Biomedical subjects
Publications and source records attributed to C Tassi.
Explore the source record for details and available documents.
Selective elimination of multidrug resistance-positive cells (LoVo/Dx) was obtained by using the monoclonal antibody MRK 16, which recognizes a surface epitope of the Mr 170,000 glycoprotein, and a sheep anti-mouse immunoglobulin antibody, conjugated to the ribosome-inactivating protein saporin 6. The killing was greatly decreased or even abolished by adding the monoclonal antibody at a 100-fold concentration. Both the MRK 16 and anti-mouse saporin 6 conjugate did not show any killing activity when they were used separately. In cell suspensions composed of 90% normal bone marrow cells and 10% multidrug resistance-positive cells, the monoclonal antibody MRK 16 followed by the anti-mouse immunotoxin caused the elimination of 99% multidrug resistance-positive cells, as revealed by immunofluorescence and immunocytochemistry as well as by a clonal assay. Human normal hematopoietic precursors (granulomonocytic colony-forming units, erythroid burst-forming units, and multipotent granulomonocytic, erythroid, and megakaryocytic-forming units) were not affected by the MRK 16 plus immunotoxin treatment. This technique might be suitable for ex vivo bone purging in an appropriate clinical setting, such as autologous bone marrow transplantation.
1. Enzymatic forms of alpha-L-fucosidase from human renal tissue and urine were investigated. 2. In renal tissue two different isoenzymatic patterns were obtained by chromatofocusing of either directly soluble or detergent solubilized extracts. 3. On the other hand the urinary isoenzymatic pattern is similar to that obtained for the renal soluble extract.
Sera from patients with confirmed or suspected trichinellosis were examined for 1 year to detect the presence of parasite-specific antibodies (IgG, IgM, and IgE) using the enzyme-linked immunosorbent assay (ELISA). The indirect ELISA was used to detect specific IgG (ELISA-IgG) and specific IgM (ELISA-IgM); an amplified technique proved the most reliable for detection of specific IgE (a-ELISA-IgE). The immunofluorescence (IF) test was used to detect specific IgG (IF-IgG). The patients were from an outbreak of trichinellosis in Salsomaggiore (northern Italy) in 1986. The parasite was isolated and isoenzymatically typed as Trichinella sp. 3. The specificity of our tests was greater than 95%. During the 1st period of infection, all tests used gave practically the same positivity rate (78.2-86.9%). One year after infection, ELISA-IgG gave the highest positivity rate (55%). With the other tests, the positivity rate was 20-38.5%. At the 2nd month of infection, the IF-IgG test was the most discriminating in patients with confirmed and suspected trichinellosis, but ELISA-IgG proved the most reliable test for detecting specific immunoglobulins in late human trichinellosis infection.
Bromodeoxyuridine (BrdUrd), an analogue of thymidine is one of the most employed marker to detect the S-phase of the cell cycle. Difficulties are described for the in situ detection of S-phase cells in normal and neoplastic growing clones. In this paper we propose new methods for the detection of BrdUrd in neoplastic clones, growing in plasma clots. In particular, these methods are based on the immunocytochemical staining with horseradish peroxidase and alkaline phosphatase, as well as on a new immunofluorescent streptavidin technique. They allow easy detection of S-phase cells with an inverted light microscope.
In a phase II study we evaluated the effect and toxicity of a new alkylating agent, PTT-119, in 26 patients with non-Hodgkin's lymphomas (NHL) resistant to or relapsed after other chemotherapy. PTT was scheduled by escalating the dose from 2.0 to 3.3 mg/kg every 3 weeks. Among 21 evaluable patients with NHL, 12 (57%) showed a good response (CR + PR) to PTT-119. Tolerance was acceptably good; no major side effects related to liver, cardiac, or renal toxicity were recorded. The most commonly recorded side effects were nausea and vomiting, alopecia, and phlebitis; diarrhea and drug-related fever were rarely seen. This report indicates a potential usefulness for PTT-119, a non-cross-resistant alkylating agent, in the treatment of NHL.
Bromodeoxyuridine (BrdUrd), an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase. In this paper a determination of the S-phase in BLV+ cattle with lymphocytosis has been performed by incorporating bromodeoxyuridine in the DNA. This evaluation was compared to the DNA content, demonstrating that i) bromodeoxyuridine incorporation is a reliable marker of S-phase in BLV+ cattle with lymphocytosis and ii) cytofluorimetry is the method of choice, together with immunocytochemistry, to demonstrate bromodeoxyuridine incorporation.
Explore the source record for details and available documents.
A system to purge the bone marrow of myeloma cells has been developed in our laboratories with the aim of treating with myeloablative radiochemotherapy patients suffering from advanced multiple myeloma. This system is based on the ex vivo incubation of the marrow with an immunotoxin composed of the 8A monoclonal antibody--that recognizes plasma cells and B-cell precursors--and the ribosome-inactivating protein momordin. 8 patients have so far been treated. 4 are surviving from 4 to 18 months after ABMT, whereas 4 died after 1 to 6 months, 2 from infections, 1 from relapsing disease and 1 from veno-occlusive disease. A marked tumour reduction was observed in all evaluable patients; however, none has achieved complete disappearance of the disease. The haemopoietic reconstitution was significantly delayed in 3 patients. These preliminary results show the feasibility of this approach in advanced MM patients with heavily infiltrated marrow. The place of ABMT in the treatment of MM remains to be determined; the selection of patients with still responding and less advanced disease would probably produce better results.
The results of an epidemiological survey on surgical cases of human hydatidosis in 9 italian regions (Central, Southern and Insular Italy) with the highest incidence of disease and a population of 27,054,000 inhabitants are reported. The period considered was from 1980 through 1984. 2,592 cases have been collected and related to sex, age, occupation, residence of surgically treated patients and cyst localization. Comparison of results from the present and a previous survey was carried out.
Explore the source record for details and available documents.
Normal granulocyte-macrophage precursors (CFU-GM) were studied in 65 multiple myeloma patients by means of culture assays. The patients were divided into separate groups on the basis of previous therapy (i.e. analysis performed at diagnosis or after chemotherapy), time elapsed from the last therapy (i.e. more or less than 1 month) and clinical features of the disease (i.e. tumor stage, immunoglobulin type, bone marrow plasma cell infiltration). The results were evaluated by Wilcoxon rank sum test and linear regression analysis. There was no statistical difference in CFU-GM cloning efficiency or in the number of CFU-GM/ml of bone marrow, even though a larger CFU-GM recovery was found in patients evaluated at diagnosis or at least 1 month or more from previous chemotherapy. In addition, no correlation was demonstrated between bone marrow plasma cell percentage and CFU-GM cloning efficiency. This finding was confirmed by the number of myeloid bone marrow cells in S-phase, assessed by the bromodeoxyuridine labeling index, which showed similar results in patients with different degrees of plasma cell infiltration. In conclusion our data indicate that the granular-monocytic lineage keeps its cell-line potentiality regardless of the degree of marrow plasma cell infiltration and the type of therapeutic approach. These data suggest that autologous bone marrow transplantation might be feasible even in patients with a large neoplastic infiltration.
Bromodeoxyuridine, an analogue of thymidine, can be detected by means of monoclonal antibodies and utilized as a marker of the S-phase of the cell cycle. In this paper a method for the detection of the labeling index of normal and neoplastic colony-forming units (CFU) growing in plasma clot semisolid medium is described and preliminary results on the cell cycle of 7th and 14th CFU granulocyte-macrophage are discussed.
33 patients with advanced refractory multiple myeloma received a combination of vincristine, cyclophosphamide, carmustine, melphalan and steroids (M-2 protocol). 20 of them had failed prior chemotherapy with alkylating agents and the remaining 13 patients had relapsed after a response to these drugs. An objective tumour cell mass reduction (greater than or equal to 50%) was achieved in 17% of the patients (6% of previously nonresponders and 33% of previously relapsing), while 9 additional patients improved (30-50% tumour reduction), for an overall response rate of 47% (39% for previously nonresponders and 58% for previously relapsing). The median duration of response was 7 months. Thrombocytopenia was the most common toxicity encountered in the study (39% of cases). Our findings indicate that M-2 protocol is an effective salvage treatment for patients who relapse from previous chemotherapy with alkylating agents. In contrast, results in patients who are primarily resistant to these drugs justify the search for different treatment programmes which can produce greater degrees of tumour reduction.
The behaviour of IgE antibodies was investigated by the micro-ELISA method (IgE-ELISA) in patients affected by hydatidosis or in patients who had already been operated on. The results were correlated with those obtained by IgG-ELISA, IgM-ELISA, IgA-ELISA and IHA tests. In the preoperative phase the IgG-ELISA method proved to be as sensitive (80%) as the IHA test (78.5%); the IgE-ELISA method showed a good sensitivity (72.8%) with a positive rate for the IgE-ELISA/IHA of 92.7%. The IgM- and IgA-ELISA methods were of moderate sensitivity. The IgE-ELISA proved to be much more suitable than the other methods for postoperative control, since the persistence of positivity 4 years after surgery suggests the involvement of a relapse.
Explore the source record for details and available documents.
BB-CK activity was measured in 11 patients with stroke and in 10 controls. Blood samples were taken 36 hours after the clinical stroke onset in every patient. Sera were stored at -80 degrees and analyzed within two months. The creatine kinase isoenzymatic pattern was determined by ion-exchange column separation and gradient elution system. The mean BB-CK concentration in patients with stroke was significantly higher than in controls (p less than 0.01). In the group of "stroke" patients we found a correlation between severity of brain damage, as suggested by the clinical picture and CT scans, and serum values of BB-CK.
Antigen fractions 0.8 M, (1.6-0.8) M and (2.5-1.6) M were prepared from sheep fertile hydatid fluid and scolices of E. granulosus by differential precipitation with ammonium sulphate. The micro-ELISA technique was used to study the specific IgM antibody response towards these six antigen fractions in sera from patients affected by hydatid disease before and after surgery. The results show 0.8 M hydatid fluid antigen to be the most suitable for eliciting a specific IgM response both during the pre-surgery phase and after operation. Furthermore the finding of specific IgM positivity in patients with active hydatidosis raises the suspicion of open or fissured cysts whereas the positivity after operation would seem to be due to the release of antigen by surgical procedures and not prognostic for relapse.