PubMed Health⌕ Search

Biomedical subjects

M L Trinca

Publications and source records attributed to M L Trinca.

7 recordsLinked to original sources
PubMed1992

Cellular heterogeneity of DNA/total-protein content in human lung tumors, as determined by flow cytometry.

With the aim of distinguishing neoplastic cell sub-populations of different prognostic and diagnostic significance, dual-parameter measurements (DNA/protein) have been simultaneously determined in a (256, 256) channel matrix in lung samples derived from 110 patients affected by neoplastic and non-neoplastic lung diseases. Biparametric analysis demonstrated that cells with abnormally high red fluorescence (i.e., protein content), which is indicative of unbalanced growth, were often observed in malignant tumors as compared with normal lung samples. Furthermore, the dual-parameter analysis allowed recognition of additional aneuploid tumor-cell lines, indicating that the frequency of cytometrically determined diploid tumor is lower than that previously described by DNA monoparametric analysis. The recognition of aneuploid subpopulations by dual-parameter analysis in clinically and histologically negative one-parameter flow-cytometric "diploid" samples assumes important diagnostic value. The results have also shown the presence of multiple protein sub-populations in clones with the same ploidy value, indicating a higher level of cellular heterogeneity than demonstrated by DNA monoparametric measurements.

Adenocarcinoma↗
PubMed1990

Cytokinetic investigation of lung tumors using the anti-bromodeoxyuridine (BUdR) monoclonal antibody method: comparison with DNA flow cytometric data.

In order to investigate the cytokinetics of malignant tumors and non-malignant lesions of the lung, tissue samples from 57 patients affected by non-small-cell carcinoma (NSCLC), small-cell carcinoma (SCLC), and benign and inflammatory lesions have been analyzed using the BUdR monoclonal antibody (MAb) method. This method is based on the preparation, at the time of surgery, of viable monocellular suspensions (using collagenase and DNase treatment) and the concomitant administration of BudR. The percentage of BudR-labelled cells was monitored by fluorescent microscopy using an FITC-labelled second antibody. In NSCLC, each histological group showed a wide range of labelling index (LI) values. On the contrary, SCLC exhibited a more homogeneous kinetic behaviour as evidenced by a narrowly distributed, higher LI. Tumors shown to be diploid by flow cytometry did not show a lower LI than aneuploid tumors. Furthermore, differences were constantly observed between the S-phase percent calculated using BUdR and that calculated using the DNA flow cytometric (FC) histogram, the latter always showing higher S-phase values. In an attempt to study the intra-tumor proliferative heterogeneity, multiple-site sampling was performed. Proliferative heterogeneity seemed to be higher inter-tumor than intra-tumor. Finally, a positive correlation (p less than 0.05) was found between LI and the actual doubling time (DT) of the primary tumor mass, evaluated using sequential radiographs. In conclusion, the present BUdR method can be considered a useful source of relevant information on in vivo cell growth, in parallel to other clinical (DT) and biological (DNA content) approaches.

Adenocarcinoma↗
PubMed1989

Profile of sequential determinants in tissue polypeptide antigen BrCN:B fragment.

A synthetic approach has been applied to determine the profile of sequential determinants of one immunodominant region of Tissue Polypeptide Antigen (TPA). Five overlapping peptides, covering 30 of the 32 amino acid residues of this fragment, were chemically synthesized, and their antibody-binding activities for rabbit anti-TPA antibodies determined by enzyme-linked immunoadsorbant assays. Anti-TPA reacted with two overlapping fragments at the COOH-terminal end of the fragment, but not with peptides that include Arg 15 considered as essential for the antigenicity of the whole fragment. This might suggest that this critical residue is involved in the formation of a complex conformational determinant.

Amino Acid Sequence↗
PubMed1988

14C-labeling of synthetic peptides.

Two methods are described for the labeling of synthetic peptides using iodo[14C]acetic acid. The first procedure may be employed when the synthetic fragment contains a cysteine with a free sulfhydryl group. Alternatively, a commercial amino-protected cysteine may be carboxymethylated using radioactive iodoacetic acid. This derivative can be added to the growing peptide chain in the manual or automatic solid-phase synthesis of the fragment.

Amino Acid Sequence↗
PubMed1988

Restriction of anti-peptide antibody specificity by enzyme-modified Sepharose-peptide immunoadsorbents.

Sepharose-peptide immunoadsorbents, employed for the isolation of specific antibodies from the sera of rabbits immunized with carrier protein-peptide conjugates, were digested with suitable proteolytic enzymes, in order to obtain the splitting of a part of the peptide bound to the gel. This new modified immunoadsorbent can be advantageously used for the isolation of antibody subsets, that do not cross-react with related peptides exhibiting high sequence homology with the immunogens.

Amino Acid Sequence↗
PubMedDate not supplied

Do monoclonal antibodies recognize linear sequential determinants?

A group of 19 anti-class II monoclonal antibodies produced in different laboratories were tested in ELISA for their ability to bind to a panel of synthetic peptides selected from HLA-DQ alpha and beta chains. No one of the antibodies tested was found to react with the synthetic fragments, thus confirming the common finding that MoAbs generally fail to recognize fragments of the native antigen. The possibility that this result might be partly due to the procedure used for screening hybridoma supernatants is discussed.

Antibodies, Monoclonal↗