Vitamin B<Subscript>12</Subscript> Immunoassay on Roche Elecsys 2010: Effects of High Excess Concentration of Serum Vitamin B<Subscript>12</Subscript> in CKD Patients on Parenteral Administration

Vitamin B₁₂ being water soluble is excreted in the urine when administered in excess. The probability of finding an abnormally excess serum concentration would be almost surreal. We report a peculiar clinical situation that may impact the vitamin B₁₂ immunoassay on the Roche Elecsys 2010 due to excess analyte concentration. In separate episodes (Feb and June 2010), the Biochemistry laboratory of a tertiary-care hospital, Kolkata, India, encountered two critically ill patients with background chronic kidney disease (CKD), low urine output, and on cyanocoabalamin supplementation, who had serum vitamin B₁₂ concentrations far exceeding expected values; even post dialysis. The B₁₂ assays (pmol/l) were performed using electrochemiluminiscence immunoassay on Roche Elecsys 2010, the assay validity confirmed by concomitant quality control runs. The immunoassays failed to deliver results, flagged with “signal level below limit”. Biotin therapy was ruled out as a possible interferent. In the first episode, re-assay of a repeat draw yielded same outcome; outsourcing on Immulite provided concentration of >738 pmol/l. Serial dilution gave result of >29520 pmol/l on Elecsys 2010. In the second, we gained from past experience. Vitamin B₁₂ concentration >59040 pmol/l was conveyed to the treating nephrologist the very day. The B₁₂ immunoassay on the Elecsys 2010 employs sequential incubation steps for competitive binding that is compromised in the event of abnormally excess B₁₂ concentration in patient sera akin to the prozone effect. This knowledge may be beneficial while assaying sera of CKD patients to avoid financial loss due unnecessary repeats and delay in turnaround time.     

运动性横纹肌溶解征并发急性肾衰竭1例报道

运动性横纹肌溶解征并发急性肾衰竭(ARF)是一类较少见的急性肾衰竭。文章通过对剧烈运动致急性肾衰竭1例的发生和临床诊治的报道,旨在加强对本病的认识与预防。     

动脉粥样硬化性心脑血管疾病患者血浆脂蛋白(a)水平与纤溶活性的关系

目的 :为了研究动脉粥样硬化性心脑血管疾病患者血浆脂蛋白 (a)水平与纤溶活性的关系 ,探讨脂蛋白 (a)促血栓形成和致动脉粥样硬化的机理。方法 :分别测定 4 2例心肌梗塞患者、4 2例心绞痛患者、4 4例脑梗塞患者及 38名健康对照者的脂蛋白 (a)浓度、组织型纤溶酶原激活剂 (tPA[lj1])及其抑制物 (PAI)活性 ,并分析其相关性。结果 :各组动脉粥样硬化性心脑血管疾病患者血浆脂蛋白 (a)浓度和PAI活性明显升高 ,tPA活性明显降低 ;各组脂蛋白 (a)与PAI活性均呈显著正相关。结论 :血浆高脂蛋白 (a)浓度是动脉粥样硬化性心脑血管疾病的主要危险因素之一 ,脂蛋白 (a)水平的升高与纤溶活性低下有关     

钒对大白鼠脾脏生长发育的影响

150只SD大白鼠随机分成5组,雌雄各半,对照组饮饲蒸馏水,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别添加钒10mg/kg、20 mg/kg、40 mg/kg、60mg/kg,于饮饲后第2、4、6、8、10周断脊处死,取脾脏称重并制作石蜡切片,HE染色,显微观察,研究微量元素钒对大白鼠脾脏生长发育的影响。结果表明,饮饲10mg/kg、20mg/kg、40 mg/kg钒,可见大白鼠脾脏重量较同一周龄对照组都有不同程度的增加,其中以20mg/kg组脾脏增重极显著(P<0.01);显微观察可见10mg/kg组、20mg/kg组、40 mg/kg组脾小结数量增多变大,动脉周围淋巴鞘增厚,椭球管腔变大,以10mg/kg组,20mg/kg组最为显著。60mg/kg组脾脏重量与同一周其他剂量组相比较轻,脾小结数量少且动脉周围淋巴鞘薄。说明大白鼠饮水中添加10~40 mg/kg钒是安全的,其中20 mg/kg钒对脾发育有促进作用,60 mg/kg钒对大白鼠脾具有抑制作用。     

急性肾功能衰竭家兔心肌损伤的体液机制

目的：观察急性肾功能衰竭（ARF）家兔心肌匀浆自由基、一氧化氮的变化，探讨心肌损伤的体液机制。方法：60只家兔均分为四组（n=15）。ARF模型1组：皮下注射1％HgCl2（1．3ml／kg．bw）；ARF模型2组：肌肉注射50％甘油（10ml／kg．bw）；以等量生理盐水代替HgCl2和甘油作为对照1、2组。24h后，所有动物颈总动脉放血备检，并选择固定位置。制备10％心肌匀浆。经Aeroset型全自动生化分析仪测定血清反映肾功能的生化指标。检测心肌匀浆丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）及其合酶（NOS）的变化。结果：与相应对照组比较，ARF模型1、2组心匀浆SOD活性下降、MDA含量升高（P〈0．05），ARF模型1、2组心匀浆NO含量增强、NOS及iNOS活性增强（P〈0．05～0．01）。结论：ARF家兔心肌损伤的机制与自由基损伤及NO升高有关。     

Lipid abnormalities in chronic renal failure

Lipid abnormalities remain to be a major cause of early mortality in patients with chronic renal failure (CRF). In present study, 114 (one hundred fourteen) CRF patients without any additional cause of dyslipidemia were divided into groups on the basis of etiologies of CRF. Blood samples from each group were analyzed for total cholesterol, triglyceride and HDL cholesterol along with blood urea nitrogen and serum creatinine. 25 healthy individuals without any obvious disease were taken as control. Patients from all the groups showed a marked hypertriglyceridemia of 232 (SD±77) mg/dl (P<0.001) as compared to control. Levels of HDL cholesterol were found to be significantly low 20 (±11) mg/dl (p<0.001) in all the groups. LDL cholesterol showed an increase 104 (±30) mg/dl as compared to control group which is not statistically significant. Present study reveals that, CRF patients show an uniform dyslipidemia irrespective of etiologies leading to CRF. This dyslipidemia is also independent of serum creatinine levels. Although, these lipid abnormalities may not solely cause mortality in CRF patients, they may act as modulators in accelerating atherogenesis which in turn cause early mortality in CRF patients.     

黄淮白山羊心脏冠状动脉形态特征研究

目的:观察黄淮白山羊心脏冠状动脉的形态学特征,为其研究提供基础资料.方法:选择成年健康黄淮白山羊10头,采用颈静脉放血方式处死,其中6只心脏取不同管径大小的冠状动脉,多聚甲醛溶液固定,经水洗、脱水、二甲苯透明,石蜡包埋以HE、Masson三色及Verhoeff VG染色等步骤,观察冠状动脉的基本组织结构特点;另4只心脏标本经左、右冠状动脉口分别加压注入丁腈苯乙烯(ABS)丙酮溶液,经凝固成型后于70%浓盐酸溶液中腐蚀,观察冠状动脉的分支与分布.结果:黄淮白山羊的心脏左、右冠状动脉均起自于主动脉窦,行走于肺动脉与左心耳之间的左冠状动脉较粗大.黄淮白山羊弹性冠状动脉中弹性纤维含量丰富,外膜层有散在分布的块状平滑肌;肌性冠状动脉内外弹性膜结构清晰,中膜层主要由发达的平滑肌构成,含少量弹性纤维;微冠状动脉由一层内皮细胞构成.结论:黄淮白山羊冠状动脉属于左优势型,可分为弹性冠状动脉、肌性冠状动脉和微动脉三种类型.     

利用胶原海绵膜构建人工真皮的研究

目的：探讨利用胶原海绵膜构建人工真皮的可行性．方法：从大鼠鼠尾肌腱中提取胶原．胶原和6-硫酸软骨素冷冻干燥，重度脱水及戊二醛交联后制得胶原海绵膜．将其行扫描电镜观察；并埋藏在Balb／c小鼠皮下，术后定期取出观察组织学变化．将成纤维细胞种植于该支架上．结果：构建的支架孔径均匀，孔径在50～100um．具有良好的组织相容性，并逐渐降解．成纤维细胞于其上生长良好．结论：该支架适合成纤维细胞生长，可作为组织工程皮肤的支架．     

Digital design of scaffold for mandibular defect repair based on tissue engineering

Mandibular defect occurs more frequently in recent years, and clinical repair operations via bone transplantation are difficult to be further improved due to some intrinsic flaws. Tissue engineering, which is a hot research field of biomedical engineering, provides a new direction for mandibular defect repair. As the basis and key part of tissue engineering, scaffolds have been widely and deeply studied in regards to the basic theory, as well as the principle of biomaterial, structure, design, and fabrication method. However, little research is targeted at tissue regeneration for clinic repair operations. Since mandibular bone has a special structure, rather than uniform and regular structure in existing studies, a methodology based on tissue engineering is proposed for mandibular defect repair in this paper. Key steps regarding scaffold digital design, such as external shape design and internal microstructure design directly based on triangular meshes are discussed in detail. By analyzing the theoretical model and the measured data from the test parts fabricated by rapid prototyping, the feasibility and effectiveness of the proposed methodology are properly verified. More works about mechanical and biological improvements need to be done to promote its clinical application in future.     

霍山石斛工厂化繁育技术研究

以野生霍山石斛种子为外植体,对霍山石斛组培快繁技术进行研究,旨在为霍山石斛规模化、标准化、产业化生产提供依据。结果表明,种子萌发与原球茎诱导最适培养基为MS+6-BA0.1mg/L+NAA0.5mg/L+20%土豆汁;原球茎继代增殖与分化最适培养基为1/2MS+6-BA0.5mg/L+NAA0.1mg/L+20%土豆汁;丛生芽增殖最适培养基为1/2MS+6-BA0.5mg/L+NAA0.5 mg/L+20%土豆汁;壮苗生根最适培养基为1/2MS+NAA0.5 mg/L+20%土豆汁;炼苗最适温度、光照及时间:温度(24±2)℃,光照6000Lx,炼苗时间10d,后3d将瓶盖打开;试管苗移栽最适基质配方:草碳根+碎木屑+碎石(1∶1∶1)。