Inter-individual variability in Ca2+ signalling in platelets from healthy volunteers: effects of aspirin and relationship with expression of endomembrane Ca2+-ATPases

Increased Ca2+ signal generation may lead to hyperactivity of platelets and contribute to thrombotic complications. Using fura-2-loaded platelets from 51 healthy volunteers, high variability was detected in the Ca2+ responses evoked by the receptor agonists, thrombin and collagen, and the inhibitor of sarco/endoplasmic reticulum Ca2+-ATPases (SERCA), thapsigargin (Tg). Oral intake of 500mg aspirin reduced the magnitude of the Ca2+ responses, and lowered the intra-individual coefficients of variance of the responses by 50%. However, the corresponding inter-individual variance coefficients were only a little influenced by aspirin intake, pointing to subject-dependent factors in Ca2+ handling that are unrelated to thromboxane formation. With each agonist, 6-9% of the subjects had platelets with relatively high Ca2+ responses (> mean + SD) both before and after aspirin intake. In 90% (9/10) of these cases the high responsiveness was confirmed in platelets obtained 6-12 months later. The Tg- but not thrombin-induced Ca2+ responses correlated inversely with the expression levels of SERCA PL/IM 430 (SERCA-3b) in platelets. After aspirin intake, the Ca2+ responses with collagen but not thrombin correlated inversely with SERCA-2b expression. These results suggest that, in the absence of potentiating effects of thromboxane, (i) the amount of PL/IM 430-recognizable SERCA may control the Ca2+ signal when SERCA-2b is specifically inhibited (with Tg), and (ii) the expression of SERCA-2b determine the collagen- but not the thrombin-evoked Ca2+ signal. Accordingly, limited Ca2+-pumping activity by low expression of one of the SERCA isoforms is likely to be one of the factors resulting in increased platelet activity towards collagen or thapsigargin but not thrombin.     

Two-laboratory collaborative study on identification of mycobacteria: molecular versus phenotypic methods

Previous studies have indicated that the conventional tests used for the identification of mycobacteria may (i) frequently result in erroneous identification and (ii) underestimate the diversity within the genus Mycobacterium. To address this issue in a more systematic fashion, a study comparing phenotypic and molecular methods for the identification of mycobacteria was initiated. Focus was given to isolates which were difficult to identify to species level and which yielded inconclusive results by conventional tests performed under day-to-day routine laboratory conditions. Traditional methods included growth rate, colonial morphology, pigmentation, biochemical profiles, and gas-liquid chromatography of short-chain fatty acids. Molecular identification was done by PCR-mediated partial sequence analysis of the gene encoding the 16S rRNA. A total of 34 isolates was included in this study; 13 of the isolates corresponded to established species, and 21 isolates corresponded to previously uncharacterized taxa. For five isolates, phenotypic and molecular analyses gave identical results. For five isolates, minor discrepancies were present; four isolates remained unidentified after biochemical testing. For 20 isolates, major discrepancies between traditional and molecular typing methods were observed. Retrospective analysis of the data revealed that the discrepant results were without exception due to erroneous biochemical test results or interpretations. In particular, phenotypic identification schemes were compromised with regard to the recognition of previously undescribed taxa. We conclude that molecular typing by 16S rRNA sequence determination is not only more rapid (12 to 36 h versus 4 to 8 weeks) but also more accurate than traditional typing.     

3D human modeling from a single depth image dealing with self-occlusion

This paper presents a 2D to 3D conversion scheme to generate a 3D human model using a single depth image with several color images. In building a complete 3D model, no prior knowledge such as a pre-computed scene structure and photometric and geometric calibrations is required since the depth camera can directly acquire the calibrated geometric and color information in real time. The proposed method deals with a self-occlusion problem which often occurs in images captured by a monocular camera. When an image is obtained from a fixed view, it may not have data for a certain part of an object due to occlusion. The proposed method consists of following steps to resolve this problem. First, the noise in a depth image is reduced by using a series of image processing techniques. Second, a 3D mesh surface is constructed using the proposed depth image-based modeling method. Third, the occlusion problem is resolved by removing the unwanted triangles in the occlusion region and filling the corresponding hole. Finally, textures are extracted and mapped to the 3D surface of the model to provide photo-realistic appearance. Comparison results with the related work demonstrate the efficiency of our method in terms of visual quality and computation time. It can be utilized in creating 3D human models in many 3D applications.     

Design and Synthesis of a Novel PLK1 Inhibitor Scaffold Using a Hybridized 3D-QSAR Model

Polo-like kinase 1 (PLK1) plays an important role in cell cycle progression and proliferation in cancer cells. PLK1 also contributes to anticancer drug resistance and is a valuable target in anticancer therapeutics. To identify additional effective PLK1 inhibitors, we performed QSAR studies of two series of known PLK1 inhibitors and proposed a new structure based on a hybridized 3D-QSAR model. Given the hybridized 3D-QSAR models, we designed and synthesized 4-benzyloxy-1-(2-arylaminopyridin-4-yl)-1H-pyrazole-3-carboxamides, and we inspected its inhibitory activities to identify novel PLK1 inhibitors with decent potency and selectivity.     

Dynamics of Bacterial Community Structure in the Rhizosphere and Root Nodule of Soybean: Impacts of Growth Stages and Varieties

Bacterial communities in rhizosphere and root nodules have significant contributions to the growth and productivity of the soybean (Glycine max (L.) Merr.). In this report, we analyzed the physiological properties and dynamics of bacterial community structure in rhizosphere and root nodules at different growth stages using BioLog EcoPlate and high-throughput sequencing technology, respectively. The BioLog assay found that the metabolic capability of rhizosphere is in increasing trend in the growth of soybeans as compared to the bulk soil. As a result of the Illumina sequencing analysis, the microbial community structure of rhizosphere and root nodules was found to be influenced by the variety and growth stage of the soybean. At the phylum level, Actinobacteria were the most abundant in rhizosphere at all growth stages, followed by Alphaproteobacteria and Acidobacteria, and the phylum Bacteroidetes showed the greatest change. But, in the root nodules Alphaproteobacteria were dominant. The results of the OTU analysis exhibited the dominance of Bradyrhizobium during the entire stage of growth, but the ratio of non-rhizobial bacteria showed an increasing trend as the soybean growth progressed. These findings revealed that bacterial community in the rhizosphere and root nodules changed according to both the variety and growth stages of soybean in the field.     

Clinical Significance of Tumor Infiltrating Lymphocytes in Association with Hormone Receptor Expression Patterns in Epithelial Ovarian Cancer

Hormone receptor expression patterns often correlate with infiltration of specific lymphocytes in tumors. Specifically, the presence of specific tumor-infiltrating lymphocytes (TILs) with particular hormone receptor expression is reportedly associated with breast cancer, however, this has not been revealed in epithelial ovarian cancer (EOC). Therefore, we investigated the association between hormone receptor expression and TILs in EOC. Here we found that ERα, AR, and GR expression increased in EOC, while PR was significantly reduced and ERβ expression showed a reduced trend compared to normal epithelium. Cluster analysis indicated poor disease-free survival (DFS) in AR+/GR+/PR+ subgroup (triple dominant group); while the Cox proportional-hazards model highlighted the triple dominant group as an independent prognostic factor for DFS. In addition, significant upregulation of FoxP3+ TILs, PD-1, and PD-L1 was observed in the triple dominant group compared to other groups. NanoString analyses further suggested that tumor necrosis factor (TNF) and/or NF-κB signaling pathways were activated with significant upregulation of RELA, MAP3K5, TNFAIP3, BCL2L1, RIPK1, TRAF2, PARP1, and AKT1 in the triple dominant EOC group. The triple dominant subgroup correlates with poor prognosis in EOC. Moreover, the TNF and/or NF-κB signaling pathways may be responsible for hormone-mediated inhibition of the immune microenvironment.     

Induction of Tertiary Phase Epileptiform Discharges after Postasphyxial Infusion of a Toll-Like Receptor 7 Agonist in Preterm Fetal Sheep

Background: Toll-like receptor (TLR) agonists are key immunomodulatory factors that can markedly ameliorate or exacerbate hypoxic–ischemic brain injury. We recently demonstrated that central infusion of the TLR7 agonist Gardiquimod (GDQ) following asphyxia was highly neuroprotective after 3 days but not 7 days of recovery. We hypothesize that this apparent transient neuroprotection is associated with modulation of seizure-genic processes and hemodynamic control. Methods: Fetuses received sham asphyxia or asphyxia induced by umbilical cord occlusion (20.9 ± 0.5 min) and were monitored continuously for 7 days. GDQ 3.34 mg or vehicle were infused intracerebroventricularly from 1 to 4 h after asphyxia. Results: GDQ infusion was associated with sustained moderate hypertension that resolved after 72 h recovery. Electrophysiologically, GDQ infusion was associated with reduced number and burden of postasphyxial seizures in the first 18 h of recovery (p < 0.05). Subsequently, GDQ was associated with induction of slow rhythmic epileptiform discharges (EDs) from 72 to 96 h of recovery (p < 0.05 vs asphyxia + vehicle). The total burden of EDs was associated with reduced numbers of neurons in the caudate nucleus (r² = 0.61, p < 0.05) and CA1/2 hippocampal region (r² = 0.66, p < 0.05). Conclusion: These data demonstrate that TLR7 activation by GDQ modulated blood pressure and suppressed seizures in the early phase of postasphyxial recovery, with subsequent prolonged induction of epileptiform activity. Speculatively, this may reflect delayed loss of early protection or contribute to differential neuronal survival in subcortical regions.     

Synergistic Flame Retardant Effects of Carbon Nanotube-Based Multilayer Nanocoatings

In an effort to develop highly functionalized flame retardant materials, hybrid nanocoatings are prepared by alternately depositing a positively charged polyaniline (PANi) and negatively charged montmorillonite (MMT) using the layer-by-layer (LbL) assembly technique. Carbon nanotubes (CNTs) are employed in polymer nanocomposites as effective reinforcement, where nanotubes are stabilized in MMT aqueous solution. The 3D structure and high density of CNTs deposited in the PANi/CNTs-MMT multilayers produce thicker and heavier coatings in comparison to the LbL assemblies without CNTs. Vertical and horizontal flame testing show that the incorporation of CNTs improves fire resistance. Additionally, cone calorimetry reveals that stacking two nanomaterials (MMT and CNTs) in a single coating shows a significant reduction in peak heat release rate (up to 51%), total smoke release (up to 47%), and total heat release (up to 37%) for the polyurethane foam. The enhancement of flame retardancy is attributed to a synergistic effect; MMT serves as a physical barrier that retards the diffusion of heat and gas. The addition of CNTs strengthens the thermal stability and high char yield. These results, coupled with the simplicity with which the LbL deposition is applied, present a viable alternative to halogen-free flame retardant nanocoatings to natural and synthetic fibers.