Clinical application of mixed reality holographic imaging technology in scaling and root planing of severe periodontitis: a proof of concept.

OBJECTIVES: The aim of this paper was to demonstrate the potential application of mixed reality (MR) holographic imaging technology in subgingival scaling and root planing (SRP) for patient with advanced periodontitis. METHODS: This case series comprised the analysis of 1566 sites from 261 teeth of 10 patients with advanced periodontitis. Digital CBCT scans and intraoral scans of the patients were digitally acquired preoperatively and aligned to create a three-dimensional periodontal visualization model. Through rendering, interactive holographic images can be displayed using MR. The surgeon first used MR images to communicate with the patients, and then facilitated SRP under their guidance. Probing pocket depth (PPD), clinical attachment loss (CAL), Plaque index (PI), and bleeding on probing (BOP) parameters were recorded at baseline and at 8-week postoperatively. Patient-reported outcome indicator questionnaires on self-efficacy were also collected. RESULTS: PPD, CAL, PI, and BOP significantly decreased at 8-week following MR hologram-assisted SRP (p<0.001). For sites with PPD≥4 mm, PPD and CAL declined by 2.33±1.23 mm and 0.69±1.07 mm, respectively. PI significantly decreased from 1.94 ± 0.61 to 0.82 ± 0.58 (p < 0.001) and BOP sites decreased significantly from 84.11% to 40.25%. After receiving MR holograms for condition communication, most patients had a better perception of the effectiveness of SRP treatment and the benefits it brings. 80% of the subjects expressed their willingness to undergo MR-assisted periodontal treatment in the future. CONCLUSION: These results provide preliminary support for MR hologram-assisted digital SRP. With this technology, images of the gingiva and alveolar bone can be displayed in real time, accurately and three-dimensionally. This improves SRP effectiveness, diminishes complications, and enhances patients' confidence in the treatment. CLINICAL SIGNIFICANCE: MR holographic imaging-based digital SRP is a clinically feasible and promising adjunctive periodontal treatment option. It may contribute to improved non-surgical treatment efficacy in patients with severe periodontitis.

Improved Analysis of Cross-Linking Mass Spectrometry Data with Kojak 2.0, Advanced by Integration into the Trans-Proteomic Pipeline.

Fragmentation ion spectral analysis of chemically cross-linked proteins is an established technology in the proteomics research repertoire for determining protein interactions, spatial orientation, and structure. Here we present Kojak version 2.0, a major update to the original Kojak algorithm, which was developed to identify cross-linked peptides from fragment ion spectra using a database search approach. A substantially improved algorithm with updated scoring metrics, support for cleavable cross-linkers, and identification of cross-links between 15N-labeled homomultimers are among the newest features of Kojak 2.0 presented here. Kojak 2.0 is now integrated into the Trans-Proteomic Pipeline, enabling access to dozens of additional tools within that suite. In particular, the PeptideProphet and iProphet tools for validation of cross-links improve the sensitivity and accuracy of correct cross-link identifications at user-defined thresholds. These new features improve the versatility of the algorithm, enabling its use in a wider range of experimental designs and analysis pipelines. Kojak 2.0 remains open-source and multiplatform.

Analysis of functional surfaces on the actin nucleation promoting factor Dip1 required for Arp2/3 complex activation and endocytic actin network assembly.

Arp2/3 complex nucleates branched actin filaments that drive processes like endocytosis and lamellipodial protrusion. WISH/DIP/SPIN90 (WDS) proteins form a class of Arp2/3 complex activators or nucleation promoting factors (NPFs) that, unlike WASP family NPFs, activate Arp2/3 complex without requiring preformed actin filaments. Therefore, activation of Arp2/3 complex by WDS proteins is thought to produce the initial actin filaments that seed branching nucleation by WASP-bound Arp2/3 complexes. However, whether activation of Arp2/3 complex by WDS proteins is important for the initiation of branched actin assembly in cells has not been directly tested. Here, we used structure-based point mutations of the Schizosaccharomyces pombe WDS protein Dip1 to test the importance of its Arp2/3-activating activity in cells. Six of thirteen Dip1 mutants caused severe defects in Arp2/3 complex activation in vitro, and we found a strong correlation between the ability of mutants to activate Arp2/3 complex and to rescue endocytic actin assembly defects caused by deleting Dip1. These data support a model in which Dip1 activates Arp2/3 complex to produce actin filaments that initiate branched actin assembly at endocytic sites. Dip1 mutants that synergized with WASP in activating Arp2/3 complex in vitro showed milder defects in cells compared to those that did not, suggesting that in cells the two NPFs may coactivate Arp2/3 complex to initiate actin assembly. Finally, the mutational data reveal important complementary electrostatic contacts at the Dip1-Arp2/3 complex interface and corroborate the previously proposed wedge model, which describes how Dip1 binding triggers structural changes that activate Arp2/3 complex.

Competing stress-dependent oligomerization pathways regulate self-assembly of the periplasmic protease-chaperone DegP.

DegP is an oligomeric protein with dual protease and chaperone activity that regulates protein homeostasis and virulence factor trafficking in the periplasm of gram-negative bacteria. A number of oligomeric architectures adopted by DegP are thought to facilitate its function. For example, DegP can form a "resting" hexamer when not engaged to substrates, mitigating undesired proteolysis of cellular proteins. When bound to substrate proteins or lipid membranes, DegP has been shown to populate a variety of cage- or bowl-like oligomeric states that have increased proteolytic activity. Though a number of DegP's substrate-engaged structures have been robustly characterized, detailed mechanistic information underpinning its remarkable oligomeric plasticity and the corresponding interplay between these dynamics and biological function has remained elusive. Here, we have used a combination of hydrodynamics and NMR spectroscopy methodologies in combination with cryogenic electron microscopy to shed light on the apo-DegP self-assembly mechanism. We find that, in the absence of bound substrates, DegP populates an ensemble of oligomeric states, mediated by self-assembly of trimers, that are distinct from those observed in the presence of substrate. The oligomeric distribution is sensitive to solution ionic strength and temperature and is shifted toward larger oligomeric assemblies under physiological conditions. Substrate proteins may guide DegP toward canonical cage-like structures by binding to these preorganized oligomers, leading to changes in conformation. The properties of DegP self-assembly identified here suggest that apo-DegP can rapidly shift its oligomeric distribution in order to respond to a variety of biological insults.

Hyperresponsiveness of human gingival fibroblasts from patients with aggressive periodontitis against bacterial lipopolysaccharide.

The present study aimed to investigate whether gingival fibroblasts (GFs) of patients with aggressive periodontitis (AgP) are more sensitive to lipopolysaccharide (LPS) stimulation than GFs of control subjects. AgP causes rapid periodontal destruction, including the production of cytokines [i.e. interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α] and matrix metalloproteinases (MMP)-1, -3 and -9 in AgP GFs. LPS upregulates IL-1ß, IL-6, TNF-α, MMP-1, MMP-3, MMP-9 and mitochondrial reactive oxygen species (mtROS). Fibroblasts are known to be associated with immune responses to bacterial virulence factors, but the precise mechanisms underlying this severe periodontal disease are unclear. In the present study, primary human GFs of four patients with AgP and four healthy subjects were challenged in vitro with LPS from Porphyromonas gingivalis (P. gingivalis). The generation of mtROS in GFs was assessed using MitoSOX Red. The expression of genes encoding inflammatory cytokines and MMPs in GFs was analyzed using reverse transcription-quantitative polymerase chain reaction, and the expression of proteins was analyzed using ELISA and Western blotting. Human GFs of patients with AgP exhibited higher levels of mtROS, and higher mRNA and protein expression levels of proinflammatory cytokines, including IL-1ß, IL-6, MMP-1, MMP-3 and MMP-9 compared with healthy human GFs following stimulation with LPS from P. gingivalis. In the present study, it was demonstrated that GFs of patients with AgP display hyperreactivity when challenged with LPS.

Maize metacaspases modulate the defense response mediated by the NLR protein Rp1-D21 likely by affecting its subcellular localization.

Plants usually employ resistance (R) genes to defend against the infection of pathogens, and most R genes encode intracellular nucleotide-binding, leucine-rich repeat (NLR) proteins. The recognition between R proteins and their cognate pathogens often triggers a rapid localized cell death at the pathogen infection sites, termed the hypersensitive response (HR). Metacaspases (MCs) belong to a cysteine protease family, structurally related to metazoan caspases. MCs play crucial roles in plant immunity. However, the underlying molecular mechanism and the link between MCs and NLR-mediated HR are not clear. In this study, we systematically investigated the MC gene family in maize and identified 11 ZmMCs belonging to two types. Further functional analysis showed that the type I ZmMC1 and ZmMC2, but not the type II ZmMC9, suppress the HR-inducing activity of the autoactive NLR protein Rp1-D21 and of its N-terminal coiled-coil (CCD21 ) signaling domain when transiently expressed in Nicotiana benthamiana. ZmMC1 and ZmMC2 physically associate with CCD21 in vivo. We further showed that ZmMC1 and ZmMC2, but not ZmMC9, are predominantly localized in a punctate distribution in both N. benthamiana and maize (Zea mays) protoplasts. Furthermore, the co-expression of ZmMC1 and ZmMC2 with Rp1-D21 and CCD21 causes their re-distribution from being uniformly distributed in the nucleocytoplasm to a punctate distribution co-localizing with ZmMC1 and ZmMC2. We reveal a novel role of plant MCs in modulating the NLR-mediated defense response and derive a model to explain it.

Unfolding and Translocation of Proteins Through an Alpha-Hemolysin Nanopore by ClpXP.

Proteins present a significant challenge for nanopore-based sequence analysis. This is partly due to their stable tertiary structures that must be unfolded for linear translocation, and the absence of regular charge density. To address these challenges, here we describe how ClpXP, an ATP-dependent protein unfoldase, can be harnessed to unfold and processively translocate multi-domain protein substrates through an alpha-hemolysin nanopore sensor. This process results in ionic current patterns that are diagnostic of protein sequence and structure at the single-molecule level.

Biomarkers in Metabolic Syndrome Patients with Chronic Periodontitis.

OBJECTIVES: To investigate whether the levels of serum C-reactive protein (CRP), salivary interleukin (IL)-6 and IL-lß in metabolic syndrome (MS) patients can be potential monitors for inflammation in MS patients with severe periodontitis. METHODS: A total of 114 MS patients and 49 systemically healthy subjects were enrolled. CRP in serum and IL-1ß and IL-6 in non-stimulated whole saliva were collected from these patients and subjects and analysed by enzyme-linked immunosorbent assay (ELISA). Dental examinations were performed and the participants completed a questionnaire. RESULTS: The serum CRP level of MS patients was higher than that of systemically healthy subjects, and increased as the number of components increased (P < 0.05). No difference was observed in the salivary level of IL-6 and IL-1ß between MS patients and controls or between MS patients with different components. The level of salivary IL-6 in MS patients with moderate/severe periodontitis was significantly higher than in MS patients with good periodontal health/mild periodontitis (P < 0.05). After adjustment for age, sex and smoking habits, multivariate analysis showed that the corresponding odds ratio (OR) for MS combined with moderate/severe periodontitis was 1.21 (95% confidence interval [CI] 1.04-1.39, P = 0.012) for subjects with high serum CRP and salivary IL-6 and IL-1ß were not risk indicators for MS combined with moderate/severe periodontitis. CONCLUSIONS: MS patients might be burdened by high levels of serum CRP. Serum CRP could be a potentially valuable biomarker to detect inflammation in MS patients with severe periodontal disease.

[Changes of chilling and heat accumulation of apple and their effects on the first flowering date in the main planting areas of northern China]. / ä¸­å›½åŒ—æ–¹ä¸»äº§åœ°è‹¹æžœå†·çƒ­ç§¯ç´¯å˜åŒ–åŠå ¶å¯¹å§‹èŠ±æœŸçš„å½±å“.

Studies on variations in chilling and heat accumulation in apple trees and their effects on first flowering date under climate change are important for guiding apple planting and productions. In this study, we carried out experiments in representative stations of apple planting areas in the northern China, including Fushan of Shandong, Wanrong of Shanxi, Xifeng of Gansu and Akesu of Xinjiang. The first flowering data and hourly temperature data during 1996-2018 were used to calculate the daily chilling and heat accumulation units by applying the dynamic model and growing degree hour model. Partial least squares regression (PLS) correlated daily chilling and heat units with the first flowering dates was used to identify the chilling and heat accumulation periods for apple flowering. We evaluated the impacts of temperatures during these periods on apples' flowering. Our results showed that the chilling accumulation period of apple trees in the examined sites started at October 1, ended in late February or mid-March, with chilling accumulations of 74.1-89.3 CP (chill portion). The heat accumulation periods were from late January to the first flowering dates with the heat accumulation of 4010-5770 GDH (growing degree hour). The chilling accumulation at Xifeng and Akesu was correlated positively with mean temperature during the respective accumulation period, with 3.8 and 5.0 CP enhancement following 1 ℃ increase during the accumulation period. Heat accumulation at all stations correlated positively with mean temperature during the respective accumulation period, with 725-967 GDH enhancement following a 1 ℃ increase during the accumulation period. Compared to the effects of chilling accumulation on tree flowering, the first flowering data of apples in the main planting areas were mainly affected by mean temperature during the heat accumulation period. Climate warming is beneficial for apple blossom and production in the areas with low mean temperature during the chilling accumulation period.

[Phenological responses of apple tree to climate warming in the main apple production areas in northern China]. / 中国北方苹果主产地苹果物候期对气候变暖的响应.

To reveal the spatio-temporal variation characteristics of apple's phenology and their critical response time period and intensity to the temperature change in the main production areas of northern China, we chose Fushan, Wanrong and Akesu to respresent the Bohai Gulf, the Loess Plateau and Xinjiang apple production areas, respectively. Apple's phenology data of buds opening (BO), first leaf unfolding (LU), first flowering (FF), fruit maturing (FM), end of leaf coloring (LC) and the end of leaf fall (LF) at the three stations during 1996-2018 were used to analyze the changes of phenological occurrence dates and different growth stage lengths. Partial least squares (PLS) regression was applied to identify the impacts of climate warming on different phenology events at daily resolution. Results showed that regional mean occurrence dates of apple's BO, LU and FF advanced by a rate of 0.36, 0.33 and 0.23 day per year, respectively. However, apple's LF postponed by 0.68 d·a-1. The FM and LC showed different trends among all the sites. The length of fruit growing period (FG) and that of tree growing period (TG) extended at average rates of 1.20 and 0.82 day per year. Apple's spring phenophases dates at all stations correlated negatively with mean temperature during early January to pre-phenophases date, with a 1 ℃ increase inducing an advancement of 3.70, 3.47 and 3.48 days for apple's BO, LU and FF, respectively. In contrast, apple's autumn phenophases correlated positively with mean temperature 21-72 days before the phenophases date, and its correlation with mean temperature was lower than the correlation for spring phenophases. Generally, the effect of temperature on spring phenophase was stronger than that of autumn phenophase, and the extension of FG and TG was mainly caused by the advance of spring phenophase. The responses of apple's phenophases to climate warming differed across all the stations. Temperature had the greatest impact on the development of apple industry in Akesu, less in Wanrong, and with the least influence in Fushan. Our results could provide theoretical basis for response to climate change for apple industry in different areas of China.

The association of outdoor temperature with blood pressure, and its influence on future cardio-cerebrovascular disease risk in cold areas.

OBJECTIVES: To explore whether lower outdoor temperature increases cardio-cerebrovascular disease risk through regulating blood pressure and whether indoor heating in winter is beneficial to prevent cardio-cerebrovascular disease in cold areas. METHODS: We analyzed the data of 38 589 participants in Harbin from the China Kadoorie Biobank (CKB) during 2004-2008, with an average of 7.14-year follow-up. Linear regression analysis was performed to estimate the relationship between outdoor temperature and blood pressure. Cox regression analysis and logistic regression analysis were used to analyze the association of blood pressure with cardio-cerebrovascular event risk. Mediation analysis was performed to explore the role of blood pressure in the association between outdoor temperature and cardio-cerebrovascular events risk. RESULTS: There was an increase of 6.7 mmHg in SBP and 2.1 mmHg in DBP for each 10 °C decrease in outdoor temperature when outdoor temperature was higher than 5 °C. There was an inverse association between outdoor temperature and cardio-cerebrovascular event morbidity. The increases in blood pressure and cardio-cerebrovascular event morbidity were attenuated in months when central heating was fully provided. Participants with hypertension have higher risks of cardio-cerebrovascular disease (hazard ratio 1.347; 95% CI 1.281--1.415), CVD (hazard ratio 1.347; 95% CI 1.282--1.416), MACE (hazard ratio 1.670; 95% CI 1.560--1.788) and stroke (hazard ratio 1.683; 95% CI 1.571--1.803). Mediation analysis demonstrated that the association between outdoor temperature and cardio-cerebrovascular events risk was potentially mediated by blood pressure. CONCLUSION: Temperature-driven blood pressure potentially mediates the association between outdoor temperature and cardio-cerebrovascular events risk. Indoor heating in winter is probably beneficial to cardio-cerebrovascular disease prevention by inhibition of blood pressure increase.

[Spicy food intake increases the risk of overweight and obesity].

OBJECTIVE: To explore the relationship between spicy food intake and overweight or obesity in the population, and provide theoretical basis for dietary prevention of obesity. METHODS: The data of this study was collected from the cross-sectional population of China Kadoorie Biobank(CKB) in Harbin from 2004 to 2008. A cluster random sampling method was used to select 57 555 subjects aged 30-79(23 254 males and 34 301 females). Demographic information and habits information such as smoking and drinking were obtained by face-to-face questionnaires. Food frequency questionnaires were used to obtain information on various foods including spicy food intake. Physical examination was used to obtain indicators of height and weight. Logistic regression method was used to analyze the influence of spicy food intake and its interaction with predilection for meat/vegetarian diet on the risk of overweight and obesity. RESULTS: Compared with people who intake spicy foods with low frequency, the risk of overweight and obesity in people with a high frequency of intake spicy foods increased by 29%(OR=1.285, 95%CI 1.251-1.319, P<0.001) in males and 33%(OR=1.329, 95%CI 1.294-1.364, P<0.001) in females. Compared with the people who intake spicy food with a slightly intensity, the risk of overweight and obesity in males and females with a extremely intensity of intake spicy foods increased by 20%(OR=1.198, 95%CI 1.137-1.259, P=0.011) and 19%(OR=1.194, 95%CI 1.141-1.247, P=0.003), respectively. In the male population, the risk of overweight and obesity was the highest among those who preferred meat and had high frequency and degree of spicy food intake. There was an interaction between meat/vegetarian preference and spicy food intake(P<0.001). CONCLUSION: Intake spicy food can increase the risk of overweight and obesity, while reducing the intake of spicy foods and meats can be more effective in prevent overweight and obesity.

Endothelial cell-specific anticoagulation reduces inflammation in a mouse model of acute lung injury.

Tissue factor (TF)-dependent coagulation contributes to lung inflammation and the pathogenesis of acute lung injury (ALI). In this study, we explored the roles of targeted endothelial anticoagulation in ALI using two strains of transgenic mice expressing either a membrane-tethered human tissue factor pathway inhibitor (hTFPI) or hirudin fusion protein on CD31+ cells, including vascular endothelial cells (ECs). ALI was induced by intratracheal injection of LPS, and after 24 h the expression of TF and protease-activated receptors (PARs) on EC in lungs were assessed, alongside the extent of inflammation and injury. The expression of TF and PARs on the EC in lungs was upregulated after ALI. In the two strains of transgenic mice, expression of either of hTFPI or hirudin by EC was associated with significant reduction of inflammation, as assessed by the extent of leukocyte infiltration or the levels of proinflammatory cytokines, and promoted survival after LPS-induced ALI. The beneficial outcomes were associated with inhibition of the expression of chemokine CCL2 in lung tissues. The protection observed in the CD31-TFPI-transgenic strain was abolished by injection of an anti-hTFPI antibody, but not by prior engraftment of the transgenic strains with WT bone marrow, confirming that the changes observed were a specific transgenic expression of anticoagulants by EC. These results demonstrate that the inflammation in ALI is TF and thrombin dependent, and that expression of anticoagulants by EC significantly inhibits the development of ALI via repression of leukocyte infiltration, most likely via inhibition of chemokine gradients. These data enhance our understanding of the pathology of ALI and suggest a novel therapeutic strategy for treatment.

Author Correction: Eosinophil differentiation in the bone marrow is promoted by protein tyrosine phosphatase SHP2.

Since the publication of the article, the authors became aware that Figs. 1c, 5k and 6m contained errors in representative image and PAS score in control groups. The corrected Figs. 1c, 5k, and 6m are given below, and the figure legends are the same as original.

Aerosolized antibiotics for ventilator-associated pneumonia: a pairwise and Bayesian network meta-analysis.

BACKGROUND: Aerosolized antibiotics have been proposed as a novel and promising treatment option for the treatment of ventilator-associated pneumonia (VAP). However, the optimum aerosolized antibiotics for VAP remain uncertain. METHODS: We included studies from two systematic reviews and searched PubMed, EMBASE, and Cochrane databases for other studies. Eligible studies included randomized controlled trials and observational studies. Extracted data were analyzed by pairwise and network meta-analysis. RESULTS: Eight observational and eight randomized studies were identified for this analysis. By pairwise meta-analysis using intravenous antibiotics as the reference, patients treated with aerosolized antibiotics were associated with significantly higher rates of clinical recovery (risk ratio (RR) 1.21, 95% confidence interval (CI) 1.09-1.34; P = 0.001) and microbiological eradication (RR 1.42, 95% CI 1.22-1.650; P < 0.0001). There were no significant differences in the risks of mortality (RR 0.88, 95% CI 0.74-1.04; P = 0.127) or nephrotoxicity (RR 1.00, 95% CI 0.72-1.39; P = 0.995). Using network meta-analysis, clinical recovery benefits were seen only with aerosolized tobramycin and colistin (especially tobramycin), and microbiological eradication benefits were seen only with colistin. Aerosolized tobramycin was also associated with significantly lower mortality when compared with aerosolized amikacin and colistin and intravenous antibiotics. The assessment of rank probabilities indicated aerosolized tobramycin presented the greatest likelihood of having benefits for clinical recovery and mortality, and aerosolized colistin presented the best benefits for microbiological eradication. CONCLUSIONS: Aerosolized antibiotics appear to be a useful treatment for VAP with respect to clinical recovery and microbiological eradication, and do not increase mortality or nephrotoxicity risks. Our network meta-analysis in patients with VAP suggests that clinical recovery benefits are associated with aerosolized tobramycin and colistin (especially tobramycin), microbiological eradication with aerosolized colistin, and survival with aerosolized tobramycin, mostly based on observational studies. Due to the low levels of evidence, definitive recommendations cannot be made before additional, large randomized studies are carried out.

Structure of the nucleation-promoting factor SPIN90 bound to the actin filament nucleator Arp2/3 complex.

Unlike the WASP family of Arp2/3 complex activators, WISH/DIP/SPIN90 (WDS) family proteins activate actin filament nucleation by the Arp2/3 complex without the need for a preformed actin filament. This allows WDS proteins to initiate branched actin network assembly by providing seed filaments that activate WASP-bound Arp2/3 complex. Despite their important role in actin network initiation, it is unclear how WDS proteins drive the activating steps that require both WASP and pre-existing actin filaments during WASP-mediated nucleation. Here, we show that SPIN90 folds into an armadillo repeat domain that binds a surface of Arp2/3 complex distinct from the two WASP sites, straddling a hinge point that may stimulate movement of the Arp2 subunit into the activated short-pitch conformation. SPIN90 binds a surface on Arp2/3 complex that overlaps with actin filament binding, explaining how it could stimulate the same structural rearrangements in the complex as pre-existing actin filaments. By revealing how WDS proteins activate the Arp2/3 complex, these data provide a molecular foundation to understand initiation of dendritic actin networks and regulation of Arp2/3 complex by its activators.

Phycotoxins in scallops (Patinopecten yessoensis) in relation to source, composition and temporal variation of phytoplankton and cysts in North Yellow Sea, China.

The North Yellow Sea is a major aquaculture production area for the scallop Patinopecten yessoensis. In this study, the temporal and spatial variation of phycotoxins in scallops, phytoplankton, and their cysts were analyzed during a survey conducted from June 2011 to April 2012 around Zhangzi Island. The study area is a semi-enclosed epicontinental sea surrounded by the Shandong Peninsula, the Liaodong Peninsula and the Korean Peninsula. The three main results of the study were as follows: (1) The saxitoxin-group toxins, okadaic acid and analogues, and pectenotoxins were the major phycotoxin residues found in scallops; (2) Six kinds of toxic microalgae were identified, Protoperidinium spp., Gonyaulax spp., and Alexandrium spp. were the dominant taxa; Seven types of potential marine toxin-producing dinoflagellates, A. tamarense, A. catenella, Dinophysis fortii, G. catenatum, Gambierdiscus toxicus, Azadinium poporum, and Pseudo-nitzschia pungen were identified as the primary source of phycotoxins and were present at relatively high density from June to October; and (3) azaspiracids and domoic acid might be new potential sources of toxin pollution. This study represents the first assessment to phycotoxins around Zhangzi Island in the North Yellow Sea.

Identification of Wiskott-Aldrich syndrome protein (WASP) binding sites on the branched actin filament nucleator Arp2/3 complex.

Arp2/3 complex nucleates branched actin filaments important for cellular motility and endocytosis. WASP family proteins are Arp2/3 complex activators that play multiple roles in branching nucleation, but little is known about the structural bases of these WASP functions, owing to an incomplete understanding of how WASP binds Arp2/3 complex. Recent data show WASP binds two sites, and biochemical and structural studies led to models in which the WASP C segment engages the barbed ends of the Arp3 and Arp2 subunits while the WASP A segment binds the back side of the complex on Arp3. However, electron microscopy reconstructions showed density for WASP inconsistent with these models on the opposite (front) side of Arp2/3 complex. Here we use chemical cross-linking and mass spectrometry (XL-MS) along with computational docking and structure-based mutational analysis to map the two WASP binding sites on the complex. Our data corroborate the barbed end and back side binding models and show one WASP binding site on Arp3, on the back side of the complex, and a second site on the bottom of the complex, spanning Arp2 and ARPC1. The XL-MS-identified cross-links rule out the front side binding model and show that the A segment of WASP binds along the bottom side of the ARPC1 subunit, instead of at the Arp2/ARPC1 interface, as suggested by FRET experiments. The identified binding sites support the Arp3 tail release model to explain WASP-mediated activating conformational changes in Arp2/3 complex and provide insight into the roles of WASP in branching nucleation.

8-Hydroxy-2-methylquinoline-modified H4SiW12O40: a reusable heterogeneous catalyst for acetal/ketal formation.

A heteropoly acid based organic hybrid heterogeneous catalyst, HMQ-STW, was prepared by combining 8-hydroxy-2-methylquinoline (HMQ) with Keggin-structured H4SiW12O40 (STW). The catalyst was characterized via elemental analysis, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TG) and potentiometric titration analysis. The catalytic performance of the catalyst was assessed in the ketalization of ketones with glycol or 1,2-propylene glycol. Various reaction parameters, such as the glycol to cyclohexanone molar ratio, catalyst dosage, reaction temperature and time, were systematically examined. HMQ-STW exhibited a relatively high yield of corresponding ketal, with 100% selectivity under the optimized reaction conditions. Moreover, catalytic recycling tests demonstrated that the heterogeneous catalyst exhibited high potential for reusability, and it was revealed that the organic modifier HMQ plays an important role in the formation of a heterogeneous system and the improvement of structural stability. These results indicated that the HMQ-STW catalyst is a promising new type of heterogeneous acid catalyst for the ketalization of ketones.

Porphyromonas gingivalis Infection Accelerates Atherosclerosis Mediated by Oxidative Stress and Inflammatory Responses in ApoE-/- Mice.

BACKGROUND: The periodontal pathogen Porphyromonas gingivalis (P. gingivalis) has been proven to accelerate the development of atherosclerosis in apolipoprotein E (ApoE)-deficient mice. In this study, we used an ApoE knockout (ApoE-/-) mouse model with chronic intravenous infection with P. gingivalis to investigate the possible mechanisms of P. gingivalis-induced atherosclerosis. METHODS: Eight-week-old ApoE-/- mice were randomly assigned to two groups: (a) ApoE-/- + PBS (n = 8); (b) ApoE-/- + P. gingivalis (n = 8). Both of the groups received intravenous injections 3 times per week. After 4 weeks, oxidative stress mediators in serum, heart, aorta, and liver tissues were analyzed by using histology, ELISA, realtime PCR, and Western blot. RESULTS: Development of atherosclerosis as plaque formation in the aorta has been confirmed upon P. gingivalis infection. An abnormal lipid profile was found in the serum (increased amounts of very low-density lipoprotein [vLDL] and oxidized low-density lipoprotein [oxLDL], and decreased amount of HDL) and in some organs including heart, aorta or liver (increased mRNA levels of oxidized low-density lipoprotein receptor-1 [LOX-1] or fatty acid synthase [FAS]). Meanwhile, aggravated oxidative stress (higher level of reactive oxygen species [ROS] in the serum, and increased mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase [NOX]-2 and/or NOX-4 in the three organs) was observed, as well as enhanced inflammatory responses (increased expression and secretion of C-reactive protein [CRP] in the liver and serum, and increased mRNA levels of cyclooxygenase-2 [NOX-2] and/or inducible nitric oxide synthase [iNOS] in the three organs). Besides, inflammatory mediators including nuclear factor of kappa B (NF-κB) and iNOS showed increased protein levels in the three organs after P. gingivalis infection. CONCLUSIONS: These results suggest that chronic intravenous infection with P. gingivalis in ApoE-/- mice could accelerate the development of atherosclerosis, possibly associated with mediating oxidative stress as well as inflammatory responses and disturbing the lipid profile.