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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Identification of a novel HLA-DPB1 allele, DPB1*9701, by sequence-based typing
No full textThis report describes the identification of a novel DPB1 allele, DPB *9701, found in an Italian Caucasian individual. The new allele was detected by human leukocyte antigen sequence-based typing carried out to investigate the role of genetic factors in determining the outcome of hepatitis C virus infection. DPB1*9701 was identical to DPB1*0501 except for a single-nucleotide substitution at codon 43 (GGG --> TGG). This nucleotide change is a non-synonymous mutation and results in the amino acid substitution glycine (G) --> tryptophan (W). The nucleotide sequence has been deposited in GenBank under the accession number AY033075, and denominated DPB1*9701 by the official World Health Organization Nomenclature Committee
Increased HLA-DR homozygosity associated with pre-eclampsia.
No full textIt is generally accepted that maternal recognition of paternally derived fetal antigens occurs during normal pregnancy and may be beneficial for implantation and maintenance of gestation. Thus, we have investigated the human leukocyte class II DR antigens (HLA-DR), whose role in self and non-self recognition is well known, in women with pre-eclampsia, their partners and in control couples. The HLA-DR antigens were tested in 70 pre-eclamptic primigravidae women and their partners and 70 healthy control couples using the serological Terasaki technique. Our results did not show any particular HLA-DR antigen to be correlated with pre-eclampsia, but a statistically significant increase of only one identifiable HLA-DR antigen, which was presumed to express homozygosity at the HLA-DR locus, in the pre-eclamptic women and their partners: 67.1 versus 7. 9% in the control couples (P < 0.000001). The analysis of HLA-DR compatibility between pre-eclamptic women and their partners showed a statistically highly significant increase of the female-to-male compatibility (P = 0.0003) and a lower but significant male-to-female compatibility in comparison with controls (P = 0.014). From our results, it emerges that HLA-DR homozygosity and reduced antigenic disparity seem to be associated to a major risk for pre-eclampsia, which consequently appears to be a 'couple's disease'
Identification of a novel HLA-DRB1*11 variant allele, DRB1*1189
No full textHere, we describe the identification of a novel human leukocyte antigen (HLA)-DRB1 allele, DRB1*1189, that was found in an Italian Caucasian individual. This sequence differs from HLA-DRB1*1134 by three nucleotide exchange at positions 286 (C-->T), 296 (A-->G), and 308 (C-->A) in exon 2
Microgeographic variation of HLA-A, -B, and -DR haplotype frequencies in Tuscany, Italy: implications for recruitment of bone marrow donors
No full textHLA-A/B haplotype frequencies were estimated in a sample of 2355 bone marrow donors born in a subregion of Tuscany (Italy), and the HLA-A, -B, -DR haplotype frequencies were estimated in a subset of 809 individuals. This area was divided in 10 subsamples (two-locus haplotypes), or six subsamples (three-locus haplotypes), all with sample size >50, based on administrative boundaries. A considerable level of heterogeneity of haplotype frequency was present among subsamples; this heterogeneity was associated to a large variation (up to 4-fold) of the number of new donors that must be typed in order to reach 50% chance of finding an HLA-A, -B phenotype of intermediate frequency. Knowledge of the genetic structure of the population at a microgeographic level may be useful in directing the search of specific bone marrow donors
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