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A Nava

Publications and source records attributed to A Nava.

At least 19 recordsLinked to original sources
PubMed2004

A finite element model for the simulation of hydrometra.

The behaviour of the human uterus under an internal (intracavital) pressure of 150 mm Hg (20 kPa) was modelled. The application of such an intracavital or intrauterine pressure corresponds to the procedure which is performed at the beginning of hysteroscopy (hydrometra). Homogenous, isotropic material laws were implemented in a three dimensional, finite element model. The volume of the distended uterine cavity was calculated with different parameters obtained from in vivo aspiration experiments on human uteri as well as from ex vivo tensile tests on rabbit uteri for comparison purposes. The calculated results were in general agreement with in vivo measurements of hydrometra performed at the University Hospital of Zurich.

Animals↗
PubMed2001

Dispersion of ventricular depolarization-repolarization: a noninvasive marker for risk stratification in arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: We retrospectively investigated the value of clinical and ECG findings as well as QT-QRS dispersion in predicting the risk of sudden death in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). METHODS AND RESULTS: Duration and interlead variability of the QT interval and QRS complex were measured manually from standard ECGs in 20 sudden death victims with ARVC diagnosed at autopsy (group I), in 20 living ARVC patients with sustained ventricular tachycardia (group II), in 20 living ARVC patients with </=3 consecutive premature ventricular beats (group III), and in 20 control subjects (group IV). QT and QRS dispersions were greater in group I (77.5+/-10.6 ms for QT and 45.7+/-8.1 ms for QRS) compared with group II (64.5+/-13.9 ms for QT [P=0.001] and 33.5+/-8.7 ms for QRS [P=0.0004]) and in group II compared with group III (48+/-8.9 ms for QT [P<0.0001] and 28+/-5.2 ms for QRS [P<0.0001]) and group IV (33.5+/-4.8 ms for QT [P<0.0001] and 18.5+/-3.6 ms for QRS [P<0.0001]). Negative T wave beyond V(1) and syncope were statistically more frequent in group I (P=0.02 and P=0.007, respectively). On multivariate analysis, QRS dispersion remained an independent predictor of sudden death (P<0.0001), followed by syncope (P=0.09). In assessing risk of sudden death, QRS dispersion >/=40 ms had a sensitivity and specificity of 90% and 77%, respectively; QT dispersion >65 ms, 85% and 75%, respectively; negative T wave beyond V(1), 85% and 42%, respectively; and syncope, 40% and 90%, respectively. CONCLUSIONS: QRS dispersion (>/=40 ms) was the strongest independent predictor of sudden death in ARVC. Syncope, QT dispersion >65 ms, and negative T wave beyond V(1) refined arrhythmic risk stratification in these patients.

Adolescent↗
PubMed2001

Right bundle branch block, right precordial st-segment elevation, and sudden death in young people.

BACKGROUND: Patients with the ECG pattern of right bundle branch block and right precordial ST-segment elevation may experience sudden death in the setting of either arrhythmogenic right ventricular cardiomyopathy (ARVC) or a functional electrical disorder such as Brugada syndrome. METHODS AND RESULTS: Among a series of 273 young (</=35 years) victims of cardiovascular sudden death who were prospectively studied from 1979 to 1998 in the Veneto Region of Italy, 12-lead ECG was available in 96 cases. Thirteen (14%; 12 males and 1 female aged 24+/-8 years) had right precordial ST-segment elevation, either isolated (9 cases) or associated with right bundle branch block (4 cases). At autopsy, all patients had ARVC (92%) except one, who had no evidence of structural heart disease. Compared with the 19 young sudden death victims with ARVC and no ST-segment abnormalities from the same series, those with AVRC and right precordial ST-segment elevation included fewer competitive athletes (17% versus 58%; P:=0.03), more often died suddenly at rest or during sleep (83% versus 26%; P:=0.003), and showed serial ECG changes over time (83% versus 0; P:=0.015), polymorphic ventricular tachycardia (33% versus 0; P:=0.016), and predominant fatty replacement of the right ventricular anterior wall (58% versus 21%; P:=0.05), CONCLUSIONS: Right precordial ST-segment elevation was found in 14% of young sudden death victims with available ECG. It mostly reflected underlying ARVC with predominant right ventricular anterior wall involvement and characterized a subgroup of patients who share with Brugada patients the propensity to die from non-exercise-related cardiac arrest and to exhibit dynamic ECG changes and polymorphic ventricular tachycardia.

Adult↗
PubMed2001

Identification of mutations in the cardiac ryanodine receptor gene in families affected with arrhythmogenic right ventricular cardiomyopathy type 2 (ARVD2).

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.

Amino Acid Sequence↗
PubMed2001

Ways of coping and the health of relatives facing drug and alcohol problems in Mexico and England.

AIMS: To compare two contrasting socio-cultural groups in terms of parameters relating to the stress - coping - health model of alcohol, drugs and the family, and to test hypotheses derived from the model in each of the two groups separately. DESIGN: Cross-sectional, comparative and correlational, using standard questionnaire data, supplemented by qualitative interview data to illuminate the findings. PARTICIPANTS: One hundred close relatives, mainly partners or parents, from separate families in Mexico City, and 100 from South West England. Data sources. Coping Questionnaire (CQ), Family Environment Scale (FES), Symptom Rating Test (SRT), Semi-structured interview. FINDINGS: Mean symptom scores were high in both groups, and not significantly different. The hypothesis that relatives in Mexico City, a more collectivist culture, would show more tolerant - inactive coping was not supported, but there was support for the prediction that relatives in South West England would show more withdrawal coping. This result may be as much due to differences in poverty and social conditions as to differences in individualism - collectivism. As predicted by the stress - coping - health model, tolerant - inactive coping was correlated with symptoms, in both groups, after controlling for family conflict, but there was only limited support for a moderating role of coping. Wives of men with alcohol problems in Mexico City, and wives of men with other drug problems in South West England, reported particularly high levels of both engaged and tolerant - inactive coping. CONCLUSIONS: Tolerant - inactive coping may be bad for relatives' health: causality may be inferred but is not yet proved. Certain groups are more at risk of coping in this way. Qualitative data help understand the nature of tolerant - inactive coping and why it occurs despite the view of relatives themselves that it is counter-productive.

Adaptation, Psychological↗
PubMed2001

Arrhythmogenic right ventricular dysplasia: cardiomyopathy current opinions on diagnostic and therapeutic aspects.

Right Ventricular Dysplasia constitutes a genetic cardiomyopathy characterized by fibrous-adipose substitution of the right and rarely of the left ventricular myocardium. This disorder is associated with ventricular arrhythmias ranging from frequent ventricular ectopic beats, nonsustained and sustained ventricular tachycardia of left bundle branch morphology and sudden death. Therefore, the syndrome has been labelled Arrhythmogenic RVD Cardiomyopathy. Diagnostic criteria, preliminary genetic data, and clinical manifestations are summarized and critical addressed, using data from the literature and from our own experience. The most important aspects of the ECG in this syndrome are reviewed and stressed with particular attention to initial versus advanced clinical subsets. The typical anatomical abnormalities and biopsy or pathology material are presented.

Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2001

Orbital and periorbital infections.

Infections of the orbit and periorbital tissues are not uncommon. Trauma, skin infections, and sinusitis are frequently the underlying cause. Studies have shown changes in epidemiology and pathogens in the last decade. Although classical manifestations are usually present, atypical cases without specific signs and symptoms may confound the diagnosis. A high index of suspicion, aided by ultrasonography, computed tomography, and magnetic resonance imaging, is frequently required for an accurate diagnosis. Prompt diagnosis and treatment may lead to resolution of the infection, thus avoiding ocular sequelae. Orbital infections may spread into the globe, causing endophthalmitis. Some patients may even need an enucleation or evisceration. New materials and techniques may improve the final result of an anophthalmic socket.

Abscess↗
PubMed2000

Characterization of C14orf4, a novel intronless human gene containing a polyglutamine repeat, mapped to the ARVD1 critical region.

Within the ARVD1 (arrhythmogenic right ventricular dysplasia/cardiomyopathy, type 1) critical region, mapped to 14q24.3, we detected an intronless gene of 4859 bp, predominantly expressed in the heart tissue. This gene encodes a 796-amino-acid, proline-rich protein showing polyglutamine and polyalanine tracks with variable length at the N-terminus and a C3HC4 RING finger domain at the C-terminus. CREB and AP-2 binding sites are present in the promoter region. The 5' flanking region contains neither a TATA box nor a CAAT box, but it is high in GC content and includes several Sp1 binding sites. Protein similarity searches revealed a significant match between the C-terminus and a human hypothetical protein, whose gene is located on the chromosome 19 long arm. The predicted protein shows PEST sequences, suggesting its rapid degradation. The novel intronless gene, provisionally named C14orf4 and probably encoding a nuclear protein, was excluded from being the ARVD1 gene.

Amino Acid Sequence↗
PubMed2000

Absence of antiphospholipid/co-factor antibodies in Takayasu arteritis.

UNLABELLED: There are anecdotal reports and small series describing the presence of anticardiolipin antibodies in patients with Takayasu Arteritis. This communication describes a systematic study searching for non-organ specific autoantibodies which includes antinuclear antibodies, anticardiolipin and anti-beta(2) GP(1) antibodies in a cohort of 28 Mexicans with angiographic definitive diagnostic of Takayasu Arteritis. MATERIAL AND METHODS: Twenty-eight consecutive patients, who fulfilled classification and diagnostic criteria for Takayasu Arteritis and had a diagnostic panaortogram, were bled to study the presence of circulating autoantibodies in a cross-sectional design. RESULTS: There were no antinuclear antibodies, although a few sera had faint cytoplasm fluorescent deposit and reacted with cell extract. We did not recognize a distinct pattern. Also, there was no IgG nor IgM anticardiolipin antibodies nor anticofactor antibodies of clinical interest. DISCUSSION AND CONCLUSIONS: The presence of circulating non-organ specific autoantibodies is not a characteristic feature in Takayasu Arteritis when strict diagnostic criteria are applied. The occasional presence of such immune markers could be due to technical differences in sample management, less strict diagnosis or biological variability in certain cases, but has no diagnostic value.

Antibodies, Anti-Idiotypic↗
PubMed2000

Arrhythmogenic right ventricular dysplasia/cardiomyopathy: need for an international registry. Study Group on Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy of the Working Groups on Myocardial and Pericardial Disease and Arrhythmias of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the World Heart Federation.

Arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C) is a heart muscle disease characterized by peculiar RV involvement and electrical instability that precipitates ventricular arrhythmias and sudden death. The purpose of the present consensus report of the Study Group on ARVD/C of the Working Groups on Myocardial and Pericardial Disease and Arrhythmias of the European Society of Cardiology and of the Scientific Council on Cardiomyopathies of the World Heart Federation is to review the considerable progress in our understanding of the etiopathogenesis, morbid anatomy, and clinical presentation of ARVD/C since it first was described in 1977. The present article focuses on important but still unanswered issues, mostly regarding risk stratification, clinical outcome, and management of affected patients. Because ARVD/C is relatively uncommon and any one center may have experience with only a few patients, an international registry is being established to accumulate information and enhance the numbers of patients that can be analyzed and thus answer pending questions. The registry also will facilitate pathological, molecular, and genetics research on the causes and pathogenesis of the ARVD/C. Furthermore, availability of an international database will enhance awareness of this largely unrecognized condition among the medical community. Physicians are encouraged to enroll patients in the International Registry of ARVD/C.

Arrhythmogenic Right Ventricular Dysplasia↗
PubMed2000

Familial effort polymorphic ventricular arrhythmias in arrhythmogenic right ventricular cardiomyopathy map to chromosome 1q42-43.

In the present study we report on another cause of an arrhythmia associated with familial arrhythmogenic right ventricular cardiomyopathy (ARVC), which is linked to chromosome 1q42-43. Two families with 48 subjects were studied with 12-lead electrocardiography, 24-hour ambulatory electrocardiography, chest x-ray, M-mode and 2-dimensional echocardiography, signal-averaging electrocardiography, and exercise stress testing. Six subjects also underwent right and left ventricular angiography and electrophysiologic study. An endomyocardial biopsy was performed in 1 subject. The genetic study included pedigree reconstruction and linkage analysis with polymorphic DNA markers. Five young subjects died suddenly during exercise; autopsy was performed in 3 and showed segmental fibro-fatty replacement of the right ventricle, mostly at the apex. Two of them experienced syncopal attacks during effort. Sixteen living subjects, without arrhythmias at rest had polymorphic ventricular arrhythmias during effort; ARVC was diagnosed in 15, whereas 1 did not have any demonstrable cardiac abnormality. The remaining family members were healthy and did not have arrhythmias. The linkage study assigned the disease locus to chromosome 1q42-q43, in close proximity to the alpha-actinin 2 locus (maximal lod score was 5.754 at theta = 0) with a 95% penetrance. Thus, these data suggest that effort-induced polymorphic ventricular arrhythmias and juvenile sudden death can be due to adrenergic stimulation in a particular genetic group of ARVC patients. In these cases the pathology was segmental, mostly localized to the right ventricular apex. Ventricular arrhythmias that are present in these families differ from the monomorphic ones that are usually seen in patients with ARVC.

Adult↗
PubMed2000

Clinical profile and long-term follow-up of 37 families with arrhythmogenic right ventricular cardiomyopathy.

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.

Adult↗