Virome identification in wheat in the Czech Republic using small RNA deep sequencing

High-throughput deep-sequencing technology and bioinformatics analysis of the small RNA(sRNA)population isolated from plants allows universal virus detection and complete virome reconstruction for a given sample.In the present sRNA deep-sequencing analysis of virus-infected wheat samples in the Czech Republic,samples were firstly tested for barley yellow dwarf viruses(BYDVs),wheat streak mosaic virus(WSMV)and wheat dwarf virus(WDV)using ELISA,RT-PCR and PCR.Subsequent sRNA sequencing of these samples yielded more than^60 million single-end 50-bp reads with high confidence for nine field samples of wheat.Overall,16.5%of reads were virus-specific and 83.5%were mapped to the host.More 21-nt reads(-7.7E+06 reads)were found than 24-nt(~6.20E+06 reads)or 22-nt(-4.30E+06 reads)reads.De novo assembly of the high-quality contigs revealed the presence of three earlier repoted viruses in the Czech Republic:BYDVs(31.48%),WSMV(24.23%)and WDV(2666%).We also showed the presence of cereal yellow dwarf virus(14.33%;two species CYDV-RPS and CYDV-RPV family Luteoviridae/Polerovirus)and wheat yellow dwarf virus(WYDV,3.30%;Luteoviridae).Phylogenetic analysis showed CYDV and WYDV grouped separately from BYDVs.Furthermore,several recombination breakpoints were found among the groups of yellow dwarf viruses(BYDVs,CYDV,and WYDV).Using RNA deep sequencing,we confirmed the presence of the three known viruses(BYDVs,WSMV,and WDV)and the first record of two species of CYDV and WYDV in wheat in the Czech Republic.

Biliary obstruction following transjugular intrahepatic portosystemic shunt placement in a patient after liver transplantation:A case report

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)is a method used to decrease portal hypertension.Biliary stricture is the rarest of the complications associated with this procedure with only 12 cases previously reported in the literature.None of these cases have documented the resolution of biliary stenosis induced by a stent graft.The only curative solutions reported are liver transplantation or bypassing the stenosis with an artificial biliary tract using advanced endoscopic techniques.CASE SUMMARY This is the first reported case of biliary obstruction secondary to TIPS placement in a transplanted liver.In our patient,a portosystemic shunt was created to treat severe veno-occlusive liver graft disease manifesting itself primarily by fluid retention.A cholestatic liver lesion and cholangitis with abscesses developed due to a stent graft-induced stricture in the dorsal segment of the right hepatic duct and the stricture diminished following percutaneous drainage.Endoscopic drainage was performed after unsuccessful removal of the percutaneous catheter resulting in a bilio-cutaneous fistula.Although the liver graft now functions well,the stricture remains refractory even after 44 mo of treatment.CONCLUSION Biliary strictures caused by TIPS in both transplanted and native livers seem refractory to endoscopic treatment.

Endoscopic radiofrequency ablation for malignant biliary obstruction

Cholangiocarcinoma and pancreatic cancer are the most common causes of malignant biliary obstruction.The majority of patients are diagnosed at a late stage when surgical resection is rarely possible.In these cases,palliative chemotherapy and radiotherapy provide only limited benefit and are associated with poor survival.Radiofrequency ablation(RFA)is a procedure for locoregional control of tumours,whereby a high-frequency alternating current turned into thermal energy causes coagulative necrosis of the tissue surrounding the catheter.The subsequent release of debris and tumour antigens by necrotic cells can stimulate local and systemic immunity.The development of endoluminal RFA catheters has led to the emergence of endoscopically delivered RFA,a treatment mainly used for malignant biliary strictures to prolong survival and/or stent patency.Other indications include recanalisation of occluded biliary stents and treatment of intraductal ampullary adenoma or benign biliary strictures.This article presents a comprehensive review of endobiliary RFA,mainly focusing on its use in patients with malignant biliary obstruction.The available data suggest that biliary RFA may be a promising modality,having positive impacts on survival and stent patency and boasting a reasonable safety profile.However,further studies with better characterised and stratified patient populations are needed before the method becomes accepted within routine clinical practice.