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Biomedical subjects

A T Chen

Publications and source records attributed to A T Chen.

At least 37 records · Page 2Linked to original sources
PubMed1982

Characterization of a new chromosomal marker for acute lymphoblastic leukemia from a long-term cell line.

A bone marrow aspirate from a child with acute lymphoblastic leukemia (ALL) at first relapse was used to establish cell line # 697. The cultured line and marrow aspirates taken at initial diagnosis and first relapse were examined and compared. Similarities in all patterns evaluated confirmed the leukemic origin of the line. Morphologically, the cells were typically lymphoblastic. Cytochemically, they were slightly acid phosphatase-positive and negative for peroxidase, ASD chloroacetate esterase, and nonspecific esterase. Immunologically, they were found positive for common-ALL antigen (CALLA), Ia-associated antigen, terminal deoxynucleotidyl transferase (TdT), and cytoplasmic IgM (cIgM) and slightly positive for surface IgM (sIgM). Testing for Epstein-Barr virus (EBV) capsid antigen was also positive. Cytogenetic evaluations performed on initial, relapse, and cell line specimens each revealed the presence of a pseudodiploid cell line characterized by a consistent marker chromosome. GTG-, QFQ-, and RF-banding identified the marker as being derived from a translocation involving chromosomes #7 and #19: t(7;19) (q11;q13). Iso 7q, -5, -9, and +2 were also found in significant association with the marker and were viewed as demonstrating continued karyotypic evolution within the cell line. From these data, cell line #697 has been classified as a leukemic line of B-cell lineage in a transitional stage between pre-B and mature B cells.

B-Lymphocytes↗
PubMed1980

First-trimester fetal chromosomal diagnosis using endocervical lavage: a negative evaluation.

A report in the literature indicated that fetal cells could be obtained by endocervical lavage during the first trimester of pregnancy and successfully cultured. This would allow prenatal diagnosis earlier in pregnancy than is currently possible with second-trimester amniocentesis. Therefore, we attempted to confirm these findings. Our results indicated that the cultural cells were maternal in origin. We disagree with interpretations of the data given in the initial report and conclude that first-trimester prenatal diagnosis is not feasible at this time.

Adolescent↗
PubMed1980

Prenatal chromosomal diagnosis. Racial and geographic variation for older women in Georgia.

In a study of Georgia women aged 40 years and older, 15% made use of prenatal chromosomal diagnosis. There was, however, substantial racial and geographic variation, ranging from a use ratio of 60% among whites in two large urban counties to 0.5% among blacks outside Augusta and Atlanta health districts. This simple population-based epidemiologic analysis suggests that future program planning for genetic services in Georgia should address ways to increase access by rural women, especially blacks. Similar analyses in other states could be used for planning genetic services.

Abortion, Therapeutic↗
PubMed1980

Prenatal diagnosis of a de novo non-fluorescent Y chromosome.

We report a case with non-mosaic Yq-, missing the fluorescent segment, and detected as a fetus studied for advanced maternal age. The father had a Y chromosome of average size and paternity was established wih a plausibility of 97.7% by HLA and erythrocyte antigen typing. The child had a normal male antigen typing. The child had a normal male phenotype at delivery and developmental milestones were normal through the first year of life. The Yq- showed no mitotic instability since it was retained in foreskin culture for its in vitro lifetime of 60 population doublings.

Adult↗
PubMed1978

Cytogenetics of recurrent abortions.

Chromosome banding studies were carried out on both partners of 37 couples who had had two or more spontaneous abortions. Three patients had chromosome disorders; one was a triple-X female and the other two (one male and one female) were t(13;14) translocation carriers. Review of the literature indicates that the over-all frequency of major chromosome disorders in couples with repeated abortions is 2.6%. About three-fourths of these disorders are reciprocal and Robersonian translocations.

Abortion, Habitual↗
PubMed1976

Association of D/D translocations with fetal wastage and aneuploidy. A report of four families.

Four families are described with a t(13q14q) segregating. Two of them were identified through index cases with Down's syndrome; their karotypes revealed the unusual 46,XY, -13, -14, +t(13q14q), +21. The other two families were identified through a chromosomal study of parents with repeated spontaneous abortions. Analysis of data on 3 of these 4 families and on 7 other from the published reports showed no evidence of increased fetal wastage among 13/14 carriers. However, the risk of producing offspring with various types of aneuploidy may be greater among carriers than among persons with a normal chromosome pattern. Qualitative and quantitative differences in D/D translocations may account for the observed variation in clinical findings. These differences add to the problem of determining genetic risks from an analysis of grouped data.

Adult↗
PubMed1976

Chromosome breakage in low birth weight newborns.

The frequency of chromosome aberrations in cells cultured from umbilical cord blood was determined for 50 low birth weight (LBW) and 50 normal birth weight (NBW) euploid newborns matched for sex, race, and maternal age. The metaphase spreads had been prepared in the course of an earlier study of frequency of aneuploidy and results are from 72-h cultures, i.e., presumably, at the second division in vitro. There were no significant differences between the two groups in the frequency of cells with chromosome breakage, chromosome gaps, or hyperdiploid cells. There was, however, a significantly higher frequency of hypodiploid cells in the LBW group. The present findings differ from those of others who have reported an increase in chromosome breakage in premature newborns.

Body Weight↗
PubMed1975

Interstitial-cell tumor of the testis. Tissue culture and ultrastructural studies.

A case of a functioning interstitial-cell tumor in a 12-year-old Negro boy is reported. The patient manifested precocious puberty, with signs of sexually aggressive behavior. The ultra-structural studies of the tumor showed features similar to those of the few cases previously reported in the literature. One characteristic finding was the presence of numerous membranous whorls within the cytoplasm. The cells grown in tissue culture were maintained for at least 9 weeks and were confirmed as testicular interstitial cells. Ultrastructurally they were similar to the cells in vivo, as evidenced by the finding of cytoplasmic organelles related to steroid synthesis.

Animals↗