An elemental correlation study in cancerous breast tissue by total reflection x-ray fluorescence

The total reflection x-ray fluorescence method (TRXRF) has been employed to determine of P, S, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Se, Rb, Sr, and Pb concentration in the benign breast tumor tissue from 68 women and in the cancerous breast tissue from 26 women. Concentrations of most of elements show enhancement in cancerous breast tissue. Examined elements compete for binding sites in the cell, change its enzymatic activity, and exert direct or indirect action on the carcinogenic process accelerating the growth of rumors. Inhibition of enzymatic activity caused by variation in trace element concentrations results in immunological breakdown of the body system. An attempt has been made to correlate measured trace element concentrations with the clinical stage of cancer. Physical bases of used analytical method, experimental setup, and the procedure of sample preparation are described.     

Effect of prolonged exercise on the level of triglycerides in the rat liver

This study examined the effect of prolonged exercise on the level of triglycerides (TG) in rat liver. The rats were divided into groups: 1-control, 2-treated with nicotinic acid, 3-fed with glucose during exercise, 4-fasted, 5-adrenalectomized, 6-adrenalectomized and fed with oil. In the control group, there was gradual accumulation of TG in the liver and their level was doubled at exhaustion as compared to the resting value. Nicotinic acid lowered the resting level of TG and prevented their accumulation during exercise. Administration of glucose during exercise partially prevented the increase in TG level in the liver. In rats fasted for 24 h before exercise, the net increase in liver TG level during exercise was similar to that in the controls. Adrenalectomy, like nicotinic acid, lowered TG level at rest and prevented its increase during exercise. Feeding the adrenalectomized rats with oil elevated the plasma free fatty acid level but did not result in accumulation of TG in the liver, either at rest or during exercise. It is concluded that prolonged exercise results in accumulation of TG in the liver and that the process depends on the supply of free fatty acids and glucose and requires the presence of glucocorticoids.     

Zinc Uptake into Synaptosomes

Zinc uptake was studied in synaptosomes, isolated by the Ficoll flotation technique, using the radiotracer 65Zn. True uptake of zinc could be discriminated from binding to the outside of the synaptosomes by the absence of accumulation at 0 degree C and the dependency of the rate of uptake on the medium osmolarity. The zinc uptake, studied in the presence of various zinc-complexing agents, showed saturation kinetics when analyzed in terms of [Zn]free, yielding Km = 0.25 microM. The zinc uptake was independent of both ATP and the Na+ gradient. No efflux of zinc could be demonstrated from preloaded synaptosomes due to the formation of insoluble zinc complexes inside the synaptosomes. The results are discussed in terms of the modulation of diverse neurochemical processes by zinc.     

Copy number variations of genes involved in stress responses reflect the redox state and DNA damage in brewing yeasts

The yeast strains of the Saccharomyces sensu stricto complex involved in beer production are a heterogeneous group whose genetic and genomic features are not adequately determined. Thus, the aim of the present study was to provide a genetic characterization of selected group of commercially available brewing yeasts both ale top-fermenting and lager bottom-fermenting strains. Molecular karyotyping revealed that the diversity of chromosome patterns and four strains with the most accented genetic variabilities were selected and subjected to genome-wide array-based comparative genomic hybridization (array-CGH) analysis. The differences in the gene copy number were found in five functional gene categories: (1) maltose metabolism and transport, (2) response to toxin, (3) siderophore transport, (4) cellular aldehyde metabolic process, and (5) L-iditol 2-dehydrogenase activity (p < 0.05). In the Saflager W-34/70 strain (Fermentis) with the most affected array-CGH profile, loss of aryl-alcohol dehydrogenase (AAD) gene dosage correlated with an imbalanced redox state, oxidative DNA damage and breaks, lower levels of nucleolar proteins Nop1 and Fob1, and diminished tolerance to fermentation-associated stress stimuli compared to other strains. We suggest that compromised stress response may not only promote oxidant-based changes in the nucleolus state that may affect fermentation performance but also provide novel directions for future strain improvement.     

Energy Metabolism in Rat Brain Synaptosomes from Nembutal-Anesthetized and Nonanesthetized Animals

Abstract: Cellular energetic parameters including the intramitochondrial and cytosolic [NAD⁺]/[NADH] ratios, the cellular [ATP]/[ADP][P_i and [creatine phosphate]/[creatine] ratios, the concentration of cytochrome c and its redox state and the respiratory rate were studied in suspensions of rat brain synapto-somes isolated from nembutal-anesthetized and nonanesthetized animals. The ratio of [3-hydroxybutyrate] to [acetoacetate] was 2.0 in synaptosomes isolated from nonanesthetized rats and 5.55 in those from anesthetized animals. The [lactate]/[pyruvate] ratio was 3.8 in the former and 10.9 in the latter preparation. The [ATP]/[ADP][P_i] was 3838 M⁻¹ in the synaptosomes from anesthetized rats and 840 M⁻¹ in those from nonanesthetized animals and the [creatine phosphate]/[creatine] ratios were 0.79 and 0.39, respectively. Cytochrome c was about 15% reduced in both preparations; however, the mitochon-drial cytochrome concentration was almost twofold higher in the synaptosomes from nonanesthetized animals. Calculations of the free energy relationships between the mitochondrial redox reactions and ATP synthesis showed that in synaptosomes isolated from the brains of nembutal-anesthetized rats the first two sites of oxidative phosphorylation were at near-equilibrium, in agreement with observations for intact cells and tissues. The energetic parameters for synaptosomes from anesthetized rats are very similar to the values for intact whole brain, whereas those for synaptosomes from nonanesthetized rats are lower and suggest that nembutal anesthesia protects against some irreversible damage to the synaptosome during isolation. It is concluded that synaptosomes isolated from brains of nembutal-anesthetized rats can be used as a convenient model system for studies of neuronal metabolism.     

Enhanced GABA release in cerebral cortical slices derived from rats with thioacetamide-induced hepatic encephalopathy

The release of newly loaded [³H]GABA was studied in slices of different brain regions derived from rats in which acute hepatic encephalopathy (HE) was induced with a hepatotoxin thioacetamide. HE increased both spontaneous and high (50 mM) ammonium chloride-evoked GABA release in cerebral cortical slices by 38% and 50%, respectively. No effects of HE were noted in cerebellar or striatal slices. An increased release of GABA in the cerebral cortex may contribute to the endogenous benzodiazepine-mediated enhancement of GABAergic tone, which is thought to be partly responsible for the pathophysiological mechanism of HE.     

Identification novel LQT syndrome-associated variants in Polish population and genotype-phenotype correlations in eight families

Congenital long QT syndrome (LQTS) is a primary cardiac channelopathy. Genetic testing has not only diagnostic but also prognostic and therapeutic implications. At present, 15 genes have been associated with the disease, with most mutations located in 3 major LQTS-susceptibility genes. During a routine genetic screening for KCNQ1, KCNH2 and SCN5A genes in index cases with LQTS, seven novel variants in KCNH2 and SCN5A genes were found. Genotype-phenotype correlations were analysed in these patients and their families. An open reading frame and splice site analysis of the exons was conducted using next-generation sequencing. In novel variants, phenotypes of carriers and their affected relatives were analysed. In 39 unrelated patients, 40 pathogenic/putative pathogenic mutations were found. Thirty-three of them, predominantly missense, were reported previously: 11 were in the KCNQ, 17 in the KCNH2 and 5 in the SCN5A gene. Seven novel missense variants were found in eight families. Among them, four variants were in typical for LQTS location. Two variants in the KCNH2 gene (p.D803Y and p.D46F) and one in the SCN5A gene (G1391R) were in amino acid (AA) position which up to present has not been reported in LQTS. Phenotype analysis showed the life-threatening course of the disease in index cases with a history of sudden cardiac death in six families. Mutation carriers presented with ECG abnormalities and some of them received beta-blocker therapy. We report three novel variants (KCNQ1 p.46, KCNH2 p.D803Y, SCN5A p.G1391R) which have never been reported for this AA location in LQTS; the phenotype-genotype correlation suggests their pathogenicity.     

Identification of novel small-molecule inhibitors of West Nile virus infection

West Nile virus (WNV) has spread throughout the United States and Canada and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to acute flaccid paralysis and lethal encephalitis. No therapy or vaccine is currently approved for use in humans. Using high-throughput screening assays that included a luciferase expressing WNV subgenomic replicon and an NS1 capture enzyme-linked immunosorbent assay, we evaluated a chemical library of over 80,000 compounds for their capacity to inhibit WNV replication. We identified 10 compounds with strong inhibitory activity against genetically diverse WNV and Kunjin virus isolates. Many of the inhibitory compounds belonged to a chemical family of secondary sulfonamides and have not been described previously to inhibit WNV or other related or unrelated viruses. Several of these compounds inhibited WNV infection in the submicromolar range, had selectivity indices of greater than 10, and inhibited replication of other flaviviruses, including dengue and yellow fever viruses. One of the most promising compounds, AP30451, specifically blocked translation of a yellow fever virus replicon but not a Sindbis virus replicon or an internal ribosome entry site containing mRNA. Overall, these compounds comprise a novel class of promising inhibitors for therapy against WNV and other flavivirus infections in humans.     

Relationships of new sibling species of Paramecium jenningsi based on sequences of the histone H4 gene fragment

Paramecium jenningsi Diller & Earl, 1958 belongs to the "aurelia" subgroup of the genus, together with Paramecium caudatum, Paramecium multimicronucleatum, Paramecium schewiakoffi and species of the Paramecium aurelia complex. The original assumption that the morphospecies P. jenningsi was a single genetic species was questioned because a comparison of genome analyses suggested the possibility that this morphospecies contained two sibling species. To refine understanding of relationships between the strains of P. jenningsi, a molecular phylogenetic analysis was conducted using H4 gene sequences. Some polymorphic sites were found among the compared sequences, and specific patterns of single nucleotide polymorphism (SNP) markers characterize two groups of strains of P. jenningsi. Phylogenetic trees constructed by different methods identified two clearly different groups (from Japan and mainland Asia) whatever the method used. The sequences of the H4 gene analyzed in the present study are closely related, and provide a good subject for phylogenetic analysis. The presence of two isolated groups of strains in the P. jenningsi group can reveal the evolutionary relationship between them; it confirms the presence of two sibling species among the known strains of P. jenningsi, and the close relationships between them and species of the P. aurelia complex.