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M Mattei

Publications and source records attributed to M Mattei.

At least 37 records · Page 2Linked to original sources
PubMed1996

Epitope specificity of anti-HIV antibodies in human and murine autoimmune diseases.

This article reports the HIV epitope specificity of antibodies present in the sera of HIV-negative patients with autoimmune diseases. Recombinant gp120 and a panel of synthetic peptides derived from the amino acid consensus sequences of either related (gp120, gp41, and p24) or unrelated (Mage-1, necdin, heat shock protein [65 kDa], and amyloid) HIV proteins were tested by a specific ELISA. The first set of experiments performed on four patients with Sjögren's syndrome (SjS) and four patients with systemic lupus erythematosus (SLE) revealed a significant anti-gp120 antibody reactivity in autoimmune patients when compared to healthy HIV-negative controls. Moreover, such binding could be almost completely inhibited by preincubation with free gp120. A significant anti-p24 reactivity was observed in 18 of 29 sera from SjS patients and in 13 of 25 sera from SLE patients, while anti-gp41 was observed only in 3 of 14 SjS and in 2 of 20 SLE-affected patients. Similar analyses were performed in the murine model of autoimmunity, showing that sera from MRL/lpr mice were able to bind all HIV-related peptides in an age-dependent manner. The analysis of a panel of HIV-unrelated peptides showed that SLE as well as MRL/lpr sera bind both HIV-related and unrelated peptides, while SjS sera failed to do so, revealing the polyclonal nature of the SLE and MRL/lpr repertoire and the oligoclonal reactivity of SjS sera. This is also supported by inhibition experiments, which showed that SLE, but not SjS, sera competitively inhibited the binding to HIV gp120 peptide of sera from autoimmune MRL/lpr mice. These results indicate that an overlapping polyclonal repertoire is present in both SLE and MRL/lpr sera, while the oligoclonal specificity of SjS antibodies may be related to a specific, nonpolyclonal, activation against putative retroviral antigens.

Amino Acid Sequence↗
PubMed1996

Differential growth of N- and S-type human neuroblastoma cells xenografted into scid mice. correlation with apoptosis.

This study concerns the role of apoptosis in the growth of human neuroblastomas transplanted into immunodeficient SCID mice. Human neuroblastoma cell lines may consist of one or more distinct phenotypes including the neural 'N-type' and flat substrate-adherent 'S-type'. A differential phenotype-specific proliferation was apparent among S- and N-type cell clones transplanted into SCID mice when compared with the wild-type SK-N-BE(2) cell line. This differential growth capacity of the tumours was correlated with spontaneous apoptosis. Another SK-N-BE(2)-derived cell line (TGA), displaying high levels of apoptosis upon stable transfection with the full length 'tissue' transglutaminase (tTG) cDNA, was unable to induce tumour development when xenografted into SCID mice. To support these observations, the expression of apoptosis-related genes (i.e., bcl-2, p53, and tTG) in the various neuroblastomas was also investigated.

Animals↗
PubMed1996

Blood pressure and arterial lactate level are early indicators of short-term survival in human septic shock.

OBJECTIVE: To identify early prognostic markers of septic shock among catheterization-derived hemodynamic and metabolic data. DESIGN: Prospective cohort study. SETTING: A medical intensive care unit in a university hospital. PATIENTS: Thirty-two consecutive patients with septic shock, separated into two groups according to short-term (10-day) evolution: 18 acute survivors and 14 fatalities. MEASUREMENTS: Usual hemodynamic and metabolic variables were measured at the onset of shock, i.e., when the catheter was inserted (T0), and 24 h later (T24). The values collected for each group at T0 and T24 and their 24-h changes were compared. RESULTS: On admission, no difference was found between acute survivors and eventual fatalities. After 24 h, fatalities presented with significantly lower mean arterial pressure (p <0.01), left ventricular stroke work index (p <0.05) and higher lactate levels (p <0.01) than acute survivors. Moreover, the 24-h changes of lactate and blood pressure were also of prognostic value (p <0.05). Oxygen delivery and oxygen consumption did not differ statistically between the two groups. At T24, a mean arterial pressure of less than 85 mmHg and a lactate level equal to or greater than 3.5 mmol/l were independently associated with poor survival (37.5% and 30.7%, respectively). Day 10 survival was only 12.5% when both criteria were present at T24. CONCLUSIONS: Changes in mean arterial pressure and arterial blood lactate within the first 24 h of treatment are strong prognostic indicators of short-term survival in patients with septic shock. After 24 h of treatment, maintenance of a mean blood pressure equal to or greater than 85 mmHg correlates with survival at day 10. Data suggest that early reductions in both cardiac function and vascular tone play a determining role in the hypotension observed in fatalities. Persistence of hyperlactatemia in hypotensive patients bodes particularly ill. Blood pressure and lactate level are simple bedside parameters that can enable the clinician to identify patients with a high risk of mortality.

Adult↗
PubMed1996

Molecular cloning of a mammalian ABC transporter homologous to Drosophila white gene.

Pigmentation of Drosophila eyes requires the concerted action of several genes, most of which have been cloned and characterized. Three of them, white, brown, and scarlet, have been directly implicated in the import of pigment precursors into the cells. These three genes encode similar proteins, belonging to the evolutionary conserved family of ATP Binding Cassette transporters. The identification of a novel mouse gene, ABC8, closely related to white is reported here, together with an analysis of its expression profile and its comparative mapping in mouse and human genome.

ATP-Binding Cassette Transporters↗
PubMed1996

Late acquisition of hyporesponsiveness to lipopolysaccharide by Mycobacterium avium-infected human macrophages in producing tumor necrosis factor-alpha but not interleukin-1 beta and -6.

To investigate whether infection with Mycobacterium avium modifies the cytokine response of human macrophages (Mphi) to lipopolysaccharide (LPS), the release of interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha was determined in infected and uninfected Mphi, unstimulated or stimulated with LPS. In unstimulated Mphi, the release of IL-1 beta and IL-6 increased with the progress of infection while that of TNF-alpha progressively decreased. When Mphi were stimulated with LPS, IL-1 beta and IL-6 levels were always higher in infected than in uninfected cells, but levels of TNF-alpha significantly decreased in infected Mphi. A similar trend was obtained for TNF-alpha mRNA expression. Altogether, these results indicate that infected Mphi react to LPS stimulus with enhanced levels of IL-1 beta and IL-6 but are unable to restore the production of TNF-alpha impaired by the growth of the intracellular mycobacteria.

Gene Expression↗
PubMed1995

[Prognosis of acute tuberculous respiratory distress syndrome. 4 cases].

OBJECTIVES: We examined the characteristics of 4 cases of adult respiratory distress syndrome in patients with tuberculosis in an attempt to improve prognosis. METHODS: Four new cases of adult respiratory distress syndrome were described together with a review of the cases reported in the literature. Inclusion criteria were the presence of the syndrome as defined according to the American-European consensus conference and the criteria described by Murray et al. and identification of the mycobacteria causing tuberculosis. RESULTS: A total of 52 cases were included in the study. The sex ratio was 0.71 and mean age 46 +/- 15 years. Eight patients had a past history of pulmonary tuberculosis. Alcoholism was the primary immunodepression factor observed (35%) followed by human immunodeficiency virus infection (13%). For 74% of the patients, the disease course lasted 7 days. The initial chest X-ray was suggestive of tuberculosis in 11. Intradermoreaction to tuberculin was positive in 2 out of 17 patients. Direct examination of non-invasive respiratory samples was positive in 44% for mycobacteria. Disseminated tuberculosis was seen in 64%. Anti-tuberculosis antibiotherapy was started on the first day of intensive care in 68% of the patients; rapid treatment was associated with better prognosis: 1.5 +/- 1.2 days versus 3 +/- 2.7 in fatal cases (p = 0.02). Adjuvant corticosteroid therapy was used in 46% of the cases and was apparently associated with unfavourable outcome: 74% mortality versus 58% without corticosteroids. Ventilatory assistance was required in 88% and associated with poor prognosis (13% survival versus 100% without assistance) (p < 10(-3)). Outcome was fatal in 36 cases (70%) with a mean delay of 9.7 +/- 10.8 days. CONCLUSION: The conditions required for improving the prognosis of adult respiratory distress syndrome in tuberculosis patients included suspecting tuberculosis in all cases of acute respiratory failure of unknown origin, particularly in the immunodepressed patient, and to avoid missing this diagnosis in case of a non-suggestive chest X-ray and a negative though exhaustive microbiology search. Adjuvant corticotherapy is uneffective and may be dangerous.

Acute Disease↗
PubMed1995

Characterization of human pancreatic adenocarcinoma cell line with high metastatic potential in SCID mice.

The CD44 molecule and CD44 isoforms are expressed on some malignant tumours and it has been suggested that their expression may correlate with tumour spread. Human pancreatic carcinoma cell line (HPC-4) expressing CD44 was established from a patient with adenocarcinoma of pancreas. This line showed a rapid growth in vitro, several chromosome abnormalities and surface expression of some adhesion molecules (ICAM-1, LFA-3, beta 1-chain of VLA integrins, VNR). Xenotransplanted HPC-4 cells were able to grow rapidly in SCID mice as subcutaneous tumour, leading to 100% mortality within 3-5 weeks when 1 x 10(5)-1 x 10(7) cells were inoculated. Spontaneous metastases in the liver, lung, spleen and kidney of SCID mice were observed. Interestingly enough, HPC-4 cells in vivo and ex vivo also expressed HLA-DR molecules, but these were rapidly lost upon culture in vitro. It is suggested that the appearance of HLA-DR may be the result of interaction of the tumour with a local environment of the host, while CD44 expression may explain the rapid growth and occurrence of distant metastases in SCID mice. The ability of HPC-4 cells to form spontaneous metastases in SCID mice may prove to be a potentially interesting model of human carcinoma for testing new treatment modalities.

Adenocarcinoma↗
PubMed1994

The MHC class-II and CD44 molecules are involved in the induction of tumour necrosis factor (TNF) gene expression by human monocytes stimulated with tumour cells.

Tumour necrosis factor alpha (TNF) mRNA is detected in the macrophage infiltrate surrounding the tumour, but the cellular/molecular interactions leading to TNF gene expression in macrophages are unknown. The in vitro system in which human blood monocytes are stimulated with human cancer cells for TNF release was used to study such interactions. Monoclonal antibodies (MAbs) against various adhesion molecules (LFA-1, LFA-3, ICAM-1, VNR, VLA beta I chain) were unable to block TNF production in co-culture of monocytes with a human pancreatic carcinoma (HPC) cell line. However, anti-CD44 and anti-HLA-DR MAbs effectively blocked TNF release and TNF-mRNA induction in monocytes. Pre-incubation of monocytes with anti-HLA-DR and tumour cells with anti-CD44 MAbs had a similar effect. It was concluded that CD44 molecules are involved in tumour-monocyte interactions and that HLA-DR determinants of monocytes are engaged in signal transduction for TNF gene activation. These findings may suggest that certain surface determinants of tumour cells act as ligands for MHC class-II molecules and induce TNF production in monocytes.

Antibodies, Monoclonal↗
PubMed1994

Induction of graft versus host disease in SCID mice by MRL/lpr cell transfer.

We have investigated the graft versus host (GvH) disease induced in immunodeficient SCID (H-2d) mice by intravenous (iv) or intraperitoneal (ip) transfer of either spleen or lymph node cells from autoimmune (MRL/lpr and MRL/++ mice, H-2k) and normal (CBA, H-2k) mice. Rapid and lethal GvH disease was observed when cells from MRL/lpr or MRL/++ were iv transferred into SCID mice, while spleen cells from nonautoimmune CBA donors were partially tolerized into SCID recipients and induced only lower levels of GvH reaction. No GvH reaction (complete tolerance) was observed when CBA lymph node cells were iv transferred into SCID recipients. In contrast, the ip injection of MRL/lpr or CBA spleen cells induces similar levels of GvH. The development of GvH disease in SCID recipients was due to the expansion of alloreactive CD8+ cells displaying significant cytotoxic activity against H-2d, but not against autologous targets. Also, a significant decrease of CD4/CD8 ratio was observed in the course of GvH caused by the iv transfer of cells from MRL/lpr mice. Altogether, these data support the hypothesis that lymphocytes from the MRL/lpr mice may escape tolerance in the GvH reaction.

Animals↗
PubMed1994

Swan-Ganz catheter-related pulmonary valve infective endocarditis: a case report.

We report the case of a 29-year-old man with decompensated alcoholic cardiomyopathy who developed a Staphylococcal pulmonic valve infective endocarditis during hemodynamic monitoring, as a consequence of catheter-related bacteremia. As experimentally demonstrated, the damaging role of the pulmonary artery catheter on the endocardial surface plays a major role in the pathogenesis of related right-sided infective endocarditis. Occurrence of bacteremia in a catheterized patient should be considered as a high risk situation, and righ-heart infective endocarditis must be suspected whenever patient presents fever or bacteremia without obvious site of infection. Doppler echocardiography is the reference diagnosis procedure.

Adult↗
PubMed1994

CD4-8- T-cells increase in MRI/lpr mice treated with thymic factors.

The in vivo effect of thymic factors on immature lymphocytes was analysed in MRL/lpr mice. This strain carries a genetic defect that causes during their life cycle a block of T-cell differentiation and abnormal proliferation of CD4-8- (double-negative, DN) T-lymphocytes. In vivo administration of four preparations of thymic factors, thymopentin (TP-1), thymopoietin (TP-5), thymolymphotropin (TLT), and thymomodulin (TMD) into young (2-month-old) MRL/lpr mice induced a significant increase of DN T-cells both in the thymus and in the peripheral lymph nodes, with a concomitant decrease of double-positive (DP) T-cells in the thymus and of single-positive (SP) T-cells in the lymph nodes. The level of DNA fragmentation measured as propidium iodide fluorescence was increased in the thymus population of young mice and in the lymph node population of old mice treated with TLT. SCID mice transplanted with lymph node cells from MRL/lpr donors (MRL-->SCID) developed graft versus host (GvH) reaction due to the activation of MRL CD8+ alloreactive T-cells. This model was used to analyse the effect of TMD/TLT in vivo on MRL cell proliferation and expansion; in fact, spleen cells from MRL-->SCID mice after treatment with TMD/TLT showed an increased cell proliferation, and an expansion of DN T-cells with a concomitant decrease of SP cells (both CD4+ and CD8+ cells). Decreased SP cell numbers in this context could explain why TMD/TLT treatment of SCID mice engrafted with MRL cells increased their survival compared to untreated MRL-->SCID mice.

Animals↗
PubMed1994

The 30-kilodalton protein present in purified fusicoccin receptor preparations is a 14-3-3-like protein.

We have recently reported on the purification of the fusicoccin (FC) receptor from corn (Zea mays L.) and its identification by photoaffinity labeling (P. Aducci, A. Ballio, V. Fogliano, M.R. Fullone, M. Marra, N. Proietti [1993] Eur J Biochem 214: 339-345). Pure preparations of FC receptors, obtained under nondenaturing conditions, showed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis two doublets of proteins with apparent molecular masses of 30 and 90 kD. In the present paper we describe the isolation and identification of the primary structure of the 30-kD doublet proteins. Sequencing studies of peptides resulting from the digestion of the 30-kD protein showed a full identity with a 14-3-3-like protein from corn, named GF14. The 14-3-3 family is a class of proteins that is widely distributed in eukaryotes and is known to play various regulatory roles. The 30-kD protein has been immunologically identified by specific antibodies prepared against a synthetic peptide based on the determined amino acid sequence. A similar protein is recognized in partially purified FC receptor preparations from bean and spinach leaves.

14-3-3 Proteins↗
PubMed1994

Analysis of the adoptive transfer of delayed hypersensitivity and T cell repertoire in severe combined immunodeficiency mice reconstituted with human lymphocytes.

The functional capacity of human T cells to passively transfer delayed hypersensitivity (DH) was analysed in severe combined immunodeficiency (SCID) mice. The tissue distribution of human peripheral blood lymphocytes (PBL) was analysed by 51chromium labelling 1 and 24 h after intravenous cell injection. Labelled PBL from purified protein derivative (PPD)-positive healthy individuals mainly localize in the spleen, liver and lungs, with no arrival in the peripheral lymphoid organs and at the site of antigen challenge (footpad). According to such defective distribution, human PPD-immune cells failed to passively transfer PPD-specific DH to SCID recipients when cells were injected either intravenously or intraperitoneally (systemic transfer). On the contrary, PPD-immune cells were able to transfer DH to PPD when injected directly into the footpad (local transfer). Both memory (CD45RA-) and naive (CD45RA+) enriched subsets were equally able to transfer local DH. The long-term reconstitution of the human immune system in SCID mice was analysed after intraperitoneal PBL transfer (hu-PBL-Scid) by phenotypic analysis, immunoglobulin level, and human DNA detection. Moreover, the reconstitution of the V beta T cell receptor (TCR) repertoire in SCID mice was analysed by anchored polymerase chain reaction (PCR) showing that all the 22 V beta families were expressed in the spleen of hu-PBL-SCID mice. Moreover, scanner analysis of Southern blotting revealed the selective expansion of distinct V beta families (V beta 3, V beta 6, V beta 8, V beta 13.1, V beta 14, V beta 17), suggesting that human lymphocytes could recognize specific antigens or superantigens in the SCID environment.

Animals↗