Psammaplysin F: A unique inhibitor of bacterial chromosomal partitioning

Described is the antibiotic activity of a marine natural product. Psammaplysin F (1) inhibited the growth of four Gram-positive strains by >80% at 50 μM, and the amine at position C-20 is responsible for the observed antibacterial activity. When tested against two strains of methicillin resistant Staphylococcus aureus (MRSA), the minimum inhibitory concentrations (MICs) for psammaplysin F (40–80 μM) were similar to the structurally-related alkaloid psammaplysin H (2). Psammaplysin F (1) increased membrane permeability by two to four-fold compared to psammaplysin H (2) or control-treated bacteria, respectively. Unlike psammaplysin H (2), we show that psammaplysin F (1) inhibits equal partitioning of DNA into each daughter cell, suggesting that this natural product is a unique prokaryotic cell division inhibitor.     

Mechanomyogram for Muscle Function Assessment: A Review

Background

Mechanomyography (MMG) has been extensively applied in clinical and experimental practice to examine muscle characteristics including muscle function (MF), prosthesis and/or switch control, signal processing, physiological exercise, and medical rehabilitation. Despite several existing MMG studies of MF, there has not yet been a review of these. This study aimed to determine the current status on the use of MMG in measuring the conditions of MFs.

Methodology/Principal Findings

Five electronic databases were extensively searched for potentially eligible studies published between 2003 and 2012. Two authors independently assessed selected articles using an MS-Word based form created for this review. Several domains (name of muscle, study type, sensor type, subject''s types, muscle contraction, measured parameters, frequency range, hardware and software, signal processing and statistical analysis, results, applications, authors'' conclusions and recommendations for future work) were extracted for further analysis. From a total of 2184 citations 119 were selected for full-text evaluation and 36 studies of MFs were identified. The systematic results find sufficient evidence that MMG may be used for assessing muscle fatigue, strength, and balance. This review also provides reason to believe that MMG may be used to examine muscle actions during movements and for monitoring muscle activities under various types of exercise paradigms.

Conclusions/Significance

Overall judging from the increasing number of articles in recent years, this review reports sufficient evidence that MMG is increasingly being used in different aspects of MF. Thus, MMG may be applied as a useful tool to examine diverse conditions of muscle activity. However, the existing studies which examined MMG for MFs were confined to a small sample size of healthy population. Therefore, future work is needed to investigate MMG, in examining MFs between a sufficient number of healthy subjects and neuromuscular patients.     

A Persistence Detector for Metabolic Network Rewiring in an Animal

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A flavone from the ethyl acetate extract of Leea rubra leaves with DNA damage protection and antineoplastic activity

Among the major constituents of Leea rubra (Family Vitaceae) leaves, phenolic and flavonoind compounds are most important for therapeutic purposes and the plant parts have been used in traditional medicine to treat several diseases for long. Thus, in order to scientifically confirm the traditional uses of the L. rubra leaves, the present study was designed to investigate the efficacy of the isolated flavones against AAPH induced oxidative damage to pUC19 DNA by gel electrophoresis and antineoplastic activity was evaluated on Ehrlich ascites carcinoma (EAC) bearing Swiss albino mice by evaluating percentage inhibition of cell growth, morphological changes of EAC cells and hematological parameters of the mice. The isolation was carried out by column chromatography and structure was revealed by ¹H-NMR and ¹³C NMR. The result shows that, the isolated compound was identified as myricetin 4'-methoxy-3-O-α-l-rhamnopyranoside based on previously reported data. The isolated flavone effectively inhibited AAPH-induced oxidative damage to DNA; because it could inhibit the formation of circular and linear forms of the DNA. In anti-proliferative assay, 76% growth inhibition of EAC cells was observed as compare to the control mice (p<0.05) at a dose 100 mg/kg body weight. Thus the isolated flavone showed great importance as a possible therapeutic agent in preventing oxidative damage to DNA and the chronic diseases caused by such DNA damage, and can also become important in cancer chemotherapy.     

Novel mutation assay with high sensitivity based on direct measurement of genomic DNA alterations: comparable results to the Ames test

Almost all of the methodologies developed to date to assay the potential mutagenicity of chemical substances are based on detection of altered phenotypic traits. The alternative approach of directly screening the whole genome for mutations is not feasible because of the logistics of carrying out mass sequencing of genes. Here we describe a novel and highly sensitive mutation assay, which we term the 'genome profiling-based mutation assay' (GPMA) that directly detects mutations generated in genomic DNA. We used GPMA to detect mutations caused by known mutagens such as AF2 and ethidium bromide even at concentrations of 30 ppb. The number of mutations detected was dependent on the number of generations in culture and the concentrations of the mutagens. Almost complete agreement was observed between GPMA and the Ames test in the discrimination of mutagens (63 out of 64). Owing to the high sensitivity of GPMA, the effects of long-term and low-dose exposures and the influence of chemicals of low solubility can also be screened. Thus, genotype-based GPMA can complement the Ames test, which is the standard technology in this field and is based on phenotypic traits.     

An Eye-Shaped Ultra-Sensitive Localized Surface Plasmon Resonance–Based Biochemical Sensor

Plasmonics - This research illustrates a parametric study based on surface plasmon resonance of a slightly gold-coated photonic crystal fiber (PCF). In verifying sensing accuracy, the proposed...     

Genetic variation,demographic history and phylogeography of tire track eel,Mastacembelus favus (Synbranchiformes: Mastacembelidae) in Southeast Asia

The complex climatic and geological history of Southeast Asia has been hypothesised to determine the most important aspects of the current phylogeographical structure and distribution of living organisms throughout the region. To test existing hypotheses, the genetic structure of the tire track eel, Mastacembelus favus, was investigated using 823 bp of mitochondrial DNA cytochrome b from 469 individuals from 51 localities encompassing its native range. The results classified all haplotypes into two major lineages, Lineage 1, which was further divided into Lineages 1a (lower Mekong, eastern Gulf of Thailand and Malay—Thai Peninsula), 1b (Banpakong River), 1c (Chao Phraya, Gulf of Thailand and Malay—Thai Peninsula) and 1d (Khlang Yai River), and Lineage 2, the upper reaches of the lower Mekong and the middle Mekong. Strong genetic discontinuities dated approximately 5 MYA were discovered in the Mekong with limited geographical overlap, suggesting a historically dissected drainage between two sections and species colonisation via different routes. The widespread Lineage 1 showed a strong signature of population expansion during the Pleistocene climate oscillation. Haplotype characteristics in the Malay—Thai Peninsula are hypothesised to result from postglacial dispersal from the Mekong and Chao Phraya through an extended Pleistocene drainage network.

     

Investigation of deleterious effects of nsSNPs in the POT1 gene: a structural genomics-based approach to understand the mechanism of cancer development

Protection of telomere 1 (POT1) is one of the key components of shelterin complex, implicated in maintaining the telomere homeostasis, and thus stability of the eukaryotic genome. A large number of non-synonymous single nucleotide polymorphisms (nsSNPs) in the POT1 gene have been reported to cause varieties of human diseases, including cancer. In recent years, a number of mutations in POT1 has been markedly increased, and interpreting the effect of these large numbers of mutations to understand the mechanism of associated diseases seems impossible using experimental approaches. Herein, we employ varieties of computational methods such as PROVEAN, PolyPhen-2, SIFT, PoPMuSiC, SDM2, STRUM, and MAESTRO to identify the effects of 387 nsSNPs on the structure and function of POT1 protein. We have identified about 183 nsSNPs as deleterious and termed them as “high-confidence nsSNPs.” Distribution of these high-confidence nsSNPs demonstrates that the mutation in oligonucleotide binding domain 1 is highly deleterious (one in every three nsSNPs), and high-confidence nsSNPs show a strong correlation with residue conservation. The structure analysis provides a detailed insights into the structural changes occurred in consequence of conserved mutations which lead to the cancer progression. This study, for the first time, offers a newer prospective on the role of POT1 mutations on the structure, function, and their relation to associated diseases.