肾上腺髓质素对豚鼠心室肌细胞L-型钙通道的作用及其信号转导机制

目的: 研究肾上腺髓质素( adrenomedullin, ADM)抑制豚鼠心室肌细胞L-型钙通道的信号转导机制。方法: 应用全细胞膜片钳技术,记录应用ADM(1-100 nmol·L^-1)前后L-型钙电流(I_Ca,L),以及分别记录应用ADM特异性受体拮抗剂ADM_22-52(100 nmol·L^-1)+ADM(100 nmol·L^-1)、蛋白激酶A (PKA) 特异性拮抗剂H-89(10 μmol·L^-1) + ADM(100 nmol·L^-1)、蛋白激酶C (PKC) 特异性拮抗剂PKC_19-36(10 μmol·L^-1)+ADM(100 nmol·L^-1)、PKC特异性激动剂PMA(1 μmol·L^-1)前后I_Ca,L。结果: ADM(1-100 nmol·L^-1)浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,并可被ADM_22-52(100 nmol·L^-1)完全阻断;H-89(10 μmol·L^-1)对ADM抑制I_Ca,L的作用无影响。PKC_19-36(10 μmol·L^-1)可完全阻断ADM 对I_Ca,L的抑制效应,且PMA(1 μmol·L^-1)可模拟ADM 对I_Ca,L的抑制效应。结论: ADM作用于特异性ADM受体可浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,此作用有可能与PKC激活相关。     

钙调神经磷酸酶在血管紧张素Ⅱ刺激的大鼠心肌细胞肥大中的作用及其活性调节

目的:观察钙调神经磷酸酶(CaN)在血管紧张素Ⅱ(AngⅡ)刺激的大鼠心肌细胞肥大中的作用及其活性调节。方法:建立AngⅡ诱导的大鼠心肌细胞肥大模型,观察CaN抑制剂对AngⅡ刺激的心肌细胞 [³H]-亮氨酸掺入的影响,以及各种因素对心肌细胞CaN酶活性的影响。结果:10、 100、 1000 nmol·L^-1的AngⅡ作用12 h分别使心肌细胞的CaN活性增加了13%、 57%(P＜0.05)、 228%(P＜0.01)。AngⅡ(10 nmol·L^-1)刺激心肌细胞2 h内,CaN活性与对照组无明显差异(P＜0.05);AngⅡ刺激心肌细胞12 h以上,CaN活性才明显增高(P＜0.05)。Losartan(50 μmol·L^-1)、H₇(50 μmol·L^-1)及Fura-2/AM(4 μmol·L^-1)可明显抑制AngⅡ刺激的心肌细胞CaN活性;而PD98059(50 μmol·L^-1)对AngⅡ刺激的心肌细胞CaN活性无明显影响。AngⅡ(10^-7mol/L)刺激的大鼠心肌细胞 [³H]-亮氨酸掺入明显高于对照组(P＜0.01),而CaN特异性抑制剂-环孢素A(0.5~5 μg/mL)可以明显抑制AngⅡ刺激的心肌细胞 [³H]-亮氨酸掺入。结论:依赖Ca²⁺/CaM活化的CaN可能在AngⅡ刺激的心肌细胞肥大中起重要作用;CaN的活化可能有赖于胞内Ca²⁺水平的持续升高,另外,CaN的活性还可能受到蛋白激酶C等信号分子的磷酸化调节。     

金属硫蛋白对羟自由基损伤的大鼠肝细胞核核苷三磷酸酶的保护作用

目的:研究金属硫蛋白(MTs)是否对羟自由基(hydroxylradical,·OH^-)损伤的大鼠肝细胞核核苷三磷酸酶(NTPase)具有保护作用。方法:以羟自由基发生系统Fe³⁺/H₂O₂单独或与MTs共同孵育大鼠离体肝细胞核,检测分别用ATP和GTP作底物时大鼠肝细胞核NTPase活性。结果:不同浓度Fe³⁺/H₂O₂(μmol·L^-1/μmol·L^-1:0.1/0.5、0.5/2.5、1/5、5/25)孵育肝细胞核,浓度依赖地增强核NTPase活性,与对照组差异显著(P＜0.01)。用不同浓度的MT(10^-9-10^-4mol·L^-1)与Fe²⁺/H₂O₂(1μmol·L^-1/5μmol·L^-1)共孵育,浓度依赖地拮抗Fe³⁺/H₂O₂诱导的效应(P＜0.01)。用MT单独孵育肝细胞核对NTPase的活性没有影响(P＞0.05)。结论:Fe³⁺/H₂O₂系统产生的·OH对核NTPase活性具有强烈的抑制效应,MT浓度依赖地拮抗·OH导致的NTPase活性降低。     

Zacopride增强心肌内向整流钾电流(IK1)效应的受体和信号转导通路

目的: 探讨5-HT₄受体激动剂兼5-HT₃受体阻断剂zacopride增强心肌内向整流钾电流(I_K1)效应的受体和细胞信号转导机制。方法: 应用全细胞膜片钳技术记录大鼠心室肌细胞膜I_K1电流,分别观察10 μmol/L 5-HT₄受体阻断剂 RS23597-190、10 μmol/L 5-HT₃受体激动剂间氯苯双胍(m-CPBG)、5 μmol/L PKA 抑制剂 KT5720、5 μmol/L PKC 抑制剂GF109203x 和 5 μmol/L PKG抑制剂 KT5823对zacopride 增强I_K1的影响。结果: 10 μmol/L 5-HT₄受体阻断剂RS23597-190本身可抑制I_K1电流,在预先应用RS23597-190的基础上,1 μmol/L zacopride仍可明显激动I_K1通道,使其内向电流(-100 mV)增强32.5% (P< 0.05)。10 μmol/L 5-HT₃受体激动剂m-CPBG对I_K1电流无明显影响,也不能逆转1 μmol/L zacopride对I_K1的增强效应(P> 0.05)。此外,5 μmol/L PKA 阻断剂 KT5720能显著抑制1 μmol/L zacopride对I_K1的增强效应(P< 0.05),而PKC 阻断剂GF109203x和PKG阻断剂KT5823则对1 μmol/L zacopride的效应无明显影响(P> 0.05)。结论: Zacopride对 I_K1的增强作用可能经由PKA介导的信号转导通路,而不依赖于5-HT₃和5-HT₄受体。     

ERKs及细胞内游离钙在内皮素-1诱导心肌细胞肥大反应中的作用

目的:研究细胞外信号调节激酶(ERKs)及细胞内游离钙(i)在内皮素-1(ET-1)介导心肌细胞肥大反应中的作用及机制。方法:利用培养的新生大鼠心肌细胞,①以蛋白合成速率、蛋白含量及细胞表面积为心肌肥大反应的指标;②用滤纸法测定ERKs活性;③用Fura-2/AM作为钙荧光指示剂测定心肌[Ca²⁺]i浓度。结果:①ET-1浓度依赖性增加新生大鼠心肌细胞蛋白质含量和心肌细胞表面积、ERKs活性及[Ca²⁺]i浓度,以上作用可被ET_A受体拮抗剂BQ123所完全抑制,被百日咳毒素(PTX)部分抑制,而ET_B受体拮抗剂BQ788则无效;②ERKs激酶特异性抑制剂PD98059可完全抑制ET-1激活ERKs的作用,钙通道拮抗剂硝苯地平可明显抑制ET-1介导的[Ca²⁺]i浓度增加,但二者皆仅部分抑制ET-1介导的心肌细胞肥大反应;③蛋白激酶C(PKC)选择性抑制剂staurosporine并不能明显抑制ET-1介导的ERKs激活,但可抑制ET-1介导的的[Ca²⁺]i浓度增加及心肌细胞肥大反应。结论:ET-1主要通过ET_A受体并经PTX敏感的G-蛋白介导心肌细胞肥大反应,该作用至少涉及两条途径:①通过PKC介导的心肌[Ca²⁺]i浓度增加;②不通过PKC介导的ERKs激活。     

甲基莲心碱对耐长春新碱人胃癌细胞多药耐药性的逆转

目的:研究甲基莲心碱(Nef)逆转耐长春新碱人胃癌细胞多药耐药性(MDR)的作用及机制。方法:采用噻唑蓝(MTT)比色法检测长春新碱(VCR)的细胞毒性;PI染色流式细胞计数测定VCR诱导细胞凋亡;间接免疫荧光流式细胞术检测细胞P-gp和MRP的表达。结果:Nef(5、10μmol·L^-1)对人胃癌细胞(SGC7901)和耐长春新碱人胃癌细胞(SGC7901/VCR)无显著毒性作用,VCR对敏感株SGC7901的IC₅₀为0.06mg·L^-1,而对MDR细胞株SGC7901/VCR的IC₅₀为2.32mg·L^-1,SGC7901/VCR较SGC7901对VCR耐药39倍,Nef(2.5、5、10μmol·L^-1)能使VCR对SGC7901/VCR细胞的IC₅₀从2.32mg·L^-1依次下降至0.34、0.12、0.05mg·L^-1,逆转倍数分别为6.8、18.1、43.8。Nef(2.5、5、10μmol·L^-1)能降低SGC7901/VCR细胞对VCR的凋亡抗性,其作用强于维拉帕米(VRP)。SGC7901/VCR细胞较SGC7901细胞高表达P-gp、MRP,Nef(10μmol·L^-1)处理24h后,SGC7901/VCR细胞P-gp、MRP的表达明显低下。结论:Nef具有逆转耐长春新碱人胃癌细胞的MDR作用,其作用机理与下调P-pg和MRP表达有关。     

汉防己碱与1, 6-二磷酸果糖对兴奋性氨基酸所致突触体内游离钙浓度升高的影响

目的:研究汉防己碱(Tet)与1, 6-二磷酸果糖(FDP)对兴奋性氨基酸(EAA)诱导的突触体内游离钙浓度升高的影响。方法:制备大鼠脑突触体, 以荧光法测定突触体内游离钙浓度;加入谷氨酸(Glu, 100μmol·L^-1), 天冬氨酸(Asp, 100μmol·L^-1), N-甲基-D-天冬氨酸(NMDA, 100μmol·L^-1)及Glu+Asp(50μmol·L^-1+50μmol·L^-1)后, 测定突触体内游离钙浓度的变化;提前给予Tet(10、30、60μmol·L^-1), FDP(15、30、75、150μmol·L^-1), MK-801(10、20μmol·L^-1)及Tet+FDP(10+15, 30+30μmol·L^-1)预孵, 再加入上述浓度的Glu、Asp、NMDA及Glu+Asp, 观察突触体内游离钙浓度的变化。结果:Glu、Asp、NMDA及Glu+Asp均呈剂量依赖性升高突触体内游离钙浓度, 提前给予不同浓度的Tet、FDP、MK-801及Tet+FDP, 均可使突触体内游离钙浓度呈剂量依赖性降低, 且以Tet+FDP的作用最明显。结论:Tet与FPD可显著抑制EAA诱导的突触体内游离钙浓度的升高, 这可能是二者保护缺血脑细胞的作用机制之一。Tet与FDP联合应用可能对缺血脑细胞有更强的保护作用。     

测定细胞培养上清液中亚硝酸盐的荧光分光光度法

目的:建立检测细胞培养上清液中亚硝酸盐的方法。方法:以2, 3-二氨基萘与亚硝酸盐反应生成荧光产物2, 3-二氨基萘三唑或1--萘三唑, 用荧光分光光度法测定。结果:2, 3-二氨基萘浓度为0.63mmol·L^-1, 反应液和终止反应后pH值各为2.00和12.10, 20℃水浴15min是较适测定条件。本法的检出限为61.34nmol·L^-1, 日内和日间变异系数分别小于3%和5%, 加入NaNO₂0.36、1.45、2.54nmol的回收率各为99.12%±4.64%、103.28%±2.68%、105.14%±4.36%。测定大鼠腹腔巨噬细胞、大鼠胎鼠大脑半球神经细胞培养上清液亚硝酸盐含量分别为(109.95±4.57)μmol·L^-1和(6.52±1.57)μmol·L^-1, 后者的95%分布范围为3.44-9.60μmol·L^-1。核磁共振氢谱显示标准品化学位移δ7.33027ppm和细胞培养上清液化学位移δ7.33023ppm。结论:本法特异、敏感、快速、简便, 对一氧化氮的研究有一定价值。     

肾上腺素在心肌细胞肥大中的作用

目的：探讨肾上腺素在心肌细胞肥大中的作用。方法：在培养新生大鼠心肌细胞上,通过测量心肌细胞[³H]-Leu的掺入量来判断心肌细胞肥大。结果：肾上腺素能明显增加心肌细胞[³H]-Leu的掺入量,酚妥拉明、心得安、百日咳毒素（PTX）和蛋白激酶C（PKC）抑制剂（calphostin C）均可抑制肾上腺素诱导的心肌细胞[³H]-Leu掺入量增加。结论：肾上腺素诱导的心肌细胞肥大反应与激动肾上腺能受体（α受体和β受体）有关,并通过G蛋白和PKC起作用。     

白三烯D4在促进培养的人气管 平滑肌细胞增殖中的作用

目的和方法:研究白三烯D₄(LTD₄)是否剌激培养的人气管平滑肌细胞(ASMC)增殖。将分离的人ASMC进行传代培养,在培养基中加入各种浓度的LTD₄,计数细胞并测定 [³H]-胸腺嘧啶核苷([³H]-TdR)掺入量和三磷酸肌醇(IP₃)累积量。结果: LTD₄在一定范围内(0.1 nmoL·L^-1~10 nmoL·L^-1)以浓度依赖的方式增加人ASMC(P＜0.01)。LTD₄也增加[³H]-TdR的掺入量和IP₃累积量(P＜0.01)。磷脂酶C抑制剂新霉素(1 μmol·L^-1)阻止IP₃累积量的增加(P＜0.01)。结论:LTD₄剌激培养的人ASMC增殖并且可能在哮喘的气道重塑中起了作用。     

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.     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

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.     

'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 in North Colombia Chimila Amerindians

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.     

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.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.