Sudden death after valve-in-valve procedure due to delayed coronary obstruction. A case report

Background: Valve-in-valve transcatheter aortic valve implantation for degenerated aortic bioprostheses is an effective option for patients at high risk for redo surgery, even if it may be burdened by complications more common in specific settings, such as, coronary artery obstruction. Case presentation: We present the case of a Caucasic 84-year-old woman with degeneration of a previously implanted aortic Mitroflow bioprosthesis. She underwent a valve-in-valve transcatheter aortic valve implantation with a CoreValve® bioprosthesis. End-procedure coronary angiography demonstrated maintained perfusion of both coronary arteries. However, few hours later, she experienced sudden cardiac death. An autopsy showed that Mitroflow prosthesis leaflets were higher than the left main coronary ostium, and no other possible cause for the sudden death. Fatality was thus ascribed to left main coronary ostium obstruction due to apposition of the Mitroflow leaflet pushed upward by the late expansion of CoreValve®. Conclusions: Coronary artery obstruction is a frequently fatal complication which usually presents just after valve implantation, but, as reported in our case, it may also have a delayed presentation. Accurate patient's selection and intraoperative preventive measures can reduce this eventuality

Urgent cesarean delivery following a spontaneous coronary artery dissection

Objective: Rare disease Background: Spontaneous coronary artery dissection is the most common etiology of pregnancy-associated myocardial infarction. It is characterized by high rates of maternal morbidity and mortality and may cause fetal complications and death as well. Case Report: A 44-year-old female (G2P1) suffered from pregnancy-related spontaneous coronary artery dissection with dissection of distal left anterior descending coronary artery. The patient was hemodynamically stable and did not required revascularization, but signs of fetal distress were detected and thus an urgent cesarean delivery was performed. This emergency procedure was undertaken in the catheterization laboratory (Cath-Lab) right after coronary angiography, thanks to a multidisciplinary team. Health conditions of the newborn were good. The patient instead suffered from a recurrence of spontaneous coronary artery dissection 6 days later, complicated by left ventricular apical thrombus and epistenocardial pericarditis. The dissection self-healed in 1 month. Conclusions: Careful evaluation of pregnancy-related spontaneous coronary artery dissection is needed to assess and manage both maternal and fetal complications. Under specific circumstances, a cesarean delivery may be required and be even performed in the Cath-Lab after coronary catheterization

Anterior mitral valve aneurysm is an uncommon complication of aortic valve infective endocarditis. A case report

Objective: Rare disease Background: Mitral valve aneurysms (MVAs) are uncommon conditions frequently associated with aortic valve endocarditis. They may be complicated by perforation and severe mitral regurgitation (MR). Optimal treatment of MVA, and in particular the best timing for surgery, are uncertain. Case Report: A 62-year-old man with a recent history of dental surgery presented to the Emergency Department complaining relapsing fever. A first echocardiogram demonstrated infective endocarditis of the aortic valve. The patient was primarily managed with specific antibiotic therapy. Despite this, a few days later he suffered from splen-ic embolization and an MVA with MR was detected. Surgical replacement of the mitral and aortic valves was therefore performed. Conclusions: MVAs are infrequent but potentially severe complications of AV endocarditis. In the absence of definite treatment indication, the correct time for surgery should depend on concomitant clinical and infective features

New "clickable" polymeric coating for glycan microarrays

The interaction of carbohydrates with a variety of biological targets, including antibodies, proteins, viruses and cells are of utmost importance in many aspects of biology. Glycan microarrays are increasingly used to determine the binding specificity of glycan-binding proteins. In this study, a novel slide is reported for the fabrication of glycan arrays that combines the higher sensitivity of a layered Si-SiO2 with a novel approach to form a polymeric coating easily modifiable by subsequent click reaction. The alkyne-containing copolymer, adsorbed from an aqueous solution, produces a coating by a single step procedure and serves as a soft, tridimensional support for the oriented immobilization of carbohydrates via azide/alkyne Cu(I) catalyzed "click" reaction. The equilibrium and kinetics parameters of the interaction of Concanavalin A with eight synthetic glycans were determined using fluorescence microarray and Reflective Phantom Interface (RPI), a recently proposed optical label-free detection approach. The enhancement of fluorescence provided by the Si-SiO2 slides enabled to extend the limit of detection at lower surface densities of lectins, in turn enabling the study of the interaction for a wide range of glycans surface density. Equilibrium dissociation constants of a few nM were extracted for multivalent glycan-lectin binding, mimicking the conditions of biological membranes, whereas hundreds of nM were observed at the lower glycan surface densities

Hysteresis and tunability characteristics of Ba(Zr,Ti)O(3) ceramics described by first order reversal curves diagrams

The First Order Reversal Curves (FORC) diagrams are proposed for the characterization of the switching process and the tunability in Ba(ZrxTi1-x)O(3) ceramics with various compositions x in the range (0, 0.5), prepared via solid state reaction. The changes induced by the compositional-induced crossover ferroelectric-to-relaxor state are investigated by monitoring the changes of the FORC diagrams (the coercive and bias fields corresponding to the maximum, ratio of the reversible/irreversible contribution to the polarization, the diffuse character of the FORC distribution). The first derivative of the FORCs related to the tunability is a function of both the applied and reversal fields. The critical fields for the highest tunability were found to be composition-dependent

A Trypanosoma cruzi Small Surface Molecule Provides the First Immunological Evidence that Chagas' Disease Is Due to a Single Parasite Lineage

Chagas' disease is a major health and economic problem caused by the protozoan Trypanosoma cruzi. Multiple independently evolving clones define a complex parasite population that can be arranged into two broad genetic lineages termed T. cruzi I and II. These lineages have different evolutionary origin and display distinct ecological and biological traits. Here we describe a novel molecule termed TSSA for trypomastigote small surface antigen that provides the first immunological marker allowing discrimination between lineages. TSSA is a surface, glycosylphosphatidyl inositol (GPI)-anchored mucin-like protein, highly antigenic during the infection. TSSA sequences from different parasite isolates reveal a population dimorphism that perfectly matches with the two T. cruzi lineages. Interestingly, this dimorphism is restricted to the central region of the molecule, which comprises the immunodominant B cell epitopes. This sequence variability has a major impact on TSSA antigenicity, leading to no immunological cross-reactivity between both isoforms for antibodies present either in immunization or infection sera. Furthermore, the absolute seroprevalence for TSSA in confirmed Chagasic patients is restricted to T. cruzi II isoform, strongly suggesting that human infections are due to this particular subgroup. Even though association of T. cruzi II with Chagas' disease has been proposed based on molecular markers, this is the first immunological evidence supporting this hypothesis. The implications of these results for the future research on Chagas' disease could be envisaged

Gastrointestinal endoscopy during the coronavirus pandemic in the New York area: results from a multi-institutional survey.

Background and study aims  The coronavirus disease 2019 (COVID-19), and measures taken to mitigate its impact, have profoundly affected the clinical care of gastroenterology patients and the work of endoscopy units. We aimed to describe the clinical care delivered by gastroenterologists and the type of procedures performed during the early to peak period of the pandemic. Methods  Endoscopy leaders in the New York region were invited to participate in an electronic survey describing operations and clinical service. Surveys were distributed on April 7, 2020 and responses were collected over the following week. A follow-up survey was distributed on April 20, 2020. Participants were asked to report procedure volumes and patient characteristics, as well protocols for staffing and testing for COVID-19. Results  Eleven large academic endoscopy units in the New York City region responded to the survey, representing every major hospital system. COVID patients occupied an average of 54.5 % (18 - 84 %) of hospital beds at the time of survey completion, with 14.5 % (2 %-23 %) of COVID patients requiring intensive care. Endoscopy procedure volume and the number of physicians performing procedures declined by 90 % (66 %-98 %) and 84.5 % (50 %-97 %) respectively following introduction of restricted practice. During this period the most common procedures were EGDs (7.9/unit/week; 88 % for bleeding; the remainder for foreign body and feeding tube placement); ERCPs (5/unit/week; for cholangitis in 67 % and obstructive jaundice in 20 %); Colonoscopies (4/unit/week for bleeding in 77 % or colitis in 23 %) and least common were EUS (3/unit/week for tumor biopsies). Of the sites, 44 % performed pre-procedure COVID testing and the proportion of COVID-positive patients undergoing procedures was 4.6 % in the first 2 weeks and up to 19.6 % in the subsequent 2 weeks. The majority of COVID-positive patients undergoing procedures underwent EGD (30.6 % COVID +) and ERCP (10.2 % COVID +). Conclusions  COVID-19 has profoundly impacted the operation of endoscopy units in the New York region. Our data show the impact of a restricted emergency practice on endoscopy volumes and the proportion of expected COVID positive cases during the peak time of the pandemic

Spontaneous superconducting islands and Hall voltage in clean superconductors

We study a clean superconductor in the Hall configuration, in the framework of a purely dissipative time-dependent Ginzburg--Landau theory. We find situations in which the order parameter differs significantly from zero in a set of islands that appear to form a periodic structure. When the pattern of islands becomes irregular, it moves in or against the direction of the current and a Hall voltage is found. Tiny differences in the initial state may reverse the sign of the Hall voltage. When the average Hall voltage vanishes, the local Hall voltage does not necessarily vanish. We examine the influence that several boundary conditions at the electrodes have on these effects.Comment: 6 pages, Includes additional cases and more detailed result