Water and 2‑Propanol Structured on Calcite (104) Probed by Frequency-Modulation Atomic Force Microscopy

The structure of liquid water and 2-propanol on the (104) surface of calcite (CaCO₃) was probed by frequency-modulation atomic force microscopy. The microscope tip scanned each liquid to record the tip–surface force perturbed by the liquid structure at the interface. In water, the force distribution on planes cross-sectional to the surface presents a 0.5-nm-thick checkerboard-like pattern matching the corrugated topography of the calcite surface. This provides evidence that the local water density was laterally and vertically modulated. With 2-propanol, a laterally uniform, vertically layered structure was found between the first laterally structured layer and the bulk liquid. These results are consistent with the density distributions of water and ethanol proposed in earlier X-ray and simulation studies

Cross-Sectional Structure of Liquid 1‑Decanol over Graphite

The interface of graphite and liquid 1-decanol was studied using frequency modulation atomic force microscopy (FM-AFM). The topography of epitaxially physisorbed decanol on the substrate was traced with submolecular resolution. The tip–surface force was monitored in the liquid as a function of the vertical and lateral tip coordinates to reveal the cross-sectional structure of the interfacial decanol. Four or more liquid layers were identified by vertically modulated force distributions. The first and second liquid layers were laterally heterogeneous, as evidenced by a force distribution that was periodically modulated along lateral coordinates. A possible structuring mechanism is proposed on the basis of energy gain by hydrogen bonding and van der Waals interactions

Urinary L-FABP levels and albuminuria.

<p>Patients with albuminuria had significantly higher urinary L-FABP levels than patients without albuminuria (7.9 μg/gCr [2.0–21.2] vs. 2.8 μg/gCr [0.3–6.1], P < 0.001).</p

Baseline patient characteristics.

<p>Data are mean (SD), median (IQR), or number of patients (%). ACR, albumin-to-creatinine ratio; ACE/ARB, angiotensin-converting enzyme/angiotensin-receptor blocker; HDL, high-density lipoprotein; eGFR, estimated glomerular filtration rate.</p><p>Baseline patient characteristics.</p

Independent predictors of urinary L-FABP^* in multivariate linear regression models.

<p>^*Log-transformed variables.</p><p>ACR, albumin-to-creatinine ratio; eGFR, estimated glomerular filtration rate; ACE/ARB, angiotensin-converting enzyme/angiotensin-receptor blocker.</p><p>Independent predictors of urinary L-FABP<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0126990#t003fn001" target="_blank">^*</a> in multivariate linear regression models.</p

Urinary L-FABP levels and anemia.

<p>Patients with anemia had significantly higher urinary L-FABP levels than patients without anemia (5.6 μg/gCr [2.3–20.2] vs. 3.3 μg/gCr [0.2–7.4], P = 0.002).</p

Beyond the Helix Pitch: Direct Visualization of Native DNA in Aqueous Solution

The DNA double helix was first elucidated by J.D. Watson and F.H.C. Crick over a half century ago. However, no one could actually “see” the well-known structure ever. Among all real-space observation methods, only atomic force microscopy (AFM) enables us to visualize the biologically active structure of natural DNA in water. However, conventional AFM measurements often caused the structural deformation of DNA because of the strong interaction forces acting on DNA. Moreover, large contact area between the AFM probe and DNA hindered us from imaging sub-molecular-scale features smaller than helical periodicity of DNA. Here, we show the direct observation of native plasmid DNA in water using an ultra-low-noise AFM with the highly sensitive force detection method (frequency modulation AFM: FM-AFM). Our micrographs of DNA vividly exhibited not only overall structure of the B-form double helix in water but also local structures which deviate from the crystallographic structures of DNA without any damage. Moreover, the interaction force area in the FM-AFM was small enough to clearly discern individual functional groups within DNA. The technique was also applied to explore the synthesized DNA nanostructures toward the current nanobiotechnology. This work will be essential for considering the structure–function relationship of biomolecular systems <i>in vivo</i> and for <i>in situ</i> analysis of DNA-based nanodevices

Effect of conditioned medium, IGF1, and IGF1R inhibitors on motility of PDAC cells.

<p>(A) Representative images of cell density in wound-healing assay. The number of PDAC cells migrating across the wound (broken line) was increased by conditioned medium (CM) from pancreas CAFs compared with that in control. IGF1 increased the number of migrating cancer cells. The IGF1R inhibitor picropodophyllin (PPP) and anti-IGF1R neutralizing antibody downregulated migration-stimulating activity by fibroblast CM. (B, C, D) CM from pancreas fibroblasts significantly stimulated the migratory activity of RWP-1 and MiaPaCa-2 cells, but not OCUP-AT, and Panc-1, under normoxia. Under hypoxia, the number of migrating cancer cells was significantly increased in all four cancer cell lines by CM from pancreas CAFs, and the migration-stimulating ability of CM in PDAC cells was inhibited by IGF1R inhibitors. Data are presented as mean ± SD.</p

Pancreatic Fibroblasts Stimulate the Motility of Pancreatic Cancer Cells through IGF1/IGF1R Signaling under Hypoxia

<div><p>Pancreatic ductal adenocarcinoma (PDAC) is characterized by its hypovascularity, with an extremely poor prognosis because of its highly invasive nature. PDAC proliferates with abundant stromal cells, suggesting that its invasive activity might be controlled by intercellular interactions between cancer cells and fibroblasts. Using four PDAC cell lines and two pancreas cancer-associated fibroblasts (CAFs), the expression of insulin-like growth factor-1 (IGF1) and IGF1 receptor (IGF1R) was evaluated by RT-PCR, FACScan, western blot, or ELISA. Correlation between IGF1R and the hypoxia marker carbonic anhydrase 9 (CA9) was examined by immunohistochemical staining of 120 pancreatic specimens. The effects of CAFs, IGF1, and IGF1R inhibitors on the motility of cancer cells were examined by wound-healing assay or invasion assay under normoxia (20% O₂) and hypoxia (1% O₂). IGF1R expression was significantly higher in RWP-1, MiaPaCa-2, and OCUP-AT cells than in Panc-1 cells. Hypoxia increased the expression level of IGF1R in RWP-1, MiaPaCa-2, and OCUP-AT cells. CA9 expression was correlated with IGF1R expression in pancreatic specimens. CAFs produced IGF1 under hypoxia, but PDAC cells did not. A conditioned medium from CAFs, which expressed αSMA, stimulated the migration and invasion ability of MiaPaCa-2, RWP-1, and OCUP-AT cells. The motility of all PDAC cells was greater under hypoxia than under normoxia. The motility-stimulating ability of CAFs was decreased by IGF1R inhibitors. These findings might suggest that pancreas CAFs stimulate the invasion activity of PDAC cells through paracrine IGF1/IGF1R signaling, especially under hypoxia. Therefore the targeting of IGF1R signaling might represent a promising therapeutic approach in IGF1R-dependent PDAC.</p></div

IGF1R inhibitor inhibits invasion-stimulating activity of CM from fibroblasts.

<p>(A), Representative pictures of invading pancreas cancer cells, Panc-1. The number of invaded cells into pore membrane filter was increased in the presence of CM from pCaF-1 in compared to the control. IGF1R-neutralizing antibody and PPP inhibited the invasion induced by CM. (B), CM from pCaF-1 significantly stimulated the invasive behavior of pancreas cancer cells. IGF1R inhibitor, IGF1R-neutralizing antibody and PPP, significantly inhibited the invasion seen in these cells.</p