Activation of the Akt/mTOR signaling pathway: A potential response to long-term neuronal loss in the hippocampus after sepsis.

Survivors of sepsis may suffer chronic cognitive impairment as a long-term sequela. However, the precise mechanisms of cognitive dysfunction after sepsis are not well understood. We employed the cecal ligation-and-puncture-induced septic mouse model. We observed elevated phosphorylation of Akt, mammalian target of rapamycin (mTOR) and p70S6K on days 14 and 60, progressive neuronal loss in the cornu ammonis 1 region, and abnormal neuronal morphology in the hippocampus in the sepsis mouse model. These findings indicate that changes in neuronal morphology and number in the hippocampus after sepsis were associated with strong activation of the Akt/mTOR signaling pathway, and may reflect a "self-rescuing" feedback response to neuronal loss after sepsis.

Etiologic features of newly diagnosed epilepsy: hospital-based study of 892 consecutive patients in West China.

PURPOSE: We evaluated data from a large cohort of newly diagnosed epilepsy patients from the biggest epilepsy center in West China. The aim was to determine the most prevalent etiologic factors in this region. METHODS: From May 2008 to May 2010, the clinical data of patients with newly diagnosed epilepsy were consecutively, systematically and prospectively recorded in a database. The data were analyzed according to sex, age, seizure type, etiology, and other factors. RESULTS: The present study examined 892 patients with newly diagnosed epilepsy. Among these patients, 346 (38.8%) were confirmed as symptomatic, with the largest constituent ratio among the elderly (63.2%). In this symptomatic group, central nervous system (CNS) infections and traumatic brain injuries (TBI) were the two most common etiologies. When analyzed according to age bracket, cortical dysplasia, mesial temporal sclerosis, and CNS infection were the most frequent causes among young patients (<18 years). On the other hand, CNS infection and TBI were the two most common causes in patients between 18 and 60 years. Stroke was the most common cause of newly diagnosed symptomatic epilepsy in the elderly (>60 years). CONCLUSIONS: More than 30% of newly diagnosed epilepsy cases were shown to be symptomatic by medical history as well as careful clinical and laboratory examination. Detailed epilepsy assessments are essential to formulate a therapeutic plan and to improve prognosis. The etiology spectrum found in this large cohort forms a comparative baseline for future studies.

Evaluation of the efficiency of inpatient 24-hour VEEG combined with MRI in consecutive patients with newly diagnosed epilepsies.

A total of 128 patients were recruited into this study to evaluate the cost efficiency of 24-hour video electroencephalography (VEEG) combined with magnetic resonance imaging (MRI) in people with newly diagnosed epilepsies. The rate of neuroimaging abnormalities detected was 14.8% higher with MRI than with computed tomography (CT), whereas 25.7% more EEG abnormalities were detected with inpatient 24-hour VEEG than with outpatient EEG. In the partial seizure (PS) group, MRI combined with 24-hour VEEG revealed that 20 of 73 (27.4%) patients had local epileptogenic lesions, whereas CT with outpatient EEG revealed a rate of 10 in 73 (13.7%). With respect to the economic impact, 27.3% of the patients spent more than 17.8% of their annual household income for 24-hour VEEG and MRI. However, 82.7% of the patients spent less than that, and among these patients, only 16.4% spent less than 5.9% of their annual household income. Hence, we conclude that the combination of MRI and 24-hour VEEG as a compulsory tool should be popularized in less developed countries.

Features of the K-complex waves in refractory nocturnal frontal lobe epilepsy.

PURPOSE: To investigate the features of the K-complex (Kc) in refractory nocturnal frontal lobe epilepsy (NFLE) and its relationship with spike discharges (Sds) and clinical seizures. METHODS: Long-term video-electroencephalographic (VEEG) monitoring was used to collect Kc data from NFLE patients and age- and sex-matched controls. We compared the morphological and frequency changes in Kcs between the intractable NFLE group and the control group. Also, the morphological changes in Kcs with Sds and seizures were compared with the other Kcs in NFLE patients. RESULTS: In the NFLE group, frequency, amplitude, and rising slope (except duration) were higher than in the control group. Out of the 30 seizures recorded, nine (30%) commenced after a Kc. These Kcs had higher amplitudes than the other Kcs in the NFLE group; there was no difference in duration or rising slope. Additionally, 28 (13.86%) of 202 Kcs of the NFLE group occurred in conjunction with Sds; there were no obvious morphological differences compared with other Kcs. CONCLUSION: Kc activity increases in NFLE, especially prior to a clinical seizure. This reflects an unstable sleep condition, which suggests a correlation between Kc and epileptic activities including seizures and Sds.

[Separation, culture and purification of rat brain microendothelial cell].

OBJECTIVE: To develop a separation method for brain microendothelial cells with the comparison of other ones. METHODS: Twice enzymatic digestion and twice gradient centrifugation were applied to separate rat brain microendothelial cells. Then, immunomagnetic beads and Thy1.1 antibody were used respectively to purify the cultured cells. RESULTS: Twice enzymatic digestion and twice gradient centrifugation could separate the cell successfully. High purification but low cell yield was obtained with immunomagnetic beads. The cells handled with Thy1.1 antibody had both higher purify coefficient and higher yield. CONCLUSION: The developed method could separate the brain microendothelial cells successfully.

Suppression of the multidrug transporter P-glycoprotein using RNA interference in cultured rat astrocytes induced by coriaria lactone.

The overexpression of the multidrug resistance gene (MDR-1) and its translational product p-glycoprotein (P-gp) may play an important role in pharmacoresistant epilepsy. We established the rat astrocyte model overexpressing P-gp induced by coriaria lactone and successfully nucleofected it with the siRNA-hairpin expression vector pSIREN-shuttle designed to target MDR-1B mRNA. The mRNA expression of MDR-1B gene was mostly knock down by 67.70% (p<0.01). The expression of P-gp in experimental group was significantly lower than that in negative control (p<0.05), and the rhodamine efflux ratio of experimental group (23.08%) was remarkably lower than that of negative control (78.35%, p<0.01). We first employed RNA interfering to the drug resistance reversal of refractory epilepsy and this may provide a new way for refractory epilepsy remedy.

[Construction of recombinant adenovirus vector for RNA interference with multidrug resistance MDR1 gene].

OBJECTIVE: To construct the recombinant adenoviral RNA interference (RNAi) vector in order to inhibit the expression of multidrug resistance MDR1 gene, and probe whether gene therapy for multidrug resistance of epilepsy is feasibility. METHODS: Three target sequences for short hairpin RNA (shRNA) expression were selected and designed according to MDR1 gene sequence of rat. Annealed oligos were inserted into the downstream of treated pSIREN-shuttle U6 promoter to construct RNAi plasmid pSIREN-shuttle-MDR1. Next, MDR1 shRNA sequence was cloned to pAdeno-X, a transfer vector of adenovirus, to produce the pAdeno-MDR1, which was then packed and amplified in HEK293 cells. Further the recombinant adenovirus was purified by CsCl and used to infect the rat astrocytes with P170-glucoprotein (P-gp) over-expression which have been induced by coriaria lactone (CL). RESULTS: It was confirmed by restriction digestion, PCR and sequencing that MDR1 shRNA expression structure was correctly cloned to pSIREN-shuttle and pAdeno-X vector respectively. Virus titer was 6 x 10(9) pfu/mL. The interference efficiency of pAdeno-MDR1 to the expression drop of multidrug resistance gene in astrocyte model neared to 100%. CONCLUSION: RNAi adenovirus vector of rat MDR1 gene has been constructed and found its high interference efficiency. It is the essential building required for the remedy of refractory epilepsy and the research on mechanism of multidrug resistance.

[Effectiveness of urokinase used in combination with batroxobin (DF-521) in rat model of focal cerebral ischemia-reperfusion].

OBJECTIVE: This study was designed to use urokinase (UK) in combination with batroxobin in thrombolytic therapy so as to see whether batroxobin(DF-521) would be effective for neuroprotection. METHODS: The model of right middle cerebral artery occlusion (MCAO) in male SD rats was established. 120 rats were randomized into 9 groups, namely control group, sham control group, and groups that were treated with batroxobin and urokinase together or separately. Each group comprised 15 rats. Intracranial bleeding, infarct volume ratio and neurological function were observed. RESULTS: Intracranial bleeding was found in 5 rats of the UK 5000 U/kg group, in 4 rats of the UK 5000 U/kg (2 h) + DF-521 5 BU/kg (2 h) group, and in only 1 rat of the UK 5000 U/kg (2 h) + DF-521 5 BU/kg (1 h) group. Cerebral infarct volume ratio was obviously reduced in 5 BU/kg batroxobin group. No difference was observed in neurological deficit scores. CONCLUSION: 5000 U/kg urokinase increased the risk of intracranial hemorrhage in rat MCAO model. Batroxobin either used separately or in combination with urokinase would not increase the risk of intracranial hemorrhage in rat MCAO model.