Microbubble disruption by ultrasound and induced cavitation phenomena

Aiming at the enhancement of in vitro sonoporation effect to cells in drug delivery, cavitation phenomena ultrasonically generated in a cylindrical vessel, which is one of a 24 wellplate, were observed with long-term photography by using a digital video camera synchronized with a repeatable flash light with the duration of 1 ?s as well as by taking a number of snapshots. A suspension consisting of distilled water and microbubbles (Sonazoid ultrasound contrast agent containing C4F10 gas) was used as a test liquid in the present experiment. It was found that microbubbles were rapidly destroyed after the ultrasound irradiation and their survival numbers were reduced by half at the exposure time of 100 ms. A maximum number of cavitation bubbles, sometimes more than sixty cavitation bubbles detected in the observation volume, were generated at a certain exposure time less than one second. Cavitation bubbles were mainly observed near the second products consisting of the fragments of the shell material and the flowing gas out of the interior of individual microbubbles. By exploring the free surface oscillation of a Sonazoid suspension, we found out that the (1,1) mode with the frequency of about 5 Hz was prominent. This seems important because the flow induced by this surface oscillation as well as by the acoustic radiation pressure can provide a higher possibility to convey the second products everywhere in the liquid. Consequently cavitation bubbles can be generated at a relatively long time after the ultrasound irradiation even though the majority of microbubbles are destroyed during an earlier period. In fact plenty of cavitation bubbles were occasionally generated even at the ultrasound exposure time of five seconds.http://deepblue.lib.umich.edu/bitstream/2027.42/84289/1/CAV2009-final109.pd

Magnetic systems at criticality: different signatures of scaling

Different aspects of critical behaviour of magnetic materials are presented and discussed. The scaling ideas are shown to arise in the context of purely magnetic properties as well as in that of thermal properties as demonstrated by magnetocaloric effect or combined scaling of excess entropy and order parameter. Two non-standard approaches to scaling phenomena are described. The presented concepts are exemplified by experimental data gathered on four representatives of molecular magnets.Comment: 33 pages, 16 figure

The Soy-Derived Peptide Lunasin Inhibits Invasive Potential of Melanoma Initiating Cells

Lunasin is a 44 amino acid peptide with multiple functional domains including an aspartic acid tail, an RGD domain, and a chromatin-binding helical domain. We recently showed that Lunasin induced a phenotype switch of cancer initiating cells (CIC) out of the stem compartment by inducing melanocyte-associated differentiation markers while simultaneously reducing stem-cell-associated transcription factors. In the present study, we advance the hypothesis that Lunasin can reduce pools of melanoma cells with stem cell-like properties, and demonstrate that Lunasin treatment effectively inhibits the invasive potential of CICs in vitro as well as in vivo in a mouse experimental metastasis model. Mice receiving Lunasin treatment had significantly reduced pulmonary colonization after injection of highly metastatic B16-F10 melanoma cells compared to mice in the control group. Mechanistic studies demonstrate that Lunasin reduced activating phosphorylations of the intracellular kinases FAK and AKT as well as reduced histone acetylation of lysine residues in H3 and H4 histones. Using peptides with mutated activity domains, we functionally demonstrated that the RGD domain is necessary for Lunasin uptake and its ability to inhibit oncosphere formation by CICs, thus confirming that Lunasin’s ability to affect CICs is at least in part due to the suppression of integrin signaling. Our studies suggest that Lunasin represents a unique anticancer agent that could be developed to help prevent metastasis and patient relapse by reducing the activity of CICs which are known to be resistant to current chemotherapies

DNA Microarray Analysis of Temporal and Spatial Variation of Bacterial Communities in Japanese Rivers

『大阪大学大学院工学研究科環境・エネルギー工学専攻生物圏環境工学領域 研究活動報告』, (2008.4.1～2009.3.31), pp.24～35, 大阪大学大学院工学研究科環境・エネルギー工学専攻環境資源・材料学講座生物圏環境工学領域, 2009.5 に掲

Multiple Detection of Occurrence of Bacterial Pathogens in Two Rivers in the Kinki District of Japan with a DNA Microarray

『大阪大学大学院工学研究科環境・エネルギー工学専攻生物圏環境工学領域 研究活動報告』, (2008.4.1～2009.3.31), pp.105～117, 大阪大学大学院工学研究科環境・エネルギー工学専攻環境資源・材料学講座生物圏環境工学領域, 2009.5 に掲

Modification of Angular Velocity by Inhomogeneous MRI Growth in Protoplanetary Disks

We have investigated evolution of magneto-rotational instability (MRI) in protoplanetary disks that have radially non-uniform magnetic field such that stable and unstable regions coexist initially, and found that a zone in which the disk gas rotates with a super-Keplerian velocity emerges as a result of the non-uniformly growing MRI turbulence. We have carried out two-dimensional resistive MHD simulations with a shearing box model. We found that if the spatially averaged magnetic Reynolds number, which is determined by widths of the stable and unstable regions in the initial conditions and values of the resistivity, is smaller than unity, the original Keplerian shear flow is transformed to the quasi-steady flow such that more flattened (rigid-rotation in extreme cases) velocity profile emerges locally and the outer part of the profile tends to be super-Keplerian. Angular momentum and mass transfer due to temporally generated MRI turbulence in the initially unstable region is responsible for the transformation. In the local super-Keplerian region, migrations due to aerodynamic gas drag and tidal interaction with disk gas are reversed. The simulation setting corresponds to the regions near the outer and inner edges of a global MRI dead zone in a disk. Therefore, the outer edge of dead zone, as well as the inner edge, would be a favorable site to accumulate dust particles to form planetesimals and retain planetary embryos against type I migration.Comment: 28 pages, 11figures, 1 table, accepted by Ap

The effect of a natural, standardized bilberry extract (Mirtoselect (R)) in dry eye: a randomized, double blinded, placebo-controlled trial

OBJECTIVE: Dry eye, a chronic disease of lachrymal fluid and corneo-conjunctival epithelium, could significantly impact visual function, affects quality of life and work productivity. Beside several conventional treatments, nutritional supplements based on bilberry extract have been identified as effective contributors to eye health. Here, we aim at investigating the bioavailability of a standardized bilberry extract, its ability to alleviate dry eye symptoms and its antioxidant potential.MATERIALS AND METHODS: Either bilberry dried standardized extract derived from Vaccinium myrtillus L. fresh frozen fruits (Mirtoselect (R)) or a highly purified anthocyanin-rich extract, devoid of the non anthocyanin component and supported on maltodextrins, were each orally a dministrated to 5 male rats. Blood samples were collected at 5, 10, 15, 20, 30, 45, 60, 90, 120 minutes after treatment, processed and analyzed by UV spectrophotometric method. In a parallel analysis, 22 otherwise healthy subjects suffering from dry eye symptoms were enrolled randomly assigned to receive the more bioavailable bilberry extract or placebo. Ophthalmological and clinical examinations including Schirmer's test, pupil constriction, diacron-reactive oxygen metabolites (d-ROMs) test and biological antioxidant potential (BAP) test were performed at inclusion and after the 4-week study period.RESULTS: The area under the curve of plasmatic levels of anthocyanosides in rats resulted 202.34 +/- 24.23 mu g . min/ml for Mirtoselect (R) and 130.93 +/- 4.93 mu g . min/ml for the highly purified anthocyanin-rich bilberry extract, notwithstanding the fact that the highly purified anthocyanin-rich extract group received an anthocyanins dosage much higher than the Mirtoselect (R) group (354 mg/Kg in anthocyanosides vs. 136 mg/Kg in anthocyanosides). 21 subjects, 11 subjects in the bilberry extract (Mirtoselect (R)) group and 10 subjects in the placebo group completed the clinical study. Schirmer's test values indicating the volume of tear secretion were significantly improved in the bilberry extract group (p=0.019), whereas no significant changes were observed in the placebo group. A subset analysis revealed that Mirtoselect (R) could be more effective in subjects with higher tendency of dry eye. In terms of antioxidant potential, the bilberry extract produced significant improvement of BAP (p=0.003) and an increase of modified BAP/d-ROMs ratio, an indicator of overall balance between antioxidant potential and oxidative stress.CONCLUSIONS: Our results suggested that natural, standardized bilberry extract (Mirtoselect (R)) is a natural more bioavailable delivery form anthocyanins, suggesting a strong matrix effect exerted by the non-anthocyanin component. Furthermore, it can improve tear secretion and plasmatic antioxidant potential in subjects suffering from DED symptoms

Detection of skewed X-chromosome inactivation in Fragile X syndrome and X chromosome aneuploidy using quantitative melt analysis.

Methylation of the fragile X mental retardation 1 (FMR1) exon 1/intron 1 boundary positioned fragile X related epigenetic element 2 (FREE2), reveals skewed X-chromosome inactivation (XCI) in fragile X syndrome full mutation (FM: CGG > 200) females. XCI skewing has been also linked to abnormal X-linked gene expression with the broader clinical impact for sex chromosome aneuploidies (SCAs). In this study, 10 FREE2 CpG sites were targeted using methylation specific quantitative melt analysis (MS-QMA), including 3 sites that could not be analysed with previously used EpiTYPER system. The method was applied for detection of skewed XCI in FM females and in different types of SCA. We tested venous blood and saliva DNA collected from 107 controls (CGG < 40), and 148 FM and 90 SCA individuals. MS-QMA identified: (i) most SCAs if combined with a Y chromosome test; (ii) locus-specific XCI skewing towards the hypomethylated state in FM females; and (iii) skewed XCI towards the hypermethylated state in SCA with 3 or more X chromosomes, and in 5% of the 47,XXY individuals. MS-QMA output also showed significant correlation with the EpiTYPER reference method in FM males and females (P < 0.0001) and SCAs (P < 0.05). In conclusion, we demonstrate use of MS-QMA to quantify skewed XCI in two applications with diagnostic utility