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Biomedical subjects

M Rusnák

Publications and source records attributed to M Rusnák.

At least 19 recordsLinked to original sources
PubMed1998

Different effects of insulin and 2-deoxy-D-glucose administration on tyrosine hydroxylase gene expression in the locus coeruleus and the adrenal medulla in rats.

The major brain norepinephrinergic nucleus, locus coeruleus, is an important integrating element of extero- and interoceptive stimuli in organisms facing different physiological challenges. We investigated the effects of single and repeated (seven times) exposure to immobilization stress (120 min daily), insulin (5 IU/kg, i.p. daily) or 2-deoxy-D-glucose (500 mg/kg, i.p. daily) administration on tyrosine hydroxylase (TH) mRNA levels, the rate-limiting enzyme in catecholamine biosynthesis, by in situ hybridization in locus coeruleus and by Northern blot analysis in the adrenal medulla of rats. Both the single and repeated immobilization caused a significant increase in TH mRNA levels in the locus coeruleus (1.5-2-fold; p < 0.05) and in the adrenal medulla (about 4-fold; p < 0.05) when compared with unstressed controls. Hypoglycemia induced by a single or repeated insulin administration led to about fourfold (p < 0.01) elevation in adrenal medullary TH mRNA levels, whereas TH mRNA in locus coeruleus remained unchanged when compared with saline-treated controls. In contrast to the effect of insulin-induced hypoglycemia, cellular glucoprivation caused by a single or repeated 2-deoxy-D-glucose administration significantly elevated TH mRNA levels in both the adrenal medulla (fourfold; p < 0.01) and the locus coeruleus (twofold; p < 0.01). Our data suggest that in contrast to immobilization or cellular glucoprivation caused by 2-deoxy-D-glucose administration, insulin-induced hypoglycemia is not a specific or quantitatively sufficient stimulus for induction of TH gene expression in the locus coeruleus, although all these stressors strongly activate the process in the adrenal medulla.

Adrenal Medulla↗
PubMed1998

Tyrosine hydroxylase mRNA levels in locus ceruleus of rats during adaptation to long-term immobilization stress exposure.

The major central norepinephrinergic nucleus, locus ceruleus (LC), is thought to participate in modulation of such brain areas as cerebral cortex, septum, hippocampus, thalamus, hypothalamus, and cerebellum in animals facing various physiological challenges, including stress. Exposure of experimental animals to different stressors causes an increase in LC activity and gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis. The aim of this work was to investigate the effect of a single and repeated (7 times) or long-term repeated (42 times) daily immobilization stress (IMMO) on TH mRNA levels in LC of laboratory rats by in situ hybridization method. A single IMMO caused significant elevation of LC TH mRNA levels in comparison to unstressed controls. This was found immediately and at 3 and 6 h after IMMO, and progressively increased up to 24 h after the first IMMO terminated. Further exposure to IMMO did not cause additional increases in LC TH mRNA levels, which stayed significantly elevated in comparison to unstressed rats. In animals that underwent IMMO for 42 times, the LC TH gene expression, 24 h after the last stress exposure, was significantly lower when compared to that of singly or seven times stressed rats. Thus, our results indicate a possible adaptation of catecholamine-synthesizing system at the level of TH gene expression in LC of rats exposed to long-term repeated IMMO.

Adaptation, Physiological↗
PubMed1997

Chronic blockade of nitric oxide synthesis elevates plasma levels of catecholamines and their metabolites at rest and during stress in rats.

Formation of nitric oxide, and endothelium-derived relaxing factor, can be inhibited by administration of N-nitro-L-arginine methylesther (L-NAME). In the present study, the activity of the sympathoadrenal system in rats with blood pressure (BP) elevation induced by L-NAME was investigated. L-NAME was administered in a dose of 50 mg/kg, i.p. every 12 h for 4 days. Blood samples were collected via chronically inserted arterial catheters in conscious, freely moving rats at rest and during immobilization stress. Plasma epinephrine (EPI), norepinephrine (NE), and dopamine (DA), as well as catecholamine metabolites dihydroxyphenylglycol (DHPG) and dihydroxyphenylacetic acid (DOPAC) were measured by HPLC method. In L-NAME treated animals, which slowed a significant increase in BP, plasma EPI levels were markedly elevated both before and during stress. Plasma NE levels were not significantly increased, however, DHPG levels, which indicate NE turnover and reuptake, were highly elevated. Plasma DA levels were not changed after L-NAME administration but DA metabolite DOPAC showed a significant elevation both under basal conditions and during stress. Thus, the present results indicate that the prolonged blockade of nitric oxide synthesis that causes arterial hypertension is associated with an activation of the sympathoadrenal system.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1995

Endogenous excitatory amino acids are involved in stress-induced adrenocorticotropin and catecholamine release.

The effect of N-methyl-D-aspartic acid (NMDA) receptor blockade on adrenocorticotropin (ACTH) and catecholamine activation during stress was investigated in conscious rats with indwelling catheters for both blood sampling and drug treatment. Secretion of ACTH in response to immobilization stress (20 min) was inhibited by pretreatment (20 min before stress exposure) with the centrally acting noncompetitive antagonist of NMDA receptors MK-801 (dizocilpine, the racemic form, 1 mg/kg i.p.) but not by 3-[(+/-)-2-carboxypiperazin-4-yl]propyl-1-phosphonic acid (CPP; 10 mg/kg i.p.), a competitive NMDA receptor antagonist. Administration of MK-801 (1 mg/kg i.p.) inhibited norepinephrine and totally prevented epinephrine response during acute immobilization stress. Pretreatment with a low dose of MK-801 (0.1 mg/kg i.p.) failed to modify basal or stress-induced ACTH and catecholamine release. The stress-induced rise in plasma epinephrine was found to be attenuated by the peripherally injected competitive antagonist CPP (10 mg/kg i.p.) suggesting that modulation not only of central but also of peripheral NMDA receptors may come into play. Our results indicate the involvement of endogenous excitatory amino acids in the control of ACTH and particularly of epinephrine secretion during stress.

Adrenocorticotropic Hormone↗
PubMed1995

Incidence and prevalence of childhood diabetes in Slovakia (1985-1992). Slovak Childhood Diabetes Epidemiology Study Group.

OBJECTIVE: To provide reliable data on the incidence and prevalence of insulin-dependent diabetes mellitus (IDDM) in children in Slovakia. RESEARCH DESIGN AND METHODS: A total of 754 Slovak children with IDDM, aged 0-14 years, were identified during an 8-year study period. There were 369 boys and 385 girls from an average population of 1,363,499 children. All patients were prospectively recorded. The primary ascertainment was based on notifications by physicians from outpatient departments. The second independent source of information was from all hospitals where the diabetic patients were hospitalized. The completeness of ascertainment was based on the capture-recapture procedure. RESULTS: The completeness of the ascertainment was 95%. In 1992, the annual incidence rate of IDDM (per 100,000) in the 0- to 14 year-old age-group was 8.92 for both sexes (7.95 for boys and 9.93 for girls). In the youngest age-group, an increase in the incidence rates from 2.89 in 1985 to 6.54 in 1992 was observed. Seasonality, with a higher incidence in autumn and winter, was observed in children older than 4 years. The prevalence rates of IDDM (per 1,000) were 0.28-0.50% in the 8-year period. CONCLUSIONS: The incidence of IDDM in Slovak children (0-14 years) is similar to what has been found in other Central European countries. In children younger than 4 years of age, in the last 2 years (1991 and 1992) more patients with diabetes were found than in any period during the preceding 6 years. The recent conspicuous increase in the incidence of IDDM among the younger children in Slovakia urges us to study its mechanisms, so far unknown, and to search for possible means of prevention.

Adolescent↗
PubMed1995

[Personal experience with determination of endogenous, digoxin-like substances in patients with myocardial infarct and other cardiopathies].

A group of 65 patients with acute infarction of myocardium (IM) who were not treated with digitalis preparations were subdued to examination to the presence of digitalis-like substances in their urine by means of radioimmuno-analytic method with use of anti-digoxin antibodies. The control group was constituted of 69 healthy subjects. Patients afflicted with IM had significantly increased concentrations of DLS in serum in comparison with health subjects. No significant relations of DLS to the activity of creatinkinase, IM localisation, occurrence of dysrhythmias, heart insufficiency and IM mortality were discovered. An increase in DLS in the blood of patients with acute IM probably coincides with a decreased cardiac output, with the activation of the stress axis and retention of sodium and fluids. The second examined group of patients was constituted of 20 subjects with other severe cardiopathies (inborn and acquired heart defects, chronic ischemic heart disease, inflammatory and degenerative diseases of the heart, and hypertension), who were subdued to catheter examinations. The authors discovered no significant differences of DLS concentrations in the blood during catheterization of individual compartments of inferior vena cava, superior vena cava, and the right ventricle. They were not successful in defining the particular site of DLS secretion on the basis of this examination. The authors pay attention to interaction of DLS during the radioimmuno-analytic examination of the digoxin serum concentration.

Adult↗
PubMed1995

[Endogenous digoxin-like and ouabain-like substances].

Despite the fact that cardioglycosides have been used in the treatment of cardiac failure for more than 2000 years, endogenous digoxin and ouabain-like substances were identified from the chemical aspect only in 1990. They are steroids, their main site of origin being the adrenals. It is assumed that they play a part in the regulation of the body fluids and sodium in the organism and participate in the regulation of cardiac activity. The stimulus which leads to their release into the blood stream are above all conditions associated with sodium and fluid retention with expansion of the intravascular volume. It is assumed that these substances participate in the pathogenesis of some types of hypertension. The authors present a general review of contemporary knowledge of endogenous digoxin and ouabain-like substances.

Digoxin↗
PubMed1993

[Incidence of rheumatic fever in Slovakia during the last 20 years].

The incidence of rheumatic fever has a declining trend in Slovakia. In 1972 there were 26.7 primary attacks and 8.7 relapses per 100,000 children aged 0-14 years, in 1990 there are 0.5 primary attacks and 0.4 relapses and in 1991 0.4 primary attacks and no relapses. The interregional (former regions) distribution was to the disadvantage of eastern parts but gradually this was evened out. Rheumatic fever occurs in girls and boys, in the majority mild arthritis forms are involved with unequivocal regression of carditic-arthritic forms. The decline can be ascribed to the rising socio-economic standard and health care.

Adolescent↗
PubMed1992

Endogenous digitalis-like factor in patients with acute myocardial infarction.

The authors examined endogenous digitalis-like factor (DLF) concentrations in the serum and urine in 65 patients with acute myocardial infarction. Radioimmunoassay was used for the examination and patients' data were analyzed in detail in relation to sex, risk factors and acute myocardial infarction complications. The concentrations of digitalis-like factor found in the serum of men (0.317 +/- 0.026 micrograms/l) and women (0.256 +/- 0.057 micrograms/l) with acute myocardial infarction were much higher compared with values of healthy men (0.009 +/- 0.004 micrograms/l) and women (0.015 +/- 0.012 micrograms/l). This finding is in agreement with data published by others and suggests a role of DLF in the pathogenesis of myocardial infarction.

Adolescent↗
PubMed1990

[Infant and neonatal mortality and its forecasting].

The authors draw attention to some trends in the development of important indicators of health care in the SR, i.e. infant and neonatal mortality. Using the method of simple analysis of trends mortality, they processed time series of data from all districts in Slovakia. They included in the analysis mortality data from 1972 to 1989. Based on the mentioned data they calculated the extrapolated trend for each district and present estimates for 1995 and 2005. They draw attention to differences between districts and discuss possible causes of this state of affairs. They draw attention of readers to the interpretation of results and warn against their absolutization.

Czechoslovakia↗
PubMed1990

[Registration of patients with chronic diseases].

The authors describe registers of chronic diseases, provisions regarding their contents and organizational aspects. They make the reader familiar with the collection, storage and evaluation of data and some problems with their safeguarding. They report their experience with recommended questionnaires and the structure of forms. They describe the activities of the doctor completing the forms as well as the activities associated with recording in the centre. The authors demonstrate possible types of outputs and whom they serve. They illustrate the results of their work on the example of data from the register for diabetes mellitus of the juvenile type I and rheumatic fever. They discuss the role of registers in the health services, their role in ensuring the health status of the population, planning and management of the health services. In the conclusion they mention new technical possibilities.

Adolescent↗
PubMed1990

[Computers in the Swedish health care system].

The author reports on his study stay in Sweden focusing on the use of computers in the health care system. He specifies the hospitalized patients, registry the modes of information collection and processing in health care computers used. His visit of the organization providing computer services enabled the author to get insight into the process which resulted in the high level of computer equipment applications in the Swedish health care system. In Uppsala he got acquainted applications with SWEDIS, a recording system of drugs and their adverse effects. On visiting the Department of Medical Informatics he became familiar with the organization of training provided to students and doctors in this speciality.

Information Systems↗
PubMed1989

[The central register for diabetes mellitus in children in Slovakia].

The central register of diabetes mellitus in the SSR keeps records of patients from birth to the age of 14 and 18 years resp. The health institution reports patients on special forms. At the end of the first half of 1988 574 patients from the entire SSR were on record. The incidence of diabetes mellitus in the last years is 6 per 100,000 children and has a slightly rising trend. The prevalence is (to the date of June 30, 1988) 34 in children under 14 years and by age groups it is 6 in children under 4 years, 29 in children under 9 years and 67 in children under 14 years per 100,000 children of the respective age group. This indicates increasing numbers of sick children with advancing age. The register records data from the family-history (incidence of diabetes, risk factors), from the patient's history at the time of the manifestation of the disease and during the period of data collection. The present state is evaluated on the basis of biochemical and clinical results. The state of compensation and quality of cooperation with the patient and parents are interlinked. In 284 families diabetes was present in another or several members (total 413) (genetic predisposition). Before the onset of diabetes mellitus 240 children an acute illness was recorded with a time interval of six weeks (infection and possible damage of islets). In addition to providing basic data for research of the disease, the register helps with dispensarization, statistical work, reports to doctors, inviting patients and planning the needs of sick children.

Adolescent↗