Songbirds and humans both rely critically on auditory feedback for learning and maintaining accurate vocalizations. During vocal learning, juvenile songbirds learn to sing by using auditory feedback to match their variable song patterns to a memorized tutor model. During song maintaining, adult songbirds monitor the integrality and accuracy of its song on-line according to auditory feedback. This form of learning requires auditory-vocal integration. The output of songs and the information of auditory feedback are integrated in some areas of the bird's brain, and then direct next vocal activity. In recent years, the lateral magnocellular nucleus of the anterior neostriatum (LMAN) has been demonstrated that it is necessary for feedback-dependent song decrystallization, and LMAN neurons exhibit highly selective responses to auditory presentation of the bird's own song (BOS). Moreover, the discovery of mirror neurons in the high vocal centre (HVC) also provides a significant clue for further study in songbirds. Here the progress of auditory feedback and the plasticity of vocal learning in songbirds are reviewed in recent years.

Objective To analyze expression of angiopoietin-2 (Ang-2) protein in human esophageal squamous cell carcinoma (ESCC),and to investigate the relationship between Ang-2 protein and clinicopathologic factors.Methods 60 cases of ESCC,5 cases of latero-carcinoma tissues and 30 cases of normal tissue were immunohistochemically stained using Ang-2 monoclonal antibodies with PV-9000 non-biotin detection system.The positive expression rate and expression level of Ang-2 were evaluated.Results Ang-2 was mainly expressed in cytoplasm.The positive expression rates in normal epithelium,latero-carcinoma tissues and ESCC were respectively 3.33 ％ (1/30),40.00 ％ (2/5),53.33 ％ (32/60).Compared ESCC with normal epithelium and latero-carcinoma tissues,Ang-2 positive expression rate was significantly higher (P ＜ 0.05).Among ESCC,expression of Ang-2 was positively correlated with the tumor infiltration depth (rs =0.621,P =0.002),and inversely correlated with tumor differentiation status (rs =-0.309,P =0.018).Conclusions Ang-2 may play an important role in the carcinogenesis and development of ESCC.Tumor differentiation degree,infiltration depth and TNM staging are the independent prognostic indicators for ESCC patients.Combinative detecting the expression of Ang-2 may provide more accurate information in early diagnosis and predicting the prognosis of ESCC.

BACKGROUND: As demonstrated by recent reports, immediate early genes (IEGs) are rapidly induced and expressed when a songbird is stimulated either by bird-song or by its vocal-behavior. The expression area and level of IEGs in the brain, such as zenk, c-fos and c-jun, are corresponding to where and how the neurons are related as a songbird is stimulated, suggesting that IEGs play important roles in vocal learning and memory.OBJECTIVE: To study the relation between vocal learning of songbird and immediate early gene so as to understand the mechanism of human language and the control of central nervous system.DATA SOURCES: All papers were cited from MEDLINE with the keywords of "songbird, vocal learning, memory, zenk, c-fos and c-jun" in English between January 1990 and December 2001. Meanwhile, we searched the Chinese journals full-text database and Wanfang database with the same keywords in Chinese between January 1990 and November 2001 were also searched.STUDY SELECTION: The papers about immediate early genes and vocal learning and memory in songbirds were selected. Then non-randomly controlled studies were excluded, and the rest full-text papers were looked up.DATA EXTRACTION: Totally 17 papers about immediate early genes and vocal learning and memory in songbirds were found. We choose 11 papers in them and 6 was excluded because of summarization.DATA SYNTHESIS: ① zenk and vocal behavior: Expression of zenk in bird's brain can affect learning and memory through adjusting synthesis of special protein. ② Reaction of c-fos to various songs: The reaction of local neurons in bird's brain to the birdsongs are made by the decision of the numbers of song factor in learning songs. ③ Associations of c-jun and cfos: zenk, fos and jun are the necessaries for maintaining long-term memory, which produce a marked effect through signal transduction, reconstruction, synthesis and transduction of induced synapse.CONCLUSION: Immediate early genes (IEGs) are rapidly induced and expressed when a songbird is stimulated either by bird-song or by its vocal-behavior. The expression area and level of IEGs in the brain, such as zenk, c-fos and c-jun, are corresponding to where and how the neurons are related as a songbird is stimulated, suggesting that IEGs play important roles in vocal learning and memory.

Objective To investigate the association between the polymorphisms of brain-derived neurotrophic factor(BDNF) gene C270T and sporadic Alzheimer's disease(SAD) in Han Chinese.Methods The polymerase chain reaction-restriction fragment length polymorphism(PCR-RELP) was used to detect BDNF gene C270T genotype and allele frequencies in 55 SAD patients and 80 age-and sex-matched healthy people(as normal control group).Results The frequencies distribution of BDNF gene C270T genotype and allele in the normal control group were suit to Hardy-Weinberg equilibrium(?2=0.167,P=0.682).The frequencies distribution of genotype and allele in the SAD group[C/C:52(94.5%),C/T:3(5.5%) and C:97.27%,T:2.73%]and normal control group[C/C:74(92.5%),C/T:6(7.5%) and C:96.25%,T:3.75%] were no statistical differences.Conclusion There is no association between the polymorphisms of BDNF gene C270T and SAD in Han Chinese.

Under the patterns of net-teaching,the construction of net-teaching database is an important tache to develop teaching favourably and improve the quality and efficiency of teaching quickly.This paper introduces the process of constructing a net-teaching database for medical haematology,the course learning of clinical hematology for the undergraduates and graduate students and the applications of the clinician in learning.

Objective To evaluate the role of esophageal visceral sensitivity in the pathogenesis of different subtypes of nonerosive reflux disease (NERD), erosive esophagitis (EE), and observe the characteristics and differences of nerve fiber endings of lower esophageal sphincter (LES) to explore the mechanism for peripheral sensitization in mediating the esophageal hypersensitivity. Method 31 NERD patients, 13 EE patients and 12 healthy volunteers were enrolled in the present study. The perception thresholds including the initial perception threshold (IPT) and the maximally tolerated pain threshold (MPT) were determined using the step-wise intraesophageal balloon distention (IEBD) protocol by esophageal barostat. The ultrastructures of nerve fiber endings of various types of synaptic vesicles were investigated with transmission electron microscope (TEM). Results IPT in NERD-H patients was significantly lower than that in NERD-N and controls (P

Objective To study the expression and effect of hepatocyte mitochondrial DNA cytochrome c oxidase subunitsⅠ (COXⅠ) gene in rat nonalcoholic fatty liver model. Methods Forty Wistar rats were randomly divided into control group and high-fat diet group, and the high-fat diet group was subsequently divided into 4 subgroups (2, 4, 8 and 12 week) with 8 rats in each. Cytochrome c oxidase activity was determined by ultraviolet spectrophotometer. Meanwhile,the expression of hepatocyte COXⅠ antigen in rat nonalcoholic steatosis model induced by high fat diet were detected by Western blotting. Mitochondrial DNA COXⅠ mRNA were assayed by reversetranscription polymerase chain reaction(RT-PCR). Results The levels of activity in nonalcoholic steatosis rats induced by high fat diet at 2, 4, 8, and 12 weeks were (0.88?0.32), (0.76?0.37), (0.48?0.26), (0.39?0.21) nmol?mg~ -1 ?min~ -1 , respectively, significantly lower than (0.98?0.37) nmol?mg~ -1 ?min~ -1 in control group (P

Objective: To optimize the formula and preparation process of docetaxel-loaded pluronic P123 micelles. Methods:Docetaxel-loaded pluronic P123 micelles were prepared by a thin-film hydration method and optimized by central composite design and response surface methodology. The influencing factors including the quantity of docetaxel, volume of organic phase, volume of hydra-tion and temperature of hydration were investigated with the entrapment efficiency as the index. The morphology of micelles was ob-served under a transmission electron microscope. The particle diameter and zeta potential were determined. The in vitro release property was measured by a dialysis method. Results:The relationship between the influencing factors and the evaluation parameter was fitted by multi-linear equation, quadratic polynomial equation and cubic polynomial equation, respectively. The results showed that the cubic polynomial equation was superior to the others according to the correlation coefficient. Docetaxel-loaded pluronic P123 micelles were spherical with the mean diameter, zeta potential, polydispersity index, encapsulation efficiency and drug loading of 108. 3 nm,-3. 99 mV, 0. 265, (97. 91 ± 0. 28)% and (3. 72 ± 0. 12)%, respectively. The cumulative release in vitro reached 95. 03% in 120 h, and docetaxel-loaded pluronic P123 micelles had notable sustained-release property. Conclusion: The technical process for do-cetaxel-loaded pluronic P123 micelles is simple and usable, and docetaxel-loaded pluronic P123 micelles show high encapsulation effi-ciency and notable sustained-release property.

The head injury patients is very common in clinic and it is complicated to cure them.Furthermore,many ethical questions are involved during the treatment,which are discussed in the article.The aim is to be helpful to protect both patients'and medical staff's right,reduce medical disputes and form a good relationship between doctors and patients from the view of ethics.Accordingly,the patients of head injury will acquire better treatment.

OBJECTIVE: To study the optimal alcohol extracting technology for Fructus Crataegi in Jiangzhibao capsules and to study its quality control method. METHODS: The content of Hyperoside and the yield of alcohol extract were studied. An orthogonal design of L9( 34) was carried out with concentration, dosage and extracting time of alcohol as three factors, and three levels of each factor were chosen for the experiment. The content of Hyperoside was determined by HPLC. RESULTS: The optimum alcohol extracting procedure was as follows: 70% alcohol was added and the solid-liquid ratio was 1∶ 10, refluxing for 1h. The process The process was repeated once again. The linear range of Hyperoside was 1. 024～ 30. 72? g? mL-1. CONCLUSION: The alcohol extracting technology is reasonable and feasible, and the preparation obtained is controllable in quality.