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Biomedical subjects

M Mathieu

Publications and source records attributed to M Mathieu.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Inborn errors of lysine metabolism].

A wide variety of inborn errors of lysine catabolism have been described. They include: abnormalities of the mitochrondrial catabolism via the "saccharopine pathway", abnormalities of the peroxisomal catabolism via the pipecolic pathway, and "lysine intolerance with periodic ammonia intoxication" linked to urea cycle pathway. These inborn errors are associated with a wide variety of clinical symptoms and biochemical profiles as persistent hyperlysinemia, saccharopinuria, "amino and ketoadipic aciduria, and glutaric aciduria.

2-Aminoadipic Acid↗
PubMed1990

Stable transfection of the estrogen receptor cDNA into Hela cells induces estrogen responsiveness of endogenous cathepsin D gene but not of cell growth.

Cathepsin D, a lysosomal protease, is induced by estrogens in hormone responsive breast cancer cells, by progesterone in normal endometrium and expressed at high constitutive levels in estrogen receptor (ER)-negative cells. To investigate whether ER is the only transacting factor missing in ER negative cells to obtain estrogen regulation, we transfected an ER cDNA expression vector (HEO) into ER-negative Hela cells and showed that it could recover estrogen sensitivity for cathepsin D gene expression but not for cell growth regulation. These results show i. that the expression of an endogenous gene in humans can be stimulated by estradiol after ER supplementation, indicating that Hela cells contain sufficient amounts of the other transcription factors required for cathepsin D estrogen inducibility; ii. that cathepsin D expression is stimulated by estrogens in this cervix cancer cell line, as it is in the ER-positive breast cancer cells, which contrasts with its regulation by progesterone in normal endometrial cells.

Cathepsin D↗
PubMed1990

Diagnosis of alcaptonuria: rapid analysis of homogentisic acid by HPLC.

The clinical and biochemical features of five cases of alcaptonuria were reported. The concentration of homogentisic acid was determined in urine and also in plasma using a rapid, sensitive and specific HPLC method. In all five cases, the concentrations of homogentisic acid were elevated in urine rising up to 46.5 mmol/24 h. In plasma, homogentisic acid levels ranged from 33 to 38 mumols/l. In healthy individuals, homogentisic acid was not detectable in plasma and urine. The method described represents a very useful and suitable analytical tool for the diagnosis of alcaptonuria.

Adult↗
PubMed1990

A putative neuroendocrine factor that stimulates glycogen mobilization in isolated glycogen cells from the marine mussel Mytilus edulis.

Glycogen synthesized by purified glycogen cells, from the labial palps of Mytilus edulis, was labeled by preincubation in culture medium containing D-[U-14C]glucose. It was stable for at least 4 hr of postincubation in the absence of 14C. Glycogen mobilization was provoked by an acid extract of the cerebral ganglia. The active factor was also found in the hemolymph. The glycogen cells exhibited a dose-dependent response to the cerebral extract. The active cerebral factor is methanol soluble and possesses hydrophobic properties. It is postulated that this factor is a neurohormone.

Animals↗
PubMed1990

Lack of association between two restriction fragment length polymorphisms in the genes for the light and heavy neurofilament proteins and Alzheimer's disease.

The etiology of Alzheimer disease (AD) remains unknown. The hypothesis of genetic factors playing a role in the causation of the disease, at least in its familial form, has been borne out by results showing linkage in several early-onset AD families to a locus on the proximal part of the long arm of chromosome 21. Linkage was not detected in several other families using the same markers. The metabolism of neurofilaments is perturbed in AD, as indicated by the presence of neurofilament epitopes in neurofibrillary tangles, as well as by the severe reduction of the expression of the gene for the light neurofilament subunit in AD brain. To detect a possible anomaly that might relate to the disease, we have searched for an association between the genes for the light subunit and the heavy subunit of the neurofilament triplet, and AD. Genotypes for restriction fragment length polymorphisms (RFLP) at each of the two loci were determined for an AD group and a control group. Allelic frequencies at a TaqI-defined RFLP for the gene for the light neurofilament subunit were 0.70 for the 3.7 kb allele and 0.30 for the 2.9 kb allele. HincII detected an RFLP for the heavy neurofilament subunit gene with frequencies of 0.31 for the 18.0 kb allele and 0.69 for the 6.8 kb allele. Frequencies were found to be similar in the two groups for both light and heavy neurofilament subunit loci. Although it cannot be excluded that mutations at other sites of the neurofilament genes are relevant to AD, the data reported here do not support an association between these genes and the disease.

Adult↗
PubMed1990

Respiratory cross-sectional area-flux measurements of the human chest wall.

A new device that utilizes the voltages induced in separate coils encircling the rib cage and abdomen by a magnetic field is described for measurement of cross-sectional areas of the human chest wall (rib cage and abdomen) and their variation during breathing. A uniform magnetic field (1.4 X 10(-7) Tesla at 100 kHz) is produced by generating an alternating current at 100 kHz in two square coils, 1.98 m on each side, parallel to the planes of the areas to be measured and placed symmetrically cephalad and caudad to these planes at a mean distance of 0.53 m. We demonstrated that the accuracy of the device on well-defined surfaces (squares, circles, rectangles, ellipses) was within 1% in all cases. Observed errors are due primarily to small inhomogeneities of the magnetic field and variation of the orientation of the coil relative to the field. Using a second magnetic field (80 kHz) perpendicular to the first, we measured the errors due to nonparallel orientation during quiet breathing and inspiratory capacity maneuvers. In 10 normal subjects, orientation effects were less than 2% for the rib cage and less than 0.7% for the abdomen. In five of these subjects, orientation effects at functional residual capacity in lateral and seated postures were generally less than or equal to 5%, but estimated tidal volume during spontaneous breathing was comparable to measurements in the supine posture. In five curarized patients, we assessed the linearity of volume-motion relationships of the rib cage and abdomen, comparing cross-sectional area and circumference measurements. Departures from linearity using cross-sectional areas were only one-third of those using circumferences. In seven normal subjects we compared cross-sectional area measurements with respiratory inductive plethysmography (RIP) and found comparable estimates of lung volume change over a wide range of relative rib cage contributions to tidal volume (-5 to 105%), with slightly higher standard deviations for the RIP (SD = 10% for RIP; SD = 4% for cross-sectional area).

Abdomen↗
PubMed1990

Comparison of red cell transfusion and polyethylene glycol-modified adenosine deaminase therapy in an adenosine deaminase-deficient child: measurement of erythrocyte deoxyadenosine triphosphate as a useful tool.

The effect of red cell transfusion and polyethylene glycol-modified adenosine deaminase therapy on biochemical abnormalities, clinical status, and immunologic function in an adenosine deaminase-deficient child was investigated. After red cell transfusions, erythrocyte deoxyadenosine triphosphate (dATP) concentrations decreased about 95% and were closely related to adenosine deaminase activities; deoxyadenosine diphosphate concentrations decreased only approximately 30%. The evolution of dATP levels was also closely related to the improvement in clinical status of the patient. However, immune function was not restored. After polyethylene glycol-modified adenosine deaminase therapy, the concentration of erythrocyte dATP decreased to undetectable levels correlated with an increase of T lymphocyte counts and an increase of lymphocyte responses to mitogens. Immune functions were restored only when dATP levels were below 15 mumols/L. It appears that red cell transfusion therapy is not sufficiently effective to reduce and maintain erythrocyte dATP levels at values compatible with normal immune function. On the contrary, polyethylene glycol-modified adenosine deaminase therapy is a suitable treatment to reduce dATP levels to near undetectable values, allowing the immune function to be restored, dATP measurement is a very useful tool for monitoring and evaluating the degree of efficiency of therapy in adenosine deaminase deficiency.

Adenosine Deaminase↗
PubMed1990

Regulation of fatty acid synthetase ribonucleic acid in the human endometrium during the menstrual cycle.

Fatty acid synthetase (FAS) is induced by progesterone in MCF7 and T47D breast cancer cell lines. We studied a possible in vivo regulation of expression of this gene by looking for FAS RNA in human endometrial biopsies at various periods of the menstrual cycle, using a cloned cDNA FAS probe. By Northern blot analysis, we detected the 8-kilobase FAS RNA throughout the cycle in 7 uterine samples. RNA in situ hybridization analysis of frozen sections from 22 endometrial biopsies showed that FAS RNA was present during follicular and luteal phases of the menstrual cycle in stromal and epithelial cells. RNA levels were quantified by counting autoradiographic silver grains using a computer-aided image analyzer. FAS RNA levels were significantly higher in epithelial cells than in fibroblasts (P less than 2 x 10(-5]. Furthermore, in both cell types, mean FAS RNA concentrations were higher in biopsies removed during the luteal phase than the follicular phase of the menstrual cycle (P = 2 x 10(-3) and 9 x 10(-5), respectively). A 2- to 3-fold increase in FAS RNA levels between days 8-14 and days 22-24 was detected in 2 normal patients who had previously undergone 2 successive biopsies. This increase was not observed in 2 patients with low plasma estradiol and progesterone concentrations, indicating a probable dysovulation. We conclude that FAS normally increases in both stromal and epithelial endometrial cells during the luteal phase. This increase is probably due to progesterone, which implies that FAS is induced in normal endometrium, as demonstrated in breast cancer.

Adult↗
PubMed1990

Interactions of cathepsin-D and insulin-like growth factor-II (IGF-II) on the IGF-II/mannose-6-phosphate receptor in human breast cancer cells and possible consequences on mitogenic activity of IGF-II.

The lysosomal enzyme cathepsin-D (cath-D) and insulin-like growth factor-II (IGF-II), which share a common IGF-II/mannose-6-phosphate (M6P) transmembrane receptor, are both synthesized and secreted by breast cancer cells, upon which they might exert an intracrine/autocrine control on proliferation. We have evaluated the binding of 125I-immunopurified human cath-D in different breast cell membrane preparations. The concentration of high affinity M6P reversible binding sites (mean Kd, 0.85 nM) varied among the different breast cancer cells (0-0.82 pmol/mg membrane protein), but there was no correlation between the presence of steroid receptor and M6P-dependent binding. Cross-linking experiments with [125I]cath-D and [125I]IGF-II showed the formation of complexes with the 270,000 mol wt IGF-II/M6P receptor molecule which migrated, respectively, at 330,000 and 270,000 mol wt in 3-10% gradient sodium dodecyl sulfate-polyacrylamide gels. [125I]IGF-II cross-linking was increased by M6P (20% above control), whereas cath-D strongly inhibited IGF-II interaction by 80%. Conversely, IGF-II reduced [125I]cath-D cross-linking by 55%. Direct ligand binding on receptors transferred onto nitrocellulose sheets by Western blotting confirmed the interaction of both ligands on the same receptor molecule. By studying IGF-II's growth-promoting activity in these cells in a wide range of concentrations, we show that IGF-II triggers its mitogenic response via IGF-II/M6P receptor at low concentrations, whereas it is mainly acting via IGF-I receptor at high concentrations. Three lines of evidences lead us to that conclusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Binding, Competitive↗
PubMed1990

[Waardenburg's syndrome and severe cyanotic cardiopathy].

Waardenburg syndrome type I is transmitted as an autosomal dominant trait. The main features are dystopia canthorum, partial pigmentary disorder and perceptive deafness. Osteo-articular and intestinal malformations may be observed. In an affected family, the unusual combination of Waardenburg syndrome and severe congenital heart disease has been observed in a child.

Child, Preschool↗
PubMed1990

[An example of detection of heterozygotes and antenatal diagnosis in four families with anhidrotic ectodermal dysplasia].

Anhidrotic ectodermal dysplasia is an X-linked inherited skin disorder; only affected males exhibit the complete syndrome, whereas females may have a few mild features. The gene involved in this disease is located in the proximal area of the long arm of the X chromosome, in the q13 position. Molecular analysis is very helpful for calculating the risk of transmission in sisters with normal phenotypes and affected individuals (family 1 provides an example), but cannot solve all problems (example of family 4). The best results are obtained when there are two informative markers, each located on either side of and very close to the mutant gene. Molecular analysis can also be applied to chorionic villi sampled at the tenth week of gestation in order to achieve antenatal diagnosis in male fetuses in high risk families. Until recently, antenatal diagnosis could be performed only at the twentieth week of gestation by the demonstration of inadequate development of skin glands in skin biopsy specimens sampled under fetoscopy. Family 2 provides an example of antenatal diagnosis and highlights the risk of error that always exists in molecular analysis studies.

Ectodermal Dysplasia↗
PubMed1990

[Adrenoleukodystrophy: significance for genetic counseling of the determination of very long-chain fatty acids and of molecular biology].

Juvenile adrenoleukodystrophy (ADL) is a peroxisomal, X-linked, consistently fatal condition for which no treatment is currently available. Detection of heterozygote females and antenatal diagnosis by determination of very long chain fatty acid levels are therefore mandatory. We report the case of a family with two affected first cousins but six unaffected maternal uncles. Plasma levels confirmed the usual X-linked pattern with transmission by the grandmother and ruled out the hypothesis of delayed adrenomyeloleukodystrophy in the grandfather with heterozygosis of all the daughters. Although all six sons are unaffected, two certainly heterozygote females have normal plasma very long chain fatty acid levels. Heterozygosis in these women was confirmed by family restriction fragment length polymorphism studies (TAQ1) using the St 14 probe whose reliability for the diagnosis of heterozygotes with normal plasma very long chain fatty acid levels has previously been documented.

Adrenoleukodystrophy↗