Rhenium Carbonyl Molecular Catalysts for CO Electroreduction: Effects on Catalysis of Bipyridine Substituents Mimicking Anchorage Functions to Modify Electrodes.

Heterogenization of molecular catalysts on (photo)electrode surfaces is required to design devices performing processes enabling to store renewable energy in chemical bonds. Among the various strategies to immobilize molecular catalysts, direct chemical bonding to conductive surfaces presents some advantages because of the robustness of the linkage. When the catalyst is, as it is often the case, a transition metal complex, the anchoring group has to be connected to the complex through the ligands, and an important question is thus raised on the influence of this function on the redox and on the catalytic properties of the complex.

MicroRNA 183 family profiles in pheochromocytomas are related to clinical parameters and SDHB expression.

This study aims to examine the expression profiles of the miR-183 cluster (miR-96/182/183) in pheochromocytoma. Pheochromocytoma tissues were prospectively collected from 50 patients with pheochromocytoma. Expression of miR-183 cluster members and SDHB protein expression were analyzed in these tissues by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively.

Fusogenic supramolecular vesicle systems induced by metal ion binding to amphiphilic ligands.

The incorporation of lipophilic ligands into the bilayer membrane of vesicles offers the possibility to induce, upon binding of suitable metal ions, a variety of processes, in particular vesicle aggregation and fusion and generation of vesicle arrays, under the control of specific metal-ligand recognition events. Synthetic bipyridine lipoligands Bn bearing a bipyridine unit as head group were prepared and incorporated into large unilamellar vesicles. The addition of Ni2+ or Co2+ metal ions led to the formation of complexes MBn and MBn2 followed by spontaneous fusion to generate giant multilamellar vesicles.

Dominant influence of gamma-globin promoter polymorphisms on fetal haemoglobin expression in sickle cell disease.

Polymorphisms of multiple cis-acting elements in the beta-globin locus are associated with variable fetal haemoglobin (HbF) level in sickle cell disease. We developed a multiplex assay permitting simultaneous analysis of three polymorphic cis elements spanning 53 kb of the beta-globin locus. We identified concordance between polymorphic alleles in gamma- and beta-globin promoters however a significant number of betaS-chromosomes were identified with polymorphisms in hypersensitive site 2 (HS2) of the beta-globin locus control region juxtaposed to atypical cis alleles in the gamma-promoter.

Nucleotide variation regulates the level of enhancement by hypersensitive site 2 of the beta-globin locus control region.

The beta-globin locus control region hypersensitive site 2 (HS2) enhancer possesses a unique property for stimulating high-level globin gene expression. Although the deletion of cis-acting motifs influences the level of enhancement conferred by HS2, there is controversy on whether polymorphism of the same elements contributes to variation of the fetal hemoglobin (HbF) level among patients with sickle cell anemia. We analyzed reporter gene activity of constructs containing variant HS2 enhancers derived from beta(S) chromosomes to directly test the effect of polymorphism on enhancer activity.

Rapid identification of hemoglobin variants by electrospray ionization mass spectrometry.

The precise identification of human hemoglobin variants, over 700 human hemoglobin variants are known, is essential for prediction of their clinical and genetic significance. A systematic approach to their rapid identification is described. Traditionally this requires protein or DNA characterization which entails lengthy analytical procedures.

Factor VIII gene polymorphisms in the Asian Indian population.

Little is known about the heterozygous frequency of factor VIII gene markers in the Asian Indian population. The objective of this study was to establish the heterozygous frequency of polymorphic markers within and flanking the factor VIII gene in Indians and identify those most informative for carrier screening and prenatal diagnosis. Factor VIII gene polymorphism analysis at intragenic and extragenic sites was carried out by the polymerase chain reaction (PCR) method and Southern blot procedure.

Unique and recurrent WAS gene mutations in Wiskott-Aldrich syndrome and X-linked thrombocytopenia.

Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are allelic phenotypes caused by defects of the WAS gene. Fourteen distinct mutations including seven novel gene defects in 16 WAS and four XLT patients were identified by single strand conformation polymorphism analysis and DNA sequencing of the WAS gene. Eleven (79%) of these mutations are located within exons 1 to 4 with clustering in exon 2.

Reversal of metabolic block in glycolysis by enzyme replacement in triosephosphate isomerase-deficient cells.

Inherited deficiency of the housekeeping enzyme triosephosphate isomerase (TPI) is the most severe clinical disorder of glycolysis. Homozygotes manifest congenital hemolytic anemia and progressive neuromuscular impairment, which in most cases pursues an inexorable course with fatal outcome in early childhood. No effective therapy is available.

Ancestral origin of variation in the triosephosphate isomerase gene promoter.

A high frequency of nucleotide substitutions -5A/G, -8G/A, -24T/G in the triosephosphate isomerase (TPI) gene promoter has been demonstrated in African-Americans. The biological significance of these promoter variants, two of which, -8G/A and -24T/G, occur within regulatory elements essential for transcription, is controversial. The geographical distribution and frequency of allelic variation in the TPI promoter was determined in 378 unrelated normal subjects from sub-Saharan African (n = 103), Caribbean (n = 26), Northern European (n = 57), Mediterranean (n = 55), Middle Eastern (n = 42), Asian Indian (n = 48) and Oriental (n = 47) populations.

Genetic and acquired predisposing factors and treatment of osteoporosis in thalassaemia major.

We have previously shown a high incidence of osteopenia and osteoporosis in patients with thalassaemia major. These bone changes, were more severe in males than females, in those with diabetes mellitus and with hypogonadal-hypogonadism. Our recent studies concern the relationship of erythroid activity, assessed by serum transferrin receptors as an overall measure of anaemia, to osteoporosis.

Localisation of cis regulatory elements at the beta-globin locus: analysis of hybrid haplotype chromosomes.

Several cis elements at the beta-globin gene cluster and the upstream locus control region (LCR) have been implicated in modulation of fetal haemoglobin (Hb F) level in beta-globin disorders. To determine the role of elements at the LCR and the beta-globin gene cluster on HbF level among sickle cell anaemia (SCA) patients, hybrid haplotype betaS chromosomes exhibiting variation in the association of alleles of LCR hypersensitive site 2 (HS2) and the beta-globin gene cluster restriction fragment length polymorphosim (RFLP) haplotypes were identified in an unselected population of 100 patients. On 15 chromosomes the polymorphic HS2 short tandem repeat(TA)xN10-12(TA)y containing a Hox2 binding motif differed from that typically associated with the corresponding beta-globin gene cluster RFLP haplotype.

Localization of a gene for familial hemophagocytic lymphohistiocytosis at chromosome 9q21.3-22 by homozygosity mapping.

Familial hemophagocytic lymphohistiocytosis (FHL), also known as familial erythrophagocytic lymphohistiocytosis and familial histiocytic reticulosis, is a rare autosomal recessive disorder of early childhood characterized by excessive immune activation. Linkage of the disease gene to an approximately 7.8-cM region between markers D9S1867 and D9S1790 at 9q21.

Quantification of Ggamma- and Agamma-globins by electrospray ionisation mass spectrometry.

Elucidation of the molecular basis for persistent fetal haemoglobin (Hb F) production in adult life has important implications for the pathophysiology and treatment of human beta haemoglobinopathies. Electrospray ionisation mass spectrometry (ESMS) was applied to analyse the pattern of gamma-globin expression in patients with hereditary persistence of fetal haemoglobin (HPFH) and sickle cell anaemia (SCA). Ggamma and Agamma-globin chains were identified by their measured molecular masses and distinguished by mass difference (14 Da) following deconvolution of ESMS spectra using maximum entropy based software.

Predominance of the HLA-H Cys282Tyr mutation in Austrian patients with genetic haemochromatosis.

Background/aims: Genetic haemochromatosis is the most common autosomal recessive disorder in Northern European populations. A major histocompatibility complex class I-like gene, HLA-H, has been proposed to be responsible for genetic haemochromatosis. The prevalence of HLA-H gene mutations 282(TGC; Cys/TAC; Tyr) and 63(CAT; His/GAT; Asp) was determined in patients of Austrian origin.

Factor VIII gene mutations found by a comparative study of SSCP, DGGE and CMC and their analysis on a molecular model of factor VIII protein.

Screening of the factor VIII (FVIII) gene which spans 186 kb and codes for 26 exons, was originally hampered by its size but is now feasible because rapid DNA scanning methodologies have been developed. The present study for the first time directly compares the three most widely applied screening methods, denaturing gradient gel electrophoresis (DGGE), single-stranded conformational polymorphism (SSCP) and chemical mismatch cleavage (CMC) for their sensitivity of mutation detection in a selected group of ten haemophilia A patients. Nine of these patients are known to be cross-reacting material positive and eight exhibited a mild to moderate phenotype.

Evidence for founder effect of the Glu104Asp substitution and identification of new mutations in triosephosphate isomerase deficiency.

Triosephosphate isomerase (TPI) deficiency is an autosomal recessive disorder of glycolysis characterized by multisystem disease and lethality in early childhood. Among seven unrelated Northern European kindreds with clinical TPI deficiency studied, a single missense mutation at codon 104 (GAG;Glu-->GAC;Asp) predominated, accounting for 11/14 (79%) mutant alleles. In three families molecular analysis revealed compound heterozygosity for Glu104Asp and novel missense mutations.

Prenatal diagnosis of triosephosphate isomerase deficiency.

First-trimester prenatal diagnosis was undertaken by chorionic villus DNA analysis in two unrelated families with the inherited glycolytic disorder triosephosphate isomerase (TPI) deficiency. The propositus in each family was shown to be homozygous for a missense mutation (GAG --> GAC) at codon 104 of the TPI gene. In the first case the fetus was heterozygous for the codon 104 mutation and therefore clinically unaffected.

Haemophilia A diagnosis by automated fluorescent DNA detection of ten factor VIII intron 13 dinucleotide repeat alleles.

Haemophilia A is a recessive X linked bleeding disorder caused by deficiency or functional abnormality of coagulation factor VIII. This disease usually has no visible phenotype in female carriers; hence, great efforts are made to offer all haemophilia A families accurate carrier diagnosis. Significant progress in this direction was made with the identification of the intron 13 variable number tandem repeat (VNTR), which is hitherto the most informative single marker within the factor VIII gene.

Analysis of the essential sequences of the factor VIII gene in twelve haemophilia A patients by single-stranded conformation polymorphism.

We report the analysis by single-stranded conformation polymorphism of the essential sequences of the factor VIII(FVIII) gene (total length about 14 kb) including the entire coding sequence, flanking intronic sequences and the putative regulatory sequences 5' to the gene, in twelve unselected haemophilia A patients of Portuguese origin. Direct sequencing of the fragments with an altered migration pattern led to the identification of the disease-producing mutations in five patients. Three of these mutations, namely a 1 bp insertion in a motif of eight consecutive A residues at codon 1439 (FVIIIPorto3); a C to T transition at codon 1966 (Arg-->Stop), found in an inhibitor-positive patient (FVIIIMontijo); and a G to A transition at codon 479 (Gly-->Arg; FVIIIPorto1), have been reported in other ethnic groups.

Haemophilia A diagnosis by simultaneous analysis of two variable dinucleotide tandem repeats within the factor VIII gene.

Haemophilia A is a bleeding disorder caused by defects in the gene coding for the co-factor, factor VIII (FVIII). The few available intragenic restriction fragment length polymorphisms (RFLPs) currently used in carrier detection and prenatal diagnosis of haemophilia A are informative in only about 65% of cases. We earlier reported a multi-allelic dinucleotide tandem repeat, (CA)n, specific to intron 13, which remains the single most informative marker within the FVIII gene.

Expression of luteinising hormone-beta subunit chloramphenicol acetyltransferase (LH-beta-CAT) fusion gene in rat pituitary cells: induction by cyclic 3'-adenosine monophosphate (cAMP).

In this study we determined the activity of the rat luteinising hormone-beta gene promoter in a heterologous rat pituitary cell line (GH3 cells). 1.7 kb of LH-beta 5' flanking sequence and the first 5 bp of the 5' untranslated region were ligated to the chloramphenicol acetyltransferase (CAT) receptor gene (LH-beta-CAT) and transiently transfected by calcium phosphate precipitation into subconfluent cultures of GH3 cells.

Haemophilia A diagnosis by analysis of a hypervariable dinucleotide repeat within the factor VIII gene.

The diagnosis of haemophilia A and the identification of carriers has greatly improved with knowledge of the structure of the gene for factor VIII. This has permitted the defect to be tracked in families by the study of restriction fragment length polymorphisms (RFLPs), irrespective of the nature of the molecular defect. However, this approach is time-consuming and the information yielded falls away as more polymorphisms are added.