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Avian influenza viruses in humans: lessons from past outbreaks.

BACKGROUND: Human infections with avian influenza viruses (AIV) represent a persistent public health threat. The principal risk factor governing human infection with AIV is from direct contact with infected poultry and is primarily observed in Asia and Egypt where live-bird markets are common. AREAS OF AGREEMENT: Changing patterns of virus transmission and a lack of obvious disease manifestations in avian species hampers early detection and efficient control of potentially zoonotic AIV. AREAS OF CONTROVERSY: Despite extensive studies on biological and environmental risk factors, the exact co…

Recalling the Future: Immunological Memory Toward Unpredictable Influenza Viruses.

Persistent and durable immunological memory forms the basis of any successful vaccination protocol. Generation of pre-existing memory B cell and T cell pools is thus the key for maintaining protective immunity to seasonal, pandemic and avian influenza viruses. Long-lived antibody secreting cells (ASCs) are responsible for maintaining antibody levels in peripheral blood. Generated with CD4+ T help after naïve B cell precursors encounter their cognate antigen, the linked processes of differentiation (including Ig class switching) and proliferation also give rise to memory B cells, which then can…

Вирусы герпеса в зрительном неврастите: похожи на причуду Белла.

ЦЕЛЬ: Оптик Нерет (ON) может проявляться либо как один внутричерепный неврит, либо как множественный склероз, широко распространенное демиелионирующее расстройство. В качестве потенциальных участников этиологии множественного склероза (МС) были предложены различные герпезные вирусы. Проанализировать потенциальное присутствие вирусов герпеса в крови и субарахноидном районе во время ВС и сопоставить полученные результаты в зависимости от долгосрочной эволюции либо как внутричерепный неврит, либо как продвижение к множественным склерозам.ПАТИЕНТЫ И МЕТОДЫ: В ходе перспективного исследования мы пр

Совпадение в аннотации оригинала
OBJECTIVE: Optic Neuritis (ON) might unfold either as a single intracranial neuritis or as multiple sclerosis, a widespread demyelinating disorder. Different herpes viruses have been proposed as potential participants in the etiology of multiple sclerosis (MS). To analyze the potential presence of herpes viruses in blood and subarachnoid area at the time of …

Detection of Enzymes, Viruses, and Bacteria Using Glucose Meters.

We have developed innovative assays that can detect enzymes rapidly. Paracetamol- or catechol-bearing compounds, when exposed to their respective enzymes, released paracetamol or catechol, which can be detected using a standard glucose meter. This approach was used to detect a number of diverse analytes that include enzymes such as β-galactosidase and α-mannosidase and pathogens such as influenza viruses, Streptococcus pneumoniae, and E. coli rapidly. The limit of detection for all analytes was extremely low and clinically relevant for influenza viruses. We also demonstrate that glucose oxidas…

Classification and Genomic Diversity of Enterically Transmitted Hepatitis Viruses.

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are significant human pathogens and are responsible for a substantial proportion of cases of severe acute hepatitis worldwide. Genetically, both viruses are heterogeneous and are classified into several genotypes that differ in their geographical distribution and risk group association. There is, however, little evidence that variants of HAV or HEV differ antigenically or in their propensity to cause severe disease. Genetically more divergent but primarily hepatotropic variants of both HAV and HEV have been found in several mammalian species,…

Standardized focus assay protocol for biosafety level four viruses.

Working in accordance with biosafety level four practices is highly complex and time-consuming. Therefore, the respective laboratory protocols should be as uniform as possible, simple to perform and straightforward in readout. Here we describe the successful application of a standardized 24-well plate focus assay protocol for the titration of Zaire ebolavirus (two isolates), Marburg virus (three isolates), Lassa virus (two isolates), Crimean Congo hemorrhagic fever virus (one isolate), and tick-borne encephalitis virus (two isolates). Viral titers are determined based on a simple visual readou

Progressive Multifocal Leukoencephalopathy: Endemic Viruses and Lethal Brain Disease.

In 1971, the first human polyomavirus was isolated from the brain of a patient who died from a rapidly progressing demyelinating disease known as progressive multifocal leukoencephalopathy. The virus was named JC virus after the initials of the patient. In that same year a second human polyomavirus was discovered in the urine of a kidney transplant patient and named BK virus. In the intervening years it became clear that both viruses were widespread in the human population but only rarely caused disease. The past decade has witnessed the discovery of eleven new human polyomaviruses, two of whi…

[Genetic diversity of human immunodeficiency viruses and antiretroviral therapy].

The lecture is devoted to the analysis of the state-of-the-art of the impact of genetic diversity of human immunodeficiency (HIV) viruses on the pattern of infection and the efficiency of antiretroviral therapy (ART). It provides brief information on the origin and evolution of HIV and on the current classification of their genetic variants. The molecular epidemiological situation of HIV infection in Russia and nearby states and the major molecular HIV variants that are dominant in these countries, as well as their origin and prevalence trends are characterized. How the diversity of HIV can af…

Drug Repurposing Identifies Inhibitors of Oseltamivir-Resistant Influenza Viruses.

The neuraminidase (NA) inhibitor, oseltamivir, is a widely used anti-influenza drug. However, oseltamivir-resistant H1N1 influenza viruses carrying the H275Y NA mutation spontaneously emerged as a result of natural genetic drift and drug treatment. Because H275Y and other potential mutations may generate a future pandemic influenza strain that is oseltamivir-resistant, alternative therapy options are needed. Herein, we show that a structure-based computational method can be used to identify existing drugs that inhibit resistant viruses, thereby providing a first line of pharmaceutical defense …

Three-dimensional cell culture models for investigating human viruses.

Three-dimensional (3D) culture models are physiologically relevant, as they provide reproducible results, experimental flexibility and can be adapted for high-throughput experiments. Moreover, these models bridge the gap between traditional two-dimensional (2D) monolayer cultures and animal models. 3D culture systems have significantly advanced basic cell science and tissue engineering, especially in the fields of cell biology and physiology, stem cell research, regenerative medicine, cancer research, drug discovery, and gene and protein expression studies. In addition, 3D models can provide u

Respiratory Viruses: Influenza, RSV, and Adenovirus in Kidney Transplantation.

Although advances in immunosuppression and antimicrobial prophylaxis have led to improved patient and graft survival, respiratory viruses continue to be a common cause of morbidity and mortality in immunocompromised populations. We describe the clinical manifestations, diagnosis and treatment options for influenza, respiratory syncytial virus and adenovirus infection in the kidney transplant population.

Imaging and tracking HIV viruses in human cervical mucus.

We describe a systematic approach to image, track, and quantify the movements of HIV viruses embedded in human cervical mucus. The underlying motivation for this study is that, in HIV-infected adults, women account for more than half of all new cases and most of these women acquire the infection through heterosexual contact. The endocervix is believed to be a susceptible site for HIV entry. Cervical mucus, which coats the endocervix, should play a protective role against the viruses. Thus, we developed a methodology to apply time-resolved confocal microscopy to examine the motion of HIV viruse…

Viruses are prevalent in non-ventilated hospital-acquired pneumonia.

BACKGROUND: Hospital-acquired pneumonia arising in non-ventilated patients (NVHAP) is traditionally thought to be caused by bacteria, and little is known about viral etiologies in this syndrome. We sought to describe the prevalence of viruses causing NVHAP and to determine factors independently associated with the isolation of a virus. METHODS: We identified patients with NVHAP over one year and reviewed their cultures to determine etiologies. Patients with a viral process were compared to those with either negative cultures or a bacterial infection to determine variables independently associ…

Hepatocarcinogenesis associated with hepatitis B, delta and C viruses.

Globally, over half a billion people are persistently infected with hepatitis B (HBV) and/or hepatitis C viruses. Chronic HBV and HCV infection frequently lead to fibrosis, cirrhosis and hepatocellular carcinoma (HCC). Co-infections with hepatitis delta virus (HDV), a subviral satellite requiring HBV for its propagation, accelerates the progression of liver disease toward HCC. The mechanisms by which these viruses cause malignant transformation, culminating in HCC, remain incompletely understood, partially due to the lack of adequate experimental models for dissecting these complex disease pro…

Development of high-yield influenza A virus vaccine viruses.

Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for us … m these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin-Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in season …

Blood donors screening for blood born viruses in Poland.

Blood donor screening of viral markers in Poland is based on serologic testing for anti-HCV, HBsAg, anti-HIV1/2 (chemiluminescence tests) and on nucleic acid testing (NAT) for RNA HCV, RNA HIV-1 and DNA HBV performed in minipools of 6 with real-time PCR (MPX 2.0 test on cobas s201) or with TMA in individual donations (Ultrio Plus or Ultrio Elite). Donors of plasma for anti-D and anti-HBs production are tested for parvovirus B19 DNA. Before implementation tests and equipment are evaluated at the Institute of Hematology and Transfusion Medicine (IHTM). The last 20 years witnessed a decreasing tr

RNA Viruses and RNAi: Quasispecies Implications for Viral Escape.

Due to high mutation rates, populations of RNA viruses exist as a collection of closely related mutants known as a quasispecies. A consequence of error-prone replication is the potential for rapid adaptation of RNA viruses when a selective pressure is applied, including host immune systems and antiviral drugs. RNA interference (RNAi) acts to inhibit protein synthesis by targeting specific mRNAs for degradation and this process has been developed to target RNA viruses, exhibiting their potential as a therapeutic against infections. However, viruses containing mutations conferring resistance to …

The RNA synthesis machinery of negative-stranded RNA viruses.

The group of Negative-Stranded RNA Viruses (NSVs) includes many human pathogens, like the influenza, measles, mumps, respiratory syncytial or Ebola viruses, which produce frequent epidemics of disease and occasional, high mortality outbreaks by transmission from animal reservoirs. The genome of NSVs consists of one to several single-stranded, negative-polarity RNA molecules that are always assembled into mega Dalton-sized complexes by association to many nucleoprotein monomers. These RNA-protein complexes or ribonucleoproteins function as templates for transcription and replication by action o…