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Biomedical subjects

V Stanek

Publications and source records attributed to V Stanek.

17 recordsLinked to original sources
PubMed2002

Effects of substituted cyclodextrins on the separation of aromatic sulphonic acids by capillary zone electrophoresis.

Effects of the addition of various additives in the working electrolyte on the selectivity of capillary electrophoretic separation of naphthalenesulphonic acids used as intermediates in the production of synthetic dyes were investigated. Cyclodextrins form inclusion complexes with various compounds and are not only excellent chiral selectors, but have been also successfully applied for separations of positional isomers. In this work, methyl-beta-cyclodextrin, heptakis(2,6-di-O-methyl)-beta-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin, (2-hydroxypropyl)-beta-cyclodextrin and (2-hydroxypropyl)-gamma-cyclodextrin were studied as isomeric selector additives and compared with unsubstituted beta-cyclodextrin. In addition to the size of the cyclodextrin cavity, the number and type of the substituents in the cyclodextrin molecules strongly affect the separation of isomeric naphthalenesulphonic acids, but the effect of the substituted cyclodextrins on the separation selectivity is different for various types of sulphonic acids. Best separations of non-substituted naphthalenesulphonic acids were achieved in a borate buffer with methyl-beta-cyclodextrin, whereas the running buffer with non-substituted beta-cyclodextrin provides superior separation of amino and hydroxynaphthalenesulphonic acids.

2-Hydroxypropyl-beta-cyclodextrin↗
PubMed2000

Percutaneous coronary intervention in the current era compared with 1985-1986: the National Heart, Lung, and Blood Institute Registries.

BACKGROUND: Although refinements have occurred in coronary angioplasty over the past decade, little is known about whether these changes have affected outcomes. METHODS AND RESULTS: Baseline features and in-hospital and 1-year outcomes of 1559 consecutive patients in the 1997-1998 Dynamic Registry who were having first coronary intervention were compared with 2431 patients in the 1985-1986 National Heart, Lung, and Blood Institute Registry. Compared with patients in the 1985-1986 Registry, Dynamic Registry patients were older (mean age, 62 versus 58 years; P:<0.001) and more often female (32.1% versus 25.5%; P:<0.001). In the Dynamic Registry, procedures were more often performed for acute myocardial infarction (22.9% versus 9.9%; P:<0.001) and treated lesions were more severe (84.5% versus 82.5% diameter reduction; P:<0.001), thrombotic (22.1% versus 11.3%; P:<0.001) or calcified (29.5% versus 10.8%; P:<0.001). Stents were used in 70.5% of Dynamic Registry patients, whereas 1985-1986 patients received balloon angioplasty alone. Procedural success was higher in the Dynamic Registry (92.0% versus 81.8%; P:<0.001) and the rate of in-hospital death, myocardial infarction, and emergency coronary bypass surgery combined was lower (4.9% versus 7.9%; P:=0.001) than in the 1985-1986 Registry. The 1-year rate for CABG was lower in the Dynamic Registry (6.9% versus 12.6%; P:<0.001). CONCLUSIONS: Although Dynamic Registry patients had more unstable and complex coronary disease than those in the 1985-1986 Registry, their rate of procedural success was higher whereas rates of complications and subsequent CABG were lower. Results of percutaneous coronary intervention have improved substantially over the past decade.

Angioplasty, Balloon, Coronary↗
PubMed1996

[Congenital coronary artery aneurysm: a rare cause of acute myocardial infarct].

An 18-year-old female presented with acute posterior wall infarction after exercise stress. Coronary angiography showed an aneurysm of the proximal right coronary artery partially occluded with thrombi, followed by a complete occlusion of the vessel. The left coronary artery was normal. Despite immediate intracoronary thrombolysis she developed a large posterior wall necrosis. Angiographic follow-up revealed worsening left ventricular function but not progression of the aneurysmatic ectasia. The diagnosis congenital coronary artery aneurysm was made since there was no evidence for an atherosclerotic, infectious or inflammatory vascular disease. The patient was treated conservatively and within 2 years of follow-up the clinical course was uneventful.

Adolescent↗
PubMed1985

[Effect of prolonged administration of beta-blockers on the hemodynamics of patients who have sustained a myocardial infarct].

The effect of prolonged treatment with the beta-blocker trimepranol on left-ventricular function was assessed in patients who survived myocardial infarction. Pulmonary arterial catheterization with a floating catheter was used for hemodynamic investigation. Hemodynamic parameters were compared in the treated (20 patients) and control (20 patients matched for age and infarction site) groups. The treated patients showed a reduction in heart rate and cardiac output at rest, as well as stress-induced elevation of the pulmonary arterial pressure and peripheral resistance. Patients with pulmonary hypertension often demonstrated changes of the pressure curve in the pulmonary artery as a possible manifestation of stress-induced mitral regurgitation. Prolonged treatment with trimepranol is associated with increased incidence of pulmonary hypertension in myocardial infarction survivers. The clinical significance of this observation is yet to be established by further studies. Stress-induced mitral regurgitation associated with a mitral subvalvular dysfunction may occasionally be the cause of elevated pulmonary blood pressure.

Cardiac Output↗
PubMed1982

Longterm follow-up of patients with pulmonary thromboembolism. Late prognosis and evolution of hemodynamic and respiratory data.

Seventy-six patients with various forms of pulmonary thromboembolic disease were followed-up for 1 to 15 years. All were free of other cardiopulmonary disease at the time of the first examination which was performed at least two months after the last pulmonary embolism. Catheterization was repeated in all survivors on average 4.8 years later. Severe chronic pulmonary hypertension (mean pulmonary artery pressure (PPA greater than 30 mm Hg) did not occur after a single episode of acute embolism, was infrequent after single subacute or recurrent emboli (8 of 9 patients), and was common after occult emboli (12 of 13 patients). Mortality in all clinical groups correlated with PPA and with the presence of right heart failure. In survivors, no correlation was found between the longterm changes of PPA and age, duration of disease, interval between catheterizations, PaO2, or cardiac output. Pulmonary hypertension progressed further in patients with initial PPA greater than 30 mm Hg. In contrast, none of the patients with normal or borderline PPA at the initial examination developed severe pulmonary hypertension during the follow-up. Since the future course of patients could be predicted from the first examination, repeated hemodynamic investigation proved to be of minor prognostic value.

Adult↗
PubMed1979

[Lung perfusion distribution study by means of 133Xe].

A method for studying regional lung perfusion employing 133Xe is described. Simple radioisotope apparatus with two catheters was used; every isotopic diagnostic department is equipped with it. The possibility of the clinical use of this method was demonstrated in 28 patients with mitral stenosis and in 11 healthy persons. A statistically significant dependence between regional movement of the perfusion to the upper regions of the lungs and the degree of hemodynamics changes in mitral stenosis was noted. Study of the distribution of persusion may be used as a simple method for appraising the hemodynamic changes in mitral stenosis. This method is simple and not burdensome for the patient. It may be recommended first of all in repeated examinations and long-term observations over patients.

Diffusion↗
PubMed1977

[Hemodynamic observations in acute myocardial infarct].

A haemodynamic study was conducted in 96 patients with acute myocardial infarction. The method of right heart catheterization at the bedside using the Swan-Ganz floating balloon-tipped catheter is safe and feisible. An elevation of pressure in the pulmonary circulation was revealed in patients with transmural myocardial infarction and in those without clinical signs of heart failure. The pressure elevation is detected the more often the sooner after the onset of infarction the examination is conducted. To evaluate fast pressure changes heart catheterization is essential and cannot be substituted by any other technique of examination Digoxin administration during the acute phase of myocardial infarction fails to produce any significant reduction of the pulmonary circulation pressure, but a prompt reduction of the pulmonary circulation pressure can be achieved by way of Phentolamine infusion. The pulmonary circulation pressure measurements during the acute phase of myocardial infarction are believed to be an indispensable component of examinations for the heart failure therapy.

Acute Disease↗
PubMedDate not supplied

Central haemodynamics during exercise in patients with restrictive pulmonary disease.

Pulmonary precapillary hypertension present only during exercise is the first stage of corpulmonale. Examination of the reaction of central haemodynamics to exercise is the only way to detect it. In a model situation like unilateral pulmonary artery occlusion (UPAO) in healthy subjects, an increase in pulmonary artery pressure (Ppa) during exercise is a linear function of restriction of the pulmonary vascular bed and blood flow increase. Central haemodynamics during exercise in younger subjects after pneumonectomy (PNE) resemble the situation with UPAO provided the remaining lung is intact. In older patients after PNE the same rise of blood flow is associated with a considerably greater rise of Ppa. PNE patients compared to healthy individuals increase their cardiac output during exercise more by increasing stroke volume. Patients with pulmonary fibrosis show a disproportionate rise in Ppa in relation to flow. This is due to reduced distensibility of the pulmonary system. Hypoxia also seems to be involved in pulmonary hypertension during exercise. Pulmonary wedge pressure rises at work but remains within the normal range, even in patients having marked hypoxaemia at rest and during exercise. In idiopathic intersitial pulmonary fibrosis (IIPF), pulmonary hypertension during exercise is greater than in other forms of pulmonary fibrosis. Inhalation of oxygen during exercise in patients IIPF leads to a reversal of hypoxaemia but the decrease of Ppa is small and due to a passive decrease of cardiac output. Finally right ventricular function in restrictive pneumopathies is discussed.

Heart Ventricles↗