Pretreatment with Methylene Blue Protects Against Acute Seizure and Oxidative Stress in a Kainic Acid-Induced Status Epilepticus Model.

BACKGROUND The aim of the present study was to investigate the potential anticonvulsant effect of methylene blue (MB) in a kainic acid (KA)-induced status epilepticus (SE) model. The effects of MB on levels of oxidative stress and glutamate (Glu) also were explored. MATERIAL AND METHODS Sixty C57BL/6 mice were randomly divided into 5 equal-sized groups: (1) controls; (2) KA; (3) MB 0.5 mg/kg+KA; (4) MB 1 mg/kg+KA; and (5) vehicle+KA. The SE model was established by intra-amygdala microinjection of KA. Behavioral observations and simultaneous electroencephalographic records of the seizures in different groups were analyzed to determine the potential anticonvulsant effect of MB. The influences of MB on oxidative stress markers and glutamate were also detected to explore the possible mechanism. RESULTS MB afforded clear protection against KA-induced acute seizure, as measured by the delayed latency of onset of generalized seizures and SE, decreased percentage of SE, and increased survival rate in mice with acute epilepsy. MB markedly increased the latency to first onset of epileptiform activity and decreased the average duration of epileptiform events, as well as the percentage of time during which the epileptiform activity occurred. Administration of MB prevented KA-induced deterioration of oxidative stress markers and Glu. CONCLUSIONS MB is protective against acute seizure in SE. This beneficial effect may be at least partially related to its potent antioxidant ability and influence on Glu level.

[Screening, identification, and phosphate solubilizing characteristics of a new efficient phosphate solubilizing fungus]. / ä¸€æ ªé«˜æ•ˆè§£ç£·çœŸèŒæ–°èŒæ ªçš„ç­›é€‰é‰´å®šåŠè§£ç£·ç‰¹æ€§.

A phosphate solubilizing fungus was isolated from the rhizosphere of tomato in greenhouse in Liaozhong County, Liaoning Province, Northeast China. The strain was identified as a new strain of Penicillium oxalicum by morphological characteristics and ITS rDNA sequence comparison, and then was named PSF1. Strain PSF1 could utilize various carbon sources such as glucose, sucrose, lactose, galactose, soluble starch and nitrogen sources such as ammonium sulfate, ammonium chloride, ammonium nitrate, potassium nitrate, urea for growth and metabolism, with an efficient phosphate solubilizing capacity. It grew well and had a high ability of phosphate solubilization under the conditions of C/N 10:1-60:1 and initial pH 7-8. Strain PSF1 had strong acid production ability, with the pH of culture mediums decreasing from 7.00-7.50 to 2.06-4.87 during the culture process. The highest phosphate solubilizing capacity in four phosphorus sources mediums was tricalcium phosphate (869.62 mg·L-1) > phosphate rock power (233.56 mg·L-1) > aluminum phosphate (44.77 mg·L-1) > iron phosphate (28.42 mg·L-1). Results from Pearson correlation analysis showed that there were significant negative correlations between the changes of phosphate solubili-zing capacity and pH in tricalcium phosphate, phosphate rock power and iron phosphate mediums, but no significant correlation in aluminum phosphate medium. Strain PSF1 had strong phosphate solu-bilizing capacity and wide growing conditions, thus would have strong phosphate solubilizing capacity in soil.

[Effects of sewage sludge compost on the growth and photosynthetic characteristics of turfgrass].

The effects of different dosages (0, 0.8%, 2%, 6% and 10%) of sewage sludge compost on the growth and photosynthetic characteristics of three turfgrass, i. e., Festuca arundinacea, Lolium perenne and Poa pratensis were studied. The results showed that the dosage of 6% had the optimal effects. The plant height, leaf area and dry biomass of three turfgrass increased significantly with the increasing sewage sludge compost dosage, while the root/shoot ratio decreased obviously. Compared with the control, the plant height of F. arundinacea, L. perenne and P. pratensis increased by 64.9%-180.8%, 97.3%-200.9% and 39.1%-156.5%, the leaf area per plant increased by 91.3%-417.4%, 186.4%-394.9% and 164.6%-508.3% and the dry biomass per plant increased by 333.4%-867.6%, 138.4%-445.1% and 316.3%-669.2%, respectively. With the increasing dosage of sewage sludge compost, the net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci) and water use efficiency (WUE) of F. arundinacea increased first and decreased then, the Pn, Tr and WUE of P. pratensis showed a significantly increasing trend, while the Ci decreased after an initial increase, and the Pn and WUE of L. perenne increased gradually, while the Ci and Tr decreased after a gradual increase. With the in- creasing sewage sludge dosage, the contents of chlorophyll a and b of the three turfgrass species increased markedly, and then decreased when the dosage was more than 6%, but the ratio of chlorophyll a/b was little changed.

[Isolation identification and characterization of halotolerant petroleum-degrading bacteria].

To obtain efficient halotolerant petroleum-degrading bacteria, 39 bacteria strains were isolated from 30 petroleum contaminated saline soil samples in Yellow River Delta, an important base of petroleum production in China. One bacterium (strain BM38) was found to efficiently degrade crude oil in highly saline environments based on a series of liquid and soil incubation experiments. According to its morphology, physiochemical characteristics and 16S rDNA sequence analysis, this strain was identified as Pseudomonas putida. Moreover, a series of liquid incubation experiments were conducted to investigate its characteristics such as halotolerance, biosurfactants production and degrading efficiency for various hydrocarbons. The salt resistance test demonstrated that strain BM38 grew well at NaCl concentrations ranging from 0.5% to 6.0%. Petroleum degradation experiments showed that strain BM38 could degrade 73.5% crude oil after 7 days in a liquid culture medium containing 1.0% NaCl and remove more than 40% of total petroleum hydrocarbons after 40 days in the soil with 0.22% and 0.61% of salinity, these results proved that the strain was effective in removing petroleum hydrocarbons. Strain BM38 could produce a bioemulsifier in a liquid culture medium. The NaCl concentration had the significant effect on the EI24 of fermentation broth, which decreased sharply if the NaCl concentration was greater than 1.0%. However, the EI24 of BM38 was still quite high in the presence of 2.0% of NaCl, and the value was 61.0%. Furthermore, this strain was also able to grow in mineral liquid media amended with hexadecane, toluene, phenanthrene, isooctane and cyclohexane as the sole carbon sources. Among these hydracarbons, strain BM38 showed relatively high ability in degrading n-alkanes and aromatic hydracarbons. The results indicated that strain BM38 had potential for application in bioremediation of petroleum-contaminated saline soil.