HIV/AIDS in Europe: trends and EU-wide priorities.
Explore the source record for details and available documents.
AIDS Serodiagnosis↗
Biomedical subjects
I Devaux
Publications and source records attributed to I Devaux.
Lack of hepcidin gene expression and severe tissue iron overload in upstream stimulatory factor 2 (USF2) knockout mice.
We previously reported the disruption of the murine gene encoding the transcription factor USF2 and its consequences on glucose-dependent gene regulation in the liver. We report here a peculiar phenotype of Usf2(-/-) mice that progressively develop multivisceral iron overload; plasma iron overcomes transferrin binding capacity, and nontransferrin-bound iron accumulates in various tissues including pancreas and heart. In contrast, the splenic iron content is strikingly lower in knockout animals than in controls. To identify genes that may account for the abnormalities of iron homeostasis in Usf2(-/-) mice, we used suppressive subtractive hybridization between livers from Usf2(-/-) and wild-type mice. We isolated a cDNA encoding a peptide, hepcidin (also referred to as LEAP-1, for liver-expressed antimicrobial peptide), that was very recently purified from human blood ultrafiltrate and from urine as a disulfide-bonded peptide exhibiting antimicrobial activity. Accumulation of iron in the liver has been recently reported to up-regulate hepcidin expression, whereas our data clearly show that a complete defect in hepcidin expression is responsible for progressive tissue iron overload. The striking similarity of the alterations in iron metabolism between HFE knockout mice, a murine model of hereditary hemochromatosis, and the Usf2(-/-) hepcidin-deficient mice suggests that hepcidin may function in the same regulatory pathway as HFE. We propose that hepcidin acts as a signaling molecule that is required in conjunction with HFE to regulate both intestinal iron absorption and iron storage in macrophages.
Animals↗
Deletion of chromosomal region 13q14.3 in childhood acute lymphoblastic leukemia.
Deletion of the 13q14 chromosomal region is frequent in B cell chronic lymphocytic leukemia (B-CLL) and is believed to inactivate a tumor supressor gene (TSG) next to RB1. We studied microsatellite markers spanning the 13q14 chromosomal region in 138 children with acute lymphoblastic leukemia (ALL). Allelic loss was demonstrated in six cases (4.3%). Deletion did not include RB1 in two cases. In five patients, the deleted region overlapped that described in B-CLL. A sixth patient harbored a smaller deletion, slightly more telomeric than minimal deleted regions reported in B-CLL. Apparent differences in the delineation of the minimal deleted region could be due to the fact that the putative TSG is a very large gene, with some deletions affecting only a part of it. Our present findings suggest that at least some of its exons lie within a region of less than 100 kb more telomeric that previously thought.
Adolescent↗
Efficacy and tolerability of entacapone as adjunctive therapy to levodopa in patients with Parkinson's disease and end-of-dose deterioration in daily medical practice: an open, multicenter study.
Entacapone is a potent, reversible and orally active inhibitor of catechol-O-methyltransferase. This open multicenter study evaluated the efficacy, safety and tolerability of entacapone as adjunct therapy to levodopa/dopa decarboxylase inhibitor (> or = 3 daily doses) in patients with idiopathic Parkinson's disease and end-of-dose motor fluctuations. The 8-week study included 489 patients under conditions of typical daily medical practice. Patients were treated with a 200-mg fixed dose of entacapone administered with each scheduled dose of levodopa to a maximum of 10 doses per day. Other antiparkinsonian medication should have been stable for at least 1 month. The primary efficacy criteria were: (1) Part II (activities of daily living, ADL) of the Unified Parkinson's Disease Rating Scale (UPDRS), (2) the reduction of 'off' time during the daily waking period as assessed by the percentage of patients improving by at least one category at Item 39 of Part IV of the UPDRS. Secondary outcome measures included: (1) the investigator's global assessment of change, (2) quality of life (QoL) was assessed using the Parkinson's Disease Questionnaire (PDQ-39). Adverse events, vital signs and liver enzymes were monitored at weeks 2 and 8. The baseline mean score for ADL was 10.5 (+/-7.04), which decreased to 8.5 (+/-6.37) at the end of the study (p < 0.0001). Compared to baseline, 40.8% of patients experienced a reduction in 'off' time during the waking period; this improvement was highly significant (p < 0.0001). A reduction in the daily dose of levodopa was observed in 35.8% of patients (mean decrease 209 +/- 149 mg). QoL was improved by a mean of 10% in all categories of the PDQ-39 (p < 0.001), except social support and cognition. This improvement was statistically significant (p < 0.001). The dyskinesia score (UPDRS Item 32) was decreased significantly from 2.3 to 2.1 from baseline to end of study (p < 0.001), although 52.7% of patients reported levodopa-induced dyskinesia as an adverse event. There was no case of increased liver enzymes. The study results confirm that the excellent risk/benefit ratio seen in phase III controlled studies can be seen in daily neurological practice. Moreover, the study suggests that the benefits of entacapone are associated with a significant improvement in QoL.
Adult↗
Infectious risk associated with wastewater reuse: an epidemiological approach applied to the case of Clermont-Ferrand, France.
Wastewater reuse raises the question of health risk and the epidemiological surveys needed. An epidemiological and environmental approach was used to check the security for the exposed populations (surrounding and agricultural population in Clermont-Ferrand. Four information systems were set up: two sentinel systems joining general physicians (15) and pharmacists (7) for the surrounding population and two follow-up surveys among field workers and farmers. Water quality monitoring and a study of aerosols from spray irrigation were performed. No epidemic event was identified with only some case clusters (not related to water exposure) being observed. All the declared cases were benign. The workers' survey underlined a substantial incidence of nettle rashes, itchy skins, sunburns, and cuts. The follow-up study among farmers and their families did not reveal any particular phenomena. The bacteriological quality of treated wastewater throughout conformed with the recommendations of the Superior Council of Public Health of France (1,000 faecal coliforms/100 mL). No faecal bacteria were observed in aerosols with water concentrations equal to 10(3) cfu/100 mL and an exposure time of 20 min. The survey of such an irrigation system, towards potential and actual risks, required the conjunction of different epidemiological information sources and microbiological data.
Adult↗
A 5' splice region G-->C mutation in exon 3 of the human beta-spectrin gene leads to decreased levels of beta-spectrin mRNA and is responsible for dominant hereditary spherocytosis (spectrin Guemene-Penfao).
We studied a family with autosomal dominant hereditary spherocytosis (HS) associated with a mild spectrin deficiency. Linkage analysis using two microsatellite markers (D14S63 and D14S271) very close to the beta-spectrin gene (SPTB) showed that HS co-segregated with alleles of these microsatellite markers and the linkage between the marker and HS was statistically significant. The presence of a beta-spectrin protein polymorphism (beta-spectrin Vay; A1880V) in trans of the HS allele was not itself deleterious, but allowed the detection of decreased membrane expression of the spherocytic beta-spectrin allele in two HS-affected subjects. Direct sequencing of the coding exons of the beta-spectrin gene in one affected subject showed the presence of a G-->C transversion at the terminal nucleotide of exon 3, which did not change the leucine codon 100 (CTG-->CTC). The presence of the mutation was confirmed by restriction enzyme digestion at the DNA level in all affected SH members of the family. The G-->C mutation severely reduced the utilization of the 5' splice site and resulted in aberrant mRNA splicing with intron 3 retention.
Base Sequence↗
Analysis of ETV6 and ETV6-AML1 proteins in acute lymphoblastic leukaemia.
The t(12;21) is a recurring chromosomal abnormality in acute lymphoblastic leukaemias (ALLs) which results in the production of an ETV6-AML1 fusion gene. The association between t(12;21) and the deletion of the untranslocated allele of ETV6 is among the most frequent abnormalities observed in B-lineage ALLs in children. In order to study the proteins encoded by ETV6 and ETV6-AML1, we raised polyclonal antibodies directed against a recombinant peptide corresponding to the junctional region of ETV6-AML1. Cell lysates from various leukaemic cell lines, and from children with B- and T-lineage ALLs, were studied by Western blot. Two isoforms of ETV6 protein were detected in normal bone marrow cells and in leukaemic cells without 12p alteration: a major form (apparent m.w. 63 kD) and a minor one (apparent m.w. 53 kD). In the REH cell line, which expresses the ETV6-AML1 fusion transcript and no normal ETV6 mRNA, the ETV6 isoforms were absent and two new bands were detected corresponding to ETV6-AML1 protein products (apparent m.w. 95 and 105 kD). A similar pattern was obtained with blast cells from patients with a t(12;21) and a deletion of ETV6. In two patients with a t(12;21) but no deletion of ETV6, four bands were detected corresponding to both the normal ETV6 and ETV6-AML1 proteins, suggesting that in these cases the second ETV6 allele was not inactivated. Surprisingly, the expression pattern of ETV6 differed widely from patient to patient. In three out of 13 patients without t(12;21), the relative intensity of the bands corresponding to ETV6 isoforms in blast cells from patients was completely different from normal cells, with a marked predominance of the 53 kD isoform. The pattern of ETV6 expression was normal in bone marrow from the same patients during remission. These finding suggest that ETV6 abnormalities are not restricted to patients with translocations or deletions involving this gene.
Blotting, Western↗
Epidemiological studies of spectrin mutations related to hereditary elliptocytosis and spectrin polymorphisms in Benin.
We studied an African population in Benin and discovered an unexpectedly high frequency (1.6%) of hereditary elliptocytosis (HE) among the 1447 subjects studied. In approximately two-thirds of HE individuals we identified molecular defects, primarily those in erythrocyte alpha-spectrin (dupL154, L260P and L207P mutations), as well as a novel mutation of erythrocyte beta-spectrin (beta-W2061R mutation). We also identified the genetic basis of a previously identified protein polymorphism of the alpha III domain of spectrin (R1331I mutation). The genetic background of HE in the African population was studied using a number of polymorphisms of the alpha-spectrin gene, including the alpha III domain polymorphism. These studies suggest that the HE mutations appear to have originated from separate genetic backgrounds in this population.
Benin↗
Search for the candidate genes in dominant hereditary spherocytosis using linkage analysis.
Hereditary spherocytosis (HS) is an inherited hemolytic anemia characterized by the presence of dense spherocytic red cells. In HS patients, red cell membrane protein gel electrophoresis has identified different subsets of abnormalities: isolated spectrin deficiency, combined spectrin and ankyrin deficiency, band 3 deficiency. To direct the search for the molecular defect in 9 families with dominant HS, we developed microsatellite markers specific for the membrane protein encoding genes possibly involved in HS (alpha- and beta-spectrin, ankyrin and band 3 genes) and genotyped each family. In 5 families with isolated spectrin deficiency, the beta-spectrin gene was designated as candidate. In one family with combined spectrin/ankyrin deficiency, only the ankyrin gene was not excluded, whereas in the 3 HS families with band 3 deficiency, only the band 3 gene was not excluded. This work allowed development of a reliable methodology to search for candidate genes in HS and showed the frequent involvement of the beta-spectrin gene in HS with isolated spectrin deficiency.
Ankyrins↗
Loss of heterozygosity in the chromosomal region 12p12-13 is very common in childhood acute lymphoblastic leukemia and permits the precise localization of a tumor-suppressor gene distinct from p27KIP1.
Abnormalities of the short arm of chromosome 12 are relatively common in hematologic malignancies and deletions of the region. 12p12-13 are found in approximately 5% of the patients with acute lymphoblastic leukemia (ALL). As a potent inhibitor of cyclin-dependent kinases, p27KIP1 prevents the progression of the cell cycle and the gene encoding p27KIP1 represents a potential tumor-suppressor gene. Its recent assignment to the chromosomal region (12p12.3) prompted us to study the p27KIP1 gene in a series of 61 children with ALL. Microsatellite polymorphic markers flanking the p27KIP1 gene were analyzed to detect losses of heterozygosity (LOH). Eleven patients displayed LOH for at least one of the markers. The deleted are encompassed the p27KIP1 gene locus in 10 cases, but inactivation of the remaining allele by deletion, translocation, or mutation was never observed. In addition, in 1 patient, the p27KIP1 gene was situated outside of the region of LOH. Thus, p27KIP1 does not seem to be the target gene of 12p12-13 alterations. However, this study indicates that 12p12-13 alterations at the molecular level, which are present in about 27% of the children with B-lineage ALL, are much more common than had previously been reported by usual chromosome analysis. Moreover, LOH mapping allowed us to better define the location of a putative tumor-suppressor gene implicated in these malignancies and should therefore help in identifying this gene.
Base Sequence↗
Protein 4.1 Lille, a novel mutation in the downstream initiation codon of protein 4.1 gene associated with heterozygous 4,1(-) hereditary elliptocytosis.
Explore the source record for details and available documents.
Base Sequence↗
Mutation in the iron responsive element of the L ferritin mRNA in a family with dominant hyperferritinaemia and cataract.
The synthesis of ferritin, the iron-storing molecule, is regulated at the translational level by iron through interaction between a cytoplasmic protein, iron regulatory protein (IRP), and a conserved nucleotide motif present in the 5' non-coding region of all ferritin mRNAs--the iron responsive element (IRE). This region forms a stem-loop structure and when the supply of iron to the cells is limited, the IRP is bound to IRE and represses ferritin synthesis. Ferritin is composed of a 24-subunit protein shell surrounding an iron core. The two types of subunit, H and L, are encoded by two genes located on chromosomes 11q13 and 19q13.1, respectively. Both genes are ubiquitously expressed but transcriptional regulation mediates tissue-specific changes in the H/L mRNA ratio and isoferritin profiles. We now report the identification of a single point mutation in the IRE of the L-ferritin mRNA in members from a family affected with dominantly inherited hyperferritinaemia and cataract. This mutation consists of an A to G change in the highly conserved CAGUGU motif that constitutes the IRE loop and mediates the high-affinity interaction with the IRP. We show that this mutation abolishes the binding of IRP in vitro and leads to a high constitutive, poorly regulated L-ferritin synthesis in cultured lymphoblastoid cells established from affected patients. This is, to our knowledge, the first mutation affecting the IRP-IRE interaction and the iron-mediated regulation of ferritin synthesis. We suggest that excess production of ferritin in tissues is responsible for the hyperferritinaemia and that intracellular accumulation of ferritin leads to cataract.
Base Sequence↗
Identification of a polymorphism in the coding region of the p27Kip1 gene.
Explore the source record for details and available documents.
Base Sequence↗
Identification of three novel spectrin alpha I/74 mutations in hereditary elliptocytosis: further support for a triple-stranded folding unit model of the spectrin heterodimer contact site.
Six individuals with hereditary elliptocytosis (HE) or hereditary pyropoikilocytosis (HPP) from three unrelated families were evaluated. Defects in the ability of spectrin (Sp) to undergo self-association were present, and associated with increased recovery of the Sp alpha I 74-kD fragment after limited tryptic digestion (Sp alpha I/74 variant). Because mutations associated with the Sp alpha I/74 variant described to date have been localized to the 5' coding region of the alpha-Sp gene (exon 2) or at the 3' coding end of the beta-Sp gene (exon 30), the polymerase chain reaction (PCR)-based single-strand conformation polymorphism (SSCP) method was used to detect mutations in these two regions. In one family with HE, an abnormal pattern of migration of PCR-amplified fragments containing exon 2 was observed, and led to the detection of a new mutation (Ile24Ser) in helix 3 of repeating segment alpha 1. In the two other families, an abnormal pattern of migration of PCR-amplified fragments containing exon 30 was observed in affected individuals, and sequencing led to the identification of two new mutations (Ala2023Val and Trp2024Arg) in helix 1 of repeating segment beta 17. The elliptogenic potential of these mutations emphasizes the importance of the conformational integrity of each of the three helices involved in the formation of the Sp heterodimer contact site, and will help identify critical amino acids involved in this interaction.
Aged↗
Spectrin alpha IIa variant in dominant and non-dominant spherocytosis.
Several polymorphic mutations are located on the spectrin alpha-chain; among these the variant termed alpha IIa is characterized by an acid shift in the isoelectric point of the tryptic digest peptides 46 kDa and 35 kDa. In this variant a single amino acid substitution (alanine to aspartic acid) occurred at position 972 of the spectrin alpha-chain due to a point mutation (GCT to GAT) in the DNA. This variant, which seemed very rare in normal people, could be related to the recessive form of hereditary spherocytosis (HS) and could be absent in the dominant form of the disease. We have studied the alpha IIa variant by denaturing electrophoresis of the spectrin tryptic digest peptides from 179 subjects: 46 controls, 78 patients with dominant (d) or non-dominant (nd) HS and 55 relatives of the patients. The confirmation of the results was obtained at the DNA level in 41 subjects. The frequency of the chromosome bearing the alpha IIa mutation was 7.6% in controls and higher (about 12-14%) in members of families with dHS as well ndHS. However, the family trees clearly showed that the mutation and the HS disease gene(s) were located on different chromosomes and inherited independently from each other. Furthermore, our study allows the conclusion that in most (if not all) cases of dHS, the alpha IIa the variant is not the cause, is not a marker, and does not influence the phenotypic expression of the disease.
Adult↗
Hereditary pyropoikilocytosis and elliptocytosis in a white French family with the spectrin alpha I/74 variant related to a CGT to CAT codon change (Arg to His) at position 22 of the spectrin alpha I domain.
We describe a white French family in which 12 subjects presented with hereditary elliptocytosis (HE) or hereditary pyropoikilocytosis (HPP). Eight of these subjects were shown to be heterozygous for a spectrin (Sp) alpha I/74 variant, as demonstrated by analysis of partial tryptic digestion fragments of spectrin. This abnormal peptide pattern was associated with a decreased ability of Sp dimers to self-associate. In this kindred, in which four generations were available for study, the clinical expression varied from mild HE to HPP with an intermediate status of hemolytic HE. The severity of the disease appeared to be correlated both with the estimated amount of variant Sp (42% to 65%) and the excess of Sp dimers found in the membrane (30% to 51%, with a normal value of 3.7% +/- 1.6%). Reassociation studies using isolated Sp alpha and beta chains from an affected patient and an unaffected control subject showed that the Sp alpha I/74 Kd abnormal tryptic peptide resulted from a defect in the Sp alpha chain. Partial amino acid sequencing showed that the Sp alpha I/74 Kd peptide resulted from cleavage at lysine residue 42 of the Sp alpha I/80 Kd domain. Knowledge of the exon/intron organization of the human alpha Sp gene allowed us to amplify by the polymerase chain reaction the second exon of the alpha Sp gene in total cellular DNA of the HPP proposita. The amplified fragment was subcloned and sequenced. We found a G to A base substitution in the 22nd codon (CAT for CGT), which changes the normal arginine to a histidine. Hybridization of amplified DNAs with allele-specific oligonucleotides corresponding to the normal and mutant sequences confirmed the presence of the mutation in six other HE and HPP members of the family. The identification of this mutation at the DNA level confirmed the transmission of the same molecular defect in Sp through four generations but with different patterns of clinical expression.
Adult↗
Sp alpha I/78: a mutation of the alpha I spectrin domain in a white kindred with HE and HPP phenotypes.
Limited tryptic digestion of spectrin (Sp) from seven related individuals manifesting hereditary elliptocytosis (HE) or hereditary pyropoikilocytosis (HPP) phenotypes revealed the presence of a novel peptide with a molecular weight of 78 Kd and a concomitant decrease in the alpha I domain (80-Kd peptide), which is the domain involved in the dimer self-association process. Sp from the normal members of this white family exhibited a normal peptide pattern, as compared with controls. The abnormal peptide pattern was associated with a decreased ability of Sp dimer to self-associate. In this kindred in which three generations were available for study, the clinical manifestations were quite variable and ranged from the asymptomatic HE carrier state to hemolytic HE or to severe anemia requiring splenectomy. The severity of the disease appeared to be correlated both with the amount of mutant spectrin (31% to 69%) and with the excess of the Sp dimer found in the membrane (26% to 60%, compared with a normal value of 5.6% +/- 2.2%). Partial amino acid sequencing showed that the alpha I/78-Kd peptide resulted from cleavage at lysine residue 10 of the alpha I/80-Kd domain. Knowledge of the exon/intron structure of cloned genomic DNA encoding the alpha I domain allowed us to amplify in vitro a DNA fragment containing the third exon of the alpha-spectrin gene. The amplified fragment was subcloned and sequenced. A G to T transversion was found in the 39th codon (AGT for AGG), which changed the normal arginine to a serine. Hybridization of amplified DNAs with allele-specific oligonucleotides corresponding to the normal and mutant sequences confirmed the presence of the mutation in three other HE members of the family (the propositus mother, brother, and sister).
Adult↗
An efficient laboratory made apparatus for DNA amplification.
DNA amplification by the polymerase chain reaction (PCR) is a method capable of producing a selective and very high enrichment of a specific DNA sequence. Hence it seems to be useful in various fields from basic research to clinical applications. In order to automatize PCR we assembled for a very low cost a mechanical system designed to carry a test tube holder successively in three thermal baths set at the required temperatures for the reaction. Two examples of the use of this machine are given: (i) amplification of DNA of a particular subtype of acute intermittent porphyria; (ii) the detection of the chimeric c-abl/bcr message found in chronic myelogenous leukemia cells.
Base Sequence↗