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1.
背景:国内外多项研究证实骨髓间充质干细胞移植对脑梗死组织具有一定的神经保护作用。依达拉奉是一种新型强效小分子羟自由基清除剂,可通过清除脑梗死产生的自由基,抑制神经细胞损伤,从而起到脑保护作用。 目的:观察骨髓间充质干细胞移植联合依达拉奉对大鼠脑梗死组织水通道蛋白4、Bcl-2、脑源性神经营养因子表达的影响。 方法:选取Wistar大鼠80只,建立右侧大脑中动脉闭塞模型,随机分为对照组、骨髓间充质干细胞组、依达拉奉组和联合治疗组。建模6 h后通过尾静脉分别注入移植液,对照组注射培养液,骨髓间充质干细胞组注射骨髓间充质干细胞,依达拉奉组给予依达拉奉注射液,联合组同时注入骨髓间充质干细胞和依达拉奉注射液。分别在伤后72 h将大鼠麻醉后断头取脑,应用RT-PCR、Western Blot法检测脑组织中水通道蛋白4、Bcl-2、脑源性神经营养因子基因表达和蛋白合成变化。伤后12,24,36 h取大鼠脑组织以TUNEL法测定细胞凋亡情况。 结果与结论:RT-PCR、Western Blot结果显示,在骨髓间充质干细胞与依达拉奉联合治疗组中,Bcl-2、脑源性神经营养因子的表达明显高于骨髓间充质干细胞组、依达拉奉组及对照组(P < 0.05);而水通道蛋白4的表达低于其余各组(P < 0.05)。TUNEL测定结果显示,联合治疗组中免疫组化呈棕色的凋亡细胞明显少于单独治疗组及对照组。提示骨髓间充质干细胞移植与依达拉奉联合应用治疗大鼠脑梗死,可进一步促进损伤局部脑源性神经营养因子及Bcl-2的表达,对神经细胞凋亡具有明显的抑制作用,同时可下调水通道蛋白4水平,减轻脑水肿程度,二者联合运用的效果明显优于单独治疗组。中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接:  相似文献   

2.
背景:目前的研究表明,从胚胎大鼠大脑皮质分离的神经干细胞在胶原蛋白凝胶中可增殖并分化为神经元、星形胶质细胞和少突胶质细胞。 目的:观察神经干细胞联合胶原蛋白支架移植对脊髓损伤后鼠大脑神经细胞凋亡的影响。 方法:取45只SD大鼠制作脊髓半切损伤模型,随机分为3组,造模1周后,细胞移植组大鼠运动皮质后部在脊髓损伤部位注入同种异体神经干细胞悬液,联合组在脊髓损伤部位注入同种异体神经干细胞结合胶原蛋白悬液,模型组不植入任何物质。 结果与结论:移植后1-8周,3组大鼠肢体运动功能均有不同程度恢复,且联合组移植后8周BBB运动评分明显高于其他两组(P < 0.05)。移植后1周苏木精-伊红染色显示3组均可见少量凋亡细胞及Bcl-2抗凋亡蛋白阳性细胞,大量Bax阳性细胞;随时间的推移,3组Bax凋亡蛋白阳性细胞、Bcl-2抗凋亡蛋白阳性细胞逐渐减少,并且移植后8周联合组、细胞移植组Bax阳性细胞明显低于模型组(P < 0.05),Bcl-2抗凋亡蛋白阳性细胞高于模型组(P < 0.05),此时3组均无凋亡细胞。表明神经干细胞联合胶原蛋白支架移植可抑制脊髓损伤后鼠大脑神经细胞的凋亡,促进脊髓神经功能的恢复。中国组织工程研究杂志出版内容重点:生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程全文链接:  相似文献   

3.
目的探讨神经干细胞移植对脑外伤大鼠神经功能及脑组织Bcl-2与Bax表达的影响。方法108只SD成年大鼠随机分为假手术组(36只)、脑外伤组(36只)和神经干细胞移植组(36只)。采用改良的Feeney氏法制作大鼠脑外伤动物模型,损伤1周后在皮质处局部注射移植神经干细胞,分别在细胞移植后的第7天、14天和21天进行神经功能评分。免疫组织化学方法和Western blot方法检测各组大鼠脑组织Bcl-2与Bax蛋白的表达。结果脑外伤组大鼠出现明显的神经功能障碍,神经干细胞移植后第7、14和21天大鼠的神经功能评分明显降低(P0.05)。与假手术组相比,不同时间点脑外伤组大鼠脑组织Bcl-2蛋白的表达显著降低,Bax蛋白的表达显著升高(P0.05);与相同时间点的脑外伤组大鼠相比,神经干细胞移植组大鼠脑组织Bcl-2蛋白的表达显著升高,Bax蛋白的表达显著降低(P0.05)。结论神经干细胞移植促进脑外伤大鼠神经功能的恢复可能与上调Bcl-2蛋白和下调Bax蛋白表达相关。  相似文献   

4.
背景:骨髓间充质干细胞移植入缺血心肌后存活率低,而低氧有可能增强骨髓间充质干细胞的增殖,促进其存活。 目的:体外模拟心肌细胞缺血微环境,探索低氧预处理后,骨髓间充质干细胞对持续缺氧诱导的心肌细胞凋亡的保护作用。 方法:取第4代SD大鼠骨髓间充质干细胞用于制备条件培养液。取胚胎大鼠心肌细胞株,随机分成4组:对照组:心肌细胞正常培养组;模型组:心肌细胞单纯缺氧;骨髓间充质干细胞组:心肌细胞与骨髓间充质干细胞条件培养液共缺氧;低氧组:心肌细胞与骨髓间充质干细胞低氧条件培养液共缺氧。MTT检测各组细胞活力变化,Annexin V-FITC双染标记心肌细胞凋亡,免疫组化检测各组Bax和Bcl-2蛋白的表达。 结果与结论:免疫组化显示,低氧组的Bcl-2表达较其他各组增强,而Bax的表达比模型组和骨髓间充质干细胞组减弱,Bcl-2/Bax比值最大。与对照组和骨髓间充质干细胞组相比,低氧组的细胞活力高(P < 0.05),凋亡率降低(P < 0.05)。提示低氧可能是通过增强旁分泌机制,从而对Bax和Bcl-2进行调节,对心肌细胞凋亡有保护效应。  相似文献   

5.
背景:脑外源性神经因子-胶质源性神经营养因子对大脑神经元具有特异性的营养作用,是脑卒中治疗中重要的神经营养因子。 目的:探讨胶质源性神经营养因子基因修饰的神经干细胞对大鼠脑卒中的神经保护作用机制。 方法:构建大鼠胶质源性神经营养因子基因pAdEasy-l-pAdTrackCMV重组体,并对新生大鼠皮质神经干细胞进行分离、培养。利用胶质源性神经营养因子基因重组腺病毒对神经干细胞进行转染,再将细胞悬液注射至暂时性(2 h)大脑中动脉缺血模型大鼠右侧脑室中,同时设单纯神经干细胞组和对照组进行对比。 结果与结论:与神经干细胞移植组比较,联合移植组再灌注2,3周的神经功能缺损评分,再灌注7 d脑缺血损伤面积均显著减小(P < 0.05);不同再灌注时间点缺血区域的神经干细胞数量神经干细胞移植组均显著少于联合移植组(P < 0.05)。再灌注7,14 d,两组Syn,PSD-95蛋白表达均高于对照组(P < 0.05),联合移植组升高较为明显。结果表明,利用经胶质源性神经营养因子基因修饰的神经干细胞治疗大鼠脑卒中可以发挥出较好的神经保护作用,效果略优于单纯神经干细胞治疗。 中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程  相似文献   

6.
背景:相关研究表明促红细胞生成素及骨髓间充质干细胞均对心肌凋亡有一定影响,但两者联合应用治疗脓毒症相关性心肌损伤少见报道。 目的:观察骨髓间充质干细胞移植联合腹腔内注射促红细胞生成素对脓毒症大鼠心肌细胞病理学改变及细胞凋亡的影响。 方法:选用SD大鼠50只,随机数字表法均分为5组(n=10),应用盲肠结扎穿孔术建立脓毒症大鼠模型。骨髓间充质干细胞组建模后即刻尾静脉输注异体间充质干细胞;促红细胞生成素组建模后即刻腹腔内注射促红细胞生成素;促红细胞生成素+细胞移植组两者联合应用;模型组行盲肠结扎穿孔术,对照组开腹后不做任何处理,均尾静脉输注相同容量的生理盐水。24 h后麻醉处死实验动物,取心肌标本,采用苏木精-伊红染色观察心肌组织形态;用Western blot方法检测心肌组织中凋亡蛋白Bax、Caspase-3,抗凋亡蛋白Bcl-2的表达量。 结果与结论:苏木精-伊红染色结果:对照组可见心肌细胞排列整齐,心肌细胞结构完整;模型组可见广泛心肌纤维断裂,排列紊乱,心肌细胞肿胀或皱缩,可见空泡变性;心肌间质血管充血、水肿,炎症细胞浸润;促红细胞生成素组与骨髓间充质干细胞组心肌组织相似,炎性细胞浸润情况较轻,期间散在分布正常心肌细胞;促红细胞生成素+细胞移植组心肌细胞损害较轻,间质充血不明显,少量炎症细胞浸润。Western blot结果:促红细胞生成素+细胞移植组Bcl-2蛋白表达显著高于促红细胞生成素组、模型组及对照组(P < 0.01),Bax及Caspase-3蛋白表达量均减低(P < 0.05)。结果显示,骨髓间充质干细胞移植联合给予促红细胞生成素在脓毒症相关性心肌损伤的治疗中可减轻心肌的病理学改变、抑制心肌细胞的凋亡,其机制可能是通过上调抗凋亡蛋白、下调凋亡蛋白的表达来实现的。中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接:  相似文献   

7.
神经调节素对实验性痴呆大鼠的干预作用和可能机制   总被引:1,自引:1,他引:0  
目的探讨神经调节素1β(NRG1β)对实验性老年痴呆大鼠神经元凋亡及Bcl-2和Bax表达的影响。方法成年健康雄性Wistar大鼠30只,随机分为假手术组、模型组、治疗组各10只,经左侧脑室微量注射淀粉样蛋白β1-40(Aβ1-40)建立实验性痴呆模型,经右侧脑室注射NRG1β干预治疗,Y型电迷宫检测大鼠的认知功能,原位缺口末端标记法(TUNEL)检测神经细胞凋亡,免疫组织化学法检测Bcl-2和Bax表达。结果造模成功后,模型组大鼠较对照组认知能力明显下降,TUNEL阳性细胞数明显增多,神经细胞Bcl-2和Bax蛋白表达增强(P0.05)。经NRG1β治疗后,治疗组大鼠较模型组认知能力显著改善,TUNEL阳性细胞显著减少,Bcl-2表达增强,Bax表达减弱(P0.05)。结论 NRG1β可能通过调节Bcl-2和Bax表达而抑制神经细胞凋亡,从而改善实验性痴呆大鼠学习记忆能力。  相似文献   

8.
背景:通过细胞移植重建损伤脑组织成为治疗脑梗死的新途径,骨髓间充质干细胞成为近年来细胞移植治疗领域的研究热点。 目的:探讨银杏达莫注射液联合骨髓间充质干细胞移植对脑梗死大鼠神经功能的改善作用及相关机制。 方法:利用线栓法制作大鼠大脑中动脉闭塞模型,建模成功后60只SD大鼠随机分为对照组、细胞移植组及联合组。对照组尾静脉注射PBS、细胞移植组尾静脉注射2.5×109 L-1的骨髓间充质干细胞悬液、联合组尾静脉注射2.5×109 L-1的骨髓间充质干细胞悬液和银杏达莫2 mL/kg,1次/d,连续注射5 d。于移植后的1,3 d及1,2 周进行mNSS行为学评分,以观察大鼠神经功能缺损状况。移植后2周RT-PCR检测脑组织中脑源性神经生长因子、生长相关蛋白43基因表达变化,TUNEL法检测细胞凋亡情况,免疫组化法检测BrdU阳性细胞数。 结果与结论:移植后的1,3 d各组大鼠神经功能缺损评分差异无显著性意义(P > 0.05),在移植后1,2周,联合组神经功能缺损评分低于细胞移植组及对照组(P < 0.05);移植后2周,联合组脑源性神经生长因子、生长相关蛋白43 mRNA表达明显高于细胞移植组及对照组(P < 0.05),联合组凋亡细胞数目明显少于细胞移植组及对照组(P < 0.05),联合组BrdU阳性细胞数量明显多于细胞移植组及对照组(P < 0.05)。结果表明骨髓间充质干细胞联合银杏达莫干预能促进脑梗死组织脑源性神经生长因子、生长相关蛋白43 mRNA的表达,抑制细胞凋亡,改善大鼠神经功能。  中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程   相似文献   

9.
余恒  周涛 《中国组织工程研究》2020,24(19):2972-2977
文题释义:人脐血来源间充质干细胞的优势:脐血从孕妇分娩后的胎盘、脐带残端收集,对于产妇和新生儿均没有任何痛苦和不良影响,也不会涉及社会、伦理及法律方面的争论;脐血受胎盘屏障的保护,其成分被病毒、细菌污染的概率低。 端粒酶:细胞中负责端粒延长的一种酶,是基本的核蛋白反转录酶,在保持端粒稳定、基因组完整、细胞长期活性和潜在的继续增殖能力等方面有重要作用。 背景:脐血间充质干细胞可以经体循环有效穿透室管膜进入脑组织,迁移至脑损伤区域并存活分化为神经细胞,作为替代细胞来源用于中枢神经系统疾病的治疗。 目的:探讨人脐血间充质干细胞移植对脑梗死大鼠神经功能恢复及脑组织端粒酶反转录酶表达的影响。 方法:选取130只大鼠为研究对象,随机分为对照组(30只)、模型组(30只)、脐血间充质干细胞1组(35只)、脐血间充质干细胞2组(35只);对照组不做任何处理,其余各组采用颈内动脉线栓法制作脑梗死大鼠模型,脐血间充质干细胞1,2组于造模成功后1,4 d尾静脉移植2×106个脐血间充质干细胞;移植后24 h检测大鼠血清中活性氧和超氧化物歧化酶水平,移植后第7,14天进行Y-迷宫实验和神经功能评分,采用TUNEL法检测病灶中心神经细胞凋亡率,Western blot法检测梗死灶周围Caspase-3、Bax、Bcl-2、端粒酶反转录酶蛋白表达,RT-PCR法检测梗死灶周围端粒酶反转录酶的mRNA表达。 结果与结论:①与对照组相比,模型组大鼠Y-迷宫实验错误次数、神经功能评分、细胞凋亡指数、Caspase-3、Bax蛋白表达、活性氧水平均显著升高(P < 0.05),Bcl-2、端粒酶反转录酶蛋白以及mRNA表达、超氧化物歧化酶水平均显著降低(P < 0.05);②与模型组相比,脐血间充质干细胞1组和脐血间充质干细胞2组大鼠Y-迷宫实验错误次数、神经功能评分、细胞凋亡指数、Caspase-3、Bax蛋白表达、活性氧水平均显著降低(P < 0.05),Bcl-2、端粒酶反转录酶蛋白以及mRNA表达、超氧化物歧化酶水平均显著升高(P < 0.05);③与脐血间充质干细胞2组相比,脐血间充质干细胞1组大鼠Y-迷宫实验错误次数、神经功能评分、细胞凋亡指数、Caspase-3、Bax蛋白表达、活性氧水平均显著降低(P < 0.05),Bcl-2、端粒酶反转录酶蛋白以及mRNA表达、超氧化物歧化酶水平均显著升高(P < 0.05);④结果表明,脐血间充质干细胞移植可以有效促进脑梗死大鼠神经功能恢复,能够提高脑组织端粒酶反转录酶表达,移植时间越早效果越显著。 ORCID: 0000-0002-4902-1553(余恒) 中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程  相似文献   

10.
目的:研究川芎嗪(tetramethylpyrazine,TMP)联合骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)对脑缺血大鼠神经细胞凋亡及Bcl-2、Bax表达的影响。方法:采用全骨髓贴壁法体外培养BMSCs,传代至第3代用于尾静脉移植。采用线栓法诱导大鼠右侧大脑中动脉阻塞模型,除假手术组外,大鼠随机分为模型组、BMSCs(1×10~9/L)组、川芎嗪(40 mg/kg)组和联合(川芎嗪+BMSCs)组,每组12只。缺血后第1、7和14天采用改良的神经损伤严重程度评分(modified neurological severity scoring,m NSS)进行神经功能评价。缺血后第14天,甲苯胺蓝染色检测脑梗死体积,HE染色观察脑组织病理学变化,采用原位末端标记(TUNEL)法观察神经细胞凋亡数,采用实时荧光定量PCR法和Western blot法检测Bax和Bcl-2的mRNA及蛋白表达。结果:与BMSCs组和川芎嗪组比较,联合组m NSS评分显著减少(P0.01),梗死体积显著减少(P0.01),缺血引起的脑缺血周边区病理性损伤明显减轻,TUNEL阳性细胞数显著减少(P0.01),Bcl-2的mRNA及蛋白表达显著增加,Bax的mRNA及蛋白表达显著降低(P0.01)。结论:川芎嗪联合BMSCs移植能显著促进脑缺血后大鼠的功能恢复,减少梗死体积,减轻脑组织缺血性损伤,抑制神经细胞凋亡,机制可能与调控Bcl-2和Bax的表达有关。  相似文献   

11.
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   

12.
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   

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.
15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.  相似文献   

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