Plantas de cobertura de solo e seus efeitos no desenvolvimento da cultura do arroz de terras altas em cultivo orgânico.

O experimento foi conduzido numa área experimental em Santo Antônio de Goiás (16º28'S, 49º17'W e altitude de 823 m), no período de junho de 2004 a março de 2005. Utilizou-se a cultivar Aimoré de arroz de terras altas, em seqüência a diferentes plantas de cobertura de solo, com o objetivo de avaliar o índice de área foliar (IAF), número de afilhos, acúmulo de massa de matéria seca (MMS) e o teor de nitrogênio acumulado na fitomassa durante o ciclo da cultura do arroz. O delineamento experimental foi o de blocos ao acaso, com cinco tratamentos e quatro repetições. Os tratamentos foram as diferentes plantas de cobertura de solo, mucuna preta (Mucuna aterrima), crotalária juncea (Crotalaria juncea), guandu anão (Cajanus cajan), sorgo forrageiro (Sorghum bicolor), e o tratamento testemunha com vegetação espontânea (pousio). As leguminosas, com destaque para a crotalária, propiciaram melhores resultados em número de afilhos, IAF, MMS e teor de nitrogênio acumulado, quando comparadas ao tratamento em que se utilizou gramínea como cobertura vegetal. Pode-se concluir que a cultura do arroz apresenta desenvolvimento satisfatório nos diversos tipos de cobertura do solo, principalmente quando conduzida após o cultivo de leguminosas, em sistema orgânico de produção

Human parvovirus 4 'PARV4' remains elusive despite a decade of study

Human parvovirus 4 ('PARV4') is a small DNA tetraparvovirus, first reported in 2005. In some populations, PARV4 infection is uncommon, and evidence of exposure is found only in individuals with risk factors for parenteral infection who are infected with other blood-borne viruses. In other settings, seroprevalence studies suggest an endemic, age-associated transmission pattern, independent of any specific risk factors. The clinical impact of PARV4 infection remains uncertain, but reported disease associations include an influenza-like syndrome, encephalitis, acceleration of HIV disease, and foetal hydrops. In this review, we set out to report progress updates from the recent literature, focusing on the investigation of cohorts in different geographical settings, now including insights from Asia, the Middle East, and South America, and discussing whether attributes of viral or host populations underpin the striking differences in epidemiology. We review progress in understanding viral phylogeny and biology, approaches to diagnostics, and insights that might be gained from studies of closely related animal pathogens. Crucial questions about pathogenicity remain unanswered, but we highlight new evidence supporting a possible link between PARV4 and an encephalitis syndrome. The unequivocal evidence that PARV4 is endemic in certain populations should drive ongoing research efforts to understand risk factors and routes of transmission and to gain new insights into the impact of this virus on human health

Discovery and Genomic Characterization of a Novel Ovine Partetravirus and a New Genotype of Bovine Partetravirus

Partetravirus is a recently described group of animal parvoviruses which include the human partetravirus, bovine partetravirus and porcine partetravirus (previously known as human parvovirus 4, bovine hokovirus and porcine hokovirus respectively). In this report, we describe the discovery and genomic characterization of partetraviruses in bovine and ovine samples from China. These partetraviruses were detected by PCR in 1.8% of bovine liver samples, 66.7% of ovine liver samples and 71.4% of ovine spleen samples. One of the bovine partetraviruses detected in the present samples is phylogenetically distinct from previously reported bovine partetraviruses and likely represents a novel genotype. The ovine partetravirus is a novel partetravirus and phylogenetically most related to the bovine partetraviruses. The genome organization is conserved amongst these viruses, including the presence of a putative transmembrane protein encoded by an overlapping reading frame in ORF2. Results from the present study provide further support to the classification of partetraviruses as a separate genus in Parvovirinae

Human Parvovirus B19 (B19V) Infection in Systemic Sclerosis Patients

BACKGROUND: Our previous reports suggested a possible association between parvovirus B19 (B19V) infection and systemic sclerosis (SSc), based on higher prevalence of B19V DNA in SSc patients in respect to controls.METHODS: In the present study, to further evaluate the differences in the pattern of B19 infection in SSc, skin biopsies and bone marrow samples from patients and controls were analysed for B19V DNA detection, genotyping and viral expression.RESULTS: B19V DNA was detected in skin biopsies from 39/49 SSc patients and from 20/28 controls. Bone marrow showed positive in 17/29 SSc patients, 5/21 haematological patients and 0/10 healthy controls. Genotype 1 was more frequent in skin and bone marrow from patients than from controls. Simultaneous persistence of 2 genotypes was detected in SSc skin and bone marrow samples, never in controls. Viral mRNA for capsid protein was detected in the skin of genotype 1-positive patients and not in control skins.CONCLUSION: The results outline some differences in the rate of persistence of B19V DNA, in the simultaneous persistence of 2 genotypes and in the pattern of viral expression among SSc patients and controls

Effectiveness of nanofiltration in removing small non-enveloped viruses from three different plasma-derived products

10noneThe objective of this study was to assess the ability of nanofiltration of albumin solution, prothrombin complex (PTC) and factor IX (FIX) to remove two small, non-enveloped DNA viruses, parvovirus B19 (B19V) and torque teno virus (TTV). Virus removal was investigated with down-scale experiments performed with sequential steps of 35-nm and 15-nm nanofiltrations of products spiked with virus DNA-positive sera. Viral loads were determined by real-time PCRs. The 15-nm nanofiltration removed more than 4.0 B19V log from all the products, TTV was reduced of more than 3.0 log from albumin solution and FIX by 35-nm and 15-nm nanofiltrations, respectively, being viral DNA undetectable after these treatments. Traces of TTV were still found in PTC after the 15-nm nanofiltration. In conclusion, nanofiltration can be efficacious in removing small naked viruses but, since viruses with similar features can differently respond to the treatment, a careful monitoring of large-scale nanofiltration should be performed. © 2009 British Blood Transfusion Society.mixedMenconi, M. C.; Maggi, F.; Zakrzewska, K.; Salotti, V.; Giovacchini, P.; Farina, C.; ANDREOLI, ELISABETTA; Corcioli, F.; Bendinelli, M.; Azzi, A.Menconi, M. C.; Maggi, F.; Zakrzewska, K.; Salotti, V.; Giovacchini, P.; Farina, C.; Andreoli, Elisabetta; Corcioli, F.; Bendinelli, M.; Azzi, A

Human parvovirus B19 experimental infection in human fibroblasts and endothelial cells cultures

With the aim to detect what kind of cells; in addition to erythroid progenitors, could be involved in the pathogenesis of B 19 infection in some connective tissue diseases, primary Cultures of human fibroblasts (HF) and endothelial cells (HUVEC) were exposed to a B 19 positive serum (350 genome copies/cell). The presence of NS1 and VP1 mRNA, in both HF and HUVEC Cultures 1, 2 and 6 days after the exposure, indicated infection by B 19 virus. However, no significant increase of B 19 DNA level in the infected H[F and HUVEC cultures was detectable through the entire incubation period of 6 days. It is possible that HF and HUVEC are not permissive for B 19 virus replication or, alternatively, that few cells only get infected by B 19 virus. HF and HUVEC stimulation with different growth factors, or cytokines could be required for a B 19 productive infection to occur

Reassortment ability of the 2009 pandemic H1N1 influenza virus with circulating human and avian influenza viruses: Public health risk implications.

Exploring the reassortment ability of the 2009 pandemic H1N1 (A/H1N1pdm09) influenza virus with other circulating human or avian influenza viruses is the main concern related to the generation of more virulent or new variants having implications for public health. After different coinfection experiments in human A549 cells, by using the A/H1N1pdm09 virus plus one of human seasonal influenza viruses of H1N1 and H3N2 subtype or one of H11, H10, H9, H7 and H1 avian influenza viruses, several reassortant viruses were obtained. Among these, the HA of H1N1 was the main segment of human seasonal influenza virus reassorted in the A/H1N1pdm09 virus backbone. Conversely, HA and each of the three polymerase segments, alone or in combination, of the avian influenza viruses mainly reassorted in the A/H1N1pdm09 virus backbone. Of note, A/H1N1pdm09 viruses that reassorted with HA of H1N1 seasonal human or H11N6 avian viruses or carried different combination of avian origin polymerase segments, exerted a higher replication effectiveness than that of the parental viruses. These results confirm that reassortment of the A/H1N1pdm09 with circulating low pathogenic avian influenza viruses should not be misjudged in the prediction of the next pandemic