Analysis of STR-PCR products with high-resolution denaturing PAGE

The Pharmacia Multiphor II horizontal electrophoresis chamber is a widespread tool for analysis of PCR products in forensic casework. Up to date, however, there is no protocol for successfully running high-resolution denaturing PAGE (poly-acrylamide gel electrophoresis) on a horizontal electrophoresis chamber. We modified the electrophoresis conditions to make this possible.     

血清亚硝酸盐的快速测定

目的：建立一种无需去蛋白的血清亚硝酸盐的快速测定方法。方法：加入蛋白活化剂后，直接用Ｇｒｉｅｓ试剂显色分光光度测定。结果：方法的检测下限为０．２μｍｏｌ／Ｌ，相对标准差为５．１３％～８．８６％，回收率为９４．５％～９９．８％（平均为９７．８％）。血清ＮＯ－２浓度为１４．３８±０．２５μｍｏｌ／Ｌ时，批内变异系数为１．７５％，ＮＯ－２浓度为５．６９±０．２５μｍｏｌ／Ｌ时，批间变异系数为４．４６％。测定５５例正常人血清，得到血清中ＮＯ－２浓度的平均值分别为５．３６±２．１６ｕｍｏｌ／Ｌ；对糖尿病病人血清测定结果表明，亚硝酸盐浓度明显高于正常人。与去蛋白的Ｇｒｉｅｓ试剂分光光度法比较，结果无统计学差异。结论：用蛋白活化剂替代蛋白沉淀剂，减少操作步骤和干扰，测定准确、简便、快速，适用于血清中ＮＯ－２的测定。     

抗性家蝇蛹期多肽的双向电泳分析

分析抗性家蝇蛹期多肽，以了解蛋白质变化情况。方法：对家蝇的抗性株、对照株和敏感株蛹体内的多肽进行了聚丙烯酸胺凝胶电泳分析。结果：抗性株具有一特异的多肽点，且有3个多肽点在量上明显多于对照株。结论：杀虫剂的作用可使抗性家蝇体内的蛋白在质和量上发生改变。     

急性有机磷中毒患者的血钾变化及临床意义的探讨

目的：探讨急性有机磷中毒患的血清钾变化及其临床意义。方法：对68例发病6小时内的急性有机磷中毒的患入院后测定血清钾，并根据不同的中毒程度、中毒方式、发病时间分组在比较，并设正常对照组对照。结果：中毒各组均有明显的低钾血症，与对照组比较均有显性意义（P＜0．01）,且重度中毒组与中、轻度组比较亦有显性意义（P＞0．05），但两种不同的中毒途径与不同的中毒时间的组间血清钾的比较无显性意义（P＞0．05）。结论：急性有机磷中毒可致明显的低钾血症，中毒越重，低钾血症越明显。在发病早期应注意监测血清钾的变化，及时纠正低血钾，预防或减轻中毒后严重合并症的产生。     

母婴ABO血型不合母体高效价IgG的低温分离与纯化

目的 分离和纯化母婴血型不合母体的特异性高效价的IgG抗体。方法 采用半饱和硫酸铵低温沉淀法分离IgG抗体，SephedexA50层析柱纯化，然后用B型红细胞(RBC)吸收放散IgG，用聚乙二醇(PEG)沉淀，真空泵脱水回收IgO。结果 200ml血浆经半饱和硫酸铵低温沉淀后得IgG粗制品2．26g，Sephedex A50层析柱纯化后得纯制品1．84g，经B型RBC吸收放散后得特异性IgG 0．55g，回收率达29．89％(0．55／1．84)。结论 采用半饱和硫酸铵低温沉淀法分离高效价IgG抗体，可以获得高纯度的IgG。     

常见阴离子对血清氯离子选择性电极法测定的影响

目的:研究离子选择性电极在测定血清氯时的影响因素。方法:用E-555电解质分析仪测定氟化钠、溴化钠、碳酸氢钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠以及叠氮钠溶液,并将溴化钠、硫氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠分别加入Cl~-均值为100mmol/L的混合血清中观察其具体的干扰情况。结果:所测8种物质中氟化钠、碳酸氢钠的影响较小,而溴化钠、铁氰化钾、碘化钾、铁氰化钾、硫化钠、叠氮钠的影响较大。结论:溴离子、碘离子、硫离子、氢氰根离子、叠氮钠对离子选择性电极法影响性较大,我们在工作中应加以重视。     

Special Pharmacokinetic Considerations in Children

Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection.     

The Toxic Effects of Serum from Patients with Type 1 Diabetes Mellitus on Mouse Neuroblastoma Cells: A New Mechanism for Development of Diabetic Autonomic Neuropathy

The pathogenesis of diabetic neuropathy is incompletely understood. The possibility that humoral neurotoxic factors contribute as a cause of diabetic neuropathy was tested by application of serum from patients with Type 1 and Type 2 diabetes to mouse neuroblastoma cells, which have the characteristics of adrenergic neurons in culture. Serum from patients with Type 1 diabetes and somatic neuropathy significantly inhibited both proliferation and differentiation of neuroblastoma cells, while serum from patients with Type 1 diabetes but no symptoms of neuropathy and patients with Type 2 diabetes and neuropathy had no effect on proliferation, and serum from Type 2 patients only marginally inhibited differentiation. The effects of Type 1 diabetic serum could be reversed by pre-absorption of the serum to neuroblastoma cells, and were independent of glucose levels. Immunoglobulins precipitated from the sera mimicked the effects of whole sera. These results suggest that Type 1 diabetes mellitus causes a change in serum composition, possibly related to autoimmunity, that is capable of contributing to adrenergic autonomic neuropathy in diabetic patients.     

Comparative studies on cytotoxic and genotoxic effects of two organic mercury compounds in lymphocytes and gastric mucosa cells of sprague-dawley rats

Human lymphocytes (HL) as well as lymphocytes (RL), hepatocytes (RH), and gastric mucosa cells (GM) of Sprague-Dawley rats were treated in vitro for 1 h with methylmercury chloride (MMC, 0.5–4 μg/ml) and dimethylmercury (DMM, 5–40 μg/ml). The cytotoxicity of the two organic mercury compounds was assessed by dye exclusion, and the extent of induced DNA fragmentation was measured with a single-cell microgel electrophoresis assay. Both MMC and DMM induced DNA damage and cytotoxicity in a dose-related manner in HL, RL, and GM. MMC was more effective in causing a significant increase in median DNA migration than DMM at doses yielding approximately the same degree of cytotoxicity. In rat hepatocytes the MMC-induced DNA damage was, however, lower than in the other cells. An analysis of repair kinetics following exposure to 2 μg/ml MMC was carried out in human lymphocytes obtained from an adult male donor. The bulk of DNA repair occurred 90 min after in vitro exposure, and it was about complete by 120 min following cessation of exposure. Finally, in order to have a basis for extrapolating to the human situation, in vivo studies were performed with Sprague-Dawley rats, also assessing the DNA damage and cytotoxicity in the lymphocytes and gastric mucosa cells. These in vivo results after oral exposure may be directly compared to the in vitro data obtained in the same cells. © 1993 Wiley-Liss, Inc.     

Serum modulates cyclic AMP-dependent morphological changes in cultured neurohypophysial astrocytes

The effects of serum on the morphological plasticity exhibited by pituicytes in explant cultures of the neurohypophysis of adult rats have been examined. Cultured pituicytes are normally nonstellate, protoplasmic, amorphous cells (< 25% are stellate with a distinct cell body and phase bright processes). After incubation (90 min) of pituicyte cultures in a HEPES buffered salt solution (HBSS) supplemented with isoproterenol or forskolin, the fraction of stellate pituicytes significantly increased. The increase in the fraction of stellate cells induced by isoproterenol was not reversed by subsequent incubation in isoproterenol-free HBSS for 90 min. In contrast, after stellation was induced in cultures by exposure to forskolin (90 min), the fraction of stellate cells was significantly reduced if these cultures were incubated in forskolin-free, serum (0.5%) supplemented HBSS for the same duration. Serum also blocked the increase in the fraction of stellate pituicytes induced by forskolin. These experiments suggest that serum components may have a significant role in controlling the plasticity of neuroglial relations in the neurohypophysis priviously demonstrated in vivo.