ABSTRACT
Two different diketopiperazines, cyclo-(L-Pro-L-Leu) and cyclo-(L-Pro-L-Phe), which were isolated from the culture filtrate of Epichloe typhina and found to be inducers of phleichrome production, were chemically synthesized and evaluated for use in the improved production of phleichrome from wild-type and UV-mutagenized strains (M0035) of Cladosporium phlei. When supplemented with PDA and V8 juice agar media, both inducers showed significant increases in the production of phleichrome. Phleichrome production was increased in a dose-dependent manner up to a concentration of maximum yield for both inducers. No further significant induction was observed by supplementing inducers over the concentration of maximum yield. Among the two inducers, cyclo-(L-Pro-L-Phe) showed better inducing capability than cyclo-(L-Pro-L-Leu). The maximum yield was observed from the M0035 strain grown on V8 juice media supplemented with 150 µM cyclo-(L-Pro-L-Phe), which was estimated to be 232.6 mg of phleichrome per gram of mycelia and 10.2 mg of secreted phleichrome per 20 agar-plugs. Interestingly, growth inhibition was observed on V8 juice agar media with 100, 150, and 200 µM cyclo-(L-Pro-L-Phe) but not on PDA with the same amount of inducer, which suggests that the inhibitory effect might be through the overproduction of phleichrome rather than the toxic effect of the inducer itself. Superoxide production by purified phleichrome was dramatically stimulated upon illumination, thus demonstrating photodynamic production of superoxide in vitro by phleichrome.
Subject(s)
Cladosporium/drug effects , Cladosporium/metabolism , Dipeptides/pharmacology , Naphthalenes/metabolism , Reactive Oxygen Species/metabolism , Culture Media/chemistry , Culture Media/metabolism , Diketopiperazines/metabolism , Mycelium/metabolism , Perylene/analogs & derivatives , Perylene/metabolism , Quinones/metabolism , Superoxides/metabolismABSTRACT
BACKGROUNDS/AIMS: Hepatic involvement is frequently observed in patients with miliary tuberculosis, but primary hepatic tuberculosis with no clinical extrahepatic manifestations of tuberculosis is uncommon. With the ever-increasing number of immunocompromised patients, it is expected that hepatic tuberculosis will occur more frequently. The aim of the present study was to establish the clinical manifestations and course of the disease. METHODS: From January 1989 to September 2008, 12 patients were diagnosed with hepatic tuberculosis by liver biopsy at Seoul National University Hospital. We retrospectively evaluated their clinical, laboratory, and imaging findings by medical record review. RESULTS: Four patients had primary hepatic tuberculosis, and eight patients had hepatic tuberculosis secondary to pulmonary or miliary tuberculosis. Three patients were immunocompromised, and six patients had no previous medical problem. An elevated serum level of alkaline phosphatase was the most frequently observed finding in laboratory tests. Imaging studies showed variable findings, including hepatosplenomegaly, multiple hepatic nodules, abscess formation, and even normal findings. Ten patients responded to antituberculosis drugs, and two cases with tuberculous liver abscess had persistent disease despite prolonged therapy. CONCLUSIONS: In patients with a protracted illness, hepatosplenomegaly and/or abnormal liver function tests, hepatic tuberculosis should be suspected, even in healthy young patients or patients with normal imaging findings. Patients with tuberculous abscess formation tend to respond poorly to antituberculosis therapy, and surgery could be considered in these patients.