Levetiracetam Protects Against Cognitive Impairment of Subthreshold Convulsant Discharge Model Rats by Activating Protein Kinase C (PKC)-Growth-Associated Protein 43 (GAP-43)-Calmodulin-Dependent Protein Kinase (CaMK) Signal Transduction Pathway.

BACKGROUND Subclinical epileptiform discharges (SEDs) are defined as epileptiform electroencephalographic (EEG) discharges without clinical signs of seizure in patients. The subthreshold convulsant discharge (SCD) is a frequently used model for SEDs. This study aimed to investigate the effect of levetiracetam (LEV), an anti-convulsant drug, on cognitive impairment of SCD model rats and to assess the associated mechanisms. MATERIAL AND METHODS A SCD rat model was established. Rats were divided into an SCD group, an SCD+ sodium valproate (VPA) group, and an SCD+ levetiracetam (LEV) group. The Morris water maze was used to evaluate the capacity of positioning navigation and space exploration. The field excitatory post-synaptic potentials (fEPSPs) were evaluated using a bipolar stimulation electrode. NCAM, GAP43, PS95, and CaMK II levels were detected using Western blot and RT-PCR, respectively. PKC activity was examined by a non-radioactive method. RESULTS LEV shortens the latency of platform seeking in SCD rats in positioning navigation. fEPSP slopes were significantly lower in the SCD group, and LEV treatment significantly enhanced the fEPSP slopes compared to the SCD group (P<0.05). The NCAM and GAP-43 levels were increased and PSD-95 levels were increased in SCD rats (P<0.05), which were improved by LEV treatment. The PKC activity and CaMK II levels were decreased in SCD rats and LEV treatment significantly enhanced PKC activity and increased CaMK II levels. CONCLUSIONS Cognitive impairment in of SCD model rats may be caused by decreased PKC activity, low expression of CaMK II, and inhibition of LTP formation. LEV can improve cognitive function by activating the PKC-GAP-43-CaMK signal transduction pathway.

[Suicide ideation among college students in Chongqing.].

OBJECTIVE: To describe the prevalence and risk factors for suicide ideation among college students in Chongqing city. METHODS: Data on suicide ideation and related factors were collected from 9808 college students at 11 colleges randomly selected in Chongqing. A multiple logistic regression model was used to identify risk factors for suicide ideation. RESULTS: 1279 (13.0%) of the 9808 students reported suicide ideation and the constituent ratio of boys and girls was 3:4 while risk factors for suicide ideation were ranked as follows: high frequency of feeling hopeless in prior year (OR = 5.07, 95%CI: 4.27 - 6.02); having psychological problems in recent 1 month that affecting daily lives and learning (2.07, 1.79 - 2.38); relatives having suicide behavior (1.77, 1.52 - 2.08); having had sexual experience (1.95, 1.65 - 2.30); being female (1.66, 1.45 - 1.90) and friends who had had suicide attempts (1.46, 1.28 - 1.67); having diseases in the last 1 month that affecting daily lives and learning (1.29, 1.08 - 1.52). CONCLUSION: The prevalence of suicide ideation among these college students was high that calls the development, implementation and assessment of suicide prevention plans for college students that focusing on the risk factors identified for suicide ideation.

Impact of drying and composting procedures on the concentrations of 4-nonylphenols, di-(2-ethylhexyl)phthalate and polychlorinated biphenyls in anaerobically digested sewage sludge.

Enhanced treatments of sewage sludge produce a more manageable product for agricultural use by stabilizing the material, removing water, and reducing the possibility of pathogen transfer. We investigated the impact of pilot-scale composting and drying of sludge on physicochemical characteristics and on the concentrations of some organic contaminants. During the 143 day composting procedure, organic matter fell 22% and moisture by half. Concentrations of 4-nonylphenols (4-NPs) fell by 88% and di-(2-ethylhexyl) phthalate (DEHP) by 60%; losses continued throughout the procedure. Losses of total polychlorinated biphenyls (PCBs) were 11%, mostly from the lower molecular weight congeners, suggesting volatilization as the most likely loss mechanism. The drying process was much shorter, 40 days, yet organic matter content decreased by 27% and moisture by 85%. Losses of 4-NPs (39%) and DEHP (22%) were less than in composting and stopped when moisture content became constant. There were no losses of PCBs. Both treatments are simple, practical procedures that reduce the volume of waste and are applicable in situ on farms. Composting would be the method of choice for reducing organic contaminants but requires much longer times than drying.

Analysis of 4-nonylphenols, phthalates, and polychlorinated biphenyls in soils and biosolids.

When sewage sludge is added to agricultural land, organic chemicals contaminants are also added. The fate of these chemicals, particularly those shown to have oestrogenic potential, has received much research and regulatory interest in recent years. A method was developed for the analysis of 4-nonylphenols, phthalates, and PCB congeners in soils, mesophilic anaerobially digested dewatered (MADD) sewage sludge, and MADD sludge-amended soil. After Soxhlet-extraction, the 4-nonylphenols and phthalates were separated from the PCBs on an isolute cyanopropyl SPE cartridge and analysed by GC-MS directly. The PCBs were acid treated on a Bakerbond PCB-A cartridge, then passed through a gel filtration column of Biobeads SX-3 resin, before GC-MS analysis. The method was successfully validated and then used for routine analysis, where average recoveries of the surrogate standards were 83+/-17% (4-n-heptylphenol), 96+/-11% (dimethyl-tere-phthalate), 101+/-12% (dibenzyl-phthalate), and 79+/-13% (PCBs 6, 54, 104, 155, and 198).