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L Delfino

Publications and source records attributed to L Delfino.

29 records · Page 2Linked to original sources
PubMed1992

Analysis of HLA DP, DQ, and DR alleles in adult Italian rheumatoid arthritis patients.

We analyzed the distribution of DRB1, DQA1, DQB1, and DPB1 allelic variants in 48 rheumatoid arthritis (RA) patients, compared with 109 Italian random controls, using PCR amplification and hybridization with specific oligonucleotides. We confirm the previously reported increase of DR4 specificity, in comparison with healthy Italian individuals. In particular, we find a statistically significant positive association of DRB1*0401 and DRB1*0404 alleles with RA. However, when we compare the DR4+ groups, none of the DRB1*04 alleles is increased in the RA group. By sequence analysis, performed on 10 patients, we demonstrate that the DRB1*04 genes of RA show no difference from the DRB1*04 sequences previously published. From the molecular analysis of the other DRB1 polymorphic variants, we find a trend of positive association of DRB1*0101 in DR4-negative patients versus DR4-negative healthy controls and, in the group of DR4-negative and/or DR1-negative patients, a similar increase of DRB1*06. Also, we observe in RA patients a statistically significant increase of DQA1*0301 and DQB1*0302 accompanied by a significant decrease of DQA1*0201, DQA1*0501 and DQB1*0201. Finally, from the analysis of DPB1 gene, it can be assessed that the distribution of DPB1 alleles does not differ significantly between RA patients and healthy controls.

Adult↗
PubMed1992

HLA-DQA1 allele and genotype frequencies in a northern Italian population.

HLA-DQA1 typing of 227 randomly selected Northern Italian people by the use of polymerase chain reaction are reported. The combined use of commercial Amplitype HLA-DQalpha system and four sequence-specific oligonucleotide probes allows the definition of 8 alleles and 36 genotypes, arranged according to World Health Organisation nomenclature. Seven of these genotypes are not observed among the analyzed samples. Allele frequencies range from 1.5 to 35.7% and genotype observations do not deviate significantly from Hardy-Weinberg equilibrium; observed heterozygosity is 0.8238 with an allelic diversity value of 0.79 and the power of discrimination is 0.925. Our Italian population sample shows differences from other Caucasian samples both for allele and genotype frequencies. This locus typing for the 8 defined alleles provides a rapid and sensitive method in individual identification and paternity investigation.

Alleles↗
PubMed1992

DNA typing of HLA-DQ alleles by gene amplification of DQA and DQB variable exons: analysis of DQA/DQB haplotypes.

In the present report, we describe a DNA typing method that allows detection of all the polymorphic variants of DQA1 and DQB1 second exons. By the oligotyping procedure provided in this paper, we are able to identify 8 DQA1 and 13 DQB1 alleles and to type random individuals in any heterozygous combination. We provide the hybridization and washing temperatures for using either 32P labelled or non-radioactive probes. The discrimination power of this procedure, compared to serological and cellular techniques, is remarkable. Therefore, this typing method finds perfect application in transplantation immunology and it will be very helpful to optimize the matching of unrelated donors before BMT. It is apparent from our results that despite the linkage disequilibrium present between DQ and DR loci, a DR specificity may frequently be associated to different DQ haplotypes. This is the case for DR4, DR7, DR8, DR9, and DR13 specificities.

Alleles↗
PubMed1992

HLA-DP genotyping in patients with systemic lupus erythematosus: correlations with autoantibody subsets.

In order to ascertain whether the HLA-DP locus plays a role in the genetic predisposition for systemic lupus erythematosus (SLE), 42 patients with SLE were typed for 17 different DPBeta haplotypes by locus specific amplification followed by allele specific oligonucleotide hybridization. Sera from the same patients were assayed for the presence of autoantibodies to Sm, RNP, Ro, La and of anticardiolipin antibodies (aCL). DPB1*0301 and DPB1*1401 were increased in patients compared with 107 healthy controls, mainly in those anti-Sm/RNP positive and aCL positive. Remarkably, DPB1*1401 and DPB1*0301 have a nearly identical nucleotide sequence, suggesting that an epitope shared by their membrane products is of major importance for the DP related susceptibility to SLE.

Adult↗
PubMed1991

Molecular analysis of HLA-DQ A alleles in coeliac disease lack of a unique disease-associated sequence.

Susceptibility to coeliac disease is strongly associated with some HLA class II antigens, encoded by the HLA-D region. Since the HLA-DQ locus seems to be primarily involved, we have analysed by polymerase chain reaction amplification and allele-specific oligonucleotide hybridization the most polymorphic region of the HLA-DQ A1 gene. No difference was observed between the 20 coeliac patients and 20 HLA-D-matched healthy controls who took part in the study. Furthermore, in patients and controls, the restriction fragment length polymorphism analysis of the HLA-DQ A gene using the restriction enzyme BglII did not disclose any specific disease-associated fragment. Our results are not consistent with a unique DQ A coeliac disease-associated sequence, but rather with the hypothesis that some polymorphic residues or allelic hypervariable regions, although found also in the normal population, can predispose to coeliac disease due to their higher frequency in this condition.

Base Sequence↗
PubMed1989

HLA-DP typing by DNA amplification and hybridization with specific oligonucleotides.

HLA-DP genotyping was performed using dot-blot analysis with synthetic oligonucleotide probes. Fourteen probes were designed based on the known sequence variations in the polymorphic segments of the DP beta second exon. Each probe was tested against genomic DNA amplified by the polymerase chain reaction, using DP beta-specific primers. A total of 45 HLA homozygous B-cell lines, selected from the Tenth International Histocompatability Workshop and pretyped for the known DP omega specificities, were analyzed. Different hybridization patterns were found for each DP omega specificity. The oligonucleotide hybridization performed on DP omega-negative B-cell lines gave a pattern distinct from those of known DP omega specificities, indicating the presence of novel DP allelic sequences. The use of sequence-specific oligonucleotides combined with DNA amplification allows a simple and reliable genotyping of DP antigens.

Cell Line↗
PubMedDate not supplied

Magnetic resonance spectroscopy of ischemic heart disease.

An overview of the basic knowledge necessary to understand the procedure of Magnetic Resonance Spectroscopy of the myocardium and its most significant applications in the study of ischemic heart disease, is presented, with reference to the personal experience. The chemical shift phenomenon, the main techniques of spectroscopic localization and the general aspects of myocardial 31P and 1H Magnetic Resonance Spectroscopy, including proton decoupling and magnetization transfer, are illustrated. Postprocessing techniques before and after Fourier transform are mentioned. 31P Magnetic Resonance Spectroscopy allows the noninvasive assessment of the metabolism of high energy phosphates, PCr/ATP ratio in particular, in the in vivo myocardial tissue with significant applications in the diagnostic approach to ischemic patients with the support of provocative tests (dobutamine). 1H Magnetic Resonance Spectroscopy allows similar evaluations based on the peak of total creatinine.

Adenosine Diphosphate↗
PubMedDate not supplied

[Allelic variations of DPB1, DQA1, DQB1 and DRB1 and rheumatoid arthritis: further genetic and statistical considerations].

We used polymerase chain reaction amplification and hybridization with specific oligonucleotides to analyze the distribution of DPB1, DQA1, DQB1, and DRB1 allelic variants in 48 patients with rheumatoid arthritis (RA) and compared our results with those from 109 randomly chosen, healthy control subjects. Our work confirms a previously reported increase in DR4 specificity in RA: in particular, we found a statistically significant positive association of the DRB1*0401 and DRB1*0404 alleles with RA. When we compared the DR4 groups, however, none of the DRB1*04 alleles were increased in the RA group. Molecular analysis of the other DRB1 polymorphic variants disclosed the trend of a positive association of DRB1*0101 (DR1) in DR4 negative patients vs DR4 negative healthy control subjects, and an increase in DRw6 (DRB1*13,*14) in the DR4 and/or DR1 negative patient group. Moreover, analysis of the association between RA and a heptapeptide motif (positions 67-74) in the third hypervariable region confirmed that this epitope confers enhanced risk for the development of RA with respect to the allele DRB1*0404 (etiologic fraction = 0.53 vs 0.12). We also observed a statistically significant increase in DQA1*0301 and DQB1*0302 accompanied by a significant decrease in DQA1*0202, DQA1*0501 and DQB1*0201 in RA patients. Analysis of DPB1 alleles disclosed no significant differences between RA patients and healthy control subjects.

Adult↗