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1.
目的:探讨肾脏部分切除手术对T_(1a)期肾癌患者炎性因子与肝肾功能的影响。方法:回顾性分析我院2013年6月至2016年12月收治的91例T_(1a)期肾癌患者的临床资料,按治疗方式不同分为对照组与试验组,对照组48例接受后腹腔镜根治性肾癌切除术治疗,试验组43例接受后腹腔镜肾脏部分切除手术治疗。比较两组的手术指标、治疗前后血清炎性因子、肝肾功能的变化及并发症发生情况。结果:对照组的手术时间、术中出血量均少于试验组(P0.05)。治疗后,试验组血清IL-1变化值低于对照组[(-19.47±-2.57)μg/L比(-41.61±-6.38)μg/L]、IL-6变化值低于对照组[(-8.71±-1.05)ng/L比(-18.96±-3.10)ng/L]、CRP变化值低于对照组[(-12.72±-1.54)mg/L比(-17.46±-2.64)mg/L]、TNF-α变化值低于对照组[(-5.66±-0.15)ng/L比(-14.33±-2.04)ng/L]、BUN变化值低于对照组[(-1.53±-0.19)mmol/L比(-3.01±-0.79)mmol/L]、AST变化值低于对照组[(-15.29±-2.46)U/L比(-33.70±-3.78)U/L]、ALT变化值低于对照组[(-19.46±-2.27)U/L比(-34.02±-5.51)U/L],试验组Ccr变化值低于对照组[(19.78±2.94)mL/min比(28.26±3.52)mL/min]、GFR变化值低于对照组[(14.45±1.48)mL/min比(29.36±1.91)mL/min],除CRP和GFR外,其余指标差异均有统计学意义(P0.05)。对照组和试验组并发症发生率分别为16.67%(8/48)和9.30%(4/43),两组比较差异无统计学意义(P0.05)。结论:后腹腔镜肾脏部分切除手术治疗T_(1a)期肾癌患者的临床效果优于后腹腔镜根治性肾癌切除术治疗,其对患者炎性因子及肝肾功能的影响较小,安全性更高。  相似文献   

2.
目的:研究腹腔镜微创技术联合频谱照射治疗小儿阑尾炎的疗效及对血清可溶性细胞间粘附分子1(Soluble intercellular adhesion molecule-1,slCAM-1)、降钙素(Calcitonin,PCT)水平的影响。方法:选取2016年2月~2018年2月我院收治的87例小儿阑尾炎患者。按照简单随机数表法将其分为观察组(n=42)和对照组(n=45),对照组采用传统手术治疗,观察组采用腹腔镜微创技术联合频谱照射治疗。观察和比较两组治疗后手术指标(手术时间、术中出血量、住院时间),肠功能恢复情况(肠鸣音恢复时间、肛门排气时间、首次排便时间),治疗前后血清slCAM-1、PCT水平的变化及不良反应的发生情况。结果:治疗后,观察组手术时间、术中出血量、住院时间显著低于对照组[(47.82±8.33)min vs (56.97±10.46)min,(46.97±9.75)mL vs (90.72±13.86)mL,(7.02±2.41)d vs(11.84±3.58)d](P0.05);肠鸣音恢复时间、肛门排气时间、首次排便时间显著低于对照组[(19.38±4.32)h vs (25.82±6.18)h,(16.98±4.59)h vs (36.83±7.29)h,(32.02±5.82)h vs (40.17±7.60)h](P0.05);血清slCAM-1、PCT水平显著低于对照组[(180.27±23.75)ng/L vs (197.06±27.30)ng/L (0.92±0.20)ng/L vs (3.87±1.03)ng/L](P0.05);不良反应总发生率显著低于对照组[7.14%(3/42) vs 22.22%(10/45)](P0.05)。结论:腹腔镜微创技术联合频谱照射治疗小儿阑尾炎疗效显著,可改善微循环,促进肠功能恢复,降低血清slCAM-1、PCT水平,并发症少,有利于术后恢复。  相似文献   

3.
池养美洲鲥卵巢周年发育和血清激素变化研究   总被引:1,自引:0,他引:1  
采用形态测量、组织化学以及酶联免疫测定等技术方法,研究了淡水池养美洲鲥卵巢发育和促性腺激素(LH和FSH)和性类固醇激素(T和E2)的年周期变化规律。结果表明,美洲鲥产卵类型属非同步分批产卵,按组织学特点其卵母细胞发育可分为5个时相,依据形态特征其卵巢发育可划分为相应的5个时期。在性腺发育过程中,雌鱼性腺指数(GSI)和肝脏指数(HSI)没有出现明显的变化(p0.05);LH在第Ⅴ时期的表达量显著性低于第Ⅱ、Ⅲ和Ⅳ时期的表达量(p0.05),其他各激素在不同时期均没有明显差异(p0.05)。不同激素间的两两相关性表明血清中LH水平和FSH水平存在显著正相关关系(r=0.613,p0.05),FSH水平和T水平显著负相关(r=-0.605,p0.05),LH水平和T水平显著负相关(r=-0.699,p0.05)。Person相关系数表明卵巢性腺指数和肝脏指数同几种激素之间没有显著的相关性(p0.05)。通过与野生美洲鲥以及其他一些硬骨鱼类卵巢发育规律比较表明:在目前养殖条件下美洲鲥雌鱼营养积累不足,其性腺发育调控受到影响。  相似文献   

4.
目的:研究腹腔内贝伐珠单抗辅助卵巢癌术后化疗对患者血清甲胎蛋白(AFP)、血管内皮生长因子(VEGF)、转化生长因子(TGF-β1)、巨噬细胞移动抑制因子(MIF)的影响。方法:选取2019年1月至2021年2月的210例卵巢癌患者。按照随机数表法分为观察组(n=101)和对照组(n=109),对照组采用化疗治疗,观察组在对照组的基础上,采用腹腔内贝伐珠单抗辅助治疗。对比两组治疗效果,血清治疗前后AFP、VEGF、TGF-β1、MIF水平变化,不良反应,随访生存分析结果。结果:治疗后,观察组总有效率显著高于对照组[89.11%(90/101)vs66.05%(72/109)](P<0.05);血清AFP、VEGF、TGF-β1、MIF水平显著低于对照组[(5.19±1.37)ng/mLvs(10.21±2.38)ng/mL,(22.61±4.32)ng/Lvs(35.76±6.34)ng/L,(168.03±20.18)ng/Lvs(203.76±28.69)ng/L,(4.81±1.01)μg/Lvs(12.79±2.50)μg/L](P<0.05);两组不良反应对比无显著差异(P>0.05);平均生存时间、2年生存率显著高于对照组[(19.23±1.36)月vs(19.23±1.36)月,79.21%(80/101)vs28.44%(31/109)](P<0.05),局部复发与转移显著低于对照组[9.90%(10/101)vs13.76%(15/109)](P<0.05)。结论:腹腔内贝伐珠单抗辅助卵巢癌术后化疗可有效改善患者的临床症状,缓解疾病发展,降低血清AFP、VEGF、TGF-β1、MIF水平,提高患者生存预后。  相似文献   

5.
目的:研究微创踝关节融合术治疗老年创伤性踝关节炎中的临床效果及对患者氧化损伤与骨代谢的影响。方法:收集2014年3月至2015年3月我院收治的94例老年创伤性踝关节炎患者,按随机数表法分为实验组和对照组,每组各45例。两组患者在手术前均进行常规检查,对照组采用常规开放式踝关节融合术,实验组采用微创踝关节融合术。对比两组治疗后血清氧化损伤指标肌红蛋白(MYO)、缺血修饰白蛋白(IMA)、总抗氧化能力(TAC)、丙二醛(MDA)水平,骨代谢指标碱性磷酸酶(ALP)、酸性磷酸酶(ACP)、甲状旁腺素(PTH)、骨钙素(BGP)、降钙素(CT)水平,视觉疼痛模拟评分(VAS)、美国矫形外科足踝协会(AOFAS)评分及不良反应的发生情况。结果:治疗后,实验组血清MYO、IMA、MDA水平显著低于对照组[(20.48±2.59)ng/mL vs.(27.07±2.97)ng/m L,(65.68±8.20)U/L vs.(74.27±9.01)U/L,(5.01±1.03)nmol/L vs.(9.64±2.17)nmol/L](P0.05),血清TAC水平显著高于对照组[(11.40±2.50)kU/L vs.(7.36±1.03)kU/L](P0.05);血清ALP、BGP、CT水平均显著高于对照组[(103.28±12.47)U/L vs.(90.53±10.02)U/L,(11.08±1.42)ng/L vs.(8.01±1.23)ng/L,(61.39±5.87)ng/L vs.(50.28±4.92)ng/L](P0.05),ACP、PTH水平均显著低于对照组[(5.21±0.60)U/L vs.(8.03±0.92)U/L,(42.95±5.38)ng/L vs.(60.49±6.92)ng/L](P0.05);VAS评分显著低于对照组[(1.06±0.23)分vs.(3.79±0.67)分](P0.05),AOFAS评分显著高于对照组[(73.02±6.28)分vs.(65.58±5.13)分](P0.05);不良反应总发生率显著低于对照组[6.66%(3/45) vs. 20.41%(10/49)](P0.05)。结论:微创踝关节融合术可调节老年创伤性踝关节炎患者的骨代谢,增强骨密度,减少术后不良反应,有利于改善患者预后。  相似文献   

6.
目的:研究急性白血病患者血清白介素-12(IL-12)、γ干扰素(IFN-γ)、促红细胞生成素(EPO)、铁蛋白的表达及临床意义。方法:选取2015年8月至2016年7月我院收治的76例急性白血病患者视为观察组,初治组31例,缓解组25例,复发组20例;另选择同期在我院进行健康体检的76例视为对照组。比较急性白血病患者、健康人群及不同疾病阶段的血清IL-12、IFN-γ、EPO、铁蛋白水平。结果:观察组的IL-12、IFN-γ水平显著低于对照组,EPO、铁蛋白水平显著高于对照组,差异均有统计学意义(P0.05)。初治组、复发组的血清IL-12、IFN-γ显著低于缓解组[(84.21±5.43)pg/mL、(98.7±7.98)pg/mL比(112.43±10.21)pg/mL,(38.54±3.56)pg/mL、(49.87±4.02)pg/mL比(108.32±8.43)pg/mL](P0.05),EPO、铁蛋白水平显著高于缓解组[(402.32±42.31)mIU/mL、(321.58±30.21)mIU/mL比(98.21±9.45)mIU/mL,(653.21±54.24)ng/mL、(512.87±43.45)ng/mL比(342.15±25.12)ng/mL](P0.05)。结论:急性白血病患者血清IL-12、IFN-γ水平较低,EPO、铁蛋白的表达较高,可通过监测上述指标变化评估病情及预后。  相似文献   

7.
目的:探讨小骨窗显微手术治疗基底节区高血压脑出血的效果及对血清gaspase切割的细胞角蛋白18(CCCK-18)、补体C1q肿瘤坏死因子相关蛋白3(CTRP-3)水平的影响。方法:选取2016年5月至2018年5月我院收治的160例基底节区高血压脑出血患者,按照随机数表法将其分为观察组(n=82)和对照组(n=78)。对照组采用传统大骨瓣开颅术治疗,观察组采用小骨窗显微手术治疗。观察和比较两组的临床疗效,血肿清除率、术中出血量、术后意识恢复时间、住院时间,治疗前后NIHSS、ADL评分、血清CCCK-18、CTRP-3水平的变化及并发症的发生情况。结果:治疗后,观察组总有效率显著高于对照组[95.12%vs. 79.48%](P0.05);血肿清除率、术中出血量、术后意识恢复时间、住院时间均显著优于对照组[(93.62±3.58)%vs.(85.40±2.19)%,(92.47±12.56)mL vs.(189.25±26.47) mL,(2.01±0.58) d vs.(8.69±2.03) d,(13.39±2.08) d vs.(19.45±3.76) d](P0.05);NIHSS评分显著低于对照组[(9.76±1.42)分vs.(20.57±3.26)分](P0.05);ADL评分显著高于对照组[(86.42±8.64)分vs.(75.39±7.02)分](P0.05);血清CCCK-18水平显著低于对照组[(201.76±32.59) U/L vs.(237.57±39.20) U/L,(29.59±5.19) ng/mL vs.(42.97±7.94)ng/mL](P0.05);CTRP-3水平显著高于对照组[(289.59±35.19)ng/mL vs.(232.97±27.94)ng/mL](P0.05);并发症总发生率显著低于对照组[3.65%(3/82) vs. 14.10%(11/78)](P0.05)。结论:小骨窗显微手术治疗基底节区高血压脑出血的疗效显著,可更有效清除血肿,缓解血肿压迫,改善神经功能,减少继发性损伤,安全性高,可能与其降低血清CCCK-18水平及升高CTRP-3水平有关。  相似文献   

8.
研究了注射促黄体激素类似物(LHRHa)后,泥鳅(Misgurnus anguillicaudatus)血清性类同醇激素的变化规律,并探讨在泥鳅繁殖季节时.孕酮(P)、睾酮(T)和雌二醇(E2)对性腺发育的作用及调节机制.实验共分两组,对照组和实验组;对照组只注射生理盐水;实验组注射LHRHa,雌鱼0.2 μg/g,雄鱼减半.注射前尾静脉采血,作为血液样本分析基础水平(Oh),注射药物后分别在7、24、48、72和96h尾静脉采血.测定雌鱼睾酮、雌二醇和孕酮,雄鱼孕酮和睾酬血清浓度.实验结果表明:注射LHRHa,雌鱼血清睾酮和雌二醇浓度显著高于对照组,雄鱼血清睾酮和孕酮显著高于对照组(P<0.05);24h浓度较高.雌鱼孕酬、睾酮和雌二醇分别为(0.710±0.082)ng/mL、(9.00±0.57)ng/mL和(696.4±26.2)pg/mL,雄鱼孕酮和睾酮分别为(0.527±0.121)ng/mL和(9.62±0.62)ng/mL.实验组雌鱼孕酮变化基本规律为,基础水平(0-7h)-逐渐升至最高(7-24h)-逐渐降至基础水平(24-48h)-维持基础水平(48-96h).实验组雌鱼睾酮和雌二醇与雄鱼孕酮和睾酮变化规律基本相似,其规律为,逐渐上升至最高(0-24h)-逐渐降至基础水平(24-72h)-维持基础水(72-96h).24h对照组雌鱼睾酮和雌二醇显著升高,浓度分别为:睾酮(2.20±0.18)ng/mL,雌二醇(269.1±36.6)pg/mL.对照组雄鱼血清孕酮和睾酮浓度实验期间均无显著变化.研究认为:LHRHa能够刺激泥鳅性类同醇激素分泌,特别是睾酮的分泌,显著提高雌鱼性腺指数(GSI).但刺激P的分泌调控能力有限,实验期间处于较低水平,诱导排卵效果差,泥鳅的性类固醇激素可能有特殊的调节机制.雌二醇和睾酮对性腺成熟有重要作用,孕酮对介导卵细胞最终成熟和排卵可能起重要作用,而雌二醇和睾酮无明显效果.  相似文献   

9.
目的观察急性高血糖影响小鼠第一时相胰岛素分泌的功能及形态学变化特点。方法给C57/BL 6J小鼠完成颈静脉插管后输注20%高糖溶液4 h,建立急性糖毒性小鼠模型,行腹腔葡萄糖耐量实验(intraperitoneal glucose tolerance test,IPGTT)及口服葡萄糖耐量实验(oral glucose tolerance test,OGTT)评价葡萄糖耐量及胰岛素分泌功能。HE染色及电镜观察胰岛形态变化及细胞内胰岛素分泌颗粒亚细胞结构变化。结果 IPGTT实验中急性糖毒性组15 min血糖值较对照组显著增加[(10.3±0.33)mmol/L vs(19.3±1.66)mmol/L],上升87%(P0.05),OGTT实验中30 min血糖值较对照组显著增加[(9.8±0.31)mmol/L vs(18.16±1.01)mmol/L],升高85%(P0.05),且早期胰岛素分泌高峰受损且分泌延迟。GSIS实验中急性糖毒性组在基础状态时(葡萄糖浓度2.8 mmol/L)和高糖(16.7 mmol/L)刺激后,胰岛素分泌较对照组显著降低[(0.481±0.003)ng/m L vs(0.702±0.121)ng/m L,(2.43±0.03)ng/m L vs(4.07±0.34)ng/m L],分别下降46%和67%(P0.05);胰岛素含量测定结果显示,急性糖毒性组比对照组降低[(97.01±2.05)ng/m L vs(65.12±0.42)ng/m L,(121.40±0.58)ng/m L vs(62.7±0.48)ng/m L],下降49%和94%(P0.05)。HE染色显示急性糖毒性胰岛边界不规则、内部细胞排列不整;透射电镜可见细胞内胰岛素分泌颗粒空泡,线粒体嵴断裂。结论急性葡萄糖毒性使胰岛β细胞内胰岛素储备减少,导致第一时相分泌胰岛素峰值降低及延迟。  相似文献   

10.
目的:探讨氯沙坦联合环磷腺苷葡胺对肺心病患者心肺功能和免疫功能的影响。方法:选择2010年9月至2015年9月我院接诊的94例肺心病患者并按随机数表法分为观察组和对照组,每组各47例。对照组给予常规肺心病治疗,观察组在对照组的基础上给予氯沙坦联合环磷腺苷葡胺进行治疗。比较两组治疗前后CO、LVEF、SV、FEV1及FEV1/FV、Ig G、Ig A、补体C3、血清白细胞介素-2(interleukin-2,IL-2)、可溶性白细胞介素2受体(soluble interleukin-2 receptor,s IL-2R)、8-异前列腺素(8-ISO prostaglandin,8-iso-PG)水平的变化以及治疗后的临床疗效。结果:治疗后,观察组CO、LVEF、SV、FEV1及FEV1/FVC水平均显著高于对照组[(5.21±0.27)vs(4.15±0.46),(63.42±6.17)vs(52.37±5.76),(74.68±9.24)vs(64.56±11.73),(1.75±0.27)vs(1.32±0.31),(75.68±10.62)vs(65.49±10.05)](P0.05),血清补体C3高于对照组[(1.34±0.12)g/L vs(1.16±0.10)g/L](P0.05);血清s IL-2R、8-iso-PG水平显著低于对照组[(371.46±161.06)U/ml vs(435.75±152.43)U/ml,(23.58±11.72)ng/L vs(31.08±11.39)ng/L](均P0.05);观察组总有效率高于对照组[(95.74)%vs(78.72)%](P0.05)。结论:氯沙坦联合环磷腺苷葡胺可有效提高肺心病患者心、肺及免疫功能。  相似文献   

11.
Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.  相似文献   

12.
葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义。综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望。  相似文献   

13.
2018年中国植物科学若干领域重要研究进展   总被引:1,自引:0,他引:1  
2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。  相似文献   

14.
2017年中国植物科学若干领域重要研究进展   总被引:1,自引:0,他引:1  
2017年中国植物科学继续保持高速发展态势, 重大成果频出, 具体表现在中国植物学家在国际顶级学术期刊发表的文章数量平稳上升。中国植物科学领域的研究工作者成果精彩纷呈, 如新型广谱抗病机制的发现、水稻广谱抗病遗传基础及机制和疫霉菌诱发病害成灾机制研究等。2017年中国生命科学领域十大进展评选中, 有两项植物科学领域的研究成果入选。水稻生物学、进化与基因组学和激素生物学等领域学科发展突出。另外, 值得一提的是, 长期从事高等植物与代谢途径调控分子网络研究和水稻品种设计育种的李家洋院士的研究成果“水稻高产优质性状形成的分子机理及品种设计”荣获2017年国家自然科学一等奖。这一具有重大国际影响的开创性贡献标志着中国植物科学在该领域的国际科学前沿居于引领和卓越地位。该文对2017年中国本土科学家在植物科学若干领域取得的重要研究成果进行了系统梳理, 旨在全面追踪和报道当前中国植物科学领域发展的最新前沿动态, 与广大读者共同分享我国科学家所取得的辉煌成就。  相似文献   

15.
Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.  相似文献   

16.
我国葫芦科植物离体培养研究进展   总被引:5,自引:0,他引:5  
葫芦科植物包括多种瓜类蔬菜,对其进行离体培养研究具有重要的理论和实践意义.综述了国内在葫芦科植物器官培养、体细胞胚胎发生、花药培养、原生质体培养和体细胞杂交及离体遗传转化等方面取得的研究进展,并对葫芦科植物离体培养、遗传转化与育种的前景作了展望.  相似文献   

17.
2018年中国植物科学继续呈现快速发展的态势, 我国科学家在国际植物科学主流学术刊物发表论文数量大幅增加, 取得了多项具有重要影响的成果。调控植物生长-代谢平衡实现可持续农业发展入选2018年度中国科学十大进展; 中国被子植物区系进化历史研究入选2018年度中国生命科学十大进展。以水稻为代表的农作物和果蔬等经济作物研究在国际上已呈现出明显的优势, 若干领域已从“追赶”状态跨越到“领跑”地位。该文对2018年中国科学家在植物科学若干领域取得的重要研究成果进行了概括性评述, 旨在全面追踪和报道当前中国植物科学领域的发展前沿和热点, 展示中国科学家所取得的杰出成就。  相似文献   

18.
Abstract. Changes are described in aquatic vegetation in oligotrophic, groundwater-fed Rhine floodplain streams in Alsace (eastern France), resulting from disturbance. Disturbance factors include changes in nutrients, either permanent ones - effluent from a waste water treatment plant or trout hatcheries - or periodic ones: flooding. Regular inputs of high levels of phosphate and ammonia modified the macrophyte vegetation in these streams. The floristic composition, which was characteristic of oligotrophic waters upstream of the eutrophicated sector, changed to that of a eutrophic situation as originally found downstream. Periodic disturbance by floods which normally occur once a year, irregularly eutrophicates the small streams, causing the development of a mixture of eutrophic and oligotrophic species. Six macrophyte communities are distinguished, indicating different trophic levels. The aquatic vegetation is adapted to the variations of phosphate and ammonia levels. Hence, aquatic macrophytes can be used as bio-indicators of fluctuations in water nutrient levels in relation to the type of disturbance.  相似文献   

19.
We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.  相似文献   

20.
Rice coleoptiles grow under anoxia. When the ultrastructure of anoxic coleoptile cells was examined, it was seen that most organelles maintain their integrity, with the exception of peroxisomes (unspecialized type). The lack of O2 greatly reduced the number of these organelles and altered the ultrastructure of the remaining ones. To examine the effect of O2 on peroxisome development in more detail, coleoptiles grown in air were transferred to N2 and anoxic coleoptiles were transferred to oxygen. Marker enzyme activity was measured in entire coleoptiles as well as in the isolated organelles. As expected, anoxia greatly depressed enzyme activity when imposed from the beginning of the germination process, while it had a lesser effect when imposed for only two days on aerobic seedlings. When coleoptiles were grown constantly under N2, the density of the organelles was 1.216 g/cm3, while the corresponding aerobic organelles showed a buoyant density of 1.241 g/cm3. When transferred to air the anoxic peroxisomes reached the intermediate density of 1.227 g/cm3. The results confirm the particular sensitivity of rice peroxisomes to O2 availability.  相似文献   

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