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Biomedical subjects

S Heim

Publications and source records attributed to S Heim.

At least 307 records · Page 17Linked to original sources

Bone marrow karyotype and prognosis in primary myelodysplastic syndromes.

Bone marrow karyotype, survival time, and the rate of progression to leukaemia were studied in 111 unselected patients with primary myelodysplastic syndromes. The 49 patients (44%) with clonal chromosome aberrations had survival time (median 29 months) similar to that found in the 62 patients with normal bone marrow karyotype (24 months, p greater than 0.10). The presence of multiple (greater than 2) abnormalities (17 patients) was strongly associated with poor prognosis, with a median survival of only 7 months (p less than 0.001). Prognostic information could be attributed to 2 specific abnormalities, del(5q) and -7: Presence of del(5q) as the sole anomaly was associated with long survival (36+ months), whereas monosomy 7 was a bad prognostic sign (6 months). The risk for leukaemia development correlated neither with the number of chromosome abnormalities nor with any particular anomaly. Our findings demonstrate the prognostic importance of quantifying the complexity of bone marrow chromosome changes. They also emphasize that different specific abnormalities convey widely different prognostic information in primary myelodysplastic syndromes.

Bone Marrow↗

Amplification of the human putative oncogene INT1 in primary retinoblastoma tumors.

We report the amplification of the putative oncogene INT1 in two of four retinoblastomas. In one case, the INT1 signal was amplified 10 to 15-fold, in the other 100-fold. In both cases there were signs of increased tumor aggressiveness with invasion of the choroid and development of metastases. The two cases without INT1 amplification had neither metastases nor locally invasive growth. Our findings indicate that INT1 amplification may be a feature of increased malignant potential in retinoblastomas.

Blotting, Southern↗

Karyotypic rearrangements in 20 uterine leiomyomas.

Short-term cultures from 106 uterine leiomyomas have been cytogenetically investigated. In 29 cases the number of metaphases was insufficient for analysis. A normal female karyotype was found in 57 tumors and clonal chromosome rearrangements in 20. A reciprocal translocation, t(12;14) (q14----q15;q23----q24), was observed in 10 tumors and probably represents a primary change of tumorigenic importance. In four of the tumors containing this specific anomaly, secondary chromosome changes were also present. The 10 karyotypically abnormal leiomyomas without a t(12;14) had various structural and numerical aberrations involving chromosomes 1, 2, 3, 4, 6, 8, 9, 10, 11, 12, 13, and 19. Different structural changes of chromosome 1 were the second most frequent abnormalities, being found in five tumors. Ring chromosomes were observed in three cases, but never as the sole change.

Animals↗

A new specific chromosomal rearrangement, t(11;20)(p15;q11), in myeloblastic leukemia with maturation.

The translocation t(11;20)(p15;q11) was found as the sole acquired clonal chromosome abnormality in two patients with acute myeloid leukemia. The bone marrow morphology in both cases corresponded to the M2 subtype of the French-American-British (FAB) classification. None of the patients achieved complete remission, and both died less than 6 months after diagnosis. This particular translocation has not previously been reported in acute nonlymphocytic leukemia.

Adolescent↗

Variant translocation t(3;15)(q21;q22) in a patient with acute promyelocytic leukemia.

Bone marrow cells from most patients with acute promyelocytic leukemia contain a highly specific cytogenetic rearrangement, a reciprocal translocation between the long arms of chromosomes 15 and 17. Several cases of variant translocations involving 17q but not 15q have been reported, leading to the suggestion that the break in 17q rather than the one in 15q is the crucial change in the regular t(15;17). We describe a hematologically typical case of acute promyelocytic leukemia with a t(3;15)(q21;q22). This is the first report in this leukemia subset of a variant translocation affecting 15q without involvement of 17q.

Acute Disease↗

Lipomas have characteristic structural chromosomal rearrangements of 12q13-q14.

Cytogenetic analysis was performed in 10 consecutive lipomas; 6 had typical benign histology whereas four had foci of atypia. Three tumors had supernumerary ring chromosomes, 6 had different balanced rearrangements, and one had a normal karyotype. Chromosome 12 was involved in 5 of the balanced rearrangements and, although less certainly, in all the ring chromosomes, with breakpoints localized to 12q13 or q14. The other rearranged chromosomes were numbers 2, 3, 7, 8, 11, 17 and 22. These results demonstrate the non-random involvement of chromosomal region 12q13-q14 in benign lipogenic tumors. The combined data from this and previous studies on benign and malignant lipogenic tumors indicate that different levels of cytogenetic specificity exist within this group of neoplasms. We suggest that myxoid liposarcoma development requires the recombination of 2 specific chromosomal bands (12q13 and 16pII), whereas for some types of benign lipogenic tumors structural changes in 12q13-q14 may be sufficient for neoplastic growth.

Aged↗

Nineteen of 26 cellular oncogenes precisely localized in the human genome map to one of the 83 bands involved in primary cancer-specific rearrangements.

A total of 83 bands have been found to be specifically involved in primary structural chromosome rearrangements in human cancer. We have compared the distribution of these cancer-specific breakpoints with the chromosomal sites of the 26 cellular oncogenes currently mapped to individual bands within the human genome. Nineteen of the 26 oncogenes are localized in cancer-associated bands. This clustering of oncogene sites and cancer breakpoints is statistically highly significant (P = 0.0000012).

Chromosome Aberrations↗

Tetraploid karyotype (92,XXYY) in two patients with acute lymphoblastic leukemia.

Tetraploid karyotypes without structural chromosome abnormalities were found in approximately 50% of the bone marrow cells in two patients with acute lymphoblastic leukemia with L2 morphology and "null cell" immunophenotype. Strict tetraploidy (4n = 92) has not been reported as the sole karyotypic rearrangement in bone marrow neoplasia, but may represent a previously unrecognized cytogenetic leukemia subtype.

Child, Preschool↗

Late appearing 5q--marker in refractory anemia.

A patient with myelodysplasia indistinguishable from the 5q--syndrome is described. No clonal chromosome abnormalities were detected in the total of 120 bone marrow cells initially examined. At the next sampling, 3 years later, del(5q) was present in all analyzed metaphases. These findings indicate that del(5q) may be only one of the pathogenetically important events in the 5q--syndrome, and that submicroscopic changes may precede the visible chromosomal rearrangement.

Anemia, Refractory↗

Marker ring chromosome--a new cytogenetic abnormality characterizing lipogenic tumors?

We have analyzed three intramuscular lipomas, two atypical and one with ordinary benign histology, as part of a systematic study of the karyotypic characteristics of mesenchymal tumors. A large ring chromosome of uncertain origin, but possibly representing a rearranged chromosome #3, was found in all three tumors. Previous reports on the chromosome banding pattern in lipogenic neoplasms are restricted to only three cases, all liposarcomas. In one of these, a well differentiated liposarcoma, a ring chromosome was described that was remarkably similar in morphology to the aberration reported here. We conclude that this ring chromosome may constitute a characteristic cytogenetic marker for lipogenic tumors.

Adult↗

Prognostic implication of cytogenetic findings in 106 patients with non-Hodgkin lymphoma.

The cytogenetic findings in samples from 106 patients with non-Hodgkin lymphomas (NHL), histopathologically classified according to the Kiel classification, have been correlated with survival time. Clonal chromosomal abnormalities were found in 60 patients, and only normal karyotypes in ten. The chromosome analysis of the remaining samples failed. The failures did not differ in survival compared with the cytogenetically successful cases, indicating that this group is not a prognostic entity within NHL. The cytogenetic findings were classified in six ways in order to evaluate the prognostic value of the cytogenetic pattern. Multivariate analysis demonstrated that presence of clonal chromosome abnormalities and the number of aberrations both were important prognostic factors independent of histopathology, whereas, the modal chromosome number, presence of translocations, or unidentified marker chromosomes were not. Some characteristic chromosome abnormalities were correlated with survival time: Patients with a 1p+ marker or +7 had a significantly shorter survival time than patients with normal karyotypes only (NN). Patients with +3, +12, 6q-, i(17q), and t(14;18)(q32;q21) did not differ significantly from the NN group.

Chromosome Aberrations↗

Clonal chromosome abnormalities in two liposarcomas.

Two liposarcomas were analyzed with chromosome banding technique. The sole chromosomal abnormality in one of the tumors, a mixed type (myxoid and round cell) liposarcoma, was t(12;16)(q13;p11), a rearrangement previously reported to be associated with myxoid liposarcoma. The other tumor, a pleomorphic liposarcoma, displayed massive numerical rearrangements (modal chromosome number 94-112), and numerous, mostly unidentifiable, marker chromosomes. The following clonal structural aberrations were recognized: del(1)(p22), del(1)(q23), t(7;?)(p22;?), i(17q), and t(19;?)(q13;?).

Adult↗

A new specific chromosomal rearrangement, t(8;16) (p11;p13), in acute monocytic leukaemia.

The translocation t(8;16) (p11;p13) was found as the sole deviation from the normal karyotype in three patients with acute monocytic leukaemia. The bone marrow morphology was strikingly similar in the two cases where smears were available for re-evaluation: the leukaemic cells showed signs of differentiation, and active erythrophagocytosis was a particularly conspicuous feature. We suggest that t(8;16) (p11;p13) represents a new consistent abnormality in acute monocytic leukaemia, specifically associated with the differentiated subtype (M5b) and with pronounced phagocytic activity by the leukaemic monocytes.

Adolescent↗

Monosomy and trisomy of 15q24----qter in a family with a translocation t(6;15)(p25;q24).

A child with multiple anomalies, including growth retardation, a left-sided diaphragmatic hernia with lung hypoplasia, and cerebral malformations is described. Cytogenetic investigation demonstrated a deletion of the distal part of one chromosome 15, del(15)(q24qter), an aberration not previously described. Family studies revealed that the mother had a balanced translocation, t(6;15)(p25;q24). Two of her subsequent pregnancies resulted in abortions after prenatal diagnosis: one fetus was trisomic for 15q24----qter, while the other had monosomy 15q24----qter and a left-sided diaphragmatic hernia similar to the first child.

Chromosome Deletion↗