Search PubMed⌕ Search

Biomedical subjects

A Kouvatsi

Publications and source records attributed to A Kouvatsi.

At least 19 recordsLinked to original sources
PubMed2006

No correlation of five gene polymorphisms with periodontal conditions in a Greek population.

BACKGROUND: Various studies have examined possible correlations between a number of cytokine gene polymorphisms and periodontal disease in populations of different origins. The present study sought the correlation between four single-nucleotide polymorphisms (IL1A+3954, IL1B+4845, TNFA-308, COL1A1 Sp1), a variable number of tandem repeats polymorphism (IL1RN intron 2) and periodontal conditions in subjects of Greek origin. METHODS: One hundred and ninety-two healthy subjects, stratified as non-periodontitis and periodontitis (chronic and aggressive) cases, participated in the present study. Genotyping was performed by polymerase chain reaction-based techniques using the primers and conditions described in the literature. The frequencies of genotypes between study groups were compared using Genepop v3.3 genetic software and Instat statistical package. RESULTS: No differences were observed among the groups concerning the distributions of genotypes under investigation. CONCLUSIONS: Carriage rates of the polymorphisms under investigation in systemically healthy subjects of Greek origin are well within the range reported for Caucasians but these polymorphisms cannot discriminate between non-periodontitis and periodontitis (chronic or aggressive) cases.

Adult↗
PubMed2001

Mitochondrial DNA sequence variation in Greeks.

Mitochondrial DNA (mtDNA) control region sequences were determined in 54 unrelated Greeks, coming from different regions in Greece, for both segments HVR-I and HVR-II. Fifty-two different mtDNA haplotypes were revealed, one of which was shared by three individuals. A very low heterogeneity was found among Greek regions. No one cluster of lineages was specific to individuals coming from a certain region. The average pairwise difference distribution showed a value of 7.599. The data were compared with that for other European or neighbor populations (British, French, Germans, Tuscans, Bulgarians, and Turks). The genetic trees that were constructed revealed homogeneity between Europeans. Median networks revealed that most of the Greek mtDNA haplotypes are clustered to the five known haplogroups and that a number of haplotypes are shared among Greeks and other European and Near Eastern populations.

Base Sequence↗
PubMed2000

The genetic legacy of Paleolithic Homo sapiens sapiens in extant Europeans: a Y chromosome perspective.

A genetic perspective of human history in Europe was derived from 22 binary markers of the nonrecombining Y chromosome (NRY). Ten lineages account for >95% of the 1007 European Y chromosomes studied. Geographic distribution and age estimates of alleles are compatible with two Paleolithic and one Neolithic migratory episode that have contributed to the modern European gene pool. A significant correlation between the NRY haplotype data and principal components based on 95 protein markers was observed, indicating the effectiveness of NRY binary polymorphisms in the characterization of human population composition and history.

Alleles↗
PubMed1999

Mitochondrial DNA polymorphism in the French population.

One hundred unrelated individuals of French origin were screened for mtDNA variation as restriction fragment length polymorphisms (RFLPs) with the restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII and HincII. Twenty enzyme morphs were detected, four of which (AvaII-37Fr, -38Fr, HincII-18Fr and -19Fr) are new. Of the 17 mitotypes detected, five are new and they were named 1-19Fr, 6-18Fr, 100Fr-2 (2-1-2-4-1-2), 101Fr-2 (2-1-1-1-38Fr-2) and 102Fr-2 (2-1-1-4-37Fr-2). All new morphs and mitotypes derive from those already known due to a single nucleotide substitution. The French population was compared with other European, Mediterranean and Caucasian populations. Calculation of the genetic distances showed close genetic affinity with European-Mediterranean populations and especially with Calabrians, Majorcans and northern Italians (at negative values).

DNA Restriction Enzymes↗
PubMed1999

Genetic studies in 5 Greek population samples using 12 highly polymorphic DNA loci.

Two minisatellite (D1S80, D17S5) and 10 microsatellite (D2S1328, TPO, D3S1358, D9S926, D11S2010, THO1, VWF, FES, D16S310, and D18S848) polymorphic loci were analyzed in 5 Greek population groups (eastern Macedonia, central Macedonia, Thessaly, Epirus, and Greeks from Asia Minor) using the polymerase chain reaction. The genotypes at these loci conformed to Hardy-Weinberg equilibrium, and pairwise comparisons between them were in agreement with the expectation of independence between loci. This along with the low values of the coefficient of gene differentiation (GST) and the high heterozygosity levels of all loci allows the use of allele frequency data from the 12 hypervariable DNA markers for medicolegal casework in the Greek population groups studied. The small genetic distances indicate a genetic affinity among the 5 population samples. However, a few markers seem to allow some discrimination among the groups. No significant differences with other European populations were found for the loci studied.

Base Sequence↗
PubMed1998

Novel intragenic polymorphisms in the tuberous sclerosis 2 (TSC2) gene. Mutations in brief no. 184. Online.

Twenty-three unrelated patients with tuberous sclerosis have been screened for the presence of mutations in six regions of the TSC2 gene. Eight novel intragenic polymorphisms have been found, one in intron 36 and seven in intron 4, with the use of SSCP analysis. Four of these polymorphisms alter the recognition sequence of specific restriction enzymes and can be detected as RFLPs. Study in a random sample of unrelated individuals from Northern Greece, showed that these polymorphisms have mean observed and expected heterozygosity values of 0.2996 and 0.3349, respectively and could be useful for linkage analysis. It is most likely that the wild type alleles from two pairs of these polymorphisms are strongly associated. A 667 bp segment of intron 4 (954 bp) and an additional 75 bp of intron 36 (352bp) were sequenced, thus completing the sequence of both introns.

Humans↗
PubMed1997

Mitochondrial DNA sequence variation and phylogeography among Salmo trutta L. (Greek brown trout) populations.

To investigate the phylogenetic relationships and geographical structure among brown trout S. trutta L. Populations from the South Adriatic-Ionian and Aegean sea basins, mitochondrial DNA sequence comparisons were used. A 310-base-pair (bp) segment of the control region (D-loop), and an additional 280-bp segment of the cytochrome beta gene were sequenced from representatives of 13 brown trout populations. Phylogenetic analyses, conducted after combining the data presented with published data from other Eurasian brown trout, revealed four major phylogenetic groups, three of which were found widely distributed within the southern Balkan region. The phylogeographical patterns revealed by mtDNA represent one of the few cases where phylogenetic discontinuity in a gene tree exists without obvious geographical localization within a species' range and has most likely resulted from the differentiation of the major mtDNA clades during Messinian or early Pleistocene times. Finally, the genetic relationships among the populations suggested by mtDNA were generally not in accordance with either allozyme or morphological data.

Animals↗
PubMed1994

Mitochondrial DNA polymorphism in northern Greece.

The polymorphism of human mitochondrial DNA (mtDNA) was studied in 118 unrelated Greeks (from northern Greece) using total blood cell DNA and the restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII, and HincII. One new morph was identified for MspI (named MspI morph 18Gr) and is the result of a mutation in a previously thought monomorphic site at 104 bp. HpaI morph 1 was detected for the first time in a European sample. Also, AvaII morph 13 was observed in Greece in a frequency higher (5.93%) than that found in any other population. Eighteen mtDNA types were identified, three of which are new [86-2 (1-3-1-4-9-2), 87-2 (2-3-1-1-13-2), and 88-2 (2-1-1-18Gr-1-2)] and can be derived from already known mtDNA types by single restriction site changes. Type 57-2 (2-3-1-4-13-2), which had been previously characterized as "Italian," was found with higher frequency (4.24%) in northern Greece. The calculation of genetic distances and chi-square values through Monte Carlo simulation shows that the Greek sample does not differ from the Italian sample.

DNA Restriction Enzymes↗
PubMed1989

Expression of ApoE gene in Chinese hamster cells with a reversible defect in O-glycosylation. Glycosylation is not required for apoE secretion.

The effects of O-glycosylation on the synthesis and secretion of apolipoprotein E (apoE, a glycoprotein with O- but not N-linked sugars) were studied with a UDP-galactose/UDP-N-acetylgalactosamine 4-epimerase-deficient cell mutant (ldlD cells) which expresses a reversible defect in protein O-glycosylation. Under normal culture conditions the mutant ldlD cells cannot add N-acetylgalactosamine (GalNAc) to proteins. GalNAc is the first sugar of mucin-type O-linked oligosaccharides attached to the protein. This O-glycosylation defect is rapidly corrected when GalNAc is added to the culture medium. These cells also require external sources of galactose for the addition of this sugar to O-linked and other oligosaccharides. A bovine papilloma virus-based expression vector for human apoE and the human metallothionein 1A gene were transfected into ldlD cells, and apoE-expressing cell clones resistant to CdCl2 were selected and used in the present studies. The structure and secretion of apoE in these cells were examined by immunoprecipitation and one- and two-dimensional gel electrophoresis and autoradiography. The synthesis, rate, and extent of secretion of apoE were unaffected by O-glycosylation (GalNAc-independent). In the presence of both galactose and GalNAc, multiple apoE isoforms were synthesized in ldlD cells as a result of variation in the extent of sialylation. ApoE sialylation was dependent on the addition of galactose as well as GalNAc to the extracellular medium, suggesting that addition of galactose to the nascent oligosaccharide chains was required for the addition of sialic acid.

Acetylgalactosamine↗
PubMed1988

Twinning in Greece.

Mean MZ and DZ twinning rates in seven big Greek cities were 3.2 and 4.75 per 1,000 maternities, respectively, during the 1980-1985 period. The seasonal variations in twinning frequencies are not significant. The total twinning rate in Greece shows a decreasing trend from 1956 to 1985.

Adult↗
PubMed1988

C3 complement types in northern Greece.

The C3 complement types were studied in 463 patients with thyroid diseases and in 211 controls. There were no significant differences with respect to gene or phenotype frequencies between patient groups and controls. In the total sample, the gene frequencies are similar to those found in other European populations.

Adult↗
PubMed1987

Gc and Tf subtypes in Greece.

PAGIF was used to investigate the distribution of Gc and Tf subtypes in a Greek population sample. The gene frequencies were compared to those reported for other European populations.

Electrophoresis, Polyacrylamide Gel↗
PubMed1987

Haptoglobin subtypes in Greece.

The HP*1S, HP*1F, HP*2SS, HP*2SF, HP*2FF alleles have been studied on 212 individuals from Northern Greece. Their frequencies are 0.311, 0.042, 0.179, 0.463 and 0.005 respectively. The results have been compared with those found in other European populations.

Alleles↗
PubMed1986

Genetic relationships among the inhabitants of nine Mediterranean countries.

Gene frequency data on 16 protein and blood group loci for the inhabitants of 9 Mediterranean countries were collected from the literature. The frequency of most of these genes was associated with longitude. The genetic distances between the same populations were also determined. The smallest genetic distances were found among the north Mediterranean countries, whereas the highest values were observed between the Algerians and the inhabitants of the other countries.

Asia, Western↗