Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although inflammatory or degenerative changes in salivary glands have been demonstrated in genetic animal models of diabetes mellitus and in experimental diabetes, no information is available in diabetics on the possible leakage in saliva of cytosolic enzymes as markers of salivary cell injury. Aspartate (GOT) and alanine (GPT) aminotransferases and lactate dehydrogenase (LDH) were determined in saliva samples collected by the Salivette method from well-controlled insulin-dependent (IDDM n = 11) and non-insulin-dependent (NIDDM n = 18) diabetic patients and from age-cross-matched healthy subjects (n = 33). In IDDM salivary concentrations of GOT (112.55 +/- 23.94 UI/L) and LDH (1120.27 +/- 168.31 UI/L) were similar to those found in the NIDDM (90.94 +/- 19.64, and 1255.43 +/- 221.40 UI/L respectively), but higher (p < 0.05) than those observed in normal subjects (33.09 +/- 3.71, and 423.58 +/- 39.94, UI/L respectively). GPT was higher in NIDDM than IDDM, which in turn was higher than in normal subjects (42.78 +/- 14.72, 16.45 +/- 3.74 and 6.85 +/- 1.52 UI/L respectively). Salivary and serum values of GOT, GPT and LDH were not correlated. Determination of cytosolic enzymes in saliva may be useful for monitoring the diabetic involvement of salivary glands.
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PMID:Aminotransferases and lactate dehydrogenase in saliva of diabetic patients. 844 46

In the Asian populations, it is not uncommon for adult patients with NIDDM to eventually lose beta-cell function and develop IDDM. Accepting that IDDM is an autoimmune disease, which occurs on a genetic background, it could by hypothesized that by measuring autoantibody prevalence and HLA DQ gene polymorphism, known important prediagnostic markers of IDDM, the prevalence of adult-onset IDDM in patients with previously undiagnosed NIDDM patients could be estimated. To do this, anti-GAD prevalence and HLA DQ A1 and DQ B1 polymorphisms after PCR amplification of genomic DNA were analyzed in 121 newly diagnosed diabetic patients of Yonchon cohort and compared to the results with those of 100 matched health control subjects. We also compared the results with those of other populations to assess the difference of genotype distribution. The overall prevalence of anti-GAD antibodies was 1.7% (2 of 121) in patients with previously undiagnosed NIDDM, whereas 1 of 100 controls had positive antibodies. Among those who were positive, their titer of antibodies to GAD were not high. No statistically significant differences in the distribution of either mean levels of anti-GAD or DQA1 and DQB1 alleles were found comparing NIDDM patients to controls. Interestingly, the frequency of DQB1*non-Asp-57 and DQA1*Arg-52 alleles in the Korean adult control population was similar to that of US Caucasians (DQB1*non-Asp-57: 0.431 vs. 0.475; DQA1*Arg-52: 0.492 vs. 0.463). The low prevalence of anti-GAD antibodies and HLA-DQA1 and DQB1 susceptibility alleles among recent-onset NIDDM patients, not different compared to controls suggests that diabetes in Korean adults is unlikely to have an autoimmune component to its pathogenesis.
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PMID:Low prevalence of immunogenetic markers of IDDM in adult Koreans with diabetes detected on OGTT. 901 68

Even among young, healthy individuals, there is more than a 10-fold variation in insulin sensitivity; however, taken in combination, all the known modifiers of insulin sensitivity - including obesity and a variety of environmental factors - explain less than one third of this variation. It is possible that genetic factors could account for the bulk of the variance observed, and hence play a major role in the development of impaired insulin sensitivity, ie insulin resistance. From the genetic point of view, insulin resistance is thought to be due to the inheritance of a number of mutations in a variety of genes. Three complementary approaches have been applied in the search for mutations: mutational analysis of candidate genes; linkage analysis of candidate genes or chromosomal regions for insulin resistance in familial type 2 diabetes; and random genome mapping with quantitative trait loci (QTL) analysis. Mutational analysis of the insulin signalling cascade has identified a glycine-arginine (Gly-Arg) substitution at codon 972 of the insulin receptor substrate-1 (IRS-1) gene with a carrier prevalence of 9% among Caucasians. Expression of this variant in 32-D cells is associated with a significant (20-30%) impairment of insulin-stimulated PI3-kinase activity, as well as reduced binding of IRS-1 to the p85 regulatory subunit of PI3-kinase. Genotype/phenotype studies stratified according to body mass index (BMI) indicate that obese subjects who are heterozygous for the mutant allele have a 50% decrease in insulin sensitivity, compared with wild-type obese subjects. This suggests that there may be an interaction between the mutant allele and obesity, such that, in the presence of obesity, the mutant variant may aggravate the obesity-associated insulin resistance. Mutational analysis has also shown that homozygous carriers of a codon Met 326 Ile mutation in the p85 subunit of phosphatidylinositol-3 (PI3)-kinase (about 2% of the Caucasian population) have lower glucose tolerance, glucose effectiveness. A further Asp to Tyr polymorphism has been identified at codon 905 of the gene encoding the regulatory subunit of glycogen-associated protein phosphatase-1 (PP1G). Individuals who are heterozygous for this polymorphism constitute 18% of the Caucasian population and appear to exhibit both tissue-specific and pathway-specific insulin resistance. It is likely that inherited insulin resistance will eventually prove to be related to subtle mutations in many such genes of the insulin signalling network and the numerous genetic components controlling energy metabolism.
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PMID:Genetics of insulin resistance. 1032 50

In this paper, the L-glutamate (L-Glu) transport system was targeted to improve the delivery of a model compound, p-di(hydroxyethyl)-amino-D-phenylalanine (D-MOD), through the blood-brain barrier (BBB) in vitro cell culture model. D-MOD is an analogue of an antitumor agent D-melphalan. To target the L-Glu transport system, D-MOD was conjugated to L-Glu to give D-MOD-L-Glu conjugate. D-MOD and D-MOD-L-Glu transport properties were evaluated using the bovine brain microvessel endothelial cell (BBMEC) monolayers. The results suggest that D-MOD-L-Glu conjugate permeates through the BBMEC monolayers more readily than the parent D-MOD. The improvement of transport may be due to the recognition of D-MOD-L-Glu by the L-Glu transport system. The transport mechanism was evaluated using several different experiments including: (a) concentration-dependent studies; (b) temperature-dependent studies; (c) substrate inhibition studies; and (d) metabolic inhibitor studies. The D-MOD-L-Glu transport was inhibited by the change of temperature from 37 degrees C to 4 degrees C. At higher concentrations, the transport of D-MOD-L-Glu reached plateau due to saturation. Furthermore, some amino acids (i.e., L-Glu, L-Asp, D-Asp, and L-Gln) inhibited the transport of D-MOD-L-Glu; presumably the conjugate was competing with these amino acids for the same transport system. Metabolic inhibitors (i.e., 2,4-dinitrophenol and sodium azide) suppressed the transport of the conjugate. However, the conjugate was not transported by monocarboxylic acid, dipeptide and neutral amino acid transporters. In conclusion, the L-Glu transport system can be utilized to facilitate a non-permeable drug across the BBB by conjugating the drug with L-Glu amino acid.
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PMID:Enhancement of transport of D-melphalan analogue by conjugation with L-glutamate across bovine brain microvessel endothelial cell monolayers. 1093 29

Electrophoretic variants of the vitamin D-binding protein (DBP) have been reported to be associated with type 2 diabetes mellitus (DM) or with prediabetic phenotypes in several non-Caucasian populations. Two frequent missense polymorphisms at codons 416 (Asp --> Glu) and 420 (Thr --> Lys) are the genetic basis for the 3 common electrophoretic variants of DBP (Gc1F, Gc1S, and Gc2) and the resulting circulating phenotypes (Gc1F/Gc1F, Gc1F/Gc1S, Gc1S/Gc1S, Gc1F/Gc2, Gc1S/Gc2, and Gc2/Gc2). In this study, we investigated the association of these polymorphisms with type 2 DM in French Caucasian subjects. Variations at codons 416 and 420 were examined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Allele frequencies at both codons did not differ in type 2 DM patients and in control subjects (Asp416: 42.4% v 46.2%, respectively, P =.33; Lys420: 25.5% v 29.0%, respectively, P =.31). Distribution of genotypes at both codons, of the haplotypes defined by the 2 codons, and of the DBP phenotypes defined by the haplotypes were also similar in diabetic and control subjects. In conclusion, our study suggests that genetic variants of the DBP gene are not associated with the susceptibility to type 2 DM in French Caucasians.
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PMID:Variations in the vitamin D-binding protein (Gc locus) and risk of type 2 diabetes mellitus in French Caucasians. 1123 Jul 93

The objective of this study was to investigate possible defects in the insulin sensitivity and/or the acute insulin response in a group of Mexican patients displaying early-onset type 2 diabetes and to evaluate the contribution of mutations in three of the genes linked to maturity-onset diabetes of the young. We studied 40 Mexican patients with an age of diagnosis between 20 and 40 yr in which the insulin sensitivity as well as the insulin secretory response were measured using the minimal model approach. A partial screening for possible mutations in 3 of the 5 genes linked to maturity-onset diabetes of the young was carried out by PCR-single strand conformation polymorphism analysis. A low insulin secretory capacity (AIRg = 68.5 +/- 5 muU/mL.min) and a near-normal insulin sensitivity (3.43 +/- 0.2 min/muU.mL x 10(4)) were found in these patients. Among this group we found two individuals carrying missense mutations in exon 4 of the hepatocyte nuclear factor-1alpha (HNF-4alpha) gene (Asp(126)-->His/Tyr and Arg(154)-->Gln, respectively) and one carrying a nonsense mutation in exon 7 of the HNF-1alpha gene (Gln(486)-->stop codon); 7.5% had positive titers for glutamic acid decarboxylase antibodies. Thirty-five percent of cases had insulin resistance; these subjects had the lipid abnormalities seen in the metabolic syndrome. A defect in insulin secretion is the hallmark in Mexican diabetic patients diagnosed between 20 and 40 yr of age. Mutations in either the HNF-1alpha or the HNF-4alpha genes are present among the individuals who develop early-onset diabetes in our population. These particular sequence changes have not been previously reported and therefore represent putative new mutations. Even in the absence of endogenous hyperinsulinemia, insulin resistance is associated with an adverse lipid profile.
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PMID:Early-onset type 2 diabetes: metabolic and genetic characterization in the mexican population. 1123 4

In vitro studies have shown that conjugation of a model compound [p-di(hydroxyethyl)-amino-D-phenylalanine (D-MOD)] with L-Glu can improve D-MOD permeation through the bovine brain microvessel endothelial cell monolayers (Sakaeda et al., 2000). The transport of this D-MOD-L-Glu conjugate is facilitated by the L-Glu transport system. In this paper, we evaluate the in vivo brain delivery of model compounds (i.e. D-MOD, p-nitro-D-phenylalanine (p-nitro-D-Phe), 5,7-dichlorokynurenic acid (DCKA) and D-kyotorphin) and their L-Glu conjugates. DCKA was also conjugated with L-Asp and L-Gln amino acids. The analgesic activities of D-kyotorphin and its L-Glu conjugate were also evaluated. The results showed that the brain-to-plasma concentration ratio of D-MOD-L-Glu was higher than the D-MOD alone; however, the plasma concentration of both compounds were the same. The plasma concentration of p-nitro-D-Phe-L-Glu conjugate was higher than the parent p-nitro-D-Phe; however, the brain-to-plasma concentration ratio of p-nitro-D-Phe was higher than its conjugate. On the other hand, both DCKA and DCKA conjugates have a low brain-to-plasma concentration ratio due to their inability to cross the blood-brain barrier (BBB). The L-Asp and L-Glu conjugates of DCKA have elevated plasma concentrations relative to DCKA; however, the DCKA-L-Gln conjugate has the same plasma concentration as DCKA. For D-kyotorphin, both the parent and the L-Glu conjugate showed similar analgesic activity. In conclusion, conjugation of a non-permeable drug with L-Glu may improve the drug's brain delivery; however, this improvement may depend on the physicochemical and receptor binding properties of the conjugate.
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PMID:Conjugation with L-Glutamate for in vivo brain drug delivery. 1137 21

Disruption of the insulin receptor substrate-2 was shown to cause type 2 diabetes in mice. This could be largely attributed to abnormal beta-cell development. In humans, a prevalent polymorphism in insulin receptor substrate-2 (Gly1057Asp) was not found be associated with type 2 diabetes in linkage and association studies. We tested the hypothesis that an extreme challenge of the beta cell might reveal subtle abnormalities in carriers of this polymorphism undetected by conventional insulin secretion tests. Therefore, in addition to assessing beta-cell function by oral glucose tolerance testing (n = 318, normal glucose tolerance), we measured the secretory response to maximal stimulation by hyperglycemia (10 mM), glucagon-like peptide-1, and arginine administered in an additive fashion (n = 77, nondiabetic). The allelic frequency of the Asp allele was approximately 37%. Neither the beta-cell function indices from the oral glucose tolerance test nor the secretory response during the hyperglycemic clamp differed measurably between carriers and controls. Moreover, maximal plasma C-peptide concentrations in response to the combined glucose, glucagon-like peptide-1, and arginine stimulus was not different between Gly/Gly (10,745 +/- 1,186 pmol/liter) and X/Asp (10,800 +/- 490 pmol/liter, P = 0.99). In conclusion, our findings strongly suggest that the Gly1057Asp polymorphism in insulin receptor substrate-2 is not associated with beta-cell dysfunction. The normal maximal insulin secretory response makes it unlikely that this common polymorphism results in abnormal beta-cell development.
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PMID:The prevalent Gly1057Asp polymorphism in the insulin receptor substrate-2 gene is not associated with impaired insulin secretion. 1160 May 48

Associations between type 2 diabetes (and/or parameters contributing to glucose homeostasis) and genetic variation in the genes encoding insulin receptor substrate (IRS)-1 and -2 have been reported in several populations. Recently, it has been reported that the Gly(972)Arg variant in IRS-1 was associated with reduced insulin secretion during hyperglycemic clamps in German subjects with normal glucose tolerance. We have examined glucose-stimulated insulin secretion in relation to gene variants in the IRS-1 (Gly(972)Arg) and IRS-2 (Gly(1057)Asp) genes in two Dutch cohorts. Subjects with normal (n = 64) or impaired (n = 94) glucose tolerance underwent 3-h hyperglycemic clamps at 10 mmol/l glucose. All subjects were genotyped for the IRS-1 and IRS-2 variants by PCR-RFLP--based methods. We did not observe any significant difference in both first- and second-phase insulin secretion between carriers and noncarriers of both gene variants, nor was there evidence for an association with other diabetes-related parameters. We conclude that the common gene variants in IRS-1 and IRS-2 are not associated with altered glucose-stimulated insulin secretion in two populations from the Netherlands.
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PMID:Variations in insulin secretion in carriers of gene variants in IRS-1 and -2. 1187 98

Polymorphisms of the genes involved in the metabolism of vitamin D may predispose to type 2 diabetes mellitus (T2DM). For example, there is evidence suggesting that vitamin D binding protein (DBP) amino acid variants at codons 416 (aspartic acid-->glutamic acid) and 420 (threonine-->lysine) may affect genetic susceptibility to T2DM. The aims of this study are: (1) to determine the allele, genotype, haplotype and haplotype combination frequencies of those DBP amino acid variants in a Polish population and (2) to examine their role in the genetic susceptibility to T2DM in a Polish population. Overall 393 individuals were included in this study: 231 T2DM patients and 162 controls. The sequence of DBP exon 11, which contains both examined variants, was amplified by polymerase chain reaction (PCR). Alleles and genotypes were determined based on electrophoresis of the DNA digestion products by specific restriction enzymes HaeIII and StyI. Since variants of DBP were in very strong linkage disequilibrium, haplotypes could be assigned to phase-unknown individuals. Differences in distributions between the groups were examined by chi(2) test. At codon 416 the frequency of Asp/Glu alleles was 44.6/55.4% in T2DM patients and 40.7/59.3% in controls (chi(2)=2.1, d.f.=1, P=0.28). At codon 420 the frequency of Thr/Lys alleles were 69.4/30.6% and 71.6/28.4%, (chi(2)=0.41, d.f.=1, P=0.52), respectively. Distribution of genotypes, haplotypes and haplotype combinations were similar in both groups. In conclusion, the frequency of amino acid variants at codons 416 and 420 of vitamin D binding protein gene in a Polish population is similar to other Caucasian populations, but differs significantly from other races. No evidence was found for an association between DBP frequent polymorphisms and T2DM in this population.
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PMID:Vitamin D binding protein gene and genetic susceptibility to type 2 diabetes mellitus in a Polish population. 1206 54


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