Study of vascular movement of Potato virus X (PVX) TGBp1, TGBp2 and CP using the Commelina yellow mottle virus promoter and GFP

Scope and Method of Study:The green fluorescent protein (GFP) was fused to Potato virus X (PVX) TGBp1, TGBp2, or coat protein (CP) genes and inserted into the plasmids next to a companion cell specific CoYMV promoter. These plasmids were used to prepare transgenic tobacco plants expressing PVX proteins specifically in the phloem. Transgenic tobacco plants expressing a GFP:GFP fusion were also prepared as a control. GFP fluorescence was used to visualize phloem translocation and exit of the fusion proteins. Immunofluorescence and immunogold labeling was used to characterize the sub-cellular distribution of the fusion proteins within phloem.Findings and Conclusions:Fluorescence due to GFP:TGBp1, GFP:TGBp2, GFP:CP, and GFP:GFP was seen in transgenic tobacco leaf veins and failed to spread to nonvascular tissue. However, following PVX inoculation of GFP:TGBp1 and GFP:CP transgenic plants fluorescence spread into nonvascular tissues. Thus the destination of GFP:TGBp1 and GFP:CP, but not GFP:TGBp2 and GFP:GFP was altered by the presence of the virus indicating that the TGBp1 and CP directly interact with the virus to unload from the veins. Further studies explored phloem translocation of proteins within the stem and petioles. In petiole cross sections all fusion proteins were seen in phloem companion cells, sieve elements, and phloem parenchyma indicating that the proteins spread from the companion cells into surrounding phloem tissues. Only GFP:TGBp1 was seen in xylem parenchyma indicating that TGBp1 has a specific ability to move extensively throughout the vasculature. Nontransgenic scions were grafted to transgenic rootstocks and after 28 days fluorescence was seen in scions indicating that all fusions were phloem mobile.Immunogold labeling and transmission electron microscopy revealed GFP:TGBp1 and GFP:CP accumulated in the chloroplasts, plastids, vacuoles and cytoplasm in companion cells, and associated with plastids and P-proteins in sieve elements. GFP:TGBp1 expressing plants showed increased numbers of starch bodies in xylem parenchyma, pericycles and endodermal cells and fewer tracheary elements in petiole cross sections suggesting that TGBp1 affects vascular development and carbohydrate partitioning

Complete nucleotide sequences and genome organization of a cherry isolate of cherry leaf roll virus

The complete nucleotide sequence of cherry leaf roll virus (CLRV, genus Nepovirus) from a naturally infected cherry tree (Prunus avium cv. Bing) in North America was determined. RNA1 and RNA2 consist of 7,893 and 6,492 nucleotides, respectively, plus a poly-(A) tail. Each RNA encodes a single potential open reading frame. The first 657 nucleotides of RNA1 and RNA2 are 99% identical and include the 5′-UTR and the first 214 deduced amino acids of the polyproteins following the first of two in-frame start codons. Phylogenetic analysis reveals close relationships between CLRV and members of subgroup C of the genus Nepovirus

Off-label drug use in hospitalized children: a prospective observational study at Gondar University Referral Hospital, Northwestern Ethiopia

Most of the medications which are currently used for the treatment of childhood diseases are either not licensed or being prescribed outside the terms of the product license (off-label prescribing). This study aimed at determining the extent of unlicensed and off-label drug uses and associated factors in children hospitalized in Gondar University Referral Hospital, Northwest Ethiopia. An institution-based prospective cross-sectional study was employed from April 15 to July 15, 2016. A total of 243 pediatric patients admitted to Gondar university referral hospital were included in the study using simple random sampling method. Data were collected using structured questionnaire, and the data collected were entered and analyzed using Statistical Packages for Social Sciences (SPSS) version 20. From the total of 800 drugs prescribed, 607 (75.8%) were off-label. Off-label medicine use was frequently observed in antimicrobials (60.6%) followed by central nervous system drugs (14.3%). The extent off-label prescribing was highest in age group of 6-13 years (30%). Inappropriate dosing and frequency (42.3%) were the most common reason for off-label medicine use. Having other variables controlled, age group and undergoing surgical procedure remained to be significant predictors of off-label prescribing in the multivariate regression analysis. Implementing evidence-based approach in prescribing by generating more quality literatures on the safety profile and effectiveness of off-label would improve the injudicious use of drugs in pediatric population

A systems model describing the impact of organic resource use on farming households in low to middle income countries

We present a new systems model that encompasses both environmental and socioeconomic outcomes to simulate impacts of organic resource use on livelihoods of smallholder farmers in low to middle income countries. It includes impacts on soils, which in many countries are degrading with long term loss of organic matter. Many farmers have easy access to animal manures that could be used to increase soil organic matter, but this precious resource is often diverted to other purposes, such as fuels, also resulting in loss of the nutrients needed for crop production. This model simulates impacts of different management options on soil organic matter turnover, availability of water and nutrients, crop and animal production, water and energy use, labour requirements and household income and expenditure. An evaluation and example application from India are presented and used to illustrate the importance of considering the whole farm system when developing recommendations to help farmers improve their soils