Oxidase activity of ceruloplasmin and concentrations of copper and zinc in serum of cancer patients.

A balance between oxidant carcinogens and endogenous antioxidant defence is of particular relevance to the carcinogenesis. Ceruloplasmin (Cp) carries up to 90% of Cu in plasma and performs ferroxidase, antioxidant and amine oxidase activity. Cu and Zn, as trace elements, have been recognized to play an important role as cofactors of SOD. The study presents the relationship of the Cp oxidase activity and concentrations of Cu and Zn in serum of 62 patients with breast (BCA), lung (LCA), gastrointestinal (GICA) and gynecological (GYNCA) cancer. The Cp oxidase activity was determined in serum with o-dianisidine as a substrate. Cu and Zn concentrations in serum were measured by using atomic absorption spectrometry. The results of the study have shown significant increase in the mean serum Cp oxidase activity and total Cu concentrations in all patient groups compared with the control one. The total mean serum Zn concentration was found to be decreased only in LCA group as compared with the control. The effect of the cancer progress on the Cp oxidase activity and concentrations of Cu and Zn was observed within the group of all cancer patients (ALLCA) and within the GICA group. The only significant difference in Cu concentrations among various stages of the disease was observed in GICA between local and distant one. Significant positive correlation coefficients were caLculated for the Cp activity and Cu concentrations in the control group and all patients groups, also according to the cancer progress. Future research is needed to evaLuate the consequences of the elevation of the serum Cp oxidase activity and concentration of Cp, Cu and Zn for the host antioxidant-oxidant balance.     

Benchmarking the effects of operating system interference on extreme-scale parallel machines

We investigate operating system noise, which we identify as one of the main reasons for a lack of synchronicity in parallel applications. Using a microbenchmark, we measure the noise on several contemporary platforms and find that, even with a general-purpose operating system, noise can be limited if certain precautions are taken. We then inject artificially generated noise into a massively parallel system and measure its influence on the performance of collective operations. Our experiments indicate that on extreme-scale platforms, the performance is correlated with the largest interruption to the application, even if the probability of such an interruption on a single process is extremely small. We demonstrate that synchronizing the noise can significantly reduce its negative influence.

Synthesis and antimalarial activities of novel 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes

The oxidative system H2O2/fluorinated alcohol (TFE, HFIP) was used for direct acid- and MeReO3-catalyzed synthesis of 1,2,4,5-tetraoxanes from cyclic (C6, C7, and C12) and acyclic ketones. The influence of ring size and alkyl chain length were studied and antimalarial activities of synthetic 3,3,6,6-tetraalkyl-1,2,4,5-tetraoxanes were determined. Variations in their antimalarial activities were significant, although they share similar electrochemical properties of the peroxide bond.     

Listeria monocytogenes strains selected on ciprofloxacin or the disinfectant benzalkonium chloride exhibit reduced susceptibility to ciprofloxacin, gentamicin, benzalkonium chloride, and other toxic compounds

Listeria monocytogenes is a leading agent for severe food-borne illness and death in the United States and other nations. Even though drug resistance has not yet threatened therapeutic interventions for listeriosis, selective pressure associated with exposure to antibiotics and disinfectants may result in reduced susceptibility to these agents. In this study, selection of several L. monocytogenes strains on either ciprofloxacin (2 μg/ml) or the quaternary ammonium disinfectant benzalkonium chloride (BC; 10 μg/ml) led to derivatives with increased MICs not only to these agents but also to several other toxic compounds, including gentamicin, the dye ethidium bromide, and the chemotherapeutic drug tetraphenylphosphonium chloride. The spectrum of compounds to which these derivatives exhibited reduced susceptibility was the same regardless of whether they were selected on ciprofloxacin or on BC. Inclusion of strains harboring the large plasmid pLM80 revealed that MICs to ciprofloxacin and gentamicin did not differ between the parental and plasmid-cured strains. However, ciprofloxacin-selected derivatives of pLM80-harboring strains had higher MICs than those derived from the plasmid-cured strains. Susceptibility to the antimicrobials was partially restored in the presence of the potent efflux inhibitor reserpine. Taken together, these data suggest that mutations in efflux systems are responsible for the multidrug resistance phenotype of strains selected on ciprofloxacin or BC.     

Biochemical mechanisms of chromium action in the human and animal organism

Modern data concerning biologic characteristics of chromium (Cr3+) its placement in nature, accessibility and metabolic action of its different forms in humans and animals is presented in this survey. Essentiality of chromium for humans is emphasized, data about consumption norms of this microelement and its use for curing different diseases especially diabetes mellitus and atherosclerosis of vessels are presented. The biochemical mechanisms of Cr3+ effect on the metabolism in the human and animal organism are analyzed. It is shown that the organism reacts to chrome additions by the change of some metabolism links. Chrome influences positively growth and development of foetus, stimulates metabolism of glucose and insulin in the humans and animals. However, at the set chromium requirements it is necessary to take into account its low availability in food, high release of Cr3+ from the organism under the influence of stress factors, considerable decline of its level with age, and also in the period of pregnancy and lactation. Therefore experimental researches of introduction of Cr3+ additions to the diet of people and forage of animals taking into account their body mass, age and clinical state, can explain the biochemical mechanisms of biological action of this microelement.     

Importance of Central Vasomotor Effects in Angiotensin-induced Hypertension

Ablation of the areas postrema in 10 dogs caused a highly significant reduction in the pressor response to intravenous infusions of angiotensin yet was without significant effect on the pressor response to intravenous infusions of noradrenaline. The reduction in the pressor response to angiotensin is almost certainly due to abolition of the specific central autonomic effects of the hormone which are dependent on the integrity of the areas postrema. It is suggested that this central effect also contributes to the cardiovascular response to endogenous angiotensin.     

Purification and characterisation of a protease inhibitor from Streptomyces chromofuscus 34-1 with an antiviral activity

The aim of this study was to purify and characterise a novel protease inhibitor (PISC-2002) isolated from culture supernatants of Streptomyces chromofuscus. PISC-2002 was purified by anion-exchange chromatography, and RP-HPLC analysis. PISC-2002 had a molecular mass of 11.2 kDa and a high content of hydrophobic amino acids and proline. N-terminal sequence gave two sequences differing by one residue. The main sequence is ASLPAVSALVLTV and the shorter sequence is SLPAVSALVLTV. This shows its homology to Streptomyces subtilisin inhibitor family. Besides its large spectrum of powerful inhibitory activities against various serine proteases, PISC-2002 displayed significant antiviral effect against influenza virus A/Rostock/34 (H7N7).     

Purification and characterisation of a protease inhibitor from Streptomyces chromofuscus 34-1 with an antiviral activity

The aim of this study was to purify and characterise a novel protease inhibitor (PISC-2002) isolated from culture supernatants of Streptomyces chromofuscus. PISC-2002 was purified by anion-exchange chromatography, and RP-HPLC analysis. PISC-2002 had a molecular mass of 11.2 kDa and a high content of hydrophobic amino acids and proline. N-terminal sequence gave two sequences differing by one residue. The main sequence is ASLPAVSALVLTV and the shorter sequence is SLPAVSALVLTV. This shows its homology to Streptomyces subtilisin inhibitor family. Besides its large spectrum of powerful inhibitory activities against various serine proteases, PISC-2002 displayed significant antiviral effect against influenza virus A/Rostock/34 (H7N7).     

Comparing the folding free‐energy landscapes of Aβ42 variants with different aggregation properties

The properties of the amyloid‐β peptide that lead to aggregation associated with Alzheimer's disease are not fully understood. This study aims at identifying conformational differences among four variants of full‐length Aβ42 that are known to display very different aggregation properties. By extensive all‐atom Monte Carlo simulations, we find that a variety of β‐sheet structures with distinct turns are readily accessible for full‐length Aβ42. In the simulations, wild type (WT) Aβ42 preferentially populates two major classes of conformations, either extended with high β‐sheet content or more compact with lower β‐sheet content. The three mutations studied alter the balance between these classes. Strong mutational effects are observed in a region centered at residues 23–26, where WT Aβ42 tends to form a turn. The aggregation‐accelerating E22G mutation associated with early onset of Alzheimer's disease makes this turn region conformationally more diverse, whereas the aggregation‐decelerating F20E mutation has the reverse effect, and the E22G/I31E mutation reduces the turn population. Comparing results for the four Aβ42 variants, we identify specific conformational properties of residues 23–26 that might play a key role in aggregation. Proteins 2010. © 2010 Wiley‐Liss, Inc.     

The parasitoid Gonatopus bartletti reduces presence of plant-pathogenic Spiroplasma kunkelii within the leafhopper vector Dalbulus maidis

Homopteran vectors (e.g., leafhoppers) of plant pathogens are vessels for reproduction of cell wall‐free bacteria. These vectors also serve as hosts for larval parasitoid dipterans, hymenopterans, and strepsipterans. However, no study has explored the relationship among these wall‐free bacteria and parasitoid larvae within the insect host. We studied the corn stunt spiroplasma (CSS), Spiroplasma kunkelii Whitcomb (Mycoplasmatales: Spiroplasmataceae), a bacterium that originated from secondary symbionts that cause corn stunt disease in maize, Zea mays L., and its reproduction in the haemolymph of the corn leafhopper, Dalbulus maidis (Delong and Wolcott) (Homoptera: Cicadellidae). We also studied the dryinid parasitoid Gonatopus bartletti Olmi (Hymenoptera: Dryinidae), the larva of which feeds in the corn leafhopper haemolymph. Our results showed that when CSS and the wasp coexisted in D. maidis, the development of the parasitoid was not affected by S. kunkelii. Parasitoid development was successfully completed when leafhoppers acquired S. kunkelii before or after parasitism and when CSS had median (10 days) and long (20 days) incubation periods in the leafhopper before parasitization. The presence of S. kunkelii did not affect parasitoid development to the adult stage. However, polymerase chain reaction showed that the presence (survival) of S. kunkelii in the leafhopper was negatively affected by the parasitoid larva. Fewer leafhoppers had CSS before and after parasitization compared with leafhoppers that only acquired the CSS. This negative effect helps to explain the high parasitism rate by G. bartletti in D. maidis and the low presence of S. kunkelii in the corn leafhopper when CSS and the wasp parasitoid overlap throughout their geographic distribution. The parasitoid larva may negatively affect S. kunkelii by (1) producing antibacterial peptides that are toxic to CSS; (2) producing teratocytes that take nutrients from the host for larval development, but these nutrients are required by CSS; (3) affecting, indirectly, CSS through other symbiotic microorganisms; and (4) producing proteins with antibacterial activity that are present in the venom of the wasp parasitoid.