PubMed Health⌕ Search

Biomedical subjects

M Beretta

Publications and source records attributed to M Beretta.

At least 55 records · Page 3Linked to original sources
PubMed1982

Genetic and demographic characterization of a population with high incidence of fucosidosis.

A random sample of unrelated students living in Grotteria and Mammola, two villages of Southern Italy from where most of the Italian patients affected with fucosidosis originate, was analyzed for seven red cell enzyme polymorphisms and seven blood group polymorphisms. The observed gene frequencies are not significantly different from those typical of Southern Italy. Demographic data on the same sample were also collected and indicate isolation and high inbreeding in these villages.

Adolescent↗
PubMed1982

Subtyping of phosphoglucomutase locus 1 (PGM1) polymorphism in some populations of Rwanda: description of variant phenotypes, "haplotype" frequencies, and linkage disequilibrium data.

Some populations of Rwanda (South Twa Pygmies, Hutu, and Tutsi) have been analyzed by acid starch gel electrophoresis for the subtyping of PGM1 polymorphism. The new polymorphic third PGM11 allele, the PGM1(1Twa), which we recently detected in Twa Pygmies from North Rwanda, has not been found in this survey, whereas the rare PGM1(6) allele attains subpolymorphic frequencies in all groups. Comparison between the various populations of Rwanda shows that they differ significantly from each other with the exception of South Twa Pygmies and Tutsi. A relatively low frequency (9.6%) of the PGM1(2S) allele appears to be typical of North Twa Pygmies; a low frequency of PGM1(2F) (1.2%-3.6%) has been found in all these groups but not in the Hutu (6.4%); and a particularly high incidence of the PGM1(1F) allele (the highest so far reported) has been observed in the South Twa Pygmies (20%) and in the Tutsi (18%). The PGM1(1Twa) and PGM1(6) enzymes, which in acid starch gel are not distinguishable, can be clearly differentiated by isoelectric focusing. In addition, the same technique has shown that the rare PGM1(7) allele observed in one Hutu is different from that found at polymorphic frequency in the Japanese and from a rare PGM1(7) allele found in Germany. On the very likely hypothesis that the PGM1(1S), PGM1(1F), PGM1(2S), and PGM1(2F) result from variations at two different polymorphic sites, 1/2 and F/S, within the PGM1 structural gene, all the available population data have been analyzed to investigate whether preferential combinations (haplotypes) were identifiable. Whereas Caucasians show a prevalence of 2F and 1S combination with an 8.02% mean value of linkage disequilibrium expressed as % Dmax, from the very few and scattered African data, it is impossible to draw any inference at present.

Alleles↗
PubMed1980

Population genetics of red cell enzymes in Pygmies: a conclusive account.

In the course of a long-term research project, three groups of Pygmies and some non-Pygmy Central Africans have been examined for the following red cell enzyme markers: ACP, PGM1, PGM2, PEPA, PEPB, and PEPC, AK, ADA, and PHI. Several other red cell enzymes (ESD, CA1 and CA2, GPT, GLO, and DIA1) have been studied in only some of these groups. This paper reports all the information we obtained, including what we have already published. The following conclusions can be drawn from the whole body of data: (1) Gene patterns of Pygmies are those typical of other Africans (e.g.: lack of ADA2 and AK2 genes, low GPT2 gene frequency, polymorphism of the CA2 locus, and presence at polymorphic frequencies of PEPA2 allele. (2) Superimposed on this African genetic makeup, a number of Pygmy characters were identified, namely, a private polymorphism for the PGM26 Pygmy allele and possibly one for the PEPC2 allele, and particularly high ACPR and low PGM12 gene frequencies. (3) Some markers, especially PGM1 and ACP, turned out also to discriminate efficiently among different groups of Pygmies.

Black People↗
PubMed1978

The polymorphism of red cell esterase D in Italy.

1,153 unrelated individuals from three different areas of Italy were tested for the red cell esterase D polymorphism. The gene frequencies found in the three groups do not differ significantly from each other. The EsD2 allele in the total sample has a frequency of 14.6% but it is difficult at the present stage to know if this figure is valid for the whole Italian population. If so, the Italian EsD2 allele frequency lies at the upper limit of the range of the European values. No variant phenotypes were observed.

Erythrocytes↗
PubMed1977

An analysis of red cell enzymatic markers in the province of Bologna (Italy).

About 280 unrelated individuals living in the province of Bologna (Northern Italy) have been studied for the following red cell enzymatic markers: phosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA) and phosphohexose isomerase (PHI). 116 subjects from the same sample have also been analysed for red cell acid phosphatase (ACP). The observed gene frequencies are PGM21 = 0.280; AK2 = 0.030; ADA2 = 0.091; ACPa = 0.297; ACPb = 0.647; ACPc = 0.056. In the PHI system two individuals with the variant PHI 3-1 phenotype have been found.

Adenosine Deaminase↗
PubMed1971

Genetic recombination in Micromonospora.

Biochemical mutants were obtained from Micromonospora chalcea, M. purpurea, and M. echinospora by using ultraviolet radiation or nitrosoguanidine. Crosses carried out between complementary nutritional mutants of the same species showed positive genetic interaction. Data are reported which indicate that the interaction between the crossed strains is due to genetic recombination. No evidence for interspecific genetic recombination was found.

Crosses, Genetic↗
PubMed1966

Genetic Recombination in Crosses Between Streptomyces aureofaciens and Streptomyces rimosus.

Polsinelli, M. (University of Pavia, Pavia, Italy), and Maria Beretta. Genetic recombination in crosses between Streptomyces aureofaciens and Streptomyces rimosus. J. Bacteriol. 91:63-68. 1966.-Biochemical mutants were obtained from Streptomyces rimosus and S. aureofaciens by ultraviolet irradiation. Crosses were performed between auxotrophic strains of S. rimosus and S. aureofaciens with positive results. Data are reported which indicate that the interaction observed in some crosses is due to gene recombination.

Journal Article↗
PubMedDate not supplied

A cline for glyoxalase I allele frequencies in Italy.

A gradient of glyoxalase I allele frequencies is described in Italian populations. The association between longitude and allele frequency is assessed through simple and multiple correlation, and gene flow is suggested as a major factor in the origin of such a pattern.

Alleles↗
PubMedDate not supplied

Surnames in Ferrara: distribution, isonymy and levels of inbreeding.

The distributions of surnames in populations of small and large towns are almost exactly linearized by a log-log transformation. This indicates probable fit of genetic models to most such distributions, even when the number of surnames is very large. Genetic parameters can then be conveniently calculated from surname distributions. It was found that inbreeding indicators calculated from isonymy are negatively correlated with the size of the towns from which the names were extracted. It was also found that the levels of inbreeding at present observed in Ferrara have little effect on the frequency of homozygotes for the beta-thalassaemia gene.

Consanguinity↗
PubMedDate not supplied

Migration pattern and genetic marker distribution of the Afro-American population of Bluefields, Nicaragua.

On a sample of the population of mixed African ancestry living in Bluefields, Nicaragua, the pattern of migration and the distribution of red cell and serum genetic markers have been studied. It is concluded that, in spite of a considerable level of internal and external migration, a distinctive genetic structure is maintained by the population. Moreover, a strongly negative assortative mating can be observed between people inhabiting the western and eastern areas of Nicaragua. It is estimated that most, if not all, of the genetic pool of the population is accounted for by a process of admixture between African and Indian peoples.

Anthropology, Cultural↗
PubMedDate not supplied

Isonymy in emigrants from Ferrara in 1981-1988.

The distribution of surnames in the emigrants from the population of the town of Ferrara in the period 1981-88 was studied by sex and place of birth, namely Ferrara versus other places. Emigrants born in Ferrara were defined as first time emigrants and those who had previously immigrated to Ferrara were defined second time emigrants. It was found that random isonymy is smaller in second time emigrants. Sex ratio is not different in the two types of emigrants. As indicators of the abundance of surnames in a distribution, the common ecological indexes derived from entropy were used and compared between types of emigrants. It was found that redundancy, as isonymy, is larger in the first time emigrants than in second time emigrants. It was observed that second time emigrants were consistently and significantly older than first time emigrants, and that a considerable fraction of them, (22.4%) returned to their place of birth. A sexual dimorphism in age at emigration was observed in second time emigrants, females emigrating at an older age than males.

Adult↗
PubMedDate not supplied

Isonymy in records of births and deaths in Ferrara.

Surname distributions were studied in records of male and female births in Ferrara in the period 1982-89, and in records of male and female deaths in the same period. Average year of birth and standard deviation was 1985 +/- 2.3 for the birth series, and 1912 +/- 14.4 for the death series. Then the surname distributions, in two independent samples at an average distance of 73 years, were compared. It was observed that random isonymy within series, which depends on the shape of the distribution, stays fairly constant at three generations of distance, indicating near-equilibrium of surname turnover. The migrational contribution is indicated by the significant decrease of random isonymy between series, measured with the method of Lasker. It was also observed that immigrants to Ferrara have a life-span significantly longer than people born in the town.

Aged↗
PubMedDate not supplied

Microevolution in Ferrara: isonymy 1890-1990.

The distribution of surnames in the population of the town of Ferrara, as it existed in the memory banks of the Municipality Computer in June 1990, was studied by sex, age and place of birth of residents. Random isonymy was studied separately in persons born before 1901, and in persons born in the nine decades thereafter, ending with the period 1981-90. Isonymy was higher in the older age groups studied. Also other indicators of the abundance of surnames in the distribution, the common ecological indexes derived from entropy, were calculated and compared between age groups. It was found that redundancy, as isonymy, is larger in older age classes than in younger classes. Surname effective number was defined as the inverse of isonymy corrected for sample size, and it was observed that it is practically identical with Fisher's alpha. It was then possible to separate random isonymy into two components, so that for sample size N its formulation becomes Ir = 1/alpha + 1/N It was found that in Ferrara alpha increased significantly in time, indicating enrichment of surnames in the population in the century 1890-1990.

Age Factors↗
PubMedDate not supplied

Microevolution in Perugia: isonymy 1890-1990.

The distribution of surnames in the population of the Comune of Perugia, as it existed in the memory banks of the Municipality Computer in autumn 1991, was studied by age and place of birth. Fisher's alpha and Karlin-McGregor's v were estimated in the total population, in persons born before 1901, and in persons born in the nine decades thereafter, ending with the period 1981-1991, for immigrants and for natives of Perugia, respectively. The wealth of surnames was significantly higher in immigrants than in natives of Perugia, as detected by alpha, v and by the log-log regression of the corresponding distributions. Among residents born in Perugia, Fisher's alpha shows a minimum value during 1921-1930, explained as a consequence of the First World War. The relationship between all possible combinations of cohorts born in the 10 different decades was studied through the Euclidean distance and through Lasker's coefficient of relationship, and a significant correlation between the former and time was revealed, both in immigrants and in natives of Perugia. When compared with the Province of Ferrara, Perugia was far richer in surnames, as measured by Fisher's alpha, for the total population and for each of the 10 decades analysed. Recent immigration, measured by Karlin-McGregor's v, was significantly higher in Perugia until the 1960s, equal in both Provinces during the 1970s, and higher in Ferrara during the 1980s.

Adolescent↗
PubMedDate not supplied

Isonymy and the genetic structure of Switzerland. I. The distributions of surnames.

The surname distribution of the population of Switzerland was studied using a sample of 1,702,000 private users registered for the year 1994 in the Helvetic Telephone Directory. These users were distributed in four linguistic areas, in 26 Cantons and 271 Communes of the Confederation. Estimates of unbiased random isonymy, of Fisher's alpha, an indicator of abundance of surnames converging to the allele effective number in standard genetic polymorphisms, and of Karlin-McGregor's v, an indicator of immigration rates, were calculated for each Commune, each Canton, each linguistic area and for the whole Confederation. The Commune with the highest value of alpha was Geneva (alpha = 5312) followed by Versoix (3713) and by the Communes of Vaud on the north shore of Lake Leman, Chavannes (3381), Montreux (3200), Nyon (3114) and Lausanne (3109). The Italian-speaking Communes of the Ticino were next. The lowest value (alpha = 29) was observed in Poschiavo, south of the Berninapass; alpha = 39 was observed in Einsiedeln (Schwyz); then Mels and Widnau (62 and 67, Canton of St Gallen), Frutingen in Bern (72), and Appenzell (80). Accordingly, the highest consanguinity values were observed in the Grisons and in the nucleus of the founding Cantons, while the lowest were observed in the Cantons of Geneva and Vaud, preferential areas of immigration to Switzerland from abroad. The effect of subdivision on isonymy is large at the Commune level, and decreases in Cantons and linguistic groups. French and Italian languages indicate minor, German and Romanisch major inbreeding.

Data Collection↗