Search results for " viral"
showing 10 items of 1354 documents
Molecular surveillance of norovirus, 2005–16 : an epidemiological analysis of data collected from the NoroNet network
2018
BACKGROUND: The development of a vaccine for norovirus requires a detailed understanding of global genetic diversity of noroviruses. We analysed their epidemiology and diversity using surveillance data from the NoroNet network.METHODS: We included genetic sequences of norovirus specimens obtained from outbreak investigations and sporadic gastroenteritis cases between 2005 and 2016 in Europe, Asia, Oceania, and Africa. We genotyped norovirus sequences and analysed sequences that overlapped at open reading frame (ORF) 1 and ORF2. Additionally, we assessed the sampling date and country of origin of the first reported sequence to assess when and where novel drift variants originated.FINDINGS: W…
Treatment options in HBV.
2005
The available evidence on interferon-alpha (IFN) treatment for chronic hepatitis B is sufficient to conclude that in patients with HBeAg positive chronic hepatitis, standard IFN therapy significantly improves clearance of HBeAg (number needed to treat [NNT] = 4), loss of HBV-DNA (NNT = 4) and clearance of HBsAg (NNT = 18). HBeAg positive patients with normal or slightly raised ALT should be treated only if there is histological evidence of progressive disease. In patients with HBeAg negative chronic hepatitis, less than 20% of subjects who have achieved an end-of-treatment virological response after a course of standard IFN maintain a sustained virological response in the long-term. IFN tre…
SARS-CoV-2 antibodies, serum inflammatory biomarkers and clinical severity of hospitalized COVID-19 patients
2020
Background The involvement of SARS-CoV-2 antibodies in mediating immunopathogenetic events in COVID-19 patients has been suggested. By using several experimental approaches, we investigated the potential association between SARS-CoV-2 IgGs recognizing the spike (S) protein receptor-binding domain (RBD), neutralizing antibodies (NtAb) targeting S, and COVID-19 severity. Patients and methods This unicenter, retrospective, observational study included 51 hospitalized patients (24 at the intensive care unit; ICU). A total of 93 sera from these patients collected at different time points from the onset of symptoms were analyzed. SARS-CoV-2 RBD IgGs were quantitated by ELISA and NtAb50 titers wer…
Assessment of SARS-CoV-2 RNA shedding in semen of 36 males with symptomatic, asymptomatic, and convalescent infection during the first and second wav…
2022
: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), has been identified in the human testis, but the risk of transmission of SARS-CoV-2 through sexual intercourse still needs to be defined. The goal of our study was to determine if SARS-CoV-2 is detectable in the semen of patients suffering or recovering from coronavirus disease-19 (COVID-19), still testing positive at nasopharyngeal swabs but showing mild or no symptoms at the time of sampling. Detection of SARS-CoV-2 RNA in semen was performed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR targeting open reading frame (ORF) 1ab. Medical …
Cloning and expression of a cDNA copy of the viral K28 killer toxin gene in yeast
1995
The killer toxin K28, secreted by certain killer strains of the yeast Saccharomyces cerevisiae is genetically encoded by a 1.9 kb double-stranded RNA, M-dsRNA (M28), that is present within the cell as a cytoplasmically inherited virus-like particle (VLP). For stable maintenance and replication, M28-VLPs depend on a second dsRNA virus (LA), which has been shown to encode the major capsid protein (cap) and a capsid-polymerase fusion protein (cap-pol) that provides the toxin-coding M-satellites with their transcription and replicase functions. K28 toxin-coding M28-VLPs were isolated, purified and used in vitro for the synthesis of the single-stranded M28 transcript, which was shown to be of pl…
A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts
2020
Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in‐house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV…
Peptide Processing Is Critical for T-Cell Memory Inflation and May Be Optimized to Improve Immune Protection by CMV-Based Vaccine Vectors.
2016
Cytomegalovirus (CMV) elicits long-term T-cell immunity of unparalleled strength, which has allowed the development of highly protective CMV-based vaccine vectors. Counterintuitively, experimental vaccines encoding a single MHC-I restricted epitope offered better immune protection than those expressing entire proteins, including the same epitope. To clarify this conundrum, we generated recombinant murine CMVs (MCMVs) encoding well-characterized MHC-I epitopes at different positions within viral genes and observed strong immune responses and protection against viruses and tumor growth when the epitopes were expressed at the protein C-terminus. We used the M45-encoded conventional epitope HGI…
Guinea pig transglutaminase immunolinked assay does not predict coeliac disease in patients with chronic liver disease
2001
BACKGROUND—It has been suggested that serological screening for coeliac disease (CD) should be performed in patients with chronic unexplained hypertransaminasaemia. AIMS—To evaluate the specificity for CD diagnosis of serum IgA antitissue transglutaminase (tTG) determination in consecutive patients with chronic hypertransaminasaemia using the most widely utilised ELISA based on tTG from guinea pig as the antigen. PATIENTS AND METHODS—We studied 98 patients with chronic hypertransaminasaemia, evaluated for the first time in a hepatology clinic. Serum anti-tTG and antiendomysial (EmA) assays were performed. Patients positive for EmA and/or anti-tTG were proposed for intestinal biopsy. Finally…
Detection of Hepatitis B Virus DNA in the Liver of Children with Chronic Hepatitis B by In Situ Hybridization and Its Relation to Other Viral Markers
1992
The aim of the study was to detect hepatitis B virus (HBV) DNA by in situ hybridization (ISH) with a 35S-labeled radioactive probe in frozen liver biopsy tissue sections of 63 hepatitis B virus surface antigen (HBsAg)-positive children. The results were compared to other markers of viral replication. HBV DNA was detected in 48 children. Of the 15 negative cases, four had hepatitis B envelope antigen (HBeAg), 10 anti-HBe, and one neither HBeAg nor anti-HBe. Free HBV DNA in serum and liver was positive in one patient. Forty of the positive children were HBeAg- and six anti-HBe-positive; two were negative for both. Of 45 36 had HBV DNA in serum. In 38 of 47 HBV DNA and in 31 of 42 HBcAg could …
Infection of murine hepatocyte cultures by herpes simplex virus (HSV) 1 and 2
1984
A study was undertaken of the interaction between liver cells and Herpes Simplex Virus (HSV) in vitro. Hepatocytes were obtained from HSV-resistant (C57/B16) and from HSV-susceptible (BALB/c, A/J, C3H) mouse strains and cultured according to standard methods. Each culture was infected with several strains of HSV-type 1 or of HSV-type 2, respectively. The multiplicity of infection was 5. The cytopathic effect was evaluated by light- and electron-microscopy. The number of infectious particles was determined using rabbit kidney or Vero cell cultures. All evaluations were made at different time intervals after infection. No difference concerning the replication rate of HSV-1 and 2 in isolated h…