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1.
多孔纯钛种植体表面快速沉积钙磷涂层的研究   总被引:2,自引:0,他引:2  
商业纯钛片经磨平、喷砂、清洗、酸洗后分成A、B两组。A组不作任何处理,B组用H2SO4和HCl混合液酸蚀,然后两组钛片同时置于37℃的仿生液SBF-A中1d及SBF-B中2d。结果两组钛片表面均可沉积磷灰石涂层,涂层为多孔片状结构,X射线衍射分析证实其为碳酸化羟基磷灰石和磷酸八钙的混合物,钙磷原子量比约1.51。这说明在多孔纯钛表面可以快速仿生沉积碳酸化磷灰石涂层。  相似文献   

2.
背景:钛合金人工颈椎间盘具有良好的生物相容性,但钛合金存在生物活性差、与骨结合强度低、在生理环境下易造成金属离子释放等问题。 目的:观察国产人工颈椎间盘钛合金终板不同涂层对大鼠骨髓间充质干细胞黏附、分化的影响。 方法:将第3代Wistar大鼠骨髓间充质干细胞,接种于含羟基磷灰石涂层、钛粉复合羟基磷灰石涂层的钛合金板及裸钛合金板的24孔板内,培养的第24,48小时后分别终止培养,扫描电镜观察细胞生长情况;接种24 h后加成骨诱导剂进行诱导,并于第3,5,7天各收集细胞裂解后离心的上清,检测碱性磷酸酶表达。 结果与结论:骨髓间充质干细胞与材料复合培养48 h后,羟基磷灰石组和钛粉复合羟基磷灰石组表面的细胞呈多角形,并伸出细长伪足伸入到材料的微孔内,与材料表面紧密黏附;而裸钛合金组骨髓间充质干细胞分化较差且黏附率低。随时间延长,各组碱性磷酸酶表达均增加,羟基磷灰石组和钛粉复合羟基磷灰石组各时间点的碱性磷酸酶表达均较裸钛合金组明显增高(P < 0.05)。表明羟基磷灰石、钛粉复合羟基磷灰石涂层可有促进大鼠骨髓间充质干细胞的黏附和分化。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.
目的电泳沉积法制备出钛合金/钙镁硅生物玻璃陶瓷涂层复合材料,优化制备工艺条件。方法用溶胶-凝胶法制备出钙镁硅生物玻璃陶瓷粉体,通过粉体在不同分散介质中的带电特性和沉积结果,筛选合适的溶剂;通过改变悬浮液陈化时间(10分钟、1小时、24小时)、悬浮液体系固含量(0.02kg/L、0.06kg/L、0.12kg/L)、电压(20V、40V、80V)及钛合金基底的预处理方法,观察不同条件对电泳沉积涂层表面形貌和性能的影响,找出较佳的制备条件。结果生物玻璃陶瓷粉体在乙醇中带正电荷,且能在钛合金阴极基底上均匀沉积;在经过机械打磨的钛合金表面沉积的涂层均匀无裂纹,而未经打磨的钛合金表面的涂层开裂严重;悬浮液的固含量为0.02kg/L,陈化时间在10分钟时为最佳分散条件;沉积电压为20V、40V、80V均能制备出均匀无裂纹的涂层,经过煅烧后的涂层为多孔结构,涂层厚度为10~250 m,XRD结果显示涂层是以透辉石,镁黄长石等为主晶相的玻璃陶瓷。结论经过条件优化,可以制备出均匀无开裂的多孔生物玻璃陶瓷涂层,涂层厚度和致密度可控。  相似文献   

4.
背景:目前多采用等离子喷涂技术在钛及其合金表面涂覆羟基磷灰石涂层,制备成复合材料。但由于羟基磷灰石与钛合金基体的热膨胀系数相差较大,涂层在冷却过程中易产生脱落。 目的:在医用镍钛形状记忆合金表面制备致密、均匀的羟基磷灰石生物陶瓷涂层,利用动物实验考查镍钛/羟基磷灰石涂层材料的生物相容性。 方法:利用阴极旋转法在低温条件下从含钙、磷离子的电解水溶液中在镍钛形状记忆合金表面沉积了磷酸钙涂层,经碱处理获得羟基磷灰石涂层。分析工艺参数对涂层结构的影响。利用动物植入实验对该复合材料的生物活性进行研究,并与镍钛/羟基磷灰石与Ca3(PO3)2•2H2O混合涂层复合材料、医用镍钛形状记忆合金、医用钛合金进行对比。 结果与结论:电化学沉积-碱处理方法适合在镍钛形状记忆合金表面制备羟基磷灰石生物活性陶瓷涂层,沉积电压、温度对涂层结构有强烈影响。4种不同材料植入动物体内后周围均出现不同程度的组织增生,在骨膜组织切片中都可见软骨细胞且有骨小梁形成,涂覆有羟基磷灰石涂层的植入材料组织反应较轻,相应的组织切片中所显示出的软骨细胞、骨小梁数量最多,分布均匀,表明羟基磷灰石涂层提高了医用镍钛形状记忆合金的生物活性。      相似文献   

5.
目的研究Ti.6A1—4V合金表面微弧氧化(MAO)涂层的表面形貌及理化性能。方法将Ti-6A1-4V合金置于含0.02mol/Lβ-甘油磷酸二钠盐及0.2mol/L乙酸钙的电解液中进行MAO处理后,通过扫描电子显微镜(SEM)观察涂层表面形貌及截面形貌;X线能谱分析(EDX)检测涂层表面钙磷比;X射线衍射分析(XRD)检测涂层晶相构成;纳米压痕试验测量涂层的微弹性模量及微硬度。结果经MAO处理后,钛合金表面形成粗糙多孔的氧化膜;XRD显示涂层主要由锐钛矿相TiO2、金红石相Ti02和羟基磷灰石(HAP)构成;EDX及纳米压痕试验测得膜层的钙磷比为1.64,弹性模量和微硬度分别为(32.07±7.07)GPa和(1.49±0.68)GPa。结论通过MAO技术可制备出具备良好理化性能的含HAP的涂层。  相似文献   

6.
背景:在钛合金基体表面制备涂层的方法多为等离子喷涂法、溶胶-凝胶法、离子束溅射法等,所制备的涂层性能不稳定、成分单一,且涂层物相组成较难控制。 目的:采用射频磁控溅射技术在Ti6Al4V基体上制备含氟羟基磷灰石梯度复合涂层HAF/YSZ。 方法:在Ti6Al4V基体上以射频磁控溅射技术制备含氟羟基磷灰石梯度复合涂层HAF/YSZ,利用X射线光电子能谱、扫描电镜等对涂层的成分分布、形貌、界面结合进行表征。通过模拟体液实验分析和评价HAF/YSZ涂层、HAF1.2涂层及羟基磷灰石涂层的生物性能。 结果与结论:所制备的HAF/YSZ梯度涂层表面粗糙,呈多孔岛状结构,有利于新生骨组织生长;涂层与基体结合紧密,各层间相互扩散,整体一致性较好;经模拟体液浸泡后,涂层表面有新生物质沉积,表现出较好的生物活性及稳定性,且梯度复合涂层较氟含量单一的氟羟基磷灰石涂层具有更好的抗体液溶解能力及稳定性。  相似文献   

7.
背景:羟基磷灰石是骨的主要成分,具有诱导成骨细胞的功能。纳米银具有广谱和高效的抗菌效果,钛基表面羟基磷灰石/纳米银复合涂层材料既有生物活性又具有抗菌特性。目的:研究钛基表面羟基磷灰石/纳米银复合涂层体外抗菌作用及影响因素,评价钛基表面羟基磷灰石/纳米银复合涂层的生物相容性和安全性。方法:选取浓度0,0.5,1.0 mmol/L银溶液制备钛基表面沉积的羟基磷灰石/纳米银复合涂层样品,将其浸提液与金黄色葡萄球菌与材料共培养,进行体外抗菌定性分析。按照国家和国际标准化组织对生物材料相容性检测标准,对健康成年昆明小鼠、新西兰兔进行热原试验、溶血试验、急性毒性试验、皮肤刺激试验,综合评价材料的生物相容性和安全性。结果与结论:钛基表面沉积制备的羟基磷灰石/纳米银复合涂层材料体外对金黄色葡萄球菌有明显抗菌作用,复合材料中银含量越高抗菌作用越明显,且动物实验中未出现明显的热原反应、溶血反应、急性毒性反应、皮肤刺激反应,与不含银的纯羟基磷灰石材料相比,生物相容性差异无显著性意义。说明钛基表面沉积制备的羟基磷灰石/纳米银复合材料,体外对金黄色葡萄球菌具有良好的抗菌作用,且具有良好的生物相容性。  相似文献   

8.
背景:有研究应用脉冲激光沉积合成技术在人工心脏机械瓣膜上沉积胶原制备了新型纳米羟基磷灰石薄膜涂层。 目的:观察此种新型纳米羟基磷灰石薄膜对人脐带静脉血管内皮细胞的毒性。 方法:分别采用纳米羟基磷灰石薄膜常温浸提液、纳米羟基磷灰石薄膜高温浸提液、高密度聚乙烯及苯酚溶液培养人脐静脉血管内皮细胞,72 h内倒置相差显微镜下观察细胞生长状况;培养7 d时采用CCK-8法检测细胞增殖与毒性分级。 结果与结论:培养24 h,纳米羟基磷灰石薄膜常温浸提液组、纳米羟基磷灰石薄膜高温浸提液组和高密度聚乙烯组细胞生长良好,呈梭形,折光性强,3组细胞形态、数量无明显差异;苯酚溶液组细胞多为悬浮、圆形、固缩的死细胞;48 h时,除了苯酚溶液组外,其余3组细胞数量明显增加,细胞生长密集,至72 h时细胞生长旺盛,间隙显著减小。培养7 d内,纳米羟基磷灰石薄膜常温浸提液组、纳米羟基磷灰石薄膜高温浸提液组和高密度聚乙烯组细胞增殖活性无差异,均高于苯酚溶液组(P < 0.05),纳米羟基磷灰石薄膜毒性级别为0至1级,表明纳米羟基磷灰石人工心脏机械瓣膜有良好的组织细胞相容性,无毒性作用。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   

9.
羟基磷灰石涂层钛合金材料生物相容性研究初探   总被引:1,自引:0,他引:1  
目的探讨一种新型的代骨材料--羟基磷灰石涂层的钛合金材料的生物相容性。方法制备羟基磷灰石涂层钛合金材料浸提液后,采用细胞毒性实验以观察实验样品浸提液对L929小鼠成纤维细胞的毒性反应;通过对小鼠尾静脉及腹腔注射试验样品浸提液后,观察其对小鼠的急性全身毒性反应;Ames实验及迟发型超敏反应实验对其遗传毒性及致敏性进行安全性评价。结果羟基磷灰石涂层钛合金材料浸提液对L929小鼠成纤维细胞的相对增殖率(RGR)为96.9%,细胞毒性反应为1级,无细胞毒性反应;对小鼠亦无明显的急性全身毒性作用,实验样品组与阴性对照组动物体质量差异无统计学意义(P0.05);遗传毒性Ames实验表明,在活化与非活化条件下,该材料浸提液对鼠伤寒沙门氏菌株的回变菌落数与对照组比均未增加2倍,对该菌株无诱变性;迟发型超敏反应实验显示,该材料浸提液无潜在的皮肤接触致敏性。结论羟基磷灰石涂层的钛合金材料具有良好的生物相容性。  相似文献   

10.
目的对骨科常用钛植入材料进行表面处理,赋予其高生物活性。方法利用酸碱腐蚀法对钛基体进行粗化与活化处理,并通过模拟体液浸泡样品,在钛表面制备了含钙、磷的生物活性无机涂层。通过腐蚀率测定、静滴接触角、SEM等方法研究了粗化及活化处理对钛合金样品表面能、润湿性、粗糙度、表面形貌等理化性能的影响;通过MG63细胞培养实验观察了不同表面处理方法对细胞粘附、分化和增殖情况的影响;并通过SEM、XRD等检测方法对不同方法处理样品在模拟体液中浸泡3天后表面形成的含钙磷沉积层进行观察和分析。结果浸泡后样品表面形成的无机沉积层成分为羟基磷灰石(HA),而且采用HCl/H2SO4混合酸于60℃下处理30分钟、5M NaOH 60℃腐蚀24小时并在600℃下保温1小时的酸碱热处理工艺所得到的钛表面粗糙度高,润湿性好,细胞在其上粘附、分化、增殖情况最佳,且其表面沉积的HA层更为致密均匀。结论通过对钛基体表面酸碱热处理工艺条件进行优化筛选,为后期生物学评价提供初步的实验依据和前期基础。  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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