Mechanism of glaucocalyxin A that induces apoptosis of glioma cell and up-regulates GEF-H1 / 药学学报

Rabdosia japonica(Burm.f.) Hara var.glaucocalyx(Maxim.) Hara is a traditional Chinese medicine, and is known to have anti-tumor effects. This study aims to investigate the effect of glaucocalyxin A (GLA), a diterpenoids extracted from Glaucocalyx Hara, on apoptosis of glioma cells and its mechanism. This study investigated the molecular signaling mechanism of GLA-induced glioma cell apoptosis by analyzing survival rate of C6 rat glioma cells, cell morphology, colony formation ability, interference ribonucleic acid, polymerase chain reaction, and Western blot. The result showed that in the presentce of GLA, the survival rate of C6 rat glioma cells decreased significantly, while the expression of guanine nucleotide-exchange factor-H1 was up-regulated, causing phosphorylation of extracellular regulated protein kinases proteins and apoptosis. Hence, the mechanism of GLA-induced glioma cell apoptosis was the GEF-H1/ERK pathway.

Effects of ketamine and alcohol on learning and memory impairment in mice / 法医学杂志

OBJECTIVE@#To study the effects of ketamine and alcohol on learning and memory in mice and its possible mechanism.@*METHODS@#Forty mice were divided into 4 groups: normal control group, ketamine group, alcohol group, and alcohol plus ketamine group. Ketamine and alcohol were given by intraperitoneal injection and intragastric administration, respectively, 1 time per day, for 14 days. The ability of learning and memory in mice was tested by the method of step-down and Morris water maze. Acetylcholine (ACh) and 5-hydroxy tryptamine(5-HT) in mice brain tissue were analyzed for the possible mechanism.@*RESULTS@#(1) Step-down: The treatment groups lessened the latency and added wrong times (P < 0.05). The number of errors in the combined treatment group significantly increased comparing with the single drug treatment group (P < 0.05). (2) Morris water-maze: The treatment groups prolonged the latency (P < 0.05), reduced the target quadrant activity time significantly (P < 0.05), and decreased the numbers of crossing the former platform significantly (P < 0.05). (3) Biochemical index determination: The concentrations of ACh and 5-HT in treatment groups decreased significantly (P < 0.05), showed a more decreasement comparing with the single drug treatment group.@*CONCLUSION@#Ketamine has a synergistic effect with alcohol on learning and memory impairment in mice, which may be related to the common inhibitive effect on the ACh and 5-HT.

Effects of ketamine on proliferation and apoptosis of pheochromocytoma cell / 法医学杂志

OBJECTIVE@#To explore the effect of ketamine on adrenal pheochromocytoma (PC12) cell proliferation inhibition and induction of apoptosis and its mechanism.@*METHODS@#PC12 cells of rats were models for dopaminergic neuron. PC12 cells were cultured with ketamine at concentrations of 0.9, 1.2, 1.5, 1.8 and 2.1 mmol/L, respectively. The cell viability was measured by MTT method after incubation at 12, 24, 48 and 72h. Hoechst stain was used to observe the morphological changes of apoptosis. PC12 cells cultured after 48 h with different concentrations of ketamine were selected to detect apoptotic rate using flow cytometry and detect the expression of bax and bcl-2 proteins using Western blotting.@*RESULTS@#For different concentrations of ketamine, vitality of PC12 cells significantly decreased with increase of the incubation time. Apoptosis was obviously observed using Hoechst staining. Flow cytometry showed that apoptosis rates significantly increased with increasing ketamine concentrations.@*CONCLUSION@#Ketamine can inhibit the proliferation of PC12 cell by inducing apoptosis of the PC12 cell in a concentrations-dependent manner. The underlying mechanism may be related to promoting the expression of bax and inhibiting the expression of bcl-2 in the cells.

Receptor antagonist of NMDA and animal models of schizophrenia / 法医学杂志

Schizophrenia is one of the common mental diseases. Because the mechanism of the schizophrenia is significantly complicated, the cause is still unknown. N-methyl-D-aspartate receptor antagonist can simulate the positive and negative symptoms, as well as the cognitive disorder of schizophrenia. Thus it has been widely used to establish the animal models of schizophrenia. The relationship of the three blocking agents of ion channels (phencyclidine, MK-801, ketamine) and the establishment of schizophrenia animal models is reviewed in this article.

The correlation between ketamine-induced schizophrenia-like signs in mice and the expressions of NRG1, ErbB4 mRNA / 法医学杂志

OBJECTIVE@#To explore the correlation between signs similar to schizophrenia in mice after ketamine administration and the expressions of NRG1 and ErbB4 mRNA in order to explain the possible pathogenesis of schizophrenia.@*METHODS@#Fifty KM mice were randomly divided into 5 groups which were administered intraperitoneally with saline, clozapine and different dosages ketamine. The ketamine groups were administered intraperitoneally with low dosage (25 mg/kg), middle dosage (50 mg/kg) and high dosage (100 mg/kg) one time every day for 7 days. After administration of 100 mg/kg ketamine for 7 days, the clozapine group was introgastrically administered 20 mg/kg with clozapine one time every day for 7 days. The pathological changes of hippocampus neurons were observed by HE stain. The expressions of the NRG1 and ErbB4 mRNA in hippocampus were detected by reverse transcriptase polymerase chain reaction (RT-PCR).@*RESULTS@#In the group with high dosage of ketamine, the levels of NRG1 and ErbB4 mRNA were significantly lower than that of the group with saline.@*CONCLUSION@#Ketamine may induce signs similar to schizophrenia in KM mice. The mechanism may be involved in the reduction of NRG1 and ErbB4 mRNA expression.

Advances in research of ketamine addiction mechanism / 法医学杂志

Ketamine is a phencyclidine derivative acting primarily as a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) excitatory glutamate receptors. As a common intravenous anaesthetic in clinic, it is also increasingly abused because of its hallucination and addiction effects. Based on the pharmacological and toxicologic characteristics of ketamine and the acknowledged addiction mechanism of other abused drugs, this article reviews the possible addiction mechanism of the ketamine in the aspects of its enhanced effects and reward systems, the anatomic structures, the related receptors and the individual differences.

Behavior study of ketamine-induced symptoms similar to schizophrenia in mice / 法医学杂志

OBJECTIVE@#To observe the symptoms similar to schizophrenia in mice after ketamine single or continuous injection and to evaluate the feasibility of schizophrenia model injected with different dose of ketamine.@*METHODS@#A total of 40 male mice were randomly divided into 4 groups, which were injected intraperitoneally with physiological saline (control group), 25 mg/kg ketamine (low dose group), 50 mg/kg ketamine (middle dose group), and 100 mg/kg ketamine (high dose group) qd for 7 days continuously. The behavior changes of mice were observed.@*RESULTS@#Hyperactivity, stereotyped behavior and ataxia (P < 0.01) were observed in high dose group after single injection. After continuous injection of ketamine for 7 days, the middle dose group showed hyperactivity, stereotyped behavior and ataxia (P < 0.05), stereotyped behavior and ataxia were more significant in high dose group (P < 0.01).@*CONCLUSION@#Ketamine can induce the symptoms similar to schizophrenia in mice after single or continuous injection. The symptoms induced by high dose ketamine will be more prominent and stable after continuous injection.

Application of correlation techniques in the analysis of corpus cavernosum electromyographic signals / 亚洲男科学杂志(英文版)

<p><b>AIM</b>To establish an objective, easy-to-use and comprehensive method to analyze corpus cavernosum electromyographic signals (CC-potentials).</p><p><b>METHODS</b>CC-potentials were recorded during flaccidity in 23 young healthy volunteers, with surface electrodes placed on the penile shaft bilaterally. Based on the correlation function of Matlab software, an application program for the analysis of CC-potentials was developed. Individual CC-potentials and their autocorrelation function were evaluated, yielding parameters amplitude (A), duration (D), and dominant frequency (DF). The cross-correlation function of both longitudinal and bilateral pairs of adjacent electrodes was calculated to assess the similarity and mutual delay of CC-potentials recorded simultaneously from different parts of the CC. The parameters derived were squared maximum cross-correlation coefficient (Rmax) and delay (tau). Based on the absolute value of tau and the corresponding inter-electrode distance, propagation velocity (PV) was calculated.</p><p><b>RESULTS</b>The values of the parameters were determined automatically. No significant difference related to the locations of the electrodes for parameters A, D, and DF was detected. The cross-correlation showed that both longitudinal and bilateral CC-potential pairs had highly similar waveforms (the absolute values of Rmax were 0.80 +/- 0.05 and 0.87 +/- 0.06, respectively). PV of longitudinal pairs was estimated as 6.15 +/- 3.98 cm/s.</p><p><b>CONCLUSION</b>The application program for correlation analysis of CC-potentials is a comprehensive and versatile method to analyze corpus cavernosum electromyographic recordings. Its objectiveness makes multi-center application possible.</p>