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Biomedical subjects

D Töllner

Publications and source records attributed to D Töllner.

12 recordsLinked to original sources
PubMed1978

[Size distribution of colonies for the detection of cytogenetic lesions due to X-rays and cytostatics].

1. The "all or nothing" principle in the colony survival test has to be given up. By reproductive death of mammalian cells we can conclude that colonies with two and more cells in the colony survival must be considered. An arbitrary drawn low limit of cell numbers can give misleading results. 2. The colony-size spectrometry registers the reproductive lethal cell damages. These cell damages could be detected qualitatively as well as quantitatively. The sensitivity of this method is greater on low and middle X-ray dose as compared with the colony-survival test. 3. Sublethal damages with tendency of recovery as produced by the split-dose effect are not observed by colony-size-spectrometry. Therefore, this damage is not due to chromosomal X-ray-damages. 4. The combination of physical and radiogenic damages as well as the combination of radiogenic and pharmacological damages and lethal reproductive cell damages also can be seen. The colony-size-spectra observed show that only additive but no potentiating effects occur. 5. There is a linear relationship between MKD and X-ray dose. This relationship becomes asymptotic using cytostatics as in the case of Bleomycin and ICRF 159 in a dose range beyond approximately 2 mg/kg.

Bleomycin↗
PubMed1977

[The effect of bleomycin, ICRF 159 and of simultaneous X-ray application on CHO-fibroblasts].

The cell damage of the cytostatics Bleomycin and ICRF 159 were studied experimentally by the use of the following parameters: colony survival, colony-size-spectrometry and multiplicity of CHO-Fibroblasts. Series of increasing drug concentrations and simultaneous irradiation with 200 rds were measured. In the above mentioned tests an additive and no potentiating effect of damage by the cytostatics in combination with irradiation of 200 rds was found. Compared with Bleomycin, ICRF 159 showed a higher degree of damage to CHO-Fibroblasts.

Animals↗
PubMed1976

[Diagnosis of breast carcinoma. Value of x-ray findings for the diagnosis of carcinoma in situ of the breast from the clinical point of view].

The x-rays-results of 35 mammae with a carcinoma in situ are presented and compared with those of 2 groups without carcinoma. In contradiction to invasive malignancies the carcinoma in situ do not show pathognomonic signs on x-ray examination. However, suspicion is raised by the appearance of microcalcifications and by striped differences in tissue density. These findings should compell to perform a biopsy, even though the clinical and roentgenologic findings may otherwise suggest a fibrocystic disease. Therefore, provided the discrete signs described in this paper are carefully considered, the technique of mammography may contribute to the pre-operative presumptive diagnosis of carcinoma in situ.

Adult↗
PubMed1976

[New intensifying screens in clinical radiology. Paper I-Experimental investigations (author's transl)].

The degree of intensification and resolution was compared using rare-earth-screens and conventional calcium tungstate screens. -In order to approximate usual phantom (DIN 6, 815) was equipped with a lead grid at a depth of 6 cm. Nine screen-film combinations were exposed at 70 to 80 kv., using a 12-pulse generator and Bucky grid till blackening of S = 1 was obtained. -Resolution depends substantially on the inherent noise of the system and improves from 0.6 Lp/mm. for the most sensitive combinations (intensitification factor 8.0) to 1.15 Lp/mm (intensification factor 1.7). Compared with the standard combination with a resolution of about 0.9 Lp/mm., dose was reduced by more than 40% with an increase in resolution of 45% (combination 3M-Trimax A4/XD).

Dose-Response Relationship, Radiation↗
PubMed1976

[Floating rates of synchronized CHO fibroblasts following 60Co gamma irradiation].

Monolayer cell colonies normally are pushing off single cells, which go into suspension. A dose-dependent increase of these cell detachments followed by readhesion and colony forming would influence the colony survival curve. Detached cells being in suspension can be verified by means of the colony forming test after decantation and inoculation of the medium. The amount of colony forming cells in the late phase of synthesis does scarcely change following 300 rds of 60Co gamma irradiation. The diminution of cell adhesion expected as a result of radiation damage could not be observed.

Animals↗
PubMed1975

[In vivo dissolving of gall-stones: the effect of chenodeoxycholic acid. (author's transl)].

Chenodeoxycholic acid (CDCA) was administered for an average of 15 months to 14 patients with gall-stones. The gall-stones were radiolucent in all but one instance (solitary calcified stone). Stones dissolved completely after 12 and 15 months of therapy, respectively, in two patients, while in four the size of the stones diminished. No change occurred in the remaining patients. In five patients multiple stones dissolved, while in one a radiolucent solitary stone dissolved. In one patient, with a negative cholecystogram for a time before being treated with CDCA, the gall-bladder perforated while on treatment. CDCA was well tolerated by all patients: upper abdominal discomfort disappeared during CDCA treatment in two patients and improved in nine. Only side-effect was occasional mild diarrhoea in five patients. Bile was analysed in seven patients, supersaturation with cholesterol being found in five. Biliary lipid composition became normal during CDCA treatment in these five patients. Serum triglyceride levels fell during CDCA administration in ten of eleven patients in which serum measurements were made; the greatest fall occurred in the five patients with hypertriglyceridaemia. The fall in triglyceride levels was associated with a diminution of the pre-beta-lipo-protein fraction and the chylomicron fraction. No significant change occurred in serum cholesterol levels.

Adult↗
PubMed1975

[Colony size spectra of 60Co-gamma-irridiated CHO fibroblasts following freeze and thaw cycles].

The production of reproductive lethal cell lesions by freeze and thaw cycles has been studied by means of colony size spectrometry in tetraploid CHO-fibroblastoma protected with glycerine. The verification sensitivity of this method is compared with that of the colony formation test, the survival curve of cells and the relative multiplicity. 20 days after a freeze and thaw cycle only the spectrometry of the colony size and survival curve of the cells and colonies suggest a cell lesion. After 44 days, changes as a consequence of reproductive lethal lesions can be detected only in the spectrum of the colony size. Survival curves of the colonies, survival curves of the cells and relative multiplicities determined on cell strains 44 days after a freeze and thaw cycle are not significatively different from the results of non-frozen control cells. The relation of the average cellular multiplicity after a freeze and thaw cycle to that of the nonfrozen control cells approaches the value of 1 with increased cultivation period after a freeze and thaw cycle. The reproductive lethal lesion after a freeze and thaw cycle is also decreasing with an increased cultivation period. Proliferation lesions by means of 60-Co gamma irradiation have been influenced in dependence of the dose by 20 days of freeze and thaw lesions of a cell population.

Animals↗