Glycine fluoromethylketones as SENP-specific activity based probes.

We report here the synthesis and biochemical properties of a new peptidyl activity-based probe 1 for SUMO proteases, SENPs. The activity-based probe has at its C terminus a glycine-derived fluoromethylketone moiety as a reactive group designed to target the active-site cysteine of SENPs. Based on a study of the interactions between SENPs and SUMOs, we introduced further design elements that allow the activity-based probe to selectively target SENPs at low micromolar to high nanomolar concentrations.

Correlations between the surface ECG and the intracavitary electrocardiogram in typical atrial flutter.

Unlabelled: Typical atrial flutter (cavo-tricuspid isthmus-dependent) has as an electrophysiological substrate a macro-reentry circuit localized in the right atrium. Depending on the right atrial depolarization sequence, the rotation of the macro-reentry circuit can be counterclockwise (with an inferior to superior activation of the right atrium free wall and superior to inferior activation of the interatrial septum), characterized by negative F waves in inferior leads (DII, DIII, aVF) and V6, and positive in V1 on the surface electrogram (ECG), or clockwise (with a superior to inferior activation of the right atrium free wall and inferior to superior activation of the interatrial septum) characterized by positive F waves in inferior leads (DII, DIII, aVF) and V6, and negative in V1. Nevertheless, it is considered that for the diagnosis of the typical or atypical nature of this arrhythmia, the surface ECG has limited value.

Catalytic activity of the caspase-8-FLIP(L) complex inhibits RIPK3-dependent necrosis.

Caspase-8 has two opposing biological functions--it promotes cell death by triggering the extrinsic pathway of apoptosis, but also has a survival activity, as it is required for embryonic development, T-lymphocyte activation, and resistance to necrosis induced by tumour necrosis factor-α (TNF-α) and related family ligands. Here we show that development of caspase-8-deficient mice is completely rescued by ablation of receptor interacting protein kinase-3 (RIPK3). Adult animals lacking both caspase-8 and RIPK3 display a progressive lymphoaccumulative disease resembling that seen with defects in CD95 or CD95-ligand (also known as FAS and FASLG, respectively), and resist the lethal effects of CD95 ligation in vivo.

Assessment of the correlation between two defining criteria for bidirectional isthmic block in the ablation of typical atrial flutter.

Background: A complete, bidirectional conduction block in the cavotricuspid isthmus (CTI) represents the end-point of the typical atrial flutter ablation. We investigated the correlation between two criteria for successful ablation, one based on the atrial bipolar electrogram morphology before and after complete CTI conduction block, compared to the standard criteria of differential pacing and reversal in the right atrial depolarization sequence during coronary sinus (CS) pacing.

Method: We conducted a retrospective study in 111 patients (81 males, average age 62±10 years) who underwent an atrial flutter ablation during September 2007 - July 2009 in the Cardiology - Rehabilitation Hospital, UMF Cluj-Napoca.

FLIP(L) induces caspase 8 activity in the absence of interdomain caspase 8 cleavage and alters substrate specificity.

Caspase 8 is an initiator caspase that is activated by death receptors to initiate the extrinsic pathway of apoptosis. Caspase 8 activation involves dimerization and subsequent interdomain autoprocessing of caspase 8 zymogens, and recently published work has established that elimination of the autoprocessing site of caspase 8 abrogates its pro-apoptotic function while leaving its proliferative function intact. The observation that the developmental abnormalities of caspase 8-deficient mice are shared by mice lacking the dimerization adapter FADD (Fas-associated death domain) or the caspase paralogue FLIP(L) [FLICE (FADD-like interleukin 1β-converting enzyme)-inhibitory protein, long form] has led to the hypothesis that FADD-dependent formation of heterodimers between caspase 8 and FLIP(L) could mediate the developmental role of caspase 8.

Activation and specificity of human caspase-10.

Two apical caspases, caspase-8 and -10, are involved in the extrinsic death receptor pathway in humans, but it is mainly caspase-8 in its apoptotic and nonapoptotic functions that has been an intense research focus. In this study we concentrate on caspase-10, its mechanism of activation, and the role of the intersubunit cleavage. Our data obtained through in vitro dimerization assays strongly suggest that caspase-10 follows the proximity-induced dimerization model for apical caspases.

Inducible dimerization and inducible cleavage reveal a requirement for both processes in caspase-8 activation.

Caspase-8 is a cysteine protease activated by membrane-bound receptors at the cytosolic face of the cell membrane, initiating the extrinsic pathway of apoptosis. Caspase-8 activation relies on recruitment of inactive monomeric zymogens to activated receptor complexes, where they produce a fully active enzyme composed of two catalytic domains. Although in vitro studies using drug-mediated affinity systems or kosmotropic salts to drive dimerization have indicated that uncleaved caspase-8 can be readily activated by dimerization alone, in vivo results using mouse models have reached the opposite conclusion.

Targeting activated integrin alphavbeta3 with patient-derived antibodies impacts late-stage multiorgan metastasis.

Advanced metastatic disease is difficult to manage and specific therapeutic targets are rare. We showed earlier that metastatic breast cancer cells use the activated conformer of adhesion receptor integrin alphavbeta3 for dissemination. We now investigated if targeting this form of the receptor can impact advanced metastatic disease, and we analyzed the mechanisms involved.

The common bile duct: size, course, relations.

The common bile duct may present a number of anatomical peculiarities regarding its size, course and relations, which should be taken into consideration by the anatomists and by the surgeons as well, during the surgery of the gallbladder, pancreas and duodenum. In the present study, we have analyzed the anatomical peculiarities of the common bile duct in 150 adult corpses of both sexes from the Anatomy Department and 22 human fetuses from the Pathology Department, University of Medicine and Pharmacy Cluj-Napoca.

The role of radiofrequency ablation as a first line therapy in the treatment of atrial flutter.

Unlabelled: Cavo-tricuspid isthmus radiofrequency (RF) ablation is an efficient option in the treatment of atrial flutter. In the case of a well-tolerated, first episode of atrial flutter, it has a class II indication, level of evidence B, the current first-line therapeutic option being electrical cardioversion, pharmacological cardioversion or atrial overdrive pacing followed by long-term antiarrhythmic therapy. The purpose of this study was to evaluate, in a prospective manner, the recurrence rate of these two different therapeutic options after the treatment of a first episode of atrial flutter.

Improved free energy parameters for RNA pseudoknotted secondary structure prediction.

Accurate prediction of RNA pseudoknotted secondary structures from the base sequence is a challenging computational problem. Since prediction algorithms rely on thermodynamic energy models to identify low-energy structures, prediction accuracy relies in large part on the quality of free energy change parameters. In this work, we use our earlier constraint generation and Boltzmann likelihood parameter estimation methods to obtain new energy parameters for two energy models for secondary structures with pseudoknots, namely, the Dirks-Pierce (DP) and the Cao-Chen (CC) models.

A constitutively active and uninhibitable caspase-3 zymogen efficiently induces apoptosis.

The caspase-3 zymogen has essentially zero activity until it is cleaved by initiator caspases during apoptosis. However, a mutation of V266E in the dimer interface activates the protease in the absence of chain cleavage. We show that low concentrations of the pseudo-activated procaspase-3 kill mammalian cells rapidly and, importantly, this protein is not cleaved nor is it inhibited efficiently by the endogenous regulator XIAP (X-linked inhibitor of apoptosis).

Structural and kinetic determinants of protease substrates.

Two fundamental questions with regard to proteolytic networks and pathways concern the structural repertoire and kinetic threshold that distinguish legitimate signaling substrates. We used N-terminal proteomics to address these issues by identifying cleavage sites within the Escherichia coli proteome that are driven by the apoptotic signaling protease caspase-3 and the bacterial protease glutamyl endopeptidase (GluC). Defying the dogma that proteases cleave primarily in natively unstructured loops, we found that both caspase-3 and GluC cleave in alpha-helices nearly as frequently as in extended loops.

Human caspases: activation, specificity, and regulation.

Caspases are intracellular proteases that propagate programmed cell death, proliferation, and inflammation. Activation of caspases occurs by a conserved mechanism subject to strict cellular regulation. Once activated by a specific stimulus, caspases execute limited proteolysis of downstream substrates to trigger a cascade of events that culminates in the desired biological response.

The Fas-FADD death domain complex structure unravels signalling by receptor clustering.

The death inducing signalling complex (DISC) formed by Fas receptor, FADD (Fas-associated death domain protein) and caspase 8 is a pivotal trigger of apoptosis. The Fas-FADD DISC represents a receptor platform, which once assembled initiates the induction of programmed cell death. A highly oligomeric network of homotypic protein interactions comprised of the death domains of Fas and FADD is at the centre of DISC formation.

Aggregation of red blood cells in suspension: study by light-scattering technique at small angles.

Red blood cells (RBCs) in the presence of plasma proteins or other macromolecules have a tendency to form aggregates. Light-scattering technique was used to investigate the RBC aggregation process. A highly diluted suspension of RBCs was illuminated with a 632.

Multicystic mesothelioma--a rare case of ascites: case report.

We present the case of a 37-year-old male, admitted to our clinic with abdominal tenderness, right supraclavicular tumour, and ascites. The presence of ascites was incidentally reported 6 years before, but no other evaluation was done at that moment or during this period. Abdominal ultrasound and CT scan revealed moderate ascites, perivascular adenopathies, and multiple abdominal cystic lesions, while thoracic CT scan revealed the same lesions in mediastinum.

The functional sphincter of Oddi disorder.

The sphincter of Oddi disorder (SOD) has been a controversial subject for many years, about which a lot has been written. However, new findings mainly using Endoscopic Retrograde Cholangiopancreatography (ERCP) and sphincter of Oddi manometry (SOM) demonstrate the fact of this diagnostic. SOD is just a part of a larger pathology, the tfunctional gastrointestinal disorders, which have been reconsidered as an important part of gastrointestinal diseases.

Caspase 3 attenuates XIAP (X-linked inhibitor of apoptosis protein)-mediated inhibition of caspase 9.

During apoptosis, the initiator caspase 9 is activated at the apoptosome after which it activates the executioner caspases 3 and 7 by proteolysis. During this process, caspase 9 is cleaved by caspase 3 at Asp(330), and it is often inferred that this proteolytic event represents a feedback amplification loop to accelerate apoptosis. However, there is substantial evidence that proteolysis per se does not activate caspase 9, so an alternative mechanism for amplification must be considered.

Role of proteolysis in caspase-8 activation and stabilization.

Caspase-8 is an apoptotic protease that is activated at the cytosolic face of the cell membrane. Activation relies on adaptor-induced dimerization of monomeric caspase-8 and is followed by specific limited autoproteolysis of the linker which separates the two subunits of the catalytic domain. However, the role of this autoproteolysis, which directly activates executioner caspases-3 and -7, is unknown for the apical caspase-8.

Role of loop bundle hydrogen bonds in the maturation and activity of (Pro)caspase-3.

During maturation, procaspase-3 is cleaved at D175, which resides in a linker that connects the large and small subunits. The intersubunit linker also connects two active site loops that rearrange following cleavage and, in part, form the so-called loop bundle. As a result of chain cleavage, new hydrogen bonds and van der Waals contacts form among three active site loops.

[Quality of life in children with bronchial asthma and allergic rhinitis].

The quality of life is a subjective parameter that evaluates the impact of asthma on daily life of the child. The authors evaluated the evolution of the quality of life score in children with persistent asthma and analyzed the impact of association of allergic rhinitis on this parameter. The evaluation of the quality of life was based on a questionnaire with 23 items (PAQLQ), which was applied on 54 children with asthma (35 of them having rhinitis allergic associated to asthma).

The apoptosome activates caspase-9 by dimerization.

The apical protease of the human intrinsic apoptotic pathway, caspase-9, is activated in a polymeric activation platform known as the apoptosome. The mechanism has been debated, and two contrasting hypotheses have been suggested. One of these postulates an allosteric activation of monomeric caspase-9; the other postulates a dimer-driven assembly at the surface of the apoptosome--the "induced proximity" model.

Influence of preoperative left ventricular contractile reserve on postoperative ejection fraction in low-gradient aortic stenosis.

Background: Dobutamine stress hemodynamics (DSH) has the potential to stratify operative risk in low-gradient aortic stenosis (AS), but little is known about the relation between left ventricle contractile reserve and postoperative left ventricular ejection fraction (LVEF). We sought to assess the value of DSH to predict postoperative improvement in LVEF.

Methods And Results: Sixty-six consecutive patients with symptomatic severe AS (aortic valve area < or =1 cm2), LVEF < or =40%, and mean pressure gradient < or =40 mm Hg prospectively enrolled in the French multicenter study on low-gradient AS and who survived to aortic valvular replacement (AVR) were included.