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Biomedical subjects

R Fraioli

Publications and source records attributed to R Fraioli.

At least 19 recordsLinked to original sources
PubMed2005

Risk factors for type 2 diabetes in women attending menopause clinics in Italy: a cross-sectional study.

OBJECTIVE: To analyze risk factors for type 2 diabetes among women attending menopause clinics in Italy for counselling about the menopause. SUBJECTS: Women attending a network of first-level outpatient menopause clinics in Italy for general counselling about menopause or treatment of menopausal symptoms. METHODS: Cross-sectional study with no exclusion criteria. Type 2 diabetes was defined according to National Diabetes Data Groups Indications and the fasting blood glucose at an oral glucose tolerance test within the previous year. RESULTS: Out of the 44 694 considered in this analysis, 808 had a diagnosis of diabetes type 2 (1.8%). In comparison with women aged < 50 years, the multivariate odds ratios (OR) of type 2 diabetes were 1.31 (95% confidence interval (CI), 0.99-1.74) for women aged 50-52 years, 1.66 (95% CI, 1.27-2.17) at 53-56 years and 2.84 (95% CI, 2.20-3.67) in women aged > or = 57 years. Type 2 diabetes was less frequently reported in more educated women (OR high school/university vs. primary school = 0.44 (95% CI, 0.36-0.55)). Being overweight was associated with an increased risk of type 2 diabetes. In comparison with women reporting a low level of physical activity, the multivariate OR of type 2 diabetes was 0.67 (95% CI, 0.54-0.84) for women reporting regular physical activity. In comparison with premenopausal women, the multivariate OR of type 2 diabetes was 1.38 (95% CI, 1.03-1.84) in women with natural menopause. This finding was present also after allowing for the potential confounding effect of age. The multivariate OR of diabetes for users of hormonal replacement therapy was 0.58 (95% CI, 0.46-0.73). CONCLUSIONS: This large cross-sectional study suggests that postmenopausal women are at higher risk of type 2 diabetes after allowance for the effect of age. Other main determinants of risk of type 2 diabetes in women around menopause were low socioeconomic status and being overweight. Diabetes was found less frequently in those taking hormone replacement therapy.

Age Distribution↗
PubMed1999

Low prevalence of selective human leukocyte antigen (HLA)-A and HLA-B epitope losses in early-passage tumor cell lines.

The down-regulation of human leukocyte antigen (HLA) class I molecules, especially the selective down-regulation of certain allelic products, is believed to represent a major mechanism of tumor escape from immune surveillance. In the present report, an original approach is described to precisely evaluate and classify HLA class I epitope losses in 30 cancer patients with malignant melanoma and lung, breast, endometrium, ovary, and colon carcinoma tumors. Early-passage tumor cell lines were established in culture from the corresponding metastatic tumor lesions obtained in each patient. Both the cell lines and the tumor lesions were compared, in their HLA-A and -B expression, to the peripheral blood mononuclear cells (PBMCs) obtained from the same patient (autologous PBMCs). On the basis of HLA-genotyping data, the appropriate monoclonal antibodies identifying mono- and poly-morphic HLA-A and HLA-B epitopes were selected from a panel of 34 antibodies for a total of 24 testable alleles. The selected antibodies were used not only in immunohistochemical assays on cryostatic tumor sections and cytospins of PBMCs but also in quantitative, sensitive flow cytometry assays on early-passage tumor cells and PBMC suspensions. With this latter method, a low overall HLA expression was detected in 26 tumor cell explants and a complete, generalized HLA-A, HLA-B, HLA-C loss in the remaining 4 cases. However, no complete, selective loss of any of the 45 tested HLA-A and HLA-B allomorphs was observed. Sequences from all of the HLA class I alleles could be detected at the genomic DNA level in tumor cells and tissues. At variance from the literature and the results of immunohistochemical experiments performed in parallel on the corresponding tumor lesions, the relative proportions of the various HLA epitopes were relatively preserved in each early-passage cell line/PBMC pair, and selective increases, rather than decreases, in the expression of polymorphic HLA epitopes had the highest prevalence and greatest magnitude. Our data suggest an alternative tumor stealth strategy in which up- and down-regulation are equally important. This alternative model of tumor-host interaction better fits the available models of tumor cell recognition by CTLs and natural killer cells bearing activatory and inhibitory receptors for HLA-A, HLA-B, HLA-C molecules.

Antibodies, Monoclonal↗
PubMed1999

Biosynthesis of HLA-C heavy chains in melanoma cells with multiple defects in the expression of HLA-A, -B, -C molecules.

Recent investigations have shown that malignant transformation may down-regulate the expression of class I HLA molecules, beta2-microglobulin (beta2m) and members of the antigen-processing machinery. In the present study, we HLA-genotyped and identified at a biochemical level the three (HLA-A25, -B8, -Cw7) class I alleles expressed by the previously described [D'Urso CM et al (1992) J Clin Invest 87: 284-292] beta2m-defective human melanoma FO-1 cell line and tested their ability to interact with calnexin, calreticulin and the TAP (transporter associated with antigen processing) complex. All these alleles were found to bind calnexin, but not calreticulin or the poorly expressed TAP complex, both in parental and beta2m-transfected FO-1 cells, demonstrating a complex defect of class I expression in FO-1 cells. In these conditions, Cw7 heavy chains interacted with calnexin more strongly than A25 and B8, and preferentially accumulated in the endoplasmic reticulum, in both a calnexin-associated and a calnexin-free form. In addition, they could be transported to the cell surface at low levels even in the absence of beta2m, without undergoing terminal glycosylation. These results establish a parallel between HLA-C and the murine Db and Ld molecules which have been found to be surface expressed and functional in beta2m-defective cells. They also demonstrate distinctive features of HLA-C molecules. We propose that the accumulation of several assembly intermediates of HLA-C might favour the binding of peptide antigens not readily bound by HLA-A and -B molecules in neoplastic cells with suboptimal class I expression.

Alleles↗
PubMed1999

HLA-A, -B, -C genotyping and expression in human nonlymphoid tumor cell lines.

A combination of molecular genotyping and protein biochemistry methods was used to assess the HLA-A, -B, -C genotyping and expression of six tumor cell lines. Four cell lines had been previously HLA typed by conventional serologic methods. Two could not be typed by serology because deficient in the surface expression of HLA-A, -B, -C molecules. As shown herein, all the 25 alleles carried by the six tested cell lines were typed at the DNA level. In addition, discrepancies between the previous serologic and the present DNA typing results were detected in 9 of the 21 tested serologic specificities. Typing at the protein level by isoelectric focusing and allele-specific monoclonal antibodies confirmed the DNA typing data. Our results exemplify the limits of the serologic typing procedures and demonstrate that molecular methods are highly desirable to conduct functional experiments and identify HLA losses in neoplastic cells at single allele level.

Alleles↗
PubMed1999

[The management of syncope in the hospital: the OESIL Study (Osservatorio Epidemiologico della Sincope nel Lazio)].

BACKGROUND: While syncope is generally considered a frequent finding in clinical practice, no clear epidemiological evidence is available about the relevance of such an event in the general population of Italy. METHODS: The OESIL Study was designed and undertaken in 15 hospitals of the Italian region of Latium in order to assess the percentage of emergency-room visits and admissions due to syncope, as well as to analyze the in-hospital diagnostic work-up performed for this condition. RESULTS: During a two-month observation period, 781 (372 males and 409 females, mean age 55.2 (22.8 years) consecutive patients came to the emergency rooms of the 15 hospitals included in the investigation due to a syncope spell (0.9% of emergency room visits); 450/781 patients (57.6%) were subsequently hospitalized (1.3% of all admissions): 48.0% of the admissions were admitted to a general medical ward, 29.3% to an observation ward, 13.3% to a cardiology section, 1.6% to a neurology section and 7.8% to other clinical sections (neurosurgery, general surgery). The mean duration of in-hospital stay was 6.9 (5.8 days; range 1-40 days). During the hospitalization period, 93.1% of patients underwent an ECG, 51.0% an EEG, 44.3% a CT scan of the central nervous system, 40.2% an echocardiogram and 19.5% a tilt-test. The syncope spell was considered to have a cardiovascular origin in 33.8% of the cases and a non-cardiovascular in 11.6% of the cases, while the origin was unknown in 54.4% of the cases. CONCLUSIONS: Collected data support the idea that syncope represents a frequent event in the general population and is responsible for a significant percentage of emergency-room visits and hospital admissions. However, the performance of conventional diagnostic work-ups is far from being satisfactory.

Adult↗
PubMed1998

Expression of the c-Kit receptor and its ligand SCF in non-small-cell lung carcinomas.

Increasing experimental evidence indicates that stem-cell factor (SCF) and its cognate receptor c-Kit may participate in the growth control of various solid human malignancies. In the present study, we have extended this analysis to non-small-cell lung carcinomas (NSCLC). The results of an immunohistochemical analysis demonstrated that c-Kit/SCF are expressed by 30%/58% of adenocarcinomas, 15%/37% of squamous-cell carcinomas and by 40%/30% of undifferentiated carcinomas respectively. In 15% of primary and 18% of metastatic tumors, co-expression of the receptor and its ligand was documented. Western-blot assays of tumor extracts demonstrated that both molecules exhibit features of the normal receptor and ligand. Since biologically active SCF is physiologically present in the bloodstream, our data indicate that SCF is available to c-kit-expressing NSCLC cells via autocrine, paracrine or endocrine mechanisms. Thus activation of c-Kit in these tumors may contribute critically to their progression.

Carcinoma, Non-Small-Cell Lung↗
PubMed1997

Characterisation and protective capacity of monoclonal antibodies elicited in mice against protein epitopes of antibiotic-exposed Escherichia coli.

The binding capacity and the protective activity of three monoclonal antibodies (MAbs)-ARM 1-4, ARM 1-7 and ARM 2-2-obtained from spleen cells of mice immunised with Escherichia coli O6:K-pre-treated with sub-MIC of aztreonam were studied. The MAbs belonged to IgG1 isotype and showed different reactivity toward protein epitopes of E. coli in an immunoblotting assay. ARM 1-4 recognised epitopes on molecules of 30 kDa and 40 kDa. ARM 1-7 identified an epitope of a molecule of 41 kDa, and ARM 2-2 recognised epitopes of molecules of 15 kDa and 41 kDa. In ELISA the MAbs cross-reacted with E. coli O7:K-, E. coli O111:B4 and E. coli O128:K- with different binding affinity. Furthermore, the MAbs showed complement-dependent bactericidal activity. The MAbs displayed different protective capacities when given to mice 90 min before lethal challenges with 2 x LD50, 4 x LD50 and 8 x LD50 of E. coli strains. In all but one instance (ARM 1-4 versus E. coli O7:K-) it was not possible to correlate protective capacity with binding affinity of a MAb to a given bacterial cell. Therefore, the epitopes recognised by the MAb may be more closely associated with bacterial virulence than in binding to the bacterial cell.

Animals↗
PubMed1994

Murine monoclonal antibody elicited with antibiotic-exposed Escherichia coli exerts protective capacity in experimental bacterial infections.

Escherichia coli pre-exposed to a sub-minimal inhibitory concentration (sub-MIC) of several antibiotics elicits an enhanced humoral response which is protective against challenges with untreated homologous and heterologous bacteria. To characterise the specificity of this response we produced murine monoclonal antibodies (MAbs) to aztreonam-treated E. coli O6:K-. This resulted in the identification of MAb MT 1F, of isotype IgG1, that recognised a 12-kDa protein component of the untreated bacterial cells. After passive transfer, the MAb displayed protective activity in mice infected with lethal doses of live E. coli O6:K- and E. coli O111:B4. In ELISA experiments the MAb cross-reacted with structures located on whole cells of E. coli O6:K-, E. coli O111:B4, E. coli J5 and Salmonella minnesota Re595 and it also exerted a bactericidal activity against live E. coli O6:K-. The modifications induced by antibiotic treatment may unmask bacterial epitopes that may elicit the production of MAbs endowed with protective capacity.

Animals↗
PubMed1992

Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha.

Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha.

Antibodies, Monoclonal↗
PubMed1992

Production and characterization of murine mAbs to the extracellular domain of human neu oncogene product GP185HER2.

The oncogene HER-2/neu encodes a transmembrane glycoprotein of 185 kDa (gp185HER-2) with tyrosine-kinase activity. Gene amplification and high levels of expression of gp185HER-2 have been found to correlate with poor clinical outcome in breast and ovarian carcinomas. Employing a somatic cell hybrid fusion protocol, which yields a high frequency production of hybridomas, we have analyzed the extent of the murine immune response to the gp 185 extracellular domain. In a single fusion experiment, using as immunogen NIH 3T3 cells expressing high levels of a transfected human HER-2 gene, we have generated mAbs, mainly of IgG1 isotype, displaying high affinity (10(7)-10(10) mol/L) to gp 185. Analysis of the epitope specificity has allowed the identification of five distinct groups of spatially related epitopes, each provided with different immunodominancy, and all resistant to formalin fixation. The use of inhibitor of N-linked glycosylation tunicamicyn has demonstrated that the mAbs bind to epitopes localized in the protein core of gp185HER-2. Because recent reports have shown that gp185HER-2 has a restricted expression in normal tissues and is homogenously detectable in metastatic foci of gp 185 + primary tumors, antibodies to this macromolecule, in addition to their prognostic value, may represent reagents for in vitro and in vivo diagnostic applications, as well as for the development of therapeutic strategies.

Animals↗
PubMed1992

Membrane compartmentalization of melanosomal gp75.

A melanosomal integral membrane glycoprotein of 75 kD (gp75) has been previously identified as the human homologue of the product specified by the murine brown locus. We presently report that this molecule may be susceptible to limited proteolysis and extrinsic radioiodination in intact, live cells. Consequently, it is suggested that its cellular location might include the plasma membrane and/or a cellular compartment easily accessible to proteases and to chemically catalyzed vectorial iodination. This is of interest in view of the potential applicative value of gp75 as a target for the radioimmunoscintography of melanoma lesions.

Antibodies, Monoclonal↗
PubMed1991

Production and characterization of two immunotoxins specific for M5b ANLL leukaemia.

We describe the production and functional characterization of 2 monocytic-cell-lineage-specific immunotoxins constructed with saporin emitoxin (SAP) from Saponaria officinalis. Interest in the production of these immunotoxins, of possible clinical relevance, has been raised by the availability of 2 MAbs of high specificity for circulating monocytes and M5b ANLL, thus envisaging their potential use in bone-marrow purging. SAP emitoxin was selected on the basis of the low cytotoxicity in unconjugated form, as opposed to highly specific cytotoxicity and favourable pharmacokinetical properties in the conjugated form. SPDP conjugation produced immunotoxins which retained serological specificity and protein-synthesis-inhibitory activity. The 2 immunotoxins did not interfere with bone-marrow progenitor-cell growth in a CFU-GM colony assay. On the contrary, they were capable of killing monocytic cells selectively, as demonstrated in phenotypical and functional assays. Thus these 2 novel immunotoxins appear to be promising reagents in purging autologous bone marrow prior to transplantation in patients suffering from monocytic leukaemia.

Antibodies, Monoclonal↗
PubMed1991

Class I major histocompatibility complex enhancement by recombinant leukocyte interferon in the peripheral blood mononuclear cells and plasma of melanoma patients.

In vivo administration of escalation doses of recombinant alpha-interferon (IFN-alpha) during a phase I trial in malignant melanoma patients caused dose-dependent increases in the mRNA accumulation, synthesis, steady state cellular content, and plasma membrane expression of class I major histocompatibility complex molecules in peripheral blood mononuclear cells. In addition, circulating levels of class I molecules were also enhanced. These findings show that (a) antigenic enhancement by biomodifiers may occur in vivo, in humans and (b) the mechanism of class I major histocompatibility complex enhancement by IFN-alpha is similar in vitro and in vivo. Furthermore, because peripheral blood mononuclear cells of different melanoma patients display different susceptibility to IFN-alpha, the entity of their antigenic modulation may represent a useful parameter to evaluate the efficacy of different therapeutic regimens and/or assess the individual susceptibility to the molecular changes induced by IFN-alpha.

Antibodies, Monoclonal↗
PubMed1991

Generation and characterization of the murine monoclonal antibody M-KID 2 to VLA-3 integrin.

Through the analysis of the antigenic phenotype of a recently established human renal carcinoma cell line (KJ29), we have demonstrated that alpha 3 subunit of the integrin family is selectively expressed by the plastic adherent cell subpopulation. Because of the scanty availability of monoclonal antibodies to this adhesion molecule, we have used KJ29 cell line as immunogen to raise novel murine monoclonal antibodies. We isolated an hybridoma secreting the mAb M-KID 2 of the IGg1k isotype that immunoprecipitates from intrinsically [35S]-Methionine labeled KJ29 cells, an heterodimer of 130/130 and 110/150 Kd, in reducing and nonreducing conditions respectively. This reactivity was completely abolished by immunodepletion of the cell extract with a polyclonal anti alpha 3 chain antiserum. Treatment of M-KID 2 immunoprecipitates with various solutions of pH ranging from 2 to 10.5, to dissociate alpha 3 from beta 1 chains, showed a retention of both alpha 3 beta 1 chains thus indicating that the epitope identified by mAb M-Kid 2 is likely to be constituted by the alpha 3 beta 1 heterodimer. Furthermore immunohistochemical studies on selected frozen and paraffin embedded tissues with mAb M-Kid 2 have provided staining pattern indicating the recognition of Vla-3. These findings demonstrate that mAb M-KID 2 can represent a valuable reagent for the study of Vla-3 integrin in normal and pathologic conditions.

Animals↗
PubMed1991

Production and characterization of the murine monoclonal antibody 2G10 to a human T4-tyrosinase epitope.

Employing as immunogen a short-term passaged, highly pigmented human melanoma cell line, we have produced the murine MoAb 2G10 of the IgG1 isotype. The antibody immunoprecipitated from 35S-methionine and 3H-glucosamine metabolically labeled human melanoma cells with a single-chain glycoprotein of 75 kD molecular weight. No such molecule could be precipitated from murine melanomas. To further investigate the fine specificity of the MoAb, immunochemical and immunohistochemical studies were performed. These studies demonstrated that MoAb 2G10 binds a significant fraction of tyrosinase activity from cell lysates, completely immunodepletes soluble cell extract of T4-tyrosinase molecules, and produces immunostaining patterns superimposable on those obtained with anti-T4-tyrosinase antibodies. Thus, MoAb 2G10 appears to recognize a human-specific determinant carried by either T4-tyrosinase or a closely related molecule. The functional relevance of this epitope remains to be evaluated.

Animals↗
PubMed1990

Modulation of the antigenic phenotype of early-passage human melanoma cells derived from multiple autologous metastases by recombinant human leukocyte, fibroblast and immune interferon.

We have investigated the relationship between in vitro cultivation of autologous melanoma metastases derived from different patients and their levels of expression of class-I and -II major histocompatibility complex (MHC) antigens and melanoma-associated antigens (MAAs). Cell cultures were established from 23 individual metastatic melanoma lesions from 10 patients and were tested early after isolation (between 3rd and 10th passages) for both constitutive expression and modulation by recombinant human leukocyte (IFN-alpha), fibroblast (IFN-beta) or immune (IFN-gamma) interferon of MHC antigens and MAA. All of the melanoma cell lines displayed altered antigen expression following IFN treatment. While in vitro cultures derived from different individuals varied in both constitutive and IFN-modified antigenic expression, cultures of autologous metastases derived from the same patient were very similar. In addition, differences in antigenic profile were apparent when early-passage in vitro cultures were compared with the same melanoma lesion, not established in culture, from which they were derived. The unique de novo and IFN-modified antigenic phenotype of cultures derived from different patients indicates that the antigenic phenotype displayed by melanoma cultures grown in vitro is genetically determined. The differences found between in vitro cultures and their corresponding in vivo lesions, as well as the antigenic heterogeneity displayed by multiple autologous melanoma lesions in vivo, suggest that the in vivo antigenic phenotype may be determined, at least in part, at an epigenetic level.

Antigens, Neoplasm↗