Search PubMed⌕ Search

Biomedical subjects

J Klose

Publications and source records attributed to J Klose.

At least 55 records · Page 3Linked to original sources
PubMed1983

Two-dimensional electrophoresis of soluble and structure-bound proteins from cultured human fibroblasts and hair root cells: qualitative and quantitative variation.

Proteins from cultured human fibroblasts and native human hair root cells were investigated using the two-dimensional electrophoresis (2DE) technique. Cell material from 35 different healthy persons was examined. Proteins of different sources were separated: total proteins of fibroblasts (12 cell lines), soluble proteins of fibroblasts (12 cell lines), structure-bound proteins of fibroblasts (eight cell lines) and soluble proteins of hair root cells (12 subjects). The protein samples of different individuals were run in pairs through the electrophoresis procedure and the two patterns of each pair were compared. All changes in the electrophoretic mobility of polypeptide spots (qualitative variants) and all clearly visible differences in the staining intensity of the spots (quantitative variants) were scored. Less than 1% of the qualitative variants per pattern was found in total cell proteins and this percentage was not increased in soluble proteins. No qualitative variation was detected in structure-bound proteins. Quantitative variation occurred to a considerably higher degree in the 2DE patterns than qualitative changes. The incidence of quantitative variants was about three times higher in soluble proteins (11%) than in structure-bound proteins (3.5%); in the total cell proteins it lay in between (7%). Cultured cells (fibroblasts) and native cells (hair root cells) showed a similar degree of variation. A comparison of the data shown here with data obtained by an investigation on inbred strains of the mouse suggest that the major part of the quantitative variants observed in the 2DE patterns of proteins were genetically determined. The results presented here and the mouse data mentioned above lead us to the conclusion that the genetic variability of proteins may be characterized by quantitative changes rather than by qualitative changes, and that the genetic variability occurs to quite different degrees in different classes of proteins: structure-bound proteins less than soluble non-enzymatic proteins less than enzymes (certain groups).

Adolescent↗
PubMed1983

Analysis of two-dimensional protein patterns from mouse embryos with different trisomies.

Two-dimensional protein patterns from whole mouse embryos with different trisomies (Ts) (Ts1, -12, -14, -19) and from different organs (normal or malformed) and developmental stages of Ts12 embryos were analyzed by comparison with control patterns. Quantitatively altered proteins were found, and a portion of these (21/approximately equal to 1,000, average) was attributable to the Ts conditions. Most of these variants were found always (regularly) in Ts embryos. They could be divided into two groups: group I shows characteristics (chromosome specific, density increased by a factor close to 1.5 +/- 0.12) compatible with proteins directly affected by the Ts; and group II (chromosome nonspecific, density decreased, seldom increased) results most likely from indirect effects. The incidence of group II variants (about 13/approximately equal to 1,000, average) was considerably greater than that of the group I variants (about 3/approximately equal to 1,000). The frequency of both types of variants, however, was far lower than was expected by a rough estimation. Apparently, a relatively small number of changes, rather than a complex, escalating effect, was induced at the protein level by the Ts. Some observations suggest that this is due to a stable regulation of protein concentrations. The proportion in which quantitative changes of different types occurred in the protein patterns did not correlate with the degree of developmental impairments (malformation, retardation, early death) of the embryos. The generalized occurrence of protein changes on the cellular level might explain the restricted viability of Ts mouse embryos.

Animals↗
PubMed1982

Teratogenic effects of cyproterone acetate and medroxyprogesterone treatment during the pre- and postimplantation period of mouse embryos. II. Cyproterone acetate and medroxyprogesterone acetate treatment before implantation in vivo and in vitro.

The study was performed to investigate direct embryotoxic effects of maternal progestin treatment during the preimplantation period. In the first experiment pregnant mice received a single subcutaneous injection of either cyproterone acetate (CA) or medroxyprogesterone acetate (MPA) on day 2 of pregnancy (5-600 mg/kg). In a second experiment four-cell embryos were exposed to CA or MPA in vitro (3 or 30 micrograms/ml medium). Our results revealed: (1) After maternal treatment the number of live embryos was reduced after the highest CA dose. Development into blastocysts was inhibited in a dose-related manner after CA but not after MPA. The number of cells in morulae, blastocysts, and of the inner cell mass (ICM) of late blastocysts was not affected. (2) When morulae and blastocysts were cultured in vitro after maternal treatment, hatching, attachment, and trophoblast outgrowth were inhibited after high doses, but development and differentiation of the ICM were inhibited even after low doses. (3) Application of 30 micrograms/ml of CA or MPA in vitro was directly embryolethal. Three micrograms/ml did not affect development into blastocysts, but ICM development and differentiation were again inhibited during subsequent culture in hormone-free medium. (4) Qualitative protein synthesis was altered in morulae and blastocysts 24 hours after maternal CA treatment. According to our results high doses of progestins are embryotoxic before implantation, low doses have delayed effects on embryonic development that are particularly evident after implantation in vitro.

Animals↗
PubMed1982

Mutagenicity testing on non-selectively cloned Chinese hamster ovary cells with the protein-mapping method.

Chemical mutagenesis was studied on Chinese hamster ovary cells by protein mapping. Cell cultures were treated with methylnitrosourea and the cells were cloned in non-selective media. The proteins of single clones were separated by 2-dimensional electrophoresis and analysed for qualitative (electrophoretic mobility) and quantitative (staining intensity; presence/absence) changes in the protein patterns. The investigation included 26 clones derived from treated cells and 26 control clones. The total number of gene loci tested was calculated from the number of protein spots analysed: it amounted to about 33 800. The protein patterns revealed 2 alterations defined as qualitative variant proteins. No alteration of this type was found in the control group. The frequency of quantitative variant proteins was increased by more than 100% compared with the control group. Our results and theoretical considerations suggest that the cellular concentration of single proteins offers a sensitive parameter for mutagenicity testing.

Animals↗
PubMed1982

Analysis of protein patterns in two-dimensional gels of cultured human cells with trisomy 21.

The occurrence of one chromosome of the cell in triplicate (trisomy, Ts) should increase the amount of all cell proteins coded by genes located on this chromosome. Many other proteins should be altered in their quantity by regulator genes, present in a threefold dosage, and by several indirect effects of the trisomy. We used two-dimensional electrophoresis to investigate the effect of the human Ts 21 on the proteins. Cells from different individuals with Ts 21 were cultured. Seven cell lines were derived from skin tissue and four from cells in amniotic fluid, and two cell clones were raised from fetal lung with Ts 21 mosaic. Stained two-dimensional protein patterns from these cell lines were compared with control patterns, and clearly visible differences in the staining intensity of corresponding polypeptide spots were evaluated. A few quantitatively variant polypeptides occurred in all trisomic cell lines investigated that were of a particular cell type, but no variants were consistently present in all of the 13 cell lines investigated. However the total number of variants (including variants not found in all individual cell lines) was considerably higher in trisomic cells than in normal cells.

Amniotic Fluid↗
PubMed1981

Genetic variability of proteins from plasma membranes and cytosols of mouse organs.

The genetic variability of membrane proteins (structure-bound proteins) and cytosol proteins (water-soluble proteins) was investigated in two inbred strains of the mouse, C57BL/6J and DBA/2J. Membrane proteins and cytosol were isolated from the brain and liver of the mouse. The proteins were separated by two-dimensional electrophoresis. A high number of genetic variant proteins (brain, 30; liver, 72) was found in the cytosol. Most of these variants represented changes in the amount of proteins. Electrophoretic mobility changes occurred only in about 1% (brain, 6; liver, 9) of all protein spots of a two-dimensional pattern. In contrast to the cytosol proteins, no genetic variation was detected among the membrane proteins, not even for the quantitative characteristics of the protein spots. The results obtained for the two classes of proteins suggest that the degree of variability in the amount of proteins is related to the degree of variability in the structure of proteins.

Animals↗
PubMed1981

High-resolution protein mapping of human fibroblasts and hair root cells: a standardized reproducible procedure considering the effect of cell culture parameters.

The effect of different cell culture parameters on two-dimensional polypeptide maps of human fibroblasts is considered. Improved culture methods are introduced to get better resolution and reproducibility. Based on these investigations, highly standardized techniques for the protein mapping of this tissue and also of hair root cell lysates are presented. These methods seem to be quite suitable for analysis of cellular synthesized proteins and study of variability in normal subjects and in patients with genetic disorders.

Chromosome Mapping↗
PubMed1981

Analysis of inborn errors of metabolism and other genetic defects in human fibroblasts using two-dimensional polypeptide mapping.

A standardized technique for the two-dimensional polypeptide mapping of cultured human fibroblasts has been used for the study of cellular protein variations in healthy controls, patients with inborn errors of metabolism and some other genetic defects. The analysis of about 50 gels has established that this method is very reproducible and enables the examination of about 600 polypeptides in a single gel. The inter-individual variation has been rather low (about 3%). In the gels from patients with genetic defects only very minor qualitative variations have been observed.

Ataxia↗
PubMed1981

High resolution protein mapping in fibroblast cell lines and hair roots from patients with genetic disease.

Protein patterns of cultured fibroblast and hair root lysates from healthy controls and patients with genetic diseases (Duchenne muscular dystrophy, Friedreich's ataxia, Marie's ataxia, Lesch-Nyhan syndrome, maple syrup urine disease, and trisomy 13, 18 and 21) were obtained with two-dimensional electrophoresis. The analysis of these patterns in 39 gels by visual comparison revealed differences in the presence and absence of 20 specific protein spots. However, this variability, which has been observed in healthy controls as well as in patients, could not provide a diagnosis for a specific genetic disease. Only in one case - trisomy 18 - was an additional spot observed, which was not present in any of the other gels.

Cell Line↗
PubMed1979

Isoelectric focusing and electrophoresis combined as a method for defining new point mutations in the mouse.

Isoelectric focusing followed by electrophoresis is a method that allows the survey of the expression of an enormous number of genes in one organism when this method is used for separation of complex protein solutions from the tissue of the organism (protein-mapping method). This makes it possible to use this method for developing a test system aiming at the detection of newly induced or spontaneous point mutations in mammals. A large number of loci could be tested on a relatively small number of individuals. The protein-mapping method was used for the separation of mouse tissue extracts containing soluble proteins or total cell proteins. Several modifications of the method are described. The applicability of this method for defining genetic differences of proteins was demonstrated by an investigation of different strains of mice. Thereafter, a mutagenicity test was initiated with the protein-mapping method. Mice were treated with methyl-nitroso-urea as a potential mutagenic substance and the fetuses of the F1 generation were investigated. Preliminary results suggest that new point mutations were detected with this method.

Animals↗
PubMed1978

Effects of various cephalosporins on the proximal tubule of the human kidney.

Cephamandol 6.0 g, cephazolin 6.0 g or cephacetrile or cephalothin 8.0 g were administered as short-term infusions on 3 consecutive days to informed volunteers, who had no history or evidence of impairment of renal function. There were 15 subjects in the cephamandol, cephacetrile and cephalothin groups and 14 subjects in the cephazolin group. Alanine-aminopeptidase, a characteristic tubule enzyme, was determined in a 24-hour urine 2 days before administration, during the 3 day administration and on the 4 subsequent days. In addition, alanine-aminopeptidase was also estimated immunologically in concentrated urine with the aid of an anti-brush border antibody. Cephamandol, cephazolin and cephalothin were completely without effect on the proximal tubule. Cephacetrile, on the other hand, showed clear reactions in 9 out of 15 subjects, in the form of elevated AAP activity in urine and in 6 of the cases membrane elimination was demonstrable immunologically. After withdrawal of the medication, the values of the responder group returned spontaneously to normal, i.e. no cumulative effect was detected. These investigations show that elimination of alanine-aminopeptidase in the urine is a very sensitive index of the action of cephalosporins on renal tubules.

Adolescent↗
PubMed1977

The protein-mapping-method employed to test for chemically induced point mutations in mice.

A test system for detecting point mutations chemically induced in the germ cells of mice has been proposed in the past. In the present investigation the effect of the mutagenic substance methylnitrosourea (MNU) in such a test system was studied. Male mice 10-12 weeks of age of the inbred strain BALB/c Han. were treated with MNU. Doses ranging from 40-150 mg/kg were administered over different time periods ranging from 4-14 days. Treatments were scheduled so that spermatogonia in resting or mitotic stages at the time of exposure to MNU would be mature sperm at the time of mating of the males. Proteins of the liver from F1-foetuses were separated by isoelectric focusing followed by electrophoresis (protein-mapping-method). The protein patterns were analysed for new protein spots which should suggest point mutations. The results obtained showed no protein variations in the patterns of 312 control animals (foetuses). However, two individuals with a variant protein were found among a relatively small group of 72 out of 463 treated animals. The animals of this group are offspring of male parents in which the spermatogonia were treated at the mitotic phase with the highest total dose (except the lethal dose) employed in this study. The results suggest that MNU, under these conditions, is capable of inducing point mutations in the germ cells of mice. Furthermore, the mutagenicity test system imployed by this investigation for the first time seems to be a useful system possessing relatively high sensitivity.

Animals↗
PubMed1975

Protein mapping by combined isoelectric focusing and electrophoresis of mouse tissues. A novel approach to testing for induced point mutations in mammals.

The protein-mapping method which combines isoelectric focusing in acrylamide gel and gel electrophoresis was previously used mainly for the separation of plant proteins and human serum proteins. We investigated with this technique soluble proteins of mouse tissues (whole embryos, the liver of fetal and adult mice, kidneys) and the proteins of mouse serum. The technique was tested under a number of different conditions to find those best for our purpose; they may represent some general improvements in the method. The protein patterns show high resolution and excellent reproducibility. About 275 spots were found for fetal liver, about 230 for whole embryos (day 14 p.c.) and about 100 for serum. The fact that a high number of protein spots can be evaluated by a single and comparatively simple experiment suggests that this method may be useful as an assay system for induced point mutations. The protein patterns demonstrated are compared and discgs of dominant lethal examinations after acute and subacute application of these three substances.

Animals↗