Multiple artificial microRNAs targeting conserved motifs of the replicase gene confer robust transgenic resistance to negative-sense single-stranded RNA plant virus

MicroRNAs (miRNAs) regulate the abundance of target mRNAs by guiding cleavage at sequence complementary regions. In this study, artificial miRNAs (amiRNAs) targeting conserved motifs of the L (replicase) gene of Watermelon silver mottle virus (WSMoV) were constructed using Arabidopsis pre-miRNA159a as the backbone. The constructs included six single amiRNAs targeting motifs A, B1, B2, C, D of E, and two triple amiRNAs targeting motifs AB1E or B2DC. Processing of pre-amiRNAs was confirmed by agro-infiltration, and transgenic Nicotiana benthamiana plants expressing each amiRNA were generated. Single amiRNA transgenic lines expressing amiR-LB2 or amiR-LD showed resistance to WSMoV by delaying symptom development. Triple amiRNA lines expressing amiR-LB2, amiR-LD and amiR-LC provided complete resistance against WSMoV, with no indication of infection 28 days after inoculation. Resistance levels were positively correlated with amiRNA expression levels in these single and triple amiRNA lines. The triple amiR-LAB1E line did not provide resistance to WSMoV. Similarly, the poorly expressed amiR-LC and amiR-LE lines did not provide resistance to WSMoV. The amiR-LA- and amiR-LB1-expressing lines were susceptible to WSMoV, and their additional susceptibility to the heterologous Turnip mosaic virus harbouring individual target sequences indicated that these two amiRNAs have no effect in vivo. Transgenic lines expressing amiR-LB2 exhibited delayed symptoms after challenge with Peanut bud necrosis virus having a single mismatch in the target site. Overall, our results indicate that two amiRNAs, amiR-LB2 and amiR-LD, of the six designed amiRNAs confer moderate resistance against WSMoV, and the triple construct including the two amiRNAs provides complete resistance

Use of tantalum cones in primary arthroplasty of acute proximal tibial fractures

Metaphyseal tantalum cones in primary total knee arthroplasty and their functional outcome is described using 3 case reports over 6 years. 3 knees in 3 individuals (mean age of 70.4 years) were operated on. Ambulation with walking frame was achieved from post-operation day 1, with weight-bearing as tolerated. Mean range of motion was 122° and Mean Knee Society Score was 88. All showed improvement in pre-operative limb alignment. Radiological fracture union was achieved on an average of 3 months. All were independent ambulators and pain-free at the latest follow-up. Our case series shows that tantalum cones are associated with significant improvements in clinical scores, patient symptoms, range of movement, early weight-bearing and low rates of complications in complex proximal tibial fractures with poor bone stock

Formal degrees and local theta correspondence

10.1007/s00222-013-0460-5Inventiones Mathematicae1953509-67