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Biomedical subjects

B K Hecht

Publications and source records attributed to B K Hecht.

At least 91 records · Page 5Linked to original sources
PubMed1984

Chromosome analysis in hematologic disorders. The leukemias.

For two decades, cytogenetic studies have been used to rule in (or out) the Philadelphia (Ph1) chromosome associated with chronic myeloid leukemia. Beyond this single purpose, chromosome studies have generally not been utilized in or applied to the practice of hematology-oncology. This report presents male and female patients, teens to 70s in age, with representative hematologic disorders, in whom the cytogenetic findings were useful clinically. These cases illustrate the following principles: (1) hematologic disorders can be characterized by chromosome analysis; (2) chromosome findings help in the diagnosis, prognosis, and treatment of blood diseases; (3) blood and bone marrow samples can be processed routinely for cytogenetic analysis; (4) these samples can be transported long distances from clinic to laboratory; and (5) the contemporary practice of hematology and oncology requires chromosome analysis for fuller evaluation and understanding of hematologic conditions.

Adult↗
PubMed1984

Cis-trans position effect in cancer translocations.

Translocations of chromosomes occurring in human cancer cells appear specific to the type of cell from which the cancer arises. To explain the action of these translocations, we propose dual position effect: Position effect of the cis type transforms the cell to malignancy, while position effect of the trans type permits the normal homologous chromosome to express a normal gene product. Thus, the translocation itself has to do with malignant transformation, while the normal homologous chromosome performs its normal function. This dual concept is illustrated by t(8;14) in Burkitt's lymphoma. The concept can be tested with t(2;18) and t(8;22) in lymphoid malignancies and with other translocations and chromosome rearrangements marking human cancer cells.

Ataxia Telangiectasia↗
PubMed1984

Direct prenatal chromosome diagnosis of a malignancy.

A fetal tumor was suspected at 31 weeks of gestation. The occurrence of polyhydramnios led to an ultrasound examination, which revealed deformation of the fetal head, face, eye, and neck. This was confirmed by computerized tomography. Amniocentesis yielded cells with an inverted duplication of chromosome #1. This abnormality of chromosome #1 marked the malignant teratoma cells in the amniotic fluid. Cytogenetic analysis of tumor tissue and of normal tissue obtained postnatally confirmed that the abnormality of chromosome #1 observed in amniotic fluid cells was confined to the tumor. The constitutional karyotype was normal. To our knowledge, this is the first report of the direct chromosomal detection of malignancy before birth.

Adult↗
PubMed1984

Aneuploidy in recurrent spontaneous aborters: the tendency to parental nondisjunction.

To test the hypothesis that parental aneuploidy, particularly involving sex chromosomes, indicates an increased risk of meiotic nondisjunction, we analyzed chromosome numbers from 283 parents who had had 2 or more spontaneous abortions and, if they had children, no abnormal offspring. A sample of 15 lymphocyte metaphases was examined per individual for a total of 4,245 metaphases. Two or more cells with the same abnormal chromosome complement were found in 19 individuals: 4 males with a minor number of 45,X cells and 15 females with minor numbers of 45,X and/or 47,XXX cells (p less than 0.001). The most logical explanation is that mitosis may, in part, reflect meiosis. This group of parents appears predisposed to chromosome errors in meiosis leading to recurrent spontaneous abortion.

Abortion, Habitual↗
PubMed1984

Fragile sites and chromosome breakpoints in constitutional rearrangements I. Amniocentesis.

Since fragile sites may conceivably predispose to chromosome breakage and rearrangements in meiosis, we examined the locations of 278 breakpoints leading to chromosome rearrangements detected in amniocenteses. Of the 278 breakpoints, 59 (21%) were observed to be in bands containing fragile sites compared to an expectation of 31 (11%), a highly significant difference (P less than 0.001). The tendency for breakpoints to be in bands with fragile sites was independent of origin of the rearrangement or class of fragile site, consistent with the concept that fragile sites predispose to heritable chromosome rearrangements.

Amniocentesis↗
PubMed1984

Fragile sites and chromosome breakpoints in constitutional rearrangements II. Spontaneous abortions, stillbirths and newborns.

Certain fragile sites may possibly predispose to chromosome breakage and rearrangements in meiosis. To test this hypothesis, we examined 894 breakpoints found in spontaneous abortions, stillbirths and livebirths of which 165 (18.5%) were in bands with fragile sites. Compared to an expectation of 98 (11%), there was a significant excess of breakpoints in fragile site bands (P less than 0.001). Together with data from amniocenteses, there is now evidence suggesting that certain fragile sites may be prone to fragility in meiosis.

Abortion, Spontaneous↗
PubMed1983

Position effect in translocation (2;8) in acute lymphocytic leukemia with kappa light chain immunoglobulin expression.

We report a correlation between t(2;8) translocation in acute lymphocytic leukemia and kappa light chain immunoglobulin production. Since the kappa chain genes are on chromosome #2, this, as well as data on Burkitt lymphoma, points to the possibility of position effect on the level of gene action. Chromosome #2 in the translocation together with chromosome #8 is concerned with malignancy, while the normal homologous chromosome #2 transcribes kappa chains. This model applies to B cell leukemias and lymphomas with changes in chromosome #2 which will predictably express kappa chains. The model also applies to B-cell malignancies with changes in chromosome #22 which will predictably express lambda chains.

Aged↗
PubMed1983

Fibrous histiocytoma cell line: chromosome studies of mouse and man.

A human cell line isolated from a lung metastasis of a malignant fibrous histiocytoma was studied chromosomally. The cell line had a modal chromosome number of 59 with multiple numerical and morphologic chromosome changes and marker chromosomes. A putative clone from this cell line had a modal number of 41 with exclusively acrocentric chromosomes and was clearly not human but mouse in origin.

Animals↗
PubMed1983

Adenocarcinoma of the gallbladder: chromosome abnormalities in a genetic form of cancer.

Chromosome studies on gallbladder adenocarcinoma in a Papago Indian woman were performed. These studies revealed a high degree of aneuploidy including multiple instances of missing chromosomes, extra chromosomes, and chromosome rearrangements. Double minute chromosomes and homogeneous staining regions on chromosomes were present in the cancer cells. To our knowledge this is the first report on the cytogenetic analysis of a gallbladder cancer. Chromosome studies on gallbladder cancers will be of unusual interest because of the relatively high frequency of this rare genetic form of cancer in American Indians.

Adenocarcinoma↗
PubMed1983

Characterization of Epstein-Barr virus-carrying cell lines established from chronic lymphocytic leukemia.

Attempts were made to establish lymphoid cell lines from the cultured peripheral blood lymphocytes of six patients with chronic lymphocytic leukemia. In only one case was cell growth obtained following the addition of exogenous transforming Epstein-Barr virus, and those cell cultures proved not to have acquired the ability to proliferate permanently. In the same case, cell lines were established spontaneously from the peripheral blood without addition of Epstein-Barr virus. The cells which grew spontaneously were large, were occasionally weakly surface adherent, and grew in suspension as loose clumps or as single cells. They were negative for surface immunoglobulins and spontaneous rosette formation with sheep erythrocytes and positive for intracytoplasmic immunoglobulins (Fc and C3 receptors). At an early passage, the spontaneous lines had an aneuploid karyotype with some triploid and some tetraploid cells. Structural chromosomal aberrations include a 14q+. Electron microscopy of the chronic lymphocytic leukemia lines revealed relatively smooth surfaces with numerous mitochondria, widespread vacuolization, and numerous unusual "myelin" figures. Five to 10% of the cells were phagocytic as detected by internalization of latex particles; however, they were Epstein-Barr nuclear antigen positive. The nature of these cells and their possible relationship to the etiology of chronic lymphocytic leukemia are discussed.

Cell Line↗