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Biomedical subjects

M Kurpisz

Publications and source records attributed to M Kurpisz.

At least 55 records · Page 3Linked to original sources

Antiinflammatory effects of NADPH oxidase inhibitors.

Proinflammatory cytokines prime the membrane-bound NADPH oxidase of neutrophils and monocytes of mice suffering from experimental arthritis so as to attain an activated state, which, upon a second stimulus, releases 6-fold increased levels of reactive oxygen species (ROS) than do unprimed phagocytes. Enhanced NADPH oxidase activity deregulates ROS-dependent signal transduction pathways of inflammation, which play a crucial role in the pathogenesis of arthritis. The antiarthritic reactivity of two inhibitors of NADPH oxidase, diphenylene iodoniumchloride (DPI) and staurosporine, was tested in male DBA/1 x B10A(4R) hybrid mice suffering from potassium peroxochromate arthritis. Daily doses of 2.8 mumol/kg of DPI or 30 nmol/kg of staurosporine sufficed to inhibit the arthritis by 50%. A complete inhibition was obtained with 10 mumol/kg of DPI, and 100 nmol/kg of staurosporine suppressed the arthritis by 85%. The onset, progression, and remission of arthritis correlated to both the activity of phagocytic NADPH oxidase (r = 0.750) and to overt disease symptoms as judged by the arthritis index. Our data support the hypothesis that oxidative stress plays a pivotal role in the pathology of arthritis, which can be therapeutically targeted by NADPH oxidase inhibitors.

Alkaloids↗

Modulation of inflammatory arthritis by inhibition of poly(ADP ribose) polymerase.

Poly(ADPR) polymerase (PARP; EC 2.4.2.30) is a nuclear enzyme, which, when activated by oxygen- and nitrogen-radical-induced DNA strand breaks, transfers ADP ribose units to nuclear proteins and initiates apoptosis by depletion of cellular NAD and ATP pools. The present study investigates whether the oxidative stress-dependent activation of PARP plays a role in the etiopathogenesis of arthritis. The antiarthritic reactivity of the biogenic PARP inhibitor nicotinamide was tested in DBA/1 x B10A(4R) mice suffering from potassium peroxochromate-induced arthritis. Daily doses of 4 mmol/kg of NA suppressed the arthritis by 35% and inhibited the phagocytic generation of reactive oxygen species, which increases sixfold during the development of arthritis. The onset, progression, and remission of arthritis correlated positively to the phorbolester-activated respiratory burst of neutrophils and monocytes, and a dose-dependent inhibition of NADPH oxidase activity was determined with human phagocytes. Our data support the hypothesis that oxidative stress-induced alterations in cellular signal transduction pathways play a pivotal role in the development of arthritis, which can be suppressed by the simultaneous inhibition of poly(ADPR) polymerase and NADPH oxidase.

Animals↗

Analysis of mRNA expression for interleukin-1 genes on human testicular cells.

We have investigated mRNA expression for IL-1 alpha and IL-1 beta gene on fractionated human testicular cells. Using RT-PCR and Northern blot hybridization technique we detected the presence of IL-1 alpha transcripts, predominantly in the intratubular compartment of the testis, comprising gametogenic and Sertoli cells. We were also able to detect mRNA for IL-1 alpha on the testicular interstitium, but at significantly lower levels. The intertubular compartment of the testis, mainly consisting of macrophages and Leydig cells, appeared however, to be a site for IL-1 beta gene expression. Our experimental data confirm previous results obtained in animal models indicating that the testis is capable of producing interleukin-1 under physiological conditions. Testicular IL-1 may function as a tissue-specific factor modulating both spermato- and steroidogenic activity of human testis.

Base Sequence↗

Hepatoprotective reactivity of a copper-di-Schiffbase active centre analogue of Cu2Zn2 superoxide dismutase.

1. The anti-inflammatory and hepatoprotective efficacy of CuPu(Py)2 ((N,N'-bis(2-pyridyl-methylene)-1,4-butanediamine) (N,N',N",N")-Cu2+), a serum-stable, copper-di-Schiffbase active centre analogue of Cu2Zn2 superoxide dismutase was tested in male NMNR mice suffering from endotoxin/galactosamine-induced hepatitis. 2. Parameters including the activities of serum transaminases and sorbitol-dehydrogenase as well as the levels of reactive oxygen and nitrogen intermediates which were used to quantify the disease activity. 3. A dose-dependent inhibition of hepatic enzyme release was noted in the presence of 0.1-10 mg/kg of CuPu(Py)2. 4. The release of transaminases from damaged liver cells was reduced by 68% and paralleled the reduction of serum levels of nitric oxides. 5. Elevated levels of reactive oxygen species were normalized to those healthy controls. 6. The copper-free apochelate Pu(Py)2, which is unable to dismutate superoxide, did not display any anti-inflammatory reactivity.

Alanine Transaminase↗

Induction of arthritis in mice and rats by potassium peroxochromate and assessment of disease activity by whole blood chemiluminescence and 99mpertechnetate-imaging.

Arthritis develops in DBA/1xB10A(4R) mice and Wistar rats upon intraplantar injection of potassium peroxochromate (K3CrO8), and is here quantified by whole blood chemiluminescence (CL) and 99mpertechnetate-imaging (99mTcO4-), and related to overt disease symptoms (the arthritis index). During the aqueous decay of K3CrO8 to chromate (VI), the chromium(V)-bound oxygen is released as superoxide, hydroxyl radicals, singlet oxygen and hydrogen peroxide, the same reactants, which are produced by activated phagocytes during inflammation. Reactive oxygen species (ROS) trigger the breakdown of the sulfhydryl-dependent antioxidant defence system and induce the nuclear factor kappa B-dependent expression of pro-inflammatory cytokines, which prime phagocytic NADPH oxidases to the enhanced production of ROS. During both the acute inflammatory response and the onset of the secondary response in non-injected paws, the phorbolester-stimulated ROS production of phagocytes was significantly enhanced (p < 0.001) and correlated well to the arthritis index (r = 0.797) and the uptake of 99mTcO4- into inflamed joints. Chromate(VI), formed during the decay of K3CrO8, contributes to the progression of arthritis by inhibition of glutathione reductase, thereby increasing intracellular H2O2 concentrations. In addition, Cr(VI) reduced to Cr(V) by ascorbate, catalyzes hydroxyl radical production in the presence of hydrogen peroxide. A stable loop forms, in which ROS, continuously produced by Cr(VI)/Cr(V) redox-cycling, drive the primary response into chronic self-perpetuating inflammation. We see the main application of K3CrO8-induced arthritis and its assessment by both 99mTcO4- imaging and chemiluminescent immunosensoring of phagocytic activity in unseparated blood as for the rapid screening of novel anti-rheumatic drugs and treatments.

Animals↗

Carbohydrate moieties on sperm surface: physiological relevance.

OBJECTIVES: To study the cross-reactions between mouse monoclonal antisperm antibodies and somatic cells or bacteria, to identify the antigenic determinants responsible for such cross-reactions, and to correlate between the antibody function and determinant recognition. DESIGN: Activities of monoclonal antibodies (mAbs) were characterized by immunosorbent assay of RIA technique; sperm epitopic characterization was performed in lectin-blocking and sugar competitive assays and correlated with functional assays. SETTING: Procedures were performed in a university laboratory. RESULTS: The extensive cross-reactivity between antigenic determinants of sperm, erythrocytes, and bacteria (but not bacterial deglycosylated lipopolysaccharides) was observed. The analytic procedures indicated predominant mAb reactions to carbohydrates such as fucose, galactose, mannose, N-acetylglucosamine and N-acetylgalactosamine. Approximately half of the 30 tested mAbs interfered in the functional assays, that is, sperm agglutination, immobilization, and zona-free penetration. CONCLUSIONS: Sperm carbohydrates seem to induce antibody reactions to common antigenic determinant(s) present on gametes, somatic cells, and infectious agents. Thus molecular mimicry between bacteria and sperm can be a major factor inducing antisperm immunological reactions. Obtained antisperm mAbs, reacting to glycosylated epitopes, presented very strong properties in sperm agglutination and/or immobilization. This did not correlate with inhibiting properties of some antibodies in xenogeneic zona-free penetration test, that is, this assay possibly is not based on oligosaccharide mediation.

Animals↗

[Immunologic reactions in the male and female reproductive system].

This review describes presence and significance of antisperm antibodies (ASA) in male and female reproductive compartments. We described their relevance to infertility in humans. A structure and function of cervical mucus as the environment of females defensive reactions against all the invasive factors is outlined. There are also briefly characterized techniques of ASA detection.

Agglutination Tests↗

X- and Y-chromosome-bearing sperm selection and detection methods. A review.

The ability to preselect the sex of human offspring would have a significant impact on the preventing of sex chromosome-linked diseases and on human reproduction. Numerous methods have been reviewed including: Sephadex gel filtration, centrifugation in density gradients, separation in albumin gradient, laminar flow, counterstreaming centrifugation, free-flow electrophoresis, galvanic method, two-phase system separation, flow cytometry, immunological exclusion. None of these methods seems to be ideal. Results obtained with the use of the most of them are contradictory, the others still need reliable confirmation. Part of the controversy related to the efficacy of methods aimed at sex selection may be due to the lack of appropriate and widely used techniques of X- and Y-chromosome bearing sperm detection. Fluorescent in situ hybridization appears to be the most suitable among the sperm sex chromosome detection techniques described in this review. Others, like quinacrine staining method, human sperm/hamster oocyte penetration assay, microinterferometry, cytometry, and polymerase chain reaction exhibit more or less disadvantageous features, which limit their application.

Cell Separation↗

Analysis of mRNA for class I HLA on human gametogenic cells.

We have studied mRNA expression for Class I HLA (human leukocyte antigen) on male germ cells by amplification of gene fragments in PCR technique and by Northern hybridization. RNA was extracted from fractionated gametogenic cells (isolated from testis) and reversely transcribed. Then, cDNA was amplified for specific HLA sequence (HLA, -A, -B, -C). The specificity of this product was confirmed in "nested" PCR of 400 bp gene fragment coding for alpha 2 domain, alpha 3 domain, and the transmembrane portion of Class I HLA. The results indicate minimal expression of classical Class I HLA on gametogenic cells. Northern hybridization with 669 bp cDNA fragment (spanning for alpha 3 domain, transmembrane, cytoplasmic, and 3' untranslated region) resulted in a low intensity signal from gametogenic cell fractions and confirmed our findings obtained by PCR. The minimal expression of classical HLA antigens may create a neutral cover for the male reproductive system, thereby preventing an immunological response during germ cell differentiation.

Blotting, Northern↗

Suppression of arthritis by an active center analogue of Cu2Zn2-superoxide dismutase.

The anti-arthritic and anti-inflammatory efficacy of CuPu(Py)2 ([N,N'-bis(2-pyridylmethylene)-1,4-butanediamine] (N,N',N",N"))-Cu(II), a serum-stable active center analogue of Cu2Zn2-superoxide dismutase (SOD; EC 1.15.1.1), was tested in male DBA/1 x B10A (4R) mice suffering from potassium-peroxochromate-induced (PIA) or collagen type II-induced arthritis (CIA). Parameters including the arthritis index, the plasma SOD activity, and the inhibition of phagocytic responses in unseparated blood were used for the assessment of disease activity. A dose-dependent suppression of arthritis was noted in both models. The ED50 was 2.5 +/- 0.4 mumol/kg/day of CuPu(Py)2 for PIA and 4.0 +/- 1.1 mumol/kg/day for CIA. The arthritis index correlated with both the levels of reactive oxygen species (ROS) generated by phorbol ester-activated neutrophils and monocytes in unseparated blood (r = 0.892) and the SOD-like activity in plasma (r = 0.857). CuPu(Py)2 inhibited also the lipoplysaccharide-induced release of tumor necrosis factor alpha from human monocytes and neutrophils in a dose-dependent manner. Unlike SOD, which exerts successful anti-rheumatic activity mainly upon intra-articular injection, the SOD-mimic CuPu(Py)2 can be applied systemically. Non-proteinaceous low molecular weight antioxidases may well be suited to control oxidative stress-derived damage in rheumatic diseases by modulation of ROS-dependent signal transduction pathways.

Animals↗

[The influence of different cryopreservation buffers on the fertilizing ability of human sperm "in vitro". II. Evaluation of the fertilizing potential of human sperm after cryopreservation].

We tried to define a potential ability of human spermatozoa for fertilization after 3 month preservation of samples in a liquid nitrogen. The functional test were applied: penetration of sperm to cervical mucus ("Penetrak") and sperm penetration to hamster zona-free oocytes. We would like to emphasize that presented way of cryo-preservation in 3 selected media with fast cooling of samples allow to maintain fertilizing ability of spermatozoa and subsequent insemination.

Adult↗

[The influence of different cryoprotectant buffers on the fertilizing ability of human sperm "in vitro". I. The choice of cryoprotective buffers and methods of freezing].

We attempted to find the optimal way of cryopreservation of male gametes. We have been tested 9 cryoprotectants currently existing in the world literature. These fluids have been so far separately investigated in different centers of infertility treatment. In this study we compared the effectivity of these fluids in preservation of viable sperm. Basic seminological parameters and two variants of freezing were tested. There were noted significant differences between fast and slow cooling of sperm samples. Nevertheless after fast cooling we found a marked decrease of seminological parameters in preserved sperm when compared to fresh samples.

Cryopreservation↗

Human immunoglobulin production in SCID mice following primary sensitisation of human lymphocytes in situ.

We have grafted human peripheral blood mononuclear cells to the peritoneal cavity of SCID mice, exposed them to soluble antigens in the absence of adjuvant and examined their ability to make specific antibody. The effect of in vitro pre-priming of donor cells on antibody production was determined. Human IgM and IgG antibodies were found in the SCID serum following in situ antigenic challenge and there was good evidence of antigen specificity. The total Ig levels and the relative antigen binding ability were diminished by in vitro pre-priming. The results demonstrate that primary human antibodies against antigens to which the donor is probably naive can be generated by in situ sensitisation in SCID mice, but that optimisation for each antigen may be required.

Animals↗

In vitro sensitization for human monoclonal antibody production.

We have found that cell adhesion prior to in vitro antigenic stimulation enriched the B-cell population and diminished the CD8 lymphocyte subset. These changes in lymphocyte proportions were favourable for increasing the percentage of antibody-producing cells after culturing in vitro followed by Epstein-Barr virus (EBV) infection. The immunodepletion of leukocytes by methyl esters did not yield satisfying results under analogous culture conditions. In vitro primary antigenic stimulations with the addition of IL-2 (25 U/ml medium) and low amounts of interferon-gamma provided better recruitment of antibody-producing cells and higher binding activity of antibodies to sperm than secondary antigenic stimulation. IL-6 did not positively influence the EBV-transformed cell lines.

Antibodies, Monoclonal↗

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↗

In situ localization of HLA class I mRNA in human testis.

We have used a 0.35-kilobase (kb) antisense RNA probe complementary to the monomorphic regions of both classical and nonclassical HLA class I sequences to detect histocompatibility-class-I-antigen-specific mRNA in human testicular tissue. The message has been clearly detected in the interstitium while less intensive staining was revealed in the peribasal compartment of the seminiferous epithelium.

Antisense Elements (Genetics)↗