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Biomedical subjects

A Piazza

Publications and source records attributed to A Piazza.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Altered glucose tolerance in carbon disulfide exposed workers.

Oral cortisone glucose tolerance tests were performed in 66 CS2-exposed workers and in 66 individually matched control subjects. Results indicate a higher and significant (p less than 0.001) prevalence of latent diabetes in the CS2-exposed group (72.7%) as compared with the control group (16.7%), and the existence of a positive and significant (p less than 0.001) correlation between blood glucose values and exposure index. Possible mechanisms of action involving zinc metabolism and pyridoxine metabolism are discussed.

Adult↗
PubMedDate not supplied

Migration rates of human populations from surname distributions.

Migration is an important factor in the biological evolution of human populations, and surnames provide one of the simplest records of identification. The distribution of surnames can supply quantitative information on the structure of human populations. Surnames considered as alleles of a gene transmitted only by the male line can be assumed to be neutral markers and therefore satisfy the expectations of the neutral theory of evolution, which is entirely described by random genetic drift, mutation and migration. As data on surnames are easier to collect than those from genes, the information yield is potentially increased, but the validity of the conclusions must be tested in actual samples. The purpose of this report is to compare the estimates of migration rates in Italy, as inferred by the surname distribution found in the telephone directories and other sources, with the corresponding estimates from official demographic sources. Our findings show that in these samples the ratio of surnames to individuals makes it possible to calculate reliable estimates of migration rates.

Genetics, Population↗
PubMedDate not supplied

Population history of Corsica: a linguistic and genetic analysis.

Genetic and linguistic differentiations within Corsica were analysed and compared; the genetic relationships of Corsica to other Mediterranean populations were also studied. Lexical distances between 49 Corsican localities were computed from a standard word list; trees built from these distances were compared with average linkage and neighbour-joining trees of genetic distances. Our lexical distance results confirmed the north/south dialectal subdivision of Corsican speeches described by linguists. No clear results were achieved with genetic distances because of the low number of loci for which data were available. Nevertheless, a tight northern cluster clearly emerged. When compared to other Mediterranean populations, Corsica showed a certain degree of differentiation, although not so marked as that of Sardinia. Corsica presented genetic affinities with Campania, Sicily, Liguria, Provence and Latium, while distances with Tuscany and Sardinia were larger. These results can be interpreted as a reflection of the prehistoric isolation of Corsica and the relative contribution to the island gene pool of prehistoric and historic invaders and immigrants from several populations.

Blood Group Antigens↗
PubMedDate not supplied

The role of DRB1 amino acid residue differences on donor-specific antibody production and acute rejection after cadaveric renal transplant.

The correlation between DRB1 amino acid residue matching, post-transplant humoral response and acute rejection (ARj) episodes was analysed in 51 renal transplant donor-recipient pairs in order to determine new criteria for organ assignment based on the alloreactivity of the residue within the peptide binding groove. HLA class I and II compatibility was defined using serological and genomic techniques; a sequence-based typing (SBT) was used for a higher resolution of DRB1 alleles. Humoral response was monitored in the first post-transplant year using triple staining flow cytometric analysis of donor-specific antibodies (Abs). Our data showed that DRB1 residue compatibility was always correlated to the absence of ARj while the presence of one or more aminoacid differences was associated with a similar frequency of ARj. Analysis of the mismatched DRB1 amino acid residue localised in the beta-pleated sheet and the alpha-helix of the DRB 1 molecule revealed that the frequency of beta-pleated sheet residue mismatches (MMs) was higher in the ARj-positive than in the ARj-negative group. A significant increase in the alpha-helix residue MMs was observed in patients with anti-class II Ab production (p = 0.034). Furthermore, analysing in detail DRB 1 MMs at the level of single amino acid residue, we found that the frequency of the mismatches localized in codon 9 and codon 28 in the beta-pleated sheet, as well as in codon 57 in the alpha-helix, was higher in patients who experienced ARj; on the other hand, MMs in codon 58 of the alpha-helix were more frequently associated with anti-class II Ab production. The identification of the residues more involved in alloreactivity onset will make it possible to define the existence of "permissive" or immunogenic" allele combinations which could simplify and increase the chances of a successful transplant.

Amino Acids↗
PubMedDate not supplied

Radioguided-surgery of early breast lesions.

BACKGROUND: Radioguided-surgery has been recently proposed in patients with clinically occult breast lesions. This study aimed to evaluate the feasibility of correctly locating and eradicating, by a single intralesional injection of a radiotracer, any breast lesion and, in the case of malignancy, to perform simultaneous sentinel lymph node (SLN) biopsy procedure. PATIENTS AND METHODS: Sixty-three women with early breast lesions were enrolled: 42 were invasive carcinomas, 16 in situ ductal carcinomas (DCIS) and 5 fibroadenomas. RESULTS: Scintigraphic images clearly identified the lesions in all patients while SLN/s were evident in 88% of them. At surgery all the breast lesions were easily radiolocalized and eradicated with minimum surgical trauma and, for those patients with invasive carcinomas, the SLN technique was performed in 86% of them. No skip metastases were found. CONCLUSION: A single intralesional administration of radiotracer is an easy and reliable procedure to simultaneously locate and remove both the non-palpable breast lesion and the SLN when primary malignancy was intraoperatively confirmed.

Adult↗
PubMedDate not supplied

Carrier detection for prenatal diagnosis of hemophilia A in Italian families.

BACKGROUND: The results obtained from a comparative analysis between phenotypic bioassays as the ratio of factor VIII: C clotting activity to factor VIII: C-related antigen, and DNA haplotypes from RFLP's TaqI/St14 and BclI/F8A in 12 hemophilia A (HeA) families are described. METHODS: DNA from HeA patients and related at-risk women has been analyzed by Southern blotting with two probes: the intragenic F8A and the extragenic St14. Factor VIII: C coagulant activity was measured by a one-stage method, and the Factor VIII-related antigen (FVIII: RAg) was assayed with bidimensional electrophoresis. Linkage analysis was performed with the LINKAGE computer programs; in particular, the risks of carrying HeA were calculated using the MLINK program. RESULTS: The observed heterozygosity for the flanking marker DXS 52 (TaqI/St14 RFLP) in combination with intragenic BclI/F8A polymorphism was 0.94. A statistically significant difference in frequency was detected at the DXS 52 locus (allele 4) in comparison with other Caucasian populations. Linkage analysis made it possible to combine the plasma bioassay values with the DNA marker haplotypes to determine the probability of carriership; 22 females at risk were investigated: 4 of them were identified as carriers and 18 were excluded. The risk of carrying hemophilia A for some women at risk in six families is reported. CONCLUSIONS: This study compares a classic method and DNA analysis in genetic counselling for hemophilia A. In some cases the two methods may give different results when identifying carriers in at-risk families. From these data it is possible to conclude that DNA analysis combined with the phenotypic bioassays for carrier detection gives more information that the two analyses taken separately.

Alleles↗
PubMedDate not supplied

Vitamin E supplementation and oxidative status of peripheral blood mononuclear cells and lymphocyte subsets in hemodialysis patients.

Increased oxidative damage to cell membrane constituents causes profound changes in the membrane cytoarchitecture and modifications of the membrane physiological properties, e.g., the ability to respond to hormonal stimuli. In uremic patients receiving intermittent hemodialysis, a metabolic block of the phosphate pentose shunt has been described. This leads to insufficient detoxication of the hydroxyl radicals formed within the cells and therefore to increased oxidative damage to the polyunsaturated fatty acid constituents of the cell membranes. Vitamin E is known to reduce this oxidative damage and its harmful effects. We studied vitamin E (alpha-tocopherol acetate) administration in 10 chronically uremic patients receiving intermittent hemodialysis for positive effects on cell membrane-receptor response. The patients were studied before and after treatment for the extent of oxidative damage in peripheral mononuclear cells and for response to monoclonal antibodies to specific markers of T-lymphocyte subsets. After vitamin E treatment, oxidative damage decreased, and the membranes of peripheral mononuclear cells contained greater amounts of some unsaturated fatty acids. This is in agreement with a modification of the membrane phenotype markers of T-lymphocyte subsets and seems to confirm in vivo that changes in membrane structure first induced by increased oxidative damage due to the blockage of the phosphate pentose shunt can be reduced by the antioxidant action of vitamin E, which significantly influences the expression of membrane determinants.

Adult↗
PubMedDate not supplied

The distribution of HLA antigens in Italy.

Human histocompatibility (HLA) gene frequencies were studied in the Italian population. A random sample of healthy individuals born in several Italian regions and provinces was studied to estimate HLA-A, -B, -C and -DR gene frequencies using the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions was evaluated by the likelihood ratio statistics. Different Italian regions and provinces show significant differences in the HLA alleles, providing further evidence for the genetic heterogeneity in the Italian population. This heterogeneity is also displayed by a synthetic geographical representation which uses colour to map the most informative gene differences. Statistically significant gametic associations between HLA-A, -B, -C and -DR loci are reported. The difference between northern and southern Italy and between continental Italy and Sardegna is clearly shown also by their heterogeneous linkage disequilibria.

Alleles↗
PubMedDate not supplied

The distribution of some polymorphisms in Italy.

A wide data collection on blood group gene frequencies in Italian regions and provinces is presented. This report is the result of a joint collaboration of human geneticists and forensic haematologists started in 1979 and updates a previous work by the same group. The following genetic polymorphisms have been examined: red-cell antigens (ABO, FY, Kell, Kidd, Lewis, Lutheran, MNSs, P, Rhesus), red-cell enzymes (ACP1, ADA, AK1, ESD, GLO1, GPT, PGD, PGM1), plasma proteins (BF, C3, GC, HP, IGK, PI, TF). Data have been classified according to genetic systems, Italian regions and provinces. Gene frequencies were estimated by the maximum likelihood method. The goodness of fit to Hardy-Weinberg proportions has been evaluated by the likelihood ratio statistics. Genetic heterogeneity of provinces and regions is reported.

Blood Group Antigens↗