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Biomedical subjects

L Guarino

Publications and source records attributed to L Guarino.

33 records · Page 2Linked to original sources
PubMed1980

Effects of an interpolated premature ventricular contraction on the AV conduction of the subsequent premature atrial depolarization. An apparent facilitation.

Nodal conduction is usually studied by tracing the H1 H2 on function of A1 A2 curves. If one interpolates a PVC before A1, there is a decrease in H1 H2. This might be explained by an A1 H1 interval lengthening (delta A1 H1). This study was done on 14 consecutive patients in whom a PVC can be interpolated (blocked at the A-V junction). In the majority of these patients, there is a downward and a right hand shift in the curve after an interpolated PVC. On other hand, the curves representing the sum H1 H2 + delta A1 H1 on function of A1 A2 were shifted upward and to the right in 12 of the 14 patients. This indicates inhibition which manifests itself not only by an ERP increase but also by an A2 H2 increase.

Arrhythmias, Cardiac↗
PubMed1979

[Aneurysm of the interauricular septum by hernia of Vieussens' valve, and suspected coronary embolism].

During the hemodynamic evaluation of a young patient with heart failure whose electrocardiogram showed sequels of anterior necrosis, an aneurysm of the fossa ovalis was seen at cineangiography. Selective coronary angiography showed an interruption of filling of the anterior interventricular artery just distal to the branching of the first septal artery: it raised therefore the possibility of the embolic origin of that myocardial infarction. In connection with this case study, angiographic aspect, pathogenesis and the embolic role of the aneurysm of the fossa ovalis were discussed.

Adult↗
PubMed1978

Polyamines of Anacystis nidulans and metabolism of exogenous spermidine and spermine.

Several biochemical parameters, including that of polyamine content, accompanying the growth of the cyanobacterium Anacystis nidulans were studied. At all stages of growth under autotrophic conditions, the organisms were found to be rich in spermidine and lacking in spermine, as is typical of procaryotic organisms. The cells were quite low in putrescine, and no unusual polyamine was observed to be present as a major component. Conjugated polyamines were not detected in the cultures. At maximal culture density, the levels of spermidine, DNA, RNA, protein, and chlorophyll were also maximal. Shortly after the inception of the stationary phase, the spermidine content of the cells was the first parameter observed to decrease in cultures which were shortly to become yellow. Spermidine lost from the cells was not recovered in the medium in a free or conjugated form. This indication of degradation of spermidine was studied by the addition of polyamines to growing cultures. Exogenous spermidine and spermine were found to be metabolized rapidly by the organisms, of which diaminopropane was one product. Putrescine was found to be markedly toxic, whereas spermidine, some other triamines, and spermine were much less toxic.

Chlorophyll↗
PubMed1977

[Paradoxical atrioventricular block within the bundle of His].

We have been able to record an atrio-ventricular block dependent upon bradycardia, but also no tachycardia, in a patient of 76 who presented with syncopal attacks. The basal electrocardiogram showed no significant delay in atrio-ventricular or intraventricular conduction. Intracavitary electrophysiological investigation allowed us to localise the site of this block in the main trunk of the bundle of His; we also established, under basal conduction conditions, a first degree block with an exactly similar relationship to the duration of the preceding diastole.

Aged↗
PubMedDate not supplied

[Comparative study of endocavitary recording and the 24-hour electrocardiogram in the study of sinus function. Apropos of 174 cases].

We compared the results of electrophysiological investigations of sino-atrial node function in a series of 174 patients (including the sino-atrial conduction time (SACT) according to the method of Narula and Strauss, the corrected sino-atrial recovery time (CSART) and, in, 22 patients, the atropine test) with the results of 24 hour Holter monitoring. 73 patients presented a pathological Strauss curve, 47 had a prolonged SACT (Strauss' method) and 19 had a pathological CSART. Of the 22 bradycardic patients, the injection of atropine relieved the bradycardia in 45.5 per cent of cases. 19 patients showed signs of sino-atrial node dysfunction on the 24 hour Holter recording. Of the 35 patients with a surface electrocardiogram (ECG) suspicious of sino-atrial node dysfunction, 21 (60%) had a prolonged SACT and 13 (37.1%) had a pathological CSART: 15 of them (42.8%) showed major electrophysiological abnormalities and 19 (54.3%) had a positive Holter. In two-thirds of the cases of pure sino-atrial bradycardia, the results of electrophysiological and Holter investigations were normal; in 50 per cent of cases of sino-atrial block and/or pause on the surface ECG, major abnormalities were found on both electrophysiology and the Holter monitor. The SACT, estimated according to the method of Strauss, is discorsdant with the SACT estimated according to Narula's method in 46 p. cent of cases. It seems that Strauss' SACT was more sensitive in our study. In 102 cases (59.3%), the SACT and the CSART were concordant. In 10 cases, the SACT was normal while the CSART was pathological and in 42 cases, the SACT was pathological while the CSART was normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗