Bacillus solisilvae sp. nov., isolated from forest soil.

A novel Gram-stain-positive, motile, endospore-forming, rod-shaped bacterial strain, NEAU-cbsb5T, was isolated from forest soil from Changbai Mountain, Heilongjiang Province, China. The isolate grew at 15-40 °C (optimum 30 °C), at pH 6.0-8.0 (optimum pH 7.0) and in the presence of up to 4 % (w/v) NaCl, although NaCl was not required for growth. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain NEAU-cbsb5T formed a distinct lineage within the genus Bacillus and was most closely related to Bacillus acidiceler DSM 18954T (99.1 % similarity) and Bacillus luciferensis JCM 12212T (99.0 %). 16S rRNA gene sequence similarity to sequences of the type strains of other Bacillus species was less than 96.0 %. Average nucleotide identity (ANI) values between NEAU-cbsb5T and its most closely related species were 78.72-84.75 % by ANIm, ANIb and OrthoANIu analysis. The in silico DNA-DNA hybridization values between strain NEAU-cbsb5T and its close relatives B. acidiceler DSM 18954T and B. luciferensis JCM 12212T were both 23.80 %, again indicating they belong to different taxa. The major cellular fatty acids of NEAU-cbsb5T were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and an unknown aminophospholipid. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the predominant menaquinones were MK-7 and MK-6. The genomic DNA G+C content was 33.0 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain NEAU-cbsb5T was classified as a representative of a novel species in the genus Bacillus, for which the name Bacillus solisilvae sp. nov. is proposed. The type strain is NEAU-cbsb5T (=CGMCC 1.14993T=DSM 100485T).

Preclinical pharmacokinetic studies of 3-deazaneplanocin A, a potent epigenetic anticancer agent, and its human pharmacokinetic prediction using GastroPlus™.

DZNep is a potential epigenetic drug, and exerts potent anti-proliferative and pro-apoptotic effects on broad-spectrum carcinomas via disruption of the EZH2 pathway. Antitumor studies on DZNep have been stuck in the preclinical phase because of the lack of information about its integral pharmacokinetic (PK) properties. To circumvent this problem, we extensively investigated the disposition characteristics of the DZNep in rats. By incorporating the disposition data across species into a whole-body physiologically based pharmacokinetic (PBPK) models using the GastroPlus(TM) software, we simulated human PK properties of DZNep and determined whether DZNep could be developed for human cancer therapy. Firstly, DZNep was found to cause nephrotoxicity in a dose-dependent manner in rats and its safe dose was determined to be 10mg/kg. DZNep showed a short plasma elimination half-life (1.1h) in rats, a low protein binding in plasma (18.5%), a low partitioning to erythrocyte (0.78), and a low intrinsic hepatic clearance in rats and humans. There was extensive tissue distribution and predominant renal excretion (80.3%). The simulated rat PBPK model of DZNep was well-verified with satisfactory coefficients of determination for all the tested tissues (R(2)>0.781). The simulated human PBPK model successfully identified that intravenous administration of DZNep at appropriate dosing regimen could be further developed for human non-small cell lung carcinoma treatments. The present findings provide valuable information regarding experimental or in silico PK characteristics of DZNep in rats and humans, which is helpful to guide future studies of DZNep in both preclinical and clinical phases.

Effects of contact lens solution disinfectants against filamentous fungi.

PURPOSE: To assess and compare the antifungal activity of polyhexamethylene biguanide (PHMB), thimerosal, cetylpyridinium chloride, and chlorhexidine, which are disinfectants used in multipurpose disinfectant solutions (MPDSs) against ocular pathogenic Fusarium solani and Aspergillus flavus isolates in vitro. METHODS: The in vitro activity of PHMB, thimerosal, cetylpyridinium chloride, and chlorhexidine was assessed against 40 isolates of ocular pathogenic fungi that included 24 F. solani and 16 A. flavus isolates. The strains were tested by broth dilution antifungal susceptibility testing of filamentous fungi approved by the CLSI (Clinical and Laboratory Standards Institute) M38-A document. RESULTS: MIC90 (minimum inhibitory concentration for 90% of the organisms) values of PHMB were 4 and 16 µg/mL for F. solani and A. flavus, respectively. MIC90 values of thimerosal were 0.0313 and 0.0625 µg/mL for F. solani and A. flavus, respectively. MIC90 values of cetylpyridinium chloride were 2 and 2 µg/mL for F. solani and A. flavus, respectively. MIC90 values of chlorhexidine were 32 and 32 µg/mL for F. solani and A. flavus, respectively. CONCLUSIONS: As a disinfectant used in MPDSs, thimerosal showed the highest levels of antimicrobial activity against ocular pathogenic F. solani and A. flavus isolates. The concentrations of PHMB (0.0001%), cetylpyridinium chloride (0.00014%), and chlorhexidine (0.003%) in MPDSs are sublethal levels for ocular pathogenic F. solani and A. flavus isolates. Although multiple ingredients within MPDSs play a role in antimicrobial efficacy, antimicrobial activity may be significantly influenced by the disinfectants used in the solution formulations.

Phytoplankton blooms: an overlooked marine source of natural endocrine disrupting chemicals.

BACKGROUND: We had previously reported high androgenic and estrogenic activities in seawaters in confined clusters close to Singapore. Further investigations revealed a hitherto unsuspected link between estrogenic/androgenic activity and net phytoplankton count. OBJECTIVE: The primary objective of this study was to investigate the cause of a correlation between net phytoplankton and endocrine activity, and corroborate this observation, and rule out other possible confounding factors. Our secondary objective was to study if these estrogenic secretions can impact human health. METHODS: Five species of phytoplankton, Gymnodinium catenatum, Prorocentrum minimum, Alexandrium leei, Chattonella marina, and Fibrocapsa japonica, were isolated from Singapore waters and mass cultured and the cells and culture media screened for estrogenic and androgenic activity using human cell-based bioassays. RESULTS: The raphidophytes C. marina and F. japonica displayed significant estrogenic activity whilst the dinoflagellates G. catenatum and P. minimum displayed significant androgenic activity in both the cell extracts and the cell culture media extract. CONCLUSIONS: Our data shows that selected phytoplankton isolates are potent secretors of estrogenic and androgenic substances, which are potential endocrine disrupting chemicals (EDCs). As the harmful nature of EDCs is largely due to their bioaccumulation in the aquatic food chain our findings imply that the impact of these phytoplankton secretions needs to be investigated especially for seafoods, which are only a single trophic level away from phytoplankton. Alternatively, should these phytoplankton-origin EDCs not accumulate through marine food chains to significantly impact humans or marine mammals, our results indicate that functional assays could greatly over-estimate the risk from naturally occurring EDCs produced by marine phytoplankton. It remains to be determined if these EDCs affect zooplankton and other organisms that directly feed on marine phytoplankton, or if the secreted EDCs can directly impact other marine fauna.

Selective estrogen receptor modulator effects of epimedium extracts on breast cancer and uterine growth in nude mice.

Epimedium is popularly used in traditional Chinese medicine to treat sexual dysfunction, menstrual irregularity, and osteoporosis. The estrogenic effects of the prenylated flavonoids of Epimedium make it an attractive alternative for hormone replacement therapy. Here, we examined the therapeutic potential of the estrogenic herb extract of Epimedium brevicornum as an alternative to hormone replacement therapy in a breast cancer mouse model. To that end, athymic and ovariectomized female nude mice were subcutaneously injected into the mammary fat pads with MCF-7 breast cancer cells, randomly grouped and fed with soy-free feeds, alone or in combination with ethinyl estradiol or different doses of the estrogenic herb extract of E. brevicornum. Our findings demonstrate that unlike ethinyl estradiol, it did not promote the growth of breast cancer xenograft volume and weight, with the highest dose showing a significant reduction in growth and ERα protein content. Moreover, the extract increased uterine weight at the lowest dose, while higher doses had no effects. Put together, our data shows for the first time that despite the estrogenic activity of E. brevicornum, its action is largely tissue specific and dose-dependent. Our data on E. brevicornum presents in vivo evidence for its selective estrogen receptor modulator effect and warrants exploration of its use as an alternative to hormone replacement therapy in menopausal women.

Prevention of murine acute graft-versus-host disease by recipient-derived paired immunoglobulin-like receptor B lentivirus-transfected dendritic cells.

Direct interaction between T-suppressor and dendritic cells (DCs) results in DC tolerance by inducing upregulation of immunoglobulin-like transcript (ILT) 3 and ILT4. DCs were treated with a lentiviral vector containing paired immunoglobulin-like B gene (PIR-B) DCs and the effect of PIR-B-DCs on graft-versus-host disease (GVHD) was analyzed after allogeneic bone marrow (BM) transplantation (BMT). Therefore, 1 × 106 recipient-derived PIR-B-DCs were injected into BALB/c (H-2k(d)) mice using BM-splenocyte grafts from major histocompatibility complex-disparate C57BL/6 (H-2k(b)). Our results showed that PIR-B-DCs deficient in surface costimulatory molecules had higher PIR-B protein expression than immature DCs and interleukin 10-treated DCs. Survival analysis showed PIR-B-DC cotransplantation resulted in significant prolongation of allograft survival (mean survival time: 46.0 ± 13.6 vs. 17.4 ± 3.6 days in untreated MST; p < 0.01). Furthermore, samples from the liver and skin of a mouse did not show clinical or histological signs of GVHD following the injection of PIR-B-DCs. These results demonstrated that PIR-B-DC cotransplantation may attenuate the severity of GVHD after BMT.

Determination of breviflavone A and B in Epimedium herbs with liquid chromatography-tandem mass spectrometry.

Two new types of minor flavonoids, breviflavone A and B, have been recently isolated and identified from Epimedium brevicornu in our previous research. Breviflavone B is a novel flavonoid with potent and specific estrogen receptor (ER) bioactivity. Its positional isomer, breviflavone A, is not ER active. Therefore, it is important to determine the two minor components, breviflavone A and B, in Epimedium herbs. In this report, a robust method for measurement of the two breviflavones in Epimedium ethanolic extracts has been developed by using liquid chromatography tandem mass spectrometry via selected-reaction monitoring (m/z 437-->m/z 367 for breviflavone A and m/z 437-->m/z 351 for breviflavone B) under negative electrospray ionization mode. This method has been successfully used to determine the two breviflavones in ethanolic herbal extracts of five major Epimedium species (E. brevicornu, E. koreanum, E. pubescens, E. sagittatum, and E. wushanese) from various sources. The contents of the two breviflavones range from 0.0181 to 0.1791% for breviflavone A and 0.0026 to 0.0252% for breviflavone B in the dried ethanolic extracts of those Epimedium herbal samples.