Fixed-point smoothing in Hilbert spaces

The fixed-point smoothing estimator and smoothing error covariance operator equations are derived for infinite-dimensional linear systems using both the Wiener-Hoph theory in Hilbert spaces developed by Falb and the abstract evolution theory. Since it is clear that the prediction problems can be solved by the same approach, the present results in conjunction with the work of Falb on filtering give a complete treatment of the infinite-dimensional linear estimation problem from the viewpoint of Wiener-Hoph theory. Finally, based on the optimal smoothing estimator in Hilbert space, the fixed-point smoothing estimator is derived for a linear distributed parameter system of parabolic type

Precise determination of atom configuration in partially disordered spinel compounds by HARECSX.

Electron channeling enhanced x-ray spectroscopy has been being widely used to determine ordered arrangement of component atoms in multinary inorganic or metallic crystals. Recent theoretical advancements in the modeling of characteristic x-ray emission by inelastic scattering of incident electrons under dynamical diffraction conditions has achieved remarkable progress, and it has enabled scientists to analyze the experimental intensity of x-ray emission in precise detail. In this study, the ion configuration in magnesium aluminate spinel (MgO{center_dot}nAl{sub 2}O{sub 3}) has been examined by measurements of characteristic x-ray emission as a function of incident electron beam direction at high angular resolution, a technique which we have termed HARECXS (high angular resolution electron channeling x-ray spectroscopy). This paper reports the results and emphasizes the applicability of HARECXS to partially disordered materials

Amphiregulin activates human hepatic stellate cells and is upregulated in non alcoholic steatohepatitis

Amphiregulin (AR) involvement in liver fibrogenesis and hepatic stellate cells (HSC) regulation is under study. Non-alcoholic fatty liver disease (NAFLD) and its more severe form non-alcoholic steatohepatitis (NASH) may progress to cirrhosis and hepatocellular cancer (HCC). Our aim was to investigate ex vivo the effect of AR on human primary HSC (hHSC) and verify in vivo the relevance of AR in NAFLD fibrogenesis. hHSC isolated from healthy liver segments were analyzed for expression of AR and its activator, TNF- converting enzyme (TACE). AR induction of hHSC proliferation and matrix production was estimated in the presence of antagonists. AR involvement in fibrogenesis was also assessed in a mouse model of NASH and in humans with NASH. hHSC time dependently expressed AR and TACE. AR increased hHSC proliferation through several mitogenic signaling pathways such as EGFR, PI3K and p38. AR also induced marked upregulation of hHSC fibrogenic markers and reduced hHSC death. AR expression was enhanced in the HSC of a murine model of NASH and of severe human NASH. In conclusion, AR induces hHSC fibrogenic activity via multiple mitogenic signaling pathways, and is upregulated in murine and human NASH, suggesting that AR antagonists may be clinically useful anti-fibrotics in NAFLD

Toxic tau oligomer formation blocked by capping of cysteine residues with 1,2-dihydroxybenzene groups

Neurofibrillary tangles, composed of hyperphosphorylated tau fibrils, are a pathological hallmark of Alzheimer's disease; the neurofibrillary tangle load correlates strongly with clinical progression of the disease. A growing body of evidence indicates that tau oligomer formation precedes the appearance of neurofibrillary tangles and contributes to neuronal loss. Here we show that tau oligomer formation can be inhibited by compounds whose chemical backbone includes 1,2-dihydroxybenzene. Specifically, we demonstrate that 1,2-dihydroxybenzene-containing compounds bind to and cap cysteine residues of tau and prevent its aggregation by hindering interactions between tau molecules. Further, we show that orally administered DL-isoproterenol, an adrenergic receptor agonist whose skeleton includes 1,2-dihydroxybenzene and which penetrates the brain, reduces the levels of detergent-insoluble tau, neuronal loss and reverses neurofibrillary tangle-associated brain dysfunction. Thus, compounds that target the cysteine residues of tau may prove useful in halting the progression of Alzheimer's disease and other tauopathies

Calcified Plaques in Patients With Acute Coronary Syndromes

OBJECTIVES: This study conducted detailed analysis of calcified culprit plaques in patients with acute coronary syndromes (ACS). BACKGROUND: Calcified plaques as an underlying pathology in patients with ACS have not been systematically studied. METHODS: From 1,241 patients presenting with ACS who had undergone pre-intervention optical coherence tomography imaging, 157 (12.7%) patients were found to have a calcified plaque at the culprit lesion. Calcified plaque was defined as a plaque with superficial calcification at the culprit site without evidence of ruptured lipid plaque. RESULTS: Three distinct types were identified: eruptive calcified nodules, superficial calcific sheet, and calcified protrusion (prevalence of 25.5%, 67.4%, and 7.1%, respectively). Eruptive calcified nodules were frequently located in the right coronary arteries (44.4%), whereas superficial calcific sheet was most frequently found in the left anterior descending coronary arteries (68.4%) (p = 0.012). Calcification index (mean calcification arc × calcification length) was greatest in eruptive calcified nodules, followed by superficial calcific sheet, and smallest in calcified protrusion (median 3,284.9 [interquartile range (IQR): 2,113.3 to 5,385.3] vs. 1,644.3 [IQR: 1,012.4 to 3,058.7] vs. 472.5 [IQR: 176.7 to 865.2]; p < 0.001). The superficial calcific sheet group had the highest peak post-intervention creatine kinase values among the groups (eruptive calcified nodules vs. superficial calcific sheet vs. calcified protrusion: 241 [IQR: 116 to 612] IU/l vs. 834 [IQR: 141 to 3,394] IU/l vs. 745 [IQR: 69 to 1,984] IU/l; p = 0.032). CONCLUSIONS: Three distinct types of calcified culprit plaques are identified in patients with ACS. Superficial calcific sheet, which is frequently located in the left anterior descending coronary artery, is the most prevalent type and is also associated with greatest post-intervention myocardial damage. (Identification of Predictors for Coronary Plaque Erosion in Patients With Acute Coronary Syndrome; NCT03479723).status: publishe

Occurrence and impact of delayed cerebral ischemia after coiling and after clipping in the International Subarachnoid Aneurysm Trial (ISAT)

Delayed cerebral ischemia (DCI) is an important cause of poor outcome after aneurysmal subarachnoid hemorrhage (SAH). We studied differences in incidence and impact of DCI as defined clinically after coiling and after clipping in the International Subarachnoid Aneurysm Trial. We calculated odds ratios (OR) for DCI for clipping versus coiling with logistic regression analysis. With coiled patients without DCI as the reference group, we calculated ORs for poor outcome at 2 months and 1 year for coiled patients with DCI and for clipped patients without, and with DCI. With these ORs, we calculated relative excess risk due to Interaction (RERI). Clipping increased the risk of DCI compared to coiling in the 2,143 patients OR 1.24, 95% confidence interval (95% CI 1.01–1.51). Coiled patients with DCI, clipped patients without DCI, and clipped patients with DCI all had higher risks of poor outcome than coiled patients without DCI. Clipping and DCI showed no interaction for poor outcome at 2 months: RERI 0.12 (95% CI −1.16 to 1.40) or 1 year: RERI −0.48 (95% CI −1.69 to 0.74). Only for patients treated within 4 days, coiling and DCI was associated with a poorer outcome at 1 year than clipping and DCI (RERI −2.02, 95% CI −3.97 to −0.08). DCI was more common after clipping than after coiling in SAH patients in ISAT. Impact of DCI on poor outcome did not differ between clipped and coiled patients, except for patients treated within 4 days, in whom DCI resulted more often in poor outcome after coiling than after clipping

Dysregulation of autophagy and stress granule-related proteins in stress-driven Tau pathology

Imbalance of neuronal proteostasis associated with misfolding and aggregation of Tau protein is a common neurodegenerative feature in Alzheimer's disease (AD) and other Tauopathies. Consistent with suggestions that lifetime stress may be an important AD precipitating factor, we previously reported that environmental stress and high glucocorticoid (GC) levels induce accumulation of aggregated Tau; however, the molecular mechanisms for such process remain unclear. Herein, we monitor a novel interplay between RNA-binding proteins (RBPs) and autophagic machinery in the underlying mechanisms through which chronic stress and high GC levels impact on Tau proteostasis precipitating Tau aggregation. Using molecular, pharmacological and behavioral analysis, we demonstrate that chronic stress and high GC trigger mTOR-dependent inhibition of autophagy, leading to accumulation of Tau aggregates and cell death in P301L-Tau expressing mice and cells. In parallel, we found that environmental stress and GC disturb cellular homeostasis and trigger the insoluble accumulation of different RBPs, such as PABP, G3BP1, TIA-1, and FUS, shown to form stress granules (SGs) and Tau aggregation. Interestingly, an mTOR-driven pharmacological stimulation of autophagy attenuates the GC-driven accumulation of Tau and SG-related proteins as well as the related cell death, suggesting a critical interface between autophagy and the response of the SG-related protein in the neurodegenerative potential of chronic stress and GC. These studies provide novel insights into the RNA-protein intracellular signaling regulating the precipitating role of environmental stress and GC on Tau-driven brain pathology.We would like to thank Professor Juergen Gotz, (University of Queensland, Australia) for the kind offer of eGFP-P301LTau SH-SY5Y cells and Dr. Bruno Almeida for his technical assistance. J.M.S. was granted with a PhD fellowship (SRFH/BD/88932/2012) by Portuguese Foundation for Science & Technology (FCT); I.S. is holder of FCT Investigator grants (IF/01799/2013), C.D. is a recipient of PhD fellowship of PHDoc program and co-tutelle PhD student of UMinho-UPMC universities. This work was funded by FCT research grants "PTDC/SAU-NMC/113934/2009" (I.S.), the Portuguese North Regional Operational Program (ON. 2) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER) as well as the Project Estrategico co-funded by FCT (PEst-C/SAU/LA0026/2013) and the European Regional Development Fund COMPETE (FCOMP-01-0124-FEDER-037298) as well as the project NORTE-01-0145-FEDER000013, supported by the Northern Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). In addition, this work was partly funded by Canon Foundation in Europe. This work has been also funded by FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145FEDER-007038. This study was also supported to BW by grants from NIH (AG050471, NS089544, and ES020395), the BrightFocus Foundation, the Alzheimer Association and the Cure Alzeimer Foundation. Human brain tissue was generously provided by the National Institute of Aging Boston University AD Center (P30AG13846).info:eu-repo/semantics/publishedVersio

A genetic locus and gene expression patterns associated with the priming effect on lettuce seed germination at elevated temperatures

Seeds of most cultivated varieties of lettuce (Lactuca sativa L.) fail to germinate at warm temperatures (i.e., above 25–30°C). Seed priming (controlled hydration followed by drying) alleviates this thermoinhibition by increasing the maximum germination temperature. We conducted a quantitative trait locus (QTL) analysis of seed germination responses to priming using a recombinant inbred line (RIL) population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. Priming significantly increased the maximum germination temperature of the RIL population, and a single major QTL was responsible for 47% of the phenotypic variation due to priming. This QTL collocated with Htg6.1, a major QTL from UC96US23 associated with high temperature germination capacity. Seeds of three near-isogenic lines (NILs) carrying an Htg6.1 introgression from UC96US23 in a Salinas genetic background exhibited synergistic increases in maximum germination temperature in response to priming. LsNCED4, a gene encoding a key enzyme (9-cis-epoxycarotinoid dioxygenase) in the abscisic acid biosynthetic pathway, maps precisely with Htg6.1. Expression of LsNCED4 after imbibition for 24 h at high temperature was greater in non-primed seeds of Salinas, of a second cultivar (Titan) and of NILs containing Htg6.1 compared to primed seeds of the same genotypes. In contrast, expression of genes encoding regulated enzymes in the gibberellin and ethylene biosynthetic pathways (LsGA3ox1 and LsACS1, respectively) was enhanced by priming and suppressed by imbibition at elevated temperatures. Developmental and temperature regulation of hormonal biosynthetic pathways is associated with seed priming effects on germination temperature sensitivity

Hypoxia Potentiates Glioma-Mediated Immunosuppression

Glioblastoma multiforme (GBM) is a lethal cancer that exerts potent immune suppression. Hypoxia is a predominant feature of GBM, but it is unclear to the degree in which tumor hypoxia contributes to this tumor-mediated immunosuppression. Utilizing GBM associated cancer stem cells (gCSCs) as a treatment resistant population that has been shown to inhibit both innate and adaptive immune responses, we compared immunosuppressive properties under both normoxic and hypoxic conditions. Functional immunosuppression was characterized based on production of immunosuppressive cytokines and chemokines, the inhibition of T cell proliferation and effector responses, induction of FoxP3+ regulatory T cells, effect on macrophage phagocytosis, and skewing to the immunosuppressive M2 phenotype. We found that hypoxia potentiated the gCSC-mediated inhibition of T cell proliferation and activation and especially the induction of FoxP3+T cells, and further inhibited macrophage phagocytosis compared to normoxia condition. These immunosuppressive hypoxic effects were mediated by signal transducer and activator of transcription 3 (STAT3) and its transcriptionally regulated products such as hypoxia inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF). Inhibitors of STAT3 and HIF-1α down modulated the gCSCs' hypoxia-induced immunosuppressive effects. Thus, hypoxia further enhances GBM-mediated immunosuppression, which can be reversed with therapeutic inhibition of STAT3 and HIF-1α and also helps to reconcile the disparate findings that immune therapeutic approaches can be used successfully in model systems but have yet to achieve generalized successful responses in the vast majority of GBM patients by demonstrating the importance of the tumor hypoxic environment