Early-onset type-II diabetes mellitus (MODY4) linked to IPF1.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to J Ferrer.
Explore the source record for details and available documents.
A strategy was developed to generate expressed sequence tags (ESTs) from human pancreatic islet gene products using differential display of mRNA. Screening of over 2,000 cDNA amplification products identified 42 cDNAs that were preferentially expressed in pancreatic islets relative to exocrine tissue. Public database analysis showed that 29 (69%) corresponded to novel genes, in contrast with only 66 of 250 (26.4%) cDNA clones randomly selected from a human islet library. Reverse transcription-polymerase chain reaction (RT-PCR) and/or Northern analysis of RNA from multiple tissues confirmed that expression was enhanced in human islet cell RNA for 11 of 15 tested cDNAs. Sequence-tagged sites developed from 19 islet cDNAs were used to map these genes to human chromosomes using a combination of monochromosomal somatic-cell hybrids, genome-wide radiation hybrids, and mega-yeast artificial chromosome analysis. These results indicate that this PCR-based cDNA selection strategy yields information on a distinct subset of pancreatic islet transcribed sequences, which complements ongoing human EST identification efforts based on random cDNA selection. These mapped ESTs may be used to assist in the positional cloning of diabetes susceptibility genes.
Signals derived from the metabolism of glucose in pancreatic beta-cells lead to insulin secretion via the closure of ATP-sensitive K+ channels (KATP). The cloning of the gene encoding the beta-cell inward rectifier Kir6.2 (Bir), a subunit of the beta-cell KATP channel, provided the opportunity to look for mutations in this gene that might contribute to the impaired insulin secretion of NIDDM. By single-strand conformational polymorphism (SSCP) analysis on 35 Northern-European Caucasian patients with NIDDM, six sequence variants were detected: Glu10gag-->Lys10aag (E1OK), Glu23gag-->Lys23aag (E23K), Leu270ctg-->Val270gtg (L270V), Ile337atc-->Val337gtc (I337V), and two silent mutations. Allelic frequencies for the missense variants were compared between the NIDDM group (n = 306) and nondiabetic control subjects (n = 175) and did not differ between the two groups. Pairwise allelic associations indicated significant linkage disequilibrium between the variants in Kir6.2 and between them and a nearby pancreatic beta-cell sulfonylurea receptor (SUR1) missense variant (S1370A), but these linkage disequilibria did not differ between the NIDDM and control groups. The results of these studies thus revealed that mutations in the coding region of Kir6.2 1) were not responsible for the previously noted association of the SUR1 variants with NIDDM (Inoue H et al., Diabetes 45:825-831, 1996) and 2) did not contribute to the impaired insulin secretion characteristic of NIDDM in Caucasian patients.
During recent years, many research teams have suggested a possible role of endogenous opiates in the control of the menstrual cycle. The level of immunoreactive beta-endorphin was measured on different days during the ovulatory cycle of 131 healthy volunteers. The levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17 beta-estradiol and progesterone were also measured. The graphic representation of opiate levels during the female menstrual cycle, where day O is the day of ovulation, shows that plasmatic beta-endorphin levels are not stable throughout. The levels increase progressively during the follicular phase, reaching a maximum (mean 139.49 pg/ml, SD 42.23 pg/ml, 95% confidence interval 121.22-157.75 pg/ml) 4 days before ovulation. During the periovulatory period (days-3 to +3) levels of beta-endorphin are very stable (mean day 0, 27.8 pg/ml, SD 6.36 pg/ml, 95% confidence interval 19.29-27.83 pg/ml) and low (p < 0.05), followed by a renewed increase during the luteal phase (mean day + 5, 87.86 pg/ml, SD 36.49 pg/ml) where a maximum level (mean 102.78 pg/ml, SD 30.35 pg/ml) is reached 24 h before the next menses. The beta-endorphin level has a negative correlation with the LH level (r = -0.50, p < 0.001) on the preovulatory days, and during the luteal phase a positive linear correlation (r = 0.47, p < 0.001) is found with the progesterone level. It seems that beta-endorphin levels in the plasma are influenced by the ovarian steroids. However, the influence of the plasmatic opiate on the gonadotropins is currently under discussion.
Secondary sicca syndrome has been described in silicotic and exposed nonpneumoconiotic individuals. Systemic autoimmune pathogenic mechanisms have been thought to be responsible. Salivary gland mineral deposition has not so far been implicated. We describe the case of a dental technician who sand-blasted dental prostheses and developed silicoproteinosis and sicca syndrome. Immunological studies were negative. Scanning electron microscopy study and energy-dispersive X-ray analysis were carried out in the patient's lung and salivary gland and in two salivary glands from nonexposed individuals diagnosed with sicca syndrome. High peaks of silicon and aluminium were detected in the patient's lung and salivary gland. Silicon/sulphur and aluminium/sulphur ratios were higher in the patient's glands (0.612 and 0.402, respectively) than in the two control salivary glands (0.193 and 0 and 0.127 and 0, respectively). We suggest that, in this case, sicca syndrome could have been caused by inorganic deposition.
Tuberculous pleural effusions occur in up to 30% of patients with tuberculosis. It appears that the percentage of patients with pleural effusion is comparable in human immunodeficiency virus (HIV)-positive and HIV-negative individuals, although there is some evidence that HIV-positive patients with CD4+ counts <200 cells x mL(-1) are less likely to have a tuberculous pleural effusion. There has recently been a considerable amount of research dealing with the immunology of tuberculous pleurisy. At present, we have more evidence that activated cells produce cytokines in a complex pleural response to mycobacteria. Intramacrophage elimination of mycobacterial antigens, granuloma formation, direct neutralization of mycobacteria and fibrosis are the main facets of this reaction. With respect to diagnosis, adenosine deaminase and interferon gamma in pleural fluid have proved to be useful tests. Detection of mycobacterial deoxyribonucleic acid (DNA) by the polymerase chain reaction is an interesting test, but its usefulness in the diagnosis of tuberculous pleurisy needs further confirmation. The recommended treatment for tuberculous pleurisy is a 6 month regimen of isoniazid and rifampicin, with the addition of pyrazinamide in the first 2 months. HIV patients may require a longer treatment. The general use of corticosteroids is not recommended at this time, but they can be used in individuals who are markedly symptomatic.
Explore the source record for details and available documents.
Up to now, only 2 cases of benign asbestos pleural effusion have been described in Spain. We report our experience of 15 patients diagnosed of benign asbestos pleural effusion (BAPE). Between 1980 and January 1995, 15 patients were diagnosed of BAPE according to the following criteria: a) evidence of pleural effusion; b) previous asbestos exposure, and c) exclusion of other etiologies of last during 3 years of follow-up. Retrospective review of diagnostic and evolutive data from the patients' clinical records. Asbestos exposure was intense in 8 patients and slight in 7. There were 11 effusions on the left side and 4 on the right side. All effusions were exudative, with a pleural adenosine deaminase level lower than 43 U/l. Eleven patients had a lymphocytic pleural fluid. All patients had nonspecific pleural histology, and asbestos bodies were detected in one case. Eleven patients achieved a radiographic resolution in less than 3 months, and 3 patients presented relapses. Fourteen patients had a good outcome, and one patient presented a lung adenocarcinoma after 5 years of follow-up. Benign asbestos pleural effusions are predominant on the left side, have a tendency to relapse and the exposition can be occasional. The outcome is good in most of the cases.
An NADP(H)-specific glutamate dehydrogenase of Haloferax mediterranei has been purified to apparent homogeneity and characterised. The purified enzyme was stabilized by glycerol in absence of salt. Glutamate dehydrogenase from Hf. mediterranei is a hexameric enzyme with a native molecular mass of 320 kDa composed of monomers each with a molecular mass of 55 kDa. At pH 8.5 the enzyme has Kms of 0.018, 0.34 and 4.2 mM for NADP+, 2-oxoglutarate and ammonium, respectively. Amino acid composition and sequence of the first 16 residues of the N-terminus have been determined.
A variety of metabolites have been found to elicit a form of inhibition or activation on an NAD-specific glutamate dehydrogenase (NAD-GDH, EC 1.4.1.2) from Halobacterium halobium. The purified halophilic enzyme was tested with several compounds known to be allosteric modifiers of mammalian glutamate dehydrogenases to determine their effects on enzyme activity. GTP, ATP, ADP and AMP did not affect the enzyme, so these effectors of bovine glutamate dehydrogenase do not play a role in the regulation of the halophilic enzyme. However, the halophilic enzyme was subject to strong inhibition by TCA intermediates. When measuring the initial rate of the reaction, the oxidative deamination of L-glutamate was inhibited by TCA metabolites such as: fumarate, oxalacetate, succinate and malate; by substrate analogues such as: NADP+, D-glutamate and glutarate; and by dicarboxylic compounds such as adipate. On the other hand, all the amino acids tested were activators of this enzyme, except the D-isomer of the substrate L-glutamate that acted as an inhibitor. The relative effectiveness of each inhibitor or activator (Ki or Ka values) was correlated with the dipole moment (mu), HOMO and LUMO molecular orbital energies, optimal distance between two carboxyl groups, and hydrophobicity. Compounds with high dipole moment acted as good activators while compounds with low dipole moment were inhibitors. We have also found that the best activators were amino acids with no polar lateral chain.
Ligand gated potassium channels, such as the ATP-regulated potassium channel, play crucial roles in coupling of stimuli to insulin secretion in pancreatic beta cells. Mutations in the genes might lead to the insulin secretory defects observed in patients with non-insulin-dependent diabetes mellitus (NIDDM). We isolated a cDNA encoding a putative subunit of a ligand gated potassium channel from a human islet cDNA library. The channel, which we designated hiGIRK2, appeared to be an alternative spliced variant and a human homologue of recently reported mbGIRK2, KATP-2/BIR1. Transcripts were detected in human brain and pancreas, but not in other tissues including cardiac muscle. The sizes of transcripts in the pancreas differed from those in the brain, suggesting tissue-specific alternative splicing and possible isoforms. We then isolated human genomic clones, determined the complete genomic structure and localized the gene to chromosome 21 (21q22). The gene was comprised of four exons and the protein was encoded by three exons. The entire coding region of the hiGIRK2 gene was scanned by polymerase chain reaction-single strand conformation polymorphism analysis in 80 Japanese NIDDM patients. We found five nucleotide substitutions; three were silent mutations of the third base of codons, one in the first intron, 9 bases upstream of exon 2, and one in the 3'-untranslated region. We conclude that mutations in the gene encoding hiGIRK2, a (subunit of) ligand gated potassium channel, is not a major determinant of the susceptibility to NIDDM in Japanese.
Insulin secretion from pancreatic beta cells is dependent on membrane potential changes that result from the concerted regulation of multiple ion channels. Among the distinct K+ channels known to be expressed in beta cells, large conductance Ca(2+)-activated K+ channels have been suggested to play an important role in stimulus-secretion coupling. In the course of a strategy to identify transcripts that are enriched in human pancreatic islet cells, we isolated a partial cDNA encoding a human large conductance Ca(2+)-activated K+ channel mRNA (hSlo). Northern analysis of mRNA showed that among a panel of human tissues hSlo is expressed at its highest levels in pancreatic islets. Screening of human insulinoma and islet cDNA libraries with the partial cDNA resulted in the isolation of 19 hSlo cDNAs. These comprised three splice variants: one shared the common underlying structure of previously reported Slo cDNAs, another variant encoded a novel 60-amino acid insertion in the putative Ca(2+)-sensing domain of hSlo, while the third group of clones had an alternate exon encoding eight amino acids in the predicted COOH-terminal end. Analysis of somatic-cell hybrids containing different portions of chromosome 10 indicated that hSlo maps to chromosome 10q22.2-q23.1. Furthermore, high resolution localization was obtained by analysis of genome-wide radiation hybrids and the CEPH "B" mega-YAC library, both of which identified for the first time a highly polymorphic genetic marker (D10S195) linked to hSlo. These studies provide tools with which to explore the physiological role of Ca(2+)-activated K+ channel proteins in pancreatic islets, and also to investigate the contribution of this locus to the inherited susceptibility to non-insulin-dependent diabetes mellitus.
Explore the source record for details and available documents.
Cytokines play an important role in the human immunological response, but the exact role of cytokines in the human immune response against parasites, especially against Echinococcus granulosus, remains unclear. IL-1, IL-2, IL-4 and tumour necrosis factor (TNF) levels in peripheral blood of 21 patients with liver hydatidosis were evaluated before surgical treatment, and the levels of IgA, IgM, IgG, IgE, specific IgE against E. granulosus, C3, C4 and DF complement fractions and CD20, CD3, CD4, CD8 and CD16 cell percentages were also determined, as was the relationship between these variables and cytokine levels. Data from hydatid patients were compared with data obtained from 21 healthy volunteers. Hydatid patients showed increases of IgG, IgE, IgEs and IL-2 (P < 0.01), and decreases of IL-1 and TNF levels (P < 0.001), but these variables (respectively) increased in patients showing cysts in the central area of the liver or with a wide opening of cysts in the biliary tract. The increase of IL-1, IL-2 and IL-4 showed a close relationship with the number, characteristics and above all the location of cysts within the liver itself. IgG and IL-4 levels and also IgG and IgE levels showed a significant correlation (P < 0.05).
One hundred forty-one children with insulin-dependent diabetes mellitus were screened for serum immunoglobulin A (IgA) antigliadin antibodies by means of an enzyme-linked immunosorbent assay (ELISA) method. None of them had gastrointestinal symptoms, and no major nutritional disturbances were detected except for a girl with moderate growth delay. Twelve patients with positive IgA antigliadin antibodies on two or more consecutive measurements underwent a small intestinal biopsy; four of them had a subtotal villous atrophy, and celiac disease was diagnosed; in another patient, a partial villous atrophy was observed. Children suffering from both diabetes and celiac disease showed an onset of diabetes at a younger age than did nonceliac patients. Prevalence of celiac disease in the screened population is 2.85%, which is higher than in the general population of the Comunidad Valenciana (one in 2,500 live births).
A freebase cocaine-smoking woman developed relapsing fever, bronchoconstriction, arthralgias and weight loss. Pulmonary infiltrates, arthritis, microhaematuria, pruriginous skin rash and mononeuritis multiplex were later added to the clinical picture. Both skin and muscle biopsies showed eosinophilic angiitis. Improvement or worsening of her clinical picture repeatedly coincided with avoidance or use of smoked cocaine, respectively. We suggest that Churg-Strauss vasculitis may be a complication of smoking freebase cocaine.
Pancreatic beta-cell mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) plays a major role in glucose-induced insulin secretion. Decreased activity of this enzyme has thus been proposed to play a role in the pathogenesis of NIDDM. Cloning of human insulinoma mGPDH cDNAs disclosed the existence of two variant transcripts with different 5' ends. Reverse transcription polymerase chain reaction (PCR) confirmed the presence of both mGPDH mRNAs in purified native human pancreatic islets and other tissues. A major 6.5-Kb mGPDH transcript was detected by Northern blot analysis in RNA from human and rat pancreatic islets, with distinctly lower levels in other human tissues, indicating that previously reported high mGPDH enzymatic activity in beta-cells is determined by high transcript levels. The mGPDH gene was mapped to chromosome 2 by PCR analysis of genomic DNA from human/rodent somatic cell hybrids, and five independent overlapping yeast artificial chromosome (YAC) clones containing the mGPDH sequence were identified from the Centre d'Etude du Polymorphisme Humain YAC library. Analysis of these YAC clones identified a highly polymorphic chromosome 2q21-q33 dinucleotide repeat genetic marker (D2S141) physically linked to the mGPDH gene. These studies provide the means to investigate the role of the human mGPDH gene in the pathogenesis of NIDDM and illustrate the value of a novel strategy to identify genetic markers for diabetes candidate genes.
NIDDM is a common heterogeneous disorder, the genetic basis of which has yet to be determined. The sulfonylurea receptor (SUR) gene, now known to encode an integral component of the pancreatic beta-cell ATP-sensitive potassium channel, IKATP, was investigated as a logical candidate for this disorder. The two nucleotide-binding fold (NBF) regions of SUR are known to be critical for normal glucose regulation of insulin secretion. Thus, single-strand conformational polymorphism analysis was used to find sequence changes in the two NBF regions of the SUR gene in 35 NIDDM patients. Eight variants were found; and three were evaluated in two Northern European white populations (Utah and the U.K.): 1) a missense mutation in exon 7 (S1370A) was found with equal frequency in patients (n = 223) and control subjects (n = 322); 2) an ACC-->ACT silent variant in exon 22 (T761T) was more common in patients than in control subjects (allele frequencies 0.07 vs. 0.02, P = 0.0008, odds ratio (OR) 3.01, 95% CI 1.54-5.87); and 3) an intronic t-->c change located at position -3 of the exon 24 splice acceptor site was also more common in patients than in control subjects (0.62 vs. 0.46, P < 0.0001, OR 1.91, 95% Cl 1.50-2.44). The combined genotypes of exon 22 C/T or T/T and intron 24 -3c/-3c occurred in 8.9% of patients and 0.5% of control subjects (P < 0.0001, OR 21.5, 95% CI 2.91-159.6). These results suggest that defects at the SUR locus may be a major contributor to the inherited basis of NIDDM in Northern European Caucasians.