Structural determinants of inhibition of Porphyromonas gingivalis gingipain K by KYT-36, a potent, selective, and bioavailable peptidase inhibitor

Abstract Porphyromonas gingivalis is a member of the dysbiotic oral microbiome and a “keystone pathogen” that causes severe periodontal disease, which is among the most prevalent infectious diseases. Part of the virulence factors secreted by P. gingivalis are the essential cysteine peptidases gingipain K (Kgp) and R (RgpA and RgpB), which account for 85% of the extracellular proteolytic activity of the pathogen and are thus prime targets for inhibition. We report the high-resolution (1.20 Å) complex structure of Kgp with KYT-36, a peptide-derived, potent, bioavailable and highly selective inhibitor, which is widely used for studies in vitro, in cells and in vivo. Sub-nanomolar inhibition of Kgp is achieved by tight binding to the active-site cleft, which is covered for its sub-sites S3 through S1’ under establishment of nine hydrophobic interactions, 14 hydrogen bonds and one salt bridge. In addition, an inhibitor carbonyl carbon that mimics the scissile carbonyl of substrates is pyramidalized and just 2.02 Å away from the catalytic nucleophile of Kgp, C477Sγ. Thus, the crystal structure emulates a reaction intermediate of the first nucleophilic attack during catalysis of cysteine peptidases. The present study sets the pace for the development of tailored next-generation drugs to tackle P. gingivalis

Exploring the impact of an evolving war and terror blogosphere on traditional media coverage of conflict

This article analyses the evolution of a war and terror blogosphere between 2001 and 2011. It identifies seven areas where blogs and related online genres could provide ‘alternative’ accounts to traditional media narratives of conflict. The article also assesses the challenges and opportunities of blogs in each area from the perspective of the working journalist in order to deepen our understanding of the changing influence of blogs on traditional media narratives of conflict. Parallel accounts and interpretations of conflict will collaborate and compete in a war and terror blogosphere in the future, but it has been significantly influenced by the adoption of blogging by military actors since 2008. The war and terror blogosphere is no longer a relatively unmonitored online space which is having an impact on both the production of ‘alternative’ accounts of conflict and the incorporation of these accounts into traditional journalism

The effectiveness of digital storytelling in the classrooms: a comprehensive study

In recent years the use of new technologies in educational systems has increased worldwide as digital cameras, personal computers, scanners, and easy-to-use software have become available to educators to harness the digital world. The impact of new technologies in educational contexts has been mostly positive as new technologies have given educators the opportunity to enhance their knowledge, skills, and therefore enhance the standard of education. Researchers have found that student engagement, achievement and motivation are enhanced through integration of such technologies. However, education systems still face many challenges: one of these challenges is how to enhance student engagement to provide better educational outcomes. It has become increasingly important to use innovative pedagogical models to engage learners. Digital storytelling is one of the innovative pedagogical approaches that can engage students in deep and meaningful learning. This research project aimed to create a constructivist learning environment with digital storytelling. The research investigated the pedagogical aspects of digital storytelling and the impact of digital storytelling on student learning when teachers and students use digital stories. A multi-site case study was conducted in one Australian school at primary and secondary levels. In selected classrooms, students and teachers had the opportunity to engage in innovative learning experiences based on digital storytelling. In order to enhance the reliability and validity of the research, multiple methods of data collection and analysis were used. Data was collected with qualitative and quantitative methods. An evaluation rubric was used to collect quantitative data, while interviews and observation were used to collect qualitative data. Data collection was guided by a mixed methods research design in order to evaluate if and how digital storytelling enhances teaching and learning outcomes. The findings from this study suggest that digital storytelling is a powerful tool to integrate instructional messages with learning activities to create more engaging and exciting learning environments. It is a meaningful approach for creating a constructivist learning environment based on novel principles of teaching and learning. Thus, this approach has the potential to enhance student engagement and provide better educational outcomes for learners

Cloud computing in industrial SMEs: Identification of the barriers to its adoption and effects of its application

ABSTRACT: Cloud computing is a new technological paradigm that may revolutionize how organizations use IT by facilitating delivery of all technology as a service. In the literature, the Cloud is treated mainly through a technological approach focused on the concept definition, service models, infrastructures for its evelopment and security problems. However, there is an important lack of works which analyze this paradigm adoption in SMEs and its results, with a gap between the technological development and its adoption by organizations. This paper uses a qualitative technique methodology -group meetings with managers- and a quantitative one-survey- and identifies which factors act as barriers to Cloud adoption and which positive effects its application generates in 94 industrial SMEs. The conclusion is that the main barriers are of a cultural type and that the positive effects go well beyond reducing costs

Just a guy in pajamas? Framing the blogs in mainstream US newspaper coverage (1999—2005)

When new technologies are introduced to the public, their widespread adoption is dependent, in part, on news coverage (Rogers, 1995).Yet, as weblogs began to play major role in the public spheres of politics and journalism, journalists faced a paradox: how to cover a social phenomenon that was too large to ignore and posed a significant threat to their profession. This article examines how blogs were framed by US newspapers as the public became more aware of the blogging world. A content analysis of blog-related stories in major US newspapers from 1999 to 2005 was conducted. Findings suggest that newspaper coverage framed blogs as more beneficial to individuals and small cohorts than to larger social entities such as politics, business and journalism. Moreover, only in the realm of journalism were blogs framed as more of a threat than a benefit, and rarely were blogs considered an actual form of journalism.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Importance of heterogeneity in Porhyromonas gingivalis lipopolysaccharide lipid A in tissue specific inflammatory signaling

Lipopolysaccharide (LPS) of Porphyromonas gingivalis exists in at least two known forms, O-LPS and A-LPS. A-LPS shows heterogeneity in which two isoforms designated LPS1435/1449 and LPS1690 appear responsible for tissue specific immune signalingpathways activation and increased virulence. The modification of lipid A to tetra-acylated1435/1449 and/or penta-acylated1690 fatty acids indicates poor growth conditions and bioavailability of hemin. Hemin protects P. gingivalis from serum resistance and the lipid A serves as a site for its binding. The LPS1435/1449 and LPS1690 isoforms can produce opposite effects on the human Toll-like receptors (TLR) TLR 2 and TLR 4 activation. This enabless P. gingivalis to select the conditions for its entry, survival and that of its co-habiting species in the host, orchestrating its virulence to control innate immune pathway activation and biofilm dysbiosis. Thismini review describes a number of effects that LPS1435/1449 and LPS1690 can exert on the host tissues such as deregulation of the innate immune system, subversion of host cell autophagy, regulation of outer membrane vesicle production and adverse effects on pregnancy outcome. The ability to change its LPS1435/1449 and/or LPS1690 composition may enables P. gingivalis to paralyze local pro-inflammatory cytokine production, thereby gaining access to its primary location in periodontal tissue

Characterisation and pure culture of putative health-associated oral bacterium BU063 (Tannerella sp. HOT-286) reveals presence of a potentially novel glycosylated S-layer

Tannerella HOT-286 (phylotype BU063) is a recently identified novel filamentous Gram-negative anaerobic oral bacterium cultured for the first time recently in co-culture with Propionibacterium acnes. In contrast to the related periodontal disease associated pathobiont Tannerella forsythia it is considered a putative health-associated bacterium. In this paper we identified that this organism could be grown in pure culture if N-acetyl muramic acid (NAM) was provided in the media, although surprisingly the genetic basis of this phenomenon is not likely to be due to a lack of NAM synthesis genes. During further microbiological investigations we showed for the first time that Tannerella HOT-286 possesses a prominent extracellular S-layer with a novel morphology putatively made up of two proteins modified with an unknown glycan. This data furthers our knowledge of this poorly understood organism and genus that is an important part of the oral and human microbiome

Chronic lymphocytic leukaemia Australasian consensus practice statement

Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naïve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance