Biomedical subjects

B Creati

Publications and source records attributed to B Creati.

5 recordsLinked to original sources

PubMed2000

Interaction between the G1057D variant of IRS-2 and overweight in the pathogenesis of type 2 diabetes.

The insulin receptor substrate-2 (IRS-2) is a major insulin signalling molecule. IRS-2 inactivation in mice induces a form of diabetes characterized by peripheral insulin resistance and reduced beta cell mass. We tested the hypothesis that a common non-conservative amino acid substitution of IRS-2 (G1057D) might interact with overweight in the pathogenesis of type 2 diabetes. The variant was genotyped in 193 Italian patients with type 2 diabetes and 206 control subjects. In the absence of overweight, the risk of type 2 diabetes decreased according to the dosage of the D1057 allele (odds ratio for GD genotype 0.46 [95% CI 0.25-0.86]; DD genotype 0.18 [0.04-0.68]; P for trend = 0.0012). Conversely, the interaction between overweight and genotype increased the risk of type 2 diabetes according to the dosage of the D1057 allele (odds ratio for GD genotype 2.50 [1.11-5.65]; DD genotype 5.74 [1.11-29. 78]; P for trend = 0.0047). Among controls, fasting C-peptide levels, after adjustment for plasma glucose, were inversely related to the dosage of the D1057 allele (P = 0.020). This finding suggested that carriers of the D1057 allele may have higher insulin sensitivity and supported the protective effect of this allele. Conversely, among overweight patients there was a parallel increase in fasting plasma glucose (P for trend = 0.037) and fasting C-peptide according to the dosage of the D1057 allele, suggesting that higher insulin resistance and relative beta cell failure contributed to the increased risk of type 2 diabetes in overweight carriers of this allele. These data provide evidence for a strong association between type 2 diabetes and the G1057D common genetic variant of IRS-2, which appears to be protective against type 2 diabetes in a codominant fashion. Overweight appears to modify the effect of this polymorphism toward a higher risk of type 2 diabetes. Carriers of this polymorphism may represent an elective target for prevention of type 2 diabetes through preventing or treating excessive weight.

Adult↗

PubMed2000

Mutational analysis of OB gene in obese and type 2 diabetes affected subjects.

Peripheral blood DNA from 12 subjects affected by familial obesity and from 35 subjects affected by type 2 diabetes were analysed for mutations in the coding sequence of the OB gene. Mutational analysis, conducted using the single strand conformation polymorphism (SSCP) technique, followed by direct sequencing did not reveal the presence of nucleotide variants in the coding region of the OB gene. The lack of mutations in the coding sequence is consistent with previous data suggesting that mutations in the coding sequence of the OB gene are not common in human familial obesity. In 2 samples displaying a non-informative pattern of SSCP and in 8 additional samples the nucleotide sequence of portion of the intron 2 bordering the coding sequence of exon 2 identified a G in the positions +14IVS and +18IVS, according to a sequence reported previously, but in contrast with some others. All samples were homozygous for these intron variants.

Adult↗

PubMed1998

A novel mutation (V191G) in a German-British type 1 Gaucher disease patient. Mutations in brief no. 131. Online.

Gaucher disease results from mutations in the glucocerebrosidase gene located on human chromosome 1q21. Three clinical forms of Gaucher disease have been described: type 1, nonneuropathic; type 2, acute neuropathic; and type 3, subacute neuropathic. We have identified a novel mutation in a German-British patient with type 1 Gaucher disease which results in V191G of the glucocerebrosidase polypeptide. Because the mutation abolishes a HphI cleavage site, its presence was confirmed by HphI RFLP analysis of PCR-amplified genomic DNA. In the second allele of the patient, the mutation identified was g.5841A G(N370S). Sequence analysis of the remainder of the coding region of the gene as well as the exon-intron boundaries showed identity to normal controls. Because mutation N370S has so far been found only in type 1 Gaucher disease and postulated to result in mild clinical presentation, and since the clinical course of this patient has been relatively mild with minimal skeletal involvement, we speculate that the V191G/N370S genotype may also result in good prognosis.

Chromosomes, Human, Pair 1↗

PubMed1998

Optimized PCR labeling in mutational and microsatellite analysis.

To optimize the labeling and visualization of PCR products we tested different variables, including deoxynucleotide concentration and ratio, dilution of labeled product, number of PCR cycles, and use of one-step or nested labeling protocols. Labeling was achieved using a fixed amount of labeled dATP, whose relative specific activity was varied by adding increasing amounts of cold dATP. Optimal PCR-labeling intensity was reached at dATP concentrations between 0.9 and 7.0 micromol/L, with a peak at 1.8 micromol/L. This concentration corresponded to an optimal ratio between the increase in specific activity and the decrease in DNA yield. Nucleotide imbalances >1:2 were not advantageous. Mutational analysis by single-strand conformational polymorphism (SSCP) was used to validate PCR-labeling protocols. The limiting nucleotide concentrations did not affect SSCP. Clear SSCP patterns were obtained using DNA templates of different sizes derived from several genes. SSCP patterns obtained using one-step or nested PCR-labeling protocols were equivalent and were visualized after overnight exposure, using [alpha35S]dATP as the label. Dilutions of labeled products ranging between 1:10 and 1:2.5 influenced SSCP patterns, and the lowest dilution tested produced better-defined and more-intense signals. Optimized SSCP conditions allowed the detection of novel and previously characterized nucleotide variants. Clear microsatellite typing was also obtained using optimized protocols and [alpha35S]dATP as the label.

Colorectal Neoplasms, Hereditary Nonpolyposis↗

PubMed1996

Intracellular distribution of polyamines in human lymphoblastoid cell line during phorbol ester-induced differentiation.

Polyamines such as putrescine, spermidine and spermine play an important role in nucleic acid metabolism. These aliphatic amines display a key role in cell-induced transformation by carcinogen substances. In particular, one of these, the phorbol myristate acetate, provokes cell differentiation and gives an increase of ornithindecarboxylase activity; enzyme regulating the pathways of polyamines. In this study we analyse the trend of the polyamines at cytoplasmic and nuclear level during phorbol treatment. Our results show a correlation between nuclear and cytoplasmic spermine, 3H-Thymidine, 3H-Leucine incorporation and cell cycle phases. These data remark that the polyamines are differently distributed into the cell during the phorbol myristate acetate-mediated differentiation process and that the spermine is down-regulated for to supply the increased protein biosynthesis.

B-Lymphocytes↗