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Biomedical subjects

I Maire

Publications and source records attributed to I Maire.

At least 91 records · Page 5Linked to original sources
PubMed1988

Urinary alanine aminopeptidase assay improved as result of multivariate response-surface analysis.

Optimization of determination of alanine aminopeptidase in urine by univariate study led to a method involving pretreatment of urine with Sephadex G50. Re-examination of the optimization by multivariate study led us to recommend higher optimal concentrations: 5.8 mmol/L for the substrate and 300 mmol/L for the Tris buffer. Under these new conditions, pretreatment of urine was no longer necessary and the assay could be completely automated.

Aminopeptidases↗
PubMed1988

[Biological diagnosis of hereditary metabolic diseases. From selective screening to the mutant-cell bank].

The experience of a specialized laboratory for the biological diagnosis of inborn errors of metabolism in selected pediatrics patients is reported. The strategy starts with a wide testing of blood and urine, as many inborn errors of metabolism can be detected through testing of blood and urine for increased concentration of specific metabolites known to be associated with the genetic defect. Then enzymatic or DNA studies are performed to confirm the diagnosis. The mutant cells mostly fibroblasts are stored in a cell bank and available for other research.

Cells, Cultured↗
PubMed1988

[Glycogenoses type 1b and 1c].

In type 1 glycogen storage diseases, glucose-6-phosphatase may be present but associated with impaired transport of glucose-6-phosphate (type 1b) or inorganic phosphate (type 1c) through microsomal membranes. The type 1c is very rare (2 published cases). The more frequent type 1b presents all the clinical manifestations of type 1a and specific signs: recurrent stomatitis, frequent infections, chronic inflammatory bowel disease secondary to neutropenia and neutrophil dysfunction. Glucose-6-phosphatase activity is low when measured on fresh liver tissue, but is restored after detergent treatment. A good metabolic control does not influence neutropenia and its consequences.

Glycogen Storage Disease Type I↗
PubMed1987

Ketogenesis in hypoglycemic neonates. Carnitine and dicarboxylic acids in neonatal hypoglycemia.

Since hypoglycemic neonates do not exhibit compensative ketosis, we investigated the possible involvement of carnitine deficiency or omega-oxidation in neonatal hypoglycemia. In a first group of 49 neonates, serum free fatty acid, acetoacetate and beta-hydroxybutyrate concentrations were similar in hypoglycemic and normoglycemic neonates. Serum free carnitine concentrations did not show any difference in the hypoglycemic small-for-date infants (median 40 mumol/l, range 16-92 mumol/l) compared to the normoglycemic small-for-date infants (median 30 mumol/l, range 8-64 mumol/l). In a second group of 45 neonates, urinary excretion of dicarboxylic acids (adipic, suberic, sebaric and succinic acids) was similar in hypoglycemic infants compared to normoglycemic neonates. Despite the limitations of interpretation of free carnitine determination, these data do not suggest an impaired beta-oxidation by carnitine depletion or an enzymatic defect in hypoglycemic neonates.

3-Hydroxybutyric Acid↗
PubMed1987

[Macroenzymes in human plasma. 2. Macrogamma-glutamyltransferase, macroalanine aminopeptidase, macroalkaline phosphatase, macroaminotransferases and other macroenzymes].

The authors propose here the second part of the review concerning the plasma macroenzymes. Informations are given about the high-molecular mass forms of gamma-glutamyltransferase (GGT), alanine aminopeptidase (AAP), alkaline phosphatase (ALP), aminotransferase, acid phosphatase and glucose-6-phosphatase dehydrogenase. For almost all these enzymes, the presence of enzyme-immunoglobulins complexes may be observed in some plasma, but a specific immune character of these complexes has not always been proved. The membrane origin of GGT, AAP and ALP is responsible for the existence of special circulating macroforms: enzyme-lipoproteins associations due to the amphiphilic nature of some forms of these enzymes, and complexes between enzymes and membrane components. Although the knowledge about the structure of all these macroenzymes is increasing, the clinical interest to consider their existence because of the diagnostic uncertainties they may induce.

Acid Phosphatase↗
PubMed1987

[Macroenzymes in human plasma. 1: Macroamylase, macrocreatine kinase, macrolactate dehydrogenase].

The authors propose here a general review of the main macroenzymes described until now. In this first part, informations will be given about the high molecular forms of alpha amylase, creatine kinase (CK) and lactate dehydrogenase (LDH) found in human plasma. Except macro CK type 2 which can be related to the mitochondrial CK, these macroenzymes are the result of the formation of enzyme immunoglobulin complexes; their specific immune character has been demonstrated in some cases. The formation of such immune complexes between the enzyme protein and plasma immunoglobulins seems a rather common phenomenon although neither the mechanism involved nor the physiopathological significance are known since they have been observed in patients and healthy individuals. Nevertheless, it is important to recognize these macromolecular forms because of the diagnostic uncertainties they may induce during isoenzyme studies and even total enzyme activity measurement.

Antigen-Antibody Complex↗
PubMed1986

Salla disease in one non-Finnish patient.

In a 5-year-old boy, an early onset psychomotor retardation with non-progressive ataxia and without dysmorphic features, associated with lysosomal storage disease found on ultrastructural examination of the conjunctiva, led to the diagnosis of Salla disease. This was supported by a tenfold excretion of urinary free sialic acid, without abnormal oligosacchariduria or anomaly in lysosomal enzymes. This boy is a native of Southern France. Screening of urinary sialic acid has to be introduced in aetiological investigations of patients with apparently non-progressive psychomotor retardation associated with ataxia or dystonic movements.

Child↗
PubMed1986

Possible prenatal diagnosis of type III glycogenosis.

This paper reports the first prenatal diagnosis in a pregnancy at risk for type III glycogenosis using a reliable test for amylo-1,6-glucosidase in cultured amniotic fluid cells. This test, based upon the different rates of glycogen and phosphorylase limit dextrin hydrolysis, was found to be more reliable in detecting a deficiency of amylo-1,6-glucosidase activity than either phosphorylase limit dextrin hydrolysis alone or [14C]glucose incorporation using leukocytes and cultured cells.

Amniotic Fluid↗
PubMed1986

[Enzymuria].

Study of enzymuria rises more and more interest in human pathology as a diagnosis parameter of renal diseases or as an index of nephrotoxicity. In this two fields, the literature demonstrated the interest of enzymes of the brush border of proximal tubuli (alanine amino peptidase, gamma glutamyl transpeptidase, alkaline phosphatase) and of lysosomal enzymes (beta glucuronidase and N acetyl beta D glucosaminidase). The authors analyse the problems limiting the present use of these methods: incomplete knowledge of enzyme of the different parts of the renal tissue and of the mechanisms of enzymuria (choice of enzymes and time periods for sampling); analytical problems referring to the study of enzymes in a complex medium (treatment and storage of samples, choice of adapted methods for activity measurement); at last the way of expression the results is still to be defined.

Clinical Enzyme Tests↗
PubMed1986

Creatine kinase: reassessment of optimal concentrations for adenosine-5'-diphosphate and magnesium.

Whereas univariate studies led to an European agreement for the choice of optimal reagent concentrations of 2 mmol/L for ADP and 10 mmol/L for Mg2+ for determining creatine kinase (EC 2.7.3.2) activity in serum, whatever its isoenzyme pattern, the results of our bivariate study led us to recommend higher optimal concentrations: 4.1 to 4.7 mmol/L for ADP and 22 mmol/L for Mg2+. The zone of maximal activity was in fact a broad plateau such that more than 99% of maximal enzyme activity was attained at ADP concentrations between 3 and 5 mmol/L and Mg2+ concentrations between 17 and 26 mmol/L. Under these new conditions the maximum activity measured was modestly increased (about 10%) over the previously recommended method but the assay could be expected to be more resistant to the variations of ADP and Mg2+ concentrations. It may become necessary to modify the European recommended method.

Adenosine Diphosphate↗
PubMed1985

[Fetal ascites as a manifestation of infantile sialidosis. Significance of a study of oligosaccharides in amniotic fluid].

Non immune hydramnios and fetal ascite are demonstrated at 31 weeks gestation. There is no familial story. All etiologic investigations (repeated ultrasonographic examinations, amniocentesis) are negative. The delivered girl has a normal development. She presents a congenital ascite and edema. The diagnosis of sialidosis (mucolipidosis type I) is supported by the early finding of vacuolated lymphocytes, the excretion of oligosaccharides in the urine and, finally, the results of the study of alpha-D-neuraminidase fibroblasts and others lysosomal enzymes activities. Oligosaccharides and enzymic studies provide same results in amniotic fluid. Authors point the particular interest of amniotic fluid oligosaccharides study when the etiologic diagnosis of idiopathic fetal ascite or hydrops is to be done.

Adult↗
PubMed1983

Variant of GM2-gangliosidosis with hexosaminidase A having a severely changed substrate specificity.

The levels of hexosaminidase A activity in cultivated fibroblasts of two patients with GM2-gangliosidosis were close to the normal range with 4-methylumbelliferyl-beta-D-2-acetamido-2-deoxyglucopyranoside and 4-methylumbelliferyl-beta-D-2-acetamido-2-deoxygalactopyranoside as substrates, and the enzymes were normal in most parameters analyzed. However, the enzymes of both patients were almost completely inactive against two specific substrates for hexosaminidase A, rho-nitrophenyl-6-sulfo-2-acetamido-2-deoxy-beta-D-glucopyranoside, and ganglioside GM2 in the presence of GM2-activator. Fibroblast extracts of both patients showed normal hexosaminidase B and GM2-activator activity, the latter was strongly decreased in two cases with variant AB. It is suggested that human hexosaminidase A may contain two different active sites which might be inactivated separately by different mutations.

Binding Sites↗
PubMed1983

[Case of mucolipidosis type I with a primary alpha-D-neuraminidase deficiency].

The authors describe a case of mucolipidosis I, the 9th reported in the world literature. The diagnosis was suspected in a 5 year old boy, from the appearance of hurler-like facial features. Lumbar kyphosis, dysostosis multiplex, cherry-red macular spot and foam cells in the bone marrow and it was confirmed by the characteristic oligosacchariduria (on thin layer chromatography) and excess sialic acid in cultured fibroblasts which also showed profoundly diminished activity of alpha D Neuraminidase (on two substrates - N-acetyl-Neuramin Lactose and 4 Methyl umbelliferyl N-acetyl-Neuraminide). The parents had intermediate enzyme activities, suggesting heterozygotism. After a review of the literature, the authors attempt to define the place of mucolipidosis I in the sialidoses.

Acetylglucosaminidase↗
PubMed1983

Human placenta as a convenient source of creatine kinase BB.

We demonstrate that human placenta is a convenient source of creatine kinase isoenzyme BB. We compare the physicochemical and catalytic properties with those of other creatine kinase isoenzymes: purified human abdominal muscle MM and brain BB. We also describe a stabilizing medium for creatine kinase BB. Human placental and brain BB have similar catalytic properties, the respective Km values for creatine phosphate being 0.66 and 0.56 mmol/L and for adenosine diphosphate 89 and 70 nmol/L.

Adenosine Diphosphate↗
PubMed1982

Detection of carriers for Duchenne muscular dystrophy. Quality control of creatine kinase assay.

A report by Bullock and coworkers has emphasized the need for standardization of the CK assay in carrier detection for DMD. A collaborative study, according to a well-specified design and involving two laboratories in Paris and Lyon, indicates that the reliability of this assay can be improved provided that special attention is paid to information about participating subjects, laboratory protocol, and repeated sampling. On a random sample of young women, mean and variance of ln(CK) are 1.66 and 0.015 respectively. Within and between variance components are in a 3:4 ratio, homogeneous between populations. Additional use of a common test serum should insure good reliability of this assay among laboratories.

Adult↗