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1.
脑膜炎奈瑟菌均表达P1类外膜蛋白,这类蛋白称为PorA蛋白。同时也表达P2或者P3类外膜蛋白,这两类蛋白称为PorB蛋白。PorA和PorB蛋白表面的抗原决定簇是血清亚型和血清型的分类基础。PorA和PorB蛋白二级结构表明,两者分别具有8个暴露在外的环状结构(loopⅠ至Ⅷ)。其中,loopⅠ和Ⅳ是PorA的可变区,而loopⅠ、Ⅴ、Ⅵ和Ⅶ是PorB的可变区,决定菌株血清亚型和血清型的抗原决定簇主要存在于两者的可变区上。我国流脑病例主要是由A群的脑膜炎奈瑟菌引起的,但近年来B和C群  相似文献   

2.
广东省历年流行性脑脊髓膜炎病原体分子特征分析   总被引:1,自引:0,他引:1  
目的 了解广东省历年流行性脑脊髓膜炎(流脑)病原体的外膜蛋白编码基因porA和porB基因特征,并确定病原体的优势克隆型.方法 对1967-2007年从流脑患者分离的18株脑膜炎奈瑟球菌(Neisseria meningitidis)进行复苏培养和生化鉴定;通过DNA序列测定分析外膜蛋白编码基因porA、porB特征;对菌株进行多位点序列分型(multilocus sequence typing, MLST),采用PHYLIP软件制作进化树,并与脑膜炎余瑟球菌MIST全球数据库(PubMLST)中的菌株比较,确定优势克隆型菌株,探讨广东省历年流脑疫情分离株的看家基因序列多态性.结果 porA可变区(VR)1的型别以20型为主,VR2的型别在2004年前主要为9型,以后呈现多态性;porB可变区Ⅰ、Ⅳ、Ⅴ、Ⅵ主要分别为4、7、11、10型,2004年后可变区Ⅴ、Ⅵ型别增多;除2007年分离的1株W135菌株外,其余菌株的porB基因均无Ⅶ、Ⅷ可变区.在7个看家基因中,abcZ等位基因多态性最低,pgm最高.广东省历年流行性脑脊髓膜炎分离株2004年前的优势克隆为ST-5克隆系,自2004年开始出现高致病性ST-4821克隆系,2007年首次出现高致病性ST-11克降系.结论 广东省历年脑膜炎奈瑟球菌分离株的外膜蛋白编码基冈呈现多态性特征,分离株为多克隆系并存,近期以高致病性克隆系为主.  相似文献   

3.
两株B群流脑菌LOS抗原性的研究   总被引:2,自引:1,他引:1  
在对我国自70年代以来从病人和带菌者中分离的91株B群脑膜炎奈瑟氏菌(Nm)进行脂寡糖(LOS)免疫型分型、外膜蛋白分型/亚型、多位点酶电泳分型等的基础上,挑选了两株具有代表性的菌株3407(B:15:P1.2:L3,7,9:RFLPb-20:克隆群I)和542852(B:NT:P1.2:L3,7,9:RFLPb-20:克隆群I)。提取并纯化了它们的LOS,通过SDS-PAGE分析发现:两株菌的L  相似文献   

4.
目前获准上市的流脑疫苗主要有A群、A+C群以及A、C、W-135及Y群的四价混合疫苗,上述疫苗的有效免疫原成分均为脑膜炎球菌的荚膜多糖。而B群脑膜炎奈瑟菌的荚膜多糖因与人类N-乙酰神经氨酸聚合物结构相似,可能产生交叉反应,引起自身免疫病,不适合用作B群流脑的疫苗候选抗原。因此,研究者把焦点转向B群脑膜炎奈瑟菌外膜蛋白,目前报道的B群流脑疫苗外膜蛋白候选抗原主要包括fHBP、NspA、NHBA、NhhA、NadA、GNA1946、GNA1162、NMB0315等。本文就上述外膜蛋白作为B群流脑疫苗候选抗原的最新进展作一综述。  相似文献   

5.
铜绿假单胞菌随机扩增多态性DNA指纹法基因分型研究   总被引:12,自引:0,他引:12  
建立了铜绿假单胞菌(PA)随机扩增多态性DNA(RAPD)指纹图基因分型方法,并应用于流行病学相关或不相关的75个PA菌株的基因分型。分型率为100%。32株新生儿暴发感染菌株,可分成4个血清型和5个RAPD谱型,其中25株属于同一谱型。在8例患者的垂直追踪菌株中,除有1例其第1和第3个分离株的血清型和RAPD谱型均相同,但与第2个分离株的血清型和RAPD谱型不同外,其余7例前后菌株的谱型相同。13株散发菌株可分成3个血清型和10个RAPD谱型;12株流行病学无关菌株的RAPD谱型均不相同。本研究结果表明,RAPD指纹图基因分型法具有分型率高、分辨力强、比较快速简便等优点,并且不需要已知核酸序列,是在分子水平上对微生物感染的病原学、发病机理及流行病学研究的较理想的方法。  相似文献   

6.
目的了解韶关市健康人群血清C群脑膜炎奈瑟菌杀菌力水平,以评价健康人群对C群脑膜炎奈瑟菌的保护水平。方法2009—2011年,每年随机抽取8个年龄组健康人群血清共计811份,采用血清杀菌力试验检测血清中杀菌力抗体水平。结果811份健康人群血清中C群脑膜炎奈瑟菌杀菌力抗体总阳性率为25.40%,总保护率为23.06%,GNT为l:5.13,95%置信区间1:4.57~1:5.89。结论韶关市健康人群对c群脑膜炎奈瑟菌的传染有易感性,年龄越低其对C群脑膜炎奈瑟菌的抵抗力越弱,应加大对A+C群流脑疫苗宣传力度,普及适龄儿童A+C群流脑疫苗的免疫接种。  相似文献   

7.
目的 为保证疫苗质量的一致性和可控性,对A、C群脑膜炎奈瑟球菌结合疫苗生产用菌株CMCC(B)29201和CMCC(B)29205株进行毒性和抗原传代稳定性研究,并对30代次菌进行脑腔毒性、免疫原性和产糖质量分析.方法 将A、C群脑膜炎奈瑟球菌工作种子批菌种分别连续传代至30代次并收获3、5、10、15、20、25及30代次菌液,小鼠腹腔注射观察各代次毒性,试管凝集试验和间接ELISA测定各代次抗原性.其中30代次菌液进行小鼠脑腔攻击观察是否引起脑组织病理改变,小鼠皮下免疫观察免疫原性,同时进行发酵培养提取荚膜多糖的质量分析.结果CMCC(B)29201株和CMCC(B)29205株工作种子批菌种的半数致死量(LD50)均≥109个/ml,30代次内的LD50也均≥109个/ml,30代次菌液脑腔毒性测定显示均无病理改变;抗原性试管凝集效价均达1∶320,30代次内的试管凝集效价均达1∶320,ELISA几何平均滴度(GMT)分别为1∶4835和1∶3915,且30代次内的ELISA效价分别为1∶4315和1∶3752以上;30代次菌液的血清杀菌抗体均≥1∶32,用第30代次工作种子批菌种生产的A群和C群脑膜炎奈瑟球菌荚膜多糖各项检定指标均达到国家标准.结论 A、C群脑膜炎奈瑟球菌结合疫苗生产用菌株CMCC(B)29201和CMCC(B)29205株毒性低、抗原性和免疫原性良好,连续传代至30代次仍保持较低的毒性和较好的抗原性及免疫原性,纯化的A群和C群脑膜炎奈瑟球菌荚膜多糖质量符合质控要求.  相似文献   

8.
脑膜炎奈瑟菌表面蛋白H因子结合蛋白(f HBP),是脑膜炎奈瑟菌的外膜蛋白和重要毒力因子,能与补体调节蛋白H因子结合。结合于脑膜炎奈瑟菌表面的H因子,能下调补体系统的激活作用,使脑膜炎奈瑟菌逃避补体系统的攻击。f HBP能诱导机体产生高水平的保护性抗体,抗f HBP抗体与f HBP结合后可阻止f HBP与H因子的结合,从而使细菌易于被补体系统杀灭和清除。因此,f HBP已成为B群流行性脑脊髓膜炎理想的疫苗候选抗原之一。现就f HBP的结构、基因的表达与调节、作为B群脑膜炎奈瑟菌疫苗候选抗原的作用、应用策略、安全性和有效性等最新研究进展进行综述。  相似文献   

9.
目的利用横断面基线调查深圳市外来劳务工人血清中A群和C群流行性脑脊髓膜炎(流脑)水平,为外来劳务工人流脑防控提供依据。方法抽取深圳市罗湖区、龙岗区、宝安区3个监测点,每个监测点选择50人份以上,3个监测点共选择1003人,采用间接ELESA法(定量)检测血清中抗A群和C群脑膜炎奈瑟菌抗体效价。结果共检测1003份血清标本,外来劳务工人A群和C群流脑抗体平均滴度分别为10.78μg/ml、2.71μg/ml。A群和C群流脑血清抗体保护率分别为93.7%、64.8%,二者差异有统计学意义(P〈0.01);不同年龄组、不同籍贯外来劳务工人A群流脑抗体保护率差异均有统计学意义(P〈0.05)。结论深圳市外来劳务工人C群流脑抗体保护率明显低于A群,为了预防可能存在的流脑C群流行和暴发,提示应加强外来劳务工C群流脑多糖疫苗免疫接种。  相似文献   

10.
目的 为保证生产四价流脑(A、C、W135、Y群)结合疫苗质量一致性和可控性,对分离自国内的W135、Y群脑膜炎球菌CMCC(B)29037株和CMCC(B)29028株进行免疫原性及遗传稳定性观察.方法 将W135/Y群脑膜炎球菌工作种子批菌种分别连续传代至30代,并收获3、5、10、15、20、25及30代次菌液,对各代次菌进行免疫原性、抗原性、生化反应、毒性、毒力测定,并将30代次菌发酵培养后提取荚膜多糖进行质量分析.结果 CMCC(B)29037株和CMCC(B)29028株工作种子批菌种诱导小鼠产生总IgG抗体分别为1∶1114和1∶2229,杀菌抗体水平与IgG抗体间差异无统计学意义;试管凝集效价均达到1∶320,生化检定两菌株均发酵葡萄糖、麦芽糖,不发酵果糖、蔗糖、甘露醇和乳糖;两菌株的LD50均>109,30代次内各代次菌的免疫原性、抗原性、生化反应和毒性均无差异.30代次菌液脑腔毒性测定显示均无病理改变,用第30代次菌生产的W135/Y群脑膜炎球菌荚膜多糖各项检定指标均合格.结论 分离自国内的CMCC(B)29037株和CMCC(B)29028株为脑膜炎球菌W135/Y群菌株,免疫原性、抗原性好,生化反应合格、安全性良好,连续传至30代次仍保持较好的安全性和免疫原性,30代次菌纯化的W135/Y群脑膜炎球菌荚膜多糖质量符合质控要求,可以用作四价流脑结合疫苗生产株.  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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