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Biomedical subjects

F Muller

Publications and source records attributed to F Muller.

At least 181 records · Page 10Linked to original sources
PubMed1982

[Atlas of the stages of development of the nervous system in the intact human embryo].

Many features of the developing nervous system are visible in the intact human embryo, and a photographic atlas from 3-7 postovulatory weeks (stages 10-19) is provided. A number of features, such as the cerebellar plate, the cerebral vesicles, and the epiphysis cerebri, can be detected on external views at as early a stage as they have previously been recorded after microscopical examination. After 7 weeks it becomes increasingly difficult to identify features of the brain from the surface.

Anatomy↗
PubMed1980

Differences between intracellular platelet and brain proteins that bind serotonin.

Two proteins with binding capacity highly specific for serotonin are present in the 100,000 g supernatant obtained from rat platelets: a glycoprotein and albumin. They were purified by means of (NH4)2SO4 fractionation, Sephadex sieve chromatography, and affinity column chromatography. The two proteins differed in most of their physical and chemical properties: (a) migration on 7.5% acrylamide gel of the complex (protein-Fe+2-[3H]serotonin); (b) molecular weight (sodium dodecyl sulfate gels); (c) carbohydrate reaction; (d) binding capacity and binding constants; (e) effect of reserpine; (f) heat stability; and (g) isoelectric point. However, they showed two similar properties: sensitivity to trypsin and dependence on Fe+2 for serotonin binding. The properties of both the glycoprotein and albumin differ considerably from those of serotonin binding protein of brain (SBP), which was not detected in platelets. Since brain serotonin binding protein is thought to be involved in storage of the amine, these results suggest that the storage form of serotonin in rat platelets is different from that in rat brain. These results also imply that the storage of serotonin in platelets may not serve as a model for the storage of serotonin in nerve terminals of the brain.

Albumins↗
PubMed1980

The human vertebral column at the end of the embryonic period proper. 1. The column as a whole.

The present investigation of the vertebral column at 8 post-ovulatory weeks, the first such study based on precise reconstructions, has revealed 33 or 34 cartilaginous vertebrae arranged in flexion and approximately 20--33 mm in total length. At the end of the embryonic period proper, a typical vertebra, such as TV6, consists of a centrum that is continuous with two neural processes. Pedicles, articular and transverse processes, but no spinous processes, are identifiable. The tips of the neural processes, which are formed by the laminae, are connected by fibrous tissue and resemble the condition of total rachischisis. The union of the laminae, the onset of ossification, and the appearance of articular cavities are characteristic of the early fetal period. The variations encountered within a single developmental stage were noted. They were mostly minor, e.g. the number of coccygeal elements and the extent of the dorsal growth of the neural processes.

Anthropometry↗
PubMedDate not supplied

Prenatal diagnosis of cystic fibrosis. I. Prospective study of 51 pregnancies.

A prenatal diagnosis was performed in 51 pregnancies with a 1-in-4 risk of having a child with cystic fibrosis. The criteria for determining an affected fetus were based on the results of alkaline phosphatase (ALP) residual activity after inhibition by phenylalanine and by homoarginine, of total ALP activity, and of gamma-glutamyltranspeptidase (GGTP) activity in the amniotic fluid taken between 16 and 19 weeks of pregnancy. The chromosomal analysis of amniotic fluid cells showed trisomy 13 in one case which was excluded from the analysis of biochemical assays. The biochemical assays were in the normal ranges in the amniotic fluid of 35 pregnancies: 26 have reached term and a normal infant has been born, 9 are still in progress. A deficiency of the ALP phenylalanine-inhibitable form, depressed values of total ALP and GGTP were observed in the amniotic fluid of 15 pregnancies: one pregnancy went to term and the infant had CF, in 14 cases the pregnancy was terminated, and meconium ileus was observed in ten of these cases. It was observed that the changes towards abnormal values became more significant with advancing gestational age and that 18 weeks appeared to be the optimum time for diagnostic amniocentesis.

Abortion, Therapeutic↗
PubMedDate not supplied

Prenatal diagnosis of cystic fibrosis. II. Meconium ileus in affected fetuses.

Meconium ileus was the presenting feature of cystic fibrosis in 46 per cent of the couples which have been referred for prenatal diagnosis. In fetuses which have been aborted on the basis of alkaline phosphatase isoenzymes assays, meconium ileus represented the only pathological feature of cystic fibrosis, and was observed in three fourths of the cases. Real-time sonographic examination of fetuses at the time of amniocentesis was able to show an echogenic mass in the abdomen corresponding to the meconium ileus, and thus may afford a complementary means of diagnosis.

Cystic Fibrosis↗
PubMedDate not supplied

Congenital erythropoietic porphyria: prenatal diagnosis and autopsy findings in two sibling fetuses.

Congenital erythropoietic porphyria is an autosomal recessive disease characterized by a deficiency of uroporphyrinogen III cosynthetase activity, with diffuse tissue accumulation of specific type I porphyrins. The diagnosis of this disease was made in two fetuses, who were siblings, and from a Caucasian nonconsanguinous family. The first fetus died in utero with hydrops fetalis and anemia, but without an etiopathogenic diagnosis. In the second case, the diagnosis was based on pink fluorescence of the amniotic fluid examined fortuitously in sunlight. DNA analysis showed that the fetus was heteroallelic for the mutation C73R. The autopsy showed brown skin, and at histological examination, porphyrin pigment was deposited in many tissues. Retrospectively, similar deposits were found in the tissues of the first fetus.

Adult↗
PubMedDate not supplied

[Placenta and trisomy 21].

Trisomy 21 is the most frequent genetic anomaly leading to mental retardation, and is prenatally diagnosed by fetal karyotyping usually performed on amniotic fluid cells. Amniocentesis is offered to patients according to three criteria: maternal age (over 38 years), fetal anomalies detected by ultrasonography, and abnormal maternal serum markers most of which are produced by the placenta. Placental development in trisomy 21 is poorly understood. We therefore studied the syncytiotrophoblast, which plays a key role in pregnancy through its involvement in fetal-maternal exchanges and in the secretion of pregnancy-specific hormones. The multinucleated syncytiotrophoblast is formed by the differentiation and fusion of mononucleated cytotrophoblasts. We show that in trisomy 21, syncytiotrophoblast formation is defective and/or delayed. This anomaly is associated with defective synthesis and the secretion of pregnancy-specific hormones. These findings enhance the understanding of placental serum markers used in the prenatal screening of trisomy 21 and clarify the impact of placental abnormalities on fetal development in trisomy 21.

Biomarkers↗
PubMedDate not supplied

Identification of fifteen novel mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene in European patients with severe hypophosphatasia.

Hypophosphatasia is an inherited disorder characterised by defective bone mineralisation and deficiency of serum and tissue liver/bone/kidney alkaline phosphatase (L/B/K ALP) activity. We report the characterisation of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 13 European families affected by perinatal, infantile or childhood hypophosphatasia. Eighteen distinct mutations were found, only three of which had been reported previously in North American and Japanese populations. Most of the 15 new mutations were missense mutations, but we also found two mutations affecting donor splice sites and a nonsense mutation. A missense mutation in the last codon of the putative signal peptide probably affects the final maturation of the protein. Despite extensive sequencing of the gene and its promotor region, only one mutation was identified in two cases, one of which was compatible with a possible dominant effect of certain mutations and the putative role of polymorphisms of the TNSALP gene. In 12 of the 13 tested families, genetic diagnosis was possible by characterisation of the mutations or by use of polymorphisms as genetic markers. Hypophosphatasia diagnosis was assigned in two families where clinical, laboratory and radiographic data were unclear and prenatal diagnosis was performed in one case. The results also show that severe hypophosphatasia is due to a very large spectrum of mutations in European populations with no prevalent mutation and that genetic diagnosis of the disease must be performed by extensive analysis of the gene.

Alkaline Phosphatase↗
PubMedDate not supplied

Pathogenesis of twin-twin transfusion syndrome: the renin-angiotensin system hypothesis.

In spite of active perinatal management, twin-twin transfusion syndrome (TTTS) remains a severe disease with a high risk of neonatal mortality and morbidity. TTTS initially results from an unbalanced blood flow from a donor to a recipient twin. However, its pathogenesis remains unclear, although cardiovascular disturbances and regulation of fetal volemia and diuresis seem central in this syndrome. Previously, we demonstrated that the renin-angiotensin system (RAS) was up-regulated in donor twins as a consequence of hypovolemia, and down-regulated in recipients. This was the first evidence of the implication of the RAS in TTTS. We hypothesize that the RAS plays a key role in the pathogenesis of TTTS. In the donor, RAS up-regulation aggravates oligohydramnios and may increase arterial resistance, which could contribute to placental dysfunction leading to intrauterine growth restriction. In the recipient, paradoxical RAS activation, due to transfer of effectors such as angiotensin II through placental shunts, could explain fetal vascular disturbances and cardiomyopathy. According to our hypothesis, TTTS would appear similar to the classical model of hypertension referred to as '2 kidneys-1 clip' with a donor twin, comparable to the clipped kidney, intoxicating its cotwin, comparable to the normal kidney.

Female↗