Intravoxel incoherent motion diffusion-weighted MR imaging of the liver: effect of triggering methods on regional variability and measurement repeatability of quantitative parameters.

PURPOSE: To compare the influence of triggering methods for diffusion-weighted imaging (DWI) on apparent diffusion coefficient (ADC) and intravoxel incoherent motion (IVIM) parameters in the liver, as well as regional variability and measurement repeatability. MATERIALS AND METHODS: In this institutional review board-approved prospective study, 12 healthy volunteers (six women, six men; mean age, 30 years) underwent 1.5-T DWI of the liver by using nine b values twice with free breathing (FB) without triggering (mean acquisition time ± standard deviation, 3.7 minutes ± 0), respiratory triggering (RT) (mean acquisition time, 6.8 minutes ± 1.4), and echocardiography triggering (ET) (mean acquisition time, 8.3 minutes ± 2.0) after providing written informed consent. ADC and IVIM parameters, including pure diffusion coefficient (D), perfusion fraction (f), and perfusion-related diffusion coefficient (D*), were measured by using 15 regions of interest (ROIs). Regional variability of ADC and IVIM parameters and measurement repeatability were evaluated by using the coefficient of variation (CV) across ROIs and within-subject CV, respectively. RESULTS: ET DWI (range of CV across ROIs, 6.69%-20.0%) resulted in significantly decreased regional variability of ADC, D, and f, compared with FB DWI (13.86%-35.8%) and RT DWI (15.15%-35.91%, P ≤. 049). ET DWI showed better repeatability of ADC measurement (within-subject CV range, 3.17%-4.12% for ET DWI; 4.15%-4.74% for FB DWI; and 2.33%-6.96% for RT DWI), D (4.05%-5.34% for ET DWI, 4.11%-12.51% for FB DWI, and 3.19%-16.17% for RT DWI), and f (7.6%-9.86% for ET DWI, 13.83%-16.81% for FB DWI, and 10.05%-12.10% for RT DWI), compared with FB DWI and RT DWI, with significant differences in within-subject CV for D in the left hepatic lobe compared with RT DWI (P = .023) and for f compared with FB DWI (P ≤ .032). For all three imaging techniques, D* showed the worst repeatability (within-subject CV, 57.05%-156.61%) among ADC and IVIM parameters. CONCLUSION: ET DWI is more effective for decreasing regional variability of ADC and IVIM parameters than FB DWI or RT DWI; it may improve measurement repeatability by reducing cardiac motion-induced measurement error.

Progress in genetic engineering of peanut (Arachis hypogaea L.)--a review.

Peanut (Arachis hypogaea L.) is a major species of the family, Leguminosae, and economically important not only for vegetable oil but as a source of proteins, minerals and vitamins. It is widely grown in the semi-arid tropics and plays a role in the world agricultural economy. Peanut production and productivity is constrained by several biotic (insect pests and diseases) and abiotic (drought, salinity, water logging and temperature aberrations) stresses, as a result of which crop experiences serious economic losses. Genetic engineering techniques such as Agrobacterium tumefaciens and DNA-bombardment-mediated transformation are used as powerful tools to complement conventional breeding and expedite peanut improvement by the introduction of agronomically useful traits in high-yield background. Resistance to several fungal, virus and insect pest have been achieved through variety of approaches ranging from gene coding for cell wall component, pathogenesis-related proteins, oxalate oxidase, bacterial chloroperoxidase, coat proteins, RNA interference, crystal proteins etc. To develop transgenic plants withstanding major abiotic stresses, genes coding transcription factors for drought and salinity, cytokinin biosynthesis, nucleic acid processing, ion antiporter and human antiapoptotic have been used. Moreover, peanut has also been used in vaccine production for the control of several animal diseases. In addition to above, this study also presents a comprehensive account on the influence of some important factors on peanut genetic engineering. Future research thrusts not only suggest the use of different approaches for higher expression of transgene(s) but also provide a way forward for the improvement of crops.

Unrevealing the role of P-protein on melanosome biology and structure, using siRNA-mediated down regulation of OCA2.

The pink-eyed dilution protein (P-protein) plays a critical role in melanin synthesis in melanocytes and retinal pigment epithelium cells. Mutation in this protein may cause complete or partial albinism. Role of the P-protein ranges in melanin synthesis to maturation and trafficking of the melanosomes. The aim of the present study was to evaluate the effect of P-protein inhibition on melanosome biology by comparing the shape, size, count, and types of melanosomes in melan-a melanocytes. The cells were extensively examined by the transmission electron microscopy. The P-protein inhibition was carried by P-protein-siRNA transfection to melan-a melanocytes, B16F10 mouse melanoma, and melan-p1 cells. Measurement of melanin contents, cellular tyrosinase, and different tyrosinase related proteins were also determined to investigate the effect of P-protein siRNA transfection on melanocytes. Results suggested that the inhibition of P-protein can significantly change the melanosomal morphology, types and their respective numbers, and provided a novel strategy for the control of melanin synthesis.

Intravoxel incoherent motion MRI for liver fibrosis assessment: a pilot study.

BACKGROUND: There has been a growing need for an imaging method for the accurate diagnosis and staging of liver fibrosis as a non-invasive alternative to liver biopsy. PURPOSE: To evaluate the feasibility of intra-voxel incoherent motion (IVIM) imaging for classifying the severity of liver fibrosis. MATERIAL AND METHODS: Fifty-seven patients who underwent navigator-triggered, diffusion-weighted imaging (DWI) of the liver on a 1.5-T system using nine b-values and had a reliable reference standard for the diagnosis of liver fibrosis (histopathologic findings [n = 27] or clinical findings for normal [n = 18] or cirrhotic liver [n = 12]), were included in our study. Liver apparent diffusion coefficient (ADC), pure diffusion (Dslow), perfusion fraction (f), and perfusion-related diffusion (Dfast), and the product f · Dfast were compared with the liver fibrosis stages (F). The accuracies of these parameters in diagnosing severe liver fibrosis (F ≥3) were evaluated using the receiver-operating characteristic (ROC) curve analysis. RESULTS: The liver fibrosis stages had the strongest negative correlation with f · Dfast (ρ = -0.52). All of the parameters, except for Dslow, were significantly lower in patients with F ≥3 than in those with F ≤2 (P ≤ 0.001). The area under the ROC curve for diagnosing severe fibrosis was the largest for f · Dfast (0.844) with an overall accuracy of 79.0% (45/57) at the optimal cutoff value and followed by f (0.834), Dfast (0.773), ADC (0.762), and Dslow (0.656). CONCLUSION: IVIM imaging is a promising method for classifying the severity of liver fibrosis, with the product f · Dfast being the most accurate parameter.

Homology modelling and virtual screening of P-protein in a quest for novel antimelanogenic agent and in vitro assessments.

An adequate knowledge on molecular mechanism of melanogenesis provides an opportunity to find the novel molecular targets for the discovery and development of new cosmetics. Among various genes, the OCA2 is being essential for proper melanin synthesis, and mutation or deletion of this gene leads to oculocutaneous albinism type 2. Thus, for this study, the product of this gene, that is P-protein, was targeted in quest for novel inhibitors as antimelanogenic agents. Based on pattern search of amino acid sequence and homology analysis, the protein structure was modelled. The role of this protein has been predicted as a tyrosine transporter of melanosomes. Thus, the molecular library was generated on the basis of tyrosine transporter inhibitor. Based on the dock score, 20 molecules have been considered as putative inhibitors for P-protein. Among these compounds, five molecules (compound #1, #4, #8, #13 and #17) were found to be quite effective as antimelanogenic without having any toxicity. Further investigations to establish the mechanism of action, the indirect methods such as tyrosinase assay, analysis for eumelanin and pheomelanins and investigation of mRNA levels were being carried out. The results from the studies offered a new lead in antimelanogenic therapy and may be very useful for further optimization work in developing them as novel depigmenting agents.

Isolation and characterization of Pseudoalteromonas sp. from fermented Korean food, as an antagonist to Vibrio harveyi.

The microbial intervention for sustainable management of aquaculture, especially use of probiotics, is one of the most popular and practical approaches towards controlling pathogens. Vibrio harveyi is a well-known pathogenic bacterium, which is associated to a huge economic loss in the aquaculture system by causing vibriosis. The present study is crafted for screening and characterization of anti-Vibrio strains, which were isolated from various traditional fermented Korean foods. A total of 196 strains have been isolated from soybean paste (78 strains), red chili paste (49 strains), soy sauce (18 strains), jeotgal-a salted fish (34 strains), and the gazami crab-Portunus trituberculatus (17 strains). Fifteen strains showed an inhibitory effect on the growth of V. harveyi when subjected to coculture condition. Among the strains isolated, one has been identified as a significant anti-Vibrio strain. Further biochemical characterization and 16S rDNA sequencing revealed it as Pseudoalteromonas aliena, which had been deposited at the Korean Culture Center of Microorganisms (KCCM), Korea and designated as KCCM 11207P. The culture supernatants did not have any antimicrobial properties either in pure or in coculture condition. The culture supernatant was not toxic when supplemented to the swimming crab, Zoea, and Artemia larvae in aquaculture system. The results were very encouraging and showed a significant reduction in accumulated mortality. Here, we reported that pathogenic vibriosis can be controlled by Pseudoalteromonas sp. under in vitro and in vivo conditions. The results indicated that the biotic treatment offers a promising alternative to the use of antibiotics in crab aquaculture.

Algal fucoidan: structural and size-dependent bioactivities and their perspectives.

Fucoidan is a complex-sulfated polysaccharide distributed in various marine organisms, and the brown algae are reported as the major producer. The fucoidan is important for their high bioactive properties, like antibacterial, anticoagulant, antiviral, anti-tumor, etc., and many more to be explored. There is a strong archival support for the bioactivity and promising properties of this molecule, which creates a hope for this molecule as future drug against thrombosis and some kind of cancers. Reports other than the above bioactive properties have also been a matter of interest for the design of signal or enzyme-arrested new class of drugs. In the past three decades, the research on isolation, molecular characterization, and screening of biological applications has significantly increased. One major issue associated with this molecule is the higher size and seasonal variation in their chemical composition; to resolve the issue and maintain its bioactivity, a prioritized and literal hydrolysis process is required to be developed. Here, in this mini-review, we have tried to summarize the algal fucoidan research and the bioactivities influenced by their molecular size.

Isolation and anti-inflammatory effect of astragalin synthesized by enzymatic hydrolysis of tea seed extract.

BACKGROUND: The application of tea seed extract (TSE) has been widely investigated because of its biological activities. In this paper, two flavonol triglycosides in TSE-camelliaside A (CamA) and camelliaside B (CamB)-were subjected to hydrolysis in the presence of two commercial enzyme complexes (Pectinex™ series): Smash and Mash. RESULTS: Smash hydrolyzed only the xylosyl moiety of CamB, and the main product was kaempferol diglycoside (nicotiflorin, NF). On the other hand, Mash induced the hydrolysis of both CamA and CamB, and kaempferol monoglycoside (astragalin, AS) was found to be a main product. Pure AS with > 96% purity was prepared by enzymatic hydrolysis of TSE using Mash, and the chemical structure of AS was confirmed by (1)H- and (13)C-nuclear magnetic resonance analyses. The prepared pure AS showed anti-inflammatory activities by significantly inhibiting cellular nitrite oxide (IC(50) = 363 µg mL(-1)), prostaglandin E(2) (IC(50) = 134 µg mL(-1)) and interleukin-6 production (IC(50) = 289 µg mL(-1)) by lipopolysaccharide -stimulated RAW 264.7 cells. CONCLUSION: It was concluded that pure AS can be prepared by enzymatic partial hydrolysis of TSE and employed as an anti-inflammatory material. This is the first study to address the preparation of pure AS from natural sources.

Ameliorating effect of Gardenia jasminoides extract on amyloid beta peptide-induced neuronal cell deficit.

The brains of Alzheimer's disease (AD) patients are characterized by large deposits of amyloid beta peptide (Abeta). Abeta is known to increase free radical production in nerve cells, leading to cell death that is characterized by lipid peroxidation, free radical formation, protein oxi-dation, and DNA/RNA oxidation. In this study, we selected an extract of Gardenia jasminoides by screening, and investigated its ameliorating effects on Abeta-induced oxidative stress using PC12 cells. The effects of the extract were evaluated using the 2,7 -dichlorofluorescein diacetate (DCF-DA) assay and the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. To find the active component, the ethanol extract was partitioned with hexane, chloroform, and ethyl acetate, respectively, and the active component was purified by silica-gel column chromatography and HPLC. The results suggested that Gardenia jasminoides extract can reduce the cytotoxicity of Abeta in PC 12 cells, possibly by reducing oxidative stress.

Inhibition of melanogenesis by dioctyl phthalate isolated from Nigella glandulifera Freyn.

Although a number of melanogenesis inhibitors have recently been reported and used as cosmetic additives, none is completely satisfactory, leaving a need for novel skin-depigmenting agents. Thus, to develop a novel skin-depigmenting agent from natural sources, the inhibition of melanogenesis by Chinese plants was evaluated. A methanolic extract of Nigella glandulifera Freyn was found to inhibit the melanin synthesis of murine B16F10 melanoma cells by 43.7% and exhibited a low cytotoxicity (8.1 %) at a concentration of 100 microg/ml. Thus, to identify the melanogenesis-inhibiting mechanism, the inhibitory activity towards tyrosinase, the key enzyme of melanogenesis, was further evaluated, and the results showed inhibitory effects on the activity of intracellular tyrosinase yet not on mushroom tyrosinase. Finally, to isolate the compounds with a hypopigmenting capability, activity-guided isolation was performed, and Dioctyl phthalate identified as inhibiting melanogenesis.

Kojic Acid Peptide: A New Compound with Anti-Tyrosinase Potential.

BACKGROUND: Kojic acid was used for decades in the cosmetic industry as an antimelanogenic agent. However, there are two major drawbacks of Kojic acid, one is cytotoxicity and second are instability on storage. These limitations led the scientist to synthesize the active Kojic acid peptides. OBJECTIVE: In the present study, we synthesize and investigate the effect of five Kojic acid peptides to overcome the limitation of Kojic acid. METHODS: The peptide was analyzed and purified by high-performance liquid chromatography and matrix-assisted laser desorption ionization time of flight mass spectroscopy. Further, the tyrosinase activities of the Kojic acid and Kojic acid peptides were compared. The toxicity was measured and the melanin content is recorded in B16F10 mouse melanoma cells. RESULTS: Maximum tyrosinase activity was measured by Kojic acid peptides. Therefore, Kojic acid peptides were subjected to melanin assay and cytotoxicity assay and finally the stability of the Kojic acid peptide was measured. CONCLUSION: It was observed that this newly synthesized Kojic acid peptide is stable and potent to inhibit the tyrosinase activity and melanin content of B16F10 mouse melanoma cells without exhibiting cell toxicity. Together, these preliminary results suggest that a further exploration is being needed to establish Kojic acid peptide as antimelanogenic agent.

Selective cadmium accumulation using recombinant Escherichia coli.

Recombinant Escherichia coli JM109 (pZH3-5/pMT), harboring a manganese transport gene (mntA) and a metal-sequestering protein (metallothionein [MT]) gene, was cultivated to accumulate cadmium (Cd) in an aqueous phase. Isopropyl beta-D-thiogalactoside (IPTG)-induced cells showed rapid Cd(2+) ion accumulation (90% of maximum accumulation in 15 min) and had an accumulation six times higher than that of the control. Under optimum conditions, i.e., pH 7, 37 degrees C and 0.5 (OD600), 1.5 mM IPTG induction resulted in the accumulation of 21.5 micromol Cd/g dry cell. Storage at 37 degrees C for 24 h had no effect on the accumulation. Significantly, Cd was selectively accumulated in a solution containing an equal concentration of three other metals, resulting in more than 90% of the total accumulated metals being Cd. The accumulation of Cd was reduced by the presence of Mn2+ ion whereas no significant effect was observed with Cu2+, Zn2+ and Pb2+ ions. A chelator, EDTA, had no effect on the accumulation up to 100 mM. The bioaccumulation rate followed Michaelis-Menten kinetics (Vm=2.7 micromol Cd2+/min.g dry cell, Km=0.67 microM). The equilibrium isotherm showed a Langmuir isotherm. In the membrane reactor experiment, 1 mg/l Cd in an inlet solution decreased to 0.2 mg/l in the effluent, removing 80% of Cd, continuously. These results indicated the potentials of a genetically modified microorganism for the highly selective accumulation of Cd at a low concentration and the future application to the removal and recovery of Cd.

Inhibitory effect of zeatin, isolated from Fiatoua villosa, on acetylcholinesterase activity from PC12 cells.

Acetylcholinesterase (AChE) inhibitors, which enhance cholinergic transmission by reducing the enzymatic degradation of acetylcholine, are the only source of the compound that is currently approved for the treatment of Alzheimer's disease (AD). The methanol extract from Fiatoua villosa among 100 traditional edible plants that were tested, showed the most potent inhibitory effect (51%) on acetylcholinesterase in vitro. After the sequential solvent fractionation of the methanol extract of Fiatoua villosa, the active fraction was repeatedly subjected to open-column chromatography on silica gel. From the highest inhibitory fraction, the chloroform fraction (75%) on AChE, the single compound, was obtained by the Sep-Pak Cartridge (C18: reverse phase column). This compound was finally purified by HPLC (micro-bondapack C18 reverse phase column: 19 x 300 mm). According to the electron impact mass spectrometry (EI-MS), we confirmed that the molecular mass was 219 m/z. The structure of this compound was identified as zeatin [2-methyl-4-(1H-purine-6-ylamino)-2-buten-1-ol], one of the derivatives of purine adenine. The concentration that was required for 50% enzyme inhibition (IC50 value) was 1.09 x 10(-4) M. This study demonstrated that the zeatin from Fiatoua villosa appeared to be the most potent AChE inhibitor in AD.

Ursolic acid of Origanum majorana L. reduces Abeta-induced oxidative injury.

Amyloid beta protein (Abeta) increases free radical production and lipid peroxidation in PC12 nerve cells, leading to apoptosis and cell death. The effect of ursolic acid from Origanum majorana L. on Abeta-induced neurotoxicity was investigated using PC12 cells. Pretreatment with isolated ursolic acid and vitamin E prevented the PC12 cell from reactive oxygen species (ROS) toxicity that is mediated by Abeta. The ursolic acid resulted in decreased Abeta toxicity assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and trypan blue assay. Thus, treatment with these antioxidants inhibited the Abeta-induced neurotoxic effect. Therefore, these results indicate that micromolar Abeta-induced oxidative cell death is reduced by ursolic acid from Origanum majorana L.

Synergistic effect of sophorolipid and loess combination in harmful algal blooms mitigation.

The inhibition effect of sophorolipid and removal efficiency of loess on Cochlodinium polykrikoides and Alexandrium tamarense was investigated separately in the laboratory. Based on this, the combination of sophorolipid and loess for harmful algal bloom mitigation was proposed. Algal sedimentation tests in the laboratory and in the field revealed that the combination of sophorolipid and loess showed synergistic effects both on the removal efficiencies and on the mitigation cost. The concentration of 1 g/l loess and 5 mg/l sophorolipid was determined as the optimum ratio for C. polykrikoides mitigation. In the field test, the effective concentration of loess and sophorolipid in the combination group was reduced to 10% and 25%, respectively, compared to the non-combination group, and the cost decreased more than 60%. The combination of loess and sophorolipid was considered as a promising novel method in harmful algal bloom mitigation.

Screening of surfactants for harmful algal blooms mitigation.

Screening experiments were conducted in order to find promising synthetic surfactants for harmful algal blooms (HABs) mitigation. The chemically synthesized surfactant cocamidopropyl betaine (CAPB) showed characteristics of relatively high inhibition efficiency, high biodegradability and low cost. The motility inhibition ratios of 10 mg/L CAPB on Cochlodinium polykrikoides and Alexandrium tamarense were about 60% after 5 min. The biodegradation test indicated that the half-life of CAPB in seawater was shorter than one day and 90% was biodegraded after five days under the initial concentration of 100 mg/L at 25 degrees C. Further cell lysis experiments revealed the selective lysis effect of CAPB on different HAB organisms. More than 90% of C. polykrikoides lysed at the concentration of 10 mg/L CAPB after 24 h and at 15 mg/L CAPB after 4 h, whereas the lysis effect of CAPB on A. tamarense was slight, no more than 10% after 2 h interaction with 50 mg/L CAPB. This research provided preliminary data for CAPB as a candidate in harmful algal blooms mitigation and pointed out unresolved problems for its practical application in the meantime.

Production and characterization Te-peptide by induced autolysis of Saccharomyces cerevisiae.

Recently, the interest in mimicking functions of chalcogen-based catalytic antioxidants like selenoenzymes, has been increased. Various attempts had been done with selenium, but very few attempts were carried out with tellurium. Bio-complex formation and characterization of tellurium was not tried earlier by using any organism. The present study was focused on tellurium peptide production, characterization, and bioactivity assessment especially Mimetic to glutathione peroxidase (GPx). The production was achieved by the autolysis of total proteins obtained from Saccharomyces cerevisiae ATCC 7752 grown with inorganic tellurium. The GPx-like activity of the hydrolyzed tellurium peptide was increased when prepared by autolysis, but decreased when prepared by acid hydrolysis. Tellurium peptide produced by autolysis of the yeast cell showed increased GPx-like activity as well as tellurium content. Tellurium peptide showed little toxicity, compared to highly toxic inorganic tellurium. The results showed the potential of tellurium peptide as an antioxidant that can be produced by simple autolysis of yeast cells.

Medicinal and cosmetic potentials of sophorolipids.

Sophorolipids, a kind of glycolipids, regarded as the most promising bio-surfactant, are synthesized by a selected number of yeast species. Instead of offering, as an environmental friendly alternative to the petrochemical based surfactants, it also exhibits various bioactivities. Sophorolipids in particular are on the brink of being incorporated into several cosmetic application. The potential of this molecule is also screened in various industries like the cosmetics, pharmaceuticals, and other medical applications. In this review, our aim is to provide an overview and updates on basic and applied research on Sophorolipid especially in terms of cosmetics and medicinal uses.

Production and characterization of low molecular weight sophorolipid under fed-batch culture.

The present study was designed for the production and optimization of the C12-C14 sophorolipid, using the yeast Candida bombicola ATCC-22214. The fermentation was carried under fed-batch culture conditions i.e., maintaining 15% coconut oil and 10% glucose as hydrophobic and hydrophilic carbon sources, respectively. A maximum yield 54.0 g/L (in 234 h) was achieved. A significant antimicrobial activity, surface activity, and emulsion ability were recorded. The native sophorolipid was found as enhancer of detergent efficacy of commercial detergent, tested on complex, smudge and oil contaminated clothes. Molecular weight of the C12 (605/623) and C14 (633/651) sophorolipids were determined by LC-MS which revealed it as diacetylated sophorolipid. This study is being important in terms of yield, which is better than the previously reported.

In silico study and validation of phosphotransacetylase (PTA) as a putative drug target for Staphylococcus aureus by homology-based modelling and virtual screening.

Staphylococcus aureus, a Gram-positive bacterium, can cause a range of illnesses from minor skin infections to life-threatening diseases, such as bacteraemia, endocarditis, meningitis, osteomyelitis, pneumonia, toxic shock syndrome and sepsis. Due to the emergence of antibiotic resistance strains, there is a need to develop of new class of antibiotics or drug for this pathogen. The phosphotransacetylase enzyme plays an important role in the acetate metabolism and found to be essential for the survival of the S. aureus. This enzyme was evaluated as a putative drug target for S. aureus by in silico analysis. The 3D structure of the phosphotransacetylase from S. aureus was modelled, using the 1TD9 chain 'A' from Bacillus subtilis as a template at the resolution of 2.75 Å. The generated model has been validated by PROCHECK, WHAT IF and SuperPose. The docking was performed by the Molegro virtual docker using the ZINC database generated ligand library. The ligand library was generated within the limitation of the Lipinski rule of five. Based on the dock-score, five molecules have been subjected to ADME/TOX analysis and subjected for pharmacophore model generation. The zinc IDs of the potential inhibitors are ZINC08442078, ZINC8442200, ZINC 8442087 and ZINC 8442184 and found to be pharmacologically active antagonist of phosphotransacetylase. The molecules were evaluated as no-carcinogenic and persistent molecule by START programme.