Kiamycin (1), a new angucyclinone derivative possessing an 1,12-epoxybenz[a]anthracene ring system, was isolated from the marine Streptomyces sp. strain M268 along with the known compounds 8-O-methyltetrangomycin (3) and 8-O-methylrabelomycin (4). Their structures were elucidated by detailed spectroscopic analysis and comparison with literature data. The new angucyclinone derivative showed inhibitory activities against the human cell lines HL-60 (leukemia), A549 (lung adenocarcinoma), and BEL-7402 (hepatoma) with inhibition rates of 68.2%, 55.9%, and 31.7%, respectively, at 100 µM. It appears to have potential as an anticancer agent with selective activity.

Recent studies have shown that sparse representation (SR) can deal well with many computer vision problems, and its kernel version owns more powerful classification capability. In this paper, we address the application of a cooperative sparse representation (Co-SR) in semisupervised image annotation which can grow the amount of labeled images for further use in training image classifiers. Provided a set of labeled (training) images and a set of unlabeled (test) images, the usual SR method, which we call forward SR, is to represent each unlabeled image with several labeled ones, and then to annotate the unlabeled image according to the annotations of these labeled ones. However, to the best of our knowledge, the SR method in an opposite direction, which we call backward SR, to represent each labeled image with several unlabeled images, and then to annotate any unlabeled image according to the annotations of the labeled images which the unlabeled image is selected by the backward SR to represent, has not been addressed by researchers. In this paper, we explore how much the backward SR can contribute to image annotation, and be complementary to the forward SR. The co-training, which has been proved to be a semi-supervised method improving each other only if two classifiers are relatively independent, is then adopted to testify this complementary nature between two SRs in opposite directions. Finally, the co-training of two SRs in kernel space builds a cooperative kernel sparse representation (Co-KSR) method for image annotation. Experimental results and analyses show that two KSRs in opposite directions are complementary, and Co-KSR improves much over either single one of them with an image annotation performance better than other state-of-the-art semi-supervised classifiers such as TSVM (Transductive Support Vector Machine), LGC (Local and Global Consistency) and GFHF (Gaussian Fields and Harmonic Functions). Comparative experiments with a non-sparse solution are also performed to show that the sparsity plays an important role in the cooperation of image representations in two opposite directions. Our work will extend the application of sparse representation in image annotation and retrieval.

BACKGROUND Moyamoya disease (MMD) is a cerebrovascular disease characterized by progressive stenosis or occlusion of the terminal portion of internal carotid arteries and the formation of a vascular network at the base of the brain. The pathogenesis of MMD is still unclear. METHODOLOGY/PRINCIPAL FINDINGS We retrospectively analyzed clinical data for 65 consecutive patients with MMD in our institutions and evaluated the histopathological and immunohistochemical findings of intracranial vessels from 3 patients. The onset age distribution was found to have 1 peak at 40-49 year-old age group, no significant difference was observed in the female-to-male ratio (F/M = 1.2). Intracranial hemorrhage was the predominant disease type (75%). Positive family history was observed in 4.6% of patients. Histopathological findings were a narrowed lumen due to intimal fibrous thickening without significant inflammatory cell infiltration, and the internal elastic lamina was markedly tortuous and stratified. All 3 autopsy cases showed vacuolar degeneration in the cerebrovascular smooth muscle cells. Immunohistochemical study showed the migration of smooth muscle cells in the thickened intima, and aberrant expression of IgG and S100A4 protein in vascular smooth muscle cells. The Complement C3 immunoreactivity was negative. CONCLUSION/SIGNIFICANCE This study indicated that aberrant expression of IgG and S100A4 protein in intracranial vascular wall of MMD patients, which suggested that immune-related factors may be involved in the functional and morphological changes of smooth muscle cells, and finally caused the thickened intima. A possible mechanism is that deposits of IgG in the damaged internal elastic lamina may underlie the disruption of internal elastic lamina, which facilitated S100A4 positive SMCs migrated into intima through broken portions of the internal elastic lamina, resulting in lumen stenosis or occlusion, leading to compensatory small vessels proliferation.

Herein we report on structural, morphological, and optical properties of homochiral and heterochiral J-aggregates that were created by nucleation-elongation assembly of atropo-enantiomerically pure and racemic perylene bisimides (PBIs), respectively. Our detailed studies with conformationally stable biphenoxy-bridged chiral PBIs by UV/Vis absorption, circular dichroism (CD) spectroscopy, and atomic force microscopy (AFM) revealed structurally as well as spectroscopically quite different kinds of J-aggregates for enantiomerically pure and racemic PBIs. AFM investigations showed that enantiopure PBIs form helical nanowires of unique diameter and large length-to-width ratio by self-recognition, while racemic PBIs provide irregular-sized particles by self-discrimination of the enantiomers at the stage of nucleation. Steady-state fluorescence spectroscopy studies revealed that the photoluminescence efficiency of homochiral J-aggregated nanowires (47±3 %) is significantly higher than that of heterochiral J-aggregated particle-like aggregates (12±3 %), which is explained in terms of highly ordered molecular stacking in one-dimensional nanowires of homochiral J-aggregates. Our present results demonstrate the high impact of homochirality on the construction of well-defined nanostructures with unique optical properties.

A large number of novel bioactive compounds were discovered from microbial secondary metabolites based on the traditional bioactivity screenings. Recent fermentation studies indicated that the crude extract of Marine Streptomyces sp. W007 possessed great potential in agricultural fungal disease control against Phomopsis asparagi, Polystigma deformans, Cladosporium cucumerinum, Monilinia fructicola and Colletotrichum lagenarium. In order to further evaluate the biosynthetic potential of secondary metabolites, we sequenced the genome of Streptomyces sp. W007 and analyzed the identifiable secondary metabolite gene clusters. Moreover, one gene cluster with type II PKS implied the possibility of Streptomyces sp. W007 to produce aromatic polyketide of angucyclinone antibiotics. Therefore, two novel compounds, 3-hydroxy-1-keto-3-methyl-8-methoxy-1,2,3,4-tetrahydro-benz[α]anthracene and kiamycin with potent cytotoxicity against human cancer cell lines, were isolated from the culture broth of Streptomyces sp. W007. In addition, other four known angucyclinone antibiotics were obtained. The gene cluster for these angucyclinone antibiotics could be assigned to 20 genes. This work provides powerful evidence for the interplay between genomic analysis and traditional natural product isolation research. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

A novel organic-silica hybrid monolithic stationary phase with a mixed-mode of hydrophilic and strong anion-exchange interactions (HI-SAX) was prepared with a modified "one-pot" process of functional monomers and alkoxysilanes. Using a hydrosoluble initiator 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA), the homogeneous prepolymerization system of this hybrid monolith was successfully obtained by a simple operation. The polycondensation of alkoxysilanes (tetramethoxysilane (TMOS) and vinyl-trimethoxysilane (VTMS)) and the in situ copolymerization of a quaternary ammonium group-containing acrylic monomer ([2-(acryloyloxy)ethyl] trimethyl ammonium methyl sulfate (AETA)) on the precondensed siloxanes were achieved. The morphologies of the hybrid-silica monolithic matrixes were observed by SEM, and the performances of the organic-silica hybrid monolithic columns were investigated by pressurized capillary electrochromatography. The mechanical stability and reproducibility of the obtained hybrid monolithic column preformed acceptable. Both hydrophilic interaction chromatography mechanism and strong anion-exchanged interaction were investigated. A mixed mode of HI-SAX was obtained for the analysis of nucleotides with a good resolution, and the separation of polar and basic nucleic acid bases and nucleosides was also achieved without peak tailing.

Synaptonemal complex protein 3 (SYCP3) is a DNA-binding protein located on the lateral elements of the synaptonemal complex. This protein plays an important role in homologous chromosome pairing and is necessary for male meiosis of spermatogenesis. To further understand the SYCP3 gene function and its relationship to cattle-yak male sterility, we investigated the characteristics of the bovine SYCP3 (bSYCP3) gene as well as its transcription level and epigenetic modification status. The bSYCP3 gene encodes a 225-amino acid protein with the Cor1 motif and two coiled-coil-forming regions, homologous with other mammals (59-77% identity overall). Real-time PCR analysis indicated that the expression level of bSYCP3 mRNA in yak testes was significantly higher than that in cattle-yak (p < 0.05). The methylation level of the bSYCP3 promoter (mainly 7th, 13th and 17th CpG sites) in cattle-yaks (40%) was significantly higher than that in yaks (0%)(p < 0.05). This suggests that bSYCP3 plays an important role in meiosis of bovine spermatogenesis; further, interspecific hybridization between yak and cattle might influence bSYCP3 gene expression in cattle-yak testes, which might be influenced by bSYCP3 gene promoter methylation.

The purpose of this study was to evaluate the effect of different frequencies of pulsed electromagnetic fields on the osteogenic differentiation of human mesenchymal stem cells. Third-generation human mesenchymal stem cells were irradiated with different frequencies of pulsed electromagnetic fields, including 5, 25, 50, 75, 100, and 150 Hz, with a field intensity of 1.1 mT, for 30 minutes per day for 21 days. Changes in human mesenchymal stem cell morphology were observed using phase contrast microscopy. Alkaline phosphatase activity and osteocalcin expression were also determined to evaluate human mesenchymal stem cell osteogenic differentiation.Different effects were observed on human mesenchymal stem cell osteoblast induction following exposure to different pulsed electromagnetic field frequencies. Levels of human mesenchymal stem cell differentiation increased when the pulsed electromagnetic field frequency was increased from 5 hz to 50 hz, but the effect was weaker when the pulsed electromagnetic field frequency was increased from 50 Hz to 150 hz. The most significant effect on human mesenchymal stem cell differentiation was observed at of 50 hz.The results of the current study show that pulsed electromagnetic field frequency is an important factor with regard to the induction of human mesenchymal stem cell differentiation. Furthermore, a pulsed electromagnetic field frequency of 50 Hz was the most effective at inducing human mesenchymal stem cell osteoblast differentiation in vitro.

The aim of this study was to investigate the detailed three-dimensional morphology of the pedicles from T1 to T12 in 120 Chinese patients using a light-speed Vct CT (General Electric). After reformatting the original images, the following parameters were studied: outer pedicle width (OPW), outer pedicle height (OPH), pedicle chord length (PCL), pedicle cortical thickness (PCT) of the isthmus, and transverse pedicle angle (TPA). The mean outer pedicle width, outer pedicle height, and pedicle chord length were significantly smaller in females than in males at all levels (P < 0.01). The percentage of outer pedicle width ≤5.0 mm and ≤4.5 mm was high at mid-thoracic pedicles. No significant differences were found in transverse pedicle angle and pedicle cortical thickness in males and females. Pedicle cortical thickness was significantly thinner in patients over 50 years old compared with patients below 50 years old at most levels. The results showed that a screw of larger than 4.5 mm would be too large for mid-thoracic segments in Chinese population, especially for female patients. Considering the amount of variation between individuals and the complicated structure of the thoracic pedicles, the use of the transpedicular screw fixation must be individualized for each patient and based on detailed preoperative assessment. Reformatted CT assessment is essential before this procedure is performed. Clin. Anat. 25:461-467, 2012. © 2011 Wiley Periodicals, Inc.

Excessive extracellular deposition of amyloid- peptide (Aβ) in the brain is the pathological hallmark of Alzheimer's disease (AD). Cumulative evidence indicates that autophagy is involved in the metabolism of Aβ and pathogenesis of AD. However, the molecular mechanism underlying the pathogenesis of AD is not yet well defined, and there has been no effective treatment for AD. We recently found that long-term treatment with a butyrolactone derivative 3-benzyl-5-((2-nitrophenoxy) methyl)-dihydrofuran- 2(3 H)-one (3BDO) increased levels of insulin-degrading enzyme and neprilysin, suppressed autophagy via an mTOR pathway, lowered levels of Aβ, and prevented AD-like cognitive deficits in the AβPP/PS1 double transgenic mouse model. Therefore, our findings suggest that 3BDO may be beneficial in the prevention and treatment of AD.