OBJECTIVESTo present a case series of modified transjugular intrahepatic portosystemic shunts (TIPS) and percutaneous transhepatic intrahepatic portosystemic shunts (PTIPS) in cirrhotic patients with ...variceal bleeding (VB). In addition, the scientific literature pertaining to PTIPS was reviewed. METHODSThis retrospective clinical case series included six cirrhotic patients with VB who were treated with PTIPS after the failure of endoscopic band ligation or endoscopic injection sclerotherapy combined with vasoactive drugs. The treatment was conducted between January 2017 and June 2019 at a single institution. Three patients suffered from severe atrophy of the right or left lobar of the liver as well as the main right or left branch of the portal vein. The remaining three patients showed severe atrophy of the whole liver and portal vein, resulting in widening of the liver fissure. A paired t-test was used to compare the changes in portal pressure gradient between before and after the PTIPS operation. The rebleeding rate, treatment efficacy, complications, and technical success rate were all assessed during follow-up. RESULTSAll six PTIPS procedures were performed successfully, with no severe procedural-related complications observed. None of the patients experienced VB during a mean follow-up of 22.8 (range, 18.0-28.0) months. The mean portosystemic pressure gradient decreased from 28.3 ± 4.3 mmHg pre-procedure to 12.3 ± 2.6 mmHg immediately post-procedure (P < 0.001). At follow-up, one patient was found to have developed grade 2 hepatic encephalopathy thrice during the first year, according to the West Haven criteria. However, this was resolved following medical treatment. CONCLUSIONSWhen the patient's portal venous anatomy is unconducive to the performance of TIPS using the transjugular approach, PTIPS can be considered as a safe, effective complementary surgical approach for patients with VB.
Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of ...sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.
Genetic sex determination by W and Z chromosomes has developed independently in different groups of organisms. To better understand the evolution of sex chromosomes and the plasticity of ...sex-determination mechanisms, we sequenced the whole genomes of a male (ZZ) and a female (ZW) half-smooth tongue sole (Cynoglossus semilaevis). In addition to insights into adaptation to a benthic lifestyle, we find that the sex chromosomes of these fish are derived from the same ancestral vertebrate protochromosome as the avian W and Z chromosomes. Notably, the same gene on the Z chromosome, dmrt1, which is the male-determining gene in birds, showed convergent evolution of features that are compatible with a similar function in tongue sole. Comparison of the relatively young tongue sole sex chromosomes with those of mammals and birds identified events that occurred during the early phase of sex-chromosome evolution. Pertinent to the current debate about heterogametic sex-chromosome decay, we find that massive gene loss occurred in the wake of sex-chromosome 'birth'.
Polyploidization has provided much genetic variation for plant adaptive evolution, but the mechanisms by which the molecular evolution of polyploid genomes establishes genetic architecture underlying ...species differentiation are unclear. Brassica is an ideal model to increase knowledge of polyploid evolution. Here we describe a draft genome sequence of Brassica oleracea, comparing it with that of its sister species B. rapa to reveal numerous chromosome rearrangements and asymmetrical gene loss in duplicated genomic blocks, asymmetrical amplification of transposable elements, differential gene co-retention for specific pathways and variation in gene expression, including alternative splicing, among a large number of paralogous and orthologous genes. Genes related to the production of anticancer phytochemicals and morphological variations illustrate consequences of genome duplication and gene divergence, imparting biochemical and morphological variation to B. oleracea. This study provides insights into Brassica genome evolution and will underpin research into the many important crops in this genus.
PDF