The Contribution of DNA Ligase 4 Polymorphisms to Colorectal Cancer.

BACKGROUND/AIM: While numerous biomarkers associated with genetic susceptibility to colorectal cancer (CRC) have been identified and validated through epidemiological studies, the specific influence of DNA ligase 4 (Lig4) genotypes remains unexplored. This study aimed to elucidate the hitherto unexamined relationship between Lig4 genotypes and CRC risk. MATERIALS AND METHODS: The genotypes of Lig4 rs1805388 were determined applying the polymerase chain reaction-restriction fragment length polymorphism methodology. The potential association between these genotypes and CRC risk was assessed in a Taiwanese population comprising 362 CRC cases and an equal number of age- and sex-matched controls. RESULTS: In the genotypic analysis, the distribution of CC, CT, and TT genotypes for Lig4 rs1805388 among CRC cases was 54.7%, 38.1%, and 7.2%, respectively. This distribution was not significantly different from the controls, which exhibited genotypic frequencies of 57.2%, 36.7%, and 6.1%, respectively (p for trend=0.7314). Analysis of allelic distribution indicated that individuals carrying the T allele of Lig4 rs1805388 displayed a slightly elevated CRC risk compared to those carrying the C allele (odds ratio=1.10, 95% confidence interval=0.87-1.39, p=0.4685). CONCLUSION: The variant genotypes of Lig4 rs1805388 may not serve as predictive markers for CRC risk in the Taiwanese population.

Interleukin-8 Rs4073 Genotypes as Prognostic Predictors for Childhood Acute Lymphocytic Leukemia.

BACKGROUND/AIM: Interleukin 8 (IL-8) is highly expressed in refractory acute lymphocytic leukemia (ALL) cells. This study aimed to investigate the contribution of IL-8 polymorphisms to the risk of childhood ALL. MATERIALS AND METHODS: The genotypes of IL-8 rs4073, rs2227306, rs2227543, and rs1126647 were determined in 266 childhood ALL cases and 266 controls using the PCR-RFLP method. Additionally, we assessed whether the interactions of these genotypes with age and sex contributed to childhood ALL risk. RESULTS: The distributions of genotypic and allelic frequencies of IL-8 rs4073, rs2227306, rs2227543, and rs1126647 were not significantly different between childhood ALL cases and controls (all p>0.05). However, carriers of the variant AA genotype at IL-8 rs4073 had a significantly higher risk of childhood ALL among those aged ≤3.5 years and among girls (OR=2.39 and 3.32, 95%CI=1.21-4.73 and 1.51-7.30, p=0.0182 and 0.0042, respectively). In the stratification analysis, IL-8 rs4073 AT and AA genotypes were associated with higher childhood ALL risk classification and shorter survival time (OR=2.21 and 4.13, 95%CI=1.29-3.78 and 1.87-9.10, p=0.0054 and 0.0002, respectively). There was no positive association for rs2227306, rs2227543, or rs1126647 (all p>0.05). CONCLUSION: The A allele of IL-8 rs4073 can serve as a diagnostic predictor for childhood ALL, but only in girls and patients younger than or equal to 3.5 years old. More importantly, it can serve as a prognostic marker for high-risk classification and shorter survival time. Further validation studies can help extend the use of this prognostic predictor in clinical practice.

The Significant Impacts of Interleukin-8 Genotypes on the Risk of Colorectal Cancer in Taiwan.

Interleukin-8 (IL-8), a pro-inflammatory cytokine, is upregulated in CRC and plays an important role in its development and progression. Genetic variants in the IL-8 gene may impact the risk of CRC by modulating IL-8 levels. Our primary objective was to investigate the role of IL-8 genotypes in the development of CRC. To accomplish this, we employed the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to analyze the genotypes of IL-8 rs4017, rs2227306, rs2227543, and rs1126647 in 362 CRC patients and 362 controls. Additionally, we evaluated the interactions between these genotypes and factors such as age, gender, smoking, alcohol consumption, and body mass index (BMI) status in relation to the risk of CRC. Furthermore, we utilized quantitative reverse transcription-PCR to measure the serum IL-8. The results demonstrated a significant difference in the distribution of rs4017 genotypes between the control and case groups (p for trend = 0.0059). Logistic regression analysis revealed that individuals with variant AA genotype had a 1.92-fold higher CRC risk (95% confidence interval [CI] = 1.28-2.89, p = 0.0023). Moreover, carriers of the IL-8 rs4017 AT + AA genotypes exhibited a significant association with CRC risk (odds ratio [OR] = 1.39, 95% CI = 1.02-1.91, p = 0.0460). Additionally, individuals with IL-8 rs4017 AA genotype displayed significantly elevated serum IL-8 compared to those with TT genotype at a 1.73-fold level (p < 0.0001), indicating a correlation between genotype and phenotype. In conclusion, the genotypes of IL-8 rs4017, along with their associated expression levels, can potentially serve as predictive markers for the risk of CRC.

Impact of Matrix Metalloproteinase-8 Genotypes on Colorectal Cancer Risk in Taiwan.

BACKGROUND/AIM: This study aimed to investigate the involvement of matrix metalloproteinase-8 (MMP-8) genotypes in the development of colorectal cancer (CRC). MATERIALS AND METHODS: The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to analyze the genotypes of MMP-8 C-799T (rs11225395), Val436Ala (rs34009635), and Lys460Thr (rs35866072) in 362 patients with CRC and 362 controls. Additionally, the potential associations between these genotypes and factors such as age, sex, smoking, alcohol consumption, and body mass index (BMI) status in relation to CRC risk were also assessed. RESULTS: No significant differences in the distribution of MMP-8 rs11225395 genotypes were found between the control and case groups (p for trend=0.3836). Logistic regression analysis demonstrated that individuals with the MMP-8 rs11225395 variant CT and TT genotypes had a 0.83 and 0.77-fold risk of CRC, respectively. Moreover, carriers of the rs11225395 CT+TT genotypes were not associated with CRC risk either (p=0.2063). Furthermore, individuals with the MMP-8 rs11225395 TT genotype exhibited significantly lower odds of CRC risk compared to those with the CC genotype among non-smokers (p=0.0379). No significant associations were observed with respect to MMP-8 rs34009635 or rs35866072. CONCLUSION: The analyzed genotypes of MMP-8 play a minor role in determining individual susceptibility to CRC risk.

Impact of Mir196a-2 Genotypes on Colorectal Cancer Risk in Taiwan.

We aimed to investigate the association between genotypes for mir146a and mir196a-2 and the risk of developing colorectal cancer (CRC). We used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to determine the mir146a rs2910164 and mir196a-2 rs11614913 genotypes in 362 CRC patients and 362 controls. We also assessed the interactions between these genotypes and age, gender, smoking, alcohol consumption, and BMI status on CRC risk. Additionally, the serum expression level of mir196a-2 was quantified using quantitative reverse transcription-PCR. Our findings demonstrated that among the controls, the proportions of TT, CT, and CC genotypes of mir196a-2 rs11614913 were 32.3%, 48.1%, and 19.6%, respectively. As for the cases, the proportions were 24.6%, 45.0%, and 30.4%, respectively. Logistic regression analysis revealed that the CC genotype carriers had a 2.04-fold increased risk (95% confidence interval [CI] = 1.36-3.06, p = 0.0008). Furthermore, carriers of the CT + CC genotypes also exhibited a significant association with CRC risk (odds ratio [OR] = 1.46, 95% CI = 1.06-2.03, p = 0.0261). Moreover, carriers of the CC genotype had significantly higher serum levels of mir196a-2 compared to those with the TT genotype (p < 0.0001), indicating a genotype-phenotype correlation. No association was found regarding mir146a rs2910164. In conclusion, mir196a-2 rs2910164 genotypes, along with their associated expression, can serve as predictive markers for CRC risk.

Significant Contribution of Interleukin-18 Genotypes to Childhood Acute Lymphocytic Leukemia Risk in Taiwanese.

BACKGROUND/AIM: Evidence has shown that interleukin-18 (IL-18) has both antitumor and pro-tumor effects in various types of leukemia. The current study aimed at investigating the contribution of IL-18 polymorphisms to the risk of childhood acute lymphocytic leukemia (ALL) in Taiwan. MATERIALS AND METHODS: IL-18 promoter -656 (rs1946519), -607 (rs1946518), and -137 (rs187238) genotypes of 266 childhood ALL cases and 266 controls were determined by polymerase chain reaction-restriction fragment length polymorphism methodology. RESULTS: The distributions of genotypic and allelic frequencies of IL-18 rs1946519, rs1946518 or rs187238, were not significantly different between childhood ALL cases and controls (all p>0.05). However, in the stratification analysis among the cases, IL-18 rs187238 GC and CC genotypes were associated with increased childhood ALL risk and shorter survival (OR=4.19 and 2.93, 95%CI=2.04-8.64 and 1.19-7.23, p=0.0001 and 0.0250, respectively). No association was found with rs1946519 and rs1946518 (all p>0.05). CONCLUSION: IL-18 rs187238 GC and CC genotypes can serve as predictors for childhood ALL prognosis among Taiwanese. Validation in larger and various populations can greatly extend the feasibility of this novel predictor.

Multilevel Understanding of the Impact of Individual- and School-Level Determinants on Lipid Profiles in Adolescents: The Cross-Level Interaction of Food Environment and Body Mass Index.

Adolescents with comparable personal risk factors may have different lipid profiles because of the school's context. Lipid determinants in adolescents should be considered using a multilevel perspective. This multilevel study investigated the effects of individual-level and school-level factors on lipid profiles in adolescents and evaluated the cross-level influence of lipid determinants. A representative adolescent cohort (n = 2727) was randomly selected from 36 schools in three diverse economic areas in Taiwan and assessed for their personal dietary patterns, physical parameters, and lipid profiles. For individual-level factors, both low physical activity and high body mass index (BMI) were associated with elevated triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) levels, and a sugar-sweetened beverage intake of >500 mL/day was associated with increases of 5.97 and 6.12 mg/dL in LDL-C and TC levels, respectively, compared with abstinence. Regarding school-level factors, students in schools with ≥2 health promotion programs per year had a 5.27 mg/dL lower level of LDL-C than those in schools with 0−1 program, and students in schools with ≥46 food outlets within 600 m of the school had 6.90 and 13.3 mg/dL higher levels of TG and TC, respectively, than those in schools with <46 food outlets. School context modified the individual-level positive correlation between BMI and TG level (the p-value for the random-slope effect was 0.003). In conclusion, individual-level and school-level factors exert a multilevel effect on adolescent lipid profiles. The food environment near the school has a stronger cross-level impact on individual TG levels in adolescents with a high BMI than in those with a normal BMI.

Stability and Transformation of Metabolic Syndrome in Adolescents: A Prospective Assessment in Relation to the Change of Cardiometabolic Risk Factors.

Underlying pathophysiological mechanisms drive excessive clustering of cardiometabolic risk factors, causing metabolic syndrome (MetS). MetS status may transform as adolescents transition to young adulthood. This study investigated the latent clustering structure and its stability for MetS during adolescence, and assessed the anthropometric and clinical metabolic determinants for MetS transformation. A community-based representative adolescent cohort (n = 1516) was evaluated for MetS using four diagnostic criteria, and was followed for 2.2 years to identify new-onset MetS. The clustering structure underlying cardiometabolic parameters was stable across adolescence; both comprised a fat-blood pressure (BP)-glucose three-factor structure (total variance explained: 68.8% and 69.7% at baseline and follow-up, respectively). Among adolescents with MetS-negative at baseline, 3.2-4.4% had incident MetS after 2.2 years. Among adolescents with MetS-positive at baseline, 52.0-61.9% experienced MetS remission, and 38.1-48.0% experienced MetS persistence. Increased systolic BP (SBP) was associated with a high MetS incidence risk, while decreased levels of SBP and glucose were associated with MetS remission. Compared with adolescents with a normal metabolic status at baseline, those with an initial abdominal obesity and increased triglycerides level had a 15.0- and 5.7-fold greater risk for persistent abnormality, respectively. Abdominal obesity and low high-density lipoprotein cholesterol are two abnormal MetS components that highly persist during adolescence, and are the intervention targets for reducing the future risk of cardiometabolic disorders.

Significant Association of CCND1 Genotypes With Susceptibility to Childhood Acute Lymphoblastic Leukemia.

BACKGROUND/AIM: This study investigated whether genetic variations in cyclin D1 (CCND1) are associated with susceptibility to childhood acute lymphoblastic leukemia (ALL). MATERIALS AND METHODS: A total of 266 childhood ALL cases and 266 healthy controls were genotyped for CCND1 rs9344 and rs678653. RESULTS: There was a significant difference in the genotypic distribution of rs9344 between childhood ALL patients and healthy controls (p=0.0077). Compared to the AA genotype, AG and GG genotypes were associated with significantly decreased risks of childhood ALL with odds ratio (OR) of 0.65 [95% confidence interval (CI)=0.44-0.94, p=0.0234] and 0.45 (95%CI=0.26-0.78, p=0.0040), respectively. Supporting this, allelic frequency distributions between childhood ALL patients and controls was significantly different (OR=0.68, 95%CI=0.53-0.88, p=0.0025). There was no significant difference in the genotypic and allelic distributions of rs678653 between cases and controls. CONCLUSION: CCND1 rs9344, but not rs678653, may serve as a predictive marker of susceptibility for childhood ALL.

Contribution of insulin resistance to the relationship between sugar-sweetened beverage intake and a constellation of cardiometabolic abnormalities in adolescents.

BACKGROUND: Insulin resistance (IR) is a pathophysiological construct that derives a series of metabolic disturbances that promote cardiometabolic dysfunction. This study evaluated mediating and modifying effects of homeostatic model assessment-based IR (HOMA-IR) on the association between sugar-sweetened beverage (SSB) consumption and a constellation of adolescent cardiometabolic abnormalities. METHODS: Comprehensive data on sociodemographics, diet, physical activity, and anthropometric and biochemical parameters for 1454 adolescents were obtained from a large-scale representative study for adolescent metabolic syndrome (MetS) conducted in Taiwan. The original (HOMA1-IR) and updated nonlinear (HOMA2-IR) HOMA-IR indicators were used as IR biomarkers. Principal component (PC) analysis was employed to create reduced groups of variables and risk scores for retained PCs. RESULTS: Higher SSB intake was associated with higher levels of HOMA1-IR and HOMA2-IR, and the two IR biomarkers were positively correlated with metabolic dysfunction clustering. Compared with SSB nondrinkers, adolescents who consumed >500 mL/day of hand-shaken high-fructose corn syrup beverages (HHB) had a 0.22 increase in the number of abnormal MetS components, and HOMA-IR mediation explained 33.9-37.9% of the effect. IR biomarkers accounted for 26.5-31.0% of the relationship between >500 mL/day of SSB consumption and bodyweight-enhanced PC scores. The effects of HOMA-IR indicators on all bodyweight-related factors were consistently intensified among >350 mL/day HHB drinkers (all Pinteraction < 0.05). CONCLUSIONS: Fructose-rich SSB intake correlates with a constellation of cardiometabolic abnormalities in adolescents, and this association may be partly mediated by HOMA-IR levels. The adverse effects of HOMA-IR on bodyweight-associated cardiometabolic risk factors depend on the type of SSB consumption, with enhanced risks observed in the intake of high amounts of HFCS-containing SSBs.

Characteristic-Grouped Adiposity Indicators for Identifying Metabolic Syndrome in Adolescents: Develop and Valid Risk Screening Tools Using Dual Population.

A simple, robust, and characterized adiposity indicator may be appropriate to be used as a risk screening tool for identifying metabolic syndrome (MetS) in adolescents. This study used dual adolescent populations to develop and validate efficient adiposity indicators from 12 characterized candidates for identifying MetS that may occur during the transition from adolescence to young adulthood. Data from the adolescent Nutrition and Health Survey in Taiwan (n = 1920, 12-18 years) and the multilevel Risk Profiles for adolescent MetS study (n = 2727, 12-16 years) were respectively used as training and validation datasets. The diagnostic criteria defined by the International Diabetes Federation for adolescents (IDF-adoMetS) and the Joint Interim Statement for adults (JIS-AdMetS) were employed to evaluate MetS. In the training dataset, principal component analysis converted 12 interrelated obesity indices into bodyfat-, lipid-, and body-shape-enhanced groups, with the first two characteristic-groups having a higher discriminatory capability in identifying IDF-adoMetS and JIS-AdMetS. In the validation dataset, abdominal volume index (AVI) among girls and waist circumference (WC) among boys were respectively validated to have a higher Youden's index (0.740-0.816 and 0.798-0.884) in identifying the two MetS. Every 7.4 and 4.3 positive tests of AVI (cutoff = 13.96) had an accurate IDF-adoMetS and JIS-AdMetS, respectively, and every 32.4 total tests of WC (cutoff = 90.5 cm) had a correct identification for the two MetS. This study stresses the discriminatory capability of bodyfat- and lipid-enhanced adiposity indicators for identifying MetS. AVI and WC were, respectively, supported as a risk screening tool for identifying female and male MetS as adolescents transition to adulthood.

Significant Association Between the MiR146a Genotypes and Susceptibility to Childhood Acute Lymphoblastic Leukemia in Taiwan.

BACKGROUND/AIM: Mounting evidence has shown that miRNAs play a critical role in the regulation of hematopoiesis of cell proliferation and apoptosis as well as in tumorigenesis. The miR146a rs2910164 polymorphism, which is closely responsive for its expression, has been reported to associate with the risk of several solid cancers. The study aimed at examining the association of the it with susceptibility to childhood acute lymphoblastic leukemia (ALL) in Taiwan. MATERIALS AND METHODS: We recruited 266 patients with childhood ALL and 266 healthy controls, and rs2910164 genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism methodology. RESULTS: The allele G was associated with decreased childhood ALL risk (OR=0.66, 95%CI=0.52-0.85, p=0.0011). Consistently, the GG genotype was associated with a decreased susceptibility (OR=0.40, 95%CI=0.23-0.67, p=0.0004). Patients with CG and GG genotypes were of earlier onset than those with CC genotype (p=0.0255 and p=0.0001). CONCLUSION: MiR146a rs2910164 G allele serves as a protective marker for childhood ALL in Taiwan.

The Significant Association of MMP-1 Genotypes With Taiwan Pterygium.

BACKGROUND/AIM: Few studies have examined the contribution of matrix metalloproteinases (MMP) to either diagnosis or prognosis of pterygium. The aim of this study was to investigate the contribution of MMP-1 genotypes to pterygium risk. PATIENTS AND METHODS: A total of 134 cases and 268 controls were included and their MMP-1 -1607 (rs1799705) genotypes were examined by polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The percentages of 2G/2G, 1G/2G, and 1G/1G for rs1799705 genotypes were 48.5, 36.6 and 14.9% among patients and 33.9, 44.8, and 21.3% among controls (p trend=0.0167). The odds ratios (ORs) after adjusting for age and gender for 1G/2G and 1G/1G genotypes at rs1799705 were 0.54 (95%CI=0.33-0.89, p=0.0168) and 0.46 (95%CI=0.27-0.88, p=0.0192), respectively. Consistently, the adjusted OR for those carrying the 1G allele at MMP-1 -1607 was 0.61 (95%CI=0.41-0.78, p=0.0167), compared with the wild-type 2G allele. CONCLUSION: The genotypes at rs1799705 play a role in determining personal susceptibility to pterygium.

Clustering of Metabolic Risk Components and Associated Lifestyle Factors: A Nationwide Adolescent Study in Taiwan.

Clustering of metabolic syndrome (MetS) risk components in childhood has been linked to a higher risk of diabetes and cardiovascular diseases in adulthood. By using data from the 2010⁻2011 Nutrition and Health Survey in Taiwan, this study investigated epidemic patterns and correlates for the clustering of MetS risk components. A total of 1920 adolescents aged 12⁻18 years were included in this study. The MetS diagnostic criteria defined by the Taiwan Pediatric Association (TPA) and International Diabetes Federation (IDF) for adolescents and the criteria defined by the Joint Interim Statement for adults (JIS-Adult) were used to evaluate MetS and its abnormal components. The prevalence of TPA-, IDF-, and JIS-Adult-defined MetS was 4.1%, 3.0%, and 4.0%, with 22.1%, 19.3%, and 17.7%⁻18.1% of adolescents having high fasting glucose, low high-density lipoprotein cholesterol, and central obesity, respectively. A 0.4-to-0.5-fold decreased risk of having ≥2 MetS abnormal components was detected among adolescents who consumed ≥1 serving/week of dairy products and fresh fruits. Boys who consumed ≥7 drinks/week of soda and girls who consumed ≥7 drinks/week of tea had a 4.6- and 5.2-fold risk of MetS, respectively. In conclusion, our findings revealed significant dimensions of adolescent MetS, including detecting population-specific prevalent patterns for MetS risk components and their clustering, and emphasized on health promotion activities that reduce sugar-sweetened beverage intake.

Effects of insulin resistance on the association between the circulating retinol-binding protein 4 level and clustering of pediatric cardiometabolic risk factors.

OBJECTIVES: Retinol-binding protein 4 (RBP4) and insulin resistance (IR) are clinical parameters associated with cardiometabolic diseases. The mediating and modifying roles of IR on children's susceptibility to cardiometabolic disorders are undetermined. This study investigated the mediating and modifying effects of the homeostatic model assessment of IR (HOMA-IR) on the relationship between the serum RBP4 level and clustering of pediatric cardiometabolic risk factors. METHODS: We assessed the diet, physical activity, cardiometabolic risk factors, and clinical parameters of 272 randomly selected adolescents from a large-scale cross-sectional study (n = 2727). Two HOMA-IRs (HOMA1-IR and HOMA2-IR) were used to evaluate the designated effects. RESULTS: Levels of serum RBP4 positively correlated with the levels of the 2 HOMA-based-IRs, and HOMA-IR correlated to all components of pediatric metabolic syndrome (MetS), the number of abnormal components, and a body-weight-weighted principal component score extracted from 12 cardiometabolic risk factors. Increased RBP4 levels had positive effects on waist circumference (WC), triglyceride, and the number of abnormal MetS components (0.310 cm, 1.384 µg/dL, and 0.021 item elevations, respectively), and the HOMA-IRs explained 17.7% to 21.9%, 11.8% to 27.6%, and 23.8% to 25.0% of these effects. The association of WC and the number of abnormal MetS components with the serum RBP4 level was enhanced by higher HOMA-IR (ß for interaction, 0.13 and 0.01 for HOMA1-IR, and 0.32 and 0.02 for HOMA2-IR, respectively). CONCLUSIONS: HOMA-IR is associated with the circulating RBP4 level and cardiometabolic risk factors in adolescents. Pediatric HOMA-IR may have mediating and modifying effects on the positive correlations between RBP4 and the clustering of MetS components.

An Efficient Wireless Recharging Mechanism for Achieving Perpetual Lifetime of Wireless Sensor Networks.

Energy recharging has received much attention in recent years. Several recharging mechanisms were proposed for achieving perpetual lifetime of a given Wireless Sensor Network (WSN). However, most of them require a mobile recharger to visit each sensor and then perform the recharging task, which increases the length of the recharging path. Another common weakness of these works is the requirement for the mobile recharger to stop at the location of each sensor. As a result, it is impossible for recharger to move with a constant speed, leading to inefficient movement. To improve the recharging efficiency, this paper takes "recharging while moving" into consideration when constructing the recharging path. We propose a Recharging Path Construction (RPC) mechanism, which enables the mobile recharger to recharge all sensors using a constant speed, aiming to minimize the length of recharging path and improve the recharging efficiency while achieving the requirement of perpetual network lifetime of a given WSN. Performance studies reveal that the proposed RPC outperforms existing proposals in terms of path length and energy utilization index, as well as visiting cycle.

Detection of haplotype mutations of the MD-2 gene promoter associated with Der p2-induced allergy using a nanostructured biosensor.

Group 2 allergens (Der p2) have been reported to be a major cause of the human immune response to dust mite allergens. In this study, we have demonstrated for the first time the effective differentiation between haplotype mutation and normal genes in the MD-2 gene promoter using a nanostructured biosensor. A 70-mer gene fragment containing the haplotype of two single nucleotide polymorphisms in the MD-2 gene promoter region was used as a probe to detect haplotype mutations associated with Der p2-induced allergy. Discrimination was achieved using electrochemical impedance spectroscopy. The discrimination experiments employed 30 haplotype mutation samples and 30 normal target samples. The haplotype mutation samples and normal target samples could be clearly discriminated, even using samples produced by a five-cycle polymerase chain reaction process. The time and cost of sample preparation for the polymerase chain reaction process in the clinical setting can thus be reduced.

Label-free detection of single-nucleotide polymorphisms associated with myeloid differentiation-2 using a nanostructured biosensor.

House dust mites are the major source of indoor allergens that are responsible for asthma. The major dust mite allergen is the group II allergen, Der p2. Myeloid differentiation-2 (MD-2) acts as an essential component in the CD14-TLR4 (toll-like receptor)/MD-2 receptor complex for Der p2 recognition. Mutations of the MD-2 associated gene on chromosome 8 degrade a human's innate responses. In this study, we report the effective detection of mutations to the MD-2 gene promoter, using a sensitive nanostructured biosensor with a sensing electrode of gold nanoparticles (GNPs) uniformly deposited in a nanohemisphere array. The 70 mer MD-2 expressed gene fragment was used to probe gene mutation. The complementary target, containing 156 mer nucleotide, was prepared using the fresh blood from patients with allergic disease. A total of 37 target samples, including 19 gene mutated samples and 18 normal samples, were prepared by a 20 cycles PCR process, and used for discrimination experiments. Experimental results illustrated that the nanostructured biosensor clearly discriminates between mutated and non-mutated MD-2 allergy genes.