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Biomedical subjects

P Paoletti

Publications and source records attributed to P Paoletti.

At least 145 records · Page 8Linked to original sources

Experimental brain tumors by transplacental ENU. Multifactorial study of the latency period.

Experimental cerebral tumors have been induced by transplacental ENU. The morphologic study of the brains of treated rats revealed that cellular hyperplasias appear at the 30th day of extrauterine life in the paraventricular white matter, i.e., before the already known "early neoplastic proliferations". Cytofluorimetric investigations failed to demonstrate differences between treated and control rats during the 1st month. On the contrary, adenylate cyclase activity is very high in that period. The duration of the latency period is discussed.

Adenylyl Cyclases↗

Pathology of human malignant gliomas after radiation and chemotherapy.

The pathological effects of radio- and chemotherapy have been studied in 31 malignant gliomas. The brains have been examined by means of the complete study technique. Many histological features have been related to surgery, localization, preoperative duration, postoperative survival, irradiation, and chemotherapy. No specific alterations have been found, but some positive correlations have been established: decrease of mitoses, occurrence of macrophages and vessel degeneration after radiation, increase of monstrous cells after chemotherapy.

Adult↗

Cerebral tumours induced by ENU; changes of adenylate cyclase activity in the tumour latency time.

Tumours of the nervous system have been induced by transplacental ENU. Until the fourth month of life the tumoural lesions appear as mixed glial proliferations or oligodendroglial foci. From the fourth month on they develop as glial micro- and macrotumours or as isomorphic and polymorphic oligodendrogliomas. The adenylate cyclase activity studied during these two distinct phases of tumour development was markedly reduced in brain tumours, independent of their cellular origin, compared with the level in the normal brain. On the other hand, the activity of the enzyme responsible for the synthesis of cyclic AMP is significantly increased during the first period of tumour development when early neoplastic proliferations are present.

Adenylyl Cyclases↗

Decreased high density lipoprotein-cholesterol levels in male patients with transient ischemic attacks.

Plasma lipid and lipoproteins levels were determined in a continuous series of 50 patients (36 males and 14 females), mean age around 50 years, with a clinical diagnosis of transient ischemic attacks (TIAs). TIA was defined as a sudden episode of focal cerebrovascular insufficiency, with complete resolution of the symptoms within 24 h. TIAs are considered an important prognostic symptom for ischemic cerebrovascular diseases, being manifest in approximately 45% of the patients later undergoing a complete stroke. Plasma total cholesterol levels did not differ in these patients, when compared with a similar series of patients of the same age and sex, free of cerebrovascular lesions. A slight elevation of mean triglyceride levels was detected in the patients of both sexes, as well as higher incidence of type IV hyperlipoproteinemia. The most significant finding, however, observed only in male TIA patients, was that of significantly reduced high density lipoprotein (HDL)-cholesterol levels. This reduction (-19.7% compared to the control group) is similar to that recently reported for patients with clear-cut ischemic cerebrovascular disease. The detection of decreased HDL-cholesterol levels in male TIA patients may be of considerable significance for a prognostic evaluation of this biochemical parameter.

Adult↗

Cerebral tumors induced by transplacental ENU: study of the different tumoral stages, particularly of early proliferations.

Experimental cerebral tumors have been induced by transplacental ENU. A systematic diachronic study of the brains has been performed starting from the 15th day of extrauterine life. The tumoral lesions firstly appear as "early stage proliferations" or oligodendroglial foci and develop as glial micro- and macrotumors or as isomorphic and polymorphic oligodendrogliomas respectively. Neurinomas appear later than glial tumors. The duration of the different lesions is sketched out. The usefulness of the model for chemotherapy studies is discussed.

Animals↗

Multidisciplinary treatment for central nervous system tumours with nitrosourea compounds.

The authors report the results of a controlled clinical trial in patients with primitive and metastatic CNS tumours treated with combined therapy: surgery, radiotherapy, and chemotherapy (BCNU or CCNU). A total of 102 patients were treated, 50 with BCNU, and 52 with CCNU. The overall response (R. + P.R.) was 68% for the BCNU group, and 65% for the CCNU group. No significant differences were found between the two types of treatment, either in terms of response or in terms of quality and length of survival.

Adolescent↗

Chemotherapy of human nervous system tumors: influence on cerebrospinal fluid sterols.

The cerebrospinal fluid levels of cholesterol, desmosterol, and the ratio 100 D:C taken from a study of 59 patients are reported. The patients, who had tumors of the nervous system, underwent neurosurgery, radiotherapy, and chemotherapy with 1,3-bis(2-chloroethyl)-1-nitrosourea or 1-(2-chlororethyl)-3-cyclohexyl-1-nitrosourea. The relationships among the levels of these three parameters and the clinical and neuroradiologic evolution are discussed.

Adult↗

Chemotherapeutic effects of some alkylating derivatives of nitrosourea on the development of tumors transplacentally induced in rats by ENU.

The application of BCNU, CCNU and MeCCNU has been shown to greatly reduce the number of tumors induced in rats by transplacentally administered ENU and to inhibit the full development of tumor proliferation. Moreover, no neurinomas appeared after treatment with CCNU. The application of GCNU proved to be much less effective. Our statistics in the form of tables showing these findings are included and discussed.

Alkylating Agents↗

Radioisotope cisternography in head-injured patients.

Of 600 patients submitted to radioisotope cisternography carried out with radioiodinated human serum albumin (I131-HSA) a group of 140 had head injuries. Our investigation was intended to study the modifications of CSF circulation and absorption which accompany cranio-cerebral trauma. Of 88 head injured patients who did not undergo operation 44 had transient loss of consciouness, and 44 were in prolonged coma. Fifty-two patients underwent operation. Of these 5 had skull fractures with dural lesions, 7 had extradural haematomas, 19 had subdural haematomas, and 21 had brain contusions. Cisternograms were performed at different time intervals after trauma, and in some instances the test was repeated in order to study the possible long tern alterations of CSF circulation and absorption. Abnormalities of cisternographic pictures are classified into the following groups: 1 degree asymmetric diffusion; 2 degree operative cavity stagnation; 3 degree ventricular reflux; 4 degree associated abnormalities. Cisternographic features are analysed in relation to the corresponding clinical and pneumoencephalographic patterns in the patients examined. These investigations may enable us to recognise possible indications for shunt procedures in the management of CSF absorption defects, which are so frequently apparent after head injury.

Brain Injuries↗