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M Colombi

Publications and source records attributed to M Colombi.

At least 19 recordsLinked to original sources
PubMed2006

Isolation and characterization of dominant and recessive IL-3-independent hematopoietic transformants.

Retroviral integration mutagenesis and treatment with the frameshift mutagen ICR191 were used to transform v-H-ras expressing PB-3c cells to interleukin-3 (IL-3) independence. Six clones displayed viral integrations into the 3' region of the IL-3 gene thus acting post-transcriptionally by disrupting the AU-rich instability element. Two clones contained reverse orientation integration into the raf-1 gene revealing an enhancer insertion mechanism. Growth by this mechanism was sensitive to the Raf-1 inhibitor BAY 43-9006 and the Mek inhibitor U0126. Following treatment with ICR191, IL-3-independent clones were recovered and studied by cell fusion. With 21/22 clones, IL-3 independence resulted from a recessive mechanism as cellular hybrids with parental cells reverted to IL-3 dependence. Recessive clone D2c displayed increased phospho-Erk1/2 levels and was growth sensitive to U0126, but not to BAY43-9006. The single dominant clone, D5a, showed no signs of mitogen-activated protein kinases pathway activation but displayed constitutive phosphorylation of Stat5. We conclude that PB-3c has several options to acquire IL-3 growth autonomy involving transcriptional or post-transcriptional mechanisms affecting the distal regulators Erk or Stat5. The reported panel of independent dominant and recessive transformants should provide a useful tool for inhibitor profiling.

Aminacrine↗
PubMed2006

Dystrophic epidermolysis bullosa pruriginosa in Italy: clinical and molecular characterization.

Dystrophic epidermolysis bullosa (DEB) pruriginosa (DEB-Pr) is a rare variant of DEB due to COL7A1 dominant and recessive mutations, which is characterized by severe itching and lichenoid or nodular prurigo-like lesions, mainly involving the extremities. Less than 30 patients have been described showing variable disease expression, and frequently, delayed age of onset. We report the clinical and molecular characterization of seven Italian DEB patients, three affected with recessive DEB-Pr and four with dominant DEB-Pr. In all the patients, the signs were typical of a mild DEB phenotype, until the onset of pruritus, which was followed by worsening of the clinical picture, with appearance of the distinctive lichenified lesions of DEB-Pr. Nine mutations were found in the COL7A1 gene, three of which were novel and one was de novo. DEB-Pr patients with either dominant or recessive mutations were shown to synthesize a normal or variably reduced amount of type VII collagen, which was correctly deposited at the dermal-epidermal junction. Since six of these mutations have been reported in DEB patients in the absence of intense pruritus, these data implicate a role of yet unidentified phenotype-modifying factors in the pathogenesis of DEB-Pr.

Adolescent↗
PubMed2003

Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias.

We verified the diagnostic and prognostic role of a simplified immunophenotypic classification (IC) in a series of 258 patients (M/F: 1.4; median age: 64 years; median follow-up: 64 months; 75 deaths) with mature B cell lymphoid leukemias (MBC-LL) for whom no histopathological diagnosis was available because of minimal or no lymph node involvement. The IC was based on the reactivity of three pivotal immunophenotypic markers: CD5, CD23 and SIg intensity. On the basis of different expression patterns, we identified four diagnostic clusters (C) characterized by distinct clinico-biological features and different prognoses: C1 (149 patients) identified most classical B cell chronic lymphocytic leukemias (CLL-type cluster; SIg(dim)/CD5+/CD23+); C2, 38 patients whose clinico-hematological characteristics were intermediate between C1 and C3 (CLL-variant cluster; SIg(bright)/CD5+/CD23+/-or SIg(dim)/CD5-/-/CD23 indifferent); C3 (16 patients) most situations consistent with mantle cell lymphoma in leukemic phase (MCL-type cluster; SIg(bright)/CD5+/CD23-); and C4, 55 cases, most of whom were consistent with leukemic phase lymphoplasmacytic/splenic marginal zone lymphomas (LP/S-type cluster; SIg(bright)/CD5-/+/CD23 indifferent). At univariate survival analysis, prognosis worsened from C1 to C4, C2 and C3 (P = 0.0001), and this was maintained at multivariate analysis (P = 0.006), together with CD11c expression (P = 0.0043), age at diagnosis (cut-off 70 years; P = 0.0008) and platelet count (cut-off 140 x 10(9)/l; P = 0.0034). Besides recognising the two well-known situations of classic B-CLL and MCL, our IC identified situations with distinct prognostic and/or clinical behaviors.

Adult↗
PubMed2003

Homozygosity mapping of a gene for arterial tortuosity syndrome to chromosome 20q13.

BACKGROUND: Arterial tortuosity syndrome (ATS) is an uncommon connective tissue disorder of unknown aetiology. The most prominent feature is tortuosity of the large arteries, but lengthening, stenosis, and aneurysm formation are also frequent. METHODS: We performed a genomewide screen by homozygosity mapping of three consanguineous multiplex families, two from Morocco, and one from Italy, which included 11 ATS patients. The two families from Morocco may possibly have a common ancestor. RESULTS: We mapped the ATS gene to chromosome 20q13. Recombinations within an extended haplotype of 11 microsatellite markers localised the ATS gene between markers D20S836 and D20S109, an interval of 9.5 cM. CONCLUSIONS: Cloning and completing functional and structural analysis of the ATS gene may provide new insights into the molecular mechanisms of elastogenesis.

Adolescent↗
PubMed2002

Different phenotypes in recessive dystrophic epidermolysis bullosa patients sharing the same mutation in compound heterozygosity with two novel mutations in the type VII collagen gene.

BACKGROUND: Dystrophic epidermolysis bullosa (DEB) is a bullous skin disease caused by mutations in the type VII collagen gene (COL7A1). OBJECTIVE: To elucidate the mutations shown by two patients with DEB and understand the clinical phenotypes that they displayed. METHODS: We have characterized two patients, one affected by the severe recessive Hallopeau-Siemens variant of DEB (HS-RDEB) and the other by a milder recessive DEB form. RESULTS: In both patients we identified the R2063W missense mutation. The second mutation, in the HS-RDEB patient, was a novel 344insG, leading to a premature termination codon of translation (PTC) in exon 3, while, in the other patient, it was a novel 4965C-->T transition, which creates a new donor splice site in exon 53. The effect of this anomalous splice site leads to the maturation of a 17-nucleotides-deleted mRNA containing a PTC. In addition to this aberrant transcript, a certain amount of full-length mRNA is also generated from the mutated pre-mRNA through splicing at the canonical site. CONCLUSIONS: In these patients therefore the severity of the phenotype depends on the second mutation. In the patient with the 344insG mutation, leading to a PTC, type VII collagen (COLVII) molecules are exclusively composed of chains containing the R2063W substitution; as a consequence, all anchoring fibrils (AF) are abnormal and the phenotype is severe. In the other patient, the 4965C-->T splicing mutation allows the synthesis of a certain quantity of normal chains and the consequent assembly of partially functional COLVII molecules and AF, thus explaining the mild phenotype.

Adolescent↗
PubMed2001

Characterization of mutations leading to recessive dystrophic epidermolysis bullosa and Marfan syndrome in a single patient.

Dystrophic epidermolysis bullosa (DEB) is a rare genetic skin disorder. In this report we have investigated an Italian child affected with recessive DEB (RDEB) and demonstrated that he was homozygous for the mutation R226X in the type VII collagen gene (COL7A1), leading to absence of type VII collagen at the dermal-epidermal junction. There was no family history of inherited skin blistering but the child's father was affected by Marfan syndrome, an autosomal dominant connective tissue disorder that results from mutations in the fibrillin-1 gene (FBN1). Analysis of this gene showed that the RDEB patient and his father were both heterozygous for a novel FBN1 mutation, C1971Y. This mutation affects one of the six obligate cysteine residues within one of the calcium-binding epidermal growth factor-like regions of the protein. At the age of 2-years the RDEB patient showed signs of early aortic dilatation, suggesting that he is likely to develop a Marfan syndrome phenotype in the future. This is a unique case of these two coexisting inherited disorders.

Child, Preschool↗
PubMed2000

Consequence analysis in LPG installation using an integrated computer package.

This paper presents the prototype of the computer code, Atlantide, developed to assess the consequences associated with accidental events that can occur in a LPG storage plant. The characteristic of Atlantide is to be simple enough but at the same time adequate to cope with consequence analysis as required by Italian legislation in fulfilling the Seveso Directive. The application of Atlantide is appropriate for LPG storage/transferring installations. The models and correlations implemented in the code are relevant to flashing liquid releases, heavy gas dispersion and other typical phenomena such as BLEVE/Fireball. The computer code allows, on the basis of the operating/design characteristics, the study of the relevant accidental events from the evaluation of the release rate (liquid, gaseous and two-phase) in the unit involved, to the analysis of the subsequent evaporation and dispersion, up to the assessment of the final phenomena of fire and explosion. This is done taking as reference simplified Event Trees which describe the evolution of accidental scenarios, taking into account the most likely meteorological conditions, the different release situations and other features typical of a LPG installation. The limited input data required and the automatic linking between the single models, that are activated in a defined sequence, depending on the accidental event selected, minimize both the time required for the risk analysis and the possibility of errors. Models and equations implemented in Atlantide have been selected from public literature or in-house developed software and tailored with the aim to be easy to use and fast to run but, nevertheless, able to provide realistic simulation of the accidental event as well as reliable results, in terms of physical effects and hazardous areas. The results have been compared with those of other internationally recognized codes and with the criteria adopted by Italian authorities to verify the Safety Reports for LPG installations. A brief of the theoretical basis of each model implemented in Atlantide and an example of application are included in the paper.

Accidents, Occupational↗
PubMed2000

A -96C-->T mutation in the promoter of the collagen type VII gene (COL7A1) abolishing transcription in a patient affected by recessive dystrophic epidermolysis bullosa.

Hereditary dystrophic epidermolysis bullosa (DEB) refers to a group of clinically heterogeneous skin blistering diseases due to mutations in the collagen type VII gene (COL7A1). We report two novel mutations found in a patient affected by the most severe form of DEB, the recessive Hallopeau-Siemens variant (HS-RDEB): the R1978X nonsense mutation, in exon 72, and the -96C-->T transition, in the promoter region. The allele specific analysis of the transcripts from skin fibroblasts of the patient showed that the -96C-->T mutation is associated to the absence of collagen type VII (COLVII) mRNA. This mutation, the first one ever identified in the promoter of COL7A1, falls in an Sp1 motif, localized between nucleotides -96 and -91. Gel shift analysis indicated that the -96/-91 sequence is a functional Sp1 site and that the -96C-->T transition inhibits the binding of the trascription factor. These data indicate that the -96/-91 sequence is a crucial Sp1 site whose integrity is necessary for COL7A1 expression. The compound heterozygosity for the -96C-->T null mutation and for the R1978X mutation leads to the absence of COLVII at skin level and to the severe phenotype of the HS-RDEB patient. Hum Mutat 16:275, 2000.

Cells, Cultured↗
PubMed2000

Dexamethasone-induced healing of chronic leg ulcers in a patient with defective organization of the extracellular matrix of fibronectin.

Previous investigations have shown that skin fibroblasts derived from patients affected by Ehlers-Danlos syndrome (EDS) lack an organized extracellular matrix (ECM) of fibronectin (FN). As retarded wound healing is a sign of EDS, we hypothesized that a young healthy man suffering from chronic recalcitrant leg ulcers might be affected by a defect of FN-ECM organization similar to that observed in EDS. Immunofluorescence of cultured skin fibroblasts obtained from skin biopsies from the patient and a control demonstrated that the patient's fibroblasts lacked FN-ECM organization, in contrast with those of the control; this was restored by 10-7 mol/L dexamethasone (DEX) in vitro. DEX treatment of the patient was associated with healing of his leg ulcers. In conclusion, DEX may be effective in reversing impaired wound healing associated with a lack of FN-ECM organization

Adult↗
PubMed2000

OPP-EBV-CAD regimen as salvage treatment in advanced refractory or resistant multiple myeloma.

With the aim of developing an effective therapy for heavily pretreated refractory MM outpatients, we evaluated the OPPEBVCAD regimen, a Hodgkin's disease-derived protocol that includes many drugs effective in MM administered in a sequential schedule. Twenty-two pts aged 42-72 years, with symptomatic highly-pretreated refractory (18 cases), or primary resistant MM (four cases. including two pts with plasma cell leukemia-PCL) received this therapy every 28 days (2-4 cycles, followed by a maintenance program). Therapeutic response (Chronic Leukemia-Myeloma Task Force criteria) and performance status (PS) and pain (W.H.O.) were evaluated. All of the pts were evaluable for response. There were 9 (40%) objective responses (OR: stabilization of blood counts and bone lesions, serum calcium normalization, 50% or more reduction in the concentration of serum monoclonal component (MC), 90% reduction in Bence-Jones proteinuria), 8 (36%) partial responses (PR: 25-50% reduction in serum MC), 1 no response or stable disease (NR), and 4 (18%) cases of progressive disease (PD). OR plus PR were 77%. Of the 4 primary resistant tumors (2 PCL and 2 MM), 2 achieved PR, 1 OR (a PCL case) and 1 progressed. Median survival was 15 months for responding pts (OR plus PR) and 4.5 months for non-responders (NR plus PD). PS and pain improved in 15 pts and did not change in 9. The most frequent side effects were cytopenias, with one drug related infective death. The OPPEBVCAD regimen proved to be an effective therapy for refractory relapsing or primary resistant MM: in responders (two-thirds of the pts), survival was prolonged by about 10 months. Its efficacy in anthracycline-treated pts, as well as the feasibility of using it on an outpatient basis without any continuous drug infusions, make this regimen a promising third line salvage therapy.

Adult↗
PubMed2000

Soluble cytokine levels correlate with the activity and clinical stage of Hodgkin's disease at diagnosis.

The serum levels of some cytokines seem to correlate with outcome in Hodgkin's disease (HD) and may be helpful in formulating new and better prognostic systems. The aim of this study was to analyse the correlations between the serum levels of different cytokines and the clinico-hematological features suggestive of a worse prognosis. The study involved 31 pts with a "de novo" diagnosis of HD (median age: 30 yrs; M/F: 13/18; stage I/II vs III/IV: 19/12; B symptoms: 12; bulky disease and extranodal disease: 9). The serum levels of sCD30, TNFalpha, TNF receptor I and II, IL6, IL6 receptor, IL10, sICAM-1 were evaluated at diagnosis, and correlated with gender, age (< or =/> 30), stage (I-II vs III-IV), systemic symptoms, bulky disease, ESR (</> or = 40), serum copper (< or =/> 170 microg/dL), WBC counts (< or =/> 15x10(9)/L), prognostic scores (PS) according to Hasenclever (</> or = 2), and the presence of extranodal disease. Stages III/IV were associated with significantly higher levels of sCD30 and TNF-RI (p=0.03), systemic symptoms with significantly higher levels of sCD30, TNFalpha, IL6, TNF-RI (p=0.027, 0.03, 0.0005, 0.002), bulky disease with TNF-RI (p=0.03), high ESR with IL6 and TNF-RI (p=0.0011, 0.0001), high WBC counts with sCD30, IL6, TNF-RI (p=0.03, 0.002, 0.01), high serum copper with sCD30 and IL6 (p=0.05, 0.0004), higher PS with sCD30, IL6, TNF-RI (p=0.002, 0.0003, 0.005), extranodal disease with TNFalpha and IL6 (p=0.05, 0.01). It was possible to define cut-off levels for some cytokines (sCD30 > 33.15 U/mL, TNFalpha > 29.71 pg/mL, IL6 > 12.43 pg/mL, TNF-RI > 3.23 ng/mL, IL6-R > 57 ng/mL) that significantly correlate with systemic symptoms, higher disease stages, ESR, serum copper, WBC counts and PS. Our study shows that high sCD30, TNFalpha, IL6 and TNF-RI levels are associated with advanced disease or a worse prognostic score. In the context of multiparametric HD staging, cytokine evaluation may be useful for identifying candidates for more intensive therapies.

Adolescent↗
PubMed1999

Three homozygous PTC mutations in the collagen type VII gene of patients affected by recessive dystrophic epidermolysis bullosa: analysis of transcript levels in dermal fibroblasts.

The Hallopeau-Siemens variant of recessive dystrophic epidermolysis bullosa (HS-RDEB) is a severe inherited skin disease characterized by the absence of collagen type VII (COLVII) and anchoring fibrils (AF), caused by mutations in collagen type VII gene (COL7A1). Mutations leading to the formation of premature termination codons (PTCs) of translation are the characteristic genetic lesions in HS-RDEB patients; many PTC mutations have been found to be associated with a marked reduction or complete absence of COLVII mRNA. In this article, we report homozygosity for three different mutations in the COL7A1 of HS-RDEB patients. One mutation, the R2685X, falling in exon 109, is a novel mutation, whereas the other two, the 425A-->G falling in exon 3 and the 497insA in exon 4, have been previously identified in compound heterozygosity with different mutations in other unrelated RDEB patients. Haplotype analysis in three Italian families carrying the 497insA mutation suggested a common origin of this mutation and indicated that this is an ancestral Italian mutation. All these mutations generate PTCs and are associated with the absence of COLVII expression, as detected by immunofluorescence analysis of the patient's skin. Evaluation of the levels of the mutated COLVII mRNAs in cultured skin fibroblasts of the patients and of their parents showed that all the mutated transcripts were expressed at consistent levels. Therefore, our results indicate that a marked mRNA reduction is not a constant feature associated with PTC mutations in COL7A1.

Adolescent↗
PubMed1999

Cyclosporin A promotes translational silencing of autocrine interleukin-3 via ribosome-associated deadenylation.

Translation is regulated predominantly by an interplay between cis elements at the 3' and 5' ends of mRNAs and trans-acting proteins. Cyclosporin A (CsA), a calcineurin antagonist and blocker of interleukin-2 (IL-2) transcription in T cells, was found to inhibit translation of IL-3 mRNA in autocrine mast cell tumor lines. The mechanism involved ribosome-associated poly(A) shortening and required an intact AU-rich element in the 3' untranslated region. FK506, another calcineurin inhibitor, shared the effect. The translational inhibition by CsA was specific to oncogenically induced lymphokines IL-3 and IL-4 but not to IL-6, c-jun, and c-myc, which are expressed in the nonmalignant precursor cells. Furthermore, no translational down-regulation of the mRNA was observed in IL-3-transfected precursor cells. These data suggest that translational silencing is associated with the tumor phenotype.

Animals↗
PubMed1999

Quantitative in situ hybridization for the evaluation of gene expression in asynchronous and synchronized cell cultures and in tissue sections.

We describe an image analysis (IA) system that has been applied for the quantitative evaluation of mRNAs evidenced by in situ hybridization (ISH) with radiolabelled probes in cultured cells and in tissue sections. The ISH-IA method was used for the evaluation of cultured cell morphological parameters such as cell and nucleous area (CA and NA, respectively) in parallel with the levels of mRNAs detected as hybridization grains areas (GA). The evaluation of these parameters, together with the analysis of the levels of mRNAs (c-jun, cyclin A) specific for given cell cycle phases (i.e. G1 and S/G2), allowed the identification, in asynchronous cultures of human skin fibroblasts, of cells in G1 and S/G2 phases. The mRNA levels measured by ISH-AI were comparable with those detected by RT-PCR. This method was also applied for the analysis of fibronectin (FN) gene expression in control skin fibroblasts in relationship with the different phases of the cell cycle and in comparison with a tumor cell line (Sk-Hep1), heterogeneous either for morphometric parameters or for the levels of this transcript. Finally, the ISH-AI was applied for the semiquantitative evaluation of the expression, localization and alternative splicing pattern of FN mRNA in normal liver and in hepatocellular carcinoma (HCC) tissue sections.

Animals↗
PubMed1998

Effect of dexamethasone on the assembly of the matrix of fibronectin and on its receptors organization in Ehlers-Danlos syndrome skin fibroblasts.

The effect of dexamethasone (DEX) on the expression of fibronectin (FN), proalpha(1)(I) collagen (Col1), integrin alpha(2), alpha(5)and beta(1)subunits mRNAs, were studied by quantitative in situ hybridization (ISH) with radiolabelled probes in relationship with the organization of the extracellular matrix (ECM) of FN in human skin fibroblasts. In particular, two fibroblast strains were analysed, one derived from a control donor, typically organizing a rich ECM of FN, and the other from a patient affected by Ehlers-Danlos syndrome (EDS), which did not assemble the FN-ECM. Treatment of both fibroblast strains with 10(-7) m DEX slightly enhanced the level of FN mRNA (by about 1.5-fold), did not influence the level of alpha(5)subunit mRNA and reduced Col1, alpha(2)and beta(1)integrin subunits mRNAs by 2-3-fold. These results show that, in these cells, DEX coordinately downregulates the expression of Col1 and its specific integrin alpha(2)beta(1). Moreover, DEX regulates in a different manner the alpha(5)and beta(1)subunits forming the main FN receptor (FNR) in skin fibroblasts. Immunofluorescence microscopy evidencing the FN-ECM and integrins containing alpha(5)and beta(1)subunits showed that in control cells DEX induced a slight enhancement of the FN-ECM and of the alpha(5)beta(1)receptors patches. Therefore, in these cells the decrease of beta(1)FN receptor subunit mRNA, as well as the decrease of Col1 and its receptor mRNAs, did not influence the FN-ECM assembly. In EDS fibroblasts, DEX decreased the cytoplasmic accumulation of FN and induced the assembly of a rich FN-ECM through the formation of large FNR integrin patches, codistributing with the FN-ECM. We suggest that in EDS skin fibroblasts DEX corrects the defective FN-ECM favouring the sorting and the organization of FN and its alpha(5)beta(1)integrin receptor.

Cells, Cultured↗
PubMed1998

Low-grade MALT lymphoma involving multiple mucosal sites and bone marrow.

Mucosa-associated lymphoid tissue (MALT) lymphomas are indolent neoplasms which tend to remain localized for a long time before spreading. We describe here the case of a 36-year-old woman with a low-grade MALT lymphoma involving the lung, stomach, lingual tonsil, and bone marrow at the time of diagnosis. The clonal origin of the pulmonary and bone marrow neoplastic infiltrates was assessed by means of gene rearrangement analysis. All of the involved sites were infiltrated by centrocyte- and monocytoid-like cells expressing the B-cell-associated antigens CD19 and CD20 and showed IgM lambda chain restriction; no CD5, CD10, or CD43 expression was detectable. As the patient had a history of recurrent bronchitis, and computed tomography performed 3 years before the lymphoma diagnosis had already revealed a lesion of the left lung, we conclude that the present case probably represents a pulmonary low-grade MALT lymphoma characterized by an early and unusual involvement of different mucosal sites and bone marrow.

Adult↗
PubMed1998

Treatment and prognosis in a series of primary extranodal lymphomas of the ocular adnexa.

BACKGROUND: The aim of this study was to assess clinicopathological characteristics and outcome in a series of primary ocular adnexal lymphomas (POALs). PATIENTS AND METHODS: Nineteen patients with localised (stage IE) POAL were followed for a median of 96 months (24-156). The diagnosis was based on surgical biopsies followed by immunohistochemistry in 16 cases or fine-needle aspiration followed by immunocytophenotypic analysis in three cases. Twelve patients were treated with local radiotherapy (RT), five with chemotherapy (CT), and two refused further therapy after apparently radical tumour removal achieved by the diagnostic excisional biopsy. RESULTS: The histological and immunological pattern was consistent with a diagnosis of MALT-type lymphoma (11 cases), follicular center non-Hodgkin's lymphoma (three cases). a large-cell variant of Burkitt's lymphoma (one case), and large-cell transformed MALT lymphoma (one case). Low-grade lymphoma was diagnosed in the three cases which underwent fine-needle aspiration biopsy. All of the patients achieved and maintained complete remission except for those treated with surgical excision alone (two MALT conjunctival lymphoma cases): one of these relapsed locally, the other experienced the systemic spread of a transformed diffuse large-cell lymphoma and died 72 months after diagnosis. The side effects consisted of two cases of RT-related cataract after 52 and 72 months. CONCLUSIONS: Regardless of histology, prognosis was excellent when surgery plus RT was adopted, and CT seems to be a valid alternative to RT. Surgery alone may be sub-optimal.

Adult↗