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Biomedical subjects

W Vogel

Publications and source records attributed to W Vogel.

At least 415 records · Page 23Linked to original sources
PubMed1984

Different effects of mutagens on sister chromatid exchange induction in three Chinese hamster cell lines.

The sister chromatid exchange (SCE) induction of mutagens with different mechanisms of action was comparatively investigated on permanent cell lines of the Chinese hamster (CHO, V-79, and DON) with and without exogenous metabolic activation and with the use of various experimental protocols. CHO and V-79 cells were treated with ethylmethanesulfonate (EMS), a direct mutagen; with the two indirect mutagens cyclophosphamide (CP) and benzo[a]pyrene (BP); as well as with the radical former hydrogen peroxide (H2O2) and hydroxyurea (HU), an inhibitor of DNA synthesis. Aside from an increased basal SCE level and a higher bromodeoxyuridine (BrdUrd) sensitivity, there was no decisive difference between CHO and V-79 cells. However, there was a distinct relationship between SCE induction and the experimental protocol used, which was most pronounced after HU treatment. Neither cell line was able to metabolize the indirect mutagen BP. Only in CHO cells did CP lead to increased SCE frequencies. However, in all cases, the simultaneous application of S9 mix produced a distinct SCE induction. In contrast, BP caused SCE induction in DON cells, whereas CP was not metabolized. The reason for these findings must obviously be sought in the metabolization of CP and BP via different monooxygenase systems, whose activity can differ in these permanent cell lines. One notable finding was that the number of SCE induced by H2O2 could be distinctly reduced by the simultaneous application of S9 mix. This effect can be explained by the fact that S9 mix contains H2O2-degrading enzymes. The results indicate that closely related cell lines differ in their capability for inducing SCE and that investigations of SCE inductions performed on only one cell line do not necessarily produce a representative response.

Animals↗
PubMed1984

The contribution of DNA single-strand breaks to the formation of chromosome aberrations and SCEs.

The induction of sister chromatid exchanges (SCEs) and chromosomal aberrations (CAs) with bleomycin (BLM), hydrogen peroxide (H2O2), short-wave ultraviolet (UV)-irradiation, and long-wave UV-irradiation was investigated in V79 cells with BrdUrd-substituted DNA. The application of a Neurospora endonuclease (NE) which specifically cleaves single-stranded DNA after these treatments showed that DNA single-strand breaks (SSBs) are induced by these agents. The SSBs are converted to double-strand breaks (DSBs) by NE and become visible as CAs on metaphase chromosomes. H2O2 and both types of UV-irradiation also led to an induction of CAs and SCEs, whereas BLM only induced aberrations. Cysteine (Cys) reduced the frequency of the induced SSB-dependent CAs in all treatments, but had no influence on the SCE frequencies after BLM and H2O2 treatment and had only a slight effect on the UV-induced SCEs. The results confirm the opinion that directly induced SSBs can contribute to the induction of CAs in cells with BrdUrd-substituted DNA, but that these SSBs are not efficiently converted to SCEs. The more recent conceptions regarding the mechanism of SCE are in accordance with these findings and the conclusions derived therefrom.

Animals↗
PubMed1984

A comparative study on steroid sulfatase and arylsulfatase C in fibroblast clones from 45,X/47,XXX and 69,XXY.

Steroid sulfatase (STS) and arylsulfatase C ( ARSC ) were studied in fibroblast clones from a 45,X/47,XXX mosaic and from a 69,XXY triploidy with one or two active X chromosomes. The comparison of the 47,XXX with 45,X clones showed an incomplete gene dosage effect (1.8 for STS and 2.0 for ARSC ). This was not the case for the triploid clones with different X-inactivation patterns. These results confirm previous reports on the non-inactivation of the STS gene, and establish X linkage and non-inactivation for the ARSC gene as well.

Adult↗
PubMed1984

Nonrandom distribution of methotrexate-induced aberrations on human chromosomes. Detection of further folic acid sensitive fragile sites.

Eleven folic acid sensitive fragile sites (3p14, 7p13, 7q31.1, 7q32, 9q32, 11p13, 14q23, 15q22, 16q23, Xp22.2, Xq22) were detected in one individual, eight of them previously unknown. These sites seem to bear each its specific sensitivity to folic acid deficiency. Six of the sites were observed simultaneously on both homologous chromosomes in at least one cell. Each of these 11 sites was also found in at least one among 12 individuals further examined. Some of these individuals showed six of these 11 sites. The fragile site 3p14 was detected in all individuals examined. The homologous sites 3p14 of one individual differed from each other in their frequency of lesions induced by methotrexate as well as fluorodeoxyuridine. This observation suggests that folic acid sensitivity is a property inherent in the chromatin of an individual chromosome at the site involved in fragility. This property seems to be responsible for the nonrandom fragility at that site and also for the individual sensitivity of each chromosomal site.

Cells, Cultured↗
PubMed1984

Induction of endoreduplication by hydrazine in Chinese hamster V 79 cells and reduced incidence of sister chromatid exchanges in endoreduplicated mitoses.

Hydrazine in high concentrations very effectively induces endoreduplication in Chinese hamster V79 cells. The addition of 5-bromodeoxyuridine (BrdU) for the duration of one cell cycle prior to the induction of endoreduplication produces diplochromosomes with sister chromatid differentiation (SCD) after differential chromatid staining. The fact that diplochromosomes with complete SCD are obtained shows that endoreduplication was induced in cells that were in G2-phase. The analysis of sister chromatid exchanges (SCEs) showed that hydrazine treatment rarely led to increased SCE frequencies in mitoses after endoreduplication, but that it caused a strong SCE induction in diploid second division metaphases in the same culture. Neither catalase nor cysteine had an effect on the induction of endoreduplication or the incidence of SCEs. Treatment of the cells with mitomycin C prior to addition of BrdU led to increased SCE frequencies. Compared with the normal mitoses from the same preparation, the mitoses after endoreduplication showed a significantly reduced induction of SCEs. In contrast to these findings, SCE induction was not reduced in the common tetraploid V 79 cells after colcemid-induced polyploidization.

Animals↗
PubMed1984

Differences in the induction of SCEs between human whole blood cultures and purified lymphocyte cultures and the effect of an S9 mix.

Studies for SCE induction are frequently performed on human blood cultures. Either whole blood cultures (WBC) or purified lymphocyte cultures (PLC) are employed. However, it has been shown that fundamental differences with respect to metabolic activity exist between these two systems. In order to further characterize the whole blood culture and the purified lymphocyte culture, differently acting substances were studied comparatively with and without an Aroclor-1254-induced S9 mix. Treatment with ethyl methanesulfonate (EMS), a direct mutagen, produced distinct SCE induction in both systems. Cyclophosphamide (CP) and benzo[a]pyrene (BP), two indirect mutagens, also led to a significant increase of SCEs both in WBC and PLC without S9 mix. Only with CP was this effect more pronounced after addition of S9 mix. Sodium selenite (Na2SeO3), which induced SCEs in WBC, did not show this effect in the PLC. After S9 mix was added to purified lymphocytes, an increase of SCEs by sodium selenite was observed as in WBC. H2O2, a radical former, led to SCE induction in purified lymphocytes but not in the whole blood culture. By adding S9 mix, a distinct reduction of the SCEs induced by H2O2 was established. These results show that human lymphocytes can metabolize indirect mutagens and that it should be kept in mind when using S9 mix that, besides mixed-function oxygenases, it also contains enzymes which influence the SCE-inducing effects of substances.

Animals↗
PubMed1984

Growth of fibroblasts and epithelioid cells on a new machinable bioactive glass ceramic in comparison with non-reactive materials.

In this study scanning electron microscopy (SEM) was used to investigate the substrate attachment, cell spreading and growth properties of fibroblasts and epithelioid cells on a newly developed machinable bioactive glass ceramic. The morphogenetic reactions of cell cultured on bioactive ceramic were compared with those of identical cells cultured on non-reactive glass and vitreous carbon. The adhesion, subsequent spreading and the growth appearance of fibroblasts and epithelioid cells on the surface of machinable glass ceramics are similar to those on nonreactive materials. Our findings concerning the behaviour of cell populations in vitro on the surface of a new machinable glass ceramic allow the conclusion that this implant material is adhesive for cells and biocompatible.

Animals↗
PubMed1984

Variations in the susceptibility to lysis of NK target cells.

Natural killer (NK) cell activity varied considerably from one subject to another and in the same subject tested on different occasions. In addition to the interindividual variations, considerable variation was also found in the susceptibility to lysis of cultured target cell lines. In this report it is shown that the susceptibility to lysis of NK target cells depends on the growth phase of these cells but is independent of the cell cycle. These results may be important for interpreting NK cell data, may have some implications for transplantation experiments in animals using cultured tumor cells and are in agreement with the data describing the sensitivity of tumor cells to radiation or chemotherapy.

Adult↗
PubMed1984

[Morphine concentrations in serum in need-controlled peridural morphine infusion].

After abdominal or thoracoabdominal operations, an epidural, on-demand morphine infusion following an initial bolus injection of 2 mg morphine was administered to 48 patients for postoperative pain relief. 34 non-intubated patients (Group I) and 14 artificially ventilated patients under intensive care conditions (Group II) received morphine solutions of 0.25% (maximum flow rate 0.31 ml/h) and 0.4% (maximum flow rate 0.5 ml/h), respectively. Total morphine consumption of the intensive care patients (Group II) until 8 p.m. on the 2nd postoperative day was 34.0 +/- 2.9 mg and was significantly higher than in non-intubated patients (Group I), with 6.4 +/- 0.4 mg (p less than 0.001). Although serum concentrations of free and metabolized morphine immunoreactivity declined in both groups in the course of treatment in accordance with the decreasing morphine demand, pharmacokinetics varied between the two groups. Whereas serum concentrations of free morphine immunoreactivity in group I, which decreased multiexponentially following the 2 mg. bolus injection, were not influenced by morphine infusion rates, serum morphine immunoreactivity in group II showed an increase until 8 p.m. on the operation day (p less than 0.005). Metabolized morphine reached plateau concentrations in both groups because of its relatively long half-life: the plateau in group II patients was significantly higher, was reached later and lasted longer than that of group I (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Epidural↗
PubMed1984

[Colloid osmotic pressure values of respiratory insufficiency in neonates of various gestational ages. Comparative presentation of measured and calculated values].

Colloid osmotic pressure (COP) is an important physiochemical factor in intercompartmental body fluid movements. In actual medical practise COP is notably measured in adult intensive care patients to control oncotic fluid therapy. Recent advances in oncometry technics led to rapid and accurate COP determinations also on very small sample volumes of neonatal intensive care patients. In 47 preterm and term newborns we determined during the first 9 days of life COP changes of calculated and measured values. The COP of patients with respiratory distress was compared to COP levels of newborns without respiratory problems. Until the sixth day of life preterm and term newborns with respiratory insufficiency showed significantly lower COP than normal newborns. The poorest correlation between measured and calculated COP was found in preterm infants with need of respiratory support therapy. During the whole observation period a rise of COP could be observed in all gestational age groups. This tendency should be considered before and during albumin therapy in newborns to avoid oncotic fluid overload, e.g. in a preterm infant. When volume replacement therapy is required in very young patients we advise measurement of COP as a guide to fluid selection.

Gestational Age↗
PubMed1983

[Experiences with continuous ambulatory peritoneal dialysis (CAPD) at the University Clinic for Internal Medicine in Innsbruck].

First described by Popovich et al. in 1978 [7], and modified by Oreopoulos et al. [6], CAPD is accepted as a simple technique which offers chronic dialysis to patients who are either unsuitable for, or noncompliant with, haemodialysis (HD). The technique of CAPD is based on the theoretical basis which predicted that adequate dialysis could be obtained if 10 litres of dialysis fluid per day are allowed to equilibrate with body fluids [5]. In practice, 2 litres of peritoneal dialysis solution are present in the peritoneal cavity, continuously, except for the periods when the patient exchanges the dialysate for fresh solution via a permanent peritoneal catheter [3]. The patient is ambulant and independent of hospital and machine. In our experience, with good technology and careful patient selection CAPD is now a well-established procedure and the preferred method of dialysis for some patients.

Adolescent↗
PubMed1983

Cytogenetic and biochemical investigations on fibroblast cultures and clones with one and two active X chromosomes of a 69,XXY triploidy.

Bromodeoxyuridine replication patterns showed that fibroblasts from a 69,XXY triploidy carried either one or two early replicating X chromosomes. The activity of alpha-galactosidase A measured in single cells fell into two classes with a ratio of 1:2. Dilute plating produced clones of both types with the activity of alpha-galactosidase A corresponding to the number of active X chromosomes. To our knowledge, this is the first report on clones of a triploidy with different numbers of active X chromosomes, and on a gene-dosage effect of an X-linked gene using triploid cells with one active X as control.

Cell Division↗
PubMed1983

Expression of the fragile site Xq27 in fibroblasts. II. Evidence for negative and positive clones from heterozygous females and possible relationship between frequency and phenotype.

An investigation of fibroblast clones from two females heterozygous for the Martin-Bell syndrome showed that the fibroblasts of these individuals consist of two sub-populations, one with cells expressing the fra(X)(q27) and another with cells in which this fragile site cannot be induced. This is to be expected and is in contrast to the fibroblast clones of hemizygous patients investigated earlier. The expression of fra(X)(q27) in females evidently depends on the presence of an X-linked defect with the normal allele inactivated on the other X chromosome. There may be a relationship between the mental status and the ratio of somatic cells with this defect on the active X and those cells with this defect on the inactive X chromosome in the heterozygotes. The divergence between the inactivation of the defective gene and expression of fra(X)(q27) on the late replicating X chromosome is discussed.

Adult↗
PubMed1983

Manifestation of the fragile site Xq27 in fibroblasts. III. A method to demonstrate R-type replication patterns and the fragile site.

A protocol is reported which allows the efficient induction of bromodeoxyuridine (BrdU)-induced R-type replication patterns in fibroblast cultures prepared to demonstrate the fragile site fra(X)(q27). The technique includes partial synchronization of the culture by fluorodeoxyuridine (FdU) blocking at the G1/S transition. This block does not impair the induction of the fragile site in medium 199 containing methotrexate. The marked increase of the mitotic index in the synchronized culture may be an advantage in the study of folic acid sensitive fragile sites in fibroblasts. Adding BrdU after block removal leads to an efficient labeling of replicating chromosomes without severely impairing the manifestation of fra(X)(q27).

Cells, Cultured↗