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Biomedical subjects

R Miesel

Publications and source records attributed to R Miesel.

35 records · Page 2Linked to original sources
PubMed1994

Assessment of collagen type II induced arthritis in mice by whole blood chemiluminescence.

Lucigenin-enhanced chemiluminescence can be measured in 100 microliters samples of whole, unseparated mouse blood. A procedure for doing so is here described in detail, using a standard clinical luminometer. The assay measures the TPA-induced oxidative burst from granulocytes and macrophages, which is believed to depend on the overall level of inflammation in the body. It is here applied to mice suffering from type II collagen-induced arthritis, and its relation to overt disease symptoms (the arthritis score) is characterised during the course of the disease. A correlation between the assay and the arthritis score is found at the height of the disease (r = 0.42, p = .039), but not at early or very late time points, although there is a strong hint that the results of an early assay may predict the subsequent disease course. The assay provides a rapid, convenient, quantitative and economical method of assessing disease activity, which can be carried out repeatedly on the same individual. It should be applicable in other mouse models of chronic inflammatory disease. It may find application for rapid screening of novel anti-rheumatic drugs and treatments.

Acridines↗
PubMed1993

Reactive nitrogen intermediates, antinuclear antibodies and copper-thionein in serum of patients with rheumatic diseases.

Sera from 354 patients with various inflammatory and autoimmune rheumatic diseases were screened for the presence of reactive nitrogen intermediates, antinuclear antibodies and the anti-oxidase copper-thionein (Cu-thionein), and compared to sera from healthy donors and patients with non-rheumatic diseases including AIDS, various internal as well as neurological diseases and carcinoma of different organs. When compared to healthy individuals, the levels of nitric oxides in sera from patients with autoimmune rheumatic diseases were elevated by 240-600% (P < 0.01). The status of reactive nitrogen intermediates (NOx, RNI) in sera from donors with inflammatory rheumatic diseases was increased by 170-540%, but was also significantly enhanced in sera of patients with non-rheumatic diseases, indicating a general inflammatory mechanism that is predominantly triggered by inducible nitric oxide (NO) syntheses of phagocytes. All rheumatic sera were dramatically depleted of the anti-oxidase Cu-thionein (P < 0.001), a powerful consumer of hydroxyl radicals and singlet oxygen and an efficient superoxide dismutase. The NOx levels were positively correlated with the serum titers of antinuclear antibodies (r = 0.77) and negatively correlated with Cu-thionein levels (r = 0.94), reflecting a high steady-state concentration of free radicals generated during inflammatory and autoimmune rheumatic diseases.

Antibodies, Antinuclear↗
PubMed1993

Elevated levels of xanthine oxidase in serum of patients with inflammatory and autoimmune rheumatic diseases.

Sera of patients with various inflammatory and autoimmune rheumatic diseases were screened for the presence of xanthine oxidase (XOD) and compared to sera from healthy donors and patients with nonrheumatic diseases including AIDS, internal diseases, and different carcinomas. Up to 50-fold higher levels of XOD were detected in rheumatic sera (P < 0.001). In addition, serum sulfhydryls (SH) were determined as sensitive markers of oxidative stress. The SH status in rheumatic patients was diminished by 45-75% (P < 0.001) and inversely correlated to the concentration of serum XOD (R = 0.73), suggesting a causal interrelation. The depletion of serum sulfhydryls by the oxyradical-producing XOD/acetaldehyde system was mimicked successfully ex vivo in human serum from healthy donors. Cortisone treatment of patients suffering from systemic lupus erythematosus and rheumatoid arthritis impressively normalized elevated XOD concentrations in rheumatic sera to those of healthy controls. The participation of xanthine oxidase in the depletion of serum antioxidants in rheumatic patients is discussed in the light of substrate availability and Km values.

Acetaldehyde↗
PubMed1993

Reactivity of an active center analog of Cu2Zn2superoxide dismutase in murine model of acute and chronic inflammation.

The antiinflammatory efficacy of CuPu(Py)2 ([[N,N'-bis(2-pyridylmethylene)-1,4-butanediamine] (N,N',N'',N''')]-Cu2+), a serum stable active center analog of Cu2Zn2superoxide dismutase (SOD), was tested in vitro and in vivo in male Wistar rats suffering from potassium peroxochromate-induced inflammation. Parameters including 99mTc gamma-scintigraphic imaging, the arthritis score, the plasma superoxide dismutase activity, the inhibition of plasma sulfhydryl depletion as well as mitogenic and phagocytic responses were used to quantify the disease activity. All parameters improved impressively during the treatment with CuPu(Py)2 and resembled those of healthy animals after 21 days. The arthritis score was inhibited by 80% (P > 0.001) and the plasma SOD activity enhanced by 380% (P > 0.001). The depletion of plasma sulfhydryls and the leukocytic responses to concanavalin A, tetradecanoylphorbolacetate, and lipopolysaccharide were significantly reduced (P > 0.001) and correlated well with the arthritis score. The collapse of antioxidant defenses in human plasma as well as the depolymerization of hyaluronic acid was mimicked in vitro and successfully inhibited by CuPu(Py)2. Oxidant-induced injury of plasma components during the aqueous decay of potassium peroxochromate were demonstrated to activate the oxidative burst of phagocytes in human blood. The role of impaired pro- and antioxidant balances in the etiology of inflammatory and autoimmune rheumatic diseases is discussed.

Acute Disease↗
PubMed1993

Copper-dependent antioxidase defenses in inflammatory and autoimmune rheumatic diseases.

Gel-filtered sera of patients with various inflammatory and autoimmune rheumatic diseases (N = 354) were screened for the presence of the inflammation marker Cu-thionein. The concentrations of Cu-thionein were significantly diminished in patients with connective tissue diseases (P < 0.001). Sera of patients suffering from inflammatory rheumatic diseases were almost totally depleted of this low-molecular-weight copper protein that exerts pronounced superoxide dismutase activity and scavenges effectively hydroxyl radicals and singlet oxygen. Cortisone treatment of patients with rheumatoid arthritis, systemic lupus erythematosus, and polymyalgia rheumatica replenished impressively the serum concentration of Cu-thionein. The partial oxidation of the EPR-silent Cu(I)-chromophore to Cu(II)/Cu(I)-thionein, which is essential for the catalytic dismutation of superoxide, was monitored by electron paramagnetic resonance in the presence of activated neutrophils and monocytes. Release of Cu-thionein during the oxidative burst of peripheral blood monocytes was demonstrated in vitro. The role of prooxidant-antioxidant imbalances in the pathogenesis of rheumatic diseases is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Oxidative stress during the interaction of gametes.

Oxidative stress, commonly defined as a disturbance in the prooxidant and antioxidant levels, may be causatively involved in the etiology of defective sperm function. To mimic the physiological situation, in this study xenogeneic activators of the oxidative burst of sperm were excluded. In addition, transition metal-driven production of reactive oxygen species was avoided by chelation of Fenton catalysts. On average, 28 +/- 4 U of superoxide dismutase (SOD) and 375 +/- 105 mumol/L of sulfhydryls were found in normozoospermic ejaculates from 10 healthy men. The in vitro inhibition of superoxide dismutase by diethyldithiocarbamate caused the rapid oxidation of seminal plasma sulfhydryls, suggesting a pivotal role for SOD in maintaining the antioxidant defense system and protecting against oxidant-induced injury. The production of superoxide by hamster sperm as well as hamster oocytes was examined by lucigenin-mediated chemiluminescence both prior to and following the addition of sperm to oocytes for in vitro fertilization. During fusion, the generation of superoxide from both sperm and oocytes was markedly suppressed. This inhibition was partially due to the superoxide dismutase released during gamete interactions.

Animals↗
PubMed1993

[Increased level of nitrogen radicals in serum of patients with rheumatic diseases and AIDS].

354 sera from venous blood of patients with various rheumatic diseases and AIDS were assayed for the presence of reactive nitrogen intermediates. Compared to healthy individuals, the serum levels of nitric oxides from patients with connective tissue diseases and inflammatory rheumatic diseases were elevated (P < 0.01) by 170-600% and those from HIV-infected patients by 220%.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Chemiluminescence assays of Cu2Zn2 superoxide dismutase mimicking Cu-complexes.

The aqueous decay of K3CrO8 was used to compare the reactivity of Cu2Zn2 superoxide dismutase and two active centre analogues where the first shell atoms around the copper are four unsaturated nitrogens. Unlike the acetate or biuret type Cu(II) chelates these di-Schiff-base complexes had an identical reactivity compared to that of the intact enzyme. Nanomolar concentrations of copper coordinated in these complexes were sufficient to inhibit the K3CrO8 induced chemiluminescence by 50%. Furthermore, a lucigenin amplified chemiluminescence assay based on isolated polymorph nuclear leucocytes in the absence and presence of whole, unseparated blood was developed and successfully employed. CuPu(Im)2 and CuPu(Py)2 equivalent to 0.5 and 0.8 SOD units, only, were required to inhibit the photon emission by 50% in the absence of bovine serum albumin. Even in the presence of 600 microM albumin mimicking the competitive copper chelation in biological fluids Cu-Pu(Py)2 and CuPu(Im)2 remained active, whereas the carboxylate- and biuret type chelates Cu(Sal)2 and Cu(Ser)2 reacted like CuSO4. The same reactivity of these low M, SOD mimics was seen in human blood.

Acridines↗
PubMed1990

Reactivity of active center analogs of Cu2Zn2 superoxide dismutase on activated polymorphonuclear leukocytes.

In unseparated human blood the Cu2Zn2 superoxide dismutase mimetic reactivity of several differently coordinated low Mr copper chelates on TPA-activated polymorphonuclear leukocytes was evaluated and compared to their apo-chelates, CuSO4, and the native enzyme. Similar to intact superoxide dismutase, 350-400 nM Cu flexibly complexed in a di-Schiff base mode in CuPu(Py)2 and CuPu(Im)2, respectively, was sufficient to inhibit the oxidative burst-dependent superoxide production of human blood phagocytes by 50%. Acetate- or biuret-type copper chelates behaved like CuSO4. The catalytic superoxide dismuting reactivity of the di-Schiff base active center analogs of SOD was confirmed using isolated porcine PMNs. Even in the presence of 600 microM albumin as a model for competitive copper chelation in biological fluids CuPu(Py)2 and CuPu(Im)2 remained active. The stability during the Cu(I)/Cu(II) redox cycling was demonstrated in the presence of activated PMNs and albumin, taking advantage of the electron paramagnetic properties of CuPu(Py)2 and CuPu(Im)2.

Animals↗
PubMed1990

Antiinflammatory reactivity of copper(I)-thionein.

In unseparated human blood the reactivity of yeast copper (I)-thionein on TPA-activated polymorphonuclear leukocytes was evaluated and compared with low Mr copper chelates exerting Cu2Zn2 superoxide dismutase mimetic activity. Cu, 18 microM, in the form of Cu-thionein was sufficient to inhibit the superoxide production of activated human blood phagocytes by 50%. Furthermore, the scavenging of hydroxyl radicals and singlet oxygen by Cu(I)-thionein was determined, using the 2-deoxyribose fragmentation assay induced by decaying K3CrO8 and the NADPH oxidation caused by UVA illuminated psoralen, respectively. The inhibitory reactivity of Cu-thionein in both assays was compared with that of serum proteins including albumin, ceruloplasmin, transferrin, and ferritin. The galactosamine/endotoxin-induced hepatitis in male NMRI mice was used to evaluate the antiinflammatory reactivity of Cu-thionein in vivo. The serum copper, superoxide dismutase, and sorbitol dehydrogenase concentrations, as well as the activity of polymorphonuclear leukocytes in unseparated blood seemed most appropriate to quantify the protective capacity of Cu-thionein in the course of an oxidative stress-dependent liver injury. The intraperitoneal application of 32.5 mumols/kg thionein-Cu limited this damage to 45%.

Animals↗
PubMed1990

Phagocytic response modifying reactivity of enzymatic cell wall digests of Nocardia opaca.

Aqueous extracts (ENOCW) and enzymatic digests of purified Nocardia opaca cell wall fragments, virtually free of muramyl peptides, were monitored for their phagocytic response modifying reactivity on polymorphonuclear leucocytes, separated or unseparated in whole human blood. In the presence of ENOCW a 74% increased production of superoxide during the respiratory burst of TPA-activated polymorphonuclear leukocytes was observed, as compared to the unprimed control. Delipidation of this preparation resulted in a further increase in reactivity (144%). Even in the presence of whole human blood, as a model for competitive binding in biological fluids, an enhanced generation of superoxide by TPA activated blood phagocytes remained detectable. A 37-75% decreased phagocytic reactivity in samples of HIV-seropositive blood was considerably restored in the presence of ENOCW.

Acridines↗
PubMed1990

Anticarcinogenic reactivity of copper-dischiffbases with superoxide dismutase-like activity.

CuPu(Py)2 and CuPu(Im)2, two novel dischiffbase coordinated low Mr active centre analogues of Cu2Zn2 superoxide dismutase, were shown to effectively catalyze the production of hydroxyl radicals in the presence and absence of TPA-activated polymorphonuclear leukocytes. These stable copper chelates exhibited a pronounced anticarcinogenic reactivity in male Sprague Dawley rats implanted with Walker 256 carcinosarcoma cells. When four doses of 5 mumol/kg CuPu(Py)2 and CuPu(Im)2, respectively, were administered intratumorally, reduction in tumor size, delay of metastasis and a significant increase in survival of the hosts were observed, resulting in 75% of total remissions. 60% of the animals recovered totally from the carcinosarcoma, when CuPu(Py)2 was applicated intravenously.

Animals↗
PubMed1990

Reactivity of active centre analogues of Cu2Zn2 superoxide dismutase.

Active centre analogues of Cu2Zn2 superoxide dismutase were devised and successfully employed. Emphasis was placed on the flexible nature of the superoxide mimicking compounds. Di-Schiff-bases proved most appropriate to fulfil these requirements. Both structural and functional aspects of the copper binding centre of the intact enzyme were met by these complexes. Nanomolar concentrations of copper coordinated in these complexes were sufficient to inhibit the K3CrO8 induced chemiluminescence identical to the reaction of Cu2Zn2 superoxide dismutase.

Animals↗
PubMedDate not supplied

Severe antioxidase deficiency in human semen samples with pathological spermiogram parameters.

Spermatozoa of 103 ejaculates from infertile patients and fertile healthy individuals were separated from seminal plasma and purified on Percoll gradient to determine the activities of superoxide dismutase (SOD) and catalase (CAT) in seminal plasma as well as in spermatozoal supernatants after hypotonic disintegration of the sperm plasma membrane. Out of collected specimens, a subgroup of ejaculates from 40 individuals was examined whose female partners had developed malignant processes in the cervix uteri (oncological subgroup). All sperm samples were classified into normal and pathological semen samples according to WHO criteria. While no significant differences of SOD levels were detected in seminal plasma of patients with primary infertility, a catalase deficiency seemed to be associated with combined sperm pathology-oligoasthenoteratozoospermia (OAT). Liberated concentrations of both SOD and catalase were diminished by 10-70% in the oncological subgroup compared to normozoospermia. In four OAT samples obtained from infertile males of the oncological subgroup, total depletion from both antioxidases was observed. A lack of sufficient antioxidase protection in cases of severe sperm pathology (OAT) may also lead to cervical dysplasia.

Catalase↗
PubMedDate not supplied

The effects of interleukin-1 receptor antagonist on oxidant-induced arthritis in mice.

OBJECTIVE: The anti-arthritic reactivity of the IL-1 receptor antagonist IL-1ra was tested in male DBA/1xB10A(4R) mice suffering from potassium peroxochromate-induced arthritis. METHODS: Inflammatory arthritis was induced in male DBA/1xB10A(4R) mice by the intraplantar application of potassium peroxochromate and was quantified by the determination of the arthritis index, whole blood chemiluminescence, serum sulfhydryls and nitric oxides. Culture supernatants of the fibroblasts were assayed spectrophotometrically for collagenase release. RESULTS: Overt arthritic symptoms, as measured by the arthritis index, were significantly inhibited after two intraperitoneal injections of 2 mg/kg IL-1ra. The phorbol-ester-stimulated chemiluminescent response of monocytes and polymorphonuclear leukocytes in whole murine blood, which increased 5-fold during the development of arthritis, was normalized to the level of healthy controls. The oxidation of serum sulfhydryls was inhibited by 25%, and the serum levels of nitric oxides was depressed by 40%. In vitro the IL-1-dependent induction of collagenase of rabbit synovial fibroblasts was completely suppressed in the presence of 0.4 mg/ml IL-1ra. CONCLUSION: IL-1ra may prove useful to control the consequences of enhanced free radical production in inflammatory rheumatic diseases.

Animals↗
PubMedDate not supplied

Oxidative stress and male infertility.

We have studied the activity of substances (superoxide dismutase [SOD], catalase [Cat], malonaldehyde, xanthine oxidase [XO], nitric oxide [NOx]) participating in oxidative stress. Seminal plasma samples of 147 ejaculates obtained from normal and from infertile males were examined. Activities of SOD, Cat, and XO were measured chemiluminometrically while malonaldehydes and NOx were measured by spectrophotometer in seminal plasma samples. Ejaculates were previously characterized according to World Health Organization andrological criteria (sperm number, motility, and morphology). Procedures were performed in a university laboratory. Statistically significant changes (in comparison to normozoospermic samples) were noted in activities of SOD, XO, and malonaldehyde levels. The SOD activity exceeded values obtained for normozoospermic samples only in oligozoospermia. Otherwise low SOD levels in analyzed infertile subgroups inversely related to elevated malonaldehydes. Because diminished activity of SOD in seminal plasma was associated with increased levels of malonaldehydes and XO, we could postulate some significance of these monitored substances in evaluation of the cause of male infertility.

Catalase↗