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Biomedical subjects

M Overgaard

Publications and source records attributed to M Overgaard.

79 records · Page 5Linked to original sources
PubMed1979

Lack of radiation protective effect of orgotein in normal and malignant mammalian cells.

The potential radiation protective effect of orgotein, a metalloprotein with superoxide dismutase activity, was investigated in L1A2 tumour cells in vitro, jejunal crypt cells and C3H mouse mammary carcinoma in vivo. No effect of orgotein, given either 2 hours before irradiation or 30 min after, was observed compared to the effect of irradiation alone. Thus, it was concluded that orgotein did not influence the primary radiation response in air in mammalian cells.

Animals↗
PubMed1978

Enhancement by Corynebacterium parvum of the normal and tumor tissue response to hyperthermia.

The effect of Corynebacterium parvum treatment on the response of tumor and normal tissue to hyperthermia (43.5 degrees) was studied. Animals were C3Hf/Sed mice from our defined flora mouse colony. The time at hyperthermia that achieved control of one-half of methylcholanthrene-induced fibrosarcomas and the foot reaction were examined after treatment. C. parvum, if given 3 to 32 days before hyperthermia, enhanced the reaction to local hyperthermia of normal tissue. No enhancement was observed if C. parvum was given after hyperthermia. This enhancement was more dramatic for tumor response resulting in a therapeutic gain factor of congruent to 2.3 (3.7/1.6). Comparative studies on combined Corynebacterium and radiation failed to demonstrate the enhancement to normal tissue.

Animals↗
PubMedDate not supplied

Hyperthermia as an adjuvant to radiotherapy in the treatment of malignant melanoma.

One hundred and fifteen cutaneous or lymph node metastases from malignant melanoma were treated with three fractions of irradiation alone in 8 days (62 tumours) or followed by heat either immediately (simultaneous treatment, 26 tumours) or after an interval of 3-4 h (sequential therapy, 27 tumours). In addition, three tumours were treated unsuccessfully with heat alone. The total doses of radiation varied between 15 and 30 Gy, allowing a dose-response analysis. For irradiation alone the isoeffective dose to obtain 50 per cent complete response (TCD50) was 26.3 Gy. Addition of heat reduced the TCD50 significantly (p less than 0.05) with a thermal enhancement ratio (TER) of 1.43 for simultaneous treatment and 1.24 for sequential therapy. Also the persistent local control at 18 months was improved by hyperthermia (56 per cent versus 86 per cent, p less than 0.05). However, simultaneous treatment also enhanced the acute skin response to the same extent as the tumour (TER 1.42 for severe erythema). This schedule thus gave no therapeutic gain. In contrast, no normal tissue enhancement was found after sequential treatment (TER 1.02). Such a treatment schedule resulted in a significantly improved therapeutic ratio of 1.22. This effect was especially prominent in larger tumours (if sufficiently heated) and an analysis corrected for volume showed a TER of 1.51. A special analysis was performed in patients with multiple lesions. 15 pairs of tumours were given the same radiation dose, with or without hyperthermia. Out of these, 11 showed a better response, three showed the same response, and only in one pair was the best response in the tumour obtained by radiation alone.

Combined Modality Therapy↗
PubMedDate not supplied

Evaluation of radiotherapy in high-risk breast cancer patients given adjuvant systemic therapy.

The Danish Breast Cancer Cooperative Groups DBCG 82b and c randomized trials are analyzed in order to illustrate the influence of radiotherapy after modified radical mastectomy in high-risk pre- and postmenopausal patients also receiving systemic therapy with respect to loco-regional tumor control, disease-free and overall survival and cardiac mortality. The results from the present randomized studies indicate that adjuvant systemic treatment does not sufficiently prevent local recurrence. An effective loco-regional treatment is therefore required in order to achieve maximal survival benefit from systemic therapy. However the temporary and persistent toxicity following each treatment modalities have to be weighed against the outcome of obtaining an optimum quality of life.

Antineoplastic Combined Chemotherapy Protocols↗