Biomedical subjects

Véronique Abadie

Publications and source records attributed to Véronique Abadie.

8 recordsLinked to original sources

PubMed2005

Olfactory evaluation in children: application to the CHARGE syndrome.

OBJECTIVE: To find an efficient tool for testing olfactory function in children and use it to investigate a group of children with CHARGE (coloboma, congenital heart disease, choanal atresia, mental and growth retardation, genital anomalies, and ear malformations and hearing loss) syndrome. METHODS: We adapted for children an olfaction test that had just been validated in an adult French population and investigated a control group of 25 healthy children aged 6 to 13 years. We then tested the olfactory capacity of a group of 14 children with CHARGE syndrome, aged 6 to 18 years. A questionnaire was completed with the parents about their children's feeding difficulties and their ability to recognize odors in everyday life. We recorded and scored the histories of feeding behavior anomalies, the visual and auditory status, and current intellectual levels. MRI of the olfactory tracts and bulbs was analyzed for 9 of 14 children. RESULTS: We showed that healthy children have similar olfactory function to that of the adult control group, which was representative of the general population, without any difference for either gender or age. We also showed that all children with CHARGE syndrome had olfactory deficiency. Half of them were anosmic, and the others had olfactory residual function (hyposmic). We found no association between olfactory deficiency and feeding behavior, visual or auditory impairment, or intellectual level. Parental subjective evaluations were accurate for only half of the group. All of the MRIs showed anomalies of the olfactory tracts and bulbs varying from moderate hypoplasia to complete aplasia, without any relation between the radiologic and the functional results. CONCLUSIONS: Olfaction can be assessed in children, even the young and disabled. Our results support the proposition that rhinencephalon anomalies should be included as a major criterion for the diagnosis of CHARGE syndrome.

Abnormalities, Multiple↗

PubMed2004

Maternal phenylketonuria: the French survey.

UNLABELLED: We report the French experience regarding pregnancies in maternal phenylketonuria (PKU). In 2001, a questionnaire was sent to each referring PKU specialist in the 20 centres of each region of France, collecting reports on 135 pregnancies in 79 women born between 1958 and 1980. The majority of the 135 pregnancies occurred after 1990. A total of 42 women were informed of the risks of untreated pregnancy, while 26 were not informed (no data for 11). A strict diet was achieved in 83% of informed and in 16% of uninformed mothers prior to conception. Healthy offspring were observed in 43% of the 135 pregnancies, spontaneous abortions in 10.4%, elective abortions in 4.4%, therapeutic abortions in 12.6%, and embryopathies (EP) in 21.5%. In 8.1% of cases, the outcomes (in earliest pregnancies) are unknown. The proportion of healthy children increased over time and reached 80% of the pregnancies of informed females. There were seven heart defects, all in cases of EP, but although microcephaly and intrauterine growth retardation (IUGR) were almost constant in EP, we also found nine healthy children with IUGR. A continuum between EP and healthy children is suggested. The anthropometric data of the mothers showed that their body mass index (BMI) distribution was shifted to the left compared to women of the general population. This lower BMI and poor weight gain during pregnancy could contribute to the IUGR observed in normal babies whose mothers received a phenylalanine-restricted diet during pregnancy. CONCLUSION: the information and the preconception diet are effective for avoiding embryopathies in maternal phenylketonuria. Nutritional parameters can influence fetal growth and the nutritional state must be closely monitored throughout pregnancies of women with phenylketonuria.

Adolescent↗

PubMed2004

Is monoamine oxydase-B a modifying gene and phenylethylamine a harmful compound in phenylketonuria?

We report here very high urinary phenylethylamine level in a phenylketonuric newborn and variable phenylethylamine levels in phenylketonuric patients with similar phenylalanine levels. As phenylethylamine, a very toxic metabolite of phenylalanine, is rapidly degraded by monoamine oxydase type B, an enzyme that has a very low activity in neonates, these results are consistent with those of the hypothesis of MAO-B acting as a modifying gene in phenylketonuria.

Adult↗

PubMed2003

Developmental molecular switches regulating breathing patterns in CNS.

The present paper presents some of the molecular switches that may operate at early embryonic stages to make development of the brainstem respiratory rhythm generator a robust and irreversible process. We concentrate on the role of transient Hox-related gene expression patterns in register with the regionalisation of the rhombencephalic neural tube along the antero-posterior axis. Using different recording and isolation procedures in chick embryos, we show that the hindbrain is subdivided at E1 into developmental units (rhombomeres) intrinsically able to produce rhythm generating neuronal circuits active at E5. At E6, intrinsic cues also allow a progressive maturation of episodic rhythm generators that persists after isolation of the hindbrain in vitro and requires odd/even rhombomeric interactions at E1. From these results and from respiratory pathologies observed in transgenic mice, we are beginning to understand that, despite diversity of breathing patterns and adaptations, there are links between developmental control genes and adult respiration.

Animals↗

PubMed2003

Different inactivating mutations of the mineralocorticoid receptor in fourteen families affected by type I pseudohypoaldosteronism.

We have analyzed the human mineralocorticoid receptor (hMR) gene in 14 families with autosomal dominant or sporadic pseudohypoaldosteronism (PHA1), a rare form of mineralocorticoid resistance characterized by neonatal renal salt wasting and failure to thrive. Six heterozygous mutations were detected. Two frameshift mutations in exon 2 (insT1354, del8bp537) and one nonsense mutation in exon 4 (C2157A, Cys645stop) generate truncated proteins due to premature stop codons. Three missense mutations (G633R, Q776R, L979P) differently affect hMR function. The DNA binding domain mutant R633 exhibits reduced maximal transactivation, although its binding characteristics and ED(50) of transactivation are comparable with wild-type hMR. Ligand binding domain mutants R776 and P979 present reduced or absent aldosterone binding, respectively, which is associated with reduced or absent ligand-dependent transactivation capacity. Finally, P979 possesses a transdominant negative effect on wild-type hMR activity, whereas mutations G633R and Q776R probably result in haploinsufficiency in PHA1 patients. We conclude that hMR mutations are a common feature of autosomal dominant PHA1, being found in 70% of our familial cases. Their absence in some families underscores the importance of an extensive investigation of the hMR gene and the role of precise diagnostic procedures to allow for identification of other genes potentially involved in the disease.

Cohort Studies↗

PubMed2002

Brainstem dysfunction: a possible neuroembryological pathogenesis of isolated Pierre Robin sequence.

UNLABELLED: Pierre Robin sequence (posterior U-shape cleft palate, glossoptosis, retrognathia) (PRS) is a frequent and heterogeneous neonatal condition of obscure origin. We show here that orodigestive and cardiorespiratory functional disorders are very frequent in PRS and that these functional disorders, as well as anatomical and embryological data, argue for the involvement of brainstem dysfunction in the pathogenesis of some cases of isolated PRS. A total of 66 infants consecutively admitted for isolated PRS were followed-up with observations and investigations focused on their orodigestive and cardiorespiratory disorders. Neonatal clinical examination and neonatal anatomical aspects of the three orofacial features of the sequence were evaluated. Feeding difficulties and respiratory disorders were recorded and infants were classified according to three grades of severity. The relation between functional severity grade and neonatal orofacial features was evaluated, as well as the relation between functional severity grade and specific criteria characterising oesophageal and laryngeal motility and cardiac orthoparasympathetic imbalance. In the first weeks of life, sucking and swallowing disorders (100%), excessive regurgitation (94%), upper airways obstruction (50%), and cardiac vagal overactivity (59%) were noted. Correlation of anatomical features with functional severity grades was poor except for extreme forms of glossoptosis and retrognathia. Specific anomalies of oesophageal motility, pharyngolaryngeal tone and parasympathetic cardiac regulation were described. These anomalies were more frequent in children with the two higher grades of functional severity. CONCLUSION: infants with Pierre Robin sequence have early and severe anomalies of orodigestive and cardiorespiratory function which do not appear to be related solely to anatomical features and which require proper medical management. We suggest a prenatal and neonatal brainstem dysfunction as a neuroembryological hypothesis to explain the onset of some cases of Pierre Robin sequence.

Brain Diseases↗

PubMed2002

Early development of respiratory rhythm generation in mouse and chick.

We are investigating neuronal circuits resulting from conservative developmental mechanisms orchestrating the segmentation of the vertebrates hindbrain into compartments called rhombomeres (r). Segmentation transcription factors Hoxa1, Krox20 and kreisler are expressed in the future rhombomeres r4-r5, r3 and r5, r5-r6, respectively. In mice, the in vivo and in vitro analysis of neuronal groups after inactivation of these three genes revealed distinct postnatal respiratory phenotypes associated with defects of central respiratory controls resulting from deletion, neoformation or reconfiguration of modular circuits. In chick and mice, we have found neuronal rhythm generators that conform to the rhombomeric anatomical pattern as early as at the end of the segmentation. By isolating chick hindbrain segments in vitro, we have also identified rhombomeric motifs allowing the formation or deletion of a specific (GABAergic) rhythm-promoting module. Therefore, primordial rhombomeric organization of the hindbrain seems to determine a modular organization of the rhythmogenic network, thereby influencing later function of brainstem respiratory control networks.

Animals↗

PubMed2002

Analysis of the olfactory capacity of healthy children before language acquisition.

The absence of a method for evaluating the olfaction of infants and children without structured language led us to perform a longitudinal study of the behavioral responses of very young children. The aim was to establish a tool for verifying a child's olfactory ability during a pediatric examination. A total of 107 subjects were observed and filmed during a regular olfactory activity. Three years of filmed observations were analyzed and showed three types of stable behavioral responses that we consider to be specific to olfactory stimulus: modification of respiratory rhythm, fixed stare, and decrease of mobility. These responses were observed for 98% of the subjects in 100% of the first presentations of the odorized tissue. Response time was not influenced by age, socioeconomic situation, or position in the family, but it was influenced by ethnic background. These responses constitute items allowing the first step of an objective assessment of a prelanguage child's olfaction without the subject's verbal participation.

Child Language↗