University of Turin

About: University of Turin is a education organization based out in Turin, Piemonte, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 29607 authors who have published 77952 publications receiving 2480900 citations. The organization is also known as: Universita degli Studi di Torino & Università degli Studi di Torino.

Centrosome localization determines neuronal polarity.

Abstract: Neuronal polarization occurs shortly after mitosis. In neurons differentiating in vitro, axon formation follows the segregation of growth-promoting activities to only one of the multiple neurites that form after mitosis. It is unresolved whether such spatial restriction makes use of an intrinsic program, like during C. elegans embryo polarization, or is extrinsic and cue-mediated, as in migratory cells. Here we show that in hippocampal neurons in vitro, the axon consistently arises from the neurite that develops first after mitosis. Centrosomes, the Golgi apparatus and endosomes cluster together close to the area where the first neurite will form, which is in turn opposite from the plane of the last mitotic division. We show that the polarized activities of these organelles are necessary and sufficient for neuronal polarization: (1) polarized microtubule polymerization and membrane transport precedes first neurite formation, (2) neurons with more than one centrosome sprout more than one axon and (3) suppression of centrosome-mediated functions precludes polarization. We conclude that asymmetric centrosome-mediated dynamics in the early post-mitotic stage instruct neuronal polarity, implying that pre-mitotic mechanisms with a role in division orientation may in turn participate in this event.

Stochastic well-formed colored nets and symmetric modeling applications

Abstract: The class of stochastic well-formed colored nets (SWN's) was defined as a syntactic restriction of stochastic high-level nets. The interest of the introduction of restrictions in the model definition is the possibility of exploiting the symbolic reachability graph (SRG) to reduce the complexity of Markovian performance evaluation with respect to classical Petri net techniques. It turns out that SWN's allow the representation of any color function in a structured form, so that any unconstrained high-level net can be transformed into a well-formed net. Moreover, most constructs useful for the modeling of distributed computer systems and architectures directly match the "well-formed" restriction, without any need of transformation. A nontrivial example of the usefulness of the technique in the performance modeling and evaluation of multiprocessor architectures is included. >

Management of brain metastases.

Abstract: Brain metastases occur in 20–40 % of patients with cancer and their frequency has increased over time. Lung, breast and skin (melanoma) are the commonest sources of brain metastases, and in up to 15 % of patients the primary site remains unknown. After the introduction of MRI, multiple lesions have outnumbered single lesions. Contrast-enhanced MRI is the gold standard for the diagnosis. There are no pathognomonic features on CT or MRI that distinguish brain metastases from primary malignant brain tumors or nonneoplastic conditions: therefore a tissue diagnosis by biopsy should be always obtained in patients with unknown primary tumor before undergoing radiotherapy and/or chemotherapy. Some factors are prognostically important: a high Performance Status, a solitary brain metastasis, an absence of systemic metastases, a controlled primary tumor and a younger age. Based on these factors, subgroups of patients with different prognosis have been identified (RPA class I, II, III). Symptomatic therapy includes corticosteroids to reduce vasogenic cerebral edema and anticonvulsants to control seizures. In patients with newly diagnosed brain metastases prophylactic anticonvulsants should not be used routinely. The combination of surgery and whole-brain radiotherapy (WBRT) is superior to WBRT alone for the treatment of single brain metastasis in patients with limited or absent systemic disease and good neurological condition. Complete surgical resection allows a relief of intracranial hypertension, seizures and focal neurological deficits. Radiosurgery, alone or in conjunction with WBRT, yields results which are comparable to those reported after surgery followed by WBRT, provided that lesion's diameter does not exceed 3–3.5 cm. Radiosurgery offers the potential of treating patients with surgically inaccessible metastases. Still controversial is the need for WBRT after surgery or radiosurgery: local control seems better with the combined approach, but overall survival does not improve. Late neurotoxicity in long surviving patients after WBRT is not negligeable; to avoid this complication patients with favorable prognostic factors must be treated with conventional schedules of RT, and monitoring of cognitive functions is important. WBRT alone is the treatment of choice in patients with single brain metastasis not amenable to surgery or radiosurgery, and with an active systemic disease, and in patients with multiple brain metastases. A small subgroup of these latter may benefit from surgery. The response rate of brain metastases to chemotherapy is similar to the response rate of the primary tumor and extracranial metastases, some tumor types being more chemosensitive (small cell lung carcinoma, breast carcinoma, germ cell tumors). New radiosensitizers and cytotoxic or cytostatic agents, and innovative technique of drug delivery are being investigated.