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Biomedical subjects

J Overgaard

Publications and source records attributed to J Overgaard.

At least 325 records · Page 18Linked to original sources
PubMed1975

rCBF in impending brain death.

Regional cerebral blood flow (rCBF) was measured in three patients after relief of elevated intracranial pressure and restoration of normal cerebral perfusion pressure. Two patients, studied within 4 hours after closed head injury were found to have marked impairment of cortical blood flow and elevation of cerebrovascular resistance. We suggest that this picture is indicative of impending brain death, and may be the result of a long period of severe cerebral ischemia. The third patient, who had a shorter period of intracranial hypertension occurring during anaesthetic induction, responded to reduction of ICP quite differently with a transient relative hyperaemia. The physiopathological explanations for these two different types of flow response and their possible clinical significance are discussed.

Accidents, Traffic↗
PubMed1975

Histologic and histochemical reactions in a mouse mammary carcinoma following exposure to combined heat-roentgen irradiation.

In mouse experiments a high curative effect on implanted tumours was obtained by successive application of low local heat and roentgen doses. Histologic and histochemical examinations of tumours so treated revealed a special reaction in the tissues. A total and rapid destruction of all hypoxic tumour tissue was observed and (in successful cases) a total blockade of all mitotic activity in euoxic tumour tissue was followed by a long-drawn necrobiotic decay of the existent tumour cells. The disturbances are electively bound to the tumour cells, only some normal tissues may secondarily be injured. A rapid and intensive lysosomal activity in all the tumour cells may probably be of importance in the reaction.

Animals↗
PubMed1974

Radiation sensitizing effect of heat.

The radiation sensitizing effect of heat is analysed. In an isologous mouse-tumour system a successive local exposition to heat and roentgen irradiation with doses of both components of a size expected separately to give no or a few cures only an evident rise in the curative results was obtained. The presence of a synergism of the factors applied is suggested. The effect obtained depends on the dose of both factors. It is independent of the sequence of the application of the two components and is not reduced by an interval of 24 h between the exposures.

Animals↗
PubMedDate not supplied

Carcinoma of the nasopharynx: analysis of treatment results in 167 consecutively admitted patients.

Radiotherapy with curative intent was administered to 159 of 167 consecutively admitted patients with nasopharyngeal carcinoma. The classification (UICC 1982) gave the staging: stage I 8%, stage II 2%, stage III 28%, and stage IV 61%. The actuarial local tumor control was 54% and correlated to the T-classification. Primary control of neck nodes was 67% but was not correlated to the N-classes. Distant failure occurred in 20% of the patients; this was correlated to the N-classification. The 10-year actuarially corrected survival rate was 37% (stage I+II 60%, stage III 49%, stage IV 27%). Late reactions were seen in 69%, and most patients had mild to moderate xerostomia. Men with high hemoglobin had a better prognosis than men with values in the lower part of the normal range. It is concluded that primary control in the T- and N-positions is the parameter most crucial to success.

Actuarial Analysis↗
PubMedDate not supplied

Potentiation of the anti-tumour effect of hyperthermia by combining with the vascular targeting agent 5,6-dimethylxanthenone-4-acetic acid.

The potential of the vascular targeting agent 5,6-dimethylxanthenone-4-acetic acid (DMXAA) to enhance the effect of hyperthermia was investigated in a C3H mouse mammary carcinoma grown in the feet of female CDF1 mice and in normal foot skin. DMXAA, when injected intraperitoneally in restrained non-anaesthetized animals, reduced tumour perfusion, as measured using the RbCl extraction procedure, and increased necrosis in histological section, but these effects were dependent on the drug dose and time interval. At a dose of 20 mg/kg, it significantly enhanced the thermal damage of this tumour, when given 1 h or more before the start of heating, as assessed by a tumour growth assay. This enhancement became larger with increasing interval between the two treatments. No thermo-potentiation was seen at doses of 10 mg/kg or lower. These combined effects seem to be associated with the tumour vascular shut-down by DMXAA. Thermal potentiation by DMXAA was also dependent on the heating temperature, with a greater enhancement relative to hyperthermia alone obtained at the lower temperatures at 40.5 and 41.5 degreesC than at the higher temperature of 42.5 degrees C. DMXAA (20 mg/kg) also enhanced the heat damage of normal skin, and this could not be explained by any DMXAA-induced TNF-alpha production. The heat enhancement-ratio by DMXAA was larger in tumours (1.9) than in normal skin (1.3-1.5), thus giving rise to a therapeutic gain.

Animals↗