Identification of GBV-D, a Novel GB-like Flavivirus from Old World Frugivorous Bats (Pteropus giganteus) in Bangladesh

Bats are reservoirs for a wide range of zoonotic agents including lyssa-, henipah-, SARS-like corona-, Marburg-, Ebola-, and astroviruses. In an effort to survey for the presence of other infectious agents, known and unknown, we screened sera from 16 Pteropus giganteus bats from Faridpur, Bangladesh, using high-throughput pyrosequencing. Sequence analyses indicated the presence of a previously undescribed virus that has approximately 50% identity at the amino acid level to GB virus A and C (GBV-A and -C). Viral nucleic acid was present in 5 of 98 sera (5%) from a single colony of free-ranging bats. Infection was not associated with evidence of hepatitis or hepatic dysfunction. Phylogenetic analysis indicates that this first GBV-like flavivirus reported in bats constitutes a distinct species within the Flaviviridae family and is ancestral to the GBV-A and -C virus clades

Hepatic progenitor cells of biliary origin with liver repopulation capacity

Hepatocytes and cholangiocytes self-renew following liver injury. Following severe injury hepatocytes are increasingly senescent, but whether hepatic progenitor cells (HPCs) then contribute to liver regeneration is unclear. Here, we describe a mouse model where the E3 ubiquitin ligase Mdm2 is inducibly deleted in more than 98% of hepatocytes, causing apoptosis, necrosis and senescence with nearly all hepatocytes expressing p21. This results in florid HPC activation, which is necessary for survival, followed by complete, functional liver reconstitution. HPCs isolated from genetically normal mice, using cell surface markers, were highly expandable and phenotypically stable in vitro. These HPCs were transplanted into adult mouse livers where hepatocyte Mdm2 was repeatedly deleted, creating a non-competitive repopulation assay. Transplanted HPCs contributed significantly to restoration of liver parenchyma, regenerating hepatocytes and biliary epithelia, highlighting their in vivo lineage potency. HPCs are therefore a potential future alternative to hepatocyte or liver transplantation for liver disease

TT virus infection in children and adults who visited a general hospital in the south of Brazil for routine procedure

TT virus (TTV) is a newly described nonenveloped human virus, with a circular, negative-stranded DNA genome, that was first identified in the blood of a patient with posttransfusion hepatitis of unknown etiology. PCR primers and conditions used for TTV DNA amplification may greatly influence the level of TTV detection in serum. Three PCR assays, with different regions of the genome as targets, were used to test TTV DNA in 130 sera from children and adults visiting a hospital in the south of Brazil, most of them for routine procedure. Forty-four percent of adult sera and 73% of sera from children aged 0-10 years were TTV positive with at least one PCR assay. However, the three assays were able to detect only 33%, 35%, and 70% of the total positive samples. Our results showed a high prevalence of TTV infection in the south of Brazil, particularly among young children, and confirmed the necessity of performing several PCR assays to assess the true TTV prevalence in a determined population