Multiplicity of allergens in peanuts

Crude peanut protein fractions from raw and roasted peanuts were examined in the RAST with 10 sera from patients showing clinical peanut sensitivity. The radioactive uptake results, which were generally high, did not reveal any distinguishable pattern. Two commercially available peanut proteins, peanut lectin and phospholipase D, gave poor RAST responses. Three purified peanut proteins, α-arachin, conarachin I, and concanavalin A-reactive glycoprotein, all gave significant RAST results that were generally lower than those obtained with the crude extracts. The extent of RAST inhibition obtained with these materials was inversely related to their abundance in the total peanut protein. Crossed immunoelectrophoresis with extracts from raw and roasted peanut indicated the presence of 22 and 10 anodically migrating antigens, respectively. Sixteen IgE binding antigens were revealed for raw peanut and seven for roasted peanut after incubation with a mixed serum from the 10 patients in crossed radioimmunoelectrophoresis (CRIE) using ¹²⁵I-labeled anti-IgE. CRIE plates treated with individual serum samples showed that all the patients had specific IgE for the major antigen peak, which has been tentatively identified as α-arachin. This major storage protein of peanut, which is known to be particularly heat resistant, may be of greater clinical significance than its apparently low RAST activity would seem to indicate.     

Postnatal Iron Supplementation with Ferrous Sulfate vs. Ferrous Bis-Glycinate Chelate: Effects on Iron Metabolism,Growth, and Central Nervous System Development in Sprague Dawley Rat Pups

Iron-fortified formulas and iron drops (both usually ferrous sulfate, FS) prevent early life iron deficiency, but may delay growth and adversely affect neurodevelopment by providing excess iron. We used a rat pup model to investigate iron status, growth, and development outcomes following daily iron supplementation (10 mg iron/kg body weight, representative of iron-fortified formula levels) with FS or an alternative, bioavailable form of iron, ferrous bis-glycinate chelate (FC). On postnatal day (PD) 2, sex-matched rat litters (n = 3 litters, 10 pups each) were randomly assigned to receive FS, FC, or vehicle control until PD 14. On PD 15, we evaluated systemic iron regulation and CNS mineral interactions and we interrogated iron loading outcomes in the hippocampus, in search of mechanisms by which iron may influence neurodevelopment. Body iron stores were elevated substantially in iron-supplemented pups. All pups gained weight normally, but brain size on PD 15 was dependent on iron source. This may have been associated with reduced hippocampal oxidative stress but was not associated with CNS mineral interactions, iron regulation, or myelination, as these were unchanged with iron supplementation. Additional studies are warranted to investigate iron form effects on neurodevelopment so that iron recommendations can be optimized for all infants.     

Effect of saline infusion on net reabsorption of endogenous sulfate relative to that of phosphate in intact and thyroparathyroidectomized rats

Clearance experiments have been performed to study the effects of saline infusion on the reabsorption of inorganic sulfate (SO₄) at endogenous levels. Adult female Sprague-Dawley rats on a standard diet were used. Both intact and thyroparathyroidectomized (TPTX) animals were infused with a 130 mmol/l sodium chloride solution at a low (0.15 ml/min) and a high (0.375 ml/min) rate. This increase of the infusion rate decreased the reabsorption of SO₄ in both groups of animals significantly. The fractional excretion of SO₄ in theintact rats increased from 9.9±5.6 to 18.4±3.6% (mean values±SD,p<0.001) and in theTPTX rats from 5.3±2.5 to 22.4±6.3% (p<0.001). It is concluded that endogenous parathyroid hormone has no major effect on the saline-induced inhibition of reabsorption of SO₄.This work was supported by a grant from the Deutsche Forschungsgemeinschaft (Fr 239/9-1)     

含有十二烷基磺酸钠的生物制剂的内毒素检测不能采用鲎试验

重组人ＩＬ－２在大肠杆菌表达时形成包含体，需经过变性和复性才具有生物学活性，在分离提取过程中常加一定量的ＳＤＳ，最低浓度每毫升不小于０．２５ｍｇ；低于此浓度会发生沉淀。鲎试验（ＬＡＬ试验）是一种灵敏度很高的检查生物制剂中致热源的常规方法。我们发现，当样本中ＳＤＳ的浓度＞０．０２５ｍｇ／ｍｌ时，可抑制尝试制的酶反应，使阳性结果转变为阴性。据此，我们建议，凡生物制剂中含有ＳＤＳ或其他酶抑制剂的产品，以尝试验来检查内毒素含量是没有意义的。     

Interaction of immunoglobulin with actin

Actin can form specific, direct associations with immunoglobulin resulting in soluble complexes or cross-linked matrices. This interaction can be detected by four in vitro assays using purified components: (1) actin enhances the cytophilic activity of guinea pig IgG2; (2) in solutions of low ionic strength, actin and IgG2 co-precipitate: (3) soluble complexes exist in 0.1 M KCl as revealed by the displacement of actin from its expected sedimentation pattern in a gradient of sucrose when in the presence of IgG 1, IgG2, or IgM; (4) immunoglobulin (IgG1, IgG2, BGG)‡: increases the viscosity of F-actin solutions, presumably by crosslinking F-actin filaments. These data suggest that direct interaction of a cytoskeletal protein with a cell surface receptor is possible.     

β Chain deficiency in three patients with dysfunctional C8 molecules

Structural and functional studies were performed on a dysfunctional C8 molecule present in the serum of two siblings and an unrelated individual. The C8 in these three sera exhibited a pattern of partial immunologic identity with C8 in normal serum but was devoid of functional activity. The C8 was immunoprecipitated from the three sera and from a control serum with an antihuman C8 antiserum and analyzed by SDS-PAGE using highly purified human C8 as a reference. A selective absence of a band of 62,000 mol. wt was observed in the immunoprecipitates from the sera containing dysfunctional C8. Experiments performed with the purified α-γ and γ subunits showed that the hemolytic activity of the C8 deficient sera could be reconstituted by the addition of the β chain but not the α-γ dimer. Binding of the dysfunctional C8 to C$\text{567}$ was excluded by the following observations: (1) EAC 1–7 treated with the C8 deficient sera and then washed could not be lysed after the addition of the β subunit and C9; and (2) the abnormal molecules did not interfere with the consumption of normal C8 by the soluble complex SC5b-7.     

Ba2+ differentially inhibits the Rb+ efflux promoting and the vasorelaxant effects of levcromakalim and minoxidil sulfate in rat isolated aorta

The K⁺ channel openers activate ATP-sensitive K⁺ channels (K_ATP) in vascular smooth muscle and induce relaxation. In this study, the relationship between these two effects was examined in rings of rat aorta using levcromakalim and minoxidil sulfate as the openers and Ba²⁺ as the K⁺ channel blocker; K⁺ channel opening was assessed by determining the rate constant of ⁸⁶Rb⁺ efflux from the preparation.Ba²⁺ inhibited the ⁸⁶Rb⁺ efflux stimulated by levcromakalim in a noncompetitive manner with an IC₅₀ value of 29 M and a Hill-coefficient of 1.2. At concentrations > 300 M, Ba²⁺ increased the tension of rat aortic rings concentration-dependently. Levcromakalim relaxed contractions to Ba²⁺ (0.5 and 1 mM) with potencies similar to those determined against KCl (25 mM) or noradrenaline as spasmogens (EC₅₀ values 15–40 nM). The vasorelaxant effect against Ba²⁺ was inhibited by the K_ATP channel blockers, glibenclamide and tedisamil, and abolished in depolarizing medium (55 mM KCl). At 3 mM Ba²⁺, levcromakalim was still able to transiently induce complete relaxation; however, within 1 h oscillations in tension developed, leading to a stable level of only 15% relaxation. A similar level of relaxation was achieved against 10 mM Ba²⁺ whereas the combination of 0.5 mM Ba²⁺ and 3 M tedisamil blocked the relaxant effect of levcromakalim completely. With minoxidil sulfate as the K_ATP channel opener the results of the ⁸⁶Rb⁺ efflux and tension experiments were similar to those obtained with levcromakalim.It is concluded that Ba²⁺ is more potent in inhibiting the K⁺ channel opening than the vasorelaxant effects of the openers. On the basis of the ⁸⁶Rb⁺ efflux experiments it is estimated that at least 97% of the channels opened by the activators can be blocked without major effects on vasorelaxation suggesting a dissociation between the two effects. However, if the block is pushed to extremes ( 99.95%) the vasorelaxant effect of the openers is also abolished suggesting a link between both effects. This paradoxon remains to be solved.     

镁对脑缺血早期脑组织中谷氨酸及一氧化氮含量的影响

为研究镁在脑缺血早期对神经元保护作用的机制,用电凝法建立大鼠大脑中动脉缺血模型,在造模前给大鼠注射２０ｇ／Ｌ硫酸镁,观察镁对脑组织中谷氨酸（Ｇｌｕ）及一氧化氮（ＮＯ）含量的影响。结果显示,高浓度镁可明显降低脑缺血皮质中Ｇｌｕ、ＮＯ含量,在缺血组Ｇｌｕ、ＮＯ的峰值浓度分别为９．８７、４４．９７ｎｍｏｌ／ｇ,而在加镁组两者浓度分别为７．６８、３３．９２ｎｍｏｌ／ｇ。提示：镁对脑缺血早期神经元的保护作用与其降低脑组织中Ｇｌｕ及ＮＯ含量有关。     

硫酸奈替米星注射液与硫酸丁胺卡那注射液临床疗效及安全性的比较

为评价硫酸奈替米星的临床疗效及安全性,在１７０例急性细菌感染性病人中作多中心临床研究。结果显示：硫酸奈替米星的有效率（９５．３％）显著高于对照药硫酸丁胺卡那的有效率（８４．１％）,试验组病人咳痰和腰痛症状的平均下降显著高于对照组;硫酸奈替米星治疗后细菌清除率达９７．２％;２组病人不良反应发生率均为４．８％,对照组中有２例（３．２％）出现耳鸣、１例（１．６％）听力减退,但试验组病人用药后未发现听力异常。结论：硫酸奈替米星临床疗效优于硫酸丁胺卡那且较少耳毒性。