PubMed Health⌕ Search

Biomedical subjects

J A Reidy

Publications and source records attributed to J A Reidy.

32 records · Page 2Linked to original sources
PubMed1983

H-Y antigen in XO mice.

We examined the expression of H-Y antigen in 14 XO female mice using three monoclonal H-Y-specific antibodies. We found that spleen and liver cells from XO mice removed the reactivity of these antibodies at the same efficacy as XY cells. However radiobinding assays on cultured XO cells suggested a qualitative or quantitative difference between XO and XY cells. In cell-mediated cytolysis (CMC), H-Y-specific reactivity was observed when XO fibroblasts were used as targets, but no reactivity was observed when XO concanavalin A (Con A) blasts were used as targets. We concluded from these studies that XO mice do express H-Y antigen, detected both by serologic assays and cell-mediated assays.

Animals↗
PubMed1983

Folic acid and chromosome breakage. I. Implications for genotoxicity studies.

Chromosome breakage is significantly lower in culture medium containing folic acid than in medium that does not. This effect is similar to that observed in studies of chromosome fragile sites and suggests that fragile sites and some types of chromosome breakage may share a common mechanism. It also suggests that high non-physiological levels of folic acid in many commonly used culture media may artifactually decrease chromosome breakage.

Cells, Cultured↗
PubMed1983

Fetal H-Y typing using human amniotic fluid.

The H-Y (male) antigen is phylogenetically conserved among vertebrate species, including the species man. Previous studies have indicated the presence of a "soluble" H-Y antigen in male serum and culture fluids of male cells. We examined over 50 samples of amniotic fluid from male and female fetuses to determine if H-Y typing could be correlated with the sex of the fetus. Samples of amniotic fluid were tested to inhibit the reactivity of monoclonal antibodies in a standard H-Y assay with protein A sheep red blood cells. We found that amniotic fluids from male fetuses inhibited 40% of the reactivity and that amniotic fluids from female fetuses inhibited 0.5% of reactivity. We could also correctly identify the sex of 90% of male fetuses and 100% of female fetuses. We have not yet identified the exact nature of the inhibiting antigen(s) in the amniotic fluids, but our results clearly indicate the feasibility of fetal H-Y typing.

Amniocentesis↗
PubMed1982

Autosomal mosaicism in amniotic fluid cells from a twin pregnancy.

Amniocentesis was performed on a 39-year-old gravida 4 woman because of maternal age. Ultrasonography demonstrated a twin pregnancy, and two amniotic fluid specimens were obtained under direct ultrasound guidance. All cells analyzed from the first specimen were 46,XX. In the second specimen, one colony in each of two flasks had trisomy 9; the remaining 3 colonies analyzed were 46,XX. The total cell count in the second specimen was 14 (24%) of 58 cells which were trisomic for chromosome 9. The parents elected to continue the pregnancy, which resulted in two live-born infants, a male and a female, both chromosomally normal. The most likely explanation for the amniotic fluid finding is that fluid from one sac was sampled twice and that trisomic cells from the amnion were obtained during the second tap.

Adult↗
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 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↗
PubMedDate not supplied

Human testicular cultures. II. Sertoli cells.

Two cell types, one epitheloid and the other fibroblast-like, were found in human testicular cultures derived from testes of patients. Ultrastructural studies indicated that, whereas the epitheloid cells were Sertoli cells, the fibroblast-like cells were fibroblasts. The Sertoli cells could maintain growth for a period of more than 4 months. In cultures derived from normal testes, only fibroblasts were observed.

Cell Membrane↗
PubMedDate not supplied

Role of deoxyuridine incorporation and DNA repair in the expression of human chromosomal fragile sites.

This paper is a discussion of the possible roles of deoxyuridine incorporation into DNA and DNA-repair processes in the expression of the folate-sensitive, common chromosomal fragile sites. Expression of aberrations at these sites increases under conditions expected to increase deoxyuridine incorporation into the chromosome. It is likely that this abnormal base is removed by an excision-repair process that results in transient chromosome breaks; these breaks are seen as chromosome aberrations if repair is not completed before metaphase. Analogous events may account for other types of chromosome aberrations including the so-called "spontaneous" aberrations, the rare folate-sensitive fragile sites, and fragile sites induced by other means.

Aphidicolin↗
PubMedDate not supplied

Measurement of eight urinary metabolites of di(2-ethylhexyl) phthalate as biomarkers for human exposure assessment.

Human metabolism of di(2-ethylhexyl) phthalate (DEHP) is complex and yields mono(2-ethylhexyl) phthalate (MEHP) and numerous oxidative metabolites. The oxidative metabolites, mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) and mono(2-carboxymethylhexyl) phthalate (MCMHP), have been considered to be better biomarkers for DEHP exposure assessment than MEHP because urinary levels of these metabolites are generally higher than MEHP, and their measurements are not subject to contamination. The urinary levels of the above metabolites, and of three other recently identified DEHP oxidative metabolites, mono(2-ethyl-3-carboxypropyl) phthalate (MECPrP), mono-2-(1-oxoethylhexyl) phthalate (MOEHP), and mono(2-ethyl-4-carboxybutyl) phthalate (MECBP), were measured in 129 adults. MECPP, MCMHP and MEHHP were present in all the samples analysed. MEHP and the other oxidative metabolites were detected less frequently: MEOHP (99%), MECBP (88%), MECPrP (84%), MEHP (83%) and MOEHP (77%). The levels of all DEHP metabolites were highly correlated (p<0.0001) with each other, confirming a common parent. The ? and ?-1 oxidative metabolites (MECPP, MCMHP, MEHHP and MEOHP) comprised 87.1% of all metabolites measured, and thus are most likely the best biomarkers for DEHP exposure assessment. The percentage of the unglucuronidated free form excreted in urine was higher for the ester linkage carboxylated DEHP metabolites compared with alcoholic and ketonic DEHP metabolites. The percentage of the unglucuronidated free form excreted in urine was higher for the DEHP metabolites with a carboxylated ester side-chain compared with alcoholic and ketonic metabolites. Further, differences were found between the DEHP metabolite profile between this adult population and that of six neonates exposed to high doses of DEHP through extensive medical treatment. In the neonates, MEHP represented 0.6% and MECPP 65.5% of the eight DEHP metabolites measured compared to 6.6% (MEHP) and 31.8% (MECPP) in the adults. Whether the observed differences reflect differences in route/duration of the exposure, age and/or health status of the individuals is presently unknown.

Adult↗
PubMedDate not supplied

Detection of mosaicism in amniotic fluid cultures: a CYTO2000 collaborative study.

PURPOSE: To evaluate the assumptions on which the American College of Medical Genetics (ACMG) Standards and Guidelines for detecting mosaicism in amniotic fluid cultures are based. METHODS: Data from 653 cases of amniotic fluid mosaicism were collected from 26 laboratories. A chi-square goodness-of-fit test was used to compare the observed number of mosaic cases with the expected number based on binomial distribution theory. RESULTS: Comparison of observed data from the in situ colony cases with the expected distribution of cases detected based on the binomial distribution did not reveal a significant difference (P = 0.525). CONCLUSIONS: The empirical data fit the binomial distribution. Therefore, binomial theory can be used as an initial discussion point for determining whether ACMG Standards and Guidelines are adequate for detecting mosaicism.

Amniotic Fluid↗