Role of Bax in quercetin-induced apoptosis in human prostate cancer cells

The aim of this study was to investigate the effect of quercetin, a flavonoid, on the apoptotic pathway in a human prostate cell line (LNCaP). We observed that treatment of cells for 24h with quercetin-induced cell death in a dose-dependent manner. A sustained inhibition of the major survival signal, Akt, occurred in quercetin-treated cells. Treatment of LNCaP cells with an apoptosis inducing concentration of quercetin (100 microM) resulted in a rapid decrease in the inhibitory Ser473 phosphorylation of Akt leading to inhibition of its kinase activity. Quercetin treatment (100 microM) also caused a decrease in Ser136 phosphorylation of Bad, which is a downstream target of Akt. Protein interaction assay revealed that during treatment with quercetin, Bcl-xL dissociated from Bax and then associated with Bad. Our results also show that quercetin decreases the Bcl-xL:Bax ratio and increases translocation and multimerization of Bax to the mitochondrial membrane. The translocation is accompanied by cytochrome c release, and procaspases-3, -8 and -9 cleavage and increased poly(ADP-ribose) polymerase (PARP) cleavage. Similar results were observed in human colon cancer HCT116Bax+/+ cell line, but not HCT116Bax-/- cell line. Interestingly, at similar concentrations (100 microM), quercetin treatment did not affect the viability or rate of apoptosis in normal human prostate epithelial cell line (PrEC) and rat prostate epithelial cell line (YPEN-1). Our results indicate that the apoptotic processes caused by quercetin are mediated by the dissociation of Bax from Bcl-xL and the activation of caspase families in human prostate cancer cells.     

Interactions Between the Prefrontal Cortex and Attentional Systems During Volitional Affective Regulation: An Effective Connectivity Reappraisal Study

Reappraisal is an emotion regulation strategy used to change reactions to emotion-related stimuli by reinterpreting their meaning. During down-regulation of negative emotions, wide areas of the prefrontal cortex (PFC) inhibit emotion-related brain areas such as the amygdala. Little is known, however, about how this control activity influences the earliest stages of affective responses by modulating perceptual and attentional areas. The aim of this study is to identify the connectivity patterns between the PFC and the core regions of two well-known attentional networks: the dorsal attentional network (which controls attention volitionally) and the ventral attentional network (which controls attention spontaneously) during reappraisal. We used a novel method to study emotional control processes: the directed transfer function, an autoregressive effective connectivity method based on Granger causality. It was applied to EEG recordings to quantify the direction and intensity of information flow during passively watching (control condition) or reappraising (experimental condition) negative film clips. Reappraisal was mostly associated with increased top-down influences from the right dorsolateral PFC over attentional and perceptual areas, reaching areas including dorsal attentional regions. The left dorsolateral PFC was associated with the activation of the ventral attentional network. Passively watching clips (control condition) resulted in increased flow from attentional areas to the left dorsolateral PFC, what is interpreted as a monitoring process. Thus, reappraisal seems to be related to both volitional and automatic control of attention, triggered by the right and left dorsolateral PFC respectively.     

Metallocene Catalyzed Polymerization of Ethylene in the Presence of Graphite, 1. Synthesis and Characterization of the Composites

Polyethylene/graphite composites have been prepared by two different methods. In a first approach, the ethylene polymerization has been catalyzed by metallocene in the presence of neat graphite particles (NGC composites). A second series of composites (TGC) has been prepared by the polymerization‐filling technique, which requires that the metallocene/methylalumoxane catalyst is fixed onto the graphite surface prior to the ethylene polymerization. The two series of composites exhibit significantly different morphology and thermal properties. The filler distribution is very heterogeneous in the NGC series. The morphology changes from an intimate mixture of PE and filler particles at low graphite content to graphite covered by patches of PE at high filler loading. The graphite distribution is much more homogeneous in the TGC samples, and the morphology consists of particles covered by a layer of PE in the whole composition range. Differences in the thermal properties are discussed in relation to the morphology.     

The impact of full-spectrum endoscopy on pathological lesion detection in different regions of the colon: a randomised,controlled trial

IntroductionColonoscopy is crucial for detecting and localising pathological lesions within the colon. Colonoscopy quality is defined by the caecal intubation rate, withdrawal time, adenoma detection rate, and polyp detection rate. The newly introduced full-spectrum endoscope (FUSE^®) provides a 330° field of view, allowing endoscopists to observe more colonic anatomy. It is intended to increase detection of pathological lesions, especially those situated behind the haustral folds of the bowel. This diagnostic modality should increase the adenoma detection rate (ADR), especially in the right hemicolon. The aim of this study was to explore the efficacy of FUSE for detecting pathologic lesions in different colonic regions.Material and methodsThe study enrolled 408 patients who were randomised to either a standard frontal view (SFV) or the novel full-spectrum colonoscopy. Analysis was performed among three broad regions of the colon: right, transverse, and left colon, according to the Boston Bowel Preparation Scale.ResultsFUSE yielded a higher diverticula detection rate (DDR) in the right and middle colon (DDR-R (p < 0.05), DDR-T (p < 0.05), DDR-L (p = 0.862)). ADR (p = 0.761), advanced ADR (aADR) (p = 0.950), and DDR (p = 0.967) in respective regions of the colon were similar between the groups; however, the total number of adenomas detected with FUSE was higher in the right and middle regions of the colon compared with those detected by SFV (p < 0.05).ConclusionsFull-spectrum colonoscopy allows for effective recognition of pathological lesions in the right and middle regions of the colon. Although full-spectrum colonoscopy did not statistically affect ADR, the absolute number of adenomas detected was higher compared with classical endoscopy.     

Migratory potential of transplanted glial progenitors as critical factor for successful translation of glia replacement therapy: The gap between mice and men

Neurological disorders are a major threat to public health. Stem cell‐based regenerative medicine is now a promising experimental paradigm for its treatment, as shown in pre‐clinical animal studies. Initial attempts have been on the replacement of neuronal cells only, but glial progenitors (GPs) are now becoming strong alternative cellular therapeutic candidates to replace oligodendrocytes and astrocytes as knowledge accumulates about their important emerging role in various disease processes. There are many examples of successful therapeutic outcomes for transplanted GPs in small animal models, but clinical translation has proved to be challenging due to the 1,000‐fold larger volume of the human brain compared to mice. Human GPs transplanted into the mouse brain migrate extensively and can induce global cell replacement, but a similar extent of migration in the human brain would only allow for local rather than global cell replacement. We review here the mechanisms that govern cell migration, which could potentially be exploited to enhance the migratory properties of GPs through cell engineering pre‐transplantation. We furthermore discuss the (dis)advantages of the various cell delivery routes that are available, with particular emphasis on intra‐arterial injection as the most suitable route for achieving global cell distribution in the larger brain. Now that therapeutic success has proven to be feasible in small animal models, future efforts will need to be directed to enhance global cell delivery and migration to make bench‐to‐bedside translation a reality.     

The bivalent ligand approach leads to highly potent and selective acylguanidine-type histamine H₂ receptor agonists

Bivalent histamine H(2) receptor (H(2)R) agonists were synthesized by connecting pharmacophoric 3-(2-amino-4-methylthiazol-5-yl)-, 3-(2-aminothiazol-5-yl)-, 3-(imidazol-4-yl)-, or 3-(1,2,4-triazol-5-yl)propylguanidine moieties by N(G)-acylation with alkanedioic acids of various chain lengths. The compounds were investigated for H(2)R agonism in GTPase and [(35)S]GTPγS binding assays at guinea pig (gp) and human (h) H(2)R-Gsα(S) fusion proteins including various H(2)R mutants, at the isolated gp right atrium, and in GTPase assays for activity on recombinant H(1), H(3), and H(4) receptors. The bivalent ligands are H(2)R partial or full agonists, up to 2 orders of magnitude more potent than monovalent acylguanidines and, with octanedioyl or decanedioyl spacers, up to 4000 times more potent than histamine at the gpH(2)R. In contrast to their imidazole analogues, the aminothiazoles are highly selective for H(2)R vs other HR subtypes. Compounds with (theoretically) sufficient spacer length (20 CH(2) groups) to simultaneously occupy two orthosteric binding sites in H(2)R dimers are nearly inactive, whereas the highest potency resides in compounds with considerably shorter spacers. Thus, there is no evidence for interaction with H(2)R dimers. The high agonistic potency may result from interaction with an accessory binding site at the same receptor protomer.     

Lack of association between CAG repeat polymorphism in the androgen receptor gene and the outcome of rheumatoid arthritis treatment with leflunomide

Purpose  

Leflunomide (LEF) is a disease-modifying antirheumatic drug used for treating rheumatoid arthritis (RA) and the action of which may be modified by sex hormones. The aim of this study was to examine the association between CAG repeat polymorphism in the androgen receptor (AR) gene and the response to treatment with LEF in women with RA.     

Routine use of CANTAB system for detection of neuropsychological deficits in patients with PKU

Several studies have reported neuropsychological deficits related to hyper phenylalaninemia in patients with phenylketonuria (PKU). As computerized neuropsychological tests seem to be promising in the detection of such abnormalities, we aimed to assess the usefulness of routine use of CANTAB system in PKU clinic. A group of 49 PKU patients aged >16 years were tested by means of computerized CANTAB tests measuring speed of response, response inhibition, sustained attention, and working memory capacity. The scores achieved by study participants were analyzed with respect to their blood phenylalanine concentrations. Proper dietary control was observed in 22 patients, whereas in the remaining 27 persons, blood phenylalanine concentrations exceeded the recommended range. The results of the tests assessing sustained attention, working memory, and inhibitory control achieved by the non-compliant patients were significantly worse in comparison with patients maintaining proper diet. However, the mean scores achieved by treatment-adherent patients were also worse than expected, what could probably be related to problems with early start of treatment during their infancy. Our results confirmed the presence of specific neuropsychological deficits related to hyperphenylalaninemia in adults and adolescents with PKU. In our opinion, routine use of computerized neuropsychological tests should be recommended in PKU clinics.     

DNA Methylation Assay for X-Chromosome Inactivation in Female Human iPS Cells

Remarkable interest in the epigenetic status of human induced pluripotent stem (iPS) cells inspired numerous studies of their X-inactivation patterns. However, both the presence and the absence of X-inactivation have been described to date in undifferentiated iPS cells. The reasons for the discordant results between different studies are unclear, and further X-inactivation testing is warranted for all female human iPS cell lines. Some of the inconsistency in the current data most likely results from the use of different X-inactivation assays by different authors. We provide a detailed protocol for a simple, reliable and affordable X-inactivation assay based on promoter methylation and CAG-repeat polymorphism in the human androgen receptor (AR) gene at Xq11.2. This assay is commonly used in clinical genetic laboratories and we propose that it could be ideal for routine assessment and monitoring of the X-inactivation status in female human iPS cell lines.