Serum contains a potent factor that decreases β-adrenergic receptor-stimulated L-type Ca2+ current in cardiac myocytes

L-type Ca²⁺ current (I _Ca) was measured in cultured atrial myocytes from hearts of adult guinea-pigs using whole-cell voltage clamp. Potentiation of I _Ca induced by -adrenergic stimulation (isoprenaline 2· 10^–7 M) could be completely antagonized by diluted sera (1100 v/v). Half-maximal inhibition of -receptorstimulated I _Ca occurred at about 11000. Basal I _Ca was not affected by serum. Atropine in a concentration (10^–6M) that completely antagonized the anti-adrenergic effect of acetylcholine (ACh, 2·10^–6 M) did not interfere with the effect of serum. In cells dialysed with cyclic adenosine monophosphate (cAMP)-containing (10^–4 M) pipette solution, potentiated I _Ca was insensitive to both ACh and serum. Preincubation of the myocytes with pertussis toxin almost completely abolished the anti-adrenergic effects of both ACh and serum. The potency of serum was not reduced by dialysis. It is concluded that serum contains a factor which, like ACh, inhibits -receptor-stimulated adenylyl cyclase via G_iprotein.A preliminary report of this work has appeared in abstract form [11]     

Renal function in relation to three candidate genes in a Chinese population

We recently found in a white population that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), -adducin (Gly460Trp), and aldosterone synthase (–344C/T) jointly influence renal function. We therefore investigated in a Chinese population the associations between the serum concentrations of creatinine and uric acid and these three genetic polymorphisms. We genotyped 471 ethnic Han Chinese subjects from 125 nuclear families recruited in northern China via random population sampling (75%) and at specialized hypertension clinics (25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. The participants were 39.7 years old and included 235 women (49.9%). The blood pressure measured at the subjects homes averaged 126/80 mmHg. Mean values were 71 µmol/l for serum creatinine, 111 ml min^–1 1.73 m^–2 for calculated creatinine clearance, and 236 µmol/l for serum uric acid. With adjustment for covariables, GEE analyses of single genes demonstrated that serum uric acid, but not serum creatinine, was positively associated with the ACE D allele. Serum uric acid concentrations were 15.8 µmol/l (95% confidence interval 3.3–28.2) and 25.7 µmol/l (11.1–40.2) higher in DD homozygotes than in ID and II subjects, respectively. Further GEE analyses of the three genes combined showed that the association between serum uric acid and the ACE polymorphism was confined to carriers of the -adducin Gly and/or aldosterone synthase C alleles. Sensitivity analyses in parents and offspring separately as well as QTDT analyses were confirmatory. Among 114 informative offspring carrying the -adducin Gly allele serum uric acid was significantly and positively associated with the transmission of the ACE D allele (=20.7 µmol/l). In conclusion, the present study extends our previous findings on the combined effects of the three candidate genes and supports the concept that these genetic polymorphisms jointly influence renal function.     

动脉粥状硬化与血清中磷脂酰胆碱特异性磷脂酶C活性的相关性研究

炎症在动脉粥状硬化(AS)形成过程中起关键作用,PC-PLC在炎症反应中扮演重要角色。为探讨PC-PLC活性与动脉粥样硬化的关系,本研究建立了动脉粥状硬化家兔模型,并用解毒活血颗粒灌胃,分别获得正常家兔血清、造模家兔血清和药物家兔血清,检测其中PC-PLC的活性。结果表明,造模组中钙离子依赖性和非钙离子依赖性两种PC-PLC活性均明显高于正常组,而加药组中这两种PC-PLC活性受到显著抑制。说明伴随动脉粥样硬化的发生,PC-PLC活性明显升高,而活血解毒颗粒能减轻动脉粥样硬化的程度,同时能显著抑制PC-PLC活性。     

69,XXY伴严重生长迟缓及眼球突出病例的产前诊断

目的分析孕中期血清筛查数据和胎儿彩色多普勒与染色体异常之间的关系。方法对一孕中期血清产前筛查18三体风险1:10,血清Free-hCGβ异常减低(值为1.29ng/ml即0.08MOM),胎儿系统结构检查提示胎儿小于孕周,头腹围比(1.63)大于正常(1.25),上唇连续性中断延至鼻底的孕妇进行羊膜腔穿刺,抽取羊水进行细胞遗传学检查。结果羊水细胞染色体核型:69,XXY。结论中孕期妇女血清Free-hCGβ异常减低和胎儿头胸围发育不同步、胎儿唇腭裂提示胎儿染色体畸变可能,血清和超声联合筛查有助于染色体疾病的检出。     

新生儿血清瘦素水平变化与胰岛素和生长激素关系的研究

目的　探讨新生儿血清瘦素来源及其与胰岛素和生长激素的关系。方法　采用放射免疫法检测 80例新生儿静脉血和脐血瘦素水平 ,根据不同胎龄新生儿出生体重值分为大于胎龄儿 (LGA)组 2 8例 ,适于胎龄儿 (AGA)组 36例 ,小于胎龄儿 (SGA)组 16例 ;采用Rohrer′s指数 =出生体重 (g)× 10 0 /身长 (cm) 3 估测新生儿营养状态。结果　早产儿血清瘦素水平明显低于足月儿 (0 6 6± 1 0 3ng/mlvs 3 5 9± 2 16ng/ml,P <0 0 1) ;AGA儿血清瘦素水平 (3 0 6± 0 96ng/m1)明显低于LGA儿(4 0 3± 2 2 2ng/m1) ,而高于SGA儿 (1 13± 1 98ng/m1) ;足月新生儿血清瘦素水平与Rohrer′s指数、新生儿体重、胎龄 ,血清胰岛素、生长激素水平呈显著正相关。结论　新生儿体内瘦素主要来源于自身脂肪组织 ,它反映新生儿的生长营养状态 ,推测瘦素可能通过胰岛素、生长激素共同调节新生儿的生长发育 ,在胎儿和新生儿生长发育中起重要作用。     

Screening 34 Peanut Introductions for Allergen Content Using ELISA

Peanut is one of the most allergenic foods and reports of accidental ingestion of peanuts in unsuspected food are increasing. No information is available on the allergen content of peanut germplasm grown commercially and used in the food and confectionery industry. The objectives of this study were: (1) to determine the allergen contents of 34 peanut introductions (PI); and (2) to identify naturally occurring allergen-free and/or low or hypoallergenic peanuts germplasm. A basic ELISA protocol was utilized to detect the presence of antigens in the peanut lines using a pool of human sera from patients with documented history of peanut allergy. Two naturally occurring low, or hypo-allergenic germplasm were identified as PI 261942 and PI 338386. Both are Valencia market types with total allergen content significantly lower (P ≤0.05) than that of PI 119880 (0.550), PI 119876 (0.415) and PI 118991 (0.410) three Valencia market types and PI 262111 (0.485), a Virginia market type. No allergen-free PI was found. Allergen content of peanut lines from Bolivia and Paraguay were significantly (P ≤0.05) different to those from Venezuela. No significant difference was observed in the allergen content of the four market types.     

Serum protein concentration and oncotic pressure relationship in the rat

Summary A formula relating oncotic pressure torat serum protein concentration was derived and found to be in complete agreement with the Landis-Pappenheimer formula derived from measurements onhuman plasma.This study was supported by the Danish Medical Research Council and Johan and Hanne Weimann's legacy.     

Heterogeneity in the complement-dependent bacteriolysis within the species of Borrelia burgdorferi

Sixteen Borrelia burgdorferi strains, including all three species, were compared in a colorimetric bactericidal assay for their ability to escape the complement-dependent bacteriolysis on incubation in normal human serum free of specific antibodies (NHS). The species B. afzelii was found to be serum resistant (EB1, EB3, FEM1, FEM2, Pko), whereas strains of the species B. garinii were found to be serum sensitive (1/B29, G1, G2, PSth, PBr, PTrob). Six strains, mainly B. burgdorferi sensu stricto, were only partially sensitive (Z25, 297, B31, PKa-I, PBi). All strains activated the complement cascade in NHS, whereas only four strains (G1, G2, PBr, PSth) could activate complement in the presence of EGTA-Mg. After complement activation, covalently bound C3 fragments (C3b, iC3b) were detected on serum-sensitive as well as serum-resistant borrelial strains. Heterogeneity, however, was observed between serum-resistant and serum-sensitive strains with respect to deposition of C6 and C9. Whereas serum-sensitive strains were strongly positive for C6 and C9 and were, therefore, killed by the terminal complement complex (TCC), serum-resistant strains were devoid of C6 and C9 on their cell surface. The serum resistance may, therefore, be due to an absent or only transient formation of TCC on the bacterial surface. Received: 17 September 1996     

血脂测定结果的临床可接受性分析

目的:通过对不同检测系统血脂测定结果的偏倚评估,分析各系统间结果的可比性和临床可接受性。方法:参照CLSI文件相关要求,以可溯源的检测系统为目标检测系统,测定总胆固醇(TCH)、甘油三酯(TG)、载脂蛋白A1(APOA1)、载脂蛋白B(APOB)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C),对本院3个不同检测系统进行朗道质控物(水平2和水平3)各测定21次和测定新鲜血清标本40份。结果:朗道质控物和新鲜血清标本TCH、TG、APOA1、APOB、HDL-C、LDL-C浓度在系统间的差异均有显著性(P<0.05)。除LDL-C在各检测系统间的相关系数为0.7859~0.9259之间外,其他项目各系统间的相关系数均大于0.975。各检测系统测定TCH、TG的不精密度CV均小于5%,其他项目的不精密度CV均小于10%;以可溯源检测系统1为目标检测系统,临床可接受性能评价:TCH、LDL-C在检测系统2和检测系统3超出临床接受范围,HDL-C在检测系统2超出临床接受范围,其他项目临床均可接受。结论:3个不同检测系统测定TG、APOA1、APOB结果具有可比性;测定HDL-C结果具有部分可比性,TCH、LDL-C结果不具有可比性,需采取整改措施。     

血清淀粉样P成分的DNA结合特性

目的 检测血清淀粉样P成分(SAP)与不同DNA的结合活性并研究SAP与DNA的结合是否有利于此类抗原的清除，探讨它在SLE发生发展中的作用及意义。方法 用亲和层析和凝胶过滤方法自小鼠和人血清中纯化SAP，分别提取来自细菌、质粒、酵母、小鼠淋巴细胞等不同DNA，用DOT-EIA方法检测SAP与它们的结合活性，用巨噬细胞吞噬实验观察SAP与DNA结合后对DNA清除的影响。结果 人和小鼠SAP均与细菌DNA结合最强，其次为质粒、酵母DNA，与淋巴细胞DNA和小牛胸腺DNA的结合较弱，与单链λDNA结合最弱；与来源于活化状态小鼠淋巴细胞DNA的结合力高于非活化状态；SAP与活化淋巴细胞DNA结合后可促进巨噬细胞对DNA的吞噬。结论 SAP与不同DNA结合活性各异。