Carbon ion and proton beam irradiation of a normal human TK6 lymphoblastoid cell line within a magnetic field of 1.0 tesla.

Background: Considering the increasing simultaneous application of magnetic resonance imaging (MRI) for more precise photon radiotherapy, it will be likely for particle radiotherapy to adopt MRI for future image guiding. It will then be imperative to evaluate the potential biological effects of a magnetic field (MF) on particle irradiation. This study explores such effects on the highly radiosensitive TK6 lymphoblastoid human cell line.

The influence of a magnetic field on photon beam radiotherapy in a normal human TK6 lymphoblastoid cell line.

Background: The implementation of magnetic resonance imaging (MRI) guided radiotherapy (RT) continues to increase. Very limited in-vitro data on the interaction of ionizing radiation and magnetic fields (MF) have been published. In these experiments we focused on the radiation response in a MF of the TK6 human lymphoblastoid cells which are known to be highly radiosensitive due to efficient radiation-induced apoptosis.

Sodium MRI of the human heart at 7.0 T: preliminary results.

The objective of this work was to examine the feasibility of three-dimensional (3D) and whole heart coverage (23)Na cardiac MRI at 7.0 T including single-cardiac-phase and cinematic (cine) regimes. A four-channel transceiver RF coil array tailored for (23)Na MRI of the heart at 7.

Skin sodium measured with ²³Na MRI at 7.0 T.

Skin sodium (Na(+) ) storage, as a physiologically important regulatory mechanism for blood pressure, volume regulation and, indeed, survival, has recently been rediscovered. This has prompted the development of MRI methods to assess Na(+) storage in humans ((23) Na MRI) at 3.0 T.

Phosphodiesterase-5 inhibitors oppose hyperoxic vasoconstriction and accelerate seizure development in rats exposed to hyperbaric oxygen.

Oxygen is a potent cerebral vasoconstrictor, but excessive exposure to hyperbaric oxygen (HBO(2)) can reverse this vasoconstriction by stimulating brain nitric oxide (NO) production, which increases cerebral blood flow (CBF)-a predictor of O(2) convulsions. We tested the hypothesis that phosphodiesterase (PDE)-5 blockers, specifically sildenafil and tadalafil, increase CBF in HBO(2) and accelerate seizure development. To estimate changes in cerebrovascular responses to hyperoxia, CBF was measured by hydrogen clearance in anesthetized rats, either control animals or those pretreated with one of these blockers, with the NO inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME), with the NO donor S-nitroso-N-acetylpenicillamine (SNAP), or with a blocker combined with l-NAME.