Pharmacological control of local oxygen regulation mechanisms in brain tissue

Identification of viable regions in "in vitro" spheroidal tumors: a mathematical investigation

In the treatment of solid tumors by hyperthermia, a major question is how to obtain an a priori knowledge of which tumors can be effectively treated with this modality. The key question is; given a solid tumor, what parameters in the various regions of the tumor, need to be measured so that a tumor-tissue model can provide a meaningful real time simulation of the hyperthermic treatment. This paper addresses the former question as a mathematical investigation, and the latter as a consequence of the former.

Effect of cholinergic drugs on the perilymphatic oxygen tension

The effect of the intravenous injection of cholinergic drugs on perilymphatic oxygen tension (PO2) was measured using the polarographic method in 20 cats. Acetylcholine, pilocarpine and neostigmine produced minimal but statistically significant changes in perilymphatic PO2. Atropine and scopolamine did not influence the PO2 of the perilymphatic space. The reported results show that under normal conditions the cholinergic receptors of the vestibular vessels have little effect on the permeability of arterial PO2.

Increase in brain tissue oxygen availability induced by localized microwave hyperthermia

The present experiments demonstrate by direct measurements, that localized hyperthermia produced by microwave irradiation increases the oxygen levels in brain tissue in a manner dependent on tissue temperature, with concomitant breaking of the oxygen autoregulation, thus allowing for an additional increase in TpO2 upon O2 breathing.