Application of analysis of causes of national death for action in quality analysis of cause of death surveillance in Hainan Province in 2020 / 中国热带医学

@#Abstract: Objective　To further investigate the underreporting of mortality surveillance data among permanent residents in Hainan Province in 2020, and to explore the application of Application of the Analysis of National Causes of Death for Action (ANACONDA) in the quality analysis of mortality surveillance. Methods　The data were collected from the Death Information Monitoring and Management System of Hainan Center for Disease Control and Prevention, and mainly included 33 418 deaths reported from 19 cities and counties in Hainan Province from January 1, 2020 to December 31, 2020. All the data were analyzed by the application of ANACONDA, and the causes of death were classified by the International Classification of Diseases, 10th Revision (ICD-10). Results　A total of 33 418 deaths were reported in Hainan Province in 2020, with a crude mortality rate of 3.6‰. The proportion of deaths in males under 85 years old was higher than that in females, while the proportion of deaths in 85 years old and above was opposite. The quality analysis of cause of death surveillance showed that there was under-reporting of death surveillance in Hainan Province in 2020, with an under-reporting rate of 30.1%. There were differences in the age composition and GBD regional composition ratio of deaths of the three major categories of diseases, and the misreporting of causes of death in the middle and high age groups was more significant. The Vital Statistics Performance Index (VSPI) score of death data in Hainan Province in 2020 was 52.8, the score of cause of death reporting quality was 85.5, and the score of specific cause of death level that could be used was 88.4. The completeness of death reports in the priority action areas for improving cause of death data quality accounted for the largest share, followed by the quality of cause of death reports. There was a difference in the proportion of specific causes of death between males and females after the survey, but the change in order was not obvious. Conclusions　The data integrity of cause-of-death surveillance is low in Hainan Province in 2020. It is suggested to improve the completeness of reporting data, strengthen the training of cause-of-death surveillance system, and regularly evaluate and supervise the system.

Polymorphisms of pvcrt-o and pvmdr1 genes of 48 Plasmodium vivax isolates from the China-Myanmar border / 中国热带医学

@#Abstract: Objective To detect the polymorphisms of drug resistance-related genes pvcrt-o and pvmdr1 of Plasmodium vivax in lazan city in the China-Myanmar border, in order to guide the treatment plan of Plasmodium vivax. Methods A total of 48 Plasmodium vivax samples were collected from Lazan in the China-Myanmar border in 2007, and fragments of pvcrt-o and pvmdr1 genes were amplified by PCR and sequenced. The sequences were aligned with the Salvador I (Sal-I) strain reference genome sequences to determine the presence of SNPs. Results The target fragments of pvcrt-o gene were amplified from 39 Plasmodium vivax samples, while pvmdr1 genes were amplified from 40 samples. Amongst them, 25 samples had AAG insertion before the 10th amino acid (K10 insertion) of pvcrt-o gene, accounting for 64.1%. Non-synonymous mutations were detected at three loci of pvmdr1 gene (T958M, Y976F, and F1076L), the mutation rates were 100%, 22.5%, and 55.0%, respectively. There were three haplotypes of pvmdr1 gene, of which the triple mutant 958M/976F/1076L accounted for 22.5% (9/40), the double mutant 958M/Y976/1076L accounted for 32.5% (13/40), and the single mutant 958M/Y976/F1076 accounted for 45.0% (18/40). The proportion of strains with pvcrt-o and pvmdr1 gene mutation is 63.16%, which is significantly different from those only with pvmdr1 mutation. Conclusions The proportion of pvcrt-o and pvmdr1 gene mutation of 48 Plasmodium vivax isolates is high in the China-Myanmar border, and there is a certain degree of correlation between the two gene mutations. To assess changes in Plasmodium vivax drug resistance in this region, it is required to improve the surveillance of these two molecular markers.

Influence of weight training on lower limb strength in soccer players / Influência do treinamento com pesos sobre a força de membros inferiores em jogadores de futebol / Influencia del entrenamiento con pesas en la fuerza de las extremidades inferiores en jugadores de fútbol

ABSTRACT Introduction Soccer games are of long duration and more confrontational; in the second half of the game, many players have a decline in their physical level, leading to loss of matches. Objective To explore the effect of weight training on lower limb fitness in soccer players. Methods 60 athletes were included as subjects and randomly divided into control group, weight training group, and traditional physical fitness training group. All athletes trained for 45 minutes 3 times a week for 6 weeks. Before and after training, lower limb strength and proprioception were evaluated, and the strength of the knee flexor and extensor group was assessed by isokinetic muscle tester. Results Both weight training and traditional physical training were able to improve the vertical jump performance of young soccer players, the training effects of both groups were equivalent. Conclusion Weight training has the same enhancing effect as traditional physical training in terms of strength and explosive power, promoting athletic performance in youth soccer players. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução Os jogos de futebol são de longa duração e de maior confrontação; na segunda metade do jogo, muitos jogadores têm um declínio em seu nível físico, levando à perda das partidas. Objetivo Explorar o efeito do treinamento com peso na condição física nos membros inferiores dos jogadores de futebol. Métodos 60 atletas foram incluídos como sujeitos e divididos aleatoriamente em grupo de controle, grupo de musculação e grupo de musculação física tradicional. Todos os atletas treinaram por 45 minutos 3 vezes por semana durante 6 semanas. Antes e depois do treinamento, a força dos membros inferiores e a propriocepção foram avaliadas, e a força do grupo flexor e extensor do joelho foi avaliada pelo testador muscular isocinético. Resultados Tanto o treinamento físico com peso quanto o treinamento físico tradicional conseguiram melhorar o desempenho do salto vertical dos jovens jogadores de futebol, os efeitos do treinamento dos dois grupos foram equivalentes. Conclusão O treinamento com peso tem o mesmo efeito de aprimoramento que o treinamento físico tradicional em termos de força e poder explosivo, promovendo o desempenho atlético em jogadores de futebol juvenil. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción Los partidos de fútbol son de larga duración y de mayor confrontación; en la segunda mitad del partido, muchos jugadores tienen un descenso en su nivel físico, lo que lleva a la pérdida de partidos. Objetivo Explorar el efecto del entrenamiento con pesas sobre la aptitud de las extremidades inferiores en jugadores de fútbol. Métodos Se incluyeron 60 atletas como sujetos y se dividieron aleatoriamente en el grupo de control, el grupo de entrenamiento con pesas y el grupo de acondicionamiento físico tradicional. Todos los atletas entrenaron 45 minutos 3 veces por semana durante 6 semanas. Antes y después del entrenamiento, se evaluó la fuerza de las extremidades inferiores y la propiocepción, y la fuerza del grupo de flexores y extensores de la rodilla se evaluó mediante un probador muscular isocinético. Resultados Tanto el entrenamiento con pesas como el entrenamiento físico tradicional fueron capaces de mejorar el rendimiento del salto vertical de los jóvenes futbolistas, los efectos del entrenamiento de ambos grupos fueron equivalentes. Conclusión El entrenamiento con pesas tiene el mismo efecto potenciador que el entrenamiento físico tradicional en términos de fuerza y potencia explosiva, promoviendo el rendimiento atlético en los jugadores de fútbol juvenil. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Influence of strength training on the explosive power of lower limbs of soccer players / Influência do treinamento de força na potência explosiva dos membros inferiores dos jogadores de futebol / Influencia del entrenamiento de fuerza en la potencia explosiva de los miembros inferiores de los futbolistas

ABSTRACT Introduction The explosive power of the lower limbs is an indispensable index in soccer. Having a good level of explosive power establishes a solid foundation for the performance and the competitive level of soccer players. Objective Promote the conditions to improve the explosive level of soccer players and improve their performance and competitive level. Methods This paper presents the influence of compound strength training on the explosive power of the lower limbs of soccer athletes. Based on 27 young 9-year-old soccer players from Zai Ming Football Club of a sports college as experimental material, the composite training was carried out. Results The growth rates of these rates in the experimental group were 3.3%, 2.3%, 5.0%, 3.6%, 9.2%, 12.1%, 20.5%, 5.7%, 11.9%, 16.9% and 19.5% respectively, while those in the control group were 1.2%, 0.7%, 4.2%, 3.1%, 6.8%, 7.8%, 5.1%, 4.2%, 4.8%, 12.5% and 19.2% respectively. The growth rate of the experimental group was higher than that of the control group and the blank control group. Conclusion Compared with the control group and the neutral control group, the experimental group with compound training has a better training effect on improving the lower limb explosiveness of youth soccer players. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução A potência explosiva dos membros inferiores é um índice indispensável no futebol. Ter um bom nível de potência explosiva estabelece uma base sólida para o desempenho e o nível competitivo dos futebolistas. Objetivo Promover as condições para melhorar o nível explosivo dos jogadores de futebol e aperfeiçoar seu desempenho e nível competitivo. Métodos Este documento apresenta a influência do treinamento de força composta no poder explosivo dos membros inferiores dos atletas de futebol. Com base em 27 jovens jogadores de futebol com 9 anos de idade do Zai Ming Football Club de uma faculdade esportiva como material experimental, foi realizado o treinamento composto. Resultados As taxas de crescimento destes índices no grupo experimental foram de 3,3%, 2,3%, 5,0%, 3,6%, 9,2%, 12,1%, 20,5%, 5,7%, 11,9%, 16,9% e 19,5% respectivamente, enquanto os do grupo de controle foram de 1,2%, 0,7%, 4,2%, 3,1%, 6,8%, 7,8%, 5,1%, 4,2%, 4,8%, 12,5% e 19,2% respectivamente. A taxa de crescimento do grupo experimental foi maior do que a do grupo de controle e do grupo de controle em branco. Conclusão Em comparação com o grupo de controle e o grupo de controle neutro, o grupo experimental com treinamento composto tem um melhor efeito de treinamento para melhorar a explosividade dos membros inferiores dos jogadores de futebol juvenil. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción La potencia explosiva de los miembros inferiores es un índice indispensable en el fútbol. Tener un buen nivel de potencia explosiva establece una base sólida para el rendimiento y el nivel competitivo de los futbolistas. Objetivo Promover las condiciones para mejorar el nivel explosivo de los futbolistas y mejorar su rendimiento y nivel competitivo. Métodos Este trabajo presenta la influencia del entrenamiento de fuerza compuesta en la potencia explosiva de los miembros inferiores de los atletas de fútbol. Se llevó a cabo el entrenamiento compuesto con 27 jóvenes jugadores de fútbol de 9 años del Club de Fútbol Zai Ming de una escuela deportiva como material experimental. Resultados Las tasas de crecimiento de estos índices en el grupo experimental fueron del 3,3%, 2,3%, 5,0%, 3,6%, 9,2%, 12,1%, 20,5%, 5,7%, 11,9%, 16,9% y 19,5% respectivamente, mientras que las del grupo de control fueron del 1,2%, 0,7%, 4,2%, 3,1%, 6,8%, 7,8%, 5,1%, 4,2%, 4,8%, 12,5% y 19,2% respectivamente. La tasa de crecimiento del grupo experimental fue mayor que la del grupo de control y del grupo de control en blanco. Conclusión En comparación con el grupo de control y el grupo de control neutro, el grupo experimental con entrenamiento compuesto tiene un mejor efecto de entrenamiento para mejorar la explosividad de las extremidades inferiores de los futbolistas juveniles. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Comparison of mini percutaneous nephrolithotomy and standard percutaneous nephrolithotomy for renal stones >2cm: a systematic review and meta-analysis

ABSTRACT Background The purpose is to compare the efficacy and safety of mini percutaneous nephrolithotomy (mini-PCNL) versus standard percutaneous nephrolithotomy (standard-PCNL) in patients with renal stones >2cm. Materials and Methods A systematic literature search was conducted in PubMed, Web of Science, Scopus, and the Cochrane Library databases to identify relevant studies before March 8, 2021. Stone-free rate (SFR), operation time, fever rate, hemoglobin drop, blood transfusion rate, and hospitalization time were used as outcomes to compare mini-PCNL and standard-PCNL. The meta-analysis was performed using the Review Manager version 5.4. Results Seven randomized controlled trials were included in our meta-analysis, involving 1407 mini-PCNL cases and 1436 standard-PCNL cases. Our results reveal that, for renal stones >2cm, mini-PCNL has a similar SFR (risk ratio (RR)=1.01, 95% confidence interval (CI): 0.98 to 1.04, p=0.57) and fever rate (RR=1.22, 95% CI: 0.97-1.51, p=0.08). Standard-PCNL was associated with a significantly shorter operating time (weighted mean difference (WMD)=8.23, 95% CI: 3.44 to 13.01, p <0.01) and a longer hospitalization time (WMD=-20.05, 95% CI: -29.28 to -10.81, p <0.01) than mini-PCNL. Subgroup analysis showed hemoglobin drop and blood transfusion for 30F standard-PCNL were more common than mini-PCNL (WMD=-0.95, 95% CI: -1.40 to -0.50, p <0.01; RR=0.20, 95% CI: 0.07 to 0.58, p <0.01). Conclusion In the treatment of >2cm renal stones, mini-PCNL should be considered an effective and reliable alternative to standard-PCNL (30F). It achieves a comparable SFR to standard-PCNL, but with less blood loss, lower transfusion rate, and shorter hospitalization. However, the mini-PCNL does not show a significant advantage over the 24F standard-PCNL. On the contrary, this procedure takes a longer operation time. Trial registration This meta-analysis was reported consistent with the PRISMA statement and was registered on PROSPERO, with registration number 2021CRD42021234893.

CCAT2 is an oncogenic long non-coding RNA in pancreatic ductal adenocarcinoma

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive with poor prognosis. Long non-coding RNAs (lncRNAs), a group of non-coding RNAs, play important roles in the progression of PDAC. This study aimed to investigate the potential involvement of lncRNA CCAT2 in PDAC tumorigenesis. Methods Expression of CCAT2 was detected by quantitative real-time PCR (qRT-PCR) in 80 human PDAC tissues and three PDAC cell lines. The effects of CCAT2 silencing in PANC-1 cells on cell proliferation and invasion were studied using MTT assay and transwell assay, respectively. The effect of CCAT2 silencing on tumorigenesis was assessed by PANC-1 xenograft in vivo. Using si-KRAS, the role of KRAS to regulate CCAT2 was evaluated by qRT-PCR and luciferase reporter assay. The involvement of MEK/ERK and PI3K/AKT signaling in CCAT2 regulation was investigated by pathway inhibitors PD98059 and LY294002, respectively. Results CCAT2 was significantly elevated in high-grade PDAC tissues and higher CCAT2 expression was correlated with lower survival rate in PDAC patients. CCAT2 was up-regulated in PDAC cell lines, as compared with normal pancreatic cells. Silencing of CCAT2 inhibited cell proliferation and invasion in PANC-1 cells in vitro, and attenuated tumorigenesis of PANC-1 xenograft in vivo. Furthermore, CCAT2 was regulated by KRAS through MEK/ERK signaling pathway. Conclusions CCAT2 is an oncogenic lncRNA in PDAC likely regulated by the KRAS-MEK/ERK pathway. It could be a potential diagnostic biomarker and therapeutic target for PDAC.

Changes in histopathology and ultrastructure of corneal epithelium in TgAPPswePS1 transgenic mice / 眼科新进展

Objective To investigate the histopathological and ultrastructural changes in the corneal epithelium in TgAPPswePS1 transgenic mice.Methods TgAPPswePS1 transgenic mice were randomly divided into experimental group (A and B sub-group) and control group.There were 15 APPswe/PSEN1dE9 transgenic mice (15-18 months old) with Alzheimer's disease (AD) in the experimental A group,and 15 APPswe/PSEN1 dE9 transgenic AD mice (8 months old) mice in the experimental B group,as well as 10 wild-type mice (8 months old) in the control group.Then,the histopathological and ultrastructural changes and the expression of amyloid β-protein (Aβ) in the corneal epithelium of the mice were detected,and finally,the apoptosis of corneal epithelial cells were observed by TUNEL assay.Results The thickness of corneal epithelium in the control group,A and B sub-group of the experimental group was (23.567 ± 2.123) μm,(15.456 ± 1.439) μm and (20.104 ± 1.763) μm,respectively.Meanwhile,murine corneal epithelial cells presented the histopathological changes of disorderly arrangement,decreased layers of cells and irregular morphology in the experimental group compared with the control group.Under transmission electron microscope,the microvilli on the surface of corneal epithelium was flat and significantly decreased in the A and B sub-group when compared with the control group.Moreover,Aβ positive expression in the experimental group was significantly upregulated compared with the control group;and the apoptotic number of the corneal epithelium in the B sub-group [(5.631 ± 2.471) cells] was smaller than that in the A sub-group [(16.329 ±3.542) cells],with the significant difference(P ＜ 0.05).Conclusion There are changes in the histopathology and ultrastructure of the corneal epithelium and the expression of Aβ in TgAPPswePS1 transgenic mice compared with wild-type mice,which are associated with the age of mice.

Satisfaction of Village Doctors with the Township and Village Health Services Integration Policy in the Western Minority-inhabited Areas of China / 华中科技大学学报（医学）（英德文版）

Township and Village Health Services Integration Management (TVHSIM) is an essential form of China's two-tiered health service integration plan at the township and village level.Its main purpose,also one of the target goals in China's new healthcare reform,is to gradually integrate rural health services and appropriately allocate rural health resources.This study aims to assess the village doctors' satisfaction with the TVHSIM and provide scientific base to further improve TVHSIM.A cross-sectional study was carried out in which 162 village doctors from Qinghai,Inner Mongolia and Xinjiang in western China were interviewed.Descriptive analysis,independent t-test,one-way ANOVA,Spearman rank correlation and multiple linear regression were used to analyze the difference and relevance between village doctors' personal characteristics and their satisfaction with TVHSIM and six subscales.Village doctors with different years of practice,social insurance status and essential medical knowledge level showed statistically significant differences in their satisfaction levels (all P＜0.05).Age (P＜0.05) and years of practice (P＜0.01) were negatively correlated with Drug and Medical Device Management and Financing Management.Essential medical knowledge level (P＜0.05) was negatively correlated with Operations Management as well.However,social insurance status (P＜0.05) was positively correlated with Human Resources Management and Drug and Medical Device management.Gender,age and years of practice respectively had significant influence on village doctors' satisfaction with TVHSIM (P＜0.01).In conclusion,in order to further promote TVHSIM policy in rural China,a well-rounded social insurance model for village doctors is urgently needed.In addition,the development of TVHSIM is regionally imbalanced.Efficient and effective measures aiming at rationalizing gender and age structure and enhancing essential medical training should be carefully considered.

Edaravone Enhances the Viability of Ischemia/reperfusion Flaps / 华中科技大学学报（医学）（英德文版）

The purpose of the experiment was to study the efficacy of edaravone in enhancing flap viability after ischemia/reperfusion (IR) and its mechanism.Forty-eight adult male SD rats were randomly divided into 3 groups:control group (n=16),IR group (n=16),and edaravone-treated IR group (n=16).An island flap at left lower abdomen (6.0 cm×3.0 cm in size),fed by the superficial epigastric artery and vein,was created in each rat of all the three groups.The arterial blood flow of flaps in IR group and edaravone-treated IR group was blocked for 10 h,and then the blood perfusion was restored.From 15 min before reperfusion,rats in the edaravone-treated IR group were intraperitoneally injected with edaravone (10 mg/kg),once every 12 h,for 3 days.Rats in the IR group and control group were intraperitoneally injected with saline,with the same method and frequency as the rats in the edaravone-treated IR group.In IR group and edaravone-treated IR group,samples of flaps were harvested after reperfusion of the flaps for 24 h.In the control group,samples of flaps were harvested 34 h after creation of the flaps.The content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) were determined,and changes in organizational structure and infiltration of inflammatory cells were observed by hematoxylin-eosin (HE) staining,apoptotic cells of vascular wall were marked by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay,and the apoptotic rate of cells in vascular wall was calculated.The ultrastructural changes of vascular endothelial cells were observed by transmission electron microscopy (TEM).Seven days after the operation,we calculated the flap viability of each group,and marked vessels of flaps by immunohistochemical staining for calculating the average number of subcutaneous vessels.The results showed that the content of MDA,the number ofmulticore inflammatory cells and apoptotic rate of cells in vascular wall in the edaravone-treated IR group were significantly lower than those in the IR group.The activity of SOD,flap viability and average number of subcutaneous vessels in the edaravone-treated IR group were significantly higher than those in the IR group.All the differences were statistically significant.The ultrastructure injury of vascular endothelial cells in the edaravone-treated IR group was slighter than that in IR group.It was concluded that edaravone can significantly enhance IR flap viability and protect flap vessels,which is related to scavenging oxygen free radicals,reducing the consumption of SOD,reducing the extent of lipid peroxidation and inflammation,and protecting functional structure of vessels in the early stages of reperfusion.

YMDD motif mutations in chronic hepatitis B antiviral treatment naïve patients: a multi-center study

OBJECTIVE: This study aimed to determine the natural prevalence of variants of tyrosine-methionine-aspartic acid-aspartic acid (YMDD) motif in patients with chronic hepatitis B (CHB), and to explore its relation with demographic and clinical features, hepatitis B virus (HBV) genotypes, and HBV DNA levels. METHODS: A total of 1,042 antiviral treatment naïve CHB patients (including with lamivudine [LAM]) in the past year were recruited from outpatient and inpatient departments of six centers from December 2008 to June 2010. YMDD variants were analyzed using the HBV drug resistance line probe assay (Inno-Lipa HBV-DR). HBV genotypes were detected with polymerase chain reaction (PCR) microcosmic nucleic acid cross-ELISA, and HBV deoxyribonucleic acid (DNA) was quantitated with real-time PCR. All serum samples underwent tests for HBV, HCV, and HDV with ELISA. RESULTS: YMDD variants were detected in 23.3% (243/1042) of CHB patients. YMDD mutation was accompanied by L180M mutation in 154 (76.9%) patients. Both wild-type HBV and YMDD variant HBV were present in 231 of 243 patients. Interestingly, 12 patients had only YIDD and/or YVDD variants without wild YMDD motif. In addition, 27.2% (98/359) of HbeAg-positive patients had YMDD mutations, which was higher than that in HbeAg-negative patients (21.2%, 145/683). The incidence of YMDD varied among patients with different HBV genotypes, but the difference was not significant. Moreover, the incidence of YMDD in patients with high HBV DNA level was significantly higher than that in those with low HBV DNA level. CONCLUSION: Mutation of YMDD motif was detectable at a high rate in CHB patients in this study. The incidence of YMDD may be correlated with HBeAg and HBV DNA level.

Surgical treatment for hepatic metastases from colorectal carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the indications and effect of surgical resection for hepatic metastases from colorectal adenocarcinoma and to discuss the implications of clinicopathologic features on the prognosis.</p><p><b>METHODS</b>A retrospective study of 61 patients undergoing hepatectomy for metastatic tumors from colorectal adenocarcinoma from January 1991 to December 2000 in our hospital was performed retrospectively.</p><p><b>RESULTS</b>The 1-, 3- and 5-year survival rates after hepatic resection were 72.13%, 58.10% and 26.01% respectively. Complications occurred in 8 cases. Tumor pesudomembrance was found in 20 cases. Dukes stage, pathologic type,the number of hepatic metastases and tumor pesudomembrance were all significant factors for prognosis after surgery (P< 0.05). The 3-year survival rate of the patients with postoperative comprehensive treatment was higher than that with non-postoperative treatment (P< 0.05). The size of hepatic metastases and the resecting time didn't affect the prognosis (P > 0.05).</p><p><b>CONCLUSION</b>The hepatic metastases from colorectal cancer should be treated by a surgical approach. The earlier stage of clinical pathology,higher differentiation extent, metastases less than 3, the formation of pesudomembrance of the metastatic tumor and the postoperative comprehensive treatment predict a better survival.</p>

Impact of low-level lead exposure on neural cell adhesion molecule expression of primarily cultured hippocampal neurons / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the impact of low-level lead exposure on neural cell adhesion molecule (NCAM) expression of primarily cultured hippocampal neurons.</p><p><b>METHODS</b>Wistar rats gestated at 18th day were anaesthetized and paunched to get the pups, the hippocampi of the pups were separated and the hippocampal neurons were primarily cultured. After co-cultivated with different dosage of PbCl(2), the NCAM expression of the neurons were tested with Western blotting at different culture time.</p><p><b>RESULTS</b>Normally, the expression of NCAM at the 1st culture day was very low and its integral obsorbency density was 14; the climax expression time of NCAM of the cultured hippocampal neurons was 3rd to 5th cultured day, and their integral obsorbency density were 2 542 to 2 580; henceforth, the NCAM expression declined. NCAM expression was inhibited significantly by lead during the 2nd to 4th cultured day, and dose-response relationship was observed. The inhibition of lead weakened along with the cultured time prolonged, at 5th cultured day, it disappeared, and the NCAM expression of 10(-2), 10(-3) and 10(-4) mmol/L groups even exceeded the control groups. After that, the expression of NCAM in all groups began to decline, and the dose-response relationship of lead to the NCAM expression was observed again.</p><p><b>CONCLUSION</b>Low-level lead might significantly inhibit the NCAM expression of the primarily cultured Wistar rats' hippocampal neurons, and might delay the climax NCAM expression time.</p>