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Biomedical subjects

B Brambati

Publications and source records attributed to B Brambati.

At least 73 records · Page 4Linked to original sources
PubMed1990

Preimplantation genetic diagnosis: a new simple uterine washing system.

A new system for lavage of the uterine cavity and blastocyst recovery has been developed. The system was tested two or more times in 11 volunteer women at high genetic risk and waiting for its clinical application. Insertion into the uterine cavity was performed under continuous ultrasonic surveillance and was successfully achieved in all cases, 73% of whom reported some pains. A volume of 40 ml of warmed sterile saline solution was injected for washing of the uterine cavity and the total volume was always recovered without any sonographically visible leakage into the peritoneal cavity. No clinical infection or menstrual irregularities were observed and the only complications after the procedure were a short lasting spotting and light menstrual-like pains. The new system, owing to its efficacy, practicality and safety, is specifically indicated for preimplantation genetic diagnosis of blastocysts.

Blastocyst↗
PubMed1990

Prevention of cystic fibrosis in Italian families by DNA studies.

We performed a feasibility study of prenatal diagnosis in the Italian population by DNA analysis utilizing the probes: metD, metH, J3.11, KM.19 and XV-2c. With these probes, 118 out of 126 families (93.7%) were fully informative. We also tested part of the families with new additional tightly linked probes, E.9 and W3D1.4. With all the probes feasibility was complete in 44 out of 45 families (97.8%). In particular with a set of only 3 tightly linked probes, KM.19 + XV-2c + W3D1.4, 71% of the families were fully informative. We carried out 8 prenatal diagnoses, 4 of which with the polymerase chain reaction (PCR) for KM.19. These data show that these probes are highly informative and can be used for feasibility studies and prenatal diagnosis of CF in the Italian population.

Cystic Fibrosis↗
PubMed1988

Transabdominal chorionic villus sampling. Clinical experience of 1159 cases.

The efficacy and risks of transabdominal free-hand ultrasound-guided fine needle aspiration technique were evaluated in 1159 pregnancies submitted to chorionic villus sampling (CVS) in the first trimester and early in the second trimester. An adequate amount of chorionic tissue was obtained by two needle insertions in 99.7 per cent of cases, and a second tapping was needed in 3.5 per cent of cases. A local peritoneal reaction was the only early complication clearly related to the procedure, and it occurred in 0.3 per cent of cases without any adverse effect on the maternal and fetal outcome. The correct abortion rate in 716 consecutive concluded pregnancies was 2.4 per cent, while the rate of late obstetrical complications and perinatal mortality and morbidity compares favourably with the rates in the general population. Because of its simplicity and practicability, transabdominal aspiration is the procedure of choice and is especially recommended for intensive CVS routine conditions.

Adult↗
PubMed1988

First-trimester maternal serum alpha-fetoprotein screening for chromosome defects.

Low maternal serum alpha-fetoprotein values during the second trimester of pregnancy are associated with an increased risk of Down syndrome in the fetus. In this study a sensitive, monoclonal-based radioimmunoassay for alpha-fetoprotein was used to determine whether such an association also applies to the first trimester and if maternal serum alpha-fetoprotein screening could successfully detect a significant number of pregnancies in which the fetus had a trisomy or other chromosome disorder. Sera were obtained prospectively from 540 women just before chorionic villus sampling for prenatal diagnosis of chromosome defects (largely because of advanced maternal age) at 8 to 12 weeks' fetal age and assayed for alpha-fetoprotein under code without knowledge of the cytogenetic results. Eight of 27 (29.6%) of all serious chromosome defects were associated with low maternal serum alpha-fetoprotein values (less than or equal to 0.6 multiples of the median). Overall, 59 of 540 patients (10.9%) had maternal serum alpha-fetoprotein values less than or equal to 0.6 multiples of the median, eight of whom had a fetus with a serious chromosome defect. Women whose maternal serum alpha-fetoprotein value was less than or equal to 0.6 multiples of the median had one in eight odds of carrying a fetus with a trisomy and one in seven odds of the fetus having any serious chromosome defect. From this study of a group of women at higher risk, we conclude that first-trimester maternal serum alpha-fetoprotein screening for chromosome defects is feasible. A prospective study to determine detection efficiency is now required of a consecutive routine pregnancy population in whom gestational age is determined by menstrual dates as is usually the case in clinical practice.

Chromosome Aberrations↗
PubMed1988

The yolk sac in early pregnancy failure.

An attempt was made to visualize the yolk sac in 845 patients scheduled for chorionic villi sampling. The distribution of yolk sac diameters and the interpolating growth curve up to 11 weeks of development were analyzed in 239 pregnant women who were delivered of normal infants. The highest visualizing rate of the yolk sac in normal pregnancies was 97 at 7 weeks of gestation. A total of 130 miscarriages occurred before chorionic villi sampling. In these cases, the diameter of the yolk sac versus crown-rump length tended to be larger than found in normal pregnancies. The visualizing rate of the yolk sac in miscarriages after the embryo had been formed was significantly higher in those women who demonstrated fetal heart activity (82.1%) than in those who did not (54.5%). On the other hand, the yolk sac was observed in 44% of miscarriages without a visible embryo. These findings suggest different types of missed abortion. An abnormal karyotype was observed in 23 of 29 chromosomal analyses performed on aborted specimens. An abnormal karyotype was observed in all eight cases with only a yolk sac-like structure within the gestational sac.

Abortion, Spontaneous↗
PubMed1988

Transabdominal versus transcervical chorionic villus sampling: a randomized trial.

Chorionic villus sampling (CVS) is still considered to be an applied research method and its safety is under evaluation in randomized trials. Moreover, no knowledge is available about the comparative efficiency and risks of transcervical and transabdominal chorionic villus sampling. A preliminary analysis of the first 639 consecutive cases of an ongoing trial in which cases are randomized between transcervical and transabdominal aspiration techniques shows: (a) an overall sampling success rate of greater than 99% obtained by both techniques; however, the number of repeat insertions of the sampling device was higher for the transcervical route; (b) a significant shift towards lighter tissue samples for the transabdominal route; however, very light specimens, less than 10 mg, were equally distributed in both groups; and (c) approximately 10% of cases underwent a different procedure from the allocated one because of an anatomical or clinical contraindication, with a higher rate of deviation for the transcervical technique.

Abdomen↗
PubMed1988

Meiotic recombination in the beta globin gene cluster causing an error in prenatal diagnosis of beta thalassaemia.

In the course of a prenatal diagnosis for beta thalassaemia by linkage analysis of restriction fragment length polymorphisms, a homozygous beta thalassaemia fetus was misdiagnosed as beta thalassaemia trait. Extensive studies of the polymorphic sites within the beta globin gene cluster in all the members of the family resulted in the conclusion that the paternal chromosome 11 of the newborn was different from that expected. Paternity was confirmed by HLA typing and blood group studies. The analysis of another polymorphic locus on chromosome 11 within the family was in agreement with the possibility of a crossing over between the two paternal chromosomes in a region 5' to the beta gene, previously indicated to contain a 'hot spot' area for recombination. This report underlines the risk of performing prenatal diagnosis using restriction polymorphisms 5' to the beta gene.

Diagnostic Errors↗
PubMed1988

Maternal age-specific rates of 47,+21 and other cytogenetic abnormalities diagnosed in the first trimester of pregnancy in chorionic villus biopsy specimens: comparison with rates expected from observations at amniocentesis.

Results are presented on chromosome analyses made on 4,481 embryos or fetuses studied through chorionic villus sampling (CVS) in whom there was no known bias to presence of a chromosome abnormality except advanced parental age. We excluded from the analysis most cases in which mosaicism was diagnosed or in which there were cytogenetic discrepancies among samples obtained from the conceptus. There remain 48 cases of 47,+21, 39 cases of other nonlethal abnormalities, and 12 lethal abnormalities diagnosed in 4,481 studied. A regression analysis (restricted to the 3,848 cases diagnosed in the 35-49-year maternal age interval) was done on rates of (1) 47,+21, (2) other abnormalities excluding lethals or (3) including them, and (4) all abnormalities excluding lethals or (5) including them. The model used was y = exp(bx + c), where y is the rate of abnormality, x is maternal age at time of CVS (the modal age of the procedure was 10 gestational weeks from the last menstrual period), and b and c were, respectively, (1) 0.288 and -15.527; (2) 0.272 and -15.173; (3) 0.253 and -14.141; (4) 0.282 and -14.753; and (5) 0.271 and -14.195. We also derived rates of abnormalities at the time of CVS that would be predicted from rates (of nonmosaics) at amniocentesis after adjustment for the difference in gestational age between the usual times that these two procedures are done. The difference between the numbers of abnormalities predicted on the basis of these adjusted amniocentesis rates and the numbers observed at CVS provides an estimate of the spontaneous loss of embryos and fetuses between the usual gestational ages of these procedures. In these data, for 47,+21 the estimated proportion lost is 21% but the result is not significant at the .05 level. For other abnormalities excluding lethals the estimated spontaneous loss is 29% (P approximately .05); including lethals it is 44%. For all abnormalities, excluding lethals, pooled together, the estimate is 24%; including lethals it is 33%. The last three values are all significant at the .05 level or lower. The observed rates of abnormalities at CVS would be approximately 10% to 15% higher if one pooled diagnosed mosaics with the nonmosaics, but the estimated proportion of spontaneous fetal loss would be lower.

Adult↗
PubMed1987

Combined use of DNA probes in first-trimester prenatal diagnosis of hemophilia A.

First-trimester prenatal diagnoses of hemophilia A were heretofore obtained by using either intragenic factor VIII markers or linked extragenic polymorphic markers. Postulating that the combined use of all the available intragenic and extragenic markers can render such diagnoses more frequently feasible and more reliable, we carried out ten first-trimester prenatal diagnoses in male fetuses at risk for hemophilia A by DNA analysis of chorionic villus employing in combination the intragenic Bcl I polymorphism and the St 14 (DXS 52) or DX 13 (DXS 15) extragenic probes. A diagnosis of hemophilia was obtained in three fetuses, with a diagnosis of normal fetus obtained in the remaining seven. Seven diagnoses are confirmed by factor VIII assays carried out at the time of abortion, in the mid-trimester or at birth. A factor VIII probe recognizing Bcl I polymorphism was useful in 4 of 6 diagnoses; St 14, in 5 of 6; and DX 13 in 3 of 5. In two cases, St 14 was the only useful probe for diagnosis. Even though no recombination between extragenic probes and factor VIII gene was detected in this study, when only extragenic markers were informative we advised diagnostic confirmation on fetal plasma obtained by fetoscopy. Hence, first-trimester prenatal diagnosis of hemophilia A is feasible for the great majority of fetuses at risk through combined use of all the available intragenic and extragenic probes, providing key family members are available.

Adult↗
PubMed1987

Chorionic villus sampling: an analysis of the obstetric experience of 1,000 cases.

Chorionic villus sampling was performed between 7 and 12 weeks gestation in 1,000 patients, 935 of whom intended to continue after fetal diagnosis. Transcervical and Transabdominal aspiration techniques were used providing a sampling success rate of 99 per cent. Anatomical and clinical contraindications to transcervical aspiration were pointed out, and the complementary role of the transabdominal approach evaluated. In the 615 concluded pregnancies an overall abortion rate of 4.1 per cent was observed. A significant association between fetal loss and number of catheter insertions was demonstrated. Bacterial inoculation by catheter insertion and colonization of uterine cavity was suspected as the cause of chorionamnionitis diagnosed in two cases (0.2 per cent) after CVS. Bleeding was the most frequent early complication (12.0 per cent) following chorionic aspiration, but was not significantly related to pregnancy wastage. Late complications, i.e. premature rupture of membranes (0.8 per cent), preterm delivery (6.3 per cent), perinatal losses (1.2 per cent), placental disorders (1.6 per cent), and congenital defects (2.6 per cent) did not exceed the expected values. Normal intrauterine growth patterns were ultrasonically estimated by cross-sectional and longitudinal studies, while the weight at birth was normally distributed in the range of the general population.

Abortion, Missed↗
PubMed1987

Transabdominal chorionic villus sampling: a freehand ultrasound-guided technique.

A simple transabdominal chorionic villus sampling method, carried out with a 20-gauge spinal needle under ultrasound guidance, was evaluated in 100 cases selected for genetic evaluation in the first trimester. Its use was limited to the management of anatomic and clinical conditions that contraindicated transcervical aspiration. The high efficacy of the method was demonstrated by an ability to obtain enough villus tissue for karyotyping in all but one case. In 94% of the cases, only one pass of the needle was required. Although the only complication observed was light bleeding in four cases, the safety of the method needs more extensive evaluation.

Adult↗
PubMed1987

Prevalence and distribution of chromosome abnormalities in a sample of first trimester internal abortions.

Cytogenetic analysis was performed directly on villus material from 202 samples obtained at the evacuation of the uterine cavity in cases of retained abortion in the first trimester, identified as such by ultrasound examination. A precise delineation of the karyotype was obtained in 94% of the cases, while the efficiency of karyotype analysis in samples of spontaneous abortion was not higher than 50%. An abnormal chromosome constitution was found in 145 fetuses (76.7%) of which 117, including mosaics, were aneuploid (70%), 16 polyploid (8.5%) and 12 had structural abnormalities (6.3%). The relative proportion of chromosome abnormalities in this material is higher than that found in spontaneous abortion for trisomies and double trisomies, but lower for 45,X and polyploidy. The method was found to be efficient in obtaining fetal karyotypes also in those cases in which the villous material was scarce (1 mg), and thus it seems appropriate for routine cytogenetic studies in the first trimester abortions.

Abortion, Spontaneous↗