Publications by authors named "Juan M Ribes"

Prions replicate via the autocatalytic conversion of cellular prion protein (PrP) into fibrillar assemblies of misfolded PrP. While this process has been extensively studied in vivo and in vitro, non-physiological reaction conditions of fibril formation in vitro have precluded the identification and mechanistic analysis of cellular proteins, which may alter PrP self-assembly and prion replication. Here, we have developed a fibril formation assay for recombinant murine and human PrP (23-231) under near-native conditions (NAA) to study the effect of cellular proteins, which may be risk factors or potential therapeutic targets in prion disease.

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The self-templating nature of prions plays a central role in prion pathogenesis and is associated with infectivity and transmissibility. Since propagation of proteopathic seeds has now been acknowledged a principal pathogenic process in many types of dementia, more insight into the molecular mechanism of prion replication is vital to delineate specific and common disease pathways. By employing highly discriminatory anti-PrP antibodies and conversion-tolerant PrP chimera, we here report that de novo PrP conversion and formation of fibril-like PrP aggregates are distinct in mechanistic and kinetic terms.

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Prion diseases are fatal neurodegenerative diseases that affect humans and animals. Prion strains, conformational variants of misfolded prion proteins, are associated with distinct clinical and pathological phenotypes. Host-strain interactions result in the selective damage of distinct brain areas and they are responsible for strain selection and/or adaptation, but the underlying molecular mechanisms are unknown.

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Genotype II.4 noroviruses (NoVs) are a leading cause of epidemic acute gastroenteritis in children and adults worldwide. The prevalence of different NoV genotypes causing outbreaks and sporadic cases of acute gastroenteritis in the region of Valencia, Spain, during a 4-year period (2008-11) was investigated.

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Acellular materials of xenogenic origin are used worldwide as xenografts, and phase I trials of viable pig pancreatic islets are currently being performed. However, limited information is available on transmission of porcine endogenous retrovirus (PERV) after xenotransplantation and on the long-term immune response of recipients to xenoantigens. We analyzed the blood of burn patients who had received living pig-skin dressings for up to 8 wk for the presence of PERV as well as for the level and nature of their long term (maximum, 34 y) immune response against pig Ags.

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Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents.

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A coronavirus vector based on the genome of the porcine transmissible gastroenteritis virus (TGEV) expressing the rotavirus VP7 protein was constructed to immunize and protect against rotavirus infections in a murine model. The tropism of this TGEV-derived vector was modified by replacing the spike S protein with the homologous protein from mouse hepatitis virus (MHV). The rotavirus gene encoding the VP7 protein was cloned into the coronavirus cDNA.

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Viruses are among the most common causes of acute gastroenteritis. In recent years, new viruses causing outbreaks of acute gastroenteritis have been described. Among these, Aichi virus was identified in Japan in 1989.

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A prospective study was conducted to evaluate two immunochromatography (ICG) commercial kits for diagnosis of rotavirus infection, VIKIA Rota-Adeno (bioMérieux) and Simple Rota-Adeno (Operon). Reverse transcriptase and polymerase chain reaction (RT-PCR) with specific primers for the VP7 gene of group A rotavirus was used as the reference method. The sensitivity and specificity of the ICG tests compared with those of the reference method were 98.

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Noroviruses are the most common cause of outbreaks of viral gastroenteritis worldwide. Norovirus outbreaks were surveyed in Catalonia and the region of Valencia (Eastern Spain) between January 2001 and December 2006 as part of the European Union funded network "Food-borne viruses in Europe". During this time the etiology and epidemiological features of 194 outbreaks of acute non-bacterial gastroenteritis were investigated and norovirus was identified as causing 169 (87.

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DNA vaccination using a plasmid encoding the rotavirus inner capsid VP6 has been explored in the mouse model of rotavirus infection. BALB/c mice were immunized with a VP6 DNA vaccine by the intramuscular, nasal and oral routes. VP6 DNA vaccination by the nasal and oral routes induced the production of anti-VP6 IgA antibodies by intestinal lymphoid cells.

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