Topical administration of Esculetin as a potential therapy for experimental dry eye syndrome

PurposeIn this study, we investigated the therapeutic effects of topical Esculetin for dry eye rabbits through the ocular tests, inflammatory factor levels and specific phosphorylated protein expressions of ERK1/2 singnal pathway.Patients and methodsThirty-two healthy adult male New Zealand white rabbits were chosen for the study. DES models were established after removing of the main lacrimal gland, Harderian gland and nictitating membrane in the left eyes and randomly divided into group DES control, group CsA, group Esculetin and group Esculetin combined with CsA (C&E), meanwhile the right eyes served as group Normal control. Schirmer's I tests, fluorescein scores, goblet cell densities, inflammatory cytokines IL-1α,IL-1β,TNF-αlevels were observed by slit-lamp microscope, conjunctival impression cytology and ELISA essay at week 0, 1, 2, 4, 8. Phosphorylated-ERK1/2 expressions were detected in Western blot analysis at week 8.ResultsAfter induction of DES, aqueous tear production and goblet cell density were decreased, FL score was much higher in group DES control throughout the study (P<0.05). Both topical Esculetin and Esculetin combing CsA increased the SIT values (10±1 mm, 14±3 mm, P<0.05) and goblet cell densities (77±12/HP, 92±12/HP, P<0.05), decreased FL scores (7.48±0.33, 5.09±0.24, P<0.05) at week 8. Alternations of IL-1α,IL-1β,TNF-αlevels had similar trend. In Western blot analysis, downregulations of p-ERK1/2 were observed in therapy groups when compared with group DES control and the most decreasing was found in group C&E (P<0.05).ConclusionTopical Esculetin improved DES symptoms, downregulated the inflammatory cytokine expressions, suppressed the ERK1/2 pathway and enhanced the therapeutic effect of CsA.

Bounded perturbation resilience of extragradient-type methods and their applications

In this paper we study the bounded perturbation resilience of the extragradient and the subgradient extragradient methods for solving a variational inequality (VI) problem in real Hilbert spaces. This is an important property of algorithms which guarantees the convergence of the scheme under summable errors, meaning that an inexact version of the methods can also be considered. Moreover, once an algorithm is proved to be bounded perturbation resilience, superiorization can be used, and this allows flexibility in choosing the bounded perturbations in order to obtain a superior solution, as well explained in the paper. We also discuss some inertial extragradient methods. Under mild and standard assumptions of monotonicity and Lipschitz continuity of the VI's associated mapping, convergence of the perturbed extragradient and subgradient extragradient methods is proved. In addition we show that the perturbed algorithms converge at the rate of [Formula: see text]. Numerical illustrations are given to demonstrate the performances of the algorithms.

An integrative model of prostate cancer interaction with the bone microenvironment

Despite advanced efforts in early diagnosis, aggressive surgical treatment, and use of targeted chemotherapies, the prognosis for many cancers is still dismal. This emphasizes the necessity to develop new strategies for understanding tumor growth and metastasis. Here we use a systems approach that combines mathematical modeling and numerical simulation to develop a predictive computational model for prostate cancer and its subversion of the bone microenvironment. This model simulates metastatic prostate cancer evolution, progressing from normal bone and hormone levels to quantifiable diseased states. The simulations clearly demonstrate phenomena similar to those found clinically in prostate cancer patients. In addition, the major prediction of this model is the existence of low and high osteogenic states that are markedly different from one another. The existence and potential realization of these steady states appear to be mediated by the Wnt signaling pathway and by the effects of PSA on TGF-β, which encourages the bone microenvironment to evolve. The model is used to explore several potential therapeutic strategies, with some potential drug targets showing more promise than others: in particular, completely blocking Wnt and greatly increasing DKK-1 had significant positive effects, while blocking RANKL did not improve the outcome.

Preparation of chitosan-collagen-alginate composite dressing and its promoting effects on wound healing

The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-β, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity.

[A multicenter clinical study for the comparison of S-1 versus capecitabine in the treatment of advanced breast cancer]

Objective: To investigate the safety, efficacy and prognostic factors of S-1 versus capecitabine in patients with advanced breast cancer (ABC). Methods: From January 1, 2012 to December 31, 2014, 154 ABC patients with pathological diagnosis were separated into two groups: S-1 with or without the 3rd generation chemotherapy drug (group S-1) and capecitabine with or without the 3rd generation chemotherapy drug (Group capecitabine). The efficacy, side effects and prognostic factors were compared between the two groups. Results: There were 70 patients in group S-1 and 84 patients in group capecitabine. The objective response rates (ORR) were 31.4% (22/70) in group S-1 and 28.6% (24/84) in group capecitabine. The disease control rates (DCR) were 74.3% (52/70) and 83.3% (70/84), respectively. There were no significant differences in DCR and ORR between two groups (P>0.05). The DCR of patients treated with capecitabine monotherapy was significantly higher than that of S-1 monotherapy [94.4%(17/18) and 64.0%(16/25), P=0.028]. The median PFS was 7.5 and 8.9 months for the patients in the group S-1 and group capecitabine, with no statistically significant difference (P=0.423). The 1-year survival rates of group S-1 and group capecitabine were 81.4% and 66.7%, respectively, with no significant differences(P=0.020). Univariate analysis showed that ER and/or PR status (P=0.004), T stage (P=0.041), and molecular typing (P=0.046) were associated with PFS. Multivariate analysis showed ER and/or PR status (P=0.034) was an independent prognostic factor related with PFS. The incidence of hemoglobin reduction was 14.3% (10/70) and 36.9% (31/84) in the group S-1 and group capecitabine, and the differences were statistically significant (P=0.002). There was no significant difference in the incidence of leukopenia, neutropenia, thrombocytopenia and hand-foot syndrome between the two groups(P>0.05). Conclusions: S-1 and capecitabine are both effective for advanced breast cancer. Neither ORR nor DCR were significantly different between these two groups. The incidence of gastrointestinal reactions and thrombocytopenia of S-1 was slightly lower than that of capecitabine.

Dynamics of microbial community during ensiling direct-cut alfalfa with and without LAB inoculant and sugar

AIM

To gain deeper insights into the clostridial community dynamics and chemical transformations during the ensiling of alfalfa.

METHODS AND RESULTS

Direct-cut alfalfa silage (with the dry matter content of 240 g kg^-1 ) was prepared with or without the addition of a lactic acid bacterial inoculant and sucrose. Silages were sampled at 0, 3, 7, 14, 28 and 56 days after ensiling and their bacterial community was determined using high-throughput sequencing with a special focus on the clostridial community. A clostridial fermentation occurred in the control silage, with high contents of acetic acid, butyric acid and ammonia nitrogen and Clostridia counts; while the inoculated silage was well preserved, with low pH and high lactic acid content. Lactic acid bacteria dominated the bacterial community during the ensiling process. In the control silage, Weissella confusa, Lactobacillus brevis, Enterococcus mundtii and Pediococcus acidilactici were identified at the beginning of the fermentation. Thereafter, W. confusa, Lactobacillus helsingborgensis and Bifidobacterium asteroides appeared and quickly prevailed. In the inoculated silage, Lactobacillus plantarum dominated the whole ensiling process. The genus Clostridium dominated the clostridial community, and was depressed with the inoculated treatment. Clostridium perfringens, Garciella sp. and Clostridium baratii were the main initiators of the clostridial fermentation of the control silage, while Clostridium tyrobutyricum became the most abundant Clostridia with prolonged ensiling. Overall in the inoculated silage, little changes in the clostridial community were observed throughout the ensiling period. Treating alfalfa silage with a homolactic acid-based bacterial inoculant prevented a clostridial fermentation resulting in more efficient fermentation.

CONCLUSION

Distinct changes in the bacterial community with a special focus on the clostridial community were associated with the development of the clostridial fermentation during the ensiling of alfalfa.

SIGNIFICANCE AND IMPACT OF THE STUDY

High-throughput sequencing based on a novel Clostridia-specific primer set proved a potentially useful tool to study the clostridial community dynamics, and could aid to elucidate the mechanism by which the clostridial fermentation develops during the ensiling of alfalfa.

Sofosbuvir plus ribavirin in treatment-naïve patients with chronic hepatitis C virus genotype 1 or 3 infection in India

Until 2014, pegylated interferon plus ribavirin was the recommended standard of care for the treatment of chronic hepatitis C virus (HCV) infection in India. This open-label phase 3b study, conducted across 14 sites in India between 31 March 2014 and 30 November 2015, evaluated the efficacy and safety of sofosbuvir plus ribavirin therapy among treatment-naïve patients with chronic genotype 1 or 3 HCV infection. A total of 117 patients with genotype 1 or 3 HCV infection were randomized 1:1 to receive sofosbuvir 400 mg and weight-based ribavirin (1000 or 1200 mg) daily for 16 or 24 weeks. Among those with genotype 1 infection, the primary efficacy endpoint of sustained virologic response at 12 weeks post-treatment (SVR12) was reported in 90% (95% confidence intervals [CI], 73-98) and 96% (95% CI, 82-100) of patients following 16 and 24 weeks of treatment, respectively. For patients with genotype 3 infection, SVR12 rates were 100% (95% CI, 88-100) and 93% (95% CI, 78-99) after 16 and 24 weeks of therapy, respectively. Adverse events, most of which were mild or moderate in severity, occurred in 69% and 57% of patients receiving 16 and 24 weeks of treatment, respectively. The most common treatment-emergent adverse events were asthenia, headache and cough. Only one patient in the 24-week group discontinued treatment with sofosbuvir during this study. Overall, sofosbuvir plus ribavirin therapy achieved SVR12 rates ≥90% and was well tolerated among treatment-naïve patients with chronic genotype 1 or 3 HCV infection in India.

Association between glycaemic control and common infections in people with Type 2 diabetes: a cohort study

AIM

To investigate the impact of glycaemic control on infection incidence in people with Type 2 diabetes.

METHODS

We compared infection rates during 2014 in people with Type 2 diabetes and people without diabetes in a large primary care cohort in the UK (the Royal College of General Practitioners Research and Surveillance Centre database). We performed multilevel logistic regression to investigate the impact of Type 2 diabetes on presentation with infection, and the effect of glycaemic control on presentation with upper respiratory tract infections, bronchitis, influenza-like illness, pneumonia, intestinal infectious diseases, herpes simplex, skin and soft tissue infections, urinary tract infections, and genital and perineal infections. People with Type 2 diabetes were stratified by good [HbA_1c < 53 mmol/mol (< 7%)], moderate [HbA_1c 53-69 mmol/mol (7-8.5%)] and poor [HbA_1c > 69 mmol/mol (> 8.5%)] glycaemic control using their most recent HbA_1c concentration. Infection incidence was adjusted for important sociodemographic factors and patient comorbidities.

RESULTS

We identified 34 278 people with Type 2 diabetes and 613 052 people without diabetes for comparison. The incidence of infections was higher in people with Type 2 diabetes for all infections except herpes simplex. Worsening glycaemic control was associated with increased incidence of bronchitis, pneumonia, skin and soft tissue infections, urinary tract infections, and genital and perineal infections, but not with upper respiratory tract infections, influenza-like illness, intestinal infectious diseases or herpes simplex.

CONCLUSIONS

Almost all infections analysed were more common in people with Type 2 diabetes. Infections that are most commonly of bacterial, fungal or yeast origin were more frequent in people with worse glycaemic control.

Bone marrow sFRP5 level is negatively associated with bone formation markers

Secreted frizzled-related protein 5 (sFRP5) level in bone marrow environment is inversely correlated with bone formation markers, suggesting that it decreases bone mass by inhibiting bone formation. Besides, it functions in a local fashion when regulating bone metabolism. sFRP5 may be a target when developing anti-osteoporotic agents.

INTRODUCTION

The purpose of the study is to investigate the relationship between bone marrow sFRP5 level and bone turnover state.

METHODS

Eighty-three total knee arthroplasty patients were enrolled in this study. Data were collected prospectively and reviewed retrospectively. Lumbar spine and femoral neck bone mineral density (BMD), marrow adipose tissue (MAT) sFRP5 messenger RNA (mRNA) expression level, sFRP5 concentrations in marrow fluid and serum, concentrations of bone formation and resorption markers were measured for each participant.

RESULTS

Marrow fluid sFRP5 concentration was positively correlated with both MAT sFRP5 expression (p = 0.040) and serum sFRP5 concentration (p = 0.043). Significantly positive correlation existed between MAT sFRP5 expression level and BMD (p < 0.05). Marrow fluid sFRP5 concentration had a moderate but not significant positive association with BMD. MAT sFRP5 was negatively related to serum bone formation markers including N-terminal propeptide of type 1 procollagen (P1NP) (p = 0.011), osteocalcin (OC), and alkaline phosphatase (ALP). Marrow fluid and serum sFRP5 concentrations also had mild negative correlations with bone formation markers but reached no significance. There was no significant correlation between bone resorption marker β-crosslaps (β-CTX) and sFRP5. The mRNA expression level of MAT sFRP5 was positively related with those of MAT leptin, peroxisome proliferator-activated receptor-γ (PPARγ), and adiponectin, and its correlation with leptin was statistically significant (p = 0.026).

CONCLUSIONS

Bone marrow sFRP5 level is closely correlated with BMD and bone formation markers. sFRP5 may be a potential negative regulator of bone mass by inhibiting bone formation. It may exert its effects on bone metabolism in a paracrine, rather than endocrine manner.

Effect of epigallocatechin-3-gallate on acrylamide-induced oxidative stress and apoptosis in PC12 cells

Acrylamide (ACR) is a chemical intermediate utilized in industry. ACR is also formed during heating of foods containing carbohydrates and amino acids. Therefore, humans are widely exposed to ACR, and ACR neurotoxicity in humans is a significant public health issue attracting wide attention. In this study, we investigated the potential neuroprotective effects of epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic compound in green tea, in PC12 cells treated with ACR. ACR-treated PC12 cells pretreated with various concentrations of EGCG (2.5, 5 and 10 μM) for 24 h had increased viability and acetylcholinesterase activity and reduced apoptosis and necrosis compared to cells exposed to ACR alone. EGCG reduced the expression of bax mRNA, decreased cytochrome c release, reduced intracellular calcium levels, inactivated caspase 3 and increased mitochondrial membrane potential, suggesting that EGCG prevents ACR-induced apoptosis through a mitochondrial-mediated pathway. In addition, EGCG inhibited the formation of reactive oxygen species and lipid peroxidation while enhancing superoxide dismutase activity and glutathione levels, thereby reducing oxidative stress. Our results indicate that pretreatment of PC12 cells with EGCG attenuates ACR-induced apoptosis by reducing oxidative stress. Therefore, drinking green tea may reduce nerve injury induced by ACR.

Activation of chrysocolla flotation by organic chelating agents

Activation of chrysocolla by organic Cu-chelating agents was studied using a series of test and analysis methods, revealing that the performance of these agents was related to their chemical activity and chrysocolla dissolution properties.

Trajectories of Nutritional Risk: The Manitoba Follow-Up Study

OBJECTIVES

To identify patterns of nutritional risk among older men over a four-year period and to project their survival rates over the next two and a half years.

DESIGN

A prospective longitudinal study.

SETTING

Canada.

PARTICIPANTS

Three hundred and thirty-six male survivors of the Manitoba Follow-up Study (MFUS) cohort with an average age of 90 years in 2011.

MEASUREMENTS

Four years of nutritional risk SCREEN II scores (five waves) from the male survivors of the MFUS cohort. The semi-parametric group-based trajectory approach and survival analysis were used to investigate the trajectories of nutritional risk.

RESULTS

Of the participants, 30% lived alone. Five distinct developmental trajectory groups for nutritional risk score were identified. Significant statistical differences were found among the five trajectory groups for SF-36 mental health (p=.02), SF-36 physical health (p=<.001), perception of aging successfully (p=.04) and living alone (p=<.001). Among the five groups, the most pairwise differences were found in appetite, intake of meat and alternatives, and vegetables and fruit, weight change, skipping meals and eating with others. Men in the poorest nutritional risk trajectory group were two times more likely to die within a 2 1/2 year period compared to men in the best nutritional risk trajectory group (hazard rate = 2.33, p=.07).

CONCLUSION

Distinct nutritional risk trajectories were found for older men over a four year period. Poor nutritional risk trajectories are associated with higher risk of mortality for very old men over a short period of time. Timely nutritional assessments by health professionals are needed to identify older men at nutritional risk. Subsequent nutrition education and follow-up may be important in preventing further decline.

Improved spatial calibration for the CXRS system on EAST

A Charge eXchange Recombination Spectroscopy (CXRS) diagnostic system has been developed to measure profiles of ion temperature and rotation since 2014 on EAST. Several techniques have been developed to improve the spatial calibration of the CXRS diagnostic. The sightline location was obtained by measuring the coordinates of three points on each sightline using an articulated flexible coordinate measuring arm when the vessel was accessible. After vacuum pumping, the effect of pressure change in the vacuum vessel was evaluated by observing the movement of the light spot from back-illuminated sightlines on the first wall using the newly developed articulated inspection arm. In addition, the rotation of the periscope after vacuum pumping was derived by using the Doppler shift of neutral beam emission spectra without magnetic field. Combining these techniques, improved spatial calibration was implemented to provide a complete and accurate description of the EAST CXRS system. Due to the effects of the change of air pressure, a ∼0.4° periscope rotation, yielding a ∼20 mm movement of the major radius of observation positions to the lower field side, was derived. Results of Zeeman splitting of neutral beam emission spectra with magnetic field also showed good agreement with the calibration results.

First measurement of the edge charge exchange recombination spectroscopy on EAST tokamak

An edge toroidal charge exchange recombination spectroscopy (eCXRS) diagnostic, based on a heating neutral beam injection (NBI), has been deployed recently on the Experimental Advanced Superconducting Tokamak (EAST). The eCXRS, which aims to measure the plasma ion temperature and toroidal rotation velocity in the edge region simultaneously, is a complement to the exiting core CXRS (cCXRS). Two rows with 32 fiber channels each cover a radial range from ∼2.15 m to ∼2.32 m with a high spatial resolution of ∼5-7 mm. Charge exchange emission of Carbon VI CVI at 529.059 nm induced by the NBI is routinely observed, but can be tuned to any interested wavelength in the spectral range from 400 to 700 nm. Double-slit fiber bundles increase the number of channels, the fibers viewing the same radial position are binned on the CCD detector to improve the signal-to-noise ratio, enabling shorter exposure time down to 5 ms. One channel is connected to a neon lamp, which provides the real-time wavelength calibration on a shot-to-shot basis. In this paper, an overview of the eCXRS diagnostic on EAST is presented and the first results from the 2015 experimental campaign will be shown. Good agreements in ion temperature and toroidal rotation are obtained between the eCXRS and cCXRS systems.

DREADD in parvalbumin interneurons of the dentate gyrus modulates anxiety, social interaction and memory extinction

Parvalbumin (PV)-positive interneurons in the hippocampus play a critical role in animal memory, such as spatial working memory. However, how PV-positive interneurons in the subregions of the hippocampus affect animal behaviors remains poorly defined. Here, we achieved specific and reversible activation of PV-positive interneurons using designer receptors exclusively activated by designer drugs (DREADD) technology. Inducible DREADD expression was demonstrated in vitro in cultured neurons, in which co-transfection of the hM3D-Gq-mCherry vector with a Cre plasmid resulted in a cellular response to hM3Dq ligand clozapine-N-oxide (CNO) stimulation. In addition, the dentate gyrus (DG) of PV-Cre mice received bilateral injection of control lentivirus or lentivirus expressing double floxed hM3D-Gq-mCherry. Selective activation of PV-positive interneurons in the DG did not affect locomotor activity or depression-related behavior in mice. Interestingly, stimulation of PV-positive interneurons induced an anxiolytic effect. Activation of PVpositive interneurons appears to impair social interaction to novelty, but has no effect on social motivation. However, this defect is likely due to the anxiolytic effect as the exploratory behavior of mice expressing hM3DGq is significantly increased. Mice expressing hM3D-Gq did not affect novel object recognition. Activation of PV-positive interneurons in the DG maintains intact cued and contextual fear memory but facilitates fear extinction. Collectively, our results demonstrated that proper control of PV interneurons activity in the DG is critical for regulation of the anxiety, social interaction and fear extinction. These results improve our fundamental understanding of the physiological role of PV-positive interneurons in the hippocampus.

Tollip SNP rs5743899 modulates human airway epithelial responses to rhinovirus infection

BACKGROUND

Rhinovirus (RV) infection in asthma induces varying degrees of airway inflammation (e.g. neutrophils), but the underlying mechanisms remain unclear.

OBJECTIVE

The major goal was to determine the role of genetic variation [e.g. single nucleotide polymorphisms (SNPs)] of Toll-interacting protein (Tollip) in airway epithelial responses to RV in a type 2 cytokine milieu.

METHODS

DNA from blood of asthmatic and normal subjects was genotyped for Tollip SNP rs5743899 AA, AG and GG genotypes. Human tracheobronchial epithelial (HTBE) cells from donors without lung disease were cultured to determine pro-inflammatory and antiviral responses to IL-13 and RV16. Tollip knockout and wild-type mice were challenged with house dust mite (HDM) and infected with RV1B to determine lung inflammation and antiviral response.

RESULTS

Asthmatic subjects carrying the AG or GG genotype (AG/GG) compared with the AA genotype demonstrated greater airflow limitation. HTBE cells with AG/GG expressed less Tollip. Upon IL-13 and RV16 treatment, cells with AG/GG (vs. AA) produced more IL-8 and expressed less antiviral genes, which was coupled with increased NF-κB activity and decreased expression of LC3, a hallmark of the autophagic pathway. Tollip co-localized and interacted with LC3. Inhibition of autophagy decreased antiviral genes in IL-13- and RV16-treated cells. Upon HDM and RV1B, Tollip knockout (vs. wild-type) mice demonstrated higher levels of lung neutrophilic inflammation and viral load, but lower levels of antiviral gene expression.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest that Tollip SNP rs5743899 may predict varying airway response to RV infection in asthma.

Diabetes mellitus and the skin

Diabetes is a debilitating, life-threatening disease accounting in 2015 for the death of 5 million people worldwide. According to new estimations, 415 million adults currently suffer from the disease, and this number is expected to rise to 642 million by 2040. High glucose blood levels also affect the skin among systemic organs, and skin disorders can often predict the onset of this metabolic disorder. In this review, we address the pathomechanistic effects of diabetes on the skin and give an overview on the most common skin diseases associated with diabetes.

[Determination of trace cobalt and tungsten in human urine by inductively coupled plasma mass spectrometry]

OBJECTIVE

To establish a method to determine cobalt and tungsten in human urine by ICP-MS.

METHODS

Both Co and W were linear within 0.05~10.00 ng/ml with r>0.999. Spike experiment showed that both Co and W received good recovery rate, which were 90%~97%. Intra-assay precisions were 3.2%~5.1% for Co and 2.2%~4.1% for W, inter-assay precisions were 4.4%~5.2% for Co and 3.7%~4.5% for W.

CONCLUSION

The method by using ICP-MS to determine urine Co and W was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

[Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr]

OBJECTIVE

To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry.

METHODS

Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection.

RESULTS

Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co.

CONCLUSION

The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.