PubMed Health⌕ Search

Biomedical subjects

A Pezzolo

Publications and source records attributed to A Pezzolo.

At least 19 recordsLinked to original sources
PubMed2006

Genetic abnormalities and CNS tumors: report of two cases of ependymoma associated with Klinefelter's Syndrome (KS).

OBJECTS: Genetic syndromes associated with ependymoma are uncommon, with the exception of NF2. We describe two cases of ependymoma presenting with Klinefelter's Syndrome (KS) as co-morbid condition. MATERIALS AND METHODS: The first patient was diagnosed for KS during pregnancy; he also presented a thyroid agenesis and a deficit of methyltetrahydrofolate reductase (MTHFR); at 30 months of age he was operated on for a grade II ependymoma of IV ventricle; after a multiple-stage surgery, he underwent oral chemotherapy and stereotactic radiotherapy, but after 15 months he presented a local recurrence and died. The second patient was diagnosed for KS at the age of 16 months; at 10 years of age, due to back pain, he underwent an MRI, which showed a cauda equine tumor. He underwent surgery and radiotherapy. Histology was of mixopapillary ependymoma. CONCLUSION: In a review of literature, various neoplasms have been described in association with KS. To our knowledge, these are the first two cases reported of ependymoma associated to KS. A retrospective study of 44 monoinstitutional ependymoma cases demonstrated association with genetic syndromes in 22%.

Central Nervous System Neoplasms↗
PubMed2006

Angiogenesis in a human neuroblastoma xenograft model: mechanisms and inhibition by tumour-derived interferon-gamma.

Tumour progression in neuroblastoma (NB) patients correlates with high vascular index. We have previously shown that the ACN NB cell line is tumorigenic and angiogenic in immunodeficient mice, and that interferon-gamma (IFN-gamma) gene transfer dampens ACN tumorigenicity. As IFN-gamma represses lymphocyte-induced tumour angiogenesis in various murine models and inhibits proliferation and migration of human endothelial cells, we have investigated the antiangiogenic activity of tumour-derived IFN-gamma and the underlying mechanism(s). In addition, we characterised the tumour vasculature of the ACN xenografts, using the chick embryo chorioallantoic membrane assay. We show that the ACN/IFN-gamma xenografts had a lower microvessel density and less in vivo angiogenic potential than the vector-transfected ACN/neo. The vascular channels of both xenografts were formed by a mixed endothelial cell population of murine and human origin, as assessed by the FICTION (fluorescence immunophenotyping and interphase cytogenetics) technique. With respect to ACN/neo, the ACN/IFN-gamma xenografts showed more terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling-positive human and murine endothelial cells, suggesting that inhibition of angiogenesis by IFN-gamma was dependent on the induction of apoptosis, likely mediated by nitric oxide. Once the dual origin of tumour vasculature is confirmed in NB patients, the xenograft model described here will prove useful in testing the efficacy of different antiangiogenic compounds.

Animals↗
PubMed2006

Catastrophic relapse of Evans syndrome five years after allogeneic BMT notwithstanding full donor chimerism. Terminal hemolytic-uremic syndrome.

A patient with severe Evans syndrome received an allo-BMT from his HLA-identical sister on November, 2000. Full marrow and blood donor chimerism were achieved only after 5 donor lymphocyte infusions (DLI), and coincided with complete clinical remission and disappearence of auto-antibodies. Five years later, hemolytic anemia recurred with rapid increase of serum bilirubin to over 50 mg%: he responded to combined therapy, but died on day +17 from admission of an acute hemolytic uremic syndrome (HUS). All circulating blood cells, including erythrocytes, were 100% donor. Ex vivo cultured and expanded T and B cells from the peripheral blood were also 100% donor. The supernatants from B cell cultures, containing either IgM or IgG, did not react with a panel of erythrocytes. Thus in this typical autoimmune disease with a predominant B cell pathogenesis the donor immune system resulted "innocent of autoimmunity". The persistence of long-lived recipient autoreactive plasma-cell lines in survival niches, still producing autoantibodies, may be hypothesized for this and similar cases. The postulated graft-versus-autoimmunity (GVA) effect was apparently not sufficient to eradicate autoimmunity in this patient.

Adolescent↗
PubMed2000

Analysis of stepwise genetic changes in an AIDS-related Burkitt's lymphoma.

In this study, immunoglobulin variable (Ig V) region genes, c-myc re-arrangement and sequence and p53 status were analyzed in clones derived from a Burkitt's lymphoma cell line (LAM) in which it was previously demonstrated that Epstein-Barr virus (EBV) infection occurred late during lymphomagenesis. Such evidence was based on the finding that 2 groups of cellular clones, characterized by the same c-myc re-arrangement but different EBV-fused termini, were obtained from the LAM cell line. The Ig V gene sequences were identical for the 2 groups of clones with different EBV-fused termini. The Ig variable heavy (V(H)) gene sequence displayed a substantial accumulation of point mutations (but no intra-clonal diversification), whereas the productive Ig V lambda (V(lambda)) gene sequence was virtually unmutated. Studies on the Ig V kappa (V(kappa)) locus suggested a receptor revision event (with a switch from kappa to lambda chain production) prior to EBV infection. Likewise, it was determined that the mutations observed in both p53 alleles and in the re-arranged c-myc gene occurred before EBV infection. Based on these findings, we present a model for the various steps of lymphomagenesis. It is proposed that stimulation by an antigen or a superantigen initially favored the clonal expansion and accumulation of other cytogenetic changes, including those involved in receptor editing. These events occurred prior to or during the germinal center (GC) phase of B-cell maturation. Thereafter, possibly upon exit of the cells from the GC, EBV infection occurred, further promoting lymphomagenesis.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Late Epstein-Barr virus infection of a hepatosplenic gamma delta T-cell lymphoma arising in a kidney transplant recipient.

BACKGROUND AND OBJECTIVE: gd T-cell lymphomas are only exceptionally observed in transplanted patients. Aim of this study was the detailed characterization of one such case. DESIGN AND METHODS: The patient developed spontaneous splenic rupture six years after kidney transplantation. The splenic red pulp was infiltrated by medium-sized and large lymphoid cells with two or more nucleoli. At autopsy, similar lymphoid cells infiltrated the hepatic sinusoids. Histologic, immunologic and molecular studies were carried out. RESULTS: By immunohistochemistry, the atypical lymphoid cells were found to express CD3, CD45 and CD43, indicating their T-lineage origin. Approximately 99% of spleen mononuclear cells (MNC) were CD3(+), gammadelta TcR+, CD4-, CD8-, alphabeta TcR-. A clonal gammadelta TcR rearrangement (Vgamma1-Jgamma1.3/2.3-Cgamma2; Vdelta1-Ddelta2-Jdelta1) was detected. The final diagnosis was peripheral T-cell lymphoma, hepato-splenic gammadelta-type. EBV infection of spleen MNC was documented by molecular studies. However, in situ hybridization for EBER-1 (EBV-RNA) showed that only a minority of malignant lymphoid cells (5-7%) were EBV-infected. INTERPRETATION AND CONCLUSIONS: It is concluded that EBV infection was as a late event involving an already transformed gd T-cell clone.

Adult↗
PubMed1997

[Prenatal diagnosis of triploidy and trisomy 21 through fetal erythroblasts isolated from maternal blood].

BACKGROUND: A long-sought goal of medical genetics has been the development of prenatal diagnostic procedures that do not endanger the conceptus. The safety of noninvasive methods for prenatal diagnosis would be especially attractive because they could be extended to all pregnant women, regardless of their ages or histories. Noninvasive prenatal diagnosis for the entire population might be possible recovering fetal cells from maternal blood. For this purpose, we have studied fetal erythroblasts. MATERIALS AND METHODS: To evaluate the potential of the method for clinical use, we studied maternal blood samples from 11 women referred to us for prenatal diagnosis between 15 and 20 weeks of gestation. For simple and effective enrichment of fetal nucleated erythrocytes from peripheral maternal blood, we combined a triple density gradient and magnetic-activated cell sorting (MACS) of anti-CD71 transferrin receptor antibody labeled cells. The isolated cells were analysed by using dual-colour interphase fluorescent in situ hybridization (FISH) with X-, Y-, 18- and 21-specific DNA probes. RESULTS: Chromosomal abnormalities detected on enriched fetal cells include trisomy 21 and triploidy. CONCLUSIONS: Based on the current results it is suggested that the technique described here is a simple, fast, efficient and reliable method for non invasive prenatal diagnosis.

Down Syndrome↗
PubMed1996

The phenotype of a 45,X male with a Y/18 translocation.

In this report, we describe a male infant with a 45,X karyotype; the entire short arm and the centromere of the Y chromosome were translocated onto the short arm of chromosome 18, resulting in an unbalanced dicentric chromosome. Breakpoints were identified by in situ fluorescence hybridization (FISH) on the proximal Yq11 and 18p11.2. Both Y and 18 centromeric alphoid sequences were identified on the derived 18 chromosome. Clinical features were compatible with 18p- syndrome and no Turner stigmata were present in our propositus. Short stature was likely to be related to the deletion of 18p and/or Yq, where a gene involved in stature determination has been located proximal to a gene involved in spermatogenesis (AZF).

Abnormalities, Multiple↗
PubMed1993

Cytogenetics of multiple endocrine neoplasia syndromes. III. Analysis of an insulinoma from a subject with MEN 1 by chromosome painting.

The cytogenetics of an insulinoma from a subject with MEN 1 characterized by the consistent presence of double minute chromosomes (dmins) and by five characteristic marker chromosomes was investigated with fluorescence in situ hybridization after labeling with a chromosome 11 library. The dmins were consistently negative for 11q material, with the exception of one metaphase which had two positive dmins. This indicated that the dmins are not derived massively from chromosome 11 and that they can be heterogeneous in their origin. One of the marker chromosomes, tentatively identified as a del (7), turned out to be the product of a 7;11 translocation.

Chromosome Aberrations↗
PubMed1993

Presence of telomeric and subtelomeric sequences at the fusion points of ring chromosomes indicates that the ring syndrome is caused by ring instability.

In situ hybridization of a telomeric (TTA-GGG)n sequence to metaphases from three cases of ring chromosome, involving respectively chromosomes 4, 16, and 20, showed the presence of the cognate sequences in all three rings. To investigate whether these ring chromosomes originated by telomere-telomere fusion, we determined, by in situ hybridization, whether telomere-associated sequences and/or specific distal sequences were still present in the ring chromosomes. The finding that these sequences were preserved in all the ring chromosomes strongly indicates that they originated by telomere-telomere fusion. All three subjects carrying the ring chromosomes are affected by the so-called ring syndrome, with failure to thrive, minor dysmorphic signs and no major anomalies. The r(4) patient has the ring in mosaic form with a normal cell line and has normal intelligence. The r(16) and the r(20) patients have moderate mental retardation and suffer from seizures. We conclude that the ring syndrome, even in its more severe manifestation, is caused by ring chromosome instability.

Adolescent↗
PubMed1993

Are the nail-patella syndrome and the autosomal Goltz-like syndrome the phenotypic expressions of different alleles at the COL5A1 locus?

The COL5A1 gene, which encodes the pro alpha 1(V) chain, was recently mapped to 9q34.3 in the same region as the nail-patella locus. This was taken as an indication that the nail-patella syndrome may be an inherited connective tissue disorder. We demonstrate COL5A1 heterozygous deletion and fibroblast under-expression of alpha 1(V) chains in a girl with an unbalanced translocation resulting in 9q32-->qter monosomy. The patient presents dysplastic nails, a sign typical of nail-patella syndrome, but normal patella. Moreover, she has skin and bone disorders similar to those found in the Goltz syndrome. We suggest that monosomy for the COL5A1 gene is responsible for these connective tissue disorders. Accordingly, the nail-patella syndrome could be attributable to mutations inside the COL5A1 gene rather than to a deletion of it.

Alleles↗
PubMed1993

ICF syndrome with variable expression in sibs.

We describe a new familial case of ICF syndrome (immunodeficiency, centromeric instability, facial anomalies) in a woman of 29 years and in her brother of 30 years. The proband showed mental retardation, facial anomalies, recurrent respiratory infections, combined deficit of IgM and IgE immunoglobulin classes, and paracentromeric heterochromatin instability of chromosomes 1, 9, and 16. The brother had minor signs of the syndrome and had an apparently normal phenotype. Their parents were healthy and non-consanguineous. Chromosome anomalies consisted of homologous and non-homologous associations, chromatid and isochromatid breaks, deletions of whole arms, interchanges in the paracentromeric region, and multibranched configurations of chromosomes 1, 9, and 16. CD bands and fluorescence in situ hybridisation with alphoid DNA sequence probes specific for the centromeres of chromosomes 1 and 16 showed that the centromere was not directly implicated in the formation of multibranched configurations. These cases indicate the autosomal recessive mode of inheritance and the variable expressivity of the ICF syndrome.

Adult↗
PubMed1993

Identification of ring Y chromosome: cytogenetic analysis, Southern blot and fluorescent in situ hybridization.

A young male with a 45, X/46, X, r(Y)/47, X, r(Y), r(Y)/48, X, r(Y), r(Y), r(Y) karyotype was described. The phenotype was substantially characterized by short stature (< 3rd centile) and by a scrotal hypospadias with a normal sized penis. Fluorescent in situ hybridization (FISH) and molecular analysis by X and Y chromosomes specific probes were performed to identify the origin of the marker chromosomes which had been impossible to define by conventional and high resolution cytogenetics techniques. Small rings was identified as Y-derived ring chromosomes, lacking the entire heterochromatic portion of the long arm and the very distal tip of the short arm. The correlation between the phenotype and the chromosome constitution of the propositus was discussed.

Adolescent↗
PubMed1992

Fine mapping and cloning of the breakpoint associated with Menkes syndrome in a female patient.

The gene responsible for Menkes syndrome has been assigned to Xq13 by a combination of comparative mapping and linkage analysis. A previous report has mapped the translocation breakpoint associated with the disease in a female patient to an interval delimited by PGK1 and a group of six more proximal Xq13 markers, including DXS56. We have characterized a number of PGK1- or DXS56-positive YACs, from which we have generated six new markers. One of them identifies a small overlap region between a PGK1-positive YAC and three DXS56-positive YACs, distal to the Menkes breakpoint. A 560-kb region covered by a DXS56-positive YAC has been restriction-mapped and subcloned, disclosing a 187-kb MluI fragment astride the breakpoint. A probe mapping distal to the rearrangement in the same interval reveals altered PGFE fragments in a hybrid constructed from the translocation patient's DNA. We describe the development of a cosmid contig extending 150 kb from a nearby CpG island across the breakpoint. This contig includes four adjacent clones displaying cross-specific hybridization.

Base Sequence↗
PubMed1992

Molecular and cytogenetic characterization of radiation hybrids specific for human chromosome 16.

Two hundred and twenty-three radiation hybrids retaining random fragments of human chromosome 16 were isolated during two successive experiments in HAT medium and screened with a total of 38 DNA probes, corresponding to anonymous DNA or gene sequences localized on chromosome 16. The presence of single or multiple human chromosomal fragments in a small subset of these hybrids was determined using in situ hybridization with total human DNA. The results confirm that individual radiation hybrids are often heterogeneous with respect to the retention and distribution of human fragments, as already suggested by their characterization with DNA probes. A number of these 223 radiation hybrids, whose detailed characterization has not been previously reported, represent a resource for the rapid isolation of new DNA markers or coding sequences from specific regions of chromosome 16 where human disease genes are already known to map.

Chromosomes, Human, Pair 16↗