Search results for "RADIATION"
showing 10 items of 5298 documents
Brain Edema and Intracerebral Necrosis Caused by Transcranial Low-Frequency 20-kHz Ultrasound
2006
Background and Purpose— Ultrasound-accelerated thrombolysis is a promising approach toward acute stroke treatment. In previous in vitro studies, we demonstrated enhanced thrombus destruction induced by 20-kHz ultrasound. However, little is known about biological interactions of low-frequency ultrasound with brain tissue. The aim of this in vivo MRI study was to assess safety aspects of transcranial low-frequency ultrasound in rats. Methods— The cranium of 33 male Wistar rats was sonificated for 20 minutes (20-kHz continuous wave). Power output was varied between 0 and 2.6 W/cm 2 . Tympanal and rectal temperature was monitored. Diffusion-weighted imaging and T2-weighted imaging was performe…
The correlation between the severity of radiotherapy-induced glossitis and endothelial cell injury in local tissues in a rat model.
2010
Objectives: To explore the correlation between the severity of radiotherapy-induced glossitis (RTG) and endothelial cell injury in local tissues in a rat model. Study Design: The RTG animal model was designed and used by our team. The Oral mucositis index(OMI) was documented daily. Immunohistochemistry (IHC) Staining of CD34 was utilized to identify endothelial cells in the RTG tissues. Apoptosis of endothelial cells in local lesions due to RTG was detected by the TUNEL assay. The dynamic relationship between the OMI and apoptotic endothelial cells was statistically analyzed by time. Results and Conclusions: The injury and apoptosis of endothelial cells were observed 3 day post-irradiation.…
Differential uptake of systemic fluorochrome Hoechst 33342 in lung and liver metastasis of B16 melanoma.
1992
The growth and vascularization patterns of B16 melanoma colonies in the liver and lungs were measured and compared by histological techniques and dye diffusion patterns after injection of the fluorochrome Hoechst 33342. In the liver, the fluorescent pattern of dye diffusion revealed that uninodular tumours measuring up to 146 microns in diameter were not functionally vascularized. However, when the nodules fused to give rise to multinodular tumours measuring between 256 and 366 microns in diameter, a reticular dye diffusion pattern revealed functional tumour vascularization. In the lungs, subpleural, parenchymal and peritubular (i.e. surrounding blood vessels and airways) tumours were obser…
Photodynamic therapy within edematous brain tissue: Considerations on sensitizer dose and time point of laser irradiation
1996
Photosensitizer is known to spread with vasogenic edema fluid arising from a cerebral lesion (Neurosurg 33:1075-1082, 1993), which may be essential for sensitizing malignant cells outside the main tumor mass. The present experiments seek to elucidate whether resultant necrosis of perifocal brain tissue after laser irradiation follows a corresponding time pattern and whether damage depends on the photosensitizer dose. Male Wistar rats were anaesthetized with chloralhydrate for venous cannulation, craniotomy and focal cold lesion in order to induce vasogenic edema. Simultaneously, Photofrin II (PF II) was administered at a dose of 5 mg kg-1. The animals were re-anaesthetized after either 4, 1…
Low-level 809 nm GaAlAs laser irradiation increases the proliferation rate of human laryngeal carcinoma cells in vitro
2002
The aim of the study was to investigate the effect of low-level 809 nm laser irradiation on the proliferation rate of human larynx carcinoma cells in vitro. Epithelial tumor cells were obtained from a laryngeal carcinoma and cultured under standard conditions. For laser treatment the cells were spread on 96-well tissue culture plates. Sixty-six cell cultures were irradiated with an 809 nm GaAlAs laser. Another 66 served as controls. Power output was 10 mW(cw) and the time of exposure 75–300 s per well, corresponding to an energy fluence of 1.96–7.84 J/cm2. Subsequent to laser treatment, the cultures were incubated for 72 h. The proliferation rate was determined by means of fluorescence acti…
Regional deprivation and non-cancer related computed tomography use in pediatric patients in Germany: Cross-sectional analysis of cohort data.
2016
BACKGROUND: Conflicting findings were observed in recent studies assessing the association between patients' area-level socio-economic status and the received number of computed tomography (CT) examinations in children. The aim was to investigate the association between area-level socio-economic status and variation in CT examination practice for pediatric patients in Germany. METHODS: Data from Radiology Information Systems for children aged 0 to < 15 years without cancer who had at least one CT examination between 2001 and 2010 were extracted in 20 hospitals across Germany. The small-area German Index of Multiple Deprivation (GIMD) was used to assess regional deprivation. The GIMD …
Childhood cancer and residential radon exposure - results of a population-based case-control study in Lower Saxony (Germany)
1999
A population-based case-control study on risk factors for childhood malignancies was used to investigate a previously reported association between elevated indoor radon concentrations and childhood cancer, with special regard to leukaemia. The patients were all children suffering from leukaemia and common solid tumours (nephroblastoma, neuroblastoma, rhabdomyosarcoma, central nervous system (CNS) tumours) diagnosed between July 1988 and June 1993 in Lower Saxony (Germany) and aged less than 15 years. Two population-based control groups were matched by age and gender to the leukaemia patients. Long-term (1 year) radon measurements were performed in those homes where the children had been liv…
Incidence, time trends and regional variation of childhood leukaemia in Germany and Europe.
2008
This paper presents data on the German and Europe-wide incidence, time trends and regional variations of childhood leukaemia. Data were provided by the German Childhood Cancer Registry (GCCR), a population-based cancer registry recording all cases of malignant diseases in children under 15 y of age residing in Germany and by the Automated Childhood Cancer Information System (ACCIS) co-ordinated at International Agency for Research on Cancer, Lyon, that combines and evaluates data from several European population-based cancer registries. The incidence of leukaemia (44.0 per million) has increased in Europe as well as in Germany in the last decades (0.6% annually on average). Germany shows no…
Different guidelines for imaging after first UTI in febrile infants: yield, cost, and radiation.
2013
OBJECTIVE: To evaluate the yield, economic, and radiation costs of 5 diagnostic algorithms compared with a protocol where all tests are performed (ultrasonography scan, cystography, and late technetium99dimercaptosuccinic acid scan) in children after the first febrile urinary tract infections. METHODS: A total of 304 children, 2 to 36 months of age, who completed the diagnostic follow-up (ultrasonography, cystourethrography, and acute and late technetium99dimercaptosuccinic acid scans) of a randomized controlled trial (Italian Renal Infection Study 1) were eligible. The guidelines applied to this cohort in a retrospective simulation were: Melbourne Royal Children’s Hospital, National Insti…
Survivors of childhood cancer for more than twenty years.
2001
Present health status, complications, and development of long-term survivors of childhood cancer followed for more than 20 years in a single institution were reviewed. The departmental database was searched to identify patients diagnosed with childhood cancer and consequently treated between 1965 and 1978. A total of 124 (77%) long-term survivors participated on a voluntary basis in the study. A semi-standardized interview consisted of measures evaluating the present health condition, sequelae of treatment, second malignancies, intellectual development and presence of offspring of the former patients. The majority of patients were treated with chemotherapy (82%). 67% received radiotherapy a…