New Insights into Parvovirus Research

The family Parvoviridae includes an ample and most diverse collection of viruses. Exploring the biological diversity and the inherent complexity in these apparently simple viruses has been a continuous commitment for the scientific community since their first discovery more than fifty years ago. The Special Issue of 'Viruses' dedicated to the 'New Insights into Parvovirus Research' aimed at presenting a 'state of the art' in many aspects of research in the field, at collecting the newest contributions on unresolved issues, and at presenting new approaches exploiting systemic (-omic) methodologies

Parvovirus B19 Achievements and Challenges

Parvovirus B19 is a widespread human pathogenic virus, member of theErythrovirusgenus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections

The clinical use of parvovirus B19 assays: recent advances

Introduction: Parvovirus B19 (B19V), a single-stranded DNA virus in the family Parvoviridae, is a human pathogenic virus, characterized by a selective but not exclusive tropism for erythroid progenitor cells. Widely diffuse, it is responsible for an ample range of clinical manifestations, whose characteristics and outcomes depend on the interplay between the viral properties and the physiological and immune status of the infected individuals. The complexity of virus\u2013host relationship and the diversity of the clinical course of infection pose a diagnostic challenge that may require non-trivial solutions. Areas covered: The review includes an updated description of the course of B19V infection in its complexity and diversity of pathogenetic mechanisms, discusses the consequent requirements for different and appropriated diagnostic approaches, presents the main diagnostic techniques, more recent technical advancements, and their application to the diverse clinical situations. Expert commentary: The complex scenario of the infectious process and the diversity in possible pathogenetic mechanisms make necessary a multi-parametric approach for an accurate and informative laboratory diagnosis of B19V infection, combining as much as possible the molecular detection of viral components, mainly viral DNA, to commonly followed immunological detection of virus-specific antibodies and a critical assessment of laboratory findings

Advances in the development of antiviral strategies against parvovirus B19

Parvovirus B19 (B19V) is a human pathogenic virus, responsible for an ample range of clinical manifestations. Infections are usually mild, self-limiting, and controlled by the development of a specific immune response, but in many cases clinical situations can be more complex and require therapy. Presently available treatments are only supportive, symptomatic, or unspecific, such as administration of intravenous immunoglobulins, and often of limited efficacy. The development of antiviral strategies against B19V should be considered of highest relevance for increasing the available options for more specific and effective therapeutic treatments. This field of research has been explored in recent years, registering some achievements as well as interesting future perspectives. In addition to immunoglobulins, some compounds have been shown to possess inhibitory activity against B19V. Hydroxyurea is an antiproliferative drug used in the treatment of sickle-cell disease that also possesses inhibitory activity against B19V. The nucleotide analogues Cidofovir and its lipid conjugate Brincidofovir are broad-range antivirals mostly active against dsDNA viruses, which showed an antiviral activity also against B19V. Newly synthesized coumarin derivatives offer possibilities for the development of molecules with antiviral activity. Identification of some flavonoid molecules, with direct inhibitory activity against the viral non-structural (NS) protein, indicates a possible line of development for direct antiviral agents. Continuing research in the field, leading to better knowledge of the viral lifecycle and a precise understanding of virus\u2013cell interactions, will offer novel opportunities for developing more efficient, targeted antiviral agents, which can be translated into available therapeutic options

Delegated Rule-making in Times of Crisis: New Challenges for Democratic Scrutiny?

The delegation of powers to the European Commission, facilitating the adoption of non-legislative acts to implement centrally provisions of European legislation, has long been an essential part of administrative governance in the European Union. However, the established practice of delegating legslative and implementing powers to the European Commission has increased over the last decade, at the same time in the context of the various crises that the EU has had to confront during this period. The crisis context has generally demonstrated that executive institutions often emergency politics, and the amplified use of delegated powers in such circumstances raises questions about the capacity of legislative institutions to carry out their usual control and scrutiny functions. The concern here is whether – at times when the established mechanisms of control need to be carried out in times of crisis, under greater time pressure – there is the risk of legislative institutions (that had originally delegated powers to the Commission) are being sidelined, with the detrimental effects that this may have on the democratic accountability of the whole process. Against this background of normative question-marks, this article examines empirically to what extent the scrutiny of the Commission’s adoption of delegated powers has fundamentally changed during times of emergency. In particular, it provides an analysis of the use of delegated powers by the European Commission in the context of the EU’s response to the Covid-19 pandemic in order to establish whether the Council and the European Parliament managed to enable the usual control mechanisms effectively. By way of conclusion, the article discusses the implications of the findings for the wider discussion and the future use of emergency governance in the European Union

Microfluidic cartridge with integrated array of amorphous silicon photosensors for chemiluminescence detection of viral DNA

Portable and simple analytical devices based on microfluidics with chemiluminescence detection are particularly attractive for point-of-care applications, offering high detectability and specificity in a simple and miniaturized analytical format. Particularly relevant for infectious disease diagnosis is the ability to sensitively and specifically detect target nucleic acid sequences in biological fluids. To reach the goal of real-life applications for such devices, however, several technological challenges related to full device integration are still to be solved, one key aspect regarding on-chip integration of the chemiluminescence signal detection device. Nowadays, the most promising approach is on-chip integration of thin-film photosensors. We recently proposed a portable cartridge with microwells aligned with an array of hydrogenated amorphous silicon (a-Si:H) photosensors, reaching attomole level limits of detection for different chemiluminescence model reactions. Herein, we explore its applicability and performance for multiplex and quantitative detection of viral DNA. In particular, the cartridge was modified to accommodate microfluidic channels and, upon immobilization of three oligonucleotide probes in different positions along each channel, each specific for a genotype of Parvovirus B19, viral nucleic acid sequences were captured and detected. With this system, taking advantage of oligoprobes specificity, chemiluminescence detectability, and photosensor sensitivity, accurate quantification of target analytes down to 70 pmol L-1 was obtained for each B19 DNA genotype, with high specificity and multiplexing ability. Results confirm the good detection capabilities and assay applicability of the proposed system, prompting the development of innovative portable analytical devices with enhanced sensitivity and multiplexed capabilities

Parvovirus B19: recent insights and implications for pathogenesis, diagnosis and therapy

Parvovirus B19 is a human pathogenic virus, a ssDNA member of the family Parvoviridae, characterized by a selective tropism for erythroid progenitor cells (EPCs) in the bone marrow and an ample pathogenetic potential. The selective tropism for EPCs can be explained both in terms of receptor-mediated tropism and of an intracellular permissive environment conditioned by the cell differentiation and proliferation stage. Infection of EPCs is productive, induces apoptosis and leads to a temporary arrest of erythropoiesis, which can usually be manifest in cases of underlying erythropoietic disorders or immune system deficiencies. Endothelial cells constitute an additional diffuse target, whose infection is mediated by ADE phenomenon, but is normally nonproductive and mainly leading to inflammatory processes. The relevance of parvovirus as a cardiotropic virus is recently emerging, while its capability of intrauterine transmission and consequences on the fetus is known and should not be overlooked. To the purpose of diagnosis, a combination of molecular and immunological methods offers the best discrimination of active infectious processes, and an application of these methods especially in cases of atypical presentations should be encouraged. Ongoing research is directed towards the development of a vaccine and the discovery of antiviral drugs that may be useful in the prevention and treatment of parvovirus B19 infections

Parvovirus B19: Insights and implication for pathogenesis, prevention and therapy

Parvovirus B19 (B19V) is a small ssDNA non-enveloped virus, member of Parvoviridae family. The infection is widely diffused and is responsible for a broad range of clinical manifestations including fifth disease in children, transient aplastic crisis in patients with haematological disorders, non-immune hydrops fetalis in pregnant women, persistent anaemia in immunocompromised patients, arthropathy and inflammation of various other tissues. B19V infects and replicates in erythroid progenitor cells (EPCs) in the bone marrow. The depletion of infected EPCs represents the pathogenetic mechanisms of some haematological B19V-associate diseases. Following a primary infection, the virus can establish lifelong persistence in several tissues. Currently, the pathological potential of persistent virus on the cellular signalling pathways remains unclear. In non-erythroid tissues, the infection is usually, abortive, and the virus seems to exert its pathological role through indirect mechanisms, such as induction of inflammatory and autoimmune processes, or through virus-induced apoptosis mediated by viral proteins. In addition to the diseases for which the etiological role of B19V has been fully demonstrated, there are several clinical conditions, including autoimmune diseases, that are presumably, but not certainly, associated with B19V infection. In this review, we describe recent findings that may give us new insight into the pathogenic role of B19V in systemic sclerosis, an autoimmune disease of unknown multifactorial aetiology. Furthermore, we describe the latest findings on the intrauterine B19V infections. Moreover, since there are some ongoing interesting studies focused on vaccine development and antiviral drug discovery for the prevention and treatment of parvovirus B19 infection we described some advances in this field of research

A multicenter prospective study of patients undergoing open ventral hernia repair with intraperitoneal positioning using the monofilament polyester composite ventral patch : interim results of the PANACEA study

This study assessed the recurrence rate and other safety and efficacy parameters following ventral hernia repair with a polyester composite prosthesis (Parietex™ Composite Ventral Patch [PCO-VP])