Relationship between natural and infection-induced antibodies in systemic autoimmune diseases (SAD): SLE, SSc and RA.

Infection or vaccine-induced T cell-dependent immune response and the subsequent high-affinity neutralizing antibody production have been extensively studied, while the connection between natural autoantibodies (nAAbs) and disease-specific antibodies has not been thoroughly investigated. Our goal was to find the relationship between immunoglobulin (Ig)M and IgG isotype nAAbs and infection or vaccine-induced and disease-related autoantibody levels in systemic autoimmune diseases (SAD). A previously described indirect enzyme-linked immunosorbent assay (ELISA) test was used for detection of IgM/IgG nAAbs against citrate synthase (anti-CS) and F4 fragment (anti-F4) of DNA topoisomerase I in 374 SAD samples, with a special focus on systemic lupus erythematosus (SLE) (n = 92), rheumatoid arthritis (n = 73) and systemic sclerosis (n = 157) disease groups. Anti-measles IgG and anti-dsDNA IgG/IgM autoantibodies were measured using commercial and in-house indirect ELISA tests. In all SAD groups the anti-measles IgG-seropositive cases showed significantly higher anti-CS IgG titers (P = 0·011). In anti-dsDNA IgG-positive SLE patients, we detected significantly higher levels of anti-CS and anti-F4 IgG nAAbs (P = 0·001 and < 0·001, respectively). Additionally, we found increased levels of IgM isotypes of anti-CS and anti-F4 nAAbs in anti-dsDNA IgM-positive SLE patients (P = 0·002 and 0·016, respectively). The association between IgG isotypes of pathogen- or autoimmune disease-related antibodies and the IgG nAAbs may underscore the immune response-inducible nature of the diseases investigated. The relationship between protective anti-dsDNA IgM and the IgM isotype of anti-F4 and anti-CS may provide immunoserological evidence for the beneficial roles of nAAbs in SLE patients.

Application of a fast and cost-effective 'three-in-one' MMR ELISA as a tool for surveying anti-MMR humoral immunity: the Hungarian experience.

In Hungary, between February 2017 and July 2019, 70 confirmed measles cases were reported, raising questions about the adequacy of population-level immunity. Although the assumed vaccination coverage is ≥99%, in a recent study, we detected potential gaps in the anti-measles humoral immunity. In Hungary, according to a decree by the Ministry of Public Welfare, beginning from 2021, the healthcare provider should conduct a serosurvey of anti-measles protection levels of healthcare professionals. To facilitate the compliance with this requirement, we developed a quick 'three-in-one' or 'triple' MMR (measles, mumps and rubella) indirect ELISA (IgG); an assay format that is currently not available commercially. High throughput applicability of the 'three-in-one' ELISA was verified using 1736 sera from routine laboratory residual samples, using an automated platform (Siemens BEP 2000 Advance). Assay verification was performed by comparing the full antigen repertoire-based 'target' assay with in-house 'control' assays using recombinant viral antigen coatings, and by validated commercially available kits. Indirect immunofluorescence was used as an independent reference method. Data were analysed using OriginLab, IBM SPSS, RStudio and MedCalc. In case of measles, we combined our current results with previously published data (Ntotal measles = 3523). Evaluation of anti-mumps and anti-rubella humoral antibody levels was based on the measurement of 1736 samples. The lowest anti-measles seropositivity (79.3%) was detected in sera of individuals vaccinated between 1978 and 1987. Considering the antigen-specific seropositivity ratios of all samples measured, anti-measles, -mumps and -rubella IgG antibody titres were adequate in 89.84%, 91.82% and 92.28%, respectively. Based on the virus-specific herd immunity threshold (HIT) values (HITMeasles = 92-95%, HITMumps = 75-86%, HITRubella = 83-86), it can be stated that regarding anti-measles immunity, certain age clusters of the population may have inadequate levels of humoral immunity. Despite the potential gaps in herd immunity, the use of MMR vaccine remains an effective and low-cost approach for the prevention of measles, mumps and rubella infections.

A population-based epidemiological study of neuromyelitis optica spectrum disorder in Hungary.

BACKGROUND AND PURPOSE: The goal of this study was to determine the prevalence and incidence of neuromyelitis optica spectrum disorder (NMOSD) in Hungary based on the 2015 International Panel of NMO Diagnosis (IPND) criteria. METHODS: A retrospective population-based cohort study was conducted of 6.4 million Hungarians (age ≥ 16 years) between 1 January 2006 and 31 December 2016. Possible NMOSD patients were selected via multistage re-evaluation from multiple sources. Crude and sex- and serostatus-specific prevalence (per 100 000 persons) and incidence rates (per 1 000 000 person-years) from 2006 to 2015 were estimated and age-adjusted rates were determined. RESULTS: Of 2262 study candidates, 154 NMOSD patients (age ≥ 16 years) with onset until 31 December 2016 were identified based on 2015 IPND criteria. The prevalence analysis on 1 January 2016 included 123 NMOSD living cases, resulting in a prevalence of 1.91 [95% confidence interval (CI) 1.52-2.28] per 100 000 persons. The 101 incident cases emerging from the observed 76 394 288 person-years provided an incidence rate of 1.32 (95% CI 1.08-1.61) per 1 000 000 person-years. Age-adjusted prevalence was 1.87 (95% CI 1.56-2.23) per 100 000 persons and incidence was 1.20 (95% CI 0.98-1.46) per 1 000 000 person-years. CONCLUSIONS: In this first report of a large population-based epidemiological study from an Eastern European Caucasian population using robust case validation, a greater prevalence and incidence of NMOSD was found compared to previous large studies in Caucasian populations.

Correlation of natural autoantibodies and cardiovascular disease-related anti-bacterial antibodies in pericardial fluid of cardiac surgery patients.

Our previous studies showed that anti-citrate synthase (anti-CS) immunoglobulin (Ig)M natural autoantibodies are present in healthy individuals without previous antigen stimulation, but no studies have investigated their presence in the pericardial fluid (PF). Therefore, we detected the natural anti-CS IgG/M autoantibody levels in plasma and PF of cardiac surgery patients and investigated their relationship with cardiovascular disease-associated bacterial pathogens. PF and blood samples of 22 coronary artery bypass graft (CABG) and 10 aortic valve replacement (AVR) patients were tested for total Ig levels, natural autoantibodies and infection-related antibodies using enzyme-linked immunosorbent assay (ELISA) and Luminex methods. The B cell subsets were measured by flow cytometry. The total Ig subclass levels were four to eight times lower in PF than in plasma, but the natural anti-CS IgM autoantibodies showed a relative increase in PF. The frequency of CD19+ B lymphocytes was significantly lower in PF than in blood (P = 0·01), with a significant relative increase of B1 cells (P = 0·005). Mycoplasma pneumoniae antibody-positive patients had significantly higher anti-CS IgM levels. In CABG patients we found a correlation between anti-CS IgG levels and M. pneumoniae, Chlamydia pneumoniae and Borrelia burgdorferi antibody titres. Our results provide the first evidence that natural autoantibodies are present in the PF, and they show a significant correlation with certain anti-bacterial antibody titres in a disease-specific manner.

Correction of T cell deficiency in ZAP-70 knock-out mice by simple intraperitoneal adoptive transfer of thymocytes.

The tyrosine kinase zeta chain-associated protein of 70 kDa (ZAP-70) plays a key role in T cell development and signalling. In the absence of ZAP-70, T cell development is arrested in the CD4+ CD8+ double-positive stage, thus ZAP-70 homozygous knockout (ZAP-70-/- ) mice have no mature T cells in their peripheral lymphoid organs and blood, causing severe immunodeficiency. We investigated the early kinetics and long-term effects of wild-type thymocyte transfer on T cell repopulation in ZAP-70-/- mice. We used a single intraperitoneal (i.p.) injection to deliver donor thymocytes to the recipients. Here, we show that after i.p. injection donor thymocytes leave the peritoneum through milky spots in the omentum and home to the thymus, where donor-originated CD4- CD8- double-negative thymocytes most probably restore T cell development and the disrupted thymic architecture. Subsequently, newly developed, donor-originated, single-positive αß T cells appear in peripheral lymphoid organs, where they form organized T cell zones. The established chimerism was found to be stable, as donor-originated cells were present in transferred ZAP-70-/- mice as late as 8 months after i.p. injection. We demonstrate that a simple i.p. injection of ZAP-70+/+ thymocytes is a feasible method for the long-term reconstitution of T cell development in ZAP-70-deficient mice.

Follow-up of serum KL-6 lung fibrosis biomarker levels in 173 patients with systemic sclerosis.

OBJECTIVES: A single-centre retrospective longitudinal study to investigate the predictive value of KL-6 serum levels for the outcome of interstitial lung fibrosis in a large systemic sclerosis (SSc) patient cohort. METHODS: ELISA tests for the mucin like glycoprotein KL-6 were performed in sera of 173 SSc patients. The clinical and laboratory data were evaluated by a standardised protocol of chest x-ray, lung function tests, echocardiography and high-resolution computed tomography. 158 patients were 29 ± 22 months later reinvestigated, 9 patients (2 lcSSc, 7 dcSSc) died from SSc-related causes, and 6 patients were lost to follow-up. RESULTS: Serum titer of KL-6 was negatively correlated with lung function parameters, independent of the time of investigation. There was a significantly higher probability of death among patients with high level of baseline KL-6. There was no statistically significant difference in the deterioration and improvement rates between groups with normal and elevated KL-6 level at study entry, even in patients in early phase of disease (disease duration <3 years). Serum levels of KL-6 significantly decreased in patients receiving cyclophosphamide treatment in spite of the fact that the spirometry results (FVC and DLCO) did not show a significant change. CONCLUSIONS: KL-6 can be used as a lung fibrosis severity marker, but its role as a marker for disease activity is questionable. Furthermore, following cyclophosphamide treatment serum KL-6 levels may decrease independently of the lung function parameters.

Serum concentration of immunoglobulin G-type antibodies against the whole Epstein-Barr nuclear antigen 1 and its aa35-58 or aa398-404 fragments in the sera of patients with systemic lupus erythematosus and multiple sclerosis.

Several studies suggest that infection by Epstein-Barr virus (EBV) might be one of the environmental factors which facilitates the development of autoimmune disorders in genetically susceptible individuals. Recent data indicate that high anti-Epstein-Barr nuclear antigen 1 (EBNA)-1 immunoglobulin (Ig)G titre is a strong risk factor for multiple sclerosis (MS) in patients both with and without the main genetic predisposing trait, human leucocyte antigen (HLA)-DRB1*15:01. Because no similar studies have been published in systemic lupus erythematosus (SLE) patients, we determined the HLA-DRB1*15:01 carrier state and the serum titres against the whole EBNA-1 and its small fragments aa35-58 and aa398-404 in 301 SLE patients, 135 MS patients and in 345 healthy controls. The carrier state of the HLA-DRB1*15:01 allele was deduced from genotyping of a tagSNP (rs3135388) by applying a Taqman-based assay. The serum concentrations of antibodies to EBNA-1 and its aa35-58 or aa398-404 fragments were determined using a commercial assay (ETI-EBNA-G) and home-made enzyme-linked immunosorbent assays, respectively. The serum concentration of anti-EBNA-1 antibodies was significantly (P < 0·001) higher both in MS and SLE patients than in controls. Similar significant differences were found both in HLA-DRB1*15:01 carriers and non-carriers. Furthermore, titres of antibodies against the aa35-58 EBNA-1 fragment were elevated both in MS and SLE patients. By contrast, the levels of aa398-404 EBNA-1 antibodies were elevated significantly only in the SLE patients. These findings indicate that high anti-EBNA-1 IgG titres are HLA-DRB1*15:01-independent risk factors not only for MS, but also for SLE, while high antibody titres against the aa398-404 fragment are characteristic for SLE.

Antibody response against gastrointestinal antigens in demyelinating diseases of the central nervous system.

BACKGROUND: Antibodies against gastrointestinal antigens may indicate altered microbiota and immune responses in the gut. Recent experimental data suggest a connection between gastrointestinal immune responses and CNS autoimmunity. METHODS: Antibodies against gliadin, tissue transglutaminase (tTG), intrinsic factor (IF), parietal cells (PC) and Saccharomyces cerevisiae (ASCA) were screened in the sera of 45 patients with AQP4-seropositive neuromyelitis optica (NMO) and NMO spectrum diseases (NMO/NMO-SD), 17 patients with AQP4-seronegative NMO, 85 patients with clinically definite multiple sclerosis (MS), and 48 healthy controls (HC). RESULTS: Thirty-seven percentages of patients with AQP4-seropositive NMO/NMO-SD and 28% of patients with MS had at least one particular antibody in contrast to 8% of HC (P < 0.01, respectively). Antibodies were most common (46%) in AQP4-seropositive myelitis (P = 0.01 versus HS, P = 0.05 versus MS). Anti-gliadin and ASCA were more frequent in the AQP4-seropositive NMO-spectrum compared to controls (P = 0.01 and P < 0.05, respectively). CONCLUSION: Antibody responses against gastrointestinal antigens are common in MS and AQP4-seropositive NMO/NMO-SD, especially in longitudinally extensive myelitis.

ZAP-70 tyrosines 315 and 492 transmit non-genomic glucocorticoid (GC) effects in T cells.

ZAP-70 kinase is a key regulator of early T-cell signaling; moreover, it also participates in non-genomic glucocorticoid (GC) signaling. Short-term high-dose GC-analogue treatment induces the phosphorylation of the kinase, and its association with the GC receptor (GR). In the present work, first, we identified those tyrosine (Y) residues of the ZAP-70 kinase which were involved in non-genomic GC signaling using an array of P116 cells (ZAP-70-deficient Jurkat subclone) lentivirally-transfected with wild type or point-mutated ZAP-70 constructs where Y-residues were replaced with phenylalanine (F) at positions 069, 126, 178, 238, 292, 315, 492 or 493. Then, we characterized the GC-analogue-induced Y-phosphorylation of 3 key substrates of the ZAP-70 kinase: SLP-76, LAT and Cbl. Finally, we studied the cross talk between the non-genomic GC- and TcR/CD3 signaling pathways. Y-F mutations at positions 315 or 492 abolished the short high-dose Dexamethasone (DX) treatment-induced ZAP-70 phosphorylation suggesting that these Y-residues were involved in ZAP-70-mediated non-genomic GC actions. DX treatment alone induced Y-phosphorylation of LAT, SLP-76 and Cbl; moreover, in F315- and F492-ZAP-70 mutated cells decreased DX-induced Y-phosphorylation of SLP-76 and Cbl was observed indicating that these molecules might transmit downstream non-genomic GC signals in a ZAP-70 dependent manner. Short, high dose DX treatment influenced significantly the anti-CD3-induced signaling events: we observed alterations in LAT, SLP-76 and Cbl Y-phosphorylation and a decreased Ca(2+)-signal. These results confirm that ZAP-70 represents an important link between the non-genomic GC and TcR/CD3 signaling pathways. Importantly, the DX-induced effects on resting and activated T-cells are differentially mediated. These fine molecular details help to better understand the complex mechanism of non-genomic GC effects in T-cells.

Insulin and leptin plasma levels after the microinjection of interleukin-1ß into the nucleus accumbens of the rat.

The nucleus accumbens (NAcc), an important basal forebrain structure, has a central integratory function in the control of feeding and metabolism. The primary cytokine interleukin-1ß (IL-1ß) exerts its neuromodulatory effects on the endocrine functions both centrally and peripherally. The present study was designed to elucidate the possible consequences of direct administration of IL-1ß into the NAcc on the endocrine regulation of metabolism. Plasma concentrations of insulin and leptin, two key hormones in the homeostatic control were determined 15 minutes after a single bilateral microinjection of IL-1ß into the NAcc of adult male Wistar rats, and the effects were compared with those found in vehicle treated control animals. Insulin plasma levels of the cytokine treated animals were significantly higher than those parameters of the control rats. No differences were found in leptin plasma concentrations between the two groups. Our findings show that IL-1ß mediated processes in the NAcc have important roles in the central neuroendocrine control.

Fine-tuning of proximal TCR signaling by ZAP-70 tyrosine residues in Jurkat cells.

Zeta-chain-associated protein kinase of 70kDa (ZAP-70) kinase is a key regulator in the early steps of TCR signaling but some aspects of its fine regulation are still unclear. From its 31 tyrosine (Y) residues, 11 phosphorylation sites have been identified, some with activator (Y315 and Y493) or inhibitory (Y292 and Y492) and others with unknown function (Y069, Y126 and Y178). In our present work, we aimed to elucidate the role of different Y residues of ZAP-70, especially those with unknown function, in calcium signaling and the autoregulation of the kinase. ZAP-70-deficient Jurkat cells (P116) were stably reconstituted with point-mutated ZAP-70 constructs where tyrosine residues 069, 126, 178, 238, 292, 315, 492 or 493 were replaced with phenylalanine (F). The anti-CD3-elicited calcium signal increased in F069-, F292- and F492-ZAP-70-expressing cell lines but decreased in the F126-, F315- and F493-ZAP-70-expressing cell lines. ZAP-70 point mutations led to phosphorylation changes predominantly in SH2 domain containing leukocyte protein of 76kDa (SLP-76) but not linker of activated T cells (LAT) during CD3-activation; moreover, we detected basal hyperphosphorylation of SLP-76 Y128 in the F126-, F178- and F492-ZAP-70-expressing cell lines. In summary, Y069, Y178, Y292 and Y492 have inhibitory, while Y126, Y315 and Y493 activator role in anti-CD3-induced T-cell activation. Phosphorylation changes in LAT and SLP-76 suggest that fine regulation of ZAP-70 on calcium signaling is rather transmitted through SLP-76 not LAT. Additionally, negative or positive autoregulatory function of Y292 and Y493 or Y315, respectively, was revealed in ZAP-70. These data indicate that previously not characterized Y069, Y126 and Y178 in ZAP-70 participate in the fine regulation of TCR signaling.

Heat shock proteins and myocardial protection during cardiopulmonary bypass.

This prospective randomized study investigated the effects of two different cardioplegia techniques on myocardial heat shock protein 70 (HSP70) mRNA levels. Patients undergoing elective coronary artery bypass grafting with cardiopulmonary bypass (CPB) were divided into two equal groups. All patients received the same anaesthesia. Myocardial preservation was achieved by delivering intermittent antegrade isothermic blood cardioplegia in one group and antegrade plus continuous retrograde isothermic blood cardioplegia in the other. Biopsies for measurement of HSP70 mRNA levels were taken from the right atria before surgical manipulation of the heart, and later from the same place following CPB. HSP70 mRNA levels were evaluated using quantitative real-time reverse transcription-polymerase chain reaction. Crossing-point values for HSP70 and ß-actin were used to evaluate up-regulation. There was a significant increase in HSP70 mRNA levels in response to CPB in both groups, but no significant between-group difference in HSP70 up-regulation. Further investigation is required to evaluate the correlation between the level of HSP induction and the degree of myocardial protection in more heterogeneous groups of patients.

Comprehensive investigation of novel serum markers of pulmonary fibrosis associated with systemic sclerosis and dermato/polymyositis.

OBJECTIVE: To investigate the association between serum levels and clinical signs of lung fibrosis in patients with systemic sclerosis and inflammatory myopathies. METHODS: ELISA tests for a mucin-like glycoprotein KL-6, von Willebrandt factor (vWF), soluble E-selectin (sES) and surfactant protein D (SP-D) were performed in sera of 104 patients with systemic sclerosis, 31 patients with poly/dermatomyositis) and 24 patients with Raynaud's phenomenon as controls. The clinical and laboratory data were evaluated by a simple standard protocol including chest x-ray, lung function tests, echocardiography and, in selected cases, high resolution computer tomography (HRCT). Clinically significant pulmonary fibrosis (PF) defined as a simultaneous presence of radiological sign of pulmonary fibrosis and restrictive impairment. Severe PF was established if HRCT scans showed diffuse interstitial lung disease with low diffusing capacity. End stage PF was determined as severe PF with very low diffusing capacity. RESULTS: Patients with pulmonary fibrosis on chest x-ray showed significantly elevated serum levels of KL-6, SP-D and vWF. Inverse correlation was found between serum levels of KL-6/SP-D and lung function parameters, such as DLCO% and FVC. With regard to HRCT findings, patients with elevated serum level of KL-6 showed significantly more frequently ground glass opacity, diffuse and honeycombing fibrosis than patients with normal level of KL-6. The sensitivity of KL-6 for PF in SSc is increased with the severity of PF (PF on chest x-ray < severe PF < end stage of PF). Lung fibrosis occurred more frequently in patients with simultaneously elevated KL-6 and sES compared to cases with a single positivity of either KL-6 or sES. CONCLUSION: KL-6, SP-D, vWF and ES are good surrogate factors of pulmonary fibrosis but can not replace conventional diagnostic procedures. However, these markers are suitable for the assessment of progression and severity of pulmonary fibrosis in systemic autoimmune disorders once the diagnosis is established.

Very rare aetiology of giant popliteal pseudoaneurysm: anterior cruciate ligament surgery.

There are various causes of the formation of arterial pseudoaneurysms, including trauma, surgical procedures, infection and iatrogenic injuries. A popliteal aneurysm was detected in a patient with pain and discomfort in his leg. The patient had a history of knee surgery. The aneurysm was treated surgically. Aneurysms following penetrating arterial injury resulting from surgical intervention requiring the use of surgical devices is one of the possible traumatic causes.

Membrane glucocorticoid receptors are down regulated by glucocorticoids in patients with systemic lupus erythematosus and use a caveolin-1-independent expression pathway.

BACKGROUND: Membrane-bound glucocorticoid receptors (mGCR) are up regulated on monocytes after in vitro stimulation and in patients with rheumatoid arthritis. Caveolin-1 is critical for the transport of plasma membrane oestrogen receptors to the cell surface. OBJECTIVES: To investigate the expression of mGCR in patients with systemic lupus erythematosus (SLE)-a disease with different aetiopathogenesis and treatment regimens-and to examine whether caveolin-1 is critical for the transport of mGCR to the cell surface. METHODS: Frequencies of mGCR+ peripheral blood mononuclear cells were measured using high-sensitivity immunofluorescent staining and tested for correlation with SLE disease activity and glucocorticoid treatment. Semiquantitative polymerase chain reaction, immunofluorescence, recombinant expression and confocal laser-scanning microscopy were used to search for an association of mGCR with caveolin-1. RESULTS: The frequencies of mGCR+ monocytes (CD14+) were considerably higher in patients with SLE (n = 33) than in healthy controls (n = 58), whereas B cells (CD19+) were not different in this regard. T cells (CD3+) were always mGCR-. The frequency of mGCR+ monocytes in patients with SLE did not correlate with disease activity, but did inversely correlate with glucocorticoid dosages; this inverse correlation was confirmed by corresponding in vitro experiments with stimulated monocytes. The induced up regulation of mGCR was not accompanied by an up regulation of caveolin-1, and mGCR are not colocalised with caveolin-1 in plasma membrane caveolae. CONCLUSION: mGCR are (a) up regulated in patients with SLE and by inflammatory stimuli and (b) down regulated by glucocorticoids, suggesting a negative feedback loop to control glucocorticoid action. Drugs binding selectively to mGCR may in future prove to be of therapeutic value.

Validation of in silico prediction by in vitro immunoserological results of fine epitope mapping on citrate synthase specific autoantibodies.

In silico antibody-antigen binding predictions are generally employed in research to rationalize epitope development. These techniques are widely spread despite their technical limitations. To validate the results of these bioinformatic calculations evidence based comparative in vitro studies are necessary. We have used a well-conserved mitochondrial inner membrane antigen-citrate synthase to develop a model for comparative analysis of the predicted and the immunoserologically verified epitopes of circulating autoantibodies. Epitopes were predicted using accepted tools: the GCG Wisconsin package and TEPITOPE 2000. An overlapping multipin ELISA assay--covering 49% of the citrate synthase molecule--was developed to map autoantibody epitopes of individuals (healthy, systemic autoimmune, and heart transplanted) in different immunopathological conditions. From the 40 synthesized decapeptides 34 were predicted in silico and 27 were validated in vitro. Thirty-two percent of epitopes were recognized by majority of sera 47% by at least one sera. False positive predictions were 21%. There was major difference in the recognized epitope pattern under different immunopathological conditions. Our results suggest that special databases are needed for training and weighing prediction methods by clinically well-characterized samples, due to the differences in the immune response under different health status. The development of these special algorithms needs a new approach. A high number of samples under these special immunological conditions are to be mapped and then used for the "fine tuning" of different prediction algorithms.

Protective antioxidant effects of carvedilol in a rat model of ischaemia-reperfusion injury.

This study investigated the protective effects of carvedilol, a potent antioxidant, in a rat model of tourniquet-induced ischaemia-reperfusion injury of the hind limb. Thirty rats were divided equally into three groups: the control group (group 1) was only anaesthetized, without creating an ischaemia-reperfusion injury; group 2 was submitted to ischaemia (4 h), followed by a 2-h reperfusion period; and group 3 was pre-treated with carvedilol (2 mg/kg per day) for 10 days prior to ischaemia-reperfusion. Ischaemia-reperfusion produced a significant decrease in superoxide dismutase and glutathione peroxidase activities in the liver, lungs, muscle and serum compared with control treatment, and pre-treatment with carvedilol prevented these changes. Ischaemia-reperfusion caused a significant increase in malondialdehyde and nitric oxide (NO) levels in liver, lungs, muscle (except NO) and serum compared with control treatment, and carvedilol prevented these changes. In conclusion, it might be inferred that carvedilol could be used safely to prevent oxidative injury during reperfusion following ischaemia in humans.

Organic hydroperoxide-induced chemiluminescence of follicular fluid and blood serum samples obtained from women pretreated for in vitro fertilization.

The organic hydroperoxide-induced chemiluminescence of follicular fluid obtained from in vitro fertilized patients and its differently separated fractions were evaluated. Peroxidative stress causes a different photo-emission in the samples which alludes to some factors playing a role in the maintenance of the pro-oxidant/antioxidant balance. Interactions between the protein compounds of the samples and the organic hydroperoxide associate with formation of excited species contributing to the distinctive light emission processes. The technique offers a special re-interpretation of the scavenger state relating to the components of follicular fluid.

Galactoside-specific misletoe lectin modulates dexamethasone-induced apoptosis and glucocorticoid receptor level in Balb/c thymocytes.

The galactoside-specific plant lectin, Viscum album agglutinin-(VAA)-I has been shown to activate the natural immune system and modulate the maturation of thymocytes in vivo. However the mechanism of this immunobiological action is not yet understood. In our previous study we demonstrated the VAA-I-induced enhancement of proliferation and selection of thymocytes which inhibited the dexamethasone (DX)-induced thymocyte depletion. In this present work we investigated the effect of 1, 4 and 21 days of VAA-I treatment on DX-induced apoptosis of thymocytes in Balb/c mice. The number of early apoptotic cells was detected with Annexin V staining while the late apoptotic cells were identified according to their propidium iodide incorporation into DNA using flow cytometry. The expression of glucocorticoid receptor (GCR) in double-negative (DN), double-positive (DP) and CD4 or CD8 single-positive (SP) cell populations was assessed. The additive effect of lectin on DX-induced apoptosis of thymocytes consisted of two different actions of VAA-I and DX. One-day VAA-I treatment caused enhanced apoptosis in SP mature cells in contrast to the apoptotic effect of DX, which was mainly directed towards immature DN and DP cells. Treatment with 30 ng/kg VAA-I for four days elevated the GCR level (mean fluorescence intensity) in DP thymocytes. Lectin treatment for 21 days caused more than 20% elevation of GCR expression in all thymocyte subpopulations (DN, DP, CD4+ and CD8+). These results suggest that VAA-I may alter the sensitivity of thymocytes to glucocorticoids and this effect may play a role in the bell-shaped dose-response curve of lectin-induced immunological effects.