ETHANOL DECREASES BASAL CYTOSOLIC-FREE CALCIUM CONCENTRATION IN CULTURED SKELETAL MUSCLE CELLS

We analysed the effect of ethanol on basal cytosolic-free calciumconcentration ([Ca²⁺]₁) in cultured rat myocytes. Ethanol causeda dose-dependent decrease of the resting [Ca²⁺]₁). Removal ofethanol was followed by a transitory increase of [Ca²⁺]₁ abovethe basal level. In cells chronically exposed to ethanol, [Ca²⁺]₁normalized to the previous level.     

Radiofrequency Ablation of Concealed Left Free-Wall Accessory Pathways Without Coronary Sinus Catheterization:

Ablation of Concealed Accessory Pathways. Introduction: Feasibility of radiofrequency (RF) ablation using a two-catheter technique without coronary sinus catheterization was studied in 100 consecutive patients with a single concealed left free-wall accessory path-way.
Methods and Results: Tachycardia was induced by electrical stimulation in the right atrium/right ventricle, and the presence of a concealed left free-wall accessory pathway was suggested electrocardiographically (negative P wave in leads I and/or a VL during orthodromic tachycardia) or by earlier atrial activation in the pulmonary artery compared to the high right atrium. Mapping of the mitral annulus was performed during right ventricular pacing or orthodromic tachycardia, and RF energy was applied at the site with the earliest retrograde atrial activation. Ablation was considered effective if tachycardia could not be induced, and if VA dissociation or exclusive retrograde nodal conduction was observed. Ablation was initially successful in 98 of 100 patients. Mean number of radiofrequency pulses were 3.2 ± 2. Mean fluoroscopy time and total procedure time was 14 ± 9 and 107 ± 32 minutes, respectively. There were no complications related to the procedure. At a mean follow-up of 22 ± 13 months, two patients experienced tachycardia recurrence and required a second procedure, which was successful.
Conclusions: Our results suggest that RF catheter ablation of concealed left free-wall accessory pathways can be safely, effectively, and rapidly performed using a simplified two-catheter technique with no need for coronary sinus catheterization.     

Opiate and cocaine consumers attending Barcelona emergency rooms: a one year survey (1989)

Due la the limitations of standard epidemiological methods, indirect indicators have often been used to describe the characteristics of drug abusing populations and to assess prevalence trends in illegal drug use. In Barcelona (Spain), a study of emergency room (ER) attendance was carried out to describe the population of opiate/cocaine consumers across the whole city who use this service. Three thousand four hundred and five consumers of opiates and/or cocaine, aged 15-44 years, who attended ERs during 1989, were identified. They accounted for 6807 episodes in the hospitals surveyed. Their mean age was 26 years, men (73%) being 1 year older than women (25.2 years). The drug of abuse was specified in the clinical records of 60% of individuals, heroin being the most frequently specified (56%). The main reason for attendance was 'other medical condition'(OMC) (55% of episodes), followed by withdrawal (34%) and overdoses (6%). Seventy-one percent of individuals were residents of Barcelona city, yielding a rate of 3.2 opiate/cocaine consumers attending ERs per thousand Barcelona residents aged 15-44. The geographical distribution of the rates in the city showed a very large difference between districts, the most deprived ones having a higher rate of consumers attending ERs. ER data can provide valuable insights into the nature and dimensions of drug abuse problems.     

Radiofrequency Ablation of Symptomatic but Benign Ventricular Arrhythmias

Two cases are presented where ablation of severely symptomatic ventricular arrhythmias not responding to medical therapy was accomplished with radiofrequency current application. After a routine programmed stimulation protocol, a quadripolar ablation catheter with a 4-mm tip was advanced percutaneously into the left ventricle in one case and into the right ventricle in the second case; and after precise pace mapping, the arrhythmogenic focus was successfully ablated using radiofrequency current. The postablation ambulatory recording revealed virtual eradication of ventricular ectopy in both cases. In conclusion, in severely symptomatic cases of "benign" ventricular arrhythmias, radiofrequency ablation offers an effective therapeutic alternative.     

GENETIC POLYMORPHISM OF LIVER ALCOHOL DEHYDROGENASE IN SPANTSH SUBJECTS: SIGNIFICANCE OF ALCOHOL CONSUMPTION AND LIVER DISEASE

Class I alcohol dehydrogenase (ADH) phenotypes have been studiedby starch gel electrophoresis and activity analysis in livertissue obtained at necropsy from 61 non-alcoholic subjects withnormal liver (controls), and in biopsies from 60 chronic alcoholicswith liver disease and from 24 subjects with non-alcoholic liverdisease. Twenty-three per cent of controls exhibited the ADH₂^2–1phenotype, which represents the highest frequency for atypicalADH found in a Caucasian population. Both alcoholic and non-alcoholicpatients with liver disease showed a lower frequency of theatypical phenotype (6.6% and 8.8%, respectively). No differencesin the ADH₂ locus were detected among groups of patients withdifferent severity of alcoholic and non-alcoholic liver disease.Theallele frequencies of the ADH₃ locus for the controls (ADH₃¹= 0.63, ADH₃² = 0.37) are common to those of other Caucasianpopulations. Similar ADH₃ allele frequencies were observed inpatients with alcoholic and non-alcoholic liver disease. Discrepanciesbetween the various phenotyping and genotyping studies now knownfor several populations suggest that local differences may existin the distribution of the ADH polymorphism in even geographicallyclose regions, and that the effect of ADH polymorphism on vulnerabilitytowards alcohol may not be identical in different populations.     

Relevance of Atrial Fibrillation Classification in Clinical Practice

Atrial Fibrillation Classification. Use of different classifications for atrial fibrillation reflects the complexity of the arrhythmia and the difficulty in grouping its different aspects. Current classifications are based on clinical presentation, etiology, substrates, mechanisms, etc. From the clinical point of view, the most relevant probably should be one directed at classifying patients in terms of therapeutic options. In this article, a review of known classifications is given, together with an attempt at a new classification based on the possibility of offering a nonpharmacologic treatment to patients.     

[d-Met2, Pro5] enkephalin [N1.5-β-d-glucopyranosyl] amide: a glycosylpeptide with high antinociceptive activity

Different synthetic strategies have been attempted for the synthesis of a glycosylpeptide resulting from the covalent bonding of a sugar residue to the C-terminal carboxyl group of an enkephalin related pentapeptide. The final structure is: Tyr-d -Met-Gly-Phe-Pro [N¹⁵-β-d -glucopyranosyl] amide. The in vitro potency on the GPI test of this analogue was IC₅₀= 64.0 nm . However, its antinociceptive activity by tail immersion tests, after intraperitoneal administration, was 2000 and 200 times higher than morphine in rats and mice, respectively.     

Effects of quinidine on ventricular repolarization

The possibility that an asynchronous increase in the ventricularmonophasic action potential duration is the basis of the quinidine-inducedtorsade de pointes, has led us to study the electrophysiologicaleffects of increasing doses of intravenous quinidine. We measuredthe monophasic action potential duration and the ventriculareffective refractory period at several right ventricular myocardialsites in the anaesthetized dog.Our results showed that quinidineinduces a dose-dependent prolongation in ventricular effectiverefractory period and in ventricular monophasic action potentialduration. These increases were uniform throughout the rightventricle. No variations in repolarization or in refractorinesswere observed between the four ventricular sites studied.Theresults suggest that quinidine does not have a direct effecton dispersion of repolarization, and that mechanisms other thanits direct electrophysiological action are involved in the developmentof torsade de pointes.