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Biomedical subjects

B Janik

Publications and source records attributed to B Janik.

At least 19 recordsLinked to original sources
PubMed1983

Measurement of glycosylated hemoglobin on cellulose acetate membranes by mobile affinity electrophoresis.

In this method for separating glycosylated from nonglycosylated hemoglobin in blood by electrophoresis on cellulose acetate membranes, we exploit the affinity of low-molecular-mass dextran sulfate for the nonglycosylated fraction, which increases the mobility of the latter relative to that of glycosylated hemoglobin. After the membrane strips are cleared and stained, the two fractions are quantified densitometrically. As evaluated by use with blood from diabetics, results compare well with those by chromatography on short columns and by electrophoresis in commercial agar gel films.

Buffers↗
PubMed1978

Nucleic acid interaction with VERO cells. A temperature barrier in the interaction pattern.

The interaction of VERO cell monolayers with spin (nitroxide)-(labeled polynucleotides (1(N)n) was examined by electron spin resonance (ESR) spectroscopy at various temperatures. Nitroxide labels covalently linked to (A)n, (dUfl)n, (U)n and (A)n . (U)n were used to monitor the interaction. The VERO cells were grown on small quartz plates with a cell viability of 95% or better and then used directly for the ESR studies. The ESR results indicated that the interaction between VERO cells and spin-labeled nucleic acids is temperature dependent. No temperature dependence was found when VERO cells were in contact with nitroxide radicals which were free in solution or covalently bound to Sepharose 4B. The temperature dependence established with nitroxide-labeled nucleic acids indicates that a temperature barrier must exist between 20 and 26 degrees C for the interaction between nucleic acids and VERO cells; namely, at 26 degrees C or above spin-labeled nucleic acids interact significantly with a VERO cell surface; whereas, at 20 degrees C the ESR signal reports no interaction. It is concluded that a temperature-dependent phase transition of membrane components or cell surface products active at 26 degrees C or above play a key role in the nucleic acid cell surface interaction process.

Cell Line↗
PubMed1978

Interferon inducing activity of (A)n.(U)n complexes of varying chain length.

Evidence is presented that the interferon-inducing activity of (A)n.(U)n in primary rabbit kidney cells with respect to the chain length of the constituting (A)n and (U)n strands is governed by the following criteria: (1) the activity increases with the length of the uninterrupted double-stranded segment in the complex whereby both chains are equally important and the number of such segments for complex molecule is without effect, (2) at a constant total concentration of constituting nucleotides, the activity increases with the number of double-stranded molecular entities available to the cell, and (3) complexes with the (U)n strand considerably overlapping the (A)n strand are inactive due to the formation of triple stranded structures.

Animals↗
PubMed1977

Effects of ionenes on interferon induction by poly(inosinic acid) . poly(cytidylic acid).

Depending on the spacing of their positive charges, ionenes, a class of quaternary ammonium polymers, increased the interferon-inducing activity of poly(inosinic acid).poly(cytidylic acid) in mouse L-929 cells, whereas they did not enhance poly(inosinic acid).poly(cytidylic acid) induced interferon production in primary rabbit kidney and human skin fibrolast cells.

Cell Line↗
PubMed1976

Effect of polyamines on the uptake of poly (2'-fluoro-2'-deoxyuridylic acid) by a mammalian cell line.

VERO cells can take up poly(dUfl)1 from the medium. The uptake involves surface adsorption and, most probably, intracellular penetration. Part of the poly(dUfl) is hydrolyzed during incubation with the cells but the hydrolysis products are not incorporated into de novo synthesized nucleic acids. The uptake is reduced by serum and stimulated by polycationic ionenes. The magnitude of stimulation depends on the structure of the ionene and the treatment regimen.

Biological Transport, Active↗
PubMed1976

Biological, biochemical and physicochemical evidence for the existence of the polyadenylate - polyuridylate - poly 2'-fluoro-2'-deoxyuridylate triple-stranded complex.

The interferon-inducing activity of the double-stranded complex poly(A) - poly(U) in primary rabbit kidney cell cultures is reduced when the cells are treated with poly(dUfl) either 1 h before, simultaneously with, or 1 h after the exposure to the double-stranded complex. It has been demonstrated in experiments involving sensitivity to hydrolysis by RNAase, UV absorbance-mixing curves, and UV absorbance-temperature profiles that this phenomenon is due to the formation of the triple-stranded complex poly(A) - poly(U) - poly(dUfl). The latter complex seems to be the principal product of interactions in the following systems: poly(A) - poly(U) + poly(dUfl); poly(A) - poly(dUfl) + poly(U); and poly(A) + poly(U) + poly (dUfl).

Animals↗