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Biomedical subjects

O Hug

Publications and source records attributed to O Hug.

At least 19 recordsLinked to original sources
PubMed1979

[Radiobiological aspects of preoperative radiotherapy (author's transl)].

Radiobiological considerations suggest the use of preoperative radiotherapy with subcurative doses in malignancies known for frequent local recurrence or for easy metastatic spread during surgery. Clinical experience with this form of preoperative radiotherapy on esophageal cancer is being analyzed in regard to its radiobiological significance.

Humans↗
PubMed1978

[Radiation sensitivity of the amelanotic hamstermelanoma in vitro and in vivo (author's transl)].

Radiation sensitivity of the hamster melanoma AMel 3 was studied in vivo and in vitro. In vitro, a dose-effect curve with the dose Do=155 rd and the extrapolation number 10 was obtained. In consideration of an oxygen enhancement factor of 2.5, the results of in-vivo examination with the quantitative transplantation method did not differ from in-vitro results. In living animals, about 40% of the tumor cells generally are hypoxic. These data do not verify the hypothesis of a particular radiation resistance of melanoma cells.

Animals↗
PubMed1977

[Pattern of recurrence of surgically treated primary malignant melanomas of the skin. Therapeutic consequences (author's transl)].

Recurrences were observed within 2 years in 14 out of 169 operatively treated malignant melanomas of the skin (Stage I). Since it cannot be excluded that local remanifestation may be the starting point of proliferative metastasis formation, an extensive low-dose irradiation therapy limited to one day preoperatively is suggested, to prevent the appearance of prognostically unfavorable local recurrences of operatively treated malignant melanoma.

Adult↗
PubMed1977

[Introduction in the problem of the time factor and its therapeutical significance (author's transl)].

Dependencies of biological radiation effects on time distribution of dose may result from a) restitution processes on all levels of effect and b) changes of radiation sensitivity by irradiation itself. In case of fractionated radiation therapy the following mechanisms are important: intercellular recovery, cell renewal, synchronization, reoxygenation and redistribution of cells within the cycle. It has to be proven whether and to what extent the particular processes differ in the radiation reaction of tumours on the side and of normal tissues on the other--so that these differences may be used for the development of optimal fractionation schemes. The Strandqvist concept of dose-time-effect relationship is to be considered as an approximation to complex biological conditions. From recent results of cell kinetic studies and of experimental tumour therapy one may expect that for various tumour types according to their specific growth-characteristics and radiation reactions individual modes of dosage may be developed in future in which the curative dose is lower than expected.

Adenocarcinoma↗
PubMed1976

Experimental induction of bone tumors by short-lived bone-seeking radionuclides.

Single and repeated applications of 224Ra and single applications of 227Th to more than 600 female NMRI mice 3 - 4 weeks old, and to male NMRI mice have led to a high rate of osteosarcomas. Tumor incidence is dose-related. 227Th is more carcinogenic than 224Ra which induced the highest tumor incidence of 60% after a single injection of 5 muCi per Kg body weight or more. Repeated injections of 224Ra to female mice yielded a tumor incidence of up to 92%. Most of these osteosarcomas consist of well-differentiated bone-forming osteoplastic tissue. Half of the tumors occurred in the spine, particularly in the lumbar region. In protraction experiments, multifocal osteosarcomas have been observed. Less than 10% of the mice with osteosarcoma had developed metastases in lung, spleen, liver, and kidney. The possible mechanisms of the protraction effect are discussed.

Animals↗