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1.
目的:模拟临床人类饮食结构改变,观察高嘌呤食饵对鹌鹑尿酸及糖脂代谢的影响,探讨高尿酸血症并糖脂代谢紊乱的发病规律与病理机制。方法:采用高嘌呤食饵诱导法塑造鹌鹑尿酸及糖脂代谢紊乱模型,动态观察各组鹌鹑血清尿酸(UA)、甘油三酯(TG)、血糖(GLU)及相关代谢酶黄嘌呤氧化酶(XOD)、鸟嘌呤脱氨酶(GuDa)、腺苷脱氨酶(ADA)、三磷酸甘油醛脱氢酶(GAPDH)酶活性、胰岛素(Ins)水平变化。结果:高嘌呤食饵诱导鹌鹑造模10-140 d血清UA水平显著升高;60-140 d伴发血清TG水平显著升高;90-140 d同时伴发血清GLU水平显著升高;造模第10、60、140 d血清XOD活性显著升高;造模第60-140 d模型组鹌鹑全血GAPDH活性显著降低;造模第60-140 d模型组鹌鹑Ins水平显著升高。结论:(1)高嘌呤饮食可诱发鹌鹑UA、TG、GLU多代谢紊乱,模拟临床尿酸及糖脂多代谢紊乱的疾病表现。(2)其发病特点表现为单纯高尿酸血症,而后伴发高甘油三酯血症,最终发展成为高尿酸并高甘油三酯/高血糖血症。(3)该病理机制可能与血清XOD活性、Ins水平升高及全血GAPDH活性降低有关。  相似文献   

2.
长期摄取高钠盐饮食引发的高血压   总被引:7,自引:1,他引:6  
目的:探讨高钠盐引发的高血压发病机制。方法:雄性SD大鼠40只,分为对照(NC)组、高盐(HS)组、高盐+L-精氨酸(HS+Arg)组、高盐+依那普利(HS+En)组和高盐+特拉唑嗪(HS+Ter)组,每组8只。各组饲料相同。NC组饮去离子水;HS组饮1.5%氯化钠溶液;HS+Arg组、HS+En组和HS+Ter组分别饮用1.5%氯化钠溶液配制的L-精氨酸(4g·kg-1·d-1)、依那普利(30mg·kg-1·d-1)和盐酸特拉唑嗪(4mg·kg-1·d-1)。第8周末,大鼠在戊巴比妥钠麻醉下,直接测量颈总动脉血压,开腹抽取下腔静脉血及剖取肾脏、肾上腺。测定前海葱苷原A样物质(PLC)水平,Na-K-ATP酶活性,NO(x)、内皮素(ET)及血管紧张素II(AngII)水平。结果:HS组大鼠血压显著高于NC组,血浆PLC、ET及肾上腺AngII水平皆显著高于NC组;血浆和肾组织NO(x)和AngII水平、肾脏Na-K-ATP酶活性皆明显低于NC组;HS+Arg组、HS+En组和HS+Ter组大鼠血压和血浆PLC水平皆显著低于HS组,血浆和肾组织NO(x)水平及Na-K-ATP酶活性皆明显高于HS组;HS+Arg组、HS+En组和HS+Ter组肾上腺AngII水平及HS+Arg组血浆ET水平明显低于HS组,并与NC组相近。结论:在高钠盐引发的高血压发病机制中,除钠泵抑制因子释放增加致细胞膜Na-K-ATP酶活性减低外,内皮功能损害致NO释放减少也可能起重要作用。  相似文献   

3.
目的: 通过研究丹参酮ⅡA(TSN)对豚鼠肥厚心肌细胞快激活延迟整流钾电流(IKr)和慢激活延迟整流钾电流(IKs)的影响,在离子通道水平探讨丹参酮ⅡA抗肥厚心肌心律失常的机制。方法: 采用腹主动脉结扎技术制造心肌肥厚模型,将豚鼠随机分为假手术组(A组)、肥厚模型组(B组)、低剂量丹参组(C组,10 mg·kg-1·d-1)、高剂量丹参组(D组,20 mg·kg-1·d-1)和缬沙坦治疗组(E组,10 mg·kg-1·d-1),每组12只。通过应用标准的全细胞膜片钳技术记录各实验组心肌细胞膜上动作电位时程(APD)、IKs和IKr密度的变化。结果: (1)与A组相比,B组、C组、D组和E组手术后4周血压均明显升高,差异有显著差异(P<0.01),B、C、D和E组间血压无显著差异(P>0.05)。(2)与A组相比,B组心肌细胞的膜电容明显升高,APD显著延长(P<0.01)。 (3)与B组相比,C、D和E组显著缩短肥大心肌细胞APD的延长,降低膜电容和阻断心肌细胞上IKr、IKs的密度(P<0.01);C和D组间无显著差异(P>0.05)。结论: 丹参酮Ⅱ-A能降低肥厚心肌细胞上IKr 和IKs的密度,可能是其干预肥厚心肌电生理异常的重要机制之一。  相似文献   

4.
目的:探讨钙调神经磷酸酶和钙泵活性在大鼠压力负荷性心肌肥厚时的变化及伊贝沙坦和培垛普利对它们的影响。方法:40只雄性SD大鼠随机分为5组。除假手术组外,其余4组大鼠采用腹主动脉部分结扎法造成压力负荷性心肌肥厚模型,术后1周分别用下列药物开始灌胃:假手术组和对照组生理盐水2mL·kg-1·d-1,伊贝沙坦组20mg·kg-1·d-1,培垛普利组2mg·kg-1·d-1及联合用药组(培垛普利2mg·kg-1·d-1,伊贝沙坦20mg·kg-1·d-1)。用药6周后检测左室质量指数、心肌细胞横径、心肌钙调神经磷酸酶及钙泵活性,免疫组化测定心肌钙调神经磷酸酶的表达。结果:联合用药组LVMI显著低于对照组及单用伊贝沙坦或培垛普利药组,各用药组TDM及钙调神经磷酸酶活性显著低于对照组,对照组心肌肌浆网钙泵活性显著低于其他各组,联合用药组钙泵活性明显高于单独用药组。免疫组化显示对照组心肌组织钙调神经磷酸酶表达显著高于其他各组。相关分析显示LVMI与TDM、CaN均呈显著正相关,与钙泵活性呈负相关。结论:伊贝沙坦和培垛普利可抑制钙调神经磷酸酶活性,增加心肌肌浆网钙泵活性,联合应用对减轻心肌肥厚有协同作用。  相似文献   

5.
目的: 探讨普伐他汀联合华法林对兔激素性股骨头坏死(SIONF)的影响。方法: 成年健康日本雌性大白兔48只,随机分为3组,对照组(CTR组)12只,激素性股骨头坏死模型组(SIONF组)18只,普伐他汀华法林治疗组(PW组)18只。SIONF组和PW组一次性肌肉注射甲基强的松龙(20 mg·kg-1)建立兔SIONF模型,CTR组仅肌注等量生理盐水。PW组口服普伐他汀2.5 mg·kg-1·d-1,华法林1.5 mg·kg-1·d-1。于实验前及实验后2、4、6、8、10、12周随机抽取动物每组2只采血测定总胆固醇(TC)、甘油三酯(TG)、血浆凝血原时间(PT)及活化部分凝血活酶时间(APTT)。在后4个时点同时行双侧髋关节X线摄片,随后处死动物,行骨组织形态学及透射电镜检查,检测3组SIONF发生率。结果: 从实验第6周开始到实验终点,与CTR组比较,PW组TC增高(P<0.05),但较SIONF组低(P<0.05),SIONF组TC显著高于CTR组(P<0.01)。3组TG水平有类似TC变化。从实验第2周开始,PW组PT较CTR组及SIONF组明显延长(P<0.01),反之,SIONF组显著缩短(P<0.01)。APTT 3组之间有类似PT的变化。骨组织形态学及影像学显示,与SIONF组比较,PW组股骨头髓内基质脂肪转化率及骨陷窝空虚率显著减少,未见血栓形成,骨细胞核固缩及自溶现象明显减轻。PW组SIONF发生率31%(5/16)显著低于SIONF组63%(10/16)(P<0.05)。结论: 普伐他汀与华法林联合应用能减少兔SIONF发生,这可能与其改善高脂高凝状态有关。  相似文献   

6.
目的:观察动脉粥样硬化(AS)发生发展过程中脂蛋白脂酶(LPL)、肝脂酶(HL)活性的变化及茶多酚(TP)的作用。方法:高脂食物AS模型兔口服茶多酚200μg·g-1·d-1,测定血浆中LPL、HL活性,同时用组织化学法检测动脉壁层组织中LPL活性、肝组织中HL活性。结果:AS组动脉粥样硬化病变血管壁与正常对照组血管壁组织中LPL活性差异无显著(P>0.05);AS组肝组织中HL活性明显低于正常对照组(P<0.05)。TP组肝组织中HL活性明显高于AS组(P<0.05)、血浆中TC和LDL-c水平低于AS组(P<0.05)、动脉粥样硬化斑块面积低于AS组(P<0.05)。各组间血浆LPL、HL活性水平差异无显著(P>0.05)。结论:茶多酚能增加实验性AS兔肝组织中HL脂酶活性,这一作用与降低血浆胆固醇水平和抗动脉粥样硬化密切相关。  相似文献   

7.
目的:观察普伐他汀和西立伐他汀对高胆固醇喂养兔的血管内皮功能的影响。方法:28只纯种日本大耳白兔,随机分为4组(每组7只):高胆固醇对照(HC)组喂以1.5%的高胆固醇饲料共8周,普伐他汀加高胆固醇(P+HC)组和西立伐他汀加高胆固醇(C+HC)组均先喂以1.5%的高胆固醇饲料4周,之后P+HC组继续喂以1.5%的高胆固醇饲料加普伐他汀10 mg·kg-1·d-1 4周,C+HC组喂以1.5%的高胆固醇饲料加西立伐他汀0.3 mg·kg-1·d-14周,正常对照组(NC组)喂以普通饲料共8周。8周后于麻醉情况下取血测定血脂,并分离胸主动脉去除脂肪和结缔组织,切成4 mm长的血管环置浴槽中做离体灌流实验,分别观察对乙酰胆碱、硝酸甘油和去甲肾上腺素的剂量反应曲线。结果:HC组血清胆固醇水平明显高于NC组,P+HC组和C+HC组则显著低于HC组。HC组血管对乙酰胆碱的内皮依赖性舒张反应明显弱于NC组,且对去甲肾上腺素的收缩反应高于NC组;而P+HC组和C+HC组这些反应接近NC组,它们之间无显著差异。4组血管对硝酸甘油的非内皮依赖性舒张反应相似。结论:普伐他汀和西立伐他汀均可预防高胆固醇喂养兔的血管内皮功能失调,二者之间无显著差异。  相似文献   

8.
目的:观察高脂血症时动脉血管紧张素Ⅱ1型受体(AT1)mRNA表达水平、外周血血管活性物质的变化特点及降脂治疗的作用, 探讨辛伐他汀逆转内皮功能障碍的机制。方法:实验包括正常对照组, 另两组通过4周建立高脂血症模型, 此后继续高脂喂养, 其中辛伐他汀治疗组在高脂喂养同时喂服辛伐他汀10mg·kg-1·d-1)而高脂血症组不予药物治疗, 第20周检测3组的血脂变化及观察AT1mRNA表达水平、外周血AngⅡ和NO浓度。结果:高脂血症组AT1mRNA表达水平高于、血NO水平低于正常对照组、而AngⅡ和收缩压无显著差异。辛伐他汀治疗组总胆固醇(TC)、甘油三脂(TG)、低密度胆固醇(LDL-C)显著低于高脂血症组, 且动脉组织AT1mRNA表达水平也显著低于高脂血症组, 血NO含量高于高脂血症组、但血AngⅡ浓度和收缩压未见显著差异。结论:辛伐他汀在调脂的同时, 下调AT1mRNA的表达、促进一氧化氮的生成, 从而逆转内皮功能障碍、阻止动脉硬化进展。  相似文献   

9.
衰老大鼠急性肺损伤诱导肾功能受损   总被引:3,自引:0,他引:3       下载免费PDF全文
目的:观察衰老大鼠的急性肺损伤(ALI)是否可进一步诱导肾功能受损。方法:Wistar雄性大鼠40只, 复制成衰老模型, 然后再随机分成对照组(静脉注射生理盐水), ALI组(静脉注射脂多糖, LPS)及LPS组(左心室内注射LPS), 后两组再分2h及6h组。每组8只。注LPS后2h或6h收集血并取肺、肾。制备肺、肾组织匀浆待测。结果:ALI组在注LPS后仅至6h时血中肌酐(Cr)、尿素氮(BUN)含量才有显著升高(均P<0.01)。而LPS组Cr、BUN含量均无显著升高。ALI组血中乳酸(LD)、丙二醛(MDA)及一氧化氮(NO)含量在注LPS后2h时均显著升高(P<0.05, P<0.01);而肺组织中谷胱甘肽过氧化物酶(GSH-PX)及Na+-K+-ATPase活性均显著下降(均P<0.01);上述变化持续至观察的6h时。ALI组在注LPS后仅至6h时, 肾组织中MDA、NO含量才有显著升高(均P<0.01)及GSH-PX、Na+-K+-ATPase活性显著下降(P<0.01)。而在LPS组, 除注LPS后2h时的血中和2h、6h的肺组织中NO含量显著升高(均P<0.05)及2h时的肺组织中Na+-K+-ATPase活性显著下降(P<0.05)外, 其它均无显著变化。结论:给衰老大鼠静脉内注射5mg/kg的LPS可致ALI, 并可进一步诱导肾功能受损。  相似文献   

10.
葡萄籽原花青素对肾血管性高血压大鼠血压的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
目的: 观察葡萄籽原花青素(GSP)对肾血管性高血压(RH)大鼠血压的影响并对其机制进行初步探讨。方法: 采用两肾一夹(2K1C)法建立RH大鼠模型,并设假手术组(control,n=8)。术后2周,选取鼠尾动脉收缩压升至130 mmHg以上的大鼠32只为RH大鼠,随机分为4组(n=8):高血压模型组(RH model);GSP低剂量治疗组(low GSP,50 mg·kg-1· d-1);GSP高剂量治疗组(high GSP,200 mg·kg-1· d-1)和卡托普利阳性对照治疗组(captopril,30 mg·kg-1· d-1)。治疗6周后,分别测定大鼠血压、血清中超氧化物歧化酶(SOD)活性、 丙二醛(MDA)和一氧化氮(NO)含量,以及总抗氧化能力(T-AOC);Western blotting法检测腹主动脉中内皮素-1(ET-1)的蛋白表达。结果: 治疗6周后,与control组相比,RH model组大鼠的尾动脉收缩压明显升高(P<0.01);与RH model组相比,GSP能显著降低RH大鼠的尾动脉收缩压、MDA含量及主动脉组织中ET-1的蛋白表达(high GSP组),升高大鼠血清中SOD活性、NO含量(high GSP组)和T-AOC。结论: GSP能显著降低RH大鼠的尾动脉收缩压,其机制可能与其增强大鼠抗氧化能力,增加NO的产生和释放,降低血管内皮中ET-1的蛋白表达有关。  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.
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   

13.
Most bodily functions require the coordinated actions of complementary and supplementary paired muscle groups. Where this essential muscular cooperation is lacking, hollow organs may burst and others become literally screwed up, giving rise to many similar spastic diseases such as Torticollis, Twisted ovarian cyst, Torsion of the Testis, Volvulus of the intestines, Varicose Veins, Megacolon, Aortamegaly, Scoliosis, Erb's Palsy, Peyronie's Disease, Main-en-Griffe, Undescended Foot (Pes Cavus), Talipes, Strabismus. Spasm is “panenepidemic” and unclassified examples of Torsion Dystonia and Dyskinesia really are as common as debt and taxes.  相似文献   

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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.
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   

18.
Zusammenfassung Eine Reihe pathologischer Zustände bedingen Magnesiummangel. Zustände mit Hypermagnesämie sind ebenfalls bekannt, doch wesentlich seltener. Für den Kardiologen beachtenswert ist, daß unter Therapie mit bestimmten Diuretica bei Herzinsuffizienz, bei Herzinfarkt, Kardiomyopathie, Digitalisintoxikation und bestimmten Herzrhythmusstörungen Hypomagnesämie beobachtet wurde. Leider kann in der klinischen Routine nur ein extracelluläres Magnesiumdefizit durch Serumbestimmungen gemessen werden; über Magnesiummangel einzelner Organe kann nichts ausgesagt werden. Hinweise für Magnesiummangel geben aber neben der Messung des Serumspiegels Anamnese, klinischer Befund, bestimmte EKG-Veränderungen wie auch evtl. Hypokalämie, ein Zustand, bei dem sich oft — besonders bei Aldosteronismus — parallele Veränderungen zeigten.Tierexperimente deuten darauf hin, daß infarktähnliche Läsionen unter Magnesiummangel entstehen, doch ob Herzinfarkt beim Menschen durch Magnesiummangel ausgelöst werden kann, ist noch ungeklärt. In Leichenherzen zeigte sich im Infarktgebiet neben Calciumakkumulation signifikanter Magnesiumverlust, wobei unklar blieb, ob sich Ursache oder Folge des Infarktes widerspiegelten. Falls ein ursächlicher Zusammenhang besteht, ist er im Myokardstoffwechsel selbst zu suchen, wie bei der Alkoholkardiomyopathie, wo myokardialer Magnesiummangel zumindest als pathogenetischer Teilfaktor anerkannt wird. Andererseits versucht man aber auch Beziehungen zwischen Atherosklerose, Blutgerinnung und Hypomagnesämie herzustellen, in der Meinung, daß Magnesiummangel auch über den coronaren Pathomechanismus des Herzinfarktes wirken könnte. Sicher scheint, daß gewisse EKG-Veränderungen und Herzrhythmusstörungen durch einen irritierten Magnesiumhaushalt bedingt sein können, da sie bei Gabe bzw. Entzug von Magnesium verschwinden. Daß Magnesiummangel die Glykosidtoleranz verringert, wird tierexperimentell bestätigt. Unter Hypomagnesämie bewirkt Acetylstrophanthidin eher und länger Rhythmusstörungen als ohne, außerdem lassen diese sich durch Magnesiumgaben eliminieren. Da in gewissen Fällen spontane und digitalisinduzierte Herzrythmusstörungen durch Magnesiuminjektionen beseitigt wurden, scheint Magnesium als Therapeuticum angebracht. Einsatz verschiedener Magnesiumsalze bei Angina pectoris, degenerativen Herzerkrankungen und Herzinsuffizienz ohne geprüften und offensichtlich gestörten Magnesiumhaushalt ist fragwürdig, weil keine eindeutigen klinischen Erfolgsbeweise vorliegen. Immerhin mag es aber larvierte, durch Serumbestimmungen nicht erfaßbare Mangelzustände geben. Allgemein erscheint es aus kardiologischer Sicht ratsam, den Magnesiumhaushalt zu überwachen und in entsprechenden Fällen auszugleichen, um möglichen Myokardläsionen oder fatalen Herzrhythmusstörungen entgegenzuwirken.  相似文献   

19.
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   

20.
There is a sharp difference in how one views TCR structure–function–behaviour dependent on whether its recognition of major histocompatibility complex‐encoded restriction elements (R) is germline selected or somatically generated. The generally accepted or Standard model is built on the assumption that recognition of R is by the V regions of the αβ TCR, which is not driven by allele specificity, whereas the competing model posits that recognition of R is allele‐specific. The establishing of allele‐specific recognition of R by the TCR would rule out the Standard model and clear the road to a consideration of a competing construct, the Tritope model. Here, the case for allele‐specific recognition (germline selected) is detailed making it obvious that the Standard model is untenable.  相似文献   

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