Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.
This service exclusively searches for literature that cites resources. Please be aware that the total number of searchable documents is limited to those containing RRIDs and does not include all open-access literature.
Poly-β(1,6)-N-acetyl-D-glucosamine (PNAG) is a major biofilm component of many pathogenic bacteria. The production, modification, and export of PNAG in Escherichia coli and Bordetella species require the protein products encoded by the pgaABCD operon. PgaB is a two-domain periplasmic protein that contains an N-terminal deacetylase domain and a C-terminal PNAG binding domain that is critical for export. However, the exact function of the PgaB C-terminal domain remains unclear. Herein, we show that the C-terminal domains of Bordetella bronchiseptica PgaB (PgaBBb) and E. coli PgaB (PgaBEc) function as glycoside hydrolases. These enzymes hydrolyze purified deacetylated PNAG (dPNAG) from Staphylococcus aureus, disrupt PNAG-dependent biofilms formed by Bordetella pertussis, Staphylococcus carnosus, Staphylococcus epidermidis, and E. coli, and potentiate bacterial killing by gentamicin. Furthermore, we found that PgaBBb was only able to hydrolyze PNAG produced in situ by the E. coli PgaCD synthase complex when an active deacetylase domain was present. Mass spectrometry analysis of the PgaB-hydrolyzed dPNAG substrate showed a GlcN-GlcNAc-GlcNAc motif at the new reducing end of detected fragments. Our 1.76 Å structure of the C-terminal domain of PgaBBb reveals a central cavity within an elongated surface groove that appears ideally suited to recognize the GlcN-GlcNAc-GlcNAc motif. The structure, in conjunction with molecular modeling and site directed mutagenesis led to the identification of the dPNAG binding subsites and D474 as the probable catalytic acid. This work expands the role of PgaB within the PNAG biosynthesis machinery, defines a new glycoside hydrolase family GH153, and identifies PgaB as a possible therapeutic agent for treating PNAG-dependent biofilm infections.
Thrombin-binding aptamer (TBA) is a DNA 15-mer of sequence 5'-GGT TGG TGT GGT TGG-3' that folds into a G-quadruplex structure linked by two T-T loops located on one side and a T-G-T loop on the other. These loops are critical for post-SELEX modification to improve TBA target affinity. With this goal in mind we synthesized a T analog, 5-(indolyl-3-acetyl-3-amino-1-propenyl)-2'-deoxyuridine (W) to substitute one T or a pair of Ts. Subsequently, the affinity for each analog was determined by biolayer interferometry. An aptamer with W at position 4 exhibited about 3-fold increased binding affinity, and replacing both T4 and T12 with W afforded an almost 10-fold enhancement compared to native TBA. To better understand the role of the substituent's aromatic moiety, an aptamer with 5-(methyl-3-acetyl-3-amino-1-propenyl)-2'-deoxyuridine (K; W without the indole moiety) in place of T4 was also synthesized. This K4 aptamer was found to improve affinity 7-fold relative to native TBA. Crystal structures of aptamers with T4 replaced by either W or K bound to thrombin provide insight into the origins of the increased affinities. Our work demonstrates that facile chemical modification of a simple DNA aptamer can be used to significantly improve its binding affinity for a well-established pharmacological target protein.
Streptozotocin (STZ) is a glucosamine-nitrosourea compound that is particularly toxic to the insulin-producing beta-cells of the pancreas in mammals; it is used for experimental simulation of sporadic Alzheimer's disease by means of intracerebroventricular administration in vivo. Here we show that the application of 3-4 mM STZ to primary culture for 48 h induces neuronal death in immature (2-3 days in vitro) cultures of rat cerebellar granule cells. Mature cultures (7-8 days in vitro) were poorly sensitive to this toxic treatment. Immature cultures demonstrated a high expression of the protein PSA-NCAM, the marker of immature neurons, and they were insensitive to the toxic effect of glutamate. In mature cultures, this protein was poorly expressed, whereas neurons showed a very high sensitivity to the toxic effect of glutamate. Measurements of the concentration of intracellular free calcium ions ([Ca2+]i) showed that the STZ-induced [Ca2+]i increase in young neurons was six times higher than that in mature neurons. Our results show that STZ is very toxic for immature neurons and probably it can significantly impair neurogenesis.
Due to their unique flight mechanism including a direct flight musculature, Odonata show impressive flight skills. Several publications addressed the details of this flight apparatus like: sclerites, wings, musculature, and flight aerodynamics. However, 3D-analysis of the thorax musculature of adult dragonflies was not studied before and this paper allows for a detailed insight. We, therefore, focused on the thorax musculature of adult Anisoptera using micro-computed tomography. Herewith, we present a comparative morphological approach to identify differences within Anisoptera: Aeshnidae, Corduliidae, Gomphidae, and Libellulidae. In total, 54 muscles were identified: 16 prothoracic, 19 mesothoracic, and 19 metathoracic. Recorded differences were for example, the reduction of muscle Idlm4 and an additional muscle IIIdlm1 in Aeshna cyanea, previously described as rudimentary or missing. Muscle Iscm1, which was previously reported missing in all Odonata, was found in all investigated species. The attachment of muscle IIpcm2 in Pantala flavescens is interpreted as a probable adaption to its long-distance migration behaviour. Furthermore, we present a review of functions of the odonatan flight muscles, considering previous publications. The data herein set a basis for functional and biomechanical studies of the flight apparatus and will therefore lay the foundation for a better understanding of the odonatan flight.
The need for fast and comprehensive characterization of biocatalysts has pushed the development of new screening platforms based on microfluidics, capable of monitoring several parameters simultaneously, with new configurations of liquid handling, sample treatment and sensing. Modular microfluidics allows the integration of these newly developed approaches in a more flexible way towards increasing applicability of the microfluidic chips to different types of biocatalysts and reactions. A highly relevant operation in such a system is biocatalyst inactivation, which can enable the precise control of reaction time by avoiding the continuation of the reaction in another module or connecting tubes. Such control is important when different modules of reactors and/or sensing units are used and changed frequently. Here we describe the development, characterization and application of a module for rapid enzyme inactivation. The thermal inactivation platform developed is compared with a standard benchtop ThermoMixer in terms of inactivation efficiency for glucose oxidase and catalase. A higher activity loss was observed for enzyme inactivation under flow conditions (inactivation achieved at 120 s residence time at 338 K and 20 s residence time at 353 K) which indicated a high heat transfer to the fluid under dynamic conditions. Moreover, partial deactivation of the enzymes was observed for the continuous thermal inactivation module, when activity measurements were performed after 1 and 2 days following inactivation. The thermal inactivation unit presented can be easily integrated into modular microfluidic platforms and can be a useful addition for enzyme characterization and screening.
Silver nanomaterials are widely used in clinically approved devices, consumer goods, and over-the-counter nutraceutical products. Despite the increase in silver nanomaterial research, few investigations have specifically distinguished the biological effects resulting from silver nanoparticles (AgNPs) versus silver ions released from AgNPs. This is in part, due to the complex analytical methods required to characterize silver ion release from AgNPs in biological media. This study sought to analyze silver ion release from AgNPs in biological media, compare silver transport from soluble AgNO3 and AgNPs through ex vivo full thickness sinus human tissue explants and human nasal epithelium and determine fractional AgNP internalization by human nasal epithelial cells. Rapid silver ion release is observed from AgNPs in human nasal epithelial cell medium over 3 h (9.6% of total silver mass). Significantly lower translocation of AgNPs is observed through human nasal epithelial cell monolayers and ex vivo human sinus tissue explants compared to silver ion (AgNO3). AgNP internalization is directly observed in AgNP-exposed human nasal epithelial cell monolayers by live cell scanning transmission electron microscopy (STEM), providing one potential mechanism for AgNP transcytosis. However, in vitro AgNP dissolution experiments suggest that silver in human nasal epithelium is primarily silver ion. Ionic AgNO3 produces significantly higher silver translocation, supporting previous results claiming silver ion as primarily responsible for biological effects of AgNPs.
Amniotic fluid contains large amounts of proteins produced by amnion epithelial cells, fetal tissues, fetal excretions and placental tissues; thus, it is an important potential source of biomarkers for identifying fetal pathologies. In this study, a pooled AF sample from 7 healthy volunteers was used to provide a comprehensive profile of normal human AF proteome using immunoaffinity depletion of 14 high-abundance proteins. Each individual AF sample was used to analyze inter-individual variations with iTRAQ method. As a result, a total of 2881 non-redundant proteins were identified, and 1624 proteins were quantified based on the peak intensity-based semi-quantification (iBAQ) method. Gene Ontology (GO) analysis showed that the AF proteome was enriched in extracellular region and extracellular matrix. Further function annotation showed that the top canonical pathway was axonal guidance signaling. The inter-individual variation analysis of 7 individual AF samples showed that the median inter-individual CV (Coefficient of variation) was 0.22. iBAQ quantification analysis revealed that the inter-individual variations were not correlated with protein abundance. GO analysis indicated that intracellular proteins tended to have higher CVs, and extracellular proteins tended to have lower CVs. These data will contribute to a better understanding of amniotic fluid proteomic analysis and biomarker discovery. SIGNIFICANCE: Amniotic fluid is an important potential source of biomarkers for identifying fetal pathologies. This study provided a large database for the normal human amniotic fluid proteome and analysis of inter-individual variations in amniotic fluid proteomes, which will offer a baseline reference for further AF proteomic analysis and pregnancy-related disease biomarker discovery.
A secondary cervical thymus (CT) is present in the neck region in about 50% of human and mice. CT in mice is an independent and functional organ, which can be colonized by T lymphocyte progenitors and generate thymocytes that are selected by the T cell receptor repertoire following the positive and negative selection. However, CT and the main thoracic thymus (TT) have been shown in mice to have significant functional differences. In this study, we use transcriptional profiling to compare mRNA or miRNAs expression patterns in murine CT and TT. We used these data to perform functional enrichment of the expression signatures and reconstruction of posttranscriptional miRNA-mRNA interaction networks. For this purpose, we compared the transcriptome profiling of paired RNA samples of whole CTs, TTs and parathyroid gland (PT), which was used as an external group, from Foxn1-GFP;Pth-Cre;R26dTomato transgenic mice that differentially label CT and TT. As expected, CT and TT featured comprehensive transcriptome similarity and this suggests that these organs are subjected to correlated transcriptional control. Nevertheless, significant differences were also observed between TT and CT, characterized by 107 differentially expressed (DE) mRNAs, and in 13 DE miRNAs, that in turn established interactions. These results suggest that functional similarity between TT and CT is reflected in their transcriptional activity and that CT functional uniqueness might be under posttranscriptional control.
A new 2,4-dinitrophenylhydrazine (DNPH)-based photometric assay is developed for the quantification of carbonyls in protein samples from any biological source by protein carbonyl-DNPH hydrazone formation at acidic pH in the presence of denaturing urea, and subsequent hydrazone solubilization in the presence of SDS and stabilization from acid hydrolysis at pH 7.0. At this neutral (ntr) pH, interfering unreacted DNPH is uncharged and its thus increased hydrophobicity permits its 100% effective removal from the solubilizate with ethyl acetate/hexane wash. The ntrDNPH assay is more reliable and sensitive than the standard (std) DNPH photometric assay because it eliminates its main limitations: (i) interfering unreacted DNPH (pKa 1.55) that is nonspecifically bound to the TCA (pKa 0.7)-protein pellet is not effectively removed after wash with EtOH: ethyl acetate because it is positively charged, (ii) acid (TCA-induced) hydrolysis of the protein carbonyl-DNPH hydrazone, (iii) sample protein concentration re-determination, (iv) loss of sample acid (TCA)-soluble proteins, (v) DNA interference, and (vi) requires high protein quantity samples (≥ 1 mg). Considering ntrDNPH assay's very low protein limit (1 µg), its cumulative and functional sensitivities are 2600- and 2000-fold higher than those of the stdDNPH assay, respectively. The present study elucidates the DNA interference mechanism on the stdDNPH assay, and also develops a standardized protocol for sample protein treatment and fractionation (into cytoplasmic/aqueous, membrane/lipid-bound, and histone/DNA-bound proteins; see Supplement section V) in order to ensure reproducible carbonyl determination on defined cell protein fractions, and to eliminate assay interference from protein samples containing (i) Cys sulfenic acid groups (via their neutralization with dithiothreitol), and (ii) DNA (via its removal by streptomycin sulfate precipitation). Lastly, the ntrDNPH assay determines carbonyl groups on cell wall polysaccharides, thus paving the way on studies to investigate cell walls acting as antioxidant defense in plants, fungi, bacteria and lichens.
Although the positive effects of preoperative oral carbohydrate administration on clinical outcomes following major surgery have been reported continuously, there are few investigations of them in minor surgical patients. The present study was designed to examine the effects of preoperative oral carbohydrate administration on patient well-being and satisfaction in patients undergoing thyroidectomy.
Japanese cedar (Cryptomeria japonica) is an important tree for Japanese forestry. Male-sterile marker development in Japanese cedar would facilitate selection of male-sterile plus trees, addressing the widespread social problem of pollinosis and facilitating the identification of heterozygotes, which are useful for breeding.
Low temperature influences the development and latex production of rubber trees (Hevea brasiliensis) when extension to suboptimal high-latitude areas. The successful extension of Hevea brasiliensis cultivation to high-latitude areas has long believed to benefit from the breeding of cold-tolerant cultivars. A puzzling incongruity is the variation in cold tolerance among the cultivated clones despite their similar genetic make-up.
Fever after stroke is common, and often caused by infections. In the current study, we aimed to test the hypothesis that pneumonia, urinary tract infection and all-cause fever (thought to include at least some proportion of endogenous fever) have different predicting factors, since they differ regarding etiology.
Anaemia in pregnant women is a public health problem, especially in developing countries. The aim of this study was to assess the prevalence and related risk factors of anaemia during pregnancy in a large multicentre retrospective study (n = 44,002) and to determine the adverse pregnancy outcomes in women with or without anaemia.
Ghana is currently undergoing a profound demographic transition, with large increases in the number of older adults in the population. Older adults require greater levels of healthcare as illness and disability increase with age. Ghana therefore provides an important and timely case study of policy implementation aimed at improving equal access to healthcare in the context of population ageing. This paper examines the determinants of National Health Insurance (NHIS) enrolment in Ghana, using two different surveys and distinguishing between younger and older adults. Two surveys are used in order to investigate consistency in insurance enrolment. The comparison between age groups is aimed at understanding whether determinants differ for older adults. Previous studies have mainly focused on the enrolment of young and middle aged adults; thus by widening the focus to include older adults and taking into account differences in their demographic and socio-economic characteristics this paper provides a unique contribution to the literature.
Genetic manipulation techniques, such as transfection, have been previously reported in many protozoan parasites. In Babesia, stable transfection systems have only been established for bovine Babesia parasites. We recently reported a transient transfection system and the selection of promoter candidates for Babesia gibsoni. The establishment of a stable transfection system for B. gibsoni is considered to be urgent to improve our understanding of the basic biology of canine Babesia parasites for a better control of babesiosis.
In the context of rising dementia prevalence, the workload of general practitioners (GPs) in dementia care is set to increase. However, there are many aspects of dementia care that GPs find challenging. Behavioural and psychological symptoms of dementia (BPSD) affect the majority of people with dementia and is an aspect of dementia care that GPs find particularly difficult to manage. The aim of this mixed methods systematic review is to undertake a synthesis of qualitative and quantitative studies on GPs' knowledge, attitudes and experiences of managing BPSD.
Ataxia Telangiectasia and Rad3 related protein (ATR) is a central mediator of the response to DNA damage that may cause the quiescent resistance of cancer initiating cells to genotoxic radiotherapy. NVP-BEZ235 is a dual PI3K/mTOR inhibitor that also effectively targets ATR with IC50 = 21 × 10- 9 M in cells. AZD6738 does not target significantly PI3K/mTOR-related kinases but specifically inhibits ATR with IC50 = 74 × 10- 9 M in cells. Both drugs have been proposed as radiosensitizers of different tumors including glioblastoma (GB), the most malignant brain tumor. In order to study the radiosensitizing properties of ATR inhibitors NVP-BEZ235 and AZD6738 towards GB, we have preliminarily investigated their capacity to penetrate the brain after systemic administration. Tumor-free CD-1 mice were inoculated i.p. with 25 mg/Kg body weight of NVP-BEZ235 or AZD6738. 1, 2, 6 and 8 h later, blood was collected by retro-orbital bleeding after which the mice were euthanized and the brains explanted. Blood and brain samples were then extracted and NVP-BEZ235 and AZD6738 concentrations determined by High Performance Liquid Chromatography/Mass Spectrometry. We found for NVP-BEZ235 and especially for AZD6738, elevated bioavailability and effective brain penetration after intraperitoneal administration. Albeit low drug and radiation dosages were used, a trend to toxicity of NVP-BEZ235 followed by ionizing radiation (IR) towards mice bearing primary glioma initiating cells (GIC)-driven orthotopic tumors was yet observed, as compared to AZD6738 + IR and vehicle+IR. Survival was never improved with median values of 99, 86 and 101 days for vehicle+IR, NVP-BEZ235 + IR and AZD6738 + IR-treated mice, respectively. Although the present results indicate favorable pharmacokinetics properties of ATR inhibitors NVP-BEZ235 and AZD6738, they do not lend support to their use as radiosensitizers of GB.
Welcome to the SPARC SAWG Resources search. From here you can search through a compilation of resources used by SPARC SAWG and see how data is organized within our community.
You are currently on the Community Resources tab looking through categories and sources that SPARC SAWG has compiled. You can navigate through those categories from here or change to a different tab to execute your search through. Each tab gives a different perspective on data.
If you have an account on SPARC SAWG then you can log in from here to get additional features in SPARC SAWG such as Collections, Saved Searches, and managing Resources.
Here is the search term that is being executed, you can type in anything you want to search for. Some tips to help searching:
You can save any searches you perform for quick access to later from here.
We recognized your search term and included synonyms and inferred terms along side your term to help get the data you are looking for.
If you are logged into SPARC SAWG you can add data records to your collections to create custom spreadsheets across multiple sources of data.
Here are the facets that you can filter your papers by.
From here we'll present any options for the literature, such as exporting your current results.
If you have any further questions please check out our FAQs Page to ask questions and see our tutorials. Click this button to view this tutorial again.
Year:
Count: