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S Elias

Publications and source records attributed to S Elias.

At least 127 records · Page 7Linked to original sources
PubMed1989

Reference standards for flow cytometry and application in comparative studies of nuclear DNA content.

Nuclear DNA mass in cells from a reference species can be used to obtain high-resolution estimates of DNA mass from a target species. In our study of DNA mass in cells from 45 selected species, representing each of the major vertebrate classes, we have obtained values of from 1.5 to 110.0 pg of DNA. Because values in or near this range would be expected in the study of nuclear DNA mass in vertebrates and other organisms, the species in this report can provide a useful catalogue of references for comparative studies of DNA.

Animals↗
PubMed1989

Resorbed co-twin as an explanation for discrepant chorionic villus results: non-mosaic 47,XX,+16 in villi (direct and culture) with normal (46,XX) amniotic fluid and neonatal blood.

Non-mosaic trisomy 16 was observed in chorionic villus cytotrophoblasts (direct) as well as cultured mesenchymal core cells derived from the pregnancy of a 38-year-old woman. Chromosome preparations from amniotic fluid and neonatal cultures (cord blood) were 46,XX. Normal fetal growth as determined by serial ultrasound examinations occurred throughout the pregnancy, which resulted in a healthy 2724 g female. Multiple biopsies taken from the umbilical cord, placental cotyledons, and fetal membranes were 46,XX. However, a placental nodule and three of six cultures initiated from membranes (amnion and chorion) showed 46,XX/47,XX,+16 mosaicism. We propose that the trisomy 16 cells arose from residual villi derived from a trisomic co-twin that never developed. This case further demonstrates that normal fetal growth may presage normal outcome irrespective of cytogenetic findings in cytotrophoblasts (direct) and cultured mesenchymal core cells.

Adult↗
PubMed1989

Transabdominal chorionic villus sampling for first-trimester prenatal diagnosis.

We report here our technique and initial experience with transabdominal chorionic villus sampling for first-trimester prenatal diagnosis at the University of Tennessee, Memphis. Eighty-seven patients underwent transabdominal chorionic villus sampling between 9 and 12 menstrual weeks of pregnancy. Sufficient chorionic villi (greater than or equal to 5 mg) were obtained from 83 of the 87 patients (95.4%); in 73 (88%) of the 83 successful samplings only a single needle passage was required. In one case a 47,XX, +21 complement was diagnosed; the patient elected to terminate the pregnancy and the diagnosis was confirmed in the abortus. In a second case a 46,XX,rcp(15;21)(p11;q21) woman had a fetus who also had the same balanced translocation. In a third case nonmosaic 47,XX, +16 was detected in both direct preparations of cytotrophoblast cells and cultured mesenchymal core cells. Amniocentesis performed at 15 weeks showed a normal 46,XX complement. The pregnancy continued, and the patient was delivered at term of a healthy female infant. Two spontaneous fetal losses occurred in this series, and one woman underwent an elective abortion after receiving the results of a 46,XX complement. To date, 39 of the women have been delivered and all infants are doing well; the remaining 44 pregnancies are continuing uneventfully. We conclude that transabdominal chorionic villus sampling can be a useful alternative to transcervical chorionic villus sampling, particularly when transcervical sampling is contraindicated (e.g., active genital herpes) or where the transcervical approach would be technically difficult.

Adult↗
PubMed1989

Child sexual abuse--genital tract findings in prepubertal girls. II. Comparison of colposcopic and unaided examinations.

In recent years the inspection of the vulva of sexually abused girls by magnification with a colposcope has become increasingly popular. However, data concerning the usefulness of colposcopy in such evaluations are lacking. In a prospective study, 130 prepubertal girls (mean age 5.5 years) who were identified by child protective agencies to be victims of sexual abuse were evaluated both by an unaided examination and by colposcopy. If the colposcopic findings differed from those of the unaided inspection, the macroscopic examination was repeated to determine whether the abnormality could have been detected without magnification. Altogether, 92 of the 130 girls were found to have abnormal findings. In the majority of girls with abnormalities (96%), the abnormalities were observed during the unaided examination. Of the four patients in whom the findings were detected initially by the colposcopic examination, these findings were observed during the repeat unaided examination. The findings were observed by colposcopic examination alone in only one patient. We conclude that unaided examination is adequate for the evaluation of most victims of sexual abuse.

Child↗
PubMed1989

Rapid chromosome analysis with the use of spontaneously dividing cells derived from umbilical cord blood (fetal and neonatal).

An accurate and reproducible method to obtain high-quality metaphases within 24 hours has been developed. Preparations can be derived from cord blood samples obtained either at delivery or by percutaneous umbilical blood sampling. Mitogens are not required. Rapid cytogenetic analysis can facilitate management of pregnancies characterized by malformations or intrauterine growth retardation.

Cell Division↗
PubMed1989

Transabdominal chorionic villus sampling in a patient with a bicornuate uterus.

In our preliminary experience with transabdominal chorionic villus sampling, we encountered a patient with a uterus bicornis bicollis and anterior fundal placenta, which posed particular technical difficulties for the transcervical approach, but in whom sampling was easily accomplished by the transabdominal route. A description of this case, as well as a discussion of our technique and experience to date, is provided.

Abdomen↗
PubMed1989

[The cell cycle in normal human chorionic and placental villi. A study using flow cytometry].

The amount of DNA in cells obtained from chorionic and placental villi by collagenase digestion was analyzed by flow cytometry. 15 cases ranging from 7th to 40th gestational weeks were analyzed. Approximately 1 X 10(4) cell nuclei were measured in each specimen. At 7th gestational week, 16-18.4% of cells were at S-phase, and 16.5-20.6% of cells at G2 + M phase. During midpregnancy, about 6.2-13.2% of cells were at S-phase and 5.3-9.1% of cells at G2 + M phase. At full term, in placentas from 40th gestational week 6.0-8.6% of cells were at S-phase and 3.0-5.0% of cells at G2 + M phase. The results suggest, that at term still 11% of placental cells are able to enter mitosis. Using flow cytometry, the DNA content in cell nuclei can be measured in specimens obtained by CVS A.

Cell Cycle↗
PubMed1989

Translocations are infrequent among couples having repeated spontaneous abortions but no other abnormal pregnancies.

During the years 1977 to 1986, cytogenetic studies were performed on 342 women and 297 men whose reproductive history included one or more first trimester spontaneous abortions. Thirty-nine women and 35 men experienced not only early fetal losses but also one or more stillborn infants, liveborn anomalous infants, or early neonatal deaths. Among the 303 women and 262 men evaluated solely because of repetitive abortions, only 1 woman and 1 man showed a translocation. Two translocations were detected among the 39 women and 35 men having not only repetitive abortions but also a stillborn infant, anomalous liveborn, or unexplained neonatal death. Only among the 25 women having abortions and other abnormal perinatal events was the frequency of translocations high (2/25 or 8%). Our data continue to indicate that balanced chromosomal translocations are relatively infrequent in individuals having repeated abortions but no other adverse perinatal outcome.

Abortion, Habitual↗
PubMed1989

Genetic analysis of HLA in the U.S. Schmiedenleut Hutterites.

The Hutterites are an Anabaptist population, highly inbred, with large family sizes and extensively documented pedigrees. As part of genetic-epidemiologic studies of the impact of HLA on fertility, HLA-A, -B, -C, -DR, and -DQ typing was performed on a total of 650 Schmiedenleut Hutterities in South Dakota. An extraordinary degree of homogeneity was found. HLA-A1, -A2, -A3, -A24, and -A26 accounted for 83%, HLA-B8, -B27, -B35, -B51, -Bw60, and -Bw62 for 75%, and HLA-DR1, -DR2, -DR3, and -DR4 for 66% of the antigens at the respective HLA-A, -B, and -DR loci. All Hutterites characterized for HLA were descendants of no more than 78 ancestors. However, family analysis identified only 45 unique HLA haplotypes thought to reflect the original gene pool. Eight haplotypes were particularly frequent, accounting for nearly 50% of all observed haplotypes; four of these were consistent with a European ancestry. Coefficients measuring linkage disequilibrium were computed from haplotypes identified by family analysis. Overall, HLA analysis portrayed the Schmiedenleut Hutterities as a homogeneous and unique population, with disequilibrium among particular alleles and a spectrum of common and uncommon European haplotypes.

Alleles↗
PubMed1988

Purification and characterization of arginyl-tRNA-protein transferase from rabbit reticulocytes. Its involvement in post-translational modification and degradation of acidic NH2 termini substrates of the ubiquitin pathway.

Conjugation of ubiquitin to certain proteins can trigger their degradation. A major question concerns the structural features of a protein which make it susceptible to ubiquitin ligation. Recent studies have shown that the selection of proteins for degradation occurs most probably on a binding site of the ubiquitin-protein ligase (E3). It was shown that a free alpha-NH2 group is one important feature of the protein structure recognized by the ubiquitin-ligating enzyme. Proteins with basic or bulky hydrophobic residues in the NH2-terminal position are recognized by the ligase, marked by ubiquitin, and degraded. This is not true, however, for proteins with an acidic residue in this position. We have previously shown that a tRNA-dependent post-translational conjugation of arginine to acidic NH2 termini of proteins is essential for their degradation via the ubiquitin pathway, and we speculated that this modification is required for their recognition by the ligase. In the present study we have partially purified from rabbit reticulocytes the modifying enzyme, arginyl-tRNA-protein transferase, and characterized it. We have separated the enzyme from other known components of the ubiquitin system and shown that it is specifically required for degradation of proteins with either an aspartate or glutamate residue in their NH2-terminal position. We have shown that the action of the transferase is required for conjugation of ubiquitin to the substrate and most probably for its recognition by the ligase. The enzyme in its native form has a molecular mass of about 360 kDa. It appears to be a complex between several molecules of arginyl-tRNA synthetase and arginyl-tRNA-protein transferase.

Acyltransferases↗
PubMed1988

Parental decision following prenatal diagnosis of fetal chromosome abnormality.

In the event of prenatal diagnosis of fetal chromosome abnormality, parents must choose between continuation and termination of the pregnancy. To determine whether parents are capable of understanding differences in severity among aneuploidy syndromes, we examined the outcome chosen for all pregnancies in which a fetal chromosome disorder was diagnosed at Northwestern Memorial Hospital between January, 1977 and June, 1986. Among amniocentesis cases, 88% with autosomal aneuploidy were terminated, but only 41% with sex chromosome abnormalities and none with de novo structural rearrangements were terminated. Among a smaller group of chorionic villus sampling cases, all with abnormal results were terminated. Similar patterns of parental behavior were noted in other prenatal diagnosis units. We conclude that parents do distinguish among, and respond specifically to, fetal chromosome disorders of differing severity, at least in the second trimester of pregnancy. However, parents appear more inclined to terminate all pregnancies with chromosome abnormalities when the diagnosis has been made in the first trimester.

Abortion, Spontaneous↗
PubMed1988

Relative deoxyribonucleic acid content of interphase leukocytes by flow cytometry: a method for indirect diagnosis of chromosomal abnormalities with potential for prenatal diagnosis.

A major goal of prenatal cytogenetic analysis is the development of minimally invasive techniques by which all pregnancies may be screened. That nucleated fetal cells exist in the maternal circulation raises the possibility that their cytogenetic status could be determined. However, these cells may not respond to commonly used mitogens. Thus it will probably be necessary to develop methods to analyze nondividing (interphase) cells. We therefore evaluated the use of flow cytometry as a means of determining whether the relative deoxyribonucleic acid content of G0-G1 leukocytes (expressed as the deoxyribonucleic acid index) could be used to verify aneuploidy or other chromosomal abnormalities. Our findings indicate this is indeed possible. We determined that the mean deoxyribonucleic acid index of circulating leukocytes from normal adult men (n = 15) was significantly different from that of leukocytes from normal adult women (n = 15). Similar results were obtained in leukocytes from umbilical cord blood of normal male neonates (n = 15) and normal female neonates (n = 15). Most importantly, values for leukocytes from each of 13 aneuploid individuals fell outside the range of values for leukocytes from normal adults of the same sex.

Adult↗