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Biomedical subjects

E Vamos

Publications and source records attributed to E Vamos.

At least 91 records · Page 5Linked to original sources
PubMed1986

Leukemia in a trisomy 21 mosaic: specific involvement of the trisomic cells.

Acute monoblastic leukemia was diagnosed in a 32-month-old boy with mild signs of Down's syndrome. Chromosome analysis of cultured skin fibroblasts and peripheral blood lymphocytes disclosed a constitutional mosaicism (46,XY/47,XY,+21). At initial diagnosis of acute leukemia, additional chromosomal changes were found in bone marrow blasts that were consistent with the M5 subtype. The cytogenetic markers of the acute leukemia were restricted to the trisomic subset and disappeared during remission. These findings add further weight to the suggestion that the propensity of Down's syndrome patients to develop leukemia is directly related to their karyotype abnormality and that leukemia might be clonal in origin.

Child, Preschool↗
PubMed1986

Lethal osteopetrosis with multiple fractures in utero.

Severe osteopetrosis was diagnosed in utero in two successive pregnancies resulting from an intermarriage. Hydrocephaly and skeletal hyperdensity were detected at 18 weeks of gestation, and fractures at 24 weeks. We report on extensive ultrasound, radiological, and pathological findings, including those on brain and bone. The markedly reduced number of osteoclasts observed in these sibs and the very early fetal involvement suggest that this form of osteopetrosis might represent a new entity: autosomal recessive lethal osteopetrosis.

Adult↗
PubMed1986

Generalized unresponsiveness to mineralocorticoid hormones: familial recessive pseudohypoaldosteronism due to aldosterone-receptor deficiency.

The present report describes two sibs--born from consanguineous parents--presenting with severe salt wasting. Generalized pseudohypoaldosteronism (PHA) was diagnosed on the basis of markedly elevated sodium concentration in urine (84 & 63 mmol/L respectively), sweat (181 & 196), saliva (- & 120) and stool (- & 189), hyponatremia (112 & 132) and hyperkalemia (10.7 & 7.3) in the presence of increased plasma aldosterone (greater than 8.5 & 5.4 ng/ml), plasma renin activity (40 & 18.9 ng/ml/hr) and urinary aldosterone (greater than 32 & 11.6 micrograms/day). Both parents investigated under basal conditions (sodium ad libitum) and under sodium restricted diet appeared to be normal. Aldosterone binding studies performed on mononuclear leukocytes showed no type I receptors in the investigated child whereas low amounts were found in both parents (90 sites/cell and 63 sites/cell in the mother and the father, respectively). Isolated renal unresponsiveness to mineralocorticoid hormones is thought to be an autosomal dominant inherited disease. In contrast, the results obtained in these two new cases of generalized PHA, as well as the fact that four of five yet reported cases were born from consanguineous parents, suggest an autosomal recessive mode of inheritance for generalized PHA.

Aldosterone↗
PubMed1986

Pathological pregnancies. Results of amniotic fluid studies and fetal outcome.

Late amniocenteses (greater than 20 weeks' gestation) were performed in 114 pregnancies with no a priori genetic risk, but referred because of abnormal clinical and/or ultrasound findings suggesting fetal malformations. Reasons for referral included polyhydramnios (51 cases), oligohydramnios (15 cases), fetal growth retardation (FGR) (16 cases) and abnormal fetal ultrasound findings excluding anencephaly (32 cases). In 42 of these cases, referral was motivated by a combination of the above abnormal findings. When polyhydramnios was the sole anomaly (25 cases), 5 fetuses were malformed (20%), abnormal fetal karyotype and/or elevated amniotic fluid alphafetoprotein (AFP) were demonstrated in 2 cases. Oligohydramnios was the sole anomaly in one case; the infant died of prematurity. Fetal growth retardation was the sole anomaly in 14 cases, 11 otherwise normal newborns were small for date, 2 died at birth and 1 was malformed (1/14, 7%). In this group all fetal karyotypes were normal and in 2 cases amniotic fluid AFP were increased. In the 32 pregnancies without abnormal amniotic fluid volume and/or FGR and with fetal malformation(s) suggested by ultrasound, all malformations except one (ovarian cyst possibly ruptured during birth) were confirmed at birth, amniotic fluid AFP was elevated, and/or karyotype was abnormal in 6 cases. In 42 pregnancies where more than one alarm sign was present, abnormal karyotype and/or elevated amniotic fluid AFP level were recorded in 21 of the 39 cases where amniocentesis was performed, 33 fetuses were malformed (79%) and 13 died in the perinatal period (31%). The high incidence of abnormal results of amniocentesis found in this survey of pathological pregnancies, particularly in those with multiple alarm signs, emphasizes the need for amniocentesis in these situations.

Congenital Abnormalities↗
PubMed1986

[Echographic evaluation of non-immunologic feto-placental anasarca. A series of 24 cases].

24 cases of non-immune feto-placental hydrops which were diagnosed by ultrasonography are presented. The precise etiology was possible in 21 of the cases using chromosome analyses, radiological assessments and carefully conducted post mortem examinations. The cause was maternal in 3 cases and due to fetal pathology in 18 cases, of which 5 were due to chromosome abnormalities. Three recessive autosomal syndrome, 9 malformations and in particular cardiac malformations and one twin pregnancy with transfusion from one fetus to the other were diagnosed. These features, which can be compared with those already in the literature, show that most of these cases of hydrops are due to genetic fetal defects and demonstrate how important it is to carry out chromosome analyses and systematic anatomo-pathological investigations. The results of these tests will indicate the way the doctors should look after the mother during pregnancy and how to deliver these mothers in subsequent pregnancies.

Adolescent↗
PubMed1984

Congenital malformations in 10,000 consecutive births in a university hospital: need for genetic counseling and prenatal diagnosis.

Ten thousand children born consecutively in a university hospital were surveyed for the presence of major congenital malformations. About 2% (174) had a major congenital defect. Seventy-eight percent (135 of 174) of these malformations are associated with increased recurrence risk (greater than 1%), and 9% carry a high recurrence risk (greater than or equal to 10%). On the basis of the recurrence risk of 1% or higher and the feasibility of prenatal diagnosis, such a procedure should be considered in future pregnancies in 45% (79 of 174) of the mothers, especially inasmuch as 40% were primiparae younger than 36 years.

Belgium↗
PubMed1984

Prenatal diagnosis of inborn errors of metabolism. Present status and new approaches.

The evolution of the techniques aiming at the prenatal diagnosis of inborn metabolic disorders has closely reflected the progress in the knowledge of their underlying molecular defects. Initially, abnormal metabolites have been looked for in amniotic fluid. Recently, improved techniques of detection have permitted fast and reliable prenatal diagnoses through biochemical studies of cell-free amniotic fluid. Presently, the most widely used approach is the search for the defective gene product in cultured amniotic cells obtained through amniocentesis. Because of its relative safety, this procedure should be recommended, provided three prerequisites are met: a most accurate diagnosis of the index patient, the knowledge of the defective enzyme and its expression in cultured cells. For a correct interpretation of the results, cell culture parameters as well as specific activities of the mutant enzyme in the index case and the parental cells must be taken into account. Fetal blood sampling is a valuable alternative for some of the genetic disorders that cannot be detected in cultured amniocytes. The recently developed technique of chorion biopsy enables now to sample fetal cells during the first trimester of gestation. Meanwhile, the progress in DNA technology has uncovered exciting perspectives for the prenatal diagnosis of monogenic disorders at the gene level. Restriction endonuclease mapping has enabled to diagnose prenatally some forms of haemoglobinopathies, first through the polymorphism of sequences adjacent to the beta-globin gene, and now for the sickle-cell disease, by direct identification of the mutation.

Amniocentesis↗
PubMed1984

[Prenatal diagnosis of malformations of the central nervous system].

Since the very start of using ultrasound to monitor pregnancy the information that the obstetrician has obtained from it has been great. Measuring the fetus (biparietal diameters, rump-crown length etc.) makes it possible to check development of the fetus in the uterus, as well as seeing the various organs and their placing and internal structure. Real time pictures make it possible to visualise the organs precisely from the point of view of their positioning and their internal structures. We report 12 cases of malformations of the central nervous system which were diagnosed in utero and we point out the value of early diagnosis in pregnancy. The 12 cases we found included four of hydrocephaly, one cyst of the choroid plexus, one hydrencephaly , two cases of holoprocencephaly and four cases of anencephaly. Since these malformations may be part of generalised malformations it is important to search for these others by ultrasound as well as by caryotyping and estimation of alpha-fetoprotein levels.

Abnormalities, Multiple↗
PubMed1983

Alphafetoprotein (AFP), concanavalin A non-reactive AFP and specific acetylcholinesterase in amniotic fluid from pathological pregnancies. Predictive values for open spina bifida.

Alphafetoprotein (AFP) and concanavalin A non-reactive alphafetoprotein determination and the acetylcholinesterase (AchE) qualitative test have been performed on amniotic fluid samples from 33 normal pregnancies, 44 pregnancies with fetal malformations and 8 normal pregnancies with elevated amniotic fluid alphafetoprotein (3 false positive AFP results, 5 contaminations with fetal blood). The validities of these three tests in detecting abnormal pregnancies are compared. The usefulness of the existing complementary tests in the detection of neural tube defects in a low neural tube defect incidence area is discussed. Risk figures for open spina bifida according to the prior risk situation and the results of maternal serum AFP, amniotic fluid AFP, AchE qualitative test and ultrasound examination have been calculated.

Acetylcholinesterase↗
PubMed1983

C heterochromatin variation in couples with recurrent early abortions.

The possible influence of the high polymorphic C heterochromatic regions of human chromosomes 1, 9, 16, and Y on meiotic chromosome segregation was investigated. Faulty chromosome segregation may be the result of either an abnormal quantity of C heterochromatin on the homologues, or disequilibrium between the homologues. The aim of our study was to determine whether either a variation in the amounts of total C heterochromatin or differences in the amounts of C heterochromatin between homologues could lead to faulty chromosome segregation. The study was performed on C banded metaphases obtained from peripheral lymphocyte cultures of 15 couples with recurrent early abortions and 15 control couples, all Caucasians. Analysis of variance was first performed on separate metaphases to measure intra-individual, inter-individual, and between population variation in a hierarchical model. Since the significant intra-individual differences covered the other parameters we performed, secondly, a one way analysis of variance on the mean values of metaphases per person in order to measure the inter-individual and between population variation. The results did not show a relationship between C heterochromatin lengths and occurrence of recurrent abortions.

Abortion, Habitual↗
PubMed1983

Alterations in cultured fibroblasts of sibs with an infantile form of a free (unbound) sialic acid storage disorder.

Cultured fibroblasts from two sibs with generalized hypertonia, hepatosplenomegaly, and psychomotor retardation within the first year of life were found to have unusual morphologic features. When examined by phase microscopy, the unstained and unfixed cells contained a large number of vacuolated structures whose gross appearance resembled that of a honeycomb in the cell cytoplasm. Electron microscopy studies, following fixation, showed the "honeycombing" to be the result of numerous, closely packed, cytoplasmic, membrane-bound vacuoles. In some of these structures the remains of fibrilogranular material could be detected. Biochemical analysis of crude sonicates of these cells revealed increased levels (4--7 x N) of an acid soluble component that reacted with thiobarbituric acid. Analysis of trimethylsilyl derivatives of this material by gas liquid chromatography and mass spectrometry showed it to be indistinguishable from sialic acid (N-acetylneuraminic acid). Quantitation of this material from the cells of one of the sibs after isolation on a Dowex column yielded 39.8 nmoles of free (unbound) sialic acid per mg protein whereas normal fibroblasts had 1--2 nmoles per mg. Bound sialic acid levels were at the upper limits of normal (24.8 versus 11--23 nmoles per mg protein). The concentration of cytidine monophosphate-sialic acid was normal. After incubation of the patient's fibroblasts with [3H]-N-acetylmannosamine for 72 h, there was a 7-fold increase (compared to normal fibroblasts) in the amount of radioactivity in free sialic acid present in the acid soluble fraction. The amount of labeled, bound sialic acid in the acid-insoluble pool, however, was the same in both patient and control fibroblasts.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1982

Infantile form of sialic acid storage disorder: clinical, ultrastructural, and biochemical studies in two siblings.

We describe two sibs with coarse facies, hepatosplenomegaly, prominent psychomotor retardation and unexpectedly fair complexion. Ultrastructural studies of conjunctival, skin, bone marrow and liver biopsies from these individuals showed generalized lysosomal storage of polysaccharide-like material, i.e., membrane bound inclusions containing sparse, fibrillo-granular material. Biochemical analyses of urine and cultured fibroblasts from these patients revealed increased levels of free (unbound) sialic acid. The ultrastructural and biochemical findings in these sibs are similar to those previously found in Salla disease, however, the clinical course is much more severe. It is concluded that these children represent a new pathogenetic entity whose basic defect is still to be defined.

Bone Marrow↗
PubMed1982

Fanconi's anaemia. Simultaneous onset in 2 siblings and unusual cytological findings.

Fanconi's anaemia is reported in 2 siblings. The simultaneous onset of pancytopenia after possible exposure to common external agents suggest that both a frail genotype and environmental factors may be etiologically involved in the disorder. One of the children died after having developed a monoblastic leukaemia. This patient disclosed very striking cytological abnormalities, including a dyserythropoietic pattern and ropalocytosis. The physiopathology of the latter abnormality, which has hitherto not been noticed in Fanconi's anaemia, is uncertain.

Adolescent↗