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1.
目的: 研究喜树碱(camptothecin,CPT)诱导Jurkat细胞凋亡过程中线粒体膜电势和线粒体质量的变化。 方法: 用喜树碱处理Jurkat细胞,利用Annexin V-FITC/PI双染流式细胞术研究细胞早期凋亡, PI染色流式细胞术测细胞周期, Annexin V-PE/DiOC6(3) 双染流式细胞术检测线粒体膜电势(△ψm),NAO染色流式细胞术检测线粒体质量。 结果: 在10 μmol·L-1 CPT诱导下,6 h 时Jurkat 细胞早期凋亡的细胞比率(22.59±1.04)%显著高于对照组(3.93±0.73)%(P<0.01)。CPT组坏死比率(2.48±0.53)%与对照组(2.78±0.63)%无显著差异(P>0.05);并可使细胞出现明显的凋亡峰。晚期凋亡的细胞比率为(13.58±0.97)%显著高于对照组(3.18±0.51)%(P<0.01),CPT组G0/G1期细胞比率(48.14±0.96)% ,明显高于对照组(44.09±0.43)%(P<0.01)。CPT组线粒体发生明显去极化现象,AnnexinV+DiOC6(3)-的细胞比率为(19.47±0.69)%,而对照组比率为(4.21±0.40)%,差异显著(P<0.01)。同时,CPT组线粒体质量显著低于对照组:CPT组NAO+细胞比率为(74.77±1.66)%,对照组为(92.24±1.41)%(P<0.01)。 结论: CPT诱导Jurkat细胞凋亡过程中线粒体去极化作用增强并且线粒体质量下降,表明该凋亡过程与线粒体途径密切相关。  相似文献   

2.
目的:研究地塞米松(DEX)介导的小鼠胸腺细胞凋亡过程中线粒体质量和结构蛋白变化特点。 方法: 以地塞米松(DEX)诱导小鼠胸腺细胞凋亡为模型,利用Annexin V-FITC/PI双染流式细胞术研究细胞凋亡和坏死,JC-1染色流式细胞术检测线粒体膜电势(△Ψm)和线粒体质量,利用CFDA-SE染色流式细胞术检测细胞结构蛋白变化。 结果: 在1×10-6mol/L DEX诱导下,小鼠胸腺细胞在6 h凋亡比率为(51.25±5.51)%,对照组为(12.03±2.00)%,差异显著(P<0.01); DEX组坏死比率为(30.25±3.67)%,对照组为(10.11±1.11)%,差异显著(P<0.01)。DEX组在6h时点的线粒体质量显著低于对照组(P<0.01),FL1平均荧光强度分别为(561.62±54.27)和(900.25±38.80)。DEX同时引起线粒体膜电势的显著下降(P<0.01),对照组FL2平均荧光强度为(267.51±26.48),DEX组为(133.17±12.29)。成熟T细胞培养48 h,CFDA-SE法仅检测到亲代单一细胞峰;而在Con A刺激条件下出现3个子代峰。对照组小鼠胸腺细胞在CFDA-SE染色培养6 h条件下,存在(5.25±1.15)%的低荧光强度细胞群,而在DEX刺激下,该群细胞占(47.39±9.76)%,并且在直方图结果上形成明显的细胞峰。 结论: DEX诱导小鼠胸腺细胞凋亡过程中,线粒体质量和细胞结构蛋白均有所下降;CFDA-SE染色流式细胞术可以作为基于细胞结构蛋白变化的凋亡定量检测方法。  相似文献   

3.
目的: 研究阻断ERK途径对地塞米松(DEX)诱导的胸腺细胞凋亡中线粒体膜电势的影响。 方法: 利用PD098059(PD)阻断小鼠胸腺细胞ERK途径,分别设对照组(control)、单纯PD组(PD only)、DEX组和PD+DEX组;在3 h、5 h和7 h时点,利用Annexin V-FITC/PI双染流式细胞术检测细胞凋亡;在3 h、7 h和11 h,利用JC-1染色流式细胞术检测线粒体膜电势(△ψm)变化。 结果: 在1 μmol·L-1 DEX刺激下,小鼠胸腺细胞在3 h、5 h和7 h凋亡率分别为(19.63±0.35)%、(41.84±1.67)%和(67.00±2.43)%,对照组分别为(4.98±0.39)%、(6.08±0.33)%和(9.31±0.34)%,差异显著(P<0.01);相同时点下,PD only组细胞凋亡率分别为(7.95±0.60)%、(10.69±0.48)%和(22.20±1.24)%,显著高于对照组(P<0.01);PD+DEX组在3 h和5 h时点细胞凋亡率显著高于DEX组(P<0.01),而在7 h时点,两组差异不显著(P>0.05)。在3 h、7 h和11 h,DEX组△ψm降低的细胞比率分别为(21.23±1.43)%、(55.34±1.78)%和(70.88±2.87)%,对照组分别为(5.25±1.22)%、(8.01±0.97)%和(12.88±1.10)%,差异显著(P<0.01);相同时点下,PD only组△ψm降低的细胞比率分别为(11.09±2.00)%、(16.21±2.25)%和(21.15±3.70)%,显著高于对照组(P<0.01);PD+DEX组在3 h和5 h时点细胞凋亡率显著高于DEX组,分别为(30.55±2.99)%和(65.22±4.32)%(P<0.01),11 h时点两组差异不显著(P>0.05)。 结论: DEX诱导小鼠胸腺细胞凋亡至少部分通过ERK途径,阻断ERK途径在该凋亡过程中具有重要生物学意义。  相似文献   

4.
目的研究一氧化氮(NO)介导的胸腺细胞凋亡中线粒体膜电位(ΔΨm)和心磷脂(CL)含量变化的特点。方法以S-亚硝基-N-乙酰青霉胺(SNAP)作为NO的供体诱导胸腺细胞凋亡,以地塞米松(DEX)作为阳性对照药物;设空白对照组、SNAP组和DEX组3个实验组;经膜联蛋白V(annexinVmAb)和碘化丙啶(PI)染色后,用流式细胞术(FCM)检测细胞磷脂酰丝氨酸(PS)外翻;用3,3’-二已基噁羰花青碘化物[DiOC6(3)]和PE-anti-annexinVmAb检测凋亡中ΔΨm变化;用壬基吖啶橙(NAO)和PE-anti-annexinVmAb检测凋亡中线粒体CL变化。结果SNAP作用后6h,胸腺细胞出现典型的细胞凋亡特征,多数annexinV阳性的细胞出现皱缩。DEX组ΔΨm降低且未凋亡的细胞比例显著高于空白对照组(P<0.01);而SNAP组该群细胞所占比例与空白对照组比较,差异无统计学意义(P>0.05)。各组中约40%~50%的DiOC6(3)阴性细胞同正常细胞的大小。SNAP组CL含量降低的凋亡细胞所占比例显著高于对照组(P<0.01),未见CL含量降低且未凋亡的细胞群。空白对照组和SNAP组中分别有(48.32±3.96)%、(43.64±4.90)%的细胞CL含量降低但大小同正常细胞。结论NO介导的小鼠胸腺细胞的凋亡过程,依次为磷脂酰丝氨酸外翻、线粒体去极化、CL氧化及细胞皱缩。同DEX模型组相比较,NO介导的小鼠胸腺细胞线粒体的变化为凋亡过程中较晚期的变化。  相似文献   

5.
目的:观察甘氨酸脂质体对缺氧/复氧损伤心肌细胞线粒体膜电位及凋亡的影响。方法:建立培养乳鼠心肌细胞缺氧/复氧(H/R)损伤模型,以DiOC6(3)为荧光分子探针检测实验各组心肌细胞线粒体膜电位;以Annexin V联合PI染色法检测实验各组心肌细胞凋亡率。结果:(1)H/R处理组心肌细胞线粒体膜电位明显低于对照组(P<0.01),甘氨酸脂质体处理组心肌细胞线粒体膜电位降低最少,弱荧光部分细胞百分率为(9.61±0.76)%。与甘氨酸组比较有显著差异(P<0.01)。(2)H/R处理组心肌细胞凋亡率为(20.78±1.58)%,明显高于对照组(P<0.01)。甘氨酸脂质体处理组心肌细胞凋亡发生率低于甘氨酸组(P<0.01)。空白脂质体组细胞凋亡发生率与H/R组比较差异无统计学意义(P>0.05)。结论:甘氨酸脂质体能抑制培养心肌细胞缺氧/复氧损伤诱导的心肌细胞线粒体膜电位下降和心肌细胞凋亡,脂质体携载甘氨酸能更好发挥其细胞保护作用。  相似文献   

6.
喜树碱诱导的HL-60细胞凋亡过程中线粒体的变化   总被引:1,自引:0,他引:1  
目的:研究喜树碱(CPT)诱导的人早幼粒细胞性白血病细胞HL-60凋亡过程中线粒体的质量和膜电势的变化。方法:以CPT诱导HL-60细胞凋亡为模型,利用膜联蛋白V(annexinV)-FITC/PI双染流式细胞术,研究HL-60细胞的凋亡和坏死。用DiOC6(3)染色流式细胞术,检测线粒体的膜电势(△ψm)。用NAO染色流式细胞术,检测线粒体的质量。结果:在4×10-6mol/LCPT的诱导下,HL-60细胞(12h)早期的凋亡率为(12.75±4.61)%,对照组为(2.88±2.49)%,二者相比较差异显著(P<0.01);CPT组坏死比率为(3.48±1.67)%,对照组为(0.71±1.10)%(P<0.01)。PI染色的结果显示,HL-60细胞(12h)晚期凋亡细胞的百分率,CPT组为(3.52±1.07)%,对照组为(0.46±1.06)%(P<0.01)。同时观察到,G2/M期细胞出现阻滞,G2/M期细胞的百分率,对照组为(22.46±2.19)%,CPT组为(13.45±1.91)%(P<0.01)。在12h时间点,CPT组线粒体的质量显著低于对照组(P<0.01),低线粒体质量的细胞所占百分率,对照组为(4.53±1.26)%,CPT组为(25.74±2.09)%。同时,CPT组线粒体的膜电势显著下降(P<0.01),CPT组线粒体膜电势降低的比率为(17.71±5.23)%,对照组为(1.64±2.00)%。结论:CPT诱导HL-60细胞凋亡过程中,线粒体的质量和膜电势均有所下降,但其去极化作用增强。  相似文献   

7.
地塞米松影响小鼠胸腺细胞线粒体膜电势变化研究   总被引:7,自引:1,他引:7       下载免费PDF全文
目的:研究地塞米松刺激小鼠胸腺细胞过程中线粒体膜电势(△Ψm)的变化。 方法: 以终浓度1×10-6mol/L地塞米松(DEX)刺激小鼠胸腺细胞,通过JC-1染色流式细胞术,在0、1、3、5、7、9、11、24和27 h时点分别检测小鼠胸腺细胞平均J-aggregate(FL2)和平均J-monomer (FL1)含量,并计算线粒体膜电势(FL2/FL1)。 结果: 本研究中,小鼠胸腺细胞离体后FL1所反映的线粒体质量迅速下降,至5 h对照组达到平台期(913.38±70.11),然后缓慢下降到27 h的(622.80±22.81)。DEX组FL1在1 h和3 h与对照组没有显著差异(P>0.05),而从5 h(660.91±72.95)开始显著低于对照组(P<0.01),并且随培养时间延长呈下降趋势,至27 h的(309.70±53.35)。对照组和DEX组FL2随培养时间延长而降低。1-9 h,对照组和DEX的△Ψm没有显著差异(P>0.05)。而在11、24和27 h,对照组△Ψm分别为(256.41±21.59)、(214.14±23.21)和(146.14±17.97),而DEX组△Ψm显著低于对照组(P<0.01),分别为(138.28±20.59)、(111.61±29.67)和(72.92±17.86)。 结论: DEX诱导小鼠胸腺细胞凋亡过程中,线粒体质量降低和△Ψm下降是早期事件,而细胞内现存线粒体△Ψm下降则是较晚期的事件。在本研究中,线粒体质量下降与现存线粒体膜电势的变化之间关系不紧密。  相似文献   

8.
三氧化二砷诱导Jurkat细胞凋亡过程中线粒体的变化   总被引:1,自引:3,他引:1  
目的: 研究三氧化二砷(As2O3)诱导Jurkat细胞凋亡过程中线粒体的变化特点。方法: 以As2O3诱导Jurkat细胞凋亡为模型,利用Annexin V-FITC/PI双染流式细胞术研究细胞凋亡和坏死,DiOC6(3)/PI染色流式细胞术检测线粒体膜电势(△ψm),壬基酚丫啶橙(NAO)/PI染色流式细胞术检测线粒体质量,利用2,7-二氯二氢荧光素乙酰乙酸(DCFH-DA)染色流式细胞术检测细胞内活性氧的变化。 结果: 在4×10-6mol/L As2O3诱导下,Jurkat细胞在48 h凋亡比率为(18.98±1.40)%, 对照组为(5.17±0.80)%,组间差异显著(P<0.01);As2O3组坏死比率为(8.56±0.70)%,对照组为(1.53±0.55)%,组间差异显著(P<0.01)。As2O3组在48 h时点的线粒体膜电势低于对照组(P<0.05), 线粒体膜电势下降的Jurkat细胞比率分别为(23.07±3.62)%和(6.63±1.46)%。 同时Jurkat细胞As2O3组线粒体质量显著低于对照组(P<0.01),线粒体质量下降的细胞比率分别为(25.90±1.80)%和(6.37±1.04)%。As2O3组自由基产生明显高于对照组(P<0.01), DCFDA平均荧光强度分别为24.41±0.75和17.06±0.48。结论: As2O3诱导Jurkat细胞凋亡过程中,线粒体膜电势和质量均下降,细胞内氧自由基水平升高。  相似文献   

9.
地塞米松影响小鼠胸腺细胞c-Myc表达以及凋亡研究   总被引:5,自引:2,他引:5       下载免费PDF全文
目的: 研究在地塞米松(DEX)诱导的小鼠胸腺细胞凋亡过程中c-Myc信号变化特点及其与下游caspase-3变化的相关性,以进一步探讨c-Myc在小鼠胸腺细胞凋亡过程中的作用机制。方法:以终浓度1 μmol/L地塞米松诱导小鼠胸腺细胞凋亡,通过Annexin V-FITC/PI双染流式细胞术测定30 min、3 h、6 h和9 h凋亡和坏死细胞比率,在6 h时点电镜观察细胞形态,利用SDS-PAGE及Western blot检测0 min、30 min、1 h和3 h细胞内c-Myc和caspase-3信号变化特点。结果:在1μmol/L DEX诱导下,小鼠胸腺细胞在30 min、3 h、6 h和9 h凋亡比率分别为(5.70±0.46)%、(35.79±1.13)%、(50.61±2.15)%和(35.52±1.66)%,对照组分别为(5.97±0.25)%、(10.20±0.71)%、(12.10±0.66)%和(15.45±0.51)%,组间差异显著(P<0.01)。相应DEX组坏死比率分别为(4.58±0.51)%、(4.66±0.67)%、(25.36±1.64)%和(46.99±2.67)%,对照组分别为(4.38±0.39)%、(4.19±0.73)%、(9.63±1.25)%和(13.38±0.72)%,组间差异显著(P<0.01);电镜观察结果显示DEX处理6 h见较多典型凋亡细胞。对照组在0 min即可检测到c-Myc的明显表达,30 min略见增多,1 h和3 h呈微弱的下降趋势;DEX组c-Myc在0 min表达强于对照组,30 min最强,而在1 h和3 h显著减弱;对照组caspase-3随培养时间延长而逐渐增多,而DEX组caspase-3在0 min表达增多,30 min最多,而在1 h和3 h显著减少。结论:本研究结果提示DEX诱导的小鼠胸腺细胞凋亡呈现c-Myc介导的细胞凋亡模式,而且在该过程中c-Myc和caspase-3信号存在着反馈抑制调节的可能性。  相似文献   

10.
目的: 离体观察CHOP/GADD 153蛋白表达变化与血管紧张素Ⅱ(AngⅡ)诱导的心肌细胞凋亡的关系,并探讨CHOP/GADD 153反义寡核苷酸抗凋亡作用。方法: 对体外培养的乳鼠心肌细胞,单用AngⅡ刺激或预加不同浓度CHOP/GADD 153反义寡核苷酸干预后,再加入AngⅡ刺激。用MTT法检测细胞活力,乳酸脱氢酶(LDH)检测试剂盒测定培养上清液中LDH含量,Annexin V流式细胞仪检测细胞凋亡率,Western blotting法检测CHOP/GADD 153、Bcl-2及Bax表达变化。结果: AngⅡ组,心肌细胞CHOP/GADD 153表达(0.75±0.06)显著高于对照组(0.20±0.02),P<0.01;心肌细胞活性(66.32±2.09)%显著低于对照组(100.00±0.00)%,P<0.05;培养上清液中LDH含量(79.36±5.69)U/L显著高于对照组(20.23±2.83)U/L;细胞凋亡率(16.62±2.09)%显著高于对照组(3.33±0.28)%,P<0.05;Bcl-2表达(0.44±0.05) 显著低于对照组(0.73±0.05),P<0.01;Bax表达(0.90±0.10) 显著高于对照组(0.69±0.08),P<0.01;Bax/Bcl-2比值(2.00±0.22)显著高于对照组 (0.93±0.09),P<0.01。预加CHOP/GADD153反义寡核苷酸干预,可显著逆转AngⅡ的以上作用,虽对Bax 蛋白表达无显著影响,但对照组Bax/Bcl-2的比值显著低于AngⅡ组 (P<0.01),而错义寡核苷酸无此效应。脂质体组与对照组无显著差异。结论: CHOP/GADD153表达升高可能是AngⅡ诱导的心肌细胞凋亡机制之一,CHOP/GADD153反义寡核苷酸能抑制AngⅡ诱导的心肌细胞凋亡。  相似文献   

11.
Renal dysplasia and asplenia in two sibs   总被引:2,自引:0,他引:2  
A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.  相似文献   

12.
Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc2 (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.  相似文献   

13.
About 1900, modern food selection and processing caused widespread epidemics of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a panhypovitaminosis B, i.e., a mixture of substrate beriberi and substrate pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse endemic disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for primates. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.  相似文献   

14.
There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.  相似文献   

15.
16.
Newton H 《Medical history》2011,55(2):153-182
Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.  相似文献   

17.
Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.  相似文献   

18.
HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.  相似文献   

19.
The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.  相似文献   

20.
Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.  相似文献   

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