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S Balint

Publications and source records attributed to S Balint.

5 recordsLinked to original sources
PubMed2006

Multiple origins of cultivated grapevine (Vitis vinifera L. ssp. sativa) based on chloroplast DNA polymorphisms.

The domestication of the Eurasian grape (Vitis vinifera ssp. sativa) from its wild ancestor (Vitis vinifera ssp. sylvestris) has long been claimed to have occurred in Transcaucasia where its greatest genetic diversity is found and where very early archaeological evidence, including grape pips and artefacts of a 'wine culture', have been excavated. Whether from Transcaucasia or the nearby Taurus or Zagros Mountains, it is hypothesized that this wine culture spread southwards and eventually westwards around the Mediterranean basin, together with the transplantation of cultivated grape cuttings. However, the existence of morphological differentiation between cultivars from eastern and western ends of the modern distribution of the Eurasian grape suggests the existence of different genetic contribution from local sylvestris populations or multilocal selection and domestication of sylvestris genotypes. To tackle this issue, we analysed chlorotype variation and distribution in 1201 samples of sylvestris and sativa genotypes from the whole area of the species' distribution and studied their genetic relationships. The results suggest the existence of at least two important origins for the cultivated germplasm, one in the Near East and another in the western Mediterranean region, the latter of which gave rise to many of the current Western European cultivars. Indeed, over 70% of the Iberian Peninsula cultivars display chlorotypes that are only compatible with their having derived from western sylvestris populations.

DNA, Chloroplast↗
PubMed1992

[Multiple sclerosis in northwestern Switzerland].

From 1980 to 1987 an epidemiologic survey was conducted in northwestern Switzerland (population 523,000) with the aim of registering as many MS cases as possible. The prevalence for the entire region was 142 per 100,000, with a maximum of 164/100,000 in the city of Basle. Extrapolation suggests there are more than 8000 MS patients living in Switzerland. Other interesting results were: a sex-ratio of 2.2 females:1 male. The mean age at clinical onset was 31.6 years. The mean survival was 30.6 years. Prevalence has grown in recent decades, mainly due to longer survival and to changes in age structure. The incidence presumably remained unchanged.

Adult↗
PubMed1988

Pacing and reperfusion induced arrhythmias: protection by slow heart rate in the rat heart.

Using the isolated perfused rat heart with transient (10 min) regional ischaemia induced by coronary artery ligation, we have shown that slow heart rate can dramatically reduce the vulnerability of the myocardium to reperfusion induced ventricular fibrillation and ventricular tachycardia. In the heart rate range of 200-400 beats.min-1, slower heart rates exerted a frequency dependent protective effect against reperfusion induced arrhythmias. At the optimal rate of 200 beats.min-1, the incidence of total ventricular fibrillation (irreversible plus reversible) and ventricular tachycardia fell to 33% and 50% of their control values (100%). The anti-arrhythmic effect was achieved with only a minor (less than 20%) effect on coronary flow. To ascertain whether or not slow heart rate achieved an absolute reduction in vulnerability to arrhythmias irrespective of the duration of ischaemia, hearts were also subjected to 5, 10, 20, 30 or 40 min of ischaemia followed by 30 min of reperfusion with and without pacing at 200 beats.min-1. A bellshaped time-response profile was obtained in both groups. In unpaced controls (n = 12) this gave a maximal vulnerability to arrhythmias after 10 min of ischaemia. In the paced hearts (n = 12) the curve was shifted to the right, with a peak vulnerability at 20 min. These results show that the action of pacing is to exert a delaying effect which extends the duration of ischaemia that can be tolerated before the heart becomes vulnerable to reperfusion induced arrhythmias. Heart rate can have a substantial effect on reperfusion induced arrhythmias and should be considered when making therapeutic interventions and risk assessments in this setting.

Animals↗
PubMed1988

Protective effect of lidocaine against ischemia and reperfusion-induced arrhythmias and shifts of myocardial sodium, potassium, and calcium content.

Isolated guinea pig hearts subjected to global ischemia, were used to investigate whether lidocaine exerts an antiarrhythmic action against reperfusion-induced arrhythmias, and the effects of this drug upon myocardial ion contents during ischemia and reperfusion were studied. In the first series of experiments, the drug was administered 5 min prior to the induction of global ischemia and maintained during reperfusion. With 3.6 X 10(-6), 7.2 X 10(-6), 14.7 X 10(-6), and 29.5 X 10(-6) mol/L lidocaine, reperfusion-induced ventricular fibrillation and tachycardia were reduced from their control incidence of 83% and 100% to 41% and 58%, 33% (p less than 0.05) and 25% (p less than 0.001), 8% (p less than 0.01) and 8% (p less than 0.001), 0% (p less than 0.001) and 0% (p less than 0.001), respectively. The ion contents of myocardium were determined by atomic absorption spectrophotometer after washout of the ions from vasculature. Ischemia induced a marked accumulation of sodium and loss of potassium in the myocardial tissue. Both ischemia-induced sodium gain and potassium loss were significantly inhibited by lidocaine treatment. During reperfusion, sodium was further increased in the control group and this value was significantly lower in the lidocaine-treated group after 1 min of reperfusion. Sodium content remained at nearly constant level for the rest of reperfusion period. Potassium was suddenly increased during the first 5 min of reperfusion then continuously decreased until the end of reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗