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1.
目的 结合流体力学模型研究灌注式生物反应器中大段组织工程化骨的构建与多孔支架内流体剪切力的关系。方法 利用灌注式生物反应器对复合骨髓基质干细胞的多孔磷酸三钙支架进行灌注培养。培养基的黏度分别为1.12mPa?s, 2.23mPa?s及3.35mPa?s。通过细胞增殖、成骨分化及组织形态学评价组织工程化骨的构建,建立流体力学模型,求解支架内的流体剪切力。结果 培养基黏度2.23mPa?s组,细胞增殖高于其他组。培养基黏度2.23mPa?s及3.35mPa?s组第28d的碱性磷酸酶活性及第7d后的骨钙素分泌高于1.12mPa?s组。培养基黏度越高,骨桥蛋白的分泌高峰出现越早。28d后,黏度3.35mPa?s组的钙化基质最多。流体力学模型分析,培养基黏度1.12mPa?s, 2.23mPa?s及3.35mPa?s组中,支架内的平均流体剪切力分别为5mPa, 11mPa和15mPa。结论 在利用复合人骨髓基质干细胞的多孔磷酸三钙构建大段组织工程化骨的过程中,15mPa的流体剪切力最有利于组织工程化骨的构建。  相似文献   

2.
目的 通过流体力学模型分析三维灌注培养条件下载体内细胞增殖与流场变化的关系。方法 利用灌注型生物反应器对复合骨髓基质干细胞的β-TCP载体进行动态灌注培养,对不同时间段的载体行组织形态学观察和计量,建立灌注系统的流体力学模型,比较载体不同区域细胞增殖速度与流场的关系。结果 细胞在β-TCP载体内增殖速度随培养时间的延长而增加。培养1周,大部分区域细胞大多呈单层排列;培养2周,部分孔道已填满了细胞。培养4周,大部分孔道被细胞填满,有些区域细胞数量减少。建立载体随机孔道结构的流体分析模型发现,细胞生长较快区域对应的流速大多在0.14~0.64 mm/s,剪切应力在0.0029~0.017 Pa。结论 载体内流体环境(流体剪切应力和流速)影响细胞在载体各个部位的生长,细胞生长导致载体内连通流道的结构和大小发生变化,其流体微环境亦随着发生变化,设计有利于成骨转化的载体结构要考虑这一因素。  相似文献   

3.
目的探讨在灌注型生物反应器中,大段磷酸三钙(β-TCP)载体内不同流速对人骨髓间充质干细胞(humanmesenchymal stem cells,hMSCs)增殖及成骨分化的影响。方法利用灌注型生物反应器对复合了hMSCs的大段β-TCP载体分别以3、6、9 mL/min的流速培养15 d,通过葡萄糖消耗量、细胞活力(MTT比色法)以及扫描电镜(SEM)观测细胞在载体内的增殖情况;以Real-time PCR检测成骨分化相关基因的表达。结果各组葡萄糖的日消耗量随培养时间的延长而增加,初期9 mL/min组细胞增殖明显快于3、6 mL/min组(P<0.001),但是灌注培养后期6 mL/min组的细胞增殖快于9、3 mL/min组(P<0.05)。灌注培养15 d后,6 mL/min组细胞活力显著高于3、9 mL/min组(P<0.001)。SEM观察发现3组β-TCP载体内均形成复合细胞层,3 mL/min组细胞层呈疏松的簇状,6 mL/min组复合细胞层部分呈膜片状,9 mL/min组复合细胞层多数呈膜片状。在进行成骨诱导灌注培养15 d后,6、9 mL/min组碱性磷酸酶(ALP)及骨桥蛋白(OP)的表达均显著高于3 mL/min组(P<0.01);3、6 mL/min组骨钙素(OC)的表达基本相同(P>0.05),而9 mL/min组OC的表达量则显著高于另外两组(P<0.001)。结论在利用灌注型生物反应器对hMSCs进行灌注培养的早期,9 mL/min的流速最有利于hMSCs的增殖,而晚期6 mL/min的流速最有利于hMSCs的增殖。β-TCP载体内流体剪切应力(flow shear stress,FSS)随灌注流速的增加而增加,适当的FSS可促进细胞外基质的合成和分布,并增加成骨相关基因的表达。  相似文献   

4.
目的本研究从血流动力学角度,利用计算流体力学CFD初探体外生命支持系统中膜式氧合器内流场分布情况。方法利用SolidWorks建立两种典型结构氧合器模型Maquet M78000-A和Medtronic Affinity NT-B。通过Ansys CFX 14.5进行数值模拟A、B在1~7 L/min流量下,流场分布情况。计算多个指标,速度、压力、流体切应力、涡强度、入口泵功率和能量损失。同时结合体外模拟实验,复方电解质液作循环液体,测量A、B在1~7 L/min流量下各自压差,对比CFD模拟结果。结果在2 L/min平均流量辅助下,A、B入口流腔内平均流速为0.037、0.146 m/s;两侧压降为6.970、11.009 mmHg;血液经过在入口流腔产生涡强度为1.967、5.301 s~(-1);产生能量损失为0.029 8、0.043 8 W。同时体外实验中测量对应压差为5、8.67 mmHg,模拟结果为6.859、10.933 mmHg。结论 CFD可定性模拟血液在氧合器内流动和流场分布。A内涡强度、形态、位置和数量随流量增加而改变;场内形态分布也越不均匀,强涡区域主要集中在入口处。B随流量增加,流场分布也呈不均匀,高流速区域集中在入出口位置,并产生不同强度涡流,造成能量损失。不同流量下,A中血液流速、跨膜压降均低于B。但A内部仍存在涡流、流动死区等,在未来仍需做出进一步优化。体外实验与CFD模拟结果基本吻合,说明CFD模拟可为解决临床问题提供一定参考依据。  相似文献   

5.
目的 建立灌注生物反应器和心肌组织构建物中流体流动及氧传递和反应的稳态数学模型。方法 以工程化心肌组织体外多通道灌注培养系统为研究对象,利用计算流体力学方法,通过商业软件来求解数学模型,并考察两种细胞密度下灌注速率对氧分布的影响。结果 通过多通道灌注生物反应器模仿毛细血管,能部分提高及改善支架材料内的氧浓度分布。在细胞密度较低时多通道灌注方式可以满足细胞生长的需要;但由于通道的数目较少以及形状简单,在细胞密度较高时,仍无法满足细胞对氧的需求。结论 该模型能够用于优化支架材料的几何尺寸以及灌注速率等流动参数。  相似文献   

6.
目的探讨人胚成骨细胞在多孔β-磷酸三钙(β-TCP)支架内灌注性接种及培养的影响因素及其作用机制,对一体化灌注法体外构建活化人工骨进行优化研究。方法应用自行设计的灌注式生物反应器进行多孔β-TCP支架内人胚成骨细胞的一体化灌注性接种和培养,以静态接种为对照。通过细胞活力(Mrrr法)测定、活细胞接种率、组织形态学观察和计量学分析等分别检测细胞接种时间、接种密度、灌注速率等因素对支架内细胞黏附和生长的作用。结果细胞灌注接种效果优于静态接种;灌注接种-灌注培养法细胞生长及分布优于静态接种-灌注培养法。接种时间、接种密度、灌注速率等因素均显著影响细胞接种及培养效果。灌注法构建活化人工骨的最优条件:接种时间12h~24h,接种密度2×10^5/ml一5×10^5/ml,灌注接种速率1ml/min,灌注培养速率0.5ml/min~2ml/min(灌注初期24h)及2ml/min(灌注24h后)。结论一体化灌注法利于多孔β-TCP支架内人胚成骨细胞的黏附和生长。接种时间、接种密度、灌注速率等因素均影响活化人工骨体外构建效果,对其进行优化有助于人工骨移植物的临床转化和推广应用。  相似文献   

7.
目的对新型生物人工肝反应器进行参数的优化测定,以寻找更适合肝细胞生长的工作条件。方法从实验和仿真两方面优化运行参数。通过调节生物反应器旋转速度、培养液流速,寻找能使细胞微载体均匀悬浮于反应器的合理运行参数。利用流体动力学仿真软件Fluent对新型生物反应器进行仿真,将仿真结果与实验结果进行对比得出合理工作范围。结果生物反应器的旋转往复周期Z越大,反应器内细胞微载体达到均匀悬浮状态时所需的培养液流速就越大,即控制培养液流动的蠕动泵转速£越大。在确保细胞微载体均匀悬浮分布下,往复周期Z=0.5min时,没有合适的,J值满足要求;往复周期Z=0.4min时,三的工作范围为120~160r/min;往复周期Z=0.3min时,£的工作范围为80~160r/min。结论合理的运行参数优化了生物人工肝的工作方式,为动物实验及临床实验奠定了基础。  相似文献   

8.
目的应用计算流体动力学(computational fluid dynamics,CFD)技术对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)患者不同程度呼吸窘迫状态时下呼吸道内气流运动特性进行模拟研究。方法基于CT影像数据建立真实健康人体下呼吸道三维模型。采用标准k-ε湍流模型对下呼吸道内的气体流动进行数值模拟,分析下呼吸道内气流的速度、流量、压力以及壁面剪切应力等参数分布特点。结果拟合下呼吸道空气流动阻力与呼吸强度的函数关系;得到下呼吸道内空气流速、压力、壁面剪切应力的分布特点以及空气流量在各肺及各叶支气管的分配情况。结论通过CFD模拟分析可以获得更为详细的下呼吸道流场相关数据,为ARDS患者的临床治疗提供理论依据。  相似文献   

9.
目的 考察振荡流动以及三维支架孔径和孔隙率对生物反应器内流速和剪切力分布的影响,并根据理论计算结果为脱细胞骨三维支架和灌注式生物反应器制备提出优化方法。方法 针对实验室前期制备的骨组织工程用脱细胞骨三维支架和灌注式生物反应器,将脱细胞骨三维支架简化为各向同性的多孔介质,对生物反应器内的流速和剪切力分布进行理论建模。结果 振荡流作用时,多孔支架材料内速度和达西剪切力呈现一致的变化规律,不同半径处流速和达西剪切力差异减小,有利于在骨组织工程中对种子细胞进行均匀三维培养。提高入口灌流速度可提高平均达西剪切力;增加多孔支架孔径或孔隙率对支架内流速峰值影响不大,但会显著降低平均达西剪切力;提高入口振荡流动振荡频率可降低支架内流速最大峰值,显著减小不同半径处流速的差异。结论 适宜的振荡流易产生利于骨组织工程干细胞所需剪切力,研究结果有望为优化骨组织工程中种子细胞的三维培养方法提供理论指导。  相似文献   

10.
通过个体化正常人体左冠状动脉CT构建不同分叉角度的流体力学模型,应用计算流体动力学(computational fluid dynamics,CFD)的方法模拟研究不同分叉角度左冠状动脉的流体力学特性,从而探讨冠状动脉分叉角度与斑块形成分布的关系。应用有限元仿真模拟并分析不同分叉角度左冠状动脉的流动力学特性。不同分叉角度的冠状动脉在壁面压强(wall pressure,WP)、壁面剪切应力(wall shear stress,WSS)、血液流场分布均存在差异。左冠状动脉分叉模型中存在两处低剪切应力区域:分叉脊附近和分叉对侧。分叉脊附近剪切应力随分叉角度增大而逐渐减小,其范围相应的增大;分叉对侧的低剪切应力及其范围并没有相应的变化。冠状动脉分叉角度与血液流体力学及斑块形成及分布有一定的关系。  相似文献   

11.
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   

12.
Boll  Irene  Eisold  H.  Gaul  H. B.  Kehr  J.  Löchte  K. H.  Niemann  W.  Stender  K.  Stockhorst  H. U.  Suchy  B. R.  Szantho von Radnoth  B.  Taj  A.  Theuner  E.  Troester  P. M.  Werner  F.  Wilke  G.  Willigerodt  P. 《Journal of molecular medicine (Berlin, Germany)》1978,56(4):187-195
Zusammenfassung Die Beeinflussung der Erythroblasten-Proliferation durch das Mikromilieu wurde in vitro mittels Auswertung durch Differential- und Mitosezählungen und Signifikanzberechnung vieler Versuchsreihen auch unter verschiedenen pathologischen Bedingungen getestet.Sowohl die Mitosehäufigkeit wie die Ausreifung waren positiv mit dem Erythropoetingehalt des Medium korreliert. Der Effekt wurde durch Folsäure, Ätiocholanolon und cAMP verstärkt. Cobalt stimulierte ebenso wie Testosteron und Methenolon in vitro unabhängig von der Erythropoetinkonzentration im Medium die Erythroblastenproliferation. Ein vermindertes Eisenangebot störte die endgültige Ausreifung der Erythroblasten zu Retikulozyten und bewirkte dadurch eine Ineffektivität der Erythorpoese. Anhaltspunkte für ein Erythrozyten-Chalon oder einen Erythropoetinhemmkörper ließen sich aus unserem Versuchsansatz nicht gewinnen, weil er die Transformation der pluripotenten in die erythropoetin-sensible Stammzelle nicht einschließt. Als Nebenbefund ergab sich eine Stimulation des granulozytopoetischen Proliferationsspeichers durch Serumzusatz zum Medium von Patienten nach akutem Blutverlust und bei Polycythämia vera.Unterstützt durch die Deutsche Forschungsgemeinschaft  相似文献   

13.
《Human immunology》2020,81(6):265-266
Aymara people has been a relatively homogeneous group since Spanish Conquest by 1,532 CE, even if previously represented a group of various cultural defined populations who gave rise to them. They were and are established in Andean Altiplano around Titikaka Lake (Bolivia, Peru), Argentina and Chile neighborhood, speak Aymara language and have been maintained after Europeans arrival at a lower social status than Quechua (Inca) speaking people. However, both Aymara and Quechua populations acknowledge Titikaka Lake as center of their origins; both languages are also related. Specific high frequencies of HLA-A*02, -A*24 and -A*68, HLA-B*35, -B*39 and -B*48, HLA-DRB1*08:02, -DRB1*09:01, and -DRB1*14:02, and HLA-DQB1*04:02, -DQB1*03:02 and -DQB1*03:01 alleles are found in Aymaras and HLA class II haplotypes common to Andean Amerindians (DRB1*08:02-DQB1*04:02 and DRB1*04:03-DQB1*03:02), like Quechua, Aymara, Uros, Lamas and Mapuche are also found in Easter and other Pacific Islands. Giant human head stone statues at Tiwanaku (Titikaka Lake, Bolivia) are also found at Easter Island. Thus, it is possible a gene and cultural flow between Andean Amerindians and Easter and other Pacific Islands, as it was demonstrated by Thor Heyerdahl in his Kon-Tiki expedition which reached Pacific Islands sailing from El Callao Harbour (Lima, Peru).  相似文献   

14.
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   

15.
A lipid analysis was performed on developing metacestodes of Taenia taeniaeformis removed from the livers of rats at times varying from 3 to 35 weeks post infection. Lipid accounted for 7–21% of the dry weight of the parasites. The highest proportions were found at the earlier stages. The distribution was as follows; neutral lipid 27–45%; glycolipid 5–11%; and phospholipid 50–61%. The major neutral lipid was cholesterol, and minor neutral lipids were sterol esters, triglycerides, diglycerides and monoglycerides. Hydrocarbons were present throughout development, but in the highest amounts at the earlier stages. Five different glycolipids were found, all of which were identified as glycosphingolipids. An increase in the proportion of more complex glycolipids was noted as parasites grew older. Ten different phospholipids were identified, with the major components being phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. Other phospholipids were: lysophosphatides, phosphatidylinositol, phosphatidic acid, diphosphatidylglycerol, sphingomyelin, and an unknown phospholipid component. Changes in the relative amounts of the two major phospholipids were found when the early and late stages were compared. Two lipids found throughout development were identified as glycosylated dolichol phosphates, and they comprised between 1 and 3% of the total phospholipid fraction. Nineteen fatty acids were detected, and the fatty acid distribution for each lipid class at each stage was determined. Seven major fatty acids were common to each. These were: hexadecanoic, octadecanoic, oleic, linoleic, arachidonic, docosanoic, and docosahexaenoic.  相似文献   

16.
Introduction: The etiology of atopic dermatitis (AD) is multifactorial with interaction between genetics, immune and environmental factors.

Areas covered: We review the role of prenatal exposures, irritants and pruritogens, pathogens, climate factors, including temperature, humidity, ultraviolet radiation, outdoor and indoor air pollutants, tobacco smoke exposure, water hardness, urban vs. rural living, diet, breastfeeding, probiotics and prebiotics on AD.

Expert commentary: The increased global prevalence of AD cannot be attributed to genetics alone, suggesting that evolving environmental exposures may trigger and/or flare disease in predisposed individuals. There is a complex interplay between different environmental factors, including individual use of personal care products and exposure to climate, pollution, food and other exogenous factors. Understanding these complex risk factors is crucial to developing targeted interventions to prevent the disease in millions. Moreover, patients require counseling on optimal regimens for minimization of exposure to irritants and pruritogens and other harmful exposures.  相似文献   


17.
An attempt was made to produce sensitive and specific polyclonal antisera against the viruses causing rice tungro disease, and to assess their potential for use in simple diagnostic tests. Using a multiple, sequential injection procedure, seven batches of polyclonal antisera against rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV) were produced. These were characterized for their sensitivity and specificity using ring-interface precipitin test and double antibody sandwich (DAS) ELISA. Thirty-one weeks after the first immunization, antiserum batch B6b for RTBV showed the highest ring interface titer (DEP = 1:1920). For RTSV, batches S3, S4b and S5b all had similar titres (DEP = 1:640). In DAS-ELISA, however, significant differences among purified antisera (IgG) batches were observed only at IgG dilution of 10-3. At that dilution, IgGB4b showed the greatest sensitivity, while IgGS3 showed greatest sensitivity for RTSV. When all IgG batches were tested against 11 tungro field isolates (dual RTBV-RTSV infections) at sample dilution of 1:10, IgGB4b and IgGB6b for RTBV and IgGS3 and IgGS6b for RTSV performed equally well. However, after cross adsorption with healthy plant extracts in a specially prepared healthy plant-Sepharose affinity column, only IgGB6b could be used specifically to detect RTBV in a simple tissue-print assay.  相似文献   

18.
Nowadays, people pay more attention to biomarkers that can predict clinical efficacy of immunotherapy for allergic rhinitis. As the only recognized aetiological treatment, the efficacy of allergen immunotherapy (AIT) has been proved by many studies. However, treatment success depends on compliance and persistence greatly, which can be impaired by the lengthy duration of AIT and socioeconomic status of patients. Besides, ineffectiveness is another factor that accounts for non-adherence. If the clinical efficacy can be predicted in the early stage of immunotherapy, it can help patients choose appropriate treatment plans, increase patient compliance and optimize the allocation of medical resources. This paper mainly focuses on five candidate biomarkers, the sIgE/tIgE ratio before treatment, serum inhibitory activity for IgE, decreased basophil activation, upregulation of Tregs and tolerogenic DCs, reviews the time when potential biomarkers can predict or monitor the efficacy of AIT, discusses the reason why these indicators could serve as efficacy biomarkers and interactions among potential biomarkers.  相似文献   

19.
Neurotransmitters are not only involved in brain function but are also important signaling molecules for many diverse cell types. Neurotransmitters are widely conserved, from evolutionarily ancient organisms lacking nervous systems through man. Here, results are reported from a loss‐ and gain‐of‐function survey, using pharmacological modulators of several neurotransmitter pathways to examine possible roles for these pathways in normal embryogenesis. Applying reagents targeting the glutamatergic, adrenergic and dopaminergic pathways to embryos of Xenopus laevis from gastrulation to organogenesis stages, we observed and quantified numerous malformations, including craniofacial defects, hyperpigmentation, muscle mispatterning and miscoiling of the gut. These data implicate several key neurotransmitters in new embryonic patterning roles, reveal novel earlier stages for processes involved in eye development, suggest new targets for subsequent molecular‐genetic investigation, and highlight the necessity for in‐depth toxicology studies of psychoactive compounds to which human embryos might be exposed during pregnancy.  相似文献   

20.
《Human immunology》2020,81(5):193-194
Huastecos or Teenek Amerindians are presently living at North East Mexico (San Luis Potosi State). They have probably one of the most ancient culture of Mexico and Central America together with Mayas and Olmec groups with which also show close relationships. Proximity to Atlantic Ocean/Mexican Gulf originated that Spaniards had very early contact with them at about 1519 CE or before. In the present paper we have aimed to study HLA gene profile which may be useful for HLA and disease epidemiology and transplant programs in Teeneks. HLA-DRB1*04:07, -DRB1*14:06 and -DRB1*04:11 have been found in high frequency like in other Amerindian groups. High frequency typical Amerindians HLA extended haplotypes have been found, such as A*02-B*35-DRB1*04:07-DQB1*03:02; A*68-B*39-DRB1*04:07-DQB1*03:02 and A*02-B*39-DRB1*04:07-DQB1*03:02; also new haplotypes have been described, like A*02-B*52-DRB1*04:11-DQB1*03:02, A*68-B*35-DRB1*14:02-DQB1*03:01 and A*68-B*40-DRB1*16:02-DQB1*03:01. Genetic proximity is observed not only to linguistically close Mayans, but also to Mazatecans, Mixtecans and Zapotecans, who speak an altogether different languages; it shows once more that genes and languages do not correlate. This population was greatly diminished after European contact between 1500 and 1600 years CE; in fact, North and South America First Inhabitants population was brought from 80 down to 8 million people because of diseases (i.e.: measles, smallpox or influenza), slavery and war.  相似文献   

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