Modulation of monocyte–tumour cell interactions by <Emphasis Type="Italic">Mycobacterium vaccae</Emphasis>

Immunotherapy with Mycobacterium vaccae as an adjuvant to chemotherapy has recently been applied to treatment of patients with cancer. One of the mechanisms of antitumour activity of Mycobacterium bovis bacillus Calmette-Guérin (BCG), the prototype immunomodulator, is associated with activation of monocytes/macrophages. These studies were undertaken to determine how M. vaccae affects monocyte–tumour cell interactions and, in particular, whether it can prevent or reverse deactivation of monocytes that occurrs following their contact with tumour cells during coculture in vitro. Deactivation is characterised by the impaired ability of monocytes to produce tumour necrosis factor (TNF-), interleukin 12 (IL-12), and enhanced IL-10 secretion following their restimulation with tumour cells. To see whether deactivation of monocytes can be either prevented or reversed, three different strains of M. vaccae—B 3805, MB 3683, and SN 920—and BCG were used to stimulate monocytes before or after exposure to tumour cells. Pretreatment of monocytes with M. vaccae MB 3683, SN 920 and BCG before coculture resulted in increased TNF- and decreased IL-10 production. All strains of M. vaccae and BCG used for treatment of deactivated monocytes enhanced depressed TNF- secretion. Strain SN 920 and BCG increased IL-12 release but only BCG treatment inhibited an enhanced IL-10 production by deactivated monocytes. Thus, although some strains of M. vaccae may either prevent or reverse tumour-induced monocyte deactivation, none of them appears to be more effective than BCG.     

Determination of the stability constants and oxidation susceptibility of nickel(II) complexes with 2'-deoxyguanosine 5'-triphosphate and L-histidine

The formation of binary Ni(II) complexes with 2'-deoxyguanosine 5'-triphosphate (dGTP, L) as well as ternary complexes thereof with L-histidine (His, A) was studied with the use of potentiometry and electronic absorption spectroscopy. In the binary and ternary systems, the complexes with stoichiometries NiH2L-, NiHL2-, NiL3- and NiH2LA2-, NiHLA3-, NiLA4- respectively, were detected. The ternary complexes are very stable at pH 7.4 and thus may constitute biologically relevant Ni(II) carriers in the cell. In the presence of hydrogen peroxide, the binary and ternary systems both generate hydroxyl radical-like species and undergo dGTP degradation with the formation of the 8-oxo-dGTP intermediate. The latter, along with dGTP complexation and degradation, may lead to mutagenesis and carcinogenesis due to base-mispairing properties of 8-oxoguanine and the disturbance in the physiological balance among the four canonical triphosphodeoxynucleotide substrates for DNA synthesis.     

Comparison of antagonist activity of spantide family at human neurokinin receptors measured by aequorin luminescence-based functional calcium assay

Neurokinin receptors (NK1, NK2, NK3) are G-protein-coupled receptors, which upon activation by a peptide agonist induce a transient increase in the concentration of intracellular calcium. The functional assay based on aequorin-derived luminescence triggered by receptor-mediated changes in Ca2+ levels was used to compare the effect of spantides I-III on SP-, NKA- and NKB-stimulated NK1, NK2 and NK3 receptors, respectively. Recombinant cell lines expressing neurokinin receptors and apoaequorin were used in the study. The obtained results indicate that all three spantides acted as competitive antagonists at the NK1 and NK2 receptors and inhibited agonist-induced calcium responses. The rank order of antagonism at the NK1 receptor was spantide II>spantide III>spantide I and at the NK2 receptor was spantide III>spantide II>spantide I. All three spantides failed to antagonize NKB-induced calcium responses at the NK3 receptor.     

Adenine nucleotides and energy charge during dormancy breaking in embryo axes of <Emphasis Type="Italic">Acer platanoides</Emphasis> and <Emphasis Type="Italic">Fagus sylvatica</Emphasis> seeds

We analysed changes in AMP, ADP, and ATP concentrations and adenylate energy charge in Norway maple (Acer platanoides L.) and European beech (Fagus sylvatica L.) seeds during dormancy breaking (at 3 °C) and in the control variant at 15 °C. Values of the studied indicators in stratified beech seeds were generally higher at 15 °C, at least until germination (+3 °C). By contrast, in maple seeds, the values recorded during dormancy breaking by cold stratification were much higher than at 15 °C. Three peaks (usually in weeks 3, 6, and 8) were observed in maple seeds at 3 °C, but not at 15 °C. Among adenine nucleotides, AMP reached the highest levels in both species in both variants of the experiment.     

Role of hexagonal structure-forming lipids in diadinoxanthin and violaxanthin solubilization and de-epoxidation

In this study, we have examined the influence of different lipids on the solubility of the xanthophyll cycle pigments diadinoxanthin (Ddx) and violaxanthin (Vx) and on the efficiency of Ddx and Vx de-epoxidation by the enzymes Vx de-epoxidase (VDE) from wheat and Ddx de-epoxidase (DDE) from the diatom Cyclotella meneghiniana, respectively. Our results show that the lipids MGDG and PE are able to solubilize both xanthophyll cycle pigments in an aqueous medium. Substrate solubilization is essential for de-epoxidase activity, because in the absence of MGDG or PE Ddx and Vx are present in an aggregated form, with limited accessibility for DDE and VDE. Our results also show that the hexagonal structure-forming lipids MGDG and PE are able to solubilize Ddx and Vx at much lower lipid concentrations than bilayer-forming lipids DGDG and PC. We furthermore found that, in the presence of MGDG or PE, Ddx is much more solubilizable than Vx. This substantial difference in Ddx and Vx solubility directly affects the respective de-epoxidation reactions. Ddx de-epoxidation by the diatom DDE is saturated at much lower MGDG or PE concentrations than Vx de-epoxidation by the higher-plant VDE. Another important result of our study is that bilayer-forming lipids DGDG and PC are not able to induce efficient xanthophyll de-epoxidation. Even in the presence of high concentrations of DGDG or PC, where Ddx and Vx are completely solubilized, a strongly inhibited Ddx de-epoxidation is observed, while Vx de-epoxidation by VDE is completely absent. This indicates that the inverted hexagonal phase domains provided by lipid MGDG or PE are essential for de-epoxidase activity. We conclude that in the natural thylakoid membrane MGDG serves to solubilize the xanthophyll cycle pigments and furthermore provides inverted hexagonal structures associated with the membrane bilayer, which are essential for efficient xanthophyll de-epoxidase activity.     

Radioisotope therapy with somatostatin analogues in neuroendocrine tumours (case report)

Restricted number of neuroendocrine tumors (NET) shows overexpression of somatostatin receptors. Therefore, long-acting somatostatin analogues are used in diagnosis and treatment of those tumors. Here we present our first case of NET, localized in pancreas treated with DOTA-D-Phe 1-Tyr 3-octreotide (DOTATATE), for receptor-mediated radioisotope therapy. DOTATATE is a newly developed somatostatin analogue labeled with beta-emitter yttrium 90 (90Y) and beta, gamma-emitter lutetium 177 (177Lu). A 34-year old woman was suffering from several years gastrointestinal symptoms. NET of the pancreas with multiple metastases into the liver was diagnosed based on histopatological, biochemical and radiological tests. First, she had chemiotherapy (leucovorin, 5-FU, cisplatin), however there was any positive effects of this therapy. Next, she received four single doses of 90Y DOTATATE at 4-6- week intervals, yielding a cumulative dose of 7.4 GBq/m2. During the 4th cycle the Lu-177 DOTATATE was additionally administered. As a renal protection i.v. infusion of amino acid solution were used during the treatment sessions. To date, patient has shown partial remission with reduction of tumor masses. We observed spectacular clinical, biochemical and radiological improvement. Radioisotope therapy could be a powerful and promising method of treatment at least in patients who had no other treatment option.     

A theoretical study on effect of the initial redox state of cytochrome b559 on maximal chlorophyll fluorescence level (F(M)): implications for photoinhibition of photosystem II

In this work, we extended the reversible radical pair model which describes energy utilization and electron transfer up to the first quinone electron acceptor (Q(A)) in photosystem II (PSII), by redox reactions involving cytochrome (cyt) b559. In the model, cyt b559 accepts electrons from the reduced primary electron acceptor in PSII, pheophytin, and donates electrons to the oxidized primary electron donor in PSII (P680+). Theoretical simulations of chlorophyll fluorescence rise based on the model show that the maximal fluorescence, F(M), increases with an increasing amount of initially reduced cyt b559. In this work we applied, the first to our knowledge, metabolic control analysis (MCA) to a model of reactions in PSII. The MCA was used to determine to what extent the reactions occurring in the model control the F(M) level and how this control depends on the initial redox state of cyt b559. The simulations also revealed that increasing the amount of initially reduced cyt b559 could protect PSII against photoinhibition. Also experimental data, which might be used to validate our theory, are presented and discussed.     

Laser interferometric investigation of solute transport through membrane-concentration boundary layer system

We investigate diffusive transport in a membrane system with a horizontally mounted membrane under concentration polarization conditions performed by a laser interferometry method. The data obtained from two different theoretical models are compared to the experimental results of the substance flux. In the first model, the membrane is considered as infinitely thin, while in the second one as a wall of finite thickness. The theoretical calculations show sufficient correspondence with the experimental results. On the basis of interferometric measurements, the relative permeability coefficient (ζ_s) for the system, consisting of the membrane and concentration boundary layers, was also obtained. This coefficient reflects the concentration polarization of the membrane system. The obtained results indicate that the coefficient ζ_s of the membrane-concentration boundary layer system decreases in time and seems to be independent of the initial concentration of the solute.     

Synthesis of New Chiral Peptide Nucleic Acid (PNA) Monomers by a Simplified Reductive Animation Method

Abstract

The aim of this work was the preparation of four new peptide nucleic acid (PNA) monomer backbone by reductive animation of N^α-Boc-protected chiral amino aldehydes, derived from Leu, Phe, Tyr(Bzl), and Thr(Bzl), with methyl glycinate. To the crude 2-substituted methyl N-(2-Boc-aminoethyl)glycinates obtained, thymin-1-ylacetic acid was coupled using TBTU procedure in a one-pot reaction. PNA monomers were isolated and characterized.     

Correlation between airborne pollen incidence,skin prick tests and serum immunoglobulins in allergic people in cracowm,poland

Fifty patients suffering from pollen allergy were observed during the period 1988–1989. At the same airborne pollen content was examined using volumetric and gravimetric sampling methods.

The mean daily symptom scores and percentages of patients with symptoms of allergy during the pollen season correlated positively with the airborne pollen content of wild Gramincae and Cerealia (Secale cereale).

Skin prick test results and elevated levels of specific serum IgE confirmed the presence of allergy to these taxa in the patients observed. Allergy to tree pollen and herb pollen was confirmed in only 3 cases.

Elevated levels of specific serum IgE for Dactylis glomerata, Pltleum pratense, and Secale cereale appeared in 70–80% of patients. Specific serum IgE levels correlated more with skin prick reactions (especially with late phase reactions) than with total serum IgE levels. Airborne pollen concentrations evaluated by volumetric sampling (Burckard trap) ad by a gravimetric method differ in so many details, that their results are not comparable. However, both methods provide largely similar information about the presence of airborne pollen presence.