PubMed Health⌕ Search

Biomedical subjects

L Terrenato

Publications and source records attributed to L Terrenato.

At least 19 recordsLinked to original sources
PubMed1992

Individual variability in the translational regulation of ribosomal protein synthesis in Xenopus laevis.

Ribosomal protein synthesis is regulated by controlling the fraction of mRNA associated with polysomes. It is known that this value changes in different developmental stages during Xenopus embryogenesis or, more generally, with changing cell growth conditions. We present here an analysis of the proportion of mRNA loaded on polysomes, carried out with probes for five different ribosomal proteins on several batches of Xenopus embryos obtained from different individuals. The results obtained indicate the existence of probe-dependent and individual differences, which reflect genetic variations in the cis- and trans-acting regulatory elements responsible for translational regulation. The fraction of ribosomal protein mRNA loaded onto polysomes can be used as an index of an individual's capacity for ribosome production.

Animals↗
PubMed1992

Autosomal dominant pure cerebellar ataxia. Neurological and genetic study.

A family with late-onset autosomal dominant pure cerebellar ataxia was studied both neurologically and genetically. Neuroimaging and electrophysiological results were in agreement with the clinical evidence showing involvement of the cerebellar system only, even many years after onset. No atrophy of inferior olives was observed by magnetic resonance imaging, while cerebellar atrophy was extremely marked. A very slow disease progression was observed in all patients. The disease can be differentiated from autosomal dominant olivo-ponto-cerebellar atrophies, and in particular from spinocerebellar ataxia type 1 mapping on chromosome 6p, which shows an early multisystemic involvement and a more rapid progression toward inability. A genetic study of the family with the 6p DNA marker D6S89 closely linked to the spinocerebellar ataxia type 1 locus was performed. Results showed significant exclusion of a linkage between the disease and the marker within a distance of 8.5% recombination, indicating that genetic heterogeneity underlies phenotypic differences.

Adult↗
PubMed1992

Natural selection associated with birth weight. VI. Towards the end of the stabilizing component.

The secular trend for stabilizing selection on birth weight has been analysed in Italy from 1954 to 1985 in order to study changes in the forces of natural selection which have occurred as a consequence of progress in health care. In previous papers we demonstrated a very rapid relaxation of stabilizing selection on birth weight. In this paper we show that in the last few years this kind of selection has been coming to an end for the vast majority of Italian newborns.

Birth Weight↗
PubMed1992

Disequilibrium of multiple DNA markers on the human Y chromosome.

We characterized four DNA polymorphisms on the Y chromosomes of 123 males from five Caucasian populations. Three markers on the male specific portion of the chromosome varied appreciably in frequency among the populations. When combined, these markers define a limited number of haplotypes compared with the maximum expected on the basis of random association. The associations found in the five groups are qualitatively similar and are thus considered to be relatively stable on an evolutionary time-scale and possibly to predate the divergence of Caucasian populations. However, the haplotype frequencies varied markedly among populations, even between weakly isolated areas such as northern vs. southern Sardinia. This may indicate rapid progression towards fixation of alternative types of Y chromosomes. We also report data suggesting that the same associations no longer hold when examining a marker as close as 275 bp from the boundary of the pseudoautosomal region on the Y chromosome.

Alleles↗
PubMed1991

A new beta-thalassaemia frameshift mutation detected by PCR after selective hybridization to immobilized oligonucleotides.

A previously undescribed mutation (-1, +3, codon 24) causing beta-thalassaemia was identified in an Egyptian patient. It consists in the concomitant deletion of a G in codon 24 and its replacement with the new trinucleotide CAC, thus resulting in the shift of the beta-globin reading frame. The sequence of the chromosome of interest was isolated from the homologous one by means of selective hybridization to an immobilized oligonucleotide. The presence of this mutation in the proband's family was confirmed by dot blot hybridization with an oligonucleotide probe.

Base Sequence↗
PubMed1991

Protection against malaria morbidity: near-fixation of the alpha-thalassemia gene in a Nepalese population.

We have previously reported that the Tharu people of the Terai region in southern Nepal have an incidence of malaria about sevenfold lower than that of synpatric non-Tharu people. In order to find out whether this marked resistance against malaria has a genetic basis, we have now determined in these populations the prevalence of candidate protective genes and have performed in-vitro cultures of Plasmodium falciparum in both Tharu and non-Tharu red cells. We have found significant but relatively low and variable frequencies of beta-thal, beta S, G6PD (-), and Duffy (a-b-) in different parts of the Terai region. The average in-vitro rate of invasion and of parasite multiplication did not differ significantly in red cells from Tharus versus those from non-Tharu controls. By contrast, the frequency of alpha-thalassemia is uniformly high in Tharus, with the majority of them having the homozygous alpha-/alpha-genotype and an overall alpha-thal gene (alpha-) frequency of .8. We suggest that holoendemic malaria has caused preferential survival of subjects with alpha-thal and that this genetic factor has enabled the Tharus as a population to survive for centuries in a malaria-holoendemic area. From our data we estimate that the alpha-thal homozygous state decreases morbidity from malaria by about 10-fold. This is an example of selection evolution toward fixation of an otherwise abnormal gene.

Animals↗
PubMed1990

The human Y chromosome shows a low level of DNA polymorphism.

Six new Y-specific probes have been isolated and are reported. Along with another six already described they have been used in a systemic search for male specific RFLPs. An overall number of 46515 nucleotides have been screened with 12 enzymes and no polymorphic pattern observed. Our data reveal a greatly reduced level of polymorphism compared with other chromosomes.

Animals↗
PubMed1990

A new beta-thalassemia mutation produced by a single nucleotide substitution in the conserved dinucleotide sequence of the IVS-I consensus acceptor site (AG----AA).

An Egyptian child with thalassemia major was found to carry two different haplotypes (I and VI) associated with two beta-thalassemic chromosomes. Analysis with several oligonucleotides and restriction enzymes, which identify the mutations most common in the Mediterranean area, allowed the identification of only one mutation, namely T----C at position 6 of the first intervening sequence (IVS-I). In order to characterize the other mutation the beta gene was amplified with polymerase chain reaction and sequenced. A G----A substitution was found at position 130 of the IVS-I which alters the conserved dinucleotide AG present in the consensus acceptor sequence, thus producing a beta (0)-thalassemia. This mutation was further confirmed by restriction analysis since it creates a new restriction site for the enzyme Afl II. It is concluded that this subject carries the IVS-I-6 mutation associated with haplotype VI, frequently observed in Mediterranean areas, and a new mutation at the acceptor site of the IVS-I, which has not been described before, associated with haplotype I. This thalassemic gene can be added to the list of mutations that can be identified by Southern analysis using Afl II.

Amino Acid Sequence↗
PubMed1990

Genetic polymorphisms in the Croatian ethno-linguistic minority of Italy.

Phenotype and gene frequencies of twelve genetic markers (ABO, RH, MNS, ACP1, ESD, PGD, PGM1, PGM2, HB, ALB, CP and HP) of the three Croatian communities (Acquaviva Collecroce, Montemitro and S. Felice del Molise) living in Southern Italy are reported. From the comparison with the surrounding Italian population and with Balkan populations, some instances of still incomplete genetic admixture can be inferred (ABO*A and O, ESD, PGD and PGM1).

Adolescent↗
PubMed1989

Frequency and molecular types of deletional alpha-thalassemia in Egypt.

The frequency of deletional alpha-thalassemia in the Egyptian population was estimated at 0.08 by DNA analysis of a newborn random sample. No alpha 0 determinants were found. The most frequent alpha+ determinant was the -alpha 3.7 type I in association with the medium allele at inter-zeta HVR. The -alpha 4.2 and alpha alpha alpha anti 3.7 arrangements were found at very low frequencies.

Chromosome Deletion↗
PubMed1988

Decreased malaria morbidity in the Tharu people compared to sympatric populations in Nepal.

The Terai region of Nepal has been known to be heavily malarious since remote times, and it has, therefore, been regarded as uninhabitable by most Nepalese people. The Tharu people, who have been living in the Terai for centuries, were reputed to have an innate resistance to malaria. Following successful control of malaria by the Nepal Malaria Eradication Organization (NMEO), a large and heterogeneous non-Tharu population now inhabits the Terai along with Tharus. By analysing NMEO records, we have found that the prevalence of cases of residual malaria is nearly seven times lower among Tharus compared to sympatric non-Tharus. This difference applies to Plasmodium vivax, which is now much more common, and to Plasmodium falciparum. We suggest that the basis for resistance to malaria in the Tharu people is a genetic factor yet to be identified.

Adolescent↗
PubMed1988

Effects of environmental changes on the phenotypic expression of human polygenic traits.

The very large increase in adult stature during the last century is well documented for many countries and this phenomenon has been associated with the rapid improvement of environmental conditions. In the case of Italy, data relative to its regions and drawn from the military records of the last century showed a rapid normalization (i.e. elimination of both negative skewness and hyperkurtosis) of the distribution (1874-1938), followed by acceleration of the average increase (1938-57), which is now approaching a plateau (1957-64). Two different interactions between genotype and environment are hypothesized: the curve normalization is interpreted as being due to the elimination of extremely unfavourable conditions which inhibit growth, while the rapid stature increase is possibly due to the achievement of an environmental threshold, such as to permit a complete expression of the genetic potential. In fact, under the multifactorial model, a perfectly normal distribution is expected, unless there is differential selection before age 18.

Adolescent↗
PubMed1987

Breakpoint distribution in constitutional chromosome rearrangements with respect to fragile sites.

In an attempt to investigate possible relationships between fragile site bands and chromosome abnormalities, we have analysed the distribution of 6391 breakpoints found in constitutional rearrangements. Were relative band lengths to be ignored, a general trend for breaks to be located in fragile site bands would be confirmed. On the other hand, no difference was detected between bands with or without fragile sites if the probability of breakage for each single band is assumed to be proportional to its length. Nevertheless, a number of bands with a great excess of breakage events were identified.

Analysis of Variance↗
PubMed1986

Secular trend of twin concordance in late fetal death.

In the present paper the secular trend of twin concordance for late fetal death rate has been analysed. The results show that, while the correlation remains unchanged in MZ twins, it is greatly reduced in DZ twins. This renders untenable the assumption of comparable secular trends in the intrauterine environment of the two types of twins. An appropriate model is given for the estimation of the environmental (intrauterine) factors in late fetal concordance, under the assumption of a wide range of frequencies for unconditional lethals.

Diseases in Twins↗
PubMed1984

The HbA/HbA2 ratio in newborns and its correlation with fetal maturity.

The relative amounts of HbF, HbA and HbA2 were determined in about 1000 newborns and their parents. In newborns the mean value of HbA2 was 0.27 +/- 0.02% and that of HbF 74.69 +/- 0.25%. The ratio HbA/HbA2 was estimated at different gestational ages and was found to range from 101 at 32 weeks gestation to 76 at 45 weeks, indicating that the relative amount of HbA2 increases with fetal maturation. The correlations between the levels of the different haemoglobins and various indexes of fetal maturation (gestational age, birth weight, crown-heel length and head circumference) are also given.

Adult↗
PubMed1984

Polymorphism of erythrocyte galactose-1-phosphate uridyl-transferase in Italy: segregation analysis in 693 families.

In the course of a population study in Italy, blood samples collected from 802 unrelated newborns and both their parents (when possible) have been examined for galactose-1-phosphate uridyltransferase (GALT) polymorphism. Electrophoresis and quantitative assay of GALT activity were not always sufficient for an accurate identification of the different GALT genotypes; segregation analysis provided better criteria for classification. A parent-child correlation coefficient for GALT activity equal to 0.107-0.155 was found when only the transmission of the normal allele was concerned, but the correlation rose to 0.618-0.682 when the Duarte and Los Angeles alleles were segregating. This confirmed the existence of a low (Duarte) and high (Los Angeles) activity variant. The overall validity of our genotype classification is supported by the good agreement between observed and expected mating types and segregations. The following gene frequencies were found for the different alleles: N = 0.9192, G = 0.0036, D = 0.0372 and LA = 0.0400.

Adult↗