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Biomedical subjects

A Ornoy

Publications and source records attributed to A Ornoy.

At least 163 records · Page 9Linked to original sources
PubMed1979

Possible evidence for secondary degeneration of central nervous system in the pathogenesis of anencephaly and brain dysraphia. A study in young human fetuses.

In an attempt to help elucidate pathogenetically those human cases exemplifying secondary degeneration of the neural tube causing brain dysraphia, macroscopic and histologic observations of two young human fetuses are described. A nine-week-old anencephalic fetus exhibited an absence of spinal cord (amyelia) with retention of neural crest derivatives (dorsal root ganglion cells and thusir processes, and sympathetic ganglia) implying the presence of a neural tube in early gestation. The second, ten-week-old exencephalic case exhibited restricted brain hemorrhage and necrosis of the telencephalon and brain stem amongst otherwise normal brain and spinal cord tissue. These two young fetal cases may represent examples of a previously normal neural tube which has undergone degeneration at a stage where neural crest has already undergone differentiation, and thus distinguishes them from cases of complete dysraphism which probably results from primary degeneration during neurulation.

Anencephaly↗
PubMed1978

Small marker chromosome mosaicism confirmed in two cases ascertained prenatally.

Two cases of chromosomal mosaicism were prenatally diagnosed and confirmed in tissues cultured from subsequently aborted fetuses. In both cases a small marker chromosome was observed which proved de novo in origin, since parental chromosomes were normal. The implications and interpretation of such findings in counselling families undergoing amniocenteses is discussed. Mosaicism for small marker chromosomes may be more frequent than hitherto suggested.

Adult↗
PubMed1978

Triploidy in human abortions.

Seven triploid embryos and fetuses, six spontaneously aborted and one resulting from pregnancy interruption are described. A wide range of malformations, from amorphous, nodular embryos, to apparently normal phenotypes were observed. The degree of hydatid degeneration in the placentae ranged from minimal to severe. In several cases large, atypical cells were present in the villous stroma. There was no apparent correlation between the degree of placental lesion and fetal malformations. It is suggested that termination of triploid pregnancies is determined more by the degree of placental damage rather than the severity and type of fetal anomalies.

Abnormalities, Multiple↗
PubMed1978

A new variant of mannosidosis with increased residual enzymatic activity and mild clinical manifestation.

A partial deficiency of alpha-mannosidase was found in cultured skin fibroblasts, serum, and extracts of leukoytes in two siblings with mild mental retardation, delayed speech, a suggestion of coarse or full facies, and limited mobility of the large joints. All other lysosomal enzymes tested were within the normal range. Their father demonstrated intermediate alpha-mannosidase activity. The addition of 2 mM Zn++ caused a 40% increase of the alpha-mannosidase activity in cell extracts of both patients and control subjects. pH profiles and Cellogel electrophoresis of the patients' cells indicated 20% residual activity of the acidic alpha-mannosidase isoenzyme (pH optimum at 4.0), whereas the activity of the isozyme with pH optimum of 6.0 was normal. Increasing substrate concentration (1--10 mM) demonstrated a 4 to 5-fold increase in the apparent Km of the acidic alpha-mannosidase in the patients' fibroblasts. This residual activity, however, was apparently not sufficient for the normal catabolism of mannose-containing molecules, since electron microscopic examination of the cultured fibroblasts demonstrated numerous lysosomal storage bodies.

Arylsulfatases↗
PubMed1978

Scanning electron microscopy studies on the origin and structure of matrix vesicles in epiphyseal cartilage from young rats.

Epiphyseal plates of young rats were examined by scanning electron microscopy to study the distribution, morphology and origin or the matrix vesicles (calcifying globules) and the results were compared with the findings on transmission electron microscopy. The matrix vesicles, 0.1 micrometer in diameter, were found to cover the intercolumnar septa and to increase gradually in number from the zone of proliferation to the zone of provisional calcification. In the intercolumnar septa of hypertrophic and calcifying cartilage, the vesicles aggregated to form calcospherites, i.e. mineralized globules about 1 micrometer in diameter. Chondrocytes showed numerous cell processes that were longer and more abundant in the more mature cells. In the zone of maturation many processes had enlarged tips with small globular projections ("bulges"), about 0.1 micrometer in diameter, which resembled the matrix vesicles covering chondrocytic lacunae. In the zones of hypertrophy and provisional calcification, many of these bulges aggregated to form larger, spherical structures. It is suggested that matrix vesicles in cartilage originate by budding from cell processess, and that in the zone of provisional calcification they aggregate to form the calcospherites, which are the loci of initial calcification of cartilage.

Animals↗
PubMed1977

Anencephaly in trisomy 18: related or unrelated?

A fetus of 20 to 21 weeks of development with the trisomy 18 syndrome has been described. In addition to the phenotypic manifestations usually associated with the syndrome, i.e., low set ears, short neck, omphalocoele, flexion of fingers with the convergence of the second and fifth digits, rocker bottom feet, urinary tract anomalies and intrauterine growth retardation, the fetus also showed left diaphragmatic hernia. Anencephaly and aplasia of the squamous part of occipital bone. Since anencephaly has never been described as one of the phenotypic manifestations of trisomy 18, it is reasonable to assume that in the present fetus it is unrelated and resulted from secondary destruction of the neural tube.

Anencephaly↗
PubMed1977

Prenatal diagnosis of mucolipidosis IV by electron microscopy.

Mucolipidosis IV, a recently recognized metabolic storage disease, is characterized clinically by corneal opacity in infancy, full facial features, and psychomotor retardation. Electron microscopy of cells from a 2-year-old affected girl revealed multiple cytoplasmic storage bodies. Cultured amniotic fluid cells, in two subsequent pregnancies, demonstrated similar abnormal storage bodies. Electron microscopic examination of various uncultured tissues from one abortus demonstrated abnormal inclusions in the cells of the brain, cornea, conjunctiva, and other epithelial tissues, thus confirming the prenatal diagnosis. This suggests that mucolipidosis IV is an autosomal recessive trait and demonstrates the efficacy of electron microscopy in the prenatal diagnosis of metabolic storage diseases whose biochemical defect is yet unknown.

Amniotic Fluid↗
PubMed1977

Prenatal diagnosis and gonadal findings in X/XXX mosaicism.

Prenatal diagnosis of a case of X/XXX mosaicism is presented. In spite of the fact that over 50% of the cells cultured from both ovaries were trisomic for the X chromosome, fetal öocytes were rarely found. This case illustrates that the presence of a triple-X cell line, even in a relatively high percentage of ovarian cells, does not necessarily protect the ovary from 'aöogenesis'. This observation might prove useful in the counselling of future cases involving the prenatal detection of sex chromosome mosaicism.

Adult↗
PubMed1977

Amniogenic bands associated with facial dysplasia and paresis.

A case of the amniogenic band syndrome is described with typical digital constriction bands amputations and syndactyly. The amniotic bands were demonstrated macroscopically and histologically, thus establishing the diagnosis. Facial dysplasia and unilateral facial paresis were attributed to undefined mechanical effects following amniotic rupture. In addition, there was evidence of partial umbilical cord compression which did not appear to have affected fetal well-being.

Abnormalities, Multiple↗
PubMed1977

Scanning electron microscopy findings in osteogenesis imperfecta fetalis.

A case of osteogenesis imperfecta fetalis in a stillborn black male infant is described. Scanning electron microscopic studies of the skeleton showed normal intercartilaginous septa in the metaphyses of long bones, covered by uniform, calcifying globules 1 mum in diameter. In the diaphyses, however, the orientation of bone trabeculae was abnormal. The trabeculae were thin, with wide and densely packed osteocytic lacunae, and with more resorbing surfaces than in the control specimens. It is concluded that in osteogenesis imperfecta there is abnormal periosteal ossification, together with increased osteocytic resorption.

Bone and Bones↗
PubMed1977

Triploidy in man: a clearly recognizable syndrome?

Complete triploidy in a 13-week-old fetus and in a full-term liveborn infant is described. A previous pregnancy of one of the mothers had resulted in a hydatidiform mole. Hydatidiform degeneration of the placenta of triploid abortuses and newborn infants may be responsible for the intrauterine growth retardation and fetal death often observed. Although many phenotypic features are common in triploidy, a review of the literature indicated that a pathognomonic syndrome could not be delineated. Nevertheless, a certain combination of findings may be suggestive of the diagnosis.

Abnormalities, Multiple↗
PubMed1976

Association between maternal bleeding during gestation and congenital anomalies in the offspring.

The incidence of maternal bleeding complicating the pregnancies of 326 children examined at the Jerusalem Community Center for Child and Family Development is surveyed. A history of bleeding during pregnancy was more frequent in children with congenital anomalies of the central nervous system (and/or psychomotor retardation) (33 per cent) and in children with congenital anomalies of other systems (29 per cent) than in control children (12 per cent). The implications of these findings are discussed in relation to placental pathophysiology and the pathogenesis of threatened abortion.

Adult↗
PubMed1976

Maternal endotoxemia, fetal anomalies, and central nervous system damage: a rat model of a human problem.

Endotoxemia is a common consequence of the gram-negative urinary tract infections that complicate human pregnancies. Only rarely, however, have the effects of maternal endotoxemia been evaluated by animal experiments or by human investigations. Data of the Collaborative Perinatal Study suggest an association between maternal endotoxemia and fetal central nervous system damage. For these reasons we performed controlled studies of the fetal effects of treatment of pregnant rats, at appropriate gestational ages, with E. coli endotoxin. We found a maximum 7 per cent incidence of fetal anomalies in the treated animals but no anomalies in controls. Placental light microscopy examinations indicated the mechanism to include Shwartzman-lixemia produces periventricular leukomalacia. We obtained an incidence of neuronal necrosis in treated fetuses that was 10 times greater than in control fetuses. It is therefore of importance that additional studies of the pathologic effects of endotoxin be performed.

Animals↗