PubMed Health⌕ Search

Biomedical subjects

S Ceruti

Publications and source records attributed to S Ceruti.

31 records · Page 2Linked to original sources
PubMed1996

[Diagnostic imaging of osteoid osteoma].

Conventional radiography, bone scintigraphy and Computed Tomography (CT) are the most useful tools to identify osteoid osteomas. We examined 26 patients (14 men and 12 women) with osteoid osteoma in different skeletal sites (13 femora, 3 tibiae, 3 hands, 2 peroneal bones, 2 humera, 2 spines and 1 talus) and compared the diagnostic yield of the above techniques. The fundamental radiographic findings in this benign bone lesion are the presence of a "nidus", with or without calcifications, perilesional sclerosis and periosteal new bone formation. Four patients in our series had soft tissue edema. In the majority of cases, conventional radiography is the imaging method of choice, because it is easily available and its diagnostic yield is adequate (17 patients in our series), especially if combined with bone scintigraphy-whose high diagnostic sensitivity was proved in all of our patients. CT is recommended for its better spatial resolution, in view of surgery, especially when soft tissues are involved. MRI is a highly valuable tool in bone tumor staging because it demonstrates cortical involvement and intramedullary and soft tissue spread. However, MR findings might be misinterpreted as indicating a more aggressive pathologic process.

Adolescent↗
PubMed1995

A novel action for adenosine: apoptosis of astroglial cells in rat brain primary cultures.

2-chloro-adenosine induced apoptosis of astroglial cells in rat brain cultures, as shown by flow cytometry and morphological analysis. The adenosine analogue was far more potent than several previously characterized sugars (including 2-deoxy-D-ribose and D-ribose, the sugar moiety of 2-chloro-adenosine), which trigger apoptosis in a variety of cell-lines [8-10], suggesting that the effects of 2-chloro-adenosine are only partially dictated by its sugar moiety. Nevertheless, 2-chloro-adenosine and 2-deoxy-D-ribose attenuated each other's cell death when used in combination, suggesting the involvement of common intracellular mechanisms. It is suggested that 2-chloro-adenosine may induce apoptosis via a yet-to-be identified adenosine receptor, which may have intriguing implications for both nervous system development and brain response to trauma and ischemia.

2-Chloroadenosine↗
PubMed1995

Effects of ATP analogues and basic fibroblast growth factor on astroglial cell differentiation in primary cultures of rat striatum.

We have used primary cultures of rat striatum to study the effects of ATP analogues on the elongation of astrocytic processes, a parameter of astroglial cell differentiation. Parallel studies were performed with basic fibroblast growth factor, a known regulator of astroglial cell function. After three days in culture, both the growth factor and alpha beta-methylene-ATP induced dramatic increases in the mean length of astrocytic processes/cell. For both agents, effects were dose-dependent. The effect of alpha beta-methylene-ATP was antagonized by the trypanoside suramin and mimicked by 2-methyl-thio-ATP, suggesting the involvement of a suramin-sensitive P2-purinoceptor. Neither an additive nor a synergistic effect between alpha beta-methylene-ATP and basic fibroblast growth factor on the elongation of processes was detected in cultures exposed to both agents. Indeed, an inhibition with respect to the effects induced by either agent alone was recorded, suggesting that the growth factor and the purine analogue can modulate astrocytic differentiation by activation of common intracellular pathways. It is concluded that, like basic fibroblast growth factor, ATP can promote the maturation of astrocytes towards a more differentiated phenotype characterized by the presence of longer astrocytic processes. These findings might have interesting implications for astroglial cell differentiation during brain development and for ischemia- and trauma-associated hypergliosis.

Adenosine Triphosphate↗
PubMed1995

SPET imaging of intracranial tumours with 99Tcm-sestamibi.

Single photon emission tomography (SPET) employing 99Tcm-sestamibi (MIBI) injected intravenously was performed in 27 patients for pre-surgical evaluation of intraparenchymal brain tumours. A computerized tomography (CT) scan was performed in 26 patients, magnetic resonance imaging (MRI) in 8 patients and digital subtraction angiography (DSA) in 14 patients. Visual analysis of the SPET scans was performed using a 4-point scale relating to background activity, to evaluate MIBI uptake in the tumour. The vascular supply and the cellular component were also evaluated using DSA and CT scans. In normal controls, MIBI uptake was observed in the scalp, in the choroid plexus and in the pituitary gland, but never in normal parenchyma. Among the astrocytoma group of patients, a trend between MIBI uptake and grade of tumour was noted. MIBI uptake in meningiomas depends primarily on the vascular supply. Our results support the hypothesis that vascular supply, integrity of the blood-brain barrier, the degree of malignancy of the neoplasm and the viability of the tumour cells may be related to MIBI uptake.

Adult↗
PubMed1995

G protein-dependent activation of phospholipase C by adenosine A3 receptors in rat brain.

The recently cloned G protein-coupled adenosine A3 receptor has been proposed to play a role in the pathophysiology of cerebral ischemia. Because phospholipase C activation occurs as a very early response to brain ischemia, we evaluated the ability of A3- selective and nonselective adenosine analogues to elicit phosphoinositide hydrolysis. In myo-[3H]inositol-labeled rat striatal and hippocampal slices, A3 agonists stimulated formation of [3H]inositol phosphates in a concentration-dependent manner. In striatum, the potency order was 2-chloro-N6-(3-iodobenzyl)- adenosine-5'-N-methyluronamide > or = N6-(3-iodobenzyl)- adenosine-5'-N-methyluronamide >> N-methyl-1,3-di-n-butylxanthine-7-beta-D-ribofuronamide > or = 5'-N-ethylcarboxamidoadenosine > or = N6-2-(4-aminophenyl)-ethyladenosine > N6-(p-sulfophenyl)-adenosine = 1,3-dibutylxanthine-7- riboside, which is identical to the potency order in binding studies at cloned rat A3 receptors. Stimulation of phospholipase C activity was abolished by guanosine-5'-O-(2-thiodiphosphate), confirming the involvement of a G protein-coupled receptor. Activation of phospholipase C was higher in the striatum than in the hippocampus, consistent with A3 receptor densities. Stimulation of phospholipase C activity by adenosine analogues was only modestly antagonized by xanthine derivatives and at much higher concentrations than needed for blocking adenosine A1, A2A, and A2b receptors. In the presence of an A1/A2 antagonist, a selective A3 in rat striation. Thus, stimulation of phospholipase C activity agonist only weakly inhibited forskolin-stimulated adenylyl cyclase activity represents a principal transduction mechanism for A3 receptors in mammalian brain, and perhaps A3 receptor-mediated increases of inositol phosphates in the ischemic brain contribute to neurodegeneration by raising intracellular calcium levels.

Adenosine↗
PubMed1993

[The temporo-mandibular joint in pathologic conditions: rheumatoid arthritis and seronegative spondyloarthritis].

Pain and dysfunction of the temporomandibular joint (TMJ) are major clinical problems, especially in arthritides and allied conditions. In the last 10 years, such new imaging methods as arthrography, CT and MRI have been developed, but many problems are still to be solved. This study was aimed at reporting the radiographic patterns of lesions in TMJ rheumatoid arthritis and seronegative spondyloarthropathies and at investigating the role of conventional radiology in the assessment of these disorders. Digital hypocycloidal tomography of the TMJ was performed on 44 patients affected with rheumatoid arthritis, on 2 with Sjögren's syndrome, 2 with ankylosing spondylitis, 4 with psoriatic arthritis and 1 with Reiter's syndrome. CT, with sagittal and coronal scans, was performed only on 9 patients (18 joints) whose clinical and radiographic findings were particularly severe. The radiographic features of the lesions--i.e., erosions, osteophytes, subchondral bone sclerosis and condylar-glenoid fossa remodelling--cannot be distinguished from one another and from the so-called allied conditions; nevertheless, in rheumatoid arthritis abnormalities are usually bilateral and symmetric, whereas in seronegative arthropathies joint involvement is usually unilateral. In the first stage of the disease, these lesions are better demonstrated by CT than by tomography, thanks to better contrast and spatial resolution of the former, especially on the lateral and medial aspects of the joint. The most common findings were: erosions (68.2%), osteophytes (31.8%), subchondral bone sclerosis (28.6%) and condylar-glenoid fossa remodelling (9.1%). In the clinical practice sagittal multidirectional tomography remains today the method of choice because it can demonstrate several areas on the condylar surface, with finer anatomical detailing, and it can solve most diagnostic problems in TMJ disorders. Thus, CT is recommended only in the patients whose diagnosis remains questionable with the above techniques.

Adult↗
PubMed1991

Aneurysm of the azygos pericallosal artery. One case.

The Authors describe a case of aneurysmal rupture of the azygos pericallosal artery, a variant of the anterior cerebral artery. The association between aneurysm and this anatomical anomaly is of interest because of its rarity and clinical-therapeutic implications.

Adult↗
PubMed1987

[Behavior and significance of phalangeal bone changes in uremic patients under periodic hemodialysis treatment].

Bone damage in hand phalanges has been evaluated with reference to age and duration of hemodialysis (on the basis of 248 radiological observations), in 93 cases with chronic renal failure (age: 20-59 years). These patients were on regular dialytic treatment (RDT) from 1 to 138 months. 72% of the patients underwent several periodic (annual) controls using the mammographic technique. The radiologic evaluations have been arranged into groups according to age. Skeletal damage was more evident when RDT was prolonged. Bone damage increases with age in the first 48 months; afterwards, on the contrary, bone changes were more evident in middle aged patients. At the beginning of RDT, acroosteolysis was the most important change always present. Both subperiosteal and intracortical resorption are more evident increasing age and duration of RDT. Radiological changes give a clear picture of the possible histo-morphologic pattern that characterizes uremic osteodystrophy.

Adult↗
PubMedDate not supplied

Apoptosis by 2-chloro-2'-deoxy-adenosine and 2-chloro-adenosine in human peripheral blood mononuclear cells.

Adenosine has profound effects on immune cells and has been implicated in the intrathymic apoptotic deletion of T-cells during development. In order to characterize adenosine effects on quiescent peripheral blood mononuclear cells (PBMC), we have evaluated the ability of the previously characterized adenosine receptor agonist 2-chloro-adenosine (2CA; Ceruti, Barbieri et al., 1997) and of the antineoplastic drug 2-chloro-2'-deoxy-adenosine (2CdA, cladribine) to trigger apoptosis of PBMC. Apoptosis was assessed by morphological changes, DNA fragmentation by agarose gel electrophoresis and appearance of hypodiploid DNA peak by flow cytometry. 2CA (10 microM) and 2CdA (1 microM) induced apoptosis in human PBMC, which are relatively insensitive to apoptosis. For both agents, the effect was concentration- and time-dependent, although 2CdA induced apoptosis more potently than 2CA. Evaluation of mitochondrial function in parallel samples using the mitochondrial membrane-potential-specific dye JC-1 showed that mitochondrial damage followed the same kinetics as apoptosis, hence an early damage of mitochondria is likely not responsible for adenosine-induced death of PBMC. The effect of 2CA was partially prevented by addition of dipyridamole (DP), a nucleoside transport inhibitor, hence some of the apoptotic effect of this nucleoside is, at least in part, due to intracellular action. Alternatively, DP did not affect 2CdA-induced apoptosis, suggesting that 2CdA may enter cells via a DP-insensitive transporter. 5-Iodotubercidin (5-Itu), a nucleoside kinase inhibitor, was also able to partially prevent the action of 2CA and was not able to affect 2CdA-induced apoptosis, suggesting a different role for phosphorylation in 2CA- vs 2CdA-induced apoptosis. To test the role of P1 receptors, agonists and antagonists selective at various P1 receptor subtypes were used. Data suggest that, for 2CA, apoptosis is partially sustained by activation of the A2A receptor subtype, whereas no role is exerted by P1 receptors in 2CdA-dependent apoptosis. Moreover, in these cells, apoptosis could also be triggered through intense activation of the A3 receptor via selective agonists such as 2-chloro-N6-(3-iodobenzyl)adenosine-5'-N-methyluronamide (Cl-IB-MECA), but this mechanism plays no role in either 2CA- or 2CdA-induced apoptosis. On the whole, our results suggest that 2CA and 2CdA follow different pathways in inducing apoptosis of immune cells. Moreover, our data also suggest that there are at least three different ways by which adenosine derivatives may induce apoptosis of human PBMC: (i) through an A2A-like extracellular membrane receptor; (ii) through entry of nucleosides into cells and direct activation of intracellular events involved in the apoptotic process; or (iii) through activation of the A3 receptor.

2-Chloroadenosine↗