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Biomedical subjects

T Billette de Villemeur

Publications and source records attributed to T Billette de Villemeur.

At least 19 recordsLinked to original sources
PubMed2004

[Management of acute visual loss in children].

Acute or rapidly progressive visual loss in children needs urgent attention and treatment. It may be unilateral orbilateral. Etiology depends upon the involved areas: eye ball, optic nerve, retro-chiasmatic pathways. Psychogenic origin is quite common in school-age children, however, it has to be considered last. Unilateral visual loss may be overlooked. Acute total transitory visual loss may be due to epilepsy or to migraine. Rapidly progressive visual loss may be due to retinal disease, optic neuritis or cortical blindness. Management of visual loss depends on clinical features, associated symptoms, and aspect of the optic disc. It needs collaboration between ophthalmologist,pediatrician and neuropediatrician. Retinal hemorrhages first call to mind a traumatic origin. Swelling of the optic disc may be due to increased intracranial pressure or due to optic neuritis. When the optic disc is normal it is necessary to rule out organic diseases before establishing the diagnosis of a psychogenic vision disturbance. In emergency, brain neuroimaging is the best way to diagnose intracranial mass and visualize optic pathways.

Acute Disease↗
PubMed2003

Perinatal-lethal Gaucher disease.

Gaucher disease is a lysosomal storage disease caused by glucocerebrosidase deficiency. Although purely visceral in most cases, some Gaucher disease patients have neurological signs. Signs of Gaucher disease appear after a symptom-free period, except in rare cases with fetal onset. The description of such cases was based mainly on single reports and siblings. We report here a series of perinatal-lethal Gaucher disease cases highlighting the specificity of this phenotype. We retrospectively studied eight original cases of proven Gaucher disease with fetal onset. Non-immune hydrops fetalis was present in all cases but one, and associated with hepatosplenomegaly, ichthyosis, arthrogryposis, and facial dysmorphy. The similarities between our cases and 33 previously described cases allow us to better delineate the perinatal-lethal Gaucher disease phenotype. Hydrops fetalis, in utero fetal death and neonatal distress are prominent features. When hydrops is absent, neurological involvement begins in the first week and leads to death within three months. Hepatosplenomegaly is a major sign, and associated with ichthyosis, arthrogryposis, and facial dysmorphy in some 35-43% of cases. Perinatal-lethal Gaucher disease is a specific entity defined by its particular course and signs that are absent in classical type 2 Gaucher disease. Our study provides clues to the diagnosis of this likely underdiagnosed condition, which must be biochemically confirmed in order to propose appropriate genetic counselling.

DNA Mutational Analysis↗
PubMed2003

[Prion diseases].

Prion is an ubiquitous membrane protein in mammals, which is mainly synthesized in central nervous system. Prion diseases are the result of an accumulation of prions having acquired a resistance to the physiological degradation and an infectious capacity. Human prion diseases are very rare diseases including sporadic Creutzfeldt-Jakob disease (the most frequent form manifesting as a presenile dementia), familial transmissible spongiform encephalopathies and two juvenile transmissible forms: iatrogenic Creutzfeldt-Jakob secondary to treatment with human extractive growth hormone and variant Creutzfeldt-Jakob disease resulting from bovine spongiform encephalopathy food transmission. Knowledge of the underlying prion biology has led to preventive measures which offer today a reasonable guarantee against the juvenile forms.

Diagnosis, Differential↗
PubMed2003

[Gaucher's disease in children: first clinical signs, natural course and benefits of enzyme replacement therapy].

OBJECTIVES: Gaucher's disease is a rare genetic disease. Paediatric patients present with highly severe disease and, until now, literature does not provide many descriptions in children only. A specific enzyme replacement therapy has been available for the last decade. Quality of life has been improved by the treatment. POPULATION AND METHODS: We studied 17 Gaucher patients (14 type 1 and 3 type 3) diagnosed before the age of 15 and treated afterwards. The first clinical signs and the course of the disease are described before and during treatment. To appreciate the impact of the treatment on quality of life, we established a clinical score with the functional symptoms of the patients. RESULTS: The mean age was 6.4 years at diagnosis and 18.3 years at the beginning of the treatment. With specific treatment, all clinical and biological symptoms dramatically improved but some specific organic damages were irreversible. CONCLUSION: The comparison of our patients with other reported paediatric cases confirm that Gaucher's disease in children is severe and has to be precociously diagnosed and treated. Clinical scores appeared to be helpful to choose the moment for treating and to follow-up the patients under treatment.

Adolescent↗
PubMed2002

[Hematologic manifestations of inborn errors of metabolism].

Haematological symptoms can be helpful for the diagnosis of metabolic diseases. A megaloblastic anemia orientates to folate and cobalamine anomalies when associated with homocystinemia and decreased plasma methionine levels, or to congenital oroticuria (hypochromia), Pearson syndrome (sideroblasts and vacuolisation of precursors) and thiamine transporter abnormality (sideroblasts) in the absence of homocystinuria. An hemolytic anemia orientates to anomalies of anaerobic glycolysis, heme synthesis, or iron metabolism, and Wilson disease. A pancytopenia orientates to organic aciduria, lysinuric protein intolerance, mevalonic aciduria and lysosomal storage diseases (Gaucher, Niemann Pick, Wolman) when hepatosplenomegaly is present. Uremic hemolytic syndrome and hemophagocytic lymphohistiocytosis respectively orientate to B12 anomalies, lysinuric protein intolerance, lysosomal storage diseases and organic aciduria.

Child↗
PubMed2001

[Study of visual field and vigabatrin treatment in children].

INTRODUCTION: Concentric visual field defects have been described in association with vigabatrin, a GABA mimetic antiepileptic agent. Few cases have been reported in children. METHODS: A systematic ophthalmological examination was performed in 14 children treated with vigabatrin for seizures. A manual kinetic perimetry test (Goldmann) was done in 11 cases. The ERG was recorded in the 3 cases where perimetry could not be done. RESULTS: All children were asymptomatic. The mean age was 9.6 years. The mean duration of vigabatrin treatment was 41 months. The visual field was abnormal when central and peripheral fields were constricted. A visual field defect was discovered in 6 cases: 4 were severe, 2 were mild. When vigabatrin treatment was stopped, 1 case became worse, 1 case was slightly better, and 1 case remained stationary. A disturbed ERG was found in 3 children (depressed b-wave, raised a/b ratio). CONCLUSION: The visual field defects discovered in children treated with vigabatrin are similar to those described in adults. The incidence and progression of visual field constriction in children with and after vigabatrin treatment are not yet well known. Children treated with vigabatrin should therefore have systematic and regular ophthalmological perimetry, and ERG examinations.

Adolescent↗
PubMed2000

[Infant diseases of neurologic origin].

Whenever abnormalities are found during the neurological examination of an infant who presented an apparent life-threatening event, traumatic or metabolic etiologies must be searched for in priority. Indeed, these etiologies require emergency diagnosis and treatment due to the major risk of recurrence, and consequent worsening of the neurological and functional prognosis or death.

Child Abuse↗
PubMed2000

[Congenital corneal anesthesia in children: diagnostic and therapeutic problems].

Congenital corneal anesthesia (CCA) is an uncommon condition difficult to diagnose. We report the case of a 9-month-old girl who presented bilateral congenital corneal anesthesia. The child had a corneal ulcer which had been unresponsive to adapted local treatment. Self-inflicted corneal injuries were present. Local treatment and arm splints led to quick healing. CCA occurs either alone or in association with neurological diseases (familial dysautonomia) or systemic congenital abnormalities (Goldenhar Gorlin syndrome). It is important to search for corneal anesthesia in children with chronic ulcerations of the cornea and self-inflicted injuries. Early diagnosis is important due to the risk for the visual prognosis. Short and longterm prevention of self-inflicted corneal injuries should be associated with a local treatment to assure rapid healing and a relapse free outcome.

Corneal Diseases↗
PubMed1999

Incubation period of Creutzfeldt-Jakob disease in human growth hormone recipients in France.

OBJECTIVE: To estimate the statistical distribution of the incubation period of Creutzfeldt-Jakob disease (CJD) in human growth hormone (hGH) recipients in France. BACKGROUND: Published papers suggest that the median incubation period of hGH-related CJD is approximately 15 years, but there are as yet no statistical data that support this assertion. METHODS: Of the 1,361 hGH recipients who were included in this study, 55 had developed CJD at the time of the study. Individual data on hGH treatment history were available. Different mathematical models were used to estimate the statistical distribution of the incubation period. One main feature of the models was to take into account the occurrence of future CJD cases. RESULTS: Models showed that the mean incubation period was 9 to 10 years, and the 95th percentile of the distribution was 15 to 16 years. Data and models indicated that the incubation period was significantly shorter in homozygotes at codon 129 of the prion protein gene than in heterozygotes. CONCLUSIONS: The short mean incubation period of CJD in French hGH recipients may be due to high infectivity in hormone lots. Estimates of the 95th percentile indicate that the number of hGH-related CJD cases may continue to increase in the coming years.

Creutzfeldt-Jakob Syndrome↗
PubMed1999

[Prion diseases in pediatrics].

Prion diseases are rare neurologic affections with a poor prognosis, occurring in both humans and animals. Creutzfeldt-Jakob disease (CJD) secondary to human extracted growth hormone treatment is the most frequent condition in pediatrics. In 1994, a new type of CJD (variant CJD) was described in young adults in the United Kingdom, only 10 years after the bovine spongiform encephalopathy epidemic, with recent works showing a direct relationship between the bovine epidemic and the human cases. An accumulation of a single protein called the prion protein (PrP) has been discovered in the brain in all of these cases, animal and human, leading to the hypothesis that a new infectious agent could proceed without any nuclear acid information; another hypothesis is that of a still unknown viral agent. The PRNP gene encoding for this PrP protein is well described: some mutations and a polymorphism in the 129th codon have been shown to be implicated in many cases of CJD. PrP is a ubiquitous protein, with yet unknown physiological function. There are still many questions to be answered: shall we expect new pediatric cases of variant CJD? Assuming that animal-human contamination is related to alimentation, are there other ways of contamination.

Adult↗
PubMed1999

[Prion diseases and blood transfusion].

Prion diseases are lethal disorders, some of which are transmissible by infectious route. Experimental data concerning neuroinvasion indicate that there is a viremia during the migration of the prion agent to the central nervous system. The possibility of accidental transmission via blood products and therefore potential transfusion risk thus arises. The analysis of experimental and epidemiological data available at present contributes to the following conclusion: the potential and theoretical risk for contamination from blood products is not null but mathematically very low, there is no indisputable experimental proof for that risk via systemic route and no case is definite and the risk is probably linked to leukocytes, and especially B lymphocytes. These conclusions are reassuring but nevertheless justify strict epidemiological survey and a reasonable discussion for each transfusion. Some groups of people have to be excluded from blood donors.

Central Nervous System Diseases↗
PubMed1998

Distribution and submicroscopic immunogold localization of cellular prion protein (PrPc) in extracerebral tissues.

In transmissible spongiform encephalopathies (TSE), such as scrapie in animals and Creutzfeldt-Jakob disease in humans, the central event is the conversion of a host-encoded amyloidogenic protein (PrPc) into an abnormal isoform (PrPsc) that accumulates as amyloid in TSE brain. PrPc is a membrane sialoglycoprotein synthesized in the central nervous system and elsewhere. We have examined the ultrastructural localization of PrPc in numerous hamster and some human extracerebral tissues, by means of a post-embedding electron-microscopic method combined with immunogold labeling. In stomach, intestine, lung, and kidney from hamsters, and in stomach, kidney, and spleen from humans, immunogold labeling specific for PrPc is observed on various cellular substructures related to secretory pathways: Golgi apparatus, secretory globules, and plasma membrane. In mucous epithelial cells of stomach and intestine, PrPc appears to be concentrated in secretory globules, suggesting a role for PrPc in the secretory function of the digestive tract. The secretory aspect of PrPc may be a key to understanding the physiopathological mechanisms underlying TSE.

Animals↗