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Biomedical subjects

G Pepe

Publications and source records attributed to G Pepe.

At least 91 records · Page 5Linked to original sources
PubMed1994

COL1A2 gene (alpha 2 gene of type I collagen) at the haplotype level as a new valuable anthropogenetic marker: a study on Sardinians.

Sardinians, a population with many distinct anthropogenetic features, has been studied for the COLIA1 and COLIA2 genes at the DNA level for two purposes: to look for new RFLPs (restriction fragment length polymorphisms) and to study the distribution of three known COLIA2 RFLPs (EcoRI, RsaI, MspI) at both the allele and the haplotype levels. None of the eleven enzyme-probe systems examined led to the discovery of a new polymorphism. The following frequency q was found for the less common allele of the three RFLPs: EcoRI, q(+) = 0.178 +/- 0.031; RsaI, q(-) = 0.316 +/- 0.038; MspI, q(-) = 0.046 +/- 0.017. EcoRI turned out to be the most discriminant of the three polymorphisms because the frequency of the (+) allele in Sardinians was about half that estimated for a large homogeneous white sample (0.18 +/- 0.03 vs. 0.30 +/- 0.01). So far as the haplotype level is concerned, the sample is made up of triplets (parents and child). Therefore all the haplotype frequencies and delta values (degrees of disequilibrium, D) were obtained by direct counting of the unambiguously identified haplotypes rather than being based on their maximum-likelihood estimates. This together with their analytical and detailed presentation makes these data comparable with future findings, provided that the two data sets are presented in a comparable way. At this level the three RFLPs are efficient in distinguishing Sardinians from Calabrians (southern Italy) but not from the central Italian population. The present results, besides adding a further discriminative criterion between Sardinians and Italians (and whites on the whole), identify the complex COLIA2 locus as a valuable anthropogenetic marker.

Anthropology, Physical↗
PubMed1993

A highly polymorphic (ACT)n VNTR (variable nucleotide of tandem repeats) locus inside intron 12 of COL1A2, one of the two genes involved in dominant osteogenesis imperfecta.

A new, highly polymorphic, region consisting of variable number of tandem repeats (VNTR) is described that occurs within intron 12 of the COL1A2 gene. This VNTR consists of the trinucleotide ACT repeated from 6 to 12 times. Of the six alleles so far detected four are common in the three major races. The two rare alleles, (ACT)11 and (ACT)12, have been found only in Africans. In addition, a rapid technique has been developed that can be used successfully with very small amounts of even partially degraded DNA, thus allowing the use of this VNTR for forensic applications. Since dominant OI can be due to mutations at either of two loci (COL1A1 and COL1A2) prenatal diagnosis becomes feasible in the majority of the affected families only if a very informative marker is available for both of these genes. This VNTR provides a very powerful marker for COL1A2. In fact the heterozygosity for it ranges from 0.634 to 0.741 with PIC values from 0.562 to 0.696, respectively. Since trinucleotide repeats can be "unstable," and sometimes pathogenic, the unexplained collagenopathies (or suspected collagenopathies) should be analyzed from this point of view.

Base Sequence↗
PubMed1993

Correct usage of a mutated G+1 splice site and transcript quantitation in a lipoprotein lipase-deficient patient.

The consequence on the splice mechanism of a mutation occurring at the donor splice site of intron 1 has been studied. We demonstrate that, in spite of the change at G+1 position, this site is still utilized and can produce correctly spliced transcript. Nevertheless the mRNA is detectable only after an 'in vitro' amplification. A procedure has been developed to reveal and quantify the minute amount present in the patient. The very low mRNA level results in a total lack of enzyme, the cause of the disease. The procedure can be useful in cases of rare transcripts and when the source is limited. Furthermore we analyse the interaction between the splice consensus sequence and the small nuclear RNA, that is the necessary intermediate of the splicing mechanism. We speculate on the reasons why cryptic sites are not utilized and only the authentic site can be used, although significantly destabilized by the mutation.

Adult↗
PubMed1992

A G----C change at the donor splice site of intron 1 causes lipoprotein lipase deficiency in a southern-Italian family.

We describe a new case of lipoprotein lipase deficiency in a proband from a Southern-Italian family. Enzyme activity and mass were absent. Amplification and sequencing of individual exons, intron boundaries and the regulatory region revealed only one homozygous G----C transversion at the first nucleotide of intron 1. The single strand conformation polymorphism analysis proved to be a helpful tool for the identification of the single base mutation. Northern hybridization failed to reveal the presence of mature lipoprotein lipase mRNA. The mutation, which destroys the conserved dinucleotide at the junction site of intron 1, causes defective mRNA splicing and it is responsible for the deficiency.

Adult↗
PubMed1992

Apo C-II deficiency type Bari.

We formerly studied an Italian family with apo C-II deficiency. Two probands were homozygous for the defect (unmeasurable circulating apolipoprotein C-II and absence of C-II bands on immunoelectrophoresis). We documented the synthesis of the protein at the intestinal level in the probands with immunohistological techniques. With the purpose of investigating the molecular basis of the defect, Southern analysis, polymerase chain reaction (PCR) amplification and sequence analysis were carried out on one of the two cases. We identified a point mutation C to G transversion in the third exon of the gene causing a premature stop codon. Our hypothesis is that the truncated protein of 36 aa., instead of 79 aa., lacks its functional domain. This causes inefficiency in the activation of lipoprotein lipase (LPL) and the instability of the circulating molecule, which could have an higher catabolic rate compared to a normal protein. The faster disappearance from the circulating compartment make it unmeasurable. The mutation destroys a Rsa I site, present in the normal gene sequence. We suggest the use of this site for a rapid Restriction Fragment Length Polymorphism (RFLP) on PCR amplification products to screen this defect in the Italian population.

Apolipoprotein C-II↗
PubMed1992

[Neuropeptide Y and heart failure].

A time course (48 hours) of plasma neuropeptide Y (NPY) levels has been carried out in a male, 66 years old, admitted to Coronary Care Unit with inferior acute myocardial infarction within 1 hour from the onset of chest pain. On admission an increase of plasma NPY levels (38 pg/ml) has been observed. The plasma NPY value decreased to normal range (15-25 pg/ml) within 12 hours and increased again (53 pg/ml) within 12 and 24 hours. A decrease in plasma NPY values to normal range has been observed within the second day in the Coronary Care Unit. A clearcut diuresis decrease, without pulmonary signs of heart failure, was present from 12 to 24 hours followed by marked polyuria within the second day. These data point out a relative importance of NPY in the diuresis adjustments. Thus, plasma NPY measurement might be a more reliable prognostic indicator of heart failure than plasma catecholamine levels. However, further investigations have to be performed.

Aged↗
PubMed1992

MtDNA polymorphisms among Tharus of eastern Terai (Nepal).

Tharus--a population of Terai (a region with a severe malarial morbidity in the past)--can be subdivided into three main groups: Western, Central and Southern Tharus. They have usually been considered a Mongoloid population and this has been further substantiated by mtDNA findings on Central Tharus. Studies on the distribution of malaria-related genes have shown an extremely high frequency (0.8) of the alpha-thal gene among Western and Central Tharus. This frequency, however, unexpectedly turned out to be only 0.04 in a sample of Eastern Tharus. This raised doubts on the common notion that Tharus are a single anthropological entity. In the present investigation mtDNA markers were studied in the same sample of Eastern Tharus previously examined for the alpha-thal gene. The findings were: 1. the same three features which confirmed the classification of Central Tharus as Mongoloids (i.e., the common occurrence of HpaI-1/HincII-1 and HaeII-5 morphs, and the lack of BamHI polymorphism) were also present in this sample. Since the only neighbouring population accessible to Tharus, until recently, has been Hindu (Caucasoids), this result strongly supports the notion that Tharus are indeed a single anthropological entity; 2. two statistically significant differences between Eastern and Central Tharus--namely, a much higher HaeII morph 5 frequency among Central Tharus, and the absence in the same group of the mutation at 15.487 bp (very common among Eastern Tharus)--together with the results on alpha-tal gene, suggested that Tharu subgroups underwent an effective reproductive isolation.

Blotting, Southern↗
PubMed1990

Identification of the mutation responsible for a case of plasmatic apolipoprotein CII deficiency (Apo CII-Bari).

We studied a case of familial Apolipoprotein CII deficiency. By Southern hybridization, amplification and sequence analysis, the genetic defect was identified. It consists in a point mutation C- greater than G in the third exon of the gene causing a premature stop codon. Truncated at the aa. 36 of the mature form, the protein loses its functional domains, becomes inefficient and cannot be detected in the plasma, because of its high instability. The mutation destroys an RsaI site, present in the normal gene sequence. This point mutation is useful in the diagnosis of this Apolipoprotein CII deficiency.

Amino Acid Sequence↗
PubMed1990

Studies on four restriction fragment length polymorphisms of the type I collagen genes in two Italian populations.

Type I collagen, the most abundant of the collagen protein family, is encoded by two genes, COL1A1 and COL1A2. Two random population samples, one from central Italy and one from southern Italy, were studied for 1 restriction fragment length polymorphism (RFLP) of COL1A1 (RsaI) and 3 RFLPs of COL1A2 (EcoRI, RsaI and MspI). A considerable heterogeneity for COL1A1/RsaI was found not only between Italians and English but even among Italians. The potential usefulness of these RFLPs and haplotypes as anthropogenetic markers, particularly in distinguishing Caucasoids from Negroids, has been discussed.

Asian People↗
PubMed1989

Sequence-dependent DNA curvature: conformational signal present in the main regulatory region of the rat mitochondrial genome.

Theoretical analysis and experimental approaches by gel electrophoresis in retarding conditions allowed us to identify the presence of an intrinsic bending in the D-loop containing region of the rat mitochondrial genome. The curvature was located in the right domain of the sequence analyzed, between the origin of replication of the heavy strand and its promoter. The preliminary evidence of a specific recognition of the bent DNA with mitochondrial matrix proteins suggests a probable role of this DNA conformation in the duplication and/or expression of the mammalian mitochondrial genome.

Animals↗
PubMed1989

The complete nucleotide sequence of the Rattus norvegicus mitochondrial genome: cryptic signals revealed by comparative analysis between vertebrates.

This paper reports the nucleotide sequence of rat mitochondrial DNA, only the fourth mammalian mitochondrial genome to be completely sequenced. Extensive comparative studies performed with similar genomes from other organisms revealed a number of interesting features. 1) Messenger RNA genes: the codon strategy is mainly dictated by the base compositional constraints of the corresponding codogenic DNA strand. The usage of the initiation and termination codons follows well-established rules. In general the canonical initiator, ATG, and terminators, TAA and TAG (in rat, only TAA), are always present when there is gene overlapping or when the mRNAs possess untranslated nucleotides at the 5' or 3' ends. 2) Transfer RNA genes: a number of features suggest the peculiar evolutionary behavior of this class of genes and confirm their role in the duplication and rearrangement processes that took place in the evolution of the animal mitochondrial genome. 3) Ribosomal RNA genes: accurate sequence analysis revealed a number of significant examples of complementarity between ribosomal and messenger RNAs. This suggests that they might play an important role in the regulation of mitochondrial translation and transcription mechanisms. The properties revealed by our work shed new light on the organization and evolution of the vertebrate mitochondrial genome and more importantly open up the way to clearly aimed experimental studies of the regulatory mechanisms in mitochondria.

Amino Acid Sequence↗
PubMed1989

Frequency of sexual dysfunctions among Roman Catholic women.

The frequency and type of sexual dysfunctions in healthy and sexually active Roman Catholic church-goers was compared with non-church-goers. All the women had had a steady psychosexual relationship with only one partner for at least one year. The sexual dysfunctions investigated were related only to vaginal intercourse. Although there is no significant difference in the frequency and type of sexual dysfunctions, the Roman Catholic church-goers more frequently complained of unsatisfying sexual relationships (P less than 0.05) or were requested by their partner on a change in their own sexual behaviour (P less than 0.05). The possible correlations between religiosity and sexual health are discussed.

Adolescent↗
PubMed1989

Sex during prepregnancy period. A study of 106 pluriparous women in relation to parity.

The authors study the correlation between sexual activity and parity in 106 pluriparous Sicilian women divided into 3 groups with parity, respectively, of 1 (57 cases), 2 (29 cases), and greater than or equal to 3 (20 cases). Sexual desire, frequency of coitus and orgasm, type of extracoital activity, preferred position during coitus, the partner who took the first initiative in sexual activity, and the contraceptive methods used were studied. The results show that in women of parity greater than or equal to 3 there is a significantly lower frequency of very frequent coitus, higher frequency of extravaginal sexual activity, and that the male more frequently took the first initiative in sexual intercourse.

Coitus↗
PubMed1989

[Absence of sexual dysfunction does not mean that the couple does not need sexual counseling].

Two-hundred women with sexual dysfunction were compared with 160 without. The number of the practising religious (46.0% vs 28.8%; p less than 0.05), of married women (58.0% vs 47.8%; p greater than 0.05), widows (4.0% vs 0%; p less than 0.01) or the separated were found in significantly higher numbers. Nulliparity does not appear to be a risk factor in sexual dysfunction. The use of contraceptive technique such as the pill and the intrauterine device is significantly lower in women with sexual dysfunction. Also significantly higher is the number of women with sexual dysfunction who report that they are not satisfied with their sexual relationship (63.0% vs 6.2%; p less than 0.001) or who would like to change the sexual behaviour of their partner (50.0% vs 7.5%; p less than or equal to 0.001) or whose husband would like a change in the sexual behaviour of the partner (64.0% vs 10.0%; p less than or equal to 0.001). 7.5% of women without sexual dysfunction consider their relationship with the current partner to be unsatisfactory. Most of these women experience their partner's request as a "problem". In conclusion, the presence of sexual dysfunction is unacceptable to women in the majority of cases as it is accompanied by a negative opinion on the quality of the sexual relationship. It is the Authors' opinion that anamnesis of the sexual life of the couple should be offered to all women who have a gynaecological examination. The absence of sexual dysfunction does not necessarily mean that the women or the couple consider their sexual relationship to be sexually satisfactory or that they do not need or would not accept, if expressly asked, sexual counseling.

Adolescent↗