Biomedical subjects

Giuseppe Privitera

Publications and source records attributed to Giuseppe Privitera.

5 recordsLinked to original sources

PubMed2005

Spectral analysis of laser-induced ultraweak delayed luminescence in cultured normal and tumor human cells: temperature dependence.

The emission spectrum of ultraviolet A laser induced ultraweak delayed luminescence in cell cultures of mammalian cells depended on the temperature during irradiation and photonic measurements. A new method using a sophisticated photomultiplier system was developed in order to find differences between normal and tumor cells. The maximal peak of the emitted light for cultures measured at low temperature of 10 degrees C was near 510 nm in the green visible region while following irradiation at 32 degrees C this maximum was shifted to yellow-orange at 570 nm both in normal and melanoma cells. Overall, this ultraweak photonic model of cultured cells provides to be a new and powerful non-invasive tool for developing new strategies in skin cancer detection.

Adult↗

PubMed2003

Solid state approach in biophoton research.

Main characteristics of the delayed luminescence (DL) emitted in the seconds range from biological systems is analyzed. The correlation between change in DL and cell's organization, and similarity with some characteristics of DL from solid state system suggest to connect DL in biological system to decay of collective electron states, formed during energy and charge transport along the macromolecular ordered structures which form the cell. Results of a proposed soliton model are discussed, together with some phenomenological evidence which emphasize the possibility of using DL measurements as an intrinsic probe in biophysical investigations.

Luminescent Measurements↗

PubMedDate not supplied

Laser-ultraviolet-A-induced ultraweak photon emission in mammalian cells.

Photobiological research in the last 30 yr has shown the existence of ultraweak photon emission in biological tissue, which can be detected with sophisticated photomultiplier systems. Although the emission of this ultraweak radiation, often termed biophotons, is extremely low in mammalian cells, it can be efficiently increased by ultraviolet light. Most recently it was shown that UV-A (330 to 380 nm) releases such very weak cell radiation in differentiated human skin fibroblasts. Based on these findings, a new and powerful tool in the form of UV-A-laser-induced biophotonic emission of cultured cells was developed with the intention to detect biophysical changes between carcinogenic and normal cells. With suspension densities ranging from 1 to 8 x 10(6) cells/mL, it was evident that an increase of the UV-A-laser-light induced photon emission intensity could be observed in normal as well as melanoma cells. Using this new detection procedure of ultraweak light emission, photons in cell suspensions as low as 100 microL could be determined, which is a factor of 100 lower compared to previous procedures. Moreover, the detection procedure has been further refined by turning off the photomultiplier system electronically during irradiation leading to the first measurements of induced light emission in the cells after less than 10 micros instead of 150 ms, as reported in previous procedures. This improvement leads to measurements of light bursts up 10(7) photons/s instead of several hundred as found with classical designs. Overall, we find decreasing induction ratings between normal and melanoma cells as well as cancer-prone and melanoma cells. Therefore, it turns out that this highly sensitive and noninvasive device enables us to detect high levels of ultraweak photon emission following UV-A-laser-induced light stimulation within the cells, which enables future development of new biophysical strategies in cell research.

Adolescent↗

PubMedDate not supplied

Clinical application of proton beams in the treatment of uveal melanoma: the first therapies carried out in Italy and preliminary results (CATANA Project).

BACKGROUND: The first Italian proton therapy facility was realized in Catania, at the INFN-LNS. With its energy (62 MeV proton beam), it is ideal for the treatment of shallow tumors like those of the ocular region: uveal melanoma, first of all (the most common primary intraocular malignancy of adults) and other less frequent lesions like choroidal hemangioma, conjunctiva melanoma, and eyelid tumors. MATERIAL AND METHODS: The first patient was enrolled in February 2002, and to date 30 patients have been treated. All patients had a localized uveal melanoma, with no systemic metastases, and had specific indications for proton beam radiation therapy: lesions between 5-25 mm basal diameter, not exceeding 15 mm thickness, absence of total retinal detachment or glaucoma. According to the tumor dimensions, 2 patients had a small lesion or T1 (6%), 3 had a medium-sized lesion or T2 (10%), 14 had a large lesion or T3 (47%), and 11 had an extra-large lesion or T3 (37%); no patient had extrascleral invasion or T4 of the TNM-AJCC Staging System. In most cases, the tumor infiltrated only the choroid (14 patients, 47%) or the choroid plus the ciliary body (14 patients, 47%). We also treated a primitive iris melanoma, without diffusion to the ciliary body. The target volume was defined as the tumor plus a safety margin of 2.5 mm, laterally and antero-posteriorly; this margin was increased to 3 mm if ciliary body involvement was present. The treatment was carried out in 4 fractions on 4 consecutive days to a total dose of 54.5 Gy (single fraction 13.6 Gy), which corresponds to 60 CGE (Cobalt Gray Equivalent; single fraction 15 CGE), because the relative biological effectiveness is 1.1. RESULTS: The first follow-up is planned at 6-8 months after the end of the treatment, and our clinical end points are local control (defined as cessation of growth or tumor shrinkage), eye retention, and maintenance of a good visual function. At the time of this writing, we had preliminary results from 13 patients. Nine patients showed tumor shrinkage (69%), 3 a substantially stable dimension (23%), but almost all patients presented an increased ultrasound reflectivity (a surrogate for tumor control). DISCUSSION AND CONCLUSIONS: The literature data show that charged particle therapy has allowed an optimal local control in the treatment of uveal melanomas (about 96% in the different series, superior to that obtained with plaquetherapy [between 83% and 92%]), a metastatic rate slightly better than enucleation reports, and a survival rate of almost 90% at 5 years. Our preliminary results show a tumor response in almost all cases, with no major acute or subacute side effects. We thus plan to continue with our treatment procedures and our dose prescription.

Cyclotrons↗

PubMedDate not supplied

Recurrent intracranial hemangiopericytoma with extracranial and unusual multiple metastases: case report and review of the literature.

Hemangiopericytoma is a rare tumor with uncommon location in the central nervous system. It has only recently been included (WHO classification 1993) in a specific group of CNS tumors and subsequently (WHO classification 1997 and 2000) as a group by itself, while before it was confused with meningeal tumors. We report on a case of a 48-year-old woman affected by this tumor. The neoplasm was located in the posterior fossa. The patient underwent primary surgery in 1990, not followed by any adjuvant therapy because of the histopathological diagnosis of meningioma. After being free from disease for eight years she developed a local recurrence in 1998. Subtotal excision of the tumor, which was finally identified as a hemangiopericytoma, was carried out, followed by adjuvant radiotherapy (64 Gy). After six months multiple metastases were found in the liver and right kidney. A radical metastasectomy was performed, followed by systemic chemotherapy. One year later (2001) the tumor recurred again intracranially and a metastases was detected in the right breast, so the patient again underwent cranial irradiation (40 Gy) and second-line chemotherapy. She died in September 2002, 12 years after the diagnosis. We may conclude that, despite the tumor's natural tendency to recur several times and the ability of intracranial hemangiopericytoma to spread outside the CNS, it is possible to ensure a long survival time.

Brain Neoplasms↗