Impact of chlorpyrifos exposure on lung function in Egyptian adolescent agriculture workers.

Chlorpyrifos (CPF) is a widely used organophosphate insecticide that has been linked to detrimental health effects that range from neurological impacts to respiratory disease. The objective of this study was to assess respiratory symptoms associated with CPF exposure throughout the application season. Urine samples were collected from Egyptian adolescent applicators ( = 206) and non-applicators ( = 72) to assess 3,5,6-trichloro-2-pyridinol (TCPy), a biomarker for CPF exposure, along with spirometry measures to determine lung ventilatory function.

Social-psychological determinants of farmer intention to adopt nutrient best management practices: Implications for resilient adaptation to climate change.

Successful adaptation to global climate change and enhancement of agricultural watersheds' resilience requires widespread use of Nutrient Best Management Practices (NBMPs) by farms of all sizes. In the US, adoption of many NBMP practices is voluntary and insufficient to achieve local and downstream conservation objectives. Despite evidence that both social-psychological factors and socio-economic factors influence farmer decision-making, very few studies of farmers' decision-making related to NBMP adoption combine these two factor groups in a theoretically rigorous way.

spe-43 is required for sperm activation in C. elegans.

Successful fertilization requires that sperm are activated prior to contacting an oocyte. In C. elegans, this activation process, called spermiogenesis, transforms round immobile spermatids into motile, fertilization-competent spermatozoa.

Crystal Structure of the Human Astrovirus Capsid Protein.

Unlabelled: Human astrovirus (HAstV) is a leading cause of viral diarrhea in infants and young children worldwide. HAstV is a nonenveloped virus with a T=3 capsid and a positive-sense RNA genome. The capsid protein (CP) of HAstV is synthesized as a 90-kDa precursor (VP90) that can be divided into three linear domains: a conserved N-terminal domain, a hypervariable domain, and an acidic C-terminal domain.

Identification of Host Cell Factors Associated with Astrovirus Replication in Caco-2 Cells.

Unlabelled: Astroviruses are small, nonenveloped viruses with a single-stranded positive-sense RNA genome causing acute gastroenteritis in children and immunocompromised patients. Since positive-sense RNA viruses have frequently been found to replicate in association with membranous structures, in this work we characterized the replication of the human astrovirus serotype 8 strain Yuc8 in Caco-2 cells, using density gradient centrifugation and free-flow zonal electrophoresis (FFZE) to fractionate cellular membranes. Structural and nonstructural viral proteins, positive- and negative-sense viral RNA, and infectious virus particles were found to be associated with a distinct population of membranes separated by FFZE.

Food sovereignty: an alternative paradigm for poverty reduction and biodiversity conservation in Latin America.

Strong feedback between global biodiversity loss and persistent, extreme rural poverty are major challenges in the face of concurrent food, energy, and environmental crises. This paper examines the role of industrial agricultural intensification and market integration as exogenous socio-ecological drivers of biodiversity loss and poverty traps in Latin America. We then analyze the potential of a food sovereignty framework, based on protecting the viability of a diverse agroecological matrix while supporting rural livelihoods and global food production.

Characterization of human astrovirus cell entry.

Human astroviruses (HAstV) are a frequent cause of gastroenteritis in young children and immunocompromised patients. To understand the early steps of HAstV infection in the highly permissive Caco-2 cell line, the binding and entry processes of the virus were characterized. The half-time of virus binding to the cell surface was about 10 min, while virus decapsidation took around 130 min.

Interactions between carbon sequestration and shade tree diversity in a smallholder coffee cooperative in El Salvador.

Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration.

Inhibition of cellular autophagy deranges dengue virion maturation.

Autophagy is an important component of the innate immune response, directly destroying many intracellular pathogens. However, some pathogens, including several RNA viruses, subvert the autophagy pathway, or components of the pathway, to facilitate their replication. In the present study, the effect of inhibiting autophagy on the growth of dengue virus was tested using a novel inhibitor, spautin-1 (specific and potent autophagy inhibitor 1).

Immature and mature human astrovirus: structure, conformational changes, and similarities to hepatitis E virus.

Human astroviruses (HAstVs) are a major cause of gastroenteritis. HAstV assembles from the structural protein VP90 and undergoes a cascade of proteolytic cleavages. Cleavage to VP70 is required for release of immature particles from cells, and subsequent cleavage by trypsin confers infectivity.

Alternative cell lines to improve the rescue of infectious human astrovirus from a cDNA clone.

A reverse genetics system for human astrovirus (HAstV) was established previously; however, it has not been exploited mainly because cells used for virus packaging are not permissive, requiring several rounds of replication to obtain acceptable infectious virus. In this work, in the search for alternative permissive cell lines to be used as packaging cells, Hek-293 and Huh7.5.

Crystal structure of the human astrovirus capsid spike.

Astroviruses are single-stranded, plus-sense RNA viruses that infect both mammals and birds, causing gastroenteritis and other extraintestinal diseases. Clinical studies have established astroviruses as the second leading cause of viral diarrhea in young children. Here we report the crystal structure of the human astrovirus dimeric surface spike determined to 1.

Role of individual caspases induced by astrovirus on the processing of its structural protein and its release from the cell through a non-lytic mechanism.

Caspases (Casp) activity has been associated with the intracellular proteolytic processing of the structural protein to yield the mature capsid formed by VP70 and with the cell release of human astrovirus (HAstV). This work describes the role of individual Casp on these events. The activity of initiator (-8, -9) and executioner (-3/7) Casp was clearly detected at 12h post-infection.

Infectivity and genome persistence of rotavirus and astrovirus in groundwater and surface water.

In this work, we have characterized the survival of Rhesus rotavirus (RRV) and human astrovirus Yuc8 in clean groundwater and contaminated surface water, as well as in phosphate-buffered solutions maintained in the same conditions as the environmental waters, and have compared the dynamics of virus inactivation with the persistence of the viral genomes, as determined by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). In addition, we also studied the tolerance of these viruses to chlorine disinfection. The reduction of infectivity of astrovirus was higher than for rotavirus, and also higher for both viruses in surface water as compared to groundwater.

Association of the astrovirus structural protein VP90 with membranes plays a role in virus morphogenesis.

VP90, the capsid polyprotein precursor of human astrovirus Yuc8, is assembled into viral particles, and its processing at the carboxy terminus by cellular caspases, to yield VP70, has been correlated with the cell release of the virus. Here, we characterized the effect of the VP90-VP70 processing on the properties of these proteins, as well as on their intracellular distribution. VP90 was found in membrane-enriched fractions (mVP90), as well as in fractions enriched in cytosolic proteins (cVP90), while VP70 was found exclusively in the latter fractions.

Caspases mediate processing of the capsid precursor and cell release of human astroviruses.

In this work we have shown that astrovirus infection induces apoptosis of Caco-2 cells, since fragmentation of cellular DNA, cleavage of cellular proteins which are substrate of activated caspases, and a change in the mitochondrial transmembrane potential occur upon virus infection. The human astrovirus Yuc8 polyprotein capsid precursor VP90 is initially processed to yield VP70, and we have shown that this processing is trypsin independent and occurs intracellularly through four cleavages at its carboxy-terminal region. We further showed that VP90-VP70 processing is mediated by caspases, since it was blocked by the pancaspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethylketone (z-VAD-fmk), and it was promoted by the apoptosis inducer TNF-related apoptosis-inducing ligand (TRAIL).

Protein products of the open reading frames encoding nonstructural proteins of human astrovirus serotype 8.

Human astroviruses have a positive-strand RNA genome, which contains three open reading frames (ORF1a, ORF1b, and ORF2). The genomic RNA is translated into two nonstructural polyproteins, nsp1a and nsp1ab, that contain sequences derived from ORF1a and from both ORF1a and ORF1b, respectively. Proteins nsp1a and nsp1ab are thought to be proteolytically processed to yield the viral proteins implicated in the replication of the virus genome; however, the intermediate and final products of this processing have been poorly characterized.

Molecular biology of rotavirus cell entry.

Rotaviruses, the leading cause of severe dehydrating diarrhea in infants and young children worldwide, are non-enveloped viruses formed by three concentric layers of protein that enclose a genome of double-stranded RNA. The entry of rotaviruses into epithelial cells appears to be a multistep process during which at least three contacts between the virus and cell receptors occur. Different rotavirus strains display different requirements to infect cells.

Proteolytic processing of a serotype 8 human astrovirus ORF2 polyprotein.

Astroviruses require the proteolytic cleavage of the capsid protein to infect the host cell. Here we describe the processing pathway of the primary translation product of the structural polyprotein (ORF2) encoded by a human astrovirus serotype 8 (strain Yuc8). The primary translation product of ORF2 is of approximately 90 kDa, which is subsequently cleaved to yield a 70-kDa protein (VP70) which is assembled into the viral particles.

Heat shock cognate protein 70 is involved in rotavirus cell entry.

In this work, we have identified the heat shock cognate protein (hsc70) as a receptor candidate for rotaviruses. hsc70 was shown to be present on the surface of MA104 cells, and antibodies to this protein blocked rotavirus infectivity, while not affecting the infectivity of reovirus and poliovirus. Preincubation of the hsc70 protein with the viruses also inhibited their infectivity.

Molecular analysis of a serotype 8 human astrovirus genome.

Human astroviruses are an important cause of gastroenteritis. As part of a molecular epidemiological study carried out in Mexico a human astrovirus isolate, Yuc-8, was adapted to grow in CaCo-2 cells, and its entire genome was sequenced. A 15 amino acid deletion in ORF1a, which has been associated with adaptation of astroviruses to grow in cells other than CaCo-2, was present in Yuc-8.