牛磺酸对大鼠局灶性脑缺血的神经保护作用

目的 观察牛磺酸对大鼠持续性局灶性脑缺血的影响。方法 采用大脑中动脉线栓法制备大鼠局灶性脑缺血模型 ,随机分为假手术组、缺血模型组和牛磺酸 (2 5 0mg·kg-1·d-1)治疗组 ,持续缺血 6h后观测各组的神经行为变化 ,脑梗死体积 ,脑组织丙二醛 (malondialdehyde ,MDA)含量和超氧化物歧化酶 (superoxidedismutase,SOD)活性 ,一氧化氮合酶 (nitricoxidesynthetase,NOS)含量及表达 ,细胞间粘附分子 1(inter cellularadhesionmolecule 1,ICAM 1)的表达。结果 ①牛磺酸可以改善大鼠持续性局灶性脑缺血引起的神经行为障碍 ,减少脑梗死体积 ;②可以提高脑组织SOD活性 ,但对MDA水平未见明显影响 ;③对脑组织NOS含量及表达未见明显影响 ;④明显减少ICAM 1阳性血管计数。结论 牛磺酸可通过增强脑组织SOD活性 ,提高清除氧自由基能力 ,以及减少脑缺血引起的ICAM 1表达 ,从而减轻脑缺血后的炎症反应 。

国产异丙酚乳剂对大鼠体外左心室功能的影响及其对心肌缺血再灌注损伤的保护作用

目的 研究国产异丙酚乳剂 (商品名 :力蒙欣 )对体外心脏左心室功能的影响及在缺血再灌注损伤中的作用并与进口异丙酚乳剂 (得普利麻 )作一比较。方法 采用大鼠体外心脏Langendorff灌注模型 ,将 30只大鼠分为 5组 ,每组 6只。在平衡灌注 2 0min后分为力蒙欣 1组 (L1组 )与力蒙欣 2组 (L2组 ) ,分别灌注含有 2 5 μmol/L及 5 0 μmol/L力蒙欣的K -H溶液 10min ;得普利麻 1组 (D1组 )与得普利麻 2组 (D2组 ) ,分别灌注含有 2 5 μmol/L及 5 0 μmol/L得普利麻的K -H溶液 10min ;Con组则继续平衡灌注 10min。然后各组均停灌 30min后再灌注 30min。分别于平衡末、用药后、再灌末记录左心室功能指标 :左心室舒张末压、左心室内压上升和下降最大速率、左心室发展压及心率。再灌注末取左心室前壁心肌 ,液氮保存 ,以反相高效液相色谱分析法 (rHPLC)测定ATP含量。结果 用药后 10min 2 5 μmol/L的力蒙欣对心肌收缩力无影响 ,2 5 μmol/L得普利麻对心肌收缩力有一定的影响 ,但两者对心率均有一定的抑制作用 (P <0 .0 5 ) ;5 0 μmol/L的力蒙欣及得普利麻对心肌收缩力和心率都有显著的抑制作用 (P <0 .0 5 ,P <0 .0 1) ;力蒙欣组及得普利麻组均促进了缺血再灌注心肌的功能恢复并且心肌组织的ATP含量较对照组高

《船舶气体保护焊工艺设计与实作》课程改革实践与探索

我国船舶工业的快速发展为高职院校进一步加快培养大批高素质技能型船舶焊接技术专门人才提供了极好的机遇。本文结合教学改革实践经验,从基于行业需要构建课程体系等方面,阐述了对《船舶气体保护焊工艺设计与实作》课程的教学内容、教学方法、考试内容以及考试形式进行的实践及其新探索。

喀喇沁旗农业保护性耕作技术应用初探

根据喀喇沁旗气候特点 ,农业生产实际确定了留高茬、免耕播种技术工艺 ,分析了一年来 保护性耕作的实施效果 。

Study on the effect of four kinds of raw materials in hypertonic dehydration cell model

It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The safety mass concentrations of four raw materials were screened by detecting cell viability,and the secretion of hyaluronic acid(HA)was determined using the ELISA method.The expression of HaCaT barrier function related genes(OVOL1,EREG,TGM1,TGM2,IVL,IRF6,THBS1,CASP14)was detected at the mRNA level to explore the regulatory effect of four raw materials on these genes.The results demonstrate that pretreatment with the four kinds of raw materials could increase the cell viability after hyperosmotic dehydration,promote the secretion of HA,and improve the expression of barrier function related genes after hyperosmotic dehydration,among which panthenol and Calendula officinalis L.are better.The results show that the four raw materials have a certain protective effect on the hyperosmotic dehydration cell model,which provides data support for its application in cosmetics.

Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa

Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage.

Protective Effects of Tea Polyphenol on Cerebral Ischemia-Reperfusion Injury in Rats and Its Scavenging Oxy-radical and Anticerebral Lipid Peroxidation Effects

AIM To study the protective effects of tea polyphenol (TP) on cerebral ischemia reperfusion injury in rats and its scavenging oxygen free radical(OFR) activities and antilipid peroxidation in vitro . METHODS Cerebral ischemia reperfusion injury was produced by bilateral ligation of the common carotid arteries with vagus nerves and reperfusion for 45 min. The mitochondrial lipid peroxidation of rat brain induced by oxygen free radical was measured by thiobarbituric acid spectrophotometry. Superoxide anion (O 2) from xanthine xanthine oxidase system and hydroxyl radical (·OH) from Fe 2+ -H 2O 2 system were determined with spectrophotometry. RESULTS During Cerebral ischemia reperfusion,TP improved the activities of superoxide dismutase ( P 【0 05), GSH peroxidase( P 【0 01) and catalase( P 【0 01), while decreasing the maiondialdchyde content in the brain( P 【0 05) and brain water content ( P 【0 01). Tea polyphenol possessed significantly scavenging effects on ·OH produced by Fenton reaction and O 2 produced by xanthine xanthine oxidase system (the IC 50 were 2 2 mmol·L -1 and 1 9 mmol·L -1 respectively). Tea polyphenol could significant inhibit the lipid peroxidation of cerbral mitochondrial membrane induced by ·OH in a concentration dependent manner. CONCLUSION The results indicate that tea polyphenol could protect the injury on cerebral ischemia reperfusion in rats for OFR, these effects may be related to its scavenging effects on oxygen free radicals and antilipid peroxidant.

The Protective Role of Xanthophyll Cycle in Resurrection Angiosperm Boea hygrometrica During Dehydration and Rehydration

The protective role of xanthophyll cycle in resurrection angiosperm Boea hygrometrica (Bunge) R.Br. was investigated by analysis of the changes of chlorophyll fluorescence and xanthophyll cycle components in response to dehydration and rehydration in detached leaves under very weak light condition (3 mumol photons.m(-2).s(-1)) and in the dark. With declines in the values of PSII photochemical efficiency (Fv/Fm), PSII actual quantum yield (Phi(PSII)), photochemical quenching (qP) and non-photochemical quenching (NPQ) during dehydration, zeaxanthin significantly increased in control Boea leaves under very weak light condition, while no zeaxanthin accumulation was detected in Boea leaves treated with dithiothreitol (DTT) and Boea leaves in the dark, and after 3 d rehydration, the parameters Fv/Fm, Phi(PSII), qP and NPQ showed full recovery in control Boea leaves under very weak light condition, but the parameters only underwent partial recovery in Boea leaves treated with DTT and Boea leaves in the dark, suggesting that the recovery of photosystem II (PSII) photochemical activities in Boea leaves was obviously affected by treatments with DTT and darkness, therefore, zeaxanthin may play an important protective role in desiccated Boea leaves even under very weak light conditions.

Protective Effect of Ascorbate-Lysine on Carbon Tetrachloride and Alcohol-Induced Liver Injury in Mice

As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.

天麻药理研究进展

综述了天麻药理研究的相关文献。这些文献主要研究了天麻的抗惊厥、心脑血管、神经保护和改善学习记忆作用等方面。上述药理作用与其多种酚性成分密切相关。

Neuroprotective Effects of Modafinil on MPTP Mouse Model of Parkinson′s Disease

Aim To observe the neuroprotective effects of modafinil on the Parkinson'sdisease ( PD ) model induced by 1-methyl-4-phenyl-1, 2,3, 6-tetrahydropyridine (MPTP ). Methods Themodel of PD was induced by intraperitoneal injection of MPTP into C57BL/6J mice for 4 d. Modafinil(ip, 50 or 100 mg·kg^(-1)·d^(-1)) was administered following MPTP for 4 d and for another 10 dconsecatirely. The effects of modafinil on the locomotor activity, and the incubation, maintenanceperiod and grade of the tremor, the duration of the climbing rod of mouse, and the distribution ofpositive cells of ty-rosine hydroxylase (TH) and Nissl bodies in the striatum and substantia nigra(SN) were observed. The contents of dopam-ine (DA) , noradrenaline (NA) and 5-hydroxytryptamine(5-HT) in the striatum were determined. Results Modafinil (50 and 100 mg·kg^(-1)) significantlyprevented the locomotor, the tremor and climbing rod defect behavior in a dose-dependent manner (P <0.05 and P < 0.01, n = 10), prevented the decrease in the number of TH-positive cells and Nisslbodies (P<0.05, n=10), and reduced the decrease of DA, NA, and 5-HT in the striatum (P < 0.05, n =10) induced by MPTP. Conclusion Modafinil improves the behavioral deficits and prevents themonoaminergic neuron lesion in seriously impaired MPTP mouse model.

Effect of Echinacea Polysaccharide on Secretion of TNF-α mRNA by IEC-6 Injured by LPS

Objective] This study was conducted to investigate Echinacea polysaccha-ride （EPS） on expression of tumor necrosis factor （TNF） under injury of intestinal epithelial cel s （lEC-6） by lipopolysaccharide （LPS）, so as to discuss the action mechanism of EPS to injured cel s. [Method] Total DNA was extracted with TRlzon reagent, TNF-α mRNA was amplified, and the amplification products were subjected to agarose gel electrophoresis and imaging. [Result] 50 μg/ml EPS could partial y in-hibited the production of TNF-α mRNA by lEC-6 under the stimulation of LPS, while the inhibition of 200 and 500 μg/ml EPS on the level of TNF-α mRNA gradual y in-creased with the concentration increasing; and lEC-6 cel s pretreated with 50, 100, 200 and 500 μg/ml EPS for 24 h and then stimulated by 10 μg/ml LPS for 1 and 4 h were analyzed by RT-PCR method, and it was found that the expression of TNF-α mRNA induced by LPS could be effectively inhibited by EPS, and the inhibition rate at 4 h was higher than that at 1 h. [Conclusion] EPS could play its role of protecting intestinal mucosa by inhibiting the secretion of TNF-α mRNA by cel s un-der the stimulation of LPS, and such inhibition effects of EPS had concentration dependency and time dependency.

PROTECTION OF ELECTROACUPUNCTURE ON HIPPOCAMPAL INJURY INDUCED BY QUINOLINIC ACID IN RATS

Objective To probe into the protective mechanism of electro-acupuncture （EA） on anti-oxygen stress in dementia-model rats. Methods A total of 30 male SD rats of cleaning grade were randomized into three groups, named sham-operation （n = 10）, model （n = 10）, model＋ EA （n = 10）. The dementia-model rat was made with hippocampal GA1 lesions by quinolinic acid （QA）. On the second day of modeling, in model＋ EA group, EA （3 Hz, 2-4 mA, continuous waves） was applied to ＂Dàzhuī＂ （大椎 GV 14） and ＂Shènshū＂ （肾俞 BL 23） for 10 min. The capability of learning and memory was evaluated by step-down test to observe the changes of nitric oxide （NO）, nitric oxide synthase （NOS） activity, superoxide dismutase （SOD） activity and malondialdehyde （MDA） of the hippocampal tissues in rats separately by biochemical methods. Results EA improved learning and memory of dementia rats with hippocampal CA1 lesions induced by QA at different degrees. It significantly increased SOD activity, reduced MDA content and improved NO level and NOS activity. Conclusion EA improves significantly the learning and memory of the dementia rats due to hippocampal CA1 lesions induced by QA, which is probably relevant with the anti-oxygen stress of EA.

Photoinhibition in Shaded Cotton Leaves After Exposing to High Light and the Time Course of Its Restoration

Chlorophyll fluorescence emission, pigment composition and photosynthetic rate of shade-grown cotton ( Gossypium hirsutum L.) plants were measured immediately after suddenly exposing to full sunlight and at regular intervals there after within 15 d. Photoinhibition occurred in shade-grown cotton leaves immediately after exposed to full sunlight. The chlorophyll fluorescence parameter F-v/F-m and PhiPS II, which reflect the efficiency of PS II,obviously decreased in shade-grown leaves, much lower than that of the full sunlight-grown leaves. On the contrary, F-o value was sharply increased. Neither of these parameters could completely recover till next morning. The photoinhibition was chronic and continued for about 4 d, while the F-v/F-m and the net photosynthetic rate ( P-n) continued to decline, then began to increase gradually 6 d later and turned stable after 10 - 12 d, appearing as an acclimation phenomenon. However, the final value of F-v/F-m and P-n did not reach the level as in those leaves grown in the full sunlight ever before. The final P-n was higher by 60% than that before exposure, but lower for more than 40% than that of the full sunlight-grown leaves. The most notable response of chloroplast pigment composition was a pronounced increase in the pool size of carotenoids in xanthophyll cycle over a period of 3 d. The results indicated that when shade-grown cotton seedlings were suddenly transferred to the full sunlight, the decline of F-v/F-m and P-n might associate with the damage of the PS II reaction center. During the light acclimation, photoprotective mechanisms such as the xanthophyll cycle-dependent energy dissipation were increased, so that photodamage in leaves transferred from low to high light might be reduced.

Role and Protection of Dongting Lake

Water and sediment in four-inlet river system and the water level at Chenglingji reflect the current relationship between Yangtze River and Dongting Lake. Since the flow in four-inlet river system is reduced gradually, the lake water level is also reduced, resulting in shrunk lake area, channelized lake, narrowed channel and reduced rfve beach. Facing the changed relationship the River and the Lake after the utilization of Three Gorges Project, the Chenglingji control engineering at the outlet of Dongting Lake and the dredging of four-inlet river system are car- ried out. Thus the roles of flood control （1.67x101~ m3） and water amount regulation （2.3~101~ m3） of Dongting Lake are fully played. The Dongting Lake plays compen- sating and scheduling roles in the flood control and water storage of the Three Gorges Reservoir. It can reduce a volume of 4.0x109 m3 of excess flood around Chenglingji. In addition, it can also provide a water supply of 5 000 m3/s to the lower reaches of Yangtze River during the dry season for about 30 d. The Dongt- ing Lake plays an important role in the stabilization of ecological environment in the watershed, the regional water resources security and the protection of Dongting Lake and Yangtze River.

Interactions between γ-TiAl melt and Y_2O_3 ceramic material during directional solidification process

A γ-TiAl alloy with nominal composition of Ti-47%Al（molar fraction） was directionally solidified in an alumina mould with an Y2O3 protective coating.The effects of processing parameters（melting temperature and interaction time） on the metal-coating interface,microstructure and chemical composition of the alloy were evaluated.The result shows that the Y2O3 protective coating exhibits an effective barrier capability to avoid direct contact between the mould base material and the TiAl melt,although the Y2O3 coating is found to suffer some erosion and be slightly dissolved by the molten TiAl due to the coating-metal interactions.The directionally solidified alloys were contaminated with Y and O,and Y2O3 inclusions were dispersed in the metal matrix.The reason for this metal contamination is the Y2O3 coating dissolution by the TiAl melt.One mode of the interaction between Y2O3 and the TiAl melt is dissolution of yttrium and atomic oxygen in the melt by reaction Y2O3（s）=2Y（in TiAl melt）＋3O（in TiAl melt）.Both the extent of alloy contamination and the volume fractions of Y2O3 inclusions depend on the melting temperature and the interaction time.

Protective effect of Radix Astragali injection on immune organs of rats with obstructive jaundice and its mechanism

AIM: To observe the protective effect of Radix Astragali injection on immune organs (lymph nodes, spleen and thymus) of rats with obstructive jaundice (OJ) and its mechanism. METHODS: SD rats were randomly divided into sham-operation group, model control group and Radix Astragali treatment group. On days 7, 14, 21 and 28 after operation, mortality rate of rats, pathological changes in immune organs, expression levels of Bax and nuclear factor (NF)-κB p65 proteins, apoptosis indexes and serum tumor necrosis factor (TNF)-α level in spleen and thymus were observed, respectively.RESULTS: Compared to model control group, the number of dead OJ rats in Radix Astragali treatment group decreased (P > 0.05). The TNF-α level (27.62 ± 12.61 vs 29.55 ± 18.02, 24.61 ± 9.09 vs 31.52 ± 10.95) on days 7 and 21, the pathological severity score for spleen [0.0 (0.0) vs 0.0 (2.0) on days 7 and 14 and for lymph nodes [0.0 (1.0) vs 1.0 (2.0), 1.0 (0.0) vs 2.0 (1.0)] on days 21 and 28, the product staining intensity and positive rate of Bax protein in spleen [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5) and thymus [0.0 (0.0) vs 1.0 (2.0), 0.0 (1.0) vs 2.0 (1.5)] on days 14 and 28, the apoptotic indexes [0.0 (0.0) vs 0.0 (0.01)] in spleen and thymus [0.0 (0.0) vs 0.0 (0.01) on days 14 and 21 were significantly lower in Radix Astragali treatment group than in model control group (P < 0.05). CONCLUSION: Radix Astragali has protective effects on immune organs of OJ rats by relieving the pathological changes in immune organs, reducing TNF-α level and inhibiting Bax expression and apoptosis in spleen and thymus.

Protective effect of estradiol on hepatocytic oxidative damage

AIM: To examine the protective effect of estradiol on the cultured hepatocytes under oxidative stress. METHODS: Hepatocytes of rat were isolated by using perfusion method, and oxidative stress was induced by a serum-free medium and FeNTA. MDA level was determined with TBA method. Cell damage was assessed by LDH assay. Apoptosis of hepatocytes was assessed with cytoflowmetric analysis. Expression of Bcl-xl in cultured hepatocytes was detected by Western blot. The radical-scavenging activity of estradiol was valued by its ability to scavenge the stable free radical of DDPH. RESULTS: Oxidative stress increased LDH from 168 +/- 25 x 10(-6)IU.cell(-1) to 780 +/- 62 x 10(-6)IU.cell(-1) and MDA(from 0.28 +/- 0.07 x 10(-6)nmol.cell(-1) to 1.35 +/- 0.12 x 10(-6)nmol.cell(-1)) levels in cultured hepatocyte, and estradiol inhibited both LDH and MDA production in a dose dependent manner. In the presence of estradiol 10(-6)mol.L(-1), 10( -7 )mol.L(-1) and 10(-8)mol.L(-1),the LDH levels are 410 +/- 53 x 10(-6)IU.cell(-1) (P【0.01 vs oxidative group), 530 +/- 37 X 10(-6)IU.cell(-1 ) (P【0.01 vs oxidative group), 687+/-42 x 10(-6)IU.cell(-1) (P【0.05 vs oxidative group) respectively, and the MDA level are 0.71+/-0.12 x 10(-6)nmol.cell(-1) (P【0.01 vs oxidative group),0.97+/-0.11 x 10(-6)nmol.cell(-1 )(P【0.01 vs oxidative group) and 1.27+/-0.19 x 10(-6)nmol.cell(-1) respectively. Estradiol suppressed apoptosis of hepatocytes induced by oxidative stress, administration of estradiol(10(-6)mol/L)decreased the apoptotic rate of hepatocytes under oxidative stress from 18.6 +/- 1.2% to 6.5 +/-2.5%, P【0.01. Bcl-xl expression was related to the degree of liver cell damage due to oxidative stress, and estradiol showed a protective action. CONCLUSION: Estradiol protects hepatocytes from oxidative damage by means of its antioxidant activity.