Cellular and cytokine immunoregulation in patients with chronic obstructive pulmonary disease and bronchial asthma

BACKGROUND: Different forms of chronic airway inflammation may involve diverse pathogenic elements. In general, deficient defence response is a feature of chronic obstructive pulmonary disease (COPD), whereas distorted immunoregulatory mechanisms lead to development of asthmatic symptoms. In addition to diverse effector mechanisms, the cellular and humoral elements participating in the development of immune response may appear to be different in COPD and bronchial asthma (BA) patients. AIMS: To evaluate the immunoregulatory properties of T cells and monocytes in cultures of peripheral blood mononuclear cells (PBMC) and to determine the chosen cytokine profiles in COPD and BA patients. METHODS: The microcultures of PBMC from COPD and BA patients were assessed for the T-cell response to mitogens, saturation of interleukin (IL)-2 receptors, T-cell suppressive activity and monokine influence on lymphocyte proliferation. Concomitantly, the cytokine (IL-1beta, interleukin-1 receptor antagonist, tumour necrosis factor-alpha, IL-4, IL-6, IL-8) concentrations were determined in the serum, the broncho-alveolar lavage fluid and in the culture supernatants. RESULTS: The T-lymphocyte reactions (response to phytohaemagglutinin, IL-2 receptor saturation, suppressive activity) were lower in BA patients than in COPD patients. Reversely, the immunogenic activity of monocytes (IL-1beta versus IL-1ra production) was higher in BA patients than in COPD patients. The highest values of cytokine concentrations were found in the culture supernatants. The concentrations of tumour necrosis factor-alpha, IL-4, IL-6 and IL-8 were significantly higher and the concentration of IL-1ra was lower in BA patients than in COPD patients. CONCLUSION: The assessments of cellular immunoregulatory properties and cytokine profiles in the cultures of blood mononuclear cells may prove helpful for diagnostic and therapeutic discrimination between BA and COPD patients.     

Binding abilities of dehydropeptides towards Cu(II) and Ni(II) ions. Impact of Z-E isomerization on metal ion binding

The study on the binding ability of dehydro-tri- and tetrapeptides has shown that the ,β-double bond has a critical effect on the peptide coordination to metal ions. It may affect the binding of the vicinal amide nitrogens by the electronic effect and stabilize the complex due to steric effects. The (Z) isomer is the most effective in stabilizing of the complexes formed. The presence of large side chain in the dehydroamino acid residue may also be critical for the coordination mode in the metallopeptide systems.     

Investigation of catalytic reaction with spectrofluorimetric method

Numerous derivatives of nicotinic acid hydrazids are suitable for sensitive fluorescence determination of metal ions. The reaction proceeds upon ultraviolet illumination in the presence of an oxidizing agent and catalyst forming a fluorescent product. Therefore, the catalyst metal ion can be quantitatively determined by fluorescence methods. We have studied the reaction of nicotinic acid (di-pyridin-2-yl-methylene)-hydrazide (NADPMH), catalyzed by Mn(II)ion, and determined the optimal parameters of metal ion method.     

Future of melatonin as a therapeutic agent

Report of the round table conference summarizing the International Symposium on "Melatonin: Clinical Significance and Therapeutic Applications" is presented in this article. Some sleep disorders and circadian rhythm disturbances are the widely accepted indications for melatonin treatment. However, other possibilities for use of melatonin in the therapy should be also taken into account, including a co-treatment in cancer patients and free radical-related diseases. All aspects of the possible therapeutic use of melatonin as well as its safety, dosage, side effects and contraindications are discussed herein based on the round table conference and they are presented in this paper.     

Oncostatic action of melatonin: facts and question marks

The paper presents the data concerning the in vivo effects of melatonin on experimentally-induced tumors in animals and the in vitro effects on animal and human tumor cells. The majority of experimental tumors responded to the melatonin treatment with growth inhibition. However, some negative or opposite results (i.e. stimulation of tumor instead of inhibition) were also reported. Some of the negative results can be attributed to the improper timing of melatonin administration. Melatonin was also shown to inhibit the growth of several animal and human tumor cell lines in vitro. On the basis of these experiments, a hypothesis of the oncostatic action of melatonin was put forward. The mechanism of the postulated action is complex and probably includes: 1) modulation of the endocrine system; 2) modulation of the immune system; 3) the direct oncostatic action of melatonin on tumor cells. The latter includes the recently discovered anti-oxidative action which probably plays an important role in the countering the DNA damage during the radiation challenge or the exposure to chemical carcinogens. It also includes the antiproliferative and pro-apoptotic effects exerted via melatonin receptors expressed by tumor cells. The involvement of the membrane melatonin receptors is mainly assumed. However, the recent data from our and other laboratories suggest also the involvement of RZR/ROR receptors (the putative melatonin nuclear receptors) in both melatonin-induced proliferation inhibition and apoptosis.     

Photosynthetic Assimilation of Sun versus Shade Norway Spruce [Picea abies (L.) Karst] Needles Under the Long-Term Impact of Elevated CO2 Concentration

The long-term impact of elevated concentration of CO₂ on assimilation activity of sun-exposed (E) versus shaded (S) foliage was investigated in a Norway spruce stand [Picea abies (L.) Karst, age 14 years] after three years of cultivation in two domes with adjustable windows (DAW). One DAW was supplied with ambient air [AC, ca. 350 µmol(CO₂) mol^–1) and the second with elevated CO₂ concentration [EC = AC plus 350 µmol(CO₂) mol^–1]. The pronounced vertical profile of the photosynthetic photon flux density (PPFD) led to the typical differentiation of the photosynthetic apparatus between the shaded and sun needles. Namely, photon-saturated values of maximal net photosynthetic rate (P _Nmax) and apparent quantum yield () were significantly higher/lower for E-needles as compared with the S-ones. The prolonged exposure to EC was responsible for the apparent assimilatory activity stimulation observed mainly in deeply shaded needles. The degree of this stimulation decreases in the order: S-needles dense part > S-needles sparse part > E-needles dense part > E-needles sparse part. In exposed needles some signals on a manifestation of the acclimation depression of the photosynthetic activity were found. The long-term effect of EC was responsible for the decrease of nitrogen content of needles and for its smoother gradient between E- and S-needles. The obtained results indicate that the E- and S-foliage respond differently to the long-term impact of EC.     

Clonal growth in a species-rich grassland: Results of a 20-year fertilization experiment

We investigated the influence of fertilization on the abundance of species with different clonal growth characteristics using the data from a 20-year fertilization experiment from the Laelatu wooded meadow, in Estonia. The experiment comprised four different fertilization treatments and created a gradient of nitrogen availability. The vegetation composition was recorded every year by measuring the proportions of aboveground biomass for all species. For each species, four parameters of vegetative propagation were measured: speed of ramet vegetative mobility (annual increment of rhizome length), frequency of rhizome branching, placement of branches, and ramet life span. The weighted average of each parameter was calculated for each plot both at the beginning and at the end of the experiment using the relative abundances of the species in the plot as weights. The community changes resulting from the fertilization are reflected in the significant changes of the average values of all studied clonal growth parameters. Increased levels of phosphorus and potassium led to a community with an increased average vegetative mobility and rhizome branching. Both of these traits, however, declined with the increasing availability of nitrogen. The proportion of species with long-living ramets in the community decreased with the increase in the productivity irrespective of the fertilizer used. There was a strong positive correlation between the average ramet life span of the community and the number of species on the plot. We concluded that fertilization increased the ramet turnover rate in this meadow community and reduced species richness. Thus, our results contradict the prediction of a higher ramet turnover rate in species-rich compared to the species-poor grasslands.