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P Parent

Publications and source records attributed to P Parent.

At least 37 records · Page 2Linked to original sources
PubMed1993

Isolation and characterization of histogranin, a natural peptide with NMDA receptor antagonist activity.

Histogranin, was co-purified with bombesin-like immunoreactive peptides from bovine adrenal medulla. Its structure, H-Met-Asn-Tyr-Ala-Leu-Lys-Gly-Gln-Gly-Arg-Thr-Leu-Tyr-Gly-Phe-COOH, was determined by gas-phase Edman degradation. It was in accordance with its amino acid composition and corresponded to a 15 amino acid fragment (fragment 86-100) of histone H4 with substitutions in positions 1 (Val), 2 (Val) and 7 (Arg). The peptide was synthesized by the solid-phase procedure and the synthetic product was identical to the natural peptide as determined by its retention time on three analytical high-performance liquid chromatography systems. An antibody was raised against synthetic [Ser1]histogranin and used to monitor the presence of histogranin in various rat tissues and subcellular fractions of bovine adrenal medulla. In rats, immunoreactive histogranin was mainly concentrated in the pituitary (5065 pmol/g) and the adrenal glands (268 pmol/g), but it was also present in other tissues including the brain (1.6 pmol/g) and blood plasma (24 fmol/ml). A neuropeptide function for the adrenal peptide was suggested by its relative high concentration in chromaffin granules (42 fmol/mg protein as compared with 1 fmol/mg protein in cytosol) and its release from perfused bovine adrenal glands. In rat brain membrane preparations, synthetic histogranin displaced the binding of [3H]CGP 39653, a specific ligand of N-methyl-D-aspartate (NMDA) receptor. The displacement curve was biphasic with IC50 of 0.6 and 3955 nM, representing 33% and 67% of the binding sites, respectively. Intracerebroventricular (i.c.v.) injection of the peptide (5-100 nmol) in mice produced a dose-dependent protection against NMDA (0.5-1.0 nmol) -induced convulsions but not against (R,S)-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA, 0.25-2.0 nmol), kainate (0.25-0.75 nmol) and bicuculline (1-10 nmol)-induced convulsions. These results suggest that histogranin may be an endogenous modulator of NMDA receptor functions.

2-Amino-5-phosphonovalerate↗
PubMed1993

[Osteogenesis imperfecta. Reflections after the prenatal diagnosis of 2 cases].

The authors report two cases of prenatal diagnosis of osteogenesis imperfecta (OI) of type II according to the classification of Sillence. When dwarfism had been discovered with deformities, fractures and low bone density, the diagnosis was made in one case at 24 and the second at 20 weeks of amenorrhoea. A recent review of the literature shows that the ideas concerning OI have changed markedly recently. All agree that within the framework of classification of diseases that there is a single entity. A dominant autosome genetic transmission is increasingly considered to be the cause for all forms of the condition. The physiopathology of collagen makes it easier to understand why these should be clinical forms. The ability to localise deleterious genes by using molecular biology makes it likely a very early antenatal diagnosis will be possible. All the same, this optimism has to be tempered with the frequent discovery in this illness of mosaicism which still leaves a large place for ultrasound.

Abortion, Therapeutic↗
PubMed1992

DNA polymorphism analysis in families with recurrence of free trisomy 21.

We used DNA polymorphic markers on the long arm of human chromosome 21 in order to determine the parental and meiotic origin of the extra chromosome 21 in families with recurrent free trisomy 21. A total of 22 families were studied, 13 in which the individuals with trisomy 21 were siblings (category 1), four families in which the individuals with trisomy 21 were second-degree relatives (category 2), and five families in which the individuals with trisomy 21 were third-degree relatives, that is, their parents were siblings (category 3). In five category 1 families, parental mosaicism was detected, while in the remaining eight families, the origin of nondisjunction was maternal. In two of the four families of category 2 the nondisjunctions originated in individuals who were related. In only one of five category 3 families, the nondisjunctions originated in related individuals. These results suggest that parental mosaicism is an important etiologic factor in recurrent free trisomy 21 (5 of 22 families) and that chance alone can explain the recurrent trisomy 21 in many of the remaining families (14 of 22 families). However, in a small number of families (3 of 22), a familial predisposing factor or undetected mosaicism cannot be excluded.

Chromosomes, Human, Pair 21↗
PubMed1990

Prenatal diagnosis of del(15)(q11q13).

A case of del(15)(q11q13) was detected in amniotic fluid cell cultures and confirmed by cordocentesis in a 27-year-old woman with a low maternal serum alpha-fetoprotein level. The fetus was shown to have a short femoral length on ultrasonography. This structural chromosome abnormality associated with the prenatal ultrasonographic findings and the morphological characteristics visualized after termination of pregnancy strongly suggest Prader-Willi syndrome.

Adult↗
PubMed1989

"Isolated" hydrocephalus in families of spina bifida and anencephaly: a coincidence?.

Hydrocephalus is a frequent complication of spina bifida. We wanted to find out if the risk of isolated hydrocephalus was greater in families with NTD (anencephaly and spina bifida) from 424 families studied between 1975 and 1984 in Brittany. The risk of recurrence of NTD is 1.8% in these families, the risk of hydrocephalus 0.3% which represents a risk three times greater than that of the population at large. This risk seems all the higher if the proband is a spina bifida of the male sex. However, no X-linked heredity can be reasonably assumed in these cases. We conclude that these families present a higher multifactorial risk of having another malformed child.

Anencephaly↗
PubMed1989

[Mucoviscidosis: current diagnostic possibilities. Applications in perinatology].

The gene of cystic fibrosis is localised on the long arm of chromosome 7. DNA probes placed close to the gene enable a study of restriction polymorphism to follow the transmission of the gene in index families. It is now possible to counsel those families, who already have an affected child, with an early antenatal diagnosis at ten weeks after the last period. In our personal experience, based on a study of the genotype of 48 families, 70% were informative when they were studied by two probes corresponding to the local pJ3.11 and met. When the latter probes Km19-XV2c were studied concurrently useful information was achieved in 96%. DNA analysis non enables the detection of the chromosome carrying the deleterious gene in practically every family where there is a child suffering from the disease.

Chromosomes, Human, Pair 7↗
PubMed1989

[Linkage disequilibrium and DNA markers associated with the gene for cystic fibrosis].

R.F.L.P. (Restriction Fragment Length Polymorphism) observed with tightly linked probes to the CF gene allows us to calculate the standardised linkage disequilibrium between CF and these markers. This approach in combination with others strategies permits to situate the gene between D9 and G2. The conditional probabilities observed with these haplotypes modify the classical genetic of CF.

Cystic Fibrosis↗
PubMed1989

[Analysis of 112 haplotypes carrying the cystic fibrosis gene. Applications in genetic counseling].

Cystic fibrosis (CF) is always a common lethal genetic disease. The locus is localized to human chromosome 7q22-7q31. Genetic linkage between the CF locus and polymorphic DNA marker is used to realize family studies. We have genotyped 56 families (352 patients) with a CF child. The informativeness with the six markers (Met D/Taq I, Met H/Taq I, Met H/Msp 1, XV2c/Taq 1, km19/pst pJ 3.11/Msp 1) is important (96%). The linkage desequilibrium between alleles detected by XV2 c and Km 19 described by Estivill and al, is also showed in our population. The haplotype B (Km 19 = 6.6 kb, XV2 c = 2.1 kb) is present on 84% of our 112 CF chromosomes. We have established the frequencies of the 10 possible genotypes in the pool of the 112 CF chromosomes and in the pool of the normal chromosome and according to Bayes obtained the predictive positive value to be heterozygote. It is possible to precise the genetic counselling in these families.

Cystic Fibrosis↗
PubMed1988

[Approaching the gene of mucoviscidosis. New data].

We used 5 polymorphic probes strongly linked to the gene of cystic fibrosis (CF) to perform the genotypical study of 48 families with at least one child presenting with the disease. The last Km19 and XV2c probes showed a very important linkage imbalance with the CF gene (allele 2 = 6.6 kb of Km19/Pstl, chi 2 = 56; allele 1 = 2.1 kb of XV2c/Taql, chi 2 = 21). These two markers define a B haplotype which confers a relative risk of 55 to be gene carrier. From these data, the predictive value for an individual presenting with this haplotype to be heterozygous was computed to be 1/5. Presently, the risk of 1/20 for a randomized subject to be gene-carrier should be reexamined after study of this genotype. These results are very important practically, as they modify the classical data of genetic counselling concerning cystic fibrosis for the couples with a risk higher than 1/4.

Alleles↗
PubMed1988

[Chondrodysplasia punctata. Report of four cases in two sibships].

Chondrodysplasia punctata has very diverse clinical and radiological features. Its diagnosis may be suggested as early as in the neonatal period in front of an abnormal facial appearance, sometimes associated with bone and vertebrae defects. Radiological exams will assert it. Its subsequent course depends on the accompanying visceral abnormalities. Genetics advice is closely related to these. Ultrasonography is the only actual possibility of prenatal diagnosis. However our attitude must be guided by the clinical course (of the disease) of the initial case in the sibship.

Chondrodysplasia Punctata↗
PubMed1988

[Prenatal diagnosis of mucoviscidosis. Contribution of DNA analysis of trophoblast biopsies].

The gene for cystic fibrosis has been localised on the long arm of chromosome 7. Genetic engineering techniques now make it possible to inform educated families that it is possible to make an early antenatal diagnosis on chorionic villus sampling at the tenth week of pregnancy. We report our experience on ten antenatal diagnosis that were made. Furthermore, we were able to study 48 families with a live child who had the disease, and were able to change the probability of another child being born with the gene. This approach makes it possible for us to change the risk for a couple of giving birth to an affected child. It is also possible to extend the indications for trophoblast analysis to parallel cases where the risk is less than 1 in 4.

Chorionic Villi Sampling↗
PubMed1988

[Molecular biology and mucoviscidosis. Brest experience in 1987].

The gene for cystic fibrosis is located on the long arm of chromosome 7 at 7q31. The close linkage between the disease locus and several DNA markers allowed a study of the DNA restriction polymorphism pattern in 30 Breton families. The frequency of the haplotypes indicated by the probes pJ 3.11, met H and met D was established reaching a 66.6% informativity for the families studies. The complete informativity of a family allows for detection of heterozygous brothers and sisters, uncles and aunts and for antenatal screening on trophoblast biopsies in case of further pregnancies.

Child↗
PubMed1987

[Keratosis follicularis decalvans: nosological discussion of Siemens' disease. Apropos of 3 cases].

We describe 3 cases of keratosis follicularis decalvans (Siemens' disease): a 15 year old boy and a 7 year old boy and his father. They represent 2 different patterns of the disease with different clinical courses and genetic background: an autosomal dominant type of good prognosis with elevated argininemia and absence of follicular atrophy in both father and son, a sporadic type, clinically severe, with follicular atrophy. This raises the question of the nosology of the so-called Siemens' disease, since it includes actually different diseases of variable prognosis.

Adolescent↗