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Biomedical subjects

A Masotti

Publications and source records attributed to A Masotti.

28 records · Page 2Linked to original sources
PubMed1994

[The use of monoclonal antibodies that recognize the neural cell adhesion molecule (NCAM) in the diagnosis of bone marrow localization of small cell lung cancer].

We have used immunocytochemistry to identify tumor cells in bone-marrow aspirates of 40 untreated patients with small cell lung cancer and we compared the results with conventional histomorphology. The monoclonal antibodies (MAbs) used were NCC-LU-243 and NCC-LU-246 (both cluster 1). For each MAb 76 slides were evaluated. Sixty bone-marrow biopsies were also obtained from these patients. The positivity rate between the 2 MAbs was not statistically different (46% for NCC-LU-246 and 43% for NCC-LU-243). Bone-marrow biopsies detected tumor localization in 8/60 specimens (13%), significantly less than immunocytochemistry with anti-NCAM MAbs (p = 0.003). Moreover, bone-marrow aspirates were positive for cluster 1 antigen in 6/16 patients with limited disease at diagnosis. The results confirm that NCC-LU-243 and NCC-LU-246 have equivalent ability to identify bone-marrow involvement; immunocytochemistry appears to be better suited for this purpose than conventional bone-marrow biopsy; a non-negligible proportion of patients with "limited disease" might be understaged; the clinical value of detecting bone marrow involvement by immunocytochemistry is still unclear.

Antibodies, Monoclonal↗
PubMed1994

Vinorelbine monochemotherapy in non-small-cell lung cancer: experience in patients with low performance status.

The aim of this study was to investigate the activity and safety of vinorelbine in patients with low performance status. From March 1992 to June 1993 we studied 14 untreated patients with Stage IV non-small-cell lung cancer (NSCLC) and a "performance status" lower than 70% of the Karnofsky score. Treatment was by means of an intravenous administration of vinorelbine (30 mg.m-2) repeated weekly. On the whole, the toxicity was mild. Of 150 cycles administered, we observed 10 cases of Grade 3 leucopenia and 4 cases of Grade 4 leucopenia. A peripheral neurotoxicity (Grade 2-3) was reported in two patients. The objective response rate was 36% partial response. Our data suggest that vinorelbine could be an active and safe treatment for those patients who cannot receive polychemotherapy because of low performance status, and justify further larger studies comparing vinorelbine, either as a single agent or in combination, to other analogues or to assess its efficacy in supportive care.

Adult↗
PubMed1991

Function of glycoprotein Ib alpha in platelet activation induced by alpha-thrombin.

We have obtained evidence that selective inhibition of high affinity thrombin-binding sites located in the amino-terminal domain of the membrane glycoprotein (GP) Ib alpha results in impaired platelet activation, as shown by abrogation or reduction of the following responses induced in normal platelets by exposure to less than 1 nM alpha-thrombin: (i) increase in intracellular ionized calcium concentration ([Ca2+]i), (ii) release of dense granule content, (iii) binding of fibrinogen, (iv) aggregation. An anti-GP Ib monoclonal antibody, LJ-Ib 10, which does not inhibit von Willebrand factor binding to platelets, obliterated the high affinity alpha-thrombin-binding sites on normal platelets. Isotherms of alpha-thrombin binding to normal platelets treated with saturating amounts of the antibody were virtually identical to those obtained with platelets from a patient with classical Bernard-Soulier syndrome. In parallel with decreased binding of the agonist, this antibody caused 50% inhibition of the maximal extent of platelet aggregation and 90% inhibition of ATP release induced by 0.3 nM alpha-thrombin. By inhibiting alpha-thrombin binding to GP Ib, the antibody prevented the activation of platelets exposed to low concentrations of the agonist, as demonstrated by abrogation of the increase in intraplatelet ionized calcium concentration induced in control platelets by 0.18 nM alpha-thrombin; under these conditions, fibrinogen binding was inhibited by 84%. Therefore, there is a correlation between occupancy of the high affinity sites for alpha-thrombin on GP Ib alpha and platelet activation, secretion, and aggregation, suggesting that GP Ib alpha is part of an alpha-thrombin receptor relevant for platelet function.

Antibodies, Monoclonal↗
PubMed1983

Histometric analysis of sheathed capillaries in congestive splenomegaly.

The structural rearrangement of human sheathed capillaries in congestive splenomegaly with hypersplenism has been evaluated by histometric analysis. In abnormal spleens the external diameter and the wall thickness were decreased, while the internal diameter was increased. Moreover, the total length and the absolute number of sheathed capillaries were increased, though not to the same high degree as the volume of the whole red pulp. Thus, in addition to the well-known changes of the sinuses, also the terminal arterial passages appear to participate in the morphological rearrangement of the red pulp in congestive splenomegaly.

Adolescent↗
PubMedDate not supplied

Efficacy and toxicity of vinorelbine-carboplatin combination in the treatment of advanced adenocarcinoma or large-cell carcinoma of the lung.

AIMS AND BACKGROUND: The aim of the study was to assess the activity and toxicity of the vinorelbine-carboplatin combination in advanced adenocarcinoma or large-cell carcinoma of the lung. The new vinca derivative, vinorelbine, shows promising activity when combined with cisplatin, but toxicity of the combination is substantial. METHODS: Accordingly, we substituted carboplatin for cisplatin in the combination in order to improve the therapeutic index. From March 1992 to March 1994, 55 untreated patients with undifferentiated unresectable or metastatic adenocarcinoma or large-cell carcinoma of the lung were recruited. The treatment consisted of a course of carboplatin (300 mg/m2) and vinorelbine (25 mg/m2) repeated every 4 weeks. The only grade 3 toxicity observed was 16 cases of grade 3 vomiting and 2 cases of grade 3 stomatitis. RESULTS: The positive response rate was 40% (partial response, 22 patients). In conclusion, the vinorelbine-carboplatin combination may be regarded as an active, safe regimen for the palliative treatment of advanced adenocarcinoma or large-cell carcinoma of the lung.

Adenocarcinoma↗
PubMedDate not supplied

Intracerebral diffusion of paramagnetic cationic liposomes containing Gd(DTPA)2- followed by MRI spectroscopy: assessment of pattern diffusion and time steadiness of a non-viral vector model.

Cationic liposomes are generally considered as the non-viral counterparts of the more common viral vectors used in several gene therapy protocols, but their use as delivery vehicles is limited by their efficiency even if they display a lower toxicity. However, cationic liposomes are promising delivery systems in cell biology due to their ability to incorporate small molecules into their inner aqueous spheres and to deliver them into cells. Additionally, on the external surface they can bind therapeutic molecules such as nucleic acids, oligonucleotides, plasmids, etc. through electrostatic interactions. The aim of this work was to study the diffusion properties of such vehicles in vivo with a non-invasive technique and to monitor their tissue migration in order to collect information to be further used in gene therapy procedures. For this purpose, cationic liposomes containing the paramagnetic contrast agent Gd(DTPA)2- (Gd(III)-diethylenetriamine-N,N,N',N",N"-pentaacetic acid) were investigated because of their extended paramagnetic persistency in vivo, compared to the use of the contrast agent alone, and they were used to monitor the diffusion of such vehicles in an animal model (rat model). In particular, these vectors were injected into the rat brain through a stereotactic frame in a preformed cavity mimicking the lesion which had originated after surgical removal of the primary tumor. For the purpose of comparison, the same injection procedure was also applied to a control series of animals without a preformed brain lesion. Pattern diffusion and steadiness of the reported paramagnetic cationic liposomes were studied by means of Magnetic Resonance Imaging (MRI) which allowed us to monitor their diffusion and assess their intracerebral time availability up to 24 hours.

Animals↗
PubMedDate not supplied

[Computerized tomography of the skull in children with lymphoblastic leukemia treated with prophylactic cranial radiation].

Thirty asymptomatic patients with acute lymphoblastic leukemia who had received prophylactic cranial irradiation (16 pts had 2400 cGy, 14 pts 1800 cGy) and intrathecal methotrexate were studied by computed tomography of the brain 60 to 148 months after initiation of prophylaxis. Three of 30 (10%) patients presented abnormal findings: widening of frontal subarachnoid space (1 patient), little area of decreased attenuation coefficient (1 patient), and intracerebral calcifications (1 patient Tomography abnormalities could be detected either in patients treated with 2400 cGy and in those treated with 1800 cGy. None of our patients showed central nervous system dysfunctions on physical examination. The results of our study suggest that tomography findings have a poor clinical significance.

Adolescent↗