OBJECTIVE: A series of recent studies have demonstrated the mechanism of migration and nerve net of neural stem cells. These theories have further substantiated neural stem cell transplantation. In view of these new findings, this paper reviewed the mode of migration and information of network. The significance of these theories was discussed.DATA SOURCE: We search on Pubmed with the key words "neural stem cell", "migration", and "nerve net", limiting the language to English and publication date from 1970 to 2004. At the same time we searched on CNKI.STUDY SELECTION: We selected the randomized and non-randomized controlled studies related to migration and nerve net building of neural stem cells. Review articles and articles with repetitive studies were excluded.DATA EXTRACTION: Among 39 papers selected, 16 papers concerning the development of this topic were selected, and the others were excluded.DATA SYNTHESIS: For retrograde lesions and severe injury of nervous system, transplantation of nerve stem cells may replace aging degenerative and dead nerve cells and rebuild neural network for the recovery of cerebral function. Migration of nerve cell and network principle can solve the survival, differentiation, migration and creation of nerve network after transplantation of nerve stem cells so as to realize the recovery and reconstruction of cerebral function.CONCLUSION: Neural stem cells can migrate to intended places and can build nerve net under some conditions, which will be useful for medicine deyelopment.

To explore the role and changes of dopamine receptor activity and their subtypes during the onset process of Parkinson disease( PD ), on the basis of 6 hydroxydopamine lesioned PD rat model, radioligand binding assay (RLBA) and Scanchard drawing were used to measure the maximal binding capacity of receptor (Bmax) and equilibrium dissociation constant (KD) of D 1 and D 2 dopamine receptors in caudal putamen of the model and control rats at different time point. The results of RLBA study revealed D 2 dopamine receptor Bmax was significantly increased and KD was significantly decreased in the caudal putamen ipsilateral to the lesion in rat model, and the changes reached the peak in one month rat model group. In contrast, the caudal putamen D 1 receptors were far less affected, with no consistent changes in the same model groups as compared with the control, except that 2 weeks model group showed Bmax was slightly decreased while KD was slightly increased. The study confirms that D 2 dopamine receptor is upregulated in the caudal putamen ipsilateral to the lesion in PD rat model, and the affinity of the receptors is increased, but the activity of D 1 dopamine receptor is not significantly changed.

A novel electrogenerated chemiluminescence (ECL) sensor for the determination of metoclopramide was developed by employing ruthenium complex as an ECL signal producer and an ordered mesoporous carbon (OMC) material as modified material. The ECL sensor was fabricated by adsorption ruthenium complex into a mixture of OMC and Nafion, which showed good electrochemical and ECL behaviors. It was found that the ECL intensity of the sensor fabricated was greatly enhanced in the presence of metoclopramide. Based on this finding, a highly sensitive and reproducible ECL method was developed for the determination of metoclopramide. The result showed that the ECL intensity was linear with the concentration of metoclopramide in the range from 1.0×10-10 to 5.0×10-7M and the detection limit was 3×10-11M. The ECL sensor exhibited a long-term stability and a fine reproducibility with relative standard deviation of 1.0 % for 1.0×10-10M metoclopramide in 18 continuous determinations. The developed method has been applied to the determination of metoclopramide in tablet samples with satisfactory results.

Objective To investigate the therapeutic effect and safety of high intensity focused ultrasound(HIFU) combined with Gemcitabine in treating unresectable pancreatic carcinoma Methods Forty one patients suffering from unresectable pancreatic carcinoma were randomly divided into two groups.The patients in experimental group(n =21) were provided with HIFU in combination with gemcitabine therapy and those in control group(n =20)received HIFU treatment alone.The effect,clinical benefit rates,changes of tumor marker carbohydrate antigen 19-9(CA19-9)and adverse reactions were compared between these two groups.The median survival time,6-month and 12-month survival rates were calculated by Kaplan-Meier method and Logrank test.Results The median survival time,6-month and 12-month survival rates were 10.22 months,76.2％(16/21) and 42.9％(9/21) in experimental group,and they were 7.43 months,50.0％(10/20) and 15.0％(3/20) respectively in control group.Among them,12-month survival rates was significantly higher in experimental group than that in control group(x2 =4.00,P ＜ 0.05).The clinical benefit rates in experimental group were significantly higher than that in control group[76.2％(16/21) vs 45.0％(9/20),x2 =4.20,P ＜0.05].But there was no significant difference on pain remission rate between the two groups(66.6％ vs45.0％,P ＞ 0.05).There was significant difference on CA19-9 after treated for 2,3,4,5 and 6 months in experimental group than that in control group(t =2.225,2.133,1.743,2.599,2.278,respectively,P ＜ 0.05)Conclusion HIFU in combination with Gemcitabine therapy is better than application of HIFU treatment alone.The former may become of the most effective treatmenffor unresectable pancreatic carcinoma.

Objective To evaluate the effects of body position and cuffed endotracheal tube (cETT) position on the intracuff pressure during tonsillectomy in the pediatric patients.Methods Sixty pediatric patients,aged 3-12 yr,scheduled for elective tonsillectomy under general anesthesia,were divided into group A and group B using a random number table,with 30 patients in each group.The cETTs were placed on one side of the blade of Davis retractor in group A.The cETTs were placed between the blade of Davis retractor and the body of tongue in group B.The intracuff pressure was recorded when the head was in the neutral position (T1),after changing to the head back position (T2) and when the retractor was placed for operation (T3).Results The intracuff pressure was significantly higher at T2 than at T1 in the two groups (P＜0.01).The intracuff pressure was significantly higher at T3 in group A and lower at T3 in group B than at T2 (P＜0.01).Compared with group A,the intracuff pressure was significantly decreased at T3 (P＜0.01),and no significant change was found in the intracuff pressure at T1,2 in group B (P＞0.05).Conclusion The intracuff pressure is affected by body position and cETT position during tonsillectomy in the pediatric patients,and routine monitoring of the intracuff pressure is recommended.

OBJECTIVE: The aim of this study was to investigate voluntary wheel running behavior in the unilateral 6-hydroxydopamine (6-OHDA) rat model. METHODS: Male Sprague-Dawley rats were assigned to 2 groups : 6-OHDA group (n=17) and control group (n=8). The unilateral 6-OHDA rat model was induced by injection of 6-OHDA into unilateral medial forebrain bundle using a stereotaxic instrument. Voluntary wheel running activity was assessed per day in successfully lesioned rats (n=10) and control rats. Each behavioral test lasted an hour. The following parameters were investigated during behavioral tests : the number of running bouts, the distance moved in the wheel, average peak speed in running bouts and average duration from the running start to the peak speed. RESULTS: The number of running bouts and the distance moved in the wheel were significantly decreased in successfully lesioned rats compared with control rats. In addition, average peak speed in running bouts was decreased, and average duration from the running start to the peak speed was increased in lesioned animals, which might indicate motor deficits in these rats. These behavioral changes were still observed 42 days after lesion. CONCLUSION: Voluntary wheel running behavior is impaired in the unilateral 6-OHDA rat model and may represent a useful tool to quantify motor deficits in this model.
Animals ; Humans ; Male ; Medial Forebrain Bundle ; Models, Animal* ; Oxidopamine* ; Parkinson Disease* ; Rats ; Rats, Sprague-Dawley ; Running*

Objective To investigate the mechanism of improvement of gait behavior in PD rat models by low frequency electrical stimulation of pedunculopontine tegmental nucleus (PPTN) by optogenetics method. Methods (1) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 1, a lesion group 1 and a photoactivation group (n=8); normal saline was injected into the right medial frontal tract (MFB) of the sham-operated group 1; 6-hydroxydopamine (6-OHDA) was injected into the lesion group 1 and photoactivation group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-ChR2-mcherry into the right PPTN of the three groups was performed, and the photoactivation group received blue-ray stimulation by implanting optical fibers into the PPTN at the same time. (2) Twenty-four healthy adult male SD rats were randomly divided into a sham-operated group 2, a lesion group 2 and a photoinhibition group (n=8);normal saline was injected into right MFB of the sham-operated group 2; 6-OHDA was injected into the lesion group 2 and photoinhibition group to induce PD models; two weeks after modeling, injection of adeno-associated virus hsynapsin-NpHR-mcherry into the right PPTN of the three groups was performed, and the photoinhibition group received yellow-ray stimulation by implanting optical fibers into the PPTN at the same time. (3) Three weeks after injection of adeno-associated virus, Catwalk gait analysis was used to assess the behavioral ability of rats in each group. Results (1) As compared with the sham-operated group 1, lesion group 1 had significantly increased front claw spacing and back front claw spacing, and significantly decreased stride length and pressure of damaged lateral and contralateral limbs, and significantly decreased swing speed of contralateral limb (P<0.05); as compared with those in the lesion group 1, the front claw spacing and back claw spacing were significantly shortened, and stride length and pressure of damaged lateral and contralateral limbs were statistically increased in the photoactivation group (P<0.05). (2) As compared with the sham-operated group 2, lesion group 2 had significantly increased front claw spacing and back front claw spacing, significantly decreased stride length of damaged lateral limb, and significantly decreased pressure and swing speed of damaged lateral and contralateral limbs (P<0.05); no significant differences were noted on the front claw spacing and back front claw spacing, pressure and swing speed of damaged lateral and contralateral limbs between lesion group 2 and photoinhibition group (P>0.05). Conclusion The mechanism of low frequency electrical stimulation of PPTN improving gait behavior of PD rat models is related to activation of PPTN neurons.

OBJECTIVETo apply pulse-field gel electrophoresis analysis(PFGE) in the analysis of cholera outbreak events and to determine the molecular epidemiological characteristics of Vibrio cholerae ( V. cholerae) isolates.

METHODSPFGE using restriction enzyme Not I was employed in the molecular subtyping of forty-one strains of V. cholerae isolated in cholera outbreak events from 2003 to 2005 in Guangzhou area and PFGE patterns were analyzed by BioNumerics Version 4.0 software to perform cluster analysis. Pattern profiles were compared by utilizing of Dice coefficient and UPGMA(unweighted pair group method with arithmetic averages). Comparison of PFGE typing results was performed with phage-biological typing and pathogenicity-associated genes typing.

RESULTSIn cholera outbreak events, PFGE could discriminate epidemiologically related and unrelated strains, having more discriminatory power than phage-biological typing and pathogenicity-associated genes-typing.

CONCLUSIONSMolecular sub-typing by PFGE could disclose the epidemiological relationships of strains from humans and the environment, providing molecular epidemiological evidence and support for the source-tracking of cholera outbreak events.

Bacterial Typing Techniques ; methods ; Cholera ; epidemiology ; microbiology ; Disease Outbreaks ; Electrophoresis, Gel, Pulsed-Field ; Humans ; Molecular Epidemiology ; Vibrio cholerae ; classification ; genetics ; isolation & purification

OBJECTIVETo apply multiplex polymerase chain reaction (MPCR) assay and sequencing in study of the carrying status of four pathogenicity-related genes of Vibrio cholerae (V.cholerae) and the variation of ctxA.

METHODSPrimers targeting cholera toxin sub-unit A gene (ctxA), toxin-coregulated pilus gene (tcpA), accessory cholera enterotoxin gene (ace), zonula occludens toxin gene (zot) were designed and the MPCR method was applied to detect the pathogenicity-related genes of 276 strains of V.cholerae isolates. The amplified fragments of ctxA gene were sequenced and the genetic homology of the amplified fragments of ctxA was analyzed.

RESULTSOf the 276 strains of V.cholerae, 93.9% strains from human sources belong to the pathogenicity-related genes type A (ctxA(+)tcpA(+)ace(+)zot(+) type) and 6.1% belong to pathogenicity-related genes type C (ctxA(-)tcpA(-)ace(-)zot(-) type). Type A strains from clinical sources were isolated from patients with mild to severe symptom and carriers, among which 68.5% were isolated from patients with mild symptom and 21.9% from carriers. All 63.6% of type C strains from clinical sources were isolated from patients with mild symptom and 36.4% from carriers. The proportion of type C strains that caused mild symptom was higher than that of type A strains. Of the 78 strains isolated from the environment, 9.0% strains belong to pathogenicity-related type A and 35.9% belong to the pathogenicity-related genes type B (ctxA(-)tcpA(-)ace(+)zot(+) type), while 55.1% belong to pathogenicity-related genes type C. The sequencing results showed little genetic variation among the amplified fragments for ctxA.

CONCLUSIONMPCR disclosed the polymorphic status of pathogenicity-related gene patterns in V.cholerae isolates of Guangzhou, providing effective means for further study on evolution of pathogenicity-related genes among V.cholerae isolates from human and environmental sources. This study also offers significant guidance for effective prevention, control and warning against cholera epidemic in local area.

China ; Cholera Toxin ; genetics ; DNA, Bacterial ; Genes, Bacterial ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Sequence Analysis ; Vibrio cholerae ; classification ; genetics ; isolation & purification