BACKGROUND: Senility is the degenerative change of every tissue and organ in biological body,which is the result due to comprehensive actions of various pathological and physiological processes. Rhodiola is a kind of natural medical plant,acting on delaying organic senility,preventing and treating senile disorders,etc. But the definite mechanisms on those have been unknown yet.OBJECTIVE: To probe into the mechanism of rhodiola extract( nuodikang capsule) on anti-senility.DESIGN: Randomized,controlled experimental research based on the experimental animals.SETTING: Neurological internal department in a military hospital affiliated to a university of Chinese PLA.MATERIALS: The experiment was performed in Pathology Experiment Room of Fourth Military Medical University of Chinese PLA from March to August 2002. Sixty Kunming mice were randomized into normal control group,model group,3 dosage groups of 1,2,4 g/kg of nuodikang successively and Vitamin E(Vit. E) positive control group 0. 1 mg/kg,10 mice in each group.INTERVENTIONS: In the model,nuodikang groups and Vit. E positive control,physiological saline solution of D-galactose 30 g/Lwas applied in subcutaneous at the back of neck,150 mg/kg per day,continuously for 8weeks. Simultaneously,in nuodikang group and Vit. E positive control,the medicine was applied by gastric perfusion,once daily,continuously for 8weeks.MAIN OUTCOME MEASURES: Effects of nuodikang capsule on activity of lactate dehydrogenase(LDH),the content of lipidperoxides(LPO),the activity of superoxide dismutase(SOD) in the brain,the content of malondialdehyde (MDA) and ultrastructure of mitochondrion in hippocampal neurons.RESULTS: In nuodikang capsule groups of 1,2,4 g/kg,the significant differences(P ＜ 0.05) presented in LPO content in brain tissue[(30. 1±2.9),(27.8±3.1),(26.9±1.9) nmol/g] and MDA content [(110.2±13.5),(95.4±20.1),(90.2±16.5) nmol/g],1 compared with the model group[ (33.4 ± 2.2),(126.5 ± 17.2) nmol/g],indicating significant differences(P ＜ 0.05),and LDH activity[(1.74±0. 14),(1.92 ±0. 23),(2.04 ±0.21) NU/g] and SOD activity[ (119. 1 ±2.2),(121.3 ± 0.9),(126.4 ± 2.0) NU/g] were remarkably increased,compared with the model group[ (1.68 ±0. 19),(115.9 ±2. 1) NU/g],indicating significant differences( P ＜ 0.05) . It was indicated by electro-microscope that nuodikang capsule groups of 2,4 g/kg acted on obvious protection on degenerative change of mitochondrion in hippocampal neurons caused by galactose.CONCLUSION: Nuodikang capsule acts significantly on anti-senility,which is related to its anti-oxidative injury and protection on neurons.

Rat brain kinesin is a conventional kinesin that uses the energy from ATP hydrolysis to walk along the microtubule progressively. Studying how the chemical energy in ATP is utilized for mechanical movement is important to understand this moving function. The monomeric motor domain, rK354, was crystallized. An ATP analog, AMPPNP, was soaked in the active site. Comparing the complex structure of rK354 x AMPPNP and that of rK354ADP, a hypothesis is proposed that Glu237 in the Switch II region sensors the presence of gamma-phosphate and transfers the signal to the microtubule binding region.
Adenosine Triphosphate ; metabolism ; Adenylyl Imidodiphosphate ; metabolism ; Animals ; Brain ; metabolism ; Catalytic Domain ; Crystallography ; Hydrolysis ; Kinesin ; metabolism ; Microtubules ; metabolism ; Phosphates ; Protein Binding ; Rats

Kinesin is a motor protein that uses the energy from ATP hydrolysis to move along the microtubule system. To investigate how the chemical energy stored in ATP is converted to mechanical movement, the corresponding N-terminal region of rat brain kinesin was expressed in BL21-Codon Plus (DE3)-RP competent cells. After SP-cation exchange chromatography and size exclusion chromatography, the protein yield reached 10 mg/L culture with the purity above 95%. The purified protein had ATPase activity and specifically reacted with the kinesin antibody in the Western blotting analysis. The purified kinesin was crystallized under the following condition: 1.7 mol/L (NH4)2SO4, 500 mmol/L NaCl, 20% glycerol. The kinesin crystal can diffract up to 2.0 angstroms resolution.
Animals ; Brain ; enzymology ; Crystallization ; Hydrolysis ; Kinesin ; chemistry ; isolation & purification ; Rats

The effect of PubMed on the development of biomedical journals and the role of its Linkout function in extending the effect of journals were analyzed , followed by a description of the technologies and methods for the full-text seamless link of journal Websites and PubMed using its Linkout function with Biomedical and Environmental Sciences as an example .

Adolescent ; Adult ; Aged ; Blood Coagulation Disorders ; Blood Coagulation Factors ; Case-Control Studies ; Child ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Vitamin K ; Vitamin K Deficiency ; Young Adult

At present, there are many effective ways to achieve high performance in cluster system storage management, including server-end disk, server-end caching, local caching and cooperative caching. The cooperative caching mechanism shares caches among different clients so as to avoid expensive disk access costs and to improve overall throughput of cluster system. In this paper, a Single Copy Cooperative Cache model is proposed together with block lookup algorithm, block replacement algorithm and the consistency algorithm based on the model. Meanwhile, the prototype system of the model is implemented in PVFS file system. Finally, the performance of this system is tested in InfiniBand Framework, the result of which shows that in contrast to the original PVFS system, read performance of PVFS file system is improved by about two times, while write performance is reduced by nearly ten percent.

OBJECTIVETo analyze the electrical activity property changes in nucleus accumbens (NAc) of heroin-induced conditioned place preference (CPP) rats during different stages of heroin dependence and to explore NAc's roles in the formation of drug dependence.

METHODSRecording electrodes were bilaterally embedded into the NAcs of rats with the aid of stereotaxic apparatus, followed by establishment of heroin-dependent rat model. The NAc electrical activity during 3 different stages of heroin dependence, including heroin pre-exposure, immediate post-exposure and heroin withdrawal, were respectively recorded using EEG wireless telemetry techniques. The frequency distribution (ranging from 0.5 to 30 Hz) and the amplitude of NAc electrical activity were analyzed and measured.

RESULTSHeroin-dependent rat models were successfully established and their withdrawal symptoms were evident. All rats showed a conditioned place preference (CPP) for the white box after 5-10 days of heroin-exposure, and displayed a maximum withdrawal symptoms on 2d after heroin- withdrawal. During all statges of heroin-dependence, the NAc electrical activity contained the highest proportion of delta rhythm and the lowest proportion of alpha2 rhythm. The discharge frequence band was similar across different stages. There was a significantly increased ratio of low-frequency discharges (delta rhythm) and decreased ratio of high-frequency discharges (beta rhythm) in NAc of rats during the immediate post- heroin exposure stage when compared with that during pre-exposure and heroin withdrawal stages. During the withdrawal stage, the ratio of at rhythm was significantly lower than during pre- and post-heroin exposure stages (P < 0.01). Further, the mean discharge amplitude in NAcs during immediate post-exposure and withdrawal stages was significantly increased relative to pre-exposure stage. However, the mean discharge amplitude during heroin withdrawal stage was significantly lower than during immediate post-exposure stage.

CONCLUSIONThe electrical activity properties in rat NAcs showed a significant change during different stages of heroin-dependence, which suggested that neuronal activities in NAcs might contribute to the modulation of drug-dependence.

Animals ; Conditioning, Operant ; Heroin ; pharmacology ; Heroin Dependence ; physiopathology ; Male ; Nucleus Accumbens ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Telemetry

OBJECTIVETo analyse the relationship between the electrical activity changes of nucleus accumbens (NAc) shell and the drug-seeking behavior by recording NAc shell electrical activity in conditioned place preference (CPP) rats induced by morphine.

METHODSForty SD rats were randomly divided into operation-only control group and the morphine-induced CPP group after stereotaxic electrode was buried on rats NAc shell and the latter group was used to establish the morphine CPP model(n = 20). A CPP video system combining with the technique of electrical activity wireless telemetry was used in the study. The NAc electrical activity from each group of rats was recorded by wireless telemetry respectively, which included staying in black or white chamber of video box, shuttling between black-white chambers and between white-black chambers. The electrical activity differences were analyzed by the percentage of each wave.

RESULTSWhen the morphine-induced rats staying in black chamber, compared with the operation-only control group, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P < 0.05, P < 0.01); when the morphine-induced rats staying in white chamber, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz and 30 - 40 Hz were increased(P < 0.05 , P < 0.01) , that of 10 - 20 Hz was reduced(P < 0.05 , P < 0. 01); when the morphine-induced rats in black- white shuttling status, the NAc shell electrical activity showed that the percentage of 0 - 10 Hz was increased(P <0.05, P <0.01), that of 10- 30 Hz was reduced( P <0.05); and in the white-black shuttling status, the electrical activity showed that the percentage of 0 - 10 Hz was reduced(P <0.05), that of 10 - 30 Hz was increased(P < 0.05) ; the electrical activity was further compared between staying status and shuttling status in the morphine-induced CPP group. There was no significant difference of electrical activity between the rats in white-black shuttling status and staying in white chamber. However, when rats in black-white shuttling status, compared with staying in black chamber, the electrical activity showed that the percentage of 0 - 10 Hz and 40 - 50 Hz were increased(P < 0.05), meanwhile, those of 10 - 20 Hz and 30 - 40 Hz were reduced(P <0.05).

CONCLUSIONThe electrical activity changes of NAc shell in morphine-induced CPP rats were different from those of the operation-only control group, and these changes might be associated to the rat's drug-seeking behavior.

Animals ; Conditioning (Psychology) ; Drug-Seeking Behavior ; Morphine ; pharmacology ; Nucleus Accumbens ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Telemetry

OBJECTIVETo study the correlation between EEG characteristics of medial prefrontal cortex (mPFC) and drug-seeking behavior of rats with morphine dependent place preference under shuttling condition.

METHODSForty rats were randomly divided into four groups (n = 10): morphine PL group, NS PL group, morphine IL group and NS IL group. After embeding the electrode in prelimbic (PL) or infralimbic (IL) cortex of each group by brain stereotaxic operation, the model of morphine dependent conditioned place preference (CPP) in rats was established. The differences of EEG wave percentage in mPFC were telemetered and analyzed when rats shuttled before and after the model.

RESULTSAfter the model, the withdrawal symptoms were evident in morphine PL and IL group, and the activity time and distance in white box were increased obviously. Compared with control group, after the model, the EEG in morphine PL group showed that: when the rats shuttled to white box, 8 wave decreased obviously, P wave increased obviously. When the rats shuttled to black box, brain waves showed opposite changes. The EEG in morphine IL group showed that: when the rats shuttled to white box, a wave increased obviously, P and a wave decreased obviously. When the rats shuttled to black box, the brain wave had no significant differences compared with control group.

CONCLUSIONThe EEG changes are different in PL and IL cortex of morphine CPP rats under shuttling condition, and the EEG changes are also different when rats shuttling to white or black box. There is possibly different mechanism, when different drug-seeking environmental cues caused EEG changes in different regions of mPFC.

Animals ; Conditioning (Psychology) ; Cues ; Drug-Seeking Behavior ; Electroencephalography ; Morphine Dependence ; physiopathology ; Prefrontal Cortex ; physiopathology ; Rats ; Telemetry