PubMed Health⌕ Search

Biomedical subjects

A Nicák

Publications and source records attributed to A Nicák.

At least 19 recordsLinked to original sources
PubMed1994

[The effect of long-term administration of levamisole and muramyl-dipeptide on phagocytic activity of polymorphonuclear leukocytes in relation to the age of rats].

The authors observed an immunostimulating effect of levamisole and MDP on fagocyting activity (FA) of neutrophile polymorphonuclear leucocytes in dependence on ageing in rats. They observed 3 age groups, namely 3, 12 and 18 month old animals. The substances were administered during a period of 30 days. It was found out that following both substances, FA elevation in 3 month old animals was significant after 15 days of medicament administration, though, in the 12 month old animals it supervened after 15 and also 30 days. In 18 month old animals following levamisole administration, a significant FA increase supervened only following 15 days; though after MDP administration, it supervened after 25 and also 30 days. It is remarkable that in this group, during administration of both medicaments, 38-50% of animals died. The study points out that age represents a factor which modifies the effect of immunostimulating substances. (Fig. 2, Ref. 16)

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1993

Differences in haemolytic action of Hg2+ in relation to its concentration and ionic strength of incubating solutions.

The haemolytic action of different concentrations of HgCl2 on rat red blood cells (RBC) was studied in vitro. The concentrations of HgCl2 in incubating media were 0.15, 0.25 and 0.50 mmol.l-1. The ionic strength of the media varied from 0 to 154 mmol.l-1 NaCl. Isotonicity of solutions was also compensated using isotonic glucose in different concentrations (287-0 mmol.l-1). Osmolarity of solutions varied from 287 to 308 mOsm. Besides these solutions the haemolysis in Krebs-Ringer solution was also studied. Haemolysis was characterized with two maxima in all concentrations of Hg2+. The first maximum was observed at low ionic strength and the second one at high ionic strength. In relation to the increased concentrations of Hg2+, the first maximum of haemolysis progressively declined towards the higher ionic strength. In the Krebs-Ringer solutions, the increased concentration of Hg2+ was followed by reduced haemolysis. The haemolytic concentration of 0.15 mmol.l-1 was found to be optimal.

Animals↗
PubMed1992

The influence of glucose and saccharose on haemolytic action of HgCl2 in relation to the ionic strength of the incubating medium.

The haemolytic action of HgCl2 (0, 15 mmol.l-1) was studied in relation to the ionic strength and concentration of glucose and saccharose in incubating medium. Blood from 94 donors, aged 19-46 years were used in our experiments. In relation to the ionic strength the haemolytic action was characteristic with two maxima of haemolysis. The first at low ionic strength and second one at the high. Both maxima in solutions containing saccharose were significantly diminished in glucose. These facts show a negative influence of saccharose on the haemorheological properties of the erythrocyte membrane.

Adult↗
PubMed1991

Effect of chlorpromazine on ulcer formation by indomethacin in histamine- and insulin-stimulated rats.

The effect of chlorpromazine on ulcer formation by indomethacin and on total gastric secretion and gastric acid secretion was studied in rats. Secretion and ulceration were evaluated under basal conditions and after the administration of histamine or insulin, i.e. substances stimulating gastric acid secretion. The authors confirmed that chlorpromazine inhibits basal secretion and found that it also inhibits histamine- and insulin-stimulated gastric secretion, in correlation to the dose. It also strongly inhibits the formation of stomach lesions caused by indomethacin under basal conditions and after pretreatment with histamine (3 and 10 mg/kg) and insulin (0.3 IU/kg). Chlorpromazine did not inhibit lesions formed after combining indomethacin with insulin in a dose of 3 IU/kg. The results show that although chlorpromazine inhibits both basal and centrally or peripherally stimulated gastric secretion, its effect on stomach lesions caused by indomethacin is not uniform. Pretreatment with insulin in a dose of 3 IU/kg demonstrates that indomethacin-induced stomach lesions are markedly potentiated by this dose of insulin and are not dependent on gastric secretion only. The inability of chlorpromazine to inhibit these lesions gives the evidence that other--probably central--mechanisms play a role in their development.

Animals↗
PubMed1991

[The effect of brilliant cresyl blue on erythrocyte degeneration in patients after acute stroke].

The authors investigated the disintegration of red cells by the action of brilliant cresyl blue in patients after an acute cerebrovascular attack and compared them with the disintegration in blood donors. In the patients the disintegration was assessed within 24 hours after the attack and after one year. The disintegration was assessed in two incubation solutions i.e. in isotonic saline and in Krebs-Ringer solution after three hours incubation at 37 degrees C. It was revealed that in the control group the disintegration of erythrocytes in isotonic saline is much greater than in Krebs-Ringer solution. The difference between the action of the two solutions is highly significant. In patients immediately after the attack as well as in the group which did not survive the period of one year (7 patients) and the group which survived the period of one year (8 patients) the difference in disintegration in the two solutions is significant but at a lower level of significance. It is thus smaller than in the control group. However, in the group which survived for one year this difference is again highly significant, similarly as in the control group. The author discusses the problem of metabolic influencing of the elasticity and deformability of the red cell membrane and its impact on the rheology of blood.

Aged↗
PubMed1990

[The effect of exaprolol and sodium salicylate on erythrocyte hemolysis in relation to age].

The effect of exaprolol and sodium salicylate on hemolysis of erythrocytes was studied in dependence on the age of rats. Rats of the Wistar strain were used in the experiment in six different age groups. Exaprolol concentration was in the range from 0.24 to 0.48 mmol.l-1. Sodium salicylate was used in the concentrations of 0.1, 1, and 5 mmol.l-1. The effect of sodium salicylate on exaprolol induced hemolysis depended on the concentration of the two drugs and on the age of the animals. Significant changes were recorded at the concentrations of 1 and 5 mmol.l-1 of sodium salicylate. In 48- and 72-week-old rats sodium salicylate stabilized the erythrocyte membrane, whereas in 3-week-old rats increased decomposition was observed. The differences in the membrane labilizing effect of exaprolol and the membrane stabilizing effect of sodium salicylate, which were found to be age dependent, are presumably determined by qualitative changes in the structure of the erythrocyte membrane occurring in the course of postnatal development.

Adrenergic beta-Antagonists↗
PubMed1989

[Experimental gerontology and the reliability theory].

The reliability theory was elaborated for the estimation of the reliable action of technical systems. When it is applied to biological systems, it is important to characterize unequivocally the disorder which will substantially after the reliable activity of the entire organism or of individual systems. The authors investigated in their experiments during the postnatal development of rats changes in the erythrocyte stability. The age-conditioned decline was evaluated as a disorder. The erythrocyte stability was assessed in animals of different age, i. e. in 4-, 6-, 10-, 18- and 24-month-old animals by the method of the haemolytical action of brilliant cresyl blue in isotonic NaCl solution. The results of experiments suggest that when red cells were incubated in isotonic NaCl solution only, there was no difference in the lysis of erythrocytes in different age groups. However, when they were incubated in isotonic NaCl with brilliant cresyl blue, there was a significantly greater haemolysis in red cells of 4-, 18- and 24-month-old rats, as compared with the lysis of red cells from 6- and 10-month-old animals. Red cell lysis conditioned by brilliant cresyl blue in relation to age is discussed from the aspect of the reliability theory.

Aging↗
PubMed1989

Influence of acute hypoxia upon brilliant cresyl blue-induced disintegration of erythrocytes in rabbits and cats.

The disintegration of erythrocytes by brilliant cresyl blue was studied in rabbits and cats during two hypoxic periods resulting in apnoea which was followed by artificial ventilation and recovery. The rate of erythrocyte disintegration was measured after 2 hours' incubation in isotonic NaCl or Krebs-Ringer solution plus brilliant cresyl blue (0.5 mmol.l-1). Significant increases of disintegration rates were found in rabbits during recovery in both incubation solutions. Erythrocytes in cats seemed to be more resistant to acute hypoxia, as their disintegration rate rose only in isotonic NaCl solution, and that only transiently. Brilliant cresyl blue--induced erythrocyte disintegration in cats did not differ from the control values during 10 min of spontaneous breathing after the first and the second period of hypoxia in the isotonic NaCl solution, but it was significantly lower in Krebs-Ringer solution. The possible factors influencing the erythrocyte disintegration rate in acute hypoxia are discussed.

Animals↗
PubMed1989

[Erythrocyte deformability in patients with acute ischemic cerebrovascular stroke].

The authors investigated in a group of 40 patients the deformability of the red cells, using the disintegration method by means of brilliant cresyl blue. The control group was formed by blood donors from the blood transfusion station. The disintegration of the red cells was investigated in vitro in isotonic NaCl solution and in Krebs-Ringer solution with two concentrations of brilliant cresyl blue, i.e. 0.25 and 0.5 nmol/l1. It was revealed that the disintegration of red cells was significantly lower in Krebs-Ringer solution in blood donors and patients in both concentrations of brilliant cresyl blue that in isotonic NaCl. In patients where blood samples were collected within 24 hours after the attack, no significant difference was found in the disintegration of red cells as compared with blood donors. There was no significant difference in the disintegration of red cells in patients 24 hours after the attack and 10 to 20 days after the attack. The authors conclude that in the above conditions no substantial changes in the deformability of the red cells occur.

Adult↗
PubMed1988

Comparison of the ulcerogenicity of indomethacin and the gastric secretion in verapamil-treated rats.

The authors studied the effect of different doses of verapamil on the ulcerogenic activity of indomethacin (20 mg.kg-1) in rats. This was compared with the effect of verapamil on total gastric juice secretion, the amount of acid and the pH. It was found that, as distinct from total secretion and the amount of HCl, which verapamil reduced in correlation to the dose, ulcerogenicity after indomethacin was inhibited the most by a dose of 10 mg.kg-1 verapamil. Larger doses (20 and 30 mg.kg-1) did not increase the anti-ulcerogenic effect any further. This implies that verapamil-induced inhibition of the ulcerogenicity of indomethacin is not related directly to inhibition of total and acid gastric juice secretion.

Animals↗
PubMed1987

Effect of phosphates on the disintegration of red blood cells by brilliant cresyl blue in correlation to age.

The author describes age-related changes in the disintegration of rat red blood cells (RBC) caused by brilliant cresyl blue (BCB) in isotonic saline containing NaCl and phosphates. Blood was taken from rats aged 21, 45, 90-105, 340-360 and 690-720 days. The RBC were incubated four hours in the given solution. The incubation of RBC from different age groups in isotonic saline with phosphates showed no significant differences between the various age groups as far as disintegration of the RBC was concerned. When BCB was added to the solution, however, there was a marked increase in the disintegration of RBC from 21-, 42- and 690- to 720-day-old rats. The differences found in RBC disintegration can be attributed to age-determined qualitative changes in the structure of the RBC membrane--in the first place, changes in cross-linkages between the chains of the structural proteins of the RBC membrane.

Aging↗
PubMed1986

Erythrocytes and age. Disintegration of erythrocytes by brilliant cresyl blue in correlation to age.

The author describes changes in the disintegration of erythrocytes by brilliant cresyl blue in correlation to age, in rats aged 21, 42, 90-105, 340-360 and 690-720 days. The erythrocytes were incubated for 4 hours in an isotonic NaCl solution, in Krebs-Ringer solution and in each of these solutions plus brilliant cresyl blue. Disintegration in plain NaCl solution was found to be the greatest in the case of erythrocytes from 690- to 720-day-old rats. In the same solution plus brilliant cresyl blue, the rate of disintegration was very high in 21-day-old, 42-day-old and 690- to 720-day-old animals; at 90-105 days it was lower and at 340-360 days it was the lowest. Disintegration of erythrocytes in plain Krebs-Ringer solution was the lowest at 21 and 42 days; in the other age groups it was slightly higher. On adding brilliant cresyl blue, the rate of disintegration rose significantly in 21-, 42- and 690- to 720-day-old animals; at 90-105 days and 340-360 days it was no different from disintegration in plain Krebs-Ringer solution. It can be seen from the results that the rate of brilliant cresyl blue-induced erythrocyte disintegration is dependent on the age of the animals from which the erythrocytes are taken.

Aging↗