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Biomedical subjects

L Poenaru

Publications and source records attributed to L Poenaru.

At least 55 records · Page 3Linked to original sources
PubMed1988

First trimester prenatal diagnosis of metachromatic leukodystrophy on chorionic villi by 'immunoprecipitation-electrophoresis'.

Prenatal diagnosis of metachromatic leukodystrophy (MLD) due to arylsulphatase A (ASA) deficiency can be performed by amniocentesis with the disadvantage of a late pregnancy termination. Whether chorionic villi (CV) obtained by trophoblast biopsy during the first trimester of pregnancy can be useful for diagnosis depends on the reliability of results. The complexity of arylsulphatase expression in CV and the existence of several isozymes make diagnosis difficult. However, the use of an anti-ASA antiserum enabled us to discriminate between ASA and a comigrating contaminant isozyme, and the antigen-antibody (Ag-Ab) complex gave better evidence of the presence or absence of ASA after enhancement of activity with 4-methylumbelliferyl sulphate (4-MUS). We propose that immunoprecipitation followed by electrophoresis could be a valuable method of MLD prenatal diagnosis on chorionic villi.

Cerebroside-Sulfatase↗
PubMed1988

[Prenatal diagnosis of hereditary metabolic diseases in 1987].

Prenatal diagnosis currently represents the only preventive method of inherited metabolic disease for which no effective treatment is available. Several fetal samplings are currently possible, which enables to adequately select the best expression of the anomaly. Chorionic villi taken by biopsy constitute the biological material of choice for a diagnosis during the first trimester of pregnancy. An early diagnosis with the marked heterogenous nature of these genetic diseases, requires a perfect cooperation between the various specialists and between specialists and family, in order to secure a prenatal diagnosis.

Female↗
PubMed1987

First trimester prenatal diagnosis of metabolic diseases: a survey in countries from the European community.

This paper presents the collected data concerning First Trimester Prenatal Diagnosis of Metabolic Diseases performed in different countries of the European Community by enzymatic methods using chorionic villi. In all, 258 diagnoses were made for 38 different metabolic diseases and 56 (22 per cent) affected fetuses have been detected. Several difficulties were encountered with regard to chorionic villus material or enzyme expression in this tissue. We stress the conditions necessary for avoiding errors in diagnosis.

Cells, Cultured↗
PubMed1985

Lysosomal hydrolase activity in chorionic villi and embryonic cells in culture.

Fourteen lysosomal enzymes were compared in 20 cultured cell lines from chorionic biopsy and corresponding embryonic tissue after voluntary abortions. Enzymatic expression appears to be similar in cultured cells from both sources with some slightly higher levels for chorionic villi. We stress the importance of culturing chorionic villi especially in the case of enzymes (alpha-L-iduronidase) or diseases (I cell disease) whose expression is unusual in fresh trophoblast tissue.

Cells, Cultured↗
PubMed1985

Prenatal diagnosis of glycogenosis type II (Pompe's disease) using chorionic villi biopsy.

Glycogenosis type II (Pompe's disease) has been diagnosed using cultured amniotic cells for several years. In this paper, we present three prenatal diagnoses based on chorionic villi biopsy in three families at risk for Pompe's disease juvenile form: a normal fetus that was diagnosed and confirmed by enzymatic assay on amniotic cells; two affected fetuses that were diagnosed and confirmed on post-abortion fetal tissues. In one case a residual acid alpha-glucosidase activity was found; we concluded that the residual activity was due to maternal contamination. Prenatal diagnosis of Pompe's disease is therefore possible using chorionic villi biopsy.

Biopsy↗
PubMed1985

[Early prenatal diagnosis of lysosomal enzymopathies from biopsies of trophoblasts].

This study was undertaken to assess the reliability of trophoblastic biopsy for early ante-natal diagnosis (10 weeks) of lysosomal diseases, including glycogenoses, sphingolipidoses and mucopolysaccharidoses. The sensitivity and specificity were excellent. In addition, cell cultures of the trophoblastic material enable further confirmation of the diagnosis. The possibility of a diagnosis and a medical decision with regards to the outcome of pregnancy at the 10th week of gestation is a considerable advance compared to diagnostic amniocentesis between the 17th and 20th weeks. In our opinion, if a total deficit is observed, the decision to terminate the pregnancy can be taken; in partial deficits or in cases with normal activity, it is wise to confirm the diagnosis by amniocentesis.

Biopsy↗
PubMed1984

Sodium taurocholate effect on beta-glucosidase activity: a new approach for identification of Gaucher disease using the synthetic substrate and leucocytes.

In this work we have studied the leucocytes and sera of 3 Gaucher patients, 4 obligate heterozygotes, 11 brothers and sisters of patients and 11 controls. Beta-glucosidase activity with 4-M-U-beta-glucopyranoside has been assayed at different pH's, in the presence of pure sodium taurocholate. At pH 4.5 and 5.0 sodium taurocholate activates the beta-glucosidase of control leucocytes, but inhibits the residual enzyme present in Gaucher leucocytes. The ratio of beta-glucosidase activity in the presence and absence of this effector seems to be a good approach to the diagnosis of Gaucher disease and it has proved indispensible in one patient's diagnosis. The apparent Km of beta-glucosidase determined for the same substrate, at pH 4.5 and 5.5 in the presence of sodium taurocholate showed markedly lower values in the patients than in the controls. An increased serum acid phosphatase activity, previously described as a secondary alteration in Gaucher disease, has also been studied and seems to be a useful complementary test, particularly when its age dependence is taken into account.

Acid Phosphatase↗
PubMed1984

Effects of antisera raised against native and denatured human alpha-glucosidase and beta-hexosaminidases on native enzyme activity.

Antisera were raised in rabbits against native and sodium dodecylsulfate denatured forms of human acid alpha-glucosidase and beta-hexosaminidases A and B. Anti-native enzyme antisera were able to precipitate all or nearly all enzyme activity from cell extracts, and to eliminate all stainable activity on electrophoresis. Antisera prepared against denatured enzymes precipitated only a minor part of enzyme activity. Electrophoretic analysis showed that these antisera were able to bind to the enzyme molecule. The result was a slowing down of the anodic migration but not immobilization. The use of variants with hexosaminidase deficiencies helped to clarify the action of the antisera on the various hexosaminidase isozymes.

Animals↗
PubMed1984

High frequency of beta-hexosaminidase deficiency in lymphoblastoid cell lines.

The activity of seven lysosomal enzymes was determined in 25 lymphoblastoid cell lines. These lines included normal controls transformed with Epstein-Barr virus, Burkitt's lymphomas and other lymphomas with or without EBV genome. Four lines were deficient in total beta-hexosaminidase activity. The deficiency was as severe as that of the variant O (Sandhoff's disease) of clinical beta-hexosaminidase deficiency. The electrophoretic pattern was also similar to that observed in Sandhoff's disease. The possible mechanisms explaining the high frequency of beta-hexosaminidase deficiency in lymphoblastoid cell lines are discussed.

Antigen-Antibody Complex↗
PubMed1984

Evaluation of possible first trimester prenatal diagnosis in lysosomal diseases by trophoblast biopsy.

The detection of enzymatic deficiency in cultured amniotic cells from second trimester pregnancies is presently used for prenatal diagnosis of lysosomal diseases. The possibility of obtaining and processing trophoblast tissue at 8-10 weeks of gestation would permit first trimester prenatal diagnosis. Using trophoblast tissue samples from normal fetuses before voluntary abortion and from placenta after therapeutic abortions of fetuses affected by several lysosomal diseases, we conclude that early diagnosis of lysosomal disorders would be possible.

Biopsy↗
PubMed1984

[Sampling, culturing and karyotyping of chorionic villi].

The authors report on 69 samples of chorionic villi taken from patients who were undergoing therapeutic termination of pregnancy. These samples were taken using small forceps which were guided by ultrasound. The reliability and the chances of culturing these villi in order to work out the caryotype of the fetus and to study the enzymes is discussed.

Chorionic Villi↗
PubMed1984

First-trimester prenatal diagnosis of mucolipidosis II (I-cell disease) by chorionic biopsy.

We investigated the possibility of mucolipidosis type II (ML II) prenatal diagnosis by lysosomal enzyme determination on trophoblast biopsy obtained at 10 weeks of gestation in two pregnancies at risk. Diagnosis of ML II was made in both cases on fresh chorionic villi on the basis of depressed beta-galactosidase activity, and after abortion, the diagnosis was confirmed on fresh fetal tissues and on cells cultured from trophoblast and fetuses. We stress the importance of culturing cells from the trophoblast biopsy to ensure a reliable diagnosis.

Biopsy, Needle↗
PubMed1984

[Biopsy of chorionic villi by forceps under ultrasonic control: technic and results].

We describe an original technique for villi sampling using a rigid forceps under ultrasound control. 120 chorion biopsies were performed, the success rate of sampling is 100%, the samples are pure without any maternal contamination in 90% of cases. The fetal loss rate needs further evaluation because the number of continuing pregnancies is still too small to allow enough accurate assessment. No miscarriage was observed among our last 70 patients. At the beginning of our experience we preferred to start our diagnoses only for high genetic risk diseases: haemoglobinopathies, hereditary metabolic diseases, lethal X-linked diseases. We insist on the efficiency and the quickness of this method and on the quality of the samples which makes the diagnosis safer.

Biopsy↗
PubMed1983

Evidence for the presence of beta-subunit of hexosaminidase in a case of Sandhoff disease using a blotting technique.

Hexosaminidases, lysosomal enzymes whose deficiency is responsible for several genetic disorders, exist as two major forms: form A, containing two types of subunits alpha and beta; and form B, containing only beta subunits. We have used a technique involving successively electrophoresis of denatured proteins, transfer (blotting) onto nitrocellulose, and labelling by appropriate antibodies raised against the dissociated forms of hexosaminidases A and B. This technique allows the detection of alpha and beta subunits in crude extracts of normal tissues. The presence of beta chains was demonstrated in the liver of a fetus affected with Sandhoff's disease, deficient in functional hexosaminidases A and B.

Electrophoresis↗
PubMed1983

Reactivating factors of human alpha-mannosidase mutant.

In a previous study, we compared the alpha-mannosidase from mannosidosis tissues to that from normal one and we characterized the mutant. In this work, we show that the mutant inactivation by dialysis is reversible in different conditions and we investigate the nature of mannosidosis reactivating factors. The results obtained on pathological tissue by dialysis and by addition of dialysis fluid (DF), pronase treated DF, amino acid mixture, bivalent ions: Ca++, Zn++, Mg++, Co++ DF containing EDTA or DF heated to 600 degrees C suggest the reactivating factor includes both peptides and ions.

Carbohydrate Metabolism, Inborn Errors↗