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Biomedical subjects

Monique Elmaleh

Publications and source records attributed to Monique Elmaleh.

5 recordsLinked to original sources

Microstructural development of human brain assessed in utero by diffusion tensor imaging.

BACKGROUND: Diffusion-weighted MR imaging (DWI) has been shown to be a great tool to assess white matter development in normal infants. Comparison of cerebral diffusion properties between preterm infants and fetuses of corresponding ages should assist in determining the impact of premature ex utero life on brain maturation. OBJECTIVE: To assess in utero maturation-dependent microstructural changes of fetal cerebral white matter using diffusion tensor MR imaging. MATERIALS AND METHODS: An echoplanar sequence with diffusion gradient (b=700 s/mm(2)) applied in six non-colinear directions was performed between 31 and 37(+3) weeks of gestation in 24 fetuses without cerebral abnormality on T1- and T2-weighted images. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in the white matter. RESULTS: Mean ADC values were 1.8 microm(2)/ms in the centrum semiovale, 1.2 microm(2)/ms in the splenium of the corpus callosum and 1.1 microm(2)/ms in the pyramidal tract. The paired Wilcoxon rank test showed significant differences in ADC between these three white matter regions. Mean FA values were 1.1%, 3.8% and 4.7%, respectively, in the centrum semiovale, corpus callosum and pyramidal tract. A significant age-related decrease in ADC and an increase in FA towards term were demonstrated in the pyramidal tract and corpus callosum. CONCLUSION: Diffusion tensor imaging in utero can provide a quantitative assessment of the microstructural development of fetal white matter. Anisotropic parameters of the diffusion tensor should improve with technical advances.

Anisotropy↗

A locus for sacral/anorectal malformations maps to 6q25.3 in a 0.3 Mb interval region.

Partial absence of the sacrum is a rare congenital defect that also occurs as an autosomal-dominant trait, whereas imperforate/ectopic anus is a relatively common malformation, usually observed in multiple congenital anomalies syndromes. We report on a girl born to healthy consanguineous parents (first cousins once removed) with anal imperforation and associated rectovaginal fistula and partial sacral agenesis. Facial dysmorphism included a high forehead, epicanthic folds, downslanting palpebral fissures, hypertelorism and a depressed nasal root. Brain MRI showed a bilateral opercular dysplasia with a unilateral (right) pachygyria; MRI and X-ray imaging of the spine disclosed a tethered cord associated with partial sacral agenesis. She showed a moderate developmental delay. Ophthalmologic examination evidenced bilateral microphthalmos and relative microcornea. Cytogenetic studies in our patient disclosed a pure de novo 6q25.3 --> qter deletion. By genotype analysis, we detected in our patient a maternal allele loss encompassing D6S363 and D6S446. Pure distal 6q deletion is a rare anomaly, reported in association with sacral/anorectal malformations (sacral agenesis, anal imperforation/ectopia) and never with cortical dysplasia. Pooling deletion mapping information in patients with pure terminal and interstitial 6q deletion allowed us to define a critical region spanning 0.3 Mb between the markers D6S959 and D6S437 for sacral/anal malformations. We hypothesize that haploinsufficiency for a gene within the deleted region may impair normal development of caudal structures, possibly acting on the notochordal development. European Journal of Human Genetics (2006) 14, 971-974. doi:10.1038/sj.ejhg.5201635; published online 17 May 2006.

Abnormalities, Multiple↗

Neuropathic visceral dysmotility, brain cysts and calcifications, facial dysmorphism and developmental delay in two sibs. A new syndrome?

Syndromes with smooth muscle dysmotility are uncommon, and may be related either to smooth muscle myopathy, or to neuropathy. In most instances, neuropathic visceral dysmotility is an isolated finding leading to chronic intestinal pseudo-obstruction syndrome (CIPO). We report here on two sibs, born to consanguineous parents, with neuropathic visceral dysmotility and CNS anomalies. They share facial dysmorphia, neurogenic megacystis, intracerebral calcifications, and developmental delay. The elder one, a girl, has microcephaly and multicystic kidneys, and her brother has a more extensive neuropathic visceral disorder leading clinically to CIPO. CIPO associated with megacystis is relatively frequent but is rarely associated with mental retardation. The cases reported in the literature are different from those described here, clinically and histologically. A recessively inherited form of CIPO associated with widespread intra-cerebral calcifications, malabsorption is known as Cockel syndrome. Severity of Cockel syndrome, absence of urinary tract involvement and neuropathologic discrepancies allow distinction with the disorder reported here. In conclusion, the two siblings described here have facial dysmorphia, vesical and (in one of them) intestinal neurogenic dysmotility, intracerebral calcifications and developmental delay that could represent a specific, recessively inherited form of CIPO.

Calcinosis↗

Fetal MRI: normal gestational landmarks for cerebral biometry, gyration and myelination.

PURPOSE: Up until the last 10 years, normal cerebral gestational landmarks were assessed by ultrasonographic and fetopathologic studies. The purpose of this paper is to display the possibilities provided by fetal MRI in the evaluation of fetal cerebral biometry, normal sulcation and myelination. METHODS: Two hundred and twenty-five fetuses (with a normal brain) were studied prospectively using a standardised method. The gestational age ranged from 22 to 38 weeks. The main data concerning biometry of various cerebral structures at those terms are given. DISCUSSION: In contrast to ultrasound, MRI allows measurements of brain (and not skull), which are available independently of the position of the fetal head. The timing of the appearance of the different sulci is also available using MRI. It is considered to be a good marker of fetal brain maturation. The biochemical modifications contemporary to myelination make it possible to evaluate this phenomenon in the fetal brain using MRI.

Aging↗

Separate-lung ventilation strategy for reimplantation of esophageal bronchus.

IMPLICATIONS: We describe an original ventilation method designed to optimize lung recruitment and gas exchanges during surgery in a newborn with congenital esophageal atresia and ectopic esophageal implantation of the left mainstem bronchus. This strategy ensured constant adaptation of the mechanical ventilatory regimen to the surgical procedure-linked constraints.

Blood Gas Analysis↗