25 research outputs found

    Analytical development to support manufacturing of a sustainable vaccine against Invasive Nontyphoidal Salmonellosis

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    GVGH is developing a candidate trivalent Salmonella vaccine to fight invasive nontyphoidal Salmonellosis (iNTS) and typhoid fever, especially aimed for sub-Saharan Africa to impact disease burden and to reduce anti-microbial resistance spread. This trivalent vaccine may be the only viable option for a sustainable iNTS vaccine in sub-Saharan Africa over the separate administration of Typhoid Conjugate Vaccines (TCV) and a vaccine against iNTS. GVGH generated the iNTS-TCV formulation by combining the GMMA technology for the iNTS components, S. Typhimurium (STm) and S. Enteritidis (SEn) GMMA adsorbed on Alhydrogel, and the Vi-CRM197 glycoconjugate, originally developed by GVGH and recently WHO prequalified as TCV TYPHIBEV by Biological E Ltd (Hyderabad, India). A set of analytical methods to support the vaccine lot release and characterization have been developed by GVGH. In particular, to quantify the key active ingredients of iNTS components a competitive ELISA-based method (FAcE, Formulated Alhydrogel competitive ELISA assay) has been setup and characterized in terms of specificity, accuracy and precision. Vi component is instead characterized by means of HPAEC-PAD method, able to specifically identify and quantify the total polysaccharide in the final drug product. With regard to safety assessment, a Monocyte Activation Test (MAT) has been developed as to monitor the intrinsic pyrogenicity of GMMA-based vaccines and applied as surveillance test for the Phase 1 clinical lot, with the plan to set release criteria based on clinical experience. In vivo potency assay has been set to characterize the immunogenicity of vaccine lots in comparison to freshly formulated material at the time of release and during real-time stability. A significant antibody response to each of the active ingredients of the trivalent vaccine is raised in mice and assessed by Parallel Line Assay. Overall, the applied analytical panel and the results support the development of an iNTS-TCV vaccine as a viable option for a sustainable iNTS vaccine in sub-Saharan Africa

    A Novel Phase Variation Mechanism in the Meningococcus Driven by a Ligand-Responsive Repressor and Differential Spacing of Distal Promoter Elements

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    Phase variable expression, mediated by high frequency reversible changes in the length of simple sequence repeats, facilitates adaptation of bacterial populations to changing environments and is frequently important in bacterial virulence. Here we elucidate a novel phase variable mechanism for NadA, an adhesin and invasin of Neisseria meningitidis. The NadR repressor protein binds to operators flanking the phase variable tract and contributes to the differential expression levels of phase variant promoters with different numbers of repeats likely due to different spacing between operators. We show that IHF binds between these operators, and may permit looping of the promoter, allowing interaction of NadR at operators located distally or overlapping the promoter. The 4-hydroxyphenylacetic acid, a metabolite of aromatic amino acid catabolism that is secreted in saliva, induces NadA expression by inhibiting the DNA binding activity of the repressor. When induced, only minor differences are evident between NadR-independent transcription levels of promoter phase variants and are likely due to differential RNA polymerase contacts leading to altered promoter activity. Our results suggest that NadA expression is under both stochastic and tight environmental-sensing regulatory control, both mediated by the NadR repressor, and may be induced during colonization of the oropharynx where it plays a major role in the successful adhesion and invasion of the mucosa. Hence, simple sequence repeats in promoter regions may be a strategy used by host-adapted bacterial pathogens to randomly switch between expression states that may nonetheless still be induced by appropriate niche-specific signals

    The Caenorhabditis elegans Elongator Complex Regulates Neuronal α-tubulin Acetylation

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    Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of α-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of α-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating α-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3) and in a scaffold subunit (Elp1) have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Cross-Layer Adaptation of MPEG4 Video Streaming Over Wireless Networks Using Unequal Error Protection and MC-CDMA

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    A novel methodology for the efficient multiplexing and streaming of MPEG4 video over wireless networks is presented and discussed. The proposed cross-layer adaptation jointly exploits variable-bitrate (VBR) multi-carrier code-division multiplexing (MC-CDM) and MPEG4 Fine-Grain-Scalability (FGS) in order to provide unequal error protection to the transmitted video stream. A shared bandwidth is partitioned into orthogonal sub-channels in order to multiplex different layers of MPEG4-coded signals. Lower layers are assigned a higher number of sub-channels (and hence an increased frequency diversity) as compared to FGS enhancement layers, in order to provide a differentiated protection against channel degradations. A 2-GHz LEO multicast satellite transmission system has been considered as a application testbed of the proposed methodology. Results achieved in terms of PSNR show that the VBR MC-CDM technique can provide better results than conventional MPEG4 single-layer MC-SS transmission. In the framework of a full-digital implementation of reconfigurable multimedia transceivers, the proposed VBR MC-CDM technique may be regarded as a convenient solution for reliable multimedia transmissions in mobile environments

    That’s ReDO: Ontologies and Regional Development Planning

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    European Cohesion Policy generates several programs at territorial levels. An evident trend is the increasing of multi-level governance in the period 2007-2013, promoting a wider participation to programming processes. It is possible to affirm that new instances are coming out. We refer to problems generally connected with participation processes. The relation between problems in knowledge management and ineffective impacts of local development plans is confirmed. Therefore, the central role of communication determines relevant issues regarding the ability to understand the meaning of general and sectoral policies by stake holders, the awareness of citizens to manage technical instruments implementing such policies. Are they conscious of ex-ante comprehensive context analysis and/or can they share possible future scenarios? A way to tackle these problems is the use of ontologies. In this work we present the structural elements and an application of ReDO ontology (Regional Development Ontology) analyzing major steps of ontology design and nodal phases of ontology building (i.e. consensus on relations and restrictions, and switch from glossary to taxonomy)

    A strategic model for developing vaccines against neglected diseases: An example of industry collaboration for sustainable development

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    Infectious diseases continue to disproportionately affect low- and middle-income countries (LMICs) and children aged <5 y. Developing vaccines against diseases endemic in LMICs relies mainly on strong public-private collaborations, but several challenges remain. We review the operating model of the GSK Vaccines Institute for Global Health (GVGH), which aims to address these challenges. The model involves i) selection of vaccine targets based on priority ranking for impact on global health; ii) development from design to clinical proof-of-concept; iii) transfer to an industrial partner, for further technical/clinical development, licensing, manufacturing, and distribution. Cost and risks associated with pre-clinical and early clinical development are assumed by GVGH, increasing the probability to make the vaccine more affordable in LMICs. A conjugate vaccine against typhoid fever, Vi-CRM197, has recently obtained WHO prequalification, within a year from licensure in India, demonstrating the success of the GVGH model for development and delivery of global health vaccines
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