Biochemical analyses of lipids deposited on silicone hydrogel lenses

AbstractPurposeThis study was performed to determine the levels of lipids deposited on in vivo worn silicone hydrogel lenses.MethodsThree silicone hydrogel materials, galyfilcon A, senofilcon A, and asmofilcon A, were worn for 2 weeks by 35 normal subjects. Total lipid deposition was determined by the sulfo-phospho-vanillin reaction. Cholesterol was estimated by a colorimetric probe through enzymatic oxidation. Phospholipid level was estimated by determining phosphorus with ammonium molybdate through enzymatic digestion.ResultsThe total lipid content recovered from galyfilcon A, senofilcon A, and asmofilcon A was 32.9 ± 33.8, 42.1 ± 14.0, and 36.6 ± 31.9 μg/lens, respectively. The cholesterol content recovered from galyfilcon A, senofilcon A, and asmofilcon A was 26.2 ± 26.9, 28.6 ± 19.4, and 31.1 ± 21.1 μg/lens, respectively. There were no statistically significant differences in total lipids and cholesterol among the contact lens types. However, the quantity of phospholipid recovered from the asmofilcon A (7.0 ± 5.5 μg/lens) lenses was significantly higher than from galyfilcon A (1.1 ± 0.8 μg/lens) and senofilcon A (2.4 ± 0.8 mg/lens) lenses (p < 0.05, Mann-Whitney test).ConclusionsThe quantity of total lipid and cholesterol deposited on the 3 silicone hydrogel lenses tested did not differ. However, there were significant differences in the amounts of phospholipid deposited among the 3 silicone hydrogel lenses, of which clinical significance should be explored in the future study

Estimation of the refractive index of volcanic ash from satellite infrared sounder data

AbstractWe investigated the spectral refractive indices (RIs) of volcanic ash materials in the wavenumber range of 700–1100cm−1 using satellite infrared sounder measurements and radiative transfer calculations. The ash RIs of 10 ash clouds from eight volcanoes were evaluated (Bezymianny on 2 September 2012, Chaitén on 3 May 2008, Kelut on 14 February 2014, Kirishimayama on 27 January 2011, Kliuchevskoi on 30 June 2007 and 18 October 2013, Puyehue–Cordon Caulle on 5 June 2011, Sangeang-Api on 31 May 2014, and Sheveluch on 28 October 2010 and 18 September 2012). We elaborated on a dataset of volcanic ash measurements made by the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. The measured brightness temperatures in the ash cloud data revealed silicate absorption features at around 10μm. By applying atmospheric profiles from results of a global data assimilation system and using ash cloud properties (ash optical depth, effective radius, and ash cloud height) as parameters for radiative transfer calculations, least squares analyses for the observed and calculated brightness temperatures were conducted using AIRS channels in the wavenumber range of 700–1100cm−1, except for the O3 absorption channels in the range of 980–1070cm−1. Using the RIs for typical volcanic rocks in the ascending order of SiO2 content, basalt, andesite, and rhyolite, a mixture of basalt and rhyolite and a mixture of andesite and rhyolite for the ash material were considered. The volume fraction of the mixture was used as a retrieval parameter and as the ash cloud parameter. Using the estimated ash cloud parameters as fixed values, and under the assumption that the RI from the estimated volume fraction had some accuracy in the wavenumber ranges of 850–980cm−1 and 1070–1100cm−1, the RI imaginary part of each eruptive ash cloud captured by AIRS was then determined from iterative calculations at wavenumbers between 750cm−1 and 980cm−1. In the wavenumber range of 850–980cm−1, the observed brightness temperatures could be approximately simulated using the reported RIs from Pollack, Toon, and Khare (1973) for andesite, basalt, and rhyolite, and their combinations. Furthermore, some estimated RIs were consistent with the reported rock types of the volcanoes, which had been previously classified by compositional analyses in the literature. Our analysis also identified weak absorptions around 750–850cm−1, which could not be reproduced by the reported RIs. These weak absorptions were likely due to Si–O and/or Al–O vibrations, which have been proposed in reports from previous laboratory experiments for some silicate glass samples. Our results suggest that the detailed RI of volcanic ash can be determined from an analysis of satellite infrared sounder data. The RI of the ash material estimated from satellite infrared sounder data can be used to improve the ash retrieval algorithms of other satellite measurements. Furthermore, an RI retrieved by sounder measurements may provide diagnostic information regarding volcanic activity from comparisons with the ash RIs from past eruptions

Causal relations of health indices inferred statistically using the DirectLiNGAM

Causal relations among many statistical variables have been assessed using a Linear non-Gaussian Acyclic Model (LiNGAM). Using access to large amounts of health checkup data from Osaka prefecture obtained during the six fiscal years of years 2012–2017, we applied the DirectLiNGAM algorithm as a trial to extract causal relations among health indices for age groups and genders. Results show that LiNGAM yields interesting and reasonable results, suggesting causal relations and correlation among the statistical indices used for these analyses

Pivotal Role of IL-22 Binding Protein in the Epithelial Autoregulation of Interleukin-22 Signaling in the Control of Skin Inflammation

Disruption of skin homeostasis can lead to inflammatory cutaneous diseases resulting from the dysregulated interplay between epithelial keratinocytes and immune cells. Interleukin (IL)-22 signaling through membrane-bound IL-22 receptor 1 (IL-22R1) is crucial to maintain cutaneous epithelial integrity, and its malfunction mediates deleterious skin inflammation. While IL-22 binding protein (IL-22BP) binds IL-22 to suppress IL-22 signaling, how IL-22BP controls epithelial functionality to prevent skin inflammation remains unclear. Here, we describe the pivotal role of IL-22BP in mediating epithelial autoregulation of IL-22 signaling for the control of cutaneous pathogenesis. Unlike prominent expression of IL-22BP in dendritic cells in lymphoid tissues, epidermal keratinocytes predominantly expressed IL-22BP in the skin in the steady state, whereas its expression decreased during the development of psoriatic inflammation. Deficiency in IL-22BP aggravates psoriasiform dermatitis, accompanied by abnormal hyperproliferation of keratinocytes and excessive cutaneous inflammation as well as enhanced dermal infiltration of granulocytes and γδT cells. Furthermore, IL-22BP abrogates the functional alternations of keratinocytes upon stimulation with IL-22. On the other hand, treatment with IL-22BP alleviates the severity of cutaneous pathology and inflammation in psoriatic mice. Thus, the fine-tuning of IL-22 signaling through autocrine IL-22BP production in keratinocytes is instrumental in the maintenance of skin homeostasis

Let-7 MicroRNA Family Is Selectively Secreted into the Extracellular Environment via Exosomes in a Metastatic Gastric Cancer Cell Line

Background: Exosomes play a major role in cell-to-cell communication, targeting cells to transfer exosomal molecules including proteins, mRNAs, and microRNAs (miRNAs) by an endocytosis-like pathway. miRNAs are small noncoding RNA molecules on average 22 nucleotides in length that regulate numerous biological processes including cancer pathogenesis and mediate gene downregulation by targeting mRNAs to induce RNA degradation and/or interfering with translation. Recent reports imply that miRNAs can be stably detected in circulating plasma and serum since miRNAs are packaged by exosomes to be protected from RNA degradation. Thus, profiling exosomal miRNAs are in need to clarify intercellular signaling and discover a novel disease marker as well. Methodology/Principal Findings: Exosomes were isolated from cultured cancer cell lines and their quality was validated by analyses of transmission electron microscopy and western blotting. One of the cell lines tested, a metastatic gastric cancer cell line, AZ-P7a, showed the highest RNA yield in the released exosomes and distinctive shape in morphology. In addition, RNAs were isolated from cells and culture media, and profiles of these three miRNA fractions were obtained using microarray analysis. By comparing signal intensities of microarray data and the following validation using RT-PCR analysis, we found that let-7 miRNA family was abundant in both the intracellular and extracellular fractions from AZ-P7a cells, while low metastatic AZ-521, the parental cell line of AZ-P7a, as well as other cancer cell lines showed no such propensity. Conclusions/Significance: The enrichment of let-7 miRNA family in the extracellular fractions, particularly, in the exosome

Light Curves and Colors of the Ejecta from Dimorphos after the DART Impact

On 26 September 2022 the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, a satellite of the asteroid 65803 Didymos. Because it is a binary system, it is possible to determine how much the orbit of the satellite changed, as part of a test of what is necessary to deflect an asteroid that might threaten Earth with an impact. In nominal cases, pre-impact predictions of the orbital period reduction ranged from ~8.8 - 17.2 minutes. Here we report optical observations of Dimorphos before, during and after the impact, from a network of citizen science telescopes across the world. We find a maximum brightening of 2.29 $\pm$ 0.14 mag upon impact. Didymos fades back to its pre-impact brightness over the course of 23.7 $\pm$ 0.7 days. We estimate lower limits on the mass contained in the ejecta, which was 0.3 - 0.5% Dimorphos' mass depending on the dust size. We also observe a reddening of the ejecta upon impact.Comment: Accepted by Natur