Biomedical subjects

I Tkác

Publications and source records attributed to I Tkác.

At least 19 recordsLinked to original sources

PubMed1995

[Neurohumoral activity in liver cirrhosis].

The authors assessed in 40 patients with cirrhosis of the liver and in 33 controls the plasma renin activity (PRA), aldosterone (PA), the atrial natriuretic factor (ANF) and the digoxin like activity (DLA) in plasma under basal conditions. In patients with cirrhosis of the liver they found significantly lower levels of PRA, PA and DLA, as compared with the control group, the ANF levels were not significantly altered. In the group with cirrhosis the highest neuroendocrine activity was recorded, in particular of PRA and PA in decompensated cirrhotics receiving diuretic treatment. Therefore it is useful to combine diuretics with preparations or measures which reduce the activity of the renin-angiotensin-aldosterone system and/or promote the activity of natriuretic substances. The authors found a negative correlation between PRA and SNa, PRA and UNaV, while ANF did not correlate with natriuresis. The main determinant of Na excretion in decompensated cirrhosis is the activity of the renin-angiotensin-aldosterone system. DLA plasma levels also correlated inversely with SNa values and Na excretion and thus also reflect the severity of fluid retention.

Adult↗

PubMed1994

[The present status of treatment of unstable angina pectoris].

UAP is a frequent manifestation of ischaemic heart disease; it is intermediary between stable angina and myocardial infarction and sudden death resp. The hospitalization mortality is 5%, approximately 15% of the patients with UAP develop myocardial infarction. The aim of UAP treatment is: 1. prevention of ischaemic episodes, 2. prevention of infarction and 3. control or elimination of risk factors, to improve the long-term prognosis in these patients. As antianginal drugs in UAP as a routine calcium antagonists, beta-blockers and nitrates are used. A very important part in the treatment of UAP is played by antithrombotic and thrombolytic treatment as in this disease rupture or fissure of plaques and subsequent thrombus formation is important. Non-occlusive thrombi are present in 80% in UAP, while in infarctions they are present in 21%. Rupture of an atherosclerotic plaque leads to thrombocyte activation, release of tissue thromboplastin and activation of the coagulation system aspirin inhibits platelet function and thus reduces thromboxane A2 formation. Heparin affects the coagulation process in UAP, reduces the number of anginal attacks and protects from the development of infarction. Treatment of UAP with streptokinase and rt-PA has no great advantages, when compared with heparin. Surgical treatment of UAP has somewhat better results than conservative treatment. Coronary angioplasty is an ideal solution in UAP when one or two arteries are damaged.

Angina, Unstable↗

PubMed1994

[Factors affecting serum lipid levels in patients with type 2 diabetes mellitus].

Serum lipid concentrations were assessed in 147 type 2 diabetics. The patients were divided into different sub-groups in order to follow up different factors which could have an impact on serum lipids. The mean total cholesterol concentrations were significantly higher in diabetic women as compared with men. The authors did not reveal significant differences in lipid concentrations between obese and non-obese diabetics. Hypertensive diabetics had higher mean total cholesterol levels and LDL-cholesterol levels, as compared with diabetic patients without hypertension. Patients using oral antidiabetics had significantly higher mean triglyceride levels and lower HDL-cholesterol levels, as compared with insulin-treated diabetics. In a multiple stepwise regression analysis correlated triglycerides with three independent variables: total cholesterol, diastolic blood pressure and inversely with HDL-cholesterol. On the other hand, total cholesterol correlated significantly with triglycerides, HDL-cholesterol and proteinuria/day. To sum up, it may be stated, that the results of the present investigation are consistent with Reaven's concept of the syndrome X, however the cholesterol concentration is affected also by the proteinuria.

Cholesterol↗

PubMed1994

[Changes in lipoprotein metabolism in patients with diabetes mellitus and the effect on lipid profile in diabetics].

Diabetic patients have a 2 to 4 times higher risk of development of atherosclerosis than non-diabetic subjects. One of the risk factors of atherosclerosis is an impaired lipid and lipoprotein metabolism which is influenced by the type of diabetes, the degree of its metabolic compensation, character of treatment and other concurrently present metabolic abnormalities. In metabolically balanced type 1 diabetes the levels of commonly assessed lipoproteins do not differ from those in non-diabetic subjects, the HDL-cholesterol level can be even higher. The lipid profile of type 2 diabetics is not very homogeneous, however, usually elevated levels of VLDL-triglycerides and of apoprotein B and a reduced HDL-cholesterol level are found. At present there are no unequivocal views on the role of the lipoprotein (a) ratio in the increased risk of atherosclerosis in diabetics as investigations devoted to the lipoprotein (a) level and its relation to macrovascular complications in diabetes did not give unequivocal results. The scope of dyslipidemia in diabetics with nephropathy is in addition to the effect of the basic disease influenced also by the extent of renal damage. The lipid disorder, on the other hand, leads to deterioration of albuminuria and progression of the renal disease.

Arteriosclerosis↗

PubMed1993

Type IV renal tubular acidosis associated with Alport's syndrome.

A case of hereditary nephritis with mild reduction of renal function associated with renal tubular acidosis type IV is described. The patient was admitted with life-threatening hyperkalaemia. To our knowledge, type IV renal tubular acidosis has not been reported previously in association with Alport's syndrome in an adult patient.

Acidosis, Renal Tubular↗

PubMed1993

[Neuroendocrine changes in chronic heart failure].

Chronic heart failure is a complex clinical syndrome characterized by many neuroendocrine manifestations by which the organism responds to the reduced cardiac output--the reduced minute volume. In order to ensure the blood flow to vitally important organs in several regions of the circulation vasoconstriction occurs. The plasma noradrenaline (NA) level rises and this correlates with the stage of chronic heart failure. In chronic heart failure the renin production in the kidney and vascular wall rises and thus also the angiotensin II (AG II) formation is increased. AG II is an affective direct arterial constrictor which facilitates NA release from terminal nerve endings and stimulates aldosterone secretion. AG II conditions also myocardial hypertrophy. Arginine vasopressin (AVP) is usually also elevated in chronic heart failure. In vasoconstriction associated with chronic heart failure participates also endothelin, an effective vasoconstrictor substance which modulates the renin-angiotensin-aldosterone system and has also an antinatriuretic effect. As a compensating response to the increased formation of vasoconstrictor substance during chronic heart failure endogenous vasodilatating and natriuretic substances are formed. Another vasodilatating factor is the atrial natriuretic factor (ANF) which is secreted by atrial myocytes as a result of atrial distension, hypernatremia or tachycardia. ANF inhibits renin, aldosterone and AVP formation. The ANF level correlates closely with the grade of chronic heart failure. With advancing heart failure also down regulation of receptors for ANF occurs. Dopamine, a natural precursor of NA, is also a vasodilatating substance and is secreted during stimulation of the sympathetic nerve. In chronic heart failure the formation of vasoconstrictor substances predominates above vasodilating ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart Failure↗

PubMed1993

[Hypercoagulation states].

Hypercoagulability is a condition where as a result of certain pathological changes in the blood inadequate cumulation of thrombocytes or fibrin occurs which finally can lead to arterial or venous thrombosis, depending on vascular wall damage. In the submitted review the authors analyze the most important inborn and acquired causes of hypercoagulation states. As to inborn causes, deficiens of natural anticoagulation proteins (antithrombin III, protein C, protein S) are most important as well as dysfibrinogenaemia, impaired fibrinolysis associated with deficiency of natural activators of fibrinolysis or increased activity of their inhibitors and homocystinuria. The most frequent acquired causes of hypercoagulation states are the presence of anticardiolipin antibodies ("lupus anticoagulans"), pregnancy, the use of oral contraceptives, malignity, nephrotic syndrome, postoperative conditions, diabetes mellitus and some other diseases.

Blood Coagulation↗

PubMed1993

Spirometric alterations in patients with reduced renal function.

Spirometric parameters were measured in 49 patients with reduced renal function. The patients were divided according to their glomerular filtration rate (GFR) into two groups: (A) GFR < 0.2 ml s-1-end stage renal failure; (B) GFR > or = 0.2 ml s-1. FEV1 and FEF25-75 were significantly lower in the end-stage renal failure group of patients. 80% of the patients with GFR < 0.2 ml s-1 and 31% of the patients with GFR > or = 0.2 ml s-1 had spirometric evidence of small airways dysfunction. In multiple stepwise regression analysis with ventilatory parameters as dependent variables and renal function, total protein, urea, creatinine, sodium, and hemoglobin levels, proteinuria, diuresis, and history of left ventricular failure as independent variables only GFR and total protein correlated significantly with FEV1 and FEF25. In conclusion, our study demonstrates that impairment of spirometric function in patients with renal insufficiency is continual, with reduction of GFR, and thus small airways dysfunction may be expected not only in patients with end-stage renal failure, but also in those with moderate GFR reduction.

Adult↗

PubMed1992

Levels of cardiovascular risk factors in type 2 diabetes mellitus are dependent on the stage of proteinuria.

Levels of cardiovascular risk factors were determined in 75 patients with Type 2 diabetes mellitus. The patients were divided into three groups according to their urinary protein excretion (UPE): (a) normal proteinuria (less than or equal to 70 mg d-1); (b) microproteinuria (70-500 mg d-1); and (c) macroproteinuria (greater than 500 mg d-1). A significant stepwise increase in mean systolic blood pressure, LDL-cholesterol and fibrinogen levels was observed from the first to the third investigated group of patients. Mean apoprotein B levels were significantly increased in the group with macroproteinuria compared to the other two groups. Significant linear correlations were found between UPE and LDL-cholesterol, total cholesterol, apoprotein B, creatinine, systolic blood pressure and diabetes duration. In summary, it is concluded that the levels of some cardiovascular risk factors increase with the stage of proteinuria in Type 2 diabetes mellitus.

Aged↗

PubMed1992

Risk factors for atherosclerosis in female type II diabetic patients with incipient diabetic nephropathy.

Risk factors for atherosclerosis were investigated in a group of 17 female Type II diabetic patients with microalbuminuria-urinary albumin excretion (UAE) in the range of 30-300 mg/day, and in a control group including 15 Type II diabetic females with UAE less than 30 mg/day. Significantly increased mean concentrations of total and LDL-cholesterol were measured in the group with microalbuminuria (p less than 0.05). Also mean levels of some other cardiovascular risk factors (systolic blood pressure, fibrinogen, apolipoprotein B, triglycerides and uric acid) were higher in the group of patients with microalbuminuria, although the differences in comparison to the control group did not reach the level of statistical significance. In the multiple stepwise regression analysis log transformed UAE values correlated significantly with three independent factors--uric acid (p less than 0.01), fibrinogen (p less than 0.05), and systolic blood pressure (p less than 0.05). It is concluded that a slight increase in the levels of a number of cardiovascular risk factors observed in incipient diabetic nephropathy suggests an additive effect favouring atherogenesis.

Albuminuria↗

PubMed1992

Hematologic changes in type 2 diabetic patients with various localizations of peripheral vascular disease.

Some hematologic parameters have been measured in 80 patients with Type 2 diabetes mellitus. The patients were divided into three groups: (a) proximal (pelvic and femoral) lower limb macroangiopathy; (b) distal (tibial) macroangiopathy; and (c) control group of diabetics without lower limb macroangiopathy. Mean hemoglobin, hematocrit and fibrinogen values were significantly higher in both the proximal and distal macroangiopathy groups in comparison with the controls. On the other hand, mean leucocyte and platelet counts were significantly elevated only in the proximal macroangiopathy group. Significant correlations were observed in univariate and multivariate analyses between blood fibrinogen concentration and pressure indices expressing severity of lower limb macroangiopathy (ankle/thigh, ankle/arm). In summary, increased levels of hematologic parameters contributing to the increase of whole blood viscosity were observed in Type 2 diabetics with arteriosclerosis obliterans. The observed relationship between fibrinogen concentration and severity of arteriosclerosis obliterans could be an evidence in favor for fibrinogen lowering therapy in this pathologic condition.

Arteriosclerosis Obliterans↗

PubMed1992

[Characteristics of diabetic macroangiopathy of the lower extremities].

Macroangiopathy of the lower extremities is one of the most frequent complications of diabetes and has a very adverse impact on the quality of life of the patients. It affects approximately as much as half the diabetics with the duration of the disease for more than 15 years. It is encountered in two forms. The first type of affection--obliterating atherosclerosis--reminds of affections of the arteries of the lower extremities in the non-diabetic population, although some differences in the site of affection, morphology of sclerotic changes as well as the spectrum of risk factors were found, when compared with obliterating atherosclerosis in non-diabetics. Risk factors of this form of macroangiopathy include cholesterol, triacylglycerols, reduced values of HDL-cholesterol, hypertension, fibrinogen, smoking and apparently also albuminuria. The second form of macroangiopathy--mediocalcinosis--is not associated with the mentioned risk factors of atherosclerosis but is probably the consequence of diabetic neuropathy. Contrary to atherosclerosis, it does not lead to the development of obliteration but has also an adverse effect on the function of blood vessels. Its incidence correlates with the duration and compensation of diabetes as well as deteriorated perception of vibrations. With regard to the high incidence of gangrenes requiring amputation, it seems rational to influence in diabetics all known risk factors of macroangiopathy although convincing results of long-term intervention studies are still lacking.

Diabetic Angiopathies↗

PubMed1992

[ECG Holter monitoring in patients with chronic renal failure in a long-term dialysis program].

Using the Holter method, the authors monitored for 24-hours 30 patients included in a long-term dialyzation programme during and after haemodialysis. A group of 15 patients who had during examination frequent or complex supraventricular or ventricular ectopia was compared with a group of 15 patients with sporadic ectopia. In the arrhythmic group paroxysmal supraventricular tachycardia was recorded in 33% and paroxysmal atrial fibrillation in 13%, polytopic or repetitive ventricular extrasystoles in 14%, couplets in 20% and volleys of ventricular extrasystoles or non-persisting ventricular tachycardia in 20%. Comparison of clinical laboratory and echocardiographic characteristics revealed in the arrhythmic group significantly higher mean ages of patients, higher levels of ionized serum calcium before haemodialysis, C terminal parathormone, the breadth of the interventricular septum, and the authors observed also a higher incidence of hyperechogenity of cardiac structures. On analysis of repolarization ECG changes significant asymptomatic depressions of the ST segment were found which were transient and dominated during the early posthaemodialyzation period in 11 patients of the whole group (37%).

Adult↗

PubMed1992

[Pulmonary embolism as a rare complication of a contusion in the inguinal region].

In the submitted case-history the authors describe the clinical case of an adolescent patient who developed phlebothrombosis of the right ileofemoral area one year after a blunt injury in the scrotal and right inguinal area. The symptoms of pulmonary embolism were detected sooner than the symptoms of phlebothrombosis. Two-dimensional echocardiography provided valuable information when the authors monitored the dynamics of changes in acute cor pulmonale and the effect of administered treatment.

Adolescent↗

PubMed1991

Proteinuria is a risk factor for proximal type of peripheral vascular disease in type 2 diabetic patients.

The levels of creatinine, urea, uric acid, UPE and blood pressure were measured in the groups of Type 2 diabetics with proximal (iliocofemoral) type (PRMA) and distal (tibial) type of macroangiopathy (DIMA) (diagnosed by means of Doppler ultrasound technique) and in a control group without lower limb macroangiopathy. Both UPE and creatinine mean values were significantly increased in the PRMA group in comparison with controls. Uric acid levels were increased in both PRMA and DIMA groups and mean urea values did not differ significantly in all three groups of patients. Systolic blood pressure values were similar in each group as well. However, a significant increase of mean diastolic pressure has been observed in the group with DIMA. In addition, significant correlation was observed between the thigh/arm index (expressing the perfusion through the ilicofemoral segment) and UPE (r = -0.464; p less than 0.001). This relationship persisted also in multivariate analysis where UPE was the only factor which entered the "best fit model". The results of the present study indicate that proteinuria might be a risk factor or a marker for proximal type of peripheral vascular disease in Type 2 diabetic mellitus.

Arteriosclerosis Obliterans↗

PubMed1990

[Uric acid--a risk factor or atherosclerosis marker in type 2 diabetes?].

The incidence of some risk factors of ischaemic heart disease (IHD) was investigated in a group of 91 type 2 diabetics. A group of 57 patients who had a myocardial infarction was compared with a control group of 34 diabetics without clinical and electrocardiographic signs of IHD. In the group of diabetics with IHD there was a significantly higher proportion of hypertonic patients (70%), as compared with the control group (47%). The diabetics with an infraction in the case-history had a significantly higher mean age and a longer mean duration of diabetes. There was not a significant difference between the two groups as regards mean values of cholesterol, triacylglycerols, blood sugar, urea, creatinine, proteinuria and cerebrovascular attacks. As to metabolic factors, there were significantly higher mean uric acid values in the whole group with a myocardial infarction in the case-history, whereby this increase was more marked in men with IHD. Regression analysis did not reveal a significant correlation between uric acid values and the serum cholesterol or triacylglycerol levels or the incidence of hypertension. A significant biserial correlation between the presence of myocardial infarction and uric acid serum levels persisted also after elimination of the effect of age and creatinine serum levels. Based on these results and analyses of data in the literature, the authors favour the view that uric acid is rather a marker than true risk factor of atherosclerosis in type 2 diabetics.

Aged↗

PubMed1990

[Pathogenic aspects of diabetic macroangiopathy].

Diabetics of both types suffer more frequently from atherosclerosis of the coronary, cerebral and peripheral arteries than the non-diabetic population of similar age groups. In the pathogenesis of atherosclerosis in diabetes an important part is played by the very frequent association of the diabetic syndrome with hyperlipoproteinaemia and hypertension, elevated levels of substances potentially toxic for the endothelium such as glucose, chylomicron remnants, sorbitol, immunocomplexes, CO and others. Changes of thrombocyte functions and of the equilibrium of the system prostacycline-thromboxane as well as disorders at different sites of the haemocoagulation an fibrinolytic cascade, no doubt, interfere in a negative way with the process of atherogenesis. Non-enzymatic glycosylation of various proteins probably is also of a certain importance for the process of atherogenesis. The genetic background of the individual has obviously an impact on atherosclerotic complications in diabetics of type 2 (U-allele) where potential atherogenic hyperinsulinaemia is one of the constant manifestations of the disease. The second form of macroangiopathy (mediocalcinosis) affects practically only diabetic subjects and is probably due to the denervation of the blood vessels of the extremities in diabetic neuropathy. Identification and influencing of risk factors of macroangiopathy could have a favourable effect on the quality of life and prognosis of diabetic patients.

Diabetic Angiopathies↗

PubMed1990

Different levels of cardiovascular risk factors in type-2 diabetic patients with lower limb proximal and distal vessel macroangiopathy.

The levels of some cardiovascular risk factors (lipids, apolipoproteins and fibrinogen) were measured in groups of Type-2 diabetic patients with lower limb proximal (ileofemoral) and distal (trifurcational) artery macroangiopathy, diagnosed by Doppler ultrasound, and in a group of diabetics without macroangiopathy. The highest mean levels of total and LDL-cholesterol, apolipoprotein B and triacylglycerols were observed in patients with proximal vessel involvement. Significant correlations were found between the thigh/arm index and total cholesterol, LDL-cholesterol, apolipoprotein B and stroke prevalence. On the other hand, a significant correlation was found between ankle/thigh index and fibrinogen. The results of the study suggest that different pathogenetic mechanisms may play a role in the development of ileofemoral and trifurcational vessel disease.

Apolipoproteins B↗