[The first experience with surgical treatment of supraventricular tachycardia].

The article analyses the late-term results of operations on 46 patients for paroxysms of supraventricular tachyarrhythmias (SVTA) which were refractory to prophylactic administration of antiarrhythmics. Transvenous electrodestruction of the atrio-ventricular junction were carried out in 39 patients. The results were good in 34 and satisfactory in 3 patients; conductivity and paroxysms reappeared in 2 patients.

[Morphogenetic patterns of isolated infundibular stenosis of the pulmonary artery].

It was found that in isolated infundibular stenosis of the pulmonary artery a mass of muscle-fibrous tissue creates an obstacle to blood flow in the right ventricle. Morphogenetic regularities of compensatory and adaptive reactions in isolated infundibular stenosis are similar to those observed in hypertrophic cardiomyopathy. It may be suggested that abnormalities in the structure of the hypertrophied myocardium in isolated stenosis of the right ventricle infundibulum is a result of a fundamental error in the cardiac morphogenesis and not a reflection of increase of the degree of cardiac hypertrophy.

[Reconstructive surgical treatment of invalids with defects of part of the tibial diaphysis].

The authors have analyzed their observations of 113 patients and concluded that it is necessary to differentially use various kinds of osteosynthesis and bone autoplasty. Good and satisfactory long-term results were obtained in 94% of the patients operated upon.

[Relationship between the molecular structure of aqueous solutions of polyethylene glycol and the compactness of double-stranded DNA molecules].

The dependence of viscosity of the water solutions of poly(ethylene glycol) (PEG) on the molecular weight has been studied. It has been shown that there is a "transitional" region in PEG properties which accounts for the formation of fluctuation polymer network of the PEG molecules. It has been shown that the "transitional" region in properties of PEG which appears at a certain concentration of PEG (CtrPEG) is characteristic of the PEG preparations with molecular weights exceeding 600 and dependence of the value of CtrPEG on the molecular weight of PEG was obtained.