graft patency after CABG. The epidemiologic design was of an exposed (mediastinitis, n = 41) versus non‐exposed (non‐mediastinitis, controls, n = 41) cohort with two endpoints: (i) obstruction of saphenous vein grafts (SVG) and (ii) obstruction of the internal mammary artery (IMA) grafts. The graft patency was evaluated with coronary CT‐angiography examination at a median follow‐up of 2·7 years. The number of occluded SVG in the mediastinitis group was 18·9% versus 15·5% in the control group. Using generalized estimating equations model with exchangeable matrix, and confounding effect of ischaemic time and patients age, we found no significant association between presence of mediastinitis and SVG obstruction [rate ratio (RR) = 0·96, 95% CI (0·52–2·67), P = 0·697]. The number of occluded IMA grafts was 10·5% in the mediastinitis group and 2·4% in the control group. Using the Poisson regression model, we estimated RR = 5·48, 95% CI (1·43–21·0) and P = 0·013. There was a significant association between mediastinitis and IMA graft obstruction, when controlling for the confounding effect of ischaemic time, body mass index, presence of diabetes mellitus and the number of diseased vessels. Presence of mediastinitis increases the risk of IMA graft obstruction. This may confirm the importance of inflammation as a major contributor to the pathogenesis of atherosclerosis and explain the negative effect of mediastinitis on a long‐term survival.     

Prevalence of cortical superficial siderosis in patients with cognitive impairment

Cortical superficial siderosis (cSS) is a magnetic resonance imaging marker of cerebral amyloid angiopathy (CAA) and can be its sole imaging sign. cSS has further been identified as a risk marker for future intracranial hemorrhage. Although uncommon in the general population, cSS may be much more prevalent in high risk populations for amyloid pathology. We aimed to determine the frequency of cSS in patients with cognitive impairment presenting to a memory clinic. We prospectively evaluated consecutive patients presenting to our memory clinic between April 2011 and April 2013. Subjects received neuropsychological testing using the Consortium to Establish a Registry for Alzheimer’s Disease battery (CERAD-NP). Two hundred and twelve patients with documented cognitive impairment further underwent a standardized 3T-MR-imaging protocol with T2*-weighted gradient-echo sequences for detection of cSS. Thirteen of 212 patients (6.1 %) displayed cSS. In seven of them (54 %) cSS was the only imaging sign of CAA. Patients with cSS did not differ from patients without cSS with regard to medical history, age or cardiovascular risk profile. Subjects with cSS performed worse in the mini-mental state examination (p = 0.001), showed more white matter hyperintensities (p = 0.005) and more often had microbleeds (p = 0.001) compared to those without cSS. cSS is common in patients with cognitive impairment. It is associated with lower cognitive scores, white matter hyperintensities and microbleeds and can be the only imaging sign for CAA in this patient group.     

Controlled release from a mechanically-stimulated thermosensitive self-heating composite hydrogel

Temperature has been extensively explored as a trigger to control the delivery of a payload from environment-sensitive polymers. The need for an external heat source only allows limited spatiotemporal control over the delivery process. We propose a new approach by using the dissipative properties of a hydrogel matrix as an internal heat source when the material is mechanically loaded. The system is comprised of a highly dissipative hydrogel matrix and thermo-sensitive nanoparticles that shrink upon an increase in temperature. Exposing the hydrogel to a cyclic mechanical loading for a period of 5 min leads to an increase of temperature of the nanoparticles. The concomitant decrease in the volume of the nanoparticles increases the permeability of the hydrogel network facilitating the release of its payload. As a proof-of-concept, we showed that the payload of the hydrogel is released after 5–8 min following the initiation of the mechanical loading. This delivery method would be particularly suited for the release of growth factor as it has been shown that cell receptor to growth factor is activated 5–20 min following a mechanical loading.     

Improved visibility of character conflicts in quasi-median networks with the EMPOP NETWORK software

Aim

To provide a valuable tool for graphical representation of mitochondrial DNA (mtDNA) data that enables visual emphasis on complex substructures within the network to highlight possible ambiguities and errors.

Method

We applied the new NETWORK graphical user interface, available via EMPOP (European DNA Profiling Group Mitochondrial DNA Population Database; www.empop.org) by means of two mtDNA data sets that were submitted for quality control.

Results

The quasi-median network torsi of the two data sets resulted in complex reticulations, suggesting ambiguous data. To check the corresponding raw data, accountable nodes and connecting branches of the network could be identified by highlighting induced subgraphs with concurrent dimming of their complements. This is achieved by accentuating the relevant substructures in the network: mouse clicking on a node displays a list of all mtDNA haplotypes included in that node; the selection of a branch specifies the mutation(s) connecting two nodes. It is indicated to evaluate these mutations by means of the raw data.

Conclusion

Inspection of the raw data confirmed the presence of phantom mutations due to suboptimal electrophoresis conditions and data misinterpretation. The network software proved to be a powerful tool to highlight problematic data and guide quality control of mtDNA data tables.It has been observed that the generation of mitochondrial (mt)DNA (population) data are prone to error (1-4). A valuable tool for graphical representation of mtDNA data is quasi-median network (QMN) construction of reduced and filtered haplotypes (1). Clerical errors, sequencing artifacts, and other ambiguous data may induce character conflicts that increase the complexity of the network, pinpointing initial points of action for quality control of mtDNA data sets (1-4). This tool is provided via the EMPOP database, a collaborative project for the provision of high-quality mtDNA population data for forensic purposes, which was initiated by the European DNA Profiling Group (EDNAP; http://www.isfg.org/ednap)in 1999. The acronym stands for “EDNAP mtDNA population database” and despite of its primary purpose of providing reliable frequency estimates, the website (www.empop.org) has regularly been used for quality control (QC) of published and newly submitted population data (3,4). QMNs form one part of the QC concept performed by EMPOP when mtDNA population data are submitted for publication in Forensic Science International Genetics (5) and International Journal of Legal Medicine (6) and thus contribute to the quality improvement of published mtDNA data sets. Also, all haplotypes presented in the mtDNA database EMPOP (3) undergo rigorous quality control prior to upload. This procedure has proven to be successful in detecting errors in individual data sets and collaborative exercises (4,7,8).While the calculation and the drawing of QMNs is supported by software (NETWORK) freely accessible via the EMPOP website, its successful interpretation and evaluation depends on the experience of the user. Users have brought to our attention that QMNs generated by NETWORK are sometimes too complex and fraught with reticulations, rendering the identification of potential errors difficult. In particular, data sets of large sample sizes (>500) were concerned, as well as data harboring haplotypes from distant phylogenies (eg, South American populations including haplogroup L, M, and N lineages).In this study, we describe the application of a new graphical user interface (GUI) of the NETWORK tool that offers the possibility to visually highlight selected structures within the graph for a better distinction of reticulations in complex areas (9). Further, haplotypes are now directly linked to the graphical representation of the nodes and can be examined in a convenient way to identify potential errors such as phantom mutations, clerical errors, violation of alignment rules, and artificial recombination. The performance and features of the new GUI are demonstrated by example of two data sets submitted to EMPOP QC.     

Traumatic distress symptoms in early breast cancer I: Acute response to diagnosis

In this study, the concept of ‘acute traumatic stress response’ was applied to breast cancer diagnosis. A total of 106 patients were studied before surgery, by means of a psychiatric interview and questionnaires (Impact of Event Scale, General Health Questionnaire and Clinical Global Impression Scale). The traumatic stress response was related to age, marital status, occurrence of breast cancer in first-degree relatives, previous physical and psychological health parameters, social support and life events during the last year. Of the patients, 44% reported a high level of intrusive symptoms (mean score 17.2) and 29% of avoidance symptoms (mean score 15.0). Younger age and being married were positively correlated with intrusive symptomology while patients with a first-degree relative with breast cancer had less intrusive distress. Previous physical and psychiatric health parameters showed no association to acute traumatic stress symptoms except for those who had experienced ‘a serious illness/accident/hospitalisation last year’ who had some more avoidant symptomology. Multiple regression showed a statistically significant effect for age only on intrusive symptoms when other factors were controlled for in this analysis.     

Traumatic distress symptoms in early breast cancer. II: Outcome six weeks post surgery

One hundred and six consecutive patients with a confirmed diagnosis of breast cancer were studied before and after surgery with a clinical psychiatric interview and questionnaires (Impact of Event Scale, General Health Questionnaire and Clinical Global Impression scale). The traumatic stress response after six weeks was related to sociodemographic factors, premorbid health problems, negative life events and clinical-oncological parameters. Symptoms of traumatic distress were significantly reduced post-surgery compared to acutely, and most so among patients with no premorbid health problems and negative life events according to pre-surgery interview and self-report data. Eighteen percent of the patients reported a high level (>19) of intrusive symptoms and 14%, avoidance symptoms. Patients with premorbid impairment in work, family and social functioning and patients who during the last year had experienced the death of a close relative or a serious illness other than cancer showed the greatest distress. Previous consultations for nervous problems, age, marital status, stage of disease, type of surgery (breast-conserving versus mastectomy) and adjuvant cytostatic treatment did not influence the traumaticstress response six weeks after surgery. The level of acute posttraumatic stress response to breast cancer surgery seems best predicted by premorbid variables.