[Cross-sectional study of current situation of glycemic control with type 1 diabetes in Guangdong Province].

OBJECTIVE: To investigate the glycemic control and the related factors of type 1 diabetic patients in Guangdong Province. METHODS: Medical records and blood samples of type 1 diabetic patients were collected in 89 tertiary and secondary hospitals from all of the 21 cities in Guangdong Province. The clinical data were analyzed to explore the correlates of glycemic control. HbA1c levels, measured in Guangdong Diabetes Center, were used to assess glycemic control. RESULTS: 851 patients were enrolled from August 6, 2010 to May 25, 2011. There were 408 males and 443 females. The median (interquartile range) age was 29.6 years (20.3 - 41.3 years). The onset age of diabetes was 25.3 years (15.7 - 35.5 years). The disease duration was 3.3 years (1.0 - 7.3 years). The BMI was 19.9 kg/m(2) (17.9 - 21.8 kg/m(2)). HbA1c levels were 8.6% (6.9% - 11.0%) and only 234 (27.50%) patients reached the age-specific target levels. Correlates with poorer glycemic control were 13 - 19 years old (vs 7 - 12 and ≥ 20 years old), lower household income, not on dietary intervention, never accepting diabetic education and shorter diabetic duration. CONCLUSION: The majority of Guangdong type 1 diabetic patients did not achieve target values for glycemic control, indicating an urgent need for comprehensive management to improve glycemic control.

An enhanced sensitive electrochemical immunosensor based on efficient encapsulation of enzyme in silica matrix for the detection of human immunodeficiency virus p24.

We report a new electrochemical immunosensor for enhanced sensitive detection of human immunodeficiency virus p24 (HIV-p24) based on graphene oxide (GO) as a nanocarrier and enzyme encapsulated in carbon nanotubes-silica as a matrix in a multienzyme amplification strategy. Greatly enhanced sensitivity was achieved by using the bioconjugates featuring horseradish peroxidase-HIV-p24 signal antibody (HRP-HIV-p24) linked to functionalized GO and thionine (TH) as well as efficient encapsulation of enzyme (HRP) in the silica matrix with retained bioactivity. After a sandwich immunoreactions, the HRP in carbon nanotubes-silica matrix and the HRP-HIV-p24-TH/GO captured onto the electrode surface produced an amplified electrocatalytic response by the reduction of enzymatically oxidized thionine in the presence of hydrogen peroxide. The increase of response current was proportional to the HIV-p24 concentration in the range of 0.5 pg/mL-8.5 ng/mL with the detection limit of 0.15 pg/mL, which was lower than that of the traditional sandwich electrochemical measurement for HIV-p24. The amplified immunoassay developed in this work shows acceptable stability and reproducibility, and the assay results for HIV-p24 spiked in human plasma also show good accuracy. This simple and low-cost immunosensor shows great promise for detection of other proteins and clinical applications.

Electrochemical immunoassay for procalcitonin antigen detection based on signal amplification strategy of multiple nanocomposites.

Procalcitonin, as a medium of inflammation, has become a new marker of the identification of severe bacterial infections in recent years and has received high attention due to its most ideal diagnostic indicators of specificity with major types of organism systemic inflammation of bacterial infection in the early stages. Thus, a novel method for the determination of procalcitonin (PCT) was developed based on a sandwich-type electrochemical immunosensor, which combined a simple immunosensor array as well as an effectively designed trace tag. The immunosensor was fabricated by layer-by-layer coating graphene (GC), carbon nanotubes (MWCNTs), chitosan (CS), glutaraldehyde (GA) composite on the working electrode, which can increase the electronic transfer rate and improve the surface area to capture a large number of primary antibodies (Ab1). The trace tag was prepared by loading high-content signal horseradish peroxidase labeled secondary PCT antibody (HRP-Ab2) with AuNPs, which were coated with mesoporous silica nanoparticles (MCM-41) through thionine linking. In comparison with conventional methods, the proposed immunosensor for PCT provided a better linear response range from 0.01 to 350 ng/mL and a lower limit of detection (LOD) of 0.5 pg/mL under optimal experimental conditions. In addition, the immunosensor exhibited convenience, low cost, rapidity, good specificity, acceptable stability and reproducibility. Moreover, satisfactory results were obtained for the determination of PCT in real human serum samples, indicating that the developed immunoassay has the potential to find application in clinical detection of PCT and other tumor markers as an alternative approach.

Simple approach for ultrasensitive electrochemical immunoassay of Clostridium difficile toxin B detection.

Clostridium difficile toxin B (Tcd B), as one of the primary contributing factors to the pathogenesis of C. difficile-associated diseases, has raised serious public concerns due to its virulence, spore-forming ability and persistence with major types of infectious diarrhea diseases, and been used as a potential biomarker in clinical diagnoses. Thus, a simple method for the determination of Tcd B was developed based on a sandwich-type electrochemical immunosensor. Greatly enhanced sensitivity was achieved based on fabricating the immunosensor by layer-by-layer coating carbon nanotubes (MWCNTs), Prussian blue (PB), Chitosan (CS), Glutaraldehyde (GA) composite on the working electrode as well as using graphene oxide (GO) as a nanocarrier in a multienzyme amplification strategy. In comparison with conventional methods, the proposed immunoassay exhibited high sensitivity and selectivity for the detection of Tcd B, providing a better linear response range from 0.003 to 320 ng/mL and a lower limit of detection (LOD) of 0.7 pg/mL (S/N=3) under optimal experimental conditions. The immunosensor exhibited convenience, low cost, rapidity, good specificity, acceptable stability and reproducibility. Moreover, satisfactory results were obtained for the determination of Tcd B in real human stool samples, indicating that the developed immunoassay has the potential to find application in clinical detection of Tcd B and other tumor markers as an alternative approach.