PubMed Health⌕ Search

Biomedical subjects

M Minárik

Publications and source records attributed to M Minárik.

13 recordsLinked to original sources
PubMed1997

Size-based separation of polyelectrolytes by capillary zone electrophoresis: migration regimes and selectivity of poly(styrenesulphonates) in solutions of derivatized cellulose.

The migration regimes and the separation selectivity of linear poly(styrenesulfonates) (PSS) were investigated in solutions of linear polymeric hydroxyethylcellulose (HEC). Variable parameters were the number of PSS monomer units (in the range of 25-6520), HEC concentration (below and above the entanglement threshold), molecular mass of HEC (between 35900 and 438000 Da) and electric field strength (from 190 to 1140 V/cm). Besides those regimes which are known for migration of polyelectrolytes in physical networks (Ogston sieving, reptation without and with orientation), the observed separation below the entanglement threshold indicates an effect of solute-chain interactions similar to that observed for the separation of double-stranded DNA. From the dependence of the separation selectivity on HEC concentration and molecular weight it was found that both parameters increase the separation. The selectivity of the solutions of higher concentrated low molecular HEC was compared to lower concentrated high molecular HEC, which has a similar bulk viscosity, and therefore obeys comparable peak dispersion due to thermal broadening. At high field strengths (preferably used in capillary electrophoresis) the former gave better separation only for shorter PSS molecules. For separation of longer PSS molecules, only high molecular HEC is applicable due to the deformation of the low molecular matrix by large analyte molecules.

Cellulose↗
PubMed1991

Isolation and purification of bacterial proteinases by means of autofocusing.

Autofocusing was used for the isolation and purification of neutral and alkaline proteinases from fermentation broth, after separation of cells. The yield of proteinases achieved was 19-78%, and was inversely proportional to the degree of purification, which varied from 3.0 to 7.9. Because of considerable losses of enzyme activity and the long duration of the process, autofocusing seems to be a non-economic technique for industrial isolation of relatively cheap enzymes.

Bacillus cereus↗
PubMed1989

Contribution to the aetiopathogenesis of orthostatic proteinuria in children: relation to the upper calyx syndrome.

The authors discuss the correlations between the upper calyx syndrome and proteinuria. The syndrome was demonstrated in 33.6 per cent of all children with orthostatic proteinuria hospitalized at the Paediatric Clinic, Martin (Czechoslovakia) during 1978-1985. They consider the possible relations between these conditions that could be mediated by the activation of the renin/angiotensin II system. The direct stimulus of this system could rest in local ischaemization of parenchyma in the region of the proximal pole of the kidney or its partial passive congestion. They assume that these changes become more marked in the standing position and may cause proteinuria of orthostatic character. The inhibition of the renin/angiotensin II system may obviously lead to decreased proteinuria.

Adolescent↗
PubMed1989

[The effect of prednisone in the development of nephropathy in Schoenlein-Henoch purpura].

The authors hospitalized in 1976-1987 39 children with Schönlein-Henoch's purpura who on admission had a normal finding in urine. Of the above patients 28 were given prednisone already at the onset of hospitalization, to 11 prednisone was not administered. Patients with prednisone developed nephropathy in one instance (3.5%), patients without prednisone 6 times (54.5%) which is a significant difference. The average prednisone dose was 1.7 mg per kg body weight per day for an average period of 21 days. Usually for 6-10 days the same dose was administered and then it was gradually reduced.

Child↗
PubMed1988

Incidence of renal complications in Schönlein-Henoch purpura syndrome in dependence of an early administration of steroids.

Between 1976 and 1986, the authors treated 33 children with Schönlein-Henoch purpura (S-H purpura), with physiological urinary finding on admission. Twenty-three of them received prednisone already at the beginning of hospitalization, 10 were not given any prednisone at all. In patients with prednisone, nephropathy occurred only once (4.3%), in those without prednisone it occurred 5 times (50%), the incidence being thus significantly higher. Prednisone was administered in doses ranging between 1.0 and 2.5 mg/kg body mass/day, on an average for 21 days (first 10 days in the same dose, later in reduced doses). Since there is a general lack of data on the positive effect of steroids upon the prevention of nephropathies in S-H purpura, the authors recommend more thorough studies in the initial stage of the disease (before the development of nephropathies).

Child↗
PubMed1988

Heart rate and its variability in juvenile hypertonics during respiratory maneuvers.

In 27 children (14 juvenile hypertonics and 13 healthy control children, with the mean age 14.7 +/- 0.4 y. or 15.2 +/- 0.5 y., respectively, P greater than 0.05) the changes of heart rate (HR), its variability (HRV) during deep inspiration and subsequent expiration, Valsalva's maneuver, doubled breathing frequency and the deepening of breathing were studied. The resting supine mean HR was significantly higher (P less than 0.001) in hypertonics than in controls. Deep inspiration was in both groups accompanied with the HR increase. However, the percentage increase in hypertonics was significantly lower than in normals (P less than 0.02). With subsequent expiration, the HR fell in both groups. There was no significant difference between the percentage decreases in both groups (P greater than 0.05). During the Valsalva's maneuver, in the first phase the tachycardic response occurred, which was in hypertonics significantly less pronounced. After the recovery of breathing a bradycardic reaction occurred which was equal in both groups (P greater than 0.05). Both, in juvenile hypertonics and in controls the doubled frequency of breathing increased the mean HR and decreased the HRV. During the deepened breathing there was an increase in mean HR in both groups, and only in the controls there was an increase in HRV. Heart rate variability in hypertonics was lower than in the controls under all the conditions.

Adolescent↗
PubMed1988

[IgA nephropathy].

Explore the source record for details and available documents.

Glomerulonephritis, IGA↗