Association of advanced glycation end products with ear lobe crease: A cross-sectional study.

OBJECTIVE: Several studies have demonstrated a significant association between the presence of the ear lobe crease (ELC) and cardiovascular disease. Advanced glycation end-products (AGEs) can affect the structures and functions of proteins and contribute to the development of diabetic complications. However, few studies have reported the relationship between AGEs and ELC. The purpose of this study was to investigate the correlation of skin autofluorescence (SAF)-AGEage (SAF-AGEs × age/100) with ELC. METHODS: This cross-sectional study enrolled 6500 eligible participants from two communities in Beijing. Skin autofluorescence (SAF) was used to measure skin AGEs (SAF-AGEs). SAF-AGEage was defined as AGEs × age/100. Binary logistic regression analysis and linear regression analysis nested in logistic models were applied to test outcomes. RESULTS: The overall prevalence of ELC with an average age of 62.7 years participants was 57.1% (n = 3714). Age, fasting blood glucose, systolic blood pressure, and lipoprotein cholesterol were all greater in participants with ELC. ELC-positive participants had higher prevalence of coronary heart disease. Logistic analysis showed a significantly positive relationship between quartiles of SAF-AGEage and ELC (odds ratio [OR] 1.526, 95% CI 1.324-1.759; OR 2.072, CI 1.791-2.396; and OR 2.983, CI 2.551-3.489) for the multivariate-adjusted models, respectively. Stratified research revealed that those with a history of diabetes, hypertension, or coronary heart disease experienced the connection between SAF-AGEage and ELC. CONCLUSION: ELC is associated with coronary heart disease, and the SAF-AGE has a potential role in ELC development in elder people.

Loopback rolling circle amplification for ultrasensitive detection of Kras gene.

Mutations in Kras gene may be used as a diagnostic marker and a target for treatment of the broad spectrum of human cancers. In this study, we developed a new class of amplification assay, double-hairpin molecular beacon (DHMB)-based cascade rolling circle amplification (RCA), for ultrasensitive and selective detection of Kras gene in a homogenous solution. Specifically, target DNA can hybridize with DHMB and activate cyclical target strand-displacement polymerization (CTDP) and nicking-mediated strand-displacement polymerization (NMDP). The resulting nicked/displaced fragments substantially outnumber target DNA and cause the cascade rolling circle amplification (C-RCA) and nicked fragment-induced strand-displacement polymerization (NFDP). Even if four amplification processes are designed, only DHMB, padlock probe and polymerization primer are involved. Under optimized conditions, this screening system exhibits a linear range of 5 orders of magnitude (from 100fM to 20nM), and the detection limit is down to 16fM. Moreover, the developed biosensing system offers a high assay specificity for perfectly matched target DNA, and the measured data from practical samples demonstrated the potential application in the cancer diagnoses. As a proof-of-concept genetic assay, the novel signaling strategy, as well as desirable analytical capability, would significantly benefit the development of versatile amplification gene profiling platforms, revealing great promise in biological studies and medical diagnostics.

Rapid analysis of trace levels of flavins by pressurized capillary electrochromatography-laser induced fluorescence detection with sulfonated N-octadecyl methacrylate monolith.

In this paper, pressurized capillary electrochromatography (pCEC) with laser induced fluorescence detection (LIF) was demonstrated as a viable approach for the separation and determination of trace flavins in human plasma, where flavins tend to be degraded ex vivo. Using a sulfonated N-octadecyl methacrylate monolithic column in isocratic pCEC separation, symmetrical peak shapes and rapid separation could be obtained in a weakly acidic mobile phase. Baseline separation of riboflavin, flavin mononucleotide and flavin adenine dinucleotide could be achieved within 4.5 min in a mobile phase containing 60% (v/v) acetonitrile and 40% (v/v) of 20 mmol L(-1) phosphate buffer (pH 4.0), with -22 kV of applied voltage and 290 psi of supplementary pressure and 0.02 mL min(-1) of flow rate. Based on a 473 nm laser diode double pumped solid state source, flavins could be determined by LIF with the detection limit (LOD) as low as 0.5 nmol L(-1) (S/N=3). The concentration ranges were 0.005-2 micromol L(-1) for RF and FMN, and 0.02-40 micromol L(-1) for FAD. Owing to the weakly acidic condition selected in this experiment, the high fluorescence quantum yields and good stability of flavins contributed to a preferable analysis. Combined with a simple clean-up procedure, this method has been proved to be effective for the rapid and selective analysis of trace levels of flavins in human plasma without sample preconcentration.

[Rapid analysis of trace levels of riboflavin and its derivatives with hydrophilic interaction monolith by pressurized capillary electrochromatography with laser induced fluorescence detection].

A novel hydrophilic interaction capillary electrochromatographic (HI-CEC) monolith with covalently bonded zwitterionic functional groups was applied for the separation of riboflavins (RF) and its derivatives. With a homemade pressurized capillary electrochromatography-laser induced fluorescence detection (pCEC-LIF) system, trace levels of RF and its derivatives, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), can be baseline separated within 8.0 min in isocratic elution mode. The effect of experimental parameters on separation was investigated. Under the optimum conditions, analytes could be determined over nearly three orders of magnitudes with the detection limits (LODs) as low as 5.0 x 10(-11) mol/L (RF), 8.0 x 10(-10) mol/L (FMN), 2.5 x 10(-9) mol/L (FAD), and the relative standard deviations (RSDs) were less than 8.2%. This method is rapid, simple, repeatable and more sensitive than the most of reported methods, and satisfied results has been achieved in serum sample. Furthermore, it can be further applied for trace analysis of RF and its derivatives in biological fluid and cells.