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Hongbin Xu - Top 30 Publications

Urachal mucinous adenocarcinoma with pseudomyxoma peritonei: A case report.

Pseudomyxoma peritonei is an unusual clinical condition, and the appendix and ovaries are reported as the primary sites.

Alarm bells ring: suicide among Chinese physicians: A STROBE compliant study.

To our surprise, there were 2 Chinese doctors who committed suicide in the last 2 months. What are the reasons for more and more Chinese doctors to commit suicide?We present 18 cases of China's physicians who committed suicide.We summarized the main reasons for the suicide of Chinese doctors from 2004 to 2017, and the main causes included clinical working stress, Job title promotion requirements stress, tension between the doctors and patients, and shying away from necessary treatment of their illness.It is a cruel fact that more and more physicians died of suicide in China. We hope that suicide among Chinese doctors could be recognized so that it could be concerned with the understanding of human societies.

S. oralis activates the Efg1 filamentation pathway in C. albicans to promote cross-kingdom interactions and mucosal biofilms.

Candida albicans and Streptococcus oralis are ubiquitous oral commensal organisms. Under host-permissive conditions these organisms can form hypervirulent mucosal biofilms. C. albicans biofilm formation is controlled by 6 master transcriptional regulators: Bcr1, Brg1, Efg1, Tec1, Ndt80, and Rob1. The objective of this work was to test whether any of these regulators play a role in cross-kingdom interactions between C. albicans and S. oralis in oral mucosal biofilms, and identify downstream target gene(s) that promote these interactions. Organotypic mucosal constructs and a mouse model of oropharyngeal infection were used to analyze mucosal biofilm growth and fungal gene expression. By screening 6 C. albicans transcription regulator reporter strains we discovered that EFG1 was strongly activated by interaction with S. oralis in late biofilm growth stages. EFG1 gene expression was increased in polymicrobial biofilms on abiotic surfaces, mucosal constructs and tongue tissues of mice infected with both organisms. EFG1 was required for robust Candida-streptococcal biofilm growth in organotypic constructs and mouse oral tissues. S. oralis stimulated C. albicans ALS1 gene expression in an EFG1-dependent manner, and Als1 was identified as a downstream effector of the Efg1 pathway which promoted C. albicans-S. oralis coaggregation interactions in mixed biofilms. We conclude that S. oralis induces an increase in EFG1 expression in C. albicans in late biofilm stages. This in turn increases expression of ALS1, which promotes coaggregation interactions and mucosal biofilm growth. Our work provides novel insights on C. albicans genes which play a role in cross-kingdom interactions with S. oralis in mucosal biofilms.

Overexpressed miR-9 promotes tumor metastasis via targeting E-cadherin in serous ovarian cancer.

MicroRNAs (miRNAs) play critical roles in the development and progression in various cancers. Dysfunctional miR-9 expression remains ambiguous, and no consensus on the metastatic progression of ovarian cancer has been reached. In this study, results from the bioinformatics analysis show that the 3'-UTR of the E-cadherin mRNA was directly regulated by miR-9. Luciferase reporter assay results confirmed that miR-9 could directly target this 3'-UTR. miR-9 and E-cadherin expression in ovarian cancer tissue was quantified by qRT-PCR. Migration and invasion were detected by wound healing and Transwell system assay in SKOV3 and A2780. qRT-PCR and Western blot were performed to detect the epithelial‒mesenchymal transition-associated mRNA and proteins. Immunofluorescence technique was used to analyze the expression and subcellular localization of E-cadherin, N-cadherin, and vimentin. The results showed that miR-9 was frequently upregulated in metastatic serous ovarian cancer tissue compared with paired primary ones. Upregulation of miR-9 could downregulate the expression of E-cadherin but upregulate the expression of mesenchymal markers (N-cadherin and vimentin). Overexpression of miR-9 could promote the cell migration and invasion in ovarian cancer, and these processes could be effectively inhibited via miR-9 inhibitor. Thus, our study demonstrates that miR-9 may promote ovarian cancer metastasis via targeting E-cadherin and a novel potential therapeutic approach to control metastasis of ovarian cancer.

Whole-transcriptome sequencing in blood provides a diagnosis of spinal muscular atrophy with progressive myoclonic epilepsy.

At least 15% of the disease-causing mutations affect mRNA splicing. Many splicing mutations are missed in a clinical setting due to limitations of in silico prediction algorithms or their location in noncoding regions. Whole-transcriptome sequencing is a promising new tool to identify these mutations; however, it will be a challenge to obtain disease-relevant tissue for RNA. Here, we describe an individual with a sporadic atypical spinal muscular atrophy, in whom clinical DNA sequencing reported one pathogenic ASAH1 mutation (c.458A>G;p.Tyr153Cys). Transcriptome sequencing on patient leukocytes identified a highly significant and atypical ASAH1 isoform not explained by c.458A>G(p<10(-16) ). Subsequent Sanger-sequencing identified the splice mutation responsible for the isoform (c.504A>C;p.Lys168Asn) and provided a molecular diagnosis of autosomal-recessive spinal muscular atrophy with progressive myoclonic epilepsy. Our findings demonstrate the utility of RNA sequencing from blood to identify splice-impacting disease mutations for nonhematological conditions, providing a diagnosis for these otherwise unsolved patients.

Glycerophosphocholine Metabolites and Cardiovascular Disease Risk Factors in Adolescents: A Cohort Study.

Glycerophosphocholine (GPC) metabolites modulate atherosclerosis and thus risk for cardiovascular disease (CVD). Preclinical CVD may start during adolescence. Here, we used targeted serum lipidomics to identify a new panel of GPCs, and tested whether any of these GPCs are associated, in adolescence, with classical risk factors of CVD, namely excess visceral fat (VF), elevated blood pressure, insulin resistance, and atherogenic dyslipidemia.

Metastatic nerve root tumor: A case report and literature review.

Nerve root metastasis of cancer has been rarely reported. We herein report the case of a cervical cancer patient with metastasis to peripheral nerve roots. A 47 year-old woman with cervical squamous cell carcinoma was admitted to our department with a 6-month history of right leg pain, and was investigated for cancer recurrence. Magnetic resonance imaging revealed lymph node metastasis near the right iliac blood vessels; the patient was then treated with chemotherapy with paclitaxel and carboplatin. However, the pain worsened and the muscle strength of her right leg decreased. On positron emission tomography/computed tomography scans, the sacral plexus L5/S1 and L4/5 nerves appeared thickened, suggesting nerve metastases. Intensity-modulated radiation therapy was applied, with notable clinical benefit. However, the patient succumbed to the disease 3 months later.

Streptococcus oralis and Candida albicans Synergistically Activate μ-Calpain to Degrade E-cadherin From Oral Epithelial Junctions.

Streptococcus oralis forms robust mucosal biofilms with Candida albicans that have increased pathogenic potential. In this study, using oral epithelial cultures, organotypic oral mucosal constructs, and a mouse model of oral infection, we demonstrated that S. oralis augmented C. albicans invasion through epithelial junctions. C. albicans and S. oralis decreased epithelial E-cadherin levels by synergistically increasing µ-calpain, a proteolytic enzyme that targets E-cadherin. In the mouse coinfection model this was accompanied by increased fungal kidney dissemination. Coinfection with a secreted aspartyl protease (sap) mutant sap2456 and S. oralis increased μ-calpain and triggered mucosal invasion and systemic dissemination, suggesting that fungal protease activity is not required for invasion during coinfection. We conclude that C. albicans and S. oralis synergize to activate host enzymes that cleave epithelial junction proteins and increase fungal invasion.

Experimental Models of C. albicans-Streptococcal Co-infection.

Interactions of C. albicans with co-colonizing bacteria at mucosal sites can be synergistic or antagonistic in disease development, depending on the bacterial species and mucosal site. Mitis group streptococci and C. albicans colonize the oral mucosa of the majority of healthy individuals. These streptococci have been termed "accessory pathogens," defined by their ability to initiate multispecies biofilm assembly and promote the virulence of the mixed bacterial biofilm community in which they participate. To demonstrate whether interactions with Mitis group streptococci limit or promote the potential of C. albicans to become an opportunistic pathogen, in vitro and in vivo co-infection models are needed. Here, we describe two C. albicans-streptococcal co-infection models: an organotypic oral mucosal tissue model that incorporates salivary flow and a mouse model of oral co-infection that requires reduced levels of immunosuppression compared to single fungal infection.

Platelet activating factors are associated with depressive symptoms in coronary artery disease patients: a hypothesis-generating study.

Depression is a frequent complication of coronary artery disease (CAD) with an unknown etiology. Platelet activating factor (PAF) lipids, which are associated with CAD, have recently been linked with novel proposed etiopathological mechanisms for depression such as inflammation, oxidative/nitrosative stress, and vascular endothelial dysfunction.

The effect of sulfur on the electrical properties of S and N co-doped ZnO thin films: experiment and first-principles calculations.

P-type sulphur-nitrogen (S-N) co-doped ZnO thin films are deposited and the effect of sulphur on the electrical properties is discussed. First-principles calculations indicate that the structure is most stable when the S atom is close to the N atom in the (0002) plane, implying that dual-doped ZnO is relatively feasible to approach. The partial density of states of S-N co-doped ZnO shows that the S impurity plays a vital role in forming the p-type conductivity.

L-arginine exacerbates experimental cerebral malaria by enhancing pro-inflammatory responses.

L-Arginine (L-Arg), the substrate for nitric oxide (NO) synthase, has been used to treat malaria to reverse endothelial dysfunction in adults. However, the safety and efficacy of L-Arg remains unknown in malaria patients under the age of five, who are at the greatest risk of developing cerebral malaria (CM), a severe malaria complication. Here, we tested effects of L-Arg treatment on the outcomes of CM using a mouse model. Experimental cerebral malaria (ECM) was induced in female C57BL/6 mice infected with Plasmodium berghei ANKA, and L-Arg was administrated either prophylactically or after parasite infection. Surprisingly, both types of L-Arg administration caused a decline in survival time and raised CM clinical scores. L-Arg treatment increased the population of CD4(+)T-bet(+)IFN-γ(+) Th1 cells and the activated macrophages (F4/80(+)CD36(+)) in the spleen. The levels of pro-inflammatory cytokines, IFN-γ and TNF-α, in splenocyte cultures were also increased by L-Arg treatment. The above changes were accompanied with a rise in the number of dendritic cells (DCs) and an increase in their maturation. However, L-Arg did not affect the population of regulatory T cells or the level of IL-10 in the spleen. Taken together, these data suggest that L-Arg may enhance the Th1 immune response, which is essential for a protective response in uncomplicated malaria but could be lethal in CM patients. Therefore, the prophylactic use of L-Arg to treat CM, based on the assumption that restoring the bioavailability of endothelial NO improves the outcome of CM, may need to be reconsidered especially for children.

Platelet-activating factors are associated with cognitive deficits in depressed coronary artery disease patients: a hypothesis-generating study.

Patients with coronary artery disease (CAD) are at risk of accelerated cognitive decline, particularly those with major depression. Mechanisms for cognitive deficits associated with CAD, and the effects of depression, remain poorly understood. However, CAD is associated with inflammatory processes that have been linked to neurodegeneration, may contribute to cognitive decline, and are elevated in depression. Platelet-activating factors (PAFs) are emerging as key lipid mediators that may be central to those processes and highly relevant to cognitive decline in CAD.

Analysis of Prognostic Factors Affecting the Outcome of Stage IB-IIB Cervical Cancer Treated by Radical Hysterectomy and Pelvic Lymphadenectomy.

The aim of this study was to identify the risk factors predicting the prognosis of patients with early-stage cervical cancer and to evaluate the effect of adjuvant therapy in patients with certain risk factors.

Antimicrobial host defence peptide, LL-37, as a potential vaginal contraceptive.

Does antimicrobial peptide, LL-37, inhibit sperm fertilizing ability?

Thermal decomposition of ammonium perchlorate in the presence of Al(OH)(3)·Cr(OH)(3) nanoparticles.

An Al(OH)(3)·Cr(OH)(3) nanoparticle preparation procedure and its catalytic effect and mechanism on thermal decomposition of ammonium perchlorate (AP) were investigated using transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis and differential scanning calorimetry (TG-DSC), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis and mass spectroscopy (TG-MS). In the preparation procedure, TEM, SAED, and FT-IR showed that the Al(OH)(3)·Cr(OH)(3) particles were amorphous particles with dimensions in the nanometer size regime containing a large amount of surface hydroxyl under the controllable preparation conditions. When the Al(OH)(3)·Cr(OH)(3) nanoparticles were used as additives for the thermal decomposition of AP, the TG-DSC results showed that the addition of Al(OH)(3)·Cr(OH)(3) nanoparticles to AP remarkably decreased the onset temperature of AP decomposition from approximately 450°C to 245°C. The FT-IR, RS and XPS results confirmed that the surface hydroxyl content of the Al(OH)(3)·Cr(OH)(3) nanoparticles decreased from 67.94% to 63.65%, and Al(OH)3·Cr(OH)3 nanoparticles were limitedly transformed from amorphous to crystalline after used as additives for the thermal decomposition of AP. Such behavior of Al(OH)(3)·Cr(OH)(3) nanoparticles promoted the oxidation of NH3 of AP to decompose to N2O first, as indicated by the TG-MS results, accelerating the AP thermal decomposition.

Origin of highly stable conductivity of H plasma exposed ZnO films.

H was intentionally incorporated into as-deposited ZnO films by plasma exposure treatment. The resistivity of ZnO films was reduced to the order of 10(-3) Ω cm after H plasma treatment, and high conductive stability was identified using a post-annealing process. To find an explanation for the stable conductivity, first-principle calculation was performed. Results predicted that H atoms trapped in oxygen vacancies (V(O)) have the lowest formation energy. By reducing oxygen vacancies in as-deposited films by adding O2 into the working atmosphere, we further testified that H in V(O) is the origin of highly stable conductivity of ZnO films. Our study provided a solution to the problem of how to incorporate H into the V(O) position to produce highly stable H doped ZnO films.

Effect of different suprahepatic vena cava reconstruction methods on the hemodynamics of rats after liver transplantation.

There are few studies on the hemodynamic changes after orthotopic liver transplantation in rats. In this study, we aimed to evaluate the effect of different suprahepatic vena cava (SHVC) reconstruction methods on the hemodynamics of rats after liver transplantation.

Using neurolipidomics to identify phospholipid mediators of synaptic (dys)function in Alzheimer's Disease.

Not all of the mysteries of life lie in our genetic code. Some can be found buried in our membranes. These shells of fat, sculpted in the central nervous system into the cellular (and subcellular) boundaries of neurons and glia, are themselves complex systems of information. The diversity of neural phospholipids, coupled with their chameleon-like capacity to transmute into bioactive molecules, provides a vast repertoire of immediate response second messengers. The effects of compositional changes on synaptic function have only begun to be appreciated. Here, we mined 29 neurolipidomic datasets for changes in neuronal membrane phospholipid metabolism in Alzheimer's Disease (AD). Three overarching metabolic disturbances were detected. We found that an increase in the hydrolysis of platelet activating factor precursors and ethanolamine-containing plasmalogens, coupled with a failure to regenerate relatively rare alkyl-acyl and alkenyl-acyl structural phospholipids, correlated with disease severity. Accumulation of specific bioactive metabolites [i.e., PC(O-16:0/2:0) and PE(P-16:0/0:0)] was associated with aggravating tau pathology, enhancing vesicular release, and signaling neuronal loss. Finally, depletion of PI(16:0/20:4), PI(16:0/22:6), and PI(18:0/22:6) was implicated in accelerating Aβ42 biogenesis. Our analysis further suggested that converging disruptions in platelet activating factor, plasmalogen, phosphoinositol, phosphoethanolamine (PE), and docosahexaenoic acid metabolism may contribute mechanistically to catastrophic vesicular depletion, impaired receptor trafficking, and morphological dendritic deformation. Together, this analysis supports an emerging hypothesis that aberrant phospholipid metabolism may be one of multiple critical determinants required for Alzheimer disease conversion.

Targeted lipidomics - advances in profiling lysophosphocholine and platelet-activating factor second messengers.

Glycerophosphocholines are the major building blocks of biological membranes. They are also precursors of low-molecular-weight second messengers with mass to charge ratios of 450-600. These messengers include lysophosphatidylcholines (LPCs) and lyso-platelet activating factors (PAFs) that may be further processed into PAFs. Often considered as a single species, LPCs, PAFs and lyso-PAFs are, in fact, families of glycerophosphocholine-derived lipids distinguished by the linkage of their sn-1 carbon chains to the phosphoglyceride backbone (ester or ether), their sn-1 carbon chain length and degree of unsaturation, and the identity of their sn-2 constituents (a hydroxyl or acetyl group). Each LPC and PAF species exhibits a different affinity for its cognate G-protein-coupled receptors, and each species elicits receptor-independent actions that play critical signalling roles. Targeted mass spectrometry-based lipidomic approaches are enabling the molecular identification and quantification of these low-abundance second messengers. Variations between datasets map the temporal landscape of second messengers available for signalling, and provide snapshots of the state of structural membrane compositional remodelling at the time of extraction. Here, we review a number of advances in lipidomic methodologies used to identify LPCs, lyso-PAFs and PAFs, and highlight how these targeted approaches are providing valuable insight into the roles played by the cellular lipidome in cell function and disease susceptibility.

A genome-wide association study identifies two new cervical cancer susceptibility loci at 4q12 and 17q12.

To identify new genetic risk factors for cervical cancer, we conducted a genome-wide association study in the Han Chinese population. The initial discovery set included 1,364 individuals with cervical cancer (cases) and 3,028 female controls, and we selected a 'stringently matched samples' subset (829 cases and 990 controls) from the discovery set on the basis of principal component analysis; the follow-up stages included two independent sample sets (1,824 cases and 3,808 controls for follow-up 1 and 2,343 cases and 3,388 controls for follow-up 2). We identified strong evidence of associations between cervical cancer and two new loci: 4q12 (rs13117307, Pcombined, stringently matched=9.69×10(-9), per-allele odds ratio (OR)stringently matched=1.26) and 17q12 (rs8067378, Pcombined, stringently matched=2.00×10(-8), per-allele ORstringently matched=1.18). We additionally replicated an association between HLA-DPB1 and HLA-DPB2 (HLA-DPB1/2) at 6p21.32 and cervical cancer (rs4282438, Pcombined, stringently matched=4.52×10(-27), per-allele ORstringently matched=0.75). Our findings provide new insights into the genetic etiology of cervical cancer.

Platelet activating factors in depression and coronary artery disease: a potential biomarker related to inflammatory mechanisms and neurodegeneration.

The persistence of a depressive episode in coronary artery disease (CAD) patients not only heightens the risk of acute ischemic events, but it is also associated with accelerated cognitive decline. Antidepressant interventions for depression in CAD have only modest effects and novel approaches are limited by a poor understanding of etiological mechanisms. This review proposes that the platelet activating factor (PAF) family of lipids might be associated with the persistence of a depressive episode and related neurodegenerative pathology in CAD due to their association with leading etiological mechanisms for depression in CAD such as inflammation, oxidative and nitrosative stress, vascular endothelial dysfunction, and platelet reactivity. The evidence implicating PAFs in CAD, vascular pathology, and neurodegenerative processes is also presented. We also propose future directions for the investigation of PAFs as mediators of persistent depression. In summary, PAFs are implicated in leading mechanisms associated with depression in CAD. PAFs may therefore be associated with the persistence of depression in CAD and related to neurodegenerative and cognitive sequelae.

Precise reconstruction of veins and bile ducts in rat liver transplantation.

Rat orthotopic liver transplantation (ROLT) remains a technically demanding procedure, especially regarding the reconstruction of the suprahepatic vena cava (SHVC). In this study, a new microsuture technique was developed for anastomosis of the SHVC, and a special single-groove cuff and blade-cut stent were introduced. With these modified techniques, we aimed to make a precise anastomosis of the SHVC and to provide optimal cuffs and stents for the reconstruction of the veins and bile ducts. According to different microsuture techniques for the SHVC and different types of cuffs and stents, three ROLT groups were created to compare the operation times and prognoses. Sham operations were performed as controls in the fourth group. The time expenditures with each step were compared among the transplantation groups. Biochemical parameters were tested at the end of a 1-month observation period. The short- and long-term survival rates of the transplantation groups were recorded and compared. Our new microsuture technique was faster than the conventional continuous suture technique for SHVC anastomosis (P < 0.05). The use of a single-groove cuff for reconstruction of the portal vein and the infrahepatic vena cava shortened the anastomotic time (P < 0.05). The use of blade-cut stents resulted in fewer biliary complications and better survival over the short and long terms (P < 0.05). Our new microsuture technique and the single-groove cuffs proved to be a precise method for venous reconstruction which shortened the anhepatic time and the anastomotic time significantly. The blade-cut stents apparently reduced the incidence of biliary complications. In summary, with this precise microsuture technique and delicate cuffs and stents, excellent long-term survival can be achieved easily and stably for ROLT.

Glucanase induces filamentation of the fungal pathogen Candida albicans.

Candida albicans is the most common human fungal pathogen. Many organisms, including C. albicans, secrete glucanases under different environmental conditions. Here, we report a novel role for beta-1, 3- glucanase in inducing Candida albicans to form filaments at 22°C and enhancing filamentation at 37°C in nutrient-rich medium. Quorum sensing, the efg1-signaling and cek1 MAP kinase pathways are involved in this process. Our data suggest that the natural antifungal agent beta-glucanase may support morphologic transformation of Candida albicans at a wide range of ambient temperatures.

Phosphoproteome analysis of an early onset mouse model (TgCRND8) of Alzheimer's disease reveals temporal changes in neuronal and glia signaling pathways.

Sustained exposure to soluble amyloid β (Aβ42 ) oligomers is predicted to impair synaptic function in the hippocampal-entorhinal circuit, signaling synaptic loss and precipitating cognitive impairment in Alzheimer's disease. Regional changes in overall patterns of protein phosphorylation are likely crucial to promote transition from a presymptomatic to a symptomatic state in response to accumulating Aβ42. Here, we used unbiased proteomic approaches to compare the phosphoproteome of presymptomatic and symptomatic TgCRND8 mice and identify network disruptions in signaling pathways implicated in the manifestation of behavioral indices of learning and memory impairment. Phosphopeptide enrichment with triple isotopic dimethylation labeling combined with online multidimensional separation and MS was used to profile phosphoproteome changes in 2- and 6-month-old TgCRND8 mice and congenic littermate controls. We identified 1026 phosphopeptides representing 1168 phosphorylation sites from 476 unique proteins. Of these, 595 phosphopeptides from 293 unique proteins were reliably quantified and 139 phosphopeptides were found to change significantly in the hippocampus of TgCRND8 mice following conversion from a presymptomatic to a symptomatic state.

15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) protects neurons from oxidative death via an Nrf2 astrocyte-specific mechanism independent of PPARγ.

Astrocytes are critical for the antioxidant support of neurons. Recently, we demonstrated that low level hydrogen peroxide (H(2) O(2) ) facilitates astrocyte-dependent neuroprotection independent of the antioxidant transcription factor Nrf2, leaving the identity of the endogenous astrocytic Nrf2 activator to question. In this study, we show that an endogenous electrophile, 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), non-cell autonomously protects neurons from death induced by depletion of the major antioxidant glutathione. Nrf2 knockdown in astrocytes abrogated 15d-PGJ2's neuroprotective effect as well as 15d-PGJ2 facilitated Nrf2-target gene induction. In contrast, knockdown of the transcription factor peroxisome proliferator activated-receptor gamma (PPARγ), a well-characterized 15d-PGJ2 target, did not alter 15d-PGJ2 non-cell autonomous neuroprotection. In addition, several PPARγ agonists of the thiazolidinedione (TZD) family failed to induce neuroprotection. Unexpectedly, however, the TZD troglitazone (which contains a chromanol moiety found on vitamin E) induced astrocyte-mediated neuroprotection, an effect which was mimicked by the vitamin E analogs alpha-tocopherol or alpha-tocotrienol. Our findings lead to two important conclusions: (i) 15d-PGJ2 induces astrocyte-mediated neuroprotection via an Nrf2 but not PPARγ mediated pathway, suggesting that 15d-PGJ2 is a candidate endogenous modulator of Nrf2 protective pathways in astrocytes; (ii) selective astrocyte treatment with analogs or compounds containing the chromanol moiety of vitamin E facilitates non-cell autonomous neuroprotection.

Visualization and Phospholipid Identification (VaLID): online integrated search engine capable of identifying and visualizing glycerophospholipids with given mass.

Establishing phospholipid identities in large lipidomic datasets is a labour-intensive process. Where genomics and proteomics capitalize on sequence-based signatures, glycerophospholipids lack easily definable molecular fingerprints. Carbon chain length, degree of unsaturation, linkage, and polar head group identity must be calculated from mass to charge (m/z) ratios under defined mass spectrometry (MS) conditions. Given increasing MS sensitivity, many m/z values are not represented in existing prediction engines. To address this need, Visualization and Phospholipid Identification is a web-based application that returns all theoretically possible phospholipids for any m/z value and MS condition. Visualization algorithms produce multiple chemical structure files for each species. Curated lipids detected by the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics are provided as high-resolution structures.

Candida albicans biofilms do not trigger reactive oxygen species and evade neutrophil killing.

Neutrophils are found within Candida albicans biofilms in vivo and could play a crucial role in clearing the pathogen from biofilms forming on catheters and mucosal surfaces. Our goal was to compare the antimicrobial activity of neutrophils against developing and mature C. albicans biofilms and identify biofilm-specific properties mediating resistance to immune cells. Antibiofilm activity was measured with the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)2H-tetrazolium-5-carboxanilide assay and a molecular Candida viability assay. Reactive oxygen species generation was assessed by measuring fluorescence of 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester in preloaded neutrophils. We found that mature biofilms were resistant to leukocytic killing and did not trigger reactive oxygen species, even though neutrophils retained their viability and functional activation potential. Beta-glucans found in the extracellular matrix negatively affected antibiofilm activities. We conclude that these polymers act as a decoy mechanism to prevent neutrophil activation and that this represents an important innate immune evasion mechanism of C. albicans biofilms.

Dissolved oxygen, COD, nitrogen and phosphorus profiles in a continuous sand filter used for WWTP effluent reclamation.

Continuous sand filtration (CSF) offers interesting potential for the extensive treatment of wastewater treatment plant (WWTP) effluents for water reclamation and/or restrictive discharge. Research on concentration profiles over the height of the CSF shows that most bacteriological conversions are restricted to the lower part of the filter bed. Dissolved oxygen (DO) rapidly decreases to below 1 mg/L in the first 0.4 m of the filter bed, applying hydraulic velocities of 12.9 ∼ 14.9 m/h and 10 ∼ 20 mm/min sand velocities, independent of the methanol dosage. The DO decrease agrees with the observed decrease in chemical oxygen demand (COD). At the given operational conditions, NO(x)-N and N-total removal is dedicated to the first 0.9 m of the filter bed. Results show that by optimising the CSF operational conditions the very restrictive effluent N and P values of 2.2 and 0.15 mg/L, respectively, as described in the European Water Framework Directive, can be met.

Two CheW coupling proteins are essential in a chemosensory pathway of Borrelia burgdorferi.

In the model organism Escherichia coli, the coupling protein CheW, which bridges the chemoreceptors and histidine kinase CheA, is essential for chemotaxis. Unlike the situation in E. coli, Borrelia burgdorferi, the causative agent of Lyme disease, has three cheW homologues (cheW(1) , cheW(2) and cheW(3) ). Here, a comprehensive approach is utilized to investigate the roles of the three cheWs in chemotaxis of B. burgdorferi. First, genetic studies indicated that both the cheW(1) and cheW(3) genes are essential for chemotaxis, as the mutants had altered swimming behaviours and were non-chemotactic. Second, immunofluorescence and cryo-electron tomography studies suggested that both CheW(1) and CheW(3) are involved in the assembly of chemoreceptor arrays at the cell poles. In contrast to cheW(1) and cheW(3) , cheW(2) is dispensable for chemotaxis and assembly of the chemoreceptor arrays. Finally, immunoprecipitation studies demonstrated that the three CheWs interact with different CheAs: CheW(1) and CheW(3) interact with CheA(2) whereas CheW(2) binds to CheA(1) . Collectively, our results indicate that CheW(1) and CheW(3) are incorporated into one chemosensory pathway that is essential for B. burgdorferi chemotaxis. Although many bacteria have more than one homologue of CheW, to our knowledge, this report provides the first experimental evidence that two CheW proteins coexist in one chemosensory pathway and that both are essential for chemotaxis.