Cryotherapy by encapsulation-dehydration is effective for in vitro eradication of latent viruses from ‘Marubakaido’ apple rootstock

USDA-ARS?s Scientific Manuscript database

Apple stem pitting virus (ASPV), Apple chlorotic leaf spot virus (ACLSV) and Apple stem grooving virus (ASGV) are several major viral pathogens of apple trees, responsible for substantial damage to the world's apple industry. This study aimed to evaluate the effectiveness of encapsulation-dehydratio...

7 CFR 932.149 - Modified minimum quality requirements for specified styles of canned olives of the ripe type.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Fragments (Pitted Style Only) Not more than 1.3% average by count Major Stems Not more than 3 HEVM Not more... per 300 grams Major Stems Not more than 3 HEVM Not more than 2 units per sample Broken Pieces and End... Fragments Average of not more than 1 by count per 300 grams Major Stems Not more than 3 HEVM Not more than 2...

7 CFR 932.149 - Modified minimum quality requirements for specified styles of canned olives of the ripe type.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Fragments (Pitted Style Only) Not more than 1.3% average by count Major Stems Not more than 3 HEVM Not more... per 300 grams Major Stems Not more than 3 HEVM Not more than 2 units per sample Broken Pieces and End... Fragments Average of not more than 1 by count per 300 grams Major Stems Not more than 3 HEVM Not more than 2...

7 CFR 932.149 - Modified minimum quality requirements for specified styles of canned olives of the ripe type.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Fragments (Pitted Style Only) Not more than 1.3% average by count Major Stems Not more than 3 HEVM Not more... per 300 grams Major Stems Not more than 3 HEVM Not more than 2 units per sample Broken Pieces and End... Fragments Average of not more than 1 by count per 300 grams Major Stems Not more than 3 HEVM Not more than 2...

7 CFR 932.149 - Modified minimum quality requirements for specified styles of canned olives of the ripe type.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Fragments (Pitted Style Only) Not more than 1.3% average by count Major Stems Not more than 3 HEVM Not more... per 300 grams Major Stems Not more than 3 HEVM Not more than 2 units per sample Broken Pieces and End... Fragments Average of not more than 1 by count per 300 grams Major Stems Not more than 3 HEVM Not more than 2...

7 CFR 932.149 - Modified minimum quality requirements for specified styles of canned olives of the ripe type.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Fragments (Pitted Style Only) Not more than 1.3% average by count Major Stems Not more than 3 HEVM Not more... per 300 grams Major Stems Not more than 3 HEVM Not more than 2 units per sample Broken Pieces and End... Fragments Average of not more than 1 by count per 300 grams Major Stems Not more than 3 HEVM Not more than 2...

Exfoliation of gastric pit-parietal cells into the gastric lumen associated with a stimulation of isolated rat gastric mucosa in vitro: a morphological study by the application of cryotechniques.

PubMed

Aoyama, Fumiyo; Sawaguchi, Akira; Ide, Soyuki; Kitamura, Kazuo; Suganuma, Tatsuo

2008-06-01

It is clinicopathologically important to elucidate the cell kinetics for the maintenance of normal gastric epithelium. In a rat gastric mucosa isolated after stimulation, a number of cells were exfoliated into the gastric lumen of the pit region. The present study was undertaken to clarify the origin of exfoliated cells and their histochemical profiles by taking the advantages of cryotechniques. As results, most of the exfoliated cells were identified as pit-parietal cells labeled with both peanut-lectin and anti-H+/K+-ATPase antibody. Quantitative analysis verified a time-dependent increase in the number of exfoliated cells in the gastric mucosa isolated after stimulation. The exfoliated cells exhibited a diffuse intracellular staining for E-cadherin, suggesting a dissociation of the adhesion molecule prior to the cell exfoliation. It should be noted that most of the exfoliated cells were negative to the apoptotic markers (TUNEL staining and caspase-3). Ultrastructurally, autophagosome-like structures consisting of H+/K+-ATPase positive membranes were frequently seen in the exfoliated pit-parietal cells. In addition, the pit-parietal cell exfoliation was accompanied by sealing of their basal portion with the cytoplasmic processes of adjacent surface mucous cells. The present morphological findings provide a new insight into the cell kinetics in the gastric epithelium in vitro.

Lower Mississippi River Environmental Program. Report 2. A Physical Description of Main Stem Levee Borrow Pits along the Lower Mississippi River

DTIC Science & Technology

1988-02-01

Eastern cottonwood, green ash, sugarberry. box elder, bald cypress, willow honey locust, slippery elm , overcup oak and bitter pecan. Principle...vines and understory. Woody vegetation surrounds the borrow pit and consists of American and slippery elms , silver maple, black willow, cottonwood, pin...aquatica Water elm Ulmus rubra Slippery elm Urtica dioica Stinging nettle Vaccinium sp. Blueberry Vaccinium spp. Vaccinum Vernonia altissima Ironweed

Colletotrichum species associated with jute (Corchorus capsularis L.) anthracnose in southeastern China.

PubMed

Niu, Xiaoping; Gao, Hong; Qi, Jianmin; Chen, Miancai; Tao, Aifen; Xu, Jiantang; Dai, Zhigang; Su, Jianguang

2016-04-28

Anthracnose, caused by the Colletotrichum species of fungi, is one of the most serious diseases affecting jute in China. The disease causes chlorotic regions with black brown sunken necrotic pits on the surfaces of stems. In late stages of disease, plants undergo defoliation, dieback and blight, which make anthracnose a major threat to jute fiber production and quality in China. In this study, 7 strains of Colletotrichum fungi were isolated from diseased jute stems from Zhejiang, Fujian, Guangxi, and Henan plantations in China. Multi-locus sequence (ACT, TUB2, CAL, GS, GAPDH and ITS) analysis coupled with morphological assessment revealed that C. fructicola, C. siamense and C. corchorum-capsularis sp. nov. were associated with jute anthracnose in southeastern China. C. fructicola and C. siamense were previously not associated with jute anthracnose. C. corchorum-capsularis is a new species formally described here. Pathogenicity tests confirmed that all species can infect jute, causing anthracnose, however the virulence of the 3 species differed. This report is the first associating these three species with jute disease worldwide and is the first description of the pathogens responsible for jute anthracnose in China.

The dynamics of gas bubbles in conduits of vascular plants and implications for embolism repair.

PubMed

Konrad, W; Roth-Nebelsick, A

2003-09-07

Pressure-induced tensions in the xylem, the water conducting tissue of vascular plants, can lead to embolism in the water-conducting cells. The details and mechanisms of embolism repair in vascular plants are still not well understood. In particular, experimental results which indicate that embolism repair may occur during xylem tension cause great problems with respect to current paradigms of plant water transport. The present paper deals with a theoretical analysis of interfacial effects at the pits (pores in the conduit walls), because it was suggested that gas-water interfaces at the pit pores may be involved in the repair process by hydraulically isolating the embolized conduit. The temporal behaviour of bubbles at the pit pores was especially studied since the question of whether these pit bubbles are able to persist is of crucial importance for the suggested mechanism to work. The results indicate that (1) the physical preconditions which are necessary for the suggested mechanism appear to be satisfied, (2) pit bubbles can achieve temporal stability and therefore persist and (3) dissolving of bubbles in the conduit lumen may lead to the final breakdown of the hydraulic isolation. The whole process is, however, complex and strongly dependent on the detailed anatomy of the pit and the contact angle.

Isolation of a Toxin from Venom of Wagler’s Pit Viper Trimeresurus wagleri

DTIC Science & Technology

1990-01-31

AUTHOR(S) Scott A. Weinstein, Alan W. Bernheimer and Leonard A. Smith 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month, Day) 15. PAGE...WAGLERI SCOTT A. WEINSTEIN, 1 ALAN W. BERNHEIMER , 2 AND LEONARD A. SMITH1 * 1 Department of Toxinology, Pathology Division, United States Army Medical...Weinstein, A. W. Bernheimer , and L. A. Smith. Isolation of a toxin from venom of Waglers pit viper Trimeresurus wagleri. Toxicon .,- ,19--. A lethal

Embryonic death and the creation of human embryonic stem cells.

PubMed

Landry, Donald W; Zucker, Howard A

2004-11-01

The creation of human embryonic stem cells through the destruction of a human embryo pits the value of a potential therapeutic tool against that of an early human life. This contest of values has resulted in a polarized debate that neglects areas of common interest and perspective. We suggest that a common ground for pursuing research on human embryonic stem cells can be found by reconsidering the death of the human embryo and by applying to this research the ethical norms of essential organ donation.

PiTS-1: Carbon Partitioning in Loblolly Pine after 13C Labeling and Shade Treatments

DOE Data Explorer

Warren, J. M.; Iversen, C. M.; Garten, Jr., C. T.; Norby, R. J.; Childs, J.; Brice, D.; Evans, R. M.; Gu, L.; Thornton, P.; Weston, D. J.

2013-01-01

The PiTS task was established with the objective of improving the C partitioning routines in existing ecosystem models by exploring mechanistic model representations of partitioning tested against field observations. We used short-term field manipulations of C flow, through 13CO2 labeling, canopy shading and stem girdling, to dramatically alter C partitioning, and resultant data are being used to test model representation of C partitioning processes in the Community Land Model (CLM4 or CLM4.5).

Diversity of citrus tristeza virus isolates indicated by dsRNA analysis.

PubMed

Dodds, J A; Jordan, R L; Roistacher, C N; Jarupat, T

1987-01-01

One major dsRNA of molecular weight (MW) 13.3 X 10(6) and two others (MW 1.9 X 10(6) and 0.8 X 10(6] were routinely detected by polyacrylamide gel electrophoresis in extracts from sweet orange (Citrus sinensis) or citron (Citrus medica) infected with each of 66 isolates of citrus tristeza virus (CTV). Several additional dsRNA were also commonly detected, usually as weakly stained bands in reproducible positions in gels, but some were very prominent, e.g., a dsRNA of MW 1.7 X 10(6) associated with a seedling yellows isolate (sy-1). No dsRNA was detected in equivalent extracts from noninoculated sweet orange and citron. End-labeled [32P] probes were made from purified full-length viral RNA or polyacrylamide gel-purified full-length dsRNA of a nonseedling yellows (nsy-1) and a seedling yellows (sy-1) isolate of CTV. Each of the four probes was able to hybridize to all major and most minor dsRNAs of both isolates in composite polyacrylamide/agrarose gels, including the 1.7 X 10(6) dsRNA specific to the seedling yellows isolate, and could readily detect CTV nucleic acid sequences in extracts from bark of infected sweet orange plants spotted onto nitrocellulose membranes. One dsRNA (MW 0.5 X 10(6] was very prominent in some isolates and much less so, or undetectable, in other isolates and 66 isolates have been screened for the presence of this dsRNA. There was a strong correlation between inability to detect the 0.5 X 10(6) dsRNA and the designation of an isolate as neither a seedling yellows type nor a stem pitting isolate of grapefruit; these properties were typical for isolates of CTV from southern California.

Easy Come, Easy Go: Capillary Forces Enable Rapid Refilling of Embolized Primary Xylem Vessels.

PubMed

Rolland, Vivien; Bergstrom, Dana M; Lenné, Thomas; Bryant, Gary; Chen, Hua; Wolfe, Joe; Holbrook, N Michele; Stanton, Daniel E; Ball, Marilyn C

2015-08-01

Protoxylem plays an important role in the hydraulic function of vascular systems of both herbaceous and woody plants, but relatively little is known about the processes underlying the maintenance of protoxylem function in long-lived tissues. In this study, embolism repair was investigated in relation to xylem structure in two cushion plant species, Azorella macquariensis and Colobanthus muscoides, in which vascular water transport depends on protoxylem. Their protoxylem vessels consisted of a primary wall with helical thickenings that effectively formed a pit channel, with the primary wall being the pit channel membrane. Stem protoxylem was organized such that the pit channel membranes connected vessels with paratracheal parenchyma or other protoxylem vessels and were not exposed directly to air spaces. Embolism was experimentally induced in excised vascular tissue and detached shoots by exposing them briefly to air. When water was resupplied, embolized vessels refilled within tens of seconds (excised tissue) to a few minutes (detached shoots) with water sourced from either adjacent parenchyma or water-filled vessels. Refilling occurred in two phases: (1) water refilled xylem pit channels, simplifying bubble shape to a rod with two menisci; and (2) the bubble contracted as the resorption front advanced, dissolving air along the way. Physical properties of the protoxylem vessels (namely pit channel membrane porosity, hydrophilic walls, vessel dimensions, and helical thickenings) promoted rapid refilling of embolized conduits independent of root pressure. These results have implications for the maintenance of vascular function in both herbaceous and woody species, because protoxylem plays a major role in the hydraulic systems of leaves, elongating stems, and roots. © 2015 American Society of Plant Biologists. All Rights Reserved.

Hydraulic and mechanical properties of young Norway spruce clones related to growth and wood structure

PubMed Central

ROSNER, SABINE; KLEIN, ANDREA; MÜLLER, ULRICH; KARLSSON, BO

2011-01-01

Summary Stem segments of eight five-year-old Norway spruce (Picea abies (L.) Karst.) clones differing in growth characteristics were tested for maximum specific hydraulic conductivity (ks100), vulnerability to cavitation and behavior under mechanical stress. The vulnerability of the clones to cavitation was assessed by measuring the applied air pressure required to cause 12 and 50% loss of conductivity (Ψ12, Ψ50) and the percent loss of conductivity at 4 MPa applied air pressure (PLC4MPa). The bending strength and stiffness and the axial compression strength and stiffness of the same stem segments were measured to characterize wood mechanical properties. Growth ring width, wood density, latewood percentage, lumen diameter, cell wall thickness, tracheid length and pit dimensions of earlywood cells, spiral grain and microfibril angles were examined to identify structure–function relationships. High ks100 was strongly and positively related to spiral grain angle, which corresponded positively to tracheid length and pit dimensions. Spiral grain may reduce flow resistance of the bordered pits of the first earlywood tracheids, which are characterized by rounded tips and an equal distribution of pits along the entire length. Wood density was unrelated to hydraulic vulnerability parameters. Traits associated with higher hydraulic vulnerability were long tracheids, high latewood percentage and thick earlywood cell walls. The positive relationship between earlywood cell wall thickness and vulnerability to cavitation suggest that air seeding through the margo of bordered pits may occur in earlywood. There was a positive phenotypic and genotypic relationship between ks100 and PLC4MPa, and both parameters were positively related to tree growth rate. Variability in mechanical properties depended mostly on wood density, but also on the amount of compression wood. Accordingly, hydraulic conductivity and mechanical strength or stiffness showed no tradeoff. PMID:17472942

25 CFR 226.22 - Prohibition of pollution.

Code of Federal Regulations, 2010 CFR

2010-04-01

... pits shall be enclosed with a fence of at least four strands of barbed wire, or an approved substitute... procedures, including but not limited to fracturing, acidizing, swabbing, and drill stem tests, shall be...

Traits and trade-offs in whole-tree hydraulic architecture along the vertical axis of Eucalyptus grandis.

PubMed

Pfautsch, Sebastian; Aspinwall, Michael J; Drake, John E; Chacon-Doria, Larissa; Langelaan, Rob J A; Tissue, David T; Tjoelker, Mark G; Lens, Frederic

2018-01-25

Sapwood traits like vessel diameter and intervessel pit characteristics play key roles in maintaining hydraulic integrity of trees. Surprisingly little is known about how sapwood traits covary with tree height and how such trait-based variation could affect the efficiency of water transport in tall trees. This study presents a detailed analysis of structural and functional traits along the vertical axes of tall Eucalyptus grandis trees. To assess a wide range of anatomical and physiological traits, light and electron microscopy was used, as well as field measurements of tree architecture, water use, stem water potential and leaf area distribution. Strong apical dominance of water transport resulted in increased volumetric water supply per unit leaf area with tree height. This was realized by continued narrowing (from 250 to 20 µm) and an exponential increase in frequency (from 600 to 13 000 cm-2) of vessels towards the apex. The widest vessels were detected at least 4 m above the stem base, where they were associated with the thickest intervessel pit membranes. In addition, this study established the lower limit of pit membrane thickness in tall E. grandis at ~375 nm. This minimum thickness was maintained over a large distance in the upper stem, where vessel diameters continued to narrow. The analyses of xylem ultrastructure revealed complex, synchronized trait covariation and trade-offs with increasing height in E. grandis. Anatomical traits related to xylem vessels and those related to architecture of pit membranes were found to increase efficiency and apical dominance of water transport. This study underlines the importance of studying tree hydraulic functioning at organismal scale. Results presented here will improve understanding height-dependent structure-function patterns in tall trees. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Colletotrichum species associated with jute (Corchorus capsularis L.) anthracnose in southeastern China

PubMed Central

Niu, Xiaoping; Gao, Hong; Qi, Jianmin; Chen, Miancai; Tao, Aifen; Xu, Jiantang; Dai, Zhigang; Su, Jianguang

2016-01-01

Anthracnose, caused by the Colletotrichum species of fungi, is one of the most serious diseases affecting jute in China. The disease causes chlorotic regions with black brown sunken necrotic pits on the surfaces of stems. In late stages of disease, plants undergo defoliation, dieback and blight, which make anthracnose a major threat to jute fiber production and quality in China. In this study, 7 strains of Colletotrichum fungi were isolated from diseased jute stems from Zhejiang, Fujian, Guangxi, and Henan plantations in China. Multi-locus sequence (ACT, TUB2, CAL, GS, GAPDH and ITS) analysis coupled with morphological assessment revealed that C. fructicola, C. siamense and C. corchorum-capsularis sp. nov. were associated with jute anthracnose in southeastern China. C. fructicola and C. siamense were previously not associated with jute anthracnose. C. corchorum-capsularis is a new species formally described here. Pathogenicity tests confirmed that all species can infect jute, causing anthracnose, however the virulence of the 3 species differed. This report is the first associating these three species with jute disease worldwide and is the first description of the pathogens responsible for jute anthracnose in China. PMID:27121760

Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: Redundant roles for PiT-1 and PiT-2

PubMed Central

Crouthamel, Matthew H.; Lau, Wei Ling; Leaf, Elizabeth M.; Chavkin, Nick; Wallingford, Mary C.; Peterson, Danielle F.; Li, Xianwu; Liu, Yonggang; Chin, Michael T.; Levi, Moshe; Giachelli, Cecilia M.

2014-01-01

Objective Elevated serum phosphate has emerged as a major risk factor for vascular calcification. The sodium-dependent phosphate cotransporter, PiT-1, was previously shown to be required for phosphate-induced osteogenic differentiation and calcification of cultured human VSMCs, but its importance in vascular calcification in vivo, as well as the potential role of its homologue, PiT-2, have not been determined. We investigated the in vivo requirement for PiT-1 in vascular calcification using a mouse model of chronic kidney disease, and the potential compensatory role of PiT-2 using in vitro knockdown and over-expression strategies. Approach and Results Mice with targeted deletion of PiT-1 in VSMCs were generated (PiT-1Δsm). PiT-1 mRNA levels were undetectable whereas PiT-2 mRNA levels were increased 2 fold in the vascular aortic media of PiT-1Δsm compared to PiT-1flox/flox control. When arterial medial calcification was induced in PiT-1Δsm and PiT-1flox/flox by chronic kidney disease followed by dietary phosphate loading, the degree of aortic calcification was not different between genotypes, suggesting compensation by PiT-2. Consistent with this possibility, VSMCs isolated from PiT-1Δsm mice had no PiT-1 mRNA expression, increased PiT-2 mRNA levels, and no difference in sodium-dependent phosphate uptake or phosphate-induced matrix calcification compared to PiT-1flox/flox VSMCs. Knockdown of PiT-2 decreased phosphate uptake and phosphate-induced calcification of PiT-1Δsm VSMCs. Furthermore, over-expression of PiT-2 restored these parameters in human PiT-1-deficient VSMCs. Conclusions PiT-2 can mediate phosphate uptake and calcification of VSMCs in the absence of PiT-1. Mechanistically, PiT-1 and PiT-2 appear to serve redundant roles in phosphate-induced calcification of vascular smooth muscle cells. PMID:23968976

Cell Wall-Degrading Enzymes Enlarge the Pore Size of Intervessel Pit Membranes in Healthy and Xylella fastidiosa-Infected Grapevines1[C][W][OA

PubMed Central

Pérez-Donoso, Alonso G.; Sun, Qiang; Roper, M. Caroline; Greve, L. Carl; Kirkpatrick, Bruce; Labavitch, John M.

2010-01-01

The pit membrane (PM) is a primary cell wall barrier that separates adjacent xylem water conduits, limiting the spread of xylem-localized pathogens and air embolisms from one conduit to the next. This paper provides a characterization of the size of the pores in the PMs of grapevine (Vitis vinifera). The PM porosity (PMP) of stems infected with the bacterium Xylella fastidiosa was compared with the PMP of healthy stems. Stems were infused with pressurized water and flow rates were determined; gold particles of known size were introduced with the water to assist in determining the size of PM pores. The effect of introducing trans-1,2-diaminocyclohexane-N,N,N′,N′-tetraacetic acid (CDTA), oligogalacturonides, and polygalacturonic acid into stems on water flux via the xylem was also measured. The possibility that cell wall-degrading enzymes could alter the pore sizes, thus facilitating the ability of X. fastidiosa to cross the PMs, was tested. Two cell wall-degrading enzymes likely to be produced by X. fastidiosa (polygalactuoronase and endo-1,4- β -glucanase) were infused into stems, and particle passage tests were performed to check for changes in PMP. Scanning electron microscopy of control and enzyme-infused stem segments revealed that the combination of enzymes opened holes in PMs, probably explaining enzyme impacts on PMP and how a small X. fastidiosa population, introduced into grapevines by insect vectors, can multiply and spread throughout the vine and cause Pierce's disease. PMID:20107028

Contrasting hydraulic architecture and function in deep and shallow roots of tree species from a semi-arid habitat

PubMed Central

Johnson, Daniel M.; Brodersen, Craig R.; Reed, Mary; Domec, Jean-Christophe; Jackson, Robert B.

2014-01-01

Background and Aims Despite the importance of vessels in angiosperm roots for plant water transport, there is little research on the microanatomy of woody plant roots. Vessels in roots can be interconnected networks or nearly solitary, with few vessel–vessel connections. Species with few connections are common in arid habitats, presumably to isolate embolisms. In this study, measurements were made of root vessel pit sizes, vessel air-seeding pressures, pit membrane thicknesses and the degree of vessel interconnectedness in deep (approx. 20 m) and shallow (<10 cm) roots of two co-occurring species, Sideroxylon lanuginosum and Quercus fusiformis. Methods Scanning electron microscopy was used to image pit dimensions and to measure the distance between connected vessels. The number of connected vessels in larger samples was determined by using high-resolution computed tomography and three-dimensional (3-D) image analysis. Individual vessel air-seeding pressures were measured using a microcapillary method. The thickness of pit membranes was measured using transmission electron microscopy. Key Results Vessel pit size varied across both species and rooting depths. Deep Q. fusiformis roots had the largest pits overall (>500 µm) and more large pits than either shallow Q. fusiformis roots or S. lanuginosum roots. Vessel air-seeding pressures were approximately four times greater in Q. fusiformis than in S. lanuginosum and 1·3–1·9 times greater in shallow roots than in deep roots. Sideroxylon lanuginosum had 34–44 % of its vessels interconnected, whereas Q. fusiformis only had 1–6 % of its vessels connected. Vessel air-seeding pressures were unrelated to pit membrane thickness but showed a positive relationship with vessel interconnectedness. Conclusions These data support the hypothesis that species with more vessel–vessel integration are often less resistant to embolism than species with isolated vessels. This study also highlights the usefulness of tomography for vessel network analysis and the important role of 3-D xylem organization in plant hydraulic function. PMID:24363350

Cotton roll isolation versus Vac-Ejector isolation.

PubMed

Wood, A J; Saravia, M E; Farrington, F H

1989-01-01

A visible-light-cured, white pit-and-fissure sealant was applied to 523 teeth in school children using either cotton rolls or a VacEjector for isolation. After a minimum of six months, the patients were recalled and the retention of the sealants was evaluated. No significant difference in sealant retention was found between the two isolation methods.

Pitting and Repair of the Space Shuttle's Inconel(Registered TradeMark) Honeycomb Conical Seal Panel

NASA Technical Reports Server (NTRS)

Zimmerman, Frank R.; Gentz, Steven J.; Miller, James B.; MacKay, Rebecca A.; Bright, Mark L.

2006-01-01

During return to flight servicing of the rudder speed brake (RSB) for each Space Shuttle Orbiter, inspectors discovered numerous small pits on the surface of the #4 right hand side honeycomb panel that covers the rudder speed brake actuators. Shortly after detection of the problem, concurrent investigations were initiated to determine the extent of damage, the root cause, and to develop a repair plan, since fabrication of a replacement panel is impractical for cost, schedule, and sourcing considerations. This paper describes the approach, findings, conclusions and recommendations associated with the investigation of the conical seal pitting. It documents the cause and contributing factors of the pitting, the means used to isolate each contributor, and the supporting evidence for the primary cause of the pitting. Finally, the selection, development and verification of the repair procedure used to restore the conical seal panel is described with supporting process and metallurgical rationale for selection.

Installation Restoration Program Information Management System (IRPIMS) Data Loading Handbook. Version 2.1

DTIC Science & Technology

1989-09-01

STEEL STL STEEL TFL TEFLON TIL TILE WD WOOD WRI WROUGHT IRON Z OTHER A-14 coam Bc~ai=L a TEST PIT ois rn iEI AR AIR - ROTARY 8 BORED OR AUGERED C CABLE-TOOL...CO CORING Cs CHILLED SHOT D DUG DH DOWN THE HOLE HAMMER HA HAND AUGERED HS HOLLOW STEM AUGER J JETTED MR DIRECT CIRCULATION ROTARY , MUD p AIR ...INSTITUTE WARI WATER AND AIR RESEARCH. INC. WIL WILSON AND CO. A-18 M 0E 7 PIT E V/n.. CK: N’Y ESCI ENGINEERING -SCIENCE NA NOT APPLICABLE RB MR

Deep Sequencing Analysis of Apple Infecting Viruses in Korea

PubMed Central

Cho, In-Sook; Igori, Davaajargal; Lim, Seungmo; Choi, Gug-Seoun; Hammond, John; Lim, Hyoun-Sub; Moon, Jae Sun

2016-01-01

Deep sequencing has generated 52 contigs derived from five viruses; Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV), Apple stem pitting virus (ASPV), Apple green crinkle associated virus (AGCaV), and Apricot latent virus (ApLV) were identified from eight apple samples showing small leaves and/or growth retardation. Nucleotide (nt) sequence identity of the assembled contigs was from 68% to 99% compared to the reference sequences of the five respective viral genomes. Sequences of ASPV and ASGV were the most abundantly represented by the 52 contigs assembled. The presence of the five viruses in the samples was confirmed by RT-PCR using specific primers based on the sequences of each assembled contig. All five viruses were detected in three of the samples, whereas all samples had mixed infections with at least two viruses. The most frequently detected virus was ASPV, followed by ASGV, ApLV, ACLSV, and AGCaV which were withal found in mixed infections in the tested samples. AGCaV was identified in assembled contigs ID 1012480 and 93549, which showed 82% and 78% nt sequence identity with ORF1 of AGCaV isolate Aurora-1. ApLV was identified in three assembled contigs, ID 65587, 1802365, and 116777, which showed 77%, 78%, and 76% nt sequence identity respectively with ORF1 of ApLV isolate LA2. Deep sequencing assay was shown to be a valuable and powerful tool for detection and identification of known and unknown virome in infected apple trees, here identifying ApLV and AGCaV in commercial orchards in Korea for the first time. PMID:27721694

Isolation Efficiency of Mouse Pancreatic Stem Cells Is Age Dependent.

PubMed

Kuise, Takashi; Noguchi, Hirofumi; Saitoh, Issei; Kataoka, Hitomi Usui; Watanabe, Masami; Noguchi, Yasufumi; Fujiwara, Toshiyoshi

2013-11-10

Mouse pancreatic stem cells have been isolated from mouse pancreata. This study evaluated the efficacy of isolating mouse pancreatic stem cells using mice of different ages. The pancreata of newborn mice, 8-week-old mice, and 24-week-old mice were harvested and digested by using collagenase. The "duct-like" cells in the digested pancreatic tissue were then inoculated into 96-well plates, cloned by limiting dilution, and cultured in DMEM with 20% FBS. Pancreatic stem cells were isolated from the pancreata of all newborn mice, while cells could only be isolated from 10% of the pancreata of 8-week-old mice and could not be isolated from the pancreata of any 24-week-old mice. These data suggest that young mice may have some pancreatic stem cells and that older mice may only have a few pancreatic stem cells. These data also indicate that it is extremely difficult to isolate pancreatic stem cells from older mice, suggesting that future research focus its efforts on finding methods of isolating pancreatic stem cells from adult mice.

Projecting cumulative benefits of multiple river restoration projects: an example from the Sacramento-San Joaquin River system in California

USGS Publications Warehouse

Kondolf, G. Mathias; Angermeier, Paul L.; Cummins, Kenneth; Dunne, Thomas; Healey, Michael; Kimmerer, Wim; Moyle, Peter B.; Murphy, Dennis; Patten, Duncan; Railsback, Steve F.; Reed, Denise J.; Spies, Robert B.; Twiss, Robert

2008-01-01

Despite increasingly large investments, the potential ecological effects of river restoration programs are still small compared to the degree of human alterations to physical and ecological function. Thus, it is rarely possible to “restore” pre-disturbance conditions; rather restoration programs (even large, well-funded ones) will nearly always involve multiple small projects, each of which can make some modest change to selected ecosystem processes and habitats. At present, such projects are typically selected based on their attributes as individual projects (e.g., consistency with programmatic goals of the funders, scientific soundness, and acceptance by local communities), and ease of implementation. Projects are rarely prioritized (at least explicitly) based on how they will cumulatively affect ecosystem function over coming decades. Such projections require an understanding of the form of the restoration response curve, or at least that we assume some plausible relations and estimate cumulative effects based thereon. Drawing on our experience with the CALFED Bay-Delta Ecosystem Restoration Program in California, we consider potential cumulative system-wide benefits of a restoration activity extensively implemented in the region: isolating/filling abandoned floodplain gravel pits captured by rivers to reduce predation of outmigrating juvenile salmon by exotic warmwater species inhabiting the pits. We present a simple spreadsheet model to show how different assumptions about gravel pit bathymetry and predator behavior would affect the cumulative benefits of multiple pit-filling and isolation projects, and how these insights could help managers prioritize which pits to fill.

Mitis group streptococci express variable pilus islet 2 pili.

PubMed

Zähner, Dorothea; Gandhi, Ashish R; Yi, Hong; Stephens, David S

2011-01-01

Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits in the Mitis group streptococci.

Primitive environment control for preservation of pit relics in archeology museums of China.

PubMed

Gu, Zhaolin; Luo, Xilian; Meng, Xiangzhao; Wang, Zanshe; Ma, Tao; Yu, Chuck; Rong, Bo; Li, Ku; Li, Wenwu; Tan, Ying

2013-02-05

Immovable historical relics in some archeology museums of China suffer deterioration due to their improper preservation environment. The existing environmental control systems used in archeology museums are often designed for the amenities of visitors, and these manipulated environments are often inappropriate for the conservation of abiotic relics. This paper points out that the large open space of the existing archeology museum could be a cause of deterioration of the relics from the point of view of indoor air convective flow. The paper illustrates the need to introduce a local pit environmental control, which could reintegrate a pit primitive environment for the preservation of the historical relics by using an air curtain system, orientated to isolate the unearthed relics, semiexposed in pits to the large gallery open space of the exhibition hall.

Achievement of insulin independence in three consecutive type-1 diabetic patients via pancreatic islet transplantation using islets isolated at a remote islet isolation center.

PubMed

Goss, John A; Schock, Angela P; Brunicardi, F Charles; Goodpastor, Sarah E; Garber, Alan J; Soltes, George; Barth, Merle; Froud, Tatiana; Alejandro, Rodolfo; Ricordi, Camillo

2002-12-27

As a result of advances in both immunosuppressive protocols and pancreatic islet isolation techniques, insulin independence has recently been achieved in several patients with type 1 diabetes mellitus via pancreatic islet transplantation (PIT). Although the dissemination of immunosuppressive protocols is quite easy, transferring the knowledge and expertise required to isolate a large number of quality human islets for transplantation is a far greater challenge. Therefore, in an attempt to centralize the critical islet processing needed for islet transplantation and to avoid the development of another islet processing center, we have established a collaborative islet transplant program between two geographically distant transplant centers. Three consecutive patients with type 1 diabetes mellitus with a history of severe hypoglycemia and metabolic instability underwent PIT at the Methodist Hospital (TMH), Houston, Texas, using pancreatic islets. All pancreatic islets were isolated from pancreata procured in Houston and subsequently transported for isolation to the Human Islet Cell Processing Facility of the Diabetes Research Institute (DRI) at the University of Miami, Miami, Florida. Pancreatic islets were isolated at DRI after enzymatic ductal perfusion (Liberase-HI) by the automated method (Ricordi Chamber) using endotoxin-free and xenoprotein-free media. After purification, the islets were immediately transported back to TMH and transplanted via percutaneous transhepatic portal embolization. Immunosuppression consisted of sirolimus, tacrolimus, and daclizumab. After donor cross-clamp in Houston, donor pancreata arrived at DRI and the isolation process began within 6.5 hr in all cases (median, 5.4 hr; range, 4.8-6.5 hr). At the completion of the isolation process, the islets were immediately transported back to TMH and transplanted. All three patients attained sustained insulin independence after transplantation of 395,567, 394,381, and 563,206 pancreatic islet equivalents (IEQ), respectively. Despite insulin independence, the first two patients received less than 10,000 IEQ/kg; therefore, to increase their functional pancreatic islet reserve, they underwent a second islet transplant with 326,720 and 768,132 IEQ, respectively. Posttransplantation follow-up for these three patients is 4, 3, and 0.5 months, respectively. The mean glycosylated hemoglobin values have been dramatically reduced in the first two patients. In addition, the mean amplitude of glycemic excursions have also been reduced in all three recipients (patient 1: before transplantation 197 mg/dL vs. after transplantation 61 mg/dL; patient 2: before transplantation 202 mg/dL vs. after transplantation 52 mg/dL; patient 3: before transplantation 245 mg/dL vs. after transplantation 58 mg/dL) after PIT. All pancreatic islet allografts demonstrated the ability to respond to an in vitro glucose stimulus at the DRI before shipment and at TMH after shipment and final processing with a median stimulation index of 2.1 and 2.2, respectively. None of the transplant recipients have had a hyper- or hypoglycemic episode since PIT and no complications have occurred. These early data demonstrate that (1) pancreatic islets remain viable after shipment to remote transplant sites; (2) pancreatic islet isolation techniques and experience can be concentrated at a small number of regional facilities that could supply islets to remote transplant centers; and (3) insulin independence via PIT can be achieved using a remote pancreatic islet isolation center.

Corrosion behaviour and biocompatibility of a novel Ni-free intermetallic coating growth on austenitic steel by hot dipping in an Al-12.6%Si alloy.

PubMed

Arenas, M A; Frutos, E; Saldaña, L; Conde, A; Labajos-Broncano, L; González-Martín, M L; González-Carrasco, J L; Vilaboa, N

2011-04-01

Commercial 316 LVM austenitic stainless steel samples have been coated by immersion in a bath of molten Al-12.6%Si alloy for 120 s. The coating consists of the Al(12)(Fe,Cr)(3)Si(2) intermetallic. In vitro corrosion behaviour has been evaluated in the Ringer's solution by means of potentiodynamic curves and electrochemical impedance spectroscopy. The results reveal that the coated specimens exhibit lower susceptibility to localised corrosion with respect to the substrate. XPS analysis suggests that the ennoblement of the pitting potential is due to the formation of a chromium oxyhydroxide containing passive layer. The intermetallic coating shows a good biocompatibility, as demonstrated by culturing human mesenchymal stem cells isolated from bone marrow which attached, grew and differentiated to the osteoblastic lineage to a similar extent on coated and bare steels. In summary, this study proposes a method that generates Ni-free coatings of the stainless steel with useful properties for biomedical applications.

Understanding the role of the cytoskeleton in wood formation in angiosperm trees: hybrid aspen (Populus tremula x P. tremuloides) as the model species.

PubMed

Chaffey, Nigel; Barlow, Peter; Sundberg, Björn

2002-03-01

The involvement of microfilaments and microtubules in the development of the radial and axial components of secondary xylem (wood) in hybrid aspen (Populus tremula L. x P. tremuloides Michx.) was studied by indirect immunofluorescent localization techniques. In addition to cambial cells, the differentiated cell types considered were early- and late-wood vessel elements, axial parenchyma, normal-wood fibers and gelatinous fibers, and contact and isolation ray cells. Microfilaments were rare in ray cambial cells, but were abundant and axially arranged in their derivatives once cell elongation had begun, and persisted in that orientation in mature ray cells. Microfilaments were axially arranged in fusiform cambial cells and persisted in that orientation in all xylem derivatives of those cells. Microtubules were randomly oriented in ray and fusiform cells of the cambial zone. Dense arrays of parallel-aligned microtubules were oriented near axially in the developing gelatinous fibers, but at a wide range of angles in normal-wood fibers. Ellipses of microfilaments were associated with pit development in fiber cells and isolation ray cells. Rings of co-localized microtubules and microfilaments were associated with developing inter-vessel bordered pits and vessel-contact ray cell contact pits, and, in the case of bordered pits, these rings decreased in diameter as the over-arching pit border increased in size. Although only microtubules were seen at the periphery of the perforation plate of vessel elements, a prominent meshwork of microfilaments overlaid the perforation plate itself. A consensus view of the roles of the cytoskeleton during wood formation in angiosperm trees is presented.

Multidimensional protein identification technology (MudPIT): technical overview of a profiling method optimized for the comprehensive proteomic investigation of normal and diseased heart tissue.

PubMed

Kislinger, Thomas; Gramolini, Anthony O; MacLennan, David H; Emili, Andrew

2005-08-01

An optimized analytical expression profiling strategy based on gel-free multidimensional protein identification technology (MudPIT) is reported for the systematic investigation of biochemical (mal)-adaptations associated with healthy and diseased heart tissue. Enhanced shotgun proteomic detection coverage and improved biological inference is achieved by pre-fractionation of excised mouse cardiac muscle into subcellular components, with each organellar fraction investigated exhaustively using multiple repeat MudPIT analyses. Functional-enrichment, high-confidence identification, and relative quantification of hundreds of organelle- and tissue-specific proteins are achieved readily, including detection of low abundance transcriptional regulators, signaling factors, and proteins linked to cardiac disease. Important technical issues relating to data validation, including minimization of artifacts stemming from biased under-sampling and spurious false discovery, together with suggestions for further fine-tuning of sample preparation, are discussed. A framework for follow-up bioinformatic examination, pattern recognition, and data mining is also presented in the context of a stringent application of MudPIT for probing fundamental aspects of heart muscle physiology as well as the discovery of perturbations associated with heart failure.

Pancreatic islet isolation variables in non-human primates (rhesus macaques).

PubMed

Andrades, P; Asiedu, C K; Gansuvd, B; Inusah, S; Goodwin, K J; Deckard, L A; Jargal, U; Thomas, J M

2008-07-01

Non-human primates (NHPs) are important preclinical models for pancreatic islet transplantation (PIT) because of their close phylogenetic and immunological relationship with humans. However, low availability of NHP tissue, long learning curves and prohibitive expenses constrain the consistency of isolated NHP islets for PIT studies. To advance preclinical studies, we attempted to identify key variables that consistently influence the quantity and quality of NHP islets. Seventy-two consecutive pancreatic islet isolations from rhesus macaques were reviewed retrospectively. A scaled down, semi-automated islet isolation method was used, and monkeys with streptozotocin-induced diabetes, weighing 3-7 kg, served as recipients for allotransplantation. We analysed the effects of 22 independent variables grouped as donor factors, surgical factors and isolation technique factors. Islet yields, success of isolation and transplantation results were used as quantitative and qualitative outcomes. In the multivariate analysis, variables that significantly affected islet yield were the type of monkey, pancreas preservation, enzyme lot and volume of enzyme delivered. The variables associated with successful isolation were the enzyme lot and volume delivered. The transplant result was correlated with pancreas preservation, enzyme lot, endotoxin levels and COBE collection method. Islet quantity and quality are highly variable between isolations. The data reviewed suggest that future NHP isolations should use bilayer preservation, infuse more than 80 ml of Liberase into the pancreas, collect non-fractioned tissue from the COBE, and strictly monitor for infection.

Construction and biological activities of the first infectious cDNA clones of the genus Foveavirus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meng, Baozhong, E-mail: bmeng@uoguelph.ca; Venkataraman, Srividhya; Li, Caihong

Grapevine rupestris stem pitting-associated virus (GRSPaV, genus Foveavirus, family Betaflexiviridae) is one of the most prevalent viruses in grapevines and is associated with three distinct diseases: rupestris stem pitting, vein necrosis and Syrah decline. Little is known about the biology and pathological properties of GRSPaV. In this work, we engineered a full-length infectious cDNA clone for GRSPaV and a GFP-tagged variant, both under the transcriptional control of Cauliflower mosaic virus 35 S promoter. We demonstrated that these cDNA clones were infectious in grapevines and Nicotiana benthamiana through fluorescence microscopy, RT-PCR, Western blotting and immuno electron microscopy. Interestingly, GRSPaV does notmore » cause systemic infection in four of the most commonly used herbaceous plants, even in the presence of the movement proteins of two other viruses which are known to complement numerous movement-defective viruses. These infectious clones are the first of members of Foveavirus which would allow further investigations into mechanisms governing different aspects of replication for GRSPaV and perhaps related viruses.« less

Successful isolation of viable adipose-derived stem cells from human adipose tissue subject to long-term cryopreservation: positive implications for adult stem cell-based therapeutics in patients of advanced age.

PubMed

Devitt, Sean M; Carter, Cynthia M; Dierov, Raia; Weiss, Scott; Gersch, Robert P; Percec, Ivona

2015-01-01

We examined cell isolation, viability, and growth in adipose-derived stem cells harvested from whole adipose tissue subject to different cryopreservation lengths (2-1159 days) from patients of varying ages (26-62 years). Subcutaneous abdominal adipose tissue was excised during abdominoplasties and was cryopreserved. The viability and number of adipose-derived stem cells isolated were measured after initial isolation and after 9, 18, and 28 days of growth. Data were analyzed with respect to cryopreservation duration and patient age. Significantly more viable cells were initially isolated from tissue cryopreserved <1 year than from tissue cryopreserved >2 years, irrespective of patient age. However, this difference did not persist with continued growth and there were no significant differences in cell viability or growth at subsequent time points with respect to cryopreservation duration or patient age. Mesenchymal stem cell markers were maintained in all cohorts tested throughout the duration of the study. Consequently, longer cryopreservation negatively impacts initial live adipose-derived stem cell isolation; however, this effect is neutralized with continued cell growth. Patient age does not significantly impact stem cell isolation, viability, or growth. Cryopreservation of adipose tissue is an effective long-term banking method for isolation of adipose-derived stem cells in patients of varying ages.

Fate of the unrevised cemented stem following cup only revision: 227 hips at an average of 6 years follow-up.

PubMed

McGonagle, L; Siney, P D; Raut, V V

2015-11-01

After primary total hip replacement, aseptic loosening of the acetabular cup is more common than loosening of the femoral stem. Removal of a well-fixed stem adds to operative time, blood loss, risk of bone loss and fracture. There is limited evidence that isolated cup revision can be a safe option in revision hip arthroplasty. We question the following regarding the unrevised cemented stem after isolated cup revision: 1) Does the unrevised stem require revision after isolated cup revision? 2) When is the stem subsequently revised? 3) Why is the stem subsequently revised? 4) Do unrevised stems exhibit radiographic loosening? We hypothesise that after isolated cup revision most unrevised stems do not need subsequent revision, and that most do not exhibit evidence of radiographic loosening. A retrospective analysis of all patients who underwent revision of the acetabular component only during revision hip arthroplasty between March 1970 and July 2013 was carried out. We assessed survival of the unrevised stem, reasons for subsequent revision, plus radiographic analysis for stem loosening. Two hundred and twenty-seven hips were included [215 patients with an average age at the time of primary surgery was 47 (13-70) years]. The Charnley stem was used in 161 cases; C-stem 65, Howse 1. Average time between primary surgery and cup revision was 15.9 (1.6-33.4) years. Average follow-up for all stems post-isolated cup revision was 6.1 (0.1-30.7) years. Twenty-eight stems (12.3%) were subsequently revised 5.1 (0.1-12.6) years after the isolated cup revision. Reasons for subsequent revision were: aseptic loosening (10); infection (8); dislocation (6); unreconstructable joint post-loose cup removal (2); fracture (2). Radiographic review was possible on 140 cases. Five femoral stems were revised and 2 others showed evidence of possible radiological loosening but were not revised. To our knowledge this is the largest series showing that isolated cup revision in the place of a well-fixed cemented stem is safe and is associated with ongoing good long-term survival of the stem. Level IV, retrospective case series. Copyright © 2015. Published by Elsevier Masson SAS.

Influence of different types of pulp treatment during isolation in the obtention of human dental pulp stem cells

PubMed Central

Viña-Almunia, Jose; Borras, Consuelo; Gambini, Juan; El Alamy, Marya; Viña, Jose

2016-01-01

Background Different methods have been used in order to isolate dental pulp stem cells. The aim of this study was to study the effect of different types of pulp treatment during isolation, under 3% O2 conditions, in the time needed and the efficacy for obtaining dental pulp stem cells. Material and Methods One hundred and twenty dental pulps were used to isolate dental pulp stem cells treating the pulp tissue during isolation using 9 different methods, using digestive, disgregation, or mechanical agents, or combining them. The cells were positive for CD133, Oct4, Nestin, Stro-1, CD34 markers, and negative for the hematopoietic cell marker CD-45, thus confirming the presence of mesenchymal stem cells. The efficacy of dental pulp stem cells obtention and the minimum time needed to obtain such cells comparing the 9 different methods was analyzed. Results Dental pulp stem cells were obtained from 97 of the 120 pulps used in the study, i.e. 80.8% of the cases. They were obtained with all the methods used except with mechanical fragmentation of the pulp, where no enzymatic digestion was performed. The minimum time needed to isolate dental pulp stem cells was 8 hours, digesting with 2mg/ml EDTA for 10 minutes, 4mg/ml of type I collagenase, 4mg/ml of type II dispase for 40 minutes, 13ng/ml of thermolysine for 40 minutes and sonicating the culture for one minute. Conclusions Dental pulp stem cells were obtained in 97 cases from a series of 120 pulps. The time for obtaining dental pulp stem cells was reduced maximally, without compromising the obtention of the cells, by combining digestive, disgregation, and mechanical agents. Key words:Dental pulp stem cells, mesenchymal stem cells, isolation method. PMID:26946201

Detection of fungal infectous agent of wheat grains in store-pits of Markazi province, Iran.

PubMed

Saberi-Riseh, R; Javan-Nikkhah, M; Heidarian, R; Hosseini, S; Soleimani, P

2004-01-01

Wheat is an economic and important crop that provides approximately 20% of food calorie in the world. It is first crop in Iran and cultivated in the most areas of this country. Store-pit fungi make undesirable changes in quality and appearance of wheat grains. Even, some fungi produce different mycotoxins which are toxic to human and livestock's that use wheat grains as source of food. In this study, several samples were randomly collected from each of five store-pits located in different areas of Markazi Province including: Arak, Mahallat, Khomein, Saveh and Sarband. Grains were treated on PDA, and blotter, agar and washing test also used for isolating and detection of fungi. At least 100 grains per each sample were randomly used for each test and treatment. The fungi that determined in this study were Cochliobolus australiensis, Cladosporium herbarum, Epicoccum sp., Tilletia leavis, Aspergillus flavus, A. niger, A. fumigatus, Alternaria alternata, Alternaria sp., Penicillium italicum, P. digitatum, Fusarium sp., Rhizopus sp., Ustilago tritici, Scytalidium sp. Among these fungi the most isolates were belonged to Cladosporium, Alternaria, Rhizopus and Fusarium. Cladosporium herbarum was the most common in different sampling areas. Tilletia laevis and Ustilago tritici were just recovered in washing test. This study revealed that different fungi are associated with wheat grains in store-pits in Markazi Province. Some of them like Aspergillus flavus normally produce aflatoxin, a very toxic and carcinogenic mycotoxin that is harmful for human.

Isolation of skeletal muscle stem cells by fluorescence-activated cell sorting.

PubMed

Liu, Ling; Cheung, Tom H; Charville, Gregory W; Rando, Thomas A

2015-10-01

The prospective isolation of purified stem cell populations has dramatically altered the field of stem cell biology, and it has been a major focus of research across tissues in different organisms. Muscle stem cells (MuSCs) are now among the most intensely studied stem cell populations in mammalian systems, and the prospective isolation of these cells has allowed cellular and molecular characterizations that were not dreamed of a decade ago. In this protocol, we describe how to isolate MuSCs from limb muscles of adult mice by fluorescence-activated cell sorting (FACS). We provide a detailed description of the physical and enzymatic dissociation of mononucleated cells from limb muscles, a procedure that is essential in order to maximize cell yield. We also describe a FACS-based method that is used subsequently to obtain highly pure populations of either quiescent or activated MuSCs (VCAM(+)CD31(-)CD45(-)Sca1(-)). The isolation process takes ∼5-6 h to complete. The protocol also allows for the isolation of endothelial cells, hematopoietic cells and mesenchymal stem cells from muscle tissue.

[Molecular pathology of congenital pituitary hypothyroidism--discovery of new clinical entities].

PubMed

Tatsumi, K; Amino, N; Miyai, K

1993-05-01

Congenital pituitary hypothyroidism (pituitary cretinism) results in severe mental and growth retardation when it is not treated soon after birth. Since the introduction of neonatal mass screening of thyrotropin (TSH), most congenital hypothyroidism has been detected except for pituitary and hypothalamic hypothyroidism. In 1971, we reported the first familial case of congenital isolated TSH deficiency and thereafter began intensively investigating the molecular pathology of congenital pituitary hypothyroidism. After determining the entire structure of the human TSH beta gene, we identified the molecular pathology in this patient. Recently, we reported a familial case of congenital combined pituitary hormone deficiency (PIT1 abnormality). To examine the PIT1 gene, which encodes pituitary specific transcription factor, Pit-1/GHF-1, we determined its genomic structure. Sequence comparisons using PCR amplified PIT1 gene sequences revealed only one nonsense mutation in the patient, and established that this alteration caused the combined deficiencies of TSH, GH and PRL. We also discuss other recent progress in molecular pathology of congenital pituitary hypothyroidism.

Isolation of Mouse Hair Follicle Bulge Stem Cells and Their Functional Analysis in a Reconstitution Assay.

PubMed

Zheng, Ying; Hsieh, Jen-Chih; Escandon, Julia; Cotsarelis, George

2016-01-01

The hair follicle (HF) is a dynamic structure readily accessible within the skin, and contains various pools of stem cells that have a broad regenerative potential during normal homeostasis and in response to injury. Recent discoveries demonstrating the multipotent capabilities of hair follicle stem cells and the easy access to skin tissue make the HF an attractive source for isolating stem cells and their subsequent application in tissue engineering and regenerative medicine. Here, we describe the isolation and purification of hair follicle bulge stem cells from mouse skin, and hair reconstitution assays that allows the functional analysis of multipotent stem cells.

Isolation of hair follicle bulge stem cells from YFP-expressing reporter mice.

PubMed

Nakrieko, Kerry-Ann; Irvine, Timothy S; Dagnino, Lina

2013-01-01

In this article we provide a method to isolate hair follicle stem cells that have undergone targeted gene inactivation. The mice from which these cells are isolated are bred into a Rosa26-yellow fluorescent protein (YFP) reporter background, which results in YFP expression in the targeted stem cell population. These cells are isolated and purified by fluorescence-activated cell sorting, using epidermal stem cell-specific markers in conjunction with YFP fluorescence. The purified cells can be used for gene expression studies, clonogenic experiments, and biological assays, such as viability and capacity for directional migration.

Isolation and purification of rabbit mesenchymal stem cells using an optimized protocol.

PubMed

Lin, Chunbo; Shen, Maorong; Chen, Weiping; Li, Xiaofeng; Luo, Daoming; Cai, Jinhong; Yang, Yuan

2015-11-01

Mesenchymal stem cells were first isolated and grown in vitro by Friedenstein over 40 yr ago; however, their isolation remains challenging as they lack unique markers for identification and are present in very small quantities in mesenchymal tissues and bone marrow. Using whole marrow samples, common methods for mesenchymal stem cell isolation are the adhesion method and density gradient fractionation. The whole marrow sample adhesion method still results in the nonspecific isolation of mononuclear cells, and activation and/or potential loss of target cells. Density gradient fractionation methods are complicated, and may result in contamination with toxic substances that affect cell viability. In the present study, we developed an optimized protocol for the isolation and purification of mesenchymal stem cells based on the principles of hypotonic lysis and natural sedimentation.

Isolation and Growth of Prostate Stem Cells and Establishing Cancer Cell Lines from Human Prostate Tumors

DTIC Science & Technology

2009-05-01

contaminating rat UGSE cells ; and regions of host mouse glands were either from circulating pluripotent stem cells or local epithelial cells which were...CONTRACT NUMBER Isolation and Growth of Prostate Stem Cells and Establishing Cancer Cell Lines from Human Prostate Tumors 5b. GRANT NUMBER 81WXH...NOTES 14. ABSTRACT The objective of this proposal was to isolate, grow, and characterize normal prostate stem cells and establish new prostate

Methods and system for subsurface stabilization using jet grouting

DOEpatents

Loomis, Guy G.; Weidner, Jerry R.; Farnsworth, Richard K.; Gardner, Bradley M.; Jessmore, James J.

1999-01-01

Methods and systems are provided for stabilizing a subsurface area such as a buried waste pit for either long term storage, or interim storage and retrieval. A plurality of holes are drilled into the subsurface area with a high pressure drilling system provided with a drill stem having jet grouting nozzles. A grouting material is injected at high pressure through the jet grouting nozzles into a formed hole while the drill stem is withdrawn from the hole at a predetermined rate of rotation and translation. A grout-filled column is thereby formed with minimal grout returns, which when overlapped with other adjacent grout-filled columns encapsulates and binds the entire waste pit area to form a subsurface agglomeration or monolith of grout, soil, and waste. The formed monolith stabilizes the buried waste site against subsidence while simultaneously providing a barrier against contaminate migration. The stabilized monolith can be left permanently in place or can be retrieved if desired by using appropriate excavation equipment. The jet grouting technique can also be utilized in a pretreatment approach prior to in situ vitrification of a buried waste site. The waste encapsulation methods and systems are applicable to buried waste materials such as mixed waste, hazardous waste, or radioactive waste.

Concave Pit-Containing Scaffold Surfaces Improve Stem Cell-Derived Osteoblast Performance and Lead to Significant Bone Tissue Formation

PubMed Central

Cusella-De Angelis, Maria Gabriella; Laino, Gregorio; Piattelli, Adriano; Pacifici, Maurizio; De Rosa, Alfredo; Papaccio, Gianpaolo

2007-01-01

Background Scaffold surface features are thought to be important regulators of stem cell performance and endurance in tissue engineering applications, but details about these fundamental aspects of stem cell biology remain largely unclear. Methodology and Findings In the present study, smooth clinical-grade lactide-coglyolic acid 85:15 (PLGA) scaffolds were carved as membranes and treated with NMP (N-metil-pyrrolidone) to create controlled subtractive pits or microcavities. Scanning electron and confocal microscopy revealed that the NMP-treated membranes contained: (i) large microcavities of 80–120 µm in diameter and 40–100 µm in depth, which we termed primary; and (ii) smaller microcavities of 10–20 µm in diameter and 3–10 µm in depth located within the primary cavities, which we termed secondary. We asked whether a microcavity-rich scaffold had distinct bone-forming capabilities compared to a smooth one. To do so, mesenchymal stem cells derived from human dental pulp were seeded onto the two types of scaffold and monitored over time for cytoarchitectural characteristics, differentiation status and production of important factors, including bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF). We found that the microcavity-rich scaffold enhanced cell adhesion: the cells created intimate contact with secondary microcavities and were polarized. These cytological responses were not seen with the smooth-surface scaffold. Moreover, cells on the microcavity-rich scaffold released larger amounts of BMP-2 and VEGF into the culture medium and expressed higher alkaline phosphatase activity. When this type of scaffold was transplanted into rats, superior bone formation was elicited compared to cells seeded on the smooth scaffold. Conclusion In conclusion, surface microcavities appear to support a more vigorous osteogenic response of stem cells and should be used in the design of therapeutic substrates to improve bone repair and bioengineering applications in the future. PMID:17551577

Endophytic Ability of Different Isolates of Entomopathogenic Fungi Beauveria bassiana (Balsamo) Vuillemin in Stem and Leaf Tissues of Maize (Zea mays L.).

PubMed

Renuka, S; Ramanujam, B; Poornesha, B

2016-06-01

The present study was conducted to examine the ability of six promising indigenous isolates of Beauveria bassiana (NBAII-Bb-5a, 7, 14, 19, 23 and 45) as an endophyte in maize stem and leaf tissues. Maize seedlings (var. Nithyashree) were inoculated with conidial suspensions and were examined for endophytic establishment in leaf and stems at different intervals during 15-90 days after treatment. All six isolates showed colonization in stem and leaf tissues with varying abilities of colonization and persistence. The mean percent colonization ranged from 7.41 to 20.37 % in older stem tissues and 3.70 to 21.29 % in young stem tissues and in leaf, it ranged from 6.46 to 27.78 % in older leaf tissues and 11.11 to 26.85 % in young leaf tissues. Among six isolates tested, Bb-23 isolate recorded the maximum mean colonization in older stem (20.37 %), older leaf (27.78 %) and in young stem (21.29 %). Bb-5a isolate showed maximum mean colonization in young leaf tissues (26.85 %). Persistence of inoculated fungal isolates decreased with increase in age of the plant. No physical symptoms of damage were observed in any of the B. bassiana treated plants. No colonization of B. bassiana was observed in the untreated control maize plants. The results obtained in plating and PCR techniques were similar with regard to the confirmation of endophytic establishment of B. bassiana. This study indicated the possibility of using B. bassiana as an endophyte in maize for management of maize stem borer, Chilo partellus.

Establishment of mouse embryonic stem cells from isolated blastomeres and whole embryos using three derivation methods

PubMed Central

González, Sheyla; Ibáñez, Elena

2010-01-01

Purpose The aim of the present study is to compare three previously described mouse embryonic stem cell derivation methods to evaluate the influence of culture conditions, number of isolated blastomeres and embryonic stage in the derivation process. Methods Three embryonic stem cell derivation methods: standard, pre-adhesion and defined culture medium method, were compared in the derivation from isolated blastomeres and whole embryos at 4- and 8-cell stages. Results A total of 200 embryonic stem cell lines were obtained with an efficiency ranging from 1.9% to 72%. Conclusions Using either isolated blastomeres or whole embryos, the highest rates of mouse embryonic stem cell establishment were achieved with the defined culture medium method and efficiencies increased as development progressed. Using isolated blastomeres, efficiencies increased in parallel to the proportion of the embryo volume used to start the derivation process. PMID:20862536

Identification and isolation of adult liver stem/progenitor cells.

PubMed

Tanaka, Minoru; Miyajima, Atsushi

2012-01-01

Hepatoblasts are considered to be liver stem/progenitor cells in the fetus because they propagate and differentiate into two types of liver epithelial cells, hepatocytes and cholangiocytes. In adults, oval cells that emerge in severely injured liver are considered facultative hepatic stem/progenitor cells. However, the nature of oval cells has remained unclear for long time due to the lack of a method to isolate them. It has also been unclear whether liver stem/progenitor cells exist in normal adult liver. Recently, we and others have successfully identified oval cells and adult liver stem/progenitor cells. Here, we describe the identification and isolation of mouse liver stem/progenitor cells by utilizing antibodies against specific cell surface marker molecules.

Isolation and evaluation of dental pulp stem cells from teeth with advanced periodontal disease.

PubMed

Derakhshani, Ali; Raoof, Maryam; Dabiri, Shahriar; Farsinejad, Ali Reza; Gorjestani, Hedayat; Yaghoobi, Mohammad Mehdi; Shokouhinejad, Noushin; Ehsani, Maryam

2015-04-01

Successful isolation of mesenchymal stem cells from waste tissues might be extremely promising for developing stem cell-based therapies. This study aimed to explore whether cells retrieved from teeth extracted due to advanced periodontal disease present mesenchymal stem cell-like properties. Pulp cells were isolated from 15 intact molars and 15 teeth with advanced periodontal disease. Cell proliferation and markers of mesenchymal stem cells were evaluated. Based on the RT-PCR and agarose gel electrophoresis, nucleostemin, Oct-4 and jmj2c, but not Nanog, were expressed in undifferentiated mesenchymal stem cells of both groups. Interestingly, diseased pulp exhibited higher gene expressions although it was not statistically significant. The average percentage of BrdU positive cells in the diseased group (84.4%, n = 5) was significantly higher than that of the control group (65.4%, n = 5) (t-test, P = 0.001). Our results indicate the successful isolation of mesenchymal stem cells from the pulp tissue of hopeless periodontally involved teeth.

Genome sequence of a novel multiple antibiotic resistant member of Erysipelotrichaceae family isolated from a swine manure storage pit

USDA-ARS?s Scientific Manuscript database

The swine gastro intestinal (GI) tract and stored manure may serve as reservoirs of antibiotic resistance genes as well as sources of novel bacteria. We report the draft genome sequence of “Cottaibacterium suis” strain MTC7, a novel antibiotic resistant bacterium. The strain was isolated from a swin...

Deep sequencing analysis of viral short RNAs from an infected Pinot Noir grapevine.

PubMed

Pantaleo, Vitantonio; Saldarelli, Pasquale; Miozzi, Laura; Giampetruzzi, Annalisa; Gisel, Andreas; Moxon, Simon; Dalmay, Tamas; Bisztray, György; Burgyan, Jozsef

2010-12-05

Virus-derived short interfering RNAs (vsiRNAs) isolated from grapevine V. vinifera Pinot Noir clone ENTAV 115 were analyzed by high-throughput sequencing using the Illumina Solexa platform. We identified and characterized vsiRNAs derived from grapevine field plants naturally infected with different viruses belonging to the genera Foveavirus, Maculavirus, Marafivirus and Nepovirus. These vsiRNAs were mainly of 21 and 22 nucleotides (nt) in size and were discontinuously distributed throughout Grapevine rupestris stem-pitting associated virus (GRSPaV) and Grapevine fleck virus (GFkV) genomic RNAs. Among the studied viruses, GRSPaV and GFkV vsiRNAs had a 5' terminal nucleotide bias, which differed from that described for experimental viral infections in Arabidopsis thaliana. VsiRNAs were found to originate from both genomic and antigenomic GRSPaV RNA strands, whereas with the grapevine tymoviruses GFkV and Grapevine Red Globe associated virus (GRGV), the large majority derived from the antigenomic viral strand, a feature never observed in other plant-virus interactions. Copyright © 2010 Elsevier Inc. All rights reserved.

Isolation and functional interrogation of adult human prostate epithelial stem cells at single cell resolution.

PubMed

Hu, Wen-Yang; Hu, Dan-Ping; Xie, Lishi; Li, Ye; Majumdar, Shyama; Nonn, Larisa; Hu, Hong; Shioda, Toshi; Prins, Gail S

2017-08-01

Using primary cultures of normal human prostate epithelial cells, we developed a novel prostasphere-based, label-retention assay that permits identification and isolation of stem cells at a single cell level. Their bona fide stem cell nature was corroborated using in vitro and in vivo regenerative assays and documentation of symmetric/asymmetric division. Robust WNT10B and KRT13 levels without E-cadherin or KRT14 staining distinguished individual stem cells from daughter progenitors in spheroids. Following FACS to isolate label-retaining stem cells from label-free progenitors, RNA-seq identified unique gene signatures for the separate populations which may serve as useful biomarkers. Knockdown of KRT13 or PRAC1 reduced sphere formation and symmetric self-renewal highlighting their role in stem cell maintenance. Pathways analysis identified ribosome biogenesis and membrane estrogen-receptor signaling enriched in stem cells with NF-ĸB signaling enriched in progenitors; activities that were biologically confirmed. Further, bioassays identified heightened autophagy flux and reduced metabolism in stem cells relative to progenitors. These approaches similarly identified stem-like cells from prostate cancer specimens and prostate, breast and colon cancer cell lines suggesting wide applicability. Together, the present studies isolate and identify unique characteristics of normal human prostate stem cells and uncover processes that maintain stem cell homeostasis in the prostate gland. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Characterization of retroviral infectivity and superinfection resistance during retrovirus-mediated transduction of mammalian cells.

PubMed

Liao, J; Wei, Q; Fan, J; Zou, Y; Song, D; Liu, J; Liu, F; Ma, C; Hu, X; Li, L; Yu, Y; Qu, X; Chen, L; Yu, X; Zhang, Z; Zhao, C; Zeng, Z; Zhang, R; Yan, S; Wu, T; Wu, X; Shu, Y; Lei, J; Li, Y; Zhang, W; Wang, J; Reid, R R; Lee, M J; Huang, W; Wolf, J M; He, T-C; Wang, J

2017-06-01

Retroviral vectors including lentiviral vectors are commonly used tools to stably express transgenes or RNA molecules in mammalian cells. Their utilities are roughly divided into two categories, stable overexpression of transgenes and RNA molecules, which requires maximal transduction efficiency, or functional selection with retrovirus (RV)-based libraries, which takes advantage of retroviral superinfection resistance. However, the dynamic features of RV-mediated transduction are not well characterized. Here, we engineered two murine stem cell virus-based retroviral vectors expressing dual fluorescence proteins and antibiotic markers, and analyzed virion production efficiency and virion stability, dynamic infectivity and superinfection resistance in different cell types, and strategies to improve transduction efficiency. We found that the highest virion production occurred between 60 and 72 h after transfection. The stability of the collected virion supernatant decreased by >60% after 3 days in storage. We found that RV infectivity varied drastically in the tested human cancer lines, while low transduction efficiency was partially overcome with increased virus titer, prolonged infection duration and/or repeated infections. Furthermore, we demonstrated that RV receptors PIT1 and PIT2 were lowly expressed in the analyzed cells, and that PIT1 and/or PIT2 overexpression significantly improved transduction efficiency in certain cell lines. Thus, our findings provide resourceful information for the optimal conditions of retroviral-mediated gene delivery.

Identification of Metastatic Tumor Stem Cell

DTIC Science & Technology

2010-09-01

addition to a tumor stem cell , an existence of a metastatic stem cell is predicted. Despite the critical importance of the concept, this idea has not been...isolating stem cell population from a unique set of breast tumor cell lines and by examining their metastatic behavior in an animal model. The overall...will (i) isolate stem - cell population from non-metastatic and metastatic cells of a pair of syngenic breast tumor cell lines, and test their metastatic

Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants.

PubMed

El-Shenawy, Z; Mansour, M A; El-Behrawi, S

1978-01-01

The highly pathogenic isolate stimulated the emergence of the squash seedlings first, caused, however, the highest death rate of the seedlings finally. Fusarium isolates and their culture filtrates inhibited the respiratory rate of squash plants significantly. However, F. oxysporum isolates inhibited respiration more than F. solani isolates. Seasonal changes of respiration decline show that the respiratory rate decreased with plant growth in the case of infested soil and of plants injected with culture filtrates. However, spraying Fusarium culture filtrates on the foliage gave opposite results when the plants grew older. Fusarium solani isolates decreased nitrogen content of squash stems and leaves, while F. oxysporum isolates gave reverse results. Injecting Fusarium culture filtrate into the plant decreased nitrogen content of both stems and leaves, while spraying the foliage with the filtrates increased nitrogen content more than that of the control. Phosphorus content of the stems of squash plants, sown in infested soil, was less than in the control when the plants were treated with F. solani and higher when they were treated with F. oxysporum isolates. On the other hand, the phosphorus content of squash leaves was higher than in the control. In the case of injected plants, however, the phosphorus content in stems and leaves was equal to that of the control or less, and with sprayed plants it was higher than in the control. Infesting the soil with Fusarium isolates and spraying the foliage with their culture filtrates increased potassium content of squash stems and leaves, while injecting the filtrates into the plants decreased potassium content of both stems and leaves.

The epidemiology of Clostridium perfringens type A on Ontario swine farms, with special reference to cpb2-positive isolates.

PubMed

Chan, Gloria; Farzan, Abdolvahab; Soltes, Glenn; Nicholson, Vivian M; Pei, Yanlong; Friendship, Robert; Prescott, John F

2012-09-04

There is poor understanding of most aspects of Clostridium perfringens type A as a possible cause of neonatal diarrhea in piglets, and the prevalence and types of C. perfringens present on Ontario swine farms is unknown. To study the prevalence of fecal C. perfringens and selected toxin genes, 48 Ontario swine farms were visited between August 2010 and May 2011, and 354 fecal samples were collected from suckling pigs, lactating sows, weanling pigs, grower-finisher pigs, and gestating sows, as well as from manure pits. The fecal samples were cultured quantitatively, and toxin genes were detected by real-time multiplex polymerase chain reaction (PCR). In mixed multivariable linear analysis, log(10) C. perfringens in fecal samples from suckling pigs were higher than that of weanling pigs, grower-finisher pigs, and manure pit samples (P <0.05). In mixed multivariable logistic analysis, the C. perfringens isolates recovered from lactating sows (OR = 0.069, P <0.001), gestating sows (OR = 0.020, P <0.001), grower-finishers (OR = 0.017, P <0.001), and manure pits (OR = 0.11, P <0.001) were less likely to be positive for the consensus beta2 toxin gene cpb2 compared to the isolates from suckling pigs. The prevalence of cpb2 in the isolates recovered from weanlings did not differ significantly from suckling pigs. C. perfringens isolates that were positive for cpb2 were more likely to carry the atypical cpb2 gene (atyp-cpb2) (OR = 19, P <0.001) compared to isolates that were negative for cpb2. Multivariable analysis did not identify farm factors affecting the presence of consensus cpb2 and atyp-cpb2 genes. This study provides baseline data on the prevalence of C. perfringens and associated toxin genes in healthy pigs at different stages of production on Ontario swine farms. The study suggests that if C. perfringens type A are involved in neonatal enteritis, there may be strains with specific characteristics that cannot be identified by the existing genotyping system.

Fragmentation, Cost and Environmental Effects of Plaster Stemming Method for Blasting at A Basalt Quarry

NASA Astrophysics Data System (ADS)

Cevizci, Halim

2014-10-01

In this study, the plaster stemming application for blasting at a basalt quarry is studied. Drill cuttings are generally used in open pits and quarries as the most common stemming material since these are most readily available at blast sites. However, dry drill cuttings eject very easily from blastholes without offering much resistance to blast energy. The plaster stemming method has been found to be better than the drill cuttings stemming method due to increased confinement inside the hole and better utilization of blast explosive energy in the rock. The main advantage of the new stemming method is the reduction in the cost of blasting. At a basalt quarry, blasting costs per unit volume of rock were reduced to 15% by increasing burden and spacing distances. In addition, better fragmentation was obtained by using the plaster stemming method. Blast trials showed that plaster stemming produced finer material. In the same blast tests, +30 cm size fragments were reduced to 47.3% of the total, compared to 32.6% in the conventional method of drill cuttings stemming. With this method of stemming, vibration and air shock values increased slightly due to more blast energy being available for rock breakage but generally these increased values were small and stayed under the permitted limit for blast damage criteria unless measuring distance is too close.

Epithelial-mesenchymal transition in colonies of rhesus monkey embryonic stem cells: a model for processes involved in gastrulation.

PubMed

Behr, Rüdiger; Heneweer, Carola; Viebahn, Christoph; Denker, Hans-Werner; Thie, Michael

2005-01-01

Rhesus monkey embryonic stem (rhES) cells were grown on mouse embryonic fibroblast (MEF) feeder layers for up to 10 days to form multilayered colonies. Within this period, stem cell colonies differentiated transiently into complex structures with a disc-like morphology. These complex colonies were characterized by morphology, immunohistochemistry, and marker mRNA expression to identify processes of epithelialization as well as epithelial-mesenchymal transition (EMT) and pattern formation. Typically, differentiated colonies were comprised of an upper and a lower ES cell layer, the former growing on top of the layer of MEF cells whereas the lower ES cell layer spread out underneath the MEF cells. Interestingly, in the central part of the colonies, a roundish pit developed. Here the feeder layer disappeared, and upper layer cells seemed to ingress and migrate through the pit downward to form the lower layer while undergoing a transition from the epithelial to the mesenchymal phenotype, which was indicated by the loss of the marker proteins E-cadherin and ZO-1 in the lower layer. In support of this, we found a concomitant 10-fold upregulation of the gene Snail2, which is a key regulator of the EMT process. Conversion of epiblast to mesoderm was also indicated by the regulated expression of the mesoderm marker Brachyury. An EMT is a characteristic process of vertebrate gastrulation. Thus, these rhES cell colonies may be an interesting model for studies on some basic processes involved in early primate embryogenesis and may open new ways to study the regulation of EMT in vitro.

A Method to Identify and Isolate Pluripotent Human Stem Cells and Mouse Epiblast Stem Cells Using Lipid Body-Associated Retinyl Ester Fluorescence

PubMed Central

Muthusamy, Thangaselvam; Mukherjee, Odity; Menon, Radhika; Megha, P.B.; Panicker, Mitradas M.

2014-01-01

Summary We describe the use of a characteristic blue fluorescence to identify and isolate pluripotent human embryonic stem cells and human-induced pluripotent stem cells. The blue fluorescence emission (450–500 nm) is readily observed by fluorescence microscopy and correlates with the expression of pluripotency markers (OCT4, SOX2, and NANOG). It allows easy identification and isolation of undifferentiated human pluripotent stem cells, high-throughput fluorescence sorting and subsequent propagation. The fluorescence appears early during somatic reprogramming. We show that the blue fluorescence arises from the sequestration of retinyl esters in cytoplasmic lipid bodies. The retinoid-sequestering lipid bodies are specific to human and mouse pluripotent stem cells of the primed or epiblast-like state and absent in naive mouse embryonic stem cells. Retinol, present in widely used stem cell culture media, is sequestered as retinyl ester specifically by primed pluripotent cells and also can induce the formation of these lipid bodies. PMID:25068130

Comparative studies of mesenchymal stem cells derived from different cord tissue compartments - The influence of cryopreservation and growth media.

PubMed

Dulugiac, Magda; Moldovan, Lucia; Zarnescu, Otilia

2015-10-01

We have identified some critical aspects concerning umbilical cord tissue mesenchymal stem cells: the lack of standards for cell isolation, expansion and cryopreservation, the lack of unanimous opinions upon their multilineage differentiation potential and the existence of very few results related to the functional characterization of the cells isolated from cryopreserved umbilical cord tissue. Umbilical cord tissue cryopreservation appears to be the optimal solution for umbilical cord tissue mesenchymal stem cells storage for future clinical use. Umbilical cord tissue cryopreservation allows mesenchymal stem cells isolation before expected use, according with the specific clinical applications, by different customized isolation and expansion protocols agreed by cell therapy institutions. Using an optimized protocol for umbilical cord tissue cryopreservation in autologous cord blood plasma, isolation explant method and growth media supplemented with FBS or human serum, we performed comparative studies with respect to the characteristics of mesenchymal stem cells (MSC) isolated from different compartments of the same umbilical cord tissue such as Wharton's jelly, vein, arteries, before cryopreservation (pre freeze) and after cryopreservation (post thaw). Expression of histochemical and immunohistochemical markers as well as electron microscopy observations revealed similar adipogenic, chondrogenic and osteogenic differentiation capacity for cells isolated from pre freeze and corresponding post thaw tissue fragments of Wharton's jelly, vein or arteries of the same umbilical cord tissue, regardless growth media used for cells isolation and expansion. Our efficient umbilical cord tissue cryopreservation protocol is reliable for clinical applicability of mesenchymal stem cells that could next be isolated and expanded in compliance with future accepted standards. Copyright © 2015 Elsevier Ltd. All rights reserved.

Co-infection of sweet orange with severe and mild strains of citrus tristeza virus is overwhelmingly dominated by the severe strain on both the transcriptional and biological levels

USDA-ARS?s Scientific Manuscript database

Citrus tristeza is one of the most destructive citrus diseases and is caused by the phloem-restricted Closterovirus, Citrus tristeza virus. Mild strain CTV-B2 does not cause obvious symptoms on indicators whereas severe strain CTV-B6 causes symptoms, including stem pitting, cupping, yellowing and s...

Treatment of a mud pit by bioremediation.

PubMed

Avdalović, Jelena; Đurić, Aleksandra; Miletić, Srdjan; Ilić, Mila; Milić, Jelena; Vrvić, Miroslav M

2016-08-01

The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg(-1) (95% degradation) during six months of treatment. © The Author(s) 2016.

Ras-dva Is a Novel Pit-1- and Glucocorticoid-Regulated Gene in the Embryonic Anterior Pituitary Gland

PubMed Central

Ellestad, Laura E.

2013-01-01

Glucocorticoids play a role in functional differentiation of pituitary somatotrophs and lactotrophs during embryogenesis. Ras-dva was identified as a gene regulated by anterior neural fold protein-1/homeobox expressed in embryonic stem cells-1, a transcription factor known to be critical in pituitary development, and has an expression profile in the chicken embryonic pituitary gland that is consistent with in vivo regulation by glucocorticoids. The objective of this study was to characterize expression and regulation of ras-dva mRNA in the developing chicken anterior pituitary. Pituitary ras-dva mRNA levels increased during embryogenesis to a maximum on embryonic day (e) 18 and then decreased and remained low or undetectable after hatch. Ras-dva expression was highly enriched in the pituitary gland on e18 relative to other tissues examined. Glucocorticoid treatment of pituitary cells from mid- and late-stage embryos rapidly increased ras-dva mRNA, suggesting it may be a direct transcriptional target of glucocorticoids. A reporter construct driven by 4 kb of the chicken ras-dva 5′-flanking region, containing six putative pituitary-specific transcription factor-1 (Pit-1) binding sites and two potential glucocorticoid receptor (GR) binding sites, was highly activated in embryonic pituitary cells and up-regulated by corticosterone. Mutagenesis of the most proximal Pit-1 site decreased promoter activity in chicken e11 pituitary cells, indicating regulation of ras-dva by Pit-1. However, mutating putative GR binding sites did not substantially reduce induction of ras-dva promoter activity by corticosterone, suggesting additional DNA elements within the 5′-flanking region are responsible for glucocorticoid regulation. We have identified ras-dva as a glucocorticoid-regulated gene that is likely expressed in cells of the Pit-1 lineage within the developing anterior pituitary gland. PMID:23161868

Ras-dva is a novel Pit-1- and glucocorticoid-regulated gene in the embryonic anterior pituitary gland.

PubMed

Ellestad, Laura E; Porter, Tom E

2013-01-01

Glucocorticoids play a role in functional differentiation of pituitary somatotrophs and lactotrophs during embryogenesis. Ras-dva was identified as a gene regulated by anterior neural fold protein-1/homeobox expressed in embryonic stem cells-1, a transcription factor known to be critical in pituitary development, and has an expression profile in the chicken embryonic pituitary gland that is consistent with in vivo regulation by glucocorticoids. The objective of this study was to characterize expression and regulation of ras-dva mRNA in the developing chicken anterior pituitary. Pituitary ras-dva mRNA levels increased during embryogenesis to a maximum on embryonic day (e) 18 and then decreased and remained low or undetectable after hatch. Ras-dva expression was highly enriched in the pituitary gland on e18 relative to other tissues examined. Glucocorticoid treatment of pituitary cells from mid- and late-stage embryos rapidly increased ras-dva mRNA, suggesting it may be a direct transcriptional target of glucocorticoids. A reporter construct driven by 4 kb of the chicken ras-dva 5'-flanking region, containing six putative pituitary-specific transcription factor-1 (Pit-1) binding sites and two potential glucocorticoid receptor (GR) binding sites, was highly activated in embryonic pituitary cells and up-regulated by corticosterone. Mutagenesis of the most proximal Pit-1 site decreased promoter activity in chicken e11 pituitary cells, indicating regulation of ras-dva by Pit-1. However, mutating putative GR binding sites did not substantially reduce induction of ras-dva promoter activity by corticosterone, suggesting additional DNA elements within the 5'-flanking region are responsible for glucocorticoid regulation. We have identified ras-dva as a glucocorticoid-regulated gene that is likely expressed in cells of the Pit-1 lineage within the developing anterior pituitary gland.

Characterization of HgCdTe and Related Materials For Third Generation Infrared Detectors

NASA Astrophysics Data System (ADS)

Vaghayenegar, Majid

Hg1-xCdxTe (MCT) has historically been the primary material used for infrared detectors. Recently, alternative substrates for MCT growth such as Si, as well as alternative infrared materials such as Hg1-xCdxSe, have been explored. This dissertation involves characterization of Hg-based infrared materials for third generation infrared detectors using a wide range of transmission electron microscopy (TEM) techniques. A microstructural study on HgCdTe/CdTe heterostructures grown by MBE on Si (211) substrates showed a thin ZnTe layer grown between CdTe and Si to mediate the large lattice mismatch of 19.5%. Observations showed large dislocation densities at the CdTe/ZnTe/Si (211) interfaces, which dropped off rapidly away from the interface. Growth of a thin HgTe buffer layer between HgCdTe and CdTe layers seemed to improve the HgCdTe layer quality by blocking some defects. A second study investigated the correlation of etch pits and dislocations in as-grown and thermal-cycle-annealed (TCA) HgCdTe (211) films. For as-grown samples, pits with triangular and fish-eye shapes were associated with Frank partial and perfect dislocations, respectively. Skew pits were determined to have a more complex nature. TCA reduced the etch-pit density by 72%. Although TCA processing eliminated the fish-eye pits, dislocations reappeared in shorter segments in the TCA samples. Large pits were observed in both as-grown and TCA samples, but the nature of any defects associated with these pits in the as-grown samples is unclear. Microstructural studies of HgCdSe revealed large dislocation density at ZnTe/Si(211) interfaces, which dropped off markedly with ZnTe thickness. Atomic-resolution STEM images showed that the large lattice mismatch at the ZnTe/Si interface was accommodated through {111}-type stacking faults. A detailed analysis showed that the stacking faults were inclined at angles of 19.5 and 90 degrees at both ZnTe/Si and HgCdSe/ZnTe interfaces. These stacking faults were associated with Shockley and Frank partial dislocations, respectively. Initial attempts to delineate individual dislocations by chemical etching revealed that while the etchants successfully attacked defective areas, many defects in close proximity to the pits were unaffected.

FACS-based Isolation of Neural and Glioma Stem Cell Populations from Fresh Human Tissues Utilizing EGF Ligand

PubMed Central

Tome-Garcia, Jessica; Doetsch, Fiona; Tsankova, Nadejda M.

2018-01-01

Direct isolation of human neural and glioma stem cells from fresh tissues permits their biological study without prior culture and may capture novel aspects of their molecular phenotype in their native state. Recently, we demonstrated the ability to prospectively isolate stem cell populations from fresh human germinal matrix and glioblastoma samples, exploiting the ability of cells to bind the Epidermal Growth Factor (EGF) ligand in fluorescence-activated cell sorting (FACS). We demonstrated that FACS-isolated EGF-bound neural and glioblastoma populations encompass the sphere-forming colonies in vitro, and are capable of both self-renewal and multilineage differentiation. Here we describe in detail the purification methodology of EGF-bound (i.e., EGFR+) human neural and glioma cells with stem cell properties from fresh postmortem and surgical tissues. The ability to prospectively isolate stem cell populations using native ligand-binding ability opens new doors for understanding both normal and tumor cell biology in uncultured conditions, and is applicable for various downstream molecular sequencing studies at both population and single-cell resolution. PMID:29516026

The Emerging British Verticillium longisporum Population Consists of Aggressive Brassica Pathogens.

PubMed

Depotter, Jasper R L; Rodriguez-Moreno, Luis; Thomma, Bart P H J; Wood, Thomas A

2017-11-01

Verticillium longisporum is an economically important fungal pathogen of brassicaceous crops that originated from at least three hybridization events between different Verticillium spp., leading to the hybrid lineages A1/D1, A1/D2, and A1/D3. Isolates of lineage A1/D1 generally cause stem striping on oilseed rape (Brassica napus), which has recently been reported for the first time to occur in the United Kingdom. Intriguingly, the emerging U.K. population is distinct from the north-central European stem striping population. Little is known about the pathogenicity of the newly emerged U.K. population; hence, pathogenicity tests were executed to compare British isolates to previously characterized reference strains. In addition to the model plant Arabidopsis thaliana, the pathogenicity of four British isolates was assessed on four cultivars of three Brassica crop species: oilseed rape (Quartz and Incentive), cauliflower (Clapton), and Chinese cabbage (Hilton). To this end, vascular discoloration of the roots, plant biomass accumulations, and fungal stem colonization upon isolate infection were evaluated. The British isolates appeared to be remarkably aggressive, because plant biomass was significantly affected and severe vascular discoloration was observed. The British isolates were successful stem colonizers and the extent of fungal colonization negatively correlated with plant biomass of cauliflower and Quartz oilseed rape. However, in Quartz, the fungal colonization of A1/D1 isolates was significantly lower than that of the virulent reference isolate from lineage A1/D3, PD589. Moreover, despite levels of stem colonization similar to those of A1/D1 strains, PD589 did not cause significant disease on Incentive. Thus, A1/D1 isolates, including British isolates, are aggressive oilseed rape pathogens despite limited colonization levels in comparison with a virulent A1/D3 isolate.

A new Late Devonian genus with seed plant affinities.

PubMed

Wang, Deming; Liu, Le

2015-02-26

Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular system, pycnoxylic-manoxylic secondary xylem with bordered pits on both tangential and radial walls of a tracheid and leaf trace divergence of Yiduxylon suggest transitional features between the early spermatophytes and ancestral aneurophyte progymnosperms.

The requirement for freshly isolated human colorectal cancer (CRC) cells in isolating CRC stem cells.

PubMed

Fan, F; Bellister, S; Lu, J; Ye, X; Boulbes, D R; Tozzi, F; Sceusi, E; Kopetz, S; Tian, F; Xia, L; Zhou, Y; Bhattacharya, R; Ellis, L M

2015-02-03

Isolation of colorectal cancer (CRC) cell populations enriched for cancer stem cells (CSCs) may facilitate target identification. There is no consensus regarding the best methods for isolating CRC stem cells (CRC-SCs). We determined the suitability of various cellular models and various stem cell markers for the isolation of CRC-SCs. Established human CRC cell lines, established CRC cell lines passaged through mice, patient-derived xenograft (PDX)-derived cells, early passage/newly established cell lines, and cells directly from clinical specimens were studied. Cells were FAC-sorted for the CRC-SC markers CD44, CD133, and aldehyde dehydrogenase (ALDH). Sphere formation and in vivo tumorigenicity studies were used to validate CRC-SC enrichment. None of the markers studied in established cell lines, grown either in vitro or in vivo, consistently enriched for CRC-SCs. In the three other cellular models, CD44 and CD133 did not reliably enrich for stemness. In contrast, freshly isolated PDX-derived cells or early passage/newly established CRC cell lines with high ALDH activity formed spheres in vitro and enhanced tumorigenicity in vivo, whereas cells with low ALDH activity did not. PDX-derived cells, early passages/newly established CRC cell lines and cells from clinical specimen with high ALDH activity can be used to identify CRC-SC-enriched populations. Established CRC cell lines should not be used to isolate CSCs.

Isolation of adipose derived stem cells and their induction to a chondrogenic phenotype

PubMed Central

Estes, Bradley T.; Diekman, Brian O.; Gimble, Jeffrey M.; Guilak, Farshid

2011-01-01

Summary The ability to isolate, expand, and differentiate adult stem cells into a chondrogenic lineage is an important step in the development of tissue engineering approaches for cartilage repair or regeneration for the treatment of joint injury or osteoarthritis, or for application in plastic or reconstructive surgery. Adipose-derived stem cells (ASCs) provide an abundant and easily accessible source of adult stem cells for use in such regenerative approaches. This protocol describes the isolation of ASCs from liposuction aspirate, as well as cell culture conditions for growth factor based induction of ASCs into chondrocyte-like cells. These methods are similar to those used for bone marrow mesenchymal stem cells but distinct due to the unique properties of ASCs. Investigators can expect consistent ASC differentiation, allowing for slight variation due to donor and serum lot effects. Approximately 10–12 weeks are needed for ASC isolation and the characterization of chondrocyte-like cells, which is also described. PMID:20595958

Morphological isolates in idioms: cranberries or real words?

PubMed

Nenonen, M; Niemi, J

The present study focuses on a subtype of Finnish nouns that appear only as complements in idiomatic verb phrases. In addition to the idioms as their sole environment, these idiomatic isolates, as we call them, are typically frozen to a single case form. In two experiments, in a subjective rating task and a lexical decision task, the isolates are pitted against ordinary nouns and nouns that appear as frozen forms in idioms in addition to being ordinary, free words. The experiments show that the isolates, in spite of their defective syntactic and morphological properties, are processed like ordinary lexical items. Copyright 1999 Academic Press.

ENHANCED REMEDIATION DEMONSTRATIONS AT HILL AFB: INTRODUCTION

EPA Science Inventory

Nine enhanced aquifer remediation technologies were demonstrated side-by-side at a Hill Air Force Base Chemical Disposal Pit/Fire Training Area site. The demonstrations were performed inside 3 x 5 m cells isolated from the surrounding shallow aquifer by steel piling. The site w...

Purification and differentiation of human adipose-derived stem cells by membrane filtration and membrane migration methods

PubMed Central

Lin, Hong Reng; Heish, Chao-Wen; Liu, Cheng-Hui; Muduli, Saradaprasan; Li, Hsing-Fen; Higuchi, Akon; Kumar, S. Suresh; Alarfaj, Abdullah A.; Munusamy, Murugan A.; Hsu, Shih-Tien; Chen, Da-Chung; Benelli, Giovanni; Murugan, Kadarkarai; Cheng, Nai-Chen; Wang, Han-Chow; Wu, Gwo-Jang

2017-01-01

Human adipose-derived stem cells (hADSCs) are easily isolated from fat tissue without ethical concerns, but differ in purity, pluripotency, differentiation ability, and stem cell marker expression, depending on the isolation method. We isolated hADSCs from a primary fat tissue solution using: (1) conventional culture, (2) a membrane filtration method, (3) a membrane migration method where the primary cell solution was permeated through membranes, adhered hADSCs were cultured, and hADSCs migrated out from the membranes. Expression of mesenchymal stem cell markers and pluripotency genes, and osteogenic differentiation were compared for hADSCs isolated by different methods using nylon mesh filter membranes with pore sizes ranging from 11 to 80 μm. hADSCs isolated by the membrane migration method had the highest MSC surface marker expression and efficient differentiation into osteoblasts. Osteogenic differentiation ability of hADSCs and MSC surface marker expression were correlated, but osteogenic differentiation ability and pluripotent gene expression were not. PMID:28071738

A multiple RT-PCR assay for simultaneous detection and differentiation of latent viruses and apscarviroids in apple trees.

PubMed

Hao, Lu; Xie, Jipeng; Chen, Shanyi; Wang, Shaojie; Gong, Zhuoqun; Ling, Kai-Shu; Guo, Liyun; Fan, Zaifeng; Zhou, Tao

2016-08-01

Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV), and Apple stem pitting virus (ASPV) are three latent viruses frequently occurring in apple trees worldwide. In field orchards, these viruses are frequently found in a mixed infection with viroids in the genus Apscarviroid, including Apple scar skin viroid, and Apple dimple fruit viroid. Together these viruses and viroids could cause serious damage to apple fruit production worldwide. Rapid and efficient detection methods are pivotal to identify and select the virus-free propagation material for healthy apple orchard management. In this study a multiplex Reverse Transcription-PCR (RT-PCR) was developed and optimized for simultaneous detection and differentiation of the three latent viruses and apscarviroids. With newly designed specific primers for ACLSV, ASGV, APSV, and EF-1α (as an internal control), and a pair of degenerate primers for apscarviroids, optimized parameters for multiplex RT-PCR were determined. The resulting PCR products from each target virus and viroid could be easily identified because their product sizes differ by at least a 100bp. The multiplex RT-PCR method is expected to detect different variants of the viruses as the test results showed that a variety of isolates from different regions in China gave positive results. To the best of our knowledge, this multiplex RT-PCR assay is the first to simultaneously detect multiple viruses and viroids infecting apple trees in a single reaction tube. This assay, therefore, offers a useful tool for routine certification and quarantine programs. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of an ethanol-paired CS on responding for ethanol and food: Comparisons with a stimulus in a Truly-Random-Control group and to a food-paired CS on responding for food.

PubMed

Lamb, R J; Ginsburg, Brett C; Schindler, Charles W

2016-12-01

Motivational increases due to exposure to alcohol-paired Conditioned Stimuli (CS) are central to some accounts of alcoholism. However, few studies isolate a stimulus's function as a CS from its other potential functions. Pavlovian-Instrumental-Transfer (PIT) procedures isolate a stimulus's function as a CS from its other functions. Though there are several relevant studies using PIT, knowledge gaps exist. Particularly, it is not clear that an alcohol-paired CS will increase alcohol seeking compared to the same stimulus in a Truly-Random-Control group, nor whether such increases are specific to alcohol seeking. To address these knowledge gaps in Experiment 1, rats responded for ethanol (0.1 ml 8% w/v) under an RI 30-sec schedule, then the lever was removed and half the rats had ethanol delivered during occasional 120-sec light presentations, while the remainder had ethanol and the light presented under independent RT schedules. Later the lever was returned and the light was presented during responding in extinction (PIT test). Following this test, levers were again removed and the light was presented without ethanol (light extinction), following again by a PIT test. Responding in the two groups during light presentations did not differ in either PIT test. Experiment 2 repeated Experiment 1 using food instead of ethanol. In Experiment 2, responding during light presentations increased in the paired group. In Experiment 3, rats were trained on a concurrent FR schedule of food and ethanol delivery. Ethanol was delivered following 5 responses and the response requirement for food adjusted so that similar numbers of food and ethanol deliveries were obtained. Subsequently, rats underwent conditioning, control and testing procedures identical to those in Experiment 1. In Experiment 3, the ethanol-paired CS increased ethanol-responding, but not food-responding. These results are most easily interpreted as changes in responding resulting from CS-elicited behavior rather than motivational changes. This interpretation is more compatible with some descriptions of the role of an alcohol-paired CS in alcoholism than others. Copyright © 2016 Elsevier Inc. All rights reserved.

Stem rots of oil palm caused by Ganoderma boninense: pathogen biology and epidemiology.

PubMed

Pilotti, C A

2005-01-01

Oil palm (Elaeis guineensis Jacq.) has been grown in Papua New Guinea since the early 1960s. The most important disease of oil palm in PNG is a stem rot of the palm base. This is the same disease that constitutes a major threat to sustainable oil palm production in SE Asia. Investigations into the causal pathogen have revealed that the stem rots in PNG are caused predominantly by the basidiomycete Ganoderma boninense, with a minor pathogen identified as G. tornatum G. tornatum was found to have a broad host range whereas G. boninense appears to be restricted to palms. The population structure of G. boninense was investigated using inter-fertility studies between isolates collected from basal stem rots on oil palm. Although the G. boninense field populations are predominantly comprised of distinct individuals, a number of isolates were found that share single mating alleles. This indicates that out-crossing had occurred over several generations in the resident or wild population of G. boninense prior to colonization of oil palm. No direct hereditary relationship between isolates on neighbouring diseased palms was found, although an indirect link between isolates causing upper stem rot and basal stem rot was detected.

Pit and Fissure Sealants in Young Adults: An Evaluation of Placement Time and Retention Rate Using Two Isolation Techniques.

DTIC Science & Technology

1983-01-01

retention by dental arch and method of isol..tion at twelve months ................................ 45 TABLE XVI Seven month inter-examiner reliability data...specific protection against the occurrence and progression of a specific disease, namely dental caries. The American Dental Association endorses the use...years. Yet many unanswered questions remain concerning the use of sealants. Only 15% of dental practitioners report that they routinely use them (4

Concurrent Isolation of 3 Distinct Cardiac Stem Cell Populations From a Single Human Heart Biopsy.

PubMed

Monsanto, Megan M; White, Kevin S; Kim, Taeyong; Wang, Bingyan J; Fisher, Kristina; Ilves, Kelli; Khalafalla, Farid G; Casillas, Alexandria; Broughton, Kathleen; Mohsin, Sadia; Dembitsky, Walter P; Sussman, Mark A

2017-07-07

The relative actions and synergism between distinct myocardial-derived stem cell populations remain obscure. Ongoing debates on optimal cell population(s) for treatment of heart failure prompted implementation of a protocol for isolation of multiple stem cell populations from a single myocardial tissue sample to develop new insights for achieving myocardial regeneration. Establish a robust cardiac stem cell isolation and culture protocol to consistently generate 3 distinct stem cell populations from a single human heart biopsy. Isolation of 3 endogenous cardiac stem cell populations was performed from human heart samples routinely discarded during implantation of a left ventricular assist device. Tissue explants were mechanically minced into 1 mm 3 pieces to minimize time exposure to collagenase digestion and preserve cell viability. Centrifugation removes large cardiomyocytes and tissue debris producing a single cell suspension that is sorted using magnetic-activated cell sorting technology. Initial sorting is based on tyrosine-protein kinase Kit (c-Kit) expression that enriches for 2 c-Kit + cell populations yielding a mixture of cardiac progenitor cells and endothelial progenitor cells. Flowthrough c-Kit - mesenchymal stem cells are positively selected by surface expression of markers CD90 and CD105. After 1 week of culture, the c-Kit + population is further enriched by selection for a CD133 + endothelial progenitor cell population. Persistence of respective cell surface markers in vitro is confirmed both by flow cytometry and immunocytochemistry. Three distinct cardiac cell populations with individualized phenotypic properties consistent with cardiac progenitor cells, endothelial progenitor cells, and mesenchymal stem cells can be successfully concurrently isolated and expanded from a single tissue sample derived from human heart failure patients. © 2017 American Heart Association, Inc.

Variation in Septoria musiva and Implications for Disease Resistance Screening

Treesearch

K.T. Ward; M.E. Ostry

2005-01-01

A set of isolates of Septoria musiva differed in aggressiveness in hybrid poplar leaf disk and stem assays and culture growth in vitro. Clone x isolate interactions were observed in one of the stem assay experiments, but not in the leaf disk assay experiments. Random amplified polymorphic DNA (RAPD) analyses were performed using 52 isolates of

SOURCE CONTROL BY HYDROLOGICAL ISOLATION: APPLICATON OF THE ANKENY MOAT

EPA Science Inventory

Prior to 1990, gasoline marketers stored their product in underground storage tanks made of mild steel. These tanks often suffered corrosion pits that allowed gasoline to escape and contaminate ground water. To control pollution from spills of gasoline, the U.S. EPA created the ...

Lower Mississippi River Environmental Program. Report 3. Bird and Mammal Use of Main Stem Levee Borrow Pits Along the Lower Mississippi River.

DTIC Science & Technology

1986-02-01

overcup oak, tupelo gum, Nuttall oak, American elm , slippery elm , i , hickories, persimmon, silver maple, deciduous holly, swamp privet, and rose mallows...cottonwood, green ash, sugarberry, box elder, deciduous holly, osage orange, swamp privet, hickories, overcup oak, water locust, honey locust, slippery elm ...wood, box elder, osage orange, hickories, honey locust, water locust, slippery elm , swamp privet, sugarberry, persimmon, and rose mallows. Where

Toward an improved model of maple sap exudation: the location and role of osmotic barriers in sugar maple, butternut and white birch.

PubMed

Cirelli, Damián; Jagels, Richard; Tyree, Melvin T

2008-08-01

Two theories have been proposed to explain how high positive pressures are developed in sugar maple stems when temperatures fluctuate around freezing. The Milburn-O'Malley theory proposes that pressure development is purely physical and does not require living cells or sucrose. The osmotic theory invokes the involvement of living cells and sucrose to generate an osmotic pressure difference between fibers and vessels, which are assumed to be separated by an osmotic barrier. We analyzed wood of Acer saccharum Marsh., Juglans cinerea L. and Betula papyrifera Marsh. (all generate positive pressures) examining three critical components of the osmotic model: pits in cell walls, selectivity of the osmotic barrier and stability of air bubbles under positive xylem pressure. We examined the distribution and type of pits directly by light and scanning electron microscopy (SEM), and indirectly by perfusion of branch segments with fluorescent dyes with molecular masses similar to sucrose. The latter approach allowed us to use osmotic surrogates for sucrose that could be tracked by epifluorescence. Infusion experiments were used to assess the compartmentalization of sucrose and to determine the behavior of gas bubbles as predicted by Fick's and Henry's laws. The SEM images of sugar maple revealed a lack of pitting between fibers and vessels but connections between fiber-tracheids and vessels were present. Fluorescein-perfusion experiments demonstrated that large molecules do not diffuse into libriform fibers but are confined within the domain of vessels, parenchyma and fiber-tracheids. Results of the infusion experiments were in agreement with those of the fluorescein perfusions and further indicated the necessity of a compartmentalized osmolyte to drive stem pressure, as well as the inability of air bubbles to maintain such pressure because of instability. These results support the osmotic model and demonstrate that the secondary cell wall is an effective osmotic barrier for molecules larger than 300 g mol(-1).

Characterization of mesenchymal stem cells from human dental pulp, preapical follicle and periodontal ligament.

PubMed

Navabazam, Ali Reza; Sadeghian Nodoshan, Fatemeh; Sheikhha, Mohammad Hasan; Miresmaeili, Sayyed Mohsen; Soleimani, Mehrdad; Fesahat, Farzaneh

2013-03-01

Human dental stem cells have high proliferative potential for self-renewal that is important to the regenerative capacity of the tissue. Objective : The aim was to isolate human dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC) and periapical follicle stem cells (PAFSC) for their potential role in tissue regeneration. In this experimental study, the postnatal stem cells were isolated from dental pulp, preapical follicle and periodontal ligament .The cells were stained for different stem cell markers by immunocytochemistry. To investigate the mesenchymal nature of cells, differentiation potential along osteoblastic and adipogenic lineages and gene expression profile were performed. For proliferation potential assay, Brdu staining and growth curve tests were performed. Finally, all three cell types were compared together regarding their proliferation, differentiation and displaying phenotype. The isolated cell populations have similar fibroblastic like morphology and expressed all examined cell surface molecule markers. These cells were capable of differentiating into osteocyte with different capability and adipocyte with the same rate. PAFSCs showed more significant proliferation rate than others. Reverse transcriptase PCR (RT-PCR) for nanog, oct4, Alkaline phosphatase (ALP) and glyceraldehydes-3-phosphate dehydrogenease (GADPH) as control gene showed strong positive expression of these genes in all three isolated cell types. PDLSCs, DPSCs and PAFSCs exist in various tissues of the teeth and can use as a source of mesenchymal stem cells for developing bioengineered organs and also in craniomaxillofacial reconstruction with varying efficiency in differentiation and proliferation.

Characterization of physical mass transport through oil sands fluid fine tailings in an end pit lake: a multi-tracer study.

PubMed

Dompierre, Kathryn A; Barbour, S Lee

2016-06-01

Soft tailings pose substantial challenges for mine reclamation due to their high void ratios and low shear strengths, particularly for conventional terrestrial reclamation practices. Oil sands mine operators have proposed the development of end pit lakes to contain the soft tailings, called fluid fine tailings (FFT), generated when bitumen is removed from oil sands ore. End pit lakes would be constructed within mined-out pits with FFT placed below the lake water. However, the feasibility of isolating the underlying FFT has yet to be fully evaluated. Chemical constituents of interest may move from the FFT into the lake water via two key processes: (1) advective-diffusive mass transport with upward pore water flow caused by settling of the FFT; and (2) mixing created by wind events or unstable density profiles through the lake water and upper portion of the FFT. In 2013 and 2014, temperature and stable isotopes of water profiles were measured through the FFT and lake water in the first end pit lake developed by Syncrude Canada Ltd. Numerical modelling was undertaken to simulate these profiles to identify the key mechanisms controlling conservative mass transport in the FFT. Shallow mixing of the upper 1.1 m of FFT with lake water was required to explain the observed temperature and isotopic profiles. Following mixing, the re-establishment of both the temperature and isotope profiles required an upward advective flux of approximately 1.5 m/year, consistent with average FFT settling rates measured at the study site. These findings provide important insight on the ability to sequester soft tailings in an end pit lake, and offer a foundation for future research on the development of end pit lakes as an oil sands reclamation strategy. Copyright © 2016 Elsevier B.V. All rights reserved.

Lgr proteins in epithelial stem cell biology.

PubMed

Barker, Nick; Tan, Shawna; Clevers, Hans

2013-06-01

The ultimate success of global efforts to exploit adult stem cells for regenerative medicine will depend heavily on the availability of robust, highly selective stem cell surface markers that facilitate the isolation of stem cells from human tissues. Any subsequent expansion or manipulation of isolated stem cells will also require an intimate knowledge of the mechanisms that regulate these cells, to ensure maintenance of their regenerative capacities and to minimize the risk of introducing undesirable growth traits that could pose health risks for patients. A subclass of leucine-rich repeat-containing G-protein-coupled receptor (Lgr) proteins has recently gained prominence as adult stem cell markers with crucial roles in maintaining stem cell functions. Here, we discuss the major impact that their discovery has had on our understanding of adult stem cell biology in various self-renewing tissues and in accelerating progress towards the development of effective stem cell therapies.

Vitrification of mouse embryo-derived ICM cells: a tool for preserving embryonic stem cell potential?

PubMed

Desai, Nina; Xu, Jing; Tsulaia, Tamara; Szeptycki-Lawson, Julia; AbdelHafez, Faten; Goldfarb, James; Falcone, Tommaso

2011-02-01

Vitrification technology presents new opportunities for preservation of embryo derived stem cells without first establishing a viable ESC line. This study tests the feasibility of cryopreserving ICM cells using vitrification. ICMs from mouse embryos were isolated and vitrified in HSV straws or on cryoloops. Upon warming, the vitrified ICMs were cultured and observed for attachment and morphology. Colonies were passaged every 3-6 days. ICMs and ICM-derived ESC colonies were tested for expression of stem cell specific markers. ICMs vitrified on both the cryoloop and the HSV straw had high survival rates. ICM derived ESCs remained undifferentiated for several passages and demonstrated expression of typical stem cell markers; SSEA-1, Sox-2, Oct 4 and alkaline phosphatase. This is the first report on successful vitrification of isolated ICMs and the subsequent derivation of ESC colonies. Vitrification of isolated ICMs is a novel approach for preservation of the "stem cell source" material.

[Isolation and identification of dog periodontal ligament stem cells].

PubMed

Chang, Xiu-Mei; Liu, Hong-Wei; Jin, Yan; Liu, Yuan; He, Hui-Xia

2009-02-01

To isolate, culture and identify a dog periodontal ligament stem cells (PDLSC) line in vitro. The adult dog periodontal ligament cells were isolated by limited dilution of culture cell for single cell clone. Cells originated from one of these clones were assessed through colony-forming efficiency and immunocytochemistry assay and alkaline phosphatase stain was used to identify the source of adult dog periodontal stem cells, at the same time, PDLSC were induced with mineralizatin solution and was found to have long protrude like an osteoblast. Differentiation of PDLSC were assessed. Mineralized potential was studied by Von-Kossa staining. The dog PDLSC expressed STRO-1, which was the marker of mesenchymal stem cells. Also Vimentin, osteoblast-like marker alkaline phosphatase and Collagen-I expressed weakly. Cells were clonegenic, highly proliferative cells and capable of differentiating into osteoblasts/cementoblasts. The evidence suggests that the cultured cells were stem cells from adult dog periodontal ligament.

Effects of halothane and methoxyflurane on regional brain and spinal cord substance P-like and beta-endorphin-like immunoreactivities in the rat.

PubMed

Karuri, A R; Agarwal, R K; Engelking, L R; Kumar, M S

1998-03-15

Effects of acute exposure (2 hr) to either 1.5% halothane or 0.5% methoxyflurane were investigated in the Sprague Dawley rat. Pituitary (PIT) and central nervous system (CNS) substance P (SP)-like and beta-endorphin (beta-end)-like immunoreactivities were evaluated immediately after anesthetic exposure (2 h), after righting reflex (4 h) or 24 hr postexposure (24 h). Only halothane significantly reduced SP-like immunoreactivity in olfactory bulbs in both the 2-h and 4-h groups. Halothane elevated SP-like immunoreactivity of hippocampus at all three time periods, and in the hypothalamus at 2 h. Both anesthetics significantly depleted thalamic concentrations of SP-like immunoreactivity. Methoxyflurane anesthesia resulted in a drastic decrease in SP-like immunoreactivity in PIT at all three time periods periods, while halothane elevated PIT concentrations of this peptide at 4 h. Both anesthetics significantly decreased beta-end-like immunoreactivity in the olfactory bulbs and thalami at 2, 4, and 24 h. However, halothane alone significantly elevated beta-end-like immunoreactivity in the spinal cord at 24 h. Halothane significantly elevated PIT beta-end-like immunoreactivity at 2 and 24 h, while methoxyflurane significantly lowered it in the 4-h group, but elevated the levels of the same in the 24-h group. Brain stem beta-end immunoreactivity were significantly reduced at 2 h by both anesthetics, and at 4 h by methoxyflurane. Results indicate that halothane and methoxyflurane may differ significantly in their actions on SP and beta-end secreting neurons in the CNS.

Used protocols for isolation and propagation of ovarian stem cells, different cells with different traits.

PubMed

Yazdekhasti, Hossein; Rajabi, Zahra; Parvari, Soraya; Abbasi, Mehdi

2016-10-20

Although existence of ovarian stem cells (OSCs) in mammalian postnatal ovary is still under controversy, however, it has been almost accepted that OSCs are contributing actively to folliculogenesis and neo-oogenesis. Recently, various methods with different efficacies have been employed for OSCs isolation from ovarian tissue, which these methods could be chosen depends on aim of isolation and accessible equipments and materials in lab. Although isolated OSCs from different methods have various traits and characterizations, which might become from their different nature and origin, however these stem cells are promising source for woman infertility treatment or source of energy for women with a history of repeat IVF failure in near future. This review has brought together and summarized currently used protocols for isolation and propagation of OSCs in vitro.

Microbial contents of soil from fire pits

NASA Astrophysics Data System (ADS)

Moon, K.; Esparza, V.; de Sandre, J.; Cheney, S.; Anderson, A.; White, M. A.

2006-12-01

Forest fires generate polycylic aromatic hydrocarbons (PAHs) that can lead to carcinogenic compounds, which are potential health risks. PAHs can be degraded to water and carbon dioxide by certain soil microbes. Thus, during participation in a NASA-funded summer research experience at Utah State University, our high school student team sampled soils from a month-old fire pit in which plant materials had been burnt. We detected in soil samples, from surface, 10 and 20 cm depths, microbes that would grow on a defined minimal medium source. Other microbes were cultured from the roots of plants that had established at the fire pit. A diversity of microbes was present in all samples based on visible differences in cell shape and color. It was surprising that the surface ash, although exposed to sunlight over the month interval, had culturable colonies. Many of these culturable bacteria were pigmented perhaps as a protection against UV radiation from the sun. We searched for genes in the microbes that encoded enzymes called dioxygenases that in other bacteria are involved in degradation of PAHs. This test involved using polymerase chain reactions to detect the genes. PCR products were found in two of the fifteen isolates tested although their sizes differed from the control gene product from a PAH-degrading mycobacterium isolate. These results suggest that the soils did contain microbes with the possible potential to alter the PAH compounds generated from vegetation fires. Our findings serve as a starting point for future studies looking at recovery and remediation of fired acreages.

Human Prostate Side Population Cells Demonstrate Stem Cell Properties in Recombination with Urogenital Sinus Mesenchyme

PubMed Central

Foster, Barbara A.; Gangavarapu, Kalyan J.; Mathew, Grinu; Azabdaftari, Gissou; Morrison, Carl D.; Miller, Austin; Huss, Wendy J.

2013-01-01

Stem cell enrichment provides a tool to examine prostate stem cells obtained from benign and malignant tissue. Functional assays can enrich stem cells based on common stem cell phenotypes, such as high ATP binding cassette (ABC) transporter mediated efflux of Hoechst substrates (side population assay). This functional assay is based upon mechanisms that protect cells from environmental insult thus contributing to the survival and protection of the stem cell population. We have isolated and analyzed cells digested from twelve clinical prostate specimens based on the side population assay. Prostate stem cell properties of the isolated cells were tested by serial recombination with rat urogenital mesenchyme. Recombinants with side population cells demonstrate an increase in the frequency of human ductal growth and the number of glands per recombinant when compared to recombinants with non-side population cells. Isolated cells were capable of prostatic growth for up to three generations in the recombination assay with as little as 125 sorted prostate cells. The ability to reproducibly use cells isolated by fluorescence activated cell sorting from human prostate tissue is an essential step to a better understanding of human prostate stem cell biology. ABC transporter G2 (ABCG2) was expressed in recombinants from side population cells indicating the side population cells have self-renewal properties. Epithelial cell differentiation of recombinants was determined by immunohistochemical analysis for expression of the basal, luminal, and neuroendocrine markers, p63, androgen receptor, prostate specific antigen, and chromogranin A, respectively. Thus, the ABCG2 expressing side population demonstrates multipotency and self-renewal properties indicating stem cells are within this population. PMID:23383057

Investigation of the expression of RIF1 gene on head and neck, pancreatic and brain cancer and cancer stem cells.

PubMed

GursesCila, Hacer E; Acar, Muradiye; Barut, Furkan B; Gunduz, Mehmet; Grenman, Reidar; Gunduz, Esra

2016-12-01

Recent studies have shown that cancer stem cells are resistant to chemotherapy. The aim of this study was to compare RIF1 gene expression in head and neck, pancreatic cancer and glioma cell lines and the cancer stem cells isolated from these cell lines. UT-SCC-74 from Turku University and UT-SCC-74B primary tumor metastasis and neck cancer cell lines, YKG-1 glioma cancer cell line from RIKEN, pancreatic cancer cell lines and ASPC-1 cells from ATCC were grown in cell culture. To isolate cancer stem cells, ALDH-1 for UT-SCC-74 and UT-SCC-74B cell line, CD-133 for YKG-1 cell line and CD-24 for ASPC-1 cell line, were used as markers of cancer stem cells. RNA isolation was performed for both cancer lines and cancer stem cells. RNAs were converted to cDNA. RIF1 gene expression was performed by qRT-PCR analysis. RIF1 gene expression was compared with cancer cell lines and cancer stem cells isolated from these cell lines. The possible effect of RIF1 gene was evaluated. In the pancreatic cells, RIF1 gene expression in the stem cell-positive cell line was 256 time that seen in the stem cell-negative cell line. Considering the importance of RIF1 in NHEJ and of NHEJ in pancreatic cancer, RIF1 may be one of the genes that plays an important role in the diagnoses and therapeutic treatment of pancreatic cancer. The results of head and neck and brain cancers are inconclusive and further studies are required to elucidate the connection between RIF1 gene and these other types of cancers.

Isolation, Characterization, Cryopreservation of Human Amniotic Stem Cells and Differentiation to Osteogenic and Adipogenic Cells

PubMed Central

Gholizadeh-Ghaleh Aziz, Shiva; Pashaei-Asl, Fatima; Fardyazar, Zahra; Pashaiasl, Maryam

2016-01-01

Human stem cells and progenitor cells can be used to treat cancer and replace dysfunctional cells within a tissue or organ. The objective of this study was to identify the appropriate cells type in regenerative medicine and targeted therapy. As an alternative to embryonic and bone marrow stem cells, we examined human amniotic fluid stem cells (hAFSCs), one of the potential source of multipotent stem cells isolated from both cell pellet (using single-stage method), and supernatant of human amniotic fluid. Source of isolation and unique property of the cells emphasize that these cells are one of the promising new tools in therapeutic field. Double sources for isolation and availability of the left over samples in diagnostic laboratory at the same time have less legal and ethical concerns compared with embryonic stem cell studies. Cells were isolated, cultured for 18th passage for 6 months and characterized using qPCR and flow cytometry. Cells showed good proliferative ability in culture condition. The cells successfully differentiated into the adipogenic and osteogenic lineages. Based on these findings, amniotic fluid can be considered as an appropriate and convenient source of human amniotic fluid stem cells. These cells provide potential tools for therapeutic applications in the field of regenerative medicine. To get a better understanding of crosstalk between Oct4/NANOG with osteogenesis and adipogenesis, we used network analysis based on Common Targets algorithm and Common Regulators algorithm as well as subnetwork discovery based on gene set enrichment. Network analysis highlighted the possible role of MIR 302A and MIR let-7g. We demonstrated the high expression of MIR 302A and low expression of MIR let7g in hAFSCs by qPCR. PMID:27434028

A modified efficient method for dental pulp stem cell isolation.

PubMed

Raoof, Maryam; Yaghoobi, Mohammad Mehdi; Derakhshani, Ali; Kamal-Abadi, Ali Mohammadi; Ebrahimi, Behnam; Abbasnejad, Mehdi; Shokouhinejad, Noushin

2014-03-01

Dental pulp stem cells can be used in regenerative endodontic therapy. The aim of this study was to introduce an efficient method for dental pulp stem cells isolation. In this in-vitro study, 60 extracted human third molars were split and pulp tissue was extracted. Dental pulp stem cells were isolated by the following three different methods: (1) digestion of pulp by collagenase/dispase enzyme and culture of the released cells; (2) outgrowth of the cells by culture of undigested pulp pieces; (3) digestion of pulp tissue pieces and fixing them. The cells were cultured in minimum essential medium alpha modification (αMEM) medium supplemented with 20% fetal bovine serum(FBS) in humid 37°C incubator with 5% CO 2. The markers of stem cells were studied by reverse transcriptase polymerase chain reaction (PCR). The student t-test was used for comparing the means of independent groups. P <0.05 was considered as significant. The results indicated that by the first method a few cell colonies with homogenous morphology were detectable after 4 days, while in the outgrowth method more time was needed (10-12 days) to allow sufficient numbers of heterogeneous phenotype stem cells to migrate out of tissue. Interestingly, with the improved third method, we obtained stem cells successfully with about 60% efficiency after 2 days. The results of RT-PCR suggested the expression of Nanog, Oct-4, and Nucleostemin markers in the isolated cells from dental pulps. This study proposes a new method with high efficacy to obtain dental pulp stem cells in a short time.

From “ES-like” cells to induced pluripotent stem cells: A historical perspective in domestic animals

PubMed Central

Koh, Sehwon; Piedrahita, Jorge A.

2013-01-01

Pluripotent stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) provide great potential as cell sources for gene editing to generate genetically modified animals, as well as in the field of regenerative medicine. Stable, long-term ESCs have been established in laboratory mouse and rat, however, isolation of true pluripotent ESCs in domesticated animals such as pigs and dogs have been less successful. Initially, domesticated animal pluripotent cell lines were referred to as “ES-like” cells due to similar morphological characteristics to mouse ESCs but accompanied by a limited ability to proliferate in vitro in an undifferentiated state. That is, they shared some but not all the characteristics of true ESCs. More recently, advances in reprogramming using exogenous transcription factors, combined with the utilization of small chemical inhibitors of key biochemical pathways, have led to the isolation of induced pluripotent stem cells. In this review, we provide a historical perspective of the isolation of various types of pluripotent stem cells in domesticated animals. In addition, we summarize the latest progress and limitations in the derivation and application of induced pluripotent stem cells. PMID:24274415

C-glycosides from the stems of Calophyllum membranaceum.

PubMed

Zhu, Ling-Juan; Yi, Sen; Li, Xue; Chen, Hai-Feng; Ming, Meng; Zhang, Xue; Yao, Xin-Sheng

2018-01-01

Three new C-glycosides, calophymembransides D-F (1-3), were isolated from the stems of Calophyllum membranaceum Gardn. et Champ.. The structures were assigned on the basis of spectroscopic data. RXRα transcriptional inhibition and α-glucosidase inhibition assays indicated that all the isolates were inactive.

Clonogenic colony-forming ability of flow cytometrically isolated hepatic progenitor cells in the murine fetal liver.

PubMed

Taniguchi, H; Kondo, R; Suzuki, A; Zheng, Y W; Takada, Y; Fukunaga, K; Seino, K; Yuzawa, K; Otsuka, M; Fukao, K; Nakauchi, H

2000-01-01

Stem cells are defined as cells having multilineage differentiation potential and self-renewal capability. Hepatic stem cells have aroused considerable interest not only because of their developmental importance but also for their therapeutic potential. However, their presence in the liver has not yet been demonstrated. With the use of a fluorescence-activated cell sorter (FACS) and monoclonal antibodies, we attempted to ascertain whether hepatic stem cells are present in the murine fetal liver. For this purpose, we optimized a cell isolation technique for FACS sorting of fetal liver cells. When isolated CD45 TER119 cells (the non-blood cell fraction in the fetal liver) were tested for their clonogenic colony-forming ability, mechanical dissociation (pipetting) was the most suitable cell isolation technique for FACS sorting. We confirmed that these colonies contained not only cells expressing hepatocyte markers but also cells expressing cholangiocyte markers. To identify hepatic stem cells, studies must focus on CD45TER119- cells in the murine fetal liver.

The low chamber pancreatic cancer cells had stem-like characteristics in modified transwell system: is it a novel method to identify and enrich cancer stem-like cells?

PubMed

Wang, Dongqing; Zhu, Haitao; Liu, Yanfang; Liu, Qing; Xie, Xiaodong; Zhou, Yuepeng; Zhang, Lirong; Zhu, Yan; Zhang, Zhijian; Su, Zhaoliang

2014-01-01

Cancer stem cells (CSCs) or cancer-initiating cells (CICs) play an important role in tumor initiation, progression, metastasis, chemoresistance, and recurrence. It is important to construct an effective method to identify and isolate CSCs for biotherapy of cancer. During the past years, many researchers had paid more attention to it; however, this method was still on seeking. Therefore, compared to the former methods that were used to isolate the cancer stem cell, in the present study, we tried to use modified transwell system to isolate and enrich CSCs from human pancreatic cancer cell lines (Panc-1). Our results clearly showed that the lower chamber cells in modified transwell system were easily forming spheres; furthermore, these spheres expressed high levels of stem cell markers (CD133/CD44/CD24/Oct-4/ESA) and exhibited chemoresistance, underwent epithelial-to-mesenchymal transition (EMT), and possessed the properties of self-renewal in vitro and tumorigenicity in vivo. Therefore, we speculated that modified transwell assay system, as a rapid and effective method, can be used to isolate and enrich CSCs.

Isolation and clonal characterization of hematopoietic and liver stem cells.

PubMed

Nakauchi, Hiromitsu

2004-11-01

Prospective isolation of stem cells is essential to understanding the mechanisms that control their proliferation and differentiation. Using 9 monoclonal antibodies and fluorescence-activated cell sorting (FACS), we have succeeded in prospectively identifying hematopoietic stem cells (HSCs) in adult mouse bone marrow. Mouse HSCs were exclusively enriched in CD34 negative, c-Kit Sca-1 Lineage Marker (CD34 KSL) cells representing 0.004% of bone marrow (BM) mononuclear cells. When single CD34-KSL cells were transplanted individually into a lethally irradiated mouse, 25% of the recipient mice survived and showed long-term reconstitution of the BM, providing evidence for multipotency and a self-renewal capacity of HSCs. Using a similar approach, we also prospectively identified hepatic stem cells with multilineage differentiation potential and self-renewal capability in the c-Met CD49f c-Kit CD45 Ter119 fraction of cells isolated from day 13.5 fetal mouse liver. On cell transplantation, these cells differentiated into hepatocytes and cholangiocytes. As an alternative to the antibody based stem cell isolation, Hoechst33342 staining is useful. To understand the mechanism responsible for SP phenotype, we performed an expression cloning and identified bcrp-1/ABCG2 gene, a member of ATP binding-cassette (ABC) transporter family. Bcrp-1 is almost exclusively expressed in CD34 KSL cells among blood cells; however their expression in other tissue specific stem cells remains to be studied. With the use of FACS and monoclonal antibodies, hematopoietic and liver stem cells were prospectively isolated and characterized. HSCs could also be purified by Hoechst 33342 staining. By expression cloning, we identify bcrp-1/ABCG2 transporter as a molecule responsible for SP phenotype. Elucidation of the physiological role of bcrp-1/ABCG2 in HSCs may provide us with clues to understand the molecular mechanisms of stem cell self-renewal and differentiation.

Cu2+ inhibition of gel secretion in the xylem and its potential implications for water uptake of cut Acacia holosericea stems.

PubMed

Ratnayake, Kamani; Joyce, Daryl C; Webb, Richard I

2013-08-01

Maintaining a high rate of water uptake is crucial for maximum longevity of cut stems. Physiological gel/tylosis formation decreases water transport efficiency in the xylem. The primary mechanism of action for post-harvest Cu(2+) treatments in improving cut flower and foliage longevity has been elusive. The effect of Cu(2+) on wound-induced xylem vessel occlusion was investigated for Acacia holosericea A. Cunn. ex G. Don. Experiments were conducted using a Cu(2+) pulse (5 h, 2.2 mM) and a Cu(2+) vase solution (0.5 mM) vs a deionized water (DIW) control. Development of xylem blockage in the stem-end region 10 mm proximal to the wounded stem surface was examined over 21 days by light and transmission electron microscopy. Xylem vessels of stems stood into DIW were occluded with gels secreted into vessel lumens via pits from surrounding axial parenchyma cells. Gel secretion was initiated within 1-2 days post-wounding and gels were detected in the xylem from day 3. In contrast, Cu(2+) treatments disrupted the surrounding parenchyma cells, thereby inhibiting gel secretion and maintaining the vessel lumens devoid of occlusions. The Cu(2+) treatments significantly improved water uptake by the cut stems as compared to the control. © 2013 Scandinavian Plant Physiology Society.

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure.

PubMed

Yun, Hongmin; Zhou, Yi; Wills, Andrew; Du, Yiqin

2016-06-01

Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration.

Stem Cells in the Trabecular Meshwork for Regulating Intraocular Pressure

PubMed Central

Yun, Hongmin; Zhou, Yi; Wills, Andrew

2016-01-01

Abstract Intraocular pressure (IOP) is still the main treatment target for glaucoma. Outflow resistance mainly exists at the trabecular meshwork (TM) outflow pathway, which is responsible for IOP regulation. Changes of TM cellularity and TM extracellular matrix turnover may play important roles in IOP regulation. In this article, we review basic anatomy and physiology of the outflow pathway and TM stem cell characteristics regarding the location, isolation, identification and function. TM stem cells are localized at the insert region of the TM and are label-retaining in vivo. They can be isolated by side-population cell sorting, cloning culture, or sphere culture. TM stem cells are multipotent with the ability to home to the TM region and differentiate into TM cells in vivo. Other stem cell types, such as adipose-derived stem cells, mesenchymal stem cells and induced pluripotent stem cells have been discovered for TM cell differentiation and TM regeneration. We also review glaucomatous animal models, which are suitable to study stem cell-based therapies for TM regeneration. PMID:27183473

[Breakthrough in research on pluripotent stem cells and their application in medicine].

PubMed

Valdimarsdóttir, Guðrún; Richter, Anne

2015-12-01

Embryonic stem cells are, as the name indicates, isolated from embryos. They are pluripotent cells which can be maintained undifferentiated or induced to differentiate into any cell type of the body. In 1998 the first isolation of human embryonic stem cells was successful and they became an interesting source for stem cell regenerative medicine. Only 8 years later pluripotent stem cells were generated by reprogramming somatic cells into induced pluripotent stem cells (iPSCs). This was a revolution in the way people thought of cell commitment during development. Since then, a lot of research has been done in understanding the molecular biology of pluripotent stem cells. iPSCs can be generated from somatic cells of a patient and therefore have the same genome. Hence, iPSCs have great potential application in medicine, as they can be utilized in disease modelling, drug screening and cell replacement therapy.

Tanacetum vulgare as a bioindicator of trace-metal contamination: a study of a naturally colonized open-pit lignite mine.

PubMed

Jasion, Mateusz; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Kempers, Alexander J

2013-10-01

We investigated the possibility of use of Tanacetum vulgare (tansy) as an ecological indicator of metal concentration in a naturally colonized open-pit lignite mine in Bełchatów (Poland). Tanacetum vulgare is the only species growing abundantly and spontaneously in the lignite mine waste dumps. Metal concentrations in roots, stems, leaves, flowers, and soil were measured in dump sites differing in type and time of reclamation and therefore differing in pollution levels. Tanacetum vulgare appeared to be an accumulator of chromium and iron in roots, whereas highest concentrations of manganese and zinc were found in leaves. A high bioaccumulation factor for cadmium (Cd) was observed in dumps and control sites, indicating that even small amounts of Cd in the environment may result in significant uptake by the plant. The lowest concentrations of metals were found in plants from sites situated on dumps reclaimed with argillaceous limestone.

Monitoring of stream restoration habitat on the main stem of the Methow River, Washington, during the pre-treatment phase (October 2008-May 2012) with a progress report for activities from March 2011 to November 2011

USGS Publications Warehouse

Tibbits, Wesley T.; Martens, Kyle D.; Connolly, Patrick J.

2012-01-01

The approach and actions taken or planned by Reclamation to modify off-channel habitat are largely untested as to their effectiveness to improve target fish species’ productivity and survival needs. Those documented strategies that identify both physical parameters and biological relationships and benefits have been identified (Reclamation, 2008). To assess biological performance, we plan to compare age structure, growth, and age at smolting between those fish that stay in natal areas versus those fish that move. To assess retention in, and movement from or into, the restoration reach, we have used a combination of within-reach and out-of-reach sampling. We are using passive integrated transponder (PIT) tags, a network of instream PIT tag interrogation systems, and smolt traps to assess differences in biological performance and the magnitude of retention in, and movement from and into, the restoration reach.

Isolation and characterization of 2 new human rotator cuff and long head of biceps tendon cells possessing stem cell-like self-renewal and multipotential differentiation capacity.

PubMed

Randelli, Pietro; Conforti, Erika; Piccoli, Marco; Ragone, Vincenza; Creo, Pasquale; Cirillo, Federica; Masuzzo, Pamela; Tringali, Cristina; Cabitza, Paolo; Tettamanti, Guido; Gagliano, Nicoletta; Anastasia, Luigi

2013-07-01

Stem cell therapy is expected to offer new alternatives to the traditional therapies of rotator cuff tendon tears. In particular, resident, tissue-specific, adult stem cells seem to have a higher regenerative potential for the tissue where they reside. Rotator cuff tendon and long head of the biceps tendon possess a resident stem cell population that, when properly stimulated, may be induced to proliferate, thus being potentially usable for tendon regeneration. Controlled laboratory study. Human tendon samples from the supraspinatus and the long head of the biceps were collected during rotator cuff tendon surgeries from 26 patients, washed with phosphate-buffered saline, cut into small pieces, and digested with collagenase type I and dispase. After centrifugation, cell pellets were resuspended in appropriate culture medium and plated. Adherent cells were cultured, phenotypically characterized, and then compared with human bone marrow stromal cells (BMSCs), as an example of adult stem cells, and human dermal fibroblasts, as normal proliferating cells with no stem cell properties. Two new adult stem cell populations from the supraspinatus and long head of the biceps tendons were isolated, characterized, and cultured in vitro. Cells showed adult stem cell characteristics (ie, they were self-renewing in vitro, clonogenic, and multipotent), as they could be induced to differentiate into different cell types--namely, osteoblasts, adipocytes, and skeletal muscle cells. This work demonstrated that human rotator cuff tendon stem cells and human long head of the biceps tendon stem cells can be isolated and possess a high regenerative potential, which is comparable with that of BMSCs. Moreover, comparative analysis of the sphingolipid pattern of isolated cells with that of BMSCs and fibroblasts revealed the possibility of using this class of lipids as new possible markers of the cell differentiation status. Rotator cuff and long head of the biceps tendons contain a stem cell population that can proliferate in vitro and could constitute an easily accessible stem cell source to develop novel therapies for tendon regeneration.

Establishment of a Novel Lingual Organoid Culture System: Generation of Organoids Having Mature Keratinized Epithelium from Adult Epithelial Stem Cells

NASA Astrophysics Data System (ADS)

Hisha, Hiroko; Tanaka, Toshihiro; Kanno, Shohei; Tokuyama, Yoko; Komai, Yoshihiro; Ohe, Shuichi; Yanai, Hirotsugu; Omachi, Taichi; Ueno, Hiroo

2013-11-01

Despite the strong need for the establishment of a lingual epithelial cell culture system, a simple and convenient culture method has not yet been established. Here, we report the establishment of a novel lingual epithelium organoid culture system using a three-dimensional matrix and growth factors. Histological analyses showed that the generated organoids had both a stratified squamous epithelial cell layer and a stratum corneum. Very recently, we showed via a multicolor lineage tracing method that Bmi1-positive stem cells exist at the base of the epithelial basal layer in the interpapillary pit. Using our new culture system, we found that organoids could be generated by single Bmi1-positive stem cells and that in the established organoids, multiple Bmi1-positive stem cells were generated at the outermost layer. Moreover, we observed that organoids harvested at an early point in culture could be engrafted and maturate in the tongue of recipient mice and that the organoids generated from carcinogen-treated mice had an abnormal morphology. Thus, this culture system presents valuable settings for studying not only the regulatory mechanisms of lingual epithelium but also lingual regeneration and carcinogenesis.

A simple modification of the separation method reduces heterogeneity of adipose-derived stem cells.

PubMed

Griesche, Nadine; Luttmann, Werner; Luttmann, Arlette; Stammermann, Thekla; Geiger, Helmut; Baer, Patrick C

2010-01-01

High hopes are put into the use of mesenchymal stem cells (MSCs) in various approaches for tissue engineering and regenerative medicine. MSCs are derived from different tissues with only small differences in their phenotype or their differentiation potential, but higher differences in the cell yield. Since fat is easily accessible and contains a high amount of MSCs to be isolated, adipose-derived stem cells (ASCs) are very promising for clinical approaches. ASCs are not a completely homogeneous cell population. Our study was initiated to explore an easy and convenient method to reduce heterogeneity. We tested different isolation methods: (1) the standard isolation method for ASCs based on plastic attachment, (2) the standard method with an initial washing step after 60 min of adherence and (3) immunomagnetic isolation by 4 typical markers (CD49a, CD90, CD105 and CD271). Cells isolated by these methods were evaluated using quantitative PCR and flow cytometry as well as by their differentiation potential. Washing led to a significantly lower expression of desmin, smA and six2, and a higher expression of the stem cell markers nestin, oct-4 and sall-1, compared to standard isolated cells, while the immunomagnetically isolated cells showed no significant changes. All cells independent of the isolation method could be induced to differentiate into adipocytes and osteoblasts. Our study demonstrates that a simple washing step reduces heterogeneity of cultured ASCs according to PCR analysis, whereas the immunomagnetic isolation only showed minor advantages compared to the standard method, but the disadvantage of significantly lower cell yields in the primary isolates. Copyright 2010 S. Karger AG, Basel.

Chemical weathering in a tropical watershed, Luquillo Mountains, Puerto Rico III: Quartz dissolution rates

USGS Publications Warehouse

Schulz, M.S.; White, A.F.

1999-01-01

The paucity of weathering rates for quartz in the natural environment stems both from the slow rate at which quartz dissolves and the difficulty in differentiating solute Si contributed by quartz from that derived from other silicate minerals. This study, a first effort in quantifying natural rates of quartz dissolution, takes advantage of extremely rapid tropical weathering, simple regolith mineralogy, and detailed information on hydrologic and chemical transport. Quartz abundances and grain sizes are relatively constant with depth in a thick saprolite. Limited quartz dissolution is indicated by solution rounding of primary angularity and by the formation of etch pits. A low correlation of surface area (0.14 and 0.42 m2 g-1) with grain size indicates that internal microfractures and pitting are the principal contributors to total surface area. Pore water silica concentration increases linearly with depth. On a molar basis, between one and three quarters of pore water silica is derived from quartz with the remainder contributed from biotite weathering. Average solute Si remains thermodynamically undersaturated with respect to recently revised estimates of quartz solubility (17-81 ??M). Etch pitting is more abundant on grains in the upper saprolite and is associated with pore waters lower in dissolved silica. Rate constants describing quartz dissolution increase with decreasing depth (from 10-14.5-10-15.1 mol m-2 s-1), which correlate with both greater thermodynamic undersaturation and increasing etch pit densities. Unlike for many aluminosilicates, the calculated natural weathering rates of quartz fall slightly below the rate constants previously reported for experimental studies (10-12.4-10-14.2 mol m-2 s-1). This agreement reflects the structural simplicity of quartz, dilute solutes, and near-hydrologic saturation.

Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas.

PubMed

May, Randal; Sureban, Sripathi M; Lightfoot, Stan A; Hoskins, Aimee B; Brackett, Daniel J; Postier, Russell G; Ramanujam, Rama; Rao, Chinthalapally V; Wyche, James H; Anant, Shrikant; Houchen, Courtney W

2010-08-01

Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer.

Identification of a novel putative pancreatic stem/progenitor cell marker DCAMKL-1 in normal mouse pancreas

PubMed Central

May, Randal; Sureban, Sripathi M.; Lightfoot, Stan A.; Hoskins, Aimee B.; Brackett, Daniel J.; Postier, Russell G.; Ramanujam, Rama; Rao, Chinthalapally V.; Wyche, James H.; Anant, Shrikant

2010-01-01

Stem cells are critical in maintaining adult homeostasis and have been proposed to be the origin of many solid tumors, including pancreatic cancer. Here we demonstrate the expression patterns of the putative intestinal stem cell marker DCAMKL-1 in the pancreas of uninjured C57BL/6 mice compared with other pancreatic stem/progenitor cell markers. We then determined the viability of isolated pancreatic stem/progenitor cells in isotransplantation assays following DCAMKL-1 antibody-based cell sorting. Sorted cells were grown in suspension culture and injected into the flanks of athymic nude mice. Here we report that DCAMKL-1 is expressed in the main pancreatic duct epithelia and islets, but not within acinar cells. Coexpression was observed with somatostatin, NGN3, and nestin, but not glucagon or insulin. Isolated DCAMKL-1+ cells formed spheroids in suspension culture and induced nodule formation in isotransplantation assays. Analysis of nodules demonstrated markers of early pancreatic development (PDX-1), glandular epithelium (cytokeratin-14 and Ep-CAM), and isletlike structures (somatostatin and secretin). These data taken together suggest that DCAMKL-1 is a novel putative stem/progenitor marker, can be used to isolate normal pancreatic stem/progenitors, and potentially regenerates pancreatic tissues. This may represent a novel tool for regenerative medicine and a target for anti-stem cell-based therapeutics in pancreatic cancer. PMID:20522640

Isolation and morphology of Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC)

NASA Astrophysics Data System (ADS)

Ariffin, Shahrul Hisham Zainal; Manogaran, Thanaletchumi; Abidin, Intan Zarina Zainol; Senafi, Sahidan; Wahab, Rohaya Megat Abdul

2016-11-01

Dental pulp is a tissue obtained from pulp chamber of deciduous and permanent tooth which contain stem cells. Stem cell isolation procedure is performed to obtain cells from tissue using enzymatic digestion. The aim of this study is to isolate and observe the morphology of stem cells during passage 0 and passage 3. Dental pulp from deciduous and permanent tooth was enzymatically digested using collagenase Type I and cells obtained were cultured in DMEM-KO that contains 10% fetal bovine serum, 1% antibiotic-antimycotic solution and 0.001× GlutaMax®. During culture, cell morphology was observed under the microscope on day 3, 16 and 33 and captured using cellB software. Giemsa staining was conducted on cells at passage 3. Cells attached at the bottom of the flask on day 3 and started forming small colonies. Cells became confluent after approximately 4 weeks. Both Stem Cells from Deciduous Tooth (SHED) and Human Dental Pulp Stem Cells (hDPSC) exhibited fibroblast-like morphology during passage 0 and passage 3. Meanwhile, Giemsa staining at passage 3 revealed single intact nucleus surrounded by fibroblastic cytoplasm structure. It can be concluded that SHED and hDPSC showed consistent fibroblast-like morphology throughout culture period.

Identification of Multipotent Stem Cells in Human Brain Tissue Following Stroke.

PubMed

Tatebayashi, Kotaro; Tanaka, Yasue; Nakano-Doi, Akiko; Sakuma, Rika; Kamachi, Saeko; Shirakawa, Manabu; Uchida, Kazutaka; Kageyama, Hiroto; Takagi, Toshinori; Yoshimura, Shinichi; Matsuyama, Tomohiro; Nakagomi, Takayuki

2017-06-01

Perivascular regions of the brain harbor multipotent stem cells. We previously demonstrated that brain pericytes near blood vessels also develop multipotency following experimental ischemia in mice and these ischemia-induced multipotent stem cells (iSCs) can contribute to neurogenesis. However, it is essential to understand the traits of iSCs in the poststroke human brain for possible applications in stem cell-based therapies for stroke patients. In this study, we report for the first time that iSCs can be isolated from the poststroke human brain. Putative iSCs were derived from poststroke brain tissue obtained from elderly stroke patients requiring decompressive craniectomy and partial lobectomy for diffuse cerebral infarction. Immunohistochemistry showed that these iSCs were localized near blood vessels within poststroke areas containing apoptotic/necrotic neurons and expressed both the stem cell marker nestin and several pericytic markers. Isolated iSCs expressed these same markers and demonstrated high proliferative potential without loss of stemness. Furthermore, isolated iSCs expressed other stem cell markers, such as Sox2, c-myc, and Klf4, and differentiated into multiple cells in vitro, including neurons. These results show that iSCs, which are likely brain pericyte derivatives, are present within the poststroke human brain. This study suggests that iSCs can contribute to neural repair in patients with stroke.

Stem cells from fetal membranes and amniotic fluid: markers for cell isolation and therapy.

PubMed

Pozzobon, Michela; Piccoli, Martina; De Coppi, Paolo

2014-06-01

Stem cell therapy is in constant need of new cell sources to conceive regenerative medicine approaches for diseases that are still without therapy. Scientists drew the attention toward amniotic membrane and amniotic fluid stem cells, since these sources possess many advantages: first of all as cells can be extracted from discarded foetal material it is inexpensive, secondly abundant stem cells can be obtained and finally, these stem cell sources are free from ethical considerations. Many studies have demonstrated the differentiation potential in vitro and in vivo toward mesenchymal and non-mesenchymal cell types; in addition the immune-modulatory properties make these cells a good candidate for allo- and xenotransplantation. This review offers an overview on markers characterisation and on the latest findings in pre-clinical or clinical setting of the stem cell populations isolated from these sources.

Pediatric Glioblastoma Therapies Based on Patient-Derived Stem Cell Resources

DTIC Science & Technology

2013-10-01

stem cell lines have been successfully isolated from adults, in this proposal we aim to isolate and characterize GSC populations from pediatric patients. In the past two years we have successfully derived and cultured eight patient-derived pediatric glioma stem cell lines. In the past year we have continued molecular and phenotypic characterization of these lines. This characterization included analysis of gene expression and patient-specific gene mutations, and also proof-of-concept shRNA screens. In addition we have begun to identify candidate

A putative mesenchymal stem cells population isolated from adult human testes.

PubMed

Gonzalez, R; Griparic, L; Vargas, V; Burgee, K; Santacruz, P; Anderson, R; Schiewe, M; Silva, F; Patel, A

2009-08-07

Mesenchymal stem cells (MSCs) isolated from several adult human tissues are reported to be a promising tool for regenerative medicine. In order to broaden the array of tools for therapeutic application, we isolated a new population of cells from adult human testis termed gonadal stem cells (GSCs). GSCs express CD105, CD166, CD73, CD90, STRO-1 and lack hematopoietic markers CD34, CD45, and HLA-DR which are characteristic identifiers of MSCs. In addition, GSCs express pluripotent markers Oct4, Nanog, and SSEA-4. GSCs propagated for at least 64 population doublings and exhibited clonogenic capability. GSCs have a broad plasticity and the potential to differentiate into adipogenic, osteogenic, and chondrogenic cells. These studies demonstrate that GSCs are easily obtainable stem cells, have growth kinetics and marker expression similar to MSCs, and differentiate into mesodermal lineage cells. Therefore, GSCs may be a valuable tool for therapeutic applications.

A sequence in the rat Pit-1 gene promoter confers synergistic activation by glucocorticoids and protein kinase-C.

PubMed

Jong, M T; Raaka, B M; Samuels, H H

1994-10-01

The 5'-flanking region of the gene for Pit-1, a pituitary-specific transcription factor, was isolated from a rat liver genomic library and sequenced. Expression of a reporter construct containing Pit-1 promoter sequences linked to the bacterial chloramphenicol acetyltransferase (CAT) gene was assessed by transient transfection in rat pituitary GH4C1 cells. Treatment of transfected cells with either dexamethasone (DEX) for 48 h or the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) for the final 20 h of the 48-h posttransfection period had minimal effects on CAT expression. However, CAT activity was elevated about 20-fold when transfected cells were treated with both DEX and TPA. This apparent synergistic activation was lost when DEX treatment was also limited to the final 20 h of the 48-h posttransfection period, suggesting that a time-dependent accumulation of a DEX-induced gene product might be involved. This putative DEX-induced product appeared to be relatively stable, because synergistic activation was observed in cells treated with DEX alone for 36 h, followed by a 10-h incubation without DEX before the addition of TPA. The Pit-1 gene promoter region between -210 and -142 from the transcription start site conferred synergistic regulation by DEX and TPA when placed upstream of position -105 in the herpes viral thymidine kinase promoter.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of electroviscosity on the hydraulic conductance of the bordered pit membrane: a theoretical investigation.

PubMed

Santiago, Michael; Pagay, Vinay; Stroock, Abraham D

2013-10-01

In perfusion experiments, the hydraulic conductance of stem segments ( ) responds to changes in the properties of the perfusate, such as the ionic strength ( ), pH, and cationic identity. We review the experimental and theoretical work on this phenomenon. We then proceed to explore the hypothesis that electrokinetic effects in the bordered pit membrane (BPM) contribute to this response. In particular, we develop a model based on electroviscosity in which hydraulic conductance of an electrically charged porous membrane varies with the properties of the electrolyte. We use standard electrokinetic theory, coupled with measurements of electrokinetic properties of plant materials from the literature, to determine how the conductance of BPMs, and therefore , may change due to electroviscosity. We predict a nonmonotonic variation of with with a maximum reduction of 18%. We explore how this reduction depends on the characteristics of the sap and features of the BPM, such as pore size, density of chargeable sites, and their dissociation constant. Our predictions are consistent with changes in observed for physiological values of sap and pH. We conclude that electroviscosity is likely responsible, at least partially, for the electrolyte dependence of conductance through pits and that electroviscosity may be strong enough to play an important role in other transport processes in xylem. We conclude by proposing experiments to differentiate the impact of electroviscosity on from that of other proposed mechanisms.

From "ES-like" cells to induced pluripotent stem cells: a historical perspective in domestic animals.

PubMed

Koh, Sehwon; Piedrahita, Jorge A

2014-01-01

Pluripotent stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) provide great potential as cell sources for gene editing to generate genetically modified animals, as well as in the field of regenerative medicine. Stable, long-term ESCs have been established in laboratory mouse and rat; however, isolation of true pluripotent ESCs in domesticated animals such as pigs and dogs have been less successful. Initially, domesticated animal pluripotent cell lines were referred to as "embryonic stem-like" cells owing to their similar morphologic characteristics to mouse ESCs, but accompanied by a limited ability to proliferate in vitro in an undifferentiated state. That is, they shared some but not all the characteristics of true ESCs. More recently, advances in reprogramming using exogenous transcription factors, combined with the utilization of small chemical inhibitors of key biochemical pathways, have led to the isolation of iPSCs. In this review, we provide a historical perspective of the isolation of various types of pluripotent stem cells in domesticated animals. In addition, we summarize the latest progress and limitations in the derivation and application of iPSCs. Copyright © 2014 Elsevier Inc. All rights reserved.

Preclinical Assessment of the Proliferation Capacity of Gingival and Periodontal Ligament Stem Cells from Diabetic Patients.

PubMed

Assem, Mostafa; Kamal, Samia; Sabry, Dina; Soliman, Nadia; Aly, Riham M

2018-02-15

Stem cells have recently received great interest as potential therapeutics alternative for a variety of diseases. The oral and maxillofacial region, in particular, encompasses a variety of distinctive mesenchymal (MSC) populations and is characterized by a potent multilineage differentiation capacity. In this report, we aimed to investigate the effect of diabetes on the proliferation potential of stem cells isolated from controlled diabetic patients (type 2) and healthy individuals. The proliferation rate of gingival and periodontal derived stem cells isolated from diabetic & healthy individuals were compared using MTT Assay. Expression levels of Survivin in isolated stem cells from all groups were measured by qRt - PCR. There was a significantly positive correlation between proliferation rate and expression of Survivin in all groups which sheds light on the importance of Survivin as a reliable indicator of proliferation. The expression of Survivin further confirmed the proliferation results from MTT Assay where the expression of stem cells from non - diabetic individuals was higher than diabetic patients. Taking together all the results, it could be concluded that PDLSC and GSC are promising candidates for autologous regenerative therapy due to their ease of accessibility in addition to their high proliferative rates.

Lycopersicon esculentum lectin is a marker of transient amplifying cells in in vitro cultures of isolated limbal stem cells.

PubMed

Vergallo, C; Fonseca, T; Pizzi, G; Dini, L

2010-08-01

The maintenance of a healthy corneal epithelium under both normal and wound healing conditions is achieved by a population of stem cells (SCs) located in the basal epithelium at the corneoscleral limbus. In the light of the development of strategies for reconstruction of the ocular surface in patients with limbal stem cell deficiency, a major challenge in corneal SCs biology remains the ability to identify stem cells in situ and in vitro. To date, not so much markers exist for the identification of different phenotypes. CESCs (corneal epithelial stem cells) isolated from limbal biopsies were maintained in primary culture for 14 days and stained with Hoechst and a panel of FITC-conjugated lectins. All lectins, with the exception of Lycopersicon esculentum, labelled CESCs irrespective of the degree of differentiation. Lycopersicon esculentum, that binds N-acetylglucosamine oligomers, labelled intensely only the surface of TACs (single corneal epithelial stem cells better than colonial cells). These results suggest that Lycopersicon esculentum lectin is a useful and easy-to-use marker for the in vitro identification of TACs (transient amplifying cells) in cultures of isolated CESCs. Copyright 2010. Published by Elsevier Ltd.

Enhanced adipogenic differentiation of bovine bone marrow-derived mesenchymal stem cells

USDA-ARS?s Scientific Manuscript database

Until now, the isolation and characterization of bovine bone marrow-derived mesenchymal stem cells (bBM-MSCs) have not been established, which prompted us to optimize the differentiation protocol for bBM-MSCs. In this study, bBM-MSCs were freshly isolated from three 6-month-old cattle and used for p...

Prospective Isolation and Comparison of Human Germinal Matrix and Glioblastoma EGFR+ Populations with Stem Cell Properties.

PubMed

Tome-Garcia, Jessica; Tejero, Rut; Nudelman, German; Yong, Raymund L; Sebra, Robert; Wang, Huaien; Fowkes, Mary; Magid, Margret; Walsh, Martin; Silva-Vargas, Violeta; Zaslavsky, Elena; Friedel, Roland H; Doetsch, Fiona; Tsankova, Nadejda M

2017-05-09

Characterization of non-neoplastic and malignant human stem cell populations in their native state can provide new insights into gliomagenesis. Here we developed a purification strategy to directly isolate EGFR +/- populations from human germinal matrix (GM) and adult subventricular zone autopsy tissues, and from de novo glioblastoma (GBM) resections, enriching for cells capable of binding EGF ligand ( LB EGFR + ), and uniquely compared their functional and molecular properties. LB EGFR + populations in both GM and GBM encompassed all sphere-forming cells and displayed proliferative stem cell properties in vitro. In xenografts, LB EGFR + GBM cells showed robust tumor initiation and progression to high-grade, infiltrative gliomas. Whole-transcriptome sequencing analysis confirmed enrichment of proliferative pathways in both developing and neoplastic freshly isolated EGFR + populations, and identified both unique and shared sets of genes. The ability to prospectively isolate stem cell populations using native ligand-binding capacity opens new doors onto understanding both normal human development and tumor cell biology. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Predictors of anxiety and depression in hematopoietic stem cell transplant patients during protective isolation.

PubMed

Tecchio, Cristina; Bonetto, Chiara; Bertani, Mariaelena; Cristofalo, Doriana; Lasalvia, Antonio; Nichele, Ilaria; Bonani, Anna; Andreini, Angelo; Benedetti, Fabio; Ruggeri, Mirella; Pizzolo, Giovanni

2013-08-01

To examine in a sample of hematopoietic stem cell transplant patients assessed throughout protective isolation (i) levels of anxiety and depression and (ii) pre-isolation factors (socio-demographics, biomedical variables and personality traits), which might predict higher levels of anxiety and depression during isolation. The study used a longitudinal prospective design. Anxiety and depression were assessed in 107 participants by the State-Trait Anxiety Inventory and Self-rating Depression Scale at admission and weekly at fixed time points throughout isolation. Among pre-isolation factors, patients' psychological status was evaluated by the Cognitive Behavioral Assessment (2.0). Predictors were explored by random-effects models. One-tenth of the patients suffered from clinically significant anxiety and depressive symptoms at admission. Although the percentage of depressed patients increased more than twofold after 2 weeks of isolation, that of anxious patients did not significantly change over time. Female gender, higher anxiety and obsessive-compulsive symptoms, intratensive personality traits and lower performance status predicted higher depression during isolation. Anxiety and depression represent a relevant problem for hematopoietic stem cell transplant patients during isolation. Early detection of predictors, such as anxiety levels, obsessive-compulsive symptoms and performance status, could help prevent depression via targeted psychological intervention. Copyright © 2012 John Wiley & Sons, Ltd.

The Use Of Laser Irradiation To Stimulate Adipose Derived Stem Cell Proliferation And Differentiation For Use In Autologous Grafts

NASA Astrophysics Data System (ADS)

Abrahamse, Heidi

2009-09-01

Stem cells are characterized by the qualities of self-renewal, long term viability, and the ability to differentiate into various cell types. Historically, stem cells have been isolated from the inner cell mass of blastocysts and harvesting these cells resulted in the death of the embryo leading to religious, political and ethical issues. The identification and subsequent isolation of adult stem cells from bone marrow stroma have been welcomed as an alternate source for stem cells. The clinical use of Mesenchymal Stem Cells (MSCs) presented problems such as limited cell number, pain and morbidity upon isolation. Adipose tissue is derived from the mesenchyme, is easily isolated, a reliable source of stem cells and able to differentiate into different cell types including smooth muscle. Over the past few years, the identification and characterization of stem cells has led the potential use of these cells as a promising alternative to cell replacement therapy. Smooth muscle is a major component of human tissues and is essential for the normal functioning of many different organs. Low intensity laser irradiation has been shown to increase viability, protein expression and migration of stem cells in vitro, and to stimulate proliferation of various types of stem cells. In addition, the use of laser irradiation to stimulate differentiation in the absence of growth factors has also been demonstrated in normal human neural progenitor cells (NHNPCs) in vitro where NHNPCs are not only capable of being sustained by light in the absence of growth factors, but that they are also able to differentiate normally as assessed by neurite formation. Our work has focused on the ability of laser irradiation to proliferate adipose derived stem cells (ADSCs), maintain ADSC character and increase the rate and maintenance of differentiation of ADSCs into smooth muscle and skin fibroblast cells. Current studies are also investigating the effect of different irradiation wavelengths and fluences on ADSC viability and proliferation. This paper reviews the development of MSCs as potential therapeutic interventions such as autologous grafts as well as the contribution of low intensity laser irradiation on the maintenance of these cells.

A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells

PubMed Central

Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang

2015-01-01

Abstract Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies. PMID:25556695

Stem cell isolation by a morphology-based selection method in postnatal mouse ovary.

PubMed

Parvari, Soraya; Abbasi, Mehdi; Abbasi, Niloufar; Malek, Valliollah Gerayeli; Amidi, Fardin; Aval, Fereydoon Sargolzaei; Roudkenar, Mehryar Habibi; Izadyar, Fariburz

2015-06-19

An increasing body of evidence has emerged regarding the existence and function of spermatogonial stem cells (SSCs); however, their female counterparts are the subject of extensive debate. Theoretically, ovarian germ stem cells (GSCs) have to reside in the murine ovary to support and replenish the follicle pool during the reproductive life span. Recently, various methods have been recruited to isolate and describe aspects of ovarian GSCs, but newer and more convenient strategies in isolation are still growing. Herein, a morphology-based method was used to isolate GSCs. A cell suspension of mouse neonatal ovaries was cultured. Colonies of GSCs were harvested mechanically and cultivated on mouse embryonic fibroblasts (MEF). Alkaline phosphatase activity was assessed to verify stemness features of cells in colonies. Expression of germ and stem cell specific genes (Oct-4, Nanog, Fragilis, C-kit, Dazl, and Mvh) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Immunofluorescence of Oct4, Dazl, Mvh, and SSEA-1 was also performed. Small colonies without a clear border appeared during the first 4 days of culture, and the size of colonies increased rapidly. Cells in colonies were positive for alkaline phosphatase activity. Reverse transcription-polymerase chain reaction showed that Oct-4, Fragilis, C-kit, Nanog, Mvh, and Dazl were expressed in colony-forming cells. Immunofluorescence revealed a positive signal for Oct4, Dazl, Mvh, and SSEA-1 in colonies as well. The applicability of morphological selection for isolation of GSCs was verified. This method is easier and more economical than other techniques. The availability of ovarian stem cells can motivate further studies in development of oocyte and cell-based therapies.

Stem cell isolation by a morphology-based selection method in postnatal mouse ovary

PubMed Central

Parvari, Soraya; Abbasi, Niloufar; Malek, Valliollah Gerayeli; Amidi, Fardin; Aval, Fereydoon Sargolzaei; Roudkenar, Mehryar Habibi; Izadyar, Fariburz

2015-01-01

Introduction An increasing body of evidence has emerged regarding the existence and function of spermatogonial stem cells (SSCs); however, their female counterparts are the subject of extensive debate. Theoretically, ovarian germ stem cells (GSCs) have to reside in the murine ovary to support and replenish the follicle pool during the reproductive life span. Recently, various methods have been recruited to isolate and describe aspects of ovarian GSCs, but newer and more convenient strategies in isolation are still growing. Herein, a morphology-based method was used to isolate GSCs. Material and methods A cell suspension of mouse neonatal ovaries was cultured. Colonies of GSCs were harvested mechanically and cultivated on mouse embryonic fibroblasts (MEF). Alkaline phosphatase activity was assessed to verify stemness features of cells in colonies. Expression of germ and stem cell specific genes (Oct-4, Nanog, Fragilis, C-kit, Dazl, and Mvh) was analyzed by reverse transcription-polymerase chain reaction (RT-PCR). Immunofluorescence of Oct4, Dazl, Mvh, and SSEA-1 was also performed. Results Small colonies without a clear border appeared during the first 4 days of culture, and the size of colonies increased rapidly. Cells in colonies were positive for alkaline phosphatase activity. Reverse transcription-polymerase chain reaction showed that Oct-4, Fragilis, C-kit, Nanog, Mvh, and Dazl were expressed in colony-forming cells. Immunofluorescence revealed a positive signal for Oct4, Dazl, Mvh, and SSEA-1 in colonies as well. Conclusions The applicability of morphological selection for isolation of GSCs was verified. This method is easier and more economical than other techniques. The availability of ovarian stem cells can motivate further studies in development of oocyte and cell-based therapies. PMID:26170863

A Convenient and Efficient Method to Enrich and Maintain Highly Proliferative Human Fetal Liver Stem Cells.

PubMed

Guo, Xuan; Wang, Shu; Dou, Ya-ling; Guo, Xiang-fei; Chen, Zhao-li; Wang, Xin-wei; Shen, Zhi-qiang; Qiu, Zhi-gang; Jin, Min; Li, Jun-wen

2015-06-01

Pluripotent human hepatic stem cells have broad research and clinical applications, which are, however, restricted by both limited resources and technical difficulties with respect to isolation of stem cells from the adult or fetal liver. In this study, we developed a convenient and efficient method involving a two-step in situ collagenase perfusion, gravity sedimentation, and Percoll density gradient centrifugation to enrich and maintain highly proliferative human fetal liver stem cells (hFLSCs). Using this method, the isolated hFLSCs entered into the exponential growth phase within 10 days and maintained sufficient proliferative activity to permit subculture for at least 20 passages without differentiation. Immunocytochemistry, immunofluorescence, and flow cytometry results showed that these cells expressed stem cell markers, such as c-kit, CD44, epithelial cell adhesion molecule (EpCAM), oval cell marker-6 (OV-6), epithelial marker cytokeratin 18 (CK18), biliary ductal marker CK19, and alpha-fetoprotein (AFP). Gene expression analysis showed that these cells had stable mRNA expression of c-Kit, EpCAM, neural cell adhesion molecule (NCAM), CK19, CK18, AFP, and claudin 3 (CLDN-3) throughout each passage while maintaining low levels of ALB, but with complete absence of cytochrome P450 3A4 (C3A4), phosphoenolpyruvate carboxykinase (PEPCK), telomeric repeat binding factor (TRF), and connexin 26 (CX26) expression. When grown in appropriate medium, these isolated liver stem cells could differentiate into hepatocytes, cholangiocytes, osteoblasts, adipocytes, or endothelial cells. Thus, we have demonstrated a more economical and efficient method to isolate hFLSCs than magnetic-activated cell sorting (MACS). This novel approach may provide an excellent tool to isolate highly proliferative hFLSCs for tissue engineering and regenerative therapies.

Simultaneous isolation of vascular endothelial cells and mesenchymal stem cells from the human umbilical cord.

PubMed

Kadam, Sachin S; Tiwari, Shubha; Bhonde, Ramesh R

2009-01-01

The umbilical cord represents the link between mother and fetus during pregnancy. This cord is usually discarded as a biological waste after the child's birth; however, its importance as a "store house" of stem cells has been explored recently. We developed a method of simultaneous isolation of endothelial cells (ECs) from the vein and mesenchymal stem cells from umbilical cord Wharton's jelly of the same cord. The isolation protocol has been simplified, modified, and improvised with respect to choice of enzyme and enzyme mixture, digestion time, cell yield, cell growth, and culture medium. Isolated human umbilical vascular ECs (hUVECs) were positive for von-Willibrand factor, a classical endothelial marker, and could form capillary-like structures when seeded on Matrigel, thus proving their functionality. The isolated human umbilical cord mesenchymal stem cells (hUCMSCs) were found positive for CD44, CD90, CD 73, and CD117 and were found negative for CD33, CD34, CD45, and CD105 surface markers; they were also positive for cytoskeleton markers of smooth muscle actin and vimentin. The hUCMSCs showed multilineage differentiation potential and differentiated into adipogenic, chondrogenic, osteogenic, and neuronal lineages under influence of lineage specific differentiation medium. Thus, isolating endothelial cells as well as mesenchymal cells from the same umbilical cord could lead to complete utilization of the available tissue for the tissue engineering and cell therapy.

Parthenogenesis-derived Multipotent Stem Cells Adapted for Tissue Engineering Applications

PubMed Central

Koh, Chester J.; Delo, Dawn M.; Lee, Jang Won; Siddiqui, M. Minhaj; Lanza, Robert P.; Soker, Shay; Yoo, James J.; Atala, Anthony

2009-01-01

Embryonic stem cells are envisioned as a viable source of pluripotent cells for use in regenerative medicine applications when donor tissue is not available. However, most current harvest techniques for embryonic stem cells require the destruction of embryos, which has led to significant political and ethical limitations on their usage. Parthenogenesis, the process by which an egg can develop into an embryo in the absence of sperm, may be a potential source of embryonic stem cells that may avoid some of the political and ethical concerns surrounding embryonic stem cells. Here we provide the technical aspects of embryonic stem cell isolation and expansion from the parthenogenetic activation of oocytes. These cells were characterized for their stem-cell properties. In addition, these cells were induced to differentiate to the myogenic, osteogenic, adipogenic, and endothelial lineages, and were able to form muscle-like and bony-like tissue in vivo. Furthermore, parthenogenetic stem cells were able to integrate into injured muscle tissue. Together, these results demonstrate that parthenogenetic stem cells can be successfully isolated and utilized for various tissue engineering applications. PMID:18799133

[Isolation and identification of human periodontal ligament stem cells in vitro].

PubMed

Shen, Tao; Chang, Hui-jun; Jian, Cong-xiang; Yang, Yan-chun; Zhou, Ji-xiang

2011-02-01

To isolate and identify human periodontal ligament stem cells (PDLSC) by improved methods and assess the characteristics of PDLSC ex vivo. The periodontal ligament cells were obtained from the healthy impacted third molars and teeth extracted for orthodontic purposes and used to isolate PDLSC by limiting dilution assay. PDLSC were cultured and expanded in alpha-MEM supplemented with 10% FBS. Colony-forming assay, immunohistochemistry, flow cytometry, osteogenic and adipogenic induction were used to identify PDLSC. The obtained cells had high colony-forming efficiency and were positive staining for vimentin and negative for pancytokeratin. Flow cytometry revealed that the isolated cells were positive for STRO-1 and CD146 antibodies and most were in the G0/G1 phase of cell cycle. Under specific conditions, they could differentiate to the osteoblast and adipocyte lineages in vitro. Limiting dilution assay is an effective method to isolate PDLSC and the single-cell-derived colonies demonstrate the properties of stem cells in vitro.

Ground Zero in the Debate over Stem-Cell Research.

ERIC Educational Resources Information Center

Southwick, Ron

2001-01-01

Describes how political, legal, and ethical battles over embryonic stem-cell research are focused on the University of Wisconsin at Madison, where the cells were first isolated. Addresses the issue of access to the university's stem cells and a recent presidential decision regarding funding for stem-cell research.(EV)

Isolation and characterisation of cancer stem cells from canine osteosarcoma.

PubMed

Wilson, H; Huelsmeyer, M; Chun, R; Young, K M; Friedrichs, K; Argyle, D J

2008-01-01

There is increasing evidence that cancer is a stem cell disease. This study sought to isolate and characterise cancer stem cells from canine osteosarcoma. One human and three canine cell lines were cultured in non-adherent culture conditions using serum-starved, semi-solid media. Primitive sarcosphere colonies from all cell lines were identified under these conditions and were characterised using molecular and cytochemical techniques for embryonic stem cell markers. Expression of the embryonic stem cell-associated genes Nanog, Oct4 and STAT3 indicated a primitive phenotype. Sarcospheres could be reproduced consistently when passaged multiple times and produced adherent cell cultures when returned to normal growth conditions. Similarities between human and canine osteosarcoma cell lines add credence to the potential of the dog as a model for human disease.

The epithelial-mesenchymal transition generates cells with properties of stem cells.

PubMed

Mani, Sendurai A; Guo, Wenjun; Liao, Mai-Jing; Eaton, Elinor Ng; Ayyanan, Ayyakkannu; Zhou, Alicia Y; Brooks, Mary; Reinhard, Ferenc; Zhang, Cheng Cheng; Shipitsin, Michail; Campbell, Lauren L; Polyak, Kornelia; Brisken, Cathrin; Yang, Jing; Weinberg, Robert A

2008-05-16

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer invasion and metastasis. We here report that the induction of an EMT in immortalized human mammary epithelial cells (HMLEs) results in the acquisition of mesenchymal traits and in the expression of stem-cell markers. Furthermore, we show that those cells have an increased ability to form mammospheres, a property associated with mammary epithelial stem cells. Independent of this, stem cell-like cells isolated from HMLE cultures form mammospheres and express markers similar to those of HMLEs that have undergone an EMT. Moreover, stem-like cells isolated either from mouse or human mammary glands or mammary carcinomas express EMT markers. Finally, transformed human mammary epithelial cells that have undergone an EMT form mammospheres, soft agar colonies, and tumors more efficiently. These findings illustrate a direct link between the EMT and the gain of epithelial stem cell properties.

Isolation and characterization of string-forming female germline stem cells from ovaries of neonatal mice.

PubMed

Liu, Jing; Shang, Dantong; Xiao, Yao; Zhong, Pei; Cheng, Hanhua; Zhou, Rongjia

2017-09-29

Germline stem cells are essential in the generation of both male and female gametes. In mammals, the male testis produces sperm throughout the entire lifetime, facilitated by testicular germline stem cells. Oocyte renewal ceases in postnatal or adult life in mammalian females, suggesting that germline stem cells are absent from the mammalian ovary. However, studies in mice, rats, and humans have recently provided evidence for ovarian female germline stem cells (FGSCs). A better understanding of the role of FGSCs in ovaries could help improve fertility treatments. Here, we developed a rapid and efficient method for isolating FGSCs from ovaries of neonatal mice. Notably, our FGSC isolation method could efficiently isolate on average 15 cell "strings" per ovary from mice at 1-3 days postpartum. FGSCs isolated from neonatal mice displayed the string-forming cell configuration at mitosis ( i.e. a "stringing" FGSC (sFGSC) phenotype) and a disperse phenotype in postnatal mice. We also found that sFGSCs undergo vigorous mitosis especially at 1-3 days postpartum. After cell division, the sFGSC membranes tended to be connected to form sFGSCs. Moreover, F-actin filaments exhibited a cell-cortex distribution in sFGSCs, and E-cadherin converged in cell-cell connection regions, resulting in the string-forming morphology. Our new method provides a platform for isolating FGSCs from the neonatal ovary, and our findings indicate that FGCSs exhibit string-forming features in neonatal mice. The sFGSCs represent a valuable resource for analysis of ovary function and an in vitro model for future clinical use to address ovarian dysfunction. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Stemness of spermatogonial stem cells encapsulated in alginate hydrogel during cryopreservation.

PubMed

Pirnia, A; Parivar, K; Hemadi, M; Yaghmaei, P; Gholami, M

2017-06-01

This study investigated the effect of spermatogonial stem cell encapsulated in alginate hydrogel during cryopreservation, as cells were protected against damage during cryopreservation within the hydrogel. Spermatogonial stem cells were isolated from the testes of Balb/c mice pups (6 days old), purified in laminin-coated dishes and CD90.1 microbeads, encapsulated in alginate hydrogel and then cryopreserved. After thawing, cell viability and Spermatogonial stem cell (SSC) colony diameter were evaluated. After RNA was isolated and cDNA was synthesised, the expression of stemness genes was considered using RT real-time PCR. Finally, spermatogonial stem cells labelled with BrdU were transplanted to busulfan azoospermic mouse models. Lin28a and Sall4 genes were significantly upregulated after cryopreservation in alginate hydrogel. However, cell viability was significantly decreased. The diameter of colonies consisting of spermatogonial stem cells freeze-thawed in alginate microbeads showed no significant difference with fresh spermatogonial stem cells and the control group. The injection of freeze-thawed spermatogonial stem cells encapsulated in alginate hydrogel resulted in spermatogenesis recovery. Alginate mimics the extracellular matrices (ECM) for spermatogonial stem cells; therefore, it can support stemness potential during the cell cryopreservation process and restart spermatogenesis after transplantation. © 2016 Blackwell Verlag GmbH.

Gastric Lgr5+ stem cells are the cellular origin of invasive intestinal-type gastric cancer in mice

PubMed Central

Li, Xiu-Bin; Yang, Guan; Zhu, Liang; Tang, Yu-Ling; Zhang, Chong; Ju, Zhenyu; Yang, Xiao; Teng, Yan

2016-01-01

The cellular origin of gastric cancer remains elusive. Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is the first identified marker of gastric stem cells. However, the role of Lgr5+ stem cells in driving malignant gastric cancer is not fully validated. Here, we deleted Smad4 and PTEN in murine gastric Lgr5+ stem cells by the inducible Cre-LoxP system and marked mutant Lgr5+ stem cells and their progeny with Cre-reporter Rosa26tdTomato. Rapid onset and progression from microadenoma and macroscopic adenoma to invasive intestinal-type gastric cancer (IGC) were found in the gastric antrum with the loss of Smad4 and PTEN. In addition, invasive IGC developed at the murine gastro-forestomach junction, where a few Lgr5+ stem cells reside. In contrast, Smad4 and PTEN deletions in differentiated cells, including antral parietal cells, pit cells and corpus Lgr5+ chief cells, failed to initiate tumor growth. Furthermore, mutant Lgr5+ cells were involved in IGC growth and progression. In the TCGA (The Cancer Genome Atlas) database, an increase in LGR5 expression was manifested in the human IGC that occurred at the gastric antrum and gastro-esophageal junction. In addition, the concurrent deletion of SMAD4 and PTEN, as well as their reduced expression and deregulated downstream pathways, were associated with human IGC. Thus, we demonstrated that gastric Lgr5+ stem cells were cancer-initiating cells and might act as cancer-propagating cells to contribute to malignant progression. PMID:27091432

Gastric Lgr5(+) stem cells are the cellular origin of invasive intestinal-type gastric cancer in mice.

PubMed

Li, Xiu-Bin; Yang, Guan; Zhu, Liang; Tang, Yu-Ling; Zhang, Chong; Ju, Zhenyu; Yang, Xiao; Teng, Yan

2016-07-01

The cellular origin of gastric cancer remains elusive. Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is the first identified marker of gastric stem cells. However, the role of Lgr5(+) stem cells in driving malignant gastric cancer is not fully validated. Here, we deleted Smad4 and PTEN in murine gastric Lgr5(+) stem cells by the inducible Cre-LoxP system and marked mutant Lgr5(+) stem cells and their progeny with Cre-reporter Rosa26(tdTomato). Rapid onset and progression from microadenoma and macroscopic adenoma to invasive intestinal-type gastric cancer (IGC) were found in the gastric antrum with the loss of Smad4 and PTEN. In addition, invasive IGC developed at the murine gastro-forestomach junction, where a few Lgr5(+) stem cells reside. In contrast, Smad4 and PTEN deletions in differentiated cells, including antral parietal cells, pit cells and corpus Lgr5(+) chief cells, failed to initiate tumor growth. Furthermore, mutant Lgr5(+) cells were involved in IGC growth and progression. In the TCGA (The Cancer Genome Atlas) database, an increase in LGR5 expression was manifested in the human IGC that occurred at the gastric antrum and gastro-esophageal junction. In addition, the concurrent deletion of SMAD4 and PTEN, as well as their reduced expression and deregulated downstream pathways, were associated with human IGC. Thus, we demonstrated that gastric Lgr5(+) stem cells were cancer-initiating cells and might act as cancer-propagating cells to contribute to malignant progression.

Isolation and functional assessment of cutaneous stem cells.

PubMed

Doucet, Yanne S; Owens, David M

2015-01-01

The epidermis and associated appendages of the skin represent a multi-lineage tissue that is maintained by perpetual rounds of renewal. During homeostasis, turnover of epidermal lineages is achieved by input from regionalized keratinocytes stem or progenitor populations with little overlap from neighboring niches. Over the last decade, molecular markers selectively expressed by a number of these stem or progenitor pools have been identified, allowing for the isolation and functional assessment of stem cells and genetic lineage tracing analysis within intact skin. These advancements have led to many fundamental observations about epidermal stem cell function such as the identification of their progeny, their role in maintenance of skin homeostasis, or their contribution to wound healing. In this chapter, we provide a methodology to identify and isolate epidermal stem cells and to assess their functional role in their respective niche. Furthermore, recent evidence has shown that the microenvironment also plays a crucial role in stem cell function. Indeed, epidermal cells are under the influence of surrounding fibroblasts, adipocytes, and sensory neurons that provide extrinsic signals and mechanical cues to the niche and contribute to skin morphogenesis and homeostasis. A better understanding of these microenvironmental cues will help engineer in vitro experimental models with more relevance to in vivo skin biology. New approaches to address and study these environmental cues in vitro will also be addressed.

Human cadaver multipotent stromal/stem cells isolated from arteries stored in liquid nitrogen for 5 years

PubMed Central

2014-01-01

Introduction Regenerative medicine challenges researchers to find noncontroversial, safe and abundant stem cell sources. In this context, harvesting from asystolic donors could represent an innovative and unlimited reservoir of different stem cells. In this study, cadaveric vascular tissues were established as an alternative source of human cadaver mesenchymal stromal/stem cells (hC-MSCs). We reported the successful cell isolation from postmortem arterial segments stored in a tissue-banking facility for at least 5 years. Methods After thawing, hC-MSCs were isolated with a high efficiency (12 × 106) and characterized with flow cytometry, immunofluorescence, molecular and ultrastructural approaches. Results In early passages, hC-MSCs were clonogenic, highly proliferative and expressed mesenchymal (CD44, CD73, CD90, CD105, HLA-G), stemness (Stro-1, Oct-4, Notch-1), pericyte (CD146, PDGFR-β, NG2) and neuronal (Nestin) markers; hematopoietic and vascular markers were negative. These cells had colony and spheroid-forming abilities, multipotency for their potential to differentiate in multiple mesengenic lineages and immunosuppressive activity to counteract proliferation of phytohemagglutinin-stimulated blood mononuclear cells. Conclusions The efficient procurement of stem cells from cadaveric sources, as postmortem vascular tissues, demonstrates that such cells can survive to prolonged ischemic insult, anoxia, freezing and dehydration injuries, thus paving the way for a scientific revolution where cadaver stromal/stem cells could effectively treat patients demanding cell therapies. PMID:24429026

Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study.

PubMed

El Baz, Hanan; Demerdash, Zeinab; Kamel, Manal; Atta, Shimaa; Salah, Faten; Hassan, Salwa; Hammam, Olfat; Khalil, Heba; Meshaal, Safa; Raafat, Inas

2018-02-01

Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

Differential marker expression by cultures rich in mesenchymal stem cells

PubMed Central

2013-01-01

Background Mesenchymal stem cells have properties that make them amenable to therapeutic use. However, the acceptance of mesenchymal stem cells in clinical practice requires standardized techniques for their specific isolation. To date, there are no conclusive marker (s) for the exclusive isolation of mesenchymal stem cells. Our aim was to identify markers differentially expressed between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. We compared and contrasted the phenotype of tissue cultures in which mesenchymal stem cells are rich and rare. By initially assessing mesenchymal stem cell differentiation, we established that bone marrow and breast adipose cultures are rich in mesenchymal stem cells while, in our hands, foreskin fibroblast and olfactory tissue cultures contain rare mesenchymal stem cells. In particular, olfactory tissue cells represent non-stem cell mesenchymal cells. Subsequently, the phenotype of the tissue cultures were thoroughly assessed using immuno-fluorescence, flow-cytometry, proteomics, antibody arrays and qPCR. Results Our analysis revealed that all tissue cultures, regardless of differentiation potential, demonstrated remarkably similar phenotypes. Importantly, it was also observed that common mesenchymal stem cell markers, and fibroblast-associated markers, do not discriminate between mesenchymal stem cell and non-stem cell mesenchymal cell cultures. Examination and comparison of the phenotypes of mesenchymal stem cell and non-stem cell mesenchymal cell cultures revealed three differentially expressed markers – CD24, CD108 and CD40. Conclusion We indicate the importance of establishing differential marker expression between mesenchymal stem cells and non-stem cell mesenchymal cells in order to determine stem cell specific markers. PMID:24304471

The morphology, proliferation rate, and population doubling time factor of adipose-derived mesenchymal stem cells cultured on to non-aqueous SiO2, TiO2, and hybrid sol-gel-derived oxide coatings.

PubMed

Marycz, Krzysztof; Krzak-Roś, Justyna; Donesz-Sikorska, Anna; Śmieszek, Agnieszka

2014-11-01

In recent years, much attention has been paid to the development of tissue engineering and regenerative medicine, especially when stem cells of various sources are concerned. In addition to the interest in mesenchymal stem cells isolated from bone marrow, recently more consideration has been given to stem cells isolated from adipose tissue (AdMSCs), due to their less invasive method of collection as well as their ease of isolation and culture. However, the development of regenerative medicine requires both the application of biocompatible material and the stem cells to accelerate the regeneration. In this study, we investigated the morphology, proliferation rate index (PRi), and population doubling time factor of adipose-derived mesenchymal stem cells cultured on non-aqueous sol-gel-derived SiO2, TiO2, and SiO2/TiO2 oxide coatings. The results indicated an increase in PRi of AdMSCs when cultured on to titanium dioxide, suggesting its high attractiveness for AdMSCs. In addition, the proper morphology and the shortest doubling time of AdMSCs were observed when cultured on titanium dioxide coating. © 2014 Wiley Periodicals, Inc.

Recent advances of in vitro culture systems for spermatogonial stem cells in mammals.

PubMed

Sahare, Mahesh G; Suyatno; Imai, Hiroshi

2018-04-01

Spermatogonial stem cells (SSCs) in the mammalian testis are unipotent stem cells for spermatozoa. They show unique cell characteristics as stem cells and germ cells after being isolated from the testis and cultured in vitro. This review introduces recent progress in the development of culture systems for the establishment of SSC lines in mammalian species, including humans. Based on the published reports, the isolation and purification of SSCs, identification and characteristics of SSCs, and culture system for mice, humans, and domestic animals have been summarized. In mice, cell lines from SSCs are established and can be reprogrammed to show pluripotent stem cell potency that is similar to embryonic stem cells. However, it is difficult to establish cell lines for animals other than mice because of the dearth of understanding about species-specific requirements for growth factors and mechanisms supporting the self-renewal of cultured SSCs. Among the factors that are associated with the development of culture systems, the enrichment of SSCs that are isolated from the testis and the combination of growth factors are essential. Providing an example of SSC culture in cattle, a rational consideration was made about how it can be possible to establish cell lines from neonatal and immature testes.

Isolation and characterization of porcine adipose tissue-derived adult stem cells.

PubMed

Williams, Kellie J; Picou, Alicia A; Kish, Sharon L; Giraldo, Angelica M; Godke, Robert A; Bondioli, Kenneth R

2008-01-01

Stem cell characteristics such as self-renewal, differentiation and expression of CD34 and CD44 stem cell markers have not been identified in porcine adipose tissue-derived adult stem (ADAS) cells. The objective of this study was to develop a protocol for the isolation and culture of porcine adipose tissue-derived cells and to determine stem cell-like characteristics. Primary cultures were established and cell cultures were maintained. Cloning capacity was determined using a ring cloning procedure. Primary cultures and clones were differentiated and stained for multiple differentiated phenotypes. CD34 and CD44 messenger ribonucleic acid (mRNA) was isolated and reverse transcriptase polymerase chain reaction was used to compare expression profiles. An average of 2,700,000 nucleated cells/ml was isolated; 26% were adherent, and cells completed a cell cycle approximately every 3.3 days. Ring cloning identified 19 colonies. Primary cultures and clones were determined to differentiate along osteogenic, adipogenic and chondrogenic tissue lineages. The mRNA expression profiles showed CD34 expression was higher for undifferentiated ADAS cells versus differentiated cell types and the CD34 expression level was lower than that of CD44 among differentiated cells. Improved culture conditions and defined cellular characteristics of these porcine ADAS cells have been identified. Porcine ADAS can self-renew, can differentiate into multiple tissue lineages and they express CD34. Copyright 2008 S. Karger AG, Basel.

Combination cell therapy with mesenchymal stem cells and neural stem cells for brain stroke in rats.

PubMed

Hosseini, Seyed Mojtaba; Farahmandnia, Mohammad; Razi, Zahra; Delavari, Somayeh; Shakibajahromi, Benafsheh; Sarvestani, Fatemeh Sabet; Kazemi, Sepehr; Semsar, Maryam

2015-05-01

Brain stroke is the second most important events that lead to disability and morbidity these days. Although, stroke is important, there is no treatment for curing this problem. Nowadays, cell therapy has opened a new window for treating central nervous system disease. In some previous studies the Mesenchymal stem cells and neural stem cells. In this study, we have designed an experiment to assess the combination cell therapy (Mesenchymal and Neural stem cells) effects on brain stroke. The Mesenchymal stem cells were isolated from adult rat bone marrow and the neural stem cells were isolated from ganglion eminence of rat embryo 14 days. The Mesenchymal stem cells were injected 1 day after middle cerebral artery occlusion (MCAO) and the neural stem cells transplanted 7 day after MCAO. After 28 days, the neurological outcomes and brain lesion volumes were evaluated. Also, the activity of Caspase 3 was assessed in different groups. The group which received combination cell therapy had better neurological examination and less brain lesion. Also the combination cell therapy group had the least Caspase 3 activity among the groups. The combination cell therapy is more effective than Mesenchymal stem cell therapy and neural stem cell therapy separately in treating the brain stroke in rats.

Characterization of Puccinia graminis f.sp. tritici isolates derived from an unusual wheat stem rust outbreak in Germany in 2013

USDA-ARS?s Scientific Manuscript database

An unusual stem rust infestation occurred in German wheat fields in summer 2013. We analyzed 48 isolates derived from 16 Puccinia graminis f. sp. tritici (Pgt) samples and six races were identified: TKTTF, TKKTF, TKPTF, TKKTP, PKPTF, and MMMTF. Infection type and genotypic data confirm that none of ...

Cardiac side population cells and Sca-1-positive cells.

PubMed

Nagai, Toshio; Matsuura, Katsuhisa; Komuro, Issei

2013-01-01

Since the resident cardiac stem/progenitor cells were discovered, their ability to maintain the architecture and functional integrity of adult heart has been broadly explored. The methods for isolation and purification of the cardiac stem cells are crucial for the precise analysis of their developmental origin and intrinsic potential as tissue stem cells. Stem cell antigen-1 (Sca-1) is one of the useful cell surface markers to purify the cardiac progenitor cells. Another purification strategy is based on the high efflux ability of the dye, which is a common feature of tissue stem cells. These dye-extruding cells have been called side population cells because they locate in the side of dye-retaining cells after fluorescent cell sorting. In this chapter, we describe the methodology for the isolation of cardiac SP cells and Sca-1 positive cells.

[Stem cells in adults].

PubMed

Borge, O J; Funderud, S

2001-08-30

We present a literature review of the plasticity observed by adult stem cells. We have reviewed the literature regarding stem cells from adults in order to summarise their ability to generate cells of other types than those of the tissue/organ from which they were isolated. Adult stem cells have recently been demonstrated to terminally differentiate into cells of other tissues than those from which they were originally isolated. For example, bone marrow cells have been shown to generate liver, nerve, heart and skeletal muscle cells in addition to their well-known ability to produce blood and mesenchymal cells. Most studies demonstrate a proof-of-principle in animal models; much more research is needed before adult stem cells can be utilised in human medicine. However, the published reports are encouraging and give reasons for a cautious optimism with regard to future clinical use.

Trichoderma species form endophytic associations within Theobroma cacao trichomes.

PubMed

Bailey, Bryan A; Strem, Mary D; Wood, Delilah

2009-12-01

Trichoderma species are usually considered soil organisms that colonize plant roots, sometimes forming a symbiotic relationship. Recent studies demonstrate that Trichoderma species are also capable of colonizing the above ground tissues of Theobroma cacao (cacao) in what has been characterized as an endophytic relationship. Trichoderma species can be re-isolated from surface sterilized cacao stem tissue, including the bark and xylem, the apical meristem, and to a lesser degree from leaves. SEM analysis of cacao stems colonized by strains of four Trichoderma species (Trichoderma ovalisporum-DIS 70a, Trichoderma hamatum-DIS 219b, Trichoderma koningiopsis-DIS 172ai, or Trichoderma harzianum-DIS 219f) showed a preference for surface colonization of glandular trichomes versus non-glandular trichomes. The Trichoderma strains colonized the glandular trichome tips and formed swellings resembling appresoria. Hyphae were observed emerging from the glandular trichomes on surface sterilized stems from cacao seedlings that had been inoculated with each of the four Trichoderma strains. Fungal hyphae were observed under the microscope emerging from the trichomes as soon as 6h after their isolation from surface sterilized cacao seedling stems. Hyphae were also observed, in some cases, emerging from stalk cells opposite the trichome head. Repeated single trichome/hyphae isolations verified that the emerging hyphae were the Trichoderma strains with which the cacao seedlings had been inoculated. Strains of four Trichoderma species were able to enter glandular trichomes during the colonization of cacao stems where they survived surface sterilization and could be re-isolated. The penetration of cacao trichomes may provide the entry point for Trichoderma species into the cacao stem allowing systemic colonization of this tissue.

Gratitude as moral sentiment: emotion-guided cooperation in economic exchange.

PubMed

DeSteno, David; Bartlett, Monica Y; Baumann, Jolie; Williams, Lisa A; Dickens, Leah

2010-04-01

Economic exchange often pits options for selfish and cooperative benefit against one another. Decisions favoring communal profit at the expense of self-interest have traditionally been thought to stem from strategic control aimed at tamping down emotional responses centered on immediate resource acquisition. In the present article, evidence is provided to argue against this limited view of the role played by emotion in shaping prosociality. Findings demonstrate that the social emotion gratitude functions to engender cooperative economic exchange even at the expense of greater individual financial gains. Using real-time inductions, increased gratitude is shown to directly mediate increased monetary giving within the context of an economic game, even where such giving increases communal profit at the expense of individual gains. Moreover, increased giving occurred regardless of whether the beneficiary was a known individual or complete stranger, thereby removing the possibility that it stemmed from simple awareness of reciprocity constraints. Copyright 2010 APA, all rights reserved.

Nuclear valve manufacturer selects stainless forgings

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1976-02-01

Forged type 316 stainless steel components for nuclear valves are described. Automatic plasma arc welding with powder filler alloys is employed for hardfacing. Seat ring forgings are surfaced four-at-a-time with Stellite No. 156 in a sequential manner to minimize heat input to the individual components. After cladding and machining, seat rings are welded into the valve body using a semiautomatic, hot-wire gas tungsten-arc process. Disc faces and guide slots are surfaced with Stellite No. 6. The valve stem is machined from 17-4PH forged bar stock in the H-1100 condition. The heat treatment is specified to minimize pitting under prolonged exposuremore » to wet packing. A 12 rms (0.3 $mu$m) surface finish minimizes tearing of the packing and subsequent leakage. The link and stem pin are SA 564 Grade 660 (in the H-1100 condition) and ASTM A637 Grade 718 respectively. (JRD)« less

Robotic Mining Competition Award Ceremony

NASA Image and Video Library

2017-05-26

Students from 45 colleges and universities gathered at Kennedy Space Center’s Saturn V Visitor Complex in Florida on Friday, May 26, to celebrate and conclude NASA’s Eight Annual Robotic Mining Competition. Awards were presented to the winning teams in multiple categories. The three-day competition pitted excavator robots designed and built by each team to mine the most simulated Martian soil in a specified amount of time. Students also were judged on how each team used its robot to inspire its respective community about careers in science, technology, engineering and math (STEM). Managed by, and held annually at Kennedy Space Center, RMC is a NASA Human Exploration and Operations Mission Directorate project designed to engage and retain students in STEM fields by expanding opportunities for student research and design. The project provides a competitive environment to foster innovative ideas and solutions with potential use on NASA’s deep space exploration missions, including to Mars.

Population structure and diversity of citrus tristeza virus (CTV) isolates in Hunan province, China.

PubMed

Xiao, Cui; Yao, Run-Xian; Li, Fang; Dai, Su-Ming; Licciardello, Grazia; Catara, Antonino; Gentile, Alessandra; Deng, Zi-Niu

2017-02-01

Stem-pitting (SP) is the main type of citrus tristeza virus (CTV) that causes severe damage to citrus trees, especially those of sweet orange, in Hunan province, China. Understanding the local CTV population structure should provide clues for effective mild strain cross-protection (MSCP) of the SP strain of CTV. In this study, markers for the p23 gene, multiple molecular markers (MMMs), and sequence analysis of the three silencing suppressor genes (p20, p23 and p25) were employed to analyze the genetic diversity and genotype composition of the CTV population based on 51 CTV-positive samples collected from 14 citrus orchards scattered around six major citrus-growing areas of Hunan. The results indicated that the CTV population structure was extremely complex and that infection was highly mixed. In total, p23 gene markers resulted in six profiles, and MMMs demonstrated 25 profiles. The severe VT and T3 types appeared to be predominantly associated with SP, while the mild T30 and RB types were related to asymptomatic samples. Based on phylogenetic analysis of the amino acid sequences of p20, p23 and p25, 19 representative CTV samples were classified into seven recently established CTV groups and a potentially novel one. A high level of genetic diversity, as well as potential recombination, was revealed among different CTV isolates. Five pure SP severe and two pure mild strains were identified by genotype composition analysis. Taken together, the results update the genetic diversity of CTV in Hunan with the detection of one possible novel strain, and this information might be applicable for the selection of appropriate mild CTV strains for controlling citrus SP disease through cross-protection.

Investigations Concerning Cavitation and Frost Fatigue in Clonal 84K Poplar Using High-Resolution Cavitron Measurements1[OPEN

PubMed Central

Feng, Feng; Ding, Fei; Tyree, Melvin T.

2015-01-01

Both drought and freezing-thawing of stems induce a loss of hydraulic conductivity (percentage loss of conductivity [PLC]) in woody plants. Drought-induced PLC is often accompanied by physical damage to pit membranes, causing a shift in vulnerability curves (cavitation fatigue). Hence, if cavitated stems are flushed to remove embolisms, the next vulnerability curve is different (shifted to lower tensions). The 84K poplar (Populus alba × Populus glandulosa) clone has small vessels that should be immune from frost-induced PLC, but results demonstrated that freezing-thawing in combination with tension synergistically increased PLC. Frost fatigue has already been defined, which is similar to cavitation fatigue but induced by freezing. Frost fatigue caused a transition from a single to a dual Weibull curve, but drought-fatigued stems had single Weibull curves shifted to lower tensions. Studying the combined impact of tension plus freezing on fatigue provided evidence that the mechanism of frost fatigue may be the extra water tension induced by freezing or thawing while spinning stems in a centrifuge rather than direct ice damage. A hypothesis is advanced that tension is enhanced as ice crystals grow or melt during the freeze or thaw event, respectively, causing a nearly identical fatigue event to that induced by drought. PMID:25786827

Role of the Stem Cell Niche in Hormone-induced Tumorigenesis in Fetal Mouse Mammary Epithelium

DTIC Science & Technology

2006-08-01

Develop an immunohistochemical method for identifying stem cells and stem cell niches, and to use this to determine if in utero estrogenic...overstimulation causes changes in the number of stem cells or their niches. To extend the power of ex vivo stem cell isolation and enumeration by providing a...marginal success due primarily to 1) most antibodies previously reputed to be stem cell specific turned out to be present in differentiated mammary

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold.

PubMed

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. A total of 15 systemically healthy individuals between the age group of 15-25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7 th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7 th day. The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant ( P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant ( P > 0.05) when compared to the cells cultured with culture media. The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells.

Circulating Tumor Cells: From Theory to Nanotechnology-Based Detection.

PubMed

Ming, Yue; Li, Yuanyuan; Xing, Haiyan; Luo, Minghe; Li, Ziwei; Chen, Jianhong; Mo, Jingxin; Shi, Sanjun

2017-01-01

Cancer stem cells with stem-cell properties are regarded as tumor initiating cells. Sharing stem-cell properties, circulating tumor cells (CTCs) are responsible for the development of metastasis, which significant affects CTC analysis in clinical practice. Due to their extremely low occurrence in blood, however, it is challenging to enumerate and analyze CTCs. Nanotechnology is able to address the problems of insufficient capture efficiency and low purity of CTCs owing to the unique structural and functional properties of nanomaterials, showing strong promise for CTC isolation and detection. In this review, we discuss the role of stem-like CTCs in metastases, provide insight into recent progress in CTC isolation and detection approaches using various nanoplatforms, and highlight the role of nanotechnology in the advancement of CTC research.

Isolation of sphere-forming stem cells from the mouse inner ear.

PubMed

Oshima, Kazuo; Senn, Pascal; Heller, Stefan

2009-01-01

The mammalian inner ear has very limited ability to regenerate lost sensory hair cells. This deficiency becomes apparent when hair cell loss leads to hearing loss as a result of either ototoxic insult or the aging process. Coincidently, with this inability to regenerate lost hair cells, the adult cochlea does not appear to harbor cells with a proliferative capacity that could serve as progenitor cells for lost cells. In contrast, adult mammalian vestibular sensory epithelia display a limited ability for hair cell regeneration, and sphere-forming cells with stem cell features can be isolated from the adult murine vestibular system. The neonatal inner ear, however, does harbor sphere-forming stem cells residing in cochlear and vestibular tissues. Here, we provide protocols to isolate sphere-forming stem cells from neonatal vestibular and cochlear sensory epithelia as well as from the spiral ganglion. We further describe procedures for sphere propagation, cell differentiation, and characterization of inner ear cell types derived from spheres. Sphere-forming stem cells from the mouse inner ear are an important tool for the development of cellular replacement strategies of damaged inner ears and are a bona fide progenitor cell source for transplantation studies.

Antishigellosis and Cytotoxic Potency of Crude Extracts and Isolated Constituents from Duranta repens

PubMed Central

Habib, M. Rowshanul; Karim, M. Rezaul; Hossain, M. Shamim; Mosaddik, M. Ashik; Haque, M. Ekramul

2008-01-01

The crude ethanol extracts (stem and fruits), their fractions and two triterpenes, β-Amyrin and 12-Oleanene 3β, 21β-diol, isolated as a mixture from the chloroform soluble fraction of an ethanolic extract of Duranta repens stem, were evaluated for antibacterial, antifungal activities by the disc diffusion method and cytotoxicity by brine shrimp lethality bioassay. The structures of the two compounds were confirmed by IR, 1H-NMR, 13C-NMR and LC-MS spectral data. The chloroform soluble fraction of stem and ethanol extract of fruits possess potent antishigellosis activity and also exhibited moderate activity against some pathogenic bacteria and fungi but the isolated compound 1 (mixture of β-Amyrin and 12-Oleanene 3β, 21β-diol) showed mild to moderate inhibitory activity to microbial growth. The minimum inhibitory concentrations (MICs) of the extracts (stem and fruits), their fractions and compound 1 were found to be in the range of 32~128 µg/ml. The chloroform soluble fractions of stem and ethanol extract of fruit showed significant cytotoxicity with LC50 value of 0.94 µg/ml and 0.49 µg/ml, respectively against brine shrimp larvae. PMID:23997620

[Studies on chemical constituents from leaves and stems of Aconitum coreanum].

PubMed

Li, Yan; Liang, Shuai

2009-05-01

To study the chemical constituents in the leaves and stems of Aconitum coreanum. The isolation and purification of chemical constituents were carried out on silica gel and polyamide column chromatographic. Their structures were identified by physico-chemical properties and spectral analysis. Five compounds were obtained and their structures were identified as guan-fu base I (1), guan-fu base R (2), beta-sitosterol (3), D-mannitol (4), daucosterol (5). Compound 2 is a new compound. Compounds 1 and 3, 4 are isolated from the leaves and stems of A. coreanum for the first time.

Isolation of stem-like cells from spontaneous feline mammary carcinomas: phenotypic characterization and tumorigenic potential.

PubMed

Barbieri, Federica; Wurth, Roberto; Ratto, Alessandra; Campanella, Chiara; Vito, Guendalina; Thellung, Stefano; Daga, Antonio; Cilli, Michele; Ferrari, Angelo; Florio, Tullio

2012-04-15

Current carcinogenesis theory states that only a small subset of tumor cells, the cancer stem cells or tumor initiating cells (TICs), are responsible for tumor formation and progression. Human breast cancer-initiating cells have been identified as CD44-expressing cells, which retain tumorigenic activity and display stem cell-like properties. Spontaneous feline mammary carcinoma (FMC) is an aggressive cancer, which shows biological similarities to the human tumor counterpart. We report the isolation and phenotypic characterization of FMC-derived stem/progenitor cells, showing in vitro self-renewal, long-lasting proliferation and in vivo tumorigenicity. Twenty-one FMC samples were collected, histologically classified and characterized for the expression of Ki67, EGFR, ER-α and CD44, by immunohistochemistry. By culture in stem cell permissive conditions, we isolated, from 13 FMCs, a CD44-positive subpopulation able to survive and proliferate in vitro as mammospheres of different sizes and morphologies. When injected in NOD/SCID mice, FMC stem-like cells initiate tumors, generating cell heterogeneity and recapitulating the original histotype. In serum-containing medium, spheroid cells showed differentiation properties as shown by morphological changes, the loss of CD44 expression and tumorigenic potential. These data show that stem-defined culture of FMC enriches for TICs and validate the use of these cells as a suitable model for comparative oncology studies of mammary biology and testing therapeutic strategies aimed at eradicating TICs. Copyright © 2012 Elsevier Inc. All rights reserved.

CD133(+)/CD44(+)/Oct4(+)/Nestin(+) stem-like cells isolated from Panc-1 cell line may contribute to multi-resistance and metastasis of pancreatic cancer.

PubMed

Wang, Dongqing; Zhu, Haitao; Zhu, Ying; Liu, Yanfang; Shen, Huiling; Yin, Ruigen; Zhang, Zhijian; Su, Zhaoliang

2013-05-01

Pancreatic cancer is an aggressive malignant disease. Owing to the lack of early symptoms, accompanied by extensive metastasis and high resistance to chemotherapy, pancreatic adenocarcinoma becomes the fourth leading cause of cancer-related deaths. In this study, we identified a subpopulation of cells isolated from the Panc-1 cell line and named pancreatic cancer stem-like cells. These Panc-1 stem-like cells expressed high levels of CD133/CD44/Oct4/Nestin. Compared to Panc-1 cells, Panc-1 stem-like cells were resistant to gemcitabine and expressed high levels of MDR1; furthermore, Panc-1 stem-like cells have high anti-apoptotic, but weak proliferative potential. These results indicated that Panc-1 stem-like cells, as a novel group, may be a potential major cause of pancreatic cancer multidrug resistance and extensive metastasis. Copyright © 2012 Elsevier GmbH. All rights reserved.

Isolated brain stem lesion in children: is it acute disseminated encephalomyelitis or not?

PubMed

Alper, G; Sreedher, G; Zuccoli, G

2013-01-01

Isolated brain stem lesions presenting with acute neurologic findings create a major diagnostic dilemma in children. Although the brain stem is frequently involved in ADEM, solitary brain stem lesions are unusual. We performed a retrospective review in 6 children who presented with an inflammatory lesion confined to the brain stem. Two children were diagnosed with connective tissue disorder, CNS lupus, and localized scleroderma. The etiology could not be determined in 1, and clinical features suggested monophasic demyelination in 3. In these 3 children, initial lesions demonstrated vasogenic edema; all showed dramatic response to high-dose corticosteroids and made a full clinical recovery. Follow-up MRI showed complete resolution of lesions, and none had relapses at >2 years of follow-up. In retrospect, these cases are best regarded as a localized form of ADEM. We conclude that though ADEM is typically a disseminated disease with multifocal lesions, it rarely presents with monofocal demyelination confined to the brain stem.

Hyperglycemic Stress Impairs the Stemness Capacity of Kidney Stem Cells in Rats.

PubMed

Yang, Guang; Jia, Yali; Li, Chunlin; Cheng, Qingli; Yue, Wen; Pei, Xuetao

2015-01-01

The incidence of acute kidney injury in patients with diabetes is significantly higher than that of patients without diabetes, and may be associated with the poor stemness capacity of kidney stem cells (KSCs) and limited recovery of injured renal tubules. To investigate the effects of hyperglycemic stress on KSC stemness, KSCs were isolated from the rat renal papilla and analyzed for their self-renewal and differentiation abilities. Our results showed that isolated KSCs expressed the mesenchymal stem cell markers N-cadherin, Nestin, CD133, CD29, CD90, and CD73. Moreover, KSCs co-cultured with hypoxia-injured renal tubular epithelial cell (RTECs) induced the expression of the mature epithelial cell marker CK18, suggesting that the KSCs could differentiate into RTECs in vitro. However, KSC proliferation, differentiation ability and tolerance to hypoxia were decreased in high-glucose cultures. Taken together, these results suggest the high-glucose microenvironment can damage the reparative ability of KSCs. It may result in a decreased of recovery capability of renal tubules from injury.

Human adipose-derived stem cells: definition, isolation, tissue-engineering applications.

PubMed

Nae, S; Bordeianu, I; Stăncioiu, A T; Antohi, N

2013-01-01

Recent researches have demonstrated that the most effective repair system of the body is represented by stem cells - unspecialized cells, capable of self-renewal through successive mitoses, which have also the ability to transform into different cell types through differentiation. The discovery of adult stem cells represented an important step in regenerative medicine because they no longer raises ethical or legal issues and are more accessible. Only in 2002, stem cells isolated from adipose tissue were described as multipotent stem cells. Adipose tissue stem cells benefits in tissue engineering and regenerative medicine are numerous. Development of adipose tissue engineering techniques offers a great potential in surpassing the existing limits faced by the classical approaches used in plastic and reconstructive surgery. Adipose tissue engineering clinical applications are wide and varied, including reconstructive, corrective and cosmetic procedures. Nowadays, adipose tissue engineering is a fast developing field, both in terms of fundamental researches and medical applications, addressing issues related to current clinical pathology or trauma management of soft tissue injuries in different body locations.

GMP-conformant on-site manufacturing of a CD133+ stem cell product for cardiovascular regeneration.

PubMed

Skorska, Anna; Müller, Paula; Gaebel, Ralf; Große, Jana; Lemcke, Heiko; Lux, Cornelia A; Bastian, Manuela; Hausburg, Frauke; Zarniko, Nicole; Bubritzki, Sandra; Ruch, Ulrike; Tiedemann, Gudrun; David, Robert; Steinhoff, Gustav

2017-02-10

CD133 + stem cells represent a promising subpopulation for innovative cell-based therapies in cardiovascular regeneration. Several clinical trials have shown remarkable beneficial effects following their intramyocardial transplantation. Yet, the purification of CD133 + stem cells is typically performed in centralized clean room facilities using semi-automatic manufacturing processes based on magnetic cell sorting (MACS®). However, this requires time-consuming and cost-intensive logistics. CD133 + stem cells were purified from patient-derived sternal bone marrow using the recently developed automatic CliniMACS Prodigy® BM-133 System (Prodigy). The entire manufacturing process, as well as the subsequent quality control of the final cell product (CP), were realized on-site and in compliance with EU guidelines for Good Manufacturing Practice. The biological activity of automatically isolated CD133 + cells was evaluated and compared to manually isolated CD133 + cells via functional assays as well as immunofluorescence microscopy. In addition, the regenerative potential of purified stem cells was assessed 3 weeks after transplantation in immunodeficient mice which had been subjected to experimental myocardial infarction. We established for the first time an on-site manufacturing procedure for stem CPs intended for the treatment of ischemic heart diseases using an automatized system. On average, 0.88 × 10 6 viable CD133 + cells with a mean log 10 depletion of 3.23 ± 0.19 of non-target cells were isolated. Furthermore, we demonstrated that these automatically isolated cells bear proliferation and differentiation capacities comparable to manually isolated cells in vitro. Moreover, the automatically generated CP shows equal cardiac regeneration potential in vivo. Our results indicate that the Prodigy is a powerful system for automatic manufacturing of a CD133 + CP within few hours. Compared to conventional manufacturing processes, future clinical application of this system offers multiple benefits including stable CP quality and on-site purification under reduced clean room requirements. This will allow saving of time, reduced logistics and diminished costs.

Establishing Clonal Cell Lines with Endothelial-Like Potential from CD9hi, SSEA-1− Cells in Embryonic Stem Cell-Derived Embryoid Bodies

PubMed Central

Lian, Qizhou; Yeo, KengSuan; Que, Jianwen; Tan, EileenKhiaWay; Yu, Fenggang; Yin, Yijun; Salto-Tellez, Manuel; Oakley, Reida Menshawe El; Lim, Sai-Kiang

2006-01-01

Background Differentiation of embryonic stem cells (ESCs) into specific cell types with minimal risk of teratoma formation could be efficiently directed by first reducing the differentiation potential of ESCs through the generation of clonal, self-renewing lineage-restricted stem cell lines. Efforts to isolate these stem cells are, however, mired in an impasse where the lack of purified lineage-restricted stem cells has hindered the identification of defining markers for these rare stem cells and, in turn, their isolation. Methodology/Principal Findings We describe here a method for the isolation of clonal lineage-restricted cell lines with endothelial potential from ESCs through a combination of empirical and rational evidence-based methods. Using an empirical protocol that we have previously developed to generate embryo-derived RoSH lines with endothelial potential, we first generated E-RoSH lines from mouse ESC-derived embryoid bodies (EBs). Despite originating from different mouse strains, RoSH and E- RoSH lines have similar gene expression profiles (r2 = 0.93) while that between E-RoSH and ESCs was 0.83. In silico gene expression analysis predicted that like RoSH cells, E-RoSH cells have an increased propensity to differentiate into vasculature. Unlike their parental ESCs, E-RoSH cells did not form teratomas and differentiate efficiently into endothelial-like cells in vivo and in vitro. Gene expression and FACS analysis revealed that RoSH and E-RoSH cells are CD9hi, SSEA-1− while ESCs are CD9lo, SSEA-1+. Isolation of CD9hi, SSEA-1− cells that constituted 1%–10% of EB-derived cultures generated an E-RoSH-like culture with an identical E-RoSH-like gene expression profile (r2 = 0.95) and a propensity to differentiate into endothelial-like cells. Conclusions By combining empirical and rational evidence-based methods, we identified definitive selectable surface antigens for the isolation and propagation of lineage-restricted stem cells with endothelial-like potential from mouse ESCs. PMID:17183690

Generation of Alveolar Epithelial Spheroids via Isolated Progenitor Cells from Human Pluripotent Stem Cells

PubMed Central

Gotoh, Shimpei; Ito, Isao; Nagasaki, Tadao; Yamamoto, Yuki; Konishi, Satoshi; Korogi, Yohei; Matsumoto, Hisako; Muro, Shigeo; Hirai, Toyohiro; Funato, Michinori; Mae, Shin-Ichi; Toyoda, Taro; Sato-Otsubo, Aiko; Ogawa, Seishi; Osafune, Kenji; Mishima, Michiaki

2014-01-01

Summary No methods for isolating induced alveolar epithelial progenitor cells (AEPCs) from human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) have been reported. Based on a study of the stepwise induction of alveolar epithelial cells (AECs), we identified carboxypeptidase M (CPM) as a surface marker of NKX2-1+ “ventralized” anterior foregut endoderm cells (VAFECs) in vitro and in fetal human and murine lungs. Using SFTPC-GFP reporter hPSCs and a 3D coculture system with fetal human lung fibroblasts, we showed that CPM+ cells isolated from VAFECs differentiate into AECs, demonstrating that CPM is a marker of AEPCs. Moreover, 3D coculture differentiation of CPM+ cells formed spheroids with lamellar-body-like structures and an increased expression of surfactant proteins compared with 2D differentiation. Methods to induce and isolate AEPCs using CPM and consequently generate alveolar epithelial spheroids would aid human pulmonary disease modeling and regenerative medicine. PMID:25241738

Characterization of apple stem grooving virus and apple chlorotic leaf spot virus identified in a crab apple tree.

PubMed

Li, Yongqiang; Deng, Congliang; Bian, Yong; Zhao, Xiaoli; Zhou, Qi

2017-04-01

Apple stem grooving virus (ASGV), apple chlorotic leaf spot virus (ACLSV), and prunus necrotic ringspot virus (PNRSV) were identified in a crab apple tree by small RNA deep sequencing. The complete genome sequence of ACLSV isolate BJ (ACLSV-BJ) was 7554 nucleotides and shared 67.0%-83.0% nucleotide sequence identity with other ACLSV isolates. A phylogenetic tree based on the complete genome sequence of all available ACLSV isolates showed that ACLSV-BJ clustered with the isolates SY01 from hawthorn, MO5 from apple, and JB, KMS and YH from pear. The complete nucleotide sequence of ASGV-BJ was 6509 nucleotides (nt) long and shared 78.2%-80.7% nucleotide sequence identity with other isolates. ASGV-BJ and the isolate ASGV_kfp clustered together in the phylogenetic tree as an independent clade. Recombination analysis showed that isolate ASGV-BJ was a naturally occurring recombinant.

Isolation and Characterization of Canine Amniotic Membrane-Derived Multipotent Stem Cells

PubMed Central

Kim, Hyung-Sik; Kang, Kyung-Sun

2012-01-01

Recent studies have shown that amniotic membrane tissue is a rich source of stem cells in humans. In clinical applications, the amniotic membrane tissue had therapeutic effects on wound healing and corneal surface reconstruction. Here, we successfully isolated and identified multipotent stem cells (MSCs) from canine amniotic membrane tissue. We cultured the canine amniotic membrane-derived multipotent stem cells (cAM-MSCs) in low glucose DMEM medium. cAM-MSCs have a fibroblast-like shape and adhere to tissue culture plastic. We characterized the immunophenotype of cAM-MSCs by flow cytometry and measured cell proliferation by the cumulative population doubling level (CPDL). We performed differentiation studies for the detection of trilineage multipotent ability, under the appropriate culture conditions. Taken together, our results show that cAM-MSCs could be a rich source of stem cells in dogs. Furthermore, cAM-MSCs may be useful as a cell therapy application for veterinary regenerative medicine. PMID:23024756

Investigating the mincing method for isolation of adipose-derived stem cells from pregnant women fat.

PubMed

Li, Yuan-Sheng; Chen, Pao-Jen; Wu, Li-Wei; Chou, Pei-Wen; Sun, Li-Yi; Chiou, Tzyy-Wen

2018-02-01

The success of stem cell application in regenerative medicine, usually require a stable source of stem or progenitor cells. Fat tissue represents a good source of stem cells because it is rich in stem cells and there are fewer ethical issues related to the use of such stem cells, unlike embryonic stem cells. Therefore, there has been increased interest in adipose-derived stem cells (ADSCs) for tissue engineering applications. Here, we aim to provide an easy processing method for isolating adult stem cells from human adipose tissue harvested from the subcutaneous fat of the abdominal wall during gynecologic surgery. We used a homogenizer to mince fat and compared the results with those obtained from the traditional cut method involving a sterile scalpel and forceps. Our results showed that our method provides another stable and quality source of stem cells that could be used in cases with a large quantity of fat. Furthermore, we found that pregnancy adipose-derived stem cells (P-ADSCs) could be maintained in vitro for extended periods with a stable population doubling and low senescence levels. P-ADSCs could also differentiate in vitro into adipogenic, osteogenic, chondrogenic, and insulin-producing cells in the presence of lineage-specific induction factors. In conclusion, like human lipoaspirates, adipose tissues obtained from pregnant women contain multipotent cells with better proliferation and showed great promise for use in both stem cell banking studies as well as in stem cell therapy.

Application of Stem Cell Technology in Dental Regenerative Medicine.

PubMed

Feng, Ruoxue; Lengner, Chistopher

2013-07-01

In this review, we summarize the current literature regarding the isolation and characterization of dental tissue-derived stem cells and address the potential of these cell types for use in regenerative cell transplantation therapy. Looking forward, platforms for the delivery of stem cells via scaffolds and the use of growth factors and cytokines for enhancing dental stem cell self-renewal and differentiation are discussed. We aim to understand the developmental origins of dental tissues in an effort to elucidate the molecular pathways governing the genesis of somatic dental stem cells. The advantages and disadvantages of several dental stem cells are discussed, including the developmental stage and specific locations from which these cells can be purified. In particular, stem cells from human exfoliated deciduous teeth may act as a very practical and easily accessibly reservoir for autologous stem cells and hold the most value in stem cell therapy. Dental pulp stem cells and periodontal ligament stem cells should also be considered for their triple lineage differentiation ability and relative ease of isolation. Further, we address the potentials and limitations of induced pluripotent stem cells as a cell source in dental regenerative. From an economical and a practical standpoint, dental stem cell therapy would be most easily applied in the prevention of periodontal ligament detachment and bone atrophy, as well as in the regeneration of dentin-pulp complex. In contrast, cell-based tooth replacement due to decay or other oral pathology seems, at the current time, an untenable approach.

Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation

DTIC Science & Technology

2012-02-01

10-1-0927 TITLE: Mesenchymal Stem Cell Therapy for Nerve Regeneration and Immunomodulation after Composite Tissue Allotransplantation...immunosuppression. Bone Marrow Derived Mesenchymal stem cells (BM-MSCs) are pluripotent cells, capable of differentiation along multiple mesenchymal lineages into...As part of implemented transition from University of Pittsburgh to Johns Hopkins University, we optimized our mesenchymal stem cell (MSC) isolation

Human serum and platelet lysate are appropriate xeno-free alternatives for clinical-grade production of human MuStem cell batches.

PubMed

Saury, Charlotte; Lardenois, Aurélie; Schleder, Cindy; Leroux, Isabelle; Lieubeau, Blandine; David, Laurent; Charrier, Marine; Guével, Laëtitia; Viau, Sabrina; Delorme, Bruno; Rouger, Karl

2018-05-02

Canine MuStem cells have demonstrated regenerative efficacy in a dog model of muscular dystrophy, and the recent characterization of human counterparts (hMuStem) has highlighted the therapeutic potential of this muscle-derived stem cell population. To date, these cells have only been generated in research-grade conditions. However, evaluation of the clinical efficacy of any such therapy will require the production of hMuStem cells in compliance with good manufacturing practices (GMPs). Because the current use of fetal bovine serum (FBS) to isolate and expand hMuStem cells raises several ethical, safety, and supply concerns, we assessed the use of two alternative xeno-free blood derivatives: human serum (HS) and a human platelet lysate (hPL). hMuStem cells were isolated and expanded in vitro in either HS-supplemented or hPL-supplemented media and the proliferation rate, clonogenicity, myogenic commitment potential, and oligopotency compared with that observed in FBS-supplemented medium. Flow cytometry and high-throughput 3'-digital gene expression RNA sequencing were used to characterize the phenotype and global gene expression pattern of hMuStem cells cultured with HS or hPL. HS-supplemented and hPL-supplemented media both supported the isolation and long-term proliferation of hMuStem cells. Compared with FBS-based medium, both supplements enhanced clonogenicity and allowed for a reduction in growth factor supplementation. Neither supplement altered the cell lineage pattern of hMuStem cells. In vitro differentiation assays revealed a decrease in myogenic commitment and in the fusion ability of hMuStem cells when cultured with hPL. In return, this reduction of myogenic potential in hPL-supplemented cultures was rapidly reversed by substitution of hPL with HS or fibrinogen-depleted hPL. Moreover, culture of hMuStem cells in hPL hydrogel and fibrinogen-depleted hPL demonstrated that myogenic differentiation potential is maintained in heparin-free hPL derivatives. Our findings indicate that HS and hPL are efficient and viable alternatives to FBS for the preparation of hMuStem cell batches in compliance with GMPs.

Isolation, characterization, and differentiation of stem cells for cartilage regeneration.

PubMed

Beane, Olivia S; Darling, Eric M

2012-10-01

The goal of tissue engineering is to create a functional replacement for tissues damaged by injury or disease. In many cases, impaired tissues cannot provide viable cells, leading to the investigation of stem cells as a possible alternative. Cartilage, in particular, may benefit from the use of stem cells since the tissue has low cellularity and cannot effectively repair itself. To address this need, researchers are investigating the chondrogenic capabilities of several multipotent stem cell sources, including adult and extra-embryonic mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). Comparative studies indicate that each cell type has advantages and disadvantages, and while direct comparisons are difficult to make, published data suggest some sources may be more promising for cartilage regeneration than others. In this review, we identify current approaches for isolating and chondrogenically differentiating MSCs from bone marrow, fat, synovium, muscle, and peripheral blood, as well as cells from extra-embryonic tissues, ESCs, and iPSCs. Additionally, we assess chondrogenic induction with growth factors, identifying standard cocktails used for each stem cell type. Cell-only (pellet) and scaffold-based studies are also included, as is a discussion of in vivo results.

Prospective isolation of multipotent pancreatic progenitors using flow-cytometric cell sorting.

PubMed

Suzuki, Atsushi; Nakauchi, Hiromitsu; Taniguchi, Hideki

2004-08-01

During pancreatic development, neogenesis, and regeneration, stem cells might act as a central player to generate endocrine, acinar, and duct cells. Although these cells are well known as pancreatic stem cells (PSCs), indisputable proof of their existence has not been reported. Identification of phenotypic markers for PSCs leads to their prospective isolation and precise characterization to clear whether stem cells exist in the pancreas. By combining flow cytometry and clonal analysis, we show here that a possible pancreatic stem or progenitor cell candidate that resides in the developing and adult mouse pancreas expresses the receptor for the hepatocyte growth factor (HGF) c-Met, but does not express hematopoietic and vascular endothelial antigens such as CD45, TER119, c-Kit, and Flk-1. These cells formed clonal colonies in vitro and differentiated into multiple pancreatic lineage cells from single cells. Some of them could largely expand with self-renewing cell divisions in culture, and, following cell transplantation, they differentiated into pancreatic endocrine and acinar cells in vivo. Furthermore, they produced cells expressing multiple markers of nonpancreatic organs including liver, stomach, and intestine in vitro. Our data strongly suggest that c-Met/HGF signaling plays an important role in stem/progenitor cell function in both developing and adult pancreas. By using this antigen, PSCs could be isolated prospectively, enabling a detailed investigation of stem cell markers and application toward regenerative therapies for diabetes.

Isolation of Small SSEA-4-Positive Putative Stem Cells from the Ovarian Surface Epithelium of Adult Human Ovaries by Two Different Methods

PubMed Central

Virant-Klun, Irma; Skutella, Thomas; Hren, Matjaz; Gruden, Kristina; Cvjeticanin, Branko; Vogler, Andrej; Sinkovec, Jasna

2013-01-01

The adult ovarian surface epithelium has already been proposed as a source of stem cells and germinal cells in the literature, therefore it has been termed the “germinal epithelium”. At present more studies have confirmed the presence of stem cells expressing markers of pluripotency in adult mammalian ovaries, including humans. The aim of this study was to isolate a population of stem cells, based on the expression of pluripotency-related stage-specific embryonic antigen-4 (SSEA-4) from adult human ovarian surface epithelium by two different methods: magnetic-activated cell sorting and fluorescence-activated cell sorting. Both methods made it possible to isolate a similar, relatively homogenous population of small, SSEA-4-positive cells with diameters of up to 4 μm from the suspension of cells retrieved by brushing of the ovarian cortex biopsies in reproductive-age and postmenopausal women and in women with premature ovarian failure. The immunocytochemistry and genetic analyses revealed that these small cells—putative stem cells—expressed some primordial germ cell and pluripotency-related markers and might be related to the in vitro development of oocyte-like cells expressing some oocyte-specific transcription factors in the presence of donated follicular fluid with substances important for oocyte growth and development. The stemness of these cells needs to be further researched. PMID:23509763

Pharmacognostic studies of the leaves and stem of Careya arborea Roxb.

PubMed Central

Gupta, Prakash Chandra; Sharma, Nisha; Rao, Ch V

2012-01-01

Objective To study detailed pharmacognostic profile of leaves and stem of Careya arborea (C. arborea) Roxb. (Lecthyidaceae), an important medicinal plant in the Indian system of medicine. Methods Leaf and stem samples of C. arborea were studied by macroscopical, microscopical, physicochemical, phytochemical, fluorescence analysis of powder of the plant and other methods for standardization recommended by WHO. Results Macroscopically, the leaves are simple, broadly obovate in shape, acuminate apex with crenate, dentate margin, petioles (0.1–1.8 cm) long. Microscopically, the leaf showed the presence of median large size vascular bundle covered with fibrous bundle sheath, arrangement of xylem in cup shape and presence of cortical vascular bundle, patches of sclerenchyma, phloem fibers in groups and brown pigment containing cells in stem are some of the diagnostic features noted from anatomical study. Powder microscopy of leaf revealed the presence of parenchyma cells, xylem with pitted vessels and epidermis with anisocytic stomata. The investigations also included leaf surface data; quantitative leaf microscopy and fluorescence analysis. Physiochemical parameters such as loss on drying, swelling index, extractive values and ash values were also determined and results showed that total ash of the stem bark was about two times higher than leaf and water soluble extractive value of leaf and stem bark was two times higher than alcohol soluble extractive value. Preliminary phytochemical screening showed the presence of triterpenoids, saponins, tannins and flavonoids. Conclusions The results of the study can serve as a valuable source of information and provide suitable standards for identification of this plant material in future investigations and applications. PMID:23569939

Effect of repeated Ribavirin treatment on grapevine viruses.

PubMed

Komínek, P; Komínková, M; Jandová, B

The effect of Ribavirin treatment for the chemotherapy of several grapevine viruses was evaluated. Four grapevine cultivars were repeatedly treated with Ribavirin in two different concentrations and with three different lengths of treatment. Repeating the Ribavirin treatment always had a significant effect on the number of healthy grapevine plants obtained. Ribavirin concentration and length of exposure showed a significant difference in sanitation of the Grapevine rupestris stem pitting-associated virus. During sanitation of the Grapevine Pinot gris virus and Grapevine fleck virus, those two factors did not show significant differences in the elimination of grapevine viruses.

Isolating LacZ-expressing cells from mouse inner ear tissues using flow cytometry.

PubMed

Jan, Taha A; Chai, Renjie; Sayyid, Zahra N; Cheng, Alan G

2011-12-23

Isolation of specific cell types allows one to analyze rare cell populations such as stem/progenitor cells. Such an approach to studying inner ear tissues presents a unique challenge because of the paucity of cells of interest and few transgenic reporter mouse models. Here, we describe a protocol using fluorescence-conjugated probes to selectively label LacZ-positive cells from the neonatal cochleae. The most common underlying pathology of sensorineural hearing loss is the irreversible damage and loss of cochlear sensory hair cells, which are required to transduce sound waves to neural impulses. Recent evidence suggests that the murine auditory and vestibular organs harbor stem/progenitor cells that may have regenerative potential. These findings warrant further investigation, including identifying specific cell types with stem/progenitor cell characteristics. The Wnt signaling pathway has been demonstrated to play a critical role in maintaining stem/progenitor cell populations in several organ systems. We have recently identified Wnt-responsive Axin2-expressing cells in the neonatal cochlea, but their function is largely unknown. To better understand the behavior of these Wnt-responsive cells in vitro, we have developed a method of isolating Axin2-expressing cells from cochleae of Axin2-LacZ reporter mice. Using flow cytometry to isolate Axin2-LacZ positive cells from the neonatal cochleae, we could in turn execute a variety of experiments on live cells to interrogate their behavior as stem/progenitor cells. Here, we describe in detail the steps for the microdissection of neonatal cochlea, dissociation of these tissues, labeling of the LacZ-positive cells using a fluorogenic substrate, and cell sorting. Techniques for dissociating cochleae into single cells and isolating cochlear cells via flow cytometry have been described. We have made modifications to these techniques to establish a novel protocol to isolate LacZ-expressing cells from the neonatal cochlea.

[Chemical constituents from stems of Ilex pubescens].

PubMed

Xing, Xian-dong; Zhang, Qian; Feng, Feng; Liu, Wen-yuan

2012-09-01

To study the chemical constituents from the stems of Ilex pubescens Hook. et Am. The chemical constituents were isolated and purified by various column chromatographic methods with diatomite, silica gel, ODS and Sephadex LH-20. Their structures were identified on physical properties and spectroscopic methods. Nine compounds were isolated and determined as luteolin(1), quercetin(2), hyperoside(3), rutin(4), 1, 5-dihydroxy-3-methyl-anthraquinone(5),3,5-dimethoxy-4-hydroxy-benzoic acid-1-O-beta-D-glucoside(6), hexadecanoic acid(7), stearic acid(8), n-tetratriacontanol(9), respectively. All the compounds are isolated from this plant for the first time, and compounds 5 and 6 are isolated from this genus for the first time.

Phylogenetic analysis of the complete genome of 11 BKV isolates obtained from allogenic stem cell transplant recipients in Ireland.

PubMed

Drew, Richard John; Walsh, Anne; Laoi, Bairbre Ni; Crowley, Brendan

2012-07-01

BK polyomavirus (family Polyomaviridae) may cause hemorrhagic cystitis (BKV-HC) in hematopoietic stem cell transplant recipients. Eleven complete BKV genomes (GenBank accession numbers: JN192431-JN192441) were sequenced from urine samples of allogenic hematopoietic stem cell transplant recipients and compared to complete BKV genomes in the published literature. Of the 11 isolates, seven (64%) were subgroup Ib-1, three (27%) isolates belonged to subgroup Ib-2 and a single isolate belonged to subtype III. The analysis of single-nucleotide polymorphisms in this study showed that isolates could be subclassified into subtypes I-IV and subgroups Ib-1 and Ib-2 on the basis of VP1 of the first part of the Large T-antigen (LTag). The non-coding control region (NCCR) of the 11 isolates was also sequenced. These sequences showed that there was consistent sequence homology within subgroups Ib-1 and Ib-2. Two new mutations were described in the isolates, G→C at O(84) in isolate SJH-LG-310, and a deletion at R(2-7) in isolate SJH-LG-309. No known transcription factor is thought to be present at the site of either of these mutations. There were no rearrangements seen in isolates and this may be because the patients were not followed up over time. There were five nucleotide positions at which subgroup Ib-1 isolated differed from subgroup Ib-2 isolates in the NCCR sequence, O(41) , P(18) , P(31) , R(4) , and S(18) . The mutation O(41) is present in the promoter granulocyte/macrophage stimulating factor) gene and the P(31) mutation is present in the NF-1 gene. Copyright © 2012 Wiley Periodicals, Inc.

Determination of the volatile and semi-volatile secondary metabolites, and aristolochic acids in Aristolochia ringens Vahl.

PubMed

Stashenko, Elena E; Andrés Ordóñez, Sergio; Marín, Néstor Armando; Martínez, Jairo René

2009-10-01

Volatile and semi-volatile secondary metabolites, as well as aristolochic acids (AA), present in leaves, stems, and flowers of Aristolochia ringens were determined by gas chromatography (GC)-mass spectrometry (MS) and high-performance liquid chromatography (HPLC) methods, respectively. Metabolite isolation was performed using different extraction techniques: microwave-assisted hydrodistillation (MWHD), supercritical fluid extraction, and headspace solid-phase microextraction (HS-SPME). The chemical composition of the extracts and oils was established by GC-MS. The determinations of AAI and AAII were conducted by methanolic extraction of different plant parts followed by HPLC analysis. Essential oil yields from leaves and stems were 0.008 +/- 0.0022% and 0.047 +/- 0.0026%, respectively. Aristolochia ringens flowers did not yield essential oil under MWHD. Sesquiterpene hydrocarbons (66%) were the main compounds in the essential oil isolated from leaves whereas monoterpene hydrocarbons (73%) predominated in the stems essential oil. Yields of extracts isolated by SFE from leaves, stems, and flowers were 4 +/- 1.8%, 1.2 +/- 0.25%, and 4 +/- 1.8%, respectively. In vivo HS-SPME of flowers isolated compounds with known unpleasant smells such as volatile aldehydes and short-chain carboxylic acids. HPLC analysis detected the presence of AAII in the flowers of Aristolochia ringens at a concentration of 610 +/- 47 mg/kg of dried flower.

Circulating Tumor Cells: From Theory to Nanotechnology-Based Detection

PubMed Central

Ming, Yue; Li, Yuanyuan; Xing, Haiyan; Luo, Minghe; Li, Ziwei; Chen, Jianhong; Mo, Jingxin; Shi, Sanjun

2017-01-01

Cancer stem cells with stem-cell properties are regarded as tumor initiating cells. Sharing stem-cell properties, circulating tumor cells (CTCs) are responsible for the development of metastasis, which significant affects CTC analysis in clinical practice. Due to their extremely low occurrence in blood, however, it is challenging to enumerate and analyze CTCs. Nanotechnology is able to address the problems of insufficient capture efficiency and low purity of CTCs owing to the unique structural and functional properties of nanomaterials, showing strong promise for CTC isolation and detection. In this review, we discuss the role of stem-like CTCs in metastases, provide insight into recent progress in CTC isolation and detection approaches using various nanoplatforms, and highlight the role of nanotechnology in the advancement of CTC research. PMID:28203204

Evidence of stratabound liquefaction in the formation of fractured topographic margins, cone chains and pit catenas along the Martian Dichotomy Boundary and in Isidis Planitia, Mars.

NASA Astrophysics Data System (ADS)

Gallagher, C.; Balme, M. R.

2012-04-01

On the low-lying plains along much of the Martian Dichotomy Boundary (MDB) and in the Isidis impact basin, cones and curving chains of cones, referred to as thumbprint terrain (TPT), are common. In the same settings, pit chains (catenas) occur in orthogonal to curving and conchoidal fracture sets between mesa-like crustal blocks, generally at or near topographic margins. Many of the fractures consist of linked pits rather than simple propagated cracks. These assemblages are often associated with the more disaggregated populations of blocks comprising chaos terrain. We show that the local planimetric arrangement of the cone chains, fractures and pit catenas is strikingly similar in both shape and scale, including lateral separation, length, longitudinal slope and radius of curvature. The summits of cones tend to be closely accordant along individual cone chains. Neighbouring cone chains tend to be mutually accordant on low gradient basin surfaces but generally stepped en echelon closer to the fractured basin margins. Similarly, the crustal blocks (including very isolated block sets) are often mutually stepped, and fractures between these en echelon blocks tend to be very close to horizontal. Hence, many cone chains, fractures and pit catenas in fractures share the property of being arranged along strike. They diverge morphologically by the cone chains being positive forms separated by narrow gulfs but the pit catenas being negative forms separated by planar blocks. All of these characteristics point to the possibility that the arcuate cone chains and the arcuate pit catenas have a common origin. In particular, we hypothesise that the cone chains characteristic of TPT along the MDB and in Isidis are filled, indurated and then exhumed pit catenas revealed by the stripping-away of intervening blocks [cf. 1]. Many other surfaces on Mars are pervaded by pits and pit catenas, with evidence of former water flow through the catenas suggesting that ground-ice thaw played a role in at least one mode of catena formation [2]. As well as presenting the morphological evidence for a genetic association between TPT and pit catenas, we present corroborative evidence that fluvial channel networks on Mars have in places increased in complexity through the linking of pits arranged in linear to arcuate arrays, culminating in a pseudo-branching channel network. Such systems do not occur at topographic margins and did not disintegrate into stepped crustal blocks. However, the scale of these channels and the volumes of liquid intermittently impounded in craters along these channel systems indicate that pit chains are associated with significant excess groundwater production leading to channelized flow, including catastrophic discharges when crater-impounded lakes along-flow were breached. Are the MDB and Isidis cone chains exhumed pit catenas and are the pits the surface expression of more deep-seated conduits? Do pit catenas indicate excess pore-water production, sufficient to link individual pits and dissect crustal blocks? Together, do these assemblages reflect the degradation of the MDB and Isidis margins and the subsequent stripping of adjacent low-lying plains? The crucial observations presented in this research (cone chains lying between crustal blocks, together with the morphometric similarities) are consistent with the interpretation of the cones and catenas having a common origin. Consequently, we hypothesise that the translated, back-rotated, tilted and capsized disposition of en echelon blocks is very reminiscent of the morphology produced during lateral spreading [3] associated with stratabound liquefaction below a low-gradient, rigid, insensitive surface. Significantly, such liquefaction events cause extensive, arcuate ground fractures along with the discharge of sediment-laden groundwater from the liquefiable substratum to the surface through pipes and conical boils confined within inter-block fractures. These conduits and their injectite are frequently indurated by secondary mineralisation, often making them more competent and less erodible than the confining material. Most often, lateral spreads occur at coastlines, with basin-ward normal faulting and extension of the original surface. Generally, seismic shaking of susceptible materials is responsible for lateral spreading but pore-water pressure changes, e.g. due to rapid marine recession and drawdown, may also play a role. Given the basin-and-margin setting of the martian cone, pit and block assemblages described in this research, we speculate that all three broad morphological types reflect the degradation of extensive marine margins and the deflation of the interiors of marine basins during long-term marine recession. [1] Williams et al. (2007) in Willis et al. (eds), Utah Geological Association Publication 36. [2] Weitz et al. (2006) Icarus 184, 436-451. [3] Wang et al. (2005) Icarus 175, 551-555.

The Isolation and Characterization of Human Prostate Cancer Stem Cells

DTIC Science & Technology

2012-02-01

established cell lines and primary patient samples) with human prostate fibroblasts hold promise as models of tumor initiation/cancer stem cell activity...We continue to optimize and validate our in vitro model of prostate cancer initiation to facilitate cancer stem cell discovery as well as drug targeting.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbieri, Federica; Wurth, Roberto; Ratto, Alessandra

Current carcinogenesis theory states that only a small subset of tumor cells, the cancer stem cells or tumor initiating cells (TICs), are responsible for tumor formation and progression. Human breast cancer-initiating cells have been identified as CD44-expressing cells, which retain tumorigenic activity and display stem cell-like properties. Spontaneous feline mammary carcinoma (FMC) is an aggressive cancer, which shows biological similarities to the human tumor counterpart. We report the isolation and phenotypic characterization of FMC-derived stem/progenitor cells, showing in vitro self-renewal, long-lasting proliferation and in vivo tumorigenicity. Twenty-one FMC samples were collected, histologically classified and characterized for the expression of Ki67,more » EGFR, ER-{alpha} and CD44, by immunohistochemistry. By culture in stem cell permissive conditions, we isolated, from 13 FMCs, a CD44-positive subpopulation able to survive and proliferate in vitro as mammospheres of different sizes and morphologies. When injected in NOD/SCID mice, FMC stem-like cells initiate tumors, generating cell heterogeneity and recapitulating the original histotype. In serum-containing medium, spheroid cells showed differentiation properties as shown by morphological changes, the loss of CD44 expression and tumorigenic potential. These data show that stem-defined culture of FMC enriches for TICs and validate the use of these cells as a suitable model for comparative oncology studies of mammary biology and testing therapeutic strategies aimed at eradicating TICs. -- Highlights: Black-Right-Pointing-Pointer Feline mammary carcinoma contain a sub-population of stem-like cells expressing CD44 Black-Right-Pointing-Pointer These grow as spheres in serum-free medium and self-renew Black-Right-Pointing-Pointer Isolated stem-like cancer cells initiate tumor in immunodeficient mice Black-Right-Pointing-Pointer Xenografted tumors are phenotypically similar to the original tumor Black-Right-Pointing-Pointer Upon differentiation, cells grow as monolayers, loosing the tumorigenic potential.« less

RNA-Sequencing Gene Expression Profiling of Orbital Adipose-Derived Stem Cell Population Implicate HOX Genes and WNT Signaling Dysregulation in the Pathogenesis of Thyroid-Associated Orbitopathy.

PubMed

Tao, Wensi; Ayala-Haedo, Juan A; Field, Matthew G; Pelaez, Daniel; Wester, Sara T

2017-12-01

The purpose of this study was to characterize the intrinsic cellular properties of orbital adipose-derived stem cells (OASC) from patients with thyroid-associated orbitopathy (TAO) and healthy controls. Orbital adipose tissue was collected from a total of nine patients: four controls and five patients with TAO. Isolated OASC were characterized with mesenchymal stem cell-specific markers. Orbital adipose-derived stem cells were differentiated into three lineages: chondrocytes, osteocytes, and adipocytes. Reverse transcription PCR of genes involved in the adipogenesis, chondrogenesis, and osteogenesis pathways were selected to assay the differentiation capacities. RNA sequencing analysis (RNA-seq) was performed and results were compared to assess for differences in gene expression between TAO and controls. Selected top-ranked results were confirmed by RT-PCR. Orbital adipose-derived stem cells isolated from orbital fat expressed high levels of mesenchymal stem cell markers, but low levels of the pluripotent stem cell markers. Orbital adipose-derived stem cells isolated from TAO patients exhibited an increase in adipogenesis, and a decrease in chondrogenesis and osteogenesis. RNA-seq disclosed 54 differentially expressed genes. In TAO OASC, expression of early neural crest progenitor marker (WNT signaling, ZIC genes and MSX2) was lost. Meanwhile, ectopic expression of HOXB2 and HOXB3 was found in the OASC from TAO. Our results suggest that there are intrinsic genetic and cellular differences in the OASC populations derived from TAO patients. The upregulation in adipogenesis in OASC of TAO may be is consistent with the clinical phenotype. Downregulation of early neural crest markers and ectopic expression of HOXB2 and HOXB3 in TAO OASC demonstrate dysregulation of developmental and tissue patterning pathways.

RNA-Sequencing Gene Expression Profiling of Orbital Adipose-Derived Stem Cell Population Implicate HOX Genes and WNT Signaling Dysregulation in the Pathogenesis of Thyroid-Associated Orbitopathy

PubMed Central

Tao, Wensi; Ayala-Haedo, Juan A.; Field, Matthew G.; Pelaez, Daniel; Wester, Sara T.

2017-01-01

Purpose The purpose of this study was to characterize the intrinsic cellular properties of orbital adipose-derived stem cells (OASC) from patients with thyroid-associated orbitopathy (TAO) and healthy controls. Methods Orbital adipose tissue was collected from a total of nine patients: four controls and five patients with TAO. Isolated OASC were characterized with mesenchymal stem cell–specific markers. Orbital adipose-derived stem cells were differentiated into three lineages: chondrocytes, osteocytes, and adipocytes. Reverse transcription PCR of genes involved in the adipogenesis, chondrogenesis, and osteogenesis pathways were selected to assay the differentiation capacities. RNA sequencing analysis (RNA-seq) was performed and results were compared to assess for differences in gene expression between TAO and controls. Selected top-ranked results were confirmed by RT-PCR. Results Orbital adipose-derived stem cells isolated from orbital fat expressed high levels of mesenchymal stem cell markers, but low levels of the pluripotent stem cell markers. Orbital adipose-derived stem cells isolated from TAO patients exhibited an increase in adipogenesis, and a decrease in chondrogenesis and osteogenesis. RNA-seq disclosed 54 differentially expressed genes. In TAO OASC, expression of early neural crest progenitor marker (WNT signaling, ZIC genes and MSX2) was lost. Meanwhile, ectopic expression of HOXB2 and HOXB3 was found in the OASC from TAO. Conclusion Our results suggest that there are intrinsic genetic and cellular differences in the OASC populations derived from TAO patients. The upregulation in adipogenesis in OASC of TAO may be is consistent with the clinical phenotype. Downregulation of early neural crest markers and ectopic expression of HOXB2 and HOXB3 in TAO OASC demonstrate dysregulation of developmental and tissue patterning pathways. PMID:29214313

In vitro Culture of Naïve Human Bone Marrow Mesenchymal Stem Cells: A Stemness Based Approach

PubMed Central

Pal, Bidisha; Das, Bikul

2017-01-01

Human bone marrow derived mesenchymal stem cells (BM-MSCs) resides in their niches in close proximity to hematopoietic stem cells (HSCs). These naïve MSCs have tremendous potential in regenerative therapeutics, and may also be exploited by cancer and infectious disease agents. Hence, it is important to study the physiological and pathological roles of naïve MSC. However, our knowledge of naïve MSCs is limited by lack of appropriate isolation and in vitro culture methods. Established culture methods use serum rich media, and serial passaging for retrospective isolation of MSCs. These primed MSCs may not reflect the true physiological and pathological roles of naive MSCs (Figure 1). Therefore, there is a strong need for direct isolation and in vitro culture of naïve MSCs to study their stemness (self-renewal and undifferentiated state) and developmental ontogeny. We have taken a niche-based approach on stemness to better maintain naïve MSCs in vitro. In this approach, stemness is broadly divided as niche dependent (extrinsic), niche independent (intrinsic) and niche modulatory (altruistic or competitive). Using this approach, we were able to maintain naïve CD271+/CD133+ BM-MSCs for 2 weeks. Furthermore, this in vitro culture system helped us to identify naïve MSCs as a protective niche site for Mycobacterium tuberculosis, the causative organism of pulmonary tuberculosis. In this review, we discuss the in vitro culture of primed vs. naïve human BM derived MSCs with a special focus on how a stemness based approach could facilitate the study of naïve BM-MSCs. PMID:28884113

Myocardial regeneration potential of adipose tissue-derived stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Xiaowen, E-mail: baixw01@yahoo.com; Alt, Eckhard, E-mail: ealt@mdanderson.org

Research highlights: {yields} Various tissue resident stem cells are receiving tremendous attention from basic scientists and clinicians and hold great promise for myocardial regeneration. {yields} For practical reasons, human adipose tissue-derived stem cells are attractive stem cells for future clinical application in repairing damaged myocardium. {yields} This review summarizes the characteristics of cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential and the, underlying mechanisms, and safety issues. -- Abstract: Various tissue resident stem cells are receiving attention from basic scientists and clinicians as they hold promise for myocardial regeneration. For practical reasons, adipose tissue-derivedmore » stem cells (ASCs) are attractive cells for clinical application in repairing damaged myocardium based on the following advantages: abundant adipose tissue in most patients and easy accessibility with minimally invasive lipoaspiration procedure. Several recent studies have demonstrated that both cultured and freshly isolated ASCs could improve cardiac function in animal model of myocardial infarction. The mechanisms underlying the beneficial effect of ASCs on myocardial regeneration are not fully understood. Growing evidence indicates that transplantation of ASCs improve cardiac function via the differentiation into cardiomyocytes and vascular cells, and through paracrine pathways. Paracrine factors secreted by injected ASCs enhance angiogenesis, reduce cell apoptosis rates, and promote neuron sprouts in damaged myocardium. In addition, Injection of ASCs increases electrical stability of the injured heart. Furthermore, there are no reported cases of arrhythmia or tumorigenesis in any studies regarding myocardial regeneration with ASCs. This review summarizes the characteristics of both cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential, and the underlying mechanisms for beneficial effect on cardiac function, and safety issues.« less

Isolation, culture and biological characteristics of multipotent porcine tendon-derived stem cells.

PubMed

Yang, Jinjuan; Zhao, Qianjun; Wang, Kunfu; Ma, Caiyun; Liu, Hao; Liu, Yingjie; Guan, Weijun

2018-06-01

Tendon-derived stem cells (TDSCs), a postulated multi-potential stem cell population, play significant role in the postnatal replenishment of tendon injuries. However, the majority of experimental materials were obtained from horse, rat, human and rabbit, but rarely from pig. In this research, 1‑day‑old pig was chosen as experimental sample source to isolate and culture TDSCs in vitro. Specific markers of TDSCs were then characterized by immunofluorescence and reverse transcription polymerase chain reaction (RT‑PCR) assays. The results showed that TDSCs could be expanded for 11 passages in vitro. The expression of specific markers, such as collagen Ⅰ, collagen Ⅲ, α‑smooth muscle actin (α‑SMA), CD105 and CD90 were observed by immunofluorescence and RT‑PCR. TDSCs were induced to differentiate into adipocytes, osteoblasts and chondrocytes, respectively. These results suggest that TDSCs isolated from porcine tendon exhibit the characteristics of multipotent stem cells. TDSCs, therefore, may be potential candidates for cellular transplantation therapy and tissue engineering in tendon injuries.

Isolation of Human Colon Stem Cells Using Surface Expression of PTK7.

PubMed

Jung, Peter; Sommer, Christian; Barriga, Francisco M; Buczacki, Simon J; Hernando-Momblona, Xavier; Sevillano, Marta; Duran-Frigola, Miquel; Aloy, Patrick; Selbach, Matthias; Winton, Douglas J; Batlle, Eduard

2015-12-08

Insertion of reporter cassettes into the Lgr5 locus has enabled the characterization of mouse intestinal stem cells (ISCs). However, low cell surface abundance of LGR5 protein and lack of high-affinity anti-LGR5 antibodies represent a roadblock to efficiently isolate human colonic stem cells (hCoSCs). We set out to identify stem cell markers that would allow for purification of hCoSCs. In an unbiased approach, membrane-enriched protein fractions derived from in vitro human colonic organoids were analyzed by quantitative mass spectrometry. Protein tyrosine pseudokinase PTK7 specified a cell population within human colonic organoids characterized by highest self-renewal and re-seeding capacity. Antibodies recognizing the extracellular domain of PTK7 allowed us to isolate and expand hCoSCs directly from patient-derived mucosa samples. Human PTK7+ cells display features of canonical Lgr5+ ISCs and include a fraction of cells that undergo differentiation toward enteroendocrine lineage that resemble crypt label retaining cells (LRCs). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

NOTCH3 is expressed in human apical papilla and in subpopulations of stem cells isolated from the tissue.

PubMed

Jamal, Mohamed; Chogle, Sami M; Karam, Sherif M; Huang, George T-J

2015-09-01

NOTCH plays a role in regulating stem cell function and fate decision. It is involved in tooth development and injury repair. Information regarding NOTCH expression in human dental root apical papilla (AP) and its residing stem cells (SCAP) is limited. Here we investigated the expression of NOTCH3, its ligand JAG1, and mesenchymal stem cell markers CD146 and STRO-1 in the AP or in the primary cultures of SCAP isolated from AP. Our in situ immunostaining showed that in the AP NOTCH3 and CD146 were co-expressed and associated with blood vessels having NOTCH3 located more peripherally. In cultured SCAP, NOTCH3 and JAG1 were co-expressed. Flow cytometry analysis showed that 7%, 16% and 98% of the isolated SCAP were positive for NOTCH3, STRO-1 and CD146, respectively with a rare 1.5% subpopulation of SCAP co-expressing all three markers. The expression level of NOTCH3 reduced when SCAP underwent osteogenic differentiation. Our findings are the first step towards defining the regulatory role of NOTCH3 in SCAP fate decision.

Proteomic Analysis of Fusarium solani Isolated from the Asian Longhorned Beetle, Anoplophora glabripennis

PubMed Central

Scully, Erin D.; Hoover, Kelli; Carlson, John; Tien, Ming; Geib, Scott M.

2012-01-01

Wood is a highly intractable food source, yet many insects successfully colonize and thrive in this challenging niche. Overcoming the lignin barrier of wood is a key challenge in nutrient acquisition, but full depolymerization of intact lignin polymers has only been conclusively demonstrated in fungi and is not known to occur by enzymes produced by insects or bacteria. Previous research validated that lignocellulose and hemicellulose degradation occur within the gut of the wood boring insect, Anoplophora glabripennis (Asian longhorned beetle), and that a fungal species, Fusarium solani (ATCC MYA 4552), is consistently associated with the larval stage. While the nature of this relationship is unresolved, we sought to assess this fungal isolate's ability to degrade lignocellulose and cell wall polysaccharides and to extract nutrients from woody tissue. This gut-derived fungal isolate was inoculated onto a wood-based substrate and shotgun proteomics using Multidimensional Protein Identification Technology (MudPIT) was employed to identify 400 expressed proteins. Through this approach, we detected proteins responsible for plant cell wall polysaccharide degradation, including proteins belonging to 28 glycosyl hydrolase families and several cutinases, esterases, lipases, pectate lyases, and polysaccharide deacetylases. Proteinases with broad substrate specificities and ureases were observed, indicating that this isolate has the capability to digest plant cell wall proteins and recycle nitrogenous waste under periods of nutrient limitation. Additionally, several laccases, peroxidases, and enzymes involved in extracellular hydrogen peroxide production previously implicated in lignin depolymerization were detected. In vitro biochemical assays were conducted to corroborate MudPIT results and confirmed that cellulases, glycosyl hydrolases, xylanases, laccases, and Mn- independent peroxidases were active in culture; however, lignin- and Mn- dependent peroxidase activities were not detected While little is known about the role of filamentous fungi and their associations with insects, these findings suggest that this isolate has the endogenous potential to degrade lignocellulose and extract nutrients from woody tissue. PMID:22496740

Effect of autologous adipose-derived mesenchymal stem cell therapy in the treatment of a post-traumatic chondral defect of the knee

PubMed Central

Freitag, Julien; Li, Douglas; Wickham, James; Shah, Kiran; Tenen, Abi

2017-01-01

Isolated chondral defects have a limited capacity to heal and predispose to the development of osteoarthritis. Current surgical management can be unpredictable in outcome. Improved understanding of the action of mesenchymal stem cells (MSCs) has seen renewed interest in their role in cartilage repair. A 26-year-old athlete presented with a post-traumatic, isolated patella chondral defect. The patient underwent an arthroscopy with removal of a chondral loose body. After failure to symptomatically improve 12 months following surgery, the patient received intra-articular autologous adipose-derived mesenchymal stem cell (ADMSC) therapy. PMID:29038190

Characterization of Amniotic Stem Cells

PubMed Central

Koike, Chika; Zhou, Kaixuan; Takeda, Yuji; Fathy, Moustafa; Okabe, Motonori; Yoshida, Toshiko; Nakamura, Yukio; Kato, Yukio

2014-01-01

Abstract The amnion membrane is developed from embryo-derived cells, and amniotic cells have been shown to exhibit multidifferentiation potential. These cells represent a desirable source for stem cells for a variety of reasons. However, to date very few molecular analyses of amnion-derived cells have been reported, and efficient markers for isolating the stem cells remain unclear. This paper assesses the characterization of amnion-derived cells as stem cells by examining stemness marker expressions for amnion-derived epithelial cells and mesenchymal cells by flow cytometry, immunocytochemistry, and quantitative PCR. Flow cytometry revealed that amnion epithelial cells expressed CD133, CD 271, and TRA-1-60, whereas mecenchymal cells expressed CD44, CD73, CD90, and CD105. Immunohistochemistry showed that both cells expressed the stemness markers Oct3/4, Sox2, Klf4, and SSEA4. Stemness genes' expression in amnion epithelial cells, mesenchymal cells, fibroblast, bone marrow–derived mesenchymal stem cells (MSCs), and induced pluripotent stem cells (iPSCs) was compared by quantitative reverse-transcription polymerase chain reaction (RT-PCR). Amnion-derived epithelial cells and mesenchymal cells expressed Oct3/4, Nanog, and Klf4 more than bone marrow–derived MSCs. The sorted TRA1-60–positive cells expressed Oct3/4, Nanog, and Klf4 more than unsorted cells or TRA1-60–negative cells. TRA1-60 can be a marker for isolating amnion epithelial stem cells. PMID:25068631

Non-toxic melanin production inhibitors from Garcinia livingstonei (Clusiaceae).

PubMed

Mulholland, Dulcie A; Mwangi, Elizabeth M; Dlova, Ncoza C; Plant, Nick; Crouch, Neil R; Coombes, Phillip H

2013-09-16

The stem bark of Garcinia livingstonei is used traditionally as a skin lightening agent. To isolate and identify compounds responsible for the observed skin lightening activity of Garcinia livingstonei and to evaluate their cytotoxicity. Constituents of the stem bark and fruits of Garcinia livingstonei were isolated using chromatographic techniques and structures were determined using 1D and 2D NMR and MS analysis. MeWo cells were used to evaluate the cytotoxicity and impact on melanin levels of extracts and compounds isolated, in vitro. Twelve known compounds, morelloflavone (1), morelloflavone-7″-sulphate (2), guttiferone A (3), sargaol (4), isojacareubin (5), 6-deoxyisojacareubin (6) and in addition to the common triterpenoids, betulin, betulin aldehyde, lupeol, lupenone, euphol and stigmasterol were isolated in this investigation. Morelloflavone, morelloflavone-7″-sulphate and sargaol, were found to be considerably less cytotoxic and more effective as skin lightening agents than hydroquinone. A range of compounds was isolated from the stem bark and fruit of Garcinia livingstonei. Although the bark extract contained the cytotoxic guttiferone A, it was found to be less toxic than hydroquinone, and morelloflavone, the 7″-sulphate derivative and sargaol show potential for development as depigmentation/skin lightening agents. © 2013 Elsevier Ireland Ltd. All rights reserved.

Endophytic bacterial flora in root and stem tissues of black pepper (Piper nigrum L.) genotype: isolation, identification and evaluation against Phytophthora capsici.

PubMed

Aravind, R; Kumar, A; Eapen, S J; Ramana, K V

2009-01-01

To isolate and identify black pepper (Piper nigrum L) associated endophytic bacteria antagonistic to Phytophthora capsici causing foot rot disease. Endophytic bacteria (74) were isolated, characterized and evaluated against P. capsici. Six genera belong to Pseudomonas spp (20 strains), Serratia (1 strain), Bacillus spp. (22 strains), Arthrobacter spp. (15 strains), Micrococcus spp. (7 strains), Curtobacterium sp. (1 strain) and eight unidentified strains were isolated from internal tissues of root and stem. Three isolates, IISRBP 35, IISRBP 25 and IISRBP 17 were found effective for Phytophthora suppression in multilevel screening assays which recorded over 70% disease suppression in greenhouse trials. A species closest match (99% similarity) of IISRBP 35 was established as Pseudomonas aeruginosa (Pseudomonas EF568931), IISRBP 25 as P. putida (Pseudomonas EF568932), and IISRBP 17 as Bacillus megaterium (B. megaterium EU071712) based on 16S rDNA sequencing. Black pepper associated P. aeruginosa, P. putida and B. megaterium were identified as effective antagonistic endophytes for biological control of Phytophthora foot rot in black pepper. This work provides the first evidence for endophytic bacterial diversity in black pepper stem and roots, with biocontrol potential against P. capsici infection.

Characterization and genetic manipulation of human umbilical cord vein mesenchymal stem cells: potential application in cell-based gene therapy.

PubMed

Kermani, Abbas Jafari; Fathi, Fardin; Mowla, Seyed Javad

2008-04-01

Stem cells are defined by two main characteristics: self-renewal capacity and commitment to multi-lineage differentiation. The cells have a great therapeutic potential in repopulating damaged tissues as well as being genetically manipulated and used in cell-based gene therapy. Umbilical cord vein is a readily available and inexpensive source of stem cells that are capable of generating various cell types. Despite the recent isolation of human umbilical cord vein mesenchymal stem cells (UVMSC), the self-renewal capacity and the potential clinical application of the cells are not well known. In the present study, we have successfully isolated and cultured human UVMSCs. Our data further revealed that the isolated cells express the self-renewal genes Oct-4, Nanog, ZFX, Bmi-1, and Nucleostemin; but not Zic-3, Hoxb-4, TCL-1, Tbx-3 and Esrrb. In addition, our immunocytochemistry results revealed the expression of SSEA-4, but not SSEA-3, TRA-1-60, and TRA-1-81 embryonic stem cell surface markers in the cells. Also, we were able to transfect the cells with a reporter, enhanced green fluorescent protein (EGFP), and a therapeutic human brain-derived neurotrophic factor (hBDNF) gene by means of electroporation and obtained a stable cell line, which could constantly express both transgenes. The latter data provide further evidence on the usefulness of umbilical cord vein mesenchymal stem cells as a readily available source of stem cells, which could be genetically manipulated and used in cell-based gene therapy applications.

Functional design criteria for interim stabilization safety class 1 trip circuit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larson, R.E., Westinghouse Hanford

1996-06-10

This Functional Design Criteria document outlines the basic requirements for the Safety Class 1 Trip Circuit. The objective of the Safety Class 1 Trip Circuit is to isolate the power circuitry to the Class 1 Division 2, Group B or lesser grade electrically fed loads located in the pump pit. The electrically fed load circuits need to have power isolated to them upon receipt of the following conditions, loss of flammable gases being released (above a predetermined threshold), and seismic(greater than 0.12g acceleration) activity. The two circuits requiring power isolation are the pump and heat trace power circuits. The Safetymore » Class 1 Trip Circuit will be used to support salt well pumping in SST`s containing potentially flammable gas-bearing / gas-producing radioactive waste.« less

Murine hepatocellular carcinoma derived stem cells reveal epithelial-to-mesenchymal plasticity.

PubMed

Jayachandran, Aparna; Shrestha, Ritu; Dhungel, Bijay; Huang, I-Tao; Vasconcelos, Marianna Yumi Kawashima; Morrison, Brian J; Ramlogan-Steel, Charmaine A; Steel, Jason C

2017-09-26

To establish a model to enrich and characterize stem-like cells from murine normal liver and hepatocellular carcinoma (HCC) cell lines and to further investigate stem-like cell association with epithelial-to-mesenchymal transition (EMT). In this study, we utilized a stem cell conditioned serum-free medium to enrich stem-like cells from mouse HCC and normal liver cell lines, Hepa 1-6 and AML12, respectively. We isolated the 3-dimensional spheres and assessed their stemness characteristics by evaluating the RNA levels of stemness genes and a cell surface stem cell marker by quantitative reverse transcriptase-PCR (qRT-PCR). Next, we examined the relationship between stem cells and EMT using qRT-PCR. Three-dimensional spheres were enriched by culturing murine HCC and normal hepatocyte cell lines in stem cell conditioned serum-free medium supplemented with epidermal growth factor, basic fibroblast growth factor and heparin sulfate. The 3-dimensional spheres had enhanced stemness markers such as Klf4 and Bmi1 and hepatic cancer stem cell (CSC) marker Cd44 compared to parental cells grown as adherent cultures. We report that epithelial markers E-cadherin and ZO-1 were downregulated, while mesenchymal markers Vimentin and Fibronectin were upregulated in 3-dimensional spheres. The 3-dimensional spheres also exhibited changes in expression of Snai , Zeb and Twist family of EMT transcription factors. Our novel method successfully enriched stem-like cells which possessed an EMT phenotype. The isolation and characterization of murine hepatic CSCs could establish a precise target for the development of more effective therapies for HCC.

Monetary, Food, and Social Rewards Induce Similar Pavlovian-to-Instrumental Transfer Effects

PubMed Central

Lehner, Rea; Balsters, Joshua H.; Herger, Andreas; Hare, Todd A.; Wenderoth, Nicole

2017-01-01

Multiple types of reward, such as money, food or social approval, are capable of driving behavior. However, most previous investigations have only focused on one of these reward classes in isolation, as such it is not clear whether different reward classes have a unique influence on instrumental responding or whether the subjective value of the reward, rather than the reward type per se, is most important in driving behavior. Here, we investigate behavior using a well-established reward paradigm, Pavlovian-to-instrumental transfer (PIT), and three different reward types: monetary, food and social rewards. The subjective value of each reward type was matched using a modified Becker-DeGroot-Marschak (BDM) auction where subjective reward value was expressed through physical effort using a bimanual grip force task. We measured the influence of reward-associated stimuli on how participants distributed forces between hands when reaching a target effort range on the screen bimanually and on how much time participants spent in this target range. Participants spent significantly more time in the target range (15% ± 2% maximal voluntary contraction) when a stimulus was presented that was associated with a reward used during instrumental conditioning or Pavlovian conditioning compared to a stimulus associated with a neutral outcome (i.e., general PIT). The strength of the PIT effect was modulated by subjective value (i.e., individuals who showed a stronger PIT effect rated the value of rewards more highly), but not by reward type, demonstrating that stimuli of all reward types were able to act as appetitive reinforcers and influenced instrumental responding, when matched to the same subjective reward value. This is the first demonstration that individually matched monetary, food and social rewards are equally effective as appetitive reinforcers in PIT. These findings strengthen the hypotheses that the subjective value is crucial for how much reward-associated stimuli influence behavior. PMID:28101010

113. ARAI Hot cell (ARA626) Building wall sections and details ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

113. ARA-I Hot cell (ARA-626) Building wall sections and details of radio chemistry lab. Shows high-bay roof over hot cells and isolation rooms below grade storage pit for fuel elements. Norman Engineering Company: 961-area/SF-626-A-4. Date: January 1959. Ineel index code no. 068-0626-00-613-102724. - Idaho National Engineering Laboratory, Army Reactors Experimental Area, Scoville, Butte County, ID

Current overview on dental stem cells applications in regenerative dentistry.

PubMed

Bansal, Ramta; Jain, Aditya

2015-01-01

Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications.

Elimination of Grapevine leafroll associated virus-3, Grapevine rupestris stem pitting associated virus and Grapevine virus A from a Tunisian Cultivar by Somatic Embryogenesis and Characterization of the Somaclones Using Ampelographic Descriptors

PubMed Central

Bouamama-Gzara, Badra; Selmi, Ilhem; Chebil, Samir; Melki, Imene; Mliki, Ahmed; Ghorbel, Abdelwahed; Carra, Angela; Carimi, Francesco; Mahfoudhi, Naima

2017-01-01

Prospecting of local grapevine (Vitis vinifera L.) germplasm revealed that Tunisia possesses a rich patrimony which presents diversified organoleptic characteristics. However, viral diseases seriously affect all local grapevine cultivars which risk a complete extinction. Sanitation programs need to be established to preserve and exploit, as a gene pool, the Tunisian vineyards areas. The presence of the Grapevine leafroll associated virus-3 (GLRaV-3), Grapevine stem pitting associated virus (GRSPaV) and Grapevine virus A (GVA), were confirmed in a Tunisian grapevine cultivar using serological and molecular analyses. The association between GRSPaV and GVA viruses induces more rugose wood symptoms and damages. For this reason the cleansing of the infected cultivar is highly advisable. Direct and recurrent somatic embryos of cv. ‘Hencha’ were successfully induced from filament, when cultured on Chée and Pool (1987). based-medium, enriched with 2 mg 1−1 of 2,4-dichlorophenoxyacetic acid and 2.5 mg 1−1 of Thidiazuron, after 36 weeks of culture. After six months of acclimatization, RT-PCR carried on 50 somaplants confirmed the absence of GVA, GRSPa-V as well as GLRaV-3 viruses in all somaplants. Ampelographic analysis, based on eight OIV descriptors, was carried out on two years acclimated somaplants, compared to the mother plant. Results demonstrated that the shape and contours of 46 somaclones leaves are identical to mother plant leaves and four phenotypically off-type plants were observed. The healthy state of 100% ‘Hencha’ somaclones and the high percentage of phenotypically true-to-type plants demonstrate that somatic embryogenesis is a promising technique to adopt for grapevine viruses elimination. PMID:29238279

Elimination of Grapevine leafroll associated virus-3, Grapevine rupestris stem pitting associated virus and Grapevine virus A from a Tunisian Cultivar by Somatic Embryogenesis and Characterization of the Somaclones Using Ampelographic Descriptors.

PubMed

Bouamama-Gzara, Badra; Selmi, Ilhem; Chebil, Samir; Melki, Imene; Mliki, Ahmed; Ghorbel, Abdelwahed; Carra, Angela; Carimi, Francesco; Mahfoudhi, Naima

2017-12-01

Prospecting of local grapevine ( Vitis vinifera L.) germplasm revealed that Tunisia possesses a rich patrimony which presents diversified organoleptic characteristics. However, viral diseases seriously affect all local grapevine cultivars which risk a complete extinction. Sanitation programs need to be established to preserve and exploit, as a gene pool, the Tunisian vineyards areas. The presence of the Grapevine leafroll associated virus-3 (GLRaV-3), Grapevine stem pitting associated virus (GRSPaV) and Grapevine virus A (GVA), were confirmed in a Tunisian grapevine cultivar using serological and molecular analyses. The association between GRSPaV and GVA viruses induces more rugose wood symptoms and damages. For this reason the cleansing of the infected cultivar is highly advisable. Direct and recurrent somatic embryos of cv. 'Hencha' were successfully induced from filament, when cultured on Chée and Pool (1987). based-medium, enriched with 2 mg 1 -1 of 2,4-dichlorophenoxyacetic acid and 2.5 mg 1 -1 of Thidiazuron, after 36 weeks of culture. After six months of acclimatization, RT-PCR carried on 50 somaplants confirmed the absence of GVA, GRSPa-V as well as GLRaV-3 viruses in all somaplants. Ampelographic analysis, based on eight OIV descriptors, was carried out on two years acclimated somaplants, compared to the mother plant. Results demonstrated that the shape and contours of 46 somaclones leaves are identical to mother plant leaves and four phenotypically off-type plants were observed. The healthy state of 100% 'Hencha' somaclones and the high percentage of phenotypically true-to-type plants demonstrate that somatic embryogenesis is a promising technique to adopt for grapevine viruses elimination.

Porcine uterus contains a population of mesenchymal stem cells.

PubMed

Miernik, Katarzyna; Karasinski, Janusz

2012-02-01

The uterus has a remarkable ability of cycling remodeling throughout the reproductive life of the female. Recent findings in the human and mouse indicate that adult stem/progenitor cells may play a prominent role in the maintenance of uterine endometrial and myometrial homeostasis. We aimed to characterize the prospective stem/progenitor cells in the porcine uterus and establish a new model for uterine stem cell research. In this study, we demonstrated that cells isolated from porcine uterus have capacity for in vitro differentiation into adipogenic and osteogenic lineages and express the mesenchymal stem cell (MSC) markers CD29, CD44, CD144, CD105, and CD140b as revealed by RT-PCR. Moreover, we showed that some cells isolated from the porcine uterus when cultured at low density produce large clones with an efficiency of 0.035%. Simultaneously, they were negative for hematopoietic stem cell markers such as CD34 and CD45. Low expression of nestin, which is specific for neural stem cells and various progenitor cells, was also detected. We conclude that the porcine uterus contains a small population of undifferentiated cells with MSC-like properties similar to human and mouse uteri.

Adult human neural stem cell therapeutics: Current developmental status and prospect.

PubMed

Nam, Hyun; Lee, Kee-Hang; Nam, Do-Hyun; Joo, Kyeung Min

2015-01-26

Over the past two decades, regenerative therapies using stem cell technologies have been developed for various neurological diseases. Although stem cell therapy is an attractive option to reverse neural tissue damage and to recover neurological deficits, it is still under development so as not to show significant treatment effects in clinical settings. In this review, we discuss the scientific and clinical basics of adult neural stem cells (aNSCs), and their current developmental status as cell therapeutics for neurological disease. Compared with other types of stem cells, aNSCs have clinical advantages, such as limited proliferation, inborn differentiation potential into functional neural cells, and no ethical issues. In spite of the merits of aNSCs, difficulties in the isolation from the normal brain, and in the in vitro expansion, have blocked preclinical and clinical study using aNSCs. However, several groups have recently developed novel techniques to isolate and expand aNSCs from normal adult brains, and showed successful applications of aNSCs to neurological diseases. With new technologies for aNSCs and their clinical strengths, previous hurdles in stem cell therapies for neurological diseases could be overcome, to realize clinically efficacious regenerative stem cell therapeutics.

Bulge Region as a Putative Hair Follicle Stem Cells Niche: A Brief Review

PubMed Central

JOULAI VEIJOUYE, Sanaz; YARI, Abazar; HEIDARI, Fatemeh; SAJEDI, Nayereh; GHOROGHI MOGHANI, Fatemeh; NOBAKHT, Maliheh

2017-01-01

Background: Hair follicle stem cells exist in different sites. Most of the hair follicle stem cells are reside in niche called bulge. Bulge region is located between the opening of sebaceous gland and the attachment site of the arrector pili muscle. Methods: Data were collected using databases and resources of PubMed, Web of Science, Science Direct, Scopus, MEDLINE and their references from the earliest available published to identify English observational studies on hair follicle bulge region. Results: Bulge stem cells are pluripotent with high proliferative capacity. Specific markers allow the bulge cells to be isolated from mouse or human hair follicle. Stem cells isolated from bulge region are label retaining and slow cycling hence these cells are defined as label-retaining cells. Bulge cell populations, due to their plasticity nature are able to differentiate into distinct linage and could contribute in tissue regeneration. Conclusion: The current review discuss about bulge stem cells characteristics and biology including their cycle, location, plasticity, specific markers and regenerative nature. Also the differences between mouse and human hair follicles are investigated. PMID:29026781

[Alkaloids and lignans from stems of Piper betle].

PubMed

Huang, Xiangzhong; Yin, Yan; Huang, Wenquan; Sun, Kuizong; Cheng, Chunmei; Bai, Lian; Dai, Yun

2010-09-01

Alkaloids and lignans from the stems of Piper betle were studied. Compounds were isolated and purified by repeated silica gel, reverse phase silica gel, Sephadex LH-20 column chromatography and preparative thin layer chromatography. The structures were elucidated on the basis of spectral analysis. From the ethyl acetate soluble fractions of the 70% acetone extract, ten compounds were isolated and identified as piperine (1), pellitorine (2), N-isobutyl-2E,4E-dodecadienamide (3), dehydropipernonaline (4), piperdardine (5), piperolein-B (6), guineensine (7), (2E,4E)-N-isobutyl-7-(3',4'-methylenedioxyphenyl)-2,4-heptadienamide (8), syringaresinol-O-beta-D-glucopyranoside (9),pinoresinol (10). All Compounds were isolated from the plant for the first time, and compounds 9 and 10 were isolated firstly from the genus.

[Studies on chemical constituents from stems and leaves of Jasminum lanceolarium].

PubMed

Sun, Jia-ming; Yang, Jun-shan; Zhang, Hui

2008-09-01

To investigate the chemical constituents in stem and leaves of Jasminum lanceolarium. The constituents of the EtOAc-soluble portion of the 95% ethanol extractive were isolated and purified by means of column chromatographic methods. Compounds were identified by their physical characteristics and spectral features. Eight compounds were isolated and identified as 5, 7, 3', 5'-tetrahydroxyflavanone (1), (2S)-5, 7, 3', 4'-tetrahydroxyflavan-5-O-beta-D-glucopyranosie (2), mannitol (3), nonacosane (4), trans-p-coumaric acid (5), cis-p-coumaric acid (6), ferulic acid (7) and, trans-cinnamic acid (8). Compounds 14 were isolated from this genus for the first time. And compounds 5 and 6 were isolated from this plant for the first time.

Isolation, identification and multipotential differentiation of mouse adipose tissue-derived stem cells.

PubMed

Taha, Masoumeh Fakhr; Hedayati, Vahideh

2010-08-01

Bone marrow and adipose tissue have provided two suitable sources of mesenchymal stem cells. Although previous studies have confirmed close similarities between bone marrow-derived stem cells (BM-MSCs) and adipose tissue-derived stem cells (ADSCs), the molecular phenotype of ADSCs is still poorly identified. In the present study, mouse ADSCs were isolated from the inguinal fat pad of 12-14 weeks old mice. Freshly isolated and three passaged ADSCs were analyzed for the expression of OCT4, Sca-1, c-kit and CD34 by RT-PCR. Three passaged ADSCs were analyzed by flow cytometry for the presence of CD11b, CD45, CD31, CD29 and CD44. Moreover, cardiogenic, adipogenic and neurogenic differentiation of ADSCs were induced in vitro. Freshly isolated ADSCs showed the expression of OCT4, Sca-1, c-kit and CD34, and two days cultured ADSCs were positively immunostained with anti-OCT4 monoclonal antibody. After three passages, the expression of OCT4, c-kit and CD34 eliminated, while the expression of Sca-1 showed a striking enhancement. These cells were identified positive for CD29 and CD44 markers, and they showed the lack of CD45 and CD31 expression. Three passaged ADSCs were differentiated to adipocyte-, cardiomyocyte- and neuron-like cells that were identified based on the positive staining with Sudan black, anti-cardiac troponin I antibody and anti-map-2 antibody, respectively. In conclusion, adipose tissue contains a stem cell population that seems to be a good multipotential cell candidate for the future cell replacement therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

s-SHIP expression identifies a subset of murine basal prostate cells as neonatal stem cells

PubMed Central

Brocqueville, Guillaume; Chmelar, Renee S.; Bauderlique-Le Roy, Hélène; Deruy, Emeric; Tian, Lu; Vessella, Robert L.; Greenberg, Norman M.; Bourette, Roland P.

2016-01-01

Isolation of prostate stem cells (PSCs) is crucial for understanding their biology during normal development and tumorigenesis. In this aim, we used a transgenic mouse model expressing GFP from the stem cell-specific s-SHIP promoter to mark putative stem cells during postnatal prostate development. Here we show that cells identified by GFP expression are present transiently during early prostate development and localize to the basal cell layer of the epithelium. These prostate GFP+ cells are a subpopulation of the Lin− CD24+ Sca-1+ CD49f+ cells and are capable of self-renewal together with enhanced growth potential in sphere-forming assay in vitro, a phenotype consistent with that of a PSC population. Transplantation assays of prostate GFP+ cells demonstrate reconstitution of prostate ducts containing both basal and luminal cells in renal grafts. Altogether, these results demonstrate that s-SHIP promoter expression is a new marker for neonatal basal prostate cells exhibiting stem cell properties that enables PSCs in situ identification and isolation via a single consistent parameter. Transcriptional profiling of these GFP+ neonatal stem cells showed an increased expression of several components of the Wnt signaling pathway. It also identified stem cell regulators with potential applications for further analyses of normal and cancer stem cells. PMID:27081082

Generation of Mesenchymal-Like Stem Cells From Urine in Pediatric Patients.

PubMed

He, W; Zhu, W; Cao, Q; Shen, Y; Zhou, Q; Yu, P; Liu, X; Ma, J; Li, Y; Hong, K

2016-01-01

Mesenchymal stem cells (MSCs) have been widely used for regenerative medicine. Traditionally, the procedures of MSC isolation are usually invasive and time-consuming. Urine is merely a body waste, and recent studies have suggested that urine represents an alternative source of stem cells. We, therefore, determined whether the possibility of isolating mesenchymal-like stem cells was practical from human urine. A total of 16 urine samples were collected from pediatric patients. Urine-derived cells were isolated, expanded, and identified for specific cell surface markers using flow cytometry. Cell morphology was observed by microscopy. Osteogenic and adipogenic differentiation potential were determinded by culturing cells in specific induction medium, and assessed by alkaline phosphatase and oil red O stainings, respectively. Clones were established and passaged successfully from primary cultures of urine cells. Cultured urine-derived cells at passage 3 were fusiform and arranged with certain directionality. Urine-derived cells at passage 5 displayed expressions of cell surface markers (CD29, CD105, CD166, CD90, and CD13). There was no expression of the general hematopoietic cell markers (CD45, CD34, and HLA-DR). Under in vitro induction conditions, urine-derived cells at passage 5 were able to differentiate into osteoblasts, but not adipocytes. Urine may be a noninvasive source for mesenchymal-like stem cells. These cells could potentially provide a new source of autologous stem cells for regenerative medicine and cell therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

Stem/progenitor cells from inflamed human dental pulp retain tissue regeneration potential

PubMed Central

Alongi, Dominick J; Yamaza, Takayoshi; Song, Yingjie; Fouad, Ashraf F; Romberg, Elaine E; Shi, Songtao; Tuan, Rocky S; Huang, George T-J

2011-01-01

Background Potent stem/progenitor cells have been isolated from normal human dental pulps termed dental pulp stem cells (DPSCs). However, it is unknown whether these cells exist in inflamed pulps (IPs). Aims To determine whether DPSCs can be identified and isolated from IPs; and if they can be successfully cultured, whether they retain tissue regeneration potential in vivo. Materials & methods DPSCs from freshly collected normal pulps (NPs) and IPs were characterized in vitro and their tissue regeneration potential tested using an in vivo study model. Results The immunohistochemical analysis showed that IPs expressed higher levels of mesenchymal stem cell markers STRO-1, CD90, CD105 and CD146 compared with NPs (p < 0.05). Flow cytometry analysis showed that DPSCs from both NPs and IPs expressed moderate to high levels of CD146, stage-specific embryonic antigen-4, CD73 and CD166. Total population doubling of DPSCs-IPs (44.6 ± 2.9) was lower than that of DPSCs-NPs (58.9 ± 2.5) (p < 0.05), and DPSCs-IPs appeared to have a decreased osteo/dentinogenic potential compared with DPSCs-NPs based on the mineral deposition in cultures. Nonetheless, DPSCs-IPs formed pulp/dentin complexes similar to DPSCs-NPs when transplanted into immunocompromised mice. Conclusion DPSCs-IPs can be isolated and their mesenchymal stem cell marker profiles are similar to those from NPs. Although some stem cell properties of DPSCs-IPs were altered, cells from some samples remained potent in tissue regeneration in vivo. PMID:20465527

Isolation and gene expression analysis of single potential human spermatogonial stem cells.

PubMed

von Kopylow, K; Schulze, W; Salzbrunn, A; Spiess, A-N

2016-04-01

It is possible to isolate pure populations of single potential human spermatogonial stem cells without somatic contamination for down-stream applications, for example cell culture and gene expression analysis. We isolated pure populations of single potential human spermatogonial stem cells (hSSC) without contaminating somatic cells and analyzed gene expression of these cells via single-cell real-time RT-PCR. The isolation of a pure hSSC fraction could enable clinical applications such as fertility preservation for prepubertal boys and in vitro-spermatogenesis. By utilizing largely nonspecific markers for the isolation of spermatogonia (SPG) and hSSC, previously published cell selection methods are not able to deliver pure target cell populations without contamination by testicular somatic cells. However, uniform cell populations free of somatic cells are necessary to guarantee defined growth conditions in cell culture experiments and to prevent unintended stem cell differentiation. Fibroblast growth factor receptor 3 (FGFR3) is a cell surface protein of human undifferentiated A-type SPG and a promising candidate marker for hSSC. It is exclusively expressed in small, non-proliferating subgroups of this spermatogonial cell type together with the pluripotency-associated protein and spermatogonial nuclear marker undifferentiated embryonic cell transcription factor 1 (UTF1). We specifically selected the FGFR3-positive spermatogonial subpopulation from two 30 mg biopsies per patient from a total of 37 patients with full spermatogenesis and three patients with meiotic arrest. We then employed cell selection with magnetic beads in combination with a fluorescence-activated cell sorter antibody directed against human FGFR3 to tag and visually identify human FGFR3-positive spermatogonia. Positively selected and bead-labeled cells were subsequently picked with a micromanipulator. Analysis of the isolated cells was carried out by single-cell real-time RT-PCR, real-time RT-PCR, immunocytochemistry and live/dead staining. Single-cell real-time RT-PCR and real-time RT-PCR of pooled cells indicate that bead-labeled single cells express FGFR3 with high heterogeneity at the mRNA level, while bead-unlabeled cells lack FGFR3 mRNA. Furthermore, isolated cells exhibit strong immunocytochemical staining for the stem cell factor UTF1 and are viable. The cell population isolated in this study has to be tested for their potential stem cell characteristics via xenotransplantation. Due to the small amount of the isolated cells, propagation by cell culture will be essential. Other potential hSSC without FGFR3 surface expression will not be captured with the provided experimental design. The technical approach as developed in this work could encourage the scientific community to test other established or novel hSSC markers on single SPG that present with potential stem cell-like features. The project was funded by the DFG Research Unit FOR1041 Germ cell potential (SCH 587/3-2) and DFG grants to K.v.K. (KO 4769/2-1) and A.-N.S. (SP 721/4-1). The authors declare no competing interests. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Are needles of Pinus pinaster more vulnerable to xylem embolism than branches? New insights from X-ray computed tomography.

PubMed

Bouche, Pauline S; Delzon, Sylvain; Choat, Brendan; Badel, Eric; Brodribb, Timothy J; Burlett, Regis; Cochard, Hervé; Charra-Vaskou, Katline; Lavigne, Bruno; Li, Shan; Mayr, Stefan; Morris, Hugh; Torres-Ruiz, José M; Zufferey, Vivian; Jansen, Steven

2016-04-01

Plants can be highly segmented organisms with an independently redundant design of organs. In the context of plant hydraulics, leaves may be less embolism resistant than stems, allowing hydraulic failure to be restricted to distal organs that can be readily replaced. We quantified drought-induced embolism in needles and stems of Pinus pinaster using high-resolution computed tomography (HRCT). HRCT observations of needles were compared with the rehydration kinetics method to estimate the contribution of extra-xylary pathways to declining hydraulic conductance. High-resolution computed tomography images indicated that the pressure inducing 50% of embolized tracheids was similar between needle and stem xylem (P50 needle xylem  = -3.62 MPa, P50 stem xylem  = -3.88 MPa). Tracheids in both organs showed no difference in torus overlap of bordered pits. However, estimations of the pressure inducing 50% loss of hydraulic conductance at the whole needle level by the rehydration kinetics method were significantly higher (P50 needle  = -1.71 MPa) than P50 needle xylem derived from HRCT. The vulnerability segmentation hypothesis appears to be valid only when considering hydraulic failure at the entire needle level, including extra-xylary pathways. Our findings suggest that native embolism in needles is limited and highlight the importance of imaging techniques for vulnerability curves. © 2015 John Wiley & Sons Ltd.

Isolation and characterization of true mesenchymal stem cells derived from human term decidua capable of multilineage differentiation into all 3 embryonic layers.

PubMed

Macias, Maria I; Grande, Jesús; Moreno, Ana; Domínguez, Irene; Bornstein, Rafael; Flores, Ana I

2010-11-01

The objective of the study was to isolate and characterize a population of mesenchymal stem cells (MSCs) from human term placental membranes. We isolated an adherent cell population from extraembryonic membranes. Morphology, phenotype, growth characteristics, karyotype, and immunological and differentiation properties were analyzed. The isolated placental MSCs were from maternal origin and named as decidua-derived mesenchymal stem cells (DMSCs). DMSCs differentiated into derivatives of all germ layers. It is the first report about placental MSC differentiation into alveolar type II cells. Clonally expanded DMSCs differentiated into all embryonic layers, including pulmonary cells. DMSCs showed higher life span than placental cells from fetal origin and proliferated without genomic instability. The data suggest that DMSCs are true multipotent MSCs, distinguishing them from other placental MSCs. DMSCs could be safely used in the mother as a potential source of MSCs for pelvic floor dysfunctions and immunological diseases. Additionally, frozen DMSCs can be stored for both autologous and allogeneic tissue regeneration. Copyright © 2010 Mosby, Inc. All rights reserved.

Semiconductor chips, genes, and stem cells: new wine for new bottles?

PubMed

Rose, Simone A

2012-01-01

This Article analogizes early semiconductor technology and its surrounding economics with isolated genes, stem cells, and related bioproducts, and their surrounding economics, to make the case for sui generis (of its own class) intellectual property protection for isolated bioproducts. Just as early semiconductors failed to meet the patent social bargain requiring novelty and non-obviousness in the 1980s, isolated genes and stem cells currently fail to meet the patent bargain requirements of non-obviousness and eligible subject matter that entitle them to traditional intellectual property protection. Like early semiconductor chip designs, nevertheless, the high cost of upstream bioproduct research and development, coupled with the need to sustain continued economic growth of the biotechnology industry, mandates that Congress provide some level of exclusive rights to ensure continued funding for this research. Sui generis intellectual property protection for isolated bioproducts would preserve the incentive to continue innovation in the field. As illustrated by the semiconductor industry, however, such sui generis protection for this technology must include limitations that address the need to provide an appropriate level of public access to facilitate downstream product development and enrich the public domain.

Comparative evaluation of the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin scaffold

PubMed Central

Khurana, Rohit; Kudva, Praveen Bhasker; Husain, Syed Yawer

2017-01-01

Background: The present study aims to comparatively evaluate the isolation and quantification of stem cells derived from dental pulp and periodontal ligament of a permanent tooth and to assess their viability and proliferation on a platelet-rich fibrin (PRF) scaffold. Materials and Methods: A total of 15 systemically healthy individuals between the age group of 15–25 years requiring third molar or orthodontic premolar extractions. Teeth were extracted atraumatically and transported to the laboratory. Stem cells were isolated from dental pulp and periodontal ligament. After attaining more than 90% confluency by the 7th day, these cells were tested for their viability and characterization. Stem cells were also incubated with PRF and viability was assessed on the 7th day. Results: The mean number of cell for dental pulp stem cells (DPSCs) and periodontal ligament stem cell (PDLSC) was statistically insignificant (P > 0.05). The mean live cell viability was compared between DPSC (98.07%) and PDLSC (98%). Both DPSC and PDLSC showed a high percentage of expression of CD73 markers, 30.40% and 29.80%, respectively. However, DPSCs and PDLSCs lacked expression of CD34 expressing only 3.47% and 3.53%, respectively. PRF membrane as a scaffold exhibited no cytotoxic effects on DPCS's or PDLSC's. The cell viability of cells cultured with PRF was statistically insignificant (P > 0.05) when compared to the cells cultured with culture media. Conclusion: The study thus indicates that dental pulp and periodontal ligament are both rich sources of mesenchymal stem cells and can be successfully used for obtaining stem cells. PRF exhibits no cytotoxic effects on the cells and can be used in conjunction with dental stem cells. PMID:29386795

Differentiation and characteristics of the enhanced green fluorescent protein gene transgenic goat neural stem cells cultured in attached and non-attached plates.

PubMed

Zheng, Yue-Mao; Dang, Yong-Hui; Qiu, Shuang; Qi, Ying-Pei; Xu, Yong-Ping; Sai, Wu-Jia-Fu

2011-08-01

The aims of this study were (i) to determine whether NSCs (neural stem cells) could be isolated from the brain of embryonic day 98 fetal goat, (ii) to determine if these stem cells have the capability of multipotent differentiation following transfection with a reporter gene, EGFP (enhanced green fluorescent protein) and (iii) to study the characteristics of the stem cells cultured in attached and non-attached plates. NSCs were isolated from embryonic day 98 fetal goat brain, transfected with EGFP gene using lipofection, and subcultured in attached and non-attached plates respectively. The transgenic stem cells were induced to differentiate into osteogenic and endothelial cells in vitro respectively. Markers associated with undifferentiated NSCs and their differentiated cells were tested by RT-PCR (reverse transcription-PCR). The results demonstrated that stem cells could be isolated from embryonic day 98 fetal goat brain, and EGFP gene could be transfected into the cells. The transgenic NSCs were capable of self-renewal, a defining property of stem cells, and were grown as free-floating neurospheres in non-attached plates. When the neurospheres were transferred and cultured in attached plates, cells migrate from the neurospheres and are grown as spindle cells. The stem cells were grown as quasi-circular cells when the single stem cells were cultured in attached plates. Both the NSCs cultured in non-attached and attached plates could express Hes1 (hairy and enhancer of split 1), Oct4 (octamer-binding protein 4), Nanog, Sox2 [SRY (sex-determining region Y)-box 2] and Nestin, while following differentiation cells expressed markers for osteogenic cells (Osteocalcin+ and Osteonectin+) and endothelium (CD34+ and eNOS+). The results demonstrated that the goat EGFP gene transgenic NSCs have the capability of multipotent differentiation, which means that the transgenic NSCs may be useful in cell transplantation studies in future.

Influence of halothane and methoxyflurane on regional brain and spinal cord concentrations of methionine-enkephalin in the rat.

PubMed

Agarwal, R K; Court, M; Chandna, V K; Mohan, A; Engelking, L R; Kumar, A M

1994-01-01

Rats were exposed to either oxygen (controls), 1.5% halothane in oxygen, or methoxyflurane (0.5%) in oxygen over a period of 2 h, then sacrificed at the end of exposure (2-h group), 4 h after removal from environmental chamber (4-h group), or at 24 h following anesthetic exposure (24-h group). Pituitary (excluding the neural lobe, Pit), brain, and spinal cord areas were isolated and processed with Met-enkephalin tissue concentrations determined. In halothane-exposed animals, Met-enkephalin concentrations in pit and across CNS areas studied were significantly lower at 2 h following anesthetic exposure than in control animals. Concentrations of Met-enkephalin in many areas of CNS and Pit of 4-h group approached control levels. Concentrations of Met-enkephalin in all areas studied except spinal cord returned to basal levels by 24 h following halothane exposure. Exposure to methoxyflurane resulted in less dramatic changes in Met-enkephalin concentrations across CNS regions examined. Exposure to methoxyflurane resulted in significant decreases in Met-enkephalin levels in olfactory bulb, thalamus, and hippocampus only. Met-Enkephalin levels did not change significantly in other areas of the central nervous system following methoxyflurane exposure. These results indicate that halothane and methoxyflurane may have differential effects on the endogenous opioid system.

Genetic Correction of Stem Cells in the Treatment of Inherited Diseases and Focus on Xeroderma Pigmentosum

PubMed Central

Rouanet, Sophie; Warrick, Emilie; Gache, Yannick; Scarzello, Sabine; Avril, Marie-Françoise; Bernerd, Françoise; Magnaldo, Thierry

2013-01-01

Somatic stem cells ensure tissue renewal along life and healing of injuries. Their safe isolation, genetic manipulation ex vivo and reinfusion in patients suffering from life threatening immune deficiencies (for example, severe combined immunodeficiency (SCID)) have demonstrated the efficacy of ex vivo gene therapy. Similarly, adult epidermal stem cells have the capacity to renew epidermis, the fully differentiated, protective envelope of our body. Stable skin replacement of severely burned patients have proven life saving. Xeroderma pigmentosum (XP) is a devastating disease due to severe defects in the repair of mutagenic DNA lesions introduced upon exposure to solar radiations. Most patients die from the consequences of budding hundreds of skin cancers in the absence of photoprotection. We have developed a safe procedure of genetic correction of epidermal stem cells isolated from XP patients. Preclinical and safety assessments indicate successful correction of XP epidermal stem cells in the long term and their capacity to regenerate a normal skin with full capacities of DNA repair. PMID:24113582

[Therapeutic strategies targeting brain tumor stem cells].

PubMed

Toda, Masahiro

2009-07-01

Progress in stem cell research reveals cancer stem cells to be present in a variety of malignant tumors. Since they exhibit resistance to anticancer drugs and radiotherapy, analysis of their properties has been rapidly carried forward as an important target for the treatment of intractable malignancies, including brain tumors. In fact, brain cancer stem cells (BCSCs) have been isolated from brain tumor tissue and brain tumor cell lines by using neural stem cell culture methods and isolation methods for side population (SP) cells, which have high drug-efflux capacity. Although the analysis of the properties of BCSCs is the most important to developing methods in treating BCSCs, the absence of BCSC purification methods should be remedied by taking it up as an important research task in the immediate future. Thus far, there are no effective treatment methods for BCSCs, and several treatment methods have been proposed based on the cell biology characteristics of BCSCs. In this article, I outline potential treatment methods damaging treatment-resistant BCSCs, including immunotherapy which is currently a topic of our research.

TGF-α equalizes age disparities in stem cell-mediated cardioprotection.

PubMed

Herrmann, Jeremy L; Fiege, Jeremy W; Abarbanell, Aaron M; Weil, Brent R; Wang, Yue; Poynter, Jeffrey A; Manukyan, Mariuxi C; Brewster, Benjamin D; Meldrum, Daniel R

2012-08-01

Neonatal mesenchymal stem cells exhibit less cardioprotective potential than their adult counterparts. Transforming growth factor-α (TGF-α) has been shown to stimulate adult stem cell VEGF production, however, it remains unknown whether it may augment neonatal stem cell paracrine function. We hypothesized that TGF-α would equalize adult and neonatal stem cell paracrine function and cardioprotection during acute ischemia/reperfusion. Bone marrow mesenchymal stem cells isolated from adult and 2.5 wk-old mice were treated with TGF-α (250 ng/mL) for 24 h. VEGF, HGF, IGF-1, IL-1β, and IL-6 production were measure in vitro, and cells were infused via an intracoronary route using a model of isolated heart perfusion. TGF-α equalized adult and neonatal stem cell VEGF production but did not affect production of HGF, IGF-1, IL-1β, or IL-6. ERK, p38 MAPK, and JNK phosphorylation were greater in adult cells in response to TGF-α. Whereas infusion of adult but not neonatal stem cells was associated with improved myocardial functional recovery during reperfusion, infusions of either TGF-α-pretreated cell group were associated with the greatest functional recovery. TGF-α equalizes adult and neonatal mesenchymal stem cell VEGF production and cardioprotection in association with differential regulation of ERK, p38 MAPK, and JNK phosphorylation. Copyright © 2012. Published by Elsevier Inc.

Stem Cells for Skeletal Muscle Tissue Engineering.

PubMed

Pantelic, Molly N; Larkin, Lisa M

2018-04-19

Volumetric muscle loss (VML) is a debilitating condition wherein muscle loss overwhelms the body's normal physiological repair mechanism. VML is particularly common among military service members who have sustained war injuries. Because of the high social and medical cost associated with VML and suboptimal current surgical treatments, there is great interest in developing better VML therapies. Skeletal muscle tissue engineering (SMTE) is a promising alternative to traditional VML surgical treatments that use autogenic tissue grafts, and rather uses isolated stem cells with myogenic potential to generate de novo skeletal muscle tissues to treat VML. Satellite cells are the native precursors to skeletal muscle tissue, and are thus the most commonly studied starting source for SMTE. However, satellite cells are difficult to isolate and purify, and it is presently unknown whether they would be a practical source in clinical SMTE applications. Alternative myogenic stem cells, including adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, perivascular stem cells, umbilical cord mesenchymal stem cells, induced pluripotent stem cells, and embryonic stem cells, each have myogenic potential and have been identified as possible starting sources for SMTE, although they have yet to be studied in detail for this purpose. These alternative stem cell varieties offer unique advantages and disadvantages that are worth exploring further to advance the SMTE field toward highly functional, safe, and practical VML treatments. The following review summarizes the current state of satellite cell-based SMTE, details the properties and practical advantages of alternative myogenic stem cells, and offers guidance to tissue engineers on how alternative myogenic stem cells can be incorporated into SMTE research.

Slow-Adhering Stem Cells Derived from Injured Skeletal Muscle Have Improved Regenerative Capacity

DTIC Science & Technology

2011-08-01

images. Flow Cytometry Assay of Stem Cell Markers SASCs (1 105) isolated from noninjured or injured muscle were collected and washed twice with...muscle. Results of flow cytometry further verified Sca-1 and CD34 expression in isolated SASCs, and a greater percentage of cells were positive for Sca-1...from both injured and control noninjured muscle were analyzed using flow cytometry for the immunofluorescent signal of Sca-1 and CD34. Results

Two-step protocol for isolation and culture of cardiospheres.

PubMed

Chen, Lijuan; Pan, Yaohua; Zhang, Lan; Wang, Yingjie; Weintraub, Neal; Tang, Yaoliang

2013-01-01

Cardiac progenitor cells (CPC) are a unique pool of progenitor cells residing in the heart that play an important role in cardiac homeostasis and physiological cardiovascular cell turnover during acute myocardial infarction (MI). Transplanting CPC into the heart has shown promise in two recent clinical trials of cardiac repair (SCIPIO & CADUCEUS). CSCs were originally isolated directly from enzymatically digested hearts followed by cell sorting using stem cell markers. However, long exposure to enzymatic digestion can affect the integrity of stem cell markers on the cell surface and also compromise stem cell function. Here, we describe a two-step procedure in which a large number of intact cardiac progenitor cells can be purified from small amount of heart tissue.

[Research on chemical constituents from stem of Gymnema sylvestre].

PubMed

Zhen, Han-shen; Zhu, Xue-yan; Lu, Ru-mei; Liang, Jie; Qiu, Qin; Meng, Qi-miao

2008-08-01

To study on the chemical constituents from the stem of Gymnema sylvestre. The constituents were extracted by percolation with ethanol. Then the extract was separated by systemic solvent separation methods. The part of n-butanol extract was isolated and purified by macroporous adsorptive resins, silica gel column chromatography, sephadex gel column chromatography and recrystallization. The isolated compounds were identified by spectrum methods. Eight compounds were isolated and identified as fallows: Conduritol A(I), 1-Heptadecanol(II), Stigmasterol glucoside(III), 1-Quercitol(IV), 1-Octadecanol(V), Potassium nitrate(VI), Lupeol cinnamate(VII), Stigmasterol(VIII). Chemical compounds II, III, V, VII are firstly obtained from this plant.

Differences of isolated dental stem cells dependent on donor age and consequences for autologous tooth replacement.

PubMed

Kellner, Manuela; Steindorff, Marina M; Strempel, Jürgen F; Winkel, Andreas; Kühnel, Mark P; Stiesch, Meike

2014-06-01

Autologous therapy via stem cell-based tissue regeneration is an aim to rebuild natural teeth. One option is the use of adult stem cells from the dental pulp (DPSCs), which have been shown to differentiate into several types of tissue in vitro and in vivo, especially into tooth-like structures. DPSCs are mainly isolated from the dental pulp of third molars routinely extracted for orthodontic reasons. Due to the extraction of third molars at various phases of life, DPSCs are isolated at different developmental stages of the tooth. The present study addressed the question whether DPSCs from patients of different ages were similar in their growth characteristics with respect to the stage of tooth development. Therefore DPSCs from third molars of 12-30 year-old patients were extracted, and growth characteristics, e.g. doubling time and maximal cell division potential were analysed. In addition, pulp and hard dental material weight were recorded. Irrespective of the age of patients almost all isolated cells reached 40-60 generations with no correlation between maximal cell division potential and patient age. Cells from patients <22 years showed a significantly faster doubling time than the cells from patients ≥22 years. The age of patients at the time of stem cell isolation is not a crucial factor concerning maximal cell division potential, but does have an impact on the doubling time. However, differences in individuals regarding growth characteristics were more pronounced than age-dependent differences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human Neural Cell-Based Biosensor

DTIC Science & Technology

2011-03-11

following areas: (1) neural progenitor isolation from induced pluripotent stem cells , (2) directed differentiation of progenitors into dopaminergic...from induced pluripotent stem cells , (2) directed differentiation of progenitors into dopaminergic neurons, motoneurons and astrocytes using defined...progenitors from mixed populations, such as induced pluripotent stem cells (iPSCs). We also developed lentiviral based methods to generate iPSCs in

Discovery of a novel stem rust resistance allele in durum wheat that exhibits differential reactions to Ug99 isolates

USDA-ARS?s Scientific Manuscript database

Wheat stem rust, caused by Puccinia graminis f. sp. tritici Erikss. & E. Henn, can incur yield losses on susceptible cultivars of durum wheat, Triticum turgidum ssp. durum (Desf.) Husnot. Though several durum cultivars possess the stem rust resistance gene Sr13, additional genes in durum wheat effec...

Stem cell transplantation in neurodegenerative disorders of the gastrointestinal tract: future or fiction?

PubMed Central

Kulkarni, Subhash; Becker, Laren; Pasricha, Pankaj Jay

2014-01-01

Current advances in our understanding of stem and precursor cell biology and in the protocols of stem cell isolation and transplantation have opened up the possibility of transplanting neural stem cells for the treatment of gastrointestinal motility disorders. This review summarises the current status of research in this field, identifies the major gaps in our knowledge and discusses the potential opportunities and hurdles for clinical application. PMID:21816959

Nobody’s perfect: can irregularities in pit structure influence vulnerability to cavitation?

PubMed Central

Plavcová, Lenka; Jansen, Steven; Klepsch, Matthias; Hacke, Uwe G.

2013-01-01

Recent studies have suggested that species-specific pit properties such as pit membrane thickness, pit membrane porosity, torus-to-aperture diameter ratio and pit chamber depth influence xylem vulnerability to cavitation. Despite the indisputable importance of using mean pit characteristics, considerable variability in pit structure within a single species or even within a single pit field should be acknowledged. According to the rare pit hypothesis, a single pit that is more air-permeable than many neighboring pits is sufficient to allow air-seeding. Therefore, any irregularities or morphological abnormalities in pit structure allowing air-seeding should be associated with increased vulnerability to cavitation. Considering the currently proposed models of air-seeding, pit features such as rare, large pores in the pit membrane, torus extensions, and plasmodesmatal pores in a torus can represent potential glitches. These aberrations in pit structure could either result from inherent developmental flaws, or from damage caused to the pit membrane by chemical and physical agents. This suggests the existence of interesting feedbacks between abiotic and biotic stresses in xylem physiology. PMID:24273549

2017 Robotic Mining Competition

NASA Image and Video Library

2017-05-24

Energy levels are high in the RoboPit as teams prepare for NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. arel using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

Cavitation and Its Discontents: Opportunities for Resolving Current Controversies1[C

PubMed Central

Rockwell, Fulton E.; Wheeler, James K.; Holbrook, N. Michele

2014-01-01

Cavitation has long been recognized as a key constraint on the structure and functional integrity of the xylem. Yet, recent results call into question how well we understand cavitation in plants. Here, we consider embolism formation in angiosperms at two scales. The first focuses on how air-seeding occurs at the level of pit membranes, raising the question of whether capillary failure is an appropriate physical model. The second addresses methodological uncertainties that affect our ability to infer the formation of embolism and its reversal in plant stems. Overall, our goal is to open up fresh perspectives on the structure-function relationships of xylem. PMID:24501002

Gingival Mesenchymal Stem/Progenitor Cells: A Unique Tissue Engineering Gem

PubMed Central

Fawzy El-Sayed, Karim M.; Dörfer, Christof E.

2016-01-01

The human gingiva, characterized by its outstanding scarless wound healing properties, is a unique tissue and a pivotal component of the periodontal apparatus, investing and surrounding the teeth in their sockets in the alveolar bone. In the last years gingival mesenchymal stem/progenitor cells (G-MSCs), with promising regenerative and immunomodulatory properties, have been isolated and characterized from the gingival lamina propria. These cells, in contrast to other mesenchymal stem/progenitor cell sources, are abundant, readily accessible, and easily obtainable via minimally invasive cell isolation techniques. The present review summarizes the current scientific evidence on G-MSCs' isolation, their characterization, the investigated subpopulations, the generated induced pluripotent stem cells- (iPSC-) like G-MSCs, their regenerative properties, and current approaches for G-MSCs' delivery. The review further demonstrates their immunomodulatory properties, the transplantation preconditioning attempts via multiple biomolecules to enhance their attributes, and the experimental therapeutic applications conducted to treat multiple diseases in experimental animal models in vivo. G-MSCs show remarkable tissue reparative/regenerative potential, noteworthy immunomodulatory properties, and primary experimental therapeutic applications of G-MSCs are very promising, pointing at future biologically based therapeutic techniques, being potentially superior to conventional clinical treatment modalities. PMID:27313628

Phytophthora ramorum disease transmission from artificially infested potting media

Treesearch

Jennifer L. Parke; Melody L. Roth; Carrie Lewis; Caroline J. Choquette

2006-01-01

Potted rhododendrons grown in potting media amended with inoculum of Phytophthora ramorum became infected and showed symptoms of stem necrosis, leaf wilting, and death. P. ramorum was isolated from roots and stems of infected plants.

Isolation of pancreatic progenitor cells with the surface marker of hematopoietic stem cells.

PubMed

Ma, Fengxia; Chen, Fang; Chi, Ying; Yang, Shaoguang; Lu, Shihong; Han, Zhongchao

2012-01-01

To isolate pancreatic progenitor cells with the surface markers of hematopoietic stem cells, the expression of stem cell antigen (Sca-1) and c-Kit and the coexpression of them with pancreatic duodenal homeobox-1 (PDX-1), neurogenin 3 (Ngn3), and insulin were examined in murine embryonic pancreas. Then different pancreatic cell subpopulations were isolated by magnet-activated cell sorting. Isolated cells were cultured overnight in hanging drops. When cells formed spheres, they were laid on floating filters at the air/medium interface. With this new culture system, pancreatic progenitor cells were induced to differentiate to endocrine and exocrine cells. It was shown that c-Kit and Sca-1 were expressed differently in embryonic pancreas at 12.5, 15.5, and 17.5 days of gestation. The expression of c-Kit and Sca-1 was the highest at 15.5 days of gestation. c-Kit rather than Sca-1 coexpressed with PDX-1, Ngn3, and insulin. Cells differentiated from c-Kit-positive cells contained more insulin-producing cells and secreted more insulin in response to glucose stimulation than that from c-Kit-negative cells. These results suggested that c-Kit could be used to isolate pancreatic progenitor cells and our new culture system permitted pancreatic progenitor cells to differentiate to mature endocrine cells.

Umbilical cord fibroblasts: Could they be considered as mesenchymal stem cells?

PubMed Central

Zeddou, Mustapha; Relic, Biserka; Malaise, Michel G

2014-01-01

In cell therapy protocols, many tissues were proposed as a source of mesenchymal stem cells (MSC) isolation. So far, bone marrow (BM) has been presented as the main source of MSC despite the invasive isolation procedure related to this source. During the last years, the umbilical cord (UC) matrix was cited in different studies as a reliable source from which long term ex vivo proliferating fibroblasts were isolated but with contradictory data about their immunophenotype, gene expression profile, and differentiation potential. Hence, an interesting question emerged: Are cells isolated from cord matrix (UC-MSC) different from other MSCs? In this review, we will summarize different studies that isolated and characterized UC-MSC. Considering BM-MSC as gold standard, we will discuss if UC-MSC fulfill different criteria that define MSC, and what remain to be done in this issue. PMID:25126385

Isolation, molecular cloning and in vitro expression of rhesus monkey (Macaca mulatta) prominin-1.s1 complementary DNA encoding a potential hematopoietic stem cell antigen.

PubMed

Husain, S M; Shou, Y; Sorrentino, B P; Handgretinger, R

2006-10-01

Human prominin-1 (CD133 or AC133) is an important cell surface marker used to isolate primitive hematopoietic stem cells. The commercially available antibody to human prominin-1 does not recognize rhesus prominin-1. Therefore, we isolated, cloned and characterized the complementary DNA (cDNA) of rhesus prominin-1 gene and determined its coding potential. Following the nomenclature of prominin family of genes, we named this cDNA as rhesus prominin-1.s1. The amino acid sequence data of the putative rhesus prominin-1.s1 could be used in designing antigenic peptides to raise antibodies for use in isolation of pure populations of rhesus prominin-1(+) hematopoietic cells. To the best of our knowledge, there has been no previously published report about the isolation of a prominin-1 cDNA from rhesus monkey (Macaca mulatta).

Biobanking human embryonic stem cell lines: policy, ethics and efficiency.

PubMed

Holm, Søren

2015-12-01

Stem cell banks curating and distributing human embryonic stem cells have been established in a number of countries and by a number of private institutions. This paper identifies and critically discusses a number of arguments that are used to justify the importance of such banks in policy discussions relating to their establishment or maintenance. It is argued (1) that 'ethical arguments' are often more important in the establishment phase and 'efficiency arguments' more important in the maintenance phase, and (2) that arguments relating to the interests of embryo and gamete donors are curiously absent from the particular stem cell banking policy discourse. This to some extent artificially isolates this discourse from the broader discussions about the flows of reproductive materials and tissues in modern society, and such isolation may lead to the interests of important actors being ignored in the policy making process.

Research on basal stem rot (BSR) of ornamental palms caused by basidiospores from Ganoderma boninense.

PubMed

Lim, H P; Fong, Y K

2005-01-01

Basidiospores were isolated from the fruiting bodies of Ganoderma infecting oil palms from an estate in Johor and from ornamental palms (including oil palms) from Singapore. The spores were then germinated to obtain homokaryotic mycelia. Based on clamp connection formation in paired hyphal fusions, tester strains were identified from the homokaryons isolated. Compatibility tests were then carried out using these testers to determine the relatedness of the homokaryotic Ganoderma isolates, both from Johor and from Singapore. Results from the compatibility tests showed that Ganoderma from both locations belong to the same species, while the Ganoderma isolates from Singapore share some common alleles. The pathogenicity tests carried out on Chrysalidocarpus lutescens seedlings using inoculum growing on rubber wood blocks showed that dikaryotic mycelia can cause basal stem rot infection.

Aedes aegypti Larvicidal Sesquiterpene Alkaloids from Maytenus oblongata.

PubMed

Touré, Seindé; Nirma, Charlotte; Falkowski, Michael; Dusfour, Isabelle; Boulogne, Isabelle; Jahn-Oyac, Arnaud; Coke, Maïra; Azam, Didier; Girod, Romain; Moriou, Céline; Odonne, Guillaume; Stien, Didier; Houël, Emeline; Eparvier, Véronique

2017-02-24

Four new sesquiterpene alkaloids (1-4) with a β-dihydroagrofuran skeleton and a new triterpenoid (5) were isolated from an ethyl acetate extract of Maytenus oblongata stems. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS and ECD experiments. The M. oblongata stem EtOAc extract and the pure compounds isolated were tested for larvicidal activity against Aedes aegypti under laboratory conditions, and compounds 2 and 3 were found to be active.

Hepatoprotective triterpenoids and lignans from the stems of Schisandra pubescens.

PubMed

Wang, Guo-Wei; Deng, Li-Qing; Luo, You-Ping; Liao, Zhi-Hua; Chen, Min

2017-08-01

One new triterpenoid (1) and 13 known compounds (2-14) were isolated from Schisandra pubescens stems. The structure of the new compound was established on the basis of 1D/2D NMR and HRESIMS spectroscopic analyses. The isolated compounds were evaluated for their hepatoprotective activities against D-GalN-induced cell injury in QSG7701 cells. Compounds 1, 13 and 14 at 10 μM showed hepatoprotective activities, with survival rates of 60.5, 50.4 and 48.9%, respectively.

A new dihydrochalcone glycoside from the stems of Homalium stenophyllum.

PubMed

Wu, Shou-Yuan; Fu, Yan-Hui; Zhou, Qi; Bai, Meng; Chen, Guang-Ying; Han, Chang-Ri; Song, Xiao-Ping

2018-04-01

A new dihydrochalcone glycoside, phloretin-4-O-β-D-glucopyranoside (1), together with seven known flavonoids (2-8), were isolated from the stems of Homalium stenophyllum. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. The known compounds (2-8) were isolated from the genus Homalium for the first time. All compounds were evaluated for their antibacterial activities against six pathogenic bacteria in vitro.

Mesenchymal Stem Cells Improve Motor Functions and Decrease Neurodegeneration in Ataxic Mice

PubMed Central

Jones, Jonathan; Estirado, Alicia; Redondo, Carolina; Pacheco-Torres, Jesus; Sirerol-Piquer, Maria-Salomé; Garcia-Verdugo, José M; Martinez, Salvador

2015-01-01

The main objective of this work is to demonstrate the feasibility of using bone marrow-derived stem cells in treating a neurodegenerative disorder such as Friedreich's ataxia. In this disease, the dorsal root ganglia of the spinal cord are the first to degenerate. Two groups of mice were injected intrathecally with mesenchymal stem cells isolated from either wild-type or Fxntm1Mkn/Tg(FXN)YG8Pook (YG8) mice. As a result, both groups presented improved motor skills compared to nontreated mice. Also, frataxin expression was increased in the dorsal root ganglia of the treated groups, along with lower expression of the apoptotic markers analyzed. Furthermore, the injected stem cells expressed the trophic factors NT3, NT4, and BDNF, which bind to sensory neurons of the dorsal root ganglia and increase their survival. The expression of antioxidant enzymes indicated that the stem cell-treated mice presented higher levels of catalase and GPX-1, which are downregulated in the YG8 mice. There were no significant differences in the use of stem cells isolated from wild-type and YG8 mice. In conclusion, bone marrow mesenchymal stem cell transplantation, both autologous and allogeneic, is a feasible therapeutic option to consider in delaying the neurodegeneration observed in the dorsal root ganglia of Friedreich's ataxia patients. PMID:25070719

What the cerveau isolé preparation tells us nowadays about sleep-wake mechanisms?

PubMed

Gottesmann, C

1988-01-01

The intercollicular transected preparation opened a rich field for investigations of sleep-wake mechanisms. Initial results showed that brain stem ascending influences are essential for maintaining an activated cortex. It was subsequently shown that the forebrain also develops activating influences, since EEG desynchronization of the cortex reappears in the chronic cerveau isolé preparation, and continuous or almost continuous theta rhythm is able to occur in the acute cerveau isolé preparation. A brief "intermediate stage" of sleep occurs during natural sleep just prior to and after paradoxical sleep. It is characterized by cortical spindle bursts, hippocampal low frequency theta activity (two patterns of the acute cerveau isolé preparation) and is accompanied by a very low thalamic transmission level, suggesting a cerveau isolé-like state. The chronic cerveau isolé preparation also demonstrates that the executive processes of paradoxical sleep are located in the lower brain stem, while the occurrence of this sleep stage seems to be modulated by forebrain structures.

Isolation and Propagation of Mesenchymal Stem Cells from the Lacrimal Gland

PubMed Central

You, Samantha; Kublin, Claire L.; Avidan, Orna; Miyasaki, David

2011-01-01

Purpose. Previously, it was reported that the murine lacrimal gland is capable of repair after experimentally induced injury and that the number of stem/progenitor cells was increased during the repair phase (2–3 days after injury). The aim of the present study was to determine whether these cells can be isolated from the lacrimal gland and propagated in vitro. Methods. Lacrimal gland injury was induced by injection of interleukin (IL)-1, and injection of saline vehicle served as control. Two and half days after injection, the lacrimal glands were removed and used to prepare explants or acinar cells for tissue culture. Cells derived from the explants and the acinar cells were grown in DMEM supplemented with 10% fetal bovine serum. Cells were stained for the stem cells markers, nestin, vimentin, ABCG2, and Sca-1. Cell proliferation was measured using an antibody against Ki67 or a cell-counting kit. The adipogenic capability of these cells was also tested in vitro. Results. Results show that nestin-positive cells can be isolated from IL-1–injected, but not saline-injected, lacrimal glands. A population of nestin-positive cells was also positive for vimentin, an intermediate filament protein expressed by mesenchymal cells. In addition, cultured cells expressed two other markers of stem cells, ABCG2 and Sca-1. These cells proliferated in vitro and can be induced to form adipocytes, attesting to their mesenchymal stem cell property. Conclusions. Murine lacrimal glands contain mesenchymal stem cells that seem to play a pivotal role in tissue repair. PMID:21178145

Stem cells isolated from adipose tissue of obese patients show changes in their transcriptomic profile that indicate loss in stemcellness and increased commitment to an adipocyte-like phenotype

PubMed Central

2013-01-01

Background The adipose tissue is an endocrine regulator and a risk factor for atherosclerosis and cardiovascular disease when by excessive accumulation induces obesity. Although the adipose tissue is also a reservoir for stem cells (ASC) their function and “stemcellness” has been questioned. Our aim was to investigate the mechanisms by which obesity affects subcutaneous white adipose tissue (WAT) stem cells. Results Transcriptomics, in silico analysis, real-time polymerase chain reaction (PCR) and western blots were performed on isolated stem cells from subcutaneous abdominal WAT of morbidly obese patients (ASCmo) and of non-obese individuals (ASCn). ASCmo and ASCn gene expression clustered separately from each other. ASCmo showed downregulation of “stemness” genes and upregulation of adipogenic and inflammatory genes with respect to ASCn. Moreover, the application of bioinformatics and Ingenuity Pathway Analysis (IPA) showed that the transcription factor Smad3 was tentatively affected in obese ASCmo. Validation of this target confirmed a significantly reduced Smad3 nuclear translocation in the isolated ASCmo. Conclusions The transcriptomic profile of the stem cells reservoir in obese subcutaneous WAT is highly modified with significant changes in genes regulating stemcellness, lineage commitment and inflammation. In addition to body mass index, cardiovascular risk factor clustering further affect the ASC transcriptomic profile inducing loss of multipotency and, hence, capacity for tissue repair. In summary, the stem cells in the subcutaneous WAT niche of obese patients are already committed to adipocyte differentiation and show an upregulated inflammatory gene expression associated to their loss of stemcellness. PMID:24040759

Alkaline phosphatase and OCT-3/4 as useful markers for predicting susceptibility of human deciduous teeth-derived dental pulp cells to reprogramming factor-induced iPS cells.

PubMed

Inada, Emi; Saitoh, Issei; Kubota, Naoko; Soda, Miki; Matsueda, Kazunari; Murakami, Tomoya; Sawami, Tadashi; Kagoshima, Akiko; Yamasaki, Youichi; Sato, Masahiro

2017-11-01

The aim of the present study was to prove that primary cells enriched with stem cells are more easily reprogrammed to generate induced pluripotent stem (iPS) cells than those with scarce numbers of stem cells. We surveyed the alkaline phosphatase (ALP) activity in five primarily-isolated human deciduous teeth-derived dental pulp cells (HDDPC) with cytochemical staining to examine the possible presence of stem cells. Next, the expression of stemness-specific factors, such as OCT(Octumer-binding transcription factor)3/4, NANOG, SOX2(SRY (sex determining region Y)-box 2), CD90, muscle segment homeodomain homeobox (MSX) 1, and MSX2, was assessed with a reverse transcription polymerase chain reaction method. Finally, these isolated HDDPC were transfected with plasmids carrying genes coding Yamanaka factors to determine whether these cells could be reprogrammed to generate iPS cells. Of the five primarily-isolated HDDPC, two (HDDPC-1 and -5) exhibited higher degrees of ALP activity. OCT-3/4 expression was also prominent in those two lines. Furthermore, these two lines proliferated faster than the other three lines. The transfection of HDDPC with Yamanaka factors resulted in the generation of iPS cells from HDDPC-1 and -5. The number of cells with the stemness property of HDDPC differs among individuals, which suggests that HDDPC showing an increased expression of both ALP and OCT-3/4 can be more easily reprogrammed to generate iPS cells after the forced expression of reprogramming factors. © 2016 John Wiley & Sons Australia, Ltd.

Pit 9 Category of Transuranic Waste Stored Below Ground within Area G

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hargis, Kenneth M.

2014-01-08

A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreementmore » between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP).This report summarizes available information on the origin, configuration, and composition of the waste containers within Pit 9, their physical and radiological characteristics, and issues that may be encountered in their retrieval and processing. Review of the available information indicates that Pit 9 should present no major issues in retrieval and processing, and most drums contain TRU waste that can be shipped to WIPP. The primary concern in retrieval is the integrity of containers that have been stored below-ground for 35 to 40 years. The most likely issue that will be encountered in processing containers retrieved from Pit 9 is the potential for items that are prohibited at WIPP such as sealed containers greater than four liters in size and free liquids that exceed limits for WIPP.« less

Stem cell sources for regenerative medicine.

PubMed

Riazi, Ali M; Kwon, Sarah Y; Stanford, William L

2009-01-01

Tissue-resident stem cells or primitive progenitors play an integral role in homeostasis of most organ systems. Recent developments in methodologies to isolate and culture embryonic and somatic stem cells have many new applications poised for clinical and preclinical trials, which will enable the potential of regenerative medicine to be realized. Here, we overview the current progress in therapeutic applications of various stem cells and discuss technical and social hurdles that must be overcome for their potential to be realized.

A Preliminary Study: Human Fibroid Stro-1+/CD44+ Stem Cells Isolated From Uterine Fibroids Demonstrate Decreased DNA Repair and Genomic Integrity Compared to Adjacent Myometrial Stro-1+/CD44+ Cells.

PubMed

Prusinski Fernung, Lauren E; Al-Hendy, Ayman; Yang, Qiwei

2018-01-01

Although uterine fibroids (UFs) continue to place a major burden on female reproductive health, the mechanisms behind their origin remain undetermined. Normal myometrial stem cells may be transformed into tumor-initiating stem cells, causing UFs, due to unknown causes of somatic mutations in MED12, found in up to 85% of sporadically formed UFs. It is well established in other tumor types that defective DNA repair increases the risk of such tumorigenic somatic mutations, mechanisms not yet studied in UFs. To examine the putative cause(s) of this stem cell transformation, we analyzed DNA repair within stem cells from human UFs compared to those from adjacent myometrium to determine whether DNA repair in fibroid stem cells is compromised. Human fibroid (F) and adjacent myometrial (Myo) stem cells were isolated from fresh tissues, and gene expression relating to DNA repair was analyzed. Fibroid stem cells differentially expressed DNA repair genes related to DNA double- (DSBs) and single-strand breaks. DNA damage was measured using alkaline comet assay. Additionally, DNA DSBs were induced in these stem cells and DNA DSB repair evaluated (1) by determining changes in phosphorylation of DNA DSB-related proteins and (2) by determining differences in γ-H2AX foci formation and relative DNA repair protein RAD50 expression. Overall, F stem cells demonstrated increased DNA damage and altered DNA repair gene expression and signaling, suggesting that human F stem cells demonstrate impaired DNA repair. Compromised F stem cell DNA repair may contribute to further mutagenesis and, consequently, further growth and propagation of UF tumors.

A Simplified and Systematic Method to Isolate, Culture, and Characterize Multiple Types of Human Dental Stem Cells from a Single Tooth.

PubMed

Bakkar, Mohammed; Liu, Younan; Fang, Dongdong; Stegen, Camille; Su, Xinyun; Ramamoorthi, Murali; Lin, Li-Chieh; Kawasaki, Takako; Makhoul, Nicholas; Pham, Huan; Sumita, Yoshinori; Tran, Simon D

2017-01-01

This chapter describes a simplified method that allows the systematic isolation of multiple types of dental stem cells such as dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC), and stem cells of the apical papilla (SCAP) from a single tooth. Of specific interest is the modified laboratory approach to harvest/retrieve the dental pulp tissue by minimizing trauma to DPSC by continuous irrigation, reduction of frictional heat from the bur rotation, and reduction of the bur contact time with the dentin. Also, the use of a chisel and a mallet will maximize the number of live DPSC for culture. Steps demonstrating the potential for multiple cell differentiation lineages of each type of dental stem cell into either osteocytes, adipocytes, or chondrocytes are described. Flow cytometry, with a detailed strategy for cell gating and analysis, is described to verify characteristic markers of human mesenchymal multipotent stromal cells (MSC) from DPSC, PDLSC, or SCAP for subsequent experiments in cell therapy and in tissue engineering. Overall, this method can be adapted to any laboratory with a general setup for cell culture experiments.

Isolation, Characterization, and Transplantation of Bone Marrow-Derived Cell Components with Hematopoietic Stem Cell Niche Properties

PubMed Central

Ahmadbeigi, Naser; Vasei, Mohammad; Gheisari, Yousof; Mortazavi, Yousef; Azadmanesh, Kayhan; Omidkhoda, Azadeh; Janzamin, Ehsan; Nardi, Nance Beyer

2013-01-01

Although the unique role of hematopoietic stem cell (HSC) niche in hematopoiesis has long been recognized, unsuccessful isolation of intact niche units limited their in vitro study, manipulation, and therapeutic application. Here, we isolated cell complexes based on size fractionation from mouse bone marrow (BM), characterized the derived cells, and transplanted them to irradiated mice. These cell complexes were the origin of both BM mesenchymal stem cells and various hematopoietic lineages when kept in appropriate culture conditions. They also had the potential of recruiting circulating HSC. Intraperitoneal transplantation of these structures into irradiated mice not only showed long-lasting hematopoietic multilineage reconstitution, but also could recover the stromal cells of BM. In conclusion, this study for the first time provides evidences on the feasibility and efficacy of transplantation of HSC in association with their native specialized microenvironment. As the molecular cross-talk between HSC and niche is crucial for their proper function, the proposed method could be considered as a novel hematopoietic transplantation strategy. PMID:23879861

Isolation and Characterization of Cancer Stem Cells of the Non-Small-Cell Lung Cancer (A549) Cell Line.

PubMed

Halim, Noor Hanis Abu; Zakaria, Norashikin; Satar, Nazilah Abdul; Yahaya, Badrul Hisham

2016-01-01

Cancer is a major health problem worldwide. The failure of current treatments to completely eradicate cancer cells often leads to cancer recurrence and dissemination. Studies have suggested that tumor growth and spread are driven by a minority of cancer cells that exhibit characteristics similar to those of normal stem cells, thus these cells are called cancer stem cells (CSCs). CSCs are believed to play an important role in initiating and promoting cancer. CSCs are resistant to currently available cancer therapies, and understanding the mechanisms that control the growth of CSCs might have great implications for cancer therapy. Cancer cells are consist of heterogeneous population of cells, thus methods of identification, isolation, and characterisation of CSCs are fundamental to obtain a pure CSC populations. Therefore, this chapter describes in detail a method for isolating and characterizing a pure population of CSCs from heterogeneous population of cancer cells and CSCs based on specific cell surface markers.

Amniotic Fluid-Derived Stem Cells for Cardiovascular Tissue Engineering Applications

PubMed Central

Petsche Connell, Jennifer; Camci-Unal, Gulden; Khademhosseini, Ali

2013-01-01

Recent research has demonstrated that a population of stem cells can be isolated from amniotic fluid removed by amniocentesis that are broadly multipotent and nontumorogenic. These amniotic fluid-derived stem cells (AFSC) could potentially provide an autologous cell source for treatment of congenital defects identified during gestation, particularly cardiovascular defects. In this review, the various methods of isolating, sorting, and culturing AFSC are compared, along with techniques for inducing differentiation into cardiac myocytes and endothelial cells. Although research has not demonstrated complete and high-yield cardiac differentiation, AFSC have been shown to effectively differentiate into endothelial cells and can effectively support cardiac tissue. Additionally, several tissue engineering and regenerative therapeutic approaches for the use of these cells in heart patches, injection after myocardial infarction, heart valves, vascularized scaffolds, and blood vessels are summarized. These applications show great promise in the treatment of congenital cardiovascular defects, and further studies of isolation, culture, and differentiation of AFSC will help to develop their use for tissue engineering, regenerative medicine, and cardiovascular therapies. PMID:23350771

Studies on the chemical constituents from the stem and leaves of Tagetes erecta.

PubMed

Zhang, Yu; Zhang, Ting-Ting

2010-09-01

To investigate the chemical constituents of the stem and leaves of Tagetes erecta. The materials extracted with ethanol were first purified with D101 resin and then separated by repeated silica gel column chromatography as well as recrystallization to get single compounds. The chemical structures of the compounds were elucidated on the basis of physicochemical properties, spectroscopic analysis and comparing with standard sample and literatures. Six compounds were identified as 4'-methoxy-eupatolitin-3-O-glucoside (I), kaempferitrin (II), rutin (III), beta-sitosterol (IV), daucosterol (V) and gallic acid (VI). Compounds I, II, III are isolated from the plant for the first time; the compounds IV, V, VI are isolated from the stem and leaves of the plant for the first time.

Antioxidant and Anti-Osteoporosis Activities of Chemical Constituents of the Stems of Zanthoxylum piperitum.

PubMed

Yang, Seo Young; Lee, Sang-Hyun; Tai, Bui Huu; Jang, Hae-Dong; Kim, Young Ho

2018-02-18

Two new lignans, zanthoxyloside C ( 1 ) and zanthoxyloside D ( 2 ), together with nine known compounds comprising lignans ( 3 - 5 ), flavonoids ( 6 - 8 ), and phenolics ( 9 - 11 ), were isolated from the methanol extract of the stems of Zanthoxylum piperitum. All isolates were evaluated for their antioxidant and anti-osteoporotic activities using oxygen radical absorbance capacity (ORAC), cupric reducing antioxidant capacity (CUPRAC), and tartrate-resistant acid phosphatase (TRAP) assays. Compounds 7 - 10 showed peroxyl radical-scavenging capacities and 4 , 6 - 7 , and 9 showed reducing capacities. Moreover, compounds 3 , 6 - 9 , and 11 significantly suppressed TRAP activities. These results indicated that the stems of Z. piperitum could be an excellent source for natural antioxidant and anti-osteoporosis.

Nucleation sites of Ge nanoislands grown on pit-patterned Si substrate prepared by electron-beam lithography

NASA Astrophysics Data System (ADS)

Smagina, Zh. V.; Zinovyev, V. A.; Rudin, S. A.; Novikov, P. L.; Rodyakina, E. E.; Dvurechenskii, A. V.

2018-04-01

Regular pit-patterned Si(001) substrates were prepared by electron-beam lithography followed by plasma chemical etching. The geometry of the pits was controlled by varying the etching conditions and the electron-beam exposure duration. It was shown that the location of three-dimensional (3D) Ge nanoislands subsequently grown on the pit-patterned Si substrates depends on the shape of the pit bottom. In the case of pits having a sharp bottom, 3D Ge islands nucleate inside the pits. For pits with a wide flat bottom, the 3D Ge island nucleation takes place at the pit periphery. This effect is attributed to the strain relaxation depending not only on the initial pit shape, but also on its evolution during the Ge wetting layer deposition. It was shown by Monte Carlo simulations that in the case of a pit with a pointed bottom, the relaxation is most effective inside the pit, while for a pit with a wide bottom, the most relaxed area migrates during Ge deposition from the pit bottom to its edges, where 3D Ge islands nucleate.

Isolation and characterization of canine perivascular stem/stromal cells for bone tissue engineering.

PubMed

James, Aaron W; Zhang, Xinli; Crisan, Mihaela; Hardy, Winters R; Liang, Pei; Meyers, Carolyn A; Lobo, Sonja; Lagishetty, Venu; Childers, Martin K; Asatrian, Greg; Ding, Catherine; Yen, Yu-Hsin; Zou, Erin; Ting, Kang; Peault, Bruno; Soo, Chia

2017-01-01

For over 15 years, human subcutaneous adipose tissue has been recognized as a rich source of tissue resident mesenchymal stem/stromal cells (MSC). The isolation of perivascular progenitor cells from human adipose tissue by a cell sorting strategy was first published in 2008. Since this time, the interest in using pericytes and related perivascular stem/stromal cell (PSC) populations for tissue engineering has significantly increased. Here, we describe a set of experiments identifying, isolating and characterizing PSC from canine tissue (N = 12 canine adipose tissue samples). Results showed that the same antibodies used for human PSC identification and isolation are cross-reactive with canine tissue (CD45, CD146, CD34). Like their human correlate, canine PSC demonstrate characteristics of MSC including cell surface marker expression, colony forming unit-fibroblast (CFU-F) inclusion, and osteogenic differentiation potential. As well, canine PSC respond to osteoinductive signals in a similar fashion as do human PSC, such as the secreted differentiation factor NEL-Like Molecule-1 (NELL-1). Nevertheless, important differences exist between human and canine PSC, including differences in baseline osteogenic potential. In summary, canine PSC represent a multipotent mesenchymogenic cell source for future translational efforts in tissue engineering.

Mesenchymal Stem Cell-Mediated Functional Tooth Regeneration in Swine

PubMed Central

Fang, Dianji; Yamaza, Takayoshi; Seo, Byoung-Moo; Zhang, Chunmei; Liu, He; Gronthos, Stan; Wang, Cun-Yu; Shi, Songtao; Wang, Songlin

2006-01-01

Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla). Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs) to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance. PMID:17183711

Prostate Cancer Stem Cells: Viewing Signaling Cascades at a Finer Resolution.

PubMed

Lin, Xiukun; Farooqi, Ammad Ahmad; Qureshi, Muhammad Zahid; Romero, Mirna Azalea; Tabassum, Sobia; Ismail, Muhammad

2016-06-01

It is becoming characteristically more understandable that within tumor cells, there lies a sub-population of tumor cells with "stem cell" like properties and remarkable ability of self-renewal. Many features of these self-renewing cells are comparable with normal stem cells and are termed as "cancer stem cells". Accumulating experimentally verified data has started to scratch the surface of spatio-temporally dysregulated intracellular signaling cascades in the biology of prostate cancer stem cells. We partition this multicomponent review into how different signaling cascades operate in cancer stem cells and how bioactive ingredients isolated from natural sources may modulate signaling network.

Bioassay-guided isolation and evaluation of antimicrobial compounds from Ixora megalophylla against some oral pathogens.

PubMed

Panyo, J; Matsunami, K; Panichayupakaranant, P

2016-09-01

Context Ixora megalophylla Chamch. (Rubiaceae) is a new plant species recently found in southern Thailand. Ethyl acetate extracts of its leaves and stems showed antimicrobial activities. Objectives To isolate and identify the antimicrobial compounds from I. megalophylla leaves and stems. Materials and methods The dried leaves (1.7 kg) and stems (3.5 kg) were consecutively extracted with petroleum ether (5 L × 4), ethyl acetate (5 L × 3) and ethanol (5 L × 4) under reflux conditions. The ethyl acetate extract was subjected to an antimicrobial assay guided isolation with Candida albicans and Streptococcus mutans. Compounds 1-10 were identified by (1)H NMR, (13)C NMR and EI-MS. Minimal lethal concentration (MLC) against C. albicans and Streptococcus spp. was determined using a broth microdilution method for 48 and 24 h, respectively. Results and discussion On the basis of the antimicrobial assay guided isolation, 10 known compounds, including vanillic acid (1), syringic acid (2), 4-hydroxy benzaldehyde (3), scopoletin (4), loliolide (5), syringaldehyde (6), sinapaldehyde (7), coniferaldehyde (8), syringaresinol (9) and 2,2'-dithiodipyridine (10), were identified. Compounds 1-5 were purified from the ethyl acetate extract of the leaves, while 6-9 and 10 were from the ethyl acetate and ethanol extracts of the stems, respectively. Among these isolates, 10 showed the strongest antibacterial activities against S. mutans and Streptococcus mitis, with minimum inhibitory concentrations (MICs) of 2-4 μg/mL, and MLC of 4 μg/mL, as well as having a weak antifungal activity against C. albicans (MIC of 125 μg/mL). This is the first report of the antimicrobial activities of 10.

C-kit+ cells isolated from developing kidneys are a novel population of stem cells with regenerative potential

PubMed Central

Rangel, Erika B; Gomes, Samirah A; Dulce, Raul A; Premer, Courtney; Rodrigues, Claudia O; Kanashiro-Takeuchi, Rosemeire M; Oskouei, Behzad; Carvalho, Decio A; Ruiz, Phillip; Reiser, Jochen; Hare, Joshua M

2013-01-01

The presence of tissue specific precursor cells is an emerging concept in organ formation and tissue homeostasis. Several progenitors are described in the kidneys. However, their identity as a true stem cell remains elusive. Here, we identify a neonatal kidney-derived c-kit+ cell population that fulfills all of the criteria as a stem cell. These cells were found in the thick ascending limb of Henle's loop and exhibited clonogenicity, self-renewal, and multipotentiality with differentiation capacity into mesoderm and ectoderm progeny. Additionally, c-kit+ cells formed spheres in nonadherent conditions when plated at clonal density and expressed markers of stem cells, progenitors, and differentiated cells. Ex-vivo expanded c-kit+ cells integrated into several compartments of the kidney, including tubules, vessels, and glomeruli, and contributed to functional and morphological improvement of the kidney following acute ischemia-reperfusion injury in rats. Together these findings document a novel neonatal rat kidney c-kit+ stem cell population that can be isolated, expanded, cloned, differentiated, and employed for kidney repair following acute kidney injury. These cells have important biological and therapeutic implications. PMID:23733311

Martian Central Pit Craters

NASA Technical Reports Server (NTRS)

Hillman, E.; Barlow, N. G.

2005-01-01

Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ( floor pits ) as well as on top of central peaks ( summit pits ). Wood et al. [1] proposed that degassing of subsurface volatiles during crater formation produced central pits. Croft [2] argued instead that central pits might form during the impact of volatile-rich comets. Although central pits are seen in impact craters on icy moons such as Ganymede, they do show some significant differences from their martian counterparts: (a) only floor pits are seen on Ganymede, and (b) central pits begin to occur at crater diameters where the peak ring interior morphology begins to appear in terrestrial planet craters [3]. A study of craters containing central pits was conducted by Barlow and Bradley [4] using Viking imagery. They found that 28% of craters displaying an interior morphology on Mars contain central pits. Diameters of craters containing central pits ranged from 16 to 64 km. Barlow and Bradley noted that summit pit craters tended to be smaller than craters containing floor pits. They also noted a correlation of central pit craters with the proposed rings of large impact basins. They argued that basin ring formation fractured the martian crust and allowed subsurface volatiles to concentrate in these locations. They favored the model that degassing of the substrate during crater formation was responsible for central pit formation due to the preferential location of central pit craters along these basin rings.

Avoidance of Maternal Cell Contamination and Overgrowth in Isolating Fetal Chorionic Villi Mesenchymal Stem Cells from Human Term Placenta

PubMed Central

Sardesai, Varda S.; Shafiee, Abbas; Fisk, Nicholas M.

2017-01-01

Abstract Human placenta is rich in mesenchymal stem/stromal cells (MSC), with their origin widely presumed fetal. Cultured placental MSCs are confounded by a high frequency of maternal cell contamination. Our recent systematic review concluded that only a small minority of placental MSC publications report fetal/maternal origin, and failed to discern a specific methodology for isolation of fetal MSC from term villi. We determined isolation conditions to yield fetal and separately maternal MSC during ex vivo expansion from human term placenta. MSCs were isolated via a range of methods in combination; selection from various chorionic regions, different commercial media, mononuclear cell digest and/or explant culture. Fetal and maternal cell identities were quantitated in gender‐discordant pregnancies by XY chromosome fluorescence in situ hybridization. We first demonstrated reproducible maternal cell contamination in MSC cultures from all chorionic anatomical locations tested. Cultures in standard media rapidly became composed entirely of maternal cells despite isolation from fetal villi. To isolate pure fetal cells, we validated a novel isolation procedure comprising focal dissection from the cotyledonary core, collagenase/dispase digestion and explant culture in endothelial growth media that selected, and provided a proliferative environment, for fetal MSC. Comparison of MSC populations within the same placenta confirmed fetal to be smaller, more osteogenic and proliferative than maternal MSC. We conclude that in standard media, fetal chorionic villi‐derived MSC (CV‐MSC) do not grow readily, whereas maternal MSC proliferate to result in maternal overgrowth during culture. Instead, fetal CV‐MSCs require isolation under specific conditions, which has implications for clinical trials using placental MSC. Stem Cells Translational Medicine 2017;6:1070–1084 PMID:28205414

RS3PE syndrome: an overview.

PubMed

Olivieri, I; Salvarani, C; Cantini, F

2000-01-01

More than ten years ago McCarty et al. described the RS3PE syndrome based on their study of 23 patients. Numerous additional cases have since been reported. In addition to the isolated or "pure" type which probably forms part of the clinical spectrum of polymyalgia rheumatica, inflammatory swelling with pitting edema of the dorsum of the hands and/or feet can be observed in different inflammatory rheumatic diseases as well as in haematological and solid malignancies.

Bilayer Hydrogel with Autologous Stem Cells Derived from Debrided Human Burn Skin for Improved Skin Regeneration

DTIC Science & Technology

2013-02-01

derived stem cells (ASCs), in particular, can be obtained in abundance with a minimally invasive liposuction technique.16,17 Unfortunately, after...substi- tutes. Stem Cells 2008;26:2713–23. 16. Aust L, Devlin B, Foster SJ, et al. Yield of human adipose- derived adult stem cells from liposuction ...Matsumoto D, et al. Character- ization of freshly isolated and cultured cells derived from the fatty and fluid portions of liposuction aspirates. J Cell

Substrate micropatterns produced by polymer demixing regulate focal adhesions, actin anisotropy, and lineage differentiation of stem cells.

PubMed

Vega, Sebastián L; Arvind, Varun; Mishra, Prakhar; Kohn, Joachim; Sanjeeva Murthy, N; Moghe, Prabhas V

2018-06-12

Stem cells are adherent cells whose multipotency and differentiation can be regulated by numerous microenvironmental signals including soluble growth factors and surface topography. This study describes a simple method for creating distinct micropatterns via microphase separation resulting from polymer demixing of poly(desaminotyrosyl-tyrosine carbonate) (PDTEC) and polystyrene (PS). Substrates with co-continuous (ribbons) or discontinuous (islands and pits) PDTEC regions were obtained by varying the ratio of PDTEC and sacrificial PS. Human mesenchymal stem cells (MSCs) cultured on co-continuous PDTEC substrates for 3 days in bipotential adipogenic/osteogenic (AD/OS) induction medium showed no change in cell morphology but exhibited increased anisotropic cytoskeletal organization and larger focal adhesions when compared to MSCs cultured on discontinuous micropatterns. After 14 days in bipotential AD/OS induction medium, MSCs cultured on co-continuous micropatterns exhibited increased expression of osteogenic markers, whereas MSCs on discontinuous PDTEC substrates showed a low expression of adipogenic and osteogenic differentiation markers. Substrates with graded micropatterns were able to reproduce the influence of local underlying topography on MSC differentiation, thus demonstrating their potential for high throughput analysis. This work presents polymer demixing as a simple, non-lithographic technique to produce a wide range of micropatterns on surfaces with complex geometries to influence cellular and tissue regenerative responses. Gaining a better understanding of how engineered microenvironments influence stem cell differentiation is integral to increasing the use of stem cells and materials in a wide range of tissue engineering applications. In this study, we show the range of topography obtained by polymer demixing is sufficient for investigating how surface topography affects stem cell morphology and differentiation. Our findings show that co-continuous topographies favor early (3-day) cytoskeletal anisotropy and focal adhesion maturation as well as long-term (14-day) expression of osteogenic differentiation markers. Taken together, this study presents a simple approach to pattern topographies that induce divergent responses in stem cell morphology and differentiation. Copyright © 2018. Published by Elsevier Ltd.

High-Throughput Microfluidic Labyrinth for the Label-free Isolation of Circulating Tumor Cells.

PubMed

Lin, Eric; Rivera-Báez, Lianette; Fouladdel, Shamileh; Yoon, Hyeun Joong; Guthrie, Stephanie; Wieger, Jacob; Deol, Yadwinder; Keller, Evan; Sahai, Vaibhav; Simeone, Diane M; Burness, Monika L; Azizi, Ebrahim; Wicha, Max S; Nagrath, Sunitha

2017-09-27

We present "Labyrinth," a label-free microfluidic device to isolate circulating tumor cells (CTCs) using the combination of long loops and sharp corners to focus both CTCs and white blood cells (WBCs) at a high throughput of 2.5 mL/min. The high yield (>90%) and purity (600 WBCs/mL) of Labyrinth enabled us to profile gene expression in CTCs. As proof of principle, we used previously established cancer stem cell gene signatures to profile single cells isolated from the blood of breast cancer patients. We observed heterogeneous subpopulations of CTCs expressing genes for stem cells, epithelial cells, mesenchymal cells, and cells transitioning between epithelial and mesenchymal. Labyrinth offers a cell-surface marker-independent single-cell isolation platform to study heterogeneous CTC subpopulations. Copyright © 2017 Elsevier Inc. All rights reserved.

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life

PubMed Central

2011-01-01

Background The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na+- or H+-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na+-dependent Pi (NaPi) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. Results We show that the human PiT2 histidine, H502, and the human PiT1 glutamate, E70, - both conserved in eukaryotic PiT family members - are critical for Pi transport function. Noticeably, human PiT2 H502 is located in the C-terminal PiT family signature sequence, and human PiT1 E70 is located in ProDom domains characteristic for all PiT family members. A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR254-V483), was found to be a fully functional Pi transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL183-V483) did also support Pi transport albeit at very low levels. Conclusions The results suggest that the overall structure of the Pi-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. PMID:21586110

Mapping of the minimal inorganic phosphate transporting unit of human PiT2 suggests a structure universal to PiT-related proteins from all kingdoms of life.

PubMed

Bøttger, Pernille; Pedersen, Lene

2011-05-17

The inorganic (Pi) phosphate transporter (PiT) family comprises known and putative Na(+)- or H(+)-dependent Pi-transporting proteins with representatives from all kingdoms. The mammalian members are placed in the outer cell membranes and suggested to supply cells with Pi to maintain house-keeping functions. Alignment of protein sequences representing PiT family members from all kingdoms reveals the presence of conserved amino acids and that bacterial phosphate permeases and putative phosphate permeases from archaea lack substantial parts of the protein sequence when compared to the mammalian PiT family members. Besides being Na(+)-dependent P(i) (NaP(i)) transporters, the mammalian PiT paralogs, PiT1 and PiT2, also are receptors for gamma-retroviruses. We have here exploited the dual-function of PiT1 and PiT2 to study the structure-function relationship of PiT proteins. We show that the human PiT2 histidine, H(502), and the human PiT1 glutamate, E(70),--both conserved in eukaryotic PiT family members--are critical for P(i) transport function. Noticeably, human PiT2 H(502) is located in the C-terminal PiT family signature sequence, and human PiT1 E(70) is located in ProDom domains characteristic for all PiT family members.A human PiT2 truncation mutant, which consists of the predicted 10 transmembrane (TM) domain backbone without a large intracellular domain (human PiT2ΔR(254)-V(483)), was found to be a fully functional P(i) transporter. Further truncation of the human PiT2 protein by additional removal of two predicted TM domains together with the large intracellular domain created a mutant that resembles a bacterial phosphate permease and an archaeal putative phosphate permease. This human PiT2 truncation mutant (human PiT2ΔL(183)-V(483)) did also support P(i) transport albeit at very low levels. The results suggest that the overall structure of the P(i)-transporting unit of the PiT family proteins has remained unchanged during evolution. Moreover, in combination, our studies of the gene structure of the human PiT1 and PiT2 genes (SLC20A1 and SLC20A2, respectively) and alignment of protein sequences of PiT family members from all kingdoms, along with the studies of the dual functions of the human PiT paralogs show that these proteins are excellent as models for studying the evolution of a protein's structure-function relationship. © 2011 Bøttger and Pedersen; licensee BioMed Central Ltd.

Further drimane sesquiterpenes from Drimys brasiliensis stem barks with cytotoxic potential.

PubMed

Fratoni, Eduarda; Claudino, Vanessa Duarte; Yunes, Rosendo Augusto; Franchi, Gilberto C; Nowill, Alexandre E; Filho, Valdir Cechinel; Monache, Franco Delle; Malheiros, Angela

2016-07-01

Drimys brasiliensis Miers (Winteraceae) is used in folk medicine for the treatment of cancer. Its anti-tumor activity has been demonstrated in vitro models using extracts and isolated compounds. This study investigates the cytotoxic effects of stem bark extracts of D. brasiliensis as well as isolated compounds that may be responsible for the activitys and evaluates them in leukemia cells. The stem bark extract were subjected to column chromatography, and the structures of compounds were elucidated based on spectroscopic methods by using NMR and infrared spectroscopy and GC/MS. The cytotoxicity of the isolated compounds was evaluated in chronic myeloid (K562) and acute B lymphoblastic (Nalm6) leukemia cells using tetrazolium assay (MTT). Two new compounds were isolated 1β-O-p-methoxy-E-cinnamoyl-5α-keto-11α-enol-albicanol (1a) and the isomer 1β-O-p-methoxy-E-cinnamoyl-5α-keto-11β-enol-albicanol (1b) and 1β-O-p-methoxy-E-cinnamoyl-isodrimeninol (2). The known compounds polygonal acid (3a) and the isomer isopolygonal acid (3b), fuegin (4a) and the isomer epifuegin (4b), the mixture drimanial (5) and 1β-O-(p-methoxy-E-cinnamoyl)-6α-hydroxypolygodial (6) were also isolated. The drimanes (1-4) and drimanial (5), 1β-(p-coumaroyloxy)-polygodial (7), 1β-(p-methoxycinnamoyl)-polygodial (8), and polygodial (9) isolated previously were assessed in tumor cells. The IC50 values were between 3.56 and 128.91 μM. 1-β-(p-cumaroiloxi)-polygodial showed the best result with IC50 8.18 and 3.56 μM by K562 and Nalm6, respectively. The chloroform extract of the stem bark of D. brasiliensis is a great source of drimane sesquiterpenes. Our experimental data suggest that drimanes are responsible for cytotoxicity activity demonstrated by this species, especially those with the aldehyde group linked to carbons C-11 and C-12.

Adipose derived stem cells (ASCs) isolated from breast cancer tissue express IL-4, IL-10 and TGF-β1 and upregulate expression of regulatory molecules on T cells: do they protect breast cancer cells from the immune response?

PubMed

Razmkhah, Mahboobeh; Jaberipour, Mansooreh; Erfani, Nasrollah; Habibagahi, Mojtaba; Talei, Abdol-rasoul; Ghaderi, Abbas

2011-01-01

Immunomodulatory function of bone marrow derived mesenchymal stem cells in cancer has recently been investigated. But the resident mesenchymal stem cells as whole in cancer and in the breast cancer tissue have not been studied well. In the present work we isolated adipose derived stem cells (ASCs) from breast cancer and normal breast tissues to investigate the expressions of IL-4, IL-10 and transforming growth factor (TGF)-β1 in ASCs and to see if ASCs isolated from patients can modulate the regulatory molecules on peripheral blood lymphocytes. Our results showed that IL-10 and TGF-β1 have significantly higher mRNA expressions in ASCs isolated from breast cancer patients than those from normal individuals (P value <0.05). The culture supernatant of ASCs isolated from breast cancer patients with pathological stage III induced upregulation of the mRNA expression levels of IL-4, TGF-β1, IL-10, CCR4 and CD25 in PBLs. In addition, the percentage of CD4+CD25(high)Foxp3(+) T regulatory cells was increased in vitro. When the same culture supernatant was added to ASCs isolated from normal subjects augmentation of the mRNA expressions of IL-4, IL-10, IL-8, MMP2, VEGF and SDF-1 in normal ASCs was also observed. These data collectively conclude that resident ASCs in breast cancer tissue may have crucial roles in breast tumor growth and progression by inducing regulatory molecules and promoting anti-inflammatory reaction within the tumor microenvironment. Further investigation is required to see if the immune suppression induced by ASCs is an independent property from tumor cells or ASCs gain their immunosuppressive potential from malignant cells. Copyright © 2010 Elsevier Inc. All rights reserved.

The three principles of action: a Pavlovian-instrumental transfer hypothesis

PubMed Central

Cartoni, Emilio; Puglisi-Allegra, Stefano; Baldassarre, Gianluca

2013-01-01

Pavlovian conditioned stimuli can influence instrumental responding, an effect called Pavlovian-instrumental transfer (PIT). During the last decade, PIT has been subdivided into two types: specific PIT and general PIT, each having its own neural substrates. Specific PIT happens when a conditioned stimulus (CS) associated with a reward enhances an instrumental response directed to the same reward. Under general PIT, instead, the CS enhances a response directed to a different reward. While important progress has been made into identifying the neural substrates, the function of specific and general PIT and how they interact with instrumental responses are still not clear. In the experimental paradigm that distinguishes specific and general PIT an effect of PIT inhibition has also been observed and is waiting for an explanation. Here we propose an hypothesis that links these three PIT effects (specific PIT, general PIT and PIT inhibition) to three aspects of action evaluation. These three aspects, which we call “principles of action”, are: context, efficacy, and utility. In goal-directed behavior, an agent has to evaluate if the context is suitable to accomplish the goal, the efficacy of his action in getting the goal, and the utility of the goal itself: we suggest that each of the three PIT effects is related to one of these aspects of action evaluation. In particular, we link specific PIT with the estimation of efficacy, general PIT with the evaluation of utility, and PIT inhibition with the adequacy of context. We also provide a latent cause Bayesian computational model that exemplifies this hypothesis. This hypothesis and the model provide a new framework and new predictions to advance knowledge about PIT functioning and its role in animal adaptation. PMID:24312025

A probability distribution model of tooth pits for evaluating time-varying mesh stiffness of pitting gears

NASA Astrophysics Data System (ADS)

Lei, Yaguo; Liu, Zongyao; Wang, Delong; Yang, Xiao; Liu, Huan; Lin, Jing

2018-06-01

Tooth damage often causes a reduction in gear mesh stiffness. Thus time-varying mesh stiffness (TVMS) can be treated as an indication of gear health conditions. This study is devoted to investigating the mesh stiffness variations of a pair of external spur gears with tooth pitting, and proposes a new model for describing tooth pitting based on probability distribution. In the model, considering the appearance and development process of tooth pitting, we model the pitting on the surface of spur gear teeth as a series of pits with a uniform distribution in the direction of tooth width and a normal distribution in the direction of tooth height, respectively. In addition, four pitting degrees, from no pitting to severe pitting, are modeled. Finally, influences of tooth pitting on TVMS are analyzed in details and the proposed model is validated by comparing with a finite element model. The comparison results show that the proposed model is effective for the TVMS evaluations of pitting gears.

Correlation of isolability of the oak wilt pathogen with leaf wilt and vascular water flow resistance

Treesearch

Garold F. Gregory

1971-01-01

Isolations and water flow-rate measurements made on short stem sections of young red oak seedlings inoculated with the oak wilt pathogen, Ceratocystis fagacearum, about 1 to 2 inches above the soil line, revealed that the oak wilt pathogen was isolable first near the inoculation site. As time after inoculation increased, the pathogen was isolated...

Divergences in hydraulic architecture form an important basis for niche differentiation between diploid and polyploid Betula species in NE China.

PubMed

Zhang, Wei-Wei; Song, Jia; Wang, Miao; Liu, Yan-Yan; Li, Na; Zhang, Yong-Jiang; Holbrook, N Michele; Hao, Guang-You

2017-05-01

Habitat differentiation between polyploid and diploid plants are frequently observed, with polyploids usually occupying more stressed environments. In woody plants, polyploidization can greatly affect wood characteristics but knowledge of its influences on xylem hydraulics is scarce. The four Betula species in NE China, representing two diploids and two polyploids with obvious habitat differentiation, provide an exceptional study system for investigating the impact of polyploidization on environmental adaptation of trees from the point view of xylem hydraulics. To test the hypothesis that changes in hydraulic architecture play an important role in determining their niche differentiation, we measured wood structural traits at both the tissue and pit levels and quantified xylem water transport efficiency and safety in these species. The two polyploids had significantly larger hydraulic weighted mean vessel diameters than the two diploids (45.1 and 45.5 vs 25.9 and 24.5 μm) although the polyploids are occupying more stressed environments. As indicated by more negative water potentials corresponding to 50% loss of stem hydraulic conductivities, the two polyploids exhibited significantly higher resistance to drought-induced embolism than the two diploids (-5.23 and -5.05 vs -3.86 and -3.13 MPa) despite their larger vessel diameters. This seeming discrepancy is reconciled by distinct characteristics favoring greater embolism resistance at the pit level in the two polyploid species. Our results showed clearly that the two polyploid species have remarkably different pit-level anatomical traits favoring greater hydraulic safety than their congeneric diploid species, which have likely contributed to the abundance of polyploid birches in more stressed habitats; however, less porous inter-conduit pits together with a reduced leaf to sapwood area may have compromised their competitiveness under more favorable conditions. Contrasts in hydraulic architecture between diploid and polyploid Betula species suggest an important functional basis for their clear habitat differentiation along environmental gradients in Changbai Mountain of NE China. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The CD11a and Endothelial Protein C Receptor Marker Combination Simplifies and Improves the Purification of Mouse Hematopoietic Stem Cells.

PubMed

Karimzadeh, Alborz; Scarfone, Vanessa M; Varady, Erika; Chao, Connie; Grathwohl, Karin; Fathman, John W; Fruman, David A; Serwold, Thomas; Inlay, Matthew A

2018-06-01

Hematopoietic stem cells (HSCs) are the self-renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish them from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, endothelial protein C receptor (EPCR), can be used to effectively identify and purify HSCs. We introduce a new two-color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist's toolkit improves the purity of and simplifies isolation of HSCs. Stem Cells Translational Medicine 2018;7:468-476. © 2018 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Embryonic Stem Cells: Isolation, Characterization and Culture

NASA Astrophysics Data System (ADS)

Amit, Michal; Itskovitz-Eldor, Joseph

Embryonic stem cells are pluripotent cells isolated from the mammalian blastocyst. Traditionally, these cells have been derived and cultured with mouse embryonic fibroblast (MEF) supportive layers, which allow their continuous growth in an undifferentiated state. However, for any future industrial or clinical application hESCs should be cultured in reproducible, defined, and xeno-free culture system, where exposure to animal pathogens is prevented. From their derivation in 1998 the methods for culturing hESCs were significantly improved. This chapter wills discuss hESC characterization and the basic methods for their derivation and maintenance.

Isolation and Growth of Prostate Stem Cells and Establishing Cancer Cell Lines from Human Prostate Tumors

DTIC Science & Technology

2008-05-01

cells. J Mol Med, 2008. 20. Collins, A. T., Habib , F. K., Maitland, N. J., and Neal, D. E. Identification and isolation of human prostate...The utility and limitations of glycosylated human CD133 epitopes in defining cancer stem cells. J Mol Med 2008;86:1025–32. 20. Collins AT, Habib FK...cells. J Cell Sci 2004;117: 3539–45. 23. Litvinov IV, Vander Griend DJ, Xu Y, Antony L, Dalrymple SL , Isaacs JT. Low-calcium serum-free defined

Isolation, in vitro culture and identification of a new type of mesenchymal stem cell derived from fetal bovine lung tissues.

PubMed

Hu, Pengfei; Pu, Yabin; Li, Xiayun; Zhu, Zhiqiang; Zhao, Yuhua; Guan, Weijun; Ma, Yuehui

2015-09-01

Lung‑derived mesenchymal stem cells (LMSCs) are considered to be important in lung tissue repair and regenerative processes. However, the biological characteristics and differentiation potential of LMSCs remain to be elucidated. In the present study, fetal lung‑derived mesenchymal stem cells (FLMSCs) were isolated from fetal bovine lung tissues by collagenase digestion. The in vitro culture conditions were optimized and stabilized and the self‑renewal ability and differentiation potential were evaluated. The results demonstrated that the FLMSCs were morphologically consistent with fibroblasts, were able to be cultured and passaged for at least 33 passages and the cell morphology and proliferative ability were stable during the first 10 passages. In addition, FLMSCs were found to express CD29, CD44, CD73 and CD166, however, they did not express hematopoietic cell specific markers, including CD34, CD45 and BOLA‑DRα. The growth kinetics of FLMSCs consisted of a lag phase, a logarithmic phase and a plateau phase, and as the passages increased, the proliferative ability of cells gradually decreased. The majority of FLMSCs were in G0/G1 phase. Following osteogenic induction, FLMSCs were positive for the expression of osteopontin and collagen type I α2. Following neurogenic differentiation, the cells were morphologically consistent with neuronal cells and positive for microtubule‑associated protein 2 and nestin expression. It was concluded that the isolated FLMSCs exhibited typical characteristics of mesenchymal stem cells and that the culture conditions were suitable for their proliferation and the maintenance of stemness. The present study illustrated the potential application of lung tissue as an adult stem cell source for regenerative therapies.

Transfer and detection of freshly isolated or cultured chicken (Gallus gallus) and exotic species' embryonic gonadal germ stem cells in host embryos.

PubMed

Imus, Nastassja; Roe, Mandi; Charter, Suellen; Durrant, Barbara; Jensen, Thomas

2014-06-01

The management of captive avian breeding programs increasingly utilizes various artificial reproductive technologies, including in ovo sexing of embryos to adjust population sex ratios. Currently, however, no attention has been given to the loss of genetic diversity following sex-selective incubation, even with respect to individuals from critically endangered species. This project evaluated the possibility of using xenotransfer of embryonic gonadal germline stem cells (GGCs) for future reintroduction of their germplasm into the gene pool. We examined and compared the host gonad colonization of freshly isolated and 3 day (3d) cultured donor GGCs from chicken and 13 species of exotic embryos. Following 3d-culture of GGCs, there was a significant increase in the percentage of stem cell marker (SSEA-1, -3, -4) positive cells. However, the percentage of positive host gonads with chicken donor-derived cells decreased from 68% (fresh) to 22% (3d), while the percentage of exotic species donor-cells positive host gonads decreased from 61% (fresh) to 49% (3d-cultured). Donor GGCs from both chicken and exotic species were localized within the caudal endoderm, including the region encompassing the gonadal ridge by 16 hours post-injection. Furthermore, donor-derived cells isolated from stage 36 host embryos were antigenic for anti SSEA-1, VASA/DDX4 and EMA-1 antibodies, presumably indicating maintenance of stem cell identity. This study demonstrates that GGCs from multiple species can migrate to the gonadal region and maintain presumed stemness following xenotransfer into a chicken host embryo, suggesting that germline stem cell migration is highly conserved in birds.

Novel use of a Dektak 150 surface profiler unmasks differences in resorption pit profiles between control and Charcot patient osteoclasts.

PubMed

Petrova, Nina L; Petrov, Peter K; Edmonds, Michael E; Shanahan, Catherine M

2014-04-01

We hypothesized that newly formed osteoclasts from patients with acute Charcot osteoarthropathy can resorb surfaces of bone more extensively compared with controls. Peripheral blood monocytes, isolated from eight Charcot patients and nine controls, were cultured in vitro on 24-well plates and bovine bone discs in duplicate with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor κβ ligand (RANKL). Osteoclast formation was assessed by tartrate-resistant acid phosphatase staining (TRAcP) at day 17. Resorption was measured at day 21 after toluidine blue staining by two methods: (1) area of resorption at the surface by image analysis (%) and (2) area of resorption under the surface (μm(2)) measured by a Dektak 150 Surface Profiler. Ten 1,000 μm-long scans were performed per disc. Pits were classified as unidented, bidented, and multidented according to their shape. Although the number of newly formed TRAcP positive multinucleated cells (>3 nuclei) was similar in M-CSF + RANKL-treated cultures between controls and Charcot patients, the latter exhibited increased resorbing activity. The area of resorption on the surface by image analysis was significantly greater in Charcot patients compared with controls (21.1 % [14.5-26.2] vs. 40.8 % [35.4-46.0], median [25-75th percentile], p < 0.01), as was the area of resorption under the surface (2.7 x 10(3) μm(2) [1.6 x 10(3)- 3.9 x 10(3)] vs. 8.3 x 10(3) μm (2) [5.6 x 10(3)- 10.6 x 10(3), [corrected] p < 0.01) after profilometry. In Charcot patients pits were deeper and wider and more frequently presented as multidented pits. This application of the Dektak 150 Surface Profiler revealed novel differences in resorption pit profile from osteoclasts derived from Charcot patients compared with controls. Resorption in Charcot patients was mediated by highly aggressive newly formed osteoclasts from monocytes eroding large and deep areas of bone.

Platelet-rich plasma derived growth factors contribute to stem cell differentiation in musculoskeletal regeneration

NASA Astrophysics Data System (ADS)

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-10-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of platelet-rich plasma derived growth factors with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Platelet-Rich Plasma Derived Growth Factors Contribute to Stem Cell Differentiation in Musculoskeletal Regeneration.

PubMed

Qian, Yun; Han, Qixin; Chen, Wei; Song, Jialin; Zhao, Xiaotian; Ouyang, Yuanming; Yuan, Weien; Fan, Cunyi

2017-01-01

Stem cell treatment and platelet-rich plasma (PRP) therapy are two significant issues in regenerative medicine. Stem cells such as bone marrow mesenchymal stem cells, adipose-derived stem cells and periodontal ligament stem cells can be successfully applied in the field of tissue regeneration. PRP, a natural product isolated from whole blood, can secrete multiple growth factors (GFs) for regulating physiological activities. These GFs can stimulate proliferation and differentiation of different stem cells in injury models. Therefore, combination of both agents receives wide expectations in regenerative medicine, especially in bone, cartilage and tendon repair. In this review, we thoroughly discussed the interaction and underlying mechanisms of PRP derived GFs with stem cells, and assessed their functions in cell differentiation for musculoskeletal regeneration.

Xylella fastidiosa Isolates from Both subsp. multiplex and fastidiosa Cause Disease on Southern Highbush Blueberry (Vaccinium sp.) Under Greenhouse Conditions.

PubMed

Oliver, J E; Cobine, P A; De La Fuente, L

2015-07-01

Xylella fastidiosa is a xylem-limited gram-negative plant pathogen that affects numerous crop species, including grape, citrus, peach, pecan, and almond. Recently, X. fastidiosa has also been found to be the cause of bacterial leaf scorch on blueberry in the southeastern United States. Thus far, all X. fastidiosa isolates obtained from infected blueberry have been classified as X. fastidiosa subsp. multiplex; however, X. fastidiosa subsp. fastidiosa isolates are also present in the southeastern United States and commonly cause Pierce's disease of grapevines. In this study, seven southeastern U.S. isolates of X. fastidiosa, including three X. fastidiosa subsp. fastidiosa isolates from grape, one X. fastidiosa subsp. fastidiosa isolate from elderberry, and three X. fastidiosa subsp. multiplex isolates from blueberry, were used to infect the southern highbush blueberry 'Rebel'. Following inoculation, all isolates colonized blueberry, and isolates from both X. fastidiosa subsp. multiplex and X. fastidiosa subsp. fastidiosa caused symptoms, including characteristic stem yellowing and leaf scorch symptoms as well as dieback of the stem tips. Two X. fastidiosa subsp. multiplex isolates from blueberry caused more severe symptoms than the other isolates examined, and infection with these two isolates also had a significant impact on host mineral nutrient content in sap and leaves. These findings have potential implications for understanding X. fastidiosa host adaptation and expansion and the development of emerging diseases caused by this bacterium.

Prospects for neural stem cell-based therapies for neurological diseases.

PubMed

Imitola, Jaime

2007-10-01

Neural stem and progenitor cells have great potential for the treatment of neurological disorders. However, many obstacles remain to translate this field to the patient's bedside, including rationales for using neural stem cells in individual neurological disorders; the challenges of neural stem cell biology; and the caveats of current strategies of isolation and culturing neural precursors. Addressing these challenges is critical for the translation of neural stem cell biology to the clinic. Recent work using neural stem cells has yielded novel biologic concepts such as the importance of the reciprocal interaction between neural stem cells and the neurodegenerative environment. The prospect of using transplants of neural stem cells and progenitors to treat neurological diseases requires a better understanding of the molecular mechanisms of both neural stem cell behavior in experimental models and the intrinsic repair capacity of the injured brain.

NIR detection of pits and pit fragments in fresh cherries (abstract)

USDA-ARS?s Scientific Manuscript database

The feasibility of using near infrared (NIR) diffuse reflectance spectroscopy for the detection of pits and pit fragments in cherries was demonstrated. For detection of whole pits, 300 cherries were obtained locally and pits were removed from half. NIR reflectance spectra were obtained in triplicate...

7 CFR 52.779 - Freedom from pits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Freedom from pits. 52.779 Section 52.779 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Freedom from pits. (a) General. The factor of freedom from pits refers to the incidence of pits and pit...

The effects of pitting on fatigue crack nucleation in 7075-T6 aluminum alloy

NASA Technical Reports Server (NTRS)

Ma, LI; Hoeppner, David W.

1994-01-01

A high-strength aluminum alloy, 7075-T6, was studied to quantitatively evaluate chemical pitting effects of its corrosion fatigue life. The study focused on pit nucleation, pit growth, and fatigue crack nucleation. Pitting corrosion fatigue experiments were conducted in 3.5 percent NaCl aqueous solution under constant amplitude sinusoidal loading at two frequencies, 5 and 20 Hz. Smooth and unnotched specimens were used in this investigation. A video recording system was developed to allow in situ observation of the surface changes of the specimens during testing. The results indicated that pitting corrosion considerably reduces the fatigue strength by accelerating fatigue crack nucleation. A metallographic examination was conducted on the specimens to evaluate the nature of corrosion pits. First, the actual shapes of the corrosion pits were evaluated by cross-sectioning the pits. Secondly, the relation between corrosion pits and microstructure was also investigated. Finally, the possibility of another corrosion mechanism that might be involved in pitting was explored in this investigation. The fractography of the tested specimens showed that corner corrosion pits were responsible for fatigue crack nucleation in the material due to the associated stress concentration. The pits exhibited variance of morphology. Fatigue life for the experimental conditions appeared to be strongly dependent on pitting kinetics and the crack nucleation stage.

Phenotypical and Pharmacological Characterization of Stem-Like Cells in Human Pituitary Adenomas.

PubMed

Würth, Roberto; Barbieri, Federica; Pattarozzi, Alessandra; Gaudenzi, Germano; Gatto, Federico; Fiaschi, Pietro; Ravetti, Jean-Louis; Zona, Gianluigi; Daga, Antonio; Persani, Luca; Ferone, Diego; Vitale, Giovanni; Florio, Tullio

2017-09-01

The presence and functional role of tumor stem cells in benign tumors, and in human pituitary adenomas in particular, is a debated issue that still lacks a definitive formal demonstration. Fifty-six surgical specimens of human pituitary adenomas were processed to establish tumor stem-like cultures by selection and expansion in stem cell-permissive medium or isolating CD133-expressing cells. Phenotypic and functional characterization of these cells was performed (1) ex vivo, by immunohistochemistry analysis on paraffin-embedded tissues; (2) in vitro, attesting marker expression, proliferation, self-renewal, differentiation, and drug sensitivity; and (3) in vivo, using a zebrafish model. Within pituitary adenomas, we identified rare cell populations expressing stem cell markers but not pituitary hormones; we isolated and expanded in vitro these cells, obtaining fibroblast-free, stem-like cultures from 38 pituitary adenoma samples. These cells grow as spheroids, express stem cell markers (Oct4, Sox2, CD133, and nestin), show sustained in vitro proliferation as compared to primary cultures of differentiated pituitary adenoma cells, and are able to differentiate in hormone-expressing pituitary cells. Besides, pituisphere cells, apparently not tumorigenic in mice, engrafted in zebrafish embryos, inducing pro-angiogenic and invasive responses. Finally, pituitary adenoma stem-like cells express regulatory pituitary receptors (D2R, SSTR2, and SSTR5), whose activation by a dopamine/somatostatin chimeric agonist exerts antiproliferative effects. In conclusion, we provide evidence that human pituitary adenomas contain a subpopulation fulfilling biological and phenotypical signatures of tumor stem cells that may represent novel therapeutic targets for therapy-resistant tumors.

Separation technologies for stem cell bioprocessing.

PubMed

Diogo, Maria Margarida; da Silva, Cláudia Lobato; Cabral, Joaquim M S

2012-11-01

Stem cells have been the focus of an intense research due to their potential in Regenerative Medicine, drug discovery, toxicology studies, as well as for fundamental studies on developmental biology and human disease mechanisms. To fully accomplish this potential, the successful application of separation processes for the isolation and purification of stem cells and stem cell-derived cells is a crucial issue. Although separation methods have been used over the past decades for the isolation and enrichment of hematopoietic stem/progenitor cells for transplantation in hemato-oncological settings, recent achievements in the stem cell field have created new challenges including the need for novel scalable separation processes with a higher resolution and more cost-effective. Important examples are the need for high-resolution methods for the separation of heterogeneous populations of multipotent adult stem cells to study their differential biological features and clinical utility, as well as for the depletion of tumorigenic cells after pluripotent stem cell differentiation. Focusing on these challenges, this review presents a critical assessment of separation processes that have been used in the stem cell field, as well as their current and potential applications. The techniques are grouped according to the fundamental principles that govern cell separation, which are defined by the main physical, biophysical, and affinity properties of cells. A special emphasis is given to novel and promising approaches such as affinity-based methods that take advantage of the use of new ligands (e.g., aptamers, lectins), as well as to novel biophysical-based methods requiring no cell labeling and integrated with microscale technologies. Copyright © 2012 Wiley Periodicals, Inc.

[Chemical Compositions from Stems and Branches of Sorbaria arborea].

PubMed

Wang, Jian; Ma, Yang-min; Yan, Meng-ru; Xu, Qian; Qu, Zi-rui; Miao, Zhi

2015-10-01

To investigate the chemical constituents from the stems and branches of Sorbaria arborea. The chemical constituents were isolated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography and recrystallization. Their structures were identified by physicochemical properties and spectra analysis. Ten compounds were isolated and identified as ursolic acid (1), cucurbitacin F (2), (-) -epicatechin (3), daucosterol (4), arbutin (5), 3-O-β-anthemisol (6), 2,6-dimethoxy-p-hydroquinone-4-O-β-D-glucopyranoside (7), lupeol (8), betulin (9) and lup-20 (29) -en-3β, 30-diol (10). All the compounds are isolated from this plant for the first time, and compounds 1, 6 - 8 and 10 are obtained from Sorbaria genus for the first time.

Steroidal saponins from fresh stems of Dracaena angustifolia

USDA-ARS?s Scientific Manuscript database

Six new steroidal saponins (1-6), angudracanosides A-F, were isolated from fresh stems of Dracaena angustifolia, together with eight known compounds. The structures of compounds 1-6 were determined by detailed spectroscopic analyses and chemical methods. Antifungal testing of all compounds showed th...

Molecular Characterization of wheat stem rust races in Kenya

USDA-ARS?s Scientific Manuscript database

Stem or black rust caused by Puccinia graminis f. sp. tritici (Pgt) Erikss. & Henning causes severe losses to wheat (Triticum aestivum L.), historically threatening global wheat production. Characterizing prevalent isolates of Pgt would enhance the knowledge of population dynamics and evolution of t...

SIRPA is a specific cell-surface marker for isolating cardiomyocytes derived from human pluripotent stem cells.

PubMed

Dubois, Nicole C; Craft, April M; Sharma, Parveen; Elliott, David A; Stanley, Edouard G; Elefanty, Andrew G; Gramolini, Anthony; Keller, Gordon

2011-10-23

To identify cell-surface markers specific to human cardiomyocytes, we screened cardiovascular cell populations derived from human embryonic stem cells (hESCs) against a panel of 370 known CD antibodies. This screen identified the signal-regulatory protein alpha (SIRPA) as a marker expressed specifically on cardiomyocytes derived from hESCs and human induced pluripotent stem cells (hiPSCs), and PECAM, THY1, PDGFRB and ITGA1 as markers of the nonmyocyte population. Cell sorting with an antibody against SIRPA allowed for the enrichment of cardiac precursors and cardiomyocytes from hESC/hiPSC differentiation cultures, yielding populations of up to 98% cardiac troponin T-positive cells. When plated in culture, SIRPA-positive cells were contracting and could be maintained over extended periods of time. These findings provide a simple method for isolating populations of cardiomyocytes from human pluripotent stem cell cultures, and thereby establish a readily adaptable technology for generating large numbers of enriched cardiomyocytes for therapeutic applications.

Generation of folliculogenic human epithelial stem cells from induced pluripotent stem cells

NASA Astrophysics Data System (ADS)

Yang, Ruifeng; Zheng, Ying; Burrows, Michelle; Liu, Shujing; Wei, Zhi; Nace, Arben; Guo, Wei; Kumar, Suresh; Cotsarelis, George; Xu, Xiaowei

2014-01-01

Epithelial stem cells (EpSCs) in the hair follicle bulge are required for hair follicle growth and cycling. The isolation and propagation of human EpSCs for tissue engineering purposes remains a challenge. Here we develop a strategy to differentiate human iPSCs (hiPSCs) into CD200+/ITGA6+ EpSCs that can reconstitute the epithelial components of the hair follicle and interfollicular epidermis. The hiPSC-derived CD200+/ITGA6+ cells show a similar gene expression signature as EpSCs directly isolated from human hair follicles. Human iPSC-derived CD200+/ITGA6+ cells are capable of generating all hair follicle lineages including the hair shaft, and the inner and outer root sheaths in skin reconstitution assays. The regenerated hair follicles possess a KRT15+ stem cell population and produce hair shafts expressing hair-specific keratins. These results suggest an approach for generating large numbers of human EpSCs for tissue engineering and new treatments for hair loss, wound healing and other degenerative skin disorders.

Mesenchymal stem cells: biological characteristics and potential clinical applications.

PubMed

Kassem, Moustapha

2004-01-01

Mesenchymal stem cells (MSC) are clonogenic, non-hematpoietic stem cells present in the bone marrow and are able to differentiate into multiple mesoderm-type cell lineages, for example, osteoblasts, chondrocytes, endothelial-cells and also non-mesoderm-type lineages, for example, neuronal-like cells. Several methods are currently available for isolation of the MSC based on their physical and physico-chemical characteristics, for example, adherence to plastics or other extracellular matrix components. Because of the ease of their isolation and their extensive differentiation potential, MSC are among the first stem cell types to be introduced in the clinic. Several studies have demonstrated the possible use of MSC in systemic transplantation for systemic diseases, local implantation for local tissue defects, as a vehicle for genes in gene therapy protocols or to generate transplantable tissues and organs in tissue engineering protocols. Before their widespread use in therapy, methods allowing the generation of large number of cells without affecting their differentiation potential as well as technologies that overcome immunological rejection (in case allogenic transplantation) must be developed.

2017 Robotic Mining Competition

NASA Image and Video Library

2017-05-23

Team members from Purdue University prepare their uniquely-designed robot miner in the RoboPit at NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

Adult Palatum as a Novel Source of Neural Crest-Related Stem Cells

PubMed Central

Widera, Darius; Zander, Christin; Heidbreder, Meike; Kasperek, Yvonne; Noll, Thomas; Seitz, Oliver; Saldamli, Belma; Sudhoff, Holger; Sader, Robert; Kaltschmidt, Christian; Kaltschmidt, Barbara

2009-01-01

Somatic neural and neural crest stem cells are promising sources for cellular therapy of several neurodegenerative diseases. However, because of practical considerations such as inadequate accessibility of the source material, the application of neural crest stem cells is strictly limited. The secondary palate is a highly regenerative and heavily innervated tissue, which develops embryonically under direct contribution of neural crest cells. Here, we describe for the first time the presence of nestin-positive neural crest-related stem cells within Meissner corpuscles and Merkel cell-neurite complexes located in the hard palate of adult Wistar rats. After isolation, palatal neural crest-related stem cells (pNC-SCs) were cultivated in the presence of epidermal growth factor and fibroblast growth factor under serum-free conditions, resulting in large amounts of neurospheres. We used immunocytochemical techniques and reverse transcriptase-polymerase chain reaction to assess the expression profile of pNC-SCs. In addition to the expression of neural crest stem cell markers such as Nestin, Sox2, and p75, we detected the expression of Klf4, Oct4, and c-Myc. pNC-SCs differentiated efficiently into neuronal and glial cells. Finally, we investigated the potential expression of stemness markers within the human palate. We identified expression of stem cell markers nestin and CD133 and the transcription factors needed for reprogramming of somatic cells into pluripotent cells: Sox2, Oct4, Klf4, and c-Myc. These data show that cells isolated from palatal rugae form neurospheres, are highly plastic, and express neural crest stem cell markers. In addition, pNC-SCs may have the ability to differentiate into functional neurons and glial cells, serving as a starting point for therapeutic studies. Stem Cells 2009;27:1899–1910 PMID:19544446

Highly osteogenic PDL stem cell clones specifically express elevated levels of ICAM1, ITGB1 and TERT.

PubMed

Sununliganon, Laddawun; Singhatanadgit, Weerachai

2012-01-01

Cells derived from the periodontal ligament (PDL) have previously been reported to have stem cell-like characteristics (PDL stem cells; PDLSCs) and play an important part in bone engineering, including that of alveolar bone. However, these populations have been heterogeneous, and thus far no specific marker has yet been established from adult human stem cells derived from PDL tissue. We have previously isolated highly purified single cell-derived PDLSC clones and delineated their phenotypic and functional characteristics. In this report, we further obtained three homogeneous and distinct PDLSC clones demonstrating low, moderate and high mineralized matrix forming ability-namely PC12, PC4 and PC3, respectively, and the expression of mesenchymal stem cell pathway-specific genes in these clones was investigated. PCR array revealed that the expression of intercellular adhesion molecule 1 (ICAM1), integrin beta 1 (ITGB1) and telomerase reverse transcriptase (TERT) was associated with highly osteogenic PDLSC clones, as determined by the expression of key osteoblastic markers and their ability to form alizarin red S positive mineralized matrix in vitro. The present results suggest that these three mesenchymal stem cell-associated markers could potentially be used to isolate PDLSCs with high osteogenic capability for engineering new bone.

Adult stem cell theory of the multi-stage, multi-mechanism theory of carcinogenesis: role of inflammation on the promotion of initiated stem cells.

PubMed

Trosko, James E; Tai, Mei-Hui

2006-01-01

Inflammation, induced by microbial agents, radiation, endogenous or exogenous chemicals, has been associated with chronic diseases, including cancer. Since carcinogenesis has been characterized as consisting of the 'initiation', 'promotion' and 'progression' phases, the inflammatory process could affect any or all three phases. The stem cell theory of carcinogenesis has been given a revival, in that isolated human adult stem cells have been isolated and shown to be 'targets' for neoplastic transformation. Oct4, a transcription factor, has been associated with adult stem cells, as well as their immortalized and tumorigenic derivatives, but not with the normal differentiated daughters. These data are consistent with the stem cell theory of carcinogenesis. In addition, Gap Junctional Intercellular Communication (GJIC) seems to play a major role in cell growth. Inhibition of GJIC by non-genotoxic chemicals or various oncogenes seems to be the mechanism for the tumor promotion and progression phases of carcinogenesis. Many of the toxins, synthetic non-genotoxicants, and endogenous inflammatory factors have been shown to inhibit GJIC and act as tumor promoters. The inhibition of GJIC might be the mechanism by which the inflammatory process affects cancer and that to intervene during tumor promotion with anti-inflammatory factors might be the most efficacious anti-cancer strategy.

Xanthium italicum, Xanthium strumarium and Arctium lappa as new hosts for Diaporthe helianthi.

PubMed

Vrandecic, Karolina; Jurkovic, Drazenka; Riccioni, Luca; Cosic, Jasenka; Duvnjak, Tomislav

2010-07-01

Sunflower (Helianthus annuus) stem canker caused by Diaporthe helianthi is one of the most important sunflower diseases in Croatia. Until recently, sunflower was the only known host for D. helianthi. In our research carried out in the area of Eastern Croatia, isolates of Diaporthe/Phomospis were collected from Xanthium italicum, X. strumarium and Arctium lappa. Using morphological, cultural and molecular ITS rDNA data, isolates from these weeds were identified as D. helianthi. The following isolates were used in the pathogenicity test: one isolate originated from sunflower (Su5/04), three from X. italicum (Xa2, Xa3 and Xa5), two from X. strumarium (Xa9 and Xa12), one from Xanthium sp. (Xa13) and one from A. lappa (Ar3). According to the results, it was determined that isolate Xa5 (originated from X. italicum) was the most pathogenic to sunflower stems. The average length of the lesion was 11.3 cm. The lowest level of pathogenicity was found in Xa9 (isolated from X. strumarium). The length of the lesion was 0.1 cm.

Dose-Dependent Dual Role of PIT-1 (POU1F1) in Somatolactotroph Cell Proliferation and Apoptosis

PubMed Central

Jullien, Nicolas; Roche, Catherine; Brue, Thierry; Figarella-Branger, Dominique; Graillon, Thomas; Barlier, Anne; Herman, Jean-Paul

2015-01-01

To test the role of wtPIT-1 (PITWT) or PIT-1 (R271W) (PIT271) in somatolactotroph cells, we established, using inducible lentiviral vectors, sublines of GH4C1 somatotroph cells that allow the blockade of the expression of endogenous PIT-1 and/or the expression of PITWT or PIT271, a dominant negative mutant of PIT-1 responsible for Combined Pituitary Hormone Deficiency in patients. Blocking expression of endogenous PIT-1 induced a marked decrease of cell proliferation. Overexpressing PITWT twofold led also to a dose-dependent decrease of cell proliferation that was accompanied by cell death. Expression of PIT271 induced a strong dose-dependent decrease of cell proliferation accompanied by a very pronounced cell death. These actions of PIT271 are independent of its interaction/competition with endogenous PIT-1, as they were unchanged when expression of endogenous PIT-1 was blocked. All these actions are specific for somatolactotroph cells, and could not be observed in heterologous cells. Cell death induced by PITWT or by PIT271 was accompanied by DNA fragmentation, but was not inhibited by inhibitors of caspases, autophagy or necrosis, suggesting that this cell death is a caspase-independent apoptosis. Altogether, our results indicate that under normal conditions PIT-1 is important for the maintenance of cell proliferation, while when expressed at supra-normal levels it induces cell death. Through this dual action, PIT-1 may play a role in the expansion/regression cycles of pituitary lactotroph population during and after lactation. Our results also demonstrate that the so-called “dominant-negative” action of PIT271 is independent of its competition with PIT-1 or a blockade of the actions of the latter, and are actions specific to this mutant variant of PIT-1. PMID:25822178

Isolation and genetic characterization of Aurantimonas and Methylobacterium strains from stems of hypernodulated soybeans.

PubMed

Anda, Mizue; Ikeda, Seishi; Eda, Shima; Okubo, Takashi; Sato, Shusei; Tabata, Satoshi; Mitsui, Hisayuki; Minamisawa, Kiwamu

2011-01-01

The aims of this study were to isolate Aurantimonas and Methylobacterium strains that responded to soybean nodulation phenotypes and nitrogen fertilization rates in a previous culture-independent analysis (Ikeda et al. ISME J. 4:315-326, 2010). Two strategies were adopted for isolation from enriched bacterial cells prepared from stems of field-grown, hypernodulated soybeans: PCR-assisted isolation for Aurantimonas and selective cultivation for Methylobacterium. Thirteen of 768 isolates cultivated on Nutrient Agar medium were identified as Aurantimonas by colony PCR specific for Aurantimonas and 16S rRNA gene sequencing. Meanwhile, among 187 isolates on methanol-containing agar media, 126 were identified by 16S rRNA gene sequences as Methylobacterium. A clustering analysis (>99% identity) of the 16S rRNA gene sequences for the combined datasets of the present and previous studies revealed 4 and 8 operational taxonomic units (OTUs) for Aurantimonas and Methylobacterium, respectively, and showed the successful isolation of target bacteria for these two groups. ERIC- and BOX-PCR showed the genomic uniformity of the target isolates. In addition, phylogenetic analyses of Aurantimonas revealed a phyllosphere-specific cluster in the genus. The isolates obtained in the present study will be useful for revealing unknown legume-microbe interactions in relation to the autoregulation of nodulation.

Rain Erosion Studies of Sapphire, Aluminum Oxynitride, Spinel, Lanthana- Doped Yttria, and TAF Glass

DTIC Science & Technology

1990-07-01

small , there is little change in average scatter for any material in any test. CONCLUSIONS AND DISCUSSION The principal conclusions are 1. ALON...20 Sample broke erosion damage 10 Slight pitting, 20 No change erosion damage 15 Pitting, cratering, 20 Small surface pits erosion damage 15 Pitting...Sample broke 10 No damage 15 Sample pitted, small edge fracture 15 Slight pitting, 1 crater, 20 Sample pitted, erosion damage small edge fracture 15 SUght

In search of the skeletal stem cell: isolation and separation strategies at the macro/micro scale for skeletal regeneration.

PubMed

Gothard, David; Tare, Rahul S; Mitchell, Peter D; Dawson, Jonathan I; Oreffo, Richard O C

2011-04-07

Skeletal stem cells (SSCs) show great capacity for bone and cartilage repair however, current in vitro cultures are heterogeneous displaying a hierarchy of differentiation potential. SSCs represent the diminutive true multipotent stem cell fraction of bone marrow mononuclear cell (BMMNC) populations. Endeavours to isolate SSCs have generated a multitude of separation methodologies. SSCs were first identified and isolated by their ability to adhere to culture plastic. Once isolated, further separation is achieved via culture in selective or conditioned media (CM). Indeed, preferential SSC growth has been demonstrated through selective in vitro culture conditions. Other approaches have utilised cell morphology (size and shape) as selection criteria. Studies have also targeted SSCs based on their preferential adhesion to specified compounds, individually or in combination, on both macro and microscale platforms. Nevertheless, most of these methods which represent macroscale function with relatively high throughput, yield insufficient purity. Consequently, research has sought to downsize isolation methodologies to the microscale for single cell analysis. The central approach is identification of the requisite cell populations of SSC-specific surface markers that can be targeted for isolation by either positive or negative selection. SELEX and phage display technology provide apt means to sift through substantial numbers of candidate markers. In contrast, single cell analysis is the paramount advantage of microfluidics, a relatively new field for cell biology. Here cells can be separated under continuous or discontinuous flow according to intrinsic phenotypic and physicochemical properties. The combination of macroscale quantity with microscale specificity to generate robust high-throughput (HT) technology for pure SSC sorting, isolation and enrichment offers significant implications therein for skeletal regenerative strategies as a consequence of lab on chip derived methodology.

Characteristics of mesenchymal stem cells isolated from bone marrow of giant panda.

PubMed

Liu, Yuliang; Liu, Yang; Yie, Shangmian; Lan, Jingchao; Pi, Jinkui; Zhang, Zhihe; Huang, He; Cai, Zhigang; Zhang, Ming; Cai, Kailai; Wang, Hairui; Hou, Rong

2013-09-01

In present study, we report on bone marrow (BM) mesenchymal stem cells (MSCs) that are isolated from giant pandas. Cells were collected from the BM of two stillborn giant pandas. The cells were cultured and expanded in 10% fetal bovine serum medium. Cell morphology was observed under an inverted microscopy, and the proliferation potential of the cells was evaluated by counting cell numbers for eight consecutive days. Differentiation potentials of the cells were determined by using a variety of differentiation protocols for osteocytes, adipocytes, neuron cells, and cardiomyocytes. Meanwhile, the specific gene expressions for MSCs or differentiated cells were analyzed by RT-PCR. The isolated cells exhibited a fibroblast-like morphology; expressed mesenchymal specific markers such as cluster of differentiation 73 (CD73), SRY (sex determining region Y)-box 2 (SOX-2), guanine nucleotide-binding protein-like 3 (GNL3), and stem cell factor receptor (SCFR); and could be differentiated into osteocytes and adipocytes that were characterized by Alizarin Red and Oil Red O staining. Under appropriate induction conditions, these cells were also able to differentiate into neuroglial-like or myocardial-like cells that expressed specific myocardial markers such as GATA transcription factors 4 (GATA-4), cardiac troponin T (cTnT), and myosin heavy chain 7B (MYH7B), or neural specific markers such as Nestin and glial fibrillary acidic protein (GFAP). This study demonstrated stem cells recovery and growth from giant pandas. The findings suggest that cells isolated from the BM of giant pandas have a high proliferative capacity and multiple differentiation potential in vitro which might aid conservation efforts.

Characterization of pancreatic stem cells derived from adult human pancreas ducts by fluorescence activated cell sorting.

PubMed

Lin, Han-Tso; Chiou, Shih-Hwa; Kao, Chung-Lan; Shyr, Yi-Ming; Hsu, Chien-Jen; Tarng, Yih-Wen; Ho, Larry L-T; Kwok, Ching-Fai; Ku, Hung-Hai

2006-07-28

To isolate putative pancreatic stem cells (PSCs) from human adult tissues of pancreas duct using serum-free, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of beta-cell differentiation in these PSCs were evaluated as well. By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The Matrigel(TM) was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting (FACS) was used to detect the phenotypic markers of putative PSCs. A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-alpha, CD73 (SH2), CD81, CD105(SH3). In this study, we successfully isolated PSCs from adult human pancreatic duct by using serum-free medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus.

Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages.

PubMed

Arsic, Nikola; Mamaeva, Daria; Lamb, Ned J; Fernandez, Anne

2008-04-01

Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal beta III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders.

Palaeoecological caracterisation of the mammoth steppe at Final Pleistocene in Central Ukraine from zooarchaeology, stable isotope analyses and direct radiocarbon dating

NASA Astrophysics Data System (ADS)

Péan, Stéphane; Drucker, Dorothée.; Bocherens, Hervé; Haesaerts, Paul; Valladas, Hélène; Stupak, Dmytro; Nuzhnyi, Dmytro

2010-05-01

In the Central Ukraine area of the Middle Dnipro Basin, including the Desna river valley, there are exceptional Upper Palaeolithic open air sites with mammoth bone dwelling structures. Mezhyrich is one of these settlements, which are attributed to the Epigravettian cultural facies and occurred in a periglacial environment, during Oxygen Isotope Stage (OIS) 2. Mammoth bone buildings are surrounded by pits, which are filled with archaeological material (tools, hunting weapons, ivory and bone ornaments) and bones of mammoth and other large mammals such as hare, fox, wolf, horse. A new site Buzhanka 2 has yielded a pit which could be related to an expected dwelling structure. These Final Pleistocene sites are particularly appropriate to shed new light upon the relation between man and environment at the time of the mammoth steppe disappearance. Multidisciplinar studies have been carried on, to cross results from zooarchaeology of the pit contents, carbon and nitrogen stable isotope (13C and 15N) analyses of bone collagen, direct 14C dates on mammal bones and microstratigraphic analyses of the loessic sediment. With almost twenty 14C dates available, from mammoth and wolf bones and from charcoals, Mezhyrich is the best dated Epigravettian mammoth bone dwelling site: around 14 500 years BP. Mammoth treatment is zooarchaeologically evidenced in Buzhanka 2, but limited excavated areas do not allow to interpret their procurement yet. In Mezhyrich, consumption of mammoth meat is evidenced from the pit contents, coming from a few juveniles and young adults, probably hunted. The bones used in the dwelling structure no. 4, which are attributed to at least 37 individuals, have two different origins: mostly isolated elements gathered from other deposits, natural accumulations or previous kill sites; a few skeletal portions in anatomical position taken from at least one quite freshly dead mammoth body, for instance a hunted individual. From the stable isotope analyses, it appears that a modification of the regional plant and climatic context may have inferred a change of food resource for mammoths, which could have been put into food competition with horses. Mammoths from Central Ukraine at late OIS 2 may have formed an isolated local population, under the pressure of modified ecological conditions, compared to the period of maximal extension of the mammoth steppe. Thus, thanks to a combined approach of zooarchaeology, stable isotopes and radiocarbon dating, in the stratigraphic context, a better knowledge of the palaeoecological context of the last mammoths at late Pleniglacial in Central Ukraine is expected.

Phosphate (Pi)-regulated heterodimerization of the high-affinity sodium-dependent Pi transporters PiT1/Slc20a1 and PiT2/Slc20a2 underlies extracellular Pi sensing independently of Pi uptake.

PubMed

Bon, Nina; Couasnay, Greig; Bourgine, Annabelle; Sourice, Sophie; Beck-Cormier, Sarah; Guicheux, Jérôme; Beck, Laurent

2018-02-09

Extracellular phosphate (P i ) can act as a signaling molecule that directly alters gene expression and cellular physiology. The ability of cells or organisms to detect changes in extracellular P i levels implies the existence of a P i -sensing mechanism that signals to the body or individual cell. However, unlike in prokaryotes, yeasts, and plants, the molecular players involved in P i sensing in mammals remain unknown. In this study, we investigated the involvement of the high-affinity, sodium-dependent P i transporters PiT1 and PiT2 in mediating P i signaling in skeletal cells. We found that deletion of PiT1 or PiT2 blunted the P i -dependent ERK1/2-mediated phosphorylation and subsequent gene up-regulation of the mineralization inhibitors matrix Gla protein and osteopontin. This result suggested that both PiTs are necessary for P i signaling. Moreover, the ERK1/2 phosphorylation could be rescued by overexpressing P i transport-deficient PiT mutants. Using cross-linking and bioluminescence resonance energy transfer approaches, we found that PiT1 and PiT2 form high-abundance homodimers and P i -regulated low-abundance heterodimers. Interestingly, in the absence of sodium-dependent P i transport activity, the PiT1-PiT2 heterodimerization was still regulated by extracellular P i levels. Of note, when two putative P i -binding residues, Ser-128 (in PiT1) and Ser-113 (in PiT2), were substituted with alanine, the PiT1-PiT2 heterodimerization was no longer regulated by extracellular P i These observations suggested that P i binding rather than P i uptake may be the key factor in mediating P i signaling through the PiT proteins. Taken together, these results demonstrate that P i -regulated PiT1-PiT2 heterodimerization mediates P i sensing independently of P i uptake. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

Analysis of the bacterial community in aged and aging pit mud of Chinese Luzhou-flavour liquor by combined PCR-DGGE and quantitative PCR assay.

PubMed

Liang, Huipeng; Li, Wenfang; Luo, Qingchun; Liu, Chaolan; Wu, Zhengyun; Zhang, Wenxue

2015-10-01

The community structure of bacteria in aged and aging pit mud, which was judged according to their sensory and physicochemical characteristics, was analysed using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) and quantitative real-time PCR (qPCR). The phyla Firmicutes, Actinobacteria, Proteobacteria, Synergistetes and Unclassified Bacteria were detected and the fermentative Firmicutes was predominant in both types of pit mud in the PCR-DGGE analysis. Among Firmicutes, Clostridiales was dominant in aged pit mud while Bacillales and Lactobacillales were dominant in aging pit mud. The diversity of bacterial communities in aged pit mud was higher than that in aging pit mud. In the qPCR analysis the abundance of Clostridium IV in aged pit mud was higher than that in aging pit mud and there were significant differences in the quantity of Clostridium IV between aged and aging pit mud of the same cellar (P < 0.05). There were some significant differences in the microbial community structure between aged and aging pit mud. The differences in the quantity of Clostridium IV might be involved in the distinction that the aged pit mud has a strong aroma while the aging pit mud does not. © 2014 Society of Chemical Industry.

Structure and function of bordered pits: new discoveries and impacts on whole-plant hydraulic function.

PubMed

Choat, Brendan; Cobb, Alexander R; Jansen, Steven

2008-01-01

Bordered pits are cavities in the lignified cell walls of xylem conduits (vessels and tracheids) that are essential components in the water-transport system of higher plants. The pit membrane, which lies in the center of each pit, allows water to pass between xylem conduits but limits the spread of embolism and vascular pathogens in the xylem. Averaged across a wide range of species, pits account for > 50% of total xylem hydraulic resistance, indicating that they are an important factor in the overall hydraulic efficiency of plants. The structure of pits varies dramatically across species, with large differences evident in the porosity and thickness of pit membranes. Because greater porosity reduces hydraulic resistance but increases vulnerability to embolism, differences in pit structure are expected to correlate with trade-offs between efficiency and safety of water transport. However, trade-offs in hydraulic function are influenced both by pit-level differences in structure (e.g. average porosity of pit membranes) and by tissue-level changes in conduit allometry (average length, diameter) and the total surface area of pit membranes that connects vessels. In this review we address the impact of variation in pit structure on water transport in plants from the level of individual pits to the whole plant.

Nodulation-dependent communities of culturable bacterial endophytes from stems of field-grown soybeans.

PubMed

Okubo, Takashi; Ikeda, Seishi; Kaneko, Takakazu; Eda, Shima; Mitsui, Hisayuki; Sato, Shusei; Tabata, Satoshi; Minamisawa, Kiwamu

2009-01-01

Endophytic bacteria (247 isolates) were randomly isolated from surface-sterilized stems of non-nodulated (Nod(-)), wild-type nodulated (Nod(+)), and hypernodulated (Nod(++)) soybeans (Glycine max [L.] Merr) on three agar media (R2A, nutrient agar, and potato dextrose agar). Their diversity was compared on the basis of 16S rRNA gene sequences. The phylogenetic composition depended on the soybean nodulation phenotype, although diversity indexes were not correlated with nodulation phenotype. The most abundant phylum throughout soybean lines tested was Proteobacteria (58-79%). Gammaproteobacteria was the dominant class (21-72%) with a group of Pseudomonas sp. significantly abundant in Nod(+) soybeans. A high abundance of Alphaproteobacteria was observed in Nod(-) soybeans, which was explained by the increase in bacterial isolates of the families Rhizobiaceae and Sphingomonadaceae. A far greater abundance of Firmicutes was observed in Nod(-) and Nod(++) mutant soybeans than in Nod(+) soybeans. An impact of culture media on the diversity of isolated endophytic bacteria was also observed: The highest diversity indexes were obtained on the R2A medium, which enabled us to access Alphaproteobacteria and other phyla more frequently. The above results indicated that the extent of nodulation changes the phylogenetic composition of culturable bacterial endophytes in soybean stems.

Differentiation of Mouse Ovarian Stem Cells Toward Oocyte-Like Structure by Coculture with Granulosa Cells.

PubMed

Parvari, Soraya; Yazdekhasti, Hossein; Rajabi, Zahra; Gerayeli Malek, Valliollah; Rastegar, Tayebeh; Abbasi, Mehdi

2016-11-01

An increasing body of evidence has confirmed existence and function of ovarian stem cells (OSCs). In this study, a novel approach on differentiation of OSCs into oocyte-like cells (OLCs) has been addressed. Recently, different methods have been recruited to isolate and describe aspects of OSCs, but newer and more convenient strategies in isolation are still growing. Herein, a morphology-based method was used to isolate OSCs. Cell suspension of mouse neonatal ovaries was cultured and formed colonies were harvested mechanically and cultivated on mouse embryonic fibroblasts. For differentiation induction, colonies transferred on inactive granulosa cells. Results showed that cells in colonies were positive for alkaline phosphatase activity and reverse transcription-polymerase chain reaction (RT-PCR) confirmed the pluripotency characteristics of cells. Immunofluorescence revealed a positive signal for OCT4, DAZL, MVH, and SSEA1 in colonies as well. Results of RT-PCR and immunofluorescence confirmed that some OLCs were generated within the germ stem cell (GSCs) colonies. The applicability of morphological selection for isolation of GSCs was verified. This method is easier and more economic than other techniques. Our results demonstrate that granulosa cells were effective in inducing the differentiation of OSCs into OLCs through direct cell-to-cell contacts.

Cellular and Molecular Characterization of Human Cardiac Stem Cells Reveals Key Features Essential for Their Function and Safety

PubMed Central

Vahdat, Sadaf; Mousavi, Seyed Ahmad; Omrani, Gholamreza; Gholampour, Maziar; Sotoodehnejadnematalahi, Fattah; Ghazizadeh, Zaniar; Gharechahi, Javad

2015-01-01

Cell therapy of heart diseases is emerging as one of the most promising known treatments in recent years. Transplantation of cardiac stem cells (CSCs) may be one of the best strategies to cure adult or pediatric heart diseases. As these patient-derived stem cells need to be isolated from small heart biopsies, it is important to select the best isolation method and CSC subpopulation with the best cardiogenic functionality. We employed three different protocols including c-KIT+ cell sorting, clonogenic expansion, and explants culture to isolate c-KIT+ cells, clonogenic expansion-derived cells (CEDCs), and cardiosphere-derived cells (CDCs), respectively. Evaluation of isolated CSC characteristics in vitro and after rat myocardial infarction (MI) model transplantation revealed that although c-KIT+ and CDCs had higher MI regenerative potential, CEDCs had more commitment into cardiomyocytes and needed lower passages that were essential to reach a definite cell count. Furthermore, genome-wide expression analysis showed that subsequent passages caused changes in characteristics of cells, downregulation of cell cycle-related genes, and upregulation of differentiation and carcinogenic genes, which might lead to senescence, commitment, and possible tumorigenicity of the cells. Because of different properties of CSC subpopulations, we suggest that appropriate CSCs subpopulation should be chosen based on their experimental or clinical use. PMID:25867933

Isolation and characterization of human CXCR4-positive pancreatic cells.

PubMed

Koblas, T; Zacharovová, K; Berková, Z; Mindlová, M; Girman, P; Dovolilová, E; Karasová, L; Saudek, F

2007-01-01

The existence of an adult PSC that may be used in the treatment of diabetes is still a matter of scientific debate as conclusive evidence of such a stem cell in the adult pancreas has not yet been presented. The main reason why putative PSC has not yet been identified is the lack of specific markers that may be used to isolate and purify them. In order to increase the list of potential PSC markers we have focused on the human pancreatic cells that express cell surface receptor CXCR4, a marker of stem cells derived from different adult tissues. Here we report that CXCR4-positive pancreatic cells express markers of pancreatic endocrine progenitors (neurogenin-3, nestin) and markers of pluripotent stem cells (Oct-4, Nanog, ABCG2, CD133, CD117). Upon in vitro differentiation, these cells form ILCC and produce key islet hormones including insulin. Based on our results, we assume that CXCR4 marks pancreatic endocrine progenitors and in combination with other cell surface markers may be used in the attempt to identify and isolate PSC.

Amnion-derived stem cells: in quest of clinical applications

PubMed Central

2011-01-01

In the promising field of regenerative medicine, human perinatal stem cells are of great interest as potential stem cells with clinical applications. Perinatal stem cells could be isolated from normally discarded human placentae, which are an ideal cell source in terms of availability, the fewer number of ethical concerns, less DNA damage, and so on. Numerous studies have demonstrated that some of the placenta-derived cells possess stem cell characteristics like pluripotent differentiation ability, particularly in amniotic epithelial (AE) cells. Term human amniotic epithelium contains a relatively large number of stem cell marker-positive cells as an adult stem cell source. In this review, we introduce a model theory of why so many AE cells possess stem cell characteristics. We also describe previous work concerning the therapeutic applications and discuss the pluripotency of the AE cells and potential pitfalls for amnion-derived stem cell research. PMID:21596003

PitScan: Computer-Assisted Feature Detection

NASA Astrophysics Data System (ADS)

Wagner, R. V.; Robinson, M. S.

2018-04-01

We developed PitScan to assist in searching the very large LROC image dataset for pits — unusual <200m wide vertical-walled holes in the Moon's surface. PitScan reduces analysts' workload by pre-filtering images to identify possible pits.

Quantitative Correlation of 7B04 Aluminum Alloys Pitting Corrosion Morphology Characteristics with Stress Concentration Factor

NASA Astrophysics Data System (ADS)

Liu, Zhiguo; Yan, Guangyao; Mu, Zhitao; Li, Xudong

2018-01-01

The accelerated pitting corrosion test of 7B04 aluminum alloy specimen was carried out according to the spectrum which simulated airport environment, and the corresponding pitting corrosion damage was obtained and was defined through three parameters A and B and C which respectively denoted the corrosion pit surface length and width and corrosion pit depth. The ratio between three parameters could determine the morphology characteristics of corrosion pits. On this basis the stress concentration factor of typical corrosion pit morphology under certain load conditions was quantitatively analyzed. The research shows that the corrosion pits gradually incline to be ellipse in surface and moderate in depth, and most value of B/A and C/A lies in 1 between 4 and few maximum exceeds 4; The stress concentration factor Kf of corrosion pits is obviously affected by the its morphology, the value of Kf increases with corrosion pits depth increasement under certain corrosion pits surface geometry. Also, the value of Kf decreases with surface width increasement under certain corrosion pits depth. The research conclusion can set theory basis for corrosion fatigue life analysis of aircraft aluminum alloy structure.

Sucrose accumulation in sweet sorghum stems occurs by apoplasmic phloem unloading and does not involve differential Sucrose transporter expression.

PubMed

Bihmidine, Saadia; Baker, R Frank; Hoffner, Cassandra; Braun, David M

2015-07-30

Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this study was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.

Spiral Ganglion Stem Cells Can Be Propagated and Differentiated Into Neurons and Glia

PubMed Central

Zecha, Veronika; Wagenblast, Jens; Arnhold, Stefan; Edge, Albert S. B.; Stöver, Timo

2014-01-01

Abstract The spiral ganglion is an essential functional component of the peripheral auditory system. Most types of hearing loss are associated with spiral ganglion cell degeneration which is irreversible due to the inner ear's lack of regenerative capacity. Recent studies revealed the existence of stem cells in the postnatal spiral ganglion, which gives rise to the hope that these cells might be useful for regenerative inner ear therapies. Here, we provide an in-depth analysis of sphere-forming stem cells isolated from the spiral ganglion of postnatal mice. We show that spiral ganglion spheres have characteristics similar to neurospheres isolated from the brain. Importantly, spiral ganglion sphere cells maintain their major stem cell characteristics after repeated propagation, which enables the culture of spheres for an extended period of time. In this work, we also demonstrate that differentiated sphere-derived cell populations not only adopt the immunophenotype of mature spiral ganglion cells but also develop distinct ultrastructural features of neurons and glial cells. Thus, our work provides further evidence that self-renewing spiral ganglion stem cells might serve as a promising source for the regeneration of lost auditory neurons. PMID:24940560

Establishment of Cancer Stem Cell Cultures from Human Conventional Osteosarcoma.

PubMed

Palmini, Gaia; Zonefrati, Roberto; Mavilia, Carmelo; Aldinucci, Alessandra; Luzi, Ettore; Marini, Francesca; Franchi, Alessandro; Capanna, Rodolfo; Tanini, Annalisa; Brandi, Maria Luisa

2016-10-14

The current improvements in therapy against osteosarcoma (OS) have prolonged the lives of cancer patients, but the survival rate of five years remains poor when metastasis has occurred. The Cancer Stem Cell (CSC) theory holds that there is a subset of tumor cells within the tumor that have stem-like characteristics, including the capacity to maintain the tumor and to resist multidrug chemotherapy. Therefore, a better understanding of OS biology and pathogenesis is needed in order to advance the development of targeted therapies to eradicate this particular subset and to reduce morbidity and mortality among patients. Isolating CSCs, establishing cell cultures of CSCs, and studying their biology are important steps to improving our understanding of OS biology and pathogenesis. The establishment of human-derived OS-CSCs from biopsies of OS has been made possible using several methods, including the capacity to create 3-dimensional stem cell cultures under nonadherent conditions. Under these conditions, CSCs are able to create spherical floating colonies formed by daughter stem cells; these colonies are termed "cellular spheres". Here, we describe a method to establish CSC cultures from primary cell cultures of conventional OS obtained from OS biopsies. We clearly describe the several passages required to isolate and characterize CSCs.

Cancer stemness and metastatic potential of the novel tumor cell line K3: an inner mutated cell of bone marrow-derived mesenchymal stem cells.

PubMed

Qian, Hui; Ding, Xiaoqing; Zhang, Jiao; Mao, Fei; Sun, Zixuan; Jia, Haoyuan; Yin, Lei; Wang, Mei; Zhang, Xu; Zhang, Bin; Yan, Yongmin; Zhu, Wei; Xu, Wenrong

2017-06-13

Mesenchymal stem cells (MSCs) transplantation has been used for therapeutic applications in various diseases. Here we report MSCs can malignantly transform in vivo. The novel neoplasm was found on the tail of female rat after injection with male rat bone marrow-derived MSCs (rBM-MSCs) and the new tumor cell line, K3, was isolated from the neoplasm. The K3 cells expressed surface antigens and pluripotent genes similar to those of rBM-MSCs and presented tumor cell features. Moreover, the K3 cells contained side population cells (SP) like cancer stem cells (CSCs), which might contribute to K3 heterogeneity and tumorigenic capacity. To investigate the metastatic potential of K3 cells, we established the nude mouse models of liver and lung metastases and isolated the corresponding metastatic cell lines K3-F4 and K3-B6. Both K3-F4 and K3-B6 cell lines with higher metastatic potential acquired more mesenchymal and stemness-related features. Epithelial-mesenchymal transition is a potential mechanism of K3-F4 and K3-B6 formation.

Monomorphous Plurihormonal Pituitary Adenoma of Pit-1 Lineage in a Giant Adolescent with Central Hyperthyroidism.

PubMed

Pereira, Bernardo Dias; Raimundo, Luísa; Mete, Ozgur; Oliveira, Ana; Portugal, Jorge; Asa, Sylvia L

2016-03-01

Thyrotropin (TSH)-secreting pituitary adenomas are exceedingly rare at the pediatric age and no cases of co-secretion with other pituitary hormones in these tumors have been described in this age range. We present a case of a monomorphous plurihormonal pituitary adenoma that co-secreted TSH and GH in a pediatric patient. A 13-year-old male presented with increasing height velocity (17.75 cm/year, 9.55SD), weight loss, and visual impairment. Initial biochemical evaluations revealed secondary hyperthyroidism. A giant pituitary tumor compressing the surrounding structures was detected by magnetic resonance, and a transsphenoidal surgery was initially performed. Pathological examinations revealed an atypical, monomorphous plurihormonal Pit-1 lineage tumor with mixed features of silent subtype 3 adenoma and acidophil stem cell adenoma. In the postoperative period, secondary hyperthyroidism recurred with high levels of both GH and IGF1. In addition, due to tumor re-growth, a multimodality treatment plan was undertaken including surgery, somatostatin analogs, and radiotherapy. We report the first pediatric case of a plurihormonal TSH- and GH-secreting pituitary adenoma, further expanding the clinical manifestations of pediatric pituitary tumors. Comprehensive pathological evaluation and close follow-up surveillance are crucial to the prompt delivery of the best therapeutic options in the context of this particularly aggressive pituitary tumor.

Recalcitrant vulnerability curves: methods of analysis and the concept of fibre bridges for enhanced cavitation resistance.

PubMed

Cai, Jing; Li, Shan; Zhang, Haixin; Zhang, Shuoxin; Tyree, Melvin T

2014-01-01

Vulnerability curves (VCs) generally can be fitted to the Weibull equation; however, a growing number of VCs appear to be recalcitrant, that is, deviate from a Weibull but seem to fit dual Weibull curves. We hypothesize that dual Weibull curves in Hippophae rhamnoides L. are due to different vessel diameter classes, inter-vessel hydraulic connections or vessels versus fibre tracheids. We used dye staining techniques, hydraulic measurements and quantitative anatomy measurements to test these hypotheses. The fibres contribute 1.3% of the total stem conductivity, which eliminates the hypothesis that fibre tracheids account for the second Weibull curve. Nevertheless, the staining pattern of vessels and fibre tracheids suggested that fibres might function as a hydraulic bridge between adjacent vessels. We also argue that fibre bridges are safer than vessel-to-vessel pits and put forward the concept as a new paradigm. Hence, we tentatively propose that the first Weibull curve may be accounted by vessels connected to each other directly by pit fields, while the second Weibull curve is associated with vessels that are connected almost exclusively by fibre bridges. Further research is needed to test the concept of fibre bridge safety in species that have recalcitrant or normal Weibull curves. © 2013 John Wiley & Sons Ltd.

Stem cell-associated genes are extremely poor prognostic factors for soft-tissue sarcoma patients.

PubMed

Taubert, H; Würl, P; Greither, T; Kappler, M; Bache, M; Bartel, F; Kehlen, A; Lautenschläger, C; Harris, L C; Kaushal, D; Füssel, S; Meye, A; Böhnke, A; Schmidt, H; Holzhausen, H-J; Hauptmann, S

2007-11-01

Cancer stem cells can play an important role in tumorigenesis and tumor progression. However, it is still difficult to detect and isolate cancer stem cells. An alternative approach is to analyse stem cell-associated gene expression. We investigated the coexpression of three stem cell-associated genes, Hiwi, hTERT and survivin, by quantitative real-time-PCR in 104 primary soft-tissue sarcomas (STS). Multivariate Cox's proportional hazards regression analyses allowed correlating gene expression with overall survival for STS patients. Coexpression of all three stem cell-associated genes resulted in a significantly increased risk of tumor-related death. Importantly, tumors of patients with the poorest prognosis were of all four tumor stages, suggesting that their risk is based upon coexpression of stem cell-associated genes rather than on tumor stage.

Acquired pit of the optic nerve: a risk factor for progression of glaucoma.

PubMed

Ugurlu, S; Weitzman, M; Nduaguba, C; Caprioli, J

1998-04-01

To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.

Parturition pit: the bony imprint of vaginal birth.

PubMed

McArthur, Tatum A; Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J; Larrison, Matthew C

2016-09-01

To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p < 0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p < 0.0001). No males had pits. Our study indicates that parturition pits are associated with prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists.

Parturition Pit: The Bony Imprint of Vaginal Birth

PubMed Central

Meyer, Isuzu; Jackson, Bradford; Pitt, Michael J.; Larrison, Matthew C.

2017-01-01

Purpose To retrospectively evaluate for pits along the dorsum of the pubic body in females and compare the presence/absence of these pits to vaginal birth data. Materials and Methods We retrospectively reviewed females with vaginal birth data who underwent pelvic CT. The presence of pits along the dorsum of the pubic body, pit grade (0 = not present; 1 = faintly imperceptible; 2 = present; 3 = prominent), and the presence of osteitis condensans ilii, preauricular sulcus, and sacroiliac joint vacuum phenomenon were assessed on imaging. Musculoskeletal radiologists who were blinded to the birth data evaluated the CTs. 48 males were also evaluated for the presence of pits. Results 482 female patients underwent CT pelvis and 171 were excluded due to lack of vaginal birth data. Of the 311 study patients, 262 had prior vaginal birth(s) and 194 had pits on CT. Only 7 of the 49 patients without prior vaginal birth had pits. There was a statistically significant association between vaginal birth and presence of pits (p<0.0001). Patients with more prominent pits (grades 2/3) had a greater number of vaginal births. As vaginal deliveries increased, the odds of having parturition pits greatly increased, adjusting for age and race at CT (p<0.0001). No males had pits. Conclusion Our study indicates that parturition pits are associated prior vaginal birth and should be considered a characteristic of the female pelvis. The lytic appearance of prominent pits on imaging can simulate disease and create a diagnostic dilemma for interpreting radiologists. PMID:27270921

The effect of normal pulsed Nd-YAG laser irradiation on pits and fissures in human teeth.

PubMed

Bahar, A; Tagomori, S

1994-01-01

The effects of normal pulsed Nd-YAG laser irradiation on the acid resistance of human dental enamel of pits and fissures, the cleaning of the pit and fissure contents and fluoride uptake into deep pits and fissures were examined. The acid resistance of the pit and fissure enamel was evaluated by the amount of dissolved calcium per square millimeter of the surface area. The pit and fissure enamel treated with laser irradiation obtained an acid resistance 30% higher than that of the unlased controls. The cleaning effect of laser irradiation on the pit and fissure contents was compared with chemicomechanical and mechanical methods. The laser irradiation was found to clean the pits and fissures to a greater depth without alterating the shape of pits and fissures, compared with the other two methods. The distribution of calcium, phosphorus and fluoride in the enamel of the pits and fissures was then measured by electron probe microanalyzer. At the entrance and in the deep part of the pits and fissures, the fluoride content of the enamel treated with acidulated phosphate fluoride after laser irradiation was higher than that of the enamel treated with acidulated phosphate fluoride alone. These results thus suggest that Nd-YAG laser irradiation might be effective in increasing the acid resistance of the pit and fissure enamel, while removing the pit and fissure debris contents and increasing the fluoride uptake into the pit and fissure enamel.

A Partnership Training Program: Studying Targeted Drug Delivery Using Nanoparticles in Breast Cancer Diagnosis and Therapy

DTIC Science & Technology

2013-10-01

labeling and tracking of mesenchymal stem cells (MSCs). MSCs are a heterogeneous group of pluripotent stromal cells that can be isolated from... mesenchymal stem cell labelling by using polyhedral superparamagnetic iron oxide nanoparticles. Chemistry 2009;15:12417-25. Wang and Shan. MRI cell ...and Differentiation of Mesenchymal Stem Cells by Carboxylated Carbon Nanotubes. ACS Nano 2010, 4, 2185–2195. 15. Bertoncini, P.; Chauvet, O

[Research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration].

PubMed

Liang, Hang; Deng, Xiangyu; Shao, Zengwu

2017-10-01

To summarize the research progress of intervertebral disc endogenous stem cells for intervertebral disc regeneration and deduce the therapeutic potential of endogenous repair for intervertebral disc degeneration. The original articles about intervertebral disc endogenous stem cells for intervertebral disc regeneration were extensively reviewed; the reparative potential in vivo and the extraction and identification in vitro of intervertebral disc endogenous stem cells were analyzed; the prospect of endogenous stem cells for intervertebral disc regeneration was predicted. Stem cell niche present in the intervertebral discs, from which stem cells migrate to injured tissues and contribute to tissues regeneration under certain specific microenvironment. Moreover, the migration of stem cells is regulated by chemokines system. Tissue specific progenitor cells have been identified and successfully extracted and isolated. The findings provide the basis for biological therapy of intervertebral disc endogenous stem cells. Intervertebral disc endogenous stem cells play a crucial role in intervertebral disc regeneration. Therapeutic strategy of intervertebral disc endogenous stem cells is proven to be a promising biological approach for intervertebral disc regeneration.

Pitting Corrosion Behaviour of New Corrosion-Resistant Reinforcement Bars in Chloride-Containing Concrete Pore Solution

PubMed Central

Liu, Yao; Chu, Hong-yan; Wang, Danqian; Ma, Han; Sun, Wei

2017-01-01

In this study, the pitting behaviour of a new corrosion-resistant alloy steel (CR) is compared to that of low-carbon steel (LC) in a simulated concrete pore solution with a chloride concentration of 5 mol/L. The electrochemical behaviour of the bars was characterised using linear polarisation resistance (LPR) and electrochemical impedance spectroscopy (EIS). The pitting profiles were detected by reflective digital holographic microscopy (DHM), scanning electron microscopy (SEM), and the chemical components produced in the pitting process were analysed by X-ray energy dispersive spectroscopy (EDS). The results show that the CR bars have a higher resistance to pitting corrosion than the LC bars. This is primarily because of the periodic occurrence of metastable pitting during pitting development. Compared to the pitting process in the LC bars, the pitting depth grows slowly in the CR bars, which greatly reduces the risk of pitting. The possible reason for this result is that the capability of the CR bars to heal the passivation film helps to restore the metastable pits to the passivation state. PMID:28777327

Experimental research on micro-pit defects of SUS 430 stainless steel strip in cold rolling process

NASA Astrophysics Data System (ADS)

Li, Changsheng; Li, Miao; Zhu, Tao; Huo, Gang

2013-05-01

In order to improve surface glossiness of stainless steel strip in tandem cold rolling, experimental research on micro-pit defects of SUS 430 ferrite stainless steel was investigated in laboratory. The surface morphology of micro-pit defects was observed by SEM. The effects of micro-pit defects on rolling reduction, roll surface roughness and emulsion parameters were analyzed. With the pass number increasing, the quantity and surface of micro-pit defects were reduced, uneven peak was decreased and gently along rolling direction, micro-pit defects had equally distributed tendency along tranverse direction. The micro-pit defects were increased with the roll surface roughness increase. The defects ratio was declined with larger gradient at pass number 1 to 3, but gentle slope at pass number 4 to 5. The effects of temperature 55° and 63°, concentration 3% and 6% of emulsion on micro-pit effects had not obvious difference. Maintain of micro-pit was effected by rolling oil or air in the micro-pit, the quality of oil was much more than the air in the micro-pit in lubrication rolling.

Isolation of mesenchymal stromal/stem cells from cryopreserved umbilical cord blood cells.

PubMed

Fujii, Sumie; Miura, Yasuo; Iwasa, Masaki; Yoshioka, Satoshi; Fujishiro, Aya; Sugino, Noriko; Kaneko, Hitomi; Nakagawa, Yoko; Hirai, Hideyo; Takaori-Kondo, Akifumi; Ichinohe, Tatsuo; Maekawa, Taira

2017-07-05

Umbilical cord blood (UCB) has advantages over other tissues because it can be obtained without an invasive procedure and complex processing. We explored the availability of cryopreserved UCB cells as a source of mesenchymal stromal/stem cells (MSCs). MSCs were successfully isolated from six of 30 UCB units (median volume, 34.0 mL; median nucleated cell number, 4.4×10 8 ) that were processed and cryopreserved using CP-1/human serum albumin. This isolation rate was lower than that (57%) from non-cryopreserved UCB cells. The number of nucleated cells before and after hydroxyethyl starch separation, UCB unit volume, and cell viability after thawing did not significantly differ between UCB units from which MSCs were successfully isolated and those from which they were not. When CryoSure-DEX40 was used as a cryoprotectant, MSCs were isolated from two of ten UCB units. Logistic regression analysis demonstrated that the cryopreservation method was not significantly associated with the success of MSC isolation. The isolated MSCs had a similar morphology and surface marker expression profile as bone marrow-derived MSCs and were able to differentiate into osteogenic, adipogenic, and chondrogenic cells. In summary, MSCs can be isolated from cryopreserved UCB cells. However, the cryopreservation process reduces the isolation rate; therefore, freshly donated UCB cells are preferable for the isolation of MSCs.

Isolation and Expansion of Hepatic Stem-like Cells from a Healthy Rat Liver and their Efficient Hepatic Differentiation of under Well-defined Vivo Hepatic like Microenvironment in a Multiwell Bioreactor

PubMed Central

Giri, Shibashish; Acikgöz, Ali; Bader, Augustinus

2015-01-01

Background Currently, undifferentiated cells are found in all tissue and term as local stem cells which are quiescent in nature and less in number under normal healthy conditions but activate upon injury and repair the tissue or organs via automated activating mechanism. Due to very scanty presence of local resident somatic local stem cells in healthy organs, isolation and expansion of these adult stems is an immense challenge for medical research and cell based therapy. Particularly organ like liver, there is an ongoing controversy about existence of liver stem cells. Methods Herein, Hepatic stem cells population was identified during culture of primary hepatocyte cells upon immediate isolation of primary hepatocyte cells. These liver stem cells has been expanded extensively and differentiated into primary hepatocytes under defined culture conditions in a nanostructured self assembling peptides modular bioreactor that mimic the state of art of liver microenvironment and compared with Matrigel as a positive control. Nanostructured self assembling peptides were used a defined extracellular matrix and Matrigel was used for undefined extracellular matrix. Proliferation of hepatic stem cells was investigated by two strategies. First strategy is to provide high concentration of hepatocyte growth factor (HGF) and second strategy is to evaluate the role of recombinant human erythropoietin (rHuEPO) in presence of trauma/ischemia cytokines (IL-6, TNF-α). Expansion to hepatic differentiation is observed by morphological analysis and was evaluated for the expression of hepatocyte-specific genes using RT-PCR and biochemical methods. Results Hepatocyte-specific genes are well expressed at final stage (day 21) of differentiation period. The differentiated hepatocytes exhibited functional hepatic characteristics such as albumin secretion, urea secretion and cytochrome P450 expression. Additionally, immunofluorescence analysis revealed that hepatic stem cells derived hepatocytes exhibited mature hepatocyte markers (albumin, CK-19, CPY3A1, alpha 1-antitrypsin). Expansion and hepatic differentiation was efficiently in nanostructured self assembling peptides without such batch to batch variation while there was much variation in Matrigel coated bioreactor. In conclusion, the results of the study suggest that the nanostructured self assembling peptides coated bioreactor supports expansion as well as hepatic differentiation of liver stem cells which is superior than Matrigel. Conclusion This defined microenvironment conditions in bioreactor module can be useful for research involving bioartificial liver system, stem cell research and engineered liver tissue which could contribute to regenerative cell therapies or drug discovery and development. PMID:26155038

Leptin differentially regulates STAT3 activation in the ob/ob mice adipose mesenchymal stem cells

USDA-ARS?s Scientific Manuscript database

Leptin-deficient genetically obese ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Studies have shown that multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute...

Isolation and Characterization of Prostate Cancer Stem Cells

DTIC Science & Technology

2013-10-01

et al. Targeting cancer stem cells by inhibiting Wnt, Notch, and Hedgehog pathways. Nat Rev Clin Oncol 2011;8:97–106. 26] Guise T. Examining the...Nitrogen or fixed in formalin and paraffin-embedded to evaluate anatomy and glandular architecture. The remainder of the tissue was mechan- ically and

Distribution, morphology, and origins of Martian pit crater chains

NASA Astrophysics Data System (ADS)

Wyrick, Danielle; Ferrill, David A.; Morris, Alan P.; Colton, Shannon L.; Sims, Darrell W.

2004-06-01

Pit craters are circular to elliptical depressions found in alignments (chains), which in many cases coalesce into linear troughs. They are common on the surface of Mars and similar to features observed on Earth and other terrestrial bodies. Pit craters lack an elevated rim, ejecta deposits, or lava flows that are associated with impact craters or calderas. It is generally agreed that the pits are formed by collapse into a subsurface cavity or explosive eruption. Hypotheses regarding the formation of pit crater chains require development of a substantial subsurface void to accommodate collapse of the overlying material. Suggested mechanisms of formation include: collapsed lava tubes, dike swarms, collapsed magma chamber, substrate dissolution (analogous to terrestrial karst), fissuring beneath loose material, and dilational faulting. The research described here is intended to constrain current interpretations of pit crater chain formation by analyzing their distribution and morphology. The western hemisphere of Mars was systematically mapped using Mars Orbiter Camera (MOC) images to generate ArcView™ Geographic Information System (GIS) coverages. All visible pit crater chains were mapped, including their orientations and associations with other structures. We found that pit chains commonly occur in areas that show regional extension or local fissuring. There is a strong correlation between pit chains and fault-bounded grabens. Frequently, there are transitions along strike from (1) visible faulting to (2) faults and pits to (3) pits alone. We performed a detailed quantitative analysis of pit crater morphology using MOC narrow angle images, Thermal Emission Imaging System (THEMIS) visual images, and Mars Orbiter Laser Altimeter (MOLA) data. This allowed us to determine a pattern of pit chain evolution and calculate pit depth, slope, and volume. Volumes of approximately 150 pits from five areas were calculated to determine volume size distribution and regional trends. The information collected in the study was then compared with non-Martian examples of pit chains and physical analog models. We evaluated the various mechanisms for pit chain development based on the data collected and conclude that dilational normal faulting and sub-vertical fissuring provide the simplest and most comprehensive mechanisms to explain the regional associations, detailed geometry, and progression of pit chain development.

Closure Report for Corrective Action Unit 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mark Krauss and Catherine Birney

2011-05-01

This Closure Report (CR) presents information supporting the closure of Corrective Action Unit (CAU) 544: Cellars, Mud Pits, and Oil Spills, Nevada National Security Site, Nevada. This CR complies with the requirements of the Federal Facility Agreement and Consent Order that was agreed to by the State of Nevada; U.S. Department of Energy (DOE), Environmental Management; U.S. Department of Defense; and DOE, Legacy Management. The corrective action sites (CASs) within CAU 544 are located within Areas 2, 7, 9, 10, 12, 19, and 20 of the Nevada National Security Site. Corrective Action Unit 544 comprises the following CASs: • 02-37-08,more » Cellar & Mud Pit • 02-37-09, Cellar & Mud Pit • 07-09-01, Mud Pit • 09-09-46, U-9itsx20 PS #1A Mud Pit • 10-09-01, Mud Pit • 12-09-03, Mud Pit • 19-09-01, Mud Pits (2) • 19-09-03, Mud Pit • 19-09-04, Mud Pit • 19-25-01, Oil Spill • 19-99-06, Waste Spill • 20-09-01, Mud Pits (2) • 20-09-02, Mud Pit • 20-09-03, Mud Pit • 20-09-04, Mud Pits (2) • 20-09-06, Mud Pit • 20-09-07, Mud Pit • 20-09-10, Mud Pit • 20-25-04, Oil Spills • 20-25-05, Oil Spills The purpose of this CR is to provide documentation supporting the completed corrective actions and data confirming that the closure objectives for CASs within CAU 544 were met. To achieve this, the following actions were performed: • Review the current site conditions, including the concentration and extent of contamination. • Implement any corrective actions necessary to protect human health and the environment. • Properly dispose of corrective action and investigation wastes. • Document Notice of Completion and closure of CAU 544 issued by the Nevada Division of Environmental Protection.« less

Comparison of virulence between vascular competent and incompetent Fusarium oxysporum f. sp. vasinfectum pathotypes

USDA-ARS?s Scientific Manuscript database

The Australian biotype and California race 4 isolates of Fusarium oxysporum f. sp. Vasinfectum (Fov) are pathologically distinct from the Fov U.S. race 1 isolates in that they do not cause disease when stem-puncture inoculated while race 1 isolates do. When root-dip inoculation method was used, bot...

Two new oxysporone derivatives from the fermentation broth of the endophytic plant fungus Pestalotiopsis karstenii isolated from stems of Camellia sasanqua.

PubMed

Luo, Du Qiang; Zhang, Lei; Shi, Bao Zhong; Song, Xiao Mei

2012-07-17

Two new oxysporone derivatives, pestalrone A (1) and pestalrone B (2), along with two known structurally related compounds 3, 4, were from the fermentation broth of the endophytic plant fungus Pestalotiopsis karstenii isolated from stems of Camellia sasanqua. Their structures and relative configurations were elucidated by extensive spectroscopic analysis and comparison of chemical shifts with related known compounds. Compound 2 exhibited significant activities agains HeLa, HepG2 and U-251 with IC₅₀ values of 12.6, 31.7 and 5.4 µg/mL, respectively.

Adipose-derived mesenchymal stem cells from liposuction and resected fat are feasible sources for regenerative medicine.

PubMed

Schneider, Sandra; Unger, Marina; van Griensven, Martijn; Balmayor, Elizabeth R

2017-05-19

The use of mesenchymal stem cells (MSCs) in research and in regenerative medicine has progressed. Bone marrow as a source has drawbacks because of subsequent morbidities. An easily accessible and valuable source is adipose tissue. This type of tissue contains a high number of MSCs, and obtaining higher quantities of tissue is more feasible. Fat tissue can be harvested using different methods such as liposuction and resection. First, a detailed isolation protocol with complete characterization is described. This also includes highlighting problems and pitfalls. Furthermore, some comparisons of these different harvesting methods exist. However, the later characterization of the cells is conducted poorly in most cases. We performed an in-depth characterization over five passages including an investigation of the effect of freezing and thawing. Characterization was performed using flow cytometry with CD markers, metabolic activity with Alamar Blue, growth potential in between passages, and cytoskeleton staining. Our results show that the cells isolated with distinct isolation methods (solid versus liposuction "liquid") have the same MSC potential. However, the percentage of cells positive for the markers CD73, CD90, and CD105 is initially quite low. The cells isolated from the liquid fat tissue grow faster at higher passages, and significantly more cells display MSC markers. In summary, we show a simple and efficient method to isolate adipose-derived mesenchymal stem cells from different preparations. Liposuctions and resection can be used, whereas liposuction has more growth potential at higher passages.

Corrosion behavior of binary titanium aluminide intermetallics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saffarian, H.M.; Gan, Q.; Hadkar, R.

1996-08-01

The corrosion behavior of arc-melted binary titanium aluminide intermetallics TiAl, Ti{sub 2}Al, and TiAl{sub 3} in aqueous sodium sulfate and sodium chloride solutions was measured and compared to that of pure Ti and Al. Effects of electrolyte composition (e.g., sulfate [0.25 M SO{sub 4}{sup 2}{sup {minus}}], chloride [0.1 to 1.0 M Cl{sup {minus}}], and pH [3 to 10]) were examined. Anodic polarization of titanium aluminides in aqueous SO{sub 4}{sup 2}{sup {minus}} solutions was similar (showing passive behavior), but no pitting or pitting potential (E{sub pit}) was observed. In aqueous NaCl, however, titanium aluminides were susceptible to pitting, and E{sub pit}more » decreased with increasing Al content (i.e., Ti{sub 3}Al had the highest E{sub pit} and, therefore, a greater resistance to pitting, followed by TiAl and TiAl{sub 3}). For TiAl, E{sub pit} was slightly dependent upon pH or Cl{sup {minus}} concentration. Pit morphology and E{sub pit} values were quite different for TiAl compared to Ti{sub 3}Al. TiAl showed numerous small pits, whereas Ti{sub 3}Al exhibited fewer but larger and deeper pits. The larger pit density for TiAl was associated with Al-rich interdendrite regions. One interesting feature of the anodic polarization curves for Ti{sub 3}Al was a small anodic peak frequently observed at {approximately}1.4 V{sub SCE} to 1.8 V{sub SCE}. Results suggested this peak was associated with pit initiation, since pitting initiated concurrently with the peak or immediately afterward.« less

Investigating pitting in X65 carbon steel using potentiostatic polarisation

NASA Astrophysics Data System (ADS)

Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

2017-11-01

Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales.

PubMed

Schwallier, Rachel; Gravendeel, Barbara; de Boer, Hugo; Nylinder, Stephan; van Heuven, Bertie Joan; Sieder, Anton; Sumail, Sukaibin; van Vugt, Rogier; Lens, Frederic

2017-05-01

Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant's iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes , while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales

PubMed Central

Gravendeel, Barbara; de Boer, Hugo; Nylinder, Stephan; van Heuven, Bertie Joan; Sieder, Anton; Sumail, Sukaibin; van Vugt, Rogier; Lens, Frederic

2017-01-01

Abstract Background and Aims Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant’s iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Methods Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Key Results Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. Conclusions The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes, while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages. PMID:28387789

[Stem cells--cloning, plasticity, bioethic].

PubMed

Pflegerl, Pamina; Keller, Thomas; Hantusch, Brigitte; Hoffmann, Thomas Sören; Kenner, Lukas

2008-01-01

Stem cells with certain characteristics have become promising tools for molecular medicine. They have the potential to self-regenerate and to differentiate into specific tissues. Besides their great potential, embryonic stem cells (ESC) run the risk of enhanced tumorigenesis. The use of human embryonic stem cells (hESC) is ethically problematic because their isolation involves the destruction of human embryos. Recently developed methods generate are able to pluripotent stem cells from fibroblasts. Alternatives for ESC are adult stem cells (ASC) derived from bone marrow, cord blood, amniotic fluid and other tissues. The following article is on the basis of testimony of Lukas Kenner for the German Bundestag about the use of ESC for research, therapy and drug development. Ethical aspects are taken into consideration.

[Studies on the chemical constituents of the stems of Piper betle].

PubMed

Yin, Yan; Huang, Xiang-Zhong; Wang, Jiong; Dai, Jian-Hui; Liang, Hui; Dai, Yun

2009-06-01

To study the chemical constituents from the stems of Piper betle. Various chromatographic techniques were used to isolate and purify the constituents. The structures of these compounds were elucidated on the basis of spectral analysis. Nine compounds were isolated from the petroleum ester and ethyl acetate soluble fractions of the 70% acetone extract and their structures were identified as 6beta-hydroxystigmast-4-en-3-one (1), beta-sitosterol (2), stigmasterol (3), oleanolic acid (4), 23-hydroxyursan-12-en-28-oic acid (5), beta-sitosterol-3-O-beta-D-glucoside-6'-O-palmitate (6), beta-daucosterol (7), (2S) -4'-hydroxy- 2,3-dihydroflavonone-7-O-beta-D-glucoside (8) and alpha-ethyl glucoside (9). Among these compounds, 1, 3 -9 are isolated from this plant for the first time.

Cryopreservation Method for the Effective Collection of Dental Pulp Stem Cells.

PubMed

Takebe, Yusuke; Tatehara, Seiko; Fukushima, Tatsuhiro; Tokuyama-Toda, Reiko; Yasuhara, Rika; Mishima, Kenji; Satomura, Kazuhito

2017-05-01

Dental pulp stem cells (DPSCs) are an attractive cell source for use in cell-based therapy, regenerative medicine, and tissue engineering because DPSCs have a high cell proliferation ability and multidifferentiation capacity. However, several problems are associated with the collection and preservation of DPSCs for use in future cell-based therapy. In particular, the isolation of DPSCs for cryopreservation is time consuming and expensive. In this study, we developed a novel cryopreservation method (NCM) for dental pulp tissues to isolate suitable DPSCs after thawing cryopreserved tissue. Using the NCM, dental pulp tissues were cultured on adhesion culture dishes for 5 days and then cryopreserved. After thawing, the cryopreserved dental pulp tissue fragments exhibited cell migration. We evaluated each property of DPSCs isolated using the NCM (DPSCs-NCM) and the explant method alone without cryopreservation (DPSCs-C). DPSCs-NCM had the same proliferation capacity as DPSCs-C. Flow cytometry (FACS) analysis indicated that both DPSCs-NCM and DPSCs-C were positive for mesenchymal stem cell markers at the same level but negative for hematopoietic cell markers. Moreover, both DPSCs-NCM and DPSCs-C could differentiate into osteogenic, chondrogenic, and adipogenic cells during culture in each induction medium. These results suggest that DPSCs-NCM may be mesenchymal stem cells. Therefore, our novel method might facilitate the less expensive cryopreservation of DPSCs, thereby providing suitable DPSCs for use in patients in future cell-based therapies.

Skeletal stem cell isolation: A review on the state-of-the-art microfluidic label-free sorting techniques.

PubMed

Xavier, Miguel; Oreffo, Richard O C; Morgan, Hywel

2016-01-01

Skeletal stem cells (SSC) are a sub-population of bone marrow stromal cells that reside in postnatal bone marrow with osteogenic, chondrogenic and adipogenic differentiation potential. SSCs reside only in the bone marrow and have organisational and regulatory functions in the bone marrow microenvironment and give rise to the haematopoiesis-supportive stroma. Their differentiation capacity is restricted to skeletal lineages and therefore the term SSC should be clearly distinguished from mesenchymal stem cells which are reported to exist in extra-skeletal tissues and, critically, do not contribute to skeletal development. SSCs are responsible for the unique regeneration capacity of bone and offer unlimited potential for application in bone regenerative therapies. A current unmet challenge is the isolation of homogeneous populations of SSCs, in vitro, with homogeneous regeneration and differentiation capacities. Challenges that limit SSC isolation include a) the scarcity of SSCs in bone marrow aspirates, estimated at between 1 in 10-100,000 mononuclear cells; b) the absence of specific markers and thus the phenotypic ambiguity of the SSC and c) the complexity of bone marrow tissue. Microfluidics provides innovative approaches for cell separation based on bio-physical features of single cells. Here we review the physical principles underlying label-free microfluidic sorting techniques and review their capacity for stem cell selection/sorting from complex (heterogeneous) samples. Copyright © 2016 Elsevier Inc. All rights reserved.

Isolation and characterization of the trophectoderm from the Arabian camel (Camelus dromedarius).

PubMed

Saadeldin, Islam M; Swelum, Ayman Abdel-Aziz; Elsafadi, Mona; Moumen, Abdullah F; Alzahrani, Faisal A; Mahmood, Amer; Alfayez, Musaad; Alowaimer, Abdullah N

2017-09-01

We isolated and characterized trophoblast from in vivo-derived camel embryos and compared with embryonic stem-like cells. Camel embryos were flushed on day 8 post-insemination and used to derive trophectoderm and embryonic stem-like cells under feeder-free culture conditions using a basement membrane matrix. Embryos were evaluated for the expression of POU5F1, MYC, KLF4, SOX2, CDX2, and KRT8 mRNA transcripts by relative quantitative polymerase chain reaction. Camel embryos grew and expanded to ∼4.5 mm and maintained their vesicular shape in vitro for 21 days post-insemination. Trophoblast and embryonic stem-like cell lines grew under feeder-free culture conditions and showed distinct morphological criteria and normal chromosomal counts. Embryonic stem-like cells showed positive staining in the alkaline phosphatase reaction. Trophoblast cells showed a significant increase in CDX2, KRT8, KLF4, and SOX2 expression compared with embryonic stem-like cells and whole embryos. Embryonic stem-like cells showed a significant decrease in CDX2 expression and increase in SOX2 and KRT8 expression compared to embryonic expression. POU5F1 and MYC expression showed no difference between embryos and both cell lines. We characterized embryo survival in vitro, particularly the derivation of trophectoderm and embryonic stem-like cells, providing a foundation for further analysis of early embryonic development and placentation in camels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparative Proteome Analysis of hAT-MSCs Isolated from Chronic Renal Failure Patients with Differences in Their Bone Turnover Status.

PubMed

Kasap, Murat; Yeğenağa, Itır; Akpinar, Gurler; Tuncay, Mehmet; Aksoy, Ayça; Karaoz, Erdal

2015-01-01

The relationship between the stem cells and the bone turnover in uremic bone disease due to chronic renal failure (CRF) is not described. The aim of this study was to investigate the effect of bone turnover status on stem cell properties. To search for the presence of such link and shed some light on stem-cell relevant mechanisms of bone turnover, we carried out a study with mesenchymal stem cells. Tissue biopsies were taken from the abdominal subcutaneous adipose tissue of a CRF patient with secondary hyperparathyroidism with the high turnover bone disease. This patient underwent parathyroidectomy operation (PTX) and another sample was taken from this patient after PTX. A CRF patient with adynamic bone disease with low turnover and a healthy control were also included. Mesenchymal stem cells isolated from the subjects were analyzed using proteomic and molecular approaches. Except ALP activity, the bone turnover status did not affect common stem cell properties. However, detailed proteome analysis revealed the presence of regulated protein spots. A total of 32 protein spots were identified following 2D gel electrophoresis and MALDI-TOF/TOF analyzes. The identified proteins were classified into seven distinct groups and their potential relationship to bone turnover were discussed. Distinct protein expression patterns emerged in relation to the bone turnover status indicate a possible link between the stem cells and bone turnover in uremic bone disease due to CRF.

Research Advancements in Porcine Derived Mesenchymal Stem Cells

PubMed Central

Bharti, Dinesh; Shivakumar, Sharath Belame; Subbarao, Raghavendra Baregundi; Rho, Gyu-Jin

2016-01-01

In the present era of stem cell biology, various animals such as Mouse, Bovine, Rabbit and Porcine have been tested for the efficiency of their mesenchymal stem cells (MSCs) before their actual use for stem cell based application in humans. Among them pigs have many similarities to humans in the form of organ size, physiology and their functioning, therefore they have been considered as a valuable model system for in vitro studies and preclinical assessments. Easy assessability, few ethical issues, successful MSC isolation from different origins like bone marrow, skin, umbilical cord blood, Wharton’s jelly, endometrium, amniotic fluid and peripheral blood make porcine a good model for stem cell therapy. Porcine derived MSCs (pMSCs) have shown greater in vitro differentiation and transdifferention potential towards mesenchymal lineages and specialized lineages such as cardiomyocytes, neurons, hepatocytes and pancreatic beta cells. Immunomodulatory and low immunogenic profiles as shown by autologous and heterologous MSCs proves them safe and appropriate models for xenotransplantation purposes. Furthermore, tissue engineered stem cell constructs can be of immense importance in relation to various osteochondral defects which are difficult to treat otherwise. Using pMSCs successful treatment of various disorders like Parkinson’s disease, cardiac ischemia, hepatic failure, has been reported by many studies. Here, in this review we highlight current research findings in the area of porcine mesenchymal stem cells dealing with their isolation methods, differentiation ability, transplantation applications and their therapeutic potential towards various diseases. PMID:26201864

CD133 Is Not Suitable Marker for Isolating Melanoma Stem Cells from D10 Cell Line.

PubMed

Rajabi Fomeshi, Motahareh; Ebrahimi, Marzieh; Mowla, Seyed Javad; Firouzi, Javad; Khosravani, Pardis

2016-01-01

Cutaneous melanoma is the most hazardous malignancy of skin cancer with a high mortality rate. It has been reported that cancer stem cells (CSCs) are responsible for malignancy in most of cancers including melanoma. The aim of this study is to compare two common methods for melanoma stem cell enriching; isolating based on the CD133 cell surface marker and spheroid cell culture. In this experimental study, melanoma stem cells were enriched by fluorescence activated cell sorting (FACS) based on the CD133 protein expression and spheroid culture of D10 melanoma cell line,. To determine stemness features, the mRNA expression analysis of ABCG2, c-MYC, NESTIN, OCT4-A and -B genes as well as colony and spheroid formation assays were utilized in unsorted CD133(+), CD133(-) and spheroid cells. Significant differences of the two experimental groups were compared using student's t tests and a two-tailed value of P<0.05 was statistically considered as a significant threshold. Our results demonstrated that spheroid cells had more colony and spheroid forming ability, rather than CD133(+) cells and the other groups. Moreover, melanospheres expressed higher mRNA expression level of ABCG2, c-MYC, NESTIN and OCT4-A com- pared to other groups (P<0.05). Although CD133(+) derived melanoma cells represented stemness fea- tures, our findings demonstrated that spheroid culture could be more effective meth- od to enrich melanoma stem cells.

CD133 Is Not Suitable Marker for Isolating Melanoma Stem Cells from D10 Cell Line

PubMed Central

Rajabi Fomeshi, Motahareh; Ebrahimi, Marzieh; Mowla, Seyed Javad; Firouzi, Javad; Khosravani, Pardis

2016-01-01

Objective Cutaneous melanoma is the most hazardous malignancy of skin cancer with a high mortality rate. It has been reported that cancer stem cells (CSCs) are responsible for malignancy in most of cancers including melanoma. The aim of this study is to compare two common methods for melanoma stem cell enriching; isolating based on the CD133 cell surface marker and spheroid cell culture. Materials and Methods In this experimental study, melanoma stem cells were enriched by fluorescence activated cell sorting (FACS) based on the CD133 protein expression and spheroid culture of D10 melanoma cell line,. To determine stemness features, the mRNA expression analysis of ABCG2, c-MYC, NESTIN, OCT4-A and -B genes as well as colony and spheroid formation assays were utilized in unsorted CD133+, CD133- and spheroid cells. Significant differences of the two experimental groups were compared using student’s t tests and a two-tailed value of P<0.05 was statistically considered as a significant threshold. Results Our results demonstrated that spheroid cells had more colony and spheroid forming ability, rather than CD133+ cells and the other groups. Moreover, melanospheres expressed higher mRNA expression level of ABCG2, c-MYC, NESTIN and OCT4-A com- pared to other groups (P<0.05). Conclusion Although CD133+ derived melanoma cells represented stemness fea- tures, our findings demonstrated that spheroid culture could be more effective meth- od to enrich melanoma stem cells. PMID:27054115

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bihmidine, Saadia; Baker, R. Frank; Hoffner, Cassandra

Background: Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this studymore » was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Results: Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Conclusions: Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.« less

Morphology and Evolution of Sublimation Pits on Pluto

NASA Astrophysics Data System (ADS)

Abu-Hashmeh, N.; Conrad, J. W.; Nimmo, F.; Moore, J. M.; Stern, A.; Olkin, C.; Weaver, H. A., Jr.; Ennico Smith, K.; Young, L. A.

2017-12-01

Pluto's Sputnik Planitia region hosts a geologically young surface of nitrogen ice that exhibits striking pitted terrain (Moore et al., Science 351, 2016). These pits are most likely formed by sublimation due to incident sunlight, similar to the southern polar cap of Mars (Byrne and Ingersoll, Science 299, 2003); however, their evolution over time has resulted in unique morphological characteristics. Motivated by this, we used the high-resolution mosaic strips captured by New Horizons' Long Range Reconnaissance Imager (LORRI) to map sublimation pits in the southernmost region of Sputnik Planitia. Statistical data shows pit orientations appearing North-South dominant; their morphology also indicates extensional evolution along the major axis caused by further sublimation and contact-coalescence processes. Qualitative analysis of the region yielded indications of an evolutionary path for individual pits that coalesce into each other and exhibit an elongated end-stage. Additionally, densely-pitted regions generally appear to correlate with regions containing longer pits, implying that coalescence may be an important process for elongation. We also model the evolution geometry through competing effects of diffusion (viscous relaxation) and retreat (sublimation) (Buhler and Ingersoll, LPSC Abstract #1746, 2017). The model demonstrates single-pit and coalescing-pit evolutions that influence overall length, as well as a potential ability for the pit center to move in space while the pit morphology evolves.

MiR-23b controls ALDH1A1 expression in cervical cancer stem cells.

PubMed

Wang, Weiwen; Li, Yang; Liu, Na; Gao, Yu; Li, Long

2017-04-27

Cancer stem cells has been widely investigated due to its essential role in cancer progression and drug resistance. Here, we try to find a new therapeutic target for cervical cancer stem cells. We detected ALDH1A1-associated miRNAs expression in our isolated tumorspheres and their corresponding parental cells. Sphere formation assay was also used to determine stemness after cells were manipulated with miR-23b plasmid or miR-23b inhibitor. We found that miR-23b was under-expressed in cervical cancer stem cells to maintain high levels of ALDH1A1. Introduction of miR-23b into cervical cancer cells could alter stemness and cisplatin sensitivity. miR-23b plays key role in maintaining stemness of cervical cancer stem cells and can be developed as therapeutic target to better fight against cervical cancer.

Initation of pitting corrosion in martensitic stainless steels. [17-4PH; 13-8Mo; Custom 450

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cieslak, W.R.; Semarge, R.E.; Bovard, F.S.

1986-01-01

The form of localized corrosion known as pitting often initiates preferentially at microstructural inhomogeneities. The pit initiation resistance, therefore, is controlled by the characteristics of the initiation sites, rather than by the bulk material composition. This investigation correlates the pit initiation resistance, as measured by critical pitting potentials, with preferred pit initiation sites for 3 martensitic stainless steels. Pit initiation sites are determined by secondary electron (SE) and backscattered electron (BSE) imaging and energy dispersive and wavelength dispersive spectrometries (EDS and WDS) with a scalling electron microscope (SEM) and an electron probe microanalyzer (EPMA).

Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

PubMed

Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

2016-07-01

The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

PubMed Central

Platz, T.; Schorghofer, N.; Prettyman, T. H.; De Sanctis, M. C.; Crown, D. A.; Schmedemann, N.; Neesemann, A.; Kneissl, T.; Marchi, S.; Schenk, P. M.; Bland, M. T.; Schmidt, B. E.; Hughson, K. H. G.; Tosi, F.; Zambon, F.; Mest, S. C.; Yingst, R. A.; Williams, D. A.; Russell, C. T.; Raymond, C. A.

2017-01-01

Abstract Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice‐rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization. PMID:28989206

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution.

PubMed

Sizemore, H G; Platz, T; Schorghofer, N; Prettyman, T H; De Sanctis, M C; Crown, D A; Schmedemann, N; Neesemann, A; Kneissl, T; Marchi, S; Schenk, P M; Bland, M T; Schmidt, B E; Hughson, K H G; Tosi, F; Zambon, F; Mest, S C; Yingst, R A; Williams, D A; Russell, C T; Raymond, C A

2017-07-16

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

USGS Publications Warehouse

Sizemore, H.G.; Platz, Thomas; Schorghofer, Norbert; Prettyman, Thomas; De Sanctis, Maria Christina; Crown, David A.; Schmedemann, Nico; Nessemann, Andeas; Kneissl, Thomas; Simone Marchi,; Schenk, Paul M.; Bland, Michael T.; Schmidt, B.E.; Hughson, Kynan H.G.; Tosi, F.; Zambon, F; Mest, S.C.; Yingst, R.A.; Williams, D.A.; Russell, C.T.; Raymond, C.A.

2017-01-01

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester.

PubMed

Zelinka, Samuel L; Bourne, Keith J; Hermanson, John C; Glass, Samuel V; Costa, Adriana; Wiedenhoeft, Alex C

2015-10-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force-displacement measurements for pit membranes of circular bordered pits, collected on a mesomechanical testing system. The system consists of a quartz microprobe attached to a microforce sensor that is positioned and advanced with a micromanipulator mounted on an inverted microscope. Membrane displacement is measured from digital image analysis. Unaspirated pits from earlywood of never-dried wood of Larix and Pinus and aspirated pits from earlywood of dried wood of Larix were tested to generate force-displacement curves up to the point of membrane failure. Two failure modes were observed: rupture or tearing of the pit membrane by the microprobe tip, and the stretching of the pit membrane until the torus was forced out of the pit chamber through the pit aperture without rupture, a condition we refer to as torus prolapse. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The growth hormone cascade: progress and long-term results of growth hormone treatment in growth hormone deficiency.

PubMed

Grumbach, M M; Bin-Abbas, B S; Kaplan, S L

1998-01-01

The growth hormone (GH) cascade and the remarkable advances over the past four decades in our knowledge of its components are considered. It is now over 40 years since human pituitary GH (pit-hGH) was purified and the first GH-deficient patient, a 17-year-old male, was successfully treated with pit-hGH. However, the shortage of pit-hGH limited its use and the dose, the biopotency of preparations varied, strict criteria of GH deficiency (GHD) were used for patient selection including peak plasma immunoreactive GH levels after provocative stimuli of <3.5-5 ng/ml, treatment was not infrequently interrupted, the mean age for initiating treatment was often late in childhood (12-13 years) and the growth deficiency severe (height -4 to -6 SDS), and finally pit-hGH therapy was often discontinued when girls attained a height of 5' and boys 5'5". Nonetheless, the effects of pit-hGH were dramatic; the final height SDS increased in isolated GHD to about -2 SDS in boys and -2.5 to -3.0 SDS in girls, and in multiple pituitary hormone deficiencies to between -1 and -2 SDS. Between 1962 and 1985 when the Creutzfeldt-Jakob disease crisis struck, the number of GH-deficient patients treated with pit-hGH increased from about 150 to over 3,000. The advent of biosynthetic GH (rhGH) and its availability to treat large numbers of idiopathic GH-deficient children (the minimum prevalence rate of which in the USA and UK is between 1 in 3,400 and 4,000) dramatically changed this picture in 1985. It is estimated that more than 60,000 patients have been or are now on treatment. With rhGH treatment the attained mean adult height SDS is now about -1.0, and in our experience with the treatment of patients under 4 years of age, final height may exceed the target height. It is now recognized that (a) the replacement dose of rhGH ranges from 0.175 to 0.35 mg/kg/week and should be individualized; (b) dividing this dose into 6 or 7 daily subcutaneous injections is more effective than giving the same total dose in three weekly portions, and (c) final height correlates significantly with pretreatment chronologic age, height SDS and predicted adult height, duration of therapy, birth length, in some studies height SDS and age at start of puberty, weight, and serum GHBP (an indicator of GH receptor mass). Early recognition of GHD is essential for an optimal height outcome. rhGH treatment should not be delayed in children with documented GHD; the greater the height deficit, the lower the probability that target height will be reached. GHD needs to be detected earlier in children with organic hypopituitarism whether due to a developmental defect, neoplasm, radiation, head trauma, or a CNS infection. Early rhGH therapy in neonatal hypopituitarism has resulted in excellent growth responses. As the height prognosis in isolated GHD is not as good (especially in girls) as in GHD associated with gonadotropin deficiency, the use of LHRH agonists to delay puberty or potent aromatase inhibitors to delay skeletal maturation should be considered in selected patients with isolated GHD. When the growth response to rhGH is less than predicted, one must consider: (a) poor compliance; (b) improper preparation of rhGH for administration or faulty injection techniques; (c) the timing of administration; (d) the dose of glucocorticoid in the ACTH-deficient patient; (e) occult hypothyroidism; (f) inadequate nutrition; (g) a chronic illness; (h) neutralizing antibodies to rhGH, and (i) the wrong diagnosis. The major cause of mortality (unrelated to Creutzfeldt-Jakob disease or a CNS neoplasm) is adrenal crisis and hypoglycemia in children with both GH and ACTH deficiency. Major adverse effects of rhGH treatment in children are uncommon and include idiopathic intracranial hypertension, slipped capital femoral epiphysis, and acute pancreatitis. The rhGH is not an added risk for leukemia in the US and Europe in the absence of coexisting risk factors, nor is there a higher risk of recurrence of b

The antiplasmodial agents of the stem bark of Entandrophragma angolense (Meliaceae).

PubMed

Bickii, Jean; Tchouya, Guy Raymond Feuya; Tchouankeu, Jean Claude; Tsamo, Etienne

2006-11-13

In the search of active principles from the stem bark of Entandrophragma angolense, we submitted the compounds isolated from the dichloromethane-methanol (1:1) extract of the stem bark to antimalarial test against chloroquine resistant strain W2 of Plasmodium falciparum malaria parasite. Only 7alpha-obacunyl acetate and a cycloartane derivative exhibited a good activity, with IC(50)s of 2 and 5.4 microg/ml respectively. Other compounds were moderately active.

The role of CD133 in the identification and characterisation of tumour-initiating cells in non-small-cell lung cancer.

PubMed

Tirino, Virginia; Camerlingo, Rosa; Franco, Renato; Malanga, Donatella; La Rocca, Antonello; Viglietto, Giuseppe; Rocco, Gaetano; Pirozzi, Giuseppe

2009-09-01

Emerging evidence suggests that specific sub-populations of cancer cells with stem cell characteristics within the bulk of tumours are implicated in the pathogenesis of heterogeneous malignant tumours. The cells that drive tumour growth have been denoted cancer-initiating cells or cancer stem cells (hereafter CSCs). CSCs have been isolated initially from leukaemias and subsequently from several solid tumours including brain, breast, prostate, colon and lung cancer. This study aimed at isolating and characterising the population of tumour-initiating cells in non-small-cell lung cancer (NSCLC). Specimens of NSCLC obtained from 89 patients undergoing tumour resection at the Cancer National Institute of Naples were analysed. Three methods to isolate the tumour-initiating cells were used: (1) flow cytometry analysis for identification of positive cells for surface markers such as CD24, CD29, CD31, CD34, CD44, CD133 and CD326; (2) Hoechst 33342 dye exclusion test for the identification of a side-population characteristic for the presence of stem cells; (3) non-adherent culture condition able to form spheres with stem cell-like characteristics. Definition of the tumourigenic potential of the cells through soft agar assay and injection into NOD/SCID mice were used to functionally define (in vitro and in vivo) putative CSCs isolated from NSCLC samples. Upon flow cytometry analysis of NSCLC samples, CD133-positive cells were found in 72% of 89 fresh specimens analysed and, on average, represented 6% of the total cells. Moreover, the number of CD133-positive cells increased markedly when the cells, isolated from NSCLC specimens, were grown as spheres in non-adherent culture conditions. Cells from NSCLC, grown as spheres, when assayed in soft agar, give rise to a 3.8-fold larger number of colonies in culture and are more tumourigenic in non-obese diabetic (NOD)/severe combined immunodeficiency (SCID) mice compared with the corresponding adherent cells. We have isolated and characterised a population of CD133-positive cells from NSCLC that is able to give rise to spheres and can act as tumour-initiating cells.

Skin Stem Cells: At the Frontier Between the Laboratory and Clinical Practice. Part 1: Epidermal Stem Cells.

PubMed

Pastushenko, I; Prieto-Torres, L; Gilaberte, Y; Blanpain, C

2015-11-01

Stem cells are characterized by their ability to self-renew and differentiate into the different cell lineages of their tissue of origin. The discovery of stem cells in adult tissues, together with the description of specific markers for their isolation, has opened up new lines of investigation, expanding the horizons of biomedical research and raising new hope in the treatment of many diseases. In this article, we review in detail the main characteristics of the stem cells that produce the specialized cells of the skin (epidermal, mesenchymal, and melanocyte stem cells) and their potential implications and applications in diseases affecting the skin. Part I deals with the principal characteristics and potential applications of epidermal stem cells in dermatology. Copyright © 2015 Elsevier España, S.L.U. and AEDV. All rights reserved.

Interferon-γ regulates the function of mesenchymal stem cells from oral lichen planus via indoleamine 2,3-dioxygenase activity.

PubMed

Zhang, Zhihui; Han, Ying; Song, Jiangyuan; Luo, Ruxi; Jin, Xin; Mu, Dongdong; Su, Sha; Ji, Xiaoli; Ren, Yan-Fang; Liu, Hongwei

2015-01-01

Little is known about mesenchymal stem cells (MSCs) in normal or inflammatory oral mucosal tissues, such as in oral lichen planus (OLP). Our objectives were to identify, isolate, and characterize MSCs from normal human oral mucosa and OLP lesions, and to evaluate indoleamine 2,3 dioxygenase (IDO) activity in mediating immunomodulation of MSCs from these tissues. Expressions of MSCs-related markers were examined in isolated cells by flow cytometry. Self-renewal and multilineage differentiations were studied to characterize these MSCs. Interferon-γ (IFN-γ), IDO, and STRO-1 were assessed by immunofluorescence. MSCs from oral mucosa and OLP or IFN-γ-pretreated MSCs were co-cultured with allogeneic mixed lymphocyte reaction assays (MLR). Proliferation and apoptosis of MLR or MSCs were detected by CCK8 and the annexin V-FITC apoptosis detection kit, respectively. IDO expression and activity were measured by real-time PCR, Western blotting, and high-performance liquid chromatography. Isolated cells from oral mucosa and OLP expressed MSC-related markers STRO-1, CD105, and CD90 but were absent for hematopoietic stem cell markers CD34. Besides, they all showed self-renewal and multilineage differentiation capacities. MSCs in OLP presented STRO-1/IDO+ phenotype by immunofluorescence. MSCs and IFN-γ-pretreated MSCs could inhibit lymphocyte proliferation via IDO activity, but not via cell apoptosis. Long-term IFN-γ could also inhibit MSC proliferation via IDO activity. Mesenchymal stem cells can be isolated from human oral mucosa and OLP tissues. Besides self-renewal and multilineage differentiation properties, these cells may participate in immunomodulation mediated by IFN-γ via IDO activity in human OLP. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Isolation and hepatocyte differentiation of mesenchymal stem cells from porcine bone marrow--"surgical waste" as a novel MSC source.

PubMed

Brückner, S; Tautenhahn, H-M; Winkler, S; Stock, P; Jonas, S; Dollinger, M; Christ, B

2013-06-01

Mesenchymal stem cells (MSC) isolated from bone marrow and differentiated into hepatocyte-like cells have increasingly gained attention for clinical cell therapy of liver diseases because of their high regenerative capacity. They are available from bone marrow aspirates of the os coxae after puncture of the crista iliaca or from bone marrow "surgical waste" gained from amputations or knee and hip operations. Thus, the aim of the study was to demonstrate whether these pBM-MSC (porcine bone marrow-derived mesenchymal stem cells) displayed mesenchymal features and hepatocyte differentiation potential. MSC were isolated either from crista iliaca punctures or after sampling and collagenase digestion of bone marrow from the os femoris. Mesenchymal features were assessed by flow cytometry for specific surface antigens and their ability to differentiate into at least 3 lineages. Functional properties, such as urea or glycogen synthesis and cytochrome P450 activity, as well as the cell morphology were examined during hepatocyte differentiation. pBM-MSC from both sources lacked the hematopoietic markers CD14 and CD45 but expressed the typical mesenchymal markers CD44, CD29, CD90, and CD105. Both cell types could differentiate into adipocyte, osteocyte, and hepatocyte lineages. After hepatocyte differentiation, CD105 expression decreased significantly and cells changed morphology from fibroblastoid into polygonal, displaying significantly increased glycogen storage, urea synthesis, and cytochrome activity. pBM-MSC from various sources were identical in respect to their mesenchymal features and their hepatocyte differentiation potential. Hence, long bones might be a particularly useful resource to isolate bone marrow mesenchymal stem cells for transplantation. Copyright © 2013 Elsevier Inc. All rights reserved.

Growth dynamics and cytoskeleton organization during stem maturation and gravity-induced stem bending in Zea mays L

NASA Technical Reports Server (NTRS)

Collings, D. A.; Winter, H.; Wyatt, S. E.; Allen, N. S.; Davies, E. (Principal Investigator)

1998-01-01

Characterization of gravitropic bending in the maize stem pulvinus, a tissue that functions specifically in gravity responses, demonstrates that the pulvinus is an ideal system for studying gravitropism. Gravistimulation during the second of three developmental phases of the pulvinus induces a gradient of cell elongation across the non-growing cells of the pulvinus, with the most elongation occurring on the lower side. This cell elongation is spatially and temporally separated from normal internodal cell elongation. The three characterized growth phases in the pulvinus correspond closely to a specialized developmental sequence in which structural features typical of cells not fully matured are retained while cell maturation occurs in surrounding internodal and nodal tissue. For example, the lignification of supporting tissue and rearrangement of transverse microtubules to oblique that occur in the internode when cell elongation ceases are delayed for up to 10 d in the adjacent cells of the pulvinus, and only occurs as a pulvinus loses its capacity to respond to gravistimulation. Gravistimulation does not modify this developmental sequence. Neither wall lignification nor rearrangement of transverse microtubules occurs in the rapidly elongating lower side or non-responsive upper side of the pulvinus until the pulvinus loses the capacity to bend further. Gravistimulation does, however, lead to the formation of putative pit fields within the expanding cells of the pulvinus.

Flood induced phenotypic plasticity in amphibious genus Elatine (Elatinaceae).

PubMed

Molnár V, Attila; Tóth, János Pál; Sramkó, Gábor; Horváth, Orsolya; Popiela, Agnieszka; Mesterházy, Attila; Lukács, Balázs András

2015-01-01

Vegetative characters are widely used in the taxonomy of the amphibious genus Elatine L. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nine Elatine species (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma and E. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors.

Flood induced phenotypic plasticity in amphibious genus Elatine (Elatinaceae)

PubMed Central

Sramkó, Gábor; Horváth, Orsolya; Popiela, Agnieszka; Mesterházy, Attila; Lukács, Balázs András

2015-01-01

Vegetative characters are widely used in the taxonomy of the amphibious genus Elatine L. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nine Elatine species (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma and E. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors. PMID:26713235

Complete tylosis formation in a latest Permian conifer stem

PubMed Central

Feng, Zhuo; Wang, Jun; Rößler, Ronny; Kerp, Hans; Wei, Hai-Bo

2013-01-01

Background and Aims Our knowledge of tylosis formation is mainly based on observations of extant plants; however, its developmental and functional significance are less well understood in fossil plants. This study, for the first time, describes a complete tylosis formation in a fossil woody conifer and discusses its ecophysiological implications. Methods The permineralized stem of Shenoxylon mirabile was collected from the upper Permian (Changhsingian) Sunjiagou Formation of Shitanjing coalfield, northern China. Samples from different portions of the stem were prepared by using the standard thin-sectioning technique and studied in transmitted light. Key Results The outgrowth of ray parenchyma cells protruded into adjacent tracheids through pits initially forming small pyriform or balloon-shaped structures, which became globular or slightly elongated when they reached their maximum size. The tracheid luminae were gradually occluded by densely spaced tyloses. The host tracheids are arranged in distinct concentric zones representing different growth phases of tylosis formation within a single growth ring. Conclusions The extensive development of tyloses from the innermost heartwood (metaxylem) tracheids to the outermost sapwood tracheids suggests that the plant was highly vulnerable and reacted strongly to environmental stress. Based on the evidence available, the tyloses were probably not produced in response to wound reaction or pathogenic infection, since evidence of wood traumatic events or fungal invasion are not recognizable. Rather, they may represent an ecophysiological response to the constant environmental stimuli. PMID:23532049

Least tern and piping plover nesting at sand pits in Nebraska

USGS Publications Warehouse

Sidle, John G.; Kirsch, E.M.

1993-01-01

Endangered Least Terns (Sterna antillarum) and threatened Piping Plovers (Charadrius melodus) nest at commercial sand and gravel mining operations (sand pits) along the Platte River system in Nebraska. Sandbar habitat has been disappearing since the early 1900's along the Platte River system, but numbers of sand pits have increased. We hypothesized that birds would more fully utilize sand pits where suitable sandbar habitat was limited. We inventoried sand pits and censused terns and plovers on both habitats along the Loup River, part of the North Loup River, and most of the Platte River during 1988-1991. Using aircraft, we also quantified features of suitable sand pits present on the central Platte in 1988 and lower Platte in 1990, and related features to abundance and presence of birds. We found 225 sand pits of which 78 were suitable and 187 were unsuitable for nesting. Along the central Platte, where sandbar habitat is severely degraded, birds nested at 81% of the suitable sand pits (N = 32) at least once during 1988-1991, and most birds (61-94%) nested on sand pits. Along the lower Platte, where both sandbar and sand pit habitat are plentiful, birds nested at 60% of the suitable sand pits (N = 35) at least once during 1988-1991, and most birds (60-86%) nested on sandbars. Numbers of terns and plovers were more weakly correlated with features of sand pits on the central Platte than on the lower Platte. Least Terns and Piping Plovers seem to use more of the suitable sand pit habitat on the central Platte than on the lower Platte. Sand pits probably have influenced the birds' distribution by providing alternative nesting habitat along rivers where suitable sandbars are rare or absent.

Efficacy of UV-Pit-light traps for discerning micro-habitat-specific beetle and ant species related with different oil palm age stands and tropical annual seasons for accurate ecology and diversity interpretations

NASA Astrophysics Data System (ADS)

Ahmad Bukhary, A. K.; Ruslan, M. Y.; Mohd. Fauzi, M. M.; Nicholas, S.; Muhamad Fahmi, M. H.; Izfa Riza, H.; Idris, A. B.

2015-09-01

A newly innovated and efficient UV-Pit-light Trap is described and the results of the experiments on its efficacy that were carried out within different oil palm age stands of the year 2013 were evaluated and compared with previous study year of 2010, with out the implementation of the UV-Pit-light Trap. In 2013 the UV-Pit-light Traps, the Malaise Traps, and the Pit-fall Traps were employed, while in 2010, the conventional canopy-height UV-Light Traps, Malaise Traps, and the Pit-fall Traps were employed. The UV-Pit-light traps caught more beetle and ant families, morpho-species, and individuals per species compared with the passive Pit-fall traps. The UV-Pit-light Trap targets different subsets of the oil palm beetles and ants' communities, specifying on epigaeic-related micro-habitats, with different oil palm age stands have different compositions of micro-habitats. The UV-Pit-light Traps have the dual quality for satisfying both the biological and statistical data requirements and evaluations. There were no significant difference between the UV-Pit-light Traps and the passive Pit-fall Traps, while the trapping difference with the Malaise traps for different seasons of the year 2013. The UV-Pit-light Traps and the Malaise Traps were complementary to each other, detecting the activities of beetles and ants around the epigaeic-related micro-habitats or having active flight activities respectively according to annual seasons. The UV-Pit-light Trap is an oil-palm specific type of passive trapping system, focusing on the insect species dwelling the upper-ground/epigaeic micro-habitats.

Expression of growth hormone and its transcription factor, Pit-1, in early bovine development.

PubMed

Joudrey, E M; Lechniak, D; Petrik, J; King, W A

2003-03-01

During bovine embryogenesis, bovine growth hormone (bGH) contributes to proliferation, differentiation, and modulation of embryo metabolism. Pituitary-specific transcription factor-1 (Pit-1) is a transcription factor that binds to promoters of GH, prolactin (PRL), and thyroid-stimulating hormone-beta (TSHbeta) encoding genes. A polymorphism in the fifth exon of the bGH gene resulting in a leucine (Leu) to valine (Val) substitution provides an Alu I restriction site when the Leu allele is present. To determine the onset of embryonic expression of the bGH gene, oocytes derived from ovaries homozygous for Leu alleles were fertilized in vitro with spermatozoa obtained from a Val homozygote. For each developmental stage examined, three separate pools of embryos composed of approximately 100 cell samples underwent RNA isolation, reverse transcription to cDNA, and amplification by nested PCR (nPCR). Bovine GH gene transcripts were identified at 2- to 4-cell (n = 162), 8- to 16-cell (n = 73), morulae (n = 51), and blastocyst (n = 15) stages. Likewise, transcripts for Pit-1 were detected at 2-cell (n = 125), 4-cell (n = 114), 8-cell (n = 56), 12-to-32-cell (n = 32), morulae (n = 68), and blastocyst (n = 14) stages. After digestion with Alu1, bGH cDNA was genotyped by restriction fragment length polymorphism (RFLP) analysis. Bovine GH mRNA was present in all pools of stages examined. Both Leu and Val alleles (maternal and paternal) were only detected in pools of embryos that had reached 8- to 16-cell stage. Results suggest that transcription of the bGH gene begins at the 8- to 16-cell stage in bovine embryos, possibly under control of the transcription factor, Pit-1, and that RFLP analysis of the bGH gene can be used to determine parental origin of transcripts in early embryonic development. Copyright 2003 Wiley-Liss, Inc.

[Isolation of endophytic fungi from medicinal plant Brucea javanica and their microbial inhibition activity].

PubMed

Liang, Zi-Ning; Zhu, Hua; Lai, Kai-Ping; Chen, Long

2014-04-01

To isolate and identify endophytic fungi from Brucea javanica, and to detect the antimicrobial activity of these strains. Endophytic fungi were isolated by tissue inoculation culture and identified by conventional morphological characteristic method. Seven kinds of pathogenic fungi and three kinds of bacteria were used as targeting microbes to test microbial inhibition activities by agar plate antagonistic action and modified agar gel diffusion methods, respectively. A total of 83 endophytic fungi strains were isolated from the root, stem, leaf and fruit of Brucea javanica. 34 strains were obtained from the stem, 32 strains were obtained from the leaf, 15 strains were isolated from the root and 2 strains came from the fruit. These 73 strains which had been identified attribute to 5 orders, 6 families and 12 genera. For the isolated strains, 14 strains had antifungal activities against at least one pathogenic fungi, 9 strains showed antibacterial activities against one or more bacteria. Especially, the strain YJ-17 which belonged to Phomopsis genus showed the best inhibitory effect on the targeting microbes. The endophytic fungi from Brucea javanica show diversity and microbial inhibition activity, and are worthy for further study on plant disease controlling.

A new phenolic glycoside from the stem of Dendrobium nobile.

PubMed

Zhou, Xue-Ming; Zheng, Cai-Juan; Wu, Jia-Ting; Chen, Guang-Ying; Zhang, Bin; Sun, Chong-Ge

2017-05-01

A new phenolic glycoside dendroside (1), together with seven known compounds (2-8) were isolated from the stems of Dendrobium nobile. The structures of these compounds were elucidated using comprehensive spectroscopic methods. The inhibitory activities of all compounds against three cancer cell lines HeLa, MCF-7 and A549 were evaluated.

Endophytic fungi from selected varieties of soybean (Glycine max L. Merr.) and corn (Zea mays L.) grown in an agricultural area of Argentina.

PubMed

Russo, María L; Pelizza, Sebastián A; Cabello, Marta N; Stenglein, Sebastián A; Vianna, María F; Scorsetti, Ana C

2016-01-01

Endophytic fungi are ubiquitous and live within host plants without causing any noticeable symptoms of disease. Little is known about the diversity and function of fungal endophytes in plants, particularly in economically important species. The aim of this study was to determine the identity and diversity of endophytic fungi in leaves, stems and roots of soybean and corn plants and to determine their infection frequencies. Plants were collected in six areas of the provinces of Buenos Aires and Entre Ríos (Argentina) two areas were selected for sampling corn and four for soybean. Leaf, stem and root samples were surface-sterilized, cut into 1cm(2) pieces using a sterile scalpel and aseptically transferred to plates containing potato dextrose agar plus antibiotics. The species were identified using both morphological and molecular data. Fungal endophyte colonization in soybean plants was influenced by tissue type and varieties whereas in corn plants only by tissue type. A greater number of endophytes were isolated from stem tissues than from leaves and root tissues in both species of plants. The most frequently isolated species in all soybean cultivars was Fusarium graminearum and the least isolated one was Scopulariopsis brevicaulis. Furthermore, the most frequently isolated species in corn plants was Aspergillus terreus whereas the least isolated one was Aspergillus flavus. These results could be relevant in the search for endophytic fungi isolates that could be of interest in the control of agricultural pests. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

One dimensional Linescan x-ray detection of pits in fresh cherries

USDA-ARS?s Scientific Manuscript database

The presence of pits in processed cherries is a concern for both processors and consumers, in many cases causing injury and potential lawsuits. While machines used for pitting cherries are extremely efficient, if one or more plungers in a pitting head become misaligned, a large number of pits may p...

Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

PubMed

Vincent, Jean-Baptiste; Bodewits, Dennis; Besse, Sébastien; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; Keller, Horst Uwe; Agarwal, Jessica; A'Hearn, Michael F; Auger, Anne-Thérèse; Barucci, M Antonella; Bertaux, Jean-Loup; Bertini, Ivano; Capanna, Claire; Cremonese, Gabriele; Da Deppo, Vania; Davidsson, Björn; Debei, Stefano; De Cecco, Mariolino; El-Maarry, Mohamed Ramy; Ferri, Francesca; Fornasier, Sonia; Fulle, Marco; Gaskell, Robert; Giacomini, Lorenza; Groussin, Olivier; Guilbert-Lepoutre, Aurélie; Gutierrez-Marques, P; Gutiérrez, Pedro J; Güttler, Carsten; Hoekzema, Nick; Höfner, Sebastian; Hviid, Stubbe F; Ip, Wing-Huen; Jorda, Laurent; Knollenberg, Jörg; Kovacs, Gabor; Kramm, Rainer; Kührt, Ekkehard; Küppers, Michael; La Forgia, Fiorangela; Lara, Luisa M; Lazzarin, Monica; Lee, Vicky; Leyrat, Cédric; Lin, Zhong-Yi; Lopez Moreno, Josè J; Lowry, Stephen; Magrin, Sara; Maquet, Lucie; Marchi, Simone; Marzari, Francesco; Massironi, Matteo; Michalik, Harald; Moissl, Richard; Mottola, Stefano; Naletto, Giampiero; Oklay, Nilda; Pajola, Maurizio; Preusker, Frank; Scholten, Frank; Thomas, Nicolas; Toth, Imre; Tubiana, Cecilia

2015-07-02

Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.

Retinal pigment epithelium culture;a potential source of retinal stem cells.

PubMed

Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-07-01

To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco's Modified Eagle's Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered.

Retinal Pigment Epithelium Culture;a Potential Source of Retinal Stem Cells

PubMed Central

Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-01-01

Purpose To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Methods Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco’s Modified Eagle’s Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Results Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Conclusion Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered. PMID:23198062

Are nestin-positive mesenchymal stromal cells a better source of cells for CNS repair?

PubMed

Lindsay, Susan L; Barnett, Susan C

2017-06-01

In recent years there has been a great deal of research within the stem cell field which has led to the definition and classification of a range of stem cells from a plethora of tissues and organs. Stem cells, by classification, are considered to be pluri- or multipotent and have both self-renewal and multi-differentiation capabilities. Presently there is a great deal of interest in stem cells isolated from both embryonic and adult tissues in the hope they hold the therapeutic key to restoring or treating damaged cells in a number of central nervous system (CNS) disorders. In this review we will discuss the role of mesenchymal stromal cells (MSCs) isolated from human olfactory mucosa, with particular emphasis on their potential role as a candidate for transplant mediated repair in the CNS. Since nestin expression defines the entire population of olfactory mucosal derived MSCs, we will compare these cells to a population of neural crest derived nestin positive population of bone marrow-MSCs. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Light scattering from laser induced pit ensembles on high power laser optics

DOE PAGES

Feigenbaum, Eyal; Elhadj, Selim; Matthews, Manyalibo J.

2015-01-01

Far-field light scattering characteristics from randomly arranged shallow Gaussian-like shaped laser induced pits, found on optics exposed to high energy laser pulses, is studied. Closed-form expressions for the far-field intensity distribution and scattered power are derived for individual pits and validated using numerical calculations of both Fourier optics and FDTD solutions to Maxwell’s equations. It is found that the scattered power is proportional to the square of the pit width and approximately also to the square of the pit depth, with the proportionality factor scaling with pit depth. As a result, the power scattered from shallow pitted optics is expectedmore » to be substantially lower than assuming complete scattering from the total visible footprint of the pits.« less

A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel.

PubMed

Yang, Zixuan; Kan, Bo; Li, Jinxu; Qiao, Lijie; Volinsky, Alex A; Su, Yanjing

2017-11-14

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance.

A Statistical Study on the Effect of Hydrostatic Pressure on Metastable Pitting Corrosion of X70 Pipeline Steel

PubMed Central

Yang, Zixuan; Kan, Bo; Li, Jinxu; Su, Yanjing; Qiao, Lijie; Volinsky, Alex A.

2017-01-01

Hydrostatic pressure effects on pitting initiation and propagation in X70 steel are investigated by evaluating metastable pitting probability using electrochemical methods and immersion corrosion tests in containing chlorine ion solution. Potentiodynamic tests indicated that hydrostatic pressure can decrease the breakdown potential and lead to a reduced transpassivity region. Metastable test results revealed that hydrostatic pressure can increase metastable pitting formation frequency and promote stabilization of metastable pitting growth. Electrochemical impedance spectroscopy (EIS) results indicate that Hydrostatic pressure decreases the charge transfer resistance and increases the dissolution rate within the cavities. Corrosion test results also indicated that pitting initiation and propagation are accelerated by hydrostatic pressure. Result validity was verified by evaluating metastable pitting to predict pitting corrosion resistance. PMID:29135912

The Effects of Hot Corrosion Pits on the Fatigue Resistance of a Disk Superalloy

NASA Technical Reports Server (NTRS)

Gabb, Timothy P.; Telesman, Jack; Hazel, Brian; Mourer, David P.

2009-01-01

The effects of hot corrosion pits on low cycle fatigue life and failure modes of the disk superalloy ME3 were investigated. Low cycle fatigue specimens were subjected to hot corrosion exposures producing pits, then tested at low and high temperatures. Fatigue lives and failure initiation points were compared to those of specimens without corrosion pits. Several tests were interrupted to estimate the fraction of fatigue life that fatigue cracks initiated at pits. Corrosion pits significantly reduced fatigue life by 60 to 98 percent. Fatigue cracks initiated at a very small fraction of life for high temperature tests, but initiated at higher fractions in tests at low temperature. Critical pit sizes required to promote fatigue cracking were estimated, based on measurements of pits initiating cracks on fracture surfaces.

Pit-1/growth hormone factor 1 splice variant expression in the rhesus monkey pituitary gland and the rhesus and human placenta.

PubMed

Schanke, J T; Conwell, C M; Durning, M; Fisher, J M; Golos, T G

1997-03-01

We have examined the expression of Pit-1 messenger RNA (mRNA) splice variants in the nonhuman primate pituitary and in rhesus and human placenta. Full-length complementary DNAs (cDNAs) representing Pit-1 and the Pit-1 beta splice variants were cloned from a rhesus monkey pituitary cDNA library and were readily detectable by RT-PCR with rhesus pituitary gland RNA. The Pit-1T variant previously reported in mouse pituitary tumor cell lines was not detectable in normal rhesus pituitary tissue, although two novel splice variants were detected. A cDNA approximating the rat Pit-1 delta 4 variant was cloned but coded for a truncated and presumably nonfunctional protein. Only by using a nested RT-PCR approach were Pit-1 and Pit-1 beta variants consistently detectable in both human and rhesus placental tissue. The Pit-1 beta variant mRNA was not detectable in JEG-3 choriocarcinoma cells unless the cells were stimulated with 8-Br-cAMP. Immunoblot studies with nuclear extracts from primary rhesus syncytiotrophoblast cultures or JEG-3 choriocarcinoma cells indicated that although mRNA levels were very low, Pit-1 protein was detectable in differentiated cytotrophoblasts, and levels increased after treatment with 8-Br-cAMP. Two major species of Pit-1 protein were detected that corresponded to the two major bands in rat pituitary GH3 cell nuclear extracts. Low levels of slightly larger bands also were seen, which may represent Pit-1 beta protein or phosphorylated species. We conclude that Pit-1 splice variants expressed in the primate pituitary gland differ from those in the rodent gland and that the Pit-1 and Pit-1 beta mRNAs expressed in the placenta give rise to a pattern of protein expression similar to that seen in pituitary cells, which is inducible by treatment with 8-Br-cAMP.

Advantages and limitations for users of double pit pour-flush latrines: a qualitative study in rural Bangladesh.

PubMed

Hussain, Faruqe; Clasen, Thomas; Akter, Shahinoor; Bawel, Victoria; Luby, Stephen P; Leontsini, Elli; Unicomb, Leanne; Barua, Milan Kanti; Thomas, Brittany; Winch, Peter J

2017-05-25

In rural Bangladesh, India and elsewhere, pour-flush pit latrines are the most common sanitation system. When a single pit latrine becomes full, users must empty it themselves and risk exposure to fresh feces, pay an emptying service to remove pit contents or build a new latrine. Double pit pour-flush latrines may serve as a long-term sanitation option including high water table areas because the pits do not need to be emptied immediately and the excreta decomposes into reusable soil. Double pit pour-flush latrines were implemented in rural Bangladesh for 'hardcore poor' households by a national NGO, BRAC. We conducted interviews, focus groups, and spot checks in two low-income, rural areas of Bangladesh to explore the advantages and limitations of using double pit latrines compared to single pit latrines. The rural households accepted the double pit pour-flush latrine model and considered it feasible to use and maintain. This latrine design increased accessibility of a sanitation facility for these low-income residents and provided privacy, convenience and comfort, compared to open defecation. Although a double pit latrine is more costly and requires more space than a single pit latrine the households perceived this sanitation system to save resources, because households did not need to hire service workers to empty pits or remove decomposed contents themselves. In addition, the excreta decomposition process produced a reusable soil product that some households used in homestead gardening. The durability of the latrine superstructures was a problem, as most of the bamboo-pole superstructure broke after 6-18 months of use. Double pit pour-flush latrines are a long-term improved sanitation option that offers users several important advantages over single pit pour-flush latrines like in rural Bangladesh which can also be used in areas with high water table. Further research can provide an understanding of the comparative health impacts and effectiveness of the model in preventing human excreta from entering the environment.

SLM Produced Hermetically Sealed Isolation Valve

NASA Technical Reports Server (NTRS)

Richard, James

2014-01-01

Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic-driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic-based valve.

SLM Produced Hermetically Sealed Isolation Valve

NASA Technical Reports Server (NTRS)

Richard, James A.

2014-01-01

Marshall Space Flight Center (MSFC) has developed a valve concept to replace traditional pyrotechnic driven isolation valves. This paper will describe the valve design and development process. The valve design uses a stem/wedge to support a disk inside the valve. That disk hermetically seals the pressurized fluids. A release mechanism holds the stem/wedge and a large spring in place. When required to open, a solenoid is energized and pulls the release mechanism allowing the spring to pull the stem/wedge away from the disk. Now the disk is unsupported and the pressure ruptures the disk allowing flow to the outlet of the valve. This paper will provide details of this design, describe the development testing, and show the results from the valve level tests performed. Also, a trade study is presented to show the advantages of this design to a conventional pyrotechnic based valve.

In Vitro Expression of Cytokeratin 19 in Adipose-Derived Stem Cells Is Induced by Epidermal Growth Factor.

PubMed

Chen, Shangliang; Wang, Mingzhu; Chen, Xinglu; Chen, Shaolian; Liu, Li; Zhu, Jianbin; Wang, Jinhui; Yang, Xiaorong; Cai, Xiangsheng

2018-06-21

BACKGROUND Cytokeratin 19 (CK19) is a typical epithelial marker. In this study, we determined whether epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) could enhance CK19 expression in adipose-derived stem cells (ADSCs), thereby inducing the differentiation of ADSCs into epithelial-like cells. MATERIAL AND METHODS ADSCs were isolated from perinephric fat, and the expression of CD29, CD90, and CD105 was confirmed. Following isolation, ADSCs were cultured in static medium or medium containing EGF or bFGF. RESULTS Flow cytometry revealed that EGF and bFGF could alter mesenchymal stem cell markers as well as the cell cycle of ADSCs. Western blotting and immunofluorescence revealed that after 14 days, EGF treatment enhanced the expression of CK19 in ADSCs. CONCLUSIONS Our findings offer important insight for the clinical use of ADSCs in the generation of epithelial-like cells in the future.

Involvement of the pituitary-specific transcription factor pit-1 in somatolactotrope cell growth and death: an approach using dominant-negative pit-1 mutants.

PubMed

Pellegrini, Isabelle; Roche, Cathy; Quentien, Marie-Helene; Ferrand, Mireille; Gunz, Ginette; Thirion, Sylvie; Bagnis, Claude; Enjalbert, Alain; Franc, Jean-Louis

2006-12-01

The anterior pituitary-specific transcription factor Pit-1 was initially identified and cloned as a transactivator of the prolactin (PRL) and GH genes and later as a regulator of the TSHb gene. It was found to be a major developmental regulator, because natural Pit-1 gene mutations cause a dwarf phenotype in mice and cause combined pituitary hormone deficiency associated with pituitary hypoplasia in humans. To further investigate the growth-promoting effects of Pit-1, we used a strategy based on the use of dominant-negative Pit-1 mutants as an alternative means of inactivating endogenous Pit-1 functions. R271W, a Pit-1 mutant identified in one allele in patients with severe combined pituitary hormone deficiency, and Pit-1Delta1-123, a deletion mutant in which only the DNA binding domain of Pit-1 is conserved, were generated, and their ability to abolish the effects of the endogenous native Pit-1 in the differentiated proliferating somatolactotrope GH4C1 cell line was investigated. Enforced expression of the dominant-negative mutants in GH4C1 cells using recombinant lentiviral vectors decreased the levels of expression of known Pit-1 target genes such as PRL and GH, abolished the hormone release, and reduced cell viability by decreasing the growth rate and inducing apoptosis via a caspase-independent pathway. These results show for the first time that the growth-promoting effects of Pit-1 are at least partly due to the fact that this transcription factor prevents apoptotic cell death.

2017 Robotic Mining Competition

NASA Image and Video Library

2017-05-23

Team Raptor members from the University of North Dakota College of Engineering and Mines check their robot, named "Marsbot," in the RoboPit at NASA's 8th Annual Robotic Mining Competition at the Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their uniquely-designed mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's Journey to Mars.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from Case Western Reserve University pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from The University of Utah pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

First-time participants from Saginaw Valley State University pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Opening Ceremony

NASA Image and Video Library

2018-05-15

On the second day of NASA's 9th Robotic Mining Competition, May 15, team members from Temple University work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from The University of Alabama pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from the South Dakota School of Mines & Technology pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Opening Ceremony

NASA Image and Video Library

2018-05-15

Team members from Iowa State University prepare their robot miner on the second day of NASA's 9th Robotic Mining Competition, May 15, in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Setup

NASA Image and Video Library

2018-05-14

On the first day of NASA's 9th Robotic Mining Competition, set-up day on May 14, college team members work on their robot miner in the RobotPits in the Educator Resource Center at Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. will use their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Martian soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from New York University work on their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from York College CUNY are with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Robotic Mining Competition - Activities

NASA Image and Video Library

2018-05-17

Team members from the University of Arkansas pause with their robot miner in the RobotPits on the fourth day of NASA's 9th Robotic Mining Competition, May 17, at NASA's Kennedy Space Center Visitor Complex in Florida. More than 40 student teams from colleges and universities around the U.S. are using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated Lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

What is a stem cell?

PubMed

Slack, Jonathan M W

2018-05-15

The historical roots of the stem cell concept are traced with respect to its usage in embryology and in hematology. The modern consensus definition of stem cells, comprising both pluripotent stem cells in culture and tissue-specific stem cells in vivo, is explained and explored. Methods for identifying stem cells are discussed with respect to cell surface markers, telomerase, label retention and transplantability, and properties of the stem cell niche are explored. The CreER method for identifying stem cells in vivo is explained, as is evidence in favor of a stochastic rather than an obligate asymmetric form of cell division. In conclusion, it is found that stem cells do not possess any unique and specific molecular markers; and stem cell behavior depends on the environment of the cell as well as the stem cell's intrinsic qualities. Furthermore, the stochastic mode of division implies that stem cell behavior is a property of a cell population not of an individual cell. In this sense, stem cells do not exist in isolation but only as a part of multicellular system. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells. © 2018 Wiley Periodicals, Inc.

Hypoxia enhances the protective effects of placenta-derived mesenchymal stem cells against scar formation through hypoxia-inducible factor-1α.

PubMed

Du, Lili; Lv, Runxiao; Yang, Xiaoyi; Cheng, Shaohang; Xu, Jing; Ma, Tingxian

2016-06-01

To explore the effect of placenta-derived mesenchymal stem cells on scar formation as well as the underlying mechanism. The isolated placenta-derived mesenchymal stem cells from mice were distributed in the wounded areas of scalded mouse models, attenuated inflammatory responses and decreased the deposition of collagens, thus performing a beneficial effect against scar formation. Hypoxia enhanced the protective effect of placenta-derived mesenchymal stem cells and hypoxia-inducible factor-1α was involved in the protective effect of placenta-derived mesenchymal stem cells in hypoxic condition. Hypoxia enhanced the protective effect of placenta-derived mesenchymal stem cells through hypoxia-inducible factor-1α and PMSCs may have a potential application in the treatment of wound.

Characterization and isolation of highly purified porcine satellite cells

PubMed Central

Ding, Shijie; Wang, Fei; Liu, Yan; Li, Sheng; Zhou, Guanghong; Hu, Ping

2017-01-01

Pig is an important food source and an excellent system to model human diseases. Careful characterization of the swine skeletal muscle stem cells (satellite cells) will shed lights on generation of swine skeletal muscle disease model and efficient production of porcine meat for the food industry. Paired box protein 7 (Pax7) is a highly conserved transcription factor shared by satellite cells from various species. However, the sequence of Pax7 has not been characterized in pig. The lack of method to isolate highly purified satellite cells hinders the thorough characterization of the swine satellite cells. Here we found molecular markers for swine satellite cells and revealed that the porcine satellite cells were heterogeneous in various pieces of skeletal muscle. We further developed a method to isolate highly purified satellite cells directly from porcine muscles using fluorescence-activated cell sorting. We next characterized the proliferation and differentiation abilities of isolated satellite cells in vitro; and found that long-term culturing of satellite cells in vitro led to stemness loss. PMID:28417015

Force-displacement measurements of earlywood bordered pits using a mesomechanical tester

Treesearch

Samuel L. Zelinka; Keith J. Bourne; John C. Hermanson; Samuel V. Glass; Adriana Costa; Alex C. Wiedenhoeft

2015-01-01

The elastic properties of pit membranes are reported to have important implications in understanding air-seeding phenomena in gymnosperms, and pit aspiration plays a large role in wood technological applications such as wood drying and preservative treatment. Here we present force–displacement measurements for pit membranes of circular bordered pits, collected on a...

Neuronal differentiation of stem cells isolated from adult muscle.

PubMed

Romero-Ramos, Marina; Vourc'h, Patrick; Young, Henry E; Lucas, Paul A; Wu, Young; Chivatakarn, Onanong; Zaman, Rumina; Dunkelman, Noushin; el-Kalay, Mohammad A; Chesselet, Marie-Françoise

2002-09-15

Lineage uncommitted pluripotent stem cells reside in the connective tissue of skeletal muscle. The present study was carried out with pluripotent stem cells (PPSCs) isolated from 6-month old rat muscle. Before differentiation, these cells were vimentin+, CD90+, CD45-, and varied in their expression of CD34. The PPSCs were expanded as non-adherent aggregates under similar conditions to those used to generate neurospheres from embryonic or neural stem cells. The PPSC-derived neurospheres were positive for nestin, an early marker present in neuronal precursors, and expressed the two alternative mRNA forms of the neuroectodermal marker Pax-6, as well as mRNA for Oct-4, a gene related to the pluripotentiality of stem cells. To confirm their neural potential, PPSC-derived neurospheres were plated on coated coverslips under varying conditions: Neurobasal medium with N2 or B27, and either NT3 or BDNF. After 4-6 days the cells expressed neuronal (Tuj1+, NF68), astrocytic (GFAP) and oligodendrocytic (MOSP+, MBP+) markers, both by immunocytochemistry and RT-PCR. In addition, PPSCs were cultured as monolayers under adherent conditions, exposed to growth factors and defined differentiating conditions for 5 hr, and subsequently kept for 2 days in a maturation medium. At this point they gave rise to a mixed population of early neural progenitors (Nestin+ or NG2+), immature and mature neurons (Tuj1+ and NF145+) and myelin producing oligodendrocytes (CNPase + and MOSP+). Our study shows that PPSCs present in adult muscle can overcome germ lineage restrictions and express the molecular characteristics of brain cells. Therefore, PPSCs isolated from adult muscle could provide a novel source for autologous cell replacement in neurodegenerative and demyelinating diseases. Copyright 2002 Wiley-Liss, Inc.

The Use of Blood Vessel–Derived Stem Cells for Meniscal Regeneration and Repair

PubMed Central

OSAWA, AKI; HARNER, CHRISTOPHER D.; GHARAIBEH, BURHAN; MATSUMOTO, TOMOYUKI; MIFUNE, YUTAKA; KOPF, SEBASTIAN; INGHAM, SHEILA J. M.; SCHREIBER, VERENA; USAS, ARVYDAS; HUARD, JOHNNY

2015-01-01

Purpose Surgical repairs of tears in the vascular region of the meniscus usually heal better than repairs performed in the avascular region; thus, we hypothesized that this region might possess a richer supply of vascular-derived stem cells than the avascular region. Methods In this study, we analyzed 6 menisci extracted from aborted human fetuses and 12 human lateral menisci extracted from adult human subjects undergoing total knee arthroplasty. Menisci were immunostained for CD34 (a stem cell marker) and CD146 (a pericyte marker) in situ, whereas other menisci were dissected into two regions (peripheral and inner) and used to isolate meniscus-derived cells by flow cytometry. Cell populations expressing CD34 and CD146 were tested for their multi-lineage differentiation potentials, including chondrogenic, osteogenic, and adipogenic lineages. Fetal peripheral meniscus cells were transplanted by intracapsular injection into the knee joints of an athymic rat meniscal tear model. Rat menisci were extracted and histologically evaluated after 4 wk posttransplantation. Results Immunohistochemistry and flow cytometric analyses demonstrated that a higher number of CD34- and CD146-positive cells were found in the peripheral region compared with the inner region. The CD34- and CD146-positive cells isolated from the vascular region of both fetal and adult menisci demonstrated multilineage differentiation capacities and were more potent than cells isolated from the inner (avascular) region. Fetal CD34- and CD146-positive cells transplanted into the athymic rat knee joint were recruited into the meniscal tear sites and contributed to meniscus repair. Conclusions The vascularized region of the meniscus contains more stem cells than the avascular region. These meniscal-derived stem cells were multi-potent and contributed to meniscal regeneration. PMID:23247715

Isolation, Characterization, and Differentiation of Dental Pulp Stem Cells in Ferrets.

PubMed

Homayounfar, Negar; Verma, Prashant; Nosrat, Ali; El Ayachi, Ikbale; Yu, Zongdong; Romberg, Elaine; Huang, George T-J; Fouad, Ashraf F

2016-03-01

The ferret canine tooth has been introduced as a suitable model for studying dental pulp regeneration. The aim of this study was to isolate and characterize ferret dental pulp stem cells (fDPSCs) and their differentiation potential. Dental pulp stem cells were isolated from freshly extracted ferret canine teeth. The cells were examined for the expression of stem cell markers STRO-1, CD90, CD105, and CD146. The osteo/odontogenic and adipogenic differentiation potential of fDPSCs was evaluated. Osteogenic and odontogenic marker genes were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR) on days 1, 4, and 8 after osteo/odontogenic induction of fDPSCs including dentin sialophosphoprotein (DSPP), dentin matrix protein-1, osteopontin, and alkaline phosphatase. Human dental pulp cells were used as the control. The results were analyzed using 3-way analysis of variance. fDPSCs were positive for STRO1, CD90, and CD105 and negative for CD146 markers with immunohistochemistry. fDPSCs showed strong osteogenic and weak adipogenic potential. The overall expression of DSPP was not significantly different between fDPSCs and human dental pulp cells. The expression of DSPP in osteo/odontogenic media was significantly higher in fDPSCs on day 4 (P < .01). The overall expression of dentin matrix protein-1, osteopontin, and alkaline phosphatase was significantly higher in fDPSCs (P = .0005). fDPSCs were positive for several markers of dental pulp stem cells resembling human DPSCs and appeared to show a stronger potential to differentiate to osteoblastic rather than odontoblastic lineage. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Manipulation of nanoscale V-pits to optimize internal quantum efficiency of InGaN multiple quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chiao-Yun; Li, Heng; Shih, Yang-Ta

2015-03-02

We systematically investigated the influence of nanoscale V-pits on the internal quantum efficiency (IQE) of InGaN multiple quantum wells (MQWs) by adjusting the underlying superlattices (SLS). The analysis indicated that high barrier energy of sidewall MQWs on V-pits and long diffusion distance between the threading dislocation (TD) center and V-pit boundary were crucial to effectively passivate the non-radiative centers of TDs. For a larger V-pit, the thicker sidewall MQW on V-pit would decrease the barrier energy. On the contrary, a shorter distance between the TD center and V-pit boundary would be observed in a smaller V-pit, which could increase themore » carrier capturing capability of TDs. An optimized V-pit size of approximately 200–250 nm in our experiment could be concluded for MQWs with 15 pairs SLS, which exhibited an IQE value of 70%.« less

Stem cells with potential to generate insulin producing cells in man.

PubMed

Zulewski, Henryk

2006-10-14

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Stem cells with potential to generate insulin-producing cells in man.

PubMed

Zulewski, Henryk

2007-03-02

Replacement of insulin-producing cells represents an almost ideal treatment for patients with diabetes mellitus type 1. Transplantation of pancreatic islets of Langerhans--although successful in experienced centres--is limited by the lack of donor organs. Generation of insulin-producing cells from stem cells represents an attractive alternative. Stem cells with the potential to differentiate into insulin-producing cells include embryonic stem cells (ESC) as well as adult stem cells from various tissues including the pancreas, liver, central nervous system, bone marrow and adipose tissue. The use of human ESC is hampered by ethical concerns and the inability to create patient specific ESC with therapeutic cloning. Among adult stem cells mesenchymal stem cells appear to have a particular developmental plasticity ex vivo that include their ability to adopt a pancreatic endocrine phenotype. The present review summarises the current knowledge on the development of insulin-producing cells from stem cells with special emphasis on human mesenchymal stem cells isolated from the pancreas and adipose tissue.

Generation of Human Induced Pluripotent Stem Cells from Peripheral Blood Mononuclear Cells Using Sendai Virus.

PubMed

Soares, Filipa A C; Pedersen, Roger A; Vallier, Ludovic

2016-01-01

This protocol describes the efficient isolation of peripheral blood mononuclear cells from circulating blood via density gradient centrifugation and subsequent generation of integration-free human induced pluripotent stem cells. Peripheral blood mononuclear cells are cultured for 9 days to allow expansion of the erythroblast population. The erythroblasts are then used to derive human induced pluripotent stem cells using Sendai viral vectors, each expressing one of the four reprogramming factors Oct4, Sox2, Klf4, and c-Myc.

Tannins from Hamamelis virginiana: identification of proanthocyanidins and hamamelitannin quantification in leaf, bark, and stem extracts.

PubMed

Vennat, B; Pourrat, H; Pouget, M P; Gross, D; Pourrat, A

1988-10-01

The tannins in leaf, bark, and stem extracts of HAMAMELIS VIRGINIANA were analyzed. Four proanthocyanidins were isolated by HPLC. One was a procyanidin polymer containing only one type of flavanol unit; the other three were polymers of procyanidin and prodelphinidin containing two types of flavanol units. A method of assay of hamamelitannin showed the bark extract to be 31 times richer in hamamelitannin than the leaf extract and 87 times richer than the stem extract.

Properties of Dental Pulp-derived Mesenchymal Stem Cells and the Effects of Culture Conditions.

PubMed

Kawashima, Nobuyuki; Noda, Sonoko; Yamamoto, Mioko; Okiji, Takashi

2017-09-01

Dental pulp mesenchymal stem cells (DPMSCs) highly express mesenchymal stem cell markers and possess the potential to differentiate into neural cells, osteoblasts, adipocytes, and chondrocytes. Thus, DPMSCs are considered suitable for tissue regeneration. The colony isolation method has commonly been used to collect relatively large amounts of heterogeneous DPMSCs. Homogenous DPMSCs can be isolated by fluorescence-activated cell sorting using antibodies against mesenchymal stem cell markers, although this method yields a limited number of cells. Both quality and quantity of DPMSCs are critical to regenerative therapy, and cell culture methods need to be improved. We thus investigated the properties of DPMSCs cultured with different methods. DPMSCs in a three-dimensional spheroid culture system, which is similar to the hanging drop culture for differentiation of embryonic stem cells, showed upregulation of odonto-/osteoblastic markers and mineralized nodule formation. This suggests that this three-dimensional spheroid culturing system for DPMSCs may be suitable for inducing hard tissues. We further examined the effect of cell culture density on the properties of DPMSCs because the properties of stem cells can be altered depending on the cell density. DPMSCs cultured under the confluent cell density condition showed slight downregulation of some mesenchymal stem cell markers compared with those under the sparse condition. The ability of DPMSCs to differentiate into hard tissue-forming cells was found to be enhanced in the confluent condition, suggesting that the confluent culture condition may not be suitable for maintaining the stemness of DPMSCs. When DPMSCs are to be used for hard tissue regeneration, dense followed by sparse cell culture conditions may be a better alternative strategy. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Human mesenchymal stem cells - current trends and future prospective

PubMed Central

Ullah, Imran; Subbarao, Raghavendra Baregundi; Rho, Gyu Jin

2015-01-01

Stem cells are cells specialized cell, capable of renewing themselves through cell division and can differentiate into multi-lineage cells. These cells are categorized as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells. Mesenchymal stem cells (MSCs) are adult stem cells which can be isolated from human and animal sources. Human MSCs (hMSCs) are the non-haematopoietic, multipotent stem cells with the capacity to differentiate into mesodermal lineage such as osteocytes, adipocytes and chondrocytes as well ectodermal (neurocytes) and endodermal lineages (hepatocytes). MSCs express cell surface markers like cluster of differentiation (CD)29, CD44, CD73, CD90, CD105 and lack the expression of CD14, CD34, CD45 and HLA (human leucocyte antigen)-DR. hMSCs for the first time were reported in the bone marrow and till now they have been isolated from various tissues, including adipose tissue, amniotic fluid, endometrium, dental tissues, umbilical cord and Wharton's jelly which harbours potential MSCs. hMSCs have been cultured long-term in specific media without any severe abnormalities. Furthermore, MSCs have immunomodulatory features, secrete cytokines and immune-receptors which regulate the microenvironment in the host tissue. Multilineage potential, immunomodulation and secretion of anti-inflammatory molecules makes MSCs an effective tool in the treatment of chronic diseases. In the present review, we have highlighted recent research findings in the area of hMSCs sources, expression of cell surface markers, long-term in vitro culturing, in vitro differentiation potential, immunomodulatory features, its homing capacity, banking and cryopreservation, its application in the treatment of chronic diseases and its use in clinical trials. PMID:25797907

Therapeutic potential of dental stem cells

PubMed Central

Chalisserry, Elna Paul; Nam, Seung Yun; Park, Sang Hyug; Anil, Sukumaran

2017-01-01

Stem cell biology has become an important field in regenerative medicine and tissue engineering therapy since the discovery and characterization of mesenchymal stem cells. Stem cell populations have also been isolated from human dental tissues, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla, dental follicle progenitor cells, and periodontal ligament stem cells. Dental stem cells are relatively easily obtainable and exhibit high plasticity and multipotential capabilities. The dental stem cells represent a gold standard for neural-crest-derived bone reconstruction in humans and can be used for the repair of body defects in low-risk autologous therapeutic strategies. The bioengineering technologies developed for tooth regeneration will make substantial contributions to understand the developmental process and will encourage future organ replacement by regenerative therapies in a wide variety of organs such as the liver, kidney, and heart. The concept of developing tooth banking and preservation of dental stem cells is promising. Further research in the area has the potential to herald a new dawn in effective treatment of notoriously difficult diseases which could prove highly beneficial to mankind in the long run. PMID:28616151

The Neurovascular Properties of Dental Stem Cells and Their Importance in Dental Tissue Engineering

PubMed Central

Ratajczak, Jessica; Bronckaers, Annelies; Dillen, Yörg; Gervois, Pascal; Vangansewinkel, Tim; Driesen, Ronald B.; Wolfs, Esther; Lambrichts, Ivo

2016-01-01

Within the field of tissue engineering, natural tissues are reconstructed by combining growth factors, stem cells, and different biomaterials to serve as a scaffold for novel tissue growth. As adequate vascularization and innervation are essential components for the viability of regenerated tissues, there is a high need for easily accessible stem cells that are capable of supporting these functions. Within the human tooth and its surrounding tissues, different stem cell populations can be distinguished, such as dental pulp stem cells, stem cells from human deciduous teeth, stem cells from the apical papilla, dental follicle stem cells, and periodontal ligament stem cells. Given their straightforward and relatively easy isolation from extracted third molars, dental stem cells (DSCs) have become an attractive source of mesenchymal-like stem cells. Over the past decade, there have been numerous studies supporting the angiogenic, neuroprotective, and neurotrophic effects of the DSC secretome. Together with their ability to differentiate into endothelial cells and neural cell types, this makes DSCs suitable candidates for dental tissue engineering and nerve injury repair. PMID:27688777

Epidermal stem cells: location, potential and contribution to cancer.

PubMed

Ambler, C A; Määttä, A

2009-01-01

Epidermal stem cells have been classically characterized as slow-cycling, long-lived cells that reside in discrete niches in the skin. Gene expression studies of niche-resident cells have revealed a number of stem cell markers and regulators, including the Wnt/beta-catenin, Notch, p63, c-Myc and Hedgehog pathways. A new study challenges the traditional developmental paradigm of slow-cycling stem cells and rapid-cycling transit amplifying cells in some epidermal regions, and there is mounting evidence to suggest that multi-lineage epidermal progenitors can be isolated from highly proliferative, non-niche regions. Whether there is a unique microenvironment surrounding these progenitors remains to be determined. Interestingly, cancer stem cells derived from epidermal tumours exist independent of the classic skin stem cell niche, yet also have stem cell properties, including multi-lineage differentiation. This review summarizes recent studies identifying the location and regulators of mouse and human epidermal stem cells and highlights the strategies used to identify cancer stem cells, including expression of normal epidermal stem cell markers, expression of cancer stem cell markers identified in other epidermal tumours and characterization of side-population tumour cells.

Distribution, formation mechanisms, and significance of lunar pits

NASA Astrophysics Data System (ADS)

Wagner, Robert V.; Robinson, Mark S.

2014-07-01

Lunar Reconnaissance Orbiter Camera images reveal the presence of steep-walled pits in mare basalt (n = 8), impact melt deposits (n = 221), and highland terrain (n = 2). Pits represent evidence of subsurface voids of unknown extents. By analogy with terrestrial counterparts, the voids associated with mare pits may extend for hundreds of meters to kilometers in length, thereby providing extensive potential habitats and access to subsurface geology. Because of their small sizes relative to the local equilibrium crater diameters, the mare pits are likely to be post-flow features rather than volcanic skylights. The impact melt pits are indirect evidence both of extensive subsurface movement of impact melt and of exploitable sublunarean voids. Due to the small sizes of pits (mare, highland, and impact melt) and the absolute ages of their host materials, it is likely that most pits formed as secondary features.

Total synthesis of agalloside, isolated from Aquilaria agallocha, by the 5-O-glycosylation of flavan.

PubMed

Arai, Midori A; Yamaguchi, Yumi; Ishibashi, Masami

2017-06-14

Agalloside (1) is a neural stem cell differentiation activator isolated from Aquilaria agallocha by our group using Hes1 immobilized beads. We conducted the first total synthesis of agalloside (1) via the 5-O-glycosylation of flavan 25 using glycosyl fluoride 20 in the presence of BF 3 ·Et 2 O. Subsequent oxidation with DDQ to flavanone 2 and deprotection successively provided agalloside (1). This synthetic strategy holds promise for use in the synthesis of 5-O-glycosylated flavonoids. The synthesized agalloside (1) accelerated neural stem cell differentiation, which is a result comparable to that for the naturally occurring compound 1.

Two new chalcone glycosides from the stems of Entada phaseoloides.

PubMed

Zhao, Zhong-xiang; Jin, Jing; Lin, Chao-zhan; Zhu, Chen-chen; Liu, Yi-ming; Lin, Ai-hua; Liu, Ying-xiang; Zhang, Li; Luo, Hua-feng

2011-10-01

Two new chalcone glycosides 4'-O-(6″-O-galloyl-β-d-glucopyranosyl)-2',4-dihydroxychalcone (1) and 4'-O-(6″-O-galloyl-β-d-glucopyranosyl)-2'-hydroxy-4-methoxychalcone (2) together with one known chalcone glycoside 4'-O-β-d-glucopyranosyl-2'-hydroxy-4-methoxychalcone (3) were isolated from the stems of Entada phaseoloides. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis, including HSQC, HMBC, (1)H-(1)H COSY, and chemical evidences. This is the first report of chalcone-type compounds isolated from the genus Entada. Copyright © 2011 Elsevier B.V. All rights reserved.

Two missense mutations, E123Q and K151E, identified in the ERG11 allele of an azole-resistant isolate of Candida kefyr recovered from a stem cell transplant patient for acute myeloid leukemia

PubMed Central

Couzigou, Célia; Gabriel, Frédéric; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

2014-01-01

We report on the first cloning and nucleotide sequencing of an ERG11 allele from a clinical isolate of Candida kefyr cross-resistant to azole antifungals. It was recovered from a stem cell transplant patient, in an oncohematology unit exhibiting unexpected high prevalence of C. kefyr. Two amino acid substitutions were identified: K151E, whose role in fluconazole resistance was already demonstrated in Candida albicans, and E123Q, a new substitution never described so far in azole-resistant Candida yeast. PMID:24936404

Two missense mutations, E123Q and K151E, identified in the ERG11 allele of an azole-resistant isolate of Candida kefyr recovered from a stem cell transplant patient for acute myeloid leukemia.

PubMed

Couzigou, Célia; Gabriel, Frédéric; Biteau, Nicolas; Fitton-Ouhabi, Valérie; Noël, Thierry; Accoceberry, Isabelle

2014-07-01

We report on the first cloning and nucleotide sequencing of an ERG11 allele from a clinical isolate of Candida kefyr cross-resistant to azole antifungals. It was recovered from a stem cell transplant patient, in an oncohematology unit exhibiting unexpected high prevalence of C. kefyr. Two amino acid substitutions were identified: K151E, whose role in fluconazole resistance was already demonstrated in Candida albicans, and E123Q, a new substitution never described so far in azole-resistant Candida yeast.

Pit Latrine Fecal Sludge Resistance Using a Dynamic Cone Penetrometer in Low Income Areas in Mzuzu City, Malawi

PubMed Central

Chirwa, Charles F. C.; Hall, Ralph P.; Krometis, Leigh-Anne H.; Vance, Eric A.; Edwards, Adam; Guan, Ting; Holm, Rochelle H.

2017-01-01

Pit latrines can provide improved household sanitation, but without effective and inexpensive emptying options, they are often abandoned once full and may pose a public health threat. Emptying techniques can be difficult, as the sludge contents of each pit latrine are different. The design of effective emptying techniques (e.g., pumps) is limited by a lack of data characterizing typical in situ latrine sludge resistance. This investigation aimed to better understand the community education and technical engineering needs necessary to improve pit latrine management. In low income areas within Mzuzu city, Malawi, 300 pit latrines from three distinct areas were assessed using a dynamic cone penetrometer to quantify fecal sludge strength, and household members were surveyed to determine their knowledge of desludging procedures and practices likely to impact fecal sludge characteristics. The results demonstrate that there is a significant difference in sludge strength between lined and unlined pits within a defined area, though sludge hardened with depth, regardless of the pit type or region. There was only limited association between cone penetration depth and household survey data. To promote the adoption of pit emptying, it is recommended that households be provided with information that supports pit emptying, such as latrine construction designs, local pit emptying options, and cost. This study indicates that the use of a penetrometer test in the field prior to pit latrine emptying may facilitate the selection of appropriate pit emptying technology. PMID:28165378

The efficiencies of cast blasting in wide pits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, R.L.; King, M.G.

Blasting activities in all four pits at Thunder Basin Coal`s Black Thunder Mine are focused on cast blasting. With widths varying from 190 feet to 265 feet and bench heights varying from 90 feet to 175 feet, casting efficiencies vary with different geometry`s. For example, the percent cast to final in the 200 foot pit is on the average higher than the 270 foot pit. The powder factors are somewhat higher in the narrower pits, thus increasing the cost of blasting. This leads to a very detailed look at the actual benefit of cast blasting and the associated cost ofmore » these benefits. The simple solution would be to reduce the width of the pits, thereby increasing the percent cast to final. However, the lower rehandle and low coal loss associated with wide pits would be fortified. Upon further review it becomes obvious that the wider pits could not be compared to the narrow pits with the cast to final percent indices. The focus should be shifted to cubic yards cast to final per lineal foot of pit. This will allow for more accurate measures of the casting efficiency of the shot. When comparing the pits with these indices their performances were much closer than the percent cast to final indices. The powder factors being higher in the narrow pits drove up the cost per cubic yard cast to final. Therefore, even though the percent cast to final was higher, the cost per cubic yard was also higher.« less

Treatment of colon cancer with oncolytic herpes simplex virus in preclinical models.

PubMed

Yang, H; Peng, T; Li, J; Wang, Y; Zhang, W; Zhang, P; Peng, S; Du, T; Li, Y; Yan, Q; Liu, B

2016-05-01

Cancer stem cells (CSCs), which are a rare population in any type of cancer, including colon cancer, are tumorigenic and responsible for cancer recurrence and metastasis. CSCs have been isolated from a number of different solid tumors recently, although the isolation of CSCs in colon cancer is still challenging. We cultured colon cancer cells in stem cell medium to obtain colonosphere cells. These cells possessed the characteristics of CSCs, with a high capacity of tumorigenicity, migration and invasion in vitro and in vivo. The isolation and identification of CSCs have provided new targets for the therapeutics. Oncolytic herpes simplex viruses (oHSV) are an effective strategy for killing colon cancer cells in preclinical models. Here, we examined the efficacy of an oncolytic herpes simplex virus type 2 (oHSV2) in killing colon cancer cells and colon cancer stem-like cells (CSLCs). oHSV2 was found to be highly cytotoxic to the adherent and sphere cells in vitro, and oHSV2 treatment in vivo significantly inhibited tumor growth. This study demonstrates that oHSV2 is effective against colon cancer cells and colon CSLCs and could be a promising strategy for treating colon cancer patients.

The CD11a and Endothelial Protein C Receptor Marker Combination Simplifies and Improves the Purification of Mouse Hematopoietic Stem Cells

PubMed Central

Karimzadeh, Alborz; Scarfone, Vanessa M.; Varady, Erika; Chao, Connie; Grathwohl, Karin; Fathman, John W.; Fruman, David A.; Serwold, Thomas

2018-01-01

Abstract Hematopoietic stem cells (HSCs) are the self‐renewing multipotent progenitors to all blood cell types. Identification and isolation of HSCs for study has depended on the expression of combinations of surface markers on HSCs that reliably distinguish them from other cell types. However, the increasing number of markers required to isolate HSCs has made it tedious, expensive, and difficult for newcomers, suggesting the need for a simpler panel of HSC markers. We previously showed that phenotypic HSCs could be separated based on expression of CD11a and that only the CD11a negative fraction contained true HSCs. Here, we show that CD11a and another HSC marker, endothelial protein C receptor (EPCR), can be used to effectively identify and purify HSCs. We introduce a new two‐color HSC sorting method that can highly enrich for HSCs with efficiencies comparable to the gold standard combination of CD150 and CD48. Our results demonstrate that adding CD11a and EPCR to the HSC biologist's toolkit improves the purity of and simplifies isolation of HSCs. stem cells translational medicine 2018;7:468–476 PMID:29543389

Ovarian cancer stem cells.

PubMed

Zeimet, A G; Reimer, D; Sopper, S; Boesch, M; Martowicz, A; Roessler, J; Wiedemair, A M; Rumpold, H; Untergasser, G; Concin, N; Hofstetter, G; Muller-Holzner, E; Fiegl, H; Marth, C; Wolf, D; Pesta, M; Hatina, J

2012-01-01

Because of its semi-solid character in dissemination and growth, advanced ovarian cancer with its hundreds of peritoneal tumor nodules and plaques appears to be an excellent in vivo model for studying the cancer stem cell hypothesis. The most important obstacle, however, is to adequately define and isolate these tumor-initiating cells endowed with the properties of anoikis-resistance and unlimited self-renewal. Until now, no universal single marker or marker constellation has been found to faithfully isolate (ovarian) cancer stem cells. As these multipotent cells are known to possess highly elaborated efflux systems for cytotoxic agents, these pump systems have been exploited to outline putative stem cells as a side-population (SP) via dye exclusion analysis. Furthermore, the cells in question have been isolated via flow cytometry on the basis of cell surface markers thought to be characteristic for stem cells.In the Vienna variant of the ovarian cancer cell line A2780 a proof-of-principle model with both a stable SP and a stable ALDH1A1+ cell population was established. Double staining clearly revealed that both cell fractions were not identical. Of note, A2780V cells were negative for expression of surface markers CD44 and CD117 (c-kit). When cultured on monolayers of healthy human mesothelial cells, green-fluorescence-protein (GFP)-transfected SP of A2780V exhibited spheroid-formation, whereas non-side-population (NSP) developed a spare monolayer growing over the healthy mesothelium. Furthermore, A2780V SP was found to be partially resistant to platinum. However, this resistance could not be explained by over-expression of the "excision repair cross-complementation group 1" (ERCC1) gene, which is essentially involved in the repair of platinated DNA damage. ERCC1 was, nonetheless, over-expressed in A2780V cells grown as spheres under stem cell-selective conditions as compared to adherent monolayers cultured under differentiating conditions. The same was true for the primary ovarian cancer cells B-57.In summary our investigations indicate that even in multi-passaged cancer cell lines hierarchic government of growth and differentiation is conserved and that the key cancer stem cell population may be composed of small overlapping cell fractions defined by various arbitrary markers.

Characterization of two types of osteoclasts from human peripheral blood monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuasa, Kimitaka; Mori, Kouki; Ishikawa, Hitoshi

2007-05-04

The two osteoclastogenesis pathways, receptor activator nuclear factor (NF)-{kappa}B ligand (RANKL)-mediated and fusion regulatory protein-1 (FRP-1)-mediated osteoclastogenesis, have recently been reported. There were significant differences in differentiation and activation mechanisms between the two pathways. When monocytes were cultured with FRP-1 without adding M-CSF, essential for the RANKL system, TRAP-positive polykaryocyte formation occurred. FRP-1-mediated osteoclasts formed larger pits on mineralized calcium phosphate plates than RANKL+M-CSF-mediated osteoclasts did. Lacunae on dentin surfaces induced by FRP-1-mediated osteoclasts were inclined to be single and isolated. However, osteoclasts induced by RANKL+M-CSF made many connected pits on dentin surfaces as if they crawled on there. Interestingly,more » FRP-1 osteoclastogenesis was enhanced by M-CSF/IL-1{alpha}, while chemotactic behavior to the dentin slices was not effected. There were differences in pH and concentration of HCO3- at culture endpoint and in adherent feature to dentin surfaces. Our findings indicate there are two types of osteoclasts with distinct properties.« less

Sucrose accumulation in sweet sorghum stems occurs by apoplasmic phloem unloading and does not involve differential Sucrose transporter expression

DOE PAGES

Bihmidine, Saadia; Baker, R. Frank; Hoffner, Cassandra; ...

2015-07-30

Background: Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this studymore » was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. Results: Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. Conclusions: Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.« less

X-ray off-specular reflectivity studies of electrochemical pitting of Cu surfaces in sodium bicarbonate solution

NASA Astrophysics Data System (ADS)

Feng, Y. P.; Sinha, S. K.; Melendres, C. A.; Lee, D. D.

1996-02-01

We have studied the electrochemically-induced pitting process on a Cu electrode in NaHCO 3 solution using in-situ X-ray off-specular reflectivity measurements. The morphology and growth dynamics of the localized corrosion sites or pits were studied as the applied potential was varied from the cathodic region where the Cu surface is relatively free of oxide films to the anodic region where surface roughening occurs by general corrosion with concomitant formation of an oxide film. Quantitative analysis of the experimental results indicates that early pitting proceeds in favor of nucleation of pit clusters over individual pit growth. It was found that the lateral distribution of the pits is not random but exhibits a short-range order as evidenced by the appearance of a side peak in the transverse off-specular reflectivity. The position, height, and width of the peak was modeled to yield the average size, nearest-neighbor distance (within any one of the clusters), and over-all density of the pits averaged over the entire illuminated surface. In addition, measurements of the longitudinal off-specular reflectivity indicate a bimodal depth distribution for the pits, suggesting a “film breaking” type of pitting mechanism.

Tank Riser Pit Decontamination System (Pit Viper) Return on Investment and Break-Even Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Joan K.; Weimar, Mark R.; Balducci, Patrick J.

2003-06-30

This study assessed the cost benefit of Pit Viper deployment for 80 tank farm pits between October 1, 2003 and September 30, 2012 under the technical baseline for applicable double-shell tank (DST) and single-shell tank (SST) projects. After this assessment had been completed, the U.S. Department of Energy (DOE) Richland Operations Office (RL) and Office of River Protection (ORP) published the Hanford Performance Management Plan (August 2003), which accelerated the schedule for SST retrieval. Then, DOE/CH2M HILL contract modification M064 (October 2002) and The Integrated Mission Acceleration Plan (March 2003) further accelerated SST retrieval and closure schedules. Twenty-six to 40more » tanks must be retrieved by 2006. Thus the schedule for SST pit entries is accelerated and the number of SST pit entries is increased. This study estimates the return on investment (ROI) and the number of pits where Pit Viper deployment would break even or save money over current manual practices. The results of the analysis indicate a positive return on the federal investment for deployment of the Pit Viper provided it is used on a sufficient number of pits.« less

Printability and inspectability of programmed pit defects on teh masks in EUV lithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, I.-Y.; Seo, H.-S.; Ahn, B.-S.

2010-03-12

Printability and inspectability of phase defects in ELlVL mask originated from substrate pit were investigated. For this purpose, PDMs with programmed pits on substrate were fabricated using different ML sources from several suppliers. Simulations with 32-nm HP L/S show that substrate pits with below {approx}20 nm in depth would not be printed on the wafer if they could be smoothed by ML process down to {approx}1 nm in depth on ML surface. Through the investigation of inspectability for programmed pits, minimum pit sizes detected by KLA6xx, AIT, and M7360 depend on ML smoothing performance. Furthermore, printability results for pit defectsmore » also correlate with smoothed pit sizes. AIT results for pattemed mask with 32-nm HP L/S represents that minimum printable size of pits could be {approx}28.3 nm of SEVD. In addition, printability of pits became more printable as defocus moves to (-) directions. Consequently, printability of phase defects strongly depends on their locations with respect to those of absorber patterns. This indicates that defect compensation by pattern shift could be a key technique to realize zero printable phase defects in EUVL masks.« less

An Autoregulatory Pathway Establishes the Definitive Chromatin Conformation at the Pit-1 Locus

PubMed Central

Cooke, Nancy E.; Liebhaber, Stephen A.

2015-01-01

The transcription factor Pit-1 (POU1-F1) plays a dominant role in cell lineage expansion and differentiation in the anterior pituitary. Prior studies of the mouse Pit-1 (mPit-1) gene revealed that this master regulatory locus is activated at embryonic day 13.5 (E13.5) by an early enhancer (EE), whereas its subsequent expression throughout adult life is maintained by a more distal definitive enhancer (DE). Here, we demonstrate that the sequential actions of these two enhancers are linked to corresponding shifts in their proximities to the Pit-1 promoter. We further demonstrate that the looping of the definitive enhancer to the mPit-1 promoter is critically dependent on a self-sustaining autoregulatory mechanism mediated by the Pit-1 protein. These Pit-1-dependent actions are accompanied by localized recruitment of CBP and enrichment for H3K27 acetylation within the Pit-1 locus. These data support a model in which the sequential actions of two developmentally activated enhancers are linked to a corresponding shift in higher-order chromatin structures. This shift establishes an autoregulatory circuit that maintains durable expression of Pit-1 throughout adult life. PMID:25691665

Cell Growth Characteristics, Differentiation Frequency, and Immunophenotype of Adult Ear Mesenchymal Stem Cells

PubMed Central

Staszkiewicz, Jaroslaw; Frazier, Trivia P.; Rowan, Brian G.; Bunnell, Bruce A.; Chiu, Ernest S.; Gimble, Jeffrey M.

2010-01-01

Ear mesenchymal stem cells (EMSCs) represent a readily accessible population of stem-like cells that are adherent, clonogenic, and have the ability to self-renew. Previously, we have demonstrated that they can be induced to differentiate into adipocyte, osteocyte, chondrocyte, and myocyte lineages. The purpose of the current study was to characterize the growth kinetics of the cells and to determine their ability to form colonies of fibroblasts, adipocytes, osteocytes, and chondrocytes. In addition, the immunophenotypes of freshly isolated and culture-expanded cells were evaluated. From 1 g of tissue, we were able to isolate an average of 7.8 × 106 cells exhibiting a cell cycle length of ∼2–3 days. Colony-forming unit (CFU) assays indicated high proliferation potential, and confirmed previously observed multipotentiality of the cells. Fluorescence-activated cell sorting (FACS) showed that EMSCs were negative for hematopoietic markers (CD4, CD45), proving that they did not derive from circulating hematopoietic cells. The FACS analyses also showed high expression of stem cell antigen-1 (Sca-1) with only a minor population of cells expressing CD117, thus identifying Sca-1 as the more robust stem cell biomarker. Additionally, flow cytometry data revealed that the expression patterns of hematopoietic, stromal, and stem cell markers were maintained in the passaged EMSCs, consistent with the persistence of an undifferentiated state. This study indicates that EMSCs provide an alternative model for in vitro analyses of adult mesenchymal stem cells (MSCs). Further studies will be necessary to determine their utility for tissue engineering and regenerative medical applications. PMID:19400629

Very small embryonic-like stem cells (VSELs) represent a real challenge in stem cell biology: recent pros and cons in the midst of a lively debate

PubMed Central

Ratajczak, M Z; Zuba-Surma, E; Wojakowski, W; Suszynska, M; Mierzejewska, K; Liu, R; Ratajczak, J; Shin, D M; Kucia, M

2014-01-01

The concept that adult tissue, including bone marrow (BM), contains early-development cells with broader differentiation potential has again been recently challenged. In response, we would like to review the accumulated evidence from several independent laboratories that adult tissues, including BM, harbor a population of very rare stem cells that may cross germ layers in their differentiation potential. Thus, the BM stem cell compartment hierarchy needs to be revisited. These dormant, early-development cells that our group described as very small embryonic-like stem cells (VSELs) most likely overlap with similar populations of stem cells that have been identified in adult tissues by other investigators as the result of various experimental strategies and have been given various names. As reported, murine VSELs have some pluripotent stem cell characteristics. Moreover, they display several epiblast/germline markers that suggest their embryonic origin and developmental deposition in adult BM. Moreover, at the molecular level, changes in expression of parentally imprinted genes (for example, Igf2–H19) and resistance to insulin/insulin-like growth factor signaling (IIS) regulates their quiescent state in adult tissues. In several emergency situations related to organ damage, VSELs can be activated and mobilized into peripheral blood, and in appropriate animal models they contribute to tissue organ/regeneration. Interestingly, their number correlates with lifespan in mice, and they may also be involved in some malignancies. VSELs have been successfully isolated in several laboratories; however, some investigators experience problems with their isolation. PMID:24018851

Derivation and characterization of human embryonic stem cell lines from poor quality embryos.

PubMed

Liu, Weiqiang; Yin, Yifei; Long, Xiaolin; Luo, Yumei; Jiang, Yonghua; Zhang, Wenhong; Du, Hongzi; Li, Shaoying; Zheng, Yuhong; Li, Qing; Chen, Xinjie; Liao, Baoping; Xiao, Guohong; Wang, Weihua; Sun, Xiaofang

2009-04-01

Poor quality embryos discarded from in vitro fertilization (IVF) laboratories are good sources for deriving human embryonic stem cell (hESC) lines. In this study, 166 poor quality embryos donated from IVF centers on day 3 were cultured in a blastocyst medium for 2 days, and 32 early blastocysts were further cultured in a blastocyst optimum culture medium for additional 2 days so that the inner cell masses (ICMs) could be identified and isolated easily. The ICMs of 17 blastocysts were isolated by a mechanical method, while those of the other 15 blastocysts were isolated by immunosurgery. All isolated ICMs were inoculated onto a feeder layer for subcultivation. The rates of ICM attachment, primary ICM colony formation and the efficiency of hESC derivation were similar between the ICMs isolated by the two methods (P>0.05). As a result, four new hESC lines were established. Three cell lines had normal karyotypes and one had an unbalanced Robertsonian translocation. All cell lines showed normal hESC characteristics and had the differentiation ability. In conclusion, we established a stable and effective method for hESC isolation and culture, and it was confirmed that the mechanical isolation was an effective method to isolate ICMs from poor embryos. These results further indicate that hESC lines can be derived from poor quality embryos discarded by IVF laboratories.

Giant weathering pits in the Entrada Sandstone, southeastern Utah: Preliminary findings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Netoff, D.I.; Shroba, R.R.

Giant weathering pits formed in outcrops of the lower Entrada Sandstone slickrock of Jurassic age are present in two areas in the Glen Canyon region of arid southeastern Utah. The pits are far larger than any previously described in the geologic literature. The pits near Cookie Jar Butte are commonly cylindrical, typically have low width-to-depth ratios (1.5--3.6), and have a depth of closure of as much as 18 m. There are no obvious lithologic or structural controls that determine their shape or location. Many of the pits at Rock Creek Bay are elongate; several of them have long axes inmore » excess of 53 m, and the longest one is 74 m. Many of the pit walls are breached at the top, and the depth of closure is generally less than 6 m. The shapes of these pits are influenced by point orientation and pit coalescence. Thin-section analyses of near-surface sandstone cores taken near Cookie Jar Butte from pit walls, floors, and rims reveal no significant diagenetic alteration of the fine-grained to very fine frained quartzose sandstone (quartz arenite). Quartz grains appear fresh, and feldspar grains are only slightly weathered. The cement between the grains is mostly CaCO[sub 3]. In several of the pits in both areas sandy sediment veneers the bedrock floor. This sediment is similar in character to the adjacent sandstone and is probably locally derived. Possible origins of the giant pits include various physical, chemical, and biological weathering processes that initiate pit development, followed by excavation by plunge-pool action, wind deflation, dissolution, and piping. Preliminary field and laboratory data do not clearly identify and single process of group of processes that account for pit development.« less

Isolation and characterisation of human gingival margin-derived STRO-1/MACS+ and MACS− cell populations

PubMed Central

El-Sayed, Karim M Fawzy; Paris, Sebastian; Graetz, Christian; Kassem, Neemat; Mekhemar, Mohamed; Ungefroren, Hendrick; Fändrich, Fred; Dörfer, Christof

2015-01-01

Recently, gingival margin-derived stem/progenitor cells isolated via STRO-1/magnetic activated cell sorting (MACS) showed remarkable periodontal regenerative potential in vivo. As a second-stage investigation, the present study's aim was to perform in vitro characterisation and comparison of the stem/progenitor cell characteristics of sorted STRO-1-positive (MACS+) and STRO-1-negative (MACS−) cell populations from the human free gingival margin. Cells were isolated from the free gingiva using a minimally invasive technique and were magnetically sorted using anti-STRO-1 antibodies. Subsequently, the MACS+ and MACS− cell fractions were characterized by flow cytometry for expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1. Colony-forming unit (CFU) and multilineage differentiation potential were assayed for both cell fractions. Mineralisation marker expression was examined using real-time polymerase chain reaction (PCR). MACS+ and MACS− cell fractions showed plastic adherence. MACS+ cells, in contrast to MACS− cells, showed all of the predefined mesenchymal stem/progenitor cell characteristics and a significantly higher number of CFUs (P<0.01). More than 95% of MACS+ cells expressed CD105, CD90 and CD73; lacked the haematopoietic markers CD45, CD34 and CD14, and expressed STRO-1 and CD146/MUC18. MACS− cells showed a different surface marker expression profile, with almost no expression of CD14 or STRO-1, and more than 95% of these cells expressed CD73, CD90 and CD146/MUC18, as well as the haematopoietic markers CD34 and CD45 and CD105. MACS+ cells could be differentiated along osteoblastic, adipocytic and chondroblastic lineages. In contrast, MACS− cells demonstrated slight osteogenic potential. Unstimulated MACS+ cells showed significantly higher expression of collagen I (P<0.05) and collagen III (P<0.01), whereas MACS− cells demonstrated higher expression of osteonectin (P<0.05; Mann–Whitney). The present study is the first to compare gingival MACS+ and MACS− cell populations demonstrating that MACS+ cells, in contrast to MACS− cells, harbour stem/progenitor cell characteristics. This study also validates the effectiveness of the STRO-1/MACS+ technique for the isolation of gingival stem/progenitor cells. Human free gingival margin-derived STRO-1/MACS+ cells are a unique renewable source of multipotent stem/progenitor cells. PMID:25257881

Redefining the potential applications of dental stem cells: An asset for future

PubMed Central

Rai, Shalu; Kaur, Mandeep; Kaur, Sandeep; Arora, Sapna Panjwani

2012-01-01

Recent exciting discoveries isolated dental stem cells from the pulp of the primary and permanent teeth, from the periodontal ligament, and from associated healthy tissues. Dental pulp stem cells (DPSCs) represent a kind of adult cell colony which has the potent capacity of self-renewing and multilineage differentiation. Stem cell-based tooth engineering is deemed as a promising approach to the making of a biological tooth (bio-tooth) or engineering of functional tooth structures. Dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be stored for future use as new therapies are developed for a range of diseases and injuries. The aim of this article is to review and understand how dental stem cells are being used for regeneration of oral and conversely nonoral tissues. A brief review on banking is also done for storing of these valuable stem cells for future use. PMID:23716933

Stem cells: a model for screening, discovery and development of drugs.

PubMed

Kitambi, Satish Srinivas; Chandrasekar, Gayathri

2011-01-01

The identification of normal and cancerous stem cells and the recent advances made in isolation and culture of stem cells have rapidly gained attention in the field of drug discovery and regenerative medicine. The prospect of performing screens aimed at proliferation, directed differentiation, and toxicity and efficacy studies using stem cells offers a reliable platform for the drug discovery process. Advances made in the generation of induced pluripotent stem cells from normal or diseased tissue serves as a platform to perform drug screens aimed at developing cell-based therapies against conditions like Parkinson's disease and diabetes. This review discusses the application of stem cells and cancer stem cells in drug screening and their role in complementing, reducing, and replacing animal testing. In addition to this, target identification and major advances in the field of personalized medicine using induced pluripotent cells are also discussed.

Identification of triterpenes from milkweed (Asclepias syriaca).

PubMed

Háznagy-Radnai, Erzsébet; Wéber, Edit; Czigle, Szilvia; Máthé, Imre

2012-09-01

The chloroform extract of Asclepias syriaca stem were investigated. Three triterpenes were isolated by TLC, VLC, and preparative chromatography, and their structures established by one and two-dimensional NMR spectroscopy. Lupenyl acetate has been isolated for the first time from A. syriaca; this is thefirst representative of a triterpene bearing a lupane skeleton in this species. In addition, alpha-amyrin acetate and alpha-amyrin butyrate were isolated.

A microfluidic chaotic mixer platform for cancer stem cell immunocapture and release

NASA Astrophysics Data System (ADS)

Shaner, Sebastian Wesley

Isolation of exceedingly rare and ambiguous cells, like cancer stem cells (CSCs), from a pool of other abundant cells is a daunting task primarily due to the inadequately defined properties of such cells. With phenotypes of different CSCs fairly well-defined, immunocapturing of CSCs is a desirable cell-specific capture technique. A microfluidic device is a proven candidate that offers the platform for user-constrained microenvironments that can be optimized for small-scale volumetric flow experimentation. In this study, we show how a well-known passive micromixer design (staggered herringbone mixer - SHM) can be optimized to induce maximum chaotic mixing within antibody-laced microchannels and, ultimately, promote CSC capture. The device's (Cancer Stem Cell Capture Chip - CSC3 (TM)) principle design configuration is called: Single-Walled Staggered Herringbone (SWaSH). The CSC3 (TM) was constructed of a polydimethylsiloxane (PDMS) foundation and thinly coated with an alginate hydrogel derivatized with streptavidin. The results of our work showed that the non-stickiness of alginate and antigen-specific antibodies allowed for superb target-specific cell isolation and negligible non-specific cell binding. Future engineering design directions include developing new configurations (e.g. Staggered High-Low Herringbone (SHiLoH) and offset SHiLoH) to optimize microvortex generation within the microchannels. This study's qualitative and quantitative results can help stimulate progress into refinements in device design and prospective advancements in cancer stem cell isolation and more comprehensive single-cell and cluster analysis.

Skeletal muscle-derived interstitial progenitor cells (PICs) display stem cell properties, being clonogenic, self-renewing, and multi-potent in vitro and in vivo.

PubMed

Cottle, Beverley J; Lewis, Fiona C; Shone, Victoria; Ellison-Hughes, Georgina M

2017-07-04

The development of cellular therapies to treat muscle wastage with disease or age is paramount. Resident muscle satellite cells are not currently regarded as a viable cell source due to their limited migration and growth capability ex vivo. This study investigated the potential of muscle-derived PW1 + /Pax7 - interstitial progenitor cells (PICs) as a source of tissue-specific stem/progenitor cells with stem cell properties and multipotency. Sca-1 + /PW1 + PICs were identified on tissue sections from hind limb muscle of 21-day-old mice, isolated by magnetic-activated cell sorting (MACS) technology and their phenotype and characteristics assessed over time in culture. Green fluorescent protein (GFP)-labelled PICs were used to determine multipotency in vivo in a tumour formation assay. Isolated PICs expressed markers of pluripotency (Oct3/4, Sox2, and Nanog), were clonogenic, and self-renewing with >60 population doublings, and a population doubling time of 15.8 ± 2.9 h. PICs demonstrated an ability to generate both striated and smooth muscle, whilst also displaying the potential to differentiate into cell types of the three germ layers both in vitro and in vivo. Moreover, PICs did not form tumours in vivo. These findings open new avenues for a variety of solid tissue engineering and regeneration approaches, utilising a single multipotent stem cell type isolated from an easily accessible source such as skeletal muscle.

Isolation of canine mesenchymal stem cells from amniotic fluid and differentiation into hepatocyte-like cells.

PubMed

Choi, Seon-A; Choi, Hoon-Sung; Kim, Keun Jung; Lee, Dong-Soo; Lee, Ji Hey; Park, Jie Yeun; Kim, Eun Young; Li, Xiaoxia; Oh, Hyun-Yang; Lee, Dong-Seok; Kim, Min Kyu

2013-01-01

Recent findings have demonstrated that amniotic fluid cells are an interesting and potential source of mesenchymal stem cells (MSCs). In this study, we isolated MSCs from canine amniotic fluid and then characterized their multilineage differentiation ability. Canine amniotic fluid stem (cAFS) cells at passage 5 had a fibroblast-like morphology instead of forming colonies and were positive for pluripotent stem cell markers such as OCT4, NANOG, and SOX2. Flow cytometry analysis showed the expression of MSC surface markers CD44, CD29, and CD90 on the cAFS cells. In addition, these cells were cultured under conditions favorable for adipogenic, chondrogenic, and osteogenic induction. The results of this experiment confirmed the mesenchymal nature of cAFS cells and their multipotent potential. Interestingly, although the cells exhibited a fibroblast-like morphology after hepatogenic induction, reverse transcription-polymerase chain reaction revealed that the expression of several hepatic genes, such as albumin, tyrosine aminotransferase, and alpha-1 antiproteinase, increased following maturation and differentiation. These findings indicated that cAFS cells have functional properties similar to those of hepatocytes. Taken together, the results of our study demonstrated that cAFS cells with mesenchymal characteristics can be successfully isolated from canine amniotic fluid and possess functional properties characteristic of hepatocytes. The findings of our work suggest that cAFS cells have the potential to be a resource for cell-based therapies in a canine model of hepatic disease.

A Protocol for Decellularizing Mouse Cochleae for Inner Ear Tissue Engineering.

PubMed

Neal, Christopher A; Nelson-Brantley, Jennifer G; Detamore, Michael S; Staecker, Hinrich; Mellott, Adam J

2018-01-01

In mammals, mechanosensory hair cells that facilitate hearing lack the ability to regenerate, which has limited treatments for hearing loss. Current regenerative medicine strategies have focused on transplanting stem cells or genetic manipulation of surrounding support cells in the inner ear to encourage replacement of damaged stem cells to correct hearing loss. Yet, the extracellular matrix (ECM) may play a vital role in inducing and maintaining function of hair cells, and has not been well investigated. Using the cochlear ECM as a scaffold to grow adult stem cells may provide unique insights into how the composition and architecture of the extracellular environment aids cells in sustaining hearing function. Here we present a method for isolating and decellularizing cochleae from mice to use as scaffolds accepting perfused adult stem cells. In the current protocol, cochleae are isolated from euthanized mice, decellularized, and decalcified. Afterward, human Wharton's jelly cells (hWJCs) that were isolated from the umbilical cord were carefully perfused into each cochlea. The cochleae were used as bioreactors, and cells were cultured for 30 days before undergoing processing for analysis. Decellularized cochleae retained identifiable extracellular structures, but did not reveal the presence of cells or noticeable fragments of DNA. Cells perfused into the cochlea invaded most of the interior and exterior of the cochlea and grew without incident over a duration of 30 days. Thus, the current method can be used to study how cochlear ECM affects cell development and behavior.

Is Playing in the Pit Really the Pits?: Pain, Strength, Music Performance Anxiety, and Workplace Satisfaction in Professional Musicians in Stage, Pit, and Combined Stage/Pit Orchestras.

PubMed

Kenny, Dianna T; Driscoll, Tim; Ackermann, Bronwen J

2016-03-01

Typically, Australian orchestral musicians perform on stage, in an orchestra pit, or in a combination of both workplaces. This study explored a range of physical and mental health indicators in musicians who played in these different orchestra types to ascertain whether orchestra environment was a risk factor affecting musician wellbeing. Participants comprised 380 full-time orchestral musicians from the eight major state orchestras in Australia comprised of two dedicated pit orchestras, three stage-only symphonic orchestras, and three mixed stage/pit orchestras. Participants completed a physical assessment and a range of self-report measures assessing performance-related musculoskeletal disorders (PRMD), physical characteristics including strength and perceived exertion, and psychological health, including music performance anxiety (MPA), workplace satisfaction, and bullying. Physical characteristics and performance-related musculoskeletal profiles were similar for most factors on the detailed survey completed by orchestra members. The exceptions were that pit musicians demonstrated greater shoulder and elbow strength, while mixed-workload orchestra musicians had greater flexibility Significantly more exertion was reported by pit musicians when rehearsing and performing. Stage/pit musicians reported less physical exertion when performing in the pit compared with performing on stage. Severity of MPA was significantly greater in pit musicians than mixed orchestra musicians. Pit musicians also reported more frequent bullying and lower job satisfaction compared with stage musicians. There were few differences in the objective physical measures between musicians in the different orchestra types. However, pit musicians appear more psychologically vulnerable and less satisfied with their work than musicians from the other two orchestra types. The physical and psychological characteristics of musicians who perform in different orchestra types have not been adequately theorized or studied. We offer some preliminary thoughts that may account for the observed differences.

Development of an aversive Pavlovian-to-instrumental transfer task in rat

PubMed Central

Campese, Vincent; McCue, Margaret; Lázaro-Muñoz, Gabriel; LeDoux, Joseph E.; Cain, Christopher K.

2013-01-01

Pavlovian-to-instrumental transfer (PIT) is an effect whereby a classically conditioned stimulus (CS) enhances ongoing instrumental responding. PIT has been extensively studied with appetitive conditioning but barely at all with aversive conditioning. Although it's been argued that conditioned suppression is a form of aversive PIT, this effect is fundamentally different from appetitive PIT because the CS suppresses, instead of facilitates, responding. Five experiments investigated the importance of a variety of factors on aversive PIT in a rodent Sidman avoidance paradigm in which ongoing shuttling behavior (unsignaled active avoidance or USAA) was facilitated by an aversive CS. Experiment 1 demonstrated a basic PIT effect. Experiment 2 found that a moderate amount of USAA extinction produces the strongest PIT with shuttling rates best at around 2 responses per minute prior to the CS. Experiment 3 tested a protocol in which the USAA behavior was required to reach the 2-response per minute mark in order to trigger the CS presentation and found that this produced robust and reliable PIT. Experiment 4 found that the Pavlovian conditioning US intensity was not a major determinant of PIT strength. Experiment 5 demonstrated that if the CS and US were not explicitly paired during Pavlovian conditioning, PIT did not occur, showing that CS-US learning is required. Together, these studies demonstrate a robust, reliable and stable aversive PIT effect that is amenable to analysis of neural circuitry. PMID:24324417

Variation in the AvrSr35 effector determines Sr35 resistance against wheat stem rust race Ug99

USDA-ARS?s Scientific Manuscript database

Puccinia graminis f. sp. tritici (Pgt) causes wheat stem rust, a devastating fungal disease. The Sr35 resistance gene confers immunity against this pathogen’s most virulent races, including Ug99. We used the comparative whole genome sequencing of chemically mutagenized and natural Pgt isolates to id...

Rauniticine-allo-oxindole B and rauniticinic-allo acid B, new heteroyohimbine-type oxindole alkaloids from the stems of Malaysian Uncaria longiflora var. pteropoda.

PubMed

Salim, Fatimah; Ismail, Nor Hadiani; Awang, Khalijah; Ahmad, Rohaya

2011-08-04

Two new heteroyohimbine-type oxindole alkaloids, rauniticine-allo-oxindole B and rauniticinic-allo acid B, have been successfully isolated from the stems extract of Malaysian Uncaria longiflora var. pteropoda. The structures of the two new alkaloids were determined by spectroscopic analysis.

Cytology and Genetics of Sexual Incompatibility in Didymella rabiei

Treesearch

A. Dan Wilson; W.J. Kaiser

1995-01-01

Mating crosses in all possible combinations between 15 monoascosporic isolates of Didymella rabiei (Ascomycotina, Dothideales), derived from diseased chickpea stems collected at a single location in Genesee, Idaho, were prepared on sterile chickpea stem pieces incubated on moist sterile filter papers in glass petri dishes for 5-6 weeks at 10°C or in...

Janceolaroside A and janceoside A, two new compounds from the stems and roots of Jasminum lanceolarium.

PubMed

Lou, Lili; Han, Lingfei; Meng, Dali; Li, Ning; Li, Xian

2011-06-01

From the stems and roots of Jasminum lanceolarium Roxb., two new compounds, janceolaroside A and janceoside A, have been isolated along with three known compounds, (-)olivil 4'-O-beta-D-glucopyranoside, (+)-cycloolivil-6-O-beta-D-glucopyranoside and syringin. The structures of the new compounds were determined by spectroscopic methods.

First report of damping-off of dent corn seedlings caused by Pythium graminicola in Georgia

USDA-ARS?s Scientific Manuscript database

An unknown disease was observed on corn seedlings in commercial corn fields in Tift County, Georgia, in April 2015. Stems of corn seedlings were brown, water-soaked, soft, decayed, and broke off easily. Disease incidence ranged from 2 to 3%. A fungus-like organism was isolated from all infected stem...

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion.

PubMed

Burleigh, Thomas D; Gierke, Casey G; Fredj, Narjes; Boston, Penelope J

2014-06-05

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water.

Observation of Eye Pattern on Super-Resolution Near-Field Structure Disk with Write-Strategy Technique

NASA Astrophysics Data System (ADS)

Fuji, Hiroshi; Kikukawa, Takashi; Tominaga, Junji

2004-07-01

Pit-edge recording at a density of 150 nm pits and spaces is carried out on a super-resolution near-field structure (super-RENS) disk with a platinum oxide layer. Pits are recorded and read using a 635-nm-wavelength laser and an objective lens with a 0.6 numerical aperture. We arrange laser pulses to correctly record the pits on the disk by a write-strategy technique. The laser-pulse figure includes a unit time of 0.25 T and intensities of Pw1, Pw2 and Pw3. After recording pits of various lengths, the observation of an eye pattern is achieved despite a pit smaller than the resolution limit. Furthermore, the eye pattern maintains its shape even though other pits fill the adjacent tracks at a track density of 600 nm. The disk can be used as a pit-edge recording system through a write-strategy technique.

Copper Tube Pitting in Santa Fe Municipal Water Caused by Microbial Induced Corrosion

PubMed Central

Burleigh, Thomas D.; Gierke, Casey G.; Fredj, Narjes; Boston, Penelope J.

2014-01-01

Many copper water lines for municipal drinking water in Santa Fe, New Mexico USA, have developed pinhole leaks. The pitting matches the description of Type I pitting of copper, which has historically been attributed to water chemistry and to contaminants on the copper tubing surface. However, more recent studies attribute copper pitting to microbial induced corrosion (MIC). In order to test for microbes, the copper tubing was fixed in hexamethyldisilazane (HMDS), then the tops of the corrosion mounds were broken open, and the interior of the corrosion pits were examined with scanning electron microscopy (SEM). The analysis found that microbes resembling actinobacteria were deep inside the pits and wedged between the crystallographic planes of the corroded copper grains. The presence of actinobacteria confirms the possibility that the cause of this pitting corrosion was MIC. This observation provides better understanding and new methods for preventing the pitting of copper tubing in municipal water. PMID:28788679

Analysis on the stress corrosion crack inception based on pit shape and size of the FV520B tensile specimen

NASA Astrophysics Data System (ADS)

Xiang, Longhao; Pan, Juyi; Chen, Songying

2018-06-01

The influence of pit shape and size on local stress concentration in the tensile specimen and the stress corrosion cracks inception was studied by employing the element remove technique. The maximum stress located in the bottom of pit on FV520B tensile specimen. The location of maximum strain was near the mouth of the pit or the shoulder and plastic strain existed in this region. Stress concentration factor and plastic deformation on four different geometrical shape pits of hemisphere, semi-ellipsoid, bullet and butterfly were numerically investigated, respectively. The simulation results showed that butterfly pit got the biggest stress concentration factor. The plastic strain rate during pit growth was in the sensitivity range of stress corrosion cracks inception, indicating that stress corrosion cracks were more likely to nucleate near the pit tip or the shoulder.

Cancer stem cells in the development of liver cancer

PubMed Central

Yamashita, Taro; Wang, Xin Wei

2013-01-01

Liver cancer is an aggressive disease with a poor outcome. Several hepatic stem/progenitor markers are useful for isolating a subset of liver cells with stem cell features, known as cancer stem cells (CSCs). These cells are responsible for tumor relapse, metastasis, and chemoresistance. Liver CSCs dictate a hierarchical organization that is shared in both organogenesis and tumorigenesis. An increased understanding of the molecular signaling events that regulate cellular hierarchy and stemness, and success in defining key CSC-specific genes, have opened up new avenues to accelerate the development of novel diagnostic and treatment strategies. This Review highlights recent advances in understanding the pathogenesis of liver CSCs and discusses unanswered questions about the concept of liver CSCs. PMID:23635789

Loss of PiT-1 Results in Abnormal Endocytosis in the Yolk Sac Visceral Endoderm

PubMed Central

Wallingford, Mary C.; Giachelli, Cecilia M.

2014-01-01

PiT-1 protein is a transmembrane sodium-dependent phosphate (Pi) transporter. PiT-1 knock out (KO) embryos die from largely unknown causes by embryonic day (E) 12.5. We tested the hypothesis that PiT-1 is required for endocytosis in the embryonic yolk sac (YS) visceral endoderm (VE). Here we present data supporting that PiT-1 KO results in a YS remodeling defect and decreased endocytosis in the YS VE. The remodeling defect is not due to an upstream cardiomyocyte requirement for PiT-1, as SM22αCre-specific KO of PiT-1 in the developing heart and the YS mesodermal layer (ME) does not recapitulate the PiT-1 global KO phenotype. Furthermore, we find that high levels of PiT-1 protein localize to the YS VE apical membrane. Together these data support that PiT-1 is likely required in YS VE. During normal development maternal immunoglobulin (IgG) is endocytosed into YS VE and accumulates in the apical side of the VE in a specialized lysosome termed the apical vacuole (AV). We have identified a reduction in PiT-1 KO VE cell height and a striking loss of IgG accumulation in the PiT-1 KO VE. The endocytosis genes Tfeb, Lamtor2 and Snx2 are increased at the RNA level. Lysotracker Red staining reveals a loss of distinct AVs, and yolk sacs incubated ex vivo with phRODO Green Dextran for Endocytosis demonstrate a functional loss of endocytosis. As yolk sac endocytosis is controlled in part by microautophagy, but expression of LC3 had not been examined, we investigated LC3 expression during yolk sac development and found stage-specific LC3 RNA expression that is predominantly from the YS VE layer at E9.5. Normalized LC3-II protein levels are decreased in the PiT-1 KO YS, supporting a requirement for PiT-1 in autophagy in the YS. Therefore, we propose the novel idea that PiT-1 is central to the regulation of endocytosis and autophagy in the YS VE. PMID:25138534

Illuminating Anaerobic Microbial Community and Cooccurrence Patterns across a Quality Gradient in Chinese Liquor Fermentation Pit Muds

PubMed Central

Hu, Xiaolong; Du, Hai; Ren, Cong

2016-01-01

Fermentation pit mud, an important reservoir of diverse anaerobic microorganisms, is essential for Chinese strong-aroma liquor production. Pit mud quality, according to its sensory characteristics, can be divided into three grades: degraded, normal, and high quality. However, the relationship between pit mud microbial community and pit mud quality is poorly understood, as are microbial associations within the pit mud ecosystem. Here, microbial communities at these grades were compared using Illumina MiSeq sequencing of the variable region V4 of the 16S rRNA gene. Our results revealed that the pit mud microbial community was correlated with its quality and environmental factors. Species richness, biodiversity, and relative and/or absolute abundances of Clostridia, Clostridium kluyveri, Bacteroidia, and Methanobacteria significantly increased, with corresponding increases in levels of pH, NH4+, and available phosphorus, from degraded to high-quality pit muds, while levels of Lactobacillus, dissolved organic carbon, and lactate significantly decreased, with normal samples in between. Furthermore, 271 pairs of significant and robust correlations (cooccurrence and negative) were identified from 76 genera using network analysis. Thirteen hubs of cooccurrence patterns, mainly under the Clostridia, Bacteroidia, Methanobacteria, and Methanomicrobia, may play important roles in pit mud ecosystem stability, which may be destroyed with rapidly increased levels of lactic acid bacteria (Lactobacillus, Pediococcus, and Streptococcus). This study may help clarify the relationships among microbial community, environmental conditions, and pit mud quality, allow the improvement of pit mud quality by using bioaugmentation and controlling environmental factors, and shed more light on the ecological rules guiding community assembly in pit mud. PMID:26896127

Isolation and culture of human multipotent stromal cells from the pancreas.

PubMed

Seeberger, Karen L; Eshpeter, Alana; Korbutt, Gregory S

2011-01-01

Mesenchymal stem cells, also termed multipotent mesenchymal stromal cells (MSCs), can be isolated from most adult tissues. Although the exact origin of MSCs expanded from the human pancreas has not been resolved, we have developed protocols to isolate and expand MSCs from human pancreatic tissue that remains after islet procurement. Similar to techniques used to isolate MSCs from bone marrow, pancreatic MSCs are isolated based on their cell adherence, expression of several cell surface antigens, and multilineage differentiation. The protocols for isolating, characterizing, and differentiating MSCs from the pancreas are presented in this chapter.

Alloy Microstructure Dictates Corrosion Modes in THA Modular Junctions.

PubMed

Pourzal, Robin; Hall, Deborah J; Ehrich, Jonas; McCarthy, Stephanie M; Mathew, Mathew T; Jacobs, Joshua J; Urban, Robert M

2017-12-01

Adverse local tissue reactions (ALTRs) triggered by corrosion products from modular taper junctions are a known cause of premature THA failure. CoCrMo devices are of particular concern because cobalt ions and chromium-orthophosphates were shown to be linked to ALTRs, even in metal-on-polyethylene THAs. The most common categories of CoCrMo alloy are cast and wrought alloy, which exhibit fundamental microstructural differences in terms of grain size and hard phases. The impact of implant alloy microstructure on the occurring modes of corrosion and subsequent metal ion release is not well understood. The purpose of this study was to determine whether (1) the microstructure of cast CoCrMo alloy varies broadly between manufacturers and can dictate specific corrosion modes; and whether (2) the microstructure of wrought CoCrMo alloy is more consistent between manufacturers and has low implications on the alloy's corrosion behavior. The alloy microstructure of four femoral-stem and three femoral-head designs from four manufacturers was metallographically and electrochemically characterized. Three stem designs were made from cast alloy; all three head designs and one stem design were made from wrought alloy. Alloy samples were sectioned from retrieved components and then polished and etched to visualize grain structure and hard phases such as carbides (eg, M 23 C 6 ) or intermetallic phases (eg, σ phase). Potentiodynamic polarization (PDP) tests were conducted to determine the corrosion potential (E corr ), corrosion current density (I corr ), and pitting potential (E pit ) for each alloy. Four devices were tested within each group, and each measurement was repeated three times to ensure repeatable results. Differences in PDP metrics between manufacturers and between alloys with different hard phase contents were compared using one-way analysis of variance and independent-sample t-tests. Microstructural features such as twin boundaries and slip bands as well as corrosion damage features were viewed and qualitatively assessed in a scanning electron microscope. We found broad variability in implant alloy microstructure for both cast and wrought alloy between manufacturers, but also within the same implant design. In cast alloys, there was no difference in PDP metrics between manufacturers. However, coarse hard phases and clusters of hard phases (mainly intermetallic phases) were associated with severe phase boundary corrosion and pitting corrosion. Furthermore, cast alloys with hard phases had a lower E pit than those without (0.46 V, SD 0.042; 0.53 V, SD 0.03, respectively; p = 0.015). Wrought alloys exhibited either no hard phases or numerous carbides (M 23 C 6 ). However, the corrosion behavior was mainly affected by lattice defects and banded structures indicative of segregations that appear to be introduced during bar stock manufacturing. Alloys with banding had a lower E corr (p = 0.008) and higher I corr (p = 0.028) than alloys without banding (-0.76 V, SD 0.003; -0.73 V, SD 0.009; and 1.14 × 10 -4 mA/cm 2 , SD 1.47 × 10 -5 ; 5.2 × 10 -5 mA/cm 2 , SD 2.57 × 10 -5 , respectively). Alloys with carbides had a slightly higher E corr (p = 0.046) than those without (-0.755 V, SD 0.005; -0.761 V, SD 0.004); however, alloys with carbides exhibited more severe corrosion damage as a result of phase boundary corrosion, hard phase detachment, and subsequent local crevice corrosion. The observed variability in CoCrMo alloy microstructure of both cast and wrought components in this study appears to be an important issue to address, perhaps through better standards, to minimize in vivo corrosion. The finding of the banded structures within wrought alloys is especially concerning because it unfavorably influences the corrosion behavior independent of the manufacturer. The findings suggest that a homogeneous alloy microstructure with a minimal hard phase fraction exhibits more favorable corrosion behavior within the in vivo environment of modular taper junctions, thus lowering metal ion release and subsequently the risk of ALTRs to corrosion products. Also, the question arises if hard phases fulfill a useful purpose in metal-on-polyethylene bearings, because they may come with a higher risk of phase boundary corrosion and pitting corrosion and the benefit they provide by adding strength is not needed (unlike in metal-on-metal bearings). Implant failure resulting from corrosion processes within modular junctions is a major concern in THA. Our results suggest that implant alloy microstructure is not sufficiently standardized and may also dictate specific corrosion modes and subsequent metal ion release.