48 research outputs found

    Treatment of Symptomatic Non-Parasitic Liver Cysts–Surgical Treatment Versus Alcohol Injection Therapy

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    Fourteen patients with benign symptomatic non-parasitic cysts of the liver were either surgically treated, had alcohol injected into the cysts, underwent deroofing of the cyst or in 5, a cystectomy was done. Alcohol was injected into 6 patients and there has been no recurrence for as long as 5 years and 8 months after the treatment. Liver dysfunction occurred in 3 patients given blood transfusion during the surgery and/or postoperative course, an elevated temperature (over 39℃) occurred in one patient. Adverse effects of alcohol injections were minor and transient. Based on our experience, the injection of alcohol is an effective treatment for benign symptomatic cyst of the liver. When a malignancy is suspected on imaging and/or cytologic studies, or when alcohol administration is ineffective, then surgery is indicated

    Comparative functional analysis of CYP71AV1 natural variants reveals an important residue for the successive oxidation of amorpha-4,11-diene

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    AbstractArtemisinin is an antimalarial sesquiterpenoid isolated from the aerial parts of the plant Artemisia annua. CYP71AV1, a cytochrome P450 monooxygenase was identified in the artemisinin biosynthetic pathway. CYP71AV1 catalyzes three successive oxidation steps at the C12 position of amorpha-4,11-diene to produce artemisinic acid. In this study, we isolated putative CYP71AV1 orthologs in different species of Artemisia. Comparative functional analysis of CYP71AV1 and its putative orthologs, together with homology modeling, enabled us to identify an amino acid residue (Ser479) critical for the second oxidation reaction catalyzed by CYP71AV1. Our results clearly show that a comparative study of natural variants is useful to investigate the structure–function relationships of CYP71AV1

    The biosynthetic pathway of potato solanidanes diverged from that of spirosolanes due to evolution of a dioxygenase

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    ジャガイモの毒α-ソラニンはトマトの苦味成分から分岐進化したことを解明. 京都大学プレスリリース. 2021-03-03.Potato (Solanum tuberosum), a worldwide major food crop, produces the toxic, bitter tasting solanidane glycoalkaloids α-solanine and α-chaconine. Controlling levels of glycoalkaloids is an important focus on potato breeding. Tomato (Solanum lycopersicum) contains a bitter spirosolane glycoalkaloid, α-tomatine. These glycoalkaloids are biosynthesized from cholesterol via a partly common pathway, although the mechanisms giving rise to the structural differences between solanidane and spirosolane remained elusive. Here we identify a 2-oxoglutarate dependent dioxygenase, designated as DPS (Dioxygenase for Potato Solanidane synthesis), that is a key enzyme for solanidane glycoalkaloid biosynthesis in potato. DPS catalyzes the ring-rearrangement from spirosolane to solanidane via C-16 hydroxylation. Evolutionary divergence of spirosolane-metabolizing dioxygenases contributes to the emergence of toxic solanidane glycoalkaloids in potato and the chemical diversity in Solanaceae

    Lovastatin insensitive 1, a novel pentatricopeptide repeat protein, is a potential regulatory factor of isoprenoid biosynthesis in Arabidopsis

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    Higher plants have two metabolic pathways for isoprenoid biosynthesis: the cytosolic mevalonate (MVA) pathway and the plastidal non-mevalonate (MEP) pathway. Despite the compartmentalization of these two pathways, metabolic flow occurs between them. However, little is known about the mechanisms that regulate the two pathways and the metabolic cross-talk. To identify such regulatory mechanisms, we isolated and characterized the Arabidopsis T-DNA insertion mutant lovastatin insensitive 1 (loi1), which is resistant to lovastatin and clomazone, inhibitors of the MVA and MEP pathways, respectively. The accumulation of the major products of these pathways, i.e. sterols and chlorophyll, was less affected by lovastatin and clomazone, respectively, in loi1 than in the wild type. Furthermore, the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) activity analysis showed higher activity of HMGR in loi1-1 treated with lovastatin than that in the WT. We consider that the lovastatin-resistant phenotype of loi1-1 was derived from this post-transcriptional up-regulation of HMGR. The LOI1 gene encodes a novel pentatricopeptide repeat (PPR) protein. PPR proteins are thought to regulate the expression of genes encoded in organelle genomes by post-transcriptional regulation in mitochondria or plastids. Our results demonstrate that LOI1 is predicted to localize in mitochondria and has the ability to bind single-stranded nucleic acids. Our investigation revealed that the post-transcriptional regulation of mitochondrial RNA may be involved in isoprenoid biosynthesis in both the MVA and MEP pathways.Peer reviewe

    Foreign DNA detection in genome-edited potatoes by high-throughput sequencing

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    Abstract Genome editing is a powerful breeding technique that introduces mutations into specific gene sequences in genomes. For genome editing in higher plants, nucleotides for artificial nuclease (e.g. TALEN or CRISPR-Cas9) are transiently or stably introduced into the plant cells. After the introduction of mutations by artificial nucleases, it is necessary to select lines that do not contain the foreign nucleotides to overcome GMO regulation; however, there is still no widely legally authorized and approved method for detecting foreign genes in genome-edited crops. Recently, k-mer analysis based on next-generation sequencing (NGS) was proposed as a new method for detecting foreign DNA in genome-edited agricultural products. Compared to conventional methods, such as PCR and Southern hybridization, in principle, this method can detect short DNA fragments with high accuracy. However, this method has not yet been applied to genome-edited potatoes. In this study, we evaluated the feasibility of k-mer analysis in tetraploid potatoes by computer simulation, and also evaluated whether the k-mer method can detect foreign genes with high accuracy by analyzing samples of genome-edited potatoes. We show that when NGS data (at a depth of × 30 the genome size) are used, the k-mer method can correctly detect foreign genes in the potato genome even with the insertion of DNA fragments of 20 nt in length. Based on these findings, we expect that k-mer analysis will be one of the main methods for detecting foreign genes in genome-edited potatoes

    Albinism and cell viability in cycloartenol synthase deficient Arabidopsis

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    Phenotypes of Arabidopsis thaliana that carry mutations in CYCLOARTENOL SYNTHASE 1 (CAS1) which is required in sterol biosynthesis have been described. Knockout mutant alleles are responsible of a male-specific transmission defect. Plants carrying a weak mutant allele cas1-1 accumulate 2,3-oxidosqualene, the substrate of CAS1, in all analyzed organs. Mutant cas1-1 plants develop albino inflorescence shoots that contain low amount of carotenoids and chlorophylls. The extent of this albinism, which affects Arabidopsis stems late in development, may be modulated by the light/dark regime. The fact that chloroplast differentiation and pigment accumulation in inflorescence shoots are associated with a low CAS1 expression could suggest the involvement of 2,3-oxidosqualene in a yet unknown regulatory mechanism linking the sterol biosynthetic segment, located in the cytoplasm, and the chlorophyll and carotenoid biosynthetic segments, located in the plastids, in the highly complex terpenoid network. CAS1 loss of function in a mosaic analysis of seedlings further demonstrated that leaf albinism associated with an accumulation of 2,3-oxidosqualene is a novel phenotype for plant sterol deficient mutant
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