[The effects of vagus nerve stimulation on hippocampal neuro-inflammatory and α7nAChR expression in rats with intractable epilepsy].

Objective: To investigate the effects of vagus nerve stimulation(VNS) on hippocampal neuro-inflammatory and α7 nicotinic acetylcholine receptor (α7nAChR) expression in rats with intractable epilepsy (IE). Methods: Eighty adult male SD rats (SPF) were randomly divided into control group, model group, VNS group and MLA+VNS group. There were respectively 20 rats in the control group and MLA+VNS group, and because of model failure and animal death, 15 rats and 14 rats in the model group and VNS group were left respectively . Except the control group, the IE model was established in other groups. Only the vagus nerve was isolated in the control group without electrical stimulation; the model group did not take any intervention measures; the VNS group was treated for 4 weeks with VNS after the model was successful; the MLA(3.4 µg/µl, 5 µl) was given to the lateral ventricle in the MLA+VNS group, and then VNS for 4 weeks. Seizure frequency and duration in each group were observed and recorded. And then the rats were decapitated, the hippocampus were quickly separated and 10% tissue homogenate was prepared. The homogenate was centrifuged and the supernatant was extracted. The activities of AChE and ChAT in the supernatant were measured by spectrophotometry, and the levels of TNF-ɑ, IL-6 and IL-1ß were detected by ELISA. The expression of α7nAChR in rat hippocampals was detected by Western blot. The expression of α7nAChR on microglias in rat hippocampals was assesed by double-labeled immunofluorescence. Results: ①After VNS for 4 weeks, the frequency and duration of seizures in rats were decreased significantly, which were lower than those of the model group (P<0.01); After treated with MLA +VNS, the frequency and duration of seizures in rats were also reduced significantly, which were lower than those of the model group, but higher than those of the VNS group (P<0.01).②Compared with the control group, the expression of ChAT in the hippocampus of rats in the model group was decreased significantly and the expression of AChE was increased significantly (P<0.01); Compared with the model group, the expressions of ChAT in the hippocampus of rats in the VNS group and MLA+VNS group were increased significantly and the expressions of AChE were decreased significantly (P<0.01); Compared with the VNS group, in the hippocampus of rats in the MLA+VNS group, the expressions of ChAT and AChE had no significant changes (P>0.05). ③Compared with the control group, the expressions of TNF-ɑ, IL-6 and IL-1ß in the hippocampus of rats in the model group were increased significantly (P<0.01). Compared with the model group, the expressions of TNF-ɑ, IL-6 and IL-1ß in the hippocampus of rats in the VNS group were decreased significantly (P<0.01). Compared with the VNS group, the expressions of TNF-ɑ, IL-6 and IL-1ß in the hippocampus of rats in the MLA+VNS group were increased significantly(P<0.01). ④Compared with the control group, the expression of α7nAChR in hippocampus and microglia of rats in the model group was decreased significantly(P<0.01); Compared with the model group, the expression of α7nAChR in hippocampus and microglia of rats in the VNS group was up-regulated significantly (P<0.01); Compared with the VNS group, coexpression of α7nAChR on microglia wasreduced significantly in the MLA+VNS group (P<0.01). Conclusion: VNS has obvious therapeutic effect on IE rats, and its mechanism may be related to activating hippocampal microglia cholinergic anti-inflammatory pathway directly and inhibiting hippocampal neuro-inflammatory response.

[Expression Level of SOCS3 in Acute Lymphoblastic Leukemia Cells Affects the Cytotoxicity of NK Cells].

OBJECTIVE: To detect the expression level of suppressors of cytokine signaling 3 （SOCS3） in acute lymphoblastic leukemia (ALL), and to observe the effect of over-expresson of SOCS3 in Jurkat cells on the cytotoxicity of NK cells. METHODS: The expression levels of SOCS3 mRNA in peripheral blood mononuclear cells of 20 children with ALL and 20 healthy children (normal control group) were detected by RT-PCR. The peripheral blood NK cells from healthy subjects were selected by immunomagnetic technique, and the purity was detected by flow cytometry. SOCS3 was overexpressed in Jurkat cells infected with lentivirus vector, and SOCS3 mRNA expression was detected by RT-PCR after lentivirus infection. The NK cells were co-cultured with the infected Jurkat, and LDH release method was used to detect the cytotoxicity of NK cells on the infected Jurkat cells. The concentrations of TNF-α and IFN-γ were determined by ELISA. The expression of NKG2D ligands MICA and MICB on the surface of Jurkat cells were detected by flow cytometry. Western blot was used to detect the effect of SOCS3 overexpression on STAT3 phosphorylation in Jurkat cells. RESULTS: Compared with the control group, the mRNA expression of SOCS3 in the peripheral blood mononucleated cells of ALL children was significantly decreased. The purity of NK cells isolated by flow cytometry could reach more than 70%. The expression of SOCS3 mRNA in Jurkat cells increased significantly after lentivirus infection. Overexpression of SOCS3 in Jurkat cells significantly promoted the killing ability of NK cells and up-regulated the secretion of TNF-α and IFN-γ from NK cells. The results of flow cytometry showed that the expression of NKG2D ligands MICA and MICB on Jurkat cells increased significantly after SOCS3 overexpression. Western blot results showed that overexpression of SOCS3 significantly reduced the phosphorylation level of STAT3 protein in Jurkat cells. CONCLUSION: SOCS3 mRNA expression was significantly decreased in ALL patients, and overexpression of SOCS3 may up-regulate the expression of MICA and MICB of NKG2D ligands on Jurkat cell surface through negative regulation of JAK/STAT signaling pathway, thereby promoting the cytotoxic function of NK cells.

[Characteristics of Stable Isotopes and Analysis of Water Vapor Sources of Precipitation at the Northern Slope of the Qilian Mountains].

This study is based on precipitation samples from eight sites at the northern slope of the Qilian Mountains, combined with meteorological factors over the same period. Precipitation isotope characteristics, influence factors and the vapor sources of precipitation were analyzed, and the results show that:① The stable isotopes of precipitation in the study area show obvious seasonal changes, which are characterized by enrichment in the summer half-year and depletion in the winter half-year. The spatial precipitation δ18O value shows a significant downward trend with increasing altitude, and the altitude effect of the annual precipitation δ18O is -0.19‰/100 m, respectively;② At all stations, the slope and intercept of local meteoric water lines show an increasing trend from low altitude to high altitude. The high-altitude mountains above 2000 m are affected by local water vapor recirculation;③ The temperature effect is more significant and the temperature effect of δ18O is 0.64‰, and there is only a weak precipitation effect in summer;④ The results indicate that sub-cloud evaporation has a great influence on the δ18O of precipitation; the average raindrop evaporation rate of δ18O is 23%, 11%, 12%, and 16%,and the δ18O composition has been enriched by 46%, 27%, 38%, and 32% in May, June, July, and August from cloud base to ground, respectively.⑤ Under the condition of continuous rainfall in summer, the vapor sources of precipitation mainly come from the west and are affected by local evaporation of water vapor. The study enhances knowledge of isotopic evolution of precipitation and provides a basis for further study of isotopic hydrology in arid regions.

[Space-Time Characteristics and Environmental Significance of the Stable Isotopes in Precipitation in the Gulang River Basin].

Based on the precipitation samples and meteorological data simultaneously collected during individual precipitation events at the Gulang (2085 m a.s.l.) and Anyuan stations (2700 m a.s.l.) in Gulang, this article analyzes the temporal variation and local meteroic water lines and discusses the relationship between precipitation stable isotopes and temperature and precipitation and relative humidity. The results show that:① Gulang and Anyuan have higher δ18O values in summer and autumn and lower δ18O values in spring and winter, respectively; ② The vaule of δ18O decreases with increasing altitude, while the value of the d-excess increases, reflecting the gradual depletion of stable isotopes of precipitation when the air mass is rising along the slope; ③ The slope and intercept of the local meteroic water lines deviate from that of the global meteroic water lines, showing that they may also be affected by local water vapor recirculation, except for the dry environment and strong evaporation effect; and ④ The temperature effect of Gulang in the low-altitude area is more significant than that of the Anyuan station and the Gulang River Basin does not show a precipitation effect. It has been proven that precipitation is not the fundamental factor determining the δ18O of the precipitation in arid areas. The results of this study are helpful to further understand the water circulation mechanism in the Gulang River Basin.

[Environmental Significance of the Stable Isotopes in Precipitation at Different Altitudes in the Tuolai River Basin].

Precipitation samples and meteorological data were collected simultaneously during individual precipitation events at Tuole station (3367 m a.s.l.) and Jiayuguan station (1658 m a.s.l.) in the Tuolai River Basin. A study of temporal variation, Local Meteoric Water Lines, and altitude change on precipitation stable isotopes was conducted. The relationships between precipitation stable isotopes and temperature, precipitation, average vapor pressure, and relative humidity were determined in order to explore the environmental significance of the stable isotopes at different altitudes in the middle reaches of the Qilian Mountains. The analysis indicated that the stable isotopes of the precipitation in Tuole and Jiayuguan station were characterized by pronounced seasonal variation, with Tuole having higher δ18O values in summer and autumn and lower δ18O values in spring and winter, while Jiayuguan displays higher δ18O values in spring and lower in other seasons. The d-excess was correlated negatively with δ18O, and the correlation coefficients between δ18O and d-excess decreased with increasing altitude due to weakening sub-cloud evaporation. The slope and intercept of the Local Meteoric Water Lines from Jiayuguan to Tuole rose significantly, showing an increasing trend from low altitude to high altitude. For the precipitation events above 10℃, δ18O of Tuole was positively correlated with the temperature, but the Jiayuguan results indicated the opposite. Sub-cloud evaporation weakened with high precipitation events in Jiayuguan. δ18O and d-excess were positively correlated with the average vapor pressure, which declined from Tuole to Jiayuguan. Since the water vapor pressure and saturated water vapor pressure increased, it was difficult to form precipitation with decreasing altitude. The local strong sub-cloud evaporation caused δ18O and δD was positive at low altitude, while the effect of moisture recycling is obvious, such that δ18O and δD are negative in high altitude areas. There is no significant positive correlation between the δ18O and the relative humidity of the precipitation in Jiayuguan, while Tuole displays an opposite pattern. The results of the study will provide a scientific basis for further study of precipitation isotopes in the Tuolai River basin.