Search PubMed⌕ Search

Biomedical subjects

N Maurin

Publications and source records attributed to N Maurin.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Neonatal screening for phenylketonuria and hypothyroidism. An optimizing system].

Screening for phenylketonuria and hypothyroidism in neonates is currently performed on blood samples collected on the 5th day of life. The efficacy of blood-sampling is evaluated subsequently. Double-sampled and non-sampled children are not always identified. We present a system which provides complete control of child, and was tested experimentally over one year on the 4,260 births in a maternity hospital. The sampling done by the maternity hospital as very thorough: only 0.47% of the children were not sampled spontaneously (ET = 1.07 10(-3)). The sampling of children transferred to pediatric units before the 5th day was a little less rigorous: 6.06% were not sampled before the telephone reminder (ET = 1.86 10(-2)). After a year our system ensured a 100% sampling after identification and telephone reminder for non sampled children, and allowed us to spot and count cases of double-sampling.

Hospital Information Systems↗
PubMed1989

[Relation between post-thrombotic syndrome, ADP-induced thrombocyte aggregation and intrathrombocyte calcium content].

Correlation between postthrombotic syndrome, ADP-induced aggregation and intracellular calcium concentration. This study presents a comparison of the ADP-induced platelet aggregation and free cytosolic platelet calcium concentration between patients with postthrombotic syndrome and healthy volunteers. The half maximal effective dose of the platelet aggregation induced by ADP was significantly decreased in postthrombotic syndrome (p less than 0.005). The mean values were 0.42 mumol/l in postthrombotic syndrome (n = 22) and 1.00 mumol/l in normal controls (n = 25). The free intracellular calcium concentration was slightly but significantly diminished in patients compared with healthy volunteers. In both groups there was seen a remarkable interindividual spread of platelet calcium concentrations. There was seen no significant correlation between cytosolic calcium concentration of platelets and the half maximal effective dose of ADP-induction. Therefore the considerable enhanced aggregability in postthrombotic syndrome cannot explained with altered cytosolic calcium content of platelets.

Adenosine Diphosphate↗
PubMed1989

CpG dinucleotides are mutation hot spots in phenylketonuria.

The coding region of the phenylalanine hydroxylase (PAH) gene contains 22 CpG dinucleotides, including five doublets in the seventh exon of the gene. We hypothesized that CpG doublets could represent mutation hot spots in PAH deficiencies and we carried out the systematic sequence analysis of exon 7 in 20 unrelated PAH-deficient kindreds of Mediterranean ancestry. This procedure resulted in the detection of two novel missense mutations whose location and nature (CG to CA and CG to TG) were consistent with the accidental deamination of a 5-methylcytosine in a CpG doublet (codon 261arg----gln and codon 252arg----trp). Moreover, the codon 261 mutation was found to be associated with mutant restriction fragment length polymorphism (RFLP) haplotype 1, the most frequent mutant RFLP haplotype at the PAH locus in the studies reported thus far. However, since the mutation was detected in only 36% of haplotype 1 mutant alleles, it appears that this haplotype at the PAH locus is genotypically heterogeneous in Mediterranean countries.

Amino Acid Sequence↗
PubMed1989

Fryns syndrome: report on 8 new cases.

The name Fryns syndrome was given to a new variable multiple congenital anomaly syndrome, almost always lethal, described in 1978, and now known to be autosomal recessive. Since that date, 20 patients have been reported in the literature. We describe 8 new cases, 6 of which were diagnosed in a series of 112,276 consecutive births (livebirths and perinatal deaths). The prevalence of this syndrome can be estimated to be around 0.7 per 10,000 births. These new cases confirm that the most frequent anomalies are diaphragmatic defects, lung hypoplasia, cleft lip and palate (often bilateral), cardiac defects (septal defects and aortic arch anomalies), renal cysts (type II, III or IV), urinary tract malformations, and distal limb hypoplasia. Most patients also have hypoplastic external genitalia and anomalies of internal genitalia (bifid or hypoplastic uterus, immature testes). The digestive tract is also often abnormal: duodenal atresia, pyloric hyperplasia, malrotation and common mesentery are present in half of the patients. When the brain was examined, more than half were abnormal (Dandy-Walker anomaly and agenesis of corpus callosum). A few patients demonstrated cloudy cornea. We examined the eyes of three patients histologically: two of them showed retinal dysplasia with rosettes and gliosis of the retina, thickness of posterior capsula of lens and irregularities of the Bowman membrane. Four of our cases were diagnosed prenatally between 24 and 27 weeks. It is to be expected that prenatal diagnosis will be made often and earlier in the future, as the spectrum of anomalies of the Fryns syndrome can easily be evidenced by sonography.

Abnormalities, Multiple↗
PubMed1988

A low molecular weight heparin in hemodialysis.

The purpose of our study was to check whether the dosage recommended for the low molecular weight heparin tested here, i.e., 50% of the corresponding unfractionated heparin dose, is adequate to prevent clot formation in the extracorporeal system. Sixteen dialysis treatments of 4-5 h were given to each of six chronic dialysis patients. In dialyses 1, 2, 15 and 16 unfractionated heparin (initial dose 35 IU/kg, continuous dose 20 IU/kg/h) was given, and in dialyses 3-14 low molecular weight heparin (initial dose 17.5 anti-Xa U/kg, continuous dose 10 anti-X U/kg/h). At these dose levels of low molecular weight heparin, clot formation occurred in the extracorporeal system in five of the six patients, despite the fact that the plasma anti-Xa level of 0.5 U/ml recommended by the manufacturer had been attained. For this reason the continuous dose of low molecular weight heparin had to be raised to approx. 80% of the corresponding continuous dose of unfractionated heparin. A plasma anti-Xa level of 0.7 U/ml is necessary to prevent extracorporeal clot formation.

Adult↗
PubMed1988

Effects of enzymatic blood defibrination in subcortical arteriosclerotic encephalopathy.

Plasma hyperviscosity is a striking abnormality in patients suffering from subcortical arteriosclerotic encephalopathy (SAE) and is thought to perpetuate the chronic ischaemic demyelinating process of the periventricular white matter. Ancrod, a defibrinating enzyme, was given to 10 patients with SAE in an attempt to reduce plasma fibrinogen, which would thus normalise hyperviscosity. This was paralleled by a significant improvement of the initially abnormal retinal arteriovenous passage time, as well as a significant augmentation of the CO2-induced cerebral vasomotor response. This did not lead, however, to any clinical improvement with respect to performance of neuropsychological tests, recurrences of strokes during a 6 month observation period or improvement of various audiological parameters. The findings indicate that hyperviscosity in patients with SAE is merely an epiphenomenon. A potentially reversible, chronic penumbral state of the brain tissue apparently does not exist in SAE.

Aged↗
PubMed1988

The in vitro bleeding time while using a stable prostacyclin analogue during hemodialysis.

A serious disadvantage of preventing clot formation by using prostacyclin (PGI2) to inhibit thrombocyte function during dialysis is that there exists no rapidly measurable monitoring parameter. The "in vitro bleeding time" (in vitro BT) is a new method for measuring primary hemostasis in vitro. Five chronic dialysis patients each underwent two dialyses: 1) with conventional full heparinization, and 2) with the stable PGI2 analogue CG 4203 and additional "low-dose" heparin. The predialytic in vitro BT is longer than normal values and values 1 h after the end of dialysis. While heparin has no significant effect on the in vitro BT, CG 4203 prolongs it concentration-dependently. Infusing CG 4203 at a rate of 25 ng/kg/min, the in vitro BT is extended beyond the measurable range of 800 microliter during the first approx. 150 min of dialysis. During the next approx. 90 min it steadily decreases.

Adult↗
PubMed1988

Prevention of coagulation during hemodialysis by a combination of the stable prostacyclin analogue CG 4203 and low-dose heparin.

In certain situations heparin used during hemodialysis can increase the risk of bleeding. Various groups have suggested that this bleeding risk can be reduced by using prostacyclin (PGI2). Since PGI2 is labile under physiological conditions and is thus difficult to use, we have used the stable PGI2 analogue CG 4203. This study in 5 chronic dialysis patients was designed to apply the following 5 different dialysis regimens with bicarbonate to each patient for 5 h: 1) conventional full heparinization; 2) CG 4203 (25 ng/kg/min) for the first 120 min, then full heparinization; 3) CG 4203 alone for 5 h (25 ng/kg/min); 4) initial bolus dose of heparin (500 IU), then continuous infusion of heparin (200 IU/h) and CG 4203 (25 ng/kg/min); 5) as 4) above but 35 ng/kg/min of CG 4203. Slight falls in thrombocytes and in some case substantial falls in leukocytes shortly after commencing the dialysis cannot be avoided when administering CG 4203 alone. Both 25 and 35 ng/kg/min doses of CG 4203 produced approx. 50% inhibition of the ADP-induced platelet aggregation for the entire 5 h administration period. At 30 min after dialysis the inhibition had fallen to approx. 20%. Although administering CG 4203 alone for 2 h produced no extracorporeal occlusion, administering CG 4203 alone for 5 h, some clots did occur after 3-5 h, which caused premature termination of the dialysis or made reinfusion impossible after 5 h. When 25 ng/kg/min was applied together with a continuous low dose of heparin for 5 h, only small clots were observed which did not impede dialysis or reinfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1986

Influence on platelet activity and red cell fluidity of epoprostenol and two stable prostacyclin analogues in vitro.

Not only epoprostenol (prostacyclin, PGI2) but also the two stable prostacyclin analogues CG 4203 (oxacyclic) and CG 4305 (carbacyclic) cause concentration dependent inhibition of thrombocyte function: pseudopod formation and aggregation after stimulation with ADP, collagen and arachidonic acid are inhibited to an extent dependent on dose. ADP-induced aggregation is inhibited 45% by 10 nmol/l epoprostenol 47% by 50 nmol/l CG 4203 and 25% by 50 nmol/l CG 4305. Epoprostenol itself improves red cell fluidity to an extent dependent on concentration, but the two analogues tested show no such effect.

Adenosine Diphosphate↗