A new compound from an endophytic fungus Alternaria tenuissima

A new secondary metabolite, named altertoxin IV (1), together with altertoxin II (2), was isolated from the fermentation broth of Alternaria tenuissima, an endophytic fungal strain residing in the stem of Tribulus terrestris L. The structure of new compound 1 was established by HR-ESI-MS, multinuclear NMR spectroscopy, and single crystal X-ray diffraction method. In their in vitro bioassay, compound 2 exhibited moderate cytotoxic activity against PC-3 cell lines with an IC₅₀ value of 14.28 μM.     

Two new compounds from the broth of the marine fungus Penicillium griseofulvum Y19-07

Two new compounds, 4-hydroxyphenethyl methyl succinate (1) and 4-hydroxyphenethyl 2-(4-hydroxyphenyl)acetate (2), were isolated from the EtOAc extract of the broth of the marine fungus Penicillium griseofulvum Y19-07. Five known compounds were also obtained in this study. The structures of the new compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. All of the isolates were evaluated for their scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl free radical by spectroscopic assays. Also, in the cytotoxicity assay of the two new compounds against HL-60 and PC-3 prostate cancer cell lines, compound 2 showed potential activity with an IC₅₀ value of 64.5 μM against human HL-60 cancer cells.     

Two new indole-diterpenoids from the fungus Penicilliumcrustosum YN-HT-15

Two new indole-diterpenoids named penijanthine B and penitrem H (1 and 2) were isolated from the metabolites of the fungus Penicilliumcrustosum YN-HT-15, which was isolated from the red soil of Yunnan Province of China. The structures were determined on spectroscopic analyses and CD spectra.     

Structure characterization and immunocompetence of a glucan from the fruiting bodies of Cantharellus cibarius

A protein-bound polysaccharide fraction (JBP-1) was obtained from the fruiting bodies of Cantharellus cibarius. Its chemical composition was studied by the cooperative usage of multiple chemical and spectral methods and characterized to be a fraction with a molecular weight of 4.8 × 10⁵ Da and only composed of glucose. Methylation analysis revealed that the sugar residues in JBP-1 are existing as t-, 1,6-, and 1,3,6-linked Glcp sugar residues. The immunocompetence of the fraction was evaluated with the proliferation assay of mouse splenocytes, and the result revealed that JBP-1 could significantly stimulate the proliferation of mouse splenocytes in a dose-dependent manner, with p < 0.001 at the concentration of 100 μg/ml and 30 μg/ml, p < 0.05 at 10 μg/ml. These results give us a primary scientific evidence to further explore the pharmaceutical function of this mushroom.     

铁皮石斛内生真菌Verticillium sp. KY-18的化学成分研究

目的研究铁皮石斛Dendrobium officinale内生真菌Verticillium sp.KY-18中氧杂环类化合物。方法采用色谱分离技术进行分离和纯化,并根据谱学数据鉴定化合物的结构。结果从Verticillium sp.KY-18的发酵产物中分离得到13个氧杂环类化合物,分别鉴定为2,6-dihydroxy-2-methyl-7-(prop-1E-enyl)-1-benzofuran-3(2H)-one(1)、nigrosporapyrone D(2)、oosponol(3)、2-甲基-4-吡喃酮(4)、6-甲基-5-[(1E)-丁烯基]-2-吡喃酮(5)、penicisochroman D(6)、verrucosapyrone B(7)、(1S,3S)-1,8-dimethoxy-3,5-dimethyl-6-hydroxyisochroman(8)、phomopsinone A(9)、pseudohalonectrin A(10)、dictafolin-A(11)、2,3-dihydro-5,7-dihydroxy-2,6,8-trimethyl-4H-1-benzopyran-4-one(12)、2-pyrone-4,6-dicarboxylic acid(13)。结论化合物2~10为首次从该属真菌中分离得到;化合物11~13为首次从该真菌中分离得到。     

Clinical significance of cultures collected from fine-needle aspiration biopsy

The rate of positive cultures in fine-needle aspiration biopsy (FNAB) specimens is evaluated, and the value of submitting FNAB culture is assessed. Review of 3,300 FNAB specimens from 2,416 patients were tabulated for culture results, when obtained from the FNAB material. For positive culture results, clinical impact was assessed. Of 3,300 FNAB specimens and 2,416 patients, 185 had cultures performed (6% of specimens, 8% of patients). Of the 185 cultured specimens, 63 (34%) were positive and 122 (66%) were negative. Of the 63 positive cultures, 23 (12% of all FNAB cultures) had a significant impact on patient care. In our institution the FNA culture rate is 6%. When cases with clinical or microscopic suspicion of infection are cultured, 34% are positive for aerobic or anaerobic bacteria, mycobacteria or fungus. Culture in FNA specimens is a useful adjunct to diagnosis and impacts care in 12% of patients cultured at FNAB. This method can be used to triage patients with suspected infectious diseases and can aid in managing patients who may have recurrent infections.     

Modelling the effect of environmental factors on the hyphal growth of the basidiomycete Physisporinus vitreus

The present work investigated the effects of environmental factors on the growth of fungal colonies of the white‐rot basidiomycetes Physisporinus vitreus using a lattice‐free discrete modeling approach called the fungal growth model (FGM), in which hyphae and nutrients are considered as discrete structures. A discrete modeling approach enables the underlying mechanistic rule concerning the basic architecture and dynamics of fungal networks to be studied on the scale of a single colony. By comparing simulations of the FGM with laboratory experiments of fungal colonies growing on malt extract agar we show that the combined effects of water activity, temperature and pH on the radial growth rate of fungal mycelia on the macroscopic scale may be explained by a power law for the costs of hyphal maintenance and expansion on the microscopic scale. Information about the response of the fungal mycelium at the micro‐ scopic level to environmental conditions is essential for simulating its behavior in complex structure substrates such as wood, where the effect of the fungus on the wood (i.e. the degradation of the cell wall) changes the local environmental condition (e.g. the permeability of the substrate and therefore the water activity in a colonized wood cell lumen). Using a combination of diffusion and moisture processes with the FGM may increase our understanding of the colonization strategy of P. vitreus and help to optimize its growth behavior for biotechnological applications such as bioincising. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Weekend compared with weekday presentations of peritoneal dialysis-associated peritonitis

♦ Objective: Management of peritoneal dialysis (PD)-associated peritonitis requires timely intervention by experienced staff, which may not be uniformly available throughout the week. The aim of the present study was to examine the effects of weekend compared with weekday presentation on peritonitis outcomes.♦ Methods: The study, which used data from the Australia and New Zealand Dialysis and Transplant Registry, included all Australian patients receiving PD between 1 October 2003 and 31 December 2008. The independent predictors of weekend presentation and subsequent peritonitis outcomes were assessed by multivariate logistic regression.♦ Results: Peritonitis presentation rates were significantly lower on Saturdays [0.46 episodes per year; 95% confidence interval (CI): 0.42 to 0.49 episodes per year] and on Sundays (0.43 episodes per year; 95% CI: 0.40 to 0.47 episodes per year) than all other weekdays; they peaked on Mondays (0.76 episodes per year; 95% CI: 0.72 to 0.81 episodes per year). Weekend presentation with a first episode of peritonitis was independently associated with lower body mass index and residence less than 100 km away from the nearest PD unit. Patients presenting with peritonitis on the weekend were significantly more likely to be hospitalized [adjusted odds ratio (OR): 2.32; 95% CI: 1.85 to 2.90], although microbial profiles and empiric antimicrobial treatments were comparable between the weekend and weekday groups. Antimicrobial cure rates were also comparable (79% vs 79%, p = 0.9), with the exception of cure rates for culture-negative peritonitis, which were lower on the weekend (80% vs 88%, p = 0.047). Antifungal prophylaxis was less likely to be co-prescribed for first peritonitis episodes presenting on weekdays (OR: 0.68; 95% CI: 0.05 to 0.89).♦ Conclusions: Patients on PD are less likely to present with peritonitis on the weekend. Nevertheless, the microbiology, treatment, and outcomes of weekend and weekday PD peritonitis presentations are remarkably similar. Exceptions include the associations of weekend presentation with a higher hospitalization rate and a lower cure rate in culture-negative infection.     

Activity of Metarhizium spp. and Isaria spp. from the Central Brazilian Cerrado against Triatoma infestans nymphs

Entomopathogenic fungi attack Chagas disease vectors, and there is a need of effective isolates for development of biological control. Ten isolates of Metarhizium spp., four of Isaria cateniannulata and two of an Isaria sp., all isolated with Triatoma infestans as a bait insect from soils collected in Central Brazil, and tested under laboratory conditions were effective against third instar nymphs of T. infestans. This is the first report of pathogenicity of M. flavoviride var. pemphigi, M. robertsii and I. cateniannulata against T. infestans. M. robertsii IP 34 and I. cateniannulata IP 141 are among the most virulent fungi reported, and both have potential for integrated control of triatomine vectors.     

Effects of atrazine, agricultural runoff, and selected effluents on antimicrobial activity of skin peptides in Xenopus laevis

Atrazine (technical and formulation), agricultural runoff containing atrazine, and treated sewage and landfill effluents were evaluated for their potential to modulate antimicrobial activity of Xenopus laevis skin secretions against the chytrid fungus, Batrachochytrium dendrobatidis. This chytrid fungus is implicated in several localized mass mortality events, yet the cause of the susceptibility of amphibians to this newly emergent pathogen is unknown. Antimicrobial peptides secreted from dermal glands are thought to provide critical protection against this pathogen. Chronic exposure of X. laevis larvae to agricultural runoff decreased protein content of collected secretions, while treated wastewater effluents increased protein content. However, the in vitro bioactivity was decreased in treatments with both increased and decreased protein. No differences were observed in protein or bioactivity following laboratory exposures of technical atrazine or a typical atrazine formulation (AAtrex^® 4L/Top Surf^®). These findings demonstrate that exposure of an amphibian model to agricultural runoff or effluent from municipal sewage treatment plants and landfills alters peptide production and in vitro activity of protective peptides. Although evidence suggests peptide production and bioactivity is a critical part of amphibian resistance to pathogens such as the chytrid fungus, the implications of observed effects for immunity and infection are not clear.