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S Elias

Publications and source records attributed to S Elias.

At least 55 records · Page 3Linked to original sources
PubMed1995

Isolating fetal nucleated red blood cells from maternal blood: the Baylor experience--1995.

In our previous work we have isolated fetal cells from maternal blood and used fluorescent in situ hybridization (FISH) for chromosome-specific probes to detect aneuploidy. Current efforts in the Baylor College of Medicine programme are focusing on obtaining consistency in flow-sorting methodology and on determining sensitivity and specificity. To this end, systematic evaluation of five glycophorin A (gly A) antibodies all produced agglutination, leading us to abandon the use of gly A antibodies for positive selection of fetal cells. Conversely, we have found LDS-751 to be useful for nuclear selection. CD45 negative selection can best be accomplished by the use of flasks coated with goat antibodies against mouse antibodies. Positive selection by flow sorting for either CD71+ cells or gamma-globin-positive cells seems to be successful. Using these two approaches, we have recently detected male (fetal) cells in pregnancies in which the fetus was 46,XY in 10 of 18 and in 12 of 14 cases, respectively.

Cell Separation↗
PubMed1995

Detection of low-grade mosaicism in fetal cells isolated from maternal blood.

Recovering and analysing fetal erythrocytes from maternal blood is being pursued for non-invasive prenatal genetic diagnosis. We report the observation of 46,XY/47,XXY mosaicism in fetal cells from a woman whose first-trimester chorionic villus sampling (CVS) initially showed only 46,XY. Only after exhaustive (500 cells) analysis were four XXY cells found in cultured villi.

Adult↗
PubMed1995

Trisomy 21 and maternal age of menopause: does reproductive age rather than chronological age influence risk of nondisjunction?

The biological basis underlying the increased risk of nondisjunction in offspring of women of advanced maternal age is not understood. We sought to test the hypothesis that maternal reproductive age (distance in time from approaching menopause) rather than chronological age is pivotal in the etiology of nondisjunction. Our results found no difference in age of menopause between women > or = 30 years old at delivery of a child with trisomy 21 (i.e., age-related nondisjunction) compared to controls. Among women < 30 years of age at delivery of a child with trisomy 21, none underwent premature menopause. Therefore, our findings fail to support the theory that reproductive age plays a major role in the etiology of nondisjunction.

Adult↗
PubMed1995

Isolated fetal choroid plexus cysts and trisomy 18: a review and meta-analysis.

OBJECTIVE: Risk of trisomy 18 in a fetus with ultrasonographic diagnosis of choroid plexus cysts and no other anomalies is controversial. Using our data and current literature, we performed a meta-analysis and estimated the positive predictive value of isolated choroid plexus cysts for trisomy 18. STUDY DESIGN: Between Jan. 1, 1989, and Dec. 31, 1992, all women undergoing ultrasonographic examination at our institution were prospectively evaluated for fetal choroid plexus cysts and cytogenetic outcome. In addition, all reports dealing with fetal choroid plexus cysts obtained from MEDLINE (1983 through 1992) were assessed. Only prospective studies with > 10 cases of choroid plexus cysts were further evaluated to determine the total number of fetuses with choroid plexus cysts and otherwise normal sonograms. Frequency of aneuploidy was determined by analysis of our data and the included studies. To estimate the positive predictive value of choroid plexus cysts from trisomy 18, a theoretic 2 x 2 table was constructed with values available from the literature. RESULTS: Eighty fetuses with choroid plexus cysts were identified in our unit. Of 74 fetuses with isolated choroid plexus cysts, there were no cases of trisomy 18. Meta-analysis identified 2 cases of trisomy 18 among 748 fetuses with isolated cysts (1/374). To derive a positive predictive value of isolated choroid plexus cysts for trisomy 18, we reviewed the literature and found a total of 50 fetuses with trisomy 18 who underwent ultrasonographic examination in the midtrimester. There were 3 cases of isolated choroid plexus cysts, and 12 of 50 (24%) had otherwise normal ultrasonographic results. Using a midtrimester incidence of 1 in 2461 for trisomy 18 (Hsu LYF. In: Milunsky A, ed. Genetic disorders of the fetus. 3rd ed. Baltimore: Johns Hopkins University Press, 1992: 155-210; Hook et al. Am J Hum Genet 1989; 45:855-61) and a prenatal prevalence of 0.95% for choroid plexus cysts (based on a review of the literature), we obtained a positive predictive value of 1 in 390. CONCLUSION: On the basis of the risk for trisomy 18 obtained from our meta-analysis (1/374) and its close approximation to the estimated positive predictive value (1/390), our data do not support the routine offering of invasive prenatal cytogenetic testing in cases of isolated choroid plexus cysts.

Brain Diseases↗
PubMed1995

Associations between adverse perinatal outcome and serially obtained second- and third-trimester maternal serum alpha-fetoprotein measurements.

OBJECTIVE: Our purpose was to determine whether third-trimester maternal serum alpha-fetoprotein predicts adverse perinatal outcome and whether use of both second- and third-trimester maternal serum alpha-fetoprotein enhances the positive predictive value for various abnormal outcomes. STUDY DESIGN: A cohort study with obstetric outcome assessed by chart analysis after delivery was performed at Regional Medical Center (Memphis, Tennessee), a hospital staffed by university-based physicians serving a large urban population with many indigent patients. A total of 650 women attending prenatal clinics in the above setting with a singleton pregnancy without a neural tube defect, contributing a maternal blood samples in both the second and third trimesters, and delivered in the above hospital participated. Various pregnancy outcomes were correlated with maternal serum alpha-fetoprotein levels in the second and third trimesters and in both. RESULTS: In the third trimester no significant associations were found between maternal serum alpha-fetoprotein elevations and pregnancy complications. In the second trimester elevation ( > or = 2.0 multiples of the median) were, by contrast, significantly associated with preterm premature rupture of the membranes, preterm birth, and low birth weight. No association was found with certain other complications. When second-trimester data were grouped according to the types of complications occurring in individual women, only preterm premature rupture of the membrane proved statistically significant. CONCLUSIONS: Second-trimester but not third-trimester maternal serum alpha-fetoprotein is significantly elevated with preterm premature rupture of the membranes, preterm birth, and low birth weight; in this cohort study no association was found with preeclampsia, oligohydramnios, or polyhydramnios.

Cohort Studies↗
PubMed1995

Isolating fetal cells in the maternal circulation.

Fetal cells exist in maternal blood and can be utilized for prenatal genetic diagnosis. The use of polymerase chain reaction (PCR) technology on maternal blood has enabled the detection of fetal sex, Mendelian disorders (e.g. beta-globin mutations), HLA polymorphisms and fetal Rhesus (D) blood type. Enrichment for erythroblasts and trophoblasts by various density gradient and flow sorting techniques followed by fluorescence in-situ hybridization (FISH) with chromosome-specific DNA probes has allowed detection of trisomy 21, trisomy 18, Klinefelter syndrome (47,XXY) and 47,XYY. The fetal cell type that has generated the most success is the nucleated erythrocyte; however, trophoblasts, lymphocytes and granulocytes are also considered to be present in maternal blood. Fetal cells circulate in maternal blood during the first and second trimesters, with frequency increasing as gestation advances. Emphasis is thus now directed toward determining the most practical and efficacious manner for this technique to be applied to prenatal genetic diagnosis. A large scale collaboration of clinical evaluations is underway in the USA, upon completion of which assessment can be made of whether this technology can serve as an alternative to conventional invasive and non-invasive methods of prenatal cytogenetic diagnosis.

Cell Separation↗
PubMed1995

Cystic fibrosis mutations among African Americans in the southeastern United States.

Since the cloning of the cystic fibrosis (CF) gene and the identification of delta F508, the most common CF mutation, screening the general population for CF has been vigorously debated. Adding to the controversy is the question of whether screening should be offered to African Americans, whose incidence of CF (1/17,000) is much lower than that of whites (1/2500). We tested for five common mutations (delta F508, G551D, G542X, R553X, and N1303K) in order to determine the frequency of common mutations in African Americans with CF from the southeastern United States. delta F508 was found on 50% of CF chromosomes; 46% of CF mutations were undetermined mutations. Our data indicate that at the current detection rate, the sensitivity of CF screening in African Americans would be appreciably lower than that of whites, and thus their inclusion in screening programs probably would not be warranted.

Black People↗
PubMed1994

Significance of septations in isolated fetal cystic hygroma detected in the first trimester.

Recent reports have indicated an increased risk for fetal chromosome abnormalities, especially autosomal trisomy, in fetuses with isolated cystic hygroma, or prominent nuchal membranes, detected by ultrasonography during the first trimester. However, these reports present contradictory information regarding the prognostic significance of septations within the cystic hygroma. We evaluated, in blind fashion, 55 consecutive cases of isolated fetal cystic hygroma detected at or before 13.9 weeks' gestation to determine the association between septations and fetal chromosome complement. Septations were associated (P < 0.05) with an increased risk for fetal chromosome abnormalities. However, the incidence of chromosome abnormalities was also increased (12.5 per cent) among cases not characterized by septations. Thus, we believe it prudent to offer invasive prenatal testing to all women found to be carrying fetuses with cystic hygroma, irrespective of the presence or absence of septations.

Adult↗
PubMed1994

Adverse perinatal outcome in patients screen-positive for neural tube defects and fetal Down syndrome.

An association between various abnormal mid-trimester maternal serum analyte values and adverse perinatal outcome has been reported. From an original sample of 14,857 women, we observed five women who were 'screen-positive' for both neural tube defects [maternal serum alpha-fetoprotein (MSAFP) > or = 2.5 multiples of the median] and Down syndrome [risk > or = 1/274 using MSAFP, maternal serum unconjugated oestriol (MSuE3), maternal serum human chorionic gonadotropin (MShCG), and maternal age]. The four patients who elected to undergo amniocentesis all demonstrated both normal karyotype and normal amniotic fluid AFP levels. All five cases were associated with intrauterine growth retardation (IUGR) and abnormal pregnancy outcomes. Two cases exhibiting severe IUGR on ultrasound examination were terminated at 19.1 and 21.2 weeks, respectively; the former also exhibited fetal calcifications and positive maternal serology for toxoplasmosis. In another case, fetal demise occurred at 36 weeks' gestation in a patient who had been treated for syphilis in the second trimester. Neither infection was confirmed in fetal tissue studies. Though resulting in live births, the remaining two cases required operative deliveries; emergency Caesarean sections for fetal distress were performed at 38 and 32 weeks, respectively, the latter case being associated with severe pre-eclampsia. We conclude that elevated mid-trimester MSAFP levels concurrent with maternal serum analyte values associated with increased risk for fetal Down syndrome may presage a poor perinatal outcome, particularly IUGR and possibly congenital infection.

Adult↗
PubMed1994

Isolating fetal cells in maternal circulation for prenatal diagnosis.

Fetal cells unequivocally exist in and can be isolated from maternal blood. Erythroblasts, trophoblasts, granulocytes and lymphocytes have all been isolated by various density gradient and flow sorting techniques. Chromosomal abnormalities detected on isolated fetal cells include trisomy 21, trisomy 18, Klinefelter syndrome (47,XXY) and 47,XYY. Polymerase chain reaction (PCR) technology has enabled the detection of fetal sex, Mendelian disorders (e.g. beta-globin mutations), HLA polymorphisms, and fetal Rhesus (D) blood type. The fetal cell type that has generated the most success is the nucleated erythrocyte; however, trophoblasts, lymphocytes and granulocytes are also considered to be present in maternal blood. Fetal cells circulate in maternal blood during the first and second trimesters, and their detection is probably not affected by Rh or ABO maternal-fetal incompatibilities. Emphasis is now directed toward determining the most practical and efficacious manner for this technique to be applied to prenatal genetic diagnosis. Only upon completion of clinical evaluations could it be considered appropriate to offer this technology as an alternative to conventional invasive and non-invasive methods of prenatal cytogenetic diagnosis.

Cell Separation↗
PubMed1994

Clinical course and outcome of fetuses with isolated cystic nuchal lesions and normal karyotypes detected in the first trimester.

OBJECTIVE: We assessed newborn outcome and infant development in cases of first-trimester fetal cystic nuchal lesion and normal karyotype. STUDY DESIGN: Information regarding newborn outcomes and infant growth and development was prospectively obtained from 32 consecutive pregnancies characterized by fetal cystic nuchal lesions detected in the first trimester (< or = 13.9 weeks' gestation) and normal karyotypes. RESULTS: Cystic nuchal lesions spontaneously resolved by the twentieth gestational week in 31 cases; all 31 infants had normal results at newborn examination and demonstrated normal growth and development at 12 months of age. Resolution did not occur in one case; prominent hygromas were repaired at birth with normal growth and development through 2 1/2 years of age. CONCLUSIONS: In most affected fetuses with normal karyotypes, spontaneous resolution will occur with favorable newborn and infant outcomes. However, patients should be counseled that resolution may not occur or that nonchromosome abnormalities may result in a less favorable outcome.

Chromosomes↗
PubMed1994

Family planning decisions after prenatal detection of fetal abnormalities.

OBJECTIVE: Our purpose was to assess the family planning decisions made by women found to be carrying fetuses with chromosome abnormalities or neural tube defects. STUDY DESIGN: We studied the family planning decisions of 132 women carrying fetuses with chromosome abnormalities (n = 91) or neural tube defects (n = 41) with regard to prenatal diagnosis, pregnancy management decision, patient's gravidity, and maternal and gestational age. RESULTS: Twenty women (17 carrying fetuses with chromosome abnormalities and 3 with fetal neural tube defects) elected permanent sterilization after completion of the affected pregnancy. Only maternal age and fetal chromosome abnormalities were associated with a decision to obtain permanent sterilization. CONCLUSIONS: Most women carrying fetuses with chromosome abnormalities or neural tube defects will not choose permanent sterilization after completion of the pregnancy. Delaying such decisions until resolution of grief and depression is now facilitated by the availability of safe, reliable, and relatively long-term reversible contraceptive agents.

Adult↗