Search PubMed⌕ Search

Biomedical subjects

A Doria

Publications and source records attributed to A Doria.

At least 55 records · Page 3Linked to original sources
PubMed2002

[Prevalence and clinical features of fibromyalgia in systemic lupus erythematosus, systemic sclerosis and Sjögren's syndrome].

BACKGROUND: We studied the prevalence of fibromyalgia in 3 different groups of patients affected respectively with systemic lupus erythematosus, systemic sclerosis (scleroderma) and primary Sjögren's syndrome. The typical fibromyalgia findings encountered in these diseases were examined. METHODS: We enrolled 250 consecutive outpatients: 100 with systemic lupus erythematosus, 50 with systemic sclerosis, 100 with primary Sjögren's syndrome and 2 control groups (30 healthy subjects and 75 patients with primary fibromyalgia). Fibromyalgia features were evaluated by algometry, VAS for pain, Mc Gill Pain Questionnaire and Fibromyalgia Impact Questionnaire. RESULTS: Fibromyalgia has been found in 1 case (1%) with systemic lupus erythematosus, 1 case with systemic sclerosis (2%), 22 cases (22%) with primary Sjögren's syndrome and in 1 (3.3%) of the healthy controls. The number of tender points was significantly higher (p<0.01) in the patients with Sjögren's syndrome in comparison with the other groups. Fibromyalgic findings were similar in the patients with primary fibromyalgia and Sjögren's syndrome with fibromyalgia, unless for both poor sleep and low algometric thresholds which were more frequently found in primary fibromyalgia (respectively p<0.001 and p=0.05). CONCLUSIONS: Our study suggests that fibromyalgia is relatively frequent in primary Sjögren's syndrome, while in systemic lupus and systemic sclerosis its prevalence is not different from that found in the healthy controls. Typical fibromyalgia findings, except algometric values, were similar between the cases with Sjögren's syndrome plus fibromyalgia and fibromyalgia alone.

Case-Control Studies↗
PubMed2001

Risk of congenital complete heart block in newborns of mothers with anti-Ro/SSA antibodies detected by counterimmunoelectrophoresis: a prospective study of 100 women.

OBJECTIVE: To assess the true prevalence of congenital complete heart block (CCHB) in infants of anti-Ro/SSA-positive women known to have connective tissue disease (CTD) and, secondarily, to evaluate the prevalence of other electrocardiographic abnormalities in these newborns at birth. METHODS: A prospective study was conducted in 4 referral hospitals. One hundred anti-Ro/SSAA-positive mothers were followed up before they became pregnant and during the index pregnancy. Counterimmunoelectrophoresis and immunoblotting were used to test for antibodies to extractable nuclear antigens. RESULTS: Of the 100 women with anti-Ro/SSA antibodies, 2 had infants who developed CCHB in utero (2%). The CCHB was detected at 22 weeks and 20 weeks, respectively. One of the 2 mothers had primary Sjögren's syndrome (SS), and the other had undifferentiated CTD (UCTD). No case of CCHB occurred among the infants of 53 mothers with systemic lupus erythematosus (SLE). No fetal death occurred due to CCHB. In 2 centers, electrocardiography was recorded in 24 unselected newborns, and 4 were found to have sinus bradycardia. CONCLUSION: The prevalence of CCHB in newborns of prospectively followed up women already known to be anti-Ro/SSA positive and with known CTD was 2%. This finding is useful with regard to preconception counseling of these women. The risk of delivering an infant with CCHB may be higher in mothers with primary SS or UCTD than in those with SLE. Additional electrocardiographic abnormalities such as sinus bradycardia and prolongation of the QT interval may be present in their children.

Antibodies, Antinuclear↗
PubMed2001

Flt-3 and its ligand are expressed in neural crest-derived tumors and promote survival and proliferation of their cell lines.

Flt-3 ligand (FL) is a cytokine that promotes the survival, proliferation, and differentiation of hematopoietic progenitors in synergy with other growth factors, such as stem cell factor. Previously we have demonstrated that stem cell factor and its receptor c-kit are expressed in neural crest-derived tumor cells and that a c-kit block induces their apoptosis. Here we have evaluated the expression of flt-3 and its ligand in 12 neuroectodermal tumor cell lines from neuroblastoma (NB), neuroepithelioma (NE), Ewing sarcoma (ES), and peripheral neuroectodermal tumor (PNET) and in 38 biopsies: 19 from NB and 19 from ES and PNET. RT-PCR demonstrated the expression of flt-3 and FL in all lines. Coexpression was observed in 42% of NB and in 74% of ES and PNET biopsies. Flow cytometry confirmed the presence of membrane and cytoplasmic flt-3 and membrane FL in all lines, whereas soluble FL protein was not measurable in their supernatants. Microphysiometric demonstration of acidification of the medium provided evidence of the specific response of cell lines to FL stimulation. Specific flt-3 phosphorylation after FL treatment was also demonstrated by Western blotting analysis. In cells growing in RPMI plus 1% fetal calf serum, FL revealed a significant proliferating activity, more evident in NB and NE lines (mean increase of viable cells, 73 +/- 26% after 1 day). Treatment with flt-3 antisense oligonucleotides significantly inhibited cell growth. FL also displayed an antiapoptotic activity: after a 12-hour culture in the presence of 0.1% fetal calf serum, FL caused a 50% reduction of apoptotic cells. These results provide further evidence that neuroectodermal and hematopoietic cells share common regulatory pathways, and could be of interest in the clinical management of neuroectodermal tumors.

Base Sequence↗
PubMed2001

The generalized torque approach for analyzing the results of pedaling tests.

This paper deals with the analysis of experimental data obtained using an ergometer apparatus. A straightforward analysis method based on the power equation and the concept of generalized torques is presented. This method makes it possible to study the influence of the net muscle joint torques and gravity and inertia forces on the crank torque. The assumptions and limitations of the proposed method are discussed and this method is compared with the methods of analysis proposed by other researchers. In order to assess the validity of the method, some experimental data are elaborated. Results show that the method can highlight the effect of training and the pedaling technique of an athlete.

Ankle Joint↗
PubMed2001

Dephosphorylation of autoantigenic ribosomal P proteins during Fas-L induced apoptosis: a possible trigger for the development of the autoimmune response in patients with systemic lupus erythematosus.

OBJECTIVES: Autoimmune diseases are characterised by the production of autoantibodies against various autoantigens. In the past few years data have been published on a possible role of apoptosis in the development of autoimmunity. These include the finding that several autoantigens become modified (for example, by cleavage) during apoptosis, and the observation that these modified antigens are translocated to the cell surface. When the normal clearance of apoptotic cells somehow is disturbed, such modified antigens might become exposed to the immune system. Because acidic ribosomal P (phospho-) proteins targeted by autoantibodies in systemic lupus erythematosus (SLE) are also concentrated at the surface of apoptotic cells, this study aimed at investigating what modifications occur on these antigens during apoptosis. METHODS: Apoptosis in Jurkat cells was induced by Fas ligand (Fas-L), and the fate of autoantigenic P proteins was analysed in both normal and apoptotic total cell extracts. RESULTS: The autoantigenic P proteins were not cleaved but dephosphorylated during Fas-L induced apoptosis. This dephosphorylation was prevented when caspase activity was inhibited. CONCLUSIONS: As has been shown for other autoantigens targeted by autoantibodies in SLE, P proteins also are modified during apoptosis. P1 and P2 are completely dephosphorylated while P0 is partly dephosphorylated. Because the epitope targeted by autoantibodies normally is phosphorylated, it is possible that the apoptotic dephosphorylation of the antigen might be the trigger for the development of the autoimmune response against P proteins.

Apoptosis↗
PubMed2001

Mutation screening of the neurogenin-3 gene in autosomal dominant diabetes.

We investigated whether genetic variability in neurogenin-3, a basic helix-loop-helix transcription factor that is expressed in the developing pancreas, contributes to the etiology of maturity-onset diabetes of the young or other forms of autosomal dominant diabetes. Ninety-one probands of families with autosomal dominant diabetes were screened for neurogenin-3 mutations by dideoxy fingerprinting. Three sequence differences were identified: a polymorphism not affecting the amino acid sequence (L75L), a CA insertion/deletion in intron 1 (-44ins/del), and a C to T transition causing a serine to phenylalanine substitution (S199F). None of these sequence differences were more frequent in the family probands than in 179 nondiabetic controls. In contrast, allele 199F was weakly, but significantly, associated with common type 2 diabetes (199F frequencies = 0.436 in 132 cases with type 2 diabetes vs. 0.346 in the family probands and 0.346 in controls; P = 0.05). The relative risk of type 2 diabetes for 199F carriers was 1.7 (95% confidence interval, 1.04-2.7). We conclude that sequence differences in the neurogenin-3 gene do not play a major role in the development of autosomal dominant diabetes. Rather, they might contribute to common type 2 diabetes, although this finding must be replicated in other populations.

Adolescent↗
PubMed2001

Type 2 diabetes locus on 12q15. Further mapping and mutation screening of two candidate genes.

We recently reported evidence of a novel type 2 diabetes locus placed on chromosome 12q15 between markers D12S375 and D12S1684 (Diabetes 48:2246-2251, 1999). Four multigenerational families having logarithm of odds (LOD) scores >1.0 in the original analysis were genotyped for 11 additional markers in this interval to refine this mapping; this allowed us to narrow the linked region to the interval between markers D12S1693 and D12S326. In a multipoint parametric analysis using the VITESSE software, the LOD score for linkage at this location reached 3.1 in one of these families. This interval contains the gene for protein tyrosine phosphatase receptor type R (PTPRR)--a protein that may be involved in both insulin secretion and action. After determining PTPRR exon-intron structure, we identified several polymorphisms in this gene but no mutation segregating with diabetes. The search for mutations was also negative for carboxypeptidase M (CPM)--another candidate gene mapped to this region. In summary, our data provide further evidence for the existence of a type 2 diabetes locus on chromosome 12q15. This locus, however, does not appear to correspond to the PTPRR or CPM, although a contribution of mutations in regulatory regions cannot be excluded at this time.

Adolescent↗
PubMed2000

The use of Tween 20 in immunoblotting assays for the detection of autoantibodies in connective tissue diseases.

Autoantibodies directed against intracellular antigens can be detected by immunoblotting (IB). Due to its high sensitivity this technique has many advantages, but it can give misleading results when the specific bands are weak or blurred against the background staining. To decrease background staining, non-ionic detergents (Tween 20, Triton X-100, Nonidet P-40) are generally used as blocking agents. Moreover, these agents appear to have a renaturating action towards proteins and antigens. Tween 20 has a more pronounced renaturating effect on proteins than other detergents and thereby improves antigen-antibody binding. To evaluate the effect of Tween 20 on specific autoantibody detection by IB, we tested the sera of 162 patients with connective tissue diseases (CTDs) by adding this detergent at certain steps of the IB assay. We found that the use of Tween 20 in the IB procedure significantly improved the binding of autoantibodies to Jo-1, Scl70, (U1)RNP 68 kDa and C, Sm B/B' and D. Moreover, it increased the sensitivity for the detection of anti-Sm D peptide in systemic lupus erythematosus (SLE) sera with no decrease in specificity. In contrast, the addition of Tween 20 significantly decreased the binding of autoantibodies specific for ribosomal P proteins, La/SSB, Ro/SSA, but not the overall sensitivity and specificity of the method. We conclude that the addition of Tween 20 to standard IB is advantageous for anti-nuclear antigen antibody detection and improves the sensitivity of the method in revealing anti-Sm-positive sera in SLE. However, Tween 20 is not recommended for the detection of anti-cytoplasmic antibodies.

Autoantibodies↗
PubMed2000

Anti-ribosomal P protein antibodies detected by immunoblotting in patients with connective tissue diseases: their specificity for SLE and association with IgG anticardiolipin antibodies.

OBJECTIVE: To assess the prevalence and clinical and serological associations of anti-ribosomal P protein antibodies (anti-P antibodies) in patients with connective tissue diseases (CTDs) and investigate the immunobiological nature of autoantibody clustering in which anti-P antibodies play a part. METHODS: IgG anti-P antibodies in the sera of 267 patients with CTDs and 31 healthy subjects were analysed by immunoblotting performed on cytoplasmic extract of Raji cells. 60 patients with systemic lupus erythematosus (SLE), 32 systemic sclerosis, 46 primary Sjögren's syndrome, 16 poly/dermatomyositis, 11 rheumatoid arthritis, 8 undifferentiated CTD, 72 overlap CTD, and 22 primary antiphospholipid syndrome were studied. Anti-P antibodies were affinity purified by elution from nitrocellulose bound antigen and tested by ELISA for their binding activity to cardiolipin. RESULTS: Anti-P antibodies were detected in 16 (6%) patients and in none of the controls: 12/60 SLE (20%) and 4/80 undifferentiated/overlap patients with CTD (5%). A close association of IgG antibodies with P proteins and with cardiolipin was seen in lupus sera (p=0.0009, odds ratio 18.33). Anti-P antibodies from 9 of 12 anti-P lupus serum samples could be affinity purified and none of the affinity purified fractions cross reacted with ELISA plate coated cardiolipin. CONCLUSIONS: Anti-P immunoreactivity is a specific marker of SLE and lupus-like disease and its detection is recommended as a powerful diagnostic tool. Anti-P antibodies are strongly clustered with IgG anticardiolipin antibodies in lupus sera, even if they are independently elicited. This suggests that their cognate autoantigens play a part in a common pathogenetic pathway in SLE.

Antibodies, Anticardiolipin↗
PubMed2000

Methods for the study of the genetic determinants of diabetes and its complications.

Diabetes and its complications have a multifactorial etiology that includes both environmental and genetic factors. This makes the aim of finding susceptibility genes difficult because of the contribution of multiple genes, the wide variety of environmental factors that are involved, the lack of a clear mode of inheritance, and the presence of genetic heterogeneity. Despite these problems, the recent advances in biotechnology offer the opportunity to dissect the genetics background of complex diseases. As in the case of other disorders, there are two major approaches to study the molecular genetics of diabetes: association studies and linkage studies in families. Association studies aim to identify susceptibility alleles through several approaches, the simplest of which is to compare unrelated cases and controls. While this study design is relatively easy, false positive results are common due to unrecognized differences between cases and controls. An alternative is to use family-based association studies such as the transmission disequillibrium test. While this approach requires more recruitment efforts, the chances of false positive results are minimized. In contrast to association studies, linkage studies are not targeted to single candidate genes, but rather investigate the cosegregation between large chromosomal regions and the disease. Linkage analysis can be performed by either non-parametric or parametric methods. Non-parametric studies are relatively easy to conduct and do not require previous knowledge of the mode of inheritance. However, they cannot detect genetic heterogeneity (i.e. the presence of multiple genes that contribute to diabetes in different families). In contrast, parametric methods require large pedigrees and the assumption of a model of genetic inheritance, but they can detect genetic heterogeneity. Several new diabetes loci and genes have already been identified through the strategies outlined above, and many more are expected to be found in the next few years with the completion of the Human Genome Project.

Chromosomes, Human, Pair 12↗
PubMed1999

The role of aldose reductase gene in the susceptibility to diabetic nephropathy in Type II (non-insulin-dependent) diabetes mellitus.

The dinucleotide repeat polymorphism (5'-ALR2) in the promoter region of the aldose reductase gene on chromosome 7q35 has been implicated in the development of diabetic nephropathy in Type I (insulin-dependent) diabetes mellitus, and markers flanking the aldose reductase locus have given evidence suggestive of a linkage between diabetic nephropathy and Type II (non-insulin-dependent) diabetes mellitus in Pima Indians. To examine whether the 5'-ALR2 polymorphism in the aldose reductase gene is involved in the development of diabetic nephropathy in Caucasians with Type II diabetes, we carried out a large association study. Patients with Type II diabetes from one outpatient clinic were screened for diabetic nephropathy and divided into three groups according to the degree of this disease: 179 patients with normoalbuminuria, 225 patients with microalbuminuria and 70 patients with proteinuria. Patients with normoalbuminuria were included in the study only if they had had Type II diabetes for 10 or more years. DNA from all patients was genotyped for the 5'-ALR2 polymorphism using a previously established polymerase chain reaction protocol. The frequency of the putative risk allele Z-2 was 34.6%, 34.2% and 33.6% in the normoalbuminuria, microalbuminuria and proteinuria groups, respectively. Similarly no difference among groups was found for the frequency of the putative protective allele Z + 2. In conclusion, the results of our association study in Caucasian patients with Type II diabetes do not support the hypothesis that the 5'-ALR2 polymorphism in the aldose reductase gene contributes to susceptibility to diabetic nephropathy.

Age of Onset↗
PubMed1999

Mutations in NEUROD1 are associated with the development of type 2 diabetes mellitus.

The helix-loop-helix (HLH) protein NEUROD1 (also known as BETA2) functions as a regulatory switch for endocrine pancreatic development. In mice homozygous for a targeted disruption of Neurod, pancreatic islet morphogenesis is abnormal and overt diabetes develops due in part to inadequate expression of the insulin gene (Ins2). NEUROD1, following its heterodimerization with the ubiquitous HLH protein E47, regulates insulin gene (INS) expression by binding to a critical E-box motif on the INS promoter. Here we describe two mutations in NEUROD1, which are associated with the development of type 2 diabetes in the heterozygous state. The first, a missense mutation at Arg 111 in the DNA-binding domain, abolishes E-box binding activity of NEUROD1. The second mutation gives rise to a truncated polypeptide lacking the carboxy-terminal trans-activation domain, a region that associates with the co-activators CBP and p300 (refs 3,4). The clinical profile of patients with the truncated NEUROD1 polypeptide is more severe than that of patients with the Arg 111 mutation. Our findings suggest that deficient binding of NEUROD1 or binding of a transcriptionally inactive NEUROD1 polypeptide to target promoters in pancreatic islets leads to the development of type 2 diabetes in humans.

Adolescent↗
PubMed1999

Hepatocyte nuclear factor-4gamma: cDNA sequence, gene organization, and mutation screening in early-onset autosomal-dominant type 2 diabetes.

The aim of this study was to investigate whether mutations in hepatocyte nuclear factor (HNF)-4gamma, a transcription factor homologous to HNF-4alpha, contribute to the etiology of early-onset type 2 diabetes. Linkage between diabetes and two polymorphic markers at the HNF-4gamma locus (D8S286 and D8S548) was evaluated in 32 multigenerational families with early-onset autosomal-dominant type 2 diabetes unlinked to known maturity-onset diabetes of the young genes. Total logarithm of odds (LOD) scores were strongly negative (-50.3 at D8S286 and -46.2 at D8S548), but linkage could not be excluded in 15 families having LOD scores >-2.0. To screen these pedigrees for HNF-4gamma mutations, the gene structure was defined. Because reverse transcriptase-polymerase chain reaction experiments indicated that the first 1,674 bp of the published cDNA sequence (3,248 bp) were a cloning artifact, the correct cDNA sequence was determined by 5' rapid amplification of cDNA ends (RACE) and primer extension assay. Based on the new cDNA sequence (1,731 bp), 11 exons were found. After screening the 5' flanking region and all coding exons for mutations, we identified several polymorphisms, one of which affected the amino acid sequence (M190I). However, no mutations segregating with diabetes could be found in these families. We conclude that genetic variability in the HNF-4gamma gene is unlikely to play a major role in the etiology of early-onset autosomal-dominant type 2 diabetes.

Base Sequence↗
PubMed1999

Evidence of a novel type 2 diabetes locus 50 cM centromeric to NIDDM2 on chromosome 12q.

To replicate the recent finding of a type 2 diabetes locus (NIDDM2) on 12q, families segregating early-onset autosomal-dominant type 2 diabetes were screened for linkage. Included were 26 Caucasian and 6 non-Caucasian pedigrees with an average age at diabetes diagnosis of 37 +/- 18 years. Affected (n = 233) and nonaffected (n = 152) family members were genotyped for 17 markers covering 90 cM on chromosome 12q. While no evidence for linkage was detected at the NIDDM2 locus, a linkage peak was observed 50 cM centromeric to NIDDM2 at markers D12S375 and D12S1052. In a nonparametric analysis, the Z(all) score was 2.9 (P = 0.015) at D12S375, and increased to 3.8 (P = 0.007) among Caucasian families. Further increase in significance was observed in pedigrees with poor insulin response, with a maximum Z(all) of 6.2 (P = 0.002) at D12S375. Suggestive evidence of linkage was also detected by the parametric analysis, with the heterogeneity logarithm of odds score peaking at 2.5 (alpha = 0.15) between D12S375 and D12S1052. In summary, our data indicate that the NIDDM2 locus does not play a major role in early-onset autosomal-dominant type 2 diabetes. Rather, they strongly suggest that a previously undetected type 2 diabetes locus exists 50 cM from NIDDM2 on 12q.

Adult↗
PubMed1999

Exclusion of insulin receptor substrate 2 (IRS-2) as a major locus for early-onset autosomal dominant type 2 diabetes.

We investigated whether variability at the insulin receptor substrate (IRS)-2 locus plays a role in the etiology of early-onset autosomal dominant type 2 diabetes. By means of radiation hybrid mapping, we placed the human IRS-2 gene on 13q at 8.6 cRays from SHGC-37358. Linkage between diabetes and two polymorphic markers located in this region (D13S285 and D13S1295) was then evaluated in 29 families with early-onset autosomal dominant type 2 diabetes. Included were 220 individuals with diabetes, impaired glucose tolerance, or gestational diabetes (mean age at diabetes diagnosis 36 +/- 17 years) and 146 nondiabetic subjects. Overall, strongly negative logarithm of odds (LOD) scores for linkage with diabetes were obtained by multipoint parametric analysis (LOD score -45.4 at D13S285 and -40.9 at D13S1295). No significant evidence of linkage was obtained under the hypothesis of heterogeneity or by nonparametric methods. Fourteen pedigrees for which linkage could not be excluded (LOD score > -2.0) were screened for mutations in the IRS-2 coding region by dideoxy fingerprinting. However, no mutations segregating with diabetes could be detected in these families. These data indicate that IRS-2 is not a major gene for early-onset autosomal dominant type 2 diabetes, although a role of mutations in the promoter region cannot be excluded at this time.

Adult↗
PubMed1999

Phenotypic characteristics of early-onset autosomal-dominant type 2 diabetes unlinked to known maturity-onset diabetes of the young (MODY) genes.

OBJECTIVE: To investigate whether there are forms of early-onset autosomal-dominant type 2 diabetes that are distinct from typical maturity-onset diabetes of the young (MODY) and to characterize their phenotypic characteristics. RESEARCH DESIGN AND METHODS: The study included 220 affected subjects from 29 families in which early-onset type 2 diabetes occurred in multiple generations and was not linked to known MODY genes (MODY gene-negative families). All individuals underwent an oral glucose tolerance test and other clinical measurements aimed at investigating the underlying metabolic defect and the presence of diabetic complications. For comparison, 79 affected carriers of MODY3 (hepatocyte nuclear factor [HNF]-1 alpha) mutations were similarly examined. RESULTS: Subjects from MODY gene-negative pedigrees were diagnosed with diabetes at an older age (36 +/- 17 vs. 21 +/- 10 years, P = 0.0001) and were more frequently obese (52 vs. 18%, P = 0.0001) than MODY3 individuals. MODY gene-negative patients who were insulin treated required more exogenous insulin than did MODY3 subjects (0.7 +/- 0.4 vs. 0.45 +/- 0.2 U.kg-1.day-1, P = 0.04), despite similar C-peptide levels. Among subjects not treated with insulin, MODY gene-negative subjects had significantly higher serum insulin levels, both fasting (16.5 +/- 15 vs. 6.5 +/- 5 microU/ml, P = 0.027) and 2 h after a glucose load (53 +/- 44 vs. 11 +/- 10, P = 0.002). They also had higher serum triglycerides (P = 0.02), higher cholesterol levels (P = 0.02), more hypertension (P = 0.0001), and more nephropathy (P = 0.001). Differences persisted when families were matched for age at diagnosis. CONCLUSIONS: Our findings indicate the existence of forms of early-onset autosomal-dominant type 2 diabetes that are distinct from MODY and are frequently characterized by insulin resistance, similar to later-onset type 2 diabetes. Because of the Mendelian pattern of inheritance, the goal of identifying the genes involved in these forms of diabetes appears to be particularly feasible.

Adult↗