Search PubMed⌕ Search

Biomedical subjects

C Mecucci

Publications and source records attributed to C Mecucci.

At least 109 records · Page 6Linked to original sources

Detection of amplified sequences at 5q11-->q13 in a homogenously staining region found by fluorescent in situ hybridization in a case of B-cell non-Hodgkin's lymphoma.

Gene amplification is one of the molecular mechanisms possibly involved in the initiation of tumorigenesis. Homogenously staining regions and double minutes have been shown to contain amplified DNA sequences. We report here a case of B-cell non-Hodgkin's lymphoma (NHL) carrying an abnormal chromosome 5 with an hsr-like region at 5q11-->q13. Chromosome "painting" with a chromosome 5-specific library (pBS5) showed that the amplified material was indeed derived from chromosome 5. Further identification of the amplified DNA sequences was performed with a set of YAC probes localized to 5q12-->q14. The amplified region contained genetic loci defined by D5S6, D5S125, D5S112, and D5S39. A three-fold level of DNA amplification was visualized by Southern blotting using a DNA probe from the amplified region. The present results suggest that unknown gene(s) at 5q11-->q13 might be involved in the process of lymphomagenesis when amplification occurs.

Chromosome Banding↗

A novel gene, AF-1p, fused to HRX in t(1;11)(p32;q23), is not related to AF-4, AF-9 nor ENL.

Most of the translocations affecting the chromosome band 11q23, frequently seen in human acute leukemias, involve a restricted area of the HRX gene. We have characterized two t(1;11)(p32;q11) translocations which fuse the HRX gene to a novel gene, AF-1p on chromosome 1p32, in two myeloid leukemias. The der (11) chromosome expresses the 1368 N-terminal amino acids of HRX, including the AT-hook, snRNP and methyltransferase similarities, fused to almost all the AF-1p product. The predicted wild type AF-1p product is a 98 kDa acidic protein which does not exhibit similarity to the AF-4, AF-9 and ENL gene products. It is highly similar to the murine eps 15 gene product, which encodes a cytoplasmic phosphoprotein. Our data indicate that AF-1p defines another class of genes fused to HRX in 11q23 abnormalities.

Adaptor Proteins, Signal Transducing↗

T-cell lymphoma developing in Hodgkin's disease: evidence for two clones.

A case of peripheral T-cell lymphoma (PTL) occurring in a patient with Hodgkin's disease (HD) in relapse is described. The second neoplasm developed 25 months after the diagnosis of HD. Cytogenetic analysis on the lymph node biopsy at the time of diagnosis of PTL revealed the co-existence of two distinct, abnormal cell clones. The first clone was characterized by a reciprocal translocation t(5;7)(q13;q35) involving 7q35, namely the TCR-beta gene, as expected in T-cell lymphomas. The second cell clone carried trisomies for chromosomes 2, 5, 7, and 14. By immunophenotypic and molecular analysis as well as by in situ hybridization, it was possible to prove that the malignant T-cells and the Reed-Sternberg cells corresponded to different cell clones, one carrying the structural chromosome abnormalities and one carrying the numerical chromosome anomalies. These results indicate that the present case represented a true composite lymphoma.

Antigens, CD↗

Rare HRAS1 alleles outside the VTR region in lymph nodes from patients with malignant lymphoma.

We found a new type of rare HRAS1 alleles arising de novo in the lymph node of lymphoma patients. Rare alleles of 6.2 kb (a0.1) and 7.3 kb (a2.3) are displayed in the presence of common alleles of 6.6 kb (a1) and 7.6 kb (a3), respectively. These rare alleles lack nucleotide sequences, present in the common alleles in the 5' part between the BamHI and XmaIII site. In addition, the rare alleles may have the classic A-G mutation in the intron at position 2719. In contrast to what is observed for rare constitutional alleles, the VTR region of these rare alleles has the same size as the common alleles. At present the significance of this new type of alleles is not clear.

Alleles↗

A translocation (8;14) in a cutaneous large B-cell lymphoma.

A 62-year-old man with a cutaneous large-cell (cleaved, noncleaved) lymphoma had multiple facial lesions and two enlarged cervical lymph nodes. Cytogenetic analysis performed on the involved skin and lymph node revealed the following karyotype: 47,XY,inv dup(1)(q11-->q32),+3,t(8;14)(q24;q32). A t(8;14)(q24;q32) translocation is the chromosome anomaly in 75% of Burkitt's lymphomas. Other types of non-Hodgkin's lymphomas, however, may show the same translocation, especially large-cell lymphomas. Duplication of material belonging to the long arm of chromosome 1 is the most frequent additional aberration to Burkitt's translocations in Burkitt's lymphoma/leukemia. Trisomy 3 may be seen in both B- and T-cell malignancies, as well as in angioimmunoblastic lymphadenopathy. Immunogenotyping of malignant cells from a lymph node showed rearrangement of the immunoglobulin heavy and lambda light chain genes. Epstein-Barr virus (EBV) serology was positive for EBV nuclear antigen and EBV capsular antigen. No integration of EBV DNA in tumor tissue, however, could be detected by polymerase chain reaction. These results may be useful in defining the biologic characteristics of cutaneous B-cell non-Hodgkin's lymphomas.

Antigens, Differentiation↗

dup(12)(q13----qter) in two t(14;18)-negative follicular B-non-Hodgkin's lymphomas.

Two t(14;18)-negative follicular B-non-Hodgkin's lymphomas with the same chromosomal abnormality, dup(12)(q13----qter), are presented. The absence of a BCL2 gene rearrangement was confirmed by molecular studies in both cases. Instead, duplication of a 12q segment was found. Further evidence for the presence of the dup(12)(q13----qter) was found using fluorescence in situ hybridization. dup(12q) may be equivalent to the trisomy 12 originally described in B-chronic lymphocytic leukemia. This chromosome anomaly has also been reported in B-non-Hodgkin's lymphomas, usually in association with other chromosome anomalies and a more aggressive tumor phenotype. Occurrence of dup(12q) in two histologically similar cases of follicular small cleaved-cell lymphoma without a typical t(14;18), suggests that this karyotypic change may play a critical role in some cases of follicle center-cell lymphomas.

Aged↗

Cytogenetic and molecular studies of the Philadelphia translocation in myelodysplastic syndromes. Report of two cases and review of the literature.

We report two patients with a myelodysplastic syndrome and the Philadelphia (Ph) chromosome. The first patient was a 73-year-old man who was diagnosed as having a chronic myelomonocytic leukemia in combination with features suggestive of a myeloproliferative syndrome. Chromosomal analysis showed a normal karyotype in the majority of cells, mixed with metaphases containing a standard Ph translocation, t(9;22)(q34;q11), as well as a translocation between chromosome 4 and 6: t(4;6)(p15;p12). Southern blot analysis showed breakpoint cluster region rearrangement as observed in classic chronic myeloid leukemia. The second patient was a 63-year-old man with a myelodysplastic syndrome, type refractory anemia. Cytogenetic study of bone marrow cells at the time of diagnosis revealed a normal karyotype: 46,XY. The initial myelodysplastic syndrome evolved to a myeloproliferative phase with progressive leukocytosis and thrombocytosis. During the terminal phase the Ph chromosome was discovered in 100% of the examined cells. We discuss the correlation between MDS and myeloproliferative diseases, the de novo acquisition of the Ph chromosome during the course of a myelodysplastic syndrome, and review the literature.

Aged↗

Unbalanced 6p translocation as primary karyotypic anomaly in secondary acute nonlymphocytic leukemia.

A case of acute nonlymphocytic leukemia after radiochemotherapy for Hodgkin's disease, with a rearrangement of 6p23 region, is described. This chromosome change, which has been previously reported in secondary leukemias or myelodysplastic syndromes, was an isolated karyotypic anomaly in our case, which strongly supports the nonrandom involvement of chromosome 6p in induced leukemias.

Adult↗

Chromosome 11q rearrangements in B non Hodgkin's lymphoma.

The clinical features, morphology and immunophenotype of 20 cases of B non Hodgkin's lymphoma (B-NHL) with chromosome abnormalities involving 11q13-14 were studied, to determine if this abnormality was closely associated with a specific sub-type of B-NHL. A t(11;14)(q13;q32) was found in 11 cases of intermediately differentiated lymphocytic lymphoma (IDLL). A breakpoint in the major translocation cluster of the BCL-1 locus was found in six of these cases. These patients were male with lymphomatous involvement of the bone marrow, marked splenomegaly and frequently had mucosa associated lymphoid tissue involvement. One patient with IDLL had a t(8;11)(p21;q13) and a rearranged BCL-1 locus, suggesting that this may be a variant of t(11;14)(q13;q32). Diagnoses of IDLL, chronic lymphocytic leukaemia, lymphoplasmacytic lymphoma and monocytoid B cell lymphoma were made in all but one of the remaining cases. These cases had either a translocation involving 11q13-14 and various partner chromosomes or an 11q13 deletion. This study demonstrates that 11q abnormalities occur mainly in a group of low-grade B-NHL of non follicle centre cell lineage.

Aged↗

Amylase-producing IgD-type multiple myeloma.

We describe the case of a 63-year-old woman with an IgD-type multiple myeloma and hyperamylasaemia. The evolution of the amylase concentration, the immunohistochemical data and the intracellular amylase contents of the plasma cell were consistent with secretion of amylase by the malignant clone. Moreover, cytogenetic analysis of the bone marrow revealed two structural rearrangements involving chromosome 1 near the amylase locus. Multiple myeloma should be added to the amylase-secreting tumours. This rare entity is not confined to Japan, where it was first recognized.

Adrenal Cortex Hormones↗

Cytogenetics.

Myelodysplastic syndromes (MDS) for a long time were an ill-defined group of disorders, the true nature of which was largely unknown. Because some patients developed acute leukemia, MDS was considered to be potentially premalignant. Cytogenetic investigations in the early 1970s brought the first clear evidence that these disorders were clonal. Further research has shown that MDS encompasses a number of cytogenetic entities, some of which are associated with clinically distinct disorders.

Chromosome Aberrations↗

Translocation (11;14): a cytogenetic anomaly associated with B-cell lymphomas of non-follicle centre cell lineage.

Nine patients with t(11;14) and B non-Hodgkin's lymphomas composed of small to intermediately sized cells with irregular nuclei are described. Immunophenotyping was performed on seven cases, which were M+, D- with light chain restriction, CD5+, CD10-, and CD20+, suggesting that they were non-follicle centre cell lymphomas. The translocation (11;14) (in three cases the only cytogenetic anomaly) was associated with rearrangement of bcl-1 in four of the five cases investigated. Translocation (11;14) has been described in an apparently heterogeneous group of low-grade lymphoid malignancies which we suggest have a non-follicle centre cell lineage in common. This translocation may be associated with these lymphomas in the same way that t(14;18) is associated with follicle centre cell lymphomas.

Adult↗

Reciprocal translocation involving 3q21 in an unusual myeloproliferative disorder with myelodysplastic features and prominent dysmegakaryopoiesis.

A case with an atypical myeloproliferative disorder (MPD) characterized by overt dysmyelopoiesis, mostly represented by abnormal thrombopoiesis and showing a t(3;18)(q21;q21), is described. The unusual hematological findings, which characterized a disease borderline between two distinct entities, namely MPD and myelodysplastic syndromes, are also discussed in relation to the cytogenetic abnormality affecting region 3q21 and possibly dictating the abnormal thrombopoiesis.

Aged↗

Chronic myelogenous leukemia after treatment with 131I for thyroid carcinoma. Report of a case and review of the literature.

A patient who developed Philadelphia chromosome-positive chronic myelogenous leukemia (CML) 5 years after successful treatment for thyroid carcinoma, is reported. The Philadelphia chromosome was the typical 9;22 translocation. Southern blot analysis showed breakpoint cluster region rearrangement as observed in classical CML. Up to now, only two cases of CML have been reported following treatment for thyroid carcinoma. This rare complication has also been described after therapy for other malignancies. At present, it is not clear whether the development of CML after thyroid carcinoma represents a therapy-induced complication, a coincidence, or an increased susceptibility to secondary malignancies due to the malignant process itself.

Adenocarcinoma↗

Unusual t(3;12)(q28;q13) in childhood acute lymphoblastic leukemia.

In this article we report a case of a 7-year-old boy affected by acute lymphoblastic leukemia of the common type. Bone marrow examination at diagnosis showed a reciprocal translocation between the long arm of chromosome 3 and the long arm of chromosome 12. This previously unpublished translocation is discussed and compared to the findings in the current literature.

Child↗

Cytogenetic characterization of three cases of unusual B-cell non-Hodgkin's lymphoma.

We report the cytogenetic results in three cases of B-cell non-Hodgkin's lymphomas with morphologic and immunophenotypic features compatible with a non-follicle center cell lymphoma. In all cases, a chromosome breakpoint at 14q32 and structural abnormalities of 1p were found. Increased copies of chromosome segment 12q and structural rearrangements of chromosome 6 were found in two cases. Translocation (14;18)(q32;q21) with rearrangement of bcl-2 was found in one case. These lymphomas have a perifollicular growth pattern and IgM+, IgD+, CD10-, and CD22+ immunophenotype features typical of non-follicle center cell lymphomas and probably belong to the follicle mantle lymphomas described recently. Little cytogenetic data about this group of lymphomas is available, possibly because in the Working Formulation for the Classification of Lymphomas they are not separated from follicle center cell lymphomas.

Adult↗