Endoscopic and clinical evaluation of treatment and prognosis of Cronkhite-Canada syndrome: a Japanese nationwide survey.

BackgroundFirst reported in 1955, Cronkhite-Canada syndrome (CCS), a rare syndrome characterized by ectodermal abnormalities and inflammatory changes of the gastrointestinal tract mucosa, has been associated with a poor prognosis and life-threatening malignant complications. In a large population survey, we endeavored to characterize the course and treatment outcome of CCS through clinical and endoscopic assessment, and to explore its optimal treatment and surveillance strategy.MethodsA retrospective analysis of 210 patients with CCS was conducted via a questionnaire-based nationwide survey of 983 teaching hospitals located throughout Japan. We assessed clinical features, endoscopic findings, treatments used, and short- and long-term outcomes.ResultsThe average age at diagnosis was 63.5 years. In all cases, upper or lower gastrointestinal tract polyposis was confirmed, accompanied by characteristic ectodermal abnormalities. Of the treatments used, oral corticosteroids (30-49 mg/day) were the most effective treatment for active disease, with adjunctive nutritional support considered beneficial. With corticosteroid treatment, abdominal symptoms were relieved within a few months, whereas polyp regression often required more than 6 months. Maintenance of endoscopic remission with or without steroids for 3 years significantly lowered the development of CCS-related cancer, compared with relapsers or nonresponders, underscoring the importance of sustained endoscopic remission for cancer prevention.ConclusionsThe prognosis of CCS has greatly improved through the use of improved medical treatment. Although CCS continues to be relentlessly progressive, carrying a high cancer risk, a sufficient dose and duration of corticosteroid therapy accompanied by nutritional support and periodic endoscopic surveillance appears to improve its natural history

A three-component monooxygenase from Rhodococcus wratislaviensis may expand industrial applications of bacterial enzymes

地球外有機化合物に対する微生物代謝の解明から全く新規な酵素系を発見 --生命分子進化の理解や産業応用に期待--. 京都大学プレスリリース. 2021-01-20.The high-valent iron-oxo species formed in the non-heme diiron enzymes have high oxidative reactivity and catalyze difficult chemical reactions. Although the hydroxylation of inert methyl groups is an industrially promising reaction, utilizing non-heme diiron enzymes as such a biocatalyst has been difficult. Here we show a three-component monooxygenase system for the selective terminal hydroxylation of α-aminoisobutyric acid (Aib) into α-methyl-D-serine. It consists of the hydroxylase component, AibH1H2, and the electron transfer component. Aib hydroxylation is the initial step of Aib catabolism in Rhodococcus wratislaviensis C31-06, which has been fully elucidated through a proteome analysis. The crystal structure analysis revealed that AibH1H2 forms a heterotetramer of two amidohydrolase superfamily proteins, of which AibHm2 is a non-heme diiron protein and functions as a catalytic subunit. The Aib monooxygenase was demonstrated to be a promising biocatalyst that is suitable for bioprocesses in which the inert C–H bond in methyl groups need to be activated

Endoscopic and clinical evaluation of treatment and prognosis of Cronkhite-Canada syndrome: a Japanese nationwide survey.

BackgroundFirst reported in 1955, Cronkhite-Canada syndrome (CCS), a rare syndrome characterized by ectodermal abnormalities and inflammatory changes of the gastrointestinal tract mucosa, has been associated with a poor prognosis and life-threatening malignant complications. In a large population survey, we endeavored to characterize the course and treatment outcome of CCS through clinical and endoscopic assessment, and to explore its optimal treatment and surveillance strategy.MethodsA retrospective analysis of 210 patients with CCS was conducted via a questionnaire-based nationwide survey of 983 teaching hospitals located throughout Japan. We assessed clinical features, endoscopic findings, treatments used, and short- and long-term outcomes.ResultsThe average age at diagnosis was 63.5 years. In all cases, upper or lower gastrointestinal tract polyposis was confirmed, accompanied by characteristic ectodermal abnormalities. Of the treatments used, oral corticosteroids (30-49 mg/day) were the most effective treatment for active disease, with adjunctive nutritional support considered beneficial. With corticosteroid treatment, abdominal symptoms were relieved within a few months, whereas polyp regression often required more than 6 months. Maintenance of endoscopic remission with or without steroids for 3 years significantly lowered the development of CCS-related cancer, compared with relapsers or nonresponders, underscoring the importance of sustained endoscopic remission for cancer prevention.ConclusionsThe prognosis of CCS has greatly improved through the use of improved medical treatment. Although CCS continues to be relentlessly progressive, carrying a high cancer risk, a sufficient dose and duration of corticosteroid therapy accompanied by nutritional support and periodic endoscopic surveillance appears to improve its natural history