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C De Boeck

Publications and source records attributed to C De Boeck.

9 recordsLinked to original sources
PubMed1994

CFTR haplotype backgrounds on normal and mutant CFTR genes.

Ten polymorphic loci, located in a 1 Mb interval across the cystic fibrosis locus, were analyzed on normal and mutant CFTR genes. A different distribution of haplotype backgrounds among normal and mutant CFTR genes was observed. With exception of the D7S8 locus, the three most common mutations, delta F508, G542X and N1303K, were found on an identical haplotype background. In agreement with the observed linkage equilibrium between the Q1463Q and D7S8 loci, both alleles at the D7S8 locus were found on delta F508 CFTR genes. However, the G542X and N1303K mutations, which have been estimated to be at least 35000 years old, were found to be associated with a single allele at the D7S8 locus. Absence of recombination between the D7S8 and Q1463Q loci was also observed on normal CFTR genes with this haplotype background. At the Tn locus in intron 8, allele 9 known to result in very efficient splicing was associated with the most frequent mutations. At the M470V locus, located in a conserved region of the first nucleotide binding fold, the amino acid methionine was found to be associated with the frequent mutations, in particular with mutations located in one of the two nucleotide binding folds which are generally known as severe mutations with regard to exocrine pancreatic function. On mutant CFTR gene, this locus was in complete association with the centromeric D9 locus, in the absence of a complete association with the intervening loci.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1993

Detection of 98.5% of the mutations in 200 Belgian cystic fibrosis alleles by reverse dot-blot and sequencing of the complete coding region and exon/intron junctions of the CFTR gene.

We have previously shown that about 85% of the mutations in 194 Belgian cystic fibrosis alleles could be detected by a reverse dot-blot assay. In the present study, 50 Belgian chromosomes were analyzed for mutations in the cystic fibrosis transmembrane conductance regulator gene by means of direct solid phase automatic sequencing of PCR products of individual exons. Twenty-six disease mutations and 14 polymorphisms were found. Twelve of these mutations and 3 polymorphisms were not described before. With the exception of one mutant allele carrying two mutations, these mutations were the only mutations found in the complete coding region and their exon/intron boundaries. The total sensitivity of mutant CF alleles that could be identified was 98.5%. Given the heterogeneity of these mutations, most of them very rare, CFTR mutation screening still remains rather complex in our population, and population screening, whether desirable or not, does not appear to be technically feasible with the methods currently available.

Alleles↗
PubMed1990

Association between XV2c/CS7/KM19/D9 haplotypes and the delta F508 mutation. A study of 57 Belgian families.

Using Southern blotting and the polymerase chain reaction, the prevalence of the haplotypes for XV2c, CS7, KM19 and D9 on CF and on normal chromosomes could be determined in 35 Belgian families. A set of primers complementary to the DNA sequence of the CF gene around the delta F508 deletion was used to amplify this particular segment of the gene. In a total of 57 families, deletion screening showed that 69 out of 116 CF chromosomes (59.5%) carried the delta F508 deletion. Both the delta F508 deletion and another mutation(s) showed strong association with the haplotype 1-2-2-2.

Belgium↗
PubMed1984

Naloxone reduces decrease in ventilation induced by hypoxia in newborn infants.

The mechanism responsible for the decrease in ventilation during breathing of low fractional concentration of inspired O2 in the newborn infant is poorly understood. The present study tested the hypothesis that endogenous opiates account for this ventilatory decrease. Eleven healthy newborn infants breathed 15% O2, balance N2 for 5 min following an injection of saline and following an injection of naloxone. Neither injection caused a change in minute ventilation (VE) or ventilatory pattern when the infants were breathing room air. However, the decreased ventilation during hypoxia following naloxone was significantly less than that following saline. VE dropped about 14% following saline but only about 4% following naloxone. However, the adult ventilatory response to hypoxemia, i.e., a relatively sustained increase in VE, was not attained. Naloxone had no influence on the occurrence of periodic breathing during hypoxemia. Thus in the healthy full-term newborn infant, endogenous opiates account only for a part of the decreased ventilation during hypoxemia.

Humans↗
PubMed1984

Indomethacin-induced fetal breathing: mechanism and site of action.

The mechanism and site of action of indomethacin-induced fetal breathing (FB) was investigated in 26 chronically prepared fetal lambs. Indomethacin, which preferentially blocks prostaglandin production, was infused into the fetal circulation in two stages, 60 mg in 10 min and 60 mg over 7 h. Indomethacin stimulated sleep-state independent FB that was greatly reduced or abolished by infusions of prostaglandin E2 (PGE2). Infusions of nordihydroguaiaretic acid, which preferentially blocks the synthesis of leukotrienes, had no consistent effect on either fetal sleep or breathing activity when administered alone or after indomethacin. This suggests that the characteristic FB induced by indomethacin is due to inhibition of prostaglandin synthesis (PGE2) and not due to an overproduction of leukotrienes. The indomethacin effect on FB was observed in all fetuses tested including those deprived of peripheral chemoreceptor function, vagotomy, decortication, or spinal cord section at the T1 level. Complete constriction of the ductus arteriosus for many hours had no effect on FB. We conclude that inhibition of PGE2 synthesis stimulates FB by a central mechanism other than the cortex.

Animals↗