Electrochemical investigation of structurally varied azinium scaffolds.

Inspired by the successful utilization of aziniums as anolytes in redox-flow batteries, we have designed and prepared a systematically extended series of (di)azinium compounds based on pyrazine, bipyridine, 1,5-naphthyridine, 3,8-phenanthroline, (E)-4,4'-diazastilbene and 1,2-bis(pyridin-4-yl)acetylene. It has been revealed that the fundamental electrochemical properties are affected mostly by the water-solubility and chemical stability of the particular redox forms. Based on the systematically evolved azinium structure and gathered electrochemical data, structure-property relationships were thoroughly elucidated. Further investigation on flow battery cells identified that the known 4,4'-bipyridinium decorated with two peripheral N-propyl-3-sulfonato pendants allows utilizing both redox steps with good cycling stability, while the naphthyridine scaffold turned out to be a new and promising scaffold for redox-flow batteries.

Redox Property Tuning in Bipyridinium Salts.

Bipyridinium salts are currently very popular due to their perspective applications in redox flow batteries. Hence, we designed and prepared a series of bipyridiniums based on 2,2'-, 3,3'-, and 4,4'-bipyridine and 2,2'-bipyrimidine. The straightforward synthesis utilizes commercially or readily available starting compounds and their direct N-alkylation, mostly using 1,3-propanesultone. All eleven target derivatives with systematically evolved structure were investigated by cyclic voltammetry, which allowed elucidating thorough structure-property relationships. The electrochemical behavior depends primarily on the parent scaffold, type of N-alkylation, number of quaternized nitrogen atoms, planarity, counter ion as well as the used media. Two derivatives featuring quasi-reversible redox processes were further tested on rotating disc electrode and in a flow battery half-cell. 4,4'-Bipyridinium derivative bearing two sultone residues showed better performance and stability in the flow half-cell with small capacity decays of 0.09/0.15% per reduction-oxidation cycle, based on the number of the utilized redox processes (one/two).

A Novel Non-Immunoglobulin (non-Ig)/BCL6 Translocation in Diffuse Large B-Cell Lymphoma Involving Chromosome 10q11.21 Loci and Review on Clinical Consequences of BCL6 Rearrangements.

BCL6 rearrangements (3q27) are the most common chromosomal abnormalities in diffuse large B-cell lymphoma (DLBCL), with numerous immunoglobulin (Ig) and non-Ig genes as partners. In DLBCL, the translocations occur predominantly in the "major breakpoint region" encompassing the first noncoding exon and a part of the first intron of BCL6; few cases with "alternative breakpoint cluster" located 245-285 kb 5' BCL6 were also described. The regulatory sequences of known Ig and non-Ig partners replace the 5' untranslated region of the BCL6 in the same transcriptional orientation. Contrary to Ig/BCL6 fusions typical by high BCL6 gene expression, in non-Ig/BCL6 translocations were observed unexpectedly low BCL6 mRNA levels. From the clinical point of view, the survival rate of DLBCL patients with non-Ig partners is inferior to those with Ig/BCL6 translocations, suggesting that non-Ig/BCL6 fusion is a poor prognostic indicator. Hereby we provide comprehensive information about known non-Ig translocation partners and clinical consequences of BCL6 rearrangements in DLBCL. Moreover, we describe a novel reciprocal translocation t(3;10) in refractory patient with DLBCL with the breaking points at 5' untranslated region of BCL6 and 5' untranslated region of the RASGEF1A gene on chromosome 10q11.21 loci; this rearrangement was associated with low BCL6 and RASGEF1A gene expressions. Our patient harbouring dual chromosomal rearrangement involving BCL2 and BCL6 genes relapsed three-times and died soon; thus, further supporting the notion that non-Ig/BCL6 fusion is a poor prognostic indicator of DLBCL. There is evidence of prognostic value of BCL6 rearrangements also in rituximab era.

Altered astrocytic swelling in the cortex of α-syntrophin-negative GFAP/EGFP mice.

Brain edema accompanying ischemic or traumatic brain injuries, originates from a disruption of ionic/neurotransmitter homeostasis that leads to accumulation of K(+) and glutamate in the extracellular space. Their increased uptake, predominantly provided by astrocytes, is associated with water influx via aquaporin-4 (AQP4). As the removal of perivascular AQP4 via the deletion of α-syntrophin was shown to delay edema formation and K(+) clearance, we aimed to elucidate the impact of α-syntrophin knockout on volume changes in individual astrocytes in situ evoked by pathological stimuli using three dimensional confocal morphometry and changes in the extracellular space volume fraction (α) in situ and in vivo in the mouse cortex employing the real-time iontophoretic method. RT-qPCR profiling was used to reveal possible differences in the expression of ion channels/transporters that participate in maintaining ionic/neurotransmitter homeostasis. To visualize individual astrocytes in mice lacking α-syntrophin we crossbred GFAP/EGFP mice, in which the astrocytes are labeled by the enhanced green fluorescent protein under the human glial fibrillary acidic protein promoter, with α-syntrophin knockout mice. Three-dimensional confocal morphometry revealed that α-syntrophin deletion results in significantly smaller astrocyte swelling when induced by severe hypoosmotic stress, oxygen glucose deprivation (OGD) or 50 mM K(+). As for the mild stimuli, such as mild hypoosmotic or hyperosmotic stress or 10 mM K(+), α-syntrophin deletion had no effect on astrocyte swelling. Similarly, evaluation of relative α changes showed a significantly smaller decrease in α-syntrophin knockout mice only during severe pathological conditions, but not during mild stimuli. In summary, the deletion of α-syntrophin markedly alters astrocyte swelling during severe hypoosmotic stress, OGD or high K(+).

[Use of archival formalin-fixed, paraffin-embedded (FFPE) tissue samples for molecular genetic analysis in diffuse large B-cell lymphoma (DLBCL)]. / Vyuzití archivovaných parafínových blocku s formalinem fixovanou tkání (FFPE) pro molekulárne genetickou analýzu u difuzního velkobunecného lymfomu (DLBCL).

The currently valid molecular genetic subclassification of patients with diffuse large B-cell lymphoma (DLBCL) into three prognostic subgroups based on expression profiling has been the objective of numerous genetic studies. In routine clinical practice, however, expression profiling technology remains unavailable for the most of centers. Apart from the technology, in some cases molecular genetic laboratories have problems obtaining high-quality material, i.e. fresh tissues, for RNA isolation to determine gene expression. One possibility is to determine the gene expression from RNA obtained by isolation from formalin-fixed, paraffin-embedded (FFPE) tissue. This pilot study aimed at isolating RNA from FFPE in patients diagnosed with DLBCL and verifying the potential use of such RNA for the expression analysis of 7 selected genes. Although the study showed that it is possible to isolate RNA and determine the expression of the selected genes from archival material, the values of relative expression of some genes in the set were too variable to be used for unambiguous prognostic classification. It was confirmed that retrospective analyses of selected genes may be performed with sufficient material obtained, and that properly archived blocks may be used for molecular biology analyses even after 8 years.

The role of steroids in the development of post-partum mental disorders.

BACKGROUND: Unfavorable post-partum changes to mental well-being affect more than half of all women, and are a risk to the health of both mother and baby. Their effects place strains on health and social systems. Currently, no generally accepted theory exists of the causes and mechanisms of post-partum mental disorders. METHODS: Literature search up to 2012, using PubMed and search words: neuroactive steroids, post-partum mental disorders, depression, corticotropin-releasing hormone and estrogens. RESULTS: There are several theories for post-partum depression. One is that autoimmune diseases are involved. Others revolve around genes responsible or that lead to increased disposition to the disorder. It is likely however that the process is associated with the separation of the placenta and the fetal zone of fetal adrenal gland, the main sources of corticotropin-releasing hormone and sexual and neuroactive steroids during pregnancy, and the ability of the receptor system to adapt to these changes. The central nervous system is able to produce neurosteroids, but the drop in levels of peripheral steroids likely leads to a sudden deficit in neuroinhibitory steroids modulating ionotropic receptors in the brain. CONCLUSIONS: Post-partum depression is a multifactorial disease with unknown etiology. It is probably associated with sudden changes in the production of hormones influencing the nervous system, and on the other hand the ability of the receptor system to adapt to these changes. When the relative changes in concentrations of hormones, rather than their absolute levels, is likely more important.

Steroid profiling in pregnancy: a focus on the human fetus.

In this review we focused on steroid metabolomics in human fetuses and newborns and its role in the physiology and pathophysiology of human pregnancy and subsequent stages of human life, and on the physiological relevance of steroids influencing the nervous systems with regards to their concentrations in the fetus. Steroid profiling provides valuable data for the diagnostics of diseases related to altered steroidogenesis in the fetal and maternal compartments and placenta. We outlined a potential use of steroid metabolomics for the prediction of reproductive disorders, misbalance of hypothalamic-pituitary-adrenal axis, and impaired insulin sensitivity in subsequent stages of human life. A possible role of steroids exhibiting a non-genomic effect in the development of gestational diabetes and in the neuroprotection via negative modulation of AMPA/kainate receptors was also indicated. Increasing progesterone synthesis and catabolism, declining production of tocolytic 5ß-pregnane steroids, and rising activities of steroid sulfotransferases with the approaching term may be of importance in sustaining pregnancy. An increasing trend was demonstrated with advancing gestation toward the production of ketones (and 3ß-hydroxyl groups in the case of 3α-hydroxy-steroids) was demonstrated in the fetus on the expense of 3α-hydroxy-, 17ß-hydroxy-, and 20α-hydroxy-groups weakening in the sequence C17, C3, and C20. There was higher production of active progestogen but lower production of active estrogen and GABAergic steroids with the approaching term. Rising activities of placental CYP19A1 and oxidative isoforms of HSD17B, and of fetal CYP3A7 with advancing gestation may protect the fetus from hyperestrogenization. This article is part of a Special Issue entitled 'Pregnancy and Steroids'.