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Biomedical subjects

M Nadal

Publications and source records attributed to M Nadal.

At least 19 recordsLinked to original sources
PubMed2002

PCDD/PCDF congener profiles in soil and herbage samples collected in the vicinity of a municipal waste incinerator before and after pronounced reductions of PCDD/PCDF emissions from the facility.

Congener profiles are the fractional distribution of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) congeners in an environmental release, or in an environmental or biological sample. In 1999, an adaptation to the EU legislation on pollutant emissions from the stack was carried out in an old municipal solid waste incinerator (MSWI) from Montcada (Barcelona, Spain). The main goal of the present study was to determine if the environmental PCDD/F levels in the area under direct influence of the facility were mainly due to PCDD/F emissions from the plant. For this purpose, soil and herbage samples were collected near the MSWI before (1998) and after (2000) the technical improvements were performed. PCDD/F congener profiles were determined and compared with those from samples collected in a suburban area of Constantí (Tarragona, Spain) outside of direct emissions from any MSWI. The results of the present study suggest that the MSWI here assessed is not the main responsible for the environmental PCDD/F concentrations in the area under evaluation. Other PCDD/F emission sources in the same area seem also to have a notable impact on the atmospheric levels of these pollutants.

Air Pollutants↗
PubMed2001

The human intersectin genes and their spliced variants are differentially expressed.

Human intersectins (ITSN1 and ITSN2) are members of a conserved family of proteins involved in clathrin-mediated endocytosis. A short and a long isoform with different protein domain compositions have been described for both human intersectins. Here, we have resolved the exon/intron structure of the ITSN2 gene to explain the genomic origin of its alternatively spliced transcripts. Comparison of the two ITSN human genes shows a high level of conservation in their genomic organization, including the main alternative splicing events. An extensive tissue expression analysis of the two predominant transcripts as well as other minor variants shows that ITSN expression is under tissue and developmental controls. Their differential expression is made more evident when the expression of both intersectins is studied by in situ hybridization in mouse brain.

Adaptor Proteins, Vesicular Transport↗
PubMed2001

A polymorphic genomic duplication on human chromosome 15 is a susceptibility factor for panic and phobic disorders.

Anxiety disorders are complex and common psychiatric illnesses associated with considerable morbidity and social cost. We have studied the molecular basis of the cooccurrence of panic and phobic disorders with joint laxity. We have identified an interstitial duplication of human chromosome 15q24-26 (named DUP25), which is significantly associated with panic/agoraphobia/social phobia/joint laxity in families, and with panic disorder in nonfamilial cases. Mosaicism, different forms of DUP25 within the same family, and absence of segregation of 15q24-26 markers with DUP25 and the psychiatric phenotypes suggest a non-Mendelian mechanism of disease-causing mutation. We propose that DUP25, which is present in 7% control subjects, is a susceptibility factor for a clinical phenotype that includes panic and phobic disorders and joint laxity.

Adult↗
PubMed2001

PTOV1, a novel protein overexpressed in prostate cancer containing a new class of protein homology blocks.

In a search for molecular markers of progression in prostate cancer by means of differential display, we have identified a new gene, which we have designated PTOV1. Semiquantitative RT-PCR has established that nine out of 11 tumors overexpress PTOV1 at levels significantly higher than benign prostatic hyperplasia or normal prostate tissue. The human PTOV1 protein consists almost entirely of two repeated blocks of homology of 151 and 147 amino acids, joined by a short linker peptide, and is encoded by a 12-exon gene localized in chromosome 19q13.3. A Drosophila melanogaster PTOV1 homolog also contains two tandemly arranged PTOV blocks. A second gene, PTOV2, was identified in humans and Drosophila, coding for proteins with a single PTOV homology block and unrelated amino- and carboxyl-terminal extensions. A 1.8-Kb PTOV1 transcript was detected abundantly in normal human brain, heart, skeletal muscle, kidney and liver, and at low levels in normal prostate. Immunocytochemical analysis and expression of chimeric GFP-PTOV1 proteins in cultured cells showed a predominantly perinuclear localization of PTOV1. In normal prostate tissue and in prostate adenomas, PTOV1 was undetectable or expressed at low levels, whereas nine out of 11 prostate adenocarcinomas showed a strong immunoreactivity, with a focal distribution in areas of carcinoma and prostatic intraepithelial neoplasia. Therefore, PTOV1 is a previously unknown gene, overexpressed in early and late stages of prostate cancer. The PTOV homology block represents a new class of conserved sequence blocks present in human, rodent and fly proteins.

Adenocarcinoma↗
PubMed2001

Genomic organization, chromosomal localization, alternative splicing, and isoforms of the human synaptosome-associated protein-23 gene implicated in vesicle-membrane fusion processes.

Synaptosome-associated protein-23 (SNAP23) is a component of the cellular mechanism required for specific membrane fusion and targetting of intracellular vesicles. We have cloned the full-length human cDNA and the SNAP23 gene. The SNAP23 gene has eight exons, with the initiation codon located in exon 2, and maps to the human chromosome 15q21-22 region. The human SNAP23 gene can generate two types of message, the full-length message (SNAP23A) and a shorter message (SNAP23B). The latter is the result of alternative splicing where exon 5 is joined to exon 7 and the skipping of exon 6; it thus lacks a region that is required for non-specific binding to plasma membranes. The two isoforms, expressed as fusion proteins with glutathione-S-transferase, interact in vitro with human syntaxin 6, thus retaining the specific protein interaction required for membrane fusion. Alterations in the SNAP23 gene might be involved in neurological and other diseases with defects in vesicle-membrane fusion processes that map to 15q15-21.

Alternative Splicing↗
PubMed2001

Dscr1, a novel endogenous inhibitor of calcineurin signaling, is expressed in the primitive ventricle of the heart and during neurogenesis.

We have demonstrated that DSCR1 acts as a negative regulator of calcineurin-mediated signaling and that its transcript is overexpressed in the Down syndrome (DS) fetal brain. To evaluate the possible involvement of DSCR1 in DS, we have cloned the mouse gene and analyzed its expression pattern in the central nervous system (CNS). Early expression of Dscr1 is detected mainly in the heart tube and in the CNS in rhombomere 4 and the pretectum. From embryonic day 14.5 onwards, Dscr1 is widely distributed in the CNS but becomes more restricted as the brain matures. We confirmed its neuronal expression pattern in the adult, preferentially in Purkinje and pyramidal cells, by double labeling with glial fibrillary acidic protein. We also show that although Dscr1 is present in trisomy in the Ts65Dn mouse, the adult brain expression pattern is not significantly altered. This expression pattern indicated that Dscr1 is a developmentally regulated gene involved in neurogenesis and cardiogenesis and suggests that it may contribute to the alterations observed in these organ systems in DS patients.

Animals↗
PubMed2001

Mitotic recombination effects homozygosity for NF1 germline mutations in neurofibromas.

Pure populations of neurofibroma-derived Schwann cells bearing both NF1 mutated alleles (NF1-/-) have been isolated from different neurofibromas showing loss of heterozygosity of nearly the entire 17q chromosome. By comparing molecular and fluorescent in situ hybridization analysis of these cells, we demonstrate mitotic recombination is the mechanism underlying this type of loss of heterozygosity leading to reduction to homozygosity of NF1 germline mutation.

Chromosomes, Human, Pair 17↗
PubMed2001

Additional complexity on human chromosome 15q: identification of a set of newly recognized duplicons (LCR15) on 15q11-q13, 15q24, and 15q26.

Several cytogenetic alterations affect the distal part of the long arm of human chromosome 15, including recurrent rearrangements between 12p13 and 15q25, which cause congenital fibrosarcoma (CFS). We present here the construction of a BAC/PAC contig map that spans 2 Mb from the neurotrophin-3 receptor (NTRK3) gene region on 15q25.3 to the proximal end of the Bloom's syndrome region on 15q26.1, and the identification of a set of new chromosome 15 duplicons. The contig reveals the existence of several regions of sequence similarity with other chromosomes (6q, 7p, and 12p) and with other 15q cytogenetic bands (15q11-q13 and 15q24). One region of similarity maps on 15q11-q13, close to the Prader-Willi/Angelman syndromes (PWS/AS) imprinting center. The 12p similar sequence maps on 12p13, at a distance to the ets variant 6 (ETV6) gene that is equivalent on 15q26.1 to the distance to the NTRK3 gene. These two genes are the targets of the CFS recurrent translocations, suggesting that misalignments between these two chromosomes regions could facilitate recombination. The most striking similarity identified is based on a low copy repeat sequence, mainly present on human chromosome 15 (LCR15), which could be considered a newly recognized duplicon. At least 10 copies of this duplicon are present on chromosome 15, mainly on 15q24 and 15q26. One copy is located close to a HERC2 sequence on the distal end of the PWS/AS region, three around the lysyl oxidase-like (LOXL1) gene on 15q24, and three on 15q26, one of which close to the IQ motif containing GTPase-activating protein 1 (IQGAP1) gene on 15q26.1. These LCR15 span between 13 and 22 kb and contain high identities with the golgin-like protein (GLP) and the SH3 domain-containing protein (SH3P18) gene sequences and have the characteristics of duplicons. Because duplicons flank chromosome regions that are rearranged in human genomic disorders, the LCR15 described here could represent new elements of rearrangements affecting different regions of human chromosome 15q.

Base Sequence↗
PubMed2000

HMG20A and HMG20B map to human chromosomes 15q24 and 19p13.3 and constitute a distinct class of HMG-box genes with ubiquitous expression.

The HMG box encodes a conserved DNA binding domain found in many proteins and is involved in the regulation of transcription and chromatin conformation. We describe HMG20A and HMG20B, two novel human HMG box-containing genes, discovered within the EURO-IMAGE Consortium full-length cDNA sequencing initiative. The predicted proteins encoded by these two genes are 48.4% identical (73.9% within the HMG domain). The HMG domain of both HMG20 proteins is most similar to that of yeast NHP6A (38% to 42%). Outside of this domain, HMG20 proteins lack any significant homology to other known proteins. We determined the genomic structure and expression pattern of HMG20A and HMG20B. Both genes have several alternative transcripts, expressed almost ubiquitously. HMG20A maps to chromosome 15q24 (near D15S1227) and HMG20B to 19p13.3 (between D19S209 and D19S216). The HMG20 genes define a distinct class of mammalian HMG box genes.

Alternative Splicing↗
PubMed1999

Cloning of the human phospholipase A2 activating protein (hPLAP) gene on the chromosome 9p21 melanoma deleted region.

Cutaneous malignant melanoma (CMM) is a common skin cancer. About 50% of CMM sporadic tumours have lost one copy of the chromosome 9p21 region. To identify genes involved in the initiation and/or progression of CMM we have characterised the 9p21 melanoma deleted region and screened the human expressed sequence tag (EST) databases (dbEST) to search for expressed genes. We have identified the gene that encodes the human orthologue of the rat phospholipase A2 activating protein (PLAP). PLAP was considered a potential candidate to be involved in malignant melanoma because it maps to the critical region for CMM and because the PLA2 gene has been identified as a modifier of the APC gene, responsible for the adenomatous polyposis phenotype in the mouse. PLAP encodes a protein of 738 amino acids and has a high DNA (90%) and protein (97%) sequence similarity with the rat and mouse PLAP protein. PLAP has a region of WD40 repeats in the amino-terminus, which allows us to include this protein in the superfamily of beta-transducin proteins. Northern blot hybridisation gave a fragment of 4.5 kb, with higher expression in heart compared to other tissues. PLAP was localised at chromosome 9p21, between marker AFM218xg11 and TEK. SSCP analysis of the coding region of PLAP revealed no variants in the studied samples, but one of six CMM samples analysed by RT-PCR showed specific inactivation of PLAP. Despite PLAP's important role in mediating several cellular responses and its localisation to the chromosome 9p21 region deleted in CMM, it is unlikely that point mutations or deletions in the coding region of PLAP are responsible for the initiation or progression of CMM. Further studies on PLAP inactivation should be performed to clarify its potential involvement in CMM.

Amino Acid Sequence↗
PubMed1999

Cloning, expression and chromosomal localization of a human testis 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase gene.

6-Phosphofructo-2-kinase/fructose 2,6-bisphosphatase (PFK-2/FBPase-2) is a bifunctional enzyme responsible for the synthesis and breakdown of Fru-2,6-P2, a key metabolite in the regulation of glycolysis. Several genes encode distinct PFK-2/FBPase-2 isozymes that differ in their tissue distribution and enzyme regulation. In this paper, we present the isolation of a cDNA from a human testis cDNA library that encodes a PFK-2/FBPase-2 isozyme. Sequencing data show an open reading frame of 1407 nucleotides that codifies for a protein of 469 amino acids. This has a calculated molecular weight of 54kDa and 97% similarity with rat testis PFK-2/FBPase-2, with complete conservation of the amino acid residues involved in the catalytic mechanism. Fluorescence in-situ hybridization (FISH) localized testis PFK-2/FBPase-2 gene (PFKFB4) in human chromosome 3 at bands p21-p22. A Northern blot analysis of different rat tissues showed the presence of a 2.4-kb mRNA expressed specifically in testis. In mammalian COS-1 cells, the human testis cDNA drives expression of an isozyme with a molecular weight of 55kDa. This isozyme shows clear PFK-2 activity. Taken together, these results provide evidence for a new PFK-2/FBPase-2 gene coding for a human testis isozyme.

Amino Acid Sequence↗
PubMed1999

Molecular cloning, characterization, and chromosomal localization of the mouse homologue of CD84, a member of the CD2 family of cell surface molecules.

CD84 is a member of the immunoglobulin gene superfamily (IgSF) with two Ig-like domains expressed primarily on B lymphocytes and macrophages. Here we describe the cloning of the mouse homologue of human CD84. Mouse CD84 cDNA clones were isolated from a macrophage library. The nucleotide sequence of mouse CD84 was shown to include an open reading frame encoding a putative 329 amino acid protein composed of a 21 amino acid leader peptide, two extracellular immunoglobulin (Ig)-like domains, a hydrophobic transmembrane region, and an 87 amino acid cytoplasmic domain. Mouse CD84 shares 57.3% amino acid sequence identity (88.7%, considering conservative amino acid substitutions) with the human homologue. Chromosome localization studies mapped the mouse CD84 gene to distal chromosome 1 adjacent to the gene for Ly-9, placing it close to the region where other members of the CD2 IgSF (CD48 and 2B4) have been mapped. Northern blot analysis revealed that the expression of mouse CD84 was predominantly restricted to hematopoietic tissues. Two species of mRNA of 3.6 kilobases (kb) and 1.5 kb were observed. The finding that the pattern of expression was restricted to the hematopoietic system and the conserved sequence of the mouse CD84 homologue suggests that the function of the CD84 glycoprotein may be similar in humans and mice.

Amino Acid Sequence↗
PubMed1999

Enhanced pancreatic tumor regression by a combination of adenovirus and retrovirus-mediated delivery of the herpes simplex virus thymidine kinase gene.

We have evaluated the effectiveness of combining the different characteristics of retrovirus and adenovirus to apply the herpes simplex virus thymidine kinase gene (HSVtk) and ganciclovir (GCV) treatment for gene therapy of pancreatic cancer. Transduction of NP-18 human pancreatic cells in culture by either the adenoviral vector (ADV/tk) or the retroviral vector (Rv/tk) followed by GCV treatment resulted in a GCV dose-dependent cytotoxic effect. A bystander effect was determined, both in NP-18 cultures and in xenogeneic cell mixtures of NP-18 and PA317 cells. Studies in vivo indicated that the effectiveness of tumor regression after HSVtk gene transfer and GCV treatment was dependent first on the tumor size at the time of viral injection and secondly, in large tumors, on the type of virus administered. The administration of the viral combination (ADV/tk + vector producer cells VPC-Rv/tk) was the best approach tested and resulted in a dramatic reduction in tumor mass after 4 days of GCV treatment which was maintained for the treatment period. Remarkably, two animals presented a complete eradication of the tumor. Thus, the HSVtk/GCV system when administered using a viral combination (ADV/tk + VPC-Rv/tk), may be a promising suicide gene therapy for pancreatic carcinomas.

Adenocarcinoma↗
PubMed1999

Analysis of DNA cleavage by reverse gyrase from Sulfolobus shibatae B12.

Reverse gyrase is a type I-5' topoisomerase, which catalyzes a positive DNA supercoiling reaction in vitro. To ascertain how this reaction takes places, we looked at the DNA sequences recognized by reverse gyrase. We used linear DNA fragments of its preferred substrate, the viral SSV1 DNA, which has been shown to be positively supercoiled in vivo. The Sulfolobus shibatae B12 strain, an SSV1 virus host, was chosen for production of reverse gyrase. This naturally occurring system (SSV1 DNA-S. shibatae reverse gyrase) allowed us to determine which SSV1 DNA sequences are bound and cleaved by the enzyme with particularly high selectivity. We show that the presence of ATP decreases the number of cleaved complexes obtained whereas the non-hydrolyzable ATP analog adenosine 5'-[beta, gamma-imido]triphosphate increases it without changing the sequence specificity.

Adenosine Triphosphate↗
PubMed1999

Cloning, expression, and mapping of PDCD9, the human homolog of Gallus gallus pro-apoptotic protein p52.

We report the sequence, tissue distribution, and chromosome location of a novel gene, PDCD9 (programmed cell death 9). PDCD9 is the mammalian counterpart of the Gallus gallus pro-apoptotic protein p52. The human cDNA has an open reading frame of 1,314 nucleotides and was predicted to encode a protein of 438 amino acids with a calculated mass of 50 kDa. The protein sequences of chicken, mouse, and human PDCD9 are remarkably conserved. PDCD9 mRNA is expressed ubiquitously in adult tissues, displaying a stronger signal in heart, skeletal muscle, kidney, and liver. PDCD9 was mapped to chromosome 5q11.

Amino Acid Sequence↗