Preparation and characterization of spray-dried valsartan-loaded Eudragit® E PO solid dispersion microparticles

AbstractThe purpose of this study was to develop the immediate release stomach-specific spray-dried formulation of valsartan (VAL) using Eudragit® E PO (EPO) as the carrier for enhancing dissolution rate in a gastric environment. Enhanced solubility and dissolution in gastric pH was achieved by formulating the solid dispersion using a spray drying technique. Different combinations of drug–polymer–surfactant were dissolved in 10% ethanol solution and spray-dried in order to obtain solid dispersion microparticles. Use of the VAL–EPO solid dispersion microparticles resulted in significant improvement of the dissolution rate of the drug at pH 1.2 and pH 4.0, compared to the free drug powder and the commercial product. A hard gelatin capsule was filled with the VAL–EPO solid dispersion powder prior to the dissolution test. The increased dissolution of VAL from solid dispersion microparticles in gastric pH was attributed to the effect of EPO and most importantly the transformation of crystalline drugs to amorphous solid dispersion powder, which was clearly shown by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and powder X-ray diffraction (P-XRD) studies. Thus, VAL, a potential antihypertensive drug in the form of a solid dispersion microparticulate powder, can be effectively delivered in the immediate release dosage form for stomach-specific drug delivery

Single-Port Transumbilical Laparoscopic-Assisted Adnexal Surgery

Single-port transumbilical laparoscopic-assisted surgery for large, benign adnexal tumors was found to be a feasible alternative to conventional laparoscopic or open surgical methods

PRIMARY PRODUCTION OF PHYTOPLANKTON AND MACROPHYTES IN AN EUTROPHIC LAGOON, LAKE KYUNGPO, KOREA

Primary production of phytoplankton and macrophytes are measured in a eutrophic lagoon, Lake Kyungpo, where 86% of the lake is inhabited by macrophytes. Phytoplankton standing crop was high, 40-130 mgChl/m³, but productivity per unit area was suppressed low by the light deficiency due to high content of inorganic suspended particles. Contribution of phytoplankton and macrophytes to the total annual production was 55% and 45%, respectively. Allochthonous organic input estimated from BOD was 36% of total organic matter supply. Nitrogen seems to be the limiting nutrient for phytoplankton, since nitrate is often depleted in the water column of macrophyte-growing region and N/P ratio is low. Turbulence and the vertical transfer of oxygen and nutrient are strongly suppressed by the dense population of macrophytes and the chemocline of high stability caused by saline bottom water.Article信州大学理学部付属諏訪臨湖実験所報告 7: 99-103(1991)departmental bulletin pape

Cellular energy stress induces AMPK-mediated regulation of YAP and the Hippo pathway.

YAP (Yes-associated protein) is a transcription co-activator in the Hippo tumour suppressor pathway and controls cell growth, tissue homeostasis and organ size. YAP is inhibited by the kinase Lats, which phosphorylates YAP to induce its cytoplasmic localization and proteasomal degradation. YAP induces gene expression by binding to the TEAD family transcription factors. Dysregulation of the Hippo-YAP pathway is frequently observed in human cancers. Here we show that cellular energy stress induces YAP phosphorylation, in part due to AMPK-dependent Lats activation, thereby inhibiting YAP activity. Moreover, AMPK directly phosphorylates YAP Ser 94, a residue essential for the interaction with TEAD, thus disrupting the YAP-TEAD interaction. AMPK-induced YAP inhibition can suppress oncogenic transformation of Lats-null cells with high YAP activity. Our study establishes a molecular mechanism and functional significance of AMPK in linking cellular energy status to the Hippo-YAP pathway