RARß Promoter Methylation as an Epigenetic Mechanism of Gene Silencing in Non-small Cell Lung Cancer.

The retinoid acid receptor-p (RARß) gene is one of the tumor suppressor genes (TSGs), which is frequently deleted or epigenetically silenced at an early stage of tumor progression. In this study we investigated the promoter methylation and expression status of the RARß gene in 60 surgically resected non-small cell lung cancer (NSCLC) tissue samples and 60 corresponding unchanged lung tissue samples, using methylation-specific PCR and real-time-polymerase chain reaction (qPCR) techniques. We correlated the results with the pathological features of tumors and clinical characteristics of patients. qPCR analysis detected a significantly lower RARß expression in the patients with adenocarcinoma (AC) and large cell carcinoma (LCC) than in those with squamous cell carcinoma (SCC) (AC vs. SCC, p = 0.032; AC and LCC vs. SCC, p = 0.0 13). Additionally, significantly lower expression of the RARß gene was revealed in the patients with non-squamous cell cancer with a history of smoking assessed as pack-years (PY < 40 vs. PY ≥ 40, p = 0.045). Regarding RARß promoter methylation, we found significant differences in the methylation index in the SCC group when considering pTNM staging; with higher index values in T1a + T1b compared with T2a + T2b and T3 + T4 groups (p = 0.024). There was no correlation between the methylation status and expression level of the RARß gene, which suggests that other molecular mechanisms influence the RARß expression in NSCLC patients. In conclusion, different expression of the RARß gene in SCC and NSCC makes the RARß gene a valuable diagnostic marker for differentiating the NSCLC subtypes.

TGF-ß and SMADs mRNA Expression in Pulmonary Sarcoidosis.

Lung fibrosis is a complication of sarcoidosis, in which TGF-ß/Smad pathway may play an important role. We evaluated gene expression of TGF-ß1, SMAD2, 3 and 7 in bronchoalveolar lavage (BAL) cells and peripheral blood (PB) lymphocytes of sarcoidosis patients (n=94) to better understand the mechanisms of sarcoid inflammation. The relative gene expression was analyzed by qPCR method. Selected clinical/radiological features and biochemical markers were taken into account in the analysis. We found that TGF-ß1 and SMAD3 expressions in PB lymphocytes were significantly higher in sarcoidosis patients. Up-regulation of SMAD7 (inhibitory Smad) and down-regulation of SMAD3 in BAL cells in all subgroups were found. The expression of TGF-ß1 in PB lymphocytes was the highest in patients with lung parenchymal involvement and in the insidious onset phenotype. The expression of TGF-ß1 in BAL cells was higher in patients with abnormal spirometry (p=0.012), and TGF-ß1 and SMAD3 in patients with restrictive pattern (p=0.034 and 0.031, respectively). Several statistically significant negative correlations were found between the expression levels of SMAD2 and 3 in BAL cells and various LFT parameters. We conclude that TGF-ß/Smad pathway is involved in the pathogenesis of pulmonary sarcoidosis. These biomarkers (especially TGF-ß1, SMAD2 and 3) are of a negative prognostic value.

Decreased FAM107A Expression in Patients with Non-small Cell Lung Cancer.

Lung cancer is the leading cause of cancer-related death in the world. Early detection, based on molecular markers, could decrease mortality from this disease. Tumor development is often associated with inactivation or loss of tumor suppressor genes (TSGs). The aim of the present study was to analyze the expression level of FAM107A gene, a TSG located in 3p21.1, in lung cancer tumors and in tumor adjacent normal lung samples. Promoter methylation status of FAM107A was evaluated as the potential mechanism of its epigenetic silencing. The relationship between gene mRNA expression and tumor staging, metastasis status, and non-small cell lung cancer (NSCLC) histopathological subtypes in 60 patients was analyzed. Total RNA was isolated from tissue samples and gene expression was assessed in qPCR assay. Gene promoter methylation status was evaluated in MSP reactions, using bisulfite converted DNA and two pairs of primers: methylated and unmethylated. We found that the expression of the gene was dramatically decreased in all NSCLC samples and was significantly lower than in tumor adjacent normal lung tissue. Promoter methylation of FAM107A gene was confirmed only in the minority of NSCLCs. The results highlight the importance of FAM107A in lung carcinogenesis, although indicate other than promoter hypermethylation mechanism of the gene decreased expression.

Expression of HIF-1A/VEGF/ING-4 Axis in Pulmonary Sarcoidosis.

Angiogenesis/angiostasis regulated by hypoxia inducible factor-1A (HIF-1A)/vascular endothelial growth factor (VEGF)/inhibitor of growth protein 4 (ING-4) axis may be crucial for the course and outcome of sarcoidosis. Overexpression of angiogenic factors (activation of VEGF through HIF-1A) may predispose to chronic course and lung fibrosis, whereas immunoangiostasis (related to an overexpression of inhibitory ING-4) may be involved in granuloma formation in early sarcoid inflammation, or sustained or recurrent formation of granulomas. In this work we investigated gene expression of HIF-1A, VEGF and ING-4 in bronchoalveolar fluid (BALF) cells and in peripheral blood (PB) lymphocytes of sarcoidosis patients (n=94), to better understand mechanisms of the disease and to search for its biomarkers. The relative gene expression level (RQ value) was analyzed by qPCR. The results were evaluated according to the presence of lung parenchymal involvement (radiological stage I vs. II-IV), acute vs. insidious onset, lung function tests, calcium metabolism parameters, percentage of lymphocytes (BALL%) and BAL CD4+/CD8+ in BALF, age, and gender. In BALF cells, the ING-4 and VEGF RQ values were increased, while HIF-1A expression was decreased. In PB lymphocytes all studied genes were overexpressed. Higher expression of HIF-1A in PB lymphocytes of patients with abnormal spirometry, and in BALF cells of patients with lung volume restriction was found. VEGF gene expression in BALF cells was also higher in patients with abnormal spirometry. These findings were in line with previous data on the role of HIF-1A/VEGF/ING-4 axis in the pathogenesis of sarcoidosis. Up-regulated HIF-1A and VEGF genes are linked to acknowledged negative prognostics.

A personalised approach to prostate cancer screening based on genotyping of risk founder alleles.

BACKGROUND: To evaluate whether genotyping for 18 prostate cancer founder variants is helpful in identifying high-risk individuals and for determining optimal screening regimens. METHODS: A serum PSA level was measured and a digital rectal examination (DRE) was performed on 2907 unaffected men aged 40-90. Three hundred and twenty-three men with an elevated PSA (≥4 ng ml⁻¹) or an abnormal DRE underwent a prostate biopsy. All men were genotyped for three founder alleles in BRCA1 (5382insC, 4153delA and C61G), for four alleles in CHEK2 (1100delC, IVS2+1G>A, del5395 and I157T), for one allele in NBS1 (657del5), for one allele in HOXB13 (G84E), and for nine low-risk single-nucleotide polymorphisms (SNPs). RESULTS: On the basis of an elevated PSA or an abnormal DRE, prostate cancer was diagnosed in 135 of 2907 men (4.6%). In men with a CHEK2 missense mutation I157T, the cancer detection rate among men with an elevated PSA or an abnormal DRE was much higher (10.2%, P=0.0008). The cancer detection rate rose with the number of SNP risk genotypes observed from 1.2% for men with no variant to 8.6% for men who carried six or more variants (P=0.04). No single variant was helpful on its own in predicting the presence of prostate cancer, however, the combination of all rare mutations and SNPs improved predictive power (area under the curve=0.59; P=0.03). CONCLUSION: These results suggest that testing for germline CHEK2 mutations improves the ability to predict the presence of prostate cancer in screened men, however, the clinical utility of incorporating DNA variants in the screening process is marginal.

An inherited NBN mutation is associated with poor prognosis prostate cancer.

BACKGROUND: To establish the contribution of eight founder alleles in three DNA damage repair genes (BRCA1, CHEK2 and NBS1) to prostate cancer in Poland, and to measure the impact of these variants on survival among patients. METHODS: Three thousand seven hundred fifty men with prostate cancer and 3956 cancer-free controls were genotyped for three founder alleles in BRCA1 (5382insC, 4153delA, C61G), four alleles in CHEK2 (1100delC, IVS2+1G>A, del5395, I157T), and one allele in NBS1 (657del5). RESULTS: The NBS1 mutation was detected in 53 of 3750 unselected cases compared with 23 of 3956 (0.6%) controls (odds ratio (OR)=2.5; P=0.0003). A CHEK2 mutation was seen in 383 (10.2%) unselected cases and in 228 (5.8%) controls (OR=1.9; P<0.0001). Mutation of BRCA1 (three mutations combined) was not associated with the risk of prostate cancer (OR=0.9; P=0.8). In a subgroup analysis, the 4153delA mutation was associated with early-onset (age ≤ 60 years) prostate cancer (OR=20.3, P=0.004). The mean follow-up was 54 months. Mortality was significantly worse for carriers of a NBS1 mutation than for non-carriers (HR=1.85; P=0.008). The 5-year survival for men with an NBS1 mutation was 49%, compared with 72% for mutation-negative cases. CONCLUSION: A mutation in NBS1 predisposes to aggressive prostate cancer. These data are relevant to the prospect of adapting personalised medicine to prostate cancer prevention and treatment.

A prospective randomized trial: a comparison of the analgesic effect and toxicity of 153Sm radioisotope treatment in monotherapy and combined therapy including local external beam radiotherapy (EBRT) among metastatic castrate resistance prostate cancer (mCRPC) patients with painful bone metastases.

Bone metastases in prostate cancer constitute the most frequent cause of systemic failure in treatment, which results in numerous complications and finally leads to patient's death. Pain is one of the first and most important clinical symptoms of bone metastases and can be found among more than 80% of patients. Therefore, the most analgetic effective and simultaneously the least toxic treatment is an important point of therapeutic management in this group of patients. The aim of this prospective clinical trial was a comparison of analgetic effectiveness and toxicity of monotherapy with 153Sm isotope to combined therapy (153Sm + EBRT) among patients diagnosed with multiple painful bone metastases due to CRPC (mCRPC). 177 patients with mCRPC were included into the prospective randomised clinical trial in which 89 patients were assigned to the 153Sm isotope monotherapy, while 88 patients were assigned to the combined therapy including 153Sm isotope therapy and EBRT. All patients were diagnosed (bone scan and X-ray or/and CT or/and MRI) with painful bone metastases (bone pain intensity >= 6 according to VAS classification). The following additional inclusion criteria were established: histologically confirmed adenocarcinoma of prostate, multifocal bone metastases, no prior chemotherapy or palliative radiotherapy to bone. All patients signed informed consent.The combination of the isotope therapy with EBRT was more effective analgetic treatment than isotope therapy alone. The highest pain decline was noticed in the first weeks after treatment termination. In the whole group, a total or partial analgesic effect was observed among 154 (87%) patients while among 23 (13%) patients there was a lack of analgesic effect or even pain intensification. The results of this clinical trial demonstrated that for patients with multiple mCRPC it is recommended to combine the 153Sm isotope therapy with local EBRT because of a greater analgetic effect. It is important to note that combined therapy did not intensify the toxicity of treatment.

Thyroid hormones affect plasma ghrelin and obestatin levels.

Using radioimmunoassay, the effects of thyroid hormones on plasma total ghrelin (Gh) and obestatin (Ob) concentrations were evaluated in thyrotoxic patients with an excess of thyroid hormones and in hypothyroid patients lacking endogenous thyroid hormones. 24 patients with thyrotoxicosis, 25 hypothyroid patents after total thyreoidectomy performed due to thyroid cancer, and 17 control subjects were examined. Compared with the controls, the ghrelin and obestatin were elevated in hypothyroidism, while they were decreased in thyrotoxicosis. The plasma Gh and Ob levels differ depending on the thyroid function. In thyroid hormones deficiency, plasma Gh and Ob are increased, while in patients with excess of thyroid hormones, the levels of both Gh and Ob are definitely lower. Gh/Ob ratio is higher in hypothyroidism than in control subjects and thyrotoxic patients.

Digit ratio (2D:4D) in women and men with lung cancer.

A prenatal sex steroid environment of high prenatal testosterone and low prenatal oestrogen inhibits lung development and may predispose individuals to be vulnerable to lung disease in later life. Therefore, the aim of this report was to investigate whether there is an association between right and left 2D:4D (biomarker of prenatal sex steroids exposure) and primary lung cancer in women and men. Also, we considered the relationship between right-left 2D:4D (Δ2D:4D, a negative correlate of high prenatal testosterone and low prenatal oestrogen) and the age of lung cancer diagnosis. The study included 109 patients (61 men) with lung cancer and 197 controls (78 men). In the study we found that: (i) women with lung cancer have lower 2D:4D compared to controls (the effect was independent of smoking), (ii) among women with cancer, age at diagnosis was positively related to 2D:4D, i.e. women with masculinized 2D:4D present earlier with the cancer than women with feminized 2D:4D, (iii) among men with lung cancer, those with the most aggressive form (small-cell lung cancer) had masculinized (low) Δ2D:4D compared to those with the less aggressive form (non-small cell lung cancer). The data suggests that masculinized right 2D:4D and Δ2D:4D are associated with a predisposition to lung cancer and/or the more aggressive forms of lung cancer.

Lipoxin A4 generation is decreased in aspirin-sensitive patients in lysine-aspirin nasal challenge in vivo model.

BACKGROUND: Lipoxins represent a group of lipoxygenase derived eicosanoids which, in contrast to leukotrienes, are potent anti-inflammatory mediators. The aim of our study was to determine lipoxin A(4) (LXA(4)) and leukotriene C(4) (LTC(4)) levels in nasal lavages after intranasal challenge with aspirin in aspirin intolerant (AIA) in comparison to aspirin tolerant (ATA) asthmatics and after allergen challenge in patients suffering from allergic rhinitis. METHODS: Twelve AIA, 8 ATA and 20 allergic patients were challenged with placebo, 16 mg of lysine-aspirin (Lys-ASA) or allergen (grasses). Nasal lavages were collected and eicosanoids' levels were determined using ELISA. RESULTS: Clinically positive Lys-ASA challenge in AIA resulted in influx of leukocytes (eosinophils and basophils) to nasal secretions and increase of LTC(4) to 106.82 pg/ml (P < 0.05 vs baseline (26.58 pg/ml)) on first hour after the challenge. We did not observe any differences in LTC(4) level before and after ASA challenge in ATA. In AIA group the mean level of LXA(4) was 43 +/- 21.5 pg/ml after placebo and decreased in 2 h after Lys-ASA challenge (29 +/- 17 pg/ml, P = 0.015). We found an increase in LXA(4) in ATA after ASA provocation as compared to placebo (33 +/- 16 pg/ml vs 52 +/- 31 pg/ml, P = 0.046). In atopic patients baseline level of LXA(4) was 33.49 +/- 16.95 pg/ml with no difference after the clinically positive allergen challenge (36.22 +/- 13.26 pg/ml, P = 0.23). CONCLUSIONS: Results of our study confirm that AIA have diminished LXs' biosynthesis capacities in vivo after ASA challenge. Taking into consideration anti-inflammatory properties of lipoxins this phenomenon may be partially responsible for the development of chronic inflammation in AIA patients.

A large germline deletion in the Chek2 kinase gene is associated with an increased risk of prostate cancer.

BACKGROUND: Germline mutations in the Chek2 kinase gene (CHEK2) have been associated with a range of cancer types. Recently, a large deletion of exons 9 and 10 of CHEK2 was identified in several unrelated patients with breast cancer of Czech or Slovak origin. The geographical and ethnic extent of this founder allele has not yet been determined. PARTICIPANTS AND METHODS: We assayed for the presence of this deletion, and of three other CHEK2 founder mutations, in 1864 patients with prostate cancer and 5496 controls from Poland. RESULTS: The deletion was detected in 24 of 5496 (0.4%) controls from the general population, and is the most common CHEK2 truncating founder allele in Polish patients. The deletion was identified in 15 of 1864 (0.8%) men with unselected prostate cancer (OR 1.9; 95% CI 0.97 to 3.5; p = 0.09) and in 4 of 249 men with familial prostate cancer (OR 3.7; 95% CI 1.3 to 10.8; p = 0.03). These ORs were similar to those associated with the other truncating mutations (IVS2+1G-->A, 1100delC). CONCLUSION: A large deletion of exons 9 and 10 of CHEK2 confers an increased risk of prostate cancer in Polish men. The del5395 founder deletion might be present in other Slavic populations, including Ukraine, Belarus, Russia, Baltic and Balkan countries. It will be of interest to see to what extent this deletion is responsible for the burden of prostate cancer in other populations.

Expression analysis of three miRNAs, miR-26a, miR-29b and miR-519d, in relation to MMP-2 expression level in non-small cell lung cancer patients: a pilot study.

Lung cancer is the most common cause of death in men and second only to breast cancer in women. MicroRNAs (miRNAs) are involved in tumorigenesis and function as oncogenes or tumor suppressor genes. Among other genes, miRNAs regulate matrix metalloproteinases (MMPs), the proteolytic enzymes playing a significant role in the degradation of extracellular matrix, enhancing tumor invasion and metastasis. The aim of the study was to evaluate the expression levels of selected miRNAs: miR-26a, miR-29b and miR-519d, and their target gene, matrix metalloproteinase-2 (MMP-2) in patients with non-small cell lung cancer (NSCLC). The results were correlated with tumor staging, NSCLC histopathological subtypes and patients' demographical features to assess the possible diagnostic/prognostic value of the studied miRNAs and MMP-2. Total RNA was isolated from 38 NSCLC tissue samples, and the expression analysis was performed using TaqMan(®) probes in qPCR assay. The results indicated underexpression of selected miRNAs and overexpression of MMP-2. The decrease in miRNA-29b expression was statistically significant and differentiated NSCLC histopathological subtypes. Additionally, statistically significant negative correlation was found between MMP-2 expression and its regulatory miR-26a. There are very few studies reporting miRNA-MMPs analysis on mRNA level in lung cancer, and no similar reports are available from Polish population. The results of our pilot study indicated the diagnostic potential of miR-29b and MMP-2, an inverse association between miR-26a and MMP-2, and proved the role of MMP-2 and the studied miRNAs in lung carcinogenesis. Further studies are needed to verify their potential usefulness for the treatment of lung cancer.

Naturally occurring mutations in human steroid 21-hydroxylase influence adrenal autoantibody binding.

Human 21-hydroxylase (21-OH) genes containing various mutations, truncations, and deletions were expressed in yeast, and autoantibody binding was studied by Western blotting using patient sera and rabbit antibodies to 21-OH. 21-OH autoantibodies in 13 Addisonian sera showed a marked reduction in their ability to recognize 21-OH mutated at Pro453-->Ser (mean +/- SD, 31 +/- 9% of binding to wild type), whereas the effect on rabbit antibody binding was small (88 +/- 11% of binding to wild type; n = 7). Mutation at Arg339-->His had a less pronounced effect on autoantibody binding (85 +/- 11% of binding to wild type; n = 13) and caused a small enhancement of rabbit antibody binding (124 +/- 16% of binding to wild type; n = 7). These studies indicate that Pro453 has a key role in forming an autoantigenic epitope on 21-OH. It is important to note, however, that the Pro453 mutation caused only partial loss of autoantibody binding, i.e. all Addisonian sera studied still reacted with the mutated protein. This may indicate that each serum sample contains at least two different populations of 21-OH autoantibodies, only one of which recognizes a site dependent on Pro453. A series of more extensive modifications of the 21-OH sequence, including truncations (amino acids 460-494, 448-494, and 418-494) and deletions (amino acids 165-379, 142-240, and 142-280) indicated that most of the sequence of amino acids from 241-494 is important for autoantibody binding. The involvement of such an extensive region of the molecule suggests that the binding sites are generated by three-dimensional folding, with Pro453 having a critical role in forming at least one major autoantigenic epitope.

Antioxidant properties of Ambroxol.

We tested whether Ambroxol, a drug which stimulates the release of surfactant by pneumocytes type II, may also possess antioxidant properties. To assess the reactivity of Ambroxol with reactive oxygen species, we analysed its ability to decompose hydrogen peroxide (H2O2) and to inhibit the superoxide (O2.-)-dependent autooxidation of pyrogallol, hydroxyl radical (.OH)-mediated deoxyribose oxidation, and hypochlorous acid (HClO-induced chlorination of monochlorodimedon. Ambroxol was found to be a sufficient scavenger of HClO and .OH and also revealed the capacity to decompose H2O2. At concentrations of 25 and 70 microM, it inhibited HClO-induced chlorination of monochlorodimedon by 22 +/- 13 and 59 +/- 14%, respectively. Similarly, at concentrations of 1, 2, and 10 mM, Ambroxol decreased .OH-mediated deoxyribose oxidation by 47 +/- 11, 75 +/- 9, and 89 +/- 4%. In addition, at concentrations of 1 to 5 mM, it completely protected linoleic acid from .OH-induced peroxidative damage. Ambroxol had a weak effect on O2.(-)-dependent autooxidation of pyrogallol. Our results indicate that Ambroxol has antioxidant activity, which may have clinical significance in protecting lung tissue from oxidant-induced injury.

Autoimmune Addison's disease. Analysis of autoantibody binding sites on human steroid 21-hydroxylase.

Human steroid 21-hydroxylase (21-OH) expressed in an in vitro translation system was found to react specifically with adrenal autoantibodies from patients with Addison's disease. The epitopes on 21-OH which reacted with autoantibodies were studied by incorporating a series of terminal and internal deletions into the 21-OH gene and analysing the expressed proteins by Western blotting. N-Terminal deletions up to amino acid 280 had no effect on autoantibody binding whereas a series of C-terminal deletions and truncations (amino acids 281-494) showed marked effects. Our results indicate that a central segment (281-379) and a C-terminal segment (380-494) of 21-OH interact to form at least one major autoantibody binding site.

Steroid 21-hydroxylase is a major autoantigen involved in adult onset autoimmune Addison's disease.

An adrenal-specific protein reacting with autoantibodies in the sera of patients with adult onset Addison's disease has been purified from human adrenal glands. The protein, mol.wt. 55K, has the biochemical characteristics of steroid 21-hydroxylase and reacts on Western blots with rabbit antibodies to recombinant 21-hydroxylase. Absorption of the native human 55K adrenal protein with human adrenal autoantibodies prevented the subsequent reaction of the 55K protein with rabbit antibodies to 21-hydroxylase in Western blot analysis. In addition, human adrenal autoantibodies reacted with recombinant 21-hydroxylase expressed in yeast. These data indicate that the adrenal specific enzyme steroid 21-hydroxylase is a major autoantigen involved in adult onset autoimmune Addison's disease.

Expression of human thyroid peroxidase in the yeasts Saccharomyces cerevisiae and Hansenula polymorpha.

Saccharomyces cerevisiae and the methylotrophic yeast Hansenula polymorpha have been used to express both full-length and a large hydrophilic domain of human thyroid peroxidase (TPO). Expression of TPO in S. cerevisiae, using the natural signal sequence or the yeast alpha-mating factor (MF alpha) signal sequence, resulted in undetectable or very low levels of recombinant TPO production. However, TPO was expressed when the natural TPO leader sequence was replaced by the yeast STE2 signal sequence. This recombinant TPO reacted with both rabbit anti-human TPO polyclonal and mouse anti-human TPO monoclonal antibodies on Western blots. In the case of H. polymorpha, TPO expression was achieved when the natural TPO leader sequence was replaced by the MF alpha leader and the construct placed under the control of the methanol-regulated promoter from the methanol oxidase gene. The recombinant TPO produced in H. polymorpha reacted with both TPO polyclonal and TPO monoclonal antibodies. No TPO was produced when the signal sequence of SUC2 (invertase) or the TPO natural signal sequence was used to direct expression.

Changes of intracellular free calcium concentration in human polymorphonuclear leukocytes after repeated stimulations with N-formyl-methionyl-leucyl-phenylalanine.

A rapid transient rise in the intracellular free calcium concentration ( Ca2+]i) is an important step in human polymorphonuclear leukocytes (PMNL) activation. This can be caused by many inflammatory mediators and has been implicated in the regulation of various cellular reactions. In this study we investigated the changes of [Ca2+]i in human PMNL activated three times with 10(-7)M n-formyl-methionyl-leucyl-phenylalanine (FMLP). PMNL in the presence of 1 mM Ca2+ were able to respond to three consecutive stimulations with FMLP. The first Ca2+ response was the highest one and was a result of Ca2+ release from internal stores (which was responsible for about 30% of maximal increment in [Ca2+]i) and the extracellular Ca2+ influx. Experiments with PMNL suspended in a medium containing 100 nM Ca2+ and pretreated with 1 nM Ni2+ (an inorganic calcium channel blocker) revealed that the second and third response is completely dependent on the extracellular Ca2+ influx. Changes of the time interval between stimulations had no influence on the occurrence of extracellular Ca2+ influx related to second addition of FMLP. Elongation of the time interval up to 30 min did not restore the release of Ca2+ from internal stores. It indicates the occurrence of dissociation of Ca2+ release from intracellular stores and extracellular Ca2+ influx during the second and third PMNL response to FMLP.

Hydrogen peroxide in expired air condensate correlates positively with early steps of peripheral neutrophil activation in asthmatic patients.

We have found an increased H2O2 level in expired air of asthmatic patients. Neutrophils from these subjects generated higher amounts of superoxide radicals after challenge with phorbol esters than those from healthy subjects which may result from an increased activity of NADPH-oxidase. The enhanced Ca2+ mobilisation in neutrophils from asthmatics could be responsible for increased production and subsequent elevated H2O2 concentration in expired breath condensate. In this study we wished to determine whether neutrophils of asthmatic patients have enhanced [Ca2+]i response after N-formyl-methionyl-leucyl-phenylalanine--fMLP challenge as compared with cells from healthy donors, and if so, does it correlate with H2O2 levels in expired air. We examined 21 patients, 10 healthy individuals as a control group (mean age 34.3 +/- 5.5, 6 males and 4 females) and 11 asthmatic subjects (mean age 38.2 +/- 7.2, 7 males and 4 females). The rise of [Ca2+]i as an early event of neutrophil activation, was measured spectrofluorimetically with Fura-2-AM. The mean H2O2 level, measured spectrofluorimetrically in the expired breath of asthmatics, was 20-fold higher than that in healthy control (0.18 +/- 0.20 vs. 0.01 +/- 0.04 microM, p < 0.05). [Ca2+]i increase after challenge by fMLP (delta [Ca2+]i) was much higher in asthmatics than in control group (205.0 +/- 44 vs. 113.0 +/- 22 nM, p < 0.05, respectively). A strong correlation was observed between H2O2 and delta [Ca2+]i and maximal velocity of increase in [Ca2+]i in asthmatics (r = 0.87, p < 0.01 and r = 0.64, p < 0.05). We conclude that elevated H2O2 level in the expired breath condensate of asthmatics can be generated by activated neutrophils in the course of mucosal inflammation observed in bronchial asthma.

Ascorbic acid enhances the decrease in peroxidase activity in inflamed tissues of mice.

The aim of this study was to explore whether intraperitoneal administration of ascorbic acid (AA) at a dose of 500 mg/kg, once a day for 3 following days, affected the peroxidase (PO) activity in inflamed feet of mice. The foot inflammatory reaction induced by the carrageenan (CAR), n-formyl-methionyl-leucyl-phenylalanine (FMLP) and xanthine-xanthine oxidase was accompanied by suppression of PO activity. Administration of AA, having no effect on the degree of foot oedema, skin temperature and microscopic picture of tissue specimens significantly enhanced the decline in PO activity provoked by inflammatory agents. This activity decreased 2.0-, 1.6- and 1.9-fold (p < 0.001, p < 0.01, p < 0.05) when inflammatory response was induced with FMLP, CAR and X-XO, respectively. Also in vitro AA (50-100 micrograms/ml) inhibited PO activity of leukocyte lysate and foot extract obtained from untreated animals. In conclusion we found that AA, having no effect on inflammatory response, significantly enhanced inhibition of PO activity in inflamed tissues in mice which could be a result of direct action of AA on the enzyme molecule.