Reactive Oxygen Metabolite Production is Inhibited by Histamine and H 1 -antagonist Dithiaden in Human PMN Leukocytes

The study evaluated the distinction between extracellular and intracellular production of reactive oxygen metabolites (ROM) in isolated polymorphonuclear leukocytes (PMNL) stimulated with opsonised zymosan (OZ) and investigated its modulation by the endogenous mediator histamine (0.1-100 &#119 mol/l) and by the H 1 -antagonist dithiaden (1-100 &#119 mol/l). For this observation, a modified luminol and an isoluminol amplified chemiluminescence (CL) technique were used. Our results showed that PMNL activated with OZ responded with a respiratory burst accompanied by both extra- and intracellular generation of ROM. Histamine and dithiaden significantly decreased both the extra- and intracellular component of chemilumiescence stimulated with OZ. While dithiaden decreased both the extra- and intracellular part of CL with the same potency, histamine decreased preferentially the extracellular part of CL. The fact that histamine as well as the H 1 -antagonist dithiaden decreased the respiratory burst indicates that not only histamine receptors but also non-receptor mechanisms could be involved in the reduction of CL. Interaction with enzymes (NADPH-oxidase, myeloperoxidase, phospholipase A 2 ) or interference with PMNL membrane structure may well result in reduction of the chemiluminescence signal.     

血栓调节蛋白化学发光免疫分析检测方法的建立*

目的:建立并评价基于板式化学发光免疫分析(CLIA)平台的血栓调节蛋白(TM)定量检测方法。方法:以链霉亲和素包被微孔板,加入待检血浆,偶联生物素和辣根过氧化物酶的配对抗体组成分析体系,采用双抗体夹心模式,建立TM抗原定量检测方法,并对其进行条件优化和性能评价。结果:生物素化抗体和酶标抗体的工作浓度分别为0.5 μg/mL和0.75 μg/mL,加样后的孵育时间选为15 min,最低检测限为0.2 TU/mL,该检测方法的检测范围为1~200 TU/mL,批间和批内精密度(CV)均小于8%,37 ℃ 10天稳定性良好,207份临床血浆测值与希森美康测值相关性较高(R²>0.96)。结论:建立了TM板式化学发光定量检测方法,且各项性能指标良好,可满足临床检测的需要。     

Sensitization of surfactants on the chemiluminescence reaction of fluorescein isothiocyanate labeled proteins

The effect of surfactants on fluorescein isothiocyanate (FITC)-bovine serum albumin (BSA)-hypochlorite (ClO(-)), FITC-human serum albumin (HSA)-ClO(-), FITC-ovoconalbumin (OVA)-ClO(-), FITC-hemoglobin (Hb)-ClO(-) systems were investigated with chemiluminescence method by the reversed phase flow injection. It was found that the chemiluminescence (CL) intensity of each system was increased greatly in the presence of cationic surfactants. Cethyltrimethylammonium bromide (CTAB) is the optimal surfactant of these systems. The optimal conditions of the CL reaction and the optimal concentration of CTAB were examined and the function of cationic surfactant CTAB on the CL reaction was also discussed.     

Chemiluminescence flow-through biosensor for glucose with eggshell membrane as enzyme immobilization platform

In this study, a new chemiluminescence (CL) flow-through biosensor for glucose was developed by immobilizing glucose oxidase (GOD) and horseradish peroxidase (HRP) on the eggshell membrane with glutaraldehyde as a cross-linker. The CL detection involved enzymatic oxidation of glucose to D-gluconic acid and hydrogen peroxide (H2O2) and then H2O2 oxidizing luminol to produce CL emission in the presence of HRP. The immobilization condition (e.g., immobilization time, GOD/HRP ratio, glutaraldehyde concentration) was studied in detail. It showed good storage stability at 4 degrees C over a 5-month period. The proposed biosensor exhibited short response time, high sensitivity, easy operation, and simple sensor assembly, and the proposed biosensor was successfully applied to the determination of glucose in human serum.     

New (diphenylphosphane)benzoic acid copper(I) derivatives of “scorpionate” ligands with superoxide scavenging activity

New copper(I) complexes have been synthesized from the reaction of CuCl with 4- or 2-(diphenylphosphane)benzoic acid and KH₂B(btz)₂, KHB(btz)₃, NaTp^Me, KpzTp, KpzTp^Me and KH₂B(im)₂(dmac). The complexes obtained have been characterized by elemental analyses and FT-IR in the solid state, and by NMR (¹H and ³¹P{¹H}) and electrospray mass spectroscopy in solution.Chemiluminescence technique was used to evaluate the superoxide scavenging activity of these new copper complexes.     

Synthesis and bioactivities of poly(ethylene glycol)–chitosan hybrids

Poly(ethylene glycol)–chitosan hybrids of various molecular weights having different degree of substitution were synthesized, by reductive N-alkylation of chitosan with poly(ethylene glycol) aldehyde, to study their bioactivities. The influence of these chitosan derivatives on the reactive oxygen species generation from canine polymorphonuclear leukocyte cells was investigated in vitro by chemiluminescence response. Reactive oxygen species generation by the influence of poly(ethylene glycol)–chitosan hybrids was decreased with the increase of degree of substitution. The reduction of interaction of poly(ethylene glycol)–chitosan hybrids with polymorphonuclear leukocyte cells might be caused by the decrease of amino group in chitosan main chain and increase of the steric hindrance by poly(ethylene glycol) chain. The influence of the poly(ethylene glycol)–chitosan hybrids on complement component C3 activation was investigated by single radial immunodiffusion method. Influence on complement component C3 activation by poly(ethylene glycol)–chitosan hybrids was almost same as chitosan.     

蝮蛇毒和眼镜蛇毒对全血化学发光的影响

目的研究蝮蛇毒和眼镜蛇毒对吞噬细胞的免疫抑制作用。方法以氢化可的松为阳性对照物,用化学发光法测定样品清除非细胞体系产生的活性氧,以及样品对酵母多糖诱导的全血化学发光的抑制作用。结果蝮蛇毒和眼镜蛇毒对非细胞体系产生的Ｏ·２和Ｈ２Ｏ２的清除作用都较弱;对全血化学发光有抑制作用,特别是酵母多糖起刺激作用之前加入蛇毒的抑制作用强于酵母多糖起作用之后加入蛇毒的抑制作用。这提示,这两种蛇毒使吞噬细胞的吞噬免疫功能下降,造成吞噬细胞的呼吸爆发减弱,导致活性氧产生不足,化学发光强度下降。眼镜蛇毒的这种免疫抑制作用比氢化可的松还强。结论蝮蛇毒和眼镜蛇毒具有氢化可的松样的免疫抑制作用,其中眼镜蛇毒可能具有作为临床免疫抑制剂使用的价值。     

Two Processes Responsible for Chemiluminescence Development in the Course of Iron-Mediated Lipid Peroxidation

The kinetics of chemiluminescence (CL) accompanying Fe²⁺-induced lipid peroxidation (LPO) in liposome suspension has been investigated. A sequence of stages was observed, namely: (1) fast CL flash (FF); (2) latent period (LP); (3) slow CL flash (SF) and (4) stationary chemiluminescence (SL). The first three stages are known to reflect the Fe²⁺-mediated LPO process. In spite of the fact that at the stage of SL Fe²⁺ has completely oxidized and MDA has not accumulated, CL intensity was found to increase and after 0.5–1 h reached a value that was several times higher than SF amplitude. The maximal SL level was linearly dependent on the initial Fe²⁺ concentration and was not dependent on liposome concentration in the suspension. The nature of the processes responsible for CL emission at the stage of SL has been investigated using free radical reaction inhibitors and measurement of CL spectra. The SL spectrum was observed in the red region (λ>590 nm) in contrast to the SF CL spectrum (maximum at 540 nm). SL amplitude was strongly inhibited by sodium azide (40%), superoxide dismutase (SOD) (30%), desferrioxamine and EDTA (30%), whereas mannitol, ethanol, α-tocopherol and butylated hydroxytoluene were ineffective. The data obtained indicate that CL at the stage of SL is not directly related to LPO process, i.e. lipid free radical recombination. The mechanism of stationary CL generation is discussed.     

Contrasting effects of Mycoplasma fermentans and M. felis on the viability and chemiluminescence response of human polymorphonuclear leukocytes

Abstract Trypan blue exclusion was used to estimate the viability of human polymorphonuclear leukocytes (PMNL) in the presence of Mycoplasma felis and two strains of M. fermentans (PG18 and incognitus). The competence of PMNL to mount a respiratory burst when challenged with the mycoplasmas was also monitored by luminol-dependent chemiluminescence (CL). Both un-opsonised and non-immune human serum opsonised M. felis cells had little effect on PMNL viability. In contrast, PMNL viability was reduced markedly by un-opsonised cells of M. fermentans strain incognitus and, to a lesser extent, strain PG18, and opsonisation of these mycoplasmas further enhanced killing. Death of PMNL in the presence of M. fermentans was not associated with the autonomous production of active oxygen species during the respiratory burst as M. felis induced a high CL response from PMNL, whereas that induced by M. fermentans strain incognitus was significantly lower. M. fermentans may invade mammalian cells and it is suggested that the mechanism of PMNL death could be related to the ability of M. fermentans to penetrate host cell membranes.     

Continuous Determination by a Chemiluminescent Method of Acetylcholine Release and Compartmentation in Torpedo Electric Organ Synaptosomes

Abstract: The detection of acetylcholine (ACh) with a chemiluminescent procedure enables one to follow continuously the release of transmitter from stimulated synaptosomes and to study the compartmentation of ACh in resting and active nerve terminals. A compartment of ACh liberated almost entirely by a single freezing and thawing could be directly measured and compared with a compartment of ACh resistant to several cycles of freezing and thawing but liberated by a detergent (60–70% of the total). It is the compartment liberated by freezing and thawing that is reduced when synaptosomes are stimulated. Up to half the total synaptosomal ACh content is readily releasable provided the calcium entry is maintained, or if a strong releasing agent such as the venom of Glycera convoluta is used. In addition, it is shown that synaptosomes contain only negligible amounts of choline, and that the proportion of the two ACh compartments is not influenced by changing extracellular calcium just before their determination.