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Biomedical subjects

B Leroux

Publications and source records attributed to B Leroux.

At least 55 records · Page 3Linked to original sources
PubMed1983

Dihydrobiopterin biosynthesis deficiency.

For the last 2 years, a program has been developed to screen all hyperphenylalaninemic babies for tetrahydrobiopterin deficiency, by measurement of pterins in urine. High neopterin and low biopterin levels were found in the urine of a 1-month-old girl. Further investigations confirmed an impaired conversion of neopterin to biopterin. No neurological signs were noted, but, in regard to the laboratory data, neurotransmitter replacement therapy was instituted at 2.5 months of age. The most remarkable feature was a rapid increase in the dietetic phenylalanine tolerance, despite the proof that the child was not able to clear a challenging dose of phenylalanine and the record of unchanged pathologically low excretion of biopterin during a 2 month period.

Biopterins↗
PubMed1976

[Treatment of hyaline membrane disease with the plasminogen urokinase combination].

The authors present the results obtained using a therapeutic combinaison of plasminogen-urokinase in vivo in 14 premature infants suffering from respiratory distress. 86 % survived, a considerable improvement over classical survival rates. In addition it appeared that the duration of oxygen therapy was shorter, secondary to limitation of extension of the disease.

Clinical Trials as Topic↗
PubMed1975

[The state of prothrombin, plasminogen and fibrinogen in the newborn infant].

The esterase activity of thrombin and plasmin on artificial substrates was used to study the kinetics of these enzymes by Lineweaver and Burk's method. In the plasma of new-born infants, plasmin obtained from streptokinase has an avidity comparable with that in adults. Thrombin is obtained by the action of staphylocoagulase and taipan venom. Its avidity has important individual variations and is different from that in adults. An inhibitor is present both in the plasma and in the serum of the new-born. Fibrinogen was studied by variations in absorption of light during coagulation by thrombin. The abnormalities observed depend on the physical and clinical conditions of the medium (ph, osmolality). These characteristics depend on the age of the infant, but also seem to depend on the conditions of the sample and, in particular, on fibrinolytic reactions. The existence of foetal fibrinogen is discussed.

Age Factors↗
PubMedDate not supplied

Results of the IPCS collaborative study on complex mixtures.

The International Programme on Chemical Safety (IPCS) sponsored a collaborative study to examine the intra- and inter-laboratory variation associated with the preparation and bioassay of complex chemical mixtures. The mixtures selected were National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs). 20 laboratories worldwide participated in the collaborative trial. The participating laboratories extracted the organic portion of two particulate samples--an air-particulate sample and a diesel-particulate sample--and bioassayed the extracts. The laboratories simultaneously bioassayed a NIST-prepared extract of coal tar and two control compounds (benzo[a]pyrene, and 1-nitropyrene). The bioassay method used was the Salmonella/mammalian microsome plate-incorporation test using strains TA98 and TA100. Study design also allowed for a comparison of sonication and Soxhlet extraction techniques. The mean extractable masses for the air particles and diesel particles were approximately 5% and 17.5%, respectively. The particulate samples were mutagenic in both strains with and without activation in all 20 laboratories. For TA100 the with and without activation slope values for the air particulate were 162 and 137 revertants per mg particles, respectively. For TA98 the respective diesel slope values were 268 and 269. The mutagenicity slope values for the diesel particles ranged from 3090 (TA98, +S9) to 6697 (TA100, +S9) revertants per mg particles. The coal tar solution was negative for both strains when exogenous activation was not used but was mutagenic in both strains with exogenous activation. The benzo[a]pyrene and 1-nitropyrene were used as positive controls and gave results consistent with the literature. This paper provides a complete summary of the data collected during the collaborative study. Companion papers provide further analysis and interpretation of the results.

Air Pollutants↗