Construction and identification of rat GDNF gene recombinant retroviral vector and gene transfection to NSC / 生物医学工程学杂志

By genetic recombinant technique, the rat GDNF cDNA was recombinated to the retroviral vector pLXSN. The recombinant plasmid pLXSN-GDNF was verified by digestion with restriction endonucleases and PCR. Then neural stem cells (NSCs) were infected with pLXSN-GDNF. Immunocytochemistry, RT-PCR and western-blot were used to detect the transfection effect. Results showed that GDNF cDNA was cloned into retroviral vector pLXSN correctly, and the pLXSN-GDNF can infect NSCs efficiently. These results provide the possibility for transplantation and gene therapy with GDNF of nervous system diseases and injury.

A Prospective Study of the Effect of Smoking and Body Mass Index on the Risk of Lung Cancer in Male Workers of Beijing Steel Industry / 中国慢性病预防与控制

Objective To assess the effect of smoking and body mass index(BMI) on lung cancer incidence density in male workers.Methods Risk factors of cardiovascular diseases in baseline were surveyed in 1974,1979 and 1980 for 5 137 men aged more than 18 years old from Beijing Capital Steel and Iron Company.Follow-up was carried out to 2001;all diseases were identified by uniform standard.Cox proportional hazards model was used to analyze the relationship between smoking,BMI and lung cancer.Results During mean follow-ups of 20.8 years,106 cases of lung cancer occurred.The crude incident rates of lung cancer were 102.2 cases per 100 000 person-years.After adjustment for age,BMI and other established risk factors,cigarettes consumption of greater than 20 cigarettes/day versus no smoking was associated with a relative risk of lung cancer of 3.45(95% confidence interval(CI): 1.58～7.53).In categories of BMI of less than 18.5(underweight),18.5～24.9(normal weight) and more than 25 kg/m2(overweight and obesity),adjusting for age and other covariables,all workers and smoking workers both showed decreasing tendencies in relative risks of lung cancer in higher BMI groups.The pattern was similar after excluding the early 5-year lung cancer patients.Grouping in smoking and BMI levels,compared with underweight smokers,the relative risks for lung cancer of normal-weight nonsmokers and nonsmokers with overweight and obesity,as well as smokers with overweight and obesity were 0.25(95% CI: 0.08～0.84),0.16(95% CI: 0.04～0.74) and 0.23(95% CI: 0.07～0.77),respectively.Smokers with underweight had higher risk for lung cancer.Conclusion Smoking and underweight increased the risk of lung cancer.Keeping normal weight and giving up tobacco were important for the prevention of lung cancer.

The experiences of project pattern in practical course of neurobiology / 中华医学教育探索杂志

Neurobiology is to study the structure,function,development and regeneration of the nervous system at molecular,cellular and whole level.The objective of neurobiological teaching is to explore the importont and difficult points in teaching' the present article attempts to design a project pattern in practical course of neurobiology,which is suited to learning mode of medical college students.

Effect of hypoxia on NR1 subunit of NMDA receptor in rat cortex and hippocampus / 第三军医大学学报

Objective To observe the expression and phosphorylation of N-methyl-D-aspartate (NMDA) receptor NR1 subunit in rat cortex and hippocampus under high altitude hypoxia. Methods The adult SD rats were exposed to hypobaric hypoxia imitating 5 500-meter high altitude for 8 h daily for 3, 7, 14, 21 d. Immunohistochemical staining, Western blotting and co-immunoprecipitation were used to detect the expression and phosphorylation of NR1 in rat cortex and hippocampus. Results Both immunohistochemistry and Western blotting showed NR1 expression in rat cortex and hippocampus was increased under hypoxia in a time-dependent manner. The tyrosine phosphorylation of hypoxia groups was increased, and reached the peak on day 14 after hypoxia, then decreased, still higher than that of control groups till day 21 (P

Effect of Dihuang Yinzi on synaptophysin,extracellular regulated protein in hippocampus of aged rats / 第三军医大学学报

Objective To explore the function and mechanism of Dihuang Yinzi (DHYZ) in promoting learning and memory and delaying brain aging. Methods The Wistar rats aged 20 months were randomly assigned to receive oral administration of 6, 12, 18 g?kg~ -1 ?d~ -1 DHYZ, or 2 ml/d normal saline (control) for 30 d (n=12 in each group), then space memory was detected with Morris Water Maze, and expression of synaptophysin (SYP) and extracellular regulated protein (ERK) were measured by immunohistochemistry and Western blotting. Results Rats administrated with DHYZ showed shorter mean escape latency (P

Chitin enhances neural reconstruction after sciatic nerve injury in rats / 第三军医大学学报

Objective To investigate the effects of chitin on the functional recovery after sciatic nerve axotomy. Methods Upon silicone-tubulization of the transected sciatic nerve in the adult rats, either 0.9% saline or 1% chitin solution was injected into the silicone chamber. The status of functional recovery of the injured sciatic nerve was observed by electrophysiological analysis, hydrogen-peroxide oxidoreductase (HRP) retrograde trace method, and axon morphometric analysis at 30 and 90 d respectively after sciatic nerve transection. Results ① Chitin shortened the latent period of CMAP by 1.79 ms and 1.29 ms, promoted the nerve conduction velocity by 16.00 m/s and 22.00 m/s, enhanced the amplitude by 8.17 mv and 12.42 mv, respectively, at 30 and 90 d after sciatic nerve transection (P

Detection of estrogen secretion by rat astrocyte and its regulation in vitro / 第三军医大学学报

Objective To measure the estrogen concentration of estrogen (E 2) in the culture medium of rat astrocytes (ASTs). Methods Astrocytes in brain cortex of the 2-day-old neonatal rats were collected and cultured. The number of astrocytes was counted and the concentration of estrogen was measured by ELISA method at 0, 7, 14, and 21 d after culture. Results The cell counts were 1?10 4/ml, 1.1?10 6/ml, 1.4?10 6/ ml, and 1.5?10 6/ml, respectively. The concentrations of E 2 were: 0 pg/ml, (117.03?21.32) pg/ml, (266.91?22.03) pg/ml, and (252.62?27.99) pg/ml, respectively. No estrogen was detected in the primary culture medium. The concentration of estrogen increased in a time-dependent manner and reached the peak at 14 d, and then decreased gradually but remained at a certain level. Conclusion E 2 is secreted by astrocytes in the brain cortex of the 2-day-old neonatal rats.

Prevalence of overweight and obesity in Chinese middle-aged populations: Current status and trend of development / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the current status on prevalence of overweight and obesity in Chinese middle-aged population, and to quantify the magnitude of the trends of development in the past two decades.</p><p><b>METHODS</b>Body mass index (BMI) was measured on 15 389 middle-aged men and women from 15 natural populations all over China with different geographical, economical (urban/rural) and occupational status. Overweight was defined as BMI >/= 25 while obesity as BMI >/= 30.</p><p><b>RESULTS</b>1) The rates of prevalence on overweight and obesity varied dramatically between populations. 2) In general, the prevalence rates were higher in the northern areas, in urban areas, and in women. 3) The current problem of obesity was related to 'pre-obese' stage, with less than 10% in most populations. 4) The prevalence of overweight and obesity started to show significantly increase from early 80's to early 90's but more prominant in the late 90's.</p><p><b>CONCLUSION</b>Prevention and intervention of overweight and obesity are in urgent need in the Chinese populations, especially in those economically fast developing areas.</p>

Effects of health promotion for eight years on knowledge, attitude and behavior of cardiovascular diseases in rural Fangshan District, Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of health promotion for eight years on cardiovascular diseases based on the changes in knowledge (K), attitude (A) and behavior (B) (KAB) before and after intervention in rural population of Fangshan, Beijing.</p><p><b>METHODS</b>Five townships in Fangshan District, Beijing were divided into intervention and control communities with cluster sampling. Totally 772 farmers were selected randomly for interviews with a questionnaire of KAB, including 424 in the intervention communities (IC) and 348 in the control communities (CC) in 1992. After community-based health promotion and education on cardiovascular prevention for eight years, 895 farmers, including 431 in IC and 464 in CC, were selected randomly again in 1999 to be interviewed with the same questionnaire of KAB used in 1992.</p><p><b>RESULTS</b>From 1992 to 1999, knowledge of cardiovascular diseases was significantly improved in residents of IC (P < 0.01) and CC. Compared to the residents in CC, there was a net increase in knowledge in residents of IC. Significant improvement was found in 10 and 11 of the 18 items of knowledge in males and females (P < 0.01), respectively. Level of knowledge in cardiovascular diseases was significantly higher in the residents of IC than those of CC in 1999. Proportions of those with positive attitudes and appropriate behaviors were significantly elevated in the residents of IC (P < 0.01), as well as prevalence of smoking and alcohol drinking decreased. However, as compared to CC, attitude and behavior in most aspects in the residents of IC changed positively, but in few aspects changed negatively. It suggested knowledge improved better than attitude and behavior changed.</p><p><b>CONCLUSIONS</b>Community-based health promotion and education for a longer term had obvious effects on improvement of knowledge in cardiovascular disease for rural population, but slower effects on changes in attitude and behavior, which suggested there still existed certain barriers to transform knowledge into healthy behavior.</p>

Prevalence and Relevant Risk Factors of Low Blood Pressure in China / 中华高血压杂志

Objective　 To study the prevalence and relevant risk factors of low blood pressure and its influence on cardiovascular diseases in China. Methods　A cross-sectional study for low blood pressure was conducted using the data of the third national survey of blood pressure in 1991. Low blood pressure was defined for systolic (SBP) and diastolic (DBP) pressure less than the tenth percentile for the sample (SBP≤98mmHg and DBP≤60mmHg). Results　The prevalence of low blood pressure for males and females were 2.7% and 7.4%, respectively. The prevalence of low blood pressure for females was higher than that of males (P<0.01). Prevalence of low blood pressure was 7.62%, 6.97%, 4.40%, 3.22%, 2.65%, 1.94% for age groups 15～, 25～, 35～, 45～, 55～, 65～, respectively. The prevalence of low blood pressure was gradually declined with aging. There was large variation in the prevalence of low blood pressure for different minorities. The prevalence of low blood pressure was higher in the southern rather than the northern part of China. Logistic regression showed that the age (OR 0.97, 95%CI 0.97～0.98, per 10 mmHg), BMI (OR 0.80, 95%CI 0.80～0.81), drinking (OR 0.89, 95%CI 0.86～0.93) and heart rate (OR 0.981, 95%CI 0.980～0.982) had reverse relationship with low blood pressure. The sex had a positive relationship with low blood pressure. The prevalence of stroke and myocardial infarction in the population with low blood pressure was lower than that of normal pressure or hypertension (P<0.01). Conclusion　The prevalence and relevant risk factors of low blood pressure in China were various. We speculate that low blood pressure in Chinese population appears to be a normal state of physiology.The difinite influence in health needs cohort studies to confirm.

he roles of hypoxia and glutamic acid on NMDA receptor channel of hypothalamic neuron in rats / 第三军医大学学报

Objective　To study the effects of hypoxia and glutamic acid on the kinetic properties of NMDA receptor channel of the hypothalamic neurons in rats. Methods　Cell-attached mode patch clamp technique was employed to record the single channel current of the NMDA receptor. Results　The open probability of NMDA receptor channel was increased after acute hypoxia compared with that of normal state, the open time τ1,τ2 was changed from (0.33±0.10)ms，(4.36±0.26)ms to (0.93±0.22)ms，(7.64±0.72)ms, and the close time τ1,τ2 was from (18.03±3.50)ms，(171.50±19.10)ms to (3.42±1.02)ms，(19.39±3.07)ms. The mean open probability was changed from 0.12±0.05 in normal state to 0.66±0.36 in hypoxia state. Furthermore, glutamic acid can increase open time and open probability of NMDA receptor channel,decrease close time. Conclusion　The excitability and the open probability of NMDA receptor channel of hypothalamic neurons increased by hypoxia is related to glutamate.

Effect of altitude hypoxia on glutamate, aspartate and NOS in the rat hypothalamus / 中国病理生理杂志

AIM: To observe the effect of altitude hypoxia on glutamate, aspartate and nitric oxide synthase (NOS) in the rat hypothalamus. METHODS: Using altitude hypoxia model, amino acid analysis system and the NADPH-d histochemistry, we determined the content of glutamate, aspartate and the number of NADPH-d neurons in the rat hypothalamus. RESULTS: After altitude hypoxia, the contents of glutamate, aspartate in the hypothalamus of rats were increased significantly, densely and deeply stained NADPH-d neurons were seen in hypothalamic paraventricular nucleus (PVN)and supraoptic nucleus(SON). If rat were pretreated with the NMDA receptor blockers Ketamine (ip,40 mg/Kg)or AP-V(i.c.v, 10 ?g) , the number of NADPH-d neurons in the rat hypothalamic PVN and SON was markedly less than that in corresponding altitude hypoxia group. CONCLUSION: NMDA receptor may take part in the expression of hypothalamic NOS induced by altitude hypoxia.

Effect of altitude hypoxia on somatostatin and ?-aminobutyric acid content of rat hypothalamus / 中国病理生理杂志

AIM:To observe the effect of altitude hypoxia on ?-aminobutyric (GABA) content and prepro-somatostatin mRNA (PPS-mRNA) in the rat hypothalamus. METHODS: Using altitude hypoxia model,in situ hybridization and amino acid analyzer, the number of PPS-mRNA and GABA content in rat hypothalamus was determined. RESULTS:After altitude hypoxia, the contents of GABA in hypothalamus and the number of PPS-mRNA neurons in periventricular nucleus (PeVN), paraventricular nucleus (PaVN) and arcuate nucleus (ArcN) increased significiantly. Bicuculline, a GABA receptor antagonits, could enhance PPS-mRNA expression evoked by altitude hypoxia, but had no effect on GABA content. CONCLUSION: Altitude hypoxia can induce neurotransmitter imbalance of hypothalamus.

Morphological localization of NG2 positive cells in the brain of adult rats / 第三军医大学学报

Objective To observe the localization of NG2 positive cells and morphological character in the brain of adult rats. Methods Immunohistochemical method was applied to determine the expression of NG2 positive cells in the cerebrum cortex, hippocampus, dentate gyrus, thalamencephalon and hypothalamus of adult rats. Image analysis program Image Pro Plus 5.0 was used to count the positive cells and for statistic analysis. Results NG2 positive cells were strongly expressed in multiple brain regions of adult rats, of which strongest signals were centralized in gray and white matter of cerebral cortex, hippocampus, dentate gyrus, thalamic subventricular zone and hypothalamic periventricular region. The NG2 positive cells were seen with abundant process arborization which bifurcated two or more times. The soma of NG2 positive cell displays a star-like morphology with different shapes in the gray and white matter of cerebrum cortex. Conclusion NG2 positive cells are numerous in adult rat brain and display the special glial with a stellate morphology.

A study on the mechanism of insulin resistance of adipose tissue after scalding in rats / 第三军医大学学报

The possible mechanism of insulin resistance of the adipose tissue after burn injury was studied.The binding activity of the insulin receptors,the insulin effects on insulin-sensitive phosphodiesterase(PDE)and the level of free fatty acid(FFA)and cAMP were observed for 4 d in the adipose tissue of the rats inflicted with 30% TBSA full thickness scalding. It was found that the maximal binding capacity of the insulin receptors was greatly decreased(P

Effect of astrocyte-derived estrogen on the regulation of the synaptic transmission in rats / 第三军医大学学报

Objective To study the effect and the mechanism of astrocytes-derived estrogen on synaptic transmission. Methods Based on the model of pure cultures of neonatal cortical neurons, the experimental groups were designed as follows: pure neuron culture (group P), ACM culture (group A), mixed culture of AST and neuron (group M), E_ 2 culture (group E), ACM+tamoxifen (estrogen receptor antagonist) culture (group A+T ), tamoxifen culture (group T). The difference among these groups of synaptic transmission was recorded by patch clamp and presynaptic vesicle releasing kinetics was marked by a dye named FM4-64. Results The mean amplitude and frequency of miniature postsynaptic currents (mPSCs) of group P, A, M, E, A+T and T were: (20.5?2) pA, (13?4) min -1 ; (29.1?3) pA, (73?16) min -1 ; (31.3?3) pA, (78?20) min -1 ; (30.2?3) pA, (76?18) min -1 ; (24.5?2) pA, (35?10) min -1 ; (22.1?2) pA, (37?10) min -1 respectivily. The treatment of pure neuron culture with ACM increased synaptic transmission of pure cultured cortical neuron. Exogenic estradiol added into pure neurons can stimulate the effect of the ACM. Tamoxifen which was the antagonist of estrogen receptor could decrease most effect of ACM on synaptic transmission. The assaying of vesicle release marked by FM4-64 showed astrocytes-derived estrogenic enhancing synaptic transmission was at least mediated by strengthening presynaptic vesicle releasing. Conclusion The estrogen from astrocytes of neonatal rat cortex may enhance neuronal synaptic transmission mainly through estrogen receptor.

THE EFFECT AND MECHANISM OF ASTROCYTE ON SYNAPTIC FORMATION IN RATS / 解剖学报

Objective To study the effect of astrocyte on synapse formation and the molecular mechanism. Methods Cortical astrocytes were isolated and purified from neonatal rats.On the 2h,7th day,14th day and 21th day after passage,we counted the number of astrocytes and the culture medium(astrocyte-conditioned medium,ACM)was harvested to measure the concentration of estrogen(E 2)by using ELISA techniques.Based on the model of pure culures of neonatal cortical neurons,the experimental groups were designed as follows:1.pure neuron cultures(group N);2.ACM cultures(group A);3.mixed cultures(group M);4.E 2 cultures(group E 2);5.ACM+Tamoxifen(estrogen receptor antagonist)cultures(group A+T);6.Tamoxifen cultures(group T).Then synaptic puncta in every group was stained and counted through immunofluorescence,and we also compared the differences in puncta number among those six groups(at 9th day in culture,number/per neuron). Results The numbers of astrocytes were:1?10 4/ml, 1.1?10 6/ml, 1.4?10 6/ml, 1.5?10 6/ml; The concentrations of E 2 were:(ng/L):0, 117?22, 266?22,252?27 respectively.No estrogen was detected in the primary culture medium.The concenteration of estrogen increased in correspondence with the culturing days and reached the peak around at the 14th day, then decreased gradually but kept at a certain high level,and the numbers of synaptic puncta of per neuron in group N,A,M,E 2,A+T,T were:14?3;79?5;83?8;80?6;32?3;29?3 respectively.The treatment of pure neuron culture with ACM increased the number of synapses on per neuron by up to 6 fold by comparison with pure neuronal culture.Exogenic estradiol added into pure neurons can mimick the effect of the ACM.Tamoxifen which is antagonist of estrogen receptor could decrease the effect of ACM by 75%.Conclusion The astrocytes of neonatal rat cortex do secrete E 2.Astrocyte-derived estrogen may be the molecule regulating the synaptic formation through estrogen receptors.