Overexpression of β1 integrin contributes to polarity reversal and a poor prognosis of breast invasive micropapillary carcinoma

© Liu et al. Invasive micropapillary carcinoma (IMPC) of the breast is a highly aggressive breast cancer. Polarity reversal exemplified by cluster growth is hypothesized to contribute to the invasiveness and metastasis of IMPC. In this study, we demonstrate that levels of β1 integrin and Rac1 expression were greater in breast IMPC than in invasive breast carcinoma of no specific type and paraneoplastic benign breast tissue. We show that silencing β1 integrin expression using the β1 integrin inhibitor AIIB2 partially restored polarity in IMPC primary cell clusters and downregulated Rac1. Thus, overexpression of β1 integrin upregulates Rac1. Univariate analysis showed that overexpression of β1 integrin and Rac1 was associated with breast cancer cell polarity reversal, lymph node metastasis, and poor disease-free survival in IMPC patients. Multivariate analysis revealed that polarity reversal was an independent predictor of poor disease-free survival. These findings indicate that overexpression of β1 integrin and the resultant upregulation of Rac1 contribute to polarity reversal and metastasis of breast IMPC, and that β1 integrin and Rac1 could be potential prognostic biomarkers and targets for treatment of breast IMPC

Medaka piwi is Essential for Primordial Germ Cell Migration

Piwi controls the number of primordial germ cells (PGCs) via protecting maternal mRNA from decay and adult germ stem cell division in Drosophila. In mouse and zebrafish, piwi controls maintenance and differentiation of adult germ stem cell during gametogenesis. Whether piwi plays a role in PGC development of vertebrates remains unsolved. We addressed this issue by using medaka (Oryzias latipes) as a vertebrate model. Molecular cloning, sequence comparison and analyses of genomic organization and chromosome synteny led to the identification in this fish of a single piwi gene, called Opiwi. By RT-PCR analyses and in situ hybridization, the Opiwi transcript is maternally supplied and becomes restricted to PGCs and the central nervous system (CNS). Opiwi knockdown did not prevent PGC formation even in the absence of any somatic structures but did significantly reduce the number of PGCs in vivo and in vitro and affect the distribution of PGCs in developing embryos. Surprisingly, depletion of zygotic Opiwi severely and specifically affected PGC migration. We conclude that Opiwi is required not only for determining the PGC number but also for controlling PGC migration. Our results demonstrate that piwi plays a generally conserved role in germ cell development from Drosophila to vertebrate and a specific role in PGC migration.Piwi controls the number of primordial germ cells (PGCs) via protecting maternal mRNA from decay and adult germ stem cell division in Drosophila. In mouse and zebrafish, piwi controls maintenance and differentiation of adult germ stem cell during gametogenesis. Whether piwi plays a role in PGC development of vertebrates remains unsolved. We addressed this issue by using medaka (Oryzias latipes) as a vertebrate model. Molecular cloning, sequence comparison and analyses of genomic organization and chromosome synteny led to the identification in this fish of a single piwi gene, called Opiwi. By RT-PCR analyses and in situ hybridization, the Opiwi transcript is maternally supplied and becomes restricted to PGCs and the central nervous system (CNS). Opiwi knockdown did not prevent PGC formation even in the absence of any somatic structures but did significantly reduce the number of PGCs in vivo and in vitro and affect the distribution of PGCs in developing embryos. Surprisingly, depletion of zygotic Opiwi severely and specifically affected PGC migration. We conclude that Opiwi is required not only for determining the PGC number but also for controlling PGC migration. Our results demonstrate that piwi plays a generally conserved role in germ cell development from Drosophila to vertebrate and a specific role in PGC migration

Theoretical and experimental studies of the bell-jar-top inductively coupled plasma

The present paper describes a systematic study of argon plasmas in a bell-jar inductively coupled plasma (ICP) source over the range of pressure 5-20 mtorr and power input 0.2-0.5 kW, Experimental measurements as well as results of numerical simulations are presented. The models used in the study include the well-known global balance model (or the global model) as well as a detailed two-dimensional (2-D) fluid model of the system, The global model is able to provide reasonably accurate values for the global electron temperature and plasma density, The 2-D model provides spatial distributions of various plasma parameters that make it possible to compare with data measured in the experiments, The experimental measurements were obtained using a tuned Langmuir double-probe technique to reduce the RF interference and obtain the light versus current (I-V) characteristics of the probe. Time-averaged electron temperature and plasma density were measured for various combinations of pressure and applied RF power, The predictions of the 2-D model were found to be in good qualitative agreement with measured data, It was found that the electron temperature distribution T-e was more or less uniform in the chamber, It was also seen that the electron temperature depends primarily on pressure, but is almost independent of the power input, except in the very low-pressure regime. The plasma density goes up almost linearly with the power input

Impact of the Kuroshio intrusion on the nutrient inventory in the upper northern South China Sea: insights from an isopycnal mixing model

Based on four cruises covering a seasonal cycle in 2009-2011, we examined the impact of the Kuroshio intrusion, featured by extremely oligotrophic waters, on the nutrient inventory in the central northern South China Sea (NSCS). The nutrient inventory in the upper 100m of the water column in the study area ranged from similar to 200 to similar to 290 mmol m(-2) for N+N (nitrate plus nitrite), from similar to 13 to similar to 24 mmol m(-2) for soluble reactive phosphate and from similar to 210 to similar to 430 mmol m(-2) for silicic acid. The nutrient inventory showed a clear seasonal pattern with the highest value appearing in summer, while the N+N inventory in spring and winter had a reduction of similar to 13 and similar to 30 %, respectively, relative to that in summer. To quantify the extent of the Kuroshio intrusion, an isopycnal mixing model was adopted to derive the proportional contribution of water masses from the SCS proper and the Kuroshio along individual isopycnal surfaces. The derived mixing ratio along the isopycnal plane was then employed to predict the genuine gradients of nutrients under the assumption of no biogeochemical alteration. These predicted nutrient concentrations, denoted as N-m, are solely determined by water mass mixing. Results showed that the nutrient inventory in the upper 100m of the NSCS was overall negatively correlated to the Kuroshio water fraction, suggesting that the Kuroshio intrusion significantly influenced the nutrient distribution in the SCS and its seasonal variation. The difference between the observed nutrient concentrations and their corresponding Nm allowed us to further quantify the nutrient removal/addition associated with the biogeochemical processes on top of the water mass mixing. We revealed that the nutrients in the upper 100m of the water column had a net consumption in both winter and spring but a net addition in fall.Based on four cruises covering a seasonal cycle in 2009-2011, we examined the impact of the Kuroshio intrusion, featured by extremely oligotrophic waters, on the nutrient inventory in the central northern South China Sea (NSCS). The nutrient inventory in the upper 100m of the water column in the study area ranged from similar to 200 to similar to 290 mmol m(-2) for N+N (nitrate plus nitrite), from similar to 13 to similar to 24 mmol m(-2) for soluble reactive phosphate and from similar to 210 to similar to 430 mmol m(-2) for silicic acid. The nutrient inventory showed a clear seasonal pattern with the highest value appearing in summer, while the N+N inventory in spring and winter had a reduction of similar to 13 and similar to 30 %, respectively, relative to that in summer. To quantify the extent of the Kuroshio intrusion, an isopycnal mixing model was adopted to derive the proportional contribution of water masses from the SCS proper and the Kuroshio along individual isopycnal surfaces. The derived mixing ratio along the isopycnal plane was then employed to predict the genuine gradients of nutrients under the assumption of no biogeochemical alteration. These predicted nutrient concentrations, denoted as N-m, are solely determined by water mass mixing. Results showed that the nutrient inventory in the upper 100m of the NSCS was overall negatively correlated to the Kuroshio water fraction, suggesting that the Kuroshio intrusion significantly influenced the nutrient distribution in the SCS and its seasonal variation. The difference between the observed nutrient concentrations and their corresponding Nm allowed us to further quantify the nutrient removal/addition associated with the biogeochemical processes on top of the water mass mixing. We revealed that the nutrients in the upper 100m of the water column had a net consumption in both winter and spring but a net addition in fall

Primary solitary retro-clival amyloidoma.

Amyloidosis encompasses a group of disorders sharing the common feature of intercellular deposition of amyloid protein by several different pathogenetic mechanisms. Primary solitary amyloidosis, or amyloidoma, is a rare subset of amyloidosis in which amyloid deposition is focal and not secondary to a systemic process or plasma cell dyscrasia.This 84-year-old female presented with history of multiple syncopal episodes, dysphagia, and ataxia. Motor strength was 3+/5 in the right upper extremity. Rheumatoid factor, cyclic citrullinated peptide (CCP), and anti-nuclear antibody (ANA) were normal. Serum and urine immune-electrophoresis detected no abnormal bands. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a non-enhancing soft-tissue mass extending from the retro-clivus to C2 posteriorly, eccentric to the right with severe mass effect on the upper cervical medullary junction. Endoscopic trans-nasal debulking of the retro-clival mass was performed with occiput to C5 posterior instrumentation for spinal stabilization.Primary solitary amyloidosis, unlike other forms of amyloidosis, has an excellent prognosis with local resection. Diagnosis requires special stains and a degree of suspicion for the disease. This is the first report to document an endoscopic trans-nasal approach for removal of a primary solitary amyloidosis of the retro-clivus. Management of vertebral amyloidoma involves aggressive local resection of the tumor when feasible and spine stabilization as the degree of tumor involvement mandates. Complete evaluation for the diagnosis of systemic amyloidosis is essential for the management and prognostication. Surgeons encountering such lesions must maintain high suspicion for this rare disease and advise pathologists accordingly to establish the correct diagnosis

DNA nanostructure-based magnetic beads for potentiometric aptasensing

In this work, a simple, general, and sensitive potentiometric platform is presented, which allows potentiometric sensing to be applied to any class of molecule irrespective of the analyte charge. DNA nanostructures are self-assembled on magnetic beads via the incorporation of an aptamer into a hybridization chain reaction. The aptamer target binding event leads to the disassembly of the DNA nanostructures, which results in a dramatic change in the surface charge of the magnetic beads. Such a surface charge change can be sensitively detected by a polycation-sensitive membrane electrode using protamine as an indicator. With an endocrine disruptor bisphenol A as a model, the proposed potentiometric method shows a wide linear range from 0.1 to 100 nM with a low detection limit of 80 pM (3 sigma). The proposed sensing strategy will lay a foundation for the development of potentiometric sensors for highly sensitive and selective detection of various targets

Designing ultrafine lamellar eutectic structure in bimodal titanium alloys by semi-solid sintering

We report on a novel approach to design typical ultrafine lamellar eutectic structure in bimodal alloys fabricated by semi-solid sintering (SSS) of a eutectic mixture. In our work ultrafine lamellar eutectic structure was implemented by controlling the phase composition of eutectic reaction and consequently by regulating the structure of eutectic reaction-induced liquid phase through varying component number. Microstructure analysis indicate that although all SSSed alloys have the same three phase constitutions of bcc beta-Ti(Fe Co) and fcc Ti-2(Co Fe) the morphology and distribution of the eutectic structure transforms from limited length and minor quantity to partial fine alternating bcc beta-Ti and bcc Ti(Fe Co) lamellae and further to typical complete ultrafine alternating continuous lamellae in the SSSed ternary Ti-Fe-Co quaternary Ti-Fe-Co-Nb and quinary Ti-Fe-Co-Nb-Al alloys. Interestingly the SSSed Ti-Fe-Co-Nb-Al alloy presents a novel bimodal microstructure of coarse fcc Ti-2(Co Fe) surrounded by an ultrafine lamellar eutectic matrix containing ultrafine bcc beta-Ti and bcc Ti(Fe Co) lamellae. This bimodal microstructure exhibits ultra-high yield strength of 2050 MPa with plasticity in compression of 19.7% which exceed published values of equivalent materials. Our results provide a novel pathway for fabricating new-structure metallic alloys for high-performance structural applications. (C) 2017 Elsevier B.V. All rights reserved.</p

Differential regulation of stiffness, topography, and dimension of substrates in rat mesenchymal stem cells

The physiological microenvironment of the stem cell niche, including the three factors of stiffness, topography, and dimension, is crucial to stem cell proliferation and differentiation. Although a growing body of evidence is present to elucidate the importance of these factors individually, the interaction of the biophysical parameters of the factors remains insufficiently characterized, particularly for stem cells. To address this issue fully, we applied a micro-fabricated polyacrylamide hydrogel substrate with two elasticities, two topographies, and three dimensions to systematically test proliferation, morphology and spreading, differentiation, and cytoskeletal re-organization of rat bone marrow mesenchymal stem cells (rBMSCs) on twelve cases. An isolated but not combinatory impact of the factors was found regarding the specific functions. Substrate stiffness or dimension is predominant in regulating cell proliferation by fostering cell growth on stiff, unevenly dimensioned substrate. Topography is a key factor for manipulating cell morphology and spreading via the formation of a large spherical shape in a pillar substrate but not in a grooved substrate. Although stiffness leads to osteogenic or neuronal differentiation of rBMSCs on a stiff or soft substrate, respectively, topography or dimension also plays a lesser role in directing cell differentiation. Neither an isolated effect nor a combinatory effect was found for actin or tubulin expression, whereas a seemingly combinatory effect of topography and dimension was found in manipulating vimentin expression. These results further the understandings of stem cell proliferation, morphology, and differentiation in a physiologically mimicking microenvironment

Optimized sixth-order monotonicity-preserving scheme by nonlinear spectral analysis

In this paper, sixth-order monotonicity-preserving optimized scheme (OMP6) for the numerical solution of conservation laws is developed on the basis of the dispersion and dissipation optimization and monotonicity-preserving technique. The nonlinear spectral analysis method is developed and is used for the purpose of minimizing the dispersion errors and controlling the dissipation errors. The new scheme (OMP6) is simple in expression and is easy for use in CFD codes. The suitability and accuracy of this new scheme have been tested through a set of one-dimensional, two-dimensional, and three-dimensional tests, including the one-dimensional Shu-Osher problem, the two-dimensional double Mach reflection, and the Rayleigh-Taylor instability problem, and the three-dimensional direct numerical simulation of decaying compressible isotropic turbulence. All numerical tests show that the new scheme has robust shock capturing capability and high resolution for the small-scale waves due to fewer numerical dispersion and dissipation errors. Moreover, the new scheme has higher computational efficiency than the well-used WENO schemes

c-axis preferential orientation of hydroxyapatite accounts for the high wear resistance of the teeth of black carp (Mylopharyngodon piceus)

Biological armors such as mollusk shells have long been recognized and studied for their values in inspiring novel designs of engineering materials with higher toughness and strength. However, no material is invincible and biological armors also have their rivals. In this paper, our attention is focused on the teeth of black carp (Mylopharyngodon piceus) which is a predator of shelled mollusks like snails and mussels. Nanoscratching test on the enameloid, the outermost layer of the teeth, indicates that the natural occlusal surface (OS) has much higher wear resistance compared to the other sections. Subsequent X-ray diffraction analysis reveals that the hydroxyapatite (HAp) crystallites in the vicinity of OS possess c-axis preferential orientation. The superior wear resistance of black carp teeth is attributed to the c-axis preferential orientation of HAp near the OS since the (001) surface of HAp crystal, which is perpendicular to the c-axis, exhibits much better wear resistance compared to the other surfaces as demonstrated by the molecular dynamics simulation. Our results not only shed light on the origin of the good wear resistance exhibited by the black carp teeth but are of great value to the design of engineering materials with better abrasion resistance