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Biomedical subjects

J Motte

Publications and source records attributed to J Motte.

At least 55 records · Page 3Linked to original sources
PubMed1994

Genetic and antigenic variability of HIV type 1 in Brazil.

Six Brazilian strains of human immunodeficiency virus type 1 (HIV-1) were isolated from infected individuals residing in different regions of Brazil between 1987 and 1989. Phylogenetic analysis based on an 860-base pair env fragment, including V3, V4, V5, and the beginning of gp41, classified the Brazilian strains significantly in genotype B, with interhost distances between 5.9 and 13.1% (mean value, 10%). Amino acid sequence analysis of the V3 loop revealed that three strains contained the North American/European GPGR motif as the tip of the loop whereas in the other three strains proline (P) was substituted by tryptophan (W), methionine (M), or phenylalanine (F). A consensus peptide, Bra-cons, was designed containing GWGR as the tip of the loop. Serological reactivity to the Bra-cons peptide and other V3 peptides (MN, SF2, HBX2, RF, MAL, ELI, Z6, and a Côte d'Ivoire peptide, CI-cons) was compared for 114 HIV-1-positive sera from Rio de Janeiro. Sixty-nine sera (60.5%) reacted with peptides belonging to genotype B, of which 10 sera also reacted with peptides belonging to genotype A (n = 7) and D (n = 3). Eighteen sera (15.8%) had binding antibodies to the Bra-cons peptide. A high number of sera (n = 43; 37.7%) had no antibodies to any of the V3 peptides tested. This result suggests that HIV-1 variants with aberrant V3 loops may circulate in Rio de Janeiro.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Base Sequence↗
PubMed1994

Genotypic subtypes of HIV-1 in Cameroon.

OBJECTIVE: The only two HIV-1 strains (ANT70 and MVP5180) reported to date from Cameroon are members of the outlier clade (group O). In this study, we assessed the prevalence of group O viruses and other HIV-1 subtypes in Cameroon. DESIGN: A phylogenetic analysis of 18 HIV-1 strains isolated from seropositive individuals from Yaoundé and Douala, Cameroon. METHODS: A 900 base-pair fragment of the env gene coding for V3, V4, V5, and the beginning of gp41 of 17 out of 18 HIV-1 isolates from Cameroon was amplified, cloned and sequenced using polymerase chain reaction. A phylogenetic tree was constructed. RESULTS: The overall env nucleotide sequence divergence among the Cameroon isolates ranged from 6.1 to 27.5%. In a phylogenetic tree, six subtypes were identified when compared with 23 reference strains of different geographic origin. Of these 17 Cameroonian strains, 11 (61%) were of subtype A of which the interpatient distances at the sequence level varied from 6.1% to 18.3% (average, 11.9%). Three (17%) strains were of subtype F, and the other three strains (6% each) belonged to subtypes B, E and H, respectively. The remaining isolate was classified as belonging to group O, on the basis of the sequence of part of the pol gene. A very broad spectrum of different tetrameric amino-acid sequences was observed at the apex of the V3 loop. Eleven strains contained the tetrameric globally predominant GPGQ sequence at the tip of the V3 motif. Two strains had the GPGR sequence typical of the American and European HIV-1 strains. The remaining tetrameric sequences included GPGS, GSGQ, GRGQ, and GLGR. CONCLUSION: These findings on a limited number of viruses suggest extensive env gene diversity of HIV-1 strains from Cameroon, and could have implications for vaccine development in Africa.

Amino Acid Sequence↗
PubMed1994

Subcortical laminar heterotopia and lissencephaly in two families: a single X linked dominant gene.

Neuronal migration disorders can now be recognised by MRI. This paper reports two families in which the mothers had subcortical laminar heterotopia and four of their children had either similar heterotopia (two girls) or severe pachygyria or lissencephaly (two boys). Laminar heterotopia was more evident on MRI T2 weighted images. The patients had mild to severe epilepsy and mental retardation depending on the extent of cortical abnormalities. In these families, subcortical laminar heterotopia, pachygyria, and lissencephaly seem to share the same X linked or autosomal dominant gene. No chromosomal abnormalities, especially of chromosome 17, could be identified. For appropriate genetic counselling of the family of a child with lissencephaly or subcortical laminar heterotopia, MRI should be performed in parents or siblings with mental retardation or epilepsy.

Adolescent↗
PubMed1993

Collaborative study of the molecular epidemiology of Tay-Sachs disease in Europe.

Tay-Sachs disease is a lipidosis due to the deficiency of the lysosomal hexosaminidase A. In order to understand the molecular mechanisms of this enzyme deficiency we studied 42 patients of different ethnic origins diagnosed in Europe. The strategy used consists in HEXA cDNA amplification followed by allele-specific oligonucleotide analysis for the frequent mutations, and by chemical cleavage mismatch and denaturing gradient gel electrophoresis for the detection of new mutations. 90% of alleles were clarified in this way, showing a high heterogeneity of HEXA lesions in Tay-Sachs disease. 28 different mutations were found, 20 being identified for the first time in this group of patients.

Adult↗
PubMed1990

Double-blind, randomized trial of diazepam versus placebo for prevention of recurrence of febrile seizures.

The aim of this study was to evaluate the efficacy and tolerance of intermittent oral administration of diazepam during hyperthermia for reducing the recurrence of febrile seizure: 185 children, between 8 months and 3 years of age, with a first febrile seizure and normal neurologic development, were randomly assigned in a double-blind fashion to receive orally administered diazepam (0.5 mg/kg, then 0.20 mg/kg, every 12 hours) or placebo, whenever the rectal temperature was more than 38 degrees C. The main criterion of efficacy was the seizure recurrence rate 1 year after the first seizure. The duration of the study was 3 years; eight different centers in France participated. There were 462 febrile episodes and 1000 days with prophylactic treatment. The recurrence rates did not differ between the diazepam group (16%) and the placebo (19.5%) group. The children with recurrent seizures were significantly younger at the time of the first seizure (17 +/- 6.9 months) than children without a recurrent seizure (21 +/- 8.5 months). In children with recurrent seizures, prophylactic treatment was correctly administered to only 1 of 15 children in the diazepam group and to 7 of 18 children in the placebo group. The following were the reasons for this poor cooperation: convulsion being the first manifestation of the fever (seven cases in each group), parents neglecting to give treatment (nine cases), and refusal to take treatment by two children. Side effects were similar in the two groups except for hyperactivity, which was more frequent in the diazepam (138 days) than in the placebo (34 days) group. Intermittent oral administration of diazepam at the onset of fever offered no advantage over placebo in preventing recurrence of seizure. This finding probably reflects a lack of efficacy of the intermittent method rather than of diazepam itself.

Administration, Oral↗
PubMed1989

Age-related changes in the density and morphology of plaques and neurofibrillary tangles in Down syndrome brain.

Fifteen cases of Down syndrome between age 25-59 years were examined neuropathologically. A variety of histological methods were used to identify plaques and neurofibrillary tangles (NFT). All cases had some plaques or NFT, but their density was generally not high before the age of 40 years. Plaques and NFT tended to appear at about the same time although in somewhat different cortical areas. Changes appeared first in the dentate gyrus, subiculum, entorhinal and association neocortex. The stages in the evolution of plaque morphology were quantitated in the dentate gyrus. The earliest change was the extracellular accumulation of fibrillar material with the histological characteristics of amyloid. In the second stage there was an exuberant neuritic reaction with swollen processes that contained little or no paired helical filaments (PHF). Stage 1 and 2 plaques were seen predominantly between ages 25-38 years, and were not obviously associated with blood vessels or glial cells. In the third stage of plaque formation neurites appeared to degenerate, contained more PHF, and surrounded a compact core of amyloid. Stage 3 plaques were never very numerous, and were seen only between ages 48-55 years. Stage 4 plaques consisted of a cloud of silver-positive debris. They appeared to be the final stage and were the predominant morphological type in the dentate gyrus after age 48 years. Amyloid angiopathy was present only after age 48, and was a prominent finding in only three cases.

Adult↗
PubMed1989

Encephalopathy with calcifications of the basal ganglia in children. A reappraisal of Fahr's syndrome with respect to 14 new cases.

Calcifications of the basal ganglia are described under the heading of "Fahr's syndrome". The clinical pattern is variable and the syndrome may be sporadic or familial. This study describes a personal series of 14 cases of encephalopathy with calcification of the basal ganglia and reviews the literature cases. A four-group classification is proposed. The first group includes encephalopathy, microcephaly, dwarfism, retinal degeneration or optic atrophy, symmetrical patchy demyelination with calcifications and probable autosomal recessive inheritance. Some cases have an early onset, a rapid evolution. Others have a later onset, longer course and retinal degeneration. In the second group, the children suffer from a congenital encephalopathy or a cerebral palsy without clear deterioration, without short stature, ocular impairment or persistent CSF abnormalities. This group has not been reported in the literature. The cases do not seem to be genetic. The precise cause in unknown but a sporadic non progressive anoxo-ischemic, or viral prenatal disease is suggested. In the third group, the association of encephalopathy, microcephaly, and persistent CSF lymphocytosis, has a high recurrence rate. The pathogenesis is still a matter of dispute. The fourth group is characterized by autosomal dominant calcifications of the basal ganglia with or without neurological abnormalities. Finally calcium metabolism disorders and mitochondrial encephalomyopathy may be associated with calcifications of the basal ganglia.

Basal Ganglia Diseases↗
PubMed1987

Sonographic diagnosis of lissencephaly.

Lissencephaly, a developmental malformation characterized by absence of sulci, may be suggested in dysmorphic or epileptic infants. Real time ultrasonographic findings correlated with typical electroencephalographic abnormalities establish the diagnosis.

Brain↗
PubMed1987

[Cerebellar ataxia preceding cutaneous symptoms in chickenpox].

The authors describe a case of cerebellar ataxia developing 8 days before the exanthema of varicella. Evolution was quickly favorable. On the occasion of this rare observation, the pathophysiology of the neurological complications of varicella are discussed.

Cerebellar Ataxia↗
PubMed1987

[Unilateral non-tumor hydrocephalus in children. Atresia of the foramen of Monro?].

The authors report 5 cases of an uncommon unilateral hydrocephalus due to non neoplastic obstruction of the foramen of Monro. Clinically, it is an early hydrocephalus, and usual absence of neurological deficit contrasts with large unilateral ventricular dilatation. CT Scan made diagnosis easier, confirming non neoplastic etiology. The authors compare their own 5 cases with 14 cases alike in the literature and emphasize the usual post shunting good prognosis of these hydrocephalus. Etiology remains uncertain.

Cerebral Ventricles↗
PubMed1986

[Benign epileptic infantile spasms].

Among 100 infants with infantile spasms studied before treatment, 14 had idiopathic spasms with a favourable outcome. They had a normal development, including reaching for objects before the age of 5 months and moderate regression without loss of eye following. Although it was hysarhythmic, the EEG tracing showed identifiable basic activity and sleep spindles; there was no slow waves focus even after diazepam administration and the spasms were "independent" even during a cluster. This type of infantile spasms seems to be a particular type of non-lesional epilepsy. It contrasts with idiopathic spasms of unfavourable outcome that apparently result from a preexisting and overlooked focal lesion responsible of later cognitive troubles.

Child, Preschool↗