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Biomedical subjects

E Arnaud

Publications and source records attributed to E Arnaud.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Craniosynostosis and faciocraniosynostosis].

The authors present a review of the aetiopathogenesis and treatment, based on a series of 1321 craniostenoses operated by the Enfants Malades team. After briefly reviewing the embryology of craniofacial growth, the authors describe the morphological classification of craniostenoses and their morphological and functional consequences. The main neurosurgical problems related to craniofacial surgery are described. The surgical techniques currently used by the unit are described for each type of craniostenosis, according to age: H or flap transposition craniectomies for scaphocephaly, unilateral advancement of a bilateral head-band for plagiocephaly, anterior transposition for oxycephaly, and fronto-orbital adbancement for brachycephaly. The results are presented with a follow-up of several years. The principles of one-stage or two-stage surgical treatment for the main types of faciocraniostenosis are recalled: initial fronto-orbital advancement then secondary treatment of maxillary recession. The prospects of one-stage combined treatment with early maxillary distraction are proposed. Surgical indications are described. The complications, morbidity and mortality are indicated for the series. It must be remembered that craniostenosis surgery is a form of plastic surgery with neurosurgical complications. To obtain optimal results with the lowest risk, craniofacial must be performed by multidisciplinary teams in specialized centres.

Child↗
PubMed1997

[Distraction of the maxilla].

The distraction of the maxilla provides very useful possibilities in young children with unstable articulation and in infants in order to avoid excessively radical operations. The principles of the distraction are reviewed. The authors report 13 clinical cases and complications. The material needs to be perfected, as numerous incidents are still observed.

Child↗
PubMed1997

[Mental prognosis of trigonocephaly and therapeutic implications].

The authors assessed the long-term mental prognosis of trigonocephaly, in a series of 76 operated cases. Mental prognosis factors were studied, showing that early cranial release and reconstruction were effective. Final assessment of mental development was performed on children of school age, and was based on the development of behavioral disturbances, learning disability, school difficulties, and intellectual efficiency. Children were graded into 3 groups: no abnormality, mild abnormalities with normal socialization, major abnormalities; 31.6% presented disorders. Preoperative C-T scans assessed the severity of the cranial deformity and identified associated intracranial abnormalities, such as agenesis of the corpus callosum, dilatation of the subdural spaces, or hydrocephalus. Associated extracranial malformations, and associated family cases were also noted. Finally, the quality of the family context was studied. Several correlations were identified; mental development was correlated with the severity of frontal stenosis, the age at surgery and the associated extracranial malformations. Family environment also had a major influence. Intracranial abnormalities were not correlated with mental development.

Child, Preschool↗
PubMed1997

[Iatrogenic extravasations of cytotoxic or hyperosmolar aqueous solutions. Value of surgical emergency by aspiration and lavage].

Iatrogenic extravasations are characterized by their unpredictable course, the possible repercussions of functional, cosmetic and psychological sequelae, and the absence of a therapeutic consensus. The authors present the protocol used in Hôpital Saint-Louis, based on a synthesis of current procedures, consisting of emergency conservative surgical aspiration and lavage, performed in a context of close collaboration with oncolosits, intensive care physicians and radiologists. From 1994 to March 1997, fifteen patients were operated following extravasation during seven chemotherapeutic protocols, three radiographic examinations with injection of contrast agents and five resuscitation procedures. This simple protocol, applied systematically, achieved cure without cutaneous or functional sequelae in all patients. Aspiration-lavage during the first twelve hours therefore constitutes the treatment of choice of iatrogenic extravasation with cytotoxic or hyperosmolar aqueous solutions.

Aged↗
PubMed1996

[Mental prognosis of Apert syndrome].

BACKGROUND: Mental retardation, considered as common in Apert syndrome could be in part due to associated brain abnormalities. POPULATION AND METHODS: Sixty patients (32 males, 28 females) were included in the study. Patient age at the last examination was over 3 years (mean 10 years, range 3-28 years) in 38 patients. IQ was assessed from psychometric tests adapted for age. Brain anatomy was studied by MRI. Age at operation and quality of familial environment were also evaluated. RESULTS: The IQ was over 70 in 12 patients (32%), over 90 in five (13%) and the mean IQ was 62 (10-114). Thirty percent of patients had abnormalities of the corpus callosum, 43% of the cerebral ventricles and 55% of the septum pellucidum. There was no anomaly in 28% of the patients. One or more operations were performed in 53 patients, before one year of age in 37. Ten children were institutionalized or in deleterious family situation. The main factor influencing the mental prognosis was the age at operation: the final IQ was over 70 in 50% of the children operated on before one year of age versus 8% in those operated on later (P = 0.01). Only the anomalies of the septum pellucidum seemed to play a role: 50% of the patients with normal septum had an IQ > 70 compared to 18% in those with septum anomalies (P < 0.04). The quality of the familial environment also influenced the mental development: 12.5% of the patients who were institutionalized or in difficult familial situation had an IQ > 70 compared to 39% of those who live in a normal family. CONCLUSIONS: Careful investigation including MRI is necessary for detecting associated brain abnormalities. The patients must be operated on early, if possible before the age of nine months. Attention has also to be paid to quality of the sociofamilial environment.

Acrocephalosyndactylia↗
PubMed1996

[Chiari "malformation" in Crouzon syndrome].

BACKGROUND: Use of MRI makes the association Chiari malformation-cranio-facial synostosis more frequent than expected. The aim of this work was to ascertain the true incidence of Chiari malformation and to understand the reasons of the association between a bone pathology and a CNS malformation. PATIENTS AND METHODS: The anatomy of the posterior cranial fossa in Crouzon syndrome was retrospectively studied on MRI scan in 49 patients. RESULTS: A chronic tonsillar herniation, similar to a Chiari malformation, was observed in 71.4% of the cases. All the patients with Crouzon syndrome and progressive hydrocephalus had a Chiari malformation, but only 19 out of the 33 patients without associated hydrocephalus had a Chiari malformation (57.6%). Significant differences between the pattern of lambdoid suture closure were founded between both groups, with and without Chiari malformation, the lambdoid closure appearing earlier in patients with Chiari malformation. CONCLUSION: The high incidence of chronic tonsillar herniation in Crouzon syndrome seems related to the premature synostosis of the lambdoid suture.

Actuarial Analysis↗
PubMed1996

[Mental prognosis in scaphocephaly].

BACKGROUND: The mental prognosis of scaphocephaly remains a controversial issue, and surgery is performed for functional or aesthetical reasons without clear evidence in the literature of which is the most important. PATIENTS AND METHODS: Three hundred and ninety six children with scaphocephaly were prospectively studied to analyse the correlation between age, intracranial pressure (ICP) and mental outcome. Before any treatment, the intracranial pressure was recorded (systematically during the first period of the study); the mental level was evaluated at first consultation and after a mean five-year follow-up. The mental evolution was compared whether the child was operated or not. RESULTS: The mental outcome of the patients was good in most of the cases whether or not they had been operated. There were significantly more normal patients in the scaphocephalies seen before one year of age at first consultation (P < 0.001) than in those seen after one year of age. There were significantly more abnormally high intracranial pressure cases in the group of patients who were seen later than one year of age (P = 0.0015). There were more retarded patients in the group with increased ICP, but the difference was not significant (P = 0.17). There was no correlations between ICP and final IQ neither in operated nor in non-operated patients. Conversely, a correlation was found between the early and late psychometric assessments in all patients. CONCLUSIONS: The main predictive factor of mental outcome appears to be the initial developmental level. Since the mental level was worse in the older children, and since the surgery does not influence the functional outcome when the initial mental level is low, we can conclude that the indication to perform surgery in scaphocephaly is sometimes not only a cosmetic problem.

Child Development↗
PubMed1996

Prognosis for mental function in Apert's syndrome.

The factors involved in the mental development of patients with Apert's syndrome were studied by the authors, focusing on the age of the patient at operation, associated brain malformations, and the quality of the family environment. Overall, 32% of patients with significant follow-up review had an intelligence quotient (IQ) greater than 70. Age at operation appeared to be the main factor associated with changes in mental development: final IQ was greater than 70 in 50% of patients operated on before 1 year of age versus only 7.1% in patients operated on later in life (p = 0.01). Malformations of the corpus callosum and size of the ventricles played no role in the final IQ, whereas anomalies of the septum pellucidum had a significant effect, with the proportion of patients with an IQ over 70 increasing more than twofold in patients with a normal septum compared with patients with septal anomalies (p < 0.04). Quality of the family environment was the third factor involved in intellectual achievement: only 12.5% of institutionalized children reached a normal IQ level compared to 39.3% of children from a normal family background.

Acrocephalosyndactylia↗
PubMed1995

Inhibition of fibroblast growth factor 2 expression by antisense RNA induced a loss of the transformed phenotype in a human hepatoma cell line.

Fibroblast growth factor 2 (FGF-2 or basic FGF) is associated with the cell-transformed phenotype. To clarify the function of FGF-2 in the malignancy of tumor cells, we designed experiments to express antisense RNA in a hepatoma cell line. Using FGF-2 mRNA, alternative initiations of translation at one AUG and three CUG start codons led to the synthesis of four isoforms. SK-Hep1 cells, which naturally produce the four FGF-2 proteins, were stably transfected with expression vectors that generate antisense RNAs targeted against different sites of human FGF-2 mRNA. A variable decrease of all of the isoforms of FGF-2 synthesis was observed compared with the control: the strongest inhibition was obtained with the smaller antisense targeted against AUG codon. Our results clearly demonstrated that inhibition of FGF-2 expression led to a loss of anchorage independence in soft agar. This effect was not reversed by adding exogenous FGF-2, indicating that an intracrine process of FGF-2 probably is involved in the phenotypic changes of SK-Hep1 cells. Furthermore, the inhibition of FGF-2 synthesis was correlated with a loss of tumorigenicity in nude mice. These results clearly argue for a key role of endogenous FGF-2 in transformation and tumorigenesis of the hepatoma cell line used in this study.

Animals↗
PubMed1995

Human thrombin variable region 1, including E39, is involved in interactions with alpha 1-antitrypsin M358R and protein C.

We used an antithrombin autoantibody (IgG D), the epitope of which encompasses ABE1 and amino acids located within variable region 1, to study thrombin interactions with R358 alpha 1-AT and protein C. IgG D inhibited the thrombin interaction with R358 alpha 1-AT, while hirugen had no effect, indicating that the interaction of R358 alpha 1-AT with thrombin may involve the VR1 subsite. We also obtained evidence that VR1 may be involved in the activation of protein C by thrombin in the absence of thrombomodulin. Moreover, IgG D attenuated the inhibitory effect of calcium ions during protein C activation by thrombin, probably by masking E39 within the VR1 site.

Amino Acid Sequence↗
PubMed1995

Prognosis for mental function in scaphocephaly.

Three hundred ninety-six children with scaphocephalies were prospectively studied to analyze the correlation between age, intracranial pressure (ICP), and mental function outcome. The ICP measurements and the early and late psychometric assessments were compared. The influence of surgery, when performed, was analyzed. In most cases, the mental function outcome of the patients was good whether or not they had undergone surgery. The mental level and the frequency of increased ICP both correlated with patient age. A correlation was found between the early and late psychometric assessments in all patients. Thus, the main predictive factor of mental function outcome appears to be the initial developmental level.

Brain↗
PubMed1995

Chronic tonsillar herniation in Crouzon's and Apert's syndromes: the role of premature synostosis of the lambdoid suture.

The incidence of chronic tonsillar herniation (CTH) was evaluated with magnetic resonance imaging in 44 patients with Crouzon's syndrome and 51 with Apert's syndrome; the incidence was 72.7% in Crouzon's syndrome and 1.9% in Apert's syndrome. All the patients with Crouzon's syndrome and progressive hydrocephalus had CTH, but of 32 individuals with Crouzon's syndrome and CTH, only 15 had progressive hydrocephalus. Five patients with Apert's syndrome were treated for progressive hydrocephalus; none had CTH. The patterns of suture closure in these two groups of patients were studied, and significant differences in coronal, sagittal, and lambdoid sutures were found between patients with Crouzon's and Apert's syndromes. In Crouzon's syndrome, significant differences in the pattern of lambdoid suture closure were found between the groups with and without CTH; in the group with CTH, the lambdoid closure appeared earlier. The authors propose that the high incidence of individuals with CTH who have Crouzon's syndrome is related to the premature synostosis of the lambdoid suture in the first 24 months of age.

Acrocephalosyndactylia↗
PubMed1995

Evaluation of the effect of early mobilization of the supraorbital bar on the frontal sinus and frontal growth.

Consequences of early frontocranial remodeling are controversial. It has been said that secondary operations are more difficult and that the frontal sinus does not develop well, with an adverse effect on forehead aesthetics. Some illustrative cases are presented, among 820 operated craniosynostoses, to demonstrate that (1) an early, well-performed frontal advancement and/or remodeling is followed by satisfactory reossification and permits easy secondary surgery, (2) frontal sinus development, which is always impaired in anterior craniosynostosis, is only moderately diminished by early supraorbital bar remodeling (when the frontal bar is repositioned after remodeling, as with trigonocephaly, the frontal sinus develops in 83 percent of cases, whereas when the advancement is significant, as with brachycephaly, the development of the frontal sinus is observed in only 50 percent of the cases), and (3) forehead aesthetics are not linked closely to the development of the frontal sinus. After a significant advancement, even if the sinus does not develop, the frontal bar projection can remain satisfactory.

Child↗
PubMed1994

An autoantibody directed against human thrombin anion-binding exosite in a patient with arterial thrombosis: effects on platelets, endothelial cells, and protein C activation.

An autoantibody, developed by a patient with severe and recurrent arterial thrombosis, was characterized to be directed against the anion-binding exosite of thrombin, and inhibited all thrombin interactions requiring this secondary binding site without interfering with the catalytic site. The effect of the antibody was studied on thrombin interactions with platelets and endothelial cells from human umbilical veins (HUVEC). The autoantibody specifically and concentration-dependently inhibited alpha-thrombin-induced platelet activation and prostacyclin (PGI2) synthesis from HUVEC. It had no effect when gamma-thrombin or the thrombin receptor activation peptide SFLLR were the inducers. The effect of the antibody on protein C activation has been studied. The antibody blocked the thrombin-thrombomodulin activation of protein C. The inhibition of the activation was maximal with a low concentration of thrombomodulin. The fact that the autoantibody inhibited concentration-dependent alpha-thrombin-induced platelet and endothelial cell functions emphasizes the crucial role of the anion-binding exosite of thrombin to activate its receptor. In regard to the pathology, the antibody inhibited two vascular processes implicated in thrombin-antithrombotic functions, PGI2 secretion, and protein C activation, which could be implicated in this arterial thrombotic disease.

Anions↗
PubMed1994

Potentiation of transforming growth factor (TGF-beta 1) by natural coral and fibrin in a rabbit cranioplasty model.

The association of a biodegradable material and a growth factor could be of clinical value for treating bone defects. We therefore tested the association of transforming growth factor beta (TGF-beta 1) in fibrin glue and coral granules to heal skull defects in rabbits. Adult rabbits underwent a double trepanation symmetrically in both parietal bones. Using histomorphometry, we compared bone repair after 1 month in control animals (n = 5) and in animals treated with either TGF-beta 1 as a single injection of 1 microgram in methylcellulose (n = 5) or in fibrin glue (n = 5), or with coral granules in fibrin glue (n = 4) or with coral granules and TGF-beta 1 1 microgram in fibrin glue (n = 5). We measured the diameter of the remaining defect and the surface of the bone growth. TGF-beta 1 without coral in either methyl cellulose or fibrin induced a partial closure of the defect as assessed by a significant decrease in the defect diameter, compared with the control group. However, the association of TGF-beta 1 in fibrin and coral induced an area of the bone growth higher than in any other groups (P < 0.05). Two months after surgery, this triple association induced a better healing of the defect than coral alone or control group. In each group treated with TGF-beta 1, the mineralization rate was increased not only at the treated side but also in the contralateral defect which was untreated, suggesting a diffusion of the growth factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Involvement of basic fibroblast growth factor NH2 terminus in nuclear accumulation.

The human basic Fibroblast Growth Factor (bFGF) gene was shown to encode four polypeptides by an alternative use of initiation codons (three CUG and one AUG). In this report, we present a comparative study of the fate and intracellular localization of individual bFGF isoforms. For this purpose, we have produced the various bFGF isoforms in E. coli and purified them to homogeneity: the 210 amino acid form initiated at CUG1 that contains a nuclear localization sequence (NLS), the 155 amino acid form (AUG-mediated initiation) and the 146 amino acid form (processed form extracted from tissues). While the different bFGFs were taken up by the cell with equal efficiency, more of the 210 amino acid form accumulated in the nucleus and represented 36% of the internalized bFGF compared with 15% in the others. A chimeric protein containing the minimal SV40 Large T NLS (SV40NLS) fused to the 155 amino acid bFGF form (SVbFGF) behaves like the native 155 amino acid form, indicating that nuclear accumulation of exogenous bFGF is not mediated by the NLS-associated function. These results suggest that the amino-terminal part of the 210 amino acid bFGF contains a sequence responsible for its nuclear retention. Bioactivities of the different forms were tested on adult bovine aortic endothelial (ABAE) cells. The bFGF degradation pathways, mitogenic activity and stimulation of rRNA synthesis appeared to be the same for all bFGFs but the stimulation of plasminogen activator was enhanced by the 210 amino acid form and correlated with nuclear accumulation.

Animals↗
PubMed1994

[Osteogenesis induced by the combination of growth factor, fibrin glue and coral; towards a substitute of autologous bone graft. An experimental study on the rabbit].

A triple mixture of TGF-beta, fibrin glue and natural coral skeleton granules (madreporic calcium carbonate) was tested in a rabbit bilateral cranioplasty model. Three-dimensional CT scan and histomorphometry demonstrated that, at one month and at two months, this association produced significantly more bone tissue than other associations, especially growth factor or coral alone. The rate of mineralization was significantly increased bilaterally in all animals having received TGF-beta. Coral resorption was also accelerated by growth factor and was replaced by histologically normal bone after two months. We emphasize the potentiation of TGF-beta by fibrin glue and natural coral skeleton and its potential application as a bone substitute.

Animals↗