Intestinal tumours induced in Apc(Min/+) mice by X-rays and neutrons.

Purpose: To compare the development of intestinal adenomas following neutron and X-ray exposure of Apc(Min/+) mice (Apc - adenomatous polyposis coli; Min - multiple intestinal neoplasia).

Materials And Methods: Adult mice were exposed to acute doses of X-rays or fission neutrons. Tumour counting was undertaken 200 days later and samples were taken for Loss of Heterozygosity (LOH) analysis.

A two-mutation model of radiation-induced acute myeloid leukemia using historical mouse data.

From studies of the atomic bomb survivors, it is well known that ionizing radiation causes several forms of leukemia. However, since the specific mechanism behind this process remains largely unknown, it is difficult to extrapolate carcinogenic effects at acute high-dose exposures to risk estimates for the chronic low-dose exposures that are important for radiation protection purposes. Recently, it has become clear that the induction of acute myeloid leukemia (AML) in CBA/H mice takes place through two key steps, both involving the Sfpi1 gene.

Microsatellite instability in radiation-induced murine tumours; influence of tumour type and radiation quality.

Purpose: To investigate microsatellite instability (MSI) in radiation-induced murine tumours, its dependence on tissue (haemopoietic, intestinal, mammary, brain and skin) and radiation type.

Materials And Methods: DNA from spontaneous, X-ray or neutron-induced mouse tumours were used in Polymerase Chain Reactions (PCR) with mono- or di-nucleotide repeat markers. Deviations from expected allele size caused by insertion/deletion events were assessed by capillary electrophoresis.

Biodistribution of (10)B for Boron Neutron Capture Therapy (BNCT) in a mouse model after injection of sodium mercaptoundecahydro-closo-dodecaborate and l-para-boronophenylalanine.

In boron neutron capture therapy, the absorbed dose from the (10)B(n,alpha)(7)Li reaction depends on the (10)B concentration and (10)B distribution in the irradiated volume. Thus compounds used in BNCT should have tumor-specific uptake and low accumulation in normal tissues. This study compares in a mouse model the (10)B uptake in different organs as delivered by l-para-boronophenylalanine (BPA, 700 mg/kg body weight, i.

Boron nanoparticles inhibit tumour growth by boron neutron capture therapy in the murine B16-OVA model.

Background: Boron neutron capture therapy usually relies on soluble, rather than particulate, boron compounds. This study evaluated the use of a novel boron nanoparticle for boron neutron capture therapy.

Materials And Methods: Two hundred and fifty thousand B16-OVA tumour cells, pre-incubated with boron nanoparticles for 12 hours, were injected subcutaneously into C57BL/6J mice.

Uptake of two 10B-compounds in liver metastases of colorectal adenocarcinoma for extracorporeal irradiation with boron neutron capture therapy (EORTC Trial 11001).

Disseminated metastases of colorectal cancer in liver are incurable. The trial EORTC 11001 investigates whether autotransplantation after extracorporeal irradiation of the liver by boron neutron capture therapy (BNCT) might become a curative treatment option because of selective uptake of the compounds sodium mercaptoundecahydro-closo-dodecaborate (BSH) or L-para-boronophenylalanine (BPA). BSH (50 mg/kg bw) or BPA (100 mg/kg bw) were infused into patients who subsequently underwent resection of hepatic metastases.

Pre-exposure to low doses: modulation of X-ray-induced dna damage and repair?

The adaptive response to ionizing radiation may be mediated by the induction of antioxidant defense mechanisms, accelerated repair or altered cell cycle progression after the conditioning dose. To gain new insight into the mechanism of the adaptive response, nondividing lymphocytes and fibroblasts were used to eliminate possible contributions of cell cycle effects. The effect of conditioning doses of 0.

Mutations of the PU.1 Ets domain are specifically associated with murine radiation-induced, but not human therapy-related, acute myeloid leukaemia.

Murine radiation-induced acute myeloid leukaemia (AML) is characterized by loss of one copy of chromosome 2. Previously, we positioned the critical haematopoietic-specific transcription factor PU.1 within a minimally deleted region.

Tissue uptake of BSH in patients with glioblastoma in the EORTC 11961 phase I BNCT trial.

Purpose: The uptake of the boron compound Na2B12H10-SH (BSH) in tumor and normal tissues was investigated in the frame of the EORTC phase I trial 'Postoperative treatment of glioblastoma with BNCT at the Petten Irradiation Facility' (protocol 11961).

Methods And Materials: The boron concentration in blood, tumor, normal brain, dura, muscle, skin and bone was detected using inductively coupled plasma-atomic emission spectroscopy in 13 evaluable patients. In a first group of 10 patients 100 mg BSH/kg bodyweight (BW) were administered; a second group of 3 patients received 22.

Dose planning with comparison to in vivo dosimetry for epithermal neutron irradiation of the dog brain.

Boron neutron capture therapy (BNCT) is an experimental type of radiotherapy, presently being used to treat glioblastoma and melanoma. To improve patient safety and to determine the radiobiological characteristics of the epithermal neutron beam of Finnish BNCT facility (FiR 1) dose-response studies were carried on the brain of dogs before starting the clinical trials. A dose planning procedure was developed and uncertainties of the epithermal neutron-induced doses were estimated.