Biomedical subjects

Fu-Tien Chiang

Publications and source records attributed to Fu-Tien Chiang.

At least 19 recordsLinked to original sources

PubMed2006

The association of human connexin 40 genetic polymorphisms with atrial fibrillation.

BACKGROUND: There is evidence showing that genetic factors contribute to the pathogenesis of atrial fibrillation (Af). We investigated the association between Af and polymorphisms of the connexin 40 (Cx40) gene, which is important in the electrical coupling between atrial myocytes. METHODS: We performed an association study between two Cx40 single nucleotide polymorphisms (SNPs) (Cx40 -44 and +71 allele) and Af. We enrolled 173 patients with Af, and the control group consisted of 232 patients without Af. The luciferase assay was performed to evaluate the promoter activities of different Cx40 haplotypes in cultured atrial myocytes. RESULTS: We found that the two SNPs were both significantly associated with Af. In pairwise linkage disequilibrium analysis, the two SNPs were completely linked (Cx40 -44G always associated with Cx40 +71A; Cx40 -44A associated with Cx40 +71G, P<0.001). In haplotype analysis, we demonstrated that the frequency of Cx40 (-44A,+71G) was significantly higher in the Af group than that in the control group (P<0.006, odds ratio=1.514, 95% confidence interval 1.13-2.04). We also performed genotype analysis using several genetic models, finding that the recessive model showed the lowest P value (P<0.004) and the largest odds ratio (2.53, 95% confidence interval 1.23-5.19). In promoter activity studies using luciferase as the reporter, Cx40 (-44A,+71G) had significantly lower promoter activity than that of the Cx40 (-44G,+71A) in atrial myocytes. CONCLUSIONS: The two SNPs in the promoter region of the Cx40 gene were significantly associated with Af. The Cx40 (-44A +71G) haplotype was associated with a higher risk for Af. This haplotype also had significantly lower promoter activity in atrial myocytes.

Aged↗

PubMed2006

A flexible computational framework for detecting, characterizing, and interpreting statistical patterns of epistasis in genetic studies of human disease susceptibility.

Detecting, characterizing, and interpreting gene-gene interactions or epistasis in studies of human disease susceptibility is both a mathematical and a computational challenge. To address this problem, we have previously developed a multifactor dimensionality reduction (MDR) method for collapsing high-dimensional genetic data into a single dimension (i.e. constructive induction) thus permitting interactions to be detected in relatively small sample sizes. In this paper, we describe a comprehensive and flexible framework for detecting and interpreting gene-gene interactions that utilizes advances in information theory for selecting interesting single-nucleotide polymorphisms (SNPs), MDR for constructive induction, machine learning methods for classification, and finally graphical models for interpretation. We illustrate the usefulness of this strategy using artificial datasets simulated from several different two-locus and three-locus epistasis models. We show that the accuracy, sensitivity, specificity, and precision of a naïve Bayes classifier are significantly improved when SNPs are selected based on their information gain (i.e. class entropy removed) and reduced to a single attribute using MDR. We then apply this strategy to detecting, characterizing, and interpreting epistatic models in a genetic study (n = 500) of atrial fibrillation and show that both classification and model interpretation are significantly improved.

Atrial Fibrillation↗

PubMed2006

Outcome of primary percutaneous coronary intervention in octogenarians with acute myocardial infarction.

BACKGROUND/PURPOSE: Acute myocardial infarction (AMI) results in more complications and increased mortality in octogenarians compared to patients in younger age groups. This study investigated the short- and long-term outcomes in octogenarians after primary percutaneous coronary intervention (PCI). METHODS: During the study period from May 1997 to August 2004, 54 patients > or = 80 years old with ST-elevation myocardial infarction (STEMI) were eligible for primary PCI. Data collected included baseline clinical characteristics and usage of cardiovascular medications. Diagnostic coronary angiography and revascularization procedures were performed using standard practices. During hospitalization, the clinical course including serial changes in cardiac enzymes, adverse events associated with myocardial infarction or treatment, and inhospital or long-term mortality of patients were recorded. RESULTS: The mean age of the 54 patients (35 men, 19 women) was 82.8 +/- 2.5 years (range, 80-89 years). Among them, 27 (50%) had anterior infarction, six (11%) had anterolateral infarction, and 21 (39%) had inferior infarction, inclusive of three patients with accompanying right ventricular infarction. Among them, 20 (37%) patients were in Killip class I, nine (17%) were in class II, two (4%) in class III, and 23 (43%) in class IV. The mean delay from onset of symptoms to arrival in hospital was 220 +/- 167 minutes, and 189 +/- 169 minutes from hospital arrival to reperfusion. Diagnostic coronary angiography revealed that 48 (89%) patients had multivessel disease. Inhospital death occurred in 23 (43%) patients, with the leading causes of death being profound cardiogenic shock (61%), and free wall rupture (26%). CONCLUSION: Octogenarian patients who developed STEMI tended to have multivessel disease. These patients had a high inhospital mortality rate that was most likely to be due to cardiogenic shock.

Aged, 80 and over↗

PubMed2005

A strategic approach to transcatheter closure of patent ductus: Gianturco coils for small-to-moderate ductus and Amplatzer duct occluder for large ductus.

OBJECTIVE: To investigate the effectiveness of the strategy of transcatheter occlusion with the Gianturco coil for small-to-moderate sized ductus and with Amplatzer duct occluder (ADO) for large ductus. PATIENT AND METHODS: For ductus closure, the following strategy was applied: ADO was used in large ductus: infants and young children weighing < 15 kg with a ductus diameter > or = 3 mm and in older children or adults with a ductus diameter > or = 4 mm and coils were employed in patients with small-to-moderate sized ductus. During a 3-year period, this strategy was applied in 136 patients. The results were compared between 214 patients (group I) undergoing ductus closure using only coil before application of this strategy and strategic closure in 136 patients (group II). Each group was divided into 2 subgroups: subgroup A with large ductus and subgroup B with small-to-moderate ductus. There were 54 patients in subgroup IA, 160 in subgroup IB, 33 in subgroup IIA and 103 in subgroup IIB, respectively. RESULTS: In group I, PDA occlusion was successful in 207 (96.7%) and failed in 7 (6 of group IA and 1 of group IB). In group II, ductus closure was successful in 134 patients (98.5%) (32/33 with ADO and 102/103 with coils). There was no significant difference in success rate between group I and II. Distal embolization occurred in 19 patients of group I and in 2 of group II, respectively (19/214 vs. 2/136, P < 0.01). There was no significant difference in success rate between group IA and IIA but the distal embolization rate was higher in group IA than IIA (13/54 vs. 1/33, P=0.014). Left pulmonary artery stenosis was found exclusively in 9 patients of group I at the 6-month follow-up (P < 0.05). Nine patients in group I required second intervention to achieve complete occlusion. CONCLUSIONS: The strategy of ductus closure worked well by reducing embolization rate, incidence of left pulmonary artery stenosis and the need of second intervention.

Adolescent↗

PubMed2005

Denaturing high-performance liquid chromatography screening of the long QT syndrome-related cardiac sodium and potassium channel genes and identification of novel mutations and single nucleotide polymorphisms.

Mutations in cardiac potassium and sodium channel genes are responsible for several hereditary cardiac arrhythmia syndromes. We established a denaturing high-performance liquid chromatography (DHPLC) protocol for rapid mutation screening of these genes, and reported mutations and variations identified by this method. We included 28 patients with Brugada syndrome, 4 with congenital long QT syndrome (LQTS), 11 with drug-induced LQTS, 4 with idiopathic ventricular fibrillation, and 50 normal volunteers. Polymerase chain reactions were performed to amplify the entire coding region of these genes. DHPLC was used to screen for heteroduplexes then DNA sequencing was performed. With this method, we identified the mutation(s) in all four patients with congenital LQTS (KCNQ1 A341V, KCNH2 N633D, KCNH2 2768Cdel and KCNE1 K70 N Y81C double mutations). We also identified the SCN5A A551T mutation in 1 of the 28 patients with Brugada syndrome. All the above-mentioned mutations were novel except KCNQ1 A341V. No mutations were identified in patients with drug-induced LQTS or idiopathic ventricular fibrillation. In total, 25 single nucleotide polymorphisms were identified, 10 of which were novel. In conclusion, DHPLC is a sensitive and rapid method for detection of cardiac sodium and potassium channel gene mutations.

Chromatography, High Pressure Liquid↗

PubMed2005

Effects of continuous intravenous epoprostenol therapy on advanced primary pulmonary hypertension in Taiwanese patients.

Primary pulmonary hypertension (PPH) is a progressive disease for which there is no cure. Continuous intravenous infusion of epoprostenol in selected patients with advanced PPH improves symptoms and survival, but the long-term impact has not been reported in Taiwanese patients. Four patients with advanced PPH treated with epoprostenol therapy were enrolled in this study from July 2000 to September 2001. The basic hemodynamic status, cardiothoracic ratio, 6-minute-walk test results, maximum oxygen consumption, New York Heart Association functional class and survival were re-evaluated before and after 12 months of epoprostenol treatment. One of the patients died after 10 months of epoprostenol therapy due to heart failure, and the other 3 were still alive after a mean of 28 months. The surviving patients had pronounced symptomatic, hemodynamic, functional and survival benefit from epoprostenol therapy. Our results suggest that chronic infusion of epoprostenol can improve functional status and survival of Taiwanese patients with advanced PPH disease.

Adult↗

PubMed2005

Low frequency of target organ damage in Taiwanese with white coat hypertension.

BACKGROUND AND PURPOSE: The clinical importance of white coat hypertension (WCH) remains to be clarified. This study investigated the target organ damage in Taiwanese with WCH. METHODS: A total of 188 consecutive Taiwanese (88 men and 100 women), aged 26 to 75 years who had an abnormal office casual blood pressure (systolic blood pressure >/= 140 mm Hg or diastolic blood pressure >/= 90 mm Hg or both) and a normal ambulatory blood pressure (ABP) average (systolic ABP average < 140 mm Hg and diastolic ABP average < 90 mm Hg) at the outpatient clinic or from a mass survey were enrolled. Office casual blood pressure measurements were obtained by standard sphygmomanometric methods. Twenty-four-hour blood pressures were recorded by a commercial ambulatory pressure recorder (Del Mar Avionics, Model 1990 Pressurometer IV System). Hypertension-related target organ complications were assessed by electrocardiogram, chest X-ray, urinalysis and eye fundus examinations. RESULTS: Target organ damage was found in 6.4% of subjects with WCH. Roentgenographic left ventricular hypertrophy (LVH) was found in 1.1% of subjects and electrocardiographic LVH in 2.7%. Proteinuria was found in 1.6% of subjects and retinopathy in 1.1%. The frequencies of various target organ damage were not significantly associated with age, gender and the definition of normal ABP average as 135/85 mm Hg or 140/90 mm Hg. CONCLUSIONS: WCH represents a low-risk stratum for target organ damage in Taiwanese. These subjects should be identified and followed up regularly. The factors responsible for the low frequency of target organ damage in Taiwanese with WCH need further study.

Adult↗

PubMed2005

Successful balloon pulmonary valvuloplasty for congenital valvular pulmonary stenosis in an octogenarian.

While balloon valvuloplasty has been widely used for the treatment of congenital valvular pulmonary stenosis (PS) in children and adults, its use in elderly patients is less common. An 80-year-old woman with congenital valvular PS received valvuloplasty with double-balloon technique. Right ventricle systolic pressure and pulmonary valve systolic pressure gradient decreased from 95 to 44 mm Hg and from 75 to 35 mm Hg, respectively. Follow-up Doppler echocardiography 2 months later showed further decrease in the transvalvular systolic pressure gradient to 29 mm Hg. The patient had symptomatic relief, and no major complication was noted. Balloon pulmonary valvuloplasty can be an effective treatment for elderly patients with congenital valvular PS.

Aged↗

PubMed2004

A novel SCN5A mutation manifests as a malignant form of long QT syndrome with perinatal onset of tachycardia/bradycardia.

OBJECTIVE: Congenital long QT syndrome (LQTS) with in utero onset of the rhythm disturbances is associated with a poor prognosis. In this study we investigated a newborn patient with fetal bradycardia, 2:1 atrioventricular block and ventricular tachycardia soon after birth. METHODS: Mutational analysis and DNA sequencing were conducted in a newborn. The 2:1 atrioventricular block improved to 1:1 conduction only after intravenous lidocaine infusion or a high dose of mexiletine, which also controlled the ventricular tachycardia. RESULTS: A novel, spontaneous LQTS-3 mutation was identified in the transmembrane segment 6 of domain IV of the Na(v)1.5 cardiac sodium channel, with a G-->A substitution at codon 1763, which changed a valine (GTG) to a methionine (ATG). The proband was heterozygous but the mutation was absent in the parents and the sister. Expression of this mutant channel in tsA201 mammalian cells by site-directed mutagenesis revealed a persistent tetrodotoxin-sensitive but lidocaine-resistant current that was associated with a positive shift of the steady-state inactivation curve, steeper activation curve and faster recovery from inactivation. We also found a similar electrophysiological profile for the neighboring V1764M mutant. But, the other neighboring I1762A mutant had no persistent current and was still associated with a positive shift of inactivation. CONCLUSIONS: These findings suggest that the Na(v)1.5/V1763M channel dysfunction and possible neighboring mutants contribute to a persistent inward current due to altered inactivation kinetics and clinically congenital LQTS with perinatal onset of arrhythmias that responded to lidocaine and mexiletine.

Bradycardia↗

PubMed2004

Three single-nucleotide polymorphisms of the angiotensinogen gene and susceptibility to hypertension: single locus genotype vs. haplotype analysis.

Although some single polymorphism analyses of the angiotensinogen (AGT) gene have been found to be associated with hypertension, the results are still inconsistent. The objectives of this study are to evaluate the association of the genotype and haplotype distributions of three single-nucleotide polymorphisms (SNPs) (G-217A, A-6G, and M235T) in the AGT gene with hypertension. In a sample of 461 hypertensive and 327 normotensive patients in Taiwan, we found that -217AA and -6GG homozygotes conferred independently an increased risk to hypertension (P = 0.008 and P = 0.037, respectively), as illustrated by their significant associations with hypertension in both single SNP and pair-wise SNPs analyses. Meanwhile, a very weak linkage disequilibrium was found between the G-217A and the A-6G polymorphisms in terms of r2 (<0.05). On the basis of likelihood ratio test, only the set of haplotypes that constituted the A-6G and the M235T polymorphisms was associated with hypertension (chi2 = 20.91, P = 0.0008), which was mainly due to the increased frequency of the recombinant haplotypes (-6A identical with 235M and -6G identical with 235T), and a pathophysiological role in the predisposition to hypertension was hence indicated. In functional assays, the promoter activities of the haplotypes -217A identical with -6A and -217G identical with -6G were significantly higher than the most common haplotype -217G identical with -6A. These results highlight the necessity of a thorough analysis of all reported variants of a candidate gene in the elucidation of genetic susceptibility to a complex disease like hypertension, even when the variants are in the same haplotype block.

Angiotensinogen↗

PubMed2004

Renin-angiotensin system gene polymorphisms and atrial fibrillation.

BACKGROUND: The activated local atrial renin-angiotensin system (RAS) has been reported to play an important role in the pathogenesis of atrial fibrillation (AF). We hypothesized that RAS genes might be among the susceptibility genes of nonfamilial structural AF and conducted a genetic case-control study to demonstrate this. METHODS AND RESULTS: A total of 250 patients with documented nonfamilial structural AF and 250 controls were selected. The controls were matched to cases on a 1-to-1 basis with regard to age, gender, presence of left ventricular dysfunction, and presence of significant valvular heart disease. The ACE gene insertion/deletion polymorphism, the T174M, M235T, G-6A, A-20C, G-152A, and G-217A polymorphisms of the angiotensinogen gene, and the A1166C polymorphism of the angiotensin II type I receptor gene were genotyped. In multilocus haplotype analysis, the angiotensinogen gene haplotype profile was significantly different between cases and controls (chi2=62.5, P=0.0002). In single-locus analysis, M235T, G-6A, and G-217A were significantly associated with AF. Frequencies of the M235, G-6, and G-217 alleles were significantly higher in cases than in controls (P=0.000, 0.005, and 0.002, respectively). The odds ratios for AF were 2.5 (95% CI 1.7 to 3.3) with M235/M235 plus M235/T235 genotype, 3.3 (95% CI 1.3 to 10.0) with G-6/G-6 genotype, and 2.0 (95% CI 1.3 to 2.5) with G-217/G-217 genotype. Furthermore, significant gene-gene interactions were detected by the multifactor-dimensionality reduction method and multilocus linkage disequilibrium tests. CONCLUSIONS: This study demonstrates the association of RAS gene polymorphisms with nonfamilial structural AF and may provide the rationale for clinical trials to investigate the use of ACE inhibitor or angiotensin II antagonist in the treatment of structural AF.

Aged↗

PubMed2004

The effect of iron stores on corrected QT dispersion in patients undergoing peritoneal dialysis.

BACKGROUND: Arrhythmia and sudden death represent striking features in patients with end-stage renal disease (ESRD). Increased QT dispersion has been shown to be associated with arrhythmias. Abnormal excitability and heterogeneous cardiac iron deposition may cause the arrhythmogenesis of human siderotic heart disease. Iron overload and precipitation with its toxicity in cardiac muscles may, therefore, cause QT prolongation in dialysis patients. METHODS: A total of 102 (65 women, 37 men; mean age, 47.7 +/- 13.4 years) nondiabetic patients undergoing peritoneal dialysis (PD) were enrolled in this study. Another 102 subjects with a serum creatinine level less than 1.5 mg/dL (133 micromol/L) were used as matched control subjects. The PD patients were divided into 2 groups according to whether their computerized measurements of corrected QT (QTc) dispersion were longer than 74 ms. A value of 74 ms has been associated with risk for serious arrhythmias related to sudden death in dialysis patients. RESULTS: The QTc dispersion of PD patients was significantly longer than that of the control subjects (69.8 +/- 40.0 versus 55.2 +/- 33.6 ms; P < 0.01). Thirty-eight PD patients with QTc dispersion longer than 74 ms had lower blood pressure ( P = 0.01), fewer left ventricle masses ( P = 0.036), and lower serum albumin levels (P = 0.046) but higher levels of serum calcium (P = 0.038) and transferrin saturation (TSAT; P = 0.022) than the other patients. Multivariate analysis identified TSAT as an independent factor for QTc dispersion (r = 0.432, P < 0.001). A linear relationship showed that at 74 ms of QTc dispersion, TSAT was 35.2%. CONCLUSION: Long-term PD patients have longer QTc dispersion than subjects with normal renal function. The high body iron stores in these patients increase the risk of increased QT dispersion. The concern over iron overload in dialysis patients is not only because of its oxidative toxicity, but also its precipitation of arrhythmias, which may be measured by the surrogate marker of QTc dispersion.

Adult↗

PubMed2003

The G-217A variant of the angiotensinogen gene affects basal transcription and is associated with hypertension in a Taiwanese population.

OBJECTIVE: Polymorphisms of the angiotensinogen (AGT) gene, especially in the promoter region, are in linkage concordance and are associated with hypertension. In this study, we examined the role of AGT promoter polymorphisms, including G-217A, A-6G and M235T variants, and their promoter function in essential hypertension in Taiwanese populations. DESIGN: An association study was conducted to assess the genotype distribution between hypertensive patients and normotensive subjects. We also used a transient transfection assay to examine basal transcriptional activity of G-217A and A-6G variants in a mammalian cell system. METHODS: Hypertensive subjects (390) and normotensive controls (388) of Taiwanese ethnicity were genotyped for the AGT G-217A, A-6G and M235T variants. Promoter activity was studied by cloning the promoter region (-614 to +41 bp) of AGT into the pSEAP2-Basic reporter vector and performing a transient transfection assay in HuH7 and HepG2 cells. RESULTS: The G-217A variant of the AGT gene was significantly associated with hypertension (P = 0.0047), but the A-6G and M235T polymorphisms were not (P = 0.17 and P = 0.33, respectively). Furthermore, the recessive model of homozygous genotype (-217AA) conferred a high risk for hypertension (odds ratio 3.64) in this population. The -217A variant expressed higher transcriptional activity than -217G in vitro. CONCLUSIONS: Our study showed a significant association between the -217A variant of the AGT gene and hypertension. This variant plays a functional role in basal transcription of AGT, and may confer a risk for hypertension in Taiwanese populations.

Adenine↗

PubMed2003

Characteristics of Chinese patients with symptomatic Brugada syndrome in Taiwan.

Since 1992, the Brugada syndrome has been increasingly recognized worldwide, although its incidence and distribution remain unclear. In Asia, several cases have been reported in Japan, Thailand, Singapore, and Vietnam. However, little information is available from the Chinese population. Since June 1997, we have identified 10 patients with the diagnosis of the Brugada syndrome from six hospitals in Taiwan. All patients were male with the mean age of 46 +/- 7 years (range 36-61). They all had a normal chemistry profile, coronary angiography and echocardiography. Clinical presentations varied from seizure and syncope to sudden cardiac death. MRI and ultrafast CT of the heart did not show any abnormalities. Sustained ventricular tachycardia/ventricular fibrillation (VF) was induced in 7 of 8 patients who underwent an electrophysiologic study. The pharmacological provocation test was positive in 4 of 5 patients. One of the 4 patients who had a genetic study showed SCN5A gene mutation. An implantable cardioverter defibrillator (ICD) was implanted in 8 patients. During a mean follow-up of 29 +/- 17 months (range 2-54), 3 of 8 patients who had an ICD received appropriate ICD discharges after implantation. These 3 patients who were subsequently treated with antiarrhythmic agents have had no further recurrent ICD discharges. Two patients who refused ICD implantation are alive and well without taking antiarrhythmic agents. Our study showed that the clinical characteristics of our patients are similar to those described in the literature and that ICD is an effective treatment modality for patients with recurrent VF. However, antiarrhythmic agents may be beneficial for suppressing arrhythmia recurrences in selected patients.

Adult↗

PubMed2003

Angiotensinogen gene haplotype and hypertension: interaction with ACE gene I allele.

There are many reports demonstrating the association of renin-angiotensin system gene polymorphisms with hypertension in different populations. In the present study, we used haplotype analyses of the angiotensinogen gene with a new permutation-based hypothesis testing method to determine the association between multilocus angiotensinogen gene polymorphisms and hypertension in a relatively homogeneous Taiwanese population. We also genotyped angiotensin-converting enzyme gene insertion/deletion polymorphism and angiotensin II type 1-receptor gene A1166C polymorphism to detect epistatic gene-gene interactions. There were 408 patients with hypertension (hypertensives) and 286 controls. The angiotensinogen gene haplotype frequencies were significantly different between hypertensives and controls, and this finding was only present in subjects with angiotensin-converting enzyme gene II genotypes when the analysis was stratified by genotype of this polymorphism. In addition, the angiotensinogen gene haplotype structure of hypertensives was more heterogeneous than that of controls. Our results showed that angiotensinogen gene haplotypes were associated with hypertension and might act synergistically with I allele of the angiotensin-converting enzyme gene.

Alleles↗

PubMed2002

Assessment of quality of life in a double-blind, randomized clinical trial of imidapril and captopril for hypertensive Chinese in Taiwan.

PURPOSE: Although the role of angiotensin-converting enzyme (ACE) inhibitors for the treatment of hypertension has been well established, no data has been generated regarding the influence of ACE inhibitors for health-related quality-of-life (QOL) dimensions for Chinese patients. MATERIALS: A double-blind, active-control, randomized clinical trial was used to compare the effects of two ACE inhibitors, imidapril and captopril, on quality-of-life dimensions in one outpatient clinic in one tertiary clinical-care facility. After a 2-3 week washout period with placebo, 59 patients with mild-to-moderate hypertension were randomly assigned to receive imidapril (5 to 10 mg per day) or captopril (25 to 50 mg twice per day) for 12 weeks. Patients completed the Short-form 36 (SF 36) health survey questionnaire, which evaluates 8 QOL dimensions, just before treatment, during the 8th week, and at the end of treatment (12th week). ANOVA for repeated measures was used to analyze the QOL-score changes over time and compare treatments, and to assess the interaction of treatment duration and group on these scores. RESULTS: No significant differences were demonstrated for changes in blood-pressure, frequency of adverse effects and withdrawal of patients from the study comparing the two drugs. Significant improvement, however, was demonstrated for mental-component summary scores after 12 weeks of treatment for both drugs (P = 0.029). No significant differences were established for individual QOL dimensions comparing the two drugs. A significantly higher baseline systolic blood pressure was found in the participants who did not complete the questionnaire than in those who did. CONCLUSIONS: Similar and significant improvements were determined for the mental-component QOL summary scores for the two ACE inhibitors, imidapril and captopril, and no significant differences were demonstrated comparing treatments.

Adult↗

PubMed2002

Association of the human minK gene 38G allele with atrial fibrillation: evidence of possible genetic control on the pathogenesis of atrial fibrillation.

BACKGROUND: Human minK protein is the beta-subunit of I(Ks) potassium channel and plays an important role in cardiac cellular electrophysiology. We investigated the association between human atrial fibrillation and the polymorphism of minK gene (38G or 38S) with a case-control study. METHODS: We included 108 patients with atrial fibrillation and 108 control subjects. The case patients and control subjects were matched regarding age, sex, presence of valvular heart disease, and presence of left ventricular dysfunction. The genotype of minK was determined with polymerase chain reaction and restriction fragment analysis. RESULTS: The results showed an association between the minK 38G allele and atrial fibrillation. The odds ratios for atrial fibrillation in patients with 1 and 2 minK 38G alleles were 2.16 (95% CI 0.81-5.74) and 3.58 (95% CI 1.38-9.27), respectively, when compared with patients without minK 38G allele. In a logistic regression model, the odds ratio for atrial fibrillation was 1.80 (95% CI 1.20-2.71, P <.0046) for patients with 1 more minK 38G allele. CONCLUSION: We report the association between the minK 38G allele and clinical atrial fibrillation. Our findings suggest possible genetic control on the pathogenesis of atrial fibrillation.

Alleles↗

PubMed2002

The 27-bp tandem repeat polymorphism in intron 4 of the endothelial nitric oxide synthase gene is not associated with coronary artery disease in a hospital-based Taiwanese population.

We studied whether the 27 base pair (bp) tandem repeat polymorphism in intron 4 of the endothelial nitric oxide synthase (eNOS) gene was associated with coronary artery disease (CAD) in a hospital-based Taiwanese population. We included 219 consecutive patients who underwent coronary angiography at our institution. Two alleles, containing 4 (eNOS4a) and 5 repeats (eNOS4b), were identified after polymerase chain reaction amplifying intron 4 of the eNOS gene. The genotype frequencies for eNOS4b/b, eNOS4a/b and eNOS4a/a were 77.9, 21.5 and 0.6% in CAD subjects, and 80, 20 and 0% in control subjects (Fisher's exact test, p = 0.90), respectively. The odds ratio (OR) for CAD in patients with at least one eNOSa allele was 1.2 (0.5-2.9) after adjustment for classical CAD risk factors. The eNOS4a allele was not associated with the severity of CAD (Fisher's exact test, p = 0.90) and the occurrence of acute myocardial infarction (AMI) or unstable angina (adjusted OR 0.6, 0.3-1.6) in patients with CAD. In conclusion, the 27-bp repeat polymorphism of the eNOS gene was not associated with CAD and the occurrence of AMI or unstable angina in a hospital-based Taiwanese population.

Aged↗