PubMed Health⌕ Search

Biomedical subjects

J Krajewski

Publications and source records attributed to J Krajewski.

At least 19 recordsLinked to original sources
PubMed1994

Standardization of HeLa cells preparations as the source of snRNA's for preliminary study on the effectors of pre-mRNA splicing.

Physical, chemical and biological parameters of HeLa cell cultures, which ensure obtaining standard nuclear material to be used as a source of snRNP and snRNA, have been determined. The secondary structure of U1 snRNA as the result of the conformational studies performed using S1 nuclease, A and T1 ribonuclease and Pb(II) ions, and reproducibility of the results obtained after 6-48 h exposure of the cells to actinomycin D at high concentration permit to accept the proposed method of standardization as satisfactory for investigation into snRNP and snRNA.

Base Sequence↗
PubMed1992

Rapid separation of tyrosine-specific tRNA from white lupin.

During isolation of total ribonucleic acids from white lupin (Lupinus albus) and their subsequent separation by 10% polyacrylamide gel electrophoresis, a fast migrating RNA band is very well separated. The nucleotide sequence analysis of 76 nucleotide long sequence with many modified nucleosides was found to be identical with that of tyrosine specific tRNA of yellow lupin seeds (Lupinus luteus) and wheat germ (Triticum aestivum). Also this tRNA(Tyr) is identical with plant amber suppressor tRNA. The presented approach offers a very rapid method of purification of plant tRNA with UAG suppressor activity.

Base Sequence↗
PubMed1992

[Principles of establishing the registries of chemical substances in the United States and Europe].

The paper presents the principles of building up the inventories of chemical substances in the USA, the countries belonging to European Economic Community (EEC) and Austria. In all countries, the appropriate legal regulations putting the manufacturers and importers of chemicals under obligation to provide some strictly determined information underlie the decision to build up these inventories. The data provided usually inform of: manufacturer's name and address, chemical substance identity, production volume and ways of distribution. The paper presents also the criteria of selection of substances to be placed in the inventory, organizational scheme of building up the inventory and the ways of exacting the respective regulations. The inventories of chemical substances issued in the USA and Austria may serve as banks of information on the place, kind and quantity of chemical substances on the territory of the whole country. Based on these data a map of chemical hazards zones may be prepared which may adversely affect either human health or environment. The inventory of EEC countries may serve only as lists of chemicals occurring in the common market.

Austria↗
PubMed1985

Chromosome studies in 3665 consecutive newborn children.

Results of chromosomal studies done on 3665 newborn children from central Poland have been described. As against a global incidence of 1:1022 for trisomy G and 1:1308 for the balanced translocation D/D in infants, the respective figures for the Polish infants were, 1:610 and 1:1221. Likewise, against the global incidence of 1:823 for the karyotype 47, XXY and of 1:1072 for the karyotype 47, XYY in infants, the respective incidence in the Polish infants was 1:626 and 1:939. The study has demonstrated also that the frequency of occurrence of the different widths of the C-bands had a distribution close to normal. The authors have noted that the children with chromosomal abnormalities were more frequently not as well developed at birth as were children with normal karyotypes.

Adult↗
PubMed1983

2,3-diphosphoglycerate concentration in the red blood cells of anaemic pregnant women in various periods of pregnancy.

The purpose of this study was to examine the intraerythrocytic 2,3-diphosphoglycerate (2,3-DPG) concentration in anaemic (haemoglobin concentration below 10.5 g/100 ml blood) and in normal pregnant women (haemoglobin concentration above 12.5 g/100 ml blood). The authors showed that the 2,3-DPG concentration increased systematically between the 16th and 42nd weeks of pregnancy, both in the control group and in pregnant women with anaemia. However, in the group of anaemic pregnant women the 2,3-DPG concentration was higher in each stage of pregnancy.

Adult↗
PubMed1983

[Goniometric studies of the human placental barrier in late pregnancy in EPH gestosis].

The structure of normal and toxemic pregnancy (EPH-gestosis) placenta was analysed by goniometric observation. Hitherto the most characteristic symptom of gestotic placenta demonstrable by measurements appeared to be thickening of the placental basallayer consisting of the basal membranes of the capillary endothelium and syncytiotrophoblast. Observations were now made on 20 normal placentas and on 20 ones with full-clinical gestotic symptoms. Specimens prepared by conventional methods were examined with a Philips EM 300 electron microscope, equipped with a goniometer stage. Measurements of the placental basal layer in three goniometer positions: 0 degrees, + 45 degrees, - 45 degrees, were made from negatives of electron micrographs with a final magnification 135,200 x. Data were analysed statistically using Wilcoxon's test. We also used the planimetric-statistic method of Casley-Smith and Davy. We found the thickness of the gestotic placental basal layer to be significantly less than in a normal one. Ultrastructural markers of transport through the feto-maternal blood barrier were more evident that in normals. We suppose the increased placental transport and decreased thickness of the placental basal layer could be compensatory reactions to the pathological lesions of gestotic pregnancy.

Basement Membrane↗