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Biomedical subjects

R Pesce

Publications and source records attributed to R Pesce.

At least 19 recordsLinked to original sources
PubMed1999

Genomic organization of the KCNQ1 K+ channel gene and identification of C-terminal mutations in the long-QT syndrome.

The voltage-gated K+ channel KVLQT1 is essential for the repolarization phase of the cardiac action potential and for K+ homeostasis in the inner ear. Mutations in the human KCNQ1 gene encoding the alpha subunit of the KVLQT1 channel cause the long-QT syndrome (LQTS). The autosomal dominant form of this cardiac disease, the Romano-Ward syndrome, is characterized by a prolongation of the QT interval, ventricular arrhythmias, and sudden death. The autosomal recessive form, the Jervell and Lange-Nielsen syndrome, also includes bilateral deafness. In the present study, we report the entire genomic structure of KCNQ1, which consists of 19 exons spanning 400 kb on chromosome 11p15.5. We describe the sequences of exon-intron boundaries and oligonucleotide primers that allow polymerase chain reaction (PCR) amplification of exons from genomic DNA. Two new (CA)n repeat microsatellites were found in introns 10 and 14. The present study provides helpful tools for the linkage analysis and mutation screening of the complete KCNQ1 gene. By use of these tools, five novel mutations were identified in LQTS patients by PCR-single-strand conformational polymorphism (SSCP) analysis in the C-terminal part of KCNQ1: two missense mutations, a 20-bp and 1-bp deletions, and a 1-bp insertion. Such mutations in the C-terminal domain of the gene may be more frequent than previously expected, because this region has not been analyzed so far. This could explain the low percentage of mutations found in large LQTS cohorts.

Base Sequence↗
PubMed1999

[Atrioventricular node catheter ablation with condenser discharge and radiofrequency].

The AV junction ablation was useful to treat patients with drug-refractory supraventricular arrhythmias. The purpose of this study was to determine short and long-term success and complications of the atrioventricular nodal catheter ablation and to compare direct current and radiofrequency energy. Forty patients underwent AV nodal ablation with direct current energy (Group I) and forty patients with radiofrequency (Group II). They were followed up for a mean of 76 +/- 49 and 28 +/- 20 months, respectively. Persistent complete AV block was successfully induced during the first ablation session in 45% of 40 patients who underwent DC energy, while in 50% it was modulated. All patients in the radiofrequency group had complete AV block. The rate of recurrence of AV conduction was 7.5% and 2.5% respectively. Immediate complications did not occur after either procedure. One patient died suddenly in each group during follow-up. AV nodal ablation with radiofrequency energy appears to be as efficacious and safe as direct current energy.

Adult↗
PubMed1991

Electrophysiologic-structural correlations in chagasic aneurysms causing malignant arrhythmias.

We studied the structure and ultrastructure of three chagasic aneurysms, the excision of which abolished malignant arrhythmias. Chronic recurrent ventricular tachycardia often occurs in patients with chagasic aneurysms, and ventricular mapping indicates that these arrhythmias originate in regions adjacent to those aneurysms. In our patients, ventricular tachycardia had been refractory to medical treatment. During surgery, epicardial and endocardial mapping showed abnormal potentials. Sutures were placed in the areas of resection, their sizes approximating those of earliest activation so that these sites could be identified. The myocardium showed chronic inflammatory reaction, myocytolysis and fibrosis. The presence of "islets" was common (normal, "early" damaged or "established" necrotic myocytes surrounded by fibrous tissue). The "early" lesions were predominant at the previously identified areas of arrhythmogenic activity. The ultrastructural studies showed hypertrophy of myocytes and partial or complete loss of myofibrils, swelling of mitochondria and disruption of mitochondrial cristae, accumulation of lipofuscin granules, and intracellular oedema. A most striking alteration was the thickening of the basement membranes of myocytes and vascular endothelial and smooth muscle cells. The interlaced fronts of respectively healthy (fast conducting) and "early" damaged (slow conducting) myocytes seen in serial sectioning produced an ideal configuration for reentry circuits. The final proof that the arrhythmias originated in these endocardial regions was their abolition by resection of the aneurysm.

Adult↗
PubMed1975

[Double clone in cells of pleural effusion caused by metastasis of oat cell carcinoma of the lung].

The Authors report a chromosome study carried out on pleural effusion cells from metastases of oat cell carcinoma. They observed a double cell clone: the former, with 44 chromosomes, with various alterations of the karyotype and a big acrocentric "marker", the latter, with 45 chromosomes with various alterations of the karyotype and a big submetacentric "marker". From these observations the Authors draw some interpretative considerations.

Antibody Formation↗