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A Válek

Publications and source records attributed to A Válek.

At least 19 recordsLinked to original sources
PubMed1992

[Clinical study of biocompatibility of dialysis membranes made from non-modified and modified cellulose].

Basic biocompatibility parameters of dialysis membranes made of non-substituted regenerated cellulose (NRC) and cellulose membranes with hydroxyl groups substituted, to a higher (H) or lower (L) degree, by dl-ethyl-amino-ethyl groups (DEAE), or by acetate (CA) were investigated in a 16-week clinical study, involving 10 long-term haemodialysis patients. In the 15th minute of dialysis, the decrease in blood leukocyte count, while using NRC (0.24 +/- 0.03 of baseline value, arithmetic mean +/- SEM) was deeper compared with that seen in DEAE-L (0.88 +/- 0.10, p < 0.001), in DEAE-H (0.79 +/- 0.10, p < 0.01), and in CA (0.73 +/- 0.05. p < 0.05). In the 15th minute of the procedure, C5a concentrations, reflecting complement activation, were higher in NRC (4.4 +/- 0.51 micrograms/L) than in DEAE-L (1.41 +/- 0.22, p < 0.001), in DEAE-H (1.68 +/- 0.47, p < 0.01), and in CA (1.68 +/- 0.22, p < 0.01). Activated clotting times were, in the 10th minute of the procedure, significantly longer in NRC (2.94 +/- 0.37 of baseline value) than in DEAE-H (1.74 +/- 0.10, p < 0.05) and, by the end of dialysis, the difference between these membranes (NRC: 1.47 +/- 0.21, DEAE-H: 0.85 +/- 0.08, p = 0.07) was close to the level of statistical significance. The authors conclude: 1. Substitution of the hydroxyl groups of regenerated cellulose reduces the decrease in leukocyte count and complement activation in the initial phase of haemodialysis. 2. At the same time, substitution by DEAE groups may raise thrombogenicity, as indicated by the shorter activated clotting times.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[14 years of the peritoneal dialysis program at the internal medicine department in Strahov (1978-1991)].

The authors present an account of 14 years experience of the department as regards treatment of chronic renal failure by peritoneal dialysis. Initial experience revealed that this method is feasible as an alternative of haemodialyzation treatment even in case of limited technical possibilities (using the so-called bottle system) but treatment was associated with a high incidence of peritonitis. During the subsequent period the incidence of peritonitis was substantially reduced in conjunction with the elaboration of hygienic provisions, enlightment of patients and a change from the regime of continual exchanges in a home environment to a regime of intermittent peritoneal dialysis performed mostly in hospital. Experience assembled in the department was also important. The longest period of treatment is 60 months. In another 18 patients it is more than 20 months. The most frequent cause of termination is loss of the ultrafiltration capacity of the peritoneum. Several patients had successful transplantations. The prolonged experience can be used at present when the so-called bag system is introduced.

Adult↗
PubMed1992

[Does therapeutic membrane plasmapheresis increase protein synthesis?].

The objective of the investigation was to assess whether therapeutic membrane plasmapheresis accelerates protein synthesis. To this end pseudouridine (PSI), a modified nucleoside was investigated which provides information on the tRNA turnover and thus indirectly also on protein synthesis. The authors made 10 plasmapheresis on a A 2008 PF monitor with Plasmaflux P2 filters which they use to exchange 1 plasma volume of the patients. Laboratory indicators were investigated one day before plasmapheresis, on the day of plasmapheresis and during its course, and on the 1st, 2nd and possibly 3rd day after plasmapheresis. They revealed that the clearance of the plasma filter for PSI (0.41 +/- 0.04 ml/s, arithmetical mean +/- SEM) did not differ significantly from the filtration rate (0.49 +/- 0.01 ml/s, p = 0.15). As compared with the initial examination (0.49 +/- 0.06 ml/s) on the first day after plasmapheresis as a result of reduced glomerular filtration rate the renal clearance of PSI was reduced (0.33 +/- 0.05, p less than 0.01). PSI serum concentrations were therefore expressed as the serum PSI/serum creatinine ratio. This ratio was, as compared with the initial examination (80.4 +/- 4.8 nmol/mumol), raised midway during the procedure (100.8 +/- 8.6, p much less than 0.05) and after its termination (132.3 +/- 6.1, p much less than 0.01). The increase was not due to disintegration of cells or dietary factors. The rise of the serum PSI/serum creatinine ratio was due to a more rapid tRNA turnover and thus provided evidence that therapeutic membrane plasmapheresis accelerates protein synthesis.

Humans↗
PubMed1992

An equation for calculating postdialysis plasma sodium.

Well defined dry weight is a must for adequate UF control during haemodialysis (HD). However, interdialytic weight gain (delta BW) must not be excessive. delta BW is closely related to interdialytic thirst which in turn is strongly influenced by post-dialysis plasma sodium (CPNa post), but little is known about the desired CPNa post. The points below serve as a basis for establishing this value. a) Thirst is mediated by osmoreceptors. b) A strong correlation has been found between delta BW and intradialytic increase in plasma sodium but no such correlation exists with the interdialytic increase in plasma urea. This indicates that fluid intake between dialyses depends solely on electrolytes. c) Pre-dialysis plasma sodium in an individual is stable, indicating that the patient is at his "set value" of electrolyte osmolality. d) Half of the potassium removed during HD comes from the extra- and half from the intracellular space. Assuming that it is desirable not to disturb a patient's pre-dialysis osmotic steady state, it can be calculated that the desired CPNa post should be higher than the pre-dialysis value by half of the intradialytic plasma potassium drop, i.e., approx. CPNa post = CPNa pre + 1 to 2 mmol/l.

Humans↗
PubMed1991

What are the factors contributing to the changes in tissue-type plasminogen activator during haemodialysis?

Haemodialysis (HD) is associated with stimulation of the fibrinolytic system. The increase of fibrinolytic activity seems to be primarily due to tissue-type plasminogen activator (t-PA) released from the vessel wall. The aim of our study was to determine whether the t-PA release is the consequence of uraemic intoxication adjustment, extracorporeal circulation effect, heparin administration, or whether a mere reflection of the circadian rhythm of fibrinolysis is involved. To identify the factor, fibrinolytic system parameters were determined during HD, sham HD (SD), after the administration of heparin alone outside HD, and during a control period (CP). The plasma concentrations of t-PA antigen indicate that HD is associated with the release of t-PA from the vessel wall; 3.70 ng/ml before HD, 4.35 (NS) at the 15th min, 4.88 (P less than 0.05) at the 20th min, and 5.09 (P less than 0.05) after HD (medians). The respective values for a CP are 4.05, 4.37 (NS), 4.40 (NS), and 4.22 (NS). The effect of heparin alone and SD was evaluated for 120 min only, with the following t-PA concentrations determined after heparin: 5.10, 6.22 (NS), 4.72 (NS), 4.72 (NS); during SD and 4.50, 5.14 (NS), 5.20 (P less than 0.05). We conclude that t-PA is released from the vessel wall during HD. A factor contributing to its release is the extracorporeal circulation system.

Adult↗
PubMed1991

Haemofiltration or haemodialysis in aluminium elimination?

Elimination of aluminium from the body during haemodialysis and haemofiltration was investigated. Without desferrioxamine administration there was no aluminium removal from the body. After DFO administration (1 g intravenously 24-40 h before dialysis or haemofiltration) removal of aluminium during blood purification methods was achieved. During haemodialysis (n = 28, cuprophane plate dialyser with urea clearance 150 ml/min, 5 h) serum aluminium decreased by 41%. Aluminium clearance was 28 ml/min. During haemofiltration (n = 36, polyamide FH 77, volume exchange 60% of body-weight, on-line system) serum aluminium decreased by 66% and a total of 1962 micrograms of aluminium was removed during one procedure. In the 60th minute of the procedure, calculated clearance was 42 mmol/l. Because of the rebound phenomenon it is reasonable to perform two haemofiltrations after a single dose of DFO. Haemofiltration is superior to haemodialysis in aluminium removal from the body.

Aluminum↗
PubMed1990

[The effect of 1,25-dihydroxycholecalciferol on immunity and the clinical state and on parameters of phospho-calcium metabolism in dialyzed patients].

Sixteen months of administration of 1,25-dihydroxycalciferol (Rocaltrol) to twelve patients with chronic renal failure led to a substantial reduction of infectious complications during the investigation period and to improvement of the clinical condition of the patients evaluated with regard to bone and muscle pain. In laboratory indicators of immunity the authors observed an increase of the originally reduced values of phagocytosis of C, albicans and candidacidal after two weeks' administration of the drugs. Changes in the ratio of sub-populations of lymphocytes were apparent also after 16 months therapy: the authors observed a continuous decline of the lymphocyte B and lymphocyte T4 ratio and rise of the cytotoxic suppressor fraction CD8+ of lymphocytes. The different trend of changes of some immunological, biochemical and clinical indicators was apparent when the patients were subdivided according to the aetiology of renal failure.

Adult↗
PubMed1990

[Comparison of the effectiveness of hemodialysis and hemofiltration in the removal of aluminum from the body].

The authors compare the excretion of aluminium from the organism of patients with chronic renal failure during haemodialysis and haemofiltration. Aluminium can be eliminated from the organism only after previous administration of Desferal. Haemodialysis and haemofiltration alone practically do not eliminate aluminium from the organism. During haemodialysis made 24-40 hours after administration of 1 g Desferal (24 procedures, cuprophan plate dialyzer Chiraplat, urea clearance 2.5 ml/s, time 5 hours) the Al serum concentration declined by 41% and the dialyzer clearance for aluminium was during the 60th minute of haemodialysis 0.47 ml/s. During haemofiltration made 24-40 hours after administration of 1 g Desferal (36 procedures, polyamide haemofilter FH 77 on-line system of fluid exchange = 60% body weight) the Al serum concentration declined by 66% and the clearance of the haemofilter for Al was during the 60th minute 0.70 ml/s. Contrary to haemodialyzation treatment of Al intoxication, treatment with haemofiltrations was not associated with clinical complications. Haemofiltration treatment is a safe and effective method for the treatment of Al intoxication and accumulation in patients with chronic renal failure.

Aluminum↗
PubMed1990

Beta 2-microglobulin serum levels during dialysis: effect of cuprophan and serum osmolality changes.

New cuprophan dialysers were used in twenty, re-used dialysers in twelve dialyses and new dialysers in ten sequential ultrafiltrations. Serum beta 2-microglobulin (beta 2m) concentration was measured before and after all these procedures. Serum osmolality changes were compared with changes in serum beta 2m concentrations. These concentrations rose in dialyses with new and re-used dialysers, but remained unchanged during sequential ultrafiltration. beta 2m increased with serum hypo-osmolality, decreased with serum hyperosmolality and did not change during iso-osmolar dialysis. These results indicate that cuprophan membrane does not raise beta 2m concentration during dialysis. It is hypo-osmolality that is responsible for the increment of beta 2m in serum.

Cellulose↗
PubMed1990

Human recombinant erythropoietin in the treatment of anaemia in chronic haemodialysis patients.

Five women aged 50-64 years with chronic renal failure caused by interstitial nephritis, maintained by chronic haemodialysis, were treated for three months with human recombinant erythropoietin. The blood haemoglobin level roce from 78.0 +/- 6.9 g/l to 108.4 +/- 15.5 g/l, haematocrit from 21.8 +/- 1.8% to 33.6 +/- 4.8%, and the rate of reticulocytes 1.8% to 4.9%. Serum ferritin concentration declined from 2213 +/- 1982 micrograms/l to 850 +/- 953 micrograms/l. Unlike the pre-treatment period, no blood transfusion had to be given during the administration of erythropoietin. The patients' general condition improved. There were no serious complications. The action of erythropoietin persisted for two months. Human recombinant erythropoietin is a significant help in the treatment of patients with chronic renal failure.

Anemia↗
PubMed1990

[Aluminum osteopathy].

Histochemical study of 155 bone biopsies from dialyzed patients revealed 43 cases with aluminium deposits in bone trabeculae localized along the mineralization line or in phagolysosomes of bone marrow macrophages. Aluminium was limited to macrophages in 5 cases, to mineralization line in 23 cases, and found in both localities in 15 patients. Patients with a positive finding mostly had osteomalacia (8 times) which was combined in some cases (35 times) with mild fibrous osteodystrophy. Authors failed to prove histochemically positive deposits in dialyzed patients with serious parathyroidism. Simultaneous deposits of aluminium and hemosiderin were found in the mineralization line in three patients. Bone deposition of aluminium seems to influence somehow the bone lesion but precise interpretation of the phenomenon has not been given.

Aluminum↗
PubMed1989

[Treatment of anemia in patients on a regular dialysis program using human recombinant erythropoietin].

Five women aged 50-64 years with chronic renal failure, due to interstitial nephritis, enlisted in a regular dialyzation programme were treated for three months with human recombinant erythropoietin. The blood haemoglobin level rose from 78.0 +/- 6.9 g/l to 108.4 +/- 15.5 g/l, the haematocrit from 21.8 +/- 1.8% to 33.6 +/- 4.9%. The serum ferritin concentration declined from 2213 +/- 1892 micrograms/l to 850 +/- 953 micrograms/l. Contrary to the period before treatment, during erythropoietin administration no blood transfusion had to be administered. The general condition of the patients improved. There were no serious complications. The action of erythropoietin persisted for two months. Human recombinant erythropoietin is significant help in the treatment of patients with chronic renal failure.

Anemia↗