Yellow Pigment Aurovertins Mediate Interactions between the Pathogenic Fungus Pochonia chlamydosporia and Its Nematode Host.

Nematophagous fungi are globally distributed soil fungi and well-known natural predators of soil-dwelling nematodes. Pochonia chlamydosporia can be found in diverse nematode-suppressive soils as a parasite of nematode eggs and is one of the most studied potential biological control agents of nematodes. However, little is known about the functions of small molecules in the process of infection of nematodes by this parasitic fungus or about small-molecule-mediated interactions between the pathogenic fungus and its host. Our recent study demonstrated that a P. chlamydosporia strain isolated from root knots of tobacco infected by the root-knot nematode Meloidogyne incognita produced a class of yellow pigment metabolite aurovertins, which induced the death of the free-living nematode Panagrellus redivevus. Here we report that nematicidal P. chlamydosporia strains obtained from the nematode worms tended to yield a total yellow pigment aurovertin production exceeding the inhibitory concentration shown in nematicidal bioassays. Aurovertin D was abundant in the pigment metabolites of P. chlamydosporia strains. Aurovertin D showed strong toxicity toward the root-knot nematode M. incognita and exerted profound and detrimental effects on the viability of Caenorhabditis elegans even at a subinhibitory concentration. Evaluation of the nematode mutation in the ß subunit of F1-ATPase, together with the application of RNA interference in screening each subunit of F1FO-ATPase in the nematode worms, demonstrated that the ß subunit of F1-ATPase might not be the specific target for aurovertins in nematodes. The resistance of C. elegans daf-2(e1370) and the hypersensitivity of C. elegans daf-16(mu86) to aurovertin D indicated that DAF-16/FOXO transcription factor in nematodes was triggered in response to the aurovertin attack. These findings advance our understanding of the roles of aurovertin production in the interactions between nematodes and the pathogen fungus P. chlamydosporia.

Regulation of the growth of cotton bollworms by metabolites from an entomopathogenic fungus Paecilomyces cateniobliquus.

Chemical investigation of one entomopathogenic fungus Paecilomyces cateniobliquus YMF1.01799 led to the isolation and identification of six metabolites, which include three new compounds (2-3, and 5) and three known metabolites. Their structures were established by spectroscopic studies such as 1D and 2D NMR and MS analysis. Insect growth experiments suggested that polyketide-derived compound 1 showed significant inhibitory effect on the growth of cotton bollworm Helicoverpa armigera, while terpenoid-derived metabolite 5 promoted the growth of the larvae. The findings revealed that the entomopathogenic fungus P. cateniobliquus could produce different types of metabolites to regulate growth of the insect.

[Impact of patient compliance on the outcomes in hypertensive patients receiving hydrochlorothiazide based combination therapy with spironolactone or captopril].

OBJECTIVE: To explore the impact of patient compliance on the long-term outcomes in hypertensive patients receiving hydrochlorothiazide (HCTZ) based combination therapy with spironolactone or captopril. METHODS: A total of 853 patients with mild to moderate hypertension were recruited and randomly divided into HCTZ group (HCTZ 12.5 mg q.d), spironolactone group (HCTZ 12.5 mg q.d and spironolactone 20 mg q.d), and captopril group (HCTZ 12.5 mg q.d and captopril 25 mg bid) after 2-week placebo washout period and 6-week loading period for HCTZ. Since the efficacy of combination therapy was proven to be better than monotherapy 1 year after therapy beginning, patients in HCTZ group were randomly assigned to spironolactone group or captopril group. The patients were followed up for 4 years. Patients were divided to compliance (n = 424) or non-compliance group (n = 429) according test drug taking questionnaire. During the follow-up time, the blood pressure and the outcomes were recorded monthly, and blood biochemical parameters were determined once a year. RESULTS: At the end of follow up, incidence of cardio-cerebral vascular events was significantly lower in compliance group (2 fatal, 8 non-fatal) than that in noncompliance group (7 fatal, 21 non-fatal, P < 0.05). Systolic blood pressure [-(19.4 +/- 20.6) mm Hg, 1 mm Hg = 0.133 kPa] and diastolic blood pressure [-(10.7 +/- 13.5) mm Hg] were significantly reduced compared values at baseline and noncompliance group (all P < 0.001) while the reduction did not reach statistically significance in noncompliance group [-(7.3 +/- 18.2) mm Hg and -(3.5 +/- 10.2) mm Hg, all P > 0.05 vs. baseline]. The serum BUN, Cr and UA levels in the compliance group were significantly higher and the serum K(+), CHO, LDL-C level were significantly lower than baseline values. The serum BUN, UA levels in the compliance group were significantly higher while the serum K(+), cholesterol levels were significantly lower than those in the noncompliance group (all P < 0.05). CONCLUSIONS: This study indicates that patient compliance could affect the long-term outcome and antihypertensive efficacy in hypertensive patients receiving HCTZ based combination therapy with spironolactone or captopril.