Maria Elena Ghiani

Sheep cheese naturally enriched in α-linolenic, conjugated linoleic and vaccenic acids improves the lipid profile and reduces anandamide in the plasma of hypercholesterolaemic subjects

Intake of dairy fat has long been considered as a risk factor for CVD. Pasture and dietary lipid supplementation have been reported to be reliable strategies in ruminant nutrition, in order to increase the content of α-linolenic acid (ALA), conjugated linoleic acid (CLA) and vaccenic acid (VA), and decrease SFA in milk fat. In the present study, we aimed at verifying whether consumption of a sheep cheese, naturally enriched in ALA, CLA and VA, would modify the plasma lipid and endocannabinoid profiles in mildly hypercholesterolaemic subjects. A total of forty-two adult volunteers (nineteen males and twenty-three females) with diagnosed mildly hypercholesterolaemia (total cholesterol 5·68-7·49 mmol/l) were randomly assigned to eat 90 g/d of a control or enriched cheese for 3 weeks, with a cross-over after 3 weeks of washout. Plasma lipids, endocannabinoids, adipokines and inflammatory markers were measured. The intake of enriched cheese significantly increased the plasma concentrations of CLA, VA, the n-3 fatty acids ALA and EPA, and more remarkably decreased that of the endocannabinoid anandamide. LDL-cholesterol decreased significantly (7%). No changes were detected in the levels of inflammatory markers; however, a significant correlation was found between the plasma levels of anandamide and leptin. The control cheese modified none of the parameters measured. The results obtained do not support the view that intake of dairy fat is detrimental to hypercholesterolaemic subjects. Indeed, they show that a naturally enriched cheese possesses beneficial properties, since it ameliorates the plasma lipid profile, and more remarkably reduces endocannabinoid biosynthesis.

Human CHIT1 gene distribution: new data from Mediterranean and European populations

AbstractA 24 bp duplication in the CHIT1 gene (H allele) is associated with a deficiency in the activity of chitotriosidase, an enzyme with the capability to hydrolyse chitin. A recent study in European and two sub-Saharan populations suggested a relationship between the presence of the mutation, improved environmental conditions, and the disappearance of parasitic diseases, including Plasmodium falciparum malaria. This result was not supported by the high frequency of the 24 bp duplication in a sample from Taiwan, an area with high malaria endemicity until 40 years ago. In this study, we analysed the frequency variability of the H allele in Mediterranean populations and its internal variability in Sardinia (Italy) with respect to malaria, which had been endemic on the island until its eradication during 1946–1950. The pattern of H frequency distributions is not consistent with the hypothesis of selective pressures acting on CHIT1 gene. The Morans index coefficient and correlogram seem to indicate, indeed, that allele distribution was determined by random factors. The pattern of frequency distribution suggests a possible Asiatic origin of the H allele, but it could be possible also that the mutant allele had diffused out of Africa, and was subsequently lost from African populations.

Prevalence and trend of overweight and obesity among Sardinian conscripts (Italy) of 1969 and 1998.

This study evaluated the prevalence of overweight and obesity in the male Sardinian population (Italy), and verifies that it has increased over the last 30 years. Data were collected during 2003-2004 from military registers in the Archive of the Military District of Cagliari for the years 1969 and 1998. A total of 22,345 forms were analysed from all Sardinia. The conscripts were classified on the basis of their place of residence and socioeconomic status. The overall prevalence of overweight and obesity in Sardinia were 4.33% and 0.55%, respectively, for the conscripts of 1969 and 9.8% and 3% for 1998. Olbia-Tempio (northern Sardinia) was the province with the highest incidence of overweight and obesity in 1969, and Nuoro (central Sardinia) had the highest incidence in 1998. Distribution of body mass index, overweight and obesity across the island showed a statistically significant heterogeneity that strongly decreased from 1969 to 1998. Among the conscripts of 1969, the incidence of overweight and obesity were higher in rural than in urban regions. An opposite trend was observed for the 1998 prevalence, it being more frequent in urban than rural regions. Comparison with other Italian regions was made. The percentages of overweight and obese individuals in Sardinia have markedly increased during the last 30 years, but their low incidence with respect to other Italian populations could be explained by the genetic peculiarity of the island. The change in the internal distribution of obesity clearly reflects socioeconomic changes.

Y-Chromosome-Specific STR Haplotype Data on the Rapanui Population (Easter Island)

ABSTRACT Located in the south Pacific Ocean, Rapanui is one of the most isolated inhabited islands in the world. Cultural and biological data suggest that the initial Rapanui population originated from central Polynesia, although the presence of foreign or exotic genes in the contemporary population, as a result of admixture with Europeans and/or South Americans during the last two centuries, also has to be considered. To estimate the genetic affinities of the Rapanui population with neighboring populations, we analyzed seven microsatellite polymorphisms of the Y chromosome that recently have been indicated as useful in the study of local population structure and recent demographic history. Phylogenetic analysis of Rapanui Y-chromosome haplotypes identified two clusters. The largest cluster contained 60% of all haplotypes and is characterized, in particular, by the presence of the DYS19*16, DYS390*20, and DYS393*14 alleles, a combination found frequently in Western Samoa. The second cluster is characterized by the presence of the DYS19*14, DYS390*24, and DYS393*13 alleles, and these have a relatively high frequency in European and European-derived populations but are either infrequent or absent in native Pacific populations. In addition to the two clusters, one male is of haplogroup Q*, which is indicative of native American ancestry. The genetic structure of the current male population of Rapanui is most likely a product of some genetic contribution from European and South American invaders who mated with the indigenous Polynesian women. However, analysis of Rapanuis relationships with other Pacific and Asian populations indicates that, as in Western Samoa and Samoa, the population has experienced extreme drift and founder events.

Significant genetic differentiation within the population of the Island of Corsica (France) revealed by y-chromosome analysis.

Using 10 Y-chromosome short tandem repeat allelic and haplotypic frequencies, we examined genetic variation within the population of Corsica and its relationship with other Mediterranean populations. The most significant finding is the high level of genetic differentiation within Corsica, with strong evidence of an effective barrier to male-mediated gene flow between the south and the rest of the island. This internal differentiation most probably results from low exogamy among small isolated populations and also from the orography of the island, with a central mountain chain running the length of the island restricting human movement. This physical barrier is reflected not only in present-day intraisland linguistic and genetic differences but also in the relatedness of Corsican regions to other Mediterranean groups. Northwest and Central Corsica are much closer to West Mediterranean populations, whereas South Corsica is closer to Central-North Sardinia and East Mediterranean populations.

Distribution of ß-Globin Cluster Haplotypes in Sardinia (Italy)

- Seven polymorphic sites in the beta-globin cluster in association with specific thalassemia mutations were analyzed in a sample from Sardinia (Italy). In order to verify previous works carried out on normal samples (betaA/betaA) and family studies on beta-thalassemia homozygotes individuals, the haplotype frequencies in both normal individuals (betaA/betaA) and betadeg39-thalassemia carriers (betaA/betadeg) were studied. In our work chromosomes carrying betadeg39 mutation are characterized by a prevalence of haplotype II (-++-+++) (52%) relative to haplotype I (+----++) (29%), in contrast, among chromosomes with betaA the frequency of haplotype I is much greater than that of haplotype II. These data confirm what was found by other authors. Nevertheless, our results disagree with those of previous studies of Sardinians, both in frequencies values and in the numbers of haplotypes identified. Population analysis performed with samples carrying the beta-thalassemic mutation highlighted the peculiarity of Sardinians with respect to other Mediterranean populations. The Corsican population is most similar to the Sardinian population, confirming previous analyses performed with both classical markers and mitochondrial and genomic DNA.

Migration and isolation effects on the Rapanui population (Easter island) through the analysis of STRs on the Y chromosome

Cultural and biological data suggests the Polynesian origin of the Rapanui population, although the presence of foreign genes in the native population, as a result of admixture with Europeans in the last two centuries has also to be considered. In order to estimate the genetic affinities of the present-day inhabitants of Easter Island and the nearby populations, we used seven polymorphisms of the Y chromosome. However we want to estimate the grade of admixture on the genetic structure that was brought from foreigners within the last two centuries upon the more geographically isolated populations in the world.The preliminary results showed the presence of 18 haplotypes analyzed on 30 male samples.The analysis of the allelic frequency showed a distribution typical of the Polynesian populations. Available data in literature, even with some differences probably due to either the founder effect or historical and ecological events that created sudden demographic variations on the island population. The phylogentic analysis of the haplotypes obtained through Network Median Joining showed two different cluster of haplotypes, of which one represents about 64% of the present haplotypes on Easter Island, which are characterized from the presence of the allele DYS19*16, very frequent in the Pacific populations. The other cluster is characterized from the presence of the allele DYS19*14, absent within the populations in the Pacific and with reasonable high frequency within the European populations and South American. Most probably the two clusters are the product of several colonizations that Easter Island had endured from the time of the Chilian and European Colonies. It was demonstrated in fact, that the arrival in 1914 of 50 German and English prisoners would have left a considerable genetic impact on the population of Rapanui, which during this period was of small size.