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Biomedical subjects

A Piazza

Publications and source records attributed to A Piazza.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Rehabilitation in myocardial infarct. Study of various coagulation parameters and platelet function].

In order to evaluate coagulation and platelet function modifications in patients undergoing a rehabilitation trial after myocardial infarction, we have studied 26 patients (24 males and 2 females) of age comprised between 37 and 62 years. The effectiveness of the trial was assessed on the basis of an increased mechanical work (expressed in Kgm) at the end of the period. Modifications in platelet number, AT III and plasminogen levels were noticed at the same time, while platelet aggregation and the levels of platelet 5 HT, plasma alfa2 macroglobulin and alfa1 antitrypsin remained unchanged. The possible effects of the trial on coagulation and platelet function are discussed.

Adult↗
PubMed1983

Multiple DNA fragment polymorphisms associated with immunoglobulin mu chain switch-like regions in man.

DNA probes containing the switch region (S) associated with the human immunoglobulin heavy chain mu gene were used to investigate polymorphisms in the germ-line human DNA. Six polymorphisms, detected by a single restriction enzyme (Sst I) are described. Linkage studies in 29 families show that five of the six polymorphisms, although relatively unassociated in random individuals, segregate in complete linkage one to the other and to Gm allotypes (markers on the heavy chain of IgG), while the sixth segregates independently. Altogether, when one considers the DNA markers at the five closely linked loci and the IgG1 and IgG3 heavy chain allotypes, 33 different haplotypes have been described; of these, 28 are detected by the DNA polymorphism alone. Study of 158-187 random haplotypes showed strong linkage disequilibrium only between one DNA polymorphism (Sst A) and Gm. Of the polymorphic Sst I loci, one, Sst E [associated with 2.2- to 2.7-kilobase (kb) fragments], is included in the mu chain S region (S mu); another, Sst A (6.8-7.4 kb), must be very close to the gamma 1-gamma 3 chain gene cluster. Based on studies of an IgE human myeloma, a third polymorphism, Sst C (4.8-5.5 kb), should map 3' of the active epsilon chain gene. An Sst I restriction enzyme map of phage clones carrying the two alpha chain genes indicates that Sst A and Sst C loci probably overlap with the alpha 1 and alpha 2 S regions, respectively. Both deletion/duplications and point mutations were detected.

Chromosome Deletion↗
PubMed1981

[Preliminary considerations on the occurrence of antigens of the HLA system in a group of chronic glomerulonephritis patients].

80 patients affected by Cronic Glomerulonephritis have been typed for HLA-A-B-C locuses, using a standard NIH Microfinphotoxicity Technique. 66 healthy blood donors have been types as controls. A significantly increased frequency of HLA-Bw35 has been reported in the patients group. Further analysis is needed for definite conclusions about linkage between this disease and HLA antigens.

Chronic Disease↗
PubMed1981

Synthetic gene frequency maps of man and selective effects of climate.

The world distribution of 39 independent gene frequencies in human populations is analyzed by multivariate techniques and synthetic geographic maps. Most genetic variation is associated with longitude, with South Asia showing a tendency to be central. Also latitude and, more particularly, distance from the equator play a significant role in a way that suggests that climatic factors exercise selective pressures, especially for certain genes.

Alleles↗
PubMed1981

DNA synthesis and cell generation pattern of chronic lymphatic leukaemia lymphocytes stimulated by phytohaemagglutinin.

A detailed analysis of the cell recruitment and of the cell generation pattern of normal lymphocytes and chronic lymphatic leukaemia (CLL) lymphocytes, simulated by phytohaemagglutinin (PHA), was performed by the bromodeoxyuridiine (BUdR) Hoechst technique. It was found that in normal cultures the majority of cells divide two or three times, producing an early peak of DNA synthesis, while only a few cells grow exponentially and pass through many rounds of replication. On the contrary, the majority of CLL responsive cells grow exponentially, producing a delayed peak of DNA synthesis, while cells which divide only two or three times are scarce or absent. No difference in the minimal cell cycle length of the normal and the CLL exponentially growing population was found. In addition, a cell population recruited into cycle for the first time 5-6 days following PHA stimulation was observed in normal cultures but not in CLL cultures.

Cell Cycle↗
PubMed1981

Genetic variation in the quantitative levels of an NADP (H)-binding protein (FX) in human erythrocytes.

FX is a red cell NADP(H)-binding protein that has been well defined biochemically and immunologically but whose function is still unknown. Preliminary data indicated that the levels of this protein are significantly increased in hemizygotes, heterozygotes, and homozygotes for the G6PD Mediterranean mutant, thus raising the question of whether or not the individual variation in FX levels is more or less directly influenced by X-linked genes. The present study, based on a large series of population and family data collected in Sardinia, confirms unequivocally the above mentioned interaction, but shows at the same time that the variances in FX levels "between sibships" are 2-3 times larger than those "within sibships," when the analysis is done separately for the G6PD-normal or the G6PD-deficient sibs. From the comparison of the interclass and intraclass correlation coefficients, it appears that about 60% of the total variation of FX is of genetic origin. Moreover, the FX levels of children, analyzed in a pairwise manner, were found to be more positively correlated with those of their fathers (r = 0.39) than with those of their maternal grandfathers (0.20). This latter finding obviously favors the conclusion that "autosomal" rather than "X-linked" genes are involved in the determination of the FX levels.

Adult↗
PubMed1980

The HLA-A,B gene frequencies in the world: migration or selection?

Multivariate methods make it possible to condense much of the information available for a large number of alleles into one or a few synthetic variables. The geographic distribution of synthetic variables can be analyzed and plotted by the same technique used in analyzing and mapping the gene frequency of a single allele. The information contained in 21 HLA-A and HLA-B alleles from 116 world populations is condensed in principal components and discriminant functions which describe the global variation of gene frequencies along longitudes and along latitudes. Most genetic variation is associated with longitude and shows a center of symmetry in Asia. Thus Asia, or some part of it, may have been the center, both geographically and historically, of late Pleistocene migrations. However, latitude also plays a significant role (perhaps 10% of the genetic variation). A remarkable symmetry of the latitude variation in opposite (north and south) hemispheres suggest that climatic factors exercise selective pressure for certain HLA alleles. More specifically A1, A3, B7, B8, and B27 show about equally high correlation coefficients (between 0.45 and 0.55) with distance from equator. This result supports the idea that the well-known linkage disequilibria between A1 and B8, A3 and B7 are probably kept by selective pressure.

Alleles↗
PubMed1979

Analysis of some factors effecting survival in malignant gliomas.

Many factors, including the histological aspect, are known to effect the survival of patients with malignant gliomas. The relation between survival and diagnoses such as primary and secondary glioblastoma, anaplastic astrocytoma, etc., is not definitely clear. In 324 malignant gliomas the relationship between survival and age, sex, tumor pathology, occurrence of lymphoplasmacytic infiltrations, and size of the examined specimen was studied. Preoperative intervals of primary and secondary glioblastomas do not differ; anaplastic astrocytomas show definitely longer preoperative intervals and slightly but not significantly longer postoperative patient survival. The correlations are discussed, focusing on importance of knowing the survival times of untreated cases in order to evaluate the efficacy of chemotherapeutic drugs in malignant gliomas.

Adult↗
PubMed1978

Synthetic maps of human gene frequencies in Europeans.

Multivarate techniques can be used to condense the information for a large number of loci and alleles into one or a few synthetic variables. The geographic distribution of synthetic variables can be plotted by the same technique used in mapping the gene frequency of a single allele. Synthetic maps were constructed for Europe and the Near East, with the use of principal components to condense the information of 38 independent alleles from ten loci. The first principal component summarizes close to 30% of the total information and shows gradients. Maps thus constructed show clines in remarkable agreement with those expected on the basis of the spread of early farming in Europe, thus supporting the hypothesis that this spread was a demic spread rather than a cultural diffusion of farming technology.

Agriculture↗
PubMed1977

Family studies and HLA typing in ankylosing spondylitis and sacroiliitis.

The families of 21 ankylosing spondylitis (AS) and 16 sacroiliitis (SI) patients were investigated and typed for HLA markers. The association of HLA B27 with AS was confirmed, but no strong evidence for the same or other HLA markers being associated with SI was found. Inheritance patterns in families were analyzed according to the multifactorial and monofactorial models. It is proposed that a major gene associated or interacting with the B27 product controls the susceptibility to AS, and that this gene behaves as a dominant with incomplete penetrance. The problem as to whether linkage disequilibrium maintained by selective pressure, or functional epistasis between the "disease gene" and the B27 antigen may be the acting mechanism of association, remains to be elucidated.

Arthritis↗
PubMed1976

Immunoglobulin allotypes in Sardinia.

1218 individuals from Sardinia island (Italy) were tested for Gm and Km markers; 10 were not tested for Gm and only 401 were typed for Am markers. The peculiar genetic makeup of the Sardinian population is confirmed by their Gm allotypes. Their differences from those found in a control population of continental Italy (Ferrara), suggest ancient contacts with the Middle East and Africa. An indication for such contacts may also be found in the striking presence of the haplotype Gm f;n;bsc5, a haplotype not previously found in a human population. A significant difference of G2m(n) allotype was observed between highland and lowland regions. If confirmed, it may suggest an adaptive pressure related to the CH2 region of the gamma2 chain, possibly due to endemic malaria in the past.

Adolescent↗
PubMed1975

[Frequency of goiter and urinary iodine in the Peidmont school children. Data on iodine contents in some local food].

The frequency of thyroid alterations was examined and dietary iodine intake was assessed via urinary iodine in 6-15 yr-old schoolchildren from 145 towns in Piedmont and the Aosta Valley. Local food iodine values were also determined in 56 towns. Alteration frequency and daily urinary elimination of iodine were inversely proportional, even within individual school populations. The endemic goitre urinary iodine threshold (around 40-50 mug I/g creatine) varied from area to area, with as much as double this value in some instances. Drinking water iodine was usually from 0 to 3 mug/l, with relatively low values in high localities. Much higher levels were noted in the presence of salsobromoiodic hot springs. Local Piedmontese foods contained less iodine than those bought in city markets.

Adolescent↗