Development of Triazoles and Triazolium Salts Based on AZT and Their Anti-Viral Activity against HIV-1.

We report herein a set of 3'-azido-3'-deoxythymidine (AZT) derivatives based on triazoles and triazolium salts for HIV-1 infection. The compounds were synthesized via click chemistry with Cu(I) and Ru(II) catalysts. Triazolium salts were synthesized by reaction with methyl iodide or methyl triflate in good yields. The antiviral activity of the compounds was tested using two methodologies: In method one the activity was measured on infected cells; in method two a pre-exposure prophylaxis experimental model was employed. For method one the activity of the compounds was moderate, and in general the triazolium salts showed a decreased activity in relation to their triazole precursors. With method two the antiviral activity was higher. All compounds were able to decrease the infection, with two compounds able to clear almost all the infection, while a lower antiviral activity was noted for the triazolium salts. These results suggest that these drugs could play an important role in the development of pre-exposure prophylaxis therapies.

A modified banding technique: experience of a center / Uma técnica de bandagem modificada: experiência de um centro

ABSTRACT Background: A well-functioning vascular access is vital to patients on regular hemodialysis. Banding the access is indicated in high-flow-associated steal syndrome. It allows for the reduction of access flow while maintaining distal limb perfusion. Nonetheless, this procedure has some limitations as it can cause hemorrhage, infection, aneurysm formation, thrombosis of access in cases of overbanding, or otherwise insufficient reduction of vascular flow. Other surgical techniques to achieve the same benefit would be useful. Methods: We performed a modified banding technique without endovascular placement of the angioplasty balloon, which is a viable alternative to other techniques. This surgery was performed in patients on chronic dialysis with steal syndrome. Pre- and post-operative access flows were measured and resolution of symptoms was recorded. Primary patency rate was defined as the intervention-free access survival from the operative time. Results: We verified that this technique allowed for access flow reduction in all our six patients, with total resolution of symptoms in all patients. Primary patency rate at 12 months was 100%. No major complications were noted during our follow-up. Conclusions: This technique allows for correction of high-flow arteriovenous fistulas in an efficient and safe way, and can be a viable alternative to other banding procedures.

RESUMO Introdução: Um acesso vascular em bom funcionamento é vital para pacientes em hemodiálise regular. A bandagem do acesso é indicada na síndrome de roubo associada a alto fluxo. Permite a redução do fluxo de acesso enquanto mantém a perfusão distal do membro. No entanto, este procedimento tem algumas limitações, pois pode causar hemorragia, infecção, formação de aneurisma, trombose de acesso em casos de excesso de bandagem (overbanding) ou, de outra forma, redução insuficiente do fluxo vascular. Outras técnicas cirúrgicas para obter o mesmo benefício seriam úteis. Métodos: Foi realizada uma técnica de bandagem modificada sem colocação endovascular do balão de angioplastia, que é uma alternativa viável às outras técnicas. Esta cirurgia foi realizada em pacientes em diálise crônica com síndrome de roubo. Os fluxos de acesso pré e pós-operatório foram medidos e a resolução dos sintomas foi registrada. A taxa de permeabilidade primária foi definida como a sobrevivência do acesso livre de intervenção desde o tempo operatório. Resultados: Verificamos que essa técnica permitiu redução do fluxo de acesso em todos os nossos seis pacientes, com resolução total dos sintomas em todos os pacientes. A taxa de patência primária em 12 meses foi de 100%. Nenhuma complicação maior foi observada durante nosso acompanhamento. Conclusões: Esta técnica permite a correção de fístulas arteriovenosas de alto fluxo de forma eficiente e segura, podendo ser uma alternativa viável a outros procedimentos de bandagem.

A modified banding technique: experience of a center.

BACKGROUND: A well-functioning vascular access is vital to patients on regular hemodialysis. Banding the access is indicated in high-flow-associated steal syndrome. It allows for the reduction of access flow while maintaining distal limb perfusion. Nonetheless, this procedure has some limitations as it can cause hemorrhage, infection, aneurysm formation, thrombosis of access in cases of overbanding, or otherwise insufficient reduction of vascular flow. Other surgical techniques to achieve the same benefit would be useful. METHODS: We performed a modified banding technique without endovascular placement of the angioplasty balloon, which is a viable alternative to other techniques. This surgery was performed in patients on chronic dialysis with steal syndrome. Pre- and post-operative access flows were measured and resolution of symptoms was recorded. Primary patency rate was defined as the intervention-free access survival from the operative time. RESULTS: We verified that this technique allowed for access flow reduction in all our six patients, with total resolution of symptoms in all patients. Primary patency rate at 12 months was 100%. No major complications were noted during our follow-up. CONCLUSIONS: This technique allows for correction of high-flow arteriovenous fistulas in an efficient and safe way, and can be a viable alternative to other banding procedures.

On how to incorporate public sources of situational context in descriptive and predictive models of traffic data.

Background: European cities are placing a larger emphasis on urban data consolidation and analysis for optimizing public transport in response to changing urban mobility dynamics. Despite the existing efforts, traffic data analysis often disregards vital situational context, including large-scale events, weather factors, traffic generation poles, social distancing norms, or traffic interdictions. Some of these sources of context data are still private, dispersed, or unavailable for the purpose of planning or managing urban mobility. Addressing the above observation, the Lisbon city Council has already established efforts for gathering historic and prospective sources of situational context in standardized semi-structured repositories, triggering new opportunities for context-aware traffic data analysis. Research questions: The work presented in this paper aims at tackling the following main research question: How to incorporate historical and prospective sources of situational context into descriptive and predictive models of urban traffic data? Methodology: We propose a methodology anchored in data science methods to integrate situational context in the descriptive and predictive models of traffic data, with a focus on the three following major spatiotemporal traffic data structures: i) georeferenced time series data; ii) origin-destination tensor data; iii) raw traffic event data. Second, we introduce additional principles for the online consolidation and labelling of heterogeneous sources of situational context from public repositories. Third, we quantify the impact produced by situational context aspects on public passenger transport data gathered from smart card validations along the bus (CARRIS), subway (METRO) and bike sharing (GIRA) modes in the city of Lisbon. Results: The gathered results stress the importance of incorporating historical and prospective context data for a guided description and prediction of urban mobility dynamics, irrespective of the underlying data representation.Overall, the research offers the following major contributions:A novel methodology on how to acquire, consolidate and incorporate different sources of context for the context-enriched analysis of traffic data;The instantiation of the proposed methodology in the city of Lisbon, discussing the role of recent initiatives for the ongoing monitoring of relevant context data sources within semi-structured repositories, and further showing how these initiatives can be extended for the context-sensitive modelling of traffic data for descriptive and predictive ends;A roadmap of practical illustrations quantifying impact of different context factors (including weather, traffic interdictions and public events) on different transportation modes using different spatiotemporal traffic data structures; andA review of state-of-the-art contributions on context-enriched traffic data analysis.The contributions reported in this work are anchored in the empirical observations gathered along the first stage of the ILU project (see footnote 1), providing a study case of interest to be followed by other European cities.

Successful treatment of chronic hepatitis C in a kidney transplant patient with only 2 weeks of direct-acting antiviral therapy / Eficacia del tiempo de tratamiento ultracorto con terapia antiviral de acción directa para la hepatitis C crónica en un paciente con trasplante de riñón: reporte de un caso

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Visceral Leishmaniasis Associated with Macrophage Activation Syndrome and Diffuse Alveolar Hemorrhage in a Lupus Patient.

Systemic lupus erythematosus is a heterogeneous and unpredictable autoimmune disease which can be complicated to approach and treat. Hemophagocytic lymphohistiocytosis and diffuse alveolar hemorrhage are rare disease complications. The authors describe a clinical case of a 32-year-old woman with lupus and fever of unknown origin. From the investigations performed, the myelogram revealed hemophagocytosis and Leishmania parasites, therefore liposomal amphotericin B was then started. In addition to directed therapy, she maintained fever that evolved with diffuse alveolar hemorrhage. The myelogram was repeated and showed that she still had hemophagocytosis but now without parasites. Corticotherapy was increased and intravenous Immunoglobulin was started, with improvement. Rituximab was started as a result of macrophage activation syndrome and diffuse alveolar hemorrhage. Months after discharge, she began once again to have sustained fever and Leishmania parasites were found again, therefore liposomal amphotericin B was started once more associated with miltefosine. She continues being followed-up as she is asymptomatic and using steroidsin weaning scheme.

O lúpus eritematoso sistémico é uma doença autoimune heterogénea e imprevisível, o que pode complicar a sua abordagem e tratamento. A linfohistiocitose hemofagocítica e a hemorragia alveolar difusa são complicações raras da doença. Os autores descrevem o caso de uma mulher de 32 anos, com lúpus e febre de origem indeterminada. Da investigação realizada, o mielograma revelou hemofagocitose e parasitas de Leishmania, pelo que iniciou anfotericina B lipossomal. Manteve febre apesar da terapêutica dirigida e evoluiu com hemorragia alveolar difusa. Repetiu mielograma, mantendo hemofagocitose já sem parasitas, tendo aumentado corticoterapia e iniciado imunoglobulina com melhoria. Dada a presença de síndrome de activação macrofágica e hemorragia alveolar difusa iniciou rituximab. Meses após a alta hospitalar, iniciou novamente febre sustentada e foram novamente identificados parasitas de Leishmania, pelo que reiniciou anfotericina B lipossomal associada a miltefosina. Mantém follow-up, encontrando-se assintomática e com corticóides em esquema de desmame.

Cross-species conservation of episome maintenance provides a basis for in vivo investigation of Kaposi's sarcoma herpesvirus LANA.

Many pathogens, including Kaposi's sarcoma herpesvirus (KSHV), lack tractable small animal models. KSHV persists as a multi-copy, nuclear episome in latently infected cells. KSHV latency-associated nuclear antigen (kLANA) binds viral terminal repeat (kTR) DNA to mediate episome persistence. Model pathogen murine gammaherpesvirus 68 (MHV68) mLANA acts analogously on mTR DNA. kLANA and mLANA differ substantially in size and kTR and mTR show little sequence conservation. Here, we find kLANA and mLANA act reciprocally to mediate episome persistence of TR DNA. Further, kLANA rescued mLANA deficient MHV68, enabling a chimeric virus to establish latent infection in vivo in germinal center B cells. The level of chimeric virus in vivo latency was moderately reduced compared to WT infection, but WT or chimeric MHV68 infected cells had similar viral genome copy numbers as assessed by immunofluorescence of LANA intranuclear dots or qPCR. Thus, despite more than 60 Ma of evolutionary divergence, mLANA and kLANA act reciprocally on TR DNA, and kLANA functionally substitutes for mLANA, allowing kLANA investigation in vivo. Analogous chimeras may allow in vivo investigation of genes of other human pathogens.

Latency-Associated Nuclear Antigen E3 Ubiquitin Ligase Activity Impacts Gammaherpesvirus-Driven Germinal Center B Cell Proliferation.

UNLABELLED: Viruses have evolved mechanisms to hijack components of cellular E3 ubiquitin ligases, thus modulating the ubiquitination pathway. However, the biological relevance of such mechanisms for viral pathogenesis in vivo remains largely unknown. Here, we utilized murid herpesvirus 4 (MuHV-4) infection of mice as a model system to address the role of MuHV-4 latency-associated nuclear antigen (mLANA) E3 ligase activity in gammaherpesvirus latent infection. We show that specific mutations in the mLANA SOCS box (V199A, V199A/L202A, or P203A/P206A) disrupted mLANA's ability to recruit Elongin C and Cullin 5, thereby impairing the formation of the Elongin BC/Cullin 5/SOCS (EC5S(mLANA)) complex and mLANA's E3 ligase activity on host NF-κB and Myc. Although these mutations resulted in considerably reduced mLANA binding to viral terminal repeat DNA as assessed by electrophoretic mobility shift assay (EMSA), the mutations did not disrupt mLANA's ability to mediate episome persistence. In vivo, MuHV-4 recombinant viruses bearing these mLANA SOCS box mutations exhibited a deficit in latency amplification in germinal center (GC) B cells. These findings demonstrate that the E3 ligase activity of mLANA contributes to gammaherpesvirus-driven GC B cell proliferation. Hence, pharmacological inhibition of viral E3 ligase activity through targeting SOCS box motifs is a putative strategy to control gammaherpesvirus-driven lymphoproliferation and associated disease. IMPORTANCE: The gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause lifelong persistent infection and play causative roles in several human malignancies. Colonization of B cells is crucial for virus persistence, and access to the B cell compartment is gained by virus-driven proliferation in germinal center (GC) B cells. Infection of B cells is predominantly latent, with the viral genome persisting as a multicopy episome and expressing only a small subset of viral genes. Here, we focused on latency-associated nuclear antigen (mLANA) encoded by murid herpesvirus-4 (MuHV-4), which exhibits homology in sequence, structure, and function to KSHV LANA (kLANA), thereby allowing the study of LANA-mediated pathogenesis in mice. Our experiments show that mLANA's E3 ubiquitin ligase activity is necessary for efficient expansion of latency in GC B cells, suggesting that the development of pharmacological inhibitors of LANA E3 ubiquitin ligase activity may allow strategies to interfere with gammaherpesvirus-driven lymphoproliferation and associated disease.

Crystal structure of the gamma-2 herpesvirus LANA DNA binding domain identifies charged surface residues which impact viral latency.

Latency-associated nuclear antigen (LANA) mediates γ2-herpesvirus genome persistence and regulates transcription. We describe the crystal structure of the murine gammaherpesvirus-68 LANA C-terminal domain at 2.2 Šresolution. The structure reveals an alpha-beta fold that assembles as a dimer, reminiscent of Epstein-Barr virus EBNA1. A predicted DNA binding surface is present and opposite this interface is a positive electrostatic patch. Targeted DNA recognition substitutions eliminated DNA binding, while certain charged patch mutations reduced bromodomain protein, BRD4, binding. Virus containing LANA abolished for DNA binding was incapable of viable latent infection in mice. Virus with mutations at the charged patch periphery exhibited substantial deficiency in expansion of latent infection, while central region substitutions had little effect. This deficiency was independent of BRD4. These results elucidate the LANA DNA binding domain structure and reveal a unique charged region that exerts a critical role in viral latent infection, likely acting through a host cell protein(s).