Effects of Sub-Acute Manganese Exposure on Thyroid Hormone and Glutamine (Gln)/Glutamate (Glu)-γ- Aminobutyric Acid (GABA) Cycle in Serum of Rats.

Excessive manganese (Mn) exposure may adversely affect the central nervous system, and cause an extrapyramidal disorder known as manganism. The glutamine (Gln)/glutamate (Glu)-γ-aminobutyric acid (GABA) cycle and thyroid hormone system may be involved in Mn-induced neurotoxicity. However, the effect of Mn on the Gln/Glu-GABA cycle in the serum has not been reported. Herein, the present study aimed to investigate the effects of sub-acute Mn exposure on the Gln/Glu-GABA cycle and thyroid hormones levels in the serum of rats, as well as their relationship. The results showed that sub-acute Mn exposure increased serum Mn levels with a correlation coefficient of 0.733. Furthermore, interruption of the Glu/Gln-GABA cycle in serum was found in Mn-exposed rats, as well as thyroid hormone disorder in the serum via increasing serum Glu levels, and decreasing serum Gln, GABA, triiodothyronine (T3) and thyroxine (T4) levels. Additionally, results of partial correlation showed that there was a close relationship between serum Mn levels and the detected indicators accompanied with a positive association between GABA and T3 levels, as well as Gln and T4 levels in the serum of Mn-exposed rats. Unexpectedly, there was no significant correlation between serum Glu and the serum T3 and T4 levels. In conclusion, the results demonstrated that both the Glu/Gln-GABA cycle and thyroid hormone system in the serum may play a potential role in Mn-induced neurotoxicity in rats. Thyroid hormone levels, T3 and T4, have a closer relationship with GABA and Gln levels, respectively, in the serum of rats.

Risk factors and prognostic factors of acute kidney injury in children: A retrospective study between 2003 and 2013.

Recent report on epidemiology of acute kidney injury (AKI) is lacking for Chinese children. We aimed to investigate the risk factors for stage and prognostic factors for renal recovery in hospitalized children. Pediatric patients (≤18 years old) admitted during 2003 to 2013 were enrolled in this study. AKI was defined and staged using Kidney Disease Improving Global Outcomes (KDIGO) criteria. Logistic regression analysis was performed to determine the risk factors and prognostic factors. The morbidity of pediatric AKI was 0.31% (205/65 237). There were 45 (22.0%) cases in stage III, 30 (14.6%) cases in stage II and 130 (63.4%) cases in stage III. The majority of etiologies were intrinsic renal defects (85.4%). Age, weight, vomit, etiology, blood urea nitrogen (BUN) at admission and several blood gas measurements were associated with AKI stage III. Age (OR=0.894; 95% CI, 0.832-0.962; P=0.003), vomit (OR=2.375; 95% CI, 1.058-5.333; P=0.036) and BUN at admission (OR=1.135; 95% CI, 1.085-1.187; P<0.001) were identified as independent risk factors for AKI stage III. After treatment, 172 (83.9%) patients achieved complete or partial recovery. The mortality was 3.9%. Variables were found as prognostic factors for renal recovery, such as age, stage, hospital stay, BUN at discharge, white blood cells, red blood cells, platelets (PLTs), blood pH and urine blood. Among them, AKI stage (stage III vs. stage I; OR, 6.506; 95% CI, 1.640-25.816; P=0.008), BUN at discharge (OR, 0.918; 95% CI, 0.856-0.984; P=0.016) and PLTs (OR, 1.007; 95% CI, 1.001-1.013; P=0.027) were identified as independent prognostic factors. AKI is still common in Chinese hospitalized children. Identified risk factors and prognostic factors provide guiding information for clinical management of AKI.

Fenofibrate pre-treatment suppressed inflammation by activating phosphoinositide 3 kinase/protein kinase B (PI3K/Akt) signaling in renal ischemia-reperfusion injury.

The aim of this study was to investigate the possible beneficial effects of Fenofibrate on renal ischemia-reperfusion injury (IRI) in mice and its potential mechanism. IRI was induced by bilateral renal ischemia for 60 min followed by reperfusion for 24 h. Eighteen male C57BL/6 mice were randomly divided into three groups: sham-operated group (sham), IRI+saline group (IRI group), IRI+Fenofibrate (FEN) group. Normal saline or Fenofibrate (3 mg/kg) was intravenously injected 60 min before renal ischemia in IRI group and FEN group, respectively. Blood samples and renal tissues were collected at the end of reperfusion. The renal function, histopathologic changes, and the expression levels of pro-inflammatory cytokines [interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-α) and IL-6] in serum and renal tissue homogenate were assessed. Moreover, the effects of Fenofibrate on activating phosphoinositide 3 kinase/protein kinase B (PI3K/Akt) signaling and peroxisome proliferator-activated receptor-α (PPAR-α) were also measured in renal IRI. The results showed that plasma levels of blood urea nitrogen and creatinine, histopathologic scores and the expression levels of TNF-α, IL-8 and IL-6 were significantly lower in FEN group than in IRI group. Moreover, Fenofibrate pretreatment could further induce PI3K/Akt signal pathway and PPAR-α activation following renal IRI. These findings indicated PPAR-α activation by Fenofibrate exerts protective effects on renal IRI in mice by suppressing inflammation via PI3K/Akt activation. Thus, Fenofibrate could be a novel therapeutic alternative in renal IRI.

[Detecting the concentrations of bisphenol A (BPA) in air of workplaces with HPLC].

OBJECTIVE: To establish the method of detecting the concentrations of bisphenol A (BPA)in air of workplaces with high performance liquid chromatographic (HPLC). METHODS: According to standards of methods for determining the chemical substances in workplace air, BPA in the air was collected by glass fiber filter, then dissolved by acetonitrile and determined by high performance liquid chromatography with FLD. RESULTS: There was a linear relationship within the range of 0.01-10.0 pg /ml, and the detection limit was 0.005 pg/ml. The lowest detected concentration was 3.3x10-5 mg/m3. The relative standard deviation was 2.5-5.5%. The dissolution efficiencies were 95.0%-101.9% and the sampling efficiencies were 99.6%. The samples in glass fiber filter membrane could be stored for 7 days at room temperature. CONCLUSION: The present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of BPA in workplace air.

[Predictors of return to work after occupational injury in a locomotive enterprise].

OBJECTIVE: To identify the potential determinants of return to work (RTW) following work-related injury. METHODS: A historical cohort of workers with occupational injury in a state-owned locomotive vehicle company in central China was followed up for RTW. Demographic, employment and medical information was retrieved from the company archival documents; and post-injury information was interviewed by questionnaires. Univariate analysis and Cox Regression Model were used to examine the associations between potential determinants and outcomes of RTW. RESULTS: Three hundred of the 323 included cases (92.9%) eventually returned to work after the median absence of 43 days (average of 49.2 days). Factors from socio-demographic, clinical, economic and psychological domains were found affecting RTW in the univariate analyses. The multivariate analysis indicated that age, injury severity, injury locus, injury nature, pain in the injury locus, self-reported health status and pre-injury monthly salary were significant determinants of RTW. CONCLUSIONS: There are multidimensional factors affecting RTW after occupational injury. Proper clinical treatment and rehabilitation, as well as economic and social support to facilitate workers' RTW would be the priorities for intervention. Future studies should be conducted in a larger representative sample to confirm the findings and to develop a multidisciplinary intervention strategy towards promoting RTW.

Effects of metsulfuron-methyl on the microbial population and enzyme activities in wheat rhizosphere soil.

The effects of metsulfuron-methyl, a sulfonylurea herbicide, on the wheat soil microorganisms were evaluated by the methods of microbial inoculation culture, and the activities of three enzymes were measured using the colorimetric method. The tolerant microorganisms that can resist 500 microg x g(-1) metsulfuron-methyl in the counting culture medium were studied specially. Metsulfuron-methyl distinctly inhibited the common aerobic heterotriphic bacteria, but the effects on common fungi and common actinomycete were not evident. In the meantime, the number of tolerant fungi increased greatly in the rhizosphere after the application of metsulfuron-methyl in contrast to the significant decrease of the amount of tolerant actinomycete. It indicates that fungi might turn into the dominant microbial type and actinomycete is the sensitive factor in the soil polluted by sulfonylurea residues. The population of aromatic compounds-decomposing bacteria, aerobic azotobacter, and nitrite bacteria all increased in the earlier period, but the aerobic azotobacter decreased rapidly in number 30 days later, and the amount of nitrite bacteria also showed a temporary decrease with time 15 days later. However, the denitrifying bacteria just began to increase significantly after the crops had grown for 50 days. The amount of sulfur-oxidizing bacteria gradually decreased with the growth of crops, and so were the sulfate-reducing bacteria after metsulfuron-methyl application. To all types of microorganisms, there were more microbes in rhizosphere samples than those in nonrhizosphere except aerobic azotobacter. It means the growth of wheat root system can stimulate the growth of most microorganisms. The activities of hydrogen peroxidase and polyphenol oxidase in soil samples after metsulfuron-methyl application were notably lower than those in the control, and the difference of the activities between the samples of rhizosphere and nonrhizosphere was evident. On the contrary, the activity of dehydrogenase was not inhibited by the application of metsulfuron-methyl, and the rhizosphere effect was not obvious either.

Studies on adsorption, desorption and biodegradation of pentachlorophenol by the anaerobic granular sludge in an upflow anaerobic sludge blanket (UASB) reactor.

PCP-degrading anaerobic granular sludge could be formed in an upflow anaerobic sludge blanket (UASB) reactor that was seeded with anaerobic sludge acclimated to chlorophenol. When hydraulic retention time (HRT) was 20-22 h and PCP loading rate was 200-220 mgL(-1)d(-1), the wastewater containing 170-180 mgL(-1) PCP could be treated effectively in UASB reactor, and PCP removal rate reached up to 99.5%. PCP adsorption and desorption by anaerobic granular sludge follow Freundlich isothermal equation and part of adsorption capacity was not reversible. And the isothermal equation could well describe the variation law of PCP adsorption and desorption by anaerobic granular sludge. The results indicated that the principal removal mechanism of PCP was biodegradation by anaerobic granular sludge, but not adsorption or volatilization.

[Comparing three methods of estimating concentration of worksite benzene.].

OBJECTIVE: benzene; Air pollution; Risk assessment in the air of workshop and validate the methods. METHODS: Expert-reference, BAYES statistics and expert-measurement were separately used to estimate benzene concentration in a slurry-applying workshop and modeling workshop of a rubber factory. The estimations were compared with current newly monitored data. RESULTS: The estimated averages of expert-reference, BAYES statistics and expert-measurement were 100.0, 16.9, 33.2 mg/m3 respectively for the slurry-applying workshop and 100, 156, 115 mg/m3 for the modeling workshop. No significant difference was observed between the estimations and validating sample except to that of the expert-reference for the former. CONCLUSION: BAYES statistics and expert-measurement were precise and expert-reference was candidate if no measurements in spite of its subjectivity.