Catecholaminergic polymorphic ventricular tachycardia is a genetic arrhythmogenic disorder characterized by stress-induced, bidirectional ventricular tachycardia that may degenerate into cardiac ...arrest and cause sudden death. The electrocardiographic pattern of this ventricular tachycardia closely resembles the arrhythmias associated with calcium overload and the delayed afterdepolarizations observed during digitalis toxicity. We speculated that a genetically determined abnormality of intracellular calcium handling might be the substrate of the disease; therefore, we considered the human cardiac ryanodine receptor gene (hRyR2) a likely candidate for this genetically transmitted arrhythmic disorder.
Twelve patients presenting with typical catecholaminergic polymorphic ventricular tachycardia in the absence of structural heart abnormalities were identified. DNA was extracted from peripheral blood lymphocytes, and single-strand conformation polymorphism analysis was performed on polymerase chain reaction-amplified exons of the hRyR2 gene. Four single nucleotide substitutions leading to missense mutations were identified in 4 probands affected by the disease. Genetic analysis of the asymptomatic parents revealed that 3 probands carried de novo mutations. In 1 case, the identical twin of the proband died suddenly after having suffered syncopal episodes. The fourth mutation was identified in the proband, in 4 clinically affected family members, and in none of 3 nonaffected family members in a kindred with 2 sudden deaths that occurred at 16 and 14 years, respectively, in the sisters of the proband.
We demonstrated that, in agreement with our hypothesis, hRyR2 is a gene responsible for catecholaminergic polymorphic ventricular tachycardia.
The main goal of this work is to evaluate some differential protein species in transgenic (T) and nontransgenic (NT) Arabidopsis thaliana plants after their cultivation in the presence or absence of ...sodium selenite. The transgenic line was obtained through insertion of CaMV 35S controlling nptII gene. Comparative proteomics through 2D‐DIGE is carried out in four different groups (NT × T; NT × Se‐NT (where Se is selenium); Se‐NT × Se‐T, and T × Se‐T). Although no differential proteins are achieved in the T × Se‐T group, for the others, 68 differential proteins (by applying a regulation factor ≥1.5) are achieved, and 27 of them accurately characterized by ESI‐MS/MS. These proteins are classified into metabolism, energy, signal transduction, disease/defense categories, and some of them are involved in the glycolysis pathway—Photosystems I and II and ROS combat. Additionally, laser ablation imaging is used for evaluating the Se and sulfur distribution in leaves of different groups, corroborating some results obtained and related to proteins involved in the glycolysis pathway. From these results, it is possible to conclude that the genetic modification also confers to the plant resistance to oxidative stress.
Gait and balance difficulties pose significant clinical challenges in Parkinson’s disease (PD). The impairment of physiological mechanisms responsible for maintaining natural orthostatism plays a ...central role in the pathophysiology of postural instability observed in PD. In addition to the well-known rigidity and abnormalities in muscles and joints, various brain regions involved in the regulation of posture, balance, and gait, such as the basal ganglia, cerebellum, and brainstem regions like the pontine peduncle nucleus, are affected in individuals with PD. The recognition of the cerebellum’s role in PD has been increasingly acknowledged. Cortical areas and their connections are associated with freezing of gait, a type of frontal lobe ataxia commonly observed in PD. Furthermore, impairments in the peripheral nervous system, including those caused by levodopatherapy, can contribute to gait impairment and imbalance in PD patients. Consequently, individuals with PD may exhibit frontal ataxia, sensory ataxia, and even cerebellar ataxia as underlying causes of gait disturbances and imbalance, starting from the early stages of the disease. The complex interplay between dysfunctional brain regions, impaired cortical connections, and peripheral nervous system abnormalities contributes to the multifaceted nature of gait and balance difficulties in PD. Understanding the intricate mechanisms is crucial for the development of effective therapeutic approaches targeting these specific deficits in PD.
Arrhythmogenic right ventricular dysplasia type 2 (ARVD2, OMIM 600996) is an autosomal dominant cardiomyopathy, characterized by partial degeneration of the myocardium of the right ventricle, ...electrical instability and sudden death. The disease locus was mapped to chromosome 1q42--q43. We report here on the physical mapping of the critical ARVD2 region, exclusion of two candidate genes (actinin 2 and nidogen), elucidation of the genomic structure of the cardiac ryanodine receptor gene (RYR2) and identification of RYR2 mutations in four independent families. In myocardial cells, the RyR2 protein, activated by Ca(2+), induces the release of calcium from the sarcoplasmic reticulum into the cytosol. RyR2 is the cardiac counterpart of RyR1, the skeletal muscle ryanodine receptor, involved in malignant hyperthermia (MH) susceptibility and in central core disease (CCD). The RyR2 mutations detected in the present study occurred in two highly conserved regions, strictly corresponding to those where mutations causing MH or CCD are clustered in the RYR1 gene. The detection of RyR2 mutations causing ARVD2, reported in this paper, opens the way to pre-symptomatic detection of carriers of the disease in childhood, thus enabling early monitoring and treatment.
OBJECTIVES
We sought to define the clinical picture and natural history of familial arrhythmogenic right ventricular cardiomyopathy (ARVC).
BACKGROUND
Arrhythmogenic right ventricular cardiomyopathy ...is a myocardial disease, often familial, clinically characterized by the impending risk of ventricular arrhythmias and sudden death.
METHODS
Thirty-seven ARVC families of northeast Italy were studied. Probands had a histologic diagnosis of ARVC, either at autopsy (19 families) or endomyocardial biopsy (18 families). Protocol of the investigation included basal electrocardiogram (ECG), 24-hour ECG, signal-averaged ECG, stress test and two-dimensional Doppler echocardiography. Invasive evaluation was performed when deemed necessary.
RESULTS
Of the 365 subjects, 151 (41%) were affected, 157 (43%) were unaffected, 17 (5%) were healthy carriers, and 40 (11%) were uncertain. Mean age at diagnosis was 31 ± 13 years. By echocardiography, 64% had mild, 30% had moderate, and 6% had severe form. Forty percent had ventricular arrhythmias, 49 were treated with antiarrhythmic drugs, and two were treated with implantable cardioverter defibrillators. Sport activity was restricted in all. Of the 28 families who underwent linkage analysis, 6 mapped to chromosome 14q23-q24, 4 to 1q42-q43, and 4 to 2q32.1-q32.3. No linkage with known loci was found in four families and 10 had uninformative results. During a follow-up of 8.5 ± 4.6 years, one patient died (0.08 patient/year mortality), and 15 developed an overt form of ARVC.
CONCLUSIONS
Arrhythmogenic right ventricular cardiomyopathy is a progressive disease appearing during adolescence and early adulthood. Systematic evaluation of family members leads to early identification of ARVC, characterized by a broad clinical spectrum with a favorable outcome. In the setting of positive family history, even minor ECG and echocardiographic abnormalities are diagnostic.
Motivation: To perform a computational and statistical study on a large set of gene expression data pertaining six adult human tissues (brain, liver, skeletal muscle, ovary, retina and uterus) for ...analyzing the expression of ribosomal protein genes. Results: Unexpectedly, in each of the considered tissues large variations in the expression of ribosomal protein genes were observed. Moreover, when comparing the expression levels of 89 ribosomal protein genes in six different tissues, 13 genes appeared differentially expressed among tissues. Avalilability: The expression data of the ribosomal protein genes together with supplementary material (complete transcriptional profiles of the considered human tissues) are freely available at the site GETProfiles (http://telethon.bio.unipd.it/GETProfiles/). Contact: danieli@bio.unipd.it * To whom all correspondence should be addressed.
Autosomal dominant arrhythmogenic right ventricular cardiomyopathy (ARVD, MIM 107970) is one of the major causes of juvenile sudden death. We have previously assigned the disease locus to chromosome ...14q23-q24. Here we report on a novel variant of ARVD, which is transmitted associated to 1q42-q43 and is characterized by a concealed form, showing effort-induced polymorphic tachycardias. Since both loci ARVD1 and ARVD2 map in proximity of alpha-actinin genes, the possible implication of these myofibrillar proteins in the pathogenesis of ARVD is discussed. Two additional ARVD families, tested with markers of chromosomes 1q42-q43 and 14q23-q24, failed to show linkage, providing evidence of further genetic heterogeneity.
Arrhythmogenic right ventricular cardiomyopathy (ARVD/C) is a genetically heterogeneous disease characterized by progressive degeneration of the right ventricular myocardium and increased risk of ...sudden death. Here, we report on a genome scan in one Italian family in which the disease appeared unlinked to any of the six different ARVD loci reported so far; we identify a mutation (S299R) in exon 7 of desmoplakin (DSP), which modifies a putative phosphorylation site in the N-terminal domain binding plakoglobin. It is interesting that a nonsense DSP mutation was reported elsewhere in the literature, inherited as a recessive trait and causing a biventricular dilative cardiomyopathy associated with palmoplantar keratoderma and woolly hairs. Therefore, different DSP mutations might produce different clinical phenotypes, with different modes of inheritance.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by progressive myocardial atrophy with fibrofatty replacement. The recent identification of ...causative mutations in plakoglobin, desmoplakin (DSP), and plakophilin-2 (PKP2) genes led to the hypothesis that ARVC is due to desmosomal defects. Therefore, desmoglein-2 (DSG2), the only desmoglein isoform expressed in cardiac myocytes, was screened in subjects with ARVC.
In a series of 80 unrelated ARVC probands, 26 carried a mutation in DSP (16%), PKP2 (14%), and transforming growth factor-beta3 (2.5%) genes; the remaining 54 were screened for DSG2 mutations by denaturing high-performance liquid chromatography and direct sequencing. Nine heterozygous DSG2 mutations (5 missense, 2 insertion-deletions, 1 nonsense, and 1 splice site mutation) were detected in 8 probands (10%). All probands fulfilled task force criteria for ARVC. An endomyocardial biopsy was obtained in 5, showing extensive loss of myocytes with fibrofatty tissue replacement. In 3 patients, electron microscopy investigation was performed, showing intercalated disc paleness, decreased desmosome number, and intercellular gap widening.
This is the first investigation demonstrating DSG2 gene mutations in a significant number of ARVC-unrelated probands. Cardiac phenotype is characterized clinically by typical ARVC features with frequent left ventricular involvement and morphologically by fibrofatty myocardial replacement and desmosomal remodeling. The presence of mutations in desmosomal encoding genes in 40% of cases confirms that many forms of ARVC are due to alterations in the desmosome complex.
In a randomized trial, patients with cardiovascular risk factors but no history of myocardial infarction were assigned to receive n−3 fatty acids or placebo. At 5 years, there was no difference in ...the rate of death from cardiovascular causes or hospitalization for cardiovascular causes.
It has been suggested that the use of n−3 polyunsaturated fatty acids derived from fish may reduce the risk of cardiovascular disease by means of beneficial effects on arrhythmic, atherosclerotic, inflammatory, and thrombotic processes.
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A benefit of n−3 fatty acids in reducing cardiovascular mortality and morbidity has been documented in patients surviving a myocardial infarction
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and in patients with heart failure.
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The Risk and Prevention Study, conceived after completion of the Primary Prevention Project
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and a pilot study,
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–
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was a double-blind, placebo-controlled trial assessing the efficacy of n−3 fatty acids in patients at high cardiovascular risk, as judged by . . .
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