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Biomedical subjects

Giovanni Gambelunghe

Publications and source records attributed to Giovanni Gambelunghe.

7 recordsLinked to original sources

MICA A8: a new allele within MHC class I chain-related A transmembrane region with eight GCT repeats.

Analysis of the MICA gene revealed a trinucleotide repeat (GCT) microsatellite polymorphism within the transmembrane region. So far, seven alleles of the exon 5 of the MICA gene, which consist of 4, 5, 6, 7, 9, and 10 repetitions of GCT or five repetitions of GCT with an additional nucleotide insertion (GGCT), have been identified. These alleles have been accordingly named A4, A5, A6, A7, A9, A10, and A5.1, and the sizes are, respectively, 179 bp, 182 bp, 186 bp, 189 bp, 194 bp, 197 bp, and 185 bp. We analyzed 1100 Italian subjects for MICA exon 5 microsatellite polymorphism. A new peak corresponding to 191-bp size was observed in one individual, and we confirmed the presence of new polymorphism in exon 5 by sequencing, which consisted of eight GCT repeats. We named this allele, as a current nomenclature, MICA8.

Alleles↗

MHC2TA single nucleotide polymorphism and genetic risk for autoimmune adrenal insufficiency.

CONTEXT: The polymorphism of class II HLA genes modulates the genetic risk for several endocrine autoimmune diseases. The constitutive class II expression on antigen-presenting cells is under the control of the MHC class II transactivator, encoded by the MHC2TA gene, which is mapped to chromosome 16p13. The MHC2TA -168 A-->G single nucleotide polymorphism (rs3087456) has been suggested to confer susceptibility to some autoimmune diseases. DESIGN: With the aim of testing whether this MHC2TA single nucleotide polymorphism is independently associated with autoimmune Addison's disease (AAD) and/or modulates the genetic risk conferred by DRB1-DQA1-DQB1 haplotypes, we analyzed DNA samples from 128 AAD patients and 406 healthy control subjects from continental Italy. RESULTS: Frequency of allele G of MHC2TA was significantly increased among AAD patients (39% alleles), compared with 29% in healthy controls (P = 0.003). Similarly, the frequency of AG+GG genotypes was significantly higher among AAD patients than among healthy control subjects, in both a codominant (P = 0.012) and a G-dominant model (P = 0.018). Multivariate logistic regression analysis showed that MHC2TA AG+GG continued to be positively associated with genetic risk for AAD (P = 0.028, odds ratio = 1.72, 95% confidence interval = 1.06-2.78), after correction for DRB1*03-DQA1*0501-DQB1*0201, DRB1*04 (not 0403)-DQA1*0301-DQB1*0302 and DRB1*0403. Similar results were obtained when the number of G alleles was included in the model (P = 0.004; odds ratio = 1.65, 95% confidence interval = 1.17-2.32). CONCLUSIONS: Our study provides the first demonstration of the association of the polymorphism of the MHC2TA gene with genetic risk for AAD that appears to be independent from the well-known association with the polymorphism of HLA class II genes.

Adolescent↗

Exercise and diabetes.

Physical activity activates has acute and chronic effects on glucose, lipid and protein metabolism. In type 1 diabetic subjects, the lack of the physiological inhibition of insulin secretion during exercise results in a potential risk of hypoglycemia. On the other hand, exercise-induced activation of counterregulatory hormones might trigger an acute metabolic derangement in severe insulin-deficient subjects. Thus, diabetic patients, before starting exercise sessions, must be carefully educated about the consequences of physical activity on their blood glucose and the appropriate modifications of diet and insulin therapy. Long-term effects of regular exercise are particularly advantageous for type 2 diabetic patients. Regular aerobic exercise reduces of visceral fat mass and body weight without decreasing lean body mass, ameliorates insulin sensitivity, glucose and blood pressure control, lipid profile and reduces the cardiovascular risk. For these reasons, regular aerobic physical activity must be considered an essential component of the cure of type 2 diabetes mellitus. In this regard, individual behavioral strategies have been documented to be effective in motivating sedentary type 2 diabetic subjects to the adoption and the maintenance of regular physical activity.

Aerobiosis↗

Retrovirus-like long-terminal repeat DQ-LTR13 and genetic susceptibility to type 1 diabetes and autoimmune Addison's disease.

Controversial data are available on the association between the retrovirus-like long-terminal repeat (LTR) DQ-LTR13 and genetic susceptibility to type 1 diabetes and other autoimmune diseases. We analyzed DNA samples from 315 type 1 diabetic patients, 166 autoimmune Addison's disease (AAD) patients, 1,054 healthy subjects, and 144 families of type 1 diabetic offspring. DQ-LTR13 was more frequent among patients than healthy subjects (P(c) < 0.0006), and a preferential transmission of DQB1*0302-LTR13(+) from parents to type 1 diabetic offspring was observed. DQ-LTR13 was in linkage disequilibrium (LD) with DQB1*0302 but not DQB1*0201. The presence of DQ-LTR13 increased the odds ratio of DQB1*0302 2.9- to 3.2-fold for type 1 diabetes and AAD. DRB1*0403 was absent in all of the 169 DRB1*04-positive patients but present in 27% (34 of 127) DRB1*04-positive healthy subjects (P(c) < 0.001). DQ-LTR13 was detected in 1 of 34 (3%) DRB1*0403-positive healthy subjects and 36 of 93 (39%) individuals carrying another DRB1*04 allele (P(c) = 0.002). Multivariate logistic regression analysis revealed that DQ-LTR13 is not independently associated with type 1 diabetes and AAD after correction for DQB1*0302 and DRB1*0403. Conversely, DQB1*0201, DQB1*0302, DRB1*0401, and DRB1*0403 were all significantly associated with disease risk also after correction for DQ-LTR13. We provide conclusive evidence that the genetic association of DQ-LTR13 with type 1 diabetes and AAD is primarily due to a LD with DQB1*0302 and DRB1*0403.

Addison Disease↗

Lack of association of CCR2-64I and CCR5-Delta 32 with type 1 diabetes and latent autoimmune diabetes in adults.

It is well known that type 1 diabetes mellitus (T1DM) is a complex genetic disease resulting from the autoimmune destruction of pancreatic beta cells. Several genes have been associated with susceptibility and/or protection for T1DM, but the disease risk is mostly influenced by genes located in the class II region of the major histocompatibility complex. The attraction of leukocytes to tissues is essential for inflammation and the beginning of autoimmune reaction. The process is controlled by chemokines, which are chemotactic cytolines. Some studies have shown that CCR2-64I and CCR5-Delta 32 might be important for protection of susceptibility to some immunologically-mediated disorders. In the present study, we demonstrate the lack of association between CCR2-64I and CCR5-Delta 32 gene polymorphism and TIDM and we describe a new method for a simple and more precise genotyping of the CCR2 gene.

Adolescent↗

CTLA-4 gene polymorphism contributes to the genetic risk for latent autoimmune diabetes in adults.

Latent autoimmune diabetes in adults (LADA) is identified by the presence of GAD65 autoantibodies in diabetic patients who do not require insulin treatment for at least six months after the diagnosis. Previous studies have shown that the risk for LADA, similarly to type 1 diabetes mellitus (T1DM), is increased in subjects carrying the HLA-DRB1*03-DQA1*0501-DQB1*0201 and/or HLA-DRB1*04-DQA1*0301-DQB1*0302 haplotypes. In the present study, we investigated the association between LADA and the CTLA-4 A/G polymorphism, another gene polymorphism associated with T1DM and other autoimmune diseases. The heterozygous A/G genotype was significantly more frequent among 80 LADA (69%) than among 85 healthy subjects of similar age and geographical provenience (47%) (OR = 2.47, corrected P = 0.023). Conversely, the homozygous A/A genotype was significantly less frequent in LADA subjects than in healthy controls (26% vs. 47%, OR = 0.4, corrected P = 0.028). The results of our study show that LADA is positively associated with the CTLA-4 A/G genotype, similarly to T1DM, thus providing further supporting evidence of the autoimmune origin of this form of diabetes mellitus of the adult.

Abatacept↗

Genetic polymorphism of chemokine receptors CCR2 and CCR5 in Swedish cervical cancer patients.

Chemokines are chemotactic cytokines that orchestrate leukocyte trafficking in tissues, thus, playing an important role in regulation of immunological processes. The aim of this study was to investigate the association of human papillomavirus (HPV) infection and cervical cancer with two DNA polymorphisms of the chemokine receptors CCR5-delta32 and CCR2-64I. The study material consisted of 50 cervical intraepithelial neoplasia (CIN) cases and 50 of age and sampling-date matched controls, 100 invasive cervix cancer cases and 100 of their corresponding matched disease-free controls. Pyrosequencing was employed to genotype the CCR2-64I polymorphism. CCR5-delta32 was genotyped using standard PCR fragment length analysis. The frequencies of CCR2 and CCR5 genotypes from 150 patients and 150 healthy controls were representative of the general population according to the Hardy-Weinberg equilibrium analysis. Risk association was computed with conditional logistic regression analysis. HPV-positive individuals with the rare CCR5deelta32/delta32 genotype have a risk of 4.58 (CI = 0.40-52.64, p-value = 0.045) compare to HPV negative group. The delta-32 mutation on the CCR locus is imperceptibly associated with increased risk of HPV infection. In total, cervical neoplasia was not associated with genetic polymorphism of CCR2 and CCR5.

Base Sequence↗