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P Eydoux

Publications and source records attributed to P Eydoux.

At least 37 records · Page 2Linked to original sources
PubMed1996

Possible new variant of Nijmegen breakage syndrome.

We report on a child with microcephaly, small facial and body size, and immune deficiency. The phenotype is consistent with Nijmegen breakage syndrome (NBS), with additional clinical manifestations and laboratory findings not reported heretofore. Most investigations, including the results of radiation-resistant DNA synthesis, concurred with the diagnosis of NBS. Cytogenetic analysis documented abnormalities in virtually all cells examined. Along with the high frequency of breaks and rearrangements of chromosomes 7 and 14, we found breakage and monosomies involving numerous other chromosomes. Because of some variation in the clinical presentation and some unusual cytogenetic findings, we suggest that our patient may represent a new variant of Nijmegen breakage syndrome.

Cells, Cultured↗
PubMed1996

Alterations in expression, binding to ligand and DNA, and transcriptional activity of rearranged and wild-type retinoid receptors in retinoid-resistant acute promyelocytic leukemia cell lines.

All-trans retinoic acid (tRA), a naturally occurring ligand of the nuclear retinoic acid receptors (RARs), induces differentiation of leukemic cells and clinical complete remission in patients with acute promyelocytic leukemia (APL). This differentiation effect can also be seen in vitro in both fresh leukemic cells and in the unique permanent APL cell line, NB4. However, APL cells become resistant to RA-induced differentiation both in vitro and in patients. Although pharmacodynamic mechanisms of resistance have been reported, there is growing evidence that resistance both in patients, as well as in vitro, can be mediated by changes in the sensitivity of leukemic cells to retinoids. To investigate possible mechanisms of retinoid resistance, we established subclones of NB4 that are stably resistant to both tRA and 9-cisRA. Unlike the previously reported NB4.306 retinoid-resistant cells, these subclones expressed PML/RAR-alpha RNA and protein, but demonstrated altered ligand binding patterns of PML/RAR-alpha and differed in retinoid-induced gene expression. They were significantly less able to stimulate transcription of an RARE driven CAT-reporter gene on induction by tRA and showed altered DNA binding activity on a RARE. These data suggest that NB4 cells selected for resistance to retinoids demonstrate abnormal ligand binding to PML/RAR-alpha that lead to altered transcriptional activation by retinoids.

Cell Differentiation↗
PubMed1996

Skeletal and cardiac malformations with thrombocytopenia: a new syndrome?

We describe a female patient with multiple anomalies suggestive of a new syndrome. Manifestations include: VSD and ASD, mild developmental delay, conductive hearing loss, minor facial anomalies, thrombocytopenia, and radiological findings (including carpal fusion). Some of these manifestations may be present in the Keutel syndrome, IVIC syndrome, and the 10qter deletion syndrome. However, none of these syndromes can explain the spectrum of anomalies seen in our patient.

Abnormalities, Multiple↗
PubMed1996

Human methionine synthase: cDNA cloning and identification of mutations in patients of the cblG complementation group of folate/cobalamin disorders.

Methionine synthase catalyzes the remethylation of homocysteine to methionine in a methylcobalamin-dependent reaction. We used specific regions of homology within the methionine synthase sequences of several lower organisms to clone a human methionine synthase cDNA by a combination of RT-PCR and inverse PCR. The enzyme is 1265 amino acids in length and contains the seven residue structure-based sequence fingerprint identified for cobalamin-containing enzymes. The gene was localized to chromosome 1q43 by the FISH technique. We have identified one missense mutation and a 3 bp deletion in patients of the cblG complementation group of inherited homocysteine/folate disorders by SSCP and sequence analysis, as well as an amino acid substitution present in high frequency in the general population. We discuss the possibility that a mild deficiency of methionine synthase activity could be associated with mild hyperhomocysteinemia, a risk factor for cardiovascular disease and possibly neural tube defects.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1996

Translocation between chromosomes 6 and 15 (45,XX,t(6;15)(q25;q11.2)) with further evidence for lack of imprinting of the insulin-like growth factor II/mannose-6-phosphate receptor in humans.

We report a 24 year old female with growth retardation, microcephaly, and congenital abnormalities who has an unbalanced de novo translocation between chromosomes 16 and 6: 45,XX,t(6;15)(q25;q11.2). FISH analysis confirmed that the deletion on chromosome 15 is proximal to the Prader-Willi locus. Several genes have been assigned to the 6q25-qter region including the insulin-like growth factor II/mannose-6-phosphate (IGF-II/M6P) receptor. DNA analysis from our patient documented the loss of one IGF2R gene copy. These data confirm the localisation of the IGF2R receptor to distal 6q25. We also showed reduced expression of the soluble and membrane bound IGF-II receptor, a gene dosage effect incompatible with imprinting. The IGF2R gene has been shown to be imprinted in the mouse but not in humans. Our data provide further evidence for lack of imprinting of this gene in humans.

Adult↗
PubMed1992

Human beta-mannosidosis: a 3-year-old boy with speech impairment and emotional instability.

Beta-mannosidosis is a recently described inherited disorder with predominantly neurological signs and symptoms as the major manifestations of the disorder. The heterogeneous manifestations of the disease have been presented in seven previous patients. We describe a further case of European descent with an infantile onset of the disease, with the features of speech impairment as the first symptom. Beta-mannosidase activity was completely deficient in the patient and a heterozygote level was found in the parents. In addition, mannosyl-N-acetylglucosamine was identified in the patient's urine in keeping with the diagnosis of beta-mannosidosis.

Affective Symptoms↗
PubMed1989

Chromosomal prenatal diagnosis: study of 936 cases of intrauterine abnormalities after ultrasound assessment.

Nine hundred and thirty-six prenatal chromosomal analyses were performed by four cytogenetic centres after ultrasound diagnosis of fetal abnormalities, amniotic fluid disorders, fetal growth retardation, and fetal or placental abnormalities. During the same period, 6515 fetal karyotypes were analysed because of maternal age. Frequencies of chromosomal aberrations in each case were respectively 4.4, 6.7 and 15.8 per cent, compared with 3.18 per cent when the fetal karyotype was performed because of maternal age. High rates of chromosomal aberrations are observed in cases of cervical hygroma, limb abnormalities, omphaloceles, duodenal stenosis, hydrocephalus, and facial abnormalities. In the case of polymalformations, this rate was 29.2 per cent. When malformations were seen together with an amniotic fluid disorder or growth retardation, 21.5 per cent chromosomal aberrations were observed. This frequency was 10.4 per cent when growth retardation was associated with an amniotic fluid disorder. Trisomy 13, 18, 21 and monosomy X accounted for 4/5 of all abnormalities in which we observed a high rate of triploidies (4.9 per cent) and balanced (3.3 per cent) or unbalanced (9.8 per cent) non-Robertsonian structural abnormalities. Sonographic ascertainment of these aberrations and prenatal characteristics of major anomalies are discussed.

Adolescent↗
PubMed1989

Chorionic villus sampling (CVS). Randomized study of efficacy of two transcervical biopsy methods: aspiration canulas and small forceps.

A randomized study of two transcervical biopsy methods was performed. One method involved the use of an aspiration catheter and the other a tissue biopsy forceps. 120 chorionic villus samplings were performed in 30 patients. The percentage of success in taking biopsies and the resulting number of karyotypes were identical in both groups. The amount of removed trophoblastic tissue was greater when the forceps was employed. When the aspiration catheter was used, a sufficient amount of trophoblastic tissue was obtained for karyotyping purposes. It was easier to insert the aspiration catheter than the forceps. The echogenicity of the catheter and forceps were identical. The aspiration catheter has two advantages. Firstly, it is malleable and fits to the anatomy of the cervical canal and the site from which the biopsy is to be taken. Secondly, it is disposable.

Adolescent↗
PubMed1989

Chorionic villus sampling after first trimester diagnosis of fetal cystic hygroma colli.

Diagnostic findings of four cases of cystic hygroma discovered at 11 weeks of gestation are reported. The discovery of cystic hygroma by echotomography was followed by sample taking of chorionic villi which revealed one case of monosomy X and three cases of trisomy 18. Caryotype determination in the presence of cystic hydroma is essential for diagnostic confirmation and subsequent genetic counselling.

Adult↗
PubMed1988

Demonstration of human kidney differentiation antigens with monoclonal antibodies.

Six human differentiation antigens (EE24.6, EG9.11, EG14.1, EI16.1, EK8.1, EK17.1) have been defined using monoclonal antibodies obtained from mice immunized with embryonic kidney cells. Their histologic distribution was determined on frozen sections of embryonic, fetal, and adult human kidneys by immunofluorescence assay. EE24.6, an ureteral bud marker, was detected only on the germ layer of mature kidney urothelium. EG9.11 and EG14.1 were detected on the S-shaped bodies and also on the adult proximal convoluted tubule for the former and the glomerular basement membrane for the latter. EI16.1, a marker of condensed mesenchyme, was detected only on epithelial cells of adult proximal convoluted tubule. EK8.1 was found in the mesangium, connective tissue, and with particularly dense labeling in the basement membranes. This labeling pattern was present throughout renal organogenesis. EK17.1 recognized both cell and plasma human fibronectins. Staining for all antibodies was nearly identical in mesonephros and metanephros. These results demonstate that some antigens follow their embryonic destiny. They indicate an antigenic similarity between the mesonephros and the metanephros and, therefore, a very early appearance of these antigens. During differentiation, these antigens concentrate on more defined structures, and staining became increased with an increased degree of differentiation.

Antibodies, Monoclonal↗
PubMed1987

[Percutaneous ultrasound-guided sampling of fetal blood].

The authors give their experience of percutaneous ultrasound-guided sampling of fetal blood carried out over a period of two years. They suggest a modification of the technique, using linear screening scanning. This has made it possible to reduce the number of unsuccessful attempts at sampling. An analysis of the indications and of the results in 49 attempts at puncture shows how to select the indications better. This is particularly so when fetal abnormalities have been found on ultrasound examination. The authors think that this method, because of its reliability and the speed with which results are obtained, should be a method of choice for screening for chromosome abnormalities which might be thought to exist from the pictures obtained by ultrasound.

Blood Specimen Collection↗
PubMed1986

[Antigenic study of the differentiation of the human kidney using monoclonal antibodies].

The production of monoclonal antibodies against human embryonic renal cells allowed to display on the adult human kidney some antigens typical of certain structures or tissues: the proximal convoluted tubule for EG 9-11 and EG 19-6 monoclonal antibodies, the glomerular basement membrane for EG 14-1, the urothelium for EE 24-6, the connective tissue for EK 8-1 and EK 17-1 and probably the capsular and tubular basement membranes for EK 8-1. Simultaneously, we could follow the spatial and temporal repartition of the antigens during the renal development. One of them (EI 16-1) seemed to disappear in the adult and might correspond to a foetal type-antigen.

Antibodies, Monoclonal↗
PubMed1986

[An unusual way of manifesting acute granulocytic leukemia: granulocytic sarcoma of the breast. Apropos of a case with trisomy 22].

A case of granulocytic breast sarcoma in a 19 year-old-girl is reported. Surgical excision of the tumor was followed by radiotherapy of the breast and lymph nodes. Then 3 months later acute M2 myelocytic leukemia was diagnosed, complete remission being attained using rubidazone-cytarabine and maintained by monthly reinduction courses. Trisomy of chromosome 22 was present in leukemic cells and disappeared during remission. Its pathogenic significance is briefly discussed.

Adolescent↗
PubMed1984

Redistribution of granulopoiesis from extramedullary territories to bone marrow in a case of spent polycythemia treated with alkylating agents.

We report a case of splenectomized spent polycythemia, where under the influence of alkylating agents (busulfan or chlorambucil), a true redistribution of granulopoiesis appeared. Before treatment, granulopoiesis was confined to the liver (within the portal spaces and the sinusoids), whereas bone marrow was depleted of any hematopoiesis, being the site of a mutilating fibrosis; the blood concentration of granulomonocytic colony-forming cells (GM-CFCs) was high. After a year of discontinuous treatment an intense granulopoiesis was present in bone marrow, comprising more than 90% of the hematopoietic cells, whereas circulating colony-forming cells were low to nil. This phenomenon was long-lasting, since after another year of treatment, a third bone marrow biopsy revealed the persistence of an active granulopoiesis. During the last year of treatment, the treatment was continuous with chlorambucil. After 6 months a decrease in polymorph and platelet values appeared and treatment had to be interrupted. Death supervened one month after treatment interruption. Histological examination revealed the lack of any intrahepatic hematopoiesis whereas bone marrow granulopoiesis was active but presented gross maturation abnormalities. The results obtained in this case permit discussion of some aspects of the physiopathology of myelofibrosis, and particularly the genesis of extramedullary hematopoiesis in this clonal disease.

Biopsy↗
PubMed1981

Gene dosage effect for GALT in 9p trisomy and in 9p tetrasomy with an improved technique for GALT determination.

A new born male and a three-year-old female with various dysmorphic features were both found to have to have a supernumerary chromosome. Clinical and cytogenetic findings confirmed the existence of a pure de novo 9p tetrasomy in the first case and a pure de novo 9p trisomy in the second case. Gene dosage effects were demonstrated for galactose-1-phosphate uridyltransferase GALT (EC 2.7.7.12) using an improved method for the assay of this enzyme in red blood cells. These findings are in agreement with previous results on similar cases and therefore confirm the assignment of the locus for GALT to 9p.

Child, Preschool↗