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M Repetto

Publications and source records attributed to M Repetto.

At least 55 records · Page 3Linked to original sources
PubMed1995

Simultaneous quantification of opiates, cocaine and cannabinoids in hair.

The present paper describes a sensitive method developed in our laboratory for the simultaneous analysis of opiates (morphine, codeine and monoacetylmorphine), cocainis (cocaine and benzoylecgonine) and cannabinoids (delta 9-tetrahydrocannabinol and 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid) in hair samples. After decontaminating the sample with dichloromethane, two consecutive hydrolyses were performed in order to achieve the best conditions for extracting the three kinds of drugs from the protein matrix. First the opiate and cocainic compounds were extracted by means of a soft acidic hydrolysis with 0.1 N HCl at 50 degrees C overnight and organic solvent extraction at pH 9.2. The cannabinoids need a stronger basic hydrolysis with 11.8 N KOH for 10 min at laboratory temperature. After adding maleic acid, the cannabinoids were extracted with an organic solvent. The derivatization was carried out with heptafluorobutyric anhydride and hexafluoropropanol. Calibration curves were linear between 0.5-100 ng/mg of hair. Recovery and reproducibility were assured. The quantification limits ranged between 0.04-0.26 ng/mg of hair. Seventy hair samples from known drug abusers were cut into 1-cm segments and analyzed by this method. The ranges of measured concentrations (ng/mg) were 0.31-89 for cocaine, 0.1-5.76 for benzoylecgonine, 0.34-45.79 for morphine, 0.45-39.59 for codeine, 0.09-48.18 for monoacetylmorphine, 0.06-7.63 for THC and 0.06-3.87 for THC-COOH. The results of sectional analyses agreed with the self reported drug histories. The usefulness of this method is in assessing earlier drug consumption, and also at the same time obtaining a chronological profile of the consumption of these three types of drugs.

Cannabinoids↗
PubMed1995

Androgen receptor gene (CAG)n repeat analysis in the differential diagnosis between Kennedy disease and other motoneuron disorders.

An increase in the number of (CAG)n repeats in the first coding exon of the androgen receptor (AR) gene has been strongly associated with Kennedy disease (KD) (spinal and bulbar muscular atrophy). This is an X-linked hereditary disorder characterized by motoneuron degeneration occurring in adults together with gynecomastia and hyperestrogenemia. We have performed AR gene molecular analysis in several members of a large family with KD as well as in 25 sporadic patients suffering from heterogeneous motoneuron disease (MND). An increase in the length of the (CAG)n repeats was detected, as expected, in all the affected males and in obligatory carrier females, some of which had minor signs of lower motoneuron involvement. There was only one possible exception, one young male with initial signs of the disease, who had an apparent normal length allele. An increased pathological allele was also found in 3 patients with MND. This indicates that the analysis of (CAG)n repeats of the AR gene plays a role in the differential diagnosis of this heterogeneous group of neurological diseases.

Adolescent↗
PubMed1995

Metal accumulation in human kidney cortex: mutual interrelations and effect of human factors.

1. Different metals were analysed in 77 post mortem samples of human renal cortex. 2. The concentrations of the metallic ions conformed to known distribution frequencies. In abnormal cases calculations were based on non parametric techniques. 3. There was no appreciable difference between the values found for each element and those described by other authors in other populations. 4. Statistically established correlations indicated that Zn was the element which was most strongly related to the others. 5. The influence of individual factors on metal concentrations was considered. Significant differences occurred only in Pb between sexes, and in Cd with age. There was no sign that drug abuse influenced the accumulation of metals in renal cortex.

Adolescent↗
PubMed1995

Coefficient of distribution of some organophosphorous pesticides in rat tissue.

Coefficient of distribution in tissue is proposed as an indicator of the affinity of xenobiotics for different tissues and their tendency to accumulate. The present study shows the distribution of some organophosphorous pesticides in rat tissues. Using the coefficient of distribution we established the preference of these insecticides for the various tissues. Each pesticide had a specific pattern of affinity for different tissues.

Adipose Tissue↗
PubMed1995

Stimulation of antioxidative enzymes by paraquat in cultured Vero cells.

Different cellular and biochemical cytotoxicity indicators have been assessed to evaluate the damages caused in Vero monkey kidney fibroblasts after 24 h exposure to paraquat (PQ), a widely used bipyridyl herbicide highly toxic through the active oxygen species that it generates by redox cycling. Cell viability, estimated by the relative neutral red uptake (EC50 = 0.5 mM), was more sensitive to PQ than cell proliferation, measured by total protein content (EC50 = 5 mM). Cell growth was more extensively inhibited in the presence of fetal bovine serum than in its absence. PQ exposure was paralleled with higher intracellular specific activities of lactate dehydrogenase and phosphofructokinase, directly assayed in the 96-wells culture plates, whereas those of succinate dehydrogenase raised only 1.35-fold and hexosaminidase was almost unaltered by PQ. The intracellular specific activities of several antioxidative enzymes were also directly determined in the microtiter plates. At the highest PQ concentration used (10 mM) glutathione reductase activity increased 4-fold, while superoxide dismutase and glucose-6-P dehydrogenase activities increased 2- and 1.8-fold compared to untreated control cells. An 1.9-fold raise in glutathione-S-transferase activity was also observed in exposed cells. The results show the action in Vero cells of a complex regulatory defensive network against PQ-induced damages.

Animals↗
PubMed1994

Comparative in vitro effects of sodium arsenite and sodium arsenate on neuroblastoma cells.

The toxic effects of arsenic at different cellular levels were assessed using two inorganic chemical species: sodium arsenite and sodium arsenate, representing the trivalent and pentavalent states of arsenic, respectively. Mouse neuroblastoma cell cultures (Neuro-2a) were exposed for 24 h, and cytotoxic effects evaluated were: cell proliferation by quantification of total protein content; cytoplasmic membrane integrity to cytosolic lactate dehydrogenase leakage; lysosomal hexosaminidase release; lactate dehydrogenase activity; mitochondrial succinate dehydrogenase activity; relative neutral red uptake by lysosomes; lysosomal hexosaminidase sphingolipid degradation activity; and acetylcholinesterase activity. As(III) was found to be five times more toxic than As(V) to neuroblastoma cell proliferation, but the relative extent of other alterations differed. Special sensitivity was detected for lactate dehydrogenase inhibition. Hexosaminidase activity was also very susceptible, being inhibited at low concentrations and stimulated at high concentrations. Less sensitive were the inhibition of cell proliferation, relative neutral red uptake, and acetylcholinesterase activity. As(III) was lysosomotropic, with secretion of hexosaminidase, but the release was decreased by As(V). Mitochondrial succinate dehydrogenase was inhibited by As(III) and stimulated by As(V). Minor sensitivity to cytoplasmic lactate dehydrogenase leakage for both compounds also shows that functional metabolic alterations produced by arsenic are more important than structural damage.

Acetylcholinesterase↗
PubMed1994

The exon-intron organization of the human X-linked gene (FLN1) encoding actin-binding protein 280.

We have determined the exon-intron organization of the human X-linked gene (FLN1) encoding actin-binding protein 280 (filamin), a ubiquitous protein that plays an important role in the mechanochemical activities of cells through its association with actin filaments and membrane components. The gene is composed of 47 exons spanning approximately 26 kb. The first and part of the second exon are untranslated. The actin-binding domain at the N-terminus is encoded by exons 2 to 5. The 96-amino-acid repeats corresponding to the elongated rod backbone of the protein are encoded by the remaining 42 exons: size, location, and boundaries of the exons cannot be easily correlated with the repeated structure, while sequences interrupting the repeats (the two hinge segments preceding repeats 16 and 24 and the 8-amino-acid (aa) segment interrupting the 15th repeat) were encoded by separate exons, suggesting that they may be recent additions to the X-linked protein. The 8-aa segment is encoded by exon 29, which is alternatively spliced.

Amino Acid Sequence↗
PubMed1993

Type 2 vasopressin receptor gene, the gene responsible nephrogenic diabetes insipidus, maps to Xq28 close to the LICAM gene.

Although long contigs have been assembled in Xq28, the interval between the anonymous probe St14 and the color vision locus is still incompletely defined. We report here that the recently cloned gene for type 2 vasopressin receptor (V2R) is physically linked to L1CAM using YACs and cosmids across about 180 kb of the region. Since it is known that L1CAM maps near the color pigment genes, this finding locates V2R in Xq28 in the area where nephrogenic diabetes insipidus (NDI) has been mapped by linkage analysis. The PFGE analysis of the clones positions V2R about 40 kb from the L1CAM gene in a region that appears to contain other unknown genes, since at least four putative CpG islands were identified by restriction analysis with rare cutter enzymes.

Animals↗
PubMed1993

ZNF75: isolation of a cDNA clone of the KRAB zinc finger gene subfamily mapped in YACs 1 Mb telomeric of HPRT.

We have previously mapped a zinc finger genomic motif (ZNF75) to the Xq26 cytogenetic band by using a hybrid panel. Here, we report the isolation of the transcribed counterpart in a cDNA clone and its further localization. The cDNA clone, from a lung fibroblast library, is assembled from three exons, including a 289 amino acid (AA) long open reading frame containing a recently described motif, the Kruppel-associated box, 42 AA long, in exon 2. By comparison with other reported members of the subfamily, the exon-intron boundaries also appear to be very well conserved. Further analysis allowed us to map this gene 1 Mb downstream from the HPRT gene in the published YAC contig that extends across Xq26. Two other motifs, 87 and 78% homologous to ZNF75 at the amino acid level, were identified by PCR on total human DNA, but map outside Xq24-qter.

Amino Acid Sequence↗
PubMed1993

Mapping of two genes encoding isoforms of the actin binding protein ABP-280, a dystrophin like protein, to Xq28 and to chromosome 7.

ABP-280 is a ubiquitous actin binding protein present in the cytoskeleton of many different cell types. ABP-280 was mapped to distal Xq28, 50-60 kb downstream of the Green Colour Pigment (GCP) genes. To establish if ABP-280 may be a candidate for one of the muscle disease localized by linkage analysis to distal Xq28 we looked for alternative forms of ABP-280 mRNA. Several different ABP-280 mRNAs were indeed identified: two are X-linked and are produced by alternative splicing of a small exon of 24 nucleotides. At least one additional gene encoding a RNA more than 70% identical to ABP-280 in the 1700 bp sequenced has also been found. It was mapped to chromosome 7. While both forms of the X-linked ABP-280 are ubiquitous, the gene on chromosome 7 is highly expressed only in skeletal muscle and heart. The two genes were therefore excellent candidates for the X-linked and for the autosomal dominant form of the Emery-Dreifuss Muscular Dystrophy (EDMD) both of which have been described. So far, however we were unable to demonstrate mutations in the coding region or affecting the alternative splicing of the X-linked form of ABP-280, in several patients studied, and we think that it is quite unlikely that this is the gene responsible for EDMD.

Amino Acid Sequence↗
PubMed1993

[Superior femoral epiphysiolysis. Long term results].

Analysis of the long-term outcome of slipped capital femoral epiphysis convincingly demonstrates that early diagnosis is essential. Chronic slipping with significant displacement are associated with a high rate of adverse outcomes including necrosis, chondrolysis, and early osteoarthritis. Orthopedic reduction increases the risk of complications. Inadequate reduction is associated with poor hip function and a high risk of early osteoarthritis. Improvements in overall long-term outcome could be achieved only by reducing the number of chronic forms with major displacement, since prognosis is generally favorable in acute forms and chronic forms with minor displacement.

Adolescent↗