Three-dimensional printing creates models for surgical planning of aortic valve replacement after previous coronary bypass grafting.

PURPOSE Resternotomy for aortic valve replacement in patients with previous coronary artery bypass grafting and an internal mammary artery graft may be a surgical problem. Thus, we are exploring the effect of using rapid prototyping techniques for surgical planning and intraoperative orientation during aortic valve replacement after previous coronary artery bypass grafting (CABG). DESCRIPTION As a proof of concept, we studied a patient who had undergone CABG 5 years earlier. At that time the patient received a left internal mammary artery graft to the left anterior descending artery and a venous graft to the right coronary artery. Now the patient required aortic valve replacement due to symptomatic aortic valve stenosis. The left internal mammary artery bypass and the right coronary artery bypass were patent and showed good flow in the angiography. The patient was examined by 128-slice computed tomography. The image data were visualized and reconstructed. Afterwards, a replica showing the anatomic structures was fabricated using a rapid prototyping machine. EVALUATION Using data derived from 128-slice computed tomography angiography linked to proprietary software, we were able to create three-dimensional reconstructions of the vascular anatomy after the previous CABG. The models were sterilized and taken to the operating theatre for orientation during the surgical procedure. CONCLUSIONS Stereolithographic replicas are helpful for choosing treatment strategies in surgical planning and for intraoperative orientation during reoperations of patients with previous CABG.

In Vitro Testing of a Temporary Catheter-Based Aortic "Parachute" Valve

Recently developed technologies allow aortic valve implantation off-pump in a beating heart. In this procedure, the native, stenotic aortic valve is not removed, but simply crushed by a pressure balloon mounted on a percutaneous catheter. Removal of the native aortic cusps before valve replacement may reduce the incidence of annular or cuspal calcium embolization and late perivalvular leaks and increase implantable valve size. However, a temporary valve system in the ascending aorta may be necessary to maintain hemodynamic stability by reducing acute aortic regurgitation and left ventricular volume overload. This study evaluates the hemodynamic effects of a wire-mounted, monoleaflet, temporary valve apparatus in a mechanical cardiovascular simulator. Aortic flow, systemic pressure and left ventricular pressure were continuously monitored. An intraluminal camera obtained real-time proximal and distal images of the valve in operation. Insertion of the parachute valve in the simulator increased diastolic pressure from 7 to 38 mm Hg. Cardiac output increased from 2.08 to 4.66 L/min and regurgitant volume decreased from 65 to 23 mL. In conclusion, placement of a temporary valve in the ascending aorta may help maintain hemodynamic stability and improve off-pump aortic valve replacement.

Coronary artery disease severity and aortic stenosis: clinical outcomes according to SYNTAX score in patients undergoing transcatheter aortic valve implantation.

AIM The aim of this study was to evaluate whether coronary artery disease (CAD) severity exerts a gradient of risk in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS A total of 445 patients with severe AS undergoing TAVI were included into a prospective registry between 2007 and 2012. The preoperative SYNTAX score (SS) was determined from baseline coronary angiograms. In case of revascularization prior to TAVI, residual SS (rSS) was also determined. Clinical outcomes were compared between patients without CAD (n = 158), patients with low SS (0-22, n = 207), and patients with high SS (SS >22, n = 80). The pre-specified primary endpoint was the composite of cardiovascular death, stroke, or myocardial infarction (MI). At 1 year, CAD severity was associated with higher rates of the primary endpoint (no CAD: 12.5%, low SS: 16.1%, high SS: 29.6%; P = 0.016). This was driven by differences in cardiovascular mortality (no CAD: 8.6%, low SS: 13.6%, high SS: 20.4%; P = 0.029), whereas the risk of stroke (no CAD: 5.1%, low SS: 3.3%, high SS: 6.7%; P = 0.79) and MI (no CAD: 1.5%, low SS: 1.1%, high SS: 4.0%; P = 0.54) was similar across the three groups. Patients with high SS received less complete revascularization as indicated by a higher rSS (21.2 ± 12.0 vs. 4.0 ± 4.4, P < 0.001) compared with patients with low SS. High rSS tertile (>14) was associated with higher rates of the primary endpoint at 1 year (no CAD: 12.5%, low rSS: 16.5%, high rSS: 26.3%, P = 0.043). CONCLUSIONS Severity of CAD appears to be associated with impaired clinical outcomes at 1 year after TAVI. Patients with SS >22 receive less complete revascularization and have a higher risk of cardiovascular death, stroke, or MI than patients without CAD or low SS.

Impairment of rat postnatal lung alveolar development by glucocorticoids: involvement of the p21CIP1 and p27KIP1 cyclin-dependent kinase inhibitors

It has been shown that glucocorticoids accelerate lung development by limiting alveolar formation resulting from a premature maturation of the alveolar septa. Based on these data, the aim of the present work was to analyze the influence of dexamethasone on cell cycle control mechanisms during postnatal lung development. Cell proliferation is regulated by a network of signaling pathways that converge to the key regulator of cell cycle machinery: the cyclin-dependent kinase (CDK) system. The activity of the various cyclin/CDK complexes can be modulated by the levels of the cyclins and their CDKs, and by expression of specific CDK inhibitors (CKIs). In the present study, newborn rats were given a 4-d treatment with dexamethasone (0.1-0.01 microg/g body weight dexamethasone sodium phosphate daily on d 1-4), or saline. Morphologically, the treatment caused a significant thinning of the septa and an acceleration of lung maturation on d 4. Study of cyclin/CDK system at d 1-36 documented a transient down-regulation of cyclin/CDK complex activities at d 4 in the dexamethasone-treated animals. Analysis of the mechanisms involved suggested a role for the CKIs p21CIP1 and p27KIP1. Indeed, we observed an increase in p21CIP1 and p27KIP1 protein levels on d 4 in the dexamethasone-treated animals. By contrast, no variations in either cyclin and CDK expression, or cyclin/CDK complex formation could be documented. We conclude that glucocorticoids may accelerate lung maturation by influencing cell cycle control mechanisms, mainly through impairment of G1 cyclin/CDK complex activation.

Representation Matters: The Impact of Descriptive Women's Representation on the Political Involvement of Women

In a cross-country comparison of 33 European countries, we tested whether a high degree of female representation attenuates the assumed negative impact of gender on political involvement. Our multilevel analyses show positive interactive effects of female representation: the degree to which the representation of women in a given country's national parliament was descriptively adequate was positively related to women's ratings of the importance of politics and self-reported political interest. With respect to political participation, the findings are mixed.

Short-term clinical outcomes among patients undergoing transcatheter aortic valve implantation in Switzerland: the Swiss TAVI registry

Aims: To evaluate short-term clinical outcomes following transcatheter aortic valve implantation (TAVI) using CE-mark approved devices in Switzerland. Methods and results: The Swiss TAVI registry is a national, prospective, multicentre, monitored cohort study evaluating clinical outcomes in consecutive patients undergoing TAVI at cardiovascular centres in Switzerland. From February 2011 to March 2013, a total of 697 patients underwent TAVI for native aortic valve stenosis (98.1%), degenerative aortic bioprosthesis (1.6%) or severe aortic regurgitation (0.3%). Patients were elderly (82.4±6 years), 52% were females, and the majority highly symptomatic (73.1% NYHA III/IV). Patients with severe aortic stenosis (mean gradient 44.8±17 mmHg, aortic valve area 0.7±0.3 cm2) were either deemed inoperable or at high risk for conventional surgery (STS 8.2%±7). The transfemoral access was the most frequently used (79.1%), followed by transapical (18.1%), direct aortic (1.7%) and subclavian access (1.1%). At 30 days, rates of all-cause mortality, cerebrovascular events and myocardial infarction were 4.8%, 3.3% and 0.4%, respectively. The most frequently observed adverse events were access-related complications (11.8%), permanent pacemaker implantation (20.5%) and bleeding complications (16.6%). The Swiss TAVI registry is registered at ClinicalTrials.gov (NCT01368250). Conclusions: The Swiss TAVI registry is a national cohort study evaluating consecutive TAVI procedures in Switzerland. This first outcome report provides favourable short-term clinical outcomes in unselected TAVI patients.

The equine DNAH3 gene: SNP discovery and exclusion of an involvement in recurrent airway obstruction (RAO) in European Warmblood horses

Recurrent airway obstruction is one of the most common airway diseases affecting mature horses. Increased bronchoalveolar mucus, neutrophil accumulation in airways, and airway obstruction are the main features of this disease. Mucociliary clearance is a key component of pulmonary defense mechanisms. Cilia are the motile part of this system and a complex linear array of dynein motors is responsible for their motility by moving along the microtubules in the axonemes of cilia and flagella. We previously detected a QTL for RAO on ECA 13 in a half-sib family of European Warmblood horses. The gene encoding DNAH3 is located in the peak of the detected QTL and encodes a dynein subunit. Therefore, we analysed this gene as a positional and functional candidate gene for RAO. In a mutation analysis of all 62 exons we detected 53 new polymorphisms including 7 non-synonymous variants. We performed an association study using 38 polymorphisms in a cohort of 422 animals. However, after correction for multiple testing we did not detect a significant association of any of these polymorphisms with RAO (P>0.05). Therefore, it seems unlikely that variants at the DNAH3 gene are responsible for the RAO QTL in European Warmblood horses.

State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair.

Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks.

The involvement of miRNA Dysregulation in Amyotrophic Lateral Sclerosis

ALS is a neurodegenerative disease that specifically affects upper and lower motor neurons leading to progressive paralysis and death. There is currently no effective treatment. Thus, identification of the signaling pathways and cellular mediators of ALS remains a major challenge in the search for novel therapeutic approaches. Recent studies have shown that non-coding RNAs have a significant impact on normal CNS development and onset and progression of neurological disorders. Based on this evidence we specifically test the hypothesis that misregulation of miRNA expression is a common feature in familiar ALS. Hence, we are exploiting human neuroblastoma cell lines either expressing the SOD1(G93A) mutation or depleted from Fused in Sarcoma (FUS) as tools to investigate the role of miRNAs in familiar ALS. To this end we performed a genome-wide scale miRNA expression on these cells, using whole-genome small RNA deep-sequencing followed by quantitative real time validation (qPCR). This strategy allowed us to find a group of dysregulated miRNAs, which are predicted to play a role in the motorneurons physiology and pathology. We verified our data on cDNA derived from SOD1-ALS mice models at early stage of the disease and on cDNA derived from lymphocytes from a small group of ALS patients. In the future, we plan to define the mechanisms responsible for the miRNA dysregulation, by silencing or stimulating the signal transduction pathways putatively involved in miRNA expression and regulation.

„The plug and the bug“ – a case of coronary embolism in bacterial endocarditis

Systemic embolism is a classic complication of infective endocarditis. Coronary involvement and acute myocardial infarction (MI) are rare and increase mortality significantly. Recognising this unusual entity is crucial to provide adequate care. Percutaneous coronary intervention and thrombus aspiration is preferred to thrombolysis, which classically increases intracerebral hemorrhage risk. The present article describes the case of an acute inferior ST-elevated MI due to a Streptococcus salivarius endocarditis in a patient with known bicuspid aortic valve.

Systemic light-chain amyloidosis revealed by progressive nail involvement, diffuse alopecia and sicca syndrome: report of an unusual case with a review of the literature.

Immunoglobulin light-chain (AL) amyloidosis is a form of systemic amyloidosis in which the fibrils are derived from monoclonal light chains. We report a case of a 66-year-old woman presenting with nail changes, parchment-like hand changes, progressive alopecia and sicca syndrome. Histopathological studies of biopsy specimens of the scalp, the nail, minor labial salivary glands and abdominal skin revealed deposits of AL κ-type amyloid. Urine protein electrophoresis exhibited a weak band of κ-type light chains. Based on this striking case, we here review the characteristic nail and hair manifestations associated with systemic amyloidosis. Knowledge of these signs is important for an early diagnosis of systemic amyloidosis, identification of the underlying disease and patient management.

Characterization of choline uptake in Trypanosoma brucei and involvement of a mitochondrial carrier in resistance to choline analogs

Choline is an essential nutrient for eukaryotic cells, where it is used as precursor for the synthesis of choline-­containing phospholipids, such as phosphatidylcholine (PC). Our experiments showed – for the first time – that Trypanosoma brucei, the causative agent of human African sleeping sickness, is able to take up choline from the culture medium to use for PC synthesis, indicating that trypanosomes express a transporter for choline at the plasma membrane. Further characterization in procyclic and bloodstream forms revealed that choline uptake is saturable and can be inhibited by HC-3, a known inhibitor of choline uptake in mammalian cells. To obtain additional insights on choline uptake and metabolism, we investigated the effects of choline-analogs that were previously shown to be toxic for T. brucei parasites in culture. Interestingly, we found that all analogs tested effectively inhibited choline uptake into both bloodstream and procyclic form parasites. Subsequently, selected compounds were used to search for possible candidate genes encoding choline transporters in T. brucei, using an RNAi library in bloodstream forms. We identified a protein belonging to the mitochondrial carrier family, previously annotated as TbMCP14, as prime candidate. Down‐regulation of TbMCP14 by RNAi prevented drug-­induced loss of mitochondrial membrane potential and conferred 8­‐fold resistance of T. brucei bloodstream forms to choline analogs. Conversely, over‐expression of the carrier increased parasite susceptibility more than 13-­fold. However, subsequent experiments demonstrated that TbMCP14 was not involved in metabolism of choline. Instead, growth curves in glucose‐depleted medium using RNAi or knock‐out parasites suggested that TbMCP14 is involved in metabolism of amino acids for energy production. Together, our data demonstrate that the identified member of the mitochondrial carrier family is involved in drug uptake into the mitochondrion and has a vital function in energy production in T. brucei.

Extent and distribution of calcification of both the aortic annulus and the left ventricular outflow tract predict aortic regurgitation after transcatheter aortic valve replacement

Aims: We sought to analyse local distribution of aortic annulus and left ventricular outflow tract (LVOT) calcification in patients undergoing transcatheter aortic valve replacement (TAVR) and its impact on aortic regurgitation (AR) immediately after device placement. Methods and results: A group of 177 patients with severe aortic stenosis undergoing multislice computed tomography of the aortic root followed by TAVR were enrolled in this single-centre study. Annular and LVOT calcifications were assessed per cusp using a semi-quantitative grading system (0: none; 1 [mild]: small, non-protruding calcifications; 2 [moderate]: protruding [>1 mm] or extensive [>50% of cusp sector] calcifications; 3 [severe]: protruding and extensive calcifications). Any calcification of the annulus or LVOT was present in 107 (61%) and 63 (36%) patients, respectively. Prevalence of annulus/LVOT calcifications in the left coronary cusp was 42% and 25%, respectively, in the non-coronary cusp 28% and 13%, in the right coronary cusp 13% and 5%. AR grade 2 to 4 assessed by the method of Sellers immediately after TAVR device implantation was observed in 55 patients (31%). Multivariate regression analysis revealed that the overall annulus calcification (OR [95% CI] 1.48 [1.10-2.00]; p=0.0106), the overall LVOT calcification (1.93 [1.26-2.96]; p=0.0026), any moderate or severe LVOT calcification (5.37 [1.52-18.99]; p=0.0092), and asymmetric LVOT calcification were independent predictors of AR. Conclusions: Calcifications of the aortic annulus and LVOT are frequent in patients undergoing TAVR, and both the distribution and the severity of calcifications appear to be independent predictors of aortic regurgitation after device implantation. - See more at: http://www.pcronline.com/eurointervention/77th_issue/126/#sthash.Hzodgju5.dpuf