Search

Epigenetics alternation of non-genetic variation and genome-wide association study proven allelic variants may associate with insulin secretion in type 2 diabetes (T2D) development. We analyzed promoter DNA methylation array to evaluate the associated with increased susceptibility to T2D (30 cases, 10 controls) and found 1,091 gene hypermethylated in promoter regions. We performed the association study of T2D and found 698 single nucleotide polymorphisms in exon and promoter sites by using 2,270 subjects (560 cases, 1,710 controls). A comparison of DNA hypermethylation and gene silencing of mouse T2D results in our T2D patients' results showed that the 5'-nucleotidase, cytosolic II (NT5C2) and fucosyltransferase 8 (FUT8) genes were strongly associated with increased susceptibility to T2D. DNA hypermethylation in promoter regions reduced NT5C2 gene expression, but not FUT8 in T2D patients. NT5C2 protein expression was decreased in pancreatic β-cells from T2D mice. Transient transfection NT5C2 into RIN-m5F cells down-regulated DNA methyltransferase I (DNMT1) expression and up-regulation of the insulin receptor. Moreover, NT5C2 knockdown induced in DNMT1 overexpression and insulin receptor inhibition. Taken together, these results showed that NT5C2 epigenetically regulated insulin receptor in patients and mice with T2D, and maybe provide for T2D therapy strategy.

Epigenetics alternation of non-genetic variation and genome-wide association study proven allelic variants may associate with insulin secretion in type 2 diabetes (T2D) development. We analyzed promoter DNA methylation array to evaluate the associated with increased susceptibility to T2D (30 cases, 10 controls) and found 1,091 gene hypermethylated in promoter regions. We performed the association study of T2D and found 698 single nucleotide polymorphisms in exon and promoter sites by using 2,270 subjects (560 cases, 1,710 controls). A comparison of DNA hypermethylation and gene silencing of mouse T2D results in our T2D patients’ results showed that the 5′-nucleotidase, cytosolic II (NT5C2) and fucosyltransferase 8 (FUT8) genes were strongly associated with increased susceptibility to T2D. DNA hypermethylation in promoter regions reduced NT5C2 gene expression, but not FUT8 in T2D patients. NT5C2 protein expression was decreased in pancreatic β-cells from T2D mice. Transient transfection NT5C2 into RIN-m5F cells down-regulated DNA methyltransferase I (DNMT1) expression and up-regulation of the insulin receptor. Moreover, NT5C2 knockdown induced in DNMT1 overexpression and insulin receptor inhibition. Taken together, these results showed that NT5C2 epigenetically regulated insulin receptor in patients and mice with T2D, and maybe provide for T2D therapy strategy.

Acrylamide (ACR), which is formed during the Maillard reaction, is used in various industrial processes. ACR accumulation in humans and laboratory animals results in genotoxicity, carcinogenicity, neurotoxicity, and reproductive toxicity. In this study, we investigated the mechanisms by which ACR may induce vasorelaxation and neuromuscular toxicity. Vasorelaxation was studied using an isolated rat aortic ring model. The aortic rings were divided into the following groups: with or without endothelium, with nitric oxide synthase (NOS) inhibition, with acetylcholine receptor inhibition, and with extracellular calcium inhibition. Changes in tension were used to indicate vasorelaxation. Neuromuscular toxicity was assessed using a phrenic nerve–diaphragm model. Changes in muscle contraction stimulated by the phrenic nerve were used to indicate neuromuscular toxicity. ACR induced the vasorelaxation of phenylephrine-precontracted aortic rings, which could be significantly attenuated by NOS inhibitors. The results of the phrenic nerve–diaphragm experiments revealed that ACR reduced muscle stimulation and contraction through nicotinic acetylcholine receptor (AChR). ACR-induced vasotoxicity was regulated by NOS through the aortic endothelium. Nicotinic AChR regulated ACR-induced neuromuscular blockage.

// Ming-Yu Lien 1, 2 , Chiao-Wen Lin 3, 4 , Hsiao-Chi Tsai 1 , Yng-Tay Chen 5 , Ming-Hsui Tsai 6 , Chun-Hung Hua 7 , Shun-Fa Yang 8, 9 and Chih-Hsin Tang 1, 10 1 Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan 2 Division of Hematology and Oncology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan 3 Institute of Oral Sciences, Chung Shan Medical University, Taichung, Taiwan 4 Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan 5 Department of Pediatrics, Medical Research and Medical Genetics, China Medical College Hospital, Taichung, Taiwan 6 Department of Otolaryngology, China Medical University Hospital, Taichung, Taiwan 7 Department of Otorhinolaryngology, China Medical University Hospital, Taichung, Taiwan 8 Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan 9 Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan 10 Department of Biotechnology, College of Health Science, Asia University, Taichung, Taiwan Correspondence to: Chih-Hsin Tang, email: chtang@mail.cmu.edu.tw Shun-Fa Yang, email: ysf@csmu.edu.tw Keywords: oral cancer, CCL4, single-nucleotide polymorphism Received: October 20, 2016 Accepted: January 22, 2017 Published: February 22, 2017 ABSTRACT In Taiwan, oral cancer has causally been associated with environmental carcinogens. CCL4 (C-C chemokine ligand 4), a macrophage inflammatory protein with a key role in inflammation and immune-regulation, was implicated in carcinogenesis by facilitating instability in the tumor environment. The purpose of this study was to identify gene polymorphisms of CCL4 specific to patients with oral squamous cell carcinoma (OSCC) susceptibility and clinicopathological characteristics. A total of 2,053 participants, including 1192 healthy people and 861 patients with oral cancer, were recruited for this study. Three single-nucleotide polymorphisms (SNPs) of the CCL4 gene were analyzed by a real-time PCR. We found that the T/T homozygotes of CCL4 rs1634507 G/T polymorphism and the GG haplotype of 2 CCL4 SNPs (rs1634507 and rs10491121) combined were associated with oral-cancer susceptibility. In addition, TA haplotype significantly decreased the risks for oral cancer by 0.118 fold. Among 1420 smokers, CCL4 polymorphisms carriers with the betel-nut chewing habit had a 15.476–20.247-fold greater risk of having oral cancer compared to CCL4 wild-type (WT) carriers without the betel-nut chewing habit. Finally, patients with oral cancer who had A/G heterozygotes of CCL4 rs10491121 A/G polymorphism showed a lower risk for an advanced tumor size (> T2) ( p =0.046), compared to those patients with AA homozygotes. Our results suggest that the CCL4 rs1634507 SNP have potential predictive significance in oral carcinogenesis. Gene-environment interactions of CCL4 polymorphisms might influence oral-cancer susceptibility. CCL4 rs10491121 may be a factor to predict the tumor size in OSCC patients.

// Yng-Tay Chen 1 , Jiunn-Wang Liao 2 , Ya-Ching Tsai 1 and Fuu-Jen Tsai 1,3,4,5,6 1 Human Genetic Center, Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan 2 Graduate Institute of Veterinary Pathobiology, Research Center for Animal Medicine, Animal Disease Diagnostic Center, National Chung Hsing University, Taichung, Taiwan 3 Graduate Institute of China Medical Science, China Medical University, Taichung, Taiwan 4 Department of Medical Genetics, China Medical University Hospital, Taichung, Taiwan 5 School of Chinese Medicine, China Medical University, Taichung, Taiwan 6 Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan Correspondence to: Fuu-Jen Tsai, email: // Keywords : type 2 diabetes, DNA methylation, NR4A1, DNMT1, epigenetics, Gerotarget Received : March 01, 2016 Accepted : May 29, 2016 Published : June 14, 2016 Abstract Our previous genome-wide association studies showed that DNA methyltransferase 1 (DNMT1) is associated with increased susceptibility to type 2 diabetes (T2D) in Han Chinese individuals. Here, we aimed to further evaluate the role of DNMT1 in T2D. We performed a genome-wide DNA methylation array and found that the nuclear receptor subfamily 4 group A member 1 ( NR4A1 ) promoter was hypermethylated in patients with T2D and in a mouse model of T2D. Moreover, DNA hypermethylation of the NR4A1 promoter reduced NR4A1 mRNA expression. Transient transfection of human NR4A1 into RIN-m5F and 293T cells caused DNMT1 inhibition and induced insulin receptor activation. NR4A1knockdown by shRNA resulted in overexpression of DNMT1 and inhibition of insulin receptor, suggesting that the NR4A1 gene is involved in the epigenetics pathway. Furthermore, T2D model mice treated with the DNMT1 inhibitor aurintricarboxylic acid (ATA) showed reduced activation of DNMT1 in pancreatic β cells; this effect reversed the changes in NR4A1 expression and decreased blood glucose in T2D model mice. Thus, our results showed for the first time that DNMT1 caused NR4A1 DNA hypermethylation and blocked insulin signaling in patients with T2D. Importantly, ATA therapy may be useful for decreasing blood glucose levels by reversing NR4A1-dependent insulin signaling. These findings improve our understanding of the crucial roles of these regulatory elements in human T2D.

Diabetes mellitus (DM) is a chronic disease. The KK Cg-Ay/J (KK-Ay) mouse is an animal model to study type 2 diabetes mellitus (T2D) disease. The present study assessed the expression of hematopoietically expressed homeobox (HHEX) protein in liver tissues of different age groups of mice (6, 16 and 42 weeks) by immunohistochemistry (IHC). The results demonstrated a significant decrease in the percentage of HHEX-positive cells in KK-Ay mice as compared with that in KK-α/α control mice. Furthermore, in Taiwan's Han Chinese population, genotypic and allelic frequency distributions of the rs61862780 single-nucleotide polymorphism (SNP) in the HHEX gene were investigated. The results demonstrated that in the rs61862780 SNP of the 3'-untranslated region (UTR) of HHEX, the frequency of the CC genotype was higher in patients (6.0%) than in controls (2.7%), while the TT genotype frequency was about equal. In the same SNP, the frequency of the C allele was higher in patients (21.0%) than in controls (17.3%), while the T allele frequency was about equal. These results may pave the road for exploring the KK-Ay mouse model and the HHEX SNP rs61862780, which was correlated with the susceptibility to T2D in a Chinese population. Based on these findings, an association of HHEX gene expression with pathological features of T2D was indicated.

Genome-wide association study (GWAS) data showed that the protein tyrosine phosphatase receptor type delta (PTPRD) is associated with increased susceptibility to type 2 diabetes (T2D) in Han Chinese. A replication study indicated that PTPRD is involved in the insulin signaling pathway; however, the underlying mechanism remains unclear. We evaluated PTPRD expression in patients with T2D and controls. PTPRD expression levels were lower in patients and were correlated with the duration of the disease. Overexpression of the human insulin receptor PPARγ2 in HepG2 cells induced overexpression of PTPRD and the insulin receptor. PTPRD knockdown, using a shRNA, resulted in down-regulation of the insulin receptor. These results indicate that PTPRD activates PPARγ2 in the insulin signaling pathway. Similar results for PTPRD expression were found using a T2D mouse model. Silencing of PTPRD was caused by DNA methylation in T2D mice and patients, and correlated with DNMT1 expression. Furthermore, we showed that a DNMT1 SNP (rs78789647) was correlated with susceptibility to T2D. This study shows for the first time that DNMT1 caused PTPRD DNA hypermethylation and induced insulin signaling silencing in T2D patients. Our findings contribute to a better understanding of the crucial roles of these regulatory elements in human T2D.

Autophagy, a double-edged sword for cell survival, is the research object on 2016 Nobel Prize in Physiology or Medicine. Autophagy is a molecular mechanism for maintaining cellular physiology and promoting survival. Defects in autophagy lead to the etiology of many diseases, including diabetes mellitus (DM), cancer, neurodegeneration, infection disease and aging. DM is a metabolic and chronic disorder and has a higher prevalence in the world as well as in Taiwan. The character of diabetes mellitus is hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and failure of producing insulin on pancreatic beta cells. In T2DM, autophagy is not only providing nutrients to maintain cellular energy during fasting, but also removes damaged organelles, lipids and miss-folded proteins. In addition, autophagy plays an important role in pancreatic beta cell dysfunction and insulin resistance. In this review, we summarize the roles of autophagy in T2DM.

The nonsense mutations of the hepatitis B virus (HBV) surface (S) gene have been reported to have oncogenic potential. We have previously identified several transforming nonsense mutations of the HBV S gene from hepatocarcinoma (HCC) patients. Among them, the sW182* mutant (the stop codon for tryptophan 182) showed the most potent oncogenicity in a mouse xenograft model using stably transfected mouse fibroblast cells. This study is aimed at understanding the molecular mechanisms leading to the oncogenic activity of the sW182* mutant.A gene expression microarray in combination with gene set enrichment analysis (GSEA) revealed differentially expressed gene sets in the sW182* cells, including those related to cell-cycle regulation, deoxyribonucleic acid repair, and genome instability. Of the differentially expressed genes, the transforming growth factor-β-induced (TGFBI) gene was further validated to be dysregulated in the sW182* cells. This dysregulation was accompanied by hypermethylation of the TGFBI promoter.The level of cyclin D1, a negatively regulated TGFBI target, was highly elevated in the sW182* mutant cells, which is consistent with the potent oncogenicity. Furthermore, frequent abnormal mitosis and multinucleation were observed in the mutant cells. Exogenous expression of TGFBI alleviated the oncogenic activity of the sW182* cells. In human HBV-related HCC cancerous tissue, expression of TGFBI was downregulated in 25 of the 55 (45%) patients examined, suggesting that TGFBI dysregulation could occur in HBV-related HCC development in some cases.These results suggest that dysregulation of TGFBI is involved in the oncogenic activity of the sW182* mutant of the hepatitis B virus S gene.

Background Kawasaki disease (KD) patients who experience a cardiovascular complication known as a coronary artery aneurysm (CAA) are at high risk of developing ischemic heart disease, which may lead to sudden death. The etiology of CAA in KD patients is unclear, and this study aims to clarify the relationship between steroid receptor coactivator-1 (SRC-1) gene polymorphisms and CAA pathogenesis. Methods We investigated four SRC-1 gene polymorphisms (rs11894248, rs17791703, rs7572475, and rs9309308) and their correlation with KD with CAA susceptibility in 327 Taiwanese people (279 KD patients without CAA and 48 KD patients with CAA). Results The results indicated a statistically significant difference in genotype and allele frequency distributions at the SRC-1 four single nucleotide polymorphisms (SNPs) between KD patients with and without CAA (P < 0.01). Additionally, Smad3 gene polymorphism (rs12901071) is well known to be associated with KD patients. In our results, Smad3 SNP did not provide a statistically significant difference between KD patients with and without CAA. Conclusion Our data show that SRC-1 polymorphisms may be the underlying cause of CAA; therefore, the polymorphisms examined in this study warrant further investigation.

Background Melamine (M), which is composed of multi-amine, has been used as a food additive to falsely increase protein contents. Furthermore, cyanuric acid (CA) is a derivative of melamine. It is known that these mixtures can cause renal toxicity. Methods The objective of this study was to investigate the possible target cells during acute renal toxicity of melamine and cyanuric acid (MCA) mixture crystals in vivo . Rats were provided with a lethal dose of MCA (1:1; 400 mg/kg) and observed after 0.5, 1, 3, 12, 24, and 48-h intervals. Results MCA caused degeneration/necrosis in the proximal tubules starting at 12 h and increased at 24 and 48 h. A small number of yellow-green crystals were observed in the dilated distal renal tubules at 48 h post-treatment. Ultrastructurally, pyknosis, mitochondrial vesicles, and cellular swelling were found in the proximal tubular cells at 0.5 h. Small needle-like crystals in the cytoplasm and large crystals in the lumen of tubules indicated physical damage to the renal cells. Conclusion These results clearly reveal that in the MCA-induced renal toxicity model, crystals are distributed to both the proximal and distal tubules in rats. The proximal tubular cells may be initially injured and subsequently block the distal tubules with MCA crystals during early acute intoxication.

Adiponectin (APN) and its receptors have been reported to be associated with metabolic phenotypes. To better understand the effects of APN levels and its receptors on diabetic retinopathy (DR), we investigated the association of the plasma APN level and variations in APN-related genes with DR, individually and in combination.Patients with type 2 diabetes (T2D; N = 1604), above 20 years of age from the Taiwanese population participated in the study. Demographic information, blood pressure, and serological markers were recorded at enrollment. Genomic DNA was isolated and genotyped. The plasma APN levels were measured by enzyme-linked immunosorbent assay.T2D patients with DR (N = 632) had diabetes for a longer duration, and had higher HbA1c, and systolic and diastolic blood pressure compared to those without DR (N = 972) (P < .001, for all the parameters). Overall, 10 single nucleotide polymorphisms (SNPs) in ADIPOQ and CDH13 susceptibility loci were associated with DR. Gene risk score (GRS) was calculated based on 10 SNPs for each subject and the cumulative effect of genes was observed. Among the subjects with plasma APN level (N = 518), natural logarithm (LN) of APN (LN [APN]; odds ratio [OR] = 1.63, 95% confidence interval [CI] = 1.19-2.25) and GRS (OR = 1.90, 95% CI = 1.11-3.26 for middle range of GRS, and OR = 2.61, 95% CI = 1.48-4.59 for high range of GRS) were independent risk factors for DR after adjustment for other parameters.In conclusion, the plasma APN level and the genetic variations in adiponectin receptors were associated with DR.

Background X-ray repair cross-complementing group 3 (XRCC3) plays a crucial role in mammalian DNA repair processes. The polymorphism of XRCC3, rs861539 (Thr > Met at codon 241), is common in populations worldwide. This study analyzed the relationship between this functional single nucleotide polymorphism and systemic lupus erythematosus (SLE) in the Han Chinese population in Taiwan (HC-TW). Methods Genotyping was performed using polymerase chain reaction restriction fragment length polymorphism on 163 SLE patients and 191 healthy participants in the control group. Results The data showed that the genotype frequency at codon 241 did not differ significantly between the SLE patients and the healthy participants in the control group; however, the allele frequency analysis indicated a significant difference between these groups. In addition, we used the genotype and allele frequencies of 191 healthy HC-TW participants for comparison with HapMap populations. The results indicated a significant difference of XRCC3 Thr241Met allele and genotype frequencies between the HC-TW population and HapMap populations, except for the other Han Chinese populations. A prior study showed that Thr241 > Met substitution in XRCC3 protein was positive as damaging and functional consequences as well. Conclusion This is the first study to demonstrate the difference of XRCC3 Thr241 > Met variant between the HC-TW population and HapMap population.

Background When melamine is used as an additive in infant formula, it may cause acute nephrotoxicity in humans as well as in other animals. This study was designed to examine the effects of a melamine–cyanuric acid mixture on cytotoxicity in vitro and rat-acute nephrotoxicity. Methods In the in vitro study, crystal formations created by the melamine–cyanuric acid mixture were evaluated in media with differing pH conditions over a 24-h period and co-treatment with sodium citrate to observe the crystal formation. In the animal study, rats were exposed to a melamine–cyanuric acid mixture (400 mg/kg, 1:1) via oral gavage 14 days and co-treated with sodium citrate to observe the crystal formation in rats. Results Melamine–cyanuric acid mixture-induced crystal was pH dependent in a conditioned medium, and sodium citrate could decrease the crystal formation. Melamine–cyanuric acid-treated rats showed marked kidney swelling, vacuolization and necrosis in the proximal tubules, and numerous polarizable crystals were located in the distal segments, causing increases in kidney weight, serum BUN and creatinine. After co-treatment with sodium citrate, these increases can all be reversed. Moreover, the degrees of nephrotoxicity, proliferating of cell nuclear antigen protein and urolithiasis-related osteopontin were also decreased in the kidneys. Conclusion Sodium citrate could decrease melamine–cyanuric acid mixture-induced crystal formation that leads to urolithiasis and nephrotoxicity in rats. These results may provide a strategy for melamine–cyanuric acid-intoxication therapy in animal.

The purpose of this study was to determine whether toll-like receptors 9 (TLR9) gene polymorphisms (rs352139 and rs352140) were markers of susceptibility to the development and progression of membranous nephropathy (MGN) in Taiwanese patients. The polymorphisms were investigated by polymerase chain reaction in 397 Taiwanese individuals (134 MGN patients and 263 controls). Patients with malignancy, chronic infectious diseases, lupus nephritis, or drug-induced secondary MGN were excluded from the study. Data showed AA genotype at rs352139 SNP or GG genotype at rs352140 SNP may indicate higher risk for MGN (odds ratio [OR] = 1.55; 95% confidence interval [CI] = 1.02-2.35, at rs352139 SNP; OR = 1.57; 95% CI = 1.03-2.39, at rs352140 SNP). However, MGN patients with A-G haplotype were susceptible for decreased creatinine clearance rate and for seriously tubule-interstitial fibrosis. The result suggests for the first time that TLR9 (rs352139 and rs352140) polymorphisms may contribute to the development and progression of MGN.

Diabetes mellitus (DM) is a chronic disease. The KK Cg-Ay/J (KK-Ay) mouse is an animal model to study type 2 diabetes mellitus (T2D) disease. The present study assessed the expression of hematopoietically expressed homeobox (HHEX) protein in liver tissues of different age groups of mice (6, 16 and 42 weeks) by immunohistochemistry (IHC). The results demonstrated a significant decrease in the percentage of HHEX-positive cells in KK-Ay mice as compared with that in KK-α/α control mice. Furthermore, in Taiwan's Han Chinese population, genotypic and allelic frequency distributions of the rs61862780 single-nucleotide polymorphism (SNP) in the HHEX gene were investigated. The results demonstrated that in the rs61862780 SNP of the 3′-untranslated region (UTR) of HHEX, the frequency of the CC genotype was higher in patients (6.0%) than in controls (2.7%), while the TT genotype frequency was about equal. In the same SNP, the frequency of the C allele was higher in patients (21.0%) than in controls (17.3%), while the T allele frequency was about equal. These results may pave the road for exploring the KK-Ay mouse model and the HHEX SNP rs61862780, which was correlated with the susceptibility to T2D in a Chinese population. Based on these findings, an association of HHEX gene expression with pathological features of T2D was indicated.

Diabetic retinopathy (DR) is one of the most feared complications of diabetes and is a leading cause of acquired blindness in working adults. The prevalence of undiagnosed diabetes in Taiwan is about 4%, and the annual incidence of T2D (Type 2 Diabetes) in Taiwan is 1.8% following the 1985 WHO criteria. Multiple mechanisms have been shown in T2DR with some signaling pathways, including the polyol pathway, PKC pathway, AGEs pathway, and MAPK pathway. However, the cause of vision loss in diabetic retinopathy is complex and remains incompletely understood. Herein, we try to fully understand the new concepts regarding hyperglycemia-induced biochemical pathways contributing to DR pathophysiology. Our work may be able to provide new strategies for the prevention and treatment of diabetic vascular complications.

2-Chloroethanol (2-CE) has been used on grapevines to accelerate grape growth, and its metabolite, chloroacetaldehyde (CAA), accumulated in the liver and blood from rats intoxicated with 2-CE. Chronic occupational injury might be a possible reason for the 2-CE intoxication. In this study, we used the in vitro and in vivo tests to examine the genotoxicity of 2-CE and CAA. First, 2-CE did not induce chromosome aberration formation in Chinese ovary hamster cells, but CAA did induce chromosome aberration formation, especially the chromosome gap-type aberration after S9 activation. Second, 2-CE at high doses (1/2 LD50), but not at low doses, induced peripheral blood micronucleus formation in mice. CAA induced micronucleus formation at low and high dosages (1/8-1/2 LD50). These results indicated that CAA plays an important role in 2-CE chronic intoxication, and the genotoxic mechanisms of CAA require further study.

Outbreaks of food-associated renal failure in pets occurred in Asia and the United States of America in 2004 and 2007. They were related to the combined intoxication of cyanuric acid and melamine. Our aims were to investigate cyanuric acid and melamine contamination of pet food and to examine subchronic toxicity in rats. Levels of 10%, 20%, 50%, and 50%–100% (w/w) of contaminated pet food were fed to rats for three months. Analytical results revealed that the tainted food contained significant levels of cyanuric acid and melamine in a ratio of 1:6.8. Rats fed the diet of 50%–100% for three months exhibited elevated serum blood urea nitrogen and creatinine, as well as dose-dependent melamine/cyanuric acid crystal-induced nephrotoxicity. The melamine/cyanuric acid crystals of various sizes were mixed with necrotic cell debris and inflammatory cells, accompanied by tubular dilation and interstitial fibrosis. The immunohistochemistry index of proliferative cellular nuclear antigen and osteopontin in the kidney of the 50%–100% group were elevated, indicating regeneration of renal cells and the formation of crystals. In conclusion, the combination ratio of cyanuric acid to melamine and the acidic urine content were two factors that, upon repeated exposure, determined the severity of the nephrotoxicity.

2-Chloroethanol (2-CE) is a commonly used solvent in industry; unfortunately, severe hypotension is one of main toxic signs during intoxication. Calcium ion modulation is considered to be an important role of vasorelaxation. The aim of this study is to evaluate either 2-CE or its main metabolite, chloroacetaldehyde (CAA), possible cause of hypotension, by using isolated rat aortic rings. Results revealed that 2-CE caused a weakly relaxation in the phenylephrine (PE) pre-induced endothelium-intact aortic rings. However, its metabolite, CAA induced vasorelaxation and showed dose dependency in endothelium-intact and -denuded aortic rings. The half inhibitory concentration (IC50 )o f2 -CE exceeded 50 mM; meanwhile, the IC50 values of CAA in the endothelium-intact and -denuded aortic rings were 3.3 and 2.7 mM, respectively. The CAA-induced relaxation could be significantly attenuated by adding calcium (CaCl2 )a nd various Ca 2+ channel blockers, dantrolene, nifedipine, and NiCl2 .N ifedipine presents the most strong inhibition effect among the calcium blockers. In conclusion, it is suggested that the hypotension effect of 2-CE intoxicated cases may be mainly mediated by its metabolite CAA, and calcium channels are partially involved inducing the vasorelaxation.

Background : Collagen structure is a key element in mitral valves. Collagen defects were proposed as the primary events causing floppy mitral valves (FMV). The role of collagen genetic variant in floppy mitral valve/mitral valve prolapse (FMV/MVP) has not been well studied. The purpose of this study is to investigate the possible relationship between the collagen gene polymorphisms and risk of FMV/MVP among the Chinese population in Taiwan. Methods : We studied 100 patients with FMV/MVP diagnosed by echocardiography and 243 age- and sex-matched normal control subjects. The polymorphisms of exon 31 and exon 52 of the collagen type III-α1 gene ( COL3A1 ) were identified by polymerase chain reaction (PCR)-based restriction analysis. Results : There was a significant difference in either the genotype distribution ( P P COL3A1 exon 31 polymorphism. An odds ratio for risk of FMV/MVP associated with COL3A1 exon 31 GG genotype was 7.42 (95% confidence interval 4.40–12.52). An odds ratio for risk of FMV/MVP associated with COL3A1 exon 31 G allele was 2.28 (95% confidence interval 1.57–3.29). There was no significant difference in the distribution of COL3A1 exon 52 genotypes ( P =0.31) and allelic frequencies ( P =0.32) between FMV/MVP cases and controls. Further categorization of the FMV/MVP patients into mild and severe subgroups revealed no statistical difference from the controls for exon 31 or exon 52 polymorphism. Conclusions : This study shows that patients with FMV/MVP have higher frequency of COL3A1 exon 31 GG genotype that supports a role of the COL3A1 exon 31 polymorphism in determining the risk of FMV/MVP among the Chinese population in Taiwan.

Abnormalities of proteoglycan, collagen, and elastic fibers were found in floppy mitral valves. Perlecan is one of the three major classes of heparan sulfate proteoglycans within the cardiovascular system. The role of perlecan genetic variant in mitral valve prolapse (MVP) has not been studied. We therefore performed a case-controlled study investigating the possible relation between the perlecan gene intron 6 BamHI polymorphism and MVP among the Chinese population in Taiwan. We studied 100 patients with MVP diagnosed by echocardiography and 100 age- and sex-matched normal control subjects. The perlecan gene intron 6 BamHI polymorphism was identified by polymerase chain reaction-based restriction analysis. There were no significant differences in either the genotype distribution or allelic frequencies between MVP cases and controls for perlecan gene intron 6 BamHI polymorphism (P = 0.20 and 0.76, respectively). Further categorization of the MVP patients into mild and severe subgroups also revealed no statistical difference from controls for perlecan gene intron 6 BamHI polymorphism. It is concluded that perlecan gene intron 6 BamHI polymorphism is not a suitable genetic marker of MVP in Taiwan Chinese.

Background Some studies have reported that patients with mitral valve prolapse syndrome (MVPS) also have a disorder in the autonomic or neuroendocrine function, which can cause a host of related symptoms. A potential role of the renin-angiotensin system in the pathogenesis of MVPS has been addressed. However, the role of angiotensin I-converting enzyme (ACE) genetic variant in MVPS has not been studied. We therefore performed a case-control study investigating the possible relation between ACE gene polymorphisms and MVPS in Taiwan Chinese. Methods We studied 100 patients with MVPS diagnosed by echocardiography and 100 age- and sex-matched normal control patients. ACE gene insertion/deletion (I/D), A-240T, and G2350A polymorphisms were identified by polymerase chain reaction-based restriction analysis. Results There was a significant difference in the distribution of ACE I/D genotypes ( P = .003) and allelic frequencies ( P = .001) between MVPS cases and control patients. An odds ratio for the risk of MVPS associated with the ACE II genotype was 2.14 (95% CI 1.20-3.80 ). An odds ratio for the risk of MVPS associated with ACE I allele was 1.96 (95% CI 1.30-2.97). The A-240T and G2350A polymorphisms of the ACE gene showed no association with MVPS ( P = .20, P = .13, respectively). Conclusions This study showed that patients with MVPS have a higher frequency of ACE II genotype, which supports a role of the ACE I/D gene polymorphism in determining the risk of MVPS among the Chinese population in Taiwan. (Am Heart J 2003;145:169-73.)

The formation of urinary stones is presumed to be associated with polymorphism of the osteocalcin gene. The most frequently seen polymorphism is the Hind III type located at the promoter region. This polymorphism has been used as a genetic marker in the search for a correlation between urolithiasis and normal subjects. In our study, a normal control group of 105 healthy people and 102 patients with calcium oxalate stones were examined. The polymorphism was seen following polymerase chain reaction-based restriction analysis. The results revealed no significant differences between normal individuals and stone patients (P = 0.978), and distribution of the TT homozygote in the control group (42.9%) was similar to that in the patient group (42.2%). Further categorization of the stone patients into normocalciuric and hypercalciuric groups also revealed no statistical differences from controls. We conclude that Hind III polymorphism of the osteocalcin gene is not a suitable genetic marker of urinary stone disease. Further searches for other polymorphisms on this gene correlated with stone disease are suggested.

BACKGROUND: X‐ray repair cross‐complementing group 3 (XRCC3) plays a crucial role in mammalian DNA repair processes. The polymorphism of XRCC3, rs861539 (Thr > Met at codon 241), is common in populations worldwide. This study analyzed the relationship between this functional single nucleotide polymorphism and systemic lupus erythematosus (SLE) in the Han Chinese population in Taiwan (HC‐TW). METHODS: Genotyping was performed using polymerase chain reaction restriction fragment length polymorphism on 163 SLE patients and 191 healthy participants in the control group. RESULTS: The data showed that the genotype frequency at codon 241 did not differ significantly between the SLE patients and the healthy participants in the control group; however, the allele frequency analysis indicated a significant difference between these groups. In addition, we used the genotype and allele frequencies of 191 healthy HC‐TW participants for comparison with HapMap populations. The results indicated a significant difference of XRCC3 Thr241Met allele and genotype frequencies between the HC‐TW population and HapMap populations, except for the other Han Chinese populations. A prior study showed that Thr241 > Met substitution in XRCC3 protein was positive as damaging and functional consequences as well. CONCLUSION: This is the first study to demonstrate the difference of XRCC3 Thr241 > Met variant between the HC‐TW population and HapMap population.

Cardiovascular effects have often been found in 2-chloroethanol (2-CE) intoxicated patients, but the 2-CE elicits cardiovascular toxicity mechanism is not clear. Recently, we have found that chloroacetaldehyde (CAA) accumulation in 2-CE-intoxicated rat’s blood and play an important role in 2-CE intoxication. In this study, we used an isolated rat atrium model to examine the cardiotoxicity of 2-CE and CAA. Results indicated that 2-CE did not cause tension arrest in isolated rat right atria, but CAA did. 2-CE caused tension inhibition in the isolated rat left atria. In addition, CAA caused significant tension inhibition and contracture in the isolated rat left atria. Nifedipine, an L-type calcium channel blocker, decreased CAA-induced tension inhibition and contracture. Meanwhile, atrial nNOS and calmodulin (CaM) had significantly greater expression in the 2-CE group and the CAA group than control group. Nifedipine could decrease CAA-induced nNOS and CaM expression. 2-CE-induced cardiovascular toxicity might be due to its metabolite CAA. CAA-induced cardiovascular toxicity might be mediated by calcium channel and nifedipine protected against nNOS-triggered cardiovascular effects.

2-Chloroethanol (2-CE) is a widely used industrial solvent. In Taiwan, Taiwanese farmers apply 2-CE on grape-vines to accelerate grape growth, a practice that in some cases have caused poisoning in humans. Thus, there is strong interest in identifying antidotes to 2-CE. This study examines the protective role in 2-CE intoxicated rats. Alcohol dehydrogenase and glutathione were hypothesized to be important in the metabolism of 2-CE. This study used fomepizole, an alcohol dehydrogenase inhibitor, and chemicals that affected glutathione metabolism to study 2-CE toxicity. Notably, fomepizole 5 mg/kg significantly increased median lethal dose (LD50) of 2-CE from 65.1 to 180 mg/kg and reduced the production of a potential toxic metabolite chloroacetaldehyde (CAA) in animal plasma. In contrast, disulfiram (DSF), an aldehyde dehydrogenase inhibitor, increased the toxicity of 2-CE on the lethality in rats. Additional or pretreatment with N-acetylcysteine (NAC) and fomepizole significantly reduced plasma CAA concentrations. Fomepizole also significantly reduced 2-CEinhibited glutathione activity. Otherwise, pretreatment with NAC for 4 days followed by co-treatment with fomepizole significantly decreased formation of the metabolic CAA. These results indicated that its catalytic enzyme might play a vital role during 2-CE intoxication, and the combination of fomepizole and NAC could be a protective role in cases of acute 2-CE intoxication.

Background : Abnormalities of collagen and elastic fibers were found in floppy mitral valves (FMV). Urokinase-plasminogen activator (PLAU) was suggested to be involved in the pathogenesis of elastin and collagen degradation in arterial aneurysm. The role of PLAU genetic variant in mitral valve prolapse (MVP) has not been studied. We, therefore, performed a case-controlled study investigating the possible relation between the PLAU gene polymorphisms and risk of MVP in Taiwan Chinese. Methods : We studied 100 patients with MVP diagnosed by echocardiography and 106 age- and sex-matched normal control subjects. The T4065C and T3995C polymorphisms of the PLAU gene were identified by polymerase chain reaction (PCR)-based restriction analysis. Results : There was a significant difference in either the genotype distribution or allelic frequencies between MVP cases and controls for PLAU gene T4065C polymorphism ( P =0.0001 and 0.0002, respectively). An odds ratio for risk of MVP associated with PLAU T4065C TC genotype was 6.03 (95% confidence interval 2.11–14.83). An odds ratio for risk of MVP associated with PLAU T4065C T allele was 4.99 (95% confidence interval 1.93–12.91). There was no significant difference in either the genotype distribution or allelic frequencies between MVP cases and controls for PLAU T3995C polymorphism. Further categorization of the MVP patients into mild and severe subgroups revealed no statistical difference between these two subgroups for PLAU T4065C and T3995C polymorphisms. Conclusions : This study shows that patients with MVP have a higher frequency of PLAU T4065C TC genotype and T allele that supports a role of the PLAU T4065C polymorphism in determining the risk of MVP among the Chinese population in Taiwan.

It has been reported that patients with mitral valve prolapse syndrome (MVPS) also have a disorder in autonomic or neuroendocrine function which can cause many related symptoms. Although a potential role of the reninangiotensin system in the pathogenesis of MVPS has been addressed, the role of the angiotensinogen (AGT) genetic variant in MVPS has not been studied. Thus, a case-controlled study was performed to investigate the possible relationship between AGT gene polymorphisms and MVPS.A total of 100 patients with MVP diagnosed by echocardiography and 100 age- and sex-matched normal control subjects was studied. AGT gene M235T and T174M polymorphisms were identified by polymerase chain reaction-based restriction analysis.There was a significant difference in the distribution of AGT gene M235T genotypes (p0.001) and allelic frequencies (p0.001) between MVPS cases and controls. An Odds Ratio (OR) for risk of MVPS associated with M235T TT genotype was 8.55 (95% CI 4.51-16.18). An OR for risk of MVPS associated with the T allele at the M235T locus of the AGT gene was 3.27 (95% CI 2.05-5.22). The T174M polymorphism of AGT gene showed no association with MVPS (p = 0.94).These findings suggest that the M235T polymorphism of the AGT gene is associated with MVPS in the Chinese population of Taiwan. The association of the TT genotype with MVPS is more noteworthy than an overall increase in the frequency of the T allele at the M235T locus.