DNA damage induced by low doses of ionizing radiation causes apoptosis, which is partially mediated via the generation of free radicals. Both free radicals and apoptosis are involved in the majority of brain diseases, including stroke, Alzheimer's disease and amyotrophic lateral sclerosis. Because previous studies have shown that tetracycline derivatives doxycycline and minocycline have anti-inflammatory effects and are protective against brain ischemia, we studied whether minocycline and doxycycline or ceftriaxone, a cephalosporin antibiotic with the potential to inhibit excitotoxicity, protect neurons against ionizing radiation in primary cortical cultures.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
February 1999
Purpose: Radiation-induced fibrosis is a common late reaction of radiation therapy. Due to a lack of feasible noninvasive techniques to assess this reaction, the long-term development of radiation fibrosis is not well described. In order to develop quantitative means for the purpose, subcutaneous fibrosis of breast cancer patients after postmastectomy radiotherapy was evaluated by clinical scoring and a new technique based on dielectric properties of the skin.
View Article and Find Full Text PDFBackground And Purpose: To measure the dielectric constant of irradiated human skin in order to test the feasibility of the dielectric measurements in the quantitation of acute and late radiation reactions.
Materials And Methods: The dielectric constant of irradiated breast skin was measured at an electromagnetic frequency of 300 MHz in 21 patients during postmastectomy radiotherapy. The measurements were performed with an open-ended coaxial line reflection method.
Neuroreport
November 1996
In situ hybridization histochemistry and immunocytochemistry were used to examine whether therapeutic ionizing radiation induces expression of immediate early genes in the rat brain. One hour following a single dose of 2 or 15 Gy the expression of c-fos and zif-268 but not of c-jun mRNAs was induced in a scattered cell population in the lateral striatum, whereas in the piriform cortex the expression of zif-268 mRNA was decreased. Other brain regions did not show consistent changes in the mRNA levels.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
October 1995
Purpose: External radiation therapy for brain tumors exposes healthy areas of brain to considerable doses of radiation. This may cause cognitive and psychological impairment, which indicate neuronal dysfunction. 1H-magnetic resonance spectroscopy (MRS) was used to study brain metabolites in the adjacent regions 0.
View Article and Find Full Text PDFWhen the whole neuraxis is irradiated, as in medulloblastoma, the large target volume makes field arrangement complicated and 3-4 adjacent fields have to be used. A calculation method, based on geometrical matching of field edges, is presented for determining optimal separation between the opposed cranial fields and the posterior spinal field as orthogonal movements of the treatment couch top. The dosimetric verification of the method with a 4 MV photon beam indicates a dose inhomogeneity below +/- 7%.
View Article and Find Full Text PDFDuring the 20-year period from 1961 to 1980, 17 cases of extranodal head and neck non-Hodgkin's lymphoma in children under 15 years of age were diagnosed in Finland. Eight cases had tumours in tonsils or nasopharyngeal adenoids and 9 cases lymphomas of other sites of the head and neck. The age-adjusted annual incidence rate for all cases was 0.
View Article and Find Full Text PDFActa Otolaryngol Suppl
January 1989
11 malignant tumours of the oral region in children under 15 years of age were diagnosed in Finland during the 20-year period from 1961 to 1980; the age adjusted annual incidence rate being 0.31 per 1,000,000 children. 5 cases were intraoral cancer and 5 cases malignant tumours of the major salivary glands.
View Article and Find Full Text PDFOnly 14 case reports of squamous cell carcinoma of the tongue in children under 15 years of age had been published until 1980. One was reported in Finland as a second tumor in a patient with retinoblastoma. According to the Finnish Cancer Registry, which covers the whole population, three cases of squamous cell carcinoma of the tongue in children under 15 years of age have been diagnosed in Finland during the 20 years from 1961 to 1980; the age-adjusted annual incidence rate being 0.
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