Development of GO/Co/Chitosan-Based Nano-Biosensor for Real-Time Detection of D-Glucose.

Electrochemical nano-biosensor systems are popular in the industrial field, along with evaluations of medical, agricultural, environmental and sports analysis, because they can simultaneously perform qualitative and quantitative analyses with high sensitivity. However, real-time detection using an electrochemical nano-biosensor is greatly affected by the surrounding environment with the performance of the electron transport materials. Therefore, many researchers are trying to find good factors for real-time detection. In this work, it was found that a composite composed of graphite oxide/cobalt/chitosan had strong stability and electron transfer capability and was applied to a bioelectrochemical nano-biosensor with high sensitivity and stability. As a mediator-modified electrode, the GO/Co/chitosan composite was electrically deposited onto an Au film electrode by covalent boding, while glucose oxidase as a receptor was immobilized on the end of the GO/Co/chitosan composite. It was confirmed that the electron transfer ability of the GO/Co/chitosan composite was excellent, as shown with power density analysis. In addition, the real-time detection of D-glucose could be successfully performed by the developed nano-biosensor with a high range of detected concentrations from 1.0 to 15.0 mM. Furthermore, the slope value composed of the current, per the concentration of D-glucose as a detection response, was significantly maintained even after 14 days.

Enhanced electron transfer mediator based on biochar from microalgal sludge for application to bioelectrochemical systems.

This study is focused on the utilization of waste microalgal sludge (MS) from microalgal extraction and its potential as an electrode material. The MS was activated under N2 at high temperature for conversion to biochar (MSB). In addition, cobalt (Co; metal hydroxide) and chitosan were used as a mediator for electron transfer by immobilization on MSB (MSB/Co/chitosan). Through analysis of the surface and components of the MSB/Co/chitosan, it was shown that Co and chitosan were properly synthesized with MSB. The enzymatic fuel cell (EFC) system successfully obtained a power density of 3.1 mW cm-2 and a current density of 9.7 mA cm-2. In addition, the glucose biosensors applied with the developed electron transfer mediator showed a sensitivity of 0.488 mA mM-1 cm-2.

Utilization of hydrolysate from lignocellulosic biomass pretreatment to generate electricity by enzymatic fuel cell system.

The waste hydrolysate after dilute acid pretreatment (DAP) of lignocellulosic biomass was utilized to generate electricity using an enzymatic fuel cell (EFC) system. During DAP, the components of biomass containing hemicellulose and other compounds are hydrolyzed, and glucose is solubilized into the dilute acid solution, called as the hydrolysate liquid. Glucose oxidase (GOD) and laccase (Lac) were assembled on the electrode of the anode and cathode, respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were measured, and the maximum power density was found to be 1.254×10(3) µW/cm(2). The results indicate that the hydrolysate from DAP is a reliable electrolyte containing the fuel of EFC. Moreover, the impurities in the hydrolysate such as phenols and furans slightly affected the charge transfer on the surface of the electrode, but did not affect the power generation of the EFC system in principal.

Neuroprotective effects of fermented soybean products (Cheonggukjang) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on trimethyltin-induced cognitive defects mice.

OBJECTIVES: This study aimed to investigate the beneficial effects of Cheonggukjang (CGK) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on neurotoxic damages. METHODS: The specific aspects of brain functions were measured in Institute for Cancer Research (ICR) mice that had been pretreated for 4 weeks with three difference doses of CGK before trimethyltin (TMT) treatment. RESULTS: The short- and long-term memory loss induced by TMT treatment was significantly improved in the CGK-pretreated group in a dose-dependent manner. The number of dead cells in the granule cell layer of the dentate gyrus was decreased in the TMT/CGK-cotreated group relative to the TMT/vehicle-treated group, whereas significant suppression of acetylcholinesterase (AChE) activity was observed in the same group. Additionally, a dose-dependent increase in nerve growth factor (NGF) concentration, activation of the NGF receptor signaling pathway including the TrkA high affinity receptor and p75(NTR) low affinity receptor, and decline in Bax/Bcl-2 level was measured in all TMT/CGK-treated groups, although a decrease in the active form of caspase-3 was observed in the TMT/H-CGK-treated group. Furthermore, superoxide dismutase (SOD) activity was enhanced in the TMT/CGK-treated group, whereas the level of malondialdehyde (MDA), a marker of lipid peroxidation, was 43-58% lower in the TMT/CGK-treated group than the TMT/vehicle-treated group. DISCUSSION: These results demonstrate that CGK fermented by mixed culture of B. subtilis and L. sakei could exert a wide range of beneficial activities for neurodegenerative diseases, including Alzheimer, Parkinson, and Huntington disease.

The usefulness of soluble transferrin receptor in the diagnosis and treatment of iron deficiency anemia in children.

PURPOSE: Soluble transferrin receptor (sTfR) is a truncated extracellular form of the membrane transferrin receptor produced by proteolysis. Concentrations of serum sTfR are related to iron status and erythropoiesis in the body. We investigated whether serum sTfR levels can aid in diagnosis and treatment of iron deficiency anemia (IDA) in children. METHODS: Ninety-eight patients with IDA were enrolled and were classified according to age at diagnosis. Group 1 comprised 78 children, aged 6-59 months, and group 2 comprised 20 adolescents, aged 12-16 years. RESULTS: In group 1, patients' serum sTfR levels correlated negatively with mean corpuscular volume; hemoglobin (Hb), ferritin, and serum iron levels; and transferrin saturation and positively with total iron binding capacity (TIBC) and red cell distribution width. In group 2, patients' serum sTfR levels did not correlate with ferritin levels and TIBC, but had a significant relationship with other iron indices. Hb and serum sTfR levels had a significant inverse relationship in both groups; however, in group 1, there was no correlation between Hb and serum ferritin levels. In 30 patients of group 1, serum sTfR levels were significantly decreased with an increase in Hb levels after iron supplementation for 1 month. CONCLUSION: Serum sTfR levels significantly correlated with other diagnostic iron parameters of IDA and inversely correlated with an increase in Hb levels following iron supplementation. Therefore, serum sTfR levels can be a useful marker for the diagnosis and treatment of IDA in children.

Toxicity of fermented soybean product (cheonggukjang) manufactured by mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 on liver and kidney of ICR mice.

To investigate the toxic effects of cheonggukjang (CKJ) manufactured using mixed cultures of Bacillus subtilis MC31 and Lactobacillus sakei 383 on the liver and kidney of ICR mice, an alteration on the related markers including body weight, organ weight, urine composition, liver pathology and kidney pathology were analyzed after oral administration at dosage of 25, 50 and 100 mg/kg body weight/day of CKJ for 14 days. Any significant toxicity was not observed on the body and organ weight, clinical phenotypes, urine parameters and mortality in the CKJ-treated group compared with the vehicle-treated group. Also, liver toxicity analysis revealed no significant increase in alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) or lactate dehydrogenase (LDH) in response to CKJ. Additionally, the specific pathological features induced by most toxic compounds were not observed upon liver histological analysis. Furthermore, kidney toxicological analysis revealed that blood urea nitrogen (BUN) and the serum creatinine (Cr) levels and pathological features on histological sections did not differ significantly between the vehicle- and CKJ-treated groups. Overall, these results suggest that CKJ does not induce any specific toxicity in liver and kidney organs of ICR at dose of 100 mg/kg body weight/day as no observed adverse effect level (NOAEL).

Fermented soybean product (Cheonggukjang) improved some attributes of protein and growth hormone measurements in Sprague-Dawley rats.

We hypothesized that the administration of Cheonggukjang (CKJ) would exert positive effects on factors implicated with growth in Sprague-Dawley (SD) rats. To test this hypothesis, we measured specific aspects of bone and organ growth in male SD rats that were treated for 6 weeks with 3 concentrations of CKJ. Although the CKJ extract contained high concentrations of flavonoids and phenolic compounds, no significant differences in body length, organ weights, or femur weight were detected between the CKJ- and vehicle-treated groups. However, thicknesses of the epiphyseal growth plate in the proximal femoral epiphysis and the compact bone in the linea aspera were broadest in the femur of the 2 CKJ-treated groups when compared with the vehicle-treated groups. Furthermore, the levels of growth hormone (GH) and calcium ion were higher in the sera of the high-concentration CKJ-treated groups, whereas the expression level of GH receptor was higher in muscle tissue of all CKJ-treated groups and in the liver tissue of the high-concentration CKJ-treated group. In the GH receptor downstream signaling pathway, the phosphorylation levels of Akt and Erk were expressed differently between liver and muscle tissues upon CKJ treatment. However, the phosphorylation level of STAT5 was very similar to the expression level of the GH receptor in all CKJ-treated groups. These results indicate that CKJ extract may increase the thickness of the epiphyseal growth plate and the compact bone of the femur, elevate GH secretion, and stimulate regulation of the GH receptor downstream signaling pathway in the liver and muscle tissues of SD rats.

Acute viral gastroenteritis in children hospitalized in Iksan, Korea during December 2010-June 2011.

PURPOSE: Viral etiology is common in cases of children with acute diarrhea, and antibiotic therapy is usually not required. Therefore, it is important to determine the distribution of common viruses among children hospitalized with acute diarrhea. METHODS: We included 186 children who suffered from acute diarrhea and were hospitalized at the Wonkwang University Hospital Pediatric ward from December 1, 2010 to June 30, 2011 in this study. Stool samples were collected and multiplex reverse transcriptase polymerase chain reaction (multiplex RT-PCR) was used to simultaneously determine the viral etiology such as rotavirus, norovirus, astrovirus, or adenovirus. RESULTS: Causative viruses were detected in 72 of the 186 cases (38.7%). The mean age of the virus-positive cases was 1 year and 9 months (range, 1 month to 11 years). Rotavirus was detected in 50/186 (26.9%); norovirus, in 18/186 (9.7%); and astrovirus, in 3/186 cases (1.6%). Adenovirus was not detected in any of the cases. Proportions of norovirus genogroups I and II were 21.1% and 78.9%, respectively. Four of the 51 rotavirus-positive cases (7.8%) had received rotavirus vaccination at least once. The mean duration of diarrhea was 2.8 days (range, 1 to 10 days) and vomiting occurred in 39 of the 72 cases (54.2%). CONCLUSION: Viral etiology was confirmed in about one-third of the children with acute diarrhea, and the most common viral agent was rotavirus, followed by norovirus.

Simultaneous analysis and monitoring of 16 UV filters in cosmetics by high-performance liquid chromatography.

Sixteen UV filters were simultaneously analyzed using the high-performance liquid chromatographic method. They were drometrizole (USAN Drometrizole), 4-methylbenzylidene camphor (USAN Enzacamene), menthyl anthranilate (USAN Menthyl anthranilate), benzophenone-3 (USAN Oxybenzone), benzophenone-8 (USAN Dioxybenzone), butyl methoxydibenzoylmethane (USAN Avobenzone), ethylhexyl triazone (USAN Octyl triazone), octocrylene (USAN Octocrylene), ethylhexyl dimethyl p-aminobenzoic acid (USAN Padimate O), ethylhexyl methoxycinnamate (USAN Octinoxate), p-aminobenzoic acid (USAN Aminobenzoic acid), 2-phenylbenzimidazole-5-sulfonic acid (USAN Ensulizole), isoamyl p-methoxycinnamate (USAN Amiloxate), and recent UV filters such as diethylhexyl butamidotriazone (USAN Iscotrizinol), methylene bis-benzotriazolyl tetramethylbutylphenol (USAN Bisoctrizole), and terephthalylidene dicamphor sulfonic acid (USAN Ecamsule). Separation of the UV filters was carried out in a C(18) column with a gradient of methanol-phosphate buffer, and the UV detection was at 300, 320, or 360 nm without any interference. The limits of detection were between 0.08 and 1.94 µg/ml, and the limits of quantitation were between 0.24 and 5.89 µg/ml. The extracting solvent for the UV filters was methanol, except for ethylhexyl triazone and methylene bis-benzotriazolyl tetramethylbutylphenol, which were prepared with tetrahydrofuran. The recoveries from spiked samples were between 94.90% and 116.54%, depending on the matrixes used. The developed method was applied to 23 sunscreens obtained from local markets, and the results were acceptable to their own criteria and to maximum authorized concentrations. Consequently, these results would provide a simple extracting method and a simultaneous determination for various UV filters, which can improve the quality control process as well as the environmental monitoring of sunscreens.

Utilization of real-time PCR to detect Rangifer Cornu contamination in Cervi Parvum Cornu.

Cervi parvum cornu (CPC) is a well-known ethnopharmacological source, whereas Rangifer cornu (RC) is not considered to be a major source. CPC is distributed in sliced form. Addition of RC to CPC has become an issue in CPC distribution because the appearance of sliced RC is not different from sliced CPC. Therefore, a real-time polymerase chain reaction (PCR) method was developed in this study to detect contaminating RC in CPC. The C-VIC and R-FAM primer/probe sets were designed to specifically amplify CPC and RC DNA, respectively. The specificities and sensitivities of real-time PCR using two primer/probe sets and the applicability of the real-time PCR to powder mixtures, which involved mixtures of powdered CPC and powdered RC in diverse ratios, were evaluated. Real-time PCR using C-VIC and R-FAM primer/probe sets specifically and sensitively amplified both CPC and RC DNA. Furthermore, real-time RCR sensitively detected RC DNA in the powder mixtures of CPC and RC. These results indicate that this real-time PCR method using two primer/probe sets is sufficiently applicable for the detection of contaminant RC in CPC.

Telomerase reverse transcriptase related with telomerase activity regulates tumorigenic potential of mouse embryonic stem cells.

Embryonic stem cell (ESC) research gave rise to the possibility that stem cell therapy could be used in the treatment of incurable diseases such as neurodegenerative disorders. However, problems related to the tumorigenicity of undifferentiated ESCs must be resolved before such cells can be used in the application of cell replacement therapies. In the present study, we attempted to determine biomarkers that predicted tumor formation of undifferentiated ESCs in vivo. We differentiated mouse ESCs (R1 cell line) into neural lineage using a 5-step method, and evaluated the expression of oncogenes (p53, Bax, c-myc, Bcl2, K-ras), telomerase-related genes (TERT, TRF), and telomerase activity and telomere length during differentiation of ESCs. The expression of oncogenes did not show a significant change during differentiation steps, but the expression of telomerase reverse transcriptase (TERT) and telomerase activity correlated with mouse ESCs differentiation. To investigate the possibility of mouse TERT (mTERT) as a biomarker of tumorigenicity of undifferentiated ESCs, we established mTERT knockdown ESCs using the shRNA lentivirus vector and evaluated its tumorigenicity in vivo using nude mice. Tumor volumes significantly decreased, and appearances of tumor formation in mice were delayed in the TERT-knockdown ESC treated group compared with the undifferentiated ESC treated group. Altogether, these results suggested that mTERT might be potentially beneficial as a biomarker, rather than oncogenes of somatic cells, for the assessment of ESCs tumorigenicity.

Compounds from Viburnum sargentii Koehne and evaluation of their cytotoxic effects on human cancer cell lines.

Compounds were isolated from a methanol extract of the dried stem barks of Viburnum sargentii Koehne. The structures of the compounds, namely 9'-O-methylvibsanol (3), furcatoside A (4) and lareciresinol (5) were elucidated by analysis of spectroscopic data and comparison with values for previously known analogues. In addition, (+)-catechin (1), (+)-epicatechin (2) were also isolated. This work also examined the cytotoxic effects of three compounds 3-5 (25-100 microM) in MCF-7 and A549 cells after 24, 48 and 72 h of exposure. Our results showed that 9'-O-methylvibsanol (3) exhibited strong concentration-dependent anticancer effects according to the MTT assay and produced morphological changes consistent with apoptosis, as confirmed by Ho3342 staining analysis revealed that more apoptotic cells were observed after 9'-Omethylvibsanol (3) treatment.

Protective effects of Vitamin E on endocrine disruptors, PCB-induced dopaminergic neurotoxicity.

UNLABELLED: The protective effect of an antioxidant, Vitamin E (dl-alpha-tocopherol, 100 mg/kg/day, 8 days p.o. in vivo and 10 and 50 microM in vitro) was tested against PCB-induced neurotoxicity. IN VIVO STUDIES: Microdialysis was used to investigate changes in the striatal extracellular dopamine level and in p-nNOS expression in PCB-treated (Aroclor 1254, 10 microg/ml, 2 microl/min, 5 h; 6 microg was infused by microdialysis probe) rats. IN VITRO STUDIES: Cell viability and levels of p-nNOS expression were observed in PCB-treated (Aroclor 1254, 5 microg/ml) immortalized dopaminergic cell line (CATH.a cells). RESULTS: Treatment with PCB: (1) decreased the extracellular dopamine level in rat striatum, (2) increased p-nNOS expression both in rat striatal tissue and in CATH.a cells, (3) reduced the cell viability of, and (4) increased LDH release by CATH.a cells. However, Vitamin E showed a protective effect against PCB-induced toxicity and downregulation of the extracellular dopamine level. These results indicate that Vitamin E may have neuroprotective effects by inhibiting PCB-induced nNOS phosphorylation.

Ginsenosides attenuate methamphetamine-induced behavioral side effects in mice via activation of adenosine A2A receptors: possible involvements of the striatal reduction in AP-1 DNA binding activity and proenkephalin gene expression.

Current evidence suggests that ginsenosides inhibit methamphetamine (MA)-induced changes in behavior, but the precise mechanisms that underlie this effect are yet to be determined. We examined the role of adenosine receptors in the ginsenoside-induced changes in hyperlocomotion and conditioned place preference (CPP) in mice that occurred in response to administration of MA (2 mg/kg, i.p. x 1 or 2 mg/kg, i.p. x 6). Changes in circling behavior paralleled changes in CPP in the presence of MA. Pre-treatment with ginsenosides (50 or 150 mg/kg, i.p.) attenuated the MA-induced circling behavior and CPP. This attenuation was reversed by the adenosine A2A receptor antagonist 1,3,7-trimethyl-8-(3-chrostyryl)xanthine (CSC; 0.5 and 1.0 mg/kg) in a dose-dependent manner, but neither the adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dimethylxanthine (CPT; 0.5 and 1.0 mg/kg) nor the A2B receptor antagonist alloxazine (ALX; 1.5 and 3.0 mg/kg) had any such effect. MA-induced increases in activator protein (AP)-1 DNA binding activity, Fos-related antigen immunoreactivity (FRA-IR), proenkephalin mRNA expression, and proenkephalin-like immunoreactivity were reduced consistently in the striatum of animals that were pretreated with ginsenosides. These reductions were largely prevented by CSC, but not by CPT or ALX. Our results suggest that the stimulation of A2A receptors by ginsenosides attenuates the changes in behavior and the increases in AP-1 DNA binding activity, FRA-IR, and proenkephalin gene expression in mouse striatum that are induced by MA.

Inhibition of aroclor 1254-induced depletion of stored calcium prevents the cell death in catecholaminergic cells.

The relationship between depleting effects of polychlorinated biphenyls (PCBs) on the intracellular calcium store and PCBs-induced cell death in dopaminergic cells has not been fully evaluated. Here, we evaluated the effects of inhibitors of the release of ER-stored calcium on the cytotoxicities induced by 10 microg/ml of Aroclor 1254 (A1254; polychlorinated biphenyl mixture) in a catecholaminergic cell-line, CATH.a cells. Exposure to A1254 produced an elevation in free calcium ([Ca2+]i) in the presence or absence of extracellular calcium and decreased in cell viability. From our results, we deduced that the A1254-induced elevation of [Ca2+]i resulted from the depletion of ER-stored calcium. The [Ca2+)]i elevation was dramatically inhibited by an inositol 1,4,5-triphosphate receptor (IP3R) antagonist, and slightly inhibited by a ryanodine receptor (RyR) blocker. IP3R blockers conferred significant protection against A1254-induced cell death, as did RyR blockers, but calcium chelators or NMDA blockers did not. However, none of these reagents inhibited the depletion of intracellular dopamine by A1254 indicating that the mechanism of PCB-induced dopamine depletion may be independent of calcium alterations. Taken together, these data suggest that agents inhibiting the receptor-mediated depletion of stored calcium can prevent the A1254-induced cell death, but not modulate the A1254-induced intracellular dopamine depletion in CATH.a cells.

Changes of the level of G protein alpha-subunit mRNA by tolerance to and withdrawal from butorphanol.

Butorphanol was infused continuously into cerebral ventricle at a constant rate of 26 nmol/microl/h for 3 days, and the withdrawal from opioid was rendered 7 h after the cessation of infusion. The G-protein alpha-subunit has been implicated in opioid tolerance and withdrawal. The effects of continuous infusion of butorphanol on the modulation of G protein alpha-subunit mRNA were investigated by using in situ hybridization techniques. In situ hybridization showed marked changes in the levels of Galpha s during butorphanol tolerance and withdrawal. Specifically, the level of Galpha s mRNA was significantly decreased in almost all areas of brain except hippocampus during the butorphanol withdrawal. It was also decreased in the septum and cerebellar granule layer in butorphanol tolerant rats. The level of Galpha i mRNA was significantly decreased only in the cerebral cortex of butorphanol tolerant rat. However, no such change was noted during the withdrawal from butorphanol. The level of Galpha o mRNA was not changed either in butorphanol tolerant or in the butorphanol withdrawal rats. No alterations were noted in the level of [3H]forskolin binding to adenylyl cyclase in butorphanol tolerant as well as withdrawing rats. The levels of pCREB were significantly elevated in the hippocampus in the butorphanol withdrawal rats. These results suggest that region-specific changes of G protein alpha-subunit mRNA and pCREB without marked changes in the level of adenylyl cyclase may underlie the tolerance to and withdrawal from butorphanol.

Development and evaluation of an immunochromatographic kit for the detection of antibody to Plasmodium vivax infection in South Korea.

Malaria is a major parasitic disease in tropical areas. Three to five hundred million people suffer from the disease and it kill a million people per year. Blood smear observation was developed for the diagnosis of malaria, but the examination needs skilled experts and exact diagnosis is time consuming. A kit based on immunochromatography can be a reliable and rapid method for clinical diagnosis, even in the hands of inexperienced personnel. However, all such currently developed kits can only diagnose P. falciparum malaria. In our previous report, the C-terminal region of P. vivax merozoite surface protein 1 (PvcMSP) was cloned and expressed in E. coli. In the present study, we developed an immunochromatographic kit using this PvcMSP for the diagnosis of specific antibody to P. vivax malaria in serum samples. The kit was used to examine sera from vivax malaria patients and non-malaria- infected person and the test showed 100% sensitivity (78/78) and 98.3% specificity (58/59). This result demonstrated that the immunochromatographic kit for P. vivax antibody detection is applicable for the rapid and precise diagnosis of P. vivax malaria.