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1.
摘要 目的:探究黄芪多糖(APS)对食管癌(EPC)模型大鼠的抑瘤作用、免疫功能及磷脂酰肌醇-3-激酶(PI3K)/蛋白激酶B(Akt)信号通路的影响。方法:选取6周龄SPF级健康SD大鼠50只,随机分为模型组(M组)、顺铂组(S组)、黄芪多糖低剂量组(APSL)、黄芪多糖中剂量组(APSM)、黄芪多糖高剂量组(APSH),每组10只。通过移植人食管癌Eca109细胞建立EPC模型,分别给予3 mg/kg顺铂和100、200、400 mg/kg的APS干预。测量各组大鼠肿瘤体积和肿瘤质量,计算肿瘤生长抑制率、胸腺指数和脾指数,HE染色观察肿瘤组织形态学,采用流式细胞仪检测外周血CD3+、CD4+、CD8+T淋巴细胞群,Western blot测定各组肿瘤组织中PI3K和Akt蛋白的相对表达。结果:经干预后,S组和各APS组大鼠肿瘤体积和肿瘤质量均显著小于M组(P<0.05);S组和APSH组肿瘤体积和肿瘤质量相显著小于APSM和APSL组(P<0.05);APSM组大鼠肿瘤体积和肿瘤质量显著小于APSL组(P<0.05);APSH、APSM和APSL组的抑瘤率分别为45.59%、32.35%和17.65%。S组大鼠的胸腺指数和脾指数均显著低于M组(P<0.05);各APS组大鼠的胸腺指数和脾指数均显著高于S组(P<0.05);APSH和APSM组大鼠胸腺指数和脾指数均显著高于M组(P<0.05)。各APS组大鼠CD3+、CD4+和CD4+/CD8+均显著高于S组和M组,而CD8+均显著低于S组和M组(P<0.05);APSH、APSM和APSL组之间两两相比亦均有统计学差异(P<0.05)。S组和各APS组PI3K/Akt信号通路蛋白的相对表达均显著低于M组(P<0.05);APSH、APSM和APSL组之间两两相比亦均有统计学差异(P<0.05)。结论:APS可通过调控PI3K/Akt 信号通路和改善免疫功能,发挥对EPC的抑制作用,为临床治疗EPC提供了新的思路和理论依据。  相似文献   

2.
摘要 目的:探讨加味八珍汤联合mFOLFOX6方案对晚期结直肠癌患者肿瘤标志物、免疫功能和外周血磷脂酰肌醇3酶(PI3K)-丝苏氨酸蛋白激酶(Akt)信号通路的影响。方法:根据随机数字表法将广州中医药大学附属北碚中医院2020年9月至2022年1月期间收治的晚期结直肠癌患者96例分为对照组(48例,mFOLFOX6方案治疗)和研究组(48例,加味八珍汤联合mFOLFOX6方案治疗)。对比两组疗效、中医证候积分、卡式评分(KPS)、肿瘤标志物、免疫功能和外周血PI3K-Akt信号通路相关指标。结果:与对照组相比,研究组的临床总有效率升高(P<0.05)。研究组治疗后的中医证候总积分低于对照组,KPS评分高于对照组(P<0.05)。研究组治疗后的CD4+、CD4+/CD8+、免疫球蛋白(Ig)M、IgA高于对照组,CD8+低于对照组(P<0.05)。研究组治疗后的血清癌胚抗原(CEA)、糖类抗原199(CA199)、糖类抗原72-4(CA72-4)低于对照组(P<0.05)。研究组治疗后的外周血PI3K、Akt mRNA表达水平低于对照组(P<0.05)。两组不良反应发生率对比无差异(P>0.05)。结论:加味八珍汤联合mFOLFOX6方案治疗晚期结直肠癌的疗效显著,可有效阻止晚期结直肠癌的疾病进展,增强免疫力,降低血清肿瘤标志物水平,其疗效机制可能与调节外周血PI3K-Akt信号通路有关。  相似文献   

3.
摘要 目的:观察扶正方对Lewis肺癌小鼠免疫功能、磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(AKT)信号通路和外周血白细胞介素(IL)-2、IL-6、γ干扰素(INF-γ)的影响。方法:将40只Lewis肺癌小鼠随机分为模型组(M组)、扶正方低剂量组(A组)、扶正方高剂量组(B组)、顺铂组(S组),每组10只,A组、B组分别给予扶正方0.4 mL/20 g、0.8 mL/20 g灌胃,M组给予生理盐水0.4 mL/20 g灌胃,S组给予顺铂1 mg/mL,0.4 mL灌胃,连续14d,比较各组小鼠一般情况、肿瘤重量,胸腺指数、脾脏指数、脾脏CD3+细胞、CD4+细胞、CD8+细胞比例细胞百分比,鼠肿瘤组织PI3K/AKT信号通路蛋白表达水平及外周血IL-2、IL-6、INF-γ水平。结果:A组、B组、S组小鼠肿瘤重量低于M组,S组小鼠肿瘤重量低于A组、B组(P<0.05),治疗前各组小鼠体重比较无统计学差异(P>0.05),治疗后A组、B组小鼠体重高于S组、M组(P<0.05)。A组、B组小鼠胸腺指数显著高于M组、S组(P<0.05)。A组、B组CD3+、CD4+、CD4+/CD8+显著高于M组、S组,CD8+显著低于M组、S组(P<0.05),B组CD3+、CD4+、CD4+/CD8+显著高于A组,CD8+低于A组(P<0.05)。A组、B组、S组小鼠肿瘤组织PI3K蛋白、AKT蛋白表达水平显著低于M组(P<0.05)。A组、B组、S组小鼠外周血IL-2、INF-γ水平显著高于M组,IL-6水平显著低于M组(P<0.05)。结论:扶正方可以提升Lewis肺癌小鼠免疫功能,调节IL-2、IL-6、INF-γ细胞因子水平,抑制PI3K/AKT信号通路起到抗肺癌的作用。  相似文献   

4.
摘要 目的:研究千金藤素腹腔注射对卵巢癌模型大鼠的作用及其机制。方法:选取30只SD级清洁级健康雌性大鼠,按照随机数字表法分成模型组、实验组与空白对照组,每组各10只。空白对照组不予以处理,模型组与实验组建立卵巢癌模型,且实验组在造模后予以千金藤素腹腔注射干预,使用剂量为20 mg/kg每次,1次/d,给药30d,模型组与空白对照组予以等量生理盐水干预。比较各组大鼠荷瘤重量、腹水量以及肿瘤体积,癌胚抗原(CEA)、糖类抗原153(CA153)及人附睾蛋白(HE4)表达水平,磷脂酰肌醇3-激酶(PI3K)、雷帕霉素靶蛋白(p-mTOR)、张力蛋白同源缺失的染色体(PTEN)表达,免疫指标水平。结果:模型组与实验组大鼠荷瘤重量、腹水量、肿瘤体积及CEA、CA153、HE4表达水平均高于空白对照组,且实验组大鼠上述各项指标水平均低于模型组(均P<0.05)。模型组及实验组大鼠的PI3K、p-mTOR、PTEN表达水平均低于空白对照组,且实验组大鼠的PI3K、p-mTOR、PTEN表达水平均高于模型组(均P<0.05)。模型组及实验组大鼠的CD4+、CD4+/CD8+水平均低于空白对照组,且实验组大鼠CD4+、CD4+/CD8+水平均高于模型组(均P<0.05);模型组及实验组大鼠的CD8+水平均高于空白对照组,且实验组大鼠CD8+水平低于模型组(均P<0.05)。结论:千金藤素腹腔注射对卵巢癌模型大鼠具有明显的抑癌作用,有利于下调肿瘤标志物水平,其主要作用机制可能与调控PI3K/mTOR信号通路、PTEN表达以及免疫功能有关。  相似文献   

5.
摘要 目的:研究肺癌患者外周血T淋巴细胞分型与抗核抗体之间的关系。方法:选择2019年1月到2021年6月在我院接受治疗的肺癌患者81例作为研究组,并选择同期健康志愿者81例作为对照组,检测并比较两组患者外周血CD4+、CD8+和CD4+/CD8+淋巴细胞比例,以及抗核抗体血清滴度。比较不同抗核抗体、年龄、性别、TNM分期、肿瘤分化程度以及病理类型肺癌患者外周血CD4+、CD8+和CD4+/CD8+淋巴细胞比例。结果:(1)肺癌患者外周血CD4+和CD4+/CD8+淋巴细胞比例显著低于对照组,而CD8+淋巴细胞比例显著高于对照组(P<0.05);(2)III+IV肺癌患者外周血CD4+、和CD4+/CD8+淋巴细胞比例均显著低于I+II肺癌患者,而CD8+淋巴细胞比例均显著高于I+II肺癌患者(P<0.05);(3)小细胞肺癌患者外周血CD4+、和CD4+/CD8+淋巴细胞比例均显著低于非小肺癌患者,而CD8+淋巴细胞比例均显著高于非小肺癌患者(P<0.05);(4)肺癌患者抗核抗体血清滴度显著高于对照组(P<0.05);(5)抗核抗体阳性患者CD4+和CD4+/CD8+淋巴细胞亚群比例均显著低于抗核抗体阴性患者,而CD8+淋巴细胞亚群比例显著高于抗核抗体阴性患者(P<0.05)。结论:肺癌患者外周血T淋巴细胞亚群表达异常,并且其表达水平可能与抗核抗体滴度有关。  相似文献   

6.
摘要 目的:观察右美托咪定联合舒芬太尼术后镇痛对老年肺癌患者T细胞亚群、血清炎性因子和疼痛介质指标的影响。方法:选取2017年7月~2020年12月期间200例我院收治的行肺癌根治术的老年患者,按随机数字表法分为研究组(n=100)、对照组(n=100)。对照组术后镇痛选用舒芬太尼,研究组术后镇痛选用右美托咪定联合舒芬太尼,观察两组患者视觉模拟评分法(VAS)评分和Ramsay镇静评分、外周血T细胞亚群、血清炎性因子和疼痛介质指标、不良反应。结果:两组术后6 h、12 h、24 h、48 h的Ramsay镇静评分、VAS评分均较术后1 h下降(P<0.05),且研究组以上时间点Ramsay镇静评分高于对照组,而VAS评分低于对照组(P<0.05)。两组术后24 h血清干扰素-γ(IFN-γ)、白细胞介素-6(IL-6)升高,但研究组术后24 h血清IFN-γ、IL-6低于对照组(P<0.05)。两组术后24 h外周血CD8+升高,CD3+、CD4+、CD4+/CD8+降低(P<0.05),但术后24 h研究组CD8+低于对照组,CD3+、CD4+、CD4+/CD8+高于对照组(P<0.05)。术后24 h两组血清β-内啡肽(β-EP)、P物质(SP)以及一氧化氮(NO)水平均升高,但研究组低于对照组(P<0.05)。两组不良反应发生率组间对比无统计学差异(P>0.05)。结论:右美托咪定联合舒芬太尼用于老年肺癌患者术后镇痛,镇痛、镇静效果确切,同时可减轻免疫抑制及炎性反应,且安全性高。  相似文献   

7.
摘要 目的:探讨独一味胶囊对复发性口腔溃疡(ROU)大鼠免疫功能和溃疡组织核因子-κB(NF-κB)炎症通路蛋白表达的影响。方法:将60只SD大鼠随机分为正常组、模型组和独一味胶囊低、中、高剂量组,每组12只。除正常组外其余各组均采用免疫法建立ROU模型,建模8周后独一味胶囊低、中、高剂量组分别灌胃给予0.01 mg/mL、0.02 mg/mL、0.03 mg/mL独一味胶囊溶液治疗,正常组和模型组灌胃给予等量生理盐水,均连续治疗20 d。记录各组大鼠口腔溃疡数目、持续时间和口腔溃疡面积,采用酶联免疫吸附法检测血清白介素(IL)-1β、IL-6、肿瘤坏死因子-α(TNF-α)水平,流式细胞术检测外周血CD3+、CD4+、CD8+百分比并计算CD4+/CD8+比值,免疫印迹法检测口腔黏膜组织NF-κB p65、磷酸化NF-κB抑制蛋白α(p-IκBα)、IkappaB激酶α(IKKα)蛋白水平。结果:正常组未出现口腔溃疡,模型组、独一味胶囊低剂量组、独一味胶囊中剂量组、独一味胶囊高剂量组溃疡数目依次降低,持续时间依次缩短,溃疡面积依次缩小(P<0.05)。模型组、独一味胶囊低剂量组、独一味胶囊中剂量组、独一味胶囊高剂量组、正常组IL-1β、IL-6、TNF-α、CD8+、NF-κB p65、p-IκBα、IKKα水平依次降低,CD3+、CD4+、CD4+/CD8+依次升高(P<0.05)。结论:独一味胶囊能显著减少ROU大鼠口腔溃疡数目和面积,缩短愈合时间,且效果呈剂量依赖性,其机制可能与改善免疫功能和抑制NF-κB炎症通路有关。  相似文献   

8.
摘要 目的:研究CAP方案联合艾迪注射液治疗晚期非小细胞肺癌的效果。方法:选择2016年1月~2019年1月我院的81例晚期非小细胞肺癌患者,随机分为两组。对照组的41例晚期非小细胞肺癌患者采用CAP方案,即快速静脉滴注吡柔比星50 mg/m2和环磷酰胺600 mg/m2,d1,顺铂80 mg/m2,d2-d4,1 个周期为28 d,共治疗2个周期。观察组的40例晚期非小细胞肺癌患者联合静脉滴注艾迪注射液,每次50 mL,每天1次,1个疗程为3 w,共治疗3个疗程。比较两组的免疫功能、生活质量和不良反应情况。结果:观察组的有效率明显高于对照组(P<0.05);观察组治疗后的CD4+、CD3+及CD4+/CD8+明显升高(P<0.05),且明显高于对照组(P<0.05);观察组的生活质量提高17例,稳定10例,降低6例,观察组的生活质量改善率为82.50%(33/40),明显高于对照组的53.66%(22/41)(P<0.05);观察组的消化道反应发生率明显低于对照组(P<0.05),两组的过敏反应、神经毒性和脱发发生率无明显差异(P>0.05)。结论:艾迪注射液联合CAP方案可以提高晚期非小细胞肺癌的化疗疗效以及生活质量,改善免疫功能,减轻化疗所致的不良反应。  相似文献   

9.
摘要 目的:探讨立体定向放疗(SBRT)联合内分泌治疗对转移性激素敏感性前列腺癌患者生活质量、免疫功能的影响。方法:选取我院2015年2月~2017年2月期间收治的转移性激素敏感性前列腺癌患者100例,根据信封抽签法将患者分为对照组(50例)和放疗组(50例),对照组给予内分泌治疗,放疗组在对照组的基础上联合SBRT治疗。对比两组前列腺特异性抗原(PSA)进展时间、PSA缓解率、治疗期间不良反应状况、3年生存率、免疫功能(CD3+、CD4+、CD8+、CD4+/CD8+)和扩展性前列腺癌复合指数量表(EPIC)各项评分。结果:随访3年,对照组有2例失访、放疗组有3例失访,放疗组的PSA进展时间长于对照组(P<0.05),放疗组的3年生存率高于对照组(P<0.05)。治疗后,两组CD3+、CD4+/CD8+、CD4+均下降,但放疗组较对照组升高(P<0.05),两组治疗后CD8+均升高,但放疗组较对照组降低(P<0.05)。治疗后6个月,放疗组性功能、激素功能、泌尿功能、肠道功能领域评分均高于对照组(P<0.05)。两组不良反应总发生率、PSA缓解率组间对比无差异(P>0.05)。结论:SBRT联合内分泌治疗转移性激素敏感性前列腺癌患者,可延长患者PSA进展时间,减轻免疫抑制,提高患者生活质量,同时还可改善患者的预后,患者耐受性良好。  相似文献   

10.
摘要 目的:探讨狼疮性肾炎(LN)患者血清中性粒细胞胞外诱捕网(NETs)、肿瘤坏死因子样凋亡微弱诱导剂(TWEAK)、外周血分化簇(CD)4+T/CD8+T比例与疾病活动度及肾脏预后的关系。方法:选取2021年8月~2022年8月川北医学院附属医院肾内科收治的LN患者137例(LN组),根据系统性红斑狼疮疾病活动指数(SLEDAI)-2000评分分为轻度活动组(52例)、中度活动组(45例)、重度活动组(40例)。随访1年,根据肾脏相关终点事件发生情况分为预后不良组(43例)和预后良好组(94例),另选取同期76名体检健康志愿者(对照组)。采用酶联免疫吸附法检测血清NETs、TWEAK水平,流式细胞术检测外周血CD4+T/CD8+T比例。Spearman相关性分析LN患者血清NETs、TWEAK和外周血CD4+T/CD8+T与SLEDAI-2000评分的相关性,多因素Logistic回归分析LN患者预后不良的因素,受试者工作特征曲线分析血清NETs、TWEAK和外周血CD4+T/CD8+T对LN患者预后不良的预测价值。结果:与对照组比较,LN组血清NETs、TWEAK水平升高,外周血CD4+T/CD8+T降低(P<0.05)。轻度活动组、中度活动组、重度活动组血清NETs、TWEAK依次升高,外周血CD4+T/CD8+T依次降低(P<0.05)。LN患者SLEDAI-2000评分与血清NETs、TWEAK呈正相关,与外周血CD4+T/CD8+T呈负相关(P<0.05)。慢性肾脏病分期4期、SLEDAI-2000评分升高、NETs升高、TWEAK升高为LN患者预后不良的独立危险因素,估算肾小球滤过率升高、CD4+T/CD8+T升高为独立保护因素(P<0.05)。血清NETs、TWEAK和外周血CD4+T/CD8+T联合预测LN患者预后不良的曲线下面积为0.943,大于血清NETs、TWEAK和外周血CD4+T/CD8+T单独预测的0.790、0.788、0.799(P<0.05)。结论:LN患者血清NETs、TWEAK水平升高,外周血CD4+T/CD8+T降低,与疾病活动度及肾脏预后不良密切相关,血清NETs、TWEAK联合外周血CD4+T/CD8+T预测LN患者肾脏预后的价值较高。  相似文献   

11.
The ATP/ADP exchange is shown to be a partial reaction of the (H+ + K+)-ATPase by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to P1, P5 -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg2+ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration (K0.5 = 116 μM) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg2+ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K+ as a function of pH and Mg2+.  相似文献   

12.
Purified cytochrome P450SCC from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of P450SCC into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When P450SCC was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the P450SCC-containing liposomes showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, P450SCC was less stable than P450SCC in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal P450SCC. Liposomal P450SCC required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal P450SCC was subjected to p-chloromercuriphenyl sulfonic acid treatment. This reagent destroyed the liposomal P450SCC. These results suggest that the heme is located in the proximity of the p-chloromercuriphenyl sulfonic acid reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.  相似文献   

13.
The partial purification of (Na+ + K+)-ATPase from pig lens has been achieved by treatment with deoxycholate followed by density gradient centrifugation. The specific activity of the final preparation, ranging from 300 to 500 nmol/h per mg protein, is increased approx. 100-fold compared to the homogenate. A parallel increase in p-nitrophenylphosphatase activity is also observed. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals six major protein bands, one of which is the 93 kDa α subunit of (Na+ + K+)-ATPase which can be phosphorylated by reaction with [γ-32P]ATP. A second band contains a glycoprotein which displays an apparent molecular weight of 51 000 and thus appears to be the β subunit of the enzyme. The enzyme is sensitive to ouabain with the I50 for (Na+ + K+)-ATPase and p-nitrophenylphosphatase inhibition being 1.2 and 1.3 μM, respectively. Several agents which inhibit Na+ + K+)-ATPase from other tissues such as oligomycin, Ca2+, vanadate, N-ethylmaleimide, p-chloromercuribenzenesulfonic acid (PCMBS) and 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) also inhibit the lens enzyme. Monovalent cations other than K+ are partially effective in activating the (Na+ + K+)-ATPase and p-nitrophenylphosphatase activities. The K+ congeners were relatively more effective in supporting (Na+ + K+)-ATPase compared to p-nitrophenylphosphatase activity. Other kinetic properties of the lens enzyme are also comparable to those of the enzyme from other tissues. Utilizing the partially purified membrane bound enzyme, discontinuities in Arrhenius plots of (Na+ + K+)-ATPase activity, p-nitrophenylphosphatase activity and fluoresence polarization of the fluidity probe, 1,6-diphenyl-1,3,5-hexatriene (DPH), are observed near the physiological temperature of lens. The possible significance of these observations for the mechanism of cataract formation are discussed.  相似文献   

14.
The modulating effect of membrane lipids on enzyme function has been described by several investigators. We have used the spin probe N-oxyl-4′,4′-dimethyloxazolidine-12-keto methyl stearate (M 12-NSE) to study this interaction in ox brain membranes enriched with (Na+ + K+)-ATPase. This methyl ester of stearic acid is practically insoluble in aqueous media, and consequently spectra of M 12-NSE-labelled preparations are free of “liquid lines”.At least two types of spectra may be obtained when ox brain microsomes are spin labelled with M 12-NSE, indicating the presence of two distinct binding sites. At one site the spin label is relatively unrestricted and gives rise to an isotropic spectrum. A second spectrum, which is obtained from spin label at another site, is similar to that which is observed after incorporation of M 12-NSE into phospholipid bilayers. This suggests that this latter site is within the core of the microsomal membrane.The two binding sites differ in their affinity for the spin probe. The low affinity site is both more abundant in crude preparations and is more easily removed by detergent treatment; spin labels at this site produce isotropic spectra. The high affinity sites are fewer in number and produce broad spectra. In addition these high affinity sites increase in concentration as the enzyme undergoes purification.The two sites are quite distinct in their sensitivity to ascorbic acid, the low affinity site showing a considerably greater rate of reduction by this agent.This study also demonstrates that the delipidation effects of sodium dodecyl sulfate and sodium deoxycholate on (Na+ + K+)-ATPase-enriched microsomes from ox brain are not identical.It is suggested that the two spin probe binding sites represent two different lipid domains, one of which is very closely associated with the (Na+ + K+)-ATPase enzyme and may reflect a protein-directed phospholipid specificity for this enzyme.  相似文献   

15.
Showdomycin inhibited pig brain (Na+ + K+)-ATPase with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na+, K+, Mg2+ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)Na+ + Mg2+ + ATP, (2) Mg2+, Mg2+ + K+, K+ and none, (3) Na+ + Mg2+, Na+, K+ + Na+ and Na+ + K+ + Mg2+, (4) Mg2+ + K+ + ATP, K+ + ATP and Mg2+ + ATP, (5)K+ + Na+ + ATP, Na+ + ATP, Na+ + ATP, Na+ + K+ + Mg2+ + ATP and ATP. The highest rate was obtained in the presence of Na+, Mg2+ and ATP. The apparent concentrations of Na+, Mg2+ and ATP for half-maximum stimulation of inhibition (K0.5s) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na+ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E1, E2, ES, E1-P and E2-P, i.e., E2 has higher reactivity with showdomycin than E1, while E2-P has almost the same reactivity as E1-P. We conclude that the reaction of (Na+ + K+)-ATPase proceeds via at least four kinds of enzyme form (E1, E2, E1 · nucleotide and EP), which all have different conformations.  相似文献   

16.
目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009(CA7)与A/California/4/2009(CA4)两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。  相似文献   

17.

Background  

Assignment of function to new molecular sequence data is an essential step in genomics projects. The usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets.  相似文献   

18.
The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.  相似文献   

19.
Quenching of the fluorescence of the (Ca2+ + Mg2+)-ATPase purified from muscle sarcoplasmic reticulum can be used to measure relative binding constants of hydrophobic compounds to the phospholipid-protein interface. We show that the binding constant for cholesterol is considerably less than that for phosphatidylcholine, so that cholesterol is effectively excluded from the phospholipid annulus around the ATPase. However, dibromocholestan-3β-ol causes quenching of the fluorescence of the ATPase, and so has access to other, non-annular sites. We suggest that these non-annular sites could be at protein/protein interfaces in ATPase oligomers. Oleic acid can bind at the phospholipid/protein interface, although its binding constant is less than that for a phosphatidylcholine, and it can also bind at the postulated non-annular sites. The effects of these compounds on the activity of the ATPase depend on the structure of the phospholipid present in the systems.  相似文献   

20.
The parameters estimated from traditional A/C i curve analysis are dependent upon some underlying assumptions that substomatal CO2 concentration (C i) equals the chloroplast CO2 concentration (C c) and the C i value at which the A/C i curve switches between Rubisco- and electron transport-limited portions of the curve (C i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C i-t value and mesophyll conductance (g m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C i curves, it showed the C i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C i and A/C c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (Vcmax), the maximum electron transport rate (Jmax) and Jmax/Vcmax estimated from A/C c curve analysis which considers the effects of g m limit and simultaneously fits parameters with the whole A/C c curve, mean Vcmax estimated from A/C i curve analysis (Vcmax-C i) was underestimated by 37.49%; mean Jmax estimated from A/C i curve analysis (Jmax-C i) was overestimated by 17.8% and (Jmax-C i)/(Vcmax-C i) was overestimated by 24.2%. However, there was a significant linear relationship between Vcmax estimated from A/C i curve analysis and Vcmax estimated from A/C c curve analysis, so was it Jmax (p<0.05).  相似文献   

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