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Biomedical subjects

R Marchesini

Publications and source records attributed to R Marchesini.

66 records · Page 4Linked to original sources
PubMed1982

Sequential half-body irradiation as systemic treatment of progressive Ewing sarcoma.

Sequential half-body irradiation (HBI) to be delivered in two sessions was used in 18 consecutive patients with metastatic Ewing sarcoma who relapsed after radiotherapy and multidrug chemotherapy. The HBI program to both upper and lower hemi body was completed in 11 patients (61%). The remaining 7 patients received only one single treatment of HBI because of relapse before the completion of the treatment program. In 20 of the 29 sessions HBI was employed to treat overt metastases. The overall objective response rate was 50%. Six of 18 patients (33%) are alive from 4 to 27 months, 3 of them without evidence of disease. No severe toxicity was observed. HBI as systemic treatment was more effective in patients who relapsed while off chemotherapy, with metastases confined to the lungs or to one single bone segment.

Adolescent↗
PubMedDate not supplied

Abdominal dosimetry for supradiaphragmatic irradiation of Hodgkin's disease in pregnancy. Experimental data and clinical considerations.

An experimental dosimetry by an Alderson Phantom was carried out at the Istituto Nazionale Tumori of Milan to evaluate the scattered radiation in the abdomen for a radiotherapeutic treatment of some lymph node supradiaphragmatic regions. This information is very important when a radiological treatment of stage I and IIA Hodgkin's disease must be set up after the 3rd month of pregnancy. A dose of 3000 rad (30 Gy) was given to left supraclavicular and mediastinum as if involved by a lymphoma. A cobalt 60 unit and a 6 MeV linear accelerator were sequentially tested. Scattered radiation was measured by TLD dosimeters in multiple abdominal sections from diaphragm to pubis ever 5 cm. Scattered radiation was lower with the linear accelerator than with cobalt. Doses to the pelvis ranged from 3.5 rad to 6.3 rad for the linear accelerator. These values are not negligible but acceptable, because the risks of fetal malformation are very low after the third month of pregnancy.

Cobalt Radioisotopes↗
PubMedDate not supplied

Image analysis in the RGB and HS colour planes for a computer-assisted diagnosis of cutaneous pigmented lesions.

AIMS AND BACKGROUND: A study was carried out to evaluate the effectiveness of image analysis performed by the two color representation models when a computer-assisted diagnosis of melanoma is involved. METHODS: Color images of 40 skin pigmented lesions, which included 12 melanomas, were acquired by a standard color RGB video camera and stored in a PC for off-line processing. Image analysis was performed in the red green and blue color representation model and using hue and saturation color components. To describe shape and color characteristics of each lesion, including area, roundness and color variegation, 16 parameters were derived from red, green, blue, hue and saturation color planes and tested as possible variables useful to differentiate melanomas from benign nevi. RESULTS: The test gave a result of significance for six of the 16 derived image descriptors. The general trend of our data was in agreement with clinical observations according to which melanoma is usually darker, more variegated and less round than a benign nevus, whereas lesion dimension of melanomas and benign lesions was not significantly different. CONCLUSIONS: Our preliminary results suggested that image analysis performed on hue and saturation-derived and red green and blue-derived data could better discriminate melanoma from nevi than separately using the two color representation models.

Color↗
PubMedDate not supplied

Effect of hyperthermia on rhodamine 123 cytotoxicity in doxorubicin-sensitive and doxorubicin-resistant human breast carcinoma cell lines in vitro.

Rhodamine 123 (Rh123) cytotoxicity and intracellular accumulation were studied in normothermic and hyperthermic conditions in a human breast carcinoma cell line (MCF7/WT) and its doxorubicin-resistant subline (MCF7/DoxR). MCF7/DoxR cells were resistant to hyperthermia and Rh123. Hyperthermic potentiation of Rh123 cytotoxicity was present in MCF7/WT but not in MCF7/DoxR cells. Results suggest that the effect observed in MCF7/WT cells is related to a heat-induced increased accumulation of Rh123 and not to a heat-induced activation of the drug. A low basal uptake and a fast release of Rh123 could explain the resistance of MCF7/DoxR to the drug. Resistance to Rh123 and lack of a heat-induced increased uptake account for the lack of hyperthermic enhancement of Rh123 cytotoxicity in the resistant cells.

Biological Transport, Active↗