Perianal rhabdomyosarcoma in an adult: A case report and review of the literature.

Perianal/perineal rhabdomyosarcomas (PRMS) is rare, and the outcome is poor. A 29-year-old female presented with perineal rhabdomyosarcomas revealed metastases to inguinal lymph nodes on the bilateral side. Disease progression was discovered when the patient got adjuvant epirubicin, ifosfamide, and bevacizumab for 2 cycles. After 3 cycles of nivolumab, dacarbazine, cisplatin, and vinblastine therapy, a partial response was identified in the patient. The surgical resection was performed. The patient received neoadjuvant chemotherapy before surgery and was weak after surgery, so he did not receive chemoradiotherapy. The patient succumbed after 11 months postoperatively due to widespread intraabdominal metastasis.

A functional polymorphism of microRNA-143 is associated with the risk of type 2 diabetes mellitus in the northern Chinese Han population.

Objective: To explore the association between two polymorphisms of microRNA-143 (miR-143) and the risk of type 2 diabetes mellitus (T2DM) in the northern Chinese Han population. Study Design: This case-control study involved 326 patients with T2DM and 342 healthy controls. Two genetic variants (rs4705342 and rs353292) of miR-143 were genotyped by the polymerase chain reaction/ligase detection reaction (PCR-LDR) method. The levels of miR-143 in the serum from 52 T2DM patients and 55 healthy subjects were investigated by quantitative real-time PCR (qRT-PCR). Results: The CC genotype frequency of rs4705342 was significantly higher in the T2DM patients than in the healthy controls (P = 0.012). After adjusting for sex, age, and body mass index, the rs4705342 CC genotype was also related to a significantly increased risk of T2DM compared with the TT genotype (adjusted OR: 1.87; 95% CI = 1.09-3.19; P = 0.022). Stratified analyses demonstrated that T2DM patients with the rs4705342 CC genotype had significantly higher levels of low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), and glycated haemoglobin (HbA1C) than those carrying the rs4705342 TT genotype. The qRT-PCR results showed that the expression levels of miR-143 were significantly higher in the serum of cases than in the serum of controls (P < 0.001). Furthermore, the levels of miR-143 were significantly higher in the serum of T2DM patients carrying the rs4705342 CC genotype than in those carrying the TC and TT genotypes of rs4705342 (P = 0.005 and 0.003, respectively). Conclusion: The CC genotype of rs4705342 might be a risk factor for developing T2DM by increasing the expression of miRNA-143 in the northern Chinese Han population.

Meta-analysis of the effect of sodium-dependent glucose transporter 2 inhibitors on C-reactive protein in type 2 diabetes.

BACKGROUND: As novel hypoglycemic drugs, the effects of sodium-dependent glucose transporter 2 inhibitors (SGLT-2I) on inflammatory factors such as C-reactive protein (CRP) remain unclear. METHODS: We conducted a meta-analysis of studies on SGLT-2I in the treatment of type 2 diabetes (T2DM) to observe the changes of CRP in patients with T2DM. We searched 4 electronic databases (CNKI, PubMed, EMBASE, and Cochrane Library) for articles published up to December 31, 2021. Studies were analyzed using a random-effects model to obtain standard deviation mean differences (SMDs) and 95% confidence intervals (CIs). Sensitivity and subgroup analyses were performed. Publication bias was evaluated using funnel plots and Egger test. RESULTS: We included data from 927 patients in 13 confirmatory trials that showed a significant decrease in CRP among patients with T2DM treated with SGLT-2I. The decrease was more significant with than without SGLT-2I. In subgroup analysis according to nationality, medication, and comorbidities, CRP reduction was associated with nationality, SGLT-2I type, and the presence of comorbidities. Sensitivity analysis showed that our results were reliable and found no evidence of substantial publication bias. CONCLUSIONS: SGLT-2I could reduce CRP levels in patients with T2DM. REGISTRATION: International Prospective Register for Systematic Reviews (PROSPERO) number CRD42021268079.

Case report: Analysis of novel compound heterozygous TPP1 variants in a Chinese patient with neuronal ceroid lipofuscinosis type 2.

Neuronal ceroid lipofuscinosis type 2 (CLN2) is an autosomal recessive neurodegenerative disease caused by variants in the TPP1 gene that lead to the deficiency of the lysosomal enzyme tripeptidyl peptidase I (TPP1) activity. Herein, we report a rare case of CLN2 caused by two novel variants of TPP1. The patient presented with seizures at onset, followed by progressive cognitive impairment, motor decline, and vision loss. Novel compound heterozygous variants, c.544_545del and c.230-3C>G, in TPP1 were identified by whole-exome sequencing. The variant assessment showed that the c.544_545del is a frameshift variant mediating mRNA decay and that c.230-3C>G is a splice variant generating aberrantly spliced TPP1 mRNA, as confirmed by a Splicing Reporter Minigene assay. In conclusion, clinical history, variant assessment, and molecular analyses demonstrate that the novel compound heterozygous variants are responsible for CLN2 disease in this patient. This study expands the mutation spectrum of TPP1.

Antidiabetic lanostane triterpenoids from the fruiting bodies of Ganoderma weberianum.

Eight previously undescribed lanostane triterpenoids, ganodeweberiols A âˆ¼ H (1-8), together with eighteen known compounds (9-26), were isolated from the fruiting bodies of Ganoderma weberianum. The structures and absolute configurations of the new compounds were determined by extensive spectroscopic analysis, as well as NMR chemical shifts and electronic circular dichroism (ECD) calculations. Compounds 2, 7, 12, and 14 showed significant α-glucosidase inhibitory activity with IC50 values ranging from 35.3 µM âˆ¼ 223.4 µM compared to the positive control acarbose (IC50, 304.6 µM). Kinetic study indicated that the most potent compound 12 was a mixed type inhibitor for α-glucosidase. Molecular docking simulation revealed the interactions of 12 with α-glucosidase. Additionally, Compounds 3 and 6 inhibited glucagon-induced hepatic glucose production in HepG2 cells with EC50 values of 42.0 and 85.9 µM, respectively. Further study revealed that compounds 3 and 6 inhibited hepatic glucose production by suppression glucagon-induced cAMP accumulation. Moreover, compounds 3 and 26 were active against HeLa cell line with IC50 values of 17.0 and 6.8 µM, respectively.

Target-driven assembly of DNAzyme probes for simultaneous electrochemical detection of multiplex microRNAs.

In this work, we employed target-driven assembly of a Mg2+-dependent DNAzyme to develop an ultrasensitive electrochemical biosensor for the simultaneous detection of miRNA-21 and miRNA-141. The target miRNAs could hybridize with two partial DNAzymes, facilitating the formation of a stable and active Mg2+-dependent DNAzyme. With the help of the Mg2+ cofactor, the DNAzyme could circularly cleave the ferrocene (Fc) or methylene blue (MB) labelled hairpin probes and release Fc and MB labels from the electrode surface, which could significantly amplify the current suppression to achieve multiple detection of small amounts of miRNA-21 and miRNA-141. This electrochemical biosensor showed high sensitivity and selectivity for the simultaneous detection of miRNA-21 and miRNA-141. Furthermore, the proposed method was also successfully applied for the determination of miRNA-21 and miRNA-141 from diluted serum samples. Overall, the proposed sensor showed several considerable advantages including simple preparation, high sensitivity, and enzyme-free signal amplification. Therefore, the proposed electrochemical biosensor could be used as a highly efficient amplification strategy for simultaneous detection of various miRNA biomarkers in bioanalysis and clinical diagnostics.

The TIM-3 Rs10053538 Polymorphism Is Associated with Clinical Prognosis of Colorectal Cancer.

BACKGROUND: Genetic variants in the T cell immunoglobulin and mucin domain-containing molecule 3 (TIM-3) gene have been reported to be associated with the risk of cancers and patients' outcomes. The aims of this study were to explore the role of TIM-3 polymorphisms in the risk of colorectal cancer (CRC) and the prognosis of CRC patients in a northern Chinese population. METHODS: Two polymorphisms of TIM-3 were genotyped using polymerase chain reaction and ligase detection reaction in 364 CRC patients and 372 healthy control subjects. The levels of TIM-3 mRNA were investigated in 65 CRC tissues by quantitative real-time PCR. RESULTS: The results showed that neither rs10053538 nor rs10515746 was associated with susceptibility to CRC. However, the CA+AA genotypes of rs10053538 were related to an advanced clinical stage and increased risk of lymph nodemetastasis (P = .046 and 0.024, respectively). Multivariate analyses performed after adjusting for clinical variables showed that patients with the CA+AA genotypes of rs10053538 exhibited a significantly shorter disease-free survival (DFS) and overall survival (OS) time compared with those carrying the CC genotype (HR = 1.91, 95% CI = 1.04-3.51; HR = 2.61, 95% CI = 1.35-5.03). In addition, the expression of TIM-3 mRNA was significantly increased in the CRC tissues of patients carrying the rs10053538 CA+AA genotypes compared with patients carrying the CC genotype (P = .019). CONCLUSION: The rs10053538 may serve as an independent molecular marker for predicting the clinical outcome of CRC patients in the study population.

Screening and Identification of Key Biomarkers of Gastric Cancer: Three Genes Jointly Predict Gastric Cancer.

BACKGROUND: Gastric cancer (GC) is one of the most common cancers all over the world, causing high mortality. Gastric cancer screening is one of the effective strategies used to reduce mortality. We expect that good biomarkers can be discovered to diagnose and treat gastric cancer as early as possible. METHODS: We download four gene expression profiling datasets of gastric cancer (GSE118916, GSE54129, GSE103236, GSE112369), which were obtained from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between gastric cancer and adjacent normal tissues were detected to explore biomarkers that may play an important role in gastric cancer. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of overlap genes were conducted by the Metascape online database; the protein-protein interaction (PPI) network was constructed by the STRING online database, and we screened the hub genes of the PPI network using the Cytoscape software. The survival curve analysis was conducted by km-plotter and the stage plots of hub genes were created by the GEPIA online database. PCR, WB, and immunohistochemistry were used to verify the expression of hub genes. A neural network model was established to quantify the predictors of gastric cancer. RESULTS: The relative expression level of cadherin-3 (CDH3), lymphoid enhancer-binding factor 1 (LEF1), and matrix metallopeptidase 7 (MMP7) were significantly higher in gastric samples, compared with the normal groups (p<0.05). Receiver operator characteristic (ROC) curves were constructed to determine the effect of the three genes' expression on gastric cancer, and the AUC was used to determine the degree of confidence: CDH3 (AUC = 0.800, P<0.05, 95% CI =0.857-0.895), LEF1 (AUC=0.620, P<0.05, 95%CI=0.632-0.714), and MMP7 (AUC=0.914, P<0.05, 95%CI=0.714-0.947). The high-risk warning indicator of gastric cancer contained 8

Study on the Correlation between Metabolism, Insulin Sensitivity and progressive weight loss change in Type-2 Diabetes.

OBJECTIVE: To observe the changes of lipid metabolism, blood glucose level and insulin sensitivity in patients with Type-2 diabetes after progressive weight loss of their body weight, so as to lay a theoretical foundation for diabetes treatment and education in the future. METHODS: One hundred obese patients with Type-2 diabetes (BMI ≥ 25 kg/m2) who visited the endocrinology department of our hospital from April 2017 to April 2018 were given diabetes health education, diabetic diet, exercise and other measures to control their weight. The changes of blood glucose, blood lipid, insulin level and insulin release test before weight loss (T1), and at the time points of weight loss reached 5% (T2), 10% (T3) and 15% (T4) were recorded respectively to understand the influence of progressive weight loss on relevant indexes of patients. RESULTS: With the decrease of body weight, the differences of TC, TG, LDL-C and HDL-C at different weight loss points were significant (p < 0.05), and the changes of fasting blood glucose in 5% and 10% weight loss were significant (p = 0.02). The 2h postprandial blood glucose showed the most significant difference when the weight loss reached 15% (p = 0.00). There was no statistical difference in the change of glycosylated hemoglobin among different weight loss points (p = 0.08). When the weight loss reached 10%, the blood insulin level was significantly lower than that before the weight loss, while the insulin level was not significantly changed when the weight loss reached 15%, but the peak of secretion was shifted forward. It is suggested that insulin sensitivity gradually increases with weight loss. CONCLUSION: Obese patients with Type-2 diabetes can benefit from weight loss, with abnormal blood glucose and lipid metabolism improved, insulin resistance relieved, and insulin sensitivity increased.

Chinese men living in urban areas of Shijiazhuang, Hebei at higher risk of overweight or obesity.

OBJECTIVE: The prevalence of overweight/obesity in China has increased dramatically in recent years; being overweight/obese can increase the risk of type 2 diabetes and cardiovascular disease. The purpose of this study was to determine the population in China at high risk of being overweight or obese, to explore the relationships between various relevant factors and overweight/obesity, and to identify preventive efforts for high-risk populations. METHODS: We administered a questionnaire survey among a group of 536 social workers in Shijiazhuang City in 2017. We used the Pearson chi-square test, Spearman's rho test, multivariate linear regression, univariate and multivariate logistic regression, and receiver operating characteristic curve analysis to investigate factors that influence overweight/obesity. RESULTS: The prevalence of overweight/obesity was 13.7% among the study participants. Urban residence, eating speed, number of daily meals, overeating, and a high-fat diet were associated with overweight/obesity. In multivariate linear regression analysis, overweight/obesity was correlated with sex, urban residence, eating speed, number of daily meals, and a high-fat diet. CONCLUSION: Among all influencing factors, dietary factors, place of residence, and sex were most closely related to being overweight/obese. Furthermore, living in an urban area and male sex were independent risk factors for being overweight/obese.

Orthogonal Test Design for Optimization of the Extraction of Polysaccharides from Inonotus cuticularis and Their Antioxidant Activities.

Medical fungi polysaccharides belong to a very important species of biological macromolecules, which are the basic substances that effectively maintain and ensure the normal operation of biological life activities. However, research on extraction and biological activity of Inonotus cuticularis polysaccharides has never been reported. In this study, the optimum yield of Inonotus cuticularis polysaccharides was determined by the orthogonal experimental design. The highest yield of 3.10±0.06 % was obtained with extraction temperature of 80 °C, extraction time of 150 min, and water to raw material ratio of 30 mL/g and repeated twice. After deproteinization for 5 times, the protein removal rate reached 70.10±1.75 %, and the content of polysaccharides and protein were 46.64 and 0.42 %. Infrared spectrometer indicated that Inonotus cuticularis polysaccharides are typical ß-pyranose with characteristic peaks of polysaccharides. Subsequently, the activities of scavenging free radicals for the deproteinated polysaccharides were studied. When the concentration of Inonotus cuticularis polysaccharides was 0.3 mg/mL, the scavenging activities of the sample on DPPH. , . OH, ABTS.+ and O2 .- reached 83.67±0.27, 65.21±4.82, 43.45±1.36 and 80.28±2.30 %, respectively, and the reducing power reached 0.46±0.01. The IC50 values scavenging DPPH. , . OH, ABTS.+ and O2 .- were 0.139±0.13, 0.162±0.14, 0.317±0.30 and 0.121±0.10 mg/mL, respectively. Results showed that Inonotus cuticularis polysaccharides present potential stronger antioxidant activities, especially .OH scavenging activity and reducing power. Experimental results could provide research basis of Inonotus cuticularis polysaccharides for further exploitation and utilization.

A Functional Polymorphism in the Promoter Region of Interleukin-12B Increases the Risk of Colorectal Cancer.

OBJECTIVE: To investigate whether the polymorphisms of interleukin-12B (IL-12B) were associated with the risk of developing colorectal cancer (CRC). Patients and Methods. Genotypes of rs17860508 and rs3212227 were determined by polymerase chain reaction with a direct sequencing method in 329 CRC patients and 342 matched healthy control subjects. The expression of IL-12B) were associated with the risk of developing colorectal cancer (CRC). RESULTS: Compared with TTAGAG/TTAGAG genotype of rs17860508, the GC/GC and TTAGAG/GC genotypes may significantly increase the risk of CRC (OR = 1.81, 95% CI = 1.18-2.78; OR = 1.46, 95% CI = 1.01-2.12, respectively). Furthermore, the mRNA levels of IL-12B) were associated with the risk of developing colorectal cancer (CRC). P=0.009) and TTAGAG/TTAGAG (P=0.009) and TTAGAG/TTAGAG (. CONCLUSION: These data suggested that the rs17860508 GC/GC genotype might upregulate IL-12B expression at the transcriptional level and thus increase the risk of CRC.IL-12B) were associated with the risk of developing colorectal cancer (CRC).

An electrochemical sensor based on poly(procaterol hydrochloride)/carboxyl multi-walled carbon nanotube for the determination of bromhexine hydrochloride.

Poly(procaterol hydrochloride) (p-ProH) polymeric film was successfully deposited onto the carboxyl multi-walled carbon nanotube (CMWCNT) modified glass carbon electrode (GCE) to construct a p-ProH/CMWCNT composite modified GCE. Due to the synergistic effect of p-ProH and CMWCNT in the composite, the developed sensor can enormously enhance the oxidation peak current of bromhexine hydrochloride (BrH) at ca. + 0.90 V. Based on this appearance, an electrochemical method was established for the sensitive and selective determination of BrH with differential pulse voltammetry (DPV). Various conditions affecting the peak current response of BrH were studied and optimized. Under the best conditions, the oxidation peak current of BrH is linear to its concentration in two linear dynamic ranges of 0.2-1.0 µmol L-1 (R = 0.9948) and 1.0-8.0 µmol L-1 (R = 0.9956), with a detection limit of 0.1 µmol L-1 (S/N = 3). Interference experiment indicated that the as-prepared electrochemical sensor showed wonderful selectivity to the recognition of BrH and was free from disturbance of many other electro-active substances such as dopamine, ascorbic and uric acid. Finally, the practicability of the BrH sensor was verified by the satisfactory results acquired from the BrH determination in pharmaceutical preparation and human serum.

Simultaneous voltammetry detection of dopamine and uric acid in human serum and urine with a poly(procaterol hydrochloride) modified glassy carbon electrode.

In the present study, procaterol hydrochloride (ProH) was successfully electropolymerized onto a glass carbon electrode (GCE) with simply cyclic voltammetry scans to construct a poly(procaterol hydrochloride) (p-ProH) membrane modified electrode. Compared with the bare GCE, much higher oxidation peak current responses and better peak potentials separation could be obtained for the simultaneous oxidation of dopamine (DA) and uric acid (UA), owning to the excellent electrocatalytic ability of the p-ProH membrane. And it's based on that a square wave voltammetry (SWV) method was developed to selective and simultaneous measurement of DA and UA. Under the optimum conditions, the linear dependence of oxidation peak current on analyte concentrations were found to be 1.0-100 µmol/L and 2-100 µmol/L, giving detection limits of 0.3 µmol/L and 0.5 µmol/L for DA and UA, separately. The as prepared modified electrode shows simplicity in construction with the merits of good reproducibility, high stability, passable selectivity and nice sensitivity. Finally, the proposed p-ProH membrane modified electrode was successfully devoted to the detection of DA and UA in biological fluids such as human serum and urine with acceptable results.

Downregulation of SM22α protein by hypermethylation of its promoter in colorectal cancer.

Silencing of tumor suppressor genes by hypermethylation in gene promoter regions is a crucial mechanism in carcinogenesis. Gene methylation may be reversible and evaluated easily, thus providing a promising substrate for the development of biomarkers for the detection and prevention of cancer, including colorectal cancer (CRC). In the present study, the protein expression and methylation status of smooth muscle protein 22α (SM22α) was investigated in 78 cases of CRC and adjacent normal tissue. The aim of the study was to investigate the function of SM22α in the pathogenesis of CRC and to identify a candidate biomarker for the early detection of CRC. The methylation status of promoter of SM22α gene was detected using methylation-specific polymerase chain reaction. The protein expression of SM22α was evaluated using western blot analysis. The results demonstrated a significant decrease of SM22α protein expression in 50 (68.5%) cases of CRC compared with that in adjacent normal tissues (P<0.001). The methylation status of SM22α promoter in CRC was significantly increased compared with that in adjacent normal tissues (P<0.001). Additionally, there was a negative correlation between the expression of SM22α protein and methylation levels of SM22α gene in CRC (P<0.001). Kaplan-Meier curves revealed that patients with CRC with an unmethylated promoter of SM22α gene exhibited an increased survival time (34.8±0.6 vs. 30.9±1.3 months; P=0.025) compared with that in patients with a methylated promoter of SM22α gene. The present study demonstrated that the protein expression of SM22α is downregulated in CRC tissues by hypermethylation of its promoter, and that the methylation of SM22 α promoter may be used as a biomarker for early detection, prognosis and prediction of CRC.

Sensitive determination of bromhexine hydrochloride based on its quenching effect on luminol/H2 O2 electrochemiluminescence system.

In this paper, the electrochemiluminescence (ECL) behavior of luminol/H2 O2 system in the presence of bromhexine hydrochloride (BrH) was investigated. It was found that the ECL intensity of luminol/H2 O2 system on a platinum electrode could be intensely quenched by BrH owing to the scavenging superoxide radical ability of BrH, and therefore the sensitive determination of BrH was possible. Under optimal conditions, the quenched ECL intensity was linear to the concentration of BrH in a wide range of 0.08 to 500 µM, with a detection limit of 0.02 µM (signal-to-noise ratio (S/N) = 3). This ECL method possessed the merits of rapid, simple and sensitive, and was successfully applied to the BrH quantification in pharmaceutical preparations with satisfactory recoveries of 91.0 ± 4.0 to 106.5 ± 3.4%. The possible route of the quenched ECL of luminol/H2 O2 in the presence of BrH was also discussed.

Electrochemical investigation and determination of procaterol hydrochloride on poly(glutamic acid)/carboxyl functionalized multiwalled carbon nanotubes/polyvinyl alcohol modified glassy carbon electrode.

Poly(glutamic acid) (P-GLU)/carboxyl functionalized multiwalled carbon nanotubes (MWCNTs-COOH)/polyvinyl alcohol (PVA) modified glassy carbon electrode (GCE) has been successfully prepared and the electrochemical behavior of procaterol hydrochloride (ProH) was studied. The results show that the as-prepared modified electrode exhibits a good electrocatalytic property towards the oxidation of ProH in 0.2M phosphate buffer solution (PBS) (pH 6.0) due to the enhanced oxidation peak current at ~+0.59V. Under optimal reaction conditions, the oxidation peak current of ProH is proportional to its concentration in the linear dynamic ranges of 0.060 - 8.0µM (R = 0.9974), with a detection limit of 8.0 × 10-9M. Finally, this method was efficiently used for the determination of ProH in tablets and human urine with recoveries of 88.5~98.7% and 89.2 ~ 108.0%, respectively.

A novel nanosuspension of andrographolide: Preparation, characterization and passive liver target evaluation in rats.

Andrographolide (Andro) is an excellent anti-inflammatory bicyclic diterpene γ-lactone. However, the poor solubility limits its application as injection for the treatment of acute inflammation. To meet the clinical needs for emergency, the Andro nanosuspensions injection was first prepared by the wet milling technique. The Andro nanosuspensions were composed of 3% Andro, 5% poloxamer 188 as the non-ionic stabilizer, 0.05% sodium deoxycholate or 0.1% sodium tauroursodeoxy cholate as the ionic stabilizer, and prepared by 350rpm speed and 12cycles of grinding with 0.4mm zirconium oxide pearls. The nanosuspensions showed hexagonal morphology with particle size of 300nm, and no change in crystalline state of Andro after milling. The nanosuspensions had a significant increase in saturation solubility, and could completely release within 0.25h (bulk Andro within 24h). The lyophilized product of Andro nanosuspensions with mannitol (5%) as lyoprotectant had good physical and chemical stability during the 6-month storage period. The pharmacokinetic and tissue distribution results showed that it was rapidly eliminated from the blood and largely distributed in the liver. Overall, the Andro nanosuspensions may be used as a potential formulation for the treatment of liver infections owing to its passive liver targeting function.

Exploring the electrochemiluminescent behavior of procaterol hydrochloride in the presence of Ru(bpy)32+ and its analytical application in pharmaceutical preparation.

Based on the strong enhancement effect of procaterol hydrochloride on the electrochemiluminescence (ECL) of Ru(bpy)32+ (bpy = 2,2'-bipyridine) in an alkaline H3 PO4 -NaOH buffer solution on a bare Pt electrode, a simple, rapid and sensitive method was developed for the determination of procaterol hydrochloride. The optimum conditions for the enhanced ECL have been developed in detail in this work. Under optimum conditions, the logarithmic ECL enhancement vs. the logarithmic concentration of procaterol hydrochloride is linear over a wide concentration range of 2.0 × 10-7 to 2.0 × 10-4  M (r = 0.9976), with a limit of detection of 1.1 × 10-8  M (S/N = 3), and a relative standard deviation of 2.1% (n = 7, c = 5.0 × 10-6  M). The proposed method was applied to the determination of this drug in tablets with recoveries of 89.7%-98.5%. In addition, a possible mechanism for the enhanced ECL of Ru(bpy)32+ , which is caused by ProH, has also been proposed.

Interfacial electron transfer of glucose oxidase on poly(glutamic acid)-modified glassy carbon electrode and glucose sensing.

The interfacial electron transfer of glucose oxidase (GOx) on a poly(glutamic acid)-modified glassy carbon electrode (PGA/GCE) was investigated. The redox peaks measured for GOx and flavin adenine dinucleotide (FAD) are similar, and the anodic peak of GOx does not increase in the presence of glucose in a mediator-free solution. These indicate that the electroactivity of GOx is not the direct electron transfer (DET) between GOx and PGA/GCE and that the observed electroactivity of GOx is ascribed to free FAD that is released from GOx. However, efficient electron transfer occurred if an appropriate mediator was placed in solution, suggesting that GOx is active. The PGA/GCE-based biosensor showed wide linear response in the range of 0.5-5.5 mM with a low detection limit of 0.12 mM and high sensitivity and selectivity for measuring glucose.