短期间歇低氧暴露对大鼠海马齿状回神经发生的影响

目的:观察不同低氧浓度环境对大鼠海马齿状回神经发生的影响。方法:取健康雄性Sprague-Dawley(SD)大鼠60只,随机分为11%和15%氧浓度干预组,分别包括常氧对照组(C11,C15),低氧4 h组(4H11,4H15)和低氧8 h组(8H11,8H15)。对所有组大鼠的脑组织切片进行BrdU和NeuN免疫荧光染色,计数海马齿状回内新生细胞数量和新生神经元数量。结果:(1)同一氧浓度组间比较:各组大鼠海马齿状回新生细胞数量(BrdU+)、新生神经元数量(BrdU+/NeuN+)以及新生神经元占新生细胞数量的百分比(Pneuron)均无显著性差异。(2)不同氧浓度、相同低氧干预时间比较:C11和C15,4H11和4H15以及8H11和8H15的BrdU+、BrdU+/NeuN+和Pneuron均无显著性差异。结论:在11%或15%氧浓度环境中,每天进行4 h和8 h的低氧干预,连续7d,对大鼠海马齿状回新生细胞的数量和新生细胞的分化无明显调节作用。     

短期间歇和急性低氧对大鼠快慢肌萎缩的影响及其作用机制

目的:探讨不同低氧干预模式对大鼠快肌和慢肌萎缩的影响差异及可能的分子机制.方法:24只10周龄雄性SD大鼠分为常氧对照组(C组)、短期间歇低氧组(IH组,于12.4％O2暴露8 h/d,持续4周)和急性低氧组(AH组,连续3 d暴露于12.4％O2),每组8只.干预后测定抓力,胫骨前肌(TA,快肌)和比目鱼肌(SOL,...     

次声对大鼠焦虑抑郁情绪的影响

目的:探讨不同暴露时程16 Hz、115 dB次声对大鼠焦虑抑郁情绪的影响。方法:健康成年雄性SD大鼠随机分为空白对照组(control)、假次声暴露组(sham exposure)和次声暴露组(infrasound exposure),空白对照组动物正常饲养于清洁级动物房,次声暴露组动物每天同一时间段置于次声实验室进行16 Hz、115 dB次声连续暴露(时程分别为7、14、21 d,2 h/d),假次声暴露组动物每天置于同一次声实验室但无次声暴露。大鼠焦虑抑郁情绪变化采用开放旷场和高架十字迷宫行为实验进行评价。结果:两组行为检测均显示,空白对照组与假暴露7、14、21 d组各行为指标均未发现统计学差异,表明次声实验室环境对大鼠行为学表现不会造成明显影响。开放旷场行为实验结果显示,次声连续暴露7 d组动物中央区运动距离显著低于假暴露7 d组(P 0.01),其他行为学实验指标未发现统计学差异;次声连续暴露14 d组动物中央区运动距离、中央区停留时间、中央区进入次数、总运动距离均显著低于假暴露14 d组,角落区停留时间、总静止时间则显著高于假暴露14 d组(P 0.05)。高架十字迷宫行为实验结果显示,次声连续暴露7 d组动物闭合臂停留时间显著多于假暴露7 d组(P 0.01),其他行为学实验指标未发现统计学差异;次声连续暴露14 d组动物闭合臂停留时间、闭合臂运动距离显著多于假暴露14 d组,开放臂进入次数、开放臂进入次数百分比、开放臂停留时间、开放臂停留时间百分比显著少于假暴露14 d组(P 0.05)。次声连续暴露21 d组动物行为学实验指标均未发现统计学差异。结论:16 Hz、115 dB次声暴露7或14 d能引发大鼠的焦虑抑郁情绪,且暴露14 d效应最为明显,随着暴露时程的延长焦虑抑郁情绪有所缓解。     

低氧训练与低氧大鼠心肌细胞凋亡及凋亡因子的表达

背景：低氧训练时,机体既要承受运动负荷,同时处于外界的低氧环境,此时, 心组织将如何适应其变化?其机制研究国内外较少。 目的：观察低氧与低氧训练对大鼠心肌细胞凋亡及Bax及Bcl-2表达的影响。 方法：SD大鼠共60只随机分为6组,常氧组、低氧8 h组、低氧12 h组、常氧训练组、低氧8 h训练组和低氧12 h训练组,每组10只。后3组大鼠每天在坡度为0的动物跑台上以25 m/min的速度训练1 h。训练完后,将低氧8 h组、低氧8 h训练组和低氧12 h组、低氧12 h训练组放入氧体积分数为12.5%(相当于海拔4 000 m)的低氧舱内8 h和12 h。实验期为4周,5 d/周。最后1次实验结束后24 h,大鼠均实施速眠新Ⅱ腹腔麻醉后取材,采用苏木精-伊红染色、原位末端脱氧核糖核苷酸转移酶介导的dUTP缺口末端标记法及蛋白免疫组织化学法检测各组大鼠心肌细胞凋亡和Bcl-2、Bax蛋白表达。 结果与结论：①与常氧组相比, 低氧12h组、常氧训练组、低氧训练组心肌细胞凋亡指数均显著增加 (P < 0.05) ;低氧12 h训练组心肌细胞凋亡指数显著多于常氧训练组和低氧8h训练组(P < 0.05) 。②与常氧组比较,其他各组Bcl-2、Bax、Bcl-2/Bax均显著性增高(P < 0.05) ;常氧训练组Bcl-2、Bax、Bcl-2/Bax表达显著高于低氧 8 h组,显著低于低氧12 h训练组(P < 0.05) ;低氧12 h训练组Bcl-2、Bax、Bcl-2/Bax表达比低氧12 h组、低氧8 h训练组显著增加(P < 0.05)。提示低氧、低氧训练可诱导大鼠心肌细胞Bcl-2、Bax蛋白表达, 运动时低氧刺激与细胞凋亡率、凋亡指数及病理损伤有关,其中以低氧12 h后运动训练组最明显,心肌细胞的凋亡调控与Bcl-2和Bax相关。     

慢性低压低氧对大鼠肺组织HIF-1ɑ、COX1蛋白及氧化应激反应的影响

目的探讨慢性低压低氧环境对大鼠肺组织细胞色素C氧化酶1(COX1)蛋白及氧化应激反应的影响。方法将大鼠随机分为常氧组(1 500 m)和低氧组(4 300 m),低氧组大鼠暴露低氧30 d后采集标本。用Western blot检测肺组织COX1蛋白的表达及ELISA检测肺组织和血清HIF-1ɑ、血浆ROS、肺组织SOD和CAT酶。用生理信号采集系统测定肺动脉压(PAP)。结果在低氧组的大鼠血清和肺组织内HIF-1α蛋白显著高于常氧组(P0.01);ROS含量显著低于常氧组(P0.01);COX1蛋白在低氧组的大鼠肺组织中表达显著下降(P0.01);血清总抗氧化能力升高(P0.01)。结论高海拔对机体的影响可能是直接性的损伤,而并非仅仅是氧化应激反应所致。     

低压性低氧暴露后大鼠骨骼肌过氧化物酶增殖激活受体-δ基因表达上调

目的探讨低压性低氧暴露对大鼠骨骼肌过氧化物酶增殖激活受体8（PPAR-δ）基因表达的影响。方法40只SD大鼠随机均分为平原组（H0组）、缺氧1d组（H1组）和缺氧15d组（H15组）。将缺氧组大鼠置于模拟海拔5，000m低压氧舱内，每天23h。平原组大鼠在平原动物房内饲养。分别于缺氧1d和15d后取双后肢腓肠肌，观察腓肠肌毛细血管密度的变化，用同位素标记法测定脂肪酸氧化率，化学比色法测定非酯化脂肪酸（NEFA）含量，RT-PCR法检测骨骼肌中PPAR-δ以及脂肪酸易位蛋白（FAT／CD36）mRNA表达的变化，并与HO组对照。结果①缺氧暴露15d后骨骼肌毛细血管密度增加。②骨骼肌NEFA含量缺氧组显著高于平原对照组（P均〈0．05），H1显著低于H15（P〈0．05）。骨骼肌脂肪酸氧化率H15显著高于H0和H1（P均〈0．05），H0与H10之间无显著性差异。③骨骼肌H1组PPAR-δ mRNA表达水平较H0和H15组分别下调39．4％和30．0％（均P〈0．05），H0和H15组间无显著性差异。H15组CD36 mRNA表达水平较Ⅲ组上调12．2％（P〈0．05），H0和H15组间以及H0和H1组间无显著性差异。结论慢性高原暴露时骨骼肌PPAR-δ mRNA表达上调，这可能是慢性高原暴露时脂肪酸氧化利用增强及骨骼肌毛细血管密度增加原因之一。     

肺动脉平滑肌细胞凋亡在大鼠低氧性肺动脉重构自然逆转中的作用及分子机制

目的:研究肺动脉平滑肌细胞(pulmonary arterial smooth muscle cells,PASMCs)凋亡在低氧性肺动脉重构自然逆转中的作用,并探讨其可能机制。方法:24只SD大鼠随机均分为常氧4周组、低氧4周组、低氧4周后复氧1周组及复氧6周组。分别检测右室收缩压(right ventricular systolic pressure,RVSP)、肺动脉中膜厚度(medial thickness,MT)和中膜面积(medial area,MA),以及肺动脉中膜自噬、凋亡等在低氧-复氧中的变化。大鼠原代PASMCs分为常氧48 h组、低氧48 h组、低氧48 h后复氧24 h组及常氧72 h组,观察PASMCs凋亡和自噬在低氧-复氧中的变化。再将PASMCs分为常氧72 h组、低氧48 h后复氧24 h组及低氧48 h+氯喹(自噬抑制剂)干预后复氧24 h组,观察PASMCs低氧阶段的自噬对其复氧阶段凋亡的影响。结果:(1)低氧使大鼠RVSP、右室肥厚指数、MT及MA显著升高(P0.05);复氧后上述指标逐渐降低。(2)低氧使肺动脉中膜LC3表达升高,P62表达降低,复氧后上述分子的表达逐步恢复正常。低氧显著降低了中膜cleaved caspase-3的表达,复氧1周其表达显著高于低氧组。(3)低氧期原代PASMCs cleaved caspase-3/PARP的表达显著低于常氧组,复氧后其表达明显升高(P0.05);PASMCs LC3和P62的表达在低氧期显著降低(P0.05)。(4)抑制了PASMCs低氧阶段的自噬后,其复氧阶段cleaved caspase-3/PARP表达显著降低(P0.05)。结论:PASMCs的凋亡参与了低氧性肺动脉重构的自然逆转;复氧期PASMCs凋亡的发生可能与其低氧期的自噬有关。     

Klotho蛋白减轻低氧/复氧诱导的心肌细胞系H9C2损伤

目的研究Klotho蛋白对低氧-复氧诱导的心肌H9C2细胞系损伤的保护作用及其机制。方法将H9C2心肌细胞分为对照组、低氧/复氧组(1%O_2低氧6 h, 5%CO_2以及95%空气培养箱中复氧2 h)和Klotho蛋白(10μg/mL)干预组。通过酶标仪间接测定细胞内钙离子([Ca~(2+)]_i)水平;CCK8法和TUNEL法分别检测细胞活性及细胞凋亡;分光光度法检测细胞中钠ATP酶(Na~+/K~+-ATPase,NKA)和反向模式钠/钙交换体(Na~+/Ca~(2+)-exchange,NCX)的活性。结果体外培养的H9C2细胞低氧/复氧(6 h/2 h)处理后可明显降低H9C2细胞活性(P0.05);增加细胞内Ca~(2+)水平和凋亡率(P0.05);降低细胞中Na~+/K~+-ATPase的活性(P0.05);增加反向模式Na~+/Ca~(2+)交换体的活性(P0.05);10μg/mL Klotho蛋白处理可明显减轻上述损伤。结论 Klotho蛋白可减轻低氧/复氧诱导下的H9C2细胞内钙超载,最终减少该细胞系细胞的凋亡。     

低氧诱导因子-1α和内皮素-1基因在大鼠低氧性肺动脉高压中的表达

目的　探讨低氧诱导因子 1(HIF 1α)和内皮素 1(ET 1)基因表达在低氧性肺动脉高压发病过程中的变化和作用。方法　复制低氧性肺动脉高压大鼠模型 ,测定平均肺动脉压 ,弹力纤维染色显示腺泡内肺动脉 ,用放射免疫法测ET含量 ,原位杂交方法进行检测HIF 1αmRNA。结果　HIF 1αmRNA在低氧各组腺泡内肺动脉有表达 ,低氧 14d组 (0 2 5 6 9± 0 0 46 8)和低氧 2 8d组 (0 2 2 5 8±0 0 45 3)染色强于低氧 5d组 (0 145 5± 0 0 2 72 )和正常组 (0 110 9± 0 0 2 2 4) ;ET 1mRNA在低氧各组腺泡内肺动脉有表达 ,低氧 14d组 (0 412 2± 0 0 783)和低氧 2 8d组 (0 36 84± 0 0 72 9)染色强于低氧5d组 (0 2 0 17± 0 0 34 9)和正常组 (0 185 5± 0 0 36 1) ,HIF 1α和ET 1基因表达在H14d组和H2 8d组明显增加 (P <0 0 5 )。肺动脉血中ET 1含量在H14d组 [(15 8 78± 2 5 14)pg/ml]和H2 8d组 [(142 93± 2 3 38)pg/ml]明显高于H5d组 [(79 6 8± 12 5 4)pg/ml]和正常组 [(6 5 37± 10 82 )pg/ml](P <0 0 5 ) ;H14d组 [(34 0± 5 8)mmHg]和H2 8d组 [(2 9 0± 4 7)mmHg]的mPAP也明显高于H5d组[(19 0± 3 5 )mmHg]和正常组 [(17 0± 2 8)mmHg](P <0 .0 5 ) ,并且与肺动脉血中ET 1含量呈正比(rs=0     

母婴分离所致的慢性内脏痛对成年大鼠空间学习记忆能力和旷场行为的影响

目的:观察母婴分离所致的慢性内脏痛对成年大鼠空间学习记忆能力和旷场行为的影响。方法:模型组大鼠于出生后第3~21 d,每天接受3 h母婴分离,对照组大鼠不做分离处理;8周龄时,使用腹壁撤退反射评分和痛阈测定方法筛选出有慢性内脏痛的大鼠;Morris水迷宫检测成年大鼠的空间学习记忆能力;旷场实验评估成年大鼠的旷场行为;Western Blot方法检测大鼠海马脑源性神经营养因子(brain derived neurotrophic factor,BDNF)的表达变化。结果:(1)母婴分离成年大鼠分别在20、40、60、80 mm Hg压力下的腹壁撤退反射评分均显著高于对照大鼠(P0.05),而其痛阈显著低于对照大鼠(P0.05)。(2)与对照组相比,母婴分离大鼠水迷宫的寻台潜伏期与平均平台象限滞留时间均无显著差异(P0.05)。(3)与对照大鼠相比,母婴分离大鼠旷场运动的总路程和总速度无显著差异(P0.05),但中心路程和中心路程时间显著减少(P0.05)。(4)Western Blot结果显示母婴分离大鼠海马内BDNF的表达与对照相比显著降低(P0.05)。结论:母婴分离所致的慢性内脏痛对成年大鼠空间学习记忆能力和自主探究行为无显著影响,但能引发成年大鼠的心理焦虑,该效应可能与海马BDNF的表达减少有关。     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

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.     

The universal muscular chain reaction,muscle spasm,Torsions, ruptures and extravasations. Chameleons of pathology and some manifestations of simple muscular disorders

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.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ 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 $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ 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 $\text{primates}$. 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.     

Hypo- und Hypermagnesämie aus kardiologischer Sicht

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.     

Environmental risk factors and their role in the management of atopic dermatitis

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.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

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.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

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.     

HLA genes in Amerindians from Mexico San Vicente Tancuayalab Teenek/Huastecos

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.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

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.