Electrolytes for Use in High Energy Lithium-ion Batteries with Wide Operating Temperature Range

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Ratnakumar, B. V.; West, W. C.; Whitcanack, L. D.; Huang, C.; Soler, J.; Krause, F. C.

2012-01-01

Met programmatic milestones for program. Demonstrated improved performance with wide operating temperature electrolytes containing ester co-solvents (i.e., methyl butyrate) containing electrolyte additives in A123 prototype cells: Previously demonstrated excellent low temperature performance, including 11C rates at -30 C and the ability to perform well down to -60 C. Excellent cycle life at room temperature has been displayed, with over 5,000 cycles being demonstrated. Good high temperature cycle life performance has also been achieved. Demonstrated improved performance with methyl propionate-containing electrolytes in large capacity prototype cells: Demonstrated the wide operating temperature range capability in large cells (12 Ah), successfully scaling up technology from 0.25 Ah size cells. Demonstrated improved performance at low temperature and good cycle life at 40 C with methyl propionate-based electrolyte containing increasing FEC content and the use of LiBOB as an additive. Utilized three-electrode cells to investigate the electrochemical characteristics of high voltage systems coupled with wide operating temperature range electrolytes: From Tafel polarization measurements on each electrode, it is evident the NMC-based cathode displays poor lithium kinetics (being the limiting electrode). The MB-based formulations containing LiBOB delivered the best rate capability at low temperature, which is attributed to improved cathode kinetics. Whereas, the use of lithium oxalate as an additive lead to the highest reversible capacity and lower irreversible losses.

Claims for Solar Cell Efficiency Put to Test at NREL | News | NREL

Science.gov Websites

cell. The record was confirmed by AIST. NREL and the other the laboratories testing these high containers with zero oxygen and zero water vapor, and were sealed in chambers that maintained zero oxygen , zero water," Emery said. "As soon as we opened the containers the cells started degrading, so

The use of Electrolyte Additives to Improve the High Temperature Resilience of Li-Ion Cells

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Lucht, B. L.; Ratnakumar, Bugga V.

2007-01-01

This viewgraph presentation reviews the use of electrolyte additves to improve the resillience of Lithium ion cells. The objective of this work is to identify lithium-ion electrolytes, which will lead to Li-ion cells with a wide operational temperature range (+60 to -60 C), and to develop Li-ion electrolytes which result in cells that display improved high temperature resilience. Significant improvement in the high temperature resilience of Li-ion cells containing these additives was observed, with the most dramatic benefit being displayed by addition of DMAc. When the electrochemical properties of the individual electrodes were analyzed, the degradation of the anode kinetics was slowed most dramatically by the incorporation of DMAc into the electrolytes. Whereas, the greatest retention in the cathode kinetics was observed in the cell containing the electrolyte with VC added.

Single-cell isolation by a modular single-cell pipette for RNA-sequencing.

PubMed

Zhang, Kai; Gao, Min; Chong, Zechen; Li, Ying; Han, Xin; Chen, Rui; Qin, Lidong

2016-11-29

Single-cell transcriptome sequencing highly requires a convenient and reliable method to rapidly isolate a live cell into a specific container such as a PCR tube. Here, we report a modular single-cell pipette (mSCP) consisting of three modular components, a SCP-Tip, an air-displacement pipette (ADP), and ADP-Tips, that can be easily assembled, disassembled, and reassembled. By assembling the SCP-Tip containing a hydrodynamic trap, the mSCP can isolate single cells from 5-10 cells per μL of cell suspension. The mSCP is compatible with microscopic identification of captured single cells to finally achieve 100% single-cell isolation efficiency. The isolated live single cells are in submicroliter volumes and well suitable for single-cell PCR analysis and RNA-sequencing. The mSCP possesses merits of convenience, rapidness, and high efficiency, making it a powerful tool to isolate single cells for transcriptome analysis.

Development of a Sox2 reporter system modeling cellular heterogeneity in glioma.

PubMed

Stoltz, Kevin; Sinyuk, Maksim; Hale, James S; Wu, Qiulian; Otvos, Balint; Walker, Kiera; Vasanji, Amit; Rich, Jeremy N; Hjelmeland, Anita B; Lathia, Justin D

2015-03-01

Malignant gliomas are complex systems containing a number of factors that drive tumor initiation and progression, including genetic aberrations that lead to extensive cellular heterogeneity within the neoplastic compartment. Mouse models recapitulate these genetic aberrations, but readily observable heterogeneity remains challenging. To interrogate cellular heterogeneity in mouse glioma models, we utilized a replication-competent avian sarcoma-leukosis virus long terminal repeat with splice acceptor/tumor virus A (RCAS-tva) system to generate spontaneous mouse gliomas that contained a Sox2-enhanced green fluorescent protein (EGFP) reporter. Glial fibrillary acidic protein-tva mice were crossed with Sox2-EGFP mice, and tumors were initiated that contained a subpopulation of Sox2-EGFP-high cells enriched for tumor-initiating cell properties such as self-renewal, multilineage differentiation potential, and perivascular localization. Following implantation into recipient mice, Sox2-EGFP-high cells generated tumors containing Sox2-EGFP-high and Sox2-EGFP-low cells. Kinomic analysis of Sox2-EGFP-high cells revealed activation of known glioma signaling pathways that are strongly correlated with patient survival including platelet-derived growth factor receptor beta, phosphoinositide-3 kinase, and vascular endothelial growth factor. Our functional analysis identified active feline sarcoma (Fes) signaling in Sox2-EGFP-high cells. Fes negatively correlated with glioma patient survival and was coexpressed with Sox2-positive cells in glioma xenografts and primary patient-derived tissue. Our RCAS-tva/Sox2-EGFP model will empower closer examination of cellular heterogeneity and will be useful for identifying novel glioma pathways as well as testing preclinical treatment efficacy. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Bladder cancer exosomes contain EDIL-3/Del1 and facilitate cancer progression.

PubMed

Beckham, Carla J; Olsen, Jayme; Yin, Peng-Nien; Wu, Chia-Hao; Ting, Huei-Ju; Hagen, Fred K; Scosyrev, Emelian; Messing, Edward M; Lee, Yi-Fen

2014-08-01

High grade bladder cancer is an extremely aggressive malignancy associated with high rates of morbidity and mortality. Understanding how exosomes may affect bladder cancer progression could reveal novel therapeutic targets. Exosomes derived from human bladder cancer cell lines and the urine of patients with high grade bladder cancer were assessed for the ability to promote cancer progression in standard assays. Exosomes purified from the high grade bladder cancer cell line TCC-SUP and the nonmalignant urothelial cell line SV-HUC were submitted for mass spectrometry analysis. EDIL-3 was identified and selected for further analysis. Western blot was done to determine EDIL-3 levels in urinary exosomes from patients with high grade bladder cancer. shRNA gene knockdown and recombinant EDIL-3 were applied to study EDIL-3 function. Exosomes isolated from high grade bladder cancer cells and the urine of patients with high grade bladder cancer promoted angiogenesis and migration of bladder cancer cells and endothelial cells. We silenced EDIL-3 expression and found that shEDIL-3 exosomes did not facilitate angiogenesis, and urothelial and endothelial cell migration. Moreover, exosomes purified from the urine of patients with high grade bladder cancer contained significantly higher EDIL-3 levels than exosomes from the urine of healthy controls. EDIL-3 activated epidermal growth factor receptor signaling while blockade of epidermal growth factor receptor signaling abrogated this EDIL-3 induced bladder cell migration. Exosomes derived from the urine of patients with bladder cancer contains bioactive molecules such as EDIL-3. Identifying these components and their associated oncogenic pathways could lead to novel therapeutic targets and treatment strategies. Copyright © 2014 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

POLYSACCHARIDES FROM CELL WALLS OF AUREOBASIDIUM (PULLULARIA) PULLULANS. PART I. GLUCANS,

DTIC Science & Technology

The cell wall of Aureobasidium (Pullularia) pullulans contains three types of beta - glucan . One, extracted with dilute alkali, has a linear backbone...insoluble in dilute alkali contains a highly crystalline, essentially linear linked glucan and an amorphous glucan . (Author)

Electron energy loss spectroscopy techniques for the study of microbial chromium(VI) reduction

NASA Technical Reports Server (NTRS)

Daulton, Tyrone L.; Little, Brenda J.; Lowe, Kristine; Jones-Meehan, Joanne

2002-01-01

Electron energy loss spectroscopy (EELS) techniques were used to determine oxidation state, at high spatial resolution, of chromium associated with the metal-reducing bacteria, Shewanella oneidensis, in anaerobic cultures containing Cr(VI)O4(2-). These techniques were applied to fixed cells examined in thin section by conventional transmission electron microscopy (TEM) as well as unfixed, hydrated bacteria examined by environmental cell (EC)-TEM. Two distinct populations of bacteria were observed by TEM: bacteria exhibiting low image contrast and bacteria exhibiting high contrast in their cell membrane (or boundary) structure which was often encrusted with high-contrast precipitates. Measurements by EELS demonstrated that cell boundaries became saturated with low concentrations of Cr and the precipitates encrusting bacterial cells contained a reduced form of Cr in oxidation state + 3 or lower.

Dll4-containing exosomes induce capillary sprout retraction in a 3D microenvironment

PubMed Central

Sharghi-Namini, Soheila; Tan, Evan; Ong, Lee-Ling Sharon; Ge, Ruowen; Asada, H. Harry

2014-01-01

Delta-like 4 (Dll4), a membrane-bound Notch ligand, plays a fundamental role in vascular development and angiogenesis. Dll4 is highly expressed in capillary endothelial tip cells and is involved in suppressing neighboring stalk cells to become tip cells during angiogenesis. Dll4-Notch signaling is mediated either by direct cell-cell contact or by Dll4-containing exosomes from a distance. However, whether Dll4-containing exosomes influence tip cells of existing capillaries is unknown. Using a 3D microfluidic device and time-lapse confocal microscopy, we show here for the first time that Dll4-containing exosomes causes tip cells to lose their filopodia and trigger capillary sprout retraction in collagen matrix. We demonstrate that Dll4 exosomes can freely travel through 3D collagen matrix and transfer Dll4 protein to distant tip cells. Upon reaching endothelial sprout, it causes filopodia and tip cell retraction. Continuous application of Dll4 exosomes from a distance lead to significant reduction of sprout formation. This effect correlates with Notch signaling activation upon Dll4-containing exosome interaction with recipient endothelial cells. Furthermore, we show that Dll4-containing exosomes increase endothelial cell motility while suppressing their proliferation. These data revealed novel functions of Dll4 in angiogenesis through exosomes. PMID:24504253

Enzymatic cleavage of uracil-containing single-stranded DNA linkers for the efficient release of affinity-selected circulating tumor cells.

PubMed

Nair, Soumya V; Witek, Małgorzata A; Jackson, Joshua M; Lindell, Maria A M; Hunsucker, Sally A; Sapp, Travis; Perry, Caroline E; Hupert, Mateusz L; Bae-Jump, Victoria; Gehrig, Paola A; Wysham, Weiya Z; Armistead, Paul M; Voorhees, Peter; Soper, Steven A

2015-02-21

We report a novel strategy to enzymatically release affinity-selected cells, such as circulating tumor cells (CTCs), from surfaces with high efficiency (∼90%) while maintaining cell viability (>85%). The strategy utilizes single-stranded DNAs that link a capture antibody to the surfaces of a CTC selection device. The DNA linkers contain a uracil residue that can be cleaved.

Rabbit embryonic stem cell lines derived from fertilized, parthenogenetic or somatic cell nuclear transfer embryos

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

Fang, Zhen F.; Gai, Hui; Huang, You Z.

2006-11-01

Embryonic stem cells were isolated from rabbit blastocysts derived from fertilization (conventional rbES cells), parthenogenesis (pES cells) and nuclear transfer (ntES cells), and propagated in a serum-free culture system. Rabbit ES (rbES) cells proliferated for a prolonged time in an undifferentiated state and maintained a normal karyotype. These cells grew in a monolayer with a high nuclear/cytoplasm ratio and contained a high level of alkaline phosphate activity. In addition, rbES cells expressed the pluripotent marker Oct-4, as well as EBAF2, FGF4, TDGF1, but not antigens recognized by antibodies against SSEA-1, SSEA-3, SSEA-4, TRA-1-10 and TRA-1-81. All 3 types of ESmore » cells formed embryoid bodies and generated teratoma that contained tissue types of all three germ layers. rbES cells exhibited a high cloning efficiency, were genetically modified readily and were used as nuclear donors to generate a viable rabbit through somatic cell nuclear transfer. In combination with genetic engineering, the ES cell technology should facilitate the creation of new rabbit lines.« less

Single-Cell Phenotypic Characterization of Human Pituitary GHomas and Non-Functioning Adenomas Based on Hormone Content and Calcium Responses to Hypothalamic Releasing Hormones

PubMed Central

Senovilla, Laura; Núñez, Lucía; de Campos, José María; de Luis, Daniel A.; Romero, Enrique; García-Sancho, Javier; Villalobos, Carlos

2015-01-01

Human pituitary tumors are generally benign adenomas causing considerable morbidity due to excess hormone secretion, hypopituitarism, and other tumor mass effects. Pituitary tumors are highly heterogeneous and difficult to type, often containing mixed cell phenotypes. We have used calcium imaging followed by multiple immunocytochemistry to type growth hormone secreting (GHomas) and non-functioning pituitary adenomas (NFPAs). Individual cells were typed for stored hormones and calcium responses to classic hypothalamic releasing hormones (HRHs). We found that GHomas contained growth hormone cells either lacking responses to HRHs or responding to all four HRHs. However, most GHoma cells were polyhormonal cells responsive to both thyrotropin-releasing hormone (TRH) and GH-releasing hormone. NFPAs were also highly heterogeneous. Some of them contained ACTH cells lacking responses to HRHs or polyhormonal gonadotropes responsive to LHRH and TRH. However, most NFPAs were made of cells storing no hormone and responded only to TRH. These results may provide new insights on the ontogeny of GHomas and NFPAs. PMID:26106585

Accumulation of senescent cells in mitotic tissue of aging primates.

PubMed

Jeyapalan, Jessie C; Ferreira, Mark; Sedivy, John M; Herbig, Utz

2007-01-01

Cellular senescence, a stress induced growth arrest of somatic cells, was first documented in cell cultures over 40 years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal fibroblasts, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal fibroblasts containing damaged telomeres reaches a value of over 15% of total fibroblasts, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing factor to aging and age related pathology and provides further evidence that cellular senescence is a physiological event.

Physics of grain boundaries in polycrystalline photovoltaic semiconductors

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

Yan, Yanfa, E-mail: yanfa.yan@utoledo.edu; Yin, Wan-Jian; Wu, Yelong

2015-03-21

Thin-film solar cells based on polycrystalline Cu(In,Ga)Se{sub 2} (CIGS) and CdTe photovoltaic semiconductors have reached remarkable laboratory efficiencies. It is surprising that these thin-film polycrystalline solar cells can reach such high efficiencies despite containing a high density of grain boundaries (GBs), which would seem likely to be nonradiative recombination centers for photo-generated carriers. In this paper, we review our atomistic theoretical understanding of the physics of grain boundaries in CIGS and CdTe absorbers. We show that intrinsic GBs with dislocation cores exhibit deep gap states in both CIGS and CdTe. However, in each solar cell device, the GBs can bemore » chemically modified to improve their photovoltaic properties. In CIGS cells, GBs are found to be Cu-rich and contain O impurities. Density-functional theory calculations reveal that such chemical changes within GBs can remove most of the unwanted gap states. In CdTe cells, GBs are found to contain a high concentration of Cl atoms. Cl atoms donate electrons, creating n-type GBs between p-type CdTe grains, forming local p-n-p junctions along GBs. This leads to enhanced current collections. Therefore, chemical modification of GBs allows for high efficiency polycrystalline CIGS and CdTe thin-film solar cells.« less

Physics of grain boundaries in polycrystalline photovoltaic semiconductors

DOE PAGES

Yan, Yanfa; Yin, Wan-Jian; Wu, Yelong; ...

2015-03-16

Thin-film solar cells based on polycrystalline Cu(In,Ga)Se 2 (CIGS) and CdTe photovoltaic semiconductors have reached remarkable laboratory efficiencies. It is surprising that these thin-film polycrystalline solar cells can reach such high efficiencies despite containing a high density of grain boundaries (GBs), which would seem likely to be nonradiative recombination centers for photo-generated carriers. In this study, we review our atomistic theoretical understanding of the physics of grain boundaries in CIGS and CdTe absorbers. We show that intrinsic GBs with dislocation cores exhibit deep gap states in both CIGS and CdTe. Although, in each solar cell device, the GBs can bemore » chemically modified to improve their photovoltaic properties. In CIGS cells, GBs are found to be Cu-rich and contain O impurities. Density-functional theory calculations reveal that such chemical changes within GBs can remove most of the unwanted gap states. In CdTe cells, GBs are found to contain a high concentration of Cl atoms. Cl atoms donate electrons, creating n-type GBs between p-type CdTe grains, forming local p-n-p junctions along GBs. This leads to enhanced current collections. In conclusion, chemical modification of GBs allows for high efficiency polycrystalline CIGS and CdTe thin-film solar cells.« less

Massively parallel nanowell-based single-cell gene expression profiling.

PubMed

Goldstein, Leonard D; Chen, Ying-Jiun Jasmine; Dunne, Jude; Mir, Alain; Hubschle, Hermann; Guillory, Joseph; Yuan, Wenlin; Zhang, Jingli; Stinson, Jeremy; Jaiswal, Bijay; Pahuja, Kanika Bajaj; Mann, Ishminder; Schaal, Thomas; Chan, Leo; Anandakrishnan, Sangeetha; Lin, Chun-Wah; Espinoza, Patricio; Husain, Syed; Shapiro, Harris; Swaminathan, Karthikeyan; Wei, Sherry; Srinivasan, Maithreyan; Seshagiri, Somasekar; Modrusan, Zora

2017-07-07

Technological advances have enabled transcriptome characterization of cell types at the single-cell level providing new biological insights. New methods that enable simple yet high-throughput single-cell expression profiling are highly desirable. Here we report a novel nanowell-based single-cell RNA sequencing system, ICELL8, which enables processing of thousands of cells per sample. The system employs a 5,184-nanowell-containing microchip to capture ~1,300 single cells and process them. Each nanowell contains preprinted oligonucleotides encoding poly-d(T), a unique well barcode, and a unique molecular identifier. The ICELL8 system uses imaging software to identify nanowells containing viable single cells and only wells with single cells are processed into sequencing libraries. Here, we report the performance and utility of ICELL8 using samples of increasing complexity from cultured cells to mouse solid tissue samples. Our assessment of the system to discriminate between mixed human and mouse cells showed that ICELL8 has a low cell multiplet rate (< 3%) and low cross-cell contamination. We characterized single-cell transcriptomes of more than a thousand cultured human and mouse cells as well as 468 mouse pancreatic islets cells. We were able to identify distinct cell types in pancreatic islets, including alpha, beta, delta and gamma cells. Overall, ICELL8 provides efficient and cost-effective single-cell expression profiling of thousands of cells, allowing researchers to decipher single-cell transcriptomes within complex biological samples.

Cobalt doped lanthanum chromite material suitable for high temperature use

DOEpatents

Ruka, R.J.

1986-12-23

A high temperature, solid electrolyte electrochemical cell, subject to thermal cycling temperatures of between about 25 C and about 1,200 C, capable of electronic interconnection to at least one other electrochemical cell and capable of operating in an environment containing oxygen and a fuel, is made; where the cell has a first and second electrode with solid electrolyte between them, where an improved interconnect material is applied along a portion of a supporting electrode; where the interconnect is made of a chemically modified lanthanum chromite, containing cobalt as the important additive, which interconnect allows for adjustment of the thermal expansion of the interconnect material to more nearly match that of other cell components, such as zirconia electrolyte, and is stable in oxygen containing atmospheres such as air and in fuel environments. 2 figs.

Liposome-based delivery of a boron-containing cholesteryl ester for high-LET particle-induced damage of prostate cancer cells: a boron neutron capture therapy study.

PubMed

Gifford, Ian; Vreeland, Wyatt; Grdanovska, Slavica; Burgett, Eric; Kalinich, John; Vergara, Vernieda; Wang, C-K Chris; Maimon, Eric; Poster, Dianne; Al-Sheikhly, Mohamad

2014-06-01

The efficacy of a boron-containing cholesteryl ester compound (BCH) as a boron neutron capture therapy (BNCT) agent for the targeted irradiation of PC-3 human prostate cancer cells was examined. Liposome-based delivery of BCH was quantified with inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC). Cytotoxicity of the BCH-containing liposomes was evaluated with neutral red, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), and lactate dehydrogenase assays. Colony formation assays were utilized to evaluate the decrease in cell survival due to high-linear energy transfer (LET) particles resulting from (10)B thermal neutron capture. BCH delivery by means of encapsulation in a lipid bilayer resulted in a boron uptake of 35.2 ± 4.3 μg/10(9) cells, with minimal cytotoxic effects. PC-3 cells treated with BCH and exposed to a 9.4 × 10(11) n/cm(2) thermal neutron fluence yielded a 20-25% decrease in clonogenic capacity. The decreased survival is attributed to the generation of high-LET α particles and (7)Li nuclei that deposit energy in densely ionizing radiation tracks. Liposome-based delivery of BCH is capable of introducing sufficient boron to PC-3 cells for BNCT. High-LET α particles and (7)Li nuclei generated from (10)B thermal neutron capture significantly decrease colony formation ability in the targeted PC-3 cells.

Molecular evidence of viral DNA in non-small cell lung cancer and non-neoplastic lung

DOE PAGES

Robinson, Lary A.; Jaing, Crystal J.; Campbell, Christine Pierce; ...

2016-07-14

Although ~20% of human cancers are caused by microorganisms, only suspicion exists for a microbial cause of lung cancer. Potential infectious agents were investigated in non-small cell lung cancer (NSCLC) and non-neoplastic lung. Seventy NSCLC tumours (33 squamous cell carcinomas, 17 adenocarcinomas, 10 adenocarcinomas with lepidic spread, and 10 oligometastases) and 10 non-neoplastic lung specimens were evaluated for molecular evidence of microorganisms. Tissues were subjected to the Lawrence Livermore Microbial Detection Array, an oncovirus panel of the International Agency for Research on Cancer, and human papillomavirus (HPV) genotyping. Associations were examined between microbial prevalence, clinical characteristics, and p16 and EGFRmore » expression. Retroviral DNA was observed in 85% squamous cell carcinomas, 47% adenocarcinomas, and 10% adenocarcinomas with lepidic spread. Human papillomavirus DNA was found in 69% of squamous cell carcinomas with 30% containing high-risk HPV types. No significant viral DNA was detected in non-neoplastic lung. Patients with tumours containing viral DNA experienced improved long-term survival compared with patients with viral DNA-negative tumours. Lastly, most squamous cell carcinomas and adenocarcinomas contained retroviral DNA and one-third of squamous cell carcinomas contained high-risk HPV DNA. Viral DNA was absent in non-neoplastic lung. Trial results encourage further study of the viral contribution to lung carcinogenesis.« less

Molecular evidence of viral DNA in non-small cell lung cancer and non-neoplastic lung

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

Robinson, Lary A.; Jaing, Crystal J.; Campbell, Christine Pierce

Although ~20% of human cancers are caused by microorganisms, only suspicion exists for a microbial cause of lung cancer. Potential infectious agents were investigated in non-small cell lung cancer (NSCLC) and non-neoplastic lung. Seventy NSCLC tumours (33 squamous cell carcinomas, 17 adenocarcinomas, 10 adenocarcinomas with lepidic spread, and 10 oligometastases) and 10 non-neoplastic lung specimens were evaluated for molecular evidence of microorganisms. Tissues were subjected to the Lawrence Livermore Microbial Detection Array, an oncovirus panel of the International Agency for Research on Cancer, and human papillomavirus (HPV) genotyping. Associations were examined between microbial prevalence, clinical characteristics, and p16 and EGFRmore » expression. Retroviral DNA was observed in 85% squamous cell carcinomas, 47% adenocarcinomas, and 10% adenocarcinomas with lepidic spread. Human papillomavirus DNA was found in 69% of squamous cell carcinomas with 30% containing high-risk HPV types. No significant viral DNA was detected in non-neoplastic lung. Patients with tumours containing viral DNA experienced improved long-term survival compared with patients with viral DNA-negative tumours. Lastly, most squamous cell carcinomas and adenocarcinomas contained retroviral DNA and one-third of squamous cell carcinomas contained high-risk HPV DNA. Viral DNA was absent in non-neoplastic lung. Trial results encourage further study of the viral contribution to lung carcinogenesis.« less

Hematological changes in nephritis in poultry induced by diets high in protein, high in calcium, containing urea, or deficient in vitamin A.

PubMed

Chandra, M; Singh, B; Singh, N; Ahuja, S P

1984-04-01

Nephritis was induced in 300, 18-day-old male Arbor Acre broiler chicks by feeding diets high (42.28%) in protein, high (3.27%) in calcium, containing urea (5%), or deficient in vitamin A. Various hematological parameters were studied at weekly intervals. Normocytic-normochromic anemia, characterized by a decrease in total erythrocyte counts, hemoglobin, packed cell volume, and an increase in erythrocyte sedimentation rate, was evident in the birds kept on diets high in protein, high in calcium, or deficient in vitamin A. Increased total erythrocytes, hemoglobin packed cell volume, and erythrocyte sedimentation rate was observed in birds fed urea. Differential leucocyte counts revealed lymphopenia, heterophilia and monocytosis in birds kept on diets high in protein, containing urea, or deficient in vitamin A. However, lymphocytosis, heteropenia , and monocytosis were recorded in birds fed the high calcium diet.

Compressed gas fuel storage system

DOEpatents

Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

2001-01-01

A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

Biosignatures of Kerala red rain cells: Implications in understanding their origin

NASA Astrophysics Data System (ADS)

Gangappa, R.; Thomas, M.; Hogg, S.

2013-09-01

The red rain that fell over Kerala, southern India (2001-2012) was characterised by the red pigmented particles. Earlier proposal claiming that these are known algal bloom blown from trees (Sampath et al, 2001; DiGregorio, 2007) has been studied by us and disproved. Also, further investigation reporting their extraordinary properties including a suggestion that they lack DNA (Louis and Kumar 2003; 2006; 2008) has been invalidated (Gangappa and Hogg, 2013). However, their claim regarding the growth and replication of these cells at 300ºC needs more investigation if it is to gain acceptance. Current study provide evidences regarding the biological properties of Kerala red rain cells to gain insights into environmental conditions from which they may have originated. Combined with various research strategies and high resolution instruments, we have demonstrated the following interesting properties of Kerala red rain cells: (1) unusually thick external envelope enclosing the central core; (2)stability of red pigment at temperatures about 100ºC and pH variations; (3) absence of eukaryotic ultrastructures; (4) possible replication at 121ºC with nanostructures (possible daughter cells) having similar morphological features inside the large mother cells at such high temperature. They contain high percentage of carbon, iron, silicon and aluminum and often enclosed in a silicon rich biofilms. Further investigation shows that the positive detection of DNA in these cells was possible only after the complete removal of red pigment, thereby providing an explanation for the negative outcome of earlier studies in this regard. Moreover, evidences are shown to support that these cells contain high amounts of UV absorbing compounds, porphyrin complexes and possible scytonemin. Kerala red rain cells may prove to be polyextermophiles belonging to prokaryotes and may have possibly originated from the environment containing above mentioned chemical elements, high energy UV exposure and possible high temperatures. This may be of high interest and red rain cells can be viewed as a possible candidate in future Astrobiological investigations.

High Efficiency Latency and Activation of Herpes Simplex Virus in Human Cells

NASA Astrophysics Data System (ADS)

Wigdahl, Brian L.; Scheck, Adrienne C.; de Clercq, Erik; Rapp, Fred

1982-09-01

Herpes simplex virus (HSV) exists in humans in a latent form that can be activated. To characterize the molecular basis of the cell-virus interactions and to analyze the state of the latent HSV genome, an in vitro model system was established. In this system a large fraction of the latently infected cells contain an HSV genome that can be activated. Cell survival was reduced minimally after repression of high multiplicity HSV type 1 (HSV-1) infection of human fibroblast cells with (E)-5-(2-bromovinyl)-2'-deoxyuridine in combination with human leukocyte interferon (IFN-α ). A minimum of 1 to 3 percent of the surviving cells contained an HSV genome that could be activated either by human cytomegalovirus superinfection or reduction in incubation temperature.

Flow cytometry of human embryonic kidney cells: A light scattering approach

NASA Technical Reports Server (NTRS)

Kunze, M. E.; Goolsby, C. L.; Todd, P. W.; Morrison, D. R.; Lewis, M. L.

1985-01-01

The mammalian kidney contains cells that transport water, convert vitamin D to active forms, synthesize hormones such a renin and erythropoietin, and produce enzymes such as urokinase, a plasminogen activator. Several of these functions are maintained by human embryonic kidney cells (HEK) cultivated in vitro. Biochemical study of these functions in their individual cell types in vitro requires purified populations of cells. Light-scattering activated cell sorting (LACS) was explored as a means of achieving such purifications. It was found that HEK cells at the first 1 to 5 passages in culture were heterogeneous with respect to 2-parameter light scattering intensity distribution, in which combined measurements included forward angle scattering (2.5 to 19 deg), 90 deg scattering, and time-of-flight size measurements. Size was measured at a resolution of 0.15 microns/channel in 256 channels using pulse-height independent pulse-width measurements. Two-parameter distributions combining these measurements were obtained for HEK cell subpopulations that had been purified by microgravity electrophoresis and subsequently propagated in culture. These distributions contained at least 3 subpopulations in all purified fractions, and results of experiments with prepurified cultured HEK cells indicated that subpopulations of living cells that were high in plasminogen-activator activity also contained the highest per cent of cells with high 90 deg light scatter intensity.

Enhanced H-filter based on Fåhræus-Lindqvist effect for efficient and robust dialysis without membrane

PubMed Central

Zheng, Wei-Chao; Xie, Rui; He, Li-Qun; Xi, Yue-Heng; Liu, Ying-Mei; Meng, Zhi-Jun; Wang, Wei; Ju, Xiao-Jie; Chen, Gang; Chu, Liang-Yin

2015-01-01

A novel microfluidic device for highly efficient and robust dialysis without membrane is highly desired for the development of portable or wearable microdialyzer. Here we report an enhanced H-filter with pillar array based on Fåhræus-Lindqvist effect (F-L effect) for highly efficient and robust membraneless dialysis of simplified blood for the first time. The H-filter employs two fluids laminarly flowing in the microchannel for continuously membraneless dialysis. With pillar array in the microchannel, the two laminar flows, with one containing blood cells and small molecules and another containing dialyzate solution, can form a cell-free layer at the interface as selective zones for separation. This provides enhanced mixing yet extremely low shear for extraction of small molecules from the blood-cell-containing flow into the dialyzate flow, resulting in robust separation with reduced cell loss and improved efficiency. We demonstrate this by first using Chlorella pyrenoidosa as model cells to quantitatively study the separation performances, and then using simplified human blood for dialysis. The advanced H-filter, with highly efficient and robust performance for membraneless dialysis, shows great potential as promising candidate for rapid blood analysis/separation, and as fundamental structure for portable dialyzer. PMID:26339313

Enhanced H-filter based on Fåhræus-Lindqvist effect for efficient and robust dialysis without membrane.

PubMed

Zheng, Wei-Chao; Xie, Rui; He, Li-Qun; Xi, Yue-Heng; Liu, Ying-Mei; Meng, Zhi-Jun; Wang, Wei; Ju, Xiao-Jie; Chen, Gang; Chu, Liang-Yin

2015-07-01

A novel microfluidic device for highly efficient and robust dialysis without membrane is highly desired for the development of portable or wearable microdialyzer. Here we report an enhanced H-filter with pillar array based on Fåhræus-Lindqvist effect (F-L effect) for highly efficient and robust membraneless dialysis of simplified blood for the first time. The H-filter employs two fluids laminarly flowing in the microchannel for continuously membraneless dialysis. With pillar array in the microchannel, the two laminar flows, with one containing blood cells and small molecules and another containing dialyzate solution, can form a cell-free layer at the interface as selective zones for separation. This provides enhanced mixing yet extremely low shear for extraction of small molecules from the blood-cell-containing flow into the dialyzate flow, resulting in robust separation with reduced cell loss and improved efficiency. We demonstrate this by first using Chlorella pyrenoidosa as model cells to quantitatively study the separation performances, and then using simplified human blood for dialysis. The advanced H-filter, with highly efficient and robust performance for membraneless dialysis, shows great potential as promising candidate for rapid blood analysis/separation, and as fundamental structure for portable dialyzer.

Nuclear microscope analysis of blood cells from the tropical ascidian Phallusia philippinensis

NASA Astrophysics Data System (ADS)

Hogarth, A. N.; Thong, P. S. P.; Lane, D. J. W.; Watt, F.

1997-07-01

The present study examines the concentrations of vanadium, bromine and sulphur contained within cryofixed/freeze dried blood cells of the ascidian Phallusia philippinensis (Millar, 1975). Elemental profiles of seven cell types were obtained using the National University of Singapore nuclear microscope. Morula cells were found to contain the following mean values; 0.8% vanadium, 3.5% bromine and 6.1% sulphur. Signet ring cells contained 0.5% vanadium, 2.4% bromine and 1.5% sulphur. Compartment cells had 0.1% vanadium, 2.1% bromine and 2.4% sulphur. Other less abundant cell types such as lymphocytes, macrogranular amoebocytes, carotenoid pigment cells and granular amoebocytes were also analysed and found to contain 0.4%, 0.7%, 0.2% and 1.0% vanadium, 2.0%, 1.6%, 0.6% and 1.2% bromine and 1.3%, 1.5%, 0.3% and 4.3% sulphur respectively. Sulphur occurred in high levels in all cell types, which could indicate its involvement in the vanadium concentration process, while bromine, incorporated into complexes, may be utilised for anti-fouling rather than as a deterrent to predators.

New Method of Filling of High-Temperature Fixed-Point Cells Based on Metal-Carbon Eutectics/Peritectics

NASA Astrophysics Data System (ADS)

Khlevnoy, B. B.; Grigoryeva, I. A.; Ibragimov, N. A.

2011-08-01

A new method of filling of high-temperature fixed-point cells based on metal-carbon eutectics and peritectics is suggested and tested. In this method a metal and carbon powder mixture is introduced not directly into the crucible, but into an additional container located just above the crucible. The mixture melts inside the container, and the already molten eutectic drops through a small hole in the bottom of the container and fills the crucible drop by drop. The method can be used to obtain a uniform ingot without porous or foundry cavities, to minimize the risk of contamination, and to avoid some other disadvantages. The method was applied to fabricate Re-C and WC-C cells using 5N purity materials. The cells demonstrated a good plateau shape with melting ranges of 0.2 K and 80 mK for Re-C and WC-C, respectively. The Re-C cell was compared with a cell built at NMIJ and showed good agreement with a difference of melting temperatures of only 45 mK.

Accumulation of Senescent Cells in Mitotic Tissue of Aging Primates

PubMed Central

Jeyapalan, Jessie C.; Ferreira, Mark; Sedivy, John M.; Herbig, Utz

2013-01-01

Cellular senescence, a stress induced growth arrest of somatic cells, was first documented in cell cultures over forty years ago, however its physiological significance has only recently been demonstrated. Using novel biomarkers of cellular senescence we examined whether senescent cells accumulate in tissues from baboons of ages encompassing the entire lifespan of this species. We show that dermal fibroblasts, displaying markers of senescence such as telomere damage, active checkpoint kinase ATM, high levels of heterochromatin proteins and elevated levels of p16, accumulate in skin biopsies from baboons with advancing age. The number of dermal fibroblasts containing damaged telomeres reaches a value of over 15% of total fibroblasts, whereas 80% of cells contain high levels of the heterochromatin protein HIRA. In skeletal muscle, a postmitotic tissue, only a small percentage of myonuclei containing damaged telomeres were detected regardless of animal age. The presence of senescent cells in mitotic tissues might therefore be a contributing factor to aging and age related pathology and provides further evidence that cellular senescence is a physiological event. PMID:17116315

Origin of high open-circuit voltage in a planar heterojunction solar cell containing a non-fullerene acceptor

NASA Astrophysics Data System (ADS)

Cheng, Nongyi; Peng, Yuelin; Andrew, Trisha L.

2017-09-01

Vapor-deposited, planar heterojunction organic solar cells containing a periflanthene donor and either a fullerene or non-fullerene acceptor are investigated. A high VOC of 1.16 V is observed in devices containing the non-fullerene, pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(4-chlorophenyl)-2,5-dihydro acceptor, whereas analogous devices containing C60 only result in a VOC of 0.8 V. The measured band energy levels of the two different acceptors do not readily explain the observed difference. Small-perturbation transient photovoltage and transient photocurrent measurements reveal that interfacial charge recombination is comparatively slower for the non-fullerene acceptor, resulting in relatively higher Voc values.

Betavoltaics Of Increased Power

NASA Technical Reports Server (NTRS)

Pool, Frederick S.; Stella, Paul

1991-01-01

Batteries of newly developed betavoltaic cells proposed as long-lived sources of power of order of watts. High-power betavoltaic cell resembles solar photo voltaic cell, except it includes layer of beta-emitting material. Betavoltaic battery cells are stacked as in chemical battery, and surrounded by material containing beta rays. Intended for use aboard spacecraft, batteries also used in surgically implanted devices requiring high power.

High strength porous support tubes for high temperature solid electrolyte electrochemical cells

DOEpatents

Rossing, Barry R.; Zymboly, Gregory E.

1986-01-01

A high temperature, solid electrolyte electrochemical cell is made, having an electrode and a solid electrolyte disposed on a porous, sintered support material containing thermally stabilized zirconia powder particles and from about 3 wt. % to about 45 wt. % of thermally stable oxide fibers.

Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode

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

Yuan, Tao; Zhu, Xiaoguang; Tu, Guoli, E-mail: tgl@hust.edu.cn

Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PF{sub EO}SO{sub 3}Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PF{sub EO}SO{sub 3}Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC{sub 71}BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC{sub 71}BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a usefulmore » approach to improve the performance of inverted polymer solar cells.« less

Two populations of double minute chromosomes harbor distinct amplicons, the MYC locus at 8q24.2 and a 0.43-Mb region at 14q24.1, in the SW613-S human carcinoma cell line.

PubMed

Guillaud-Bataille, M; Brison, O; Danglot, G; Lavialle, C; Raynal, B; Lazar, V; Dessen, P; Bernheim, A

2009-01-01

High-level amplifications observed in tumor cells are usually indicative of genes involved in oncogenesis. We report here a high resolution characterization of a new amplified region in the SW613-S carcinoma cell line. This cell line contains tumorigenic cells displaying high-level MYC amplification in the form of double minutes (DM(+) cells) and non tumorigenic cells exhibiting low-level MYC amplification in the form of homogeneously staining regions (DM(-) cells). Both cell types were studied at genomic and functional levels. The DM(+) cells display a second amplification, corresponding to the 14q24.1 region, in a distinct population of DMs. The 0.43-Mb amplified and overexpressed region contains the PLEK2, PIGH, ARG2, VTI1B, RDH11, and ZFYVE26 genes. Both amplicons were stably maintained upon in vitro and in vivo propagation. However, the 14q24.1 amplicon was not found in cells with high-level MYC amplification in the form of HSRs, either obtained after spontaneous integration of endogenous DM MYC copies or after transfection of DM(-) cells with a MYC gene expression vector. These HSR-bearing cells are highly tumorigenic. The 14q24.1 amplification may not play a role in malignancy per se but might contribute to maintaining the amplification in the form of DMs. Copyright 2009 S. Karger AG, Basel.

Hybrid anodes for redox flow batteries

DOEpatents

Wang, Wei; Xiao, Jie; Wei, Xiaoliang; Liu, Jun; Sprenkle, Vincent L.

2015-12-15

RFBs having solid hybrid electrodes can address at least the problems of active material consumption, electrode passivation, and metal electrode dendrite growth that can be characteristic of traditional batteries, especially those operating at high current densities. The RFBs each have a first half cell containing a first redox couple dissolved in a solution or contained in a suspension. The solution or suspension can flow from a reservoir to the first half cell. A second half cell contains the solid hybrid electrode, which has a first electrode connected to a second electrode, thereby resulting in an equipotential between the first and second electrodes. The first and second half cells are separated by a separator or membrane.

Development of an all-metal thick film cost effective metallization system for solar cells

NASA Technical Reports Server (NTRS)

Ross, B.; Parker, J.

1983-01-01

Improved thick film solar cell contacts for the high volume production of low cost silicon solar arrays are needed. All metal screenable pastes made from economical base metals and suitable for application to low to high conductivity silicon were examined. Silver fluoride containing copper pastes and fluorocarbon containing copper pastes were discussed. The effect of hydrogen on the adhesion of metals to silicon was investigated. A cost analysis of various paste materials is provided.

A simple cell-based high throughput screening (HTS) assay for inhibitors of Salmonella enterica RNA polymerase containing the general stress response regulator RpoS (σS).

PubMed

Campos-Gomez, Javier; Benitez, Jorge A

2018-07-01

RNA polymerase containing the stress response regulator σ S subunit (RpoS) plays a key role in bacterial survival in hostile environments in nature and during infection. Here we devise and validate a simple cell-based high throughput luminescence assay for this holoenzyme suitable for screening large chemical libraries in a robotic platform. Copyright © 2018 Elsevier B.V. All rights reserved.

Management of advanced NK/T-cell lymphoma.

PubMed

Tse, Eric; Kwong, Yok-Lam

2014-09-01

NK/T-cell lymphomas are aggressive malignancies, and the outlook is poor when conventional anthracycline-containing regimens designed for B-cell lymphomas are used. With the advent of L-asparaginase-containing regimens, treatment outcome has significantly improved. L-asparaginase-containing regimens are now considered the standard in the management of NK/T-cell lymphomas. In advanced diseases, however, outcome remains unsatisfactory, with durable remission achieved in only about 50% of cases. Stratification of patients with advanced NK/T-cell lymphomas is needed, so that poor-risk patients can be given additional therapy to improve outcome. Conventional presentation parameters are untested and appear inadequate for prognostication when L-asparaginase-containing regimens are used. Recent evidence suggests that dynamic factors during treatment and interim assessment, including Epstein-Barr virus (EBV) DNA quantification and positron emission tomography computed tomography findings, are more useful in patient stratification. The role of high-dose chemotherapy and haematopoietic stem cell transplantation requires evaluation in an overall risk-adapted treatment algorithm.

High energy density electrochemical cell

NASA Technical Reports Server (NTRS)

Byrne, J. J.; Williams, D. L.

1970-01-01

Primary cell has an anode of lithium, a cathode containing dihaloisocyanuric acid, and a nonaqueous electrolyte comprised of a solution of lithium perchlorate in methyl formate. It produces an energy density of 213 watt hrs/lb and can achieve a high current density.

Characterization of nonderivatized plant cell walls using high-resolution solution-state NMR spectroscopy

Treesearch

Daniel J. Yelle; John Ralph; Charles R. Frihart

2008-01-01

A recently described plant cell wall dissolution system has been modified to use perdeuterated solvents to allow direct in-NMR-tube dissolution and high-resolution solution-state NMR of the whole cell wall without derivatization. Finely ground cell wall material dissolves in a solvent system containing dimethylsulfoxide-d6 and 1-methylimidazole-d6 in a ratio of 4:1 (v/...

High-Collection-Efficiency Fluorescence Detection Cell

NASA Technical Reports Server (NTRS)

Hanisco, Thomas; Cazorla, Maria; Swanson, Andrew

2013-01-01

A new fluorescence cell has been developed for the laser induced fluorescence (LIF) detection of formaldehyde. The cell is used to sample a flow of air that contains trace concentrations of formaldehyde. The cell provides a hermetically sealed volume in which a flow of air containing formaldehyde can be illuminated by a laser. The cell includes the optics for transmitting the laser beam that is used to excite the formaldehyde and for collecting the resulting fluorescence. The novelty of the cell is its small size and simple design that provides a more robust and cheaper alternative to the state of the art. Despite its simplicity, the cell provides the same sensitivity to detection as larger, more complicated cells.

High-throughput single-cell PCR using microfluidic emulsions

NASA Astrophysics Data System (ADS)

Guo, Mira; Mazutis, Linas; Agresti, Jeremy; Sommer, Morten; Dantas, Gautam; Church, George; Turnbaugh, Peter; Weitz, David

2012-02-01

The human gut and other environmental samples contain large populations of diverse bacteria that are poorly characterized and unculturable, yet have many functions relevant to human health. Our goal is to identify exactly which species carry some gene of interest, such as a carbohydrate metabolism gene. Conventional metagenomic assays sequence DNA extracted in bulk from populations of mixed cell types, and are therefore unable to associate a gene of interest with a species-identifying 16S gene, to determine that the two genes originated from the same cell. We solve this problem by microfluidically encapsulating single bacteria cells in drops, using PCR to amplify the two genes inside any drop whose encapsulated cell contains both genes, and sequencing the DNA from those drops that contain both amplification products.

Symmetry breaking in human neuroblastoma cells

PubMed Central

Izumi, Hideki; Kaneko, Yasuhiko

2014-01-01

Asymmetric cell division (ACD) is a characteristic of cancer stem cells, which exhibit high malignant potential. However, the cellular mechanisms that regulate symmetric (self-renewal) and asymmetric cell divisions are mostly unknown. Using human neuroblastoma cells, we found that the oncosuppressor protein tripartite motif containing 32 (TRIM32) positively regulates ACD. PMID:27308367

Indium oxide/n-silicon heterojunction solar cells

DOEpatents

Feng, Tom; Ghosh, Amal K.

1982-12-28

A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

Changes in pituitary growth hormone cells prepared from rats flown on Spacelab 3

NASA Technical Reports Server (NTRS)

Grindeland, R.; Hymer, W. C.; Farrington, M.; Fast, T.; Hayes, C.; Motter, K.; Patil, L.; Vasques, M.

1987-01-01

The effect of exposure to microgravity on pituitary gland was investigated by examining cells isolated from anterior pituitaries of rats flown on the 7-day Spacelab 3 mission and, subsequently, cultured for 6 days. Compared with ground controls, flight cells contained more intracellular growth hormone (GH); however, the flight cells released less GH over the 6-day culture period and after implantation into hypophysectomized rats than did the control cells. Compared with control rats, glands from large rats (400 g) contained more somatotrophs (44 percent compared with 37 percent in control rats); small rats (200 g) showed no difference. No major differences were found in the somatotroph ultrastructure (by TEM) or in the pattern of the immunoactive GH variants. However, high-performance liquid chromatography fractionation of culture media indicated that flight cells released much less of a biologically active high-molecular weight GH variant, suggesting that space flight may lead to secretory dysfunction.

High efficiency solar panel /HESP/

NASA Technical Reports Server (NTRS)

Stella, P. M.; Gay, C.; Uno, F.; Scott-Monck, J.

1978-01-01

A family of high efficiency, weldable silicon solar cells, incorporating nearly every feature of advanced cell technology developed in the past four years, was produced and subjected to space qualification testing. This matrix contained both field and non-field cells ranging in thickness from 0.10 mm to 0.30 mm, and in base resistivity from nominal two to one hundred ohm-cm. Initial power outputs as high as 20 mW/sq cm (14.8% AM0 efficiency) were produced by certain cell types within the matrix.

Effect of Different Carbon Sources on Relative Growth Rate, Internal Carbohydrates, and Mannitol 1-Oxidoreductase Activity in Celery Suspension Cultures.

PubMed Central

Stoop, JMH.; Pharr, D. M.

1993-01-01

Little information exists concerning the biochemical route of mannitol catabolism in higher plant cells. In this study, the role of a recently discovered mannitol 1-oxidoreductase (MDH) in mannitol catabolism was investigated. Suspension cultures of celery (Apium graveolens L. var dulce [Mill.] Pers.) were successfully grown on nutrient media with either mannitol, mannose, or sucrose as the sole carbon source. Cell cultures grown on any of the three carbon sources did not differ in relative growth rate, as measured by packed cell volume, but differed drastically in internal carbohydrate concentration. Mannitol-grown cells contained high concentrations of mannitol and extremely low concentrations of sucrose, fructose, glucose, and mannose. Sucrose-grown cells had high concentrations of sucrose early in the growth cycle and contained a substantial hexose pool. Mannose-grown cells had a high mannose concentration early in the cycle, which decreased during the growth cycle, whereas their internal sucrose concentrations remained relatively constant during the entire growth cycle. Celery suspension cultures on all three carbon substrates contained an NAD-dependent MDH. Throughout the growth cycle, MDH activity was 2- to 4-fold higher in mannitol-grown cells compared with sucrose- or mannose-grown cells, which did not contain detectable levels of mannitol, indicating that MDH functions pre-dominantly in an oxidative capacity in situ. The MDH activity observed in celery cells was 3-fold higher than the minimum amount required to account for the observed rate of mannitol utilization from the media. Cultures transferred from mannitol to mannose underwent a decrease in MDH activity over a period of days, and transfer from mannose to mannitol resulted in an increase in MDH activity. These data provide strong evidence that MDH plays an important role in mannitol utilization in celery suspension cultures. PMID:12231996

Life Functions and Cells: Level II, Unit 7, Lesson 1; Cell Structure: Lesson 2; Tissues, Organs, Systems: Lesson 3; Growth and Nutrition: Lesson 4; Metabolism: Lesson 5. Advanced General Education Program. A High School Self-Study Program.

ERIC Educational Resources Information Center

Manpower Administration (DOL), Washington, DC. Job Corps.

This self-study program for high-school level contains lessons on: Life Functions and Cells; Cell Structure; Tissues, Organs, Systems; Growth and Nutrition; and Metabolism. Each of the lessons concludes with a Mastery Test to be completed by the student. (DB)

Nitrogen fixation system of tungsten-resistant mutants of Azotobacter vinelandii.

PubMed Central

Riddle, G D; Simonson, J G; Hales, B J; Braymer, H D

1982-01-01

Mutants of Azotobacter vinelandii ATCC 12837 were isolated which could fix N2 in the presence of high tungsten concentrations. The most studied of these mutants (WD2) grew well in N-free modified Burk broth containing 10 mM W, whereas the wild type would not grow in this medium. WD2 would also grow in Burk N-free broth at about the same rate as the wild type. WD2 in broth containing W exhibited 22% of the whole cell acetylene reduction activity of the wild type in broth containing Mo and showed a lowered affinity for acetylene. Two-dimensional gel electrophoresis experiments showed that N2-fixing cells of WD2 from broth containing W or Mo did not produce significant amounts of component I of native nitrogenase protein. Electron spin resonance spectra of whole cells and cell-free extracts of WD2 from broth containing W lacked any trace of the g = 3.6 resonance associated with FeMoCo. Images PMID:6956567

Semi-continuous production of high-activity pectinases by immobilized Rhizopus oryzae using tobacco wastewater as substrate and their utilization in the hydrolysis of pectin-containing lignocellulosic biomass at high solid content.

PubMed

Zheng, Yu-Xi; Wang, Yuan-Liang; Pan, Jun; Zhang, Jian-Rong; Dai, Ya; Chen, Kun-Yan

2017-10-01

In this study, highly reactive endo- and exo-polygalacturonases (PGs) were produced from the tobacco industry wastewater using immobilized Rhizopus oryzae. Compared with free cells, immobilized cells increased enzyme activity 2.8-fold and reduced production time to 24h by shake-flask production. Moreover, the immobilized cells enabled the semi-continuous production of enzymes through repeated-batch mode for seven consecutive cycles in a scale-up bioreactor. During the first five cycles, the average endo-PG and exo-PG activities reached 307.5 and 242.6U/ml, respectively. The addition of crude enzyme for the hydrolysis of pectin-containing lignocellulosic biomass under high-gravity conditions increased glucose release 4.2-fold (115.4 vs. 29.0g/L), compared with hydrolysis using cellulase alone. This process achieves the efficient production of pectin-degrading enzymes, provides a cost-effective method for tobacco wastewater treatment, and offers the possibility to obtain fermentable sugars with high-titer from pectin-containing lignocellulosic biomass, which has important potential for the commercial production of bio-fuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

A stem cell medium containing neural stimulating factor induces a pancreatic cancer stem-like cell-enriched population

PubMed Central

WATANABE, YUSAKU; YOSHIMURA, KIYOSHI; YOSHIKAWA, KOICHI; TSUNEDOMI, RYOICHI; SHINDO, YOSHITARO; MATSUKUMA, SOU; MAEDA, NORIKO; KANEKIYO, SHINSUKE; SUZUKI, NOBUAKI; KURAMASU, ATSUO; SONODA, KOUHEI; TAMADA, KOJI; KOBAYASHI, SEI; SAYA, HIDEYUKI; HAZAMA, SHOICHI; OKA, MASAAKI

2014-01-01

Cancer stem cells (CSCs) have been studied for their self-renewal capacity and pluripotency, as well as their resistance to anticancer therapy and their ability to metastasize to distant organs. CSCs are difficult to study because their population is quite low in tumor specimens. To overcome this problem, we established a culture method to induce a pancreatic cancer stem-like cell (P-CSLC)-enriched population from human pancreatic cancer cell lines. Human pancreatic cancer cell lines established at our department were cultured in CSC-inducing media containing epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF), neural cell survivor factor-1 (NSF-1), and N-acetylcysteine. Sphere cells were obtained and then transferred to a laminin-coated dish and cultured for approximately two months. The surface markers, gene expression, aldehyde dehydrogenase (ALDH) activity, cell cycle, and tumorigenicity of these induced cells were examined for their stem cell-like characteristics. The population of these induced cells expanded within a few months. The ratio of CD24high, CD44high, epithelial specific antigen (ESA) high, and CD44variant (CD44v) high cells in the induced cells was greatly enriched. The induced cells stayed in the G0/G1 phase and demonstrated mesenchymal and stemness properties. The induced cells had high tumorigenic potential. Thus, we established a culture method to induce a P-CSLCenriched population from human pancreatic cancer cell lines. The CSLC population was enriched approximately 100-fold with this method. Our culture method may contribute to the precise analysis of CSCs and thus support the establishment of CSC-targeting therapy. PMID:25118635

Mycobacterial Cultures Contain Cell Size and Density Specific Sub-populations of Cells with Significant Differential Susceptibility to Antibiotics, Oxidative and Nitrite Stress

PubMed Central

Vijay, Srinivasan; Nair, Rashmi Ravindran; Sharan, Deepti; Jakkala, Kishor; Mukkayyan, Nagaraja; Swaminath, Sharmada; Pradhan, Atul; Joshi, Niranjan V.; Ajitkumar, Parthasarathi

2017-01-01

The present study shows the existence of two specific sub-populations of Mycobacterium smegmatis and Mycobacterium tuberculosis cells differing in size and density, in the mid-log phase (MLP) cultures, with significant differential susceptibility to antibiotic, oxidative, and nitrite stress. One of these sub-populations (~10% of the total population), contained short-sized cells (SCs) generated through highly-deviated asymmetric cell division (ACD) of normal/long-sized mother cells and symmetric cell divisions (SCD) of short-sized mother cells. The other sub-population (~90% of the total population) contained normal/long-sized cells (NCs). The SCs were acid-fast stainable and heat-susceptible, and contained high density of membrane vesicles (MVs, known to be lipid-rich) on their surface, while the NCs possessed negligible density of MVs on the surface, as revealed by scanning and transmission electron microscopy. Percoll density gradient fractionation of MLP cultures showed the SCs-enriched fraction (SCF) at lower density (probably indicating lipid-richness) and the NCs-enriched fraction (NCF) at higher density of percoll fractions. While live cell imaging showed that the SCs and the NCs could grow and divide to form colony on agarose pads, the SCF, and NCF cells could independently regenerate MLP populations in liquid and solid media, indicating their full genomic content and population regeneration potential. CFU based assays showed the SCF cells to be significantly more susceptible than NCF cells to a range of concentrations of rifampicin and isoniazid (antibiotic stress), H2O2 (oxidative stress),and acidified NaNO2 (nitrite stress). Live cell imaging showed significantly higher susceptibility of the SCs of SC-NC sister daughter cell pairs, formed from highly-deviated ACD of normal/long-sized mother cells, to rifampicin and H2O2, as compared to the sister daughter NCs, irrespective of their comparable growth rates. The SC-SC sister daughter cell pairs, formed from the SCDs of short-sized mother cells and having comparable growth rates, always showed comparable stress-susceptibility. These observations and the presence of M. tuberculosis SCs and NCs in pulmonary tuberculosis patients' sputum earlier reported by us imply a physiological role for the SCs and the NCs under the stress conditions. The plausible reasons for the higher stress susceptibility of SCs and lower stress susceptibility of NCs are discussed. PMID:28377757

Method for forming indium oxide/n-silicon heterojunction solar cells

DOEpatents

Feng, Tom; Ghosh, Amal K.

1984-03-13

A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

Multifunctional biocompatible graphene oxide quantum dots decorated magnetic nanoplatform for efficient capture and two-photon imaging of rare tumor cells.

PubMed

Shi, Yongliang; Pramanik, Avijit; Tchounwou, Christine; Pedraza, Francisco; Crouch, Rebecca A; Chavva, Suhash Reddy; Vangara, Aruna; Sinha, Sudarson Sekhar; Jones, Stacy; Sardar, Dhiraj; Hawker, Craig; Ray, Paresh Chandra

2015-05-27

Circulating tumor cells (CTCs) are extremely rare cells in blood containing billions of other cells. The selective capture and identification of rare cells with sufficient sensitivity is a real challenge. Driven by this need, this manuscript reports the development of a multifunctional biocompatible graphene oxide quantum dots (GOQDs) coated, high-luminescence magnetic nanoplatform for the selective separation and diagnosis of Glypican-3 (GPC3)-expressed Hep G2 liver cancer tumor CTCs from infected blood. Experimental data show that an anti-GPC3-antibody-attached multifunctional nanoplatform can be used for selective Hep G2 hepatocellular carcinoma tumor cell separation from infected blood containing 10 tumor cells/mL of blood in a 15 mL sample. Reported data indicate that, because of an extremely high two-photon absorption cross section (40530 GM), an anti-GPC3-antibody-attached GOQDs-coated magnetic nanoplatform can be used as a two-photon luminescence platform for selective and very bright imaging of a Hep G2 tumor cell in a biological transparency window using 960 nm light. Experimental results with nontargeted GPC3(-) and SK-BR-3 breast cancer cells show that multifunctional-nanoplatform-based cell separation, followed by two-photon imaging, is highly selective for Hep G2 hepatocellular carcinoma tumor cells.

Thin HSIL of the Cervix: Detecting a Variant of High-grade Squamous Intraepithelial Lesions With a p16INK4a Antibody.

PubMed

Reich, Olaf; Regauer, Sigrid

2017-01-01

The WHO defines thin high-grade squamous intraepithelial lesions (HSIL) as a high-grade intraepithelial lesion of the cervix that is usually ≤9 cells thick. These lesions usually develop in early metaplastic squamous epithelium without anteceding low-grade squamous intraepithelial lesions (LSIL). The prevalence of thin HSIL is not well documented. We evaluated different characteristics of thin HSIL at time of treatment. We studied 25 formalin-fixed and paraffin-embedded conization specimens processed as step-serial sections. HSIL≤9 cells thick were classified as thin HSIL. HSIL≥10 cells thick were classified as classic HSIL. Immunohistochemical p16 staining was used to confirm lesions of thin HSIL. Overall, 19 (76%) specimens contained both thin HSIL and classic HSIL, 4 (16%) contained thin HSIL only, 1 (4%) contained classic-type HSIL only, and 1 (4%) contained thin HSIL and LSIL. Thin HSILs developed in both the columnar surface epithelium and deep cervical glandular epithelium. Most thin HSILs were 5 cells thick. All HSILs (thin and classic) were located inside the transformation zone and had a median horizontal extension of 8 mm (range, 0.3 to 21 mm). Our findings suggest that thin HSILs are frequent findings, that they coexist with classic HSIL, and preferably arise in the exposed parts of the transformation zone including the glandular crypts.

Crystalline pteridines in the stromal pigment cells of the iris of the great horned owl.

PubMed

Oliphant, L W

1981-01-01

The bright yellow color of the iris of the Great Horned Owl (Bubo virginianus) is due to unusual pigment cells in the iris stroma. These cells are spherical and contain numerous clear lipid droplets. Around the periphery of these cells are ovoid crystalline granules that are highly birefringent and vary in color from yellow to clear gray. Differential extraction of the lipid droplets and peripheral granules with lipid solvents and 2% KOH confirmed the localization of the yellow pigment in these granules. The color, solubility, fluorescence, chromatographic mobility and ultraviolet absorption of the extracted pigment suggest it is primarily xanthopterin. It is proposed that the peripheral granules are crystalline pterinosomes capable of reflecting light. Most of the cells contain yellow reflecting granules and can be considered reflecting xanthophores. Cells lying deeper in the stroma have colorless reflecting granules and can be considered pteridine containing leucophores.

Proliferation and morphological transformation of RMK cells exposed to hydroquinine containing ionomers.

PubMed

Harvey, Veronica; Benghuzzi, Hamed; Tucci, Michell; Puckett, Aaron; Cason, Zelma

2002-01-01

Recent research in our laboratories has been directed towards the development of ionomeric polymers and monomers for use in biomedical applications such as adhesives, drug delivery matrices and tissue scaffolds. The chemical Hydroquinone (HQ) aids as a stabilizer and represents a major component in the development of the ionomers. However, hydroquinone in high concentration has the potential to initiate carcinogenic effects on cells. The curing reactions are based on free radical chemistry that require a radical scavenger, ascorbic acid (Asc) to adjust working and setting times and shelf-life stability. The few studies published on HQ have suggested that high dosages of HQ may stimulate apoptosis as well as an increased cellular leakage, however the effect of HQ on the biocompatability is unknown. Therefore the objectives of this study were to measure the functional capacity, cell proliferation and structural integrity of Rhesus monkey kidney epithelial (RMK) cells exposed to ionomer formulations containing 4 different levels of HQ. A total of 90 tubes of RMK (40,000 cells per tube) cells were divided equally into five equal groups. Group I served as a control and group II-V were subjected to ionomers containing 0, 500, 1000, and 2000 ppm HQ. Cell numbers, morphology, cellular and supermatant MDA levels, and total protein analysis were performed. The results suggest: (I) All ionomer groups increased cellular proliferation except for the 2000 ppm HQ group, (II) MDA levels were increased in cells containing 2000 ppm HQ at 24 hours; and 0 ppm at 48 hours. It may be concluded that HQ concentrations over 1000 ppm may adversely affect biocompatability.

Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, Thomas C.; McLarnon, Frank R.; Cairns, Elton J.

1994-01-01

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K.sub.2 CO.sub.3 salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

Serosal Cavities Contain Two Populations of Innate-like integrin α4highCD4+ T Cells, Integrin α4β1+α6β1+α4β7- and α4β1+α6β1-α4β7+ Cells.

PubMed

Yang, Jeong In; Park, Chanho; Kho, Inseong; Lee, Sujin; Suh, Kyung-Suk; Kim, Tae Jin

2017-12-01

We previously reported peritoneal innate-like integrin α4 (CD49d) high CD4 + T cells that provided help for B-1a cells. Here we analyzed the expression of various integrin chains on the peritoneal and pleural integrin α4 high CD4 + T cells and investigated the functional heterogeneity of the subpopulations based on the integrin expression. Pleural cavity contained a lower ratio of integrin α4 high CD4 + T cells to integrin α4 low CD4 + T cells than peritoneal cavity, but the pleural integrin α4 high CD4 + T cells have the same characteristics of the peritoneal integrin α4 high CD4 + T cells. Most of integrin α4 high CD4 + T cells were integrin β1 high β7 - , but a minor population of integrin α4 high CD4 + T cells was integrin β1 + β7 + . Interestingly, the integrin α4 high β1 high β7 - CD4 + T cells expressed high levels of integrin α4β1 and α6β1, whereas integrin α4 high β1 + β7 + CD4 + T cells expressed high levels of integrin α4β1 and α4β7, suggesting an alternative expression of integrin α6β1 or α4β7 in combination with α4β1 in respective major and minor populations of integrin α4 high CD4 + T cells. The minor population, integrin α4 high β1 + β7 + CD4 + T cells, were different from the integrin α4 high β1 high β7 - CD4 + T cells in that they secreted a smaller amount of Th1 cytokines upon stimulation and expressed lower levels of Th1-related chemokine receptors CCR5 and CXCR3 than the integrin α4 high β 1 high β 7 - CD4 + T cells. In summary, the innate-like integrin α4 high CD4 + T cells could be divided into 2 populations, integrin α4β1 + α6β1 + α4β7 - and α4β1 + α6β1 - α4β7 + cells. The functional significance of serosal integrin α4β7 + CD4 + T cells needed to be investigated especially in view of mucosal immunity.

A tumor suppressor locus within 3p14-p12 mediates rapid cell death of renal cell carcinoma in vivo.

PubMed Central

Sanchez, Y; el-Naggar, A; Pathak, S; Killary, A M

1994-01-01

High frequency loss of alleles and cytogenetic aberrations on the short arm of chromosome 3 have been documented in renal cell carcinoma (RCC). Potentially, three distinct regions on 3p could encode tumor suppressor genes involved in the genesis of this cancer. We report that the introduction of a centric fragment of 3p, encompassing 3p14-q11, into a highly malignant RCC cell line resulted in a dramatic suppression of tumor growth in athymic nude mice. Another defined deletion hybrid contained the region 3p12-q24 of the introduced human chromosome and failed to suppress tumorigenicity. These data functionally define a tumor suppressor locus, nonpapillary renal carcinoma-1 (NRC-1), within 3p14-p12, the most proximal region of high frequency allele loss in sporadic RCC as well as the region containing the translocation breakpoint in familial RCC. Furthermore, we provide functional evidence that NRC-1 controls the growth of RCC cells by inducing rapid cell death in vivo. Images PMID:8159756

Porous electronic current collector bodies for electrochemical cell configurations

DOEpatents

Pollack, William; Reichner, Philip

1989-01-01

A high-temperature, solid electrolyte electrochemical cell configuration is made comprising a plurality of elongated electrochemical cells 1, having inner electrodes 3, outer electrodes 6 and solid electrolyte 4 therebetween, the cells being electronically connected in series and parallel by flexible, porous, fibrous strips 7, where the strips contain flexible, electronically conductive fibers bonded together and coated with a refractory oxide, and where the oxide coating is effective to prevent additional bonding of fibers during electrochemical cell operation at high temperatures.

Changes in neuroendocrine elements in bronchial mucosa in chronic lung disease in adults.

PubMed

Pilmane, M; Luts, A; Sundler, F

1995-05-01

It is not clear whether there is any association between metaplasia of the bronchial epithelium and changes in the distribution of neuroendocrine cells. This study examined, by immunohistological techniques, the distribution of neuroendocrine cells and juxtamucoscal nerve fibres in bronchial biopsies showing metaplastic changes. Bronchial biopsies from 12 subjects with epithelial metaplasia associated with bronchiectasis and diffuse pulmonary fibrosis were examined by conventional light microscopy and immunohistological techniques for protein gene product 9.5 (PGP), chromogranin A and B (CAB), serotonin, vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), calcitonin (CT), and gastrin releasing peptide (GRP). Regions of non-metaplastic epithelium contained numerous PGP and serotonin immunoreactive cells. Sub-populations of these cells displayed CAB, CGRP, CT, and GRP immunoreactivity. Metaplastic epithelium contained only a few weakly stained PGP, serotonin, CAB, GRP, CT and CGRP immunoreactive cells in six cases. Metaplastic epithelium was characterised by a high number of CAB-containing cells in six cases and in these biopsies prominent PGP-containing nerve bundles were seen in the subepithelial layer beneath the metaplastic epithelium. The distribution patterns of neuroendocrine cells and neuronal elements vary between areas of normal and metaplastic epithelium and within areas of metaplastic epithelium. Neuronal hyperplasia was associated with an increase in the number of CAB-containing cells within the metaplastic epithelium.

Changes in neuroendocrine elements in bronchial mucosa in chronic lung disease in adults.

PubMed Central

Pilmane, M.; Luts, A.; Sundler, F.

1995-01-01

BACKGROUND--It is not clear whether there is any association between metaplasia of the bronchial epithelium and changes in the distribution of neuroendocrine cells. This study examined, by immunohistological techniques, the distribution of neuroendocrine cells and juxtamucoscal nerve fibres in bronchial biopsies showing metaplastic changes. METHODS--Bronchial biopsies from 12 subjects with epithelial metaplasia associated with bronchiectasis and diffuse pulmonary fibrosis were examined by conventional light microscopy and immunohistological techniques for protein gene product 9.5 (PGP), chromogranin A and B (CAB), serotonin, vasoactive intestinal peptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), calcitonin (CT), and gastrin releasing peptide (GRP). RESULTS--Regions of non-metaplastic epithelium contained numerous PGP and serotonin immunoreactive cells. Sub-populations of these cells displayed CAB, CGRP, CT, and GRP immunoreactivity. Metaplastic epithelium contained only a few weakly stained PGP, serotonin, CAB, GRP, CT and CGRP immunoreactive cells in six cases. Metaplastic epithelium was characterised by a high number of CAB-containing cells in six cases and in these biopsies prominent PGP-containing nerve bundles were seen in the subepithelial layer beneath the metaplastic epithelium. CONCLUSIONS--The distribution patterns of neuroendocrine cells and neuronal elements vary between areas of normal and metaplastic epithelium and within areas of metaplastic epithelium. Neuronal hyperplasia was associated with an increase in the number of CAB-containing cells within the metaplastic epithelium. Images PMID:7541167

Interpretation of the Raji cell assay in sera containing anti-nuclear antibodies and immune complexes.

PubMed Central

Horsfall, A C; Venables, P J; Mumford, P A; Maini, R N

1981-01-01

The Raji cell assay is regarded as a test for the detection and quantitation of immune complexes. It is frequently positive in sera from patients with SLE. We have demonstrated a relationship between Raji cell binding and antibodies to DNA and soluble cellular antigens. In five sera containing high titres of antibodies of known single specificity, most of the Raji cell binding occurred in the 7S IgG fraction where the majority of anti-nuclear antibody was also found. When each of these sera was incubated with its specific antigen, Raji cell binding increased. Subsequent fractionation showed that this binding was in the high molecular weight fraction (greater than 200,000 daltons) and that Raji cell binding and antibody activity were abolished in the 7S fraction. These data confirm that Raji cell bind immune complexes but also indicate that 7S anti-nuclear antibodies may interact directly with Raji cells by an unknown mechanism. Therefore, in sera of patients with anti-nuclear antibodies, binding to Raji cells does not necessarily imply the presence of immune complexes alone. PMID:6975676

Breast milk from Tanzanian women has divergent effects on cell-free and cell-associated HIV-1 infection in vitro.

PubMed

Lyimo, Magdalena A; Mosi, Matilda Ngarina; Housman, Molly L; Zain-Ul-Abideen, Muhammad; Lee, Frederick V; Howell, Alexandra L; Connor, Ruth I

2012-01-01

Transmission of HIV-1 during breastfeeding is a significant source of new pediatric infections in sub-Saharan Africa. Breast milk from HIV-positive mothers contains both cell-free and cell-associated virus; however, the impact of breast milk on HIV-1 infectivity remains poorly understood. In the present study, breast milk was collected from HIV-positive and HIV-negative Tanzanian women attending antenatal clinics in Dar es Salaam. Milk was analyzed for activity in vitro against both cell-free and cell-associated HIV-1. Potent inhibition of cell-free R5 and X4 HIV-1 occurred in the presence of milk from all donors regardless of HIV-1 serostatus. Inhibition of cell-free HIV-1 infection positively correlated with milk levels of sialyl-Lewis(X) from HIV-positive donors. In contrast, milk from 8 of 16 subjects enhanced infection with cell-associated HIV-1 regardless of donor serostatus. Milk from two of these subjects contained high levels of multiple pro-inflammatory cytokines including TNFα, IL-1β, IL-6, IL-8, MIP-1α, MIP-1β, MCP-1 and IP-10, and enhanced cell-associated HIV-1 infection at dilutions as high as 1∶500. These findings indicate that breast milk contains innate factors with divergent activity against cell-free and cell-associated HIV-1 in vitro. Enhancement of cell-associated HIV-1 infection by breast milk may be associated with inflammatory conditions in the mother and may contribute to infant infection during breastfeeding.

Cryopreservation of nucellar cells of navel orange (Citrus sinensis Osb. var. brasiliensis Tanaka) by vitrification.

PubMed

Sakai, A; Kobayashi, S; Oiyama, I

1990-06-01

The nucellar cells of navel orange(Citrus sinensis Osb. var. brasiliensis Tanaka) were successfully cryopreserved by vitrification. In this method, cells were sufficiently dehydrated with highly concentrated cryoprotective solution(PVS2) prior to direct plunge in liquid nitrogen. The PVS2 contains(w/v) 30% glycerol, 15% ethylene glycol and 15% DMSO in Murashige-Tucker medium(MT) containing 0.15 M sucrose. Cells were treated with 60% PVS2 at 25°C for 5 min and then chilled PVS2 at 0°C for 3 min. The cell suspension of about 0.1 ml was loaded in a 0.5 ml transparent plastic straw and directly plunged in liquid nitrogen for 30 min. After rapid warming, the cell suspension was expelled in 2 ml of MT medium containing 1.2 M sucrose. The average rate of survival was about 80%. The vitrified cells regenerated plantlets. This method is very simple and the time required for cryopreservation is only about 10 min.

How the Curriculum Guideline "The Cell Is to Be Studied Longitudinally" Is Expressed in Six Israeli Junior-High-School Textbooks

ERIC Educational Resources Information Center

Cohen, Rachel; Yarden, Anat

2010-01-01

The most recent science and technology curriculum for junior high school in Israel contains a new guideline stating that the cell topic is to be taught "longitudinally in conjunction with other study contents." This guideline confers a change in teaching the cell topic and provides an opportunity to form meaningful relationships between…

Predicted energy densitites for nickel-hydrogen and silver-hydrogen cells embodying metallic hydrides for hydrogen storage

NASA Technical Reports Server (NTRS)

Easter, R. W.

1974-01-01

Simplified design concepts were used to estimate gravimetric and volumetric energy densities for metal hydrogen battery cells for assessing the characteristics of cells containing metal hydrides as compared to gaseous storage cells, and for comparing nickel cathode and silver cathode systems. The silver cathode was found to yield superior energy densities in all cases considered. The inclusion of hydride forming materials yields cells with very high volumetric energy densities that also retain gravimetric energy densities nearly as high as those of gaseous storage cells.

Chemoprevention by Elimination of Cancer-Prone, Mutant p53-Containing Breast Cells

DTIC Science & Technology

2009-09-01

Briefly, 50 AL reaction mixture were used for each reaction, which contained 2 QuantiTect SYBR Green RT-PCR Master Mix, 0.5 AL QuantiTect RT mix, 0.5 Amol ...cysteine-free DMEM, containing 5% dialyzed FCS and 50 Amol /L MG132. Cells were then labeled with 100 ACi/mL of [35S]-methionine (MP Biochemicals) for 5 min...with much high drug doses up to 10 Amol /L to achieve a moderate effect. Interestingly, digoxin or ouabain failed to reduce the endogenous wt p53

Solid polymer electrolyte electrochemical storage cell containing a redox shuttle additive for overcharge protection

DOEpatents

Richardson, Thomas J.; Ross, Philip N.

1999-01-01

A class of organic redox shuttle additives is described, preferably comprising nitrogen-containing aromatics compounds, which can be used in a high temperature (85.degree. C. or higher) electrochemical storage cell comprising a positive electrode, a negative electrode, and a solid polymer electrolyte to provide overcharge protection to the cell. The organic redox additives or shuttles are characterized by a high diffusion coefficient of at least 2.1.times.10.sup.-8 cm.sup.2 /second and a high onset potential of 2.5 volts or higher. Examples of such organic redox shuttle additives include an alkali metal salt of 1,2,4-triazole, an alkali metal salt of imidazole, 2,3,5,6-tetramethylpyrazine, 1,3,5-tricyanobenzene, and a dialkali metal salt of 3-4-dihydroxy-3-cyclobutene-1,2-dione.

Studies of hemidesmosomes in human amnion: the use of a detergent extraction protocol for compositional and ultrastructural analysis and preparation of a hemidesmosome-enriched fraction from tissue.

PubMed

Behzad, F; Jones, C J; Ball, S; Alvares, T; Aplin, J D

1995-01-01

A method is described for the sequential detergent and high ionic strength extraction of human amnion with the progressive enrichment of the intermediate filament (IF) cytoskeleton and its associated structures including hemidesmosomes (HD). TEM of the extracted epithelium in situ reveals IF bundles beneath the apical cell surface, around the nucleus and at the lateral edges of the cells where association with desmosomes occurs. IF bundles are also very prominent within basal cell processes where they loop through the cytoplasm adjacent to the HDs. A novel connecting filament network is observed running between the IFs and the hemidesmosomal dense plaque. The adjacent IF network contains both cytokeratin and vimentin, the latter revealed much more fully as a result of the extraction protocol. The hemidesmosomal plasma membrane contains integrin subunits alpha 6 and beta 4 and these are quantitatively retained as the basal cell surface during extraction, while nonjunctional plasma membrane is solubilised. Integrin beta 1 is found at the basolateral cell surface but, like actin, is extracted quantitatively and is not present in HDs. The extracted epithelial cells may be recovered by scraping and the IF network depolymerised to produce a particulate fraction containing short residual IFs, associated thin filaments and plaque material. This fraction contains immunoreactive cytokeratin and vimentin. Integrin alpha 6 beta 4 has been used as a biochemical criterion of the presence of HD material in the fraction. Both subunits are highly enriched. The fraction also contains the hemidesmosomal components HD1, BP230 and BP180. This method is likely to be useful in further characterisation of the HD.

Increased iron supplied through Fet3p results in replicative life span extension of Saccharomyces cerevisiae under conditions requiring respiratory metabolism.

PubMed

Botta, Gabriela; Turn, Christina S; Quintyne, Nicholas J; Kirchman, Paul A

2011-10-01

We have previously shown that copper supplementation extends the replicative life span of Saccharomyces cerevisiae when grown under conditions forcing cells to respire. We now show that copper's effect on life span is through Fet3p, a copper containing enzyme responsible for high affinity transport of iron into yeast cells. Life span extensions can also be obtained by supplementing the growth medium with 1mM ferric chloride. Extension by high iron levels is still dependent on the presence of Fet3p. Life span extension by iron or copper requires growth on media containing glycerol as the sole carbon source, which forces yeast to respire. Yeast grown on glucose containing media supplemented with iron show no extension of life span. The iron associated with cells grown in media supplemented with copper or iron is 1.4-1.8 times that of cells grown without copper or iron supplementation. As with copper supplementation, iron supplementation partially rescues the life span of superoxide dismutase mutants. Cells grown with copper supplementation display decreased production of superoxide as measured by dihydroethidium staining. Copyright © 2011 Elsevier Inc. All rights reserved.

Single-cell-type Proteomics: Toward a Holistic Understanding of Plant Function*

PubMed Central

Dai, Shaojun; Chen, Sixue

2012-01-01

Multicellular organisms such as plants contain different types of cells with specialized functions. Analyzing the protein characteristics of each type of cell will not only reveal specific cell functions, but also enhance understanding of how an organism works. Most plant proteomics studies have focused on using tissues and organs containing a mixture of different cells. Recent single-cell-type proteomics efforts on pollen grains, guard cells, mesophyll cells, root hairs, and trichomes have shown utility. We expect that high resolution proteomic analyses will reveal novel functions in single cells. This review provides an overview of recent developments in plant single-cell-type proteomics. We discuss application of the approach for understanding important cell functions, and we consider the technical challenges of extending the approach to all plant cell types. Finally, we consider the integration of single-cell-type proteomics with transcriptomics and metabolomics with the goal of providing a holistic understanding of plant function. PMID:22982375

Anatomical Analysis of Saccharomyces cerevisiae Stalk-Like Structures Reveals Spatial Organization and Cell Specialization

PubMed Central

Scherz, Ruth; Shinder, Vera; Engelberg, David

2001-01-01

Recently we reported an unusual multicellular organization in yeast that we termed stalk-like structures. These structures are tall (0.5 to 3 cm long) and narrow (1 to 3 mm in diameter). They are formed in response to UV radiation of cultures spread on high agar concentrations. Here we present an anatomical analysis of the stalks. Microscopic inspection of cross sections taken from stalks revealed that stalks are composed of an inner core in which cells are dense and vital and a layer of cells (four to six rows) that surrounds the core. This outer layer is physically separated from the core and contains many dead cells. The outer layer may form a protective shell for the core cells. Through electron microscopy analysis we observed three types of cells within the stalk population: (i) cells containing many unusual vesicles, which might be undergoing some kind of cell death; (ii) cells containing spores (usually one or two spores only); and (iii) familiar rounded cells. We suggest that stalk cells are not only spatially organized but may undergo processes that induce a certain degree of cell specialization. We also show that high agar concentration alone, although not sufficient to induce stalk formation, induces dramatic changes in a colony's morphology. Most striking among the agar effects is the induction of growth into the agar, forming peg-like structures. Colonies grown on 4% agar or higher are reminiscent of stalks in some aspects. The agar concentration effects are mediated in part by the Ras pathway and are related to the invasive-growth phenomenon. PMID:11514526

Are Your Cells Pregnant? Relating Biology Laboratory Exercises to Everyday Life.

ERIC Educational Resources Information Center

Rhodes, Simon J.; Banner, Lisa R.

2001-01-01

Presents a laboratory exercise that allows students to investigate the principles of hormone release from endocrine cells, which is highly relevant to students' everyday lives. (Contains 17 references.) (ASK)

Separation of mouse testis cells on a Celsep (TM) apparatus and their usefulness as a source of high molecular weight DNA or RNA

NASA Technical Reports Server (NTRS)

Wolgemuth, D. J.; Gizang-Ginsberg, E.; Engelmyer, E.; Gavin, B. J.; Ponzetto, C.

1985-01-01

The use of a self-contained unit-gravity cell separation apparatus for separation of populations of mouse testicular cells is described. The apparatus, a Celsep (TM), maximizes the unit area over which sedimentation occurs, reduces the amount of separation medium employed, and is quite reproducible. Cells thus isolated have been good sources for isolation of DNA, and notably, high molecular weight RNA.

Fabrication of cell container arrays with overlaid surface topographies.

PubMed

Truckenmüller, Roman; Giselbrecht, Stefan; Escalante-Marun, Maryana; Groenendijk, Max; Papenburg, Bernke; Rivron, Nicolas; Unadkat, Hemant; Saile, Volker; Subramaniam, Vinod; van den Berg, Albert; van Blitterswijk, Clemens; Wessling, Matthias; de Boer, Jan; Stamatialis, Dimitrios

2012-02-01

This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a micro- or nanoscale. For microthermoforming, we apply a new process on the basis of temporary back moulding of polymer films and use the novel concept of a perforated-sheet-like mould. Thermal micro- or nanoimprinting is applied for prepatterning. The novel cell container arrays are fabricated from polylactic acid (PLA) films. The thin-walled microcontainer structures have the shape of a spherical calotte merging into a hexagonal shape at their upper circumferential edges. In the arrays, the cell containers are arranged densely packed in honeycomb fashion. The inner surfaces of the highly curved container walls are provided with various topographical micro- and nanopatterns. For a first validation of the microcontainer arrays as in vitro cell culture substrates, C2C12 mouse premyoblasts are cultured in containers with microgrooved surfaces and shown to align along the grooves in the three-dimensional film substrates. In future stem-cell-biological and tissue engineering applications, microcontainers fabricated using the proposed technology may act as geometrically defined artificial microenvironments or niches.

Safer Electrolytes for Lithium-Ion Cells

NASA Technical Reports Server (NTRS)

Kejha, Joe; Smith, Novis; McCloseky, Joel

2004-01-01

A number of nonvolatile, low-flammability liquid oligomers and polymers based on aliphatic organic carbonate molecular structures have been found to be suitable to be blended with ethylene carbonate to make electrolytes for lithium-ion electrochemical cells. Heretofore, such electrolytes have often been made by blending ethylene carbonate with volatile, flammable organic carbonates. The present nonvolatile electrolytes have been found to have adequate conductivity (about 2 mS/cm) for lithium ions and to remain liquid at temperatures down to -5 C. At normal charge and discharge rates, lithiumion cells containing these nonvolatile electrolytes but otherwise of standard design have been found to operate at current and energy densities comparable to those of cells now in common use. They do not perform well at high charge and discharge rates -- an effect probably attributable to electrolyte viscosity. Cells containing the nonvolatile electrolytes have also been found to be, variously, nonflammable or at least self-extinguishing. Hence, there appears to be a basis for the development of safer high-performance lithium-ion cells.

Toxicology and drug delivery by cucurbit[n]uril type molecular containers.

PubMed

Hettiarachchi, Gaya; Nguyen, Duc; Wu, Jing; Lucas, Derick; Ma, Da; Isaacs, Lyle; Briken, Volker

2010-05-06

Many drug delivery systems are based on the ability of certain macrocyclic compounds - such as cyclodextrins (CDs) - to act as molecular containers for pharmaceutical agents in water. Indeed beta-CD and its derivatives have been widely used in the formulation of hydrophobic pharmaceuticals despite their poor abilities to act as a molecular container (e.g., weak binding (K(a)<10(4) M(-1)) and their challenges toward chemical functionalization. Cucurbit[n]urils (CB[n]) are a class of molecular containers that bind to a variety of cationic and neutral species with high affinity (K(a)>10(4) M(-1)) and therefore show great promise as a drug delivery system. In this study we investigated the toxicology, uptake, and bioactivity of two cucurbit[n]urils (CB[5] and CB[7]) and three CB[n]-type containers (Pentamer 1, methyl hexamer 2, and phenyl hexamer 3). All five containers demonstrated high cell tolerance at concentrations of up to 1 mM in cell lines originating from kidney, liver or blood tissue using assays for metabolic activity and cytotoxicity. Furthermore, the CB[7] molecular container was efficiently internalized by macrophages indicating their potential for the intracellular delivery of drugs. Bioactivity assays showed that the first-line tuberculosis drug, ethambutol, was as efficient in treating mycobacteria infected macrophages when loaded into CB[7] as when given in the unbound form. This result suggests that CB[7]-bound drug molecules can be released from the container to find their intracellular target. Our study reveals very low toxicity of five members of the cucurbit[n]uril family of nanocontainers. It demonstrates the uptake of containers by cells and intracellular release of container-loaded drugs. These results provide initial proof-of-concept towards the use of CB[n] molecular containers as an advanced drug delivery system.

Multifunctional Biocompatible Graphene Oxide Quantum Dots Decorated Magnetic Nanoplatform for Efficient Capture and Two-Photon Imaging of Rare Tumor Cells

PubMed Central

2016-01-01

Circulating tumor cells (CTCs) are extremely rare cells in blood containing billions of other cells. The selective capture and identification of rare cells with sufficient sensitivity is a real challenge. Driven by this need, this manuscript reports the development of a multifunctional biocompatible graphene oxide quantum dots (GOQDs) coated, high-luminescence magnetic nanoplatform for the selective separation and diagnosis of Glypican-3 (GPC3)-expressed Hep G2 liver cancer tumor CTCs from infected blood. Experimental data show that an anti-GPC3-antibody-attached multifunctional nanoplatform can be used for selective Hep G2 hepatocellular carcinoma tumor cell separation from infected blood containing 10 tumor cells/mL of blood in a 15 mL sample. Reported data indicate that, because of an extremely high two-photon absorption cross section (40530 GM), an anti-GPC3-antibody-attached GOQDs-coated magnetic nanoplatform can be used as a two-photon luminescence platform for selective and very bright imaging of a Hep G2 tumor cell in a biological transparency window using 960 nm light. Experimental results with nontargeted GPC3(−) and SK-BR-3 breast cancer cells show that multifunctional-nanoplatform-based cell separation, followed by two-photon imaging, is highly selective for Hep G2 hepatocellular carcinoma tumor cells. PMID:25939643

Distribution of CGRP in the minipig brainstem.

PubMed

Lisardo Sánchez, Manuel; Vecino, Elena; Coveñas, Rafael

2014-05-01

For the first time, an in-depth study has been made of the distribution of fibers and cell bodies containing calcitonin gene-related peptide (CGRP) in the minipig brainstem using an indirect immunoperoxidase technique. The animals studied were not treated with colchicine. Cell bodies containing CGRP were found in 20 nuclei/regions of the brainstem. These perikarya were located in somatomotor, brachiomotor and raphae nuclei, nucleus ambiguus, substantia nigra, nucleus reticularis tegmenti pontis, nucleus prepositus hypoglossi, nuclei olivaris inferior and superior, nuclei pontis, formatio reticularis, nucleus dorsalis tegmenti of Gudden, and in the nucleus reticularis lateralis. Fourteen of the 20 brainstem nuclei showed a high density of immunoreactive cell bodies. In comparison with other species, the minipig, together with the rat, show the most widespread distribution of cell bodies containing CGRP in the mammalian brainstem. Immunoreactive fibers were also observed in the brainstem. However, in the minipig brainstem the density of these fibers is low, as in many brainstem nuclei only single immunoreactive fibers were observed. A high density of immunoreactive fibers was only observed in the pars caudalis of the nucleus tractus spinalis nervi trigemini and in the nucleus ventralis tegmenti of Gudden. According to the observed anatomical distribution of the immunoreactive structures containing CGRP, the peptide could be involved in motor, somatosensory, gustative, and autonomic mechanisms. Copyright © 2014 Wiley Periodicals, Inc.

Three-Dimensional Transgenic Cell Models to Quantify Space Genotoxic Effects

NASA Technical Reports Server (NTRS)

Gonda, S.; Wu, H.; Pingerelli, P.; Glickman, B.

2000-01-01

In this paper we describe a three-dimensional, multicellular tissue-equivalent model, produced in NASA-designed, rotating wall bioreactors using mammalian cells engineered for genomic containment of mUltiple copies of defined target genes for genotoxic assessment. The Rat 2(lambda) fibroblasts (Stratagene, Inc.) were genetically engineered to contain high-density target genes for mutagenesis. Stable three-dimensional, multicellular spheroids were formed when human mammary epithelial cells and Rat 2(lambda) fibroblasts were cocultured on Cytodex 3 Beads in a rotating wall bioreactor. The utility of this spheroidal model for genotoxic assessment was indicated by a linear dose response curve and by results of gene sequence analysis of mutant clones from 400micron diameter spheroids following low-dose, high-energy, neon radiation exposure

High temperature EXAFS experiments in molten actinide fluorides: The challenge of a triple containment cell for radioactive and aggressive liquids

NASA Astrophysics Data System (ADS)

Bessada, Catherine; Zanghi, Didier; Pauvert, Olivier; Maksoud, Louis; Gil-Martin, Ana; Sarou-Kanian, Vincent; Melin, Philippe; Brassamin, Séverine; Nezu, Atsushi; Matsuura, Haruaki

2017-10-01

An airtight double barrier cell with simple geometry has been developed for X-rays absorption measurements at high temperature in solid and molten actinide fluorides. The aim was both to improve the air tightness, to avoid any possible leakage and to maintain the high quality of the signal. The dimensions of the heating chamber were also constrained and minimized to be compatible with the limited space available usually on synchrotron beam lines and with a geometry suitable for absorption/diffraction measurements at high temperature. The design of the double barrier cell was also driven by the safety requirements in every experiment involving radioactive materials. The furnace itself was designed to ensure easy operating modes and disassembly, the aim being to consider the furnace as the ultimate containment. The cell has been tested with different molten fluorides up to more than 1000 °C, starting from non-radioactive LiF-ZrF4 mixtures in order to prove that the cell is absolutely airtight and that not any contamination of the environment occurs. Then it has been successfully applied to thorium fluoride- and uranium fluoride-alkali fluorides mixtures.

Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, T.C.; McLarnon, F.R.; Cairns, E.J.

1994-04-12

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing KOH and a combination of KF and K[sub 2]CO[sub 3] salts which inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics. 8 figures.

Revascularization of ischemic limbs after transplantation of human bone marrow cells with high aldehyde dehydrogenase activity

PubMed Central

Capoccia, Benjamin J.; Robson, Debra L.; Levac, Krysta D.; Maxwell, Dustin J.; Hohm, Sarah A.; Neelamkavil, Marian J.; Bell, Gillian I.; Xenocostas, Anargyros; Link, Daniel C.; Piwnica-Worms, David; Nolta, Jan A.

2009-01-01

The development of cell therapies to treat peripheral vascular disease has proven difficult because of the contribution of multiple cell types that coordinate revascularization. We characterized the vascular regenerative potential of transplanted human bone marrow (BM) cells purified by high aldehyde dehydrogenase (ALDHhi) activity, a progenitor cell function conserved between several lineages. BM ALDHhi cells were enriched for myelo-erythroid progenitors that produced multipotent hematopoietic reconstitution after transplantation and contained nonhematopoietic precursors that established colonies in mesenchymal-stromal and endothelial culture conditions. The regenerative capacity of human ALDHhi cells was assessed by intravenous transplantation into immune-deficient mice with limb ischemia induced by femoral artery ligation/transection. Compared with recipients injected with unpurified nucleated cells containing the equivalent of 2- to 4-fold more ALDHhi cells, mice transplanted with purified ALDHhi cells showed augmented recovery of perfusion and increased blood vessel density in ischemic limbs. ALDHhi cells transiently recruited to ischemic regions but did not significantly integrate into ischemic tissue, suggesting that transient ALDHhi cell engraftment stimulated endogenous revascularization. Thus, human BM ALDHhi cells represent a progenitor-enriched population of several cell lineages that improves perfusion in ischemic limbs after transplantation. These clinically relevant cells may prove useful in the treatment of critical ischemia in humans. PMID:19324906

Characterization of aerosols produced by cell sorters and evaluation of containment

PubMed Central

Holmes, Kevin L.

2011-01-01

In spite of the recognition by the flow cytometry community of potential aerosol hazards associated with cell sorting, there has been no previous study that has thoroughly characterized the aerosols that can be produced by cell sorters. In this study an Aerodynamic Particle Sizer was used to determine the concentration and aerodynamic diameter of aerosols produced by a FACS Aria II cell sorter under various conditions. Aerosol containment and evacuation was also evaluated using this novel methodology. The results showed that high concentrations of aerosols in the range of 1–3 μm can be produced in fail mode and that with decreased sheath pressure, aerosol concentration decreased and aerodynamic diameter increased. Although the engineering controls of the FACS Aria II for containment were effective, sort chamber evacuation of aerosols following a simulated nozzle obstruction was ineffective. However, simple modifications to the FACS Aria II are described that greatly improved sort chamber aerosol evacuation. The results of this study will facilitate the risk assessment of cell sorting potentially biohazardous samples by providing much needed data regarding aerosol production and containment. PMID:22052694

Establishment of two new cell lines derived from human breast carcinomas with HER-2/neu amplification.

PubMed Central

Meltzer, P.; Leibovitz, A.; Dalton, W.; Villar, H.; Kute, T.; Davis, J.; Nagle, R.; Trent, J.

1991-01-01

Two human cell lines (UACC-812 and 893), both containing significant amplification of the HER-2/neu gene, were established from biopsy specimens of breast carcinomas. One patient had Stage II breast carcinoma; the other had metastatic disease. Characterisation of these lines has revealed that both are highly aneuploid containing multiple clonal chromosome alterations, have doubling times near 100 h, and are oestrogen and progesterone receptor negative. Electron microscopy demonstrates that both lines contain numerous microvilli, cytoplasmic filaments, multivesicular bodies, and desmosomes. Immunoblot analysis for P-glycoprotein using the monoclonal antibody C219 was negative for both patient cell lines. These relatively rare cell lines may represent a useful model to investigate human breast carcinomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1674877

Design and fabrication of silver-hydrogen cells

NASA Technical Reports Server (NTRS)

Klein, M. G.

1975-01-01

The design and fabrication of silver-hydrogen secondary cells capable of delivering higher energy densities than comparable nickel-cadmium and nickel-hydrogen cells and relatively high cycle life is presented. An experimental task utilizing single electrode pairs for the optimization of the individual electrode components, the preparation of a design for lightweight 20Ahr cells, and the fabrication of four 20Ahr cells in heavy wall test housing containing electrode stacks of the lightweight design are described. The design approach is based on the use of a single cylindrical self-contained cell with a stacked disc sequence of electrodes. The electrode stack design is based on the use of NASA- Astropower Separator Material, PPF fuel cell anodes, an intercell electrolyte reservoir concept and sintered silver electrodes. Results of performance tests are given.

Operation of the 25kW NASA Lewis Research Center Solar Regenerative Fuel Cell Tested Facility

NASA Technical Reports Server (NTRS)

Moore, S. H.; Voecks, G. E.

1997-01-01

Assembly of the NASA Lewis Research Center(LeRC)Solar Regenerative Fuel Cell (RFC) Testbed Facility has been completed and system testing has proceeded. This facility includes the integration of two 25kW photovoltaic solar cell arrays, a 25kW proton exchange membrane (PEM) electrolysis unit, four 5kW PEM fuel cells, high pressure hydrogen and oxygen storage vessels, high purity water storage containers, and computer monitoring, control and data acquisition.

Construction of Halomonas bluephagenesis capable of high cell density growth for efficient PHA production.

PubMed

Ren, Yilin; Ling, Chen; Hajnal, Ivan; Wu, Qiong; Chen, Guo-Qiang

2018-05-01

High-cell-density cultivation is an effective way to improve the productivity of microbial fermentations and in turn reduce the cost of the final products, especially in the case of intracellular products. Halomonas bluephagenesis TD01 is a halophilic platform bacterium for the next generation of industrial biotechnology with a native PHA synthetic pathway, able to grow under non-sterile continuous fermentation conditions. A selection strategy for mutant strains that can grow to a high cell density was developed. Based on an error-prone DNA polymerase III ε subunit, a genome-wide random mutagenesis system was established and used in conjunction with an artificial high cell density culture environment during the selection process. A high-cell-density H. bluephagenesis TDHCD-R3 obtained after 3 rounds of selection showed an obvious enhancement of resistance to toxic metabolites including acetate, formate, lactate and ethanol compared to wild-type. H. bluephagenesis TDHCD-R3-8-3 constructed from H. bluephagenesis TDHCD-R3 by overexpressing an optimized phaCAB operon was able to grow to 15 g/L cell dry weight (CDW) containing 94% PHA in shake flask studies. H. bluephagenesis TDHCD-R3-8-3 was grown to more than 90 g/L CDW containing 79% PHA compared with only 81 g/L with 70% PHA by the wild type when incubated in a 7-L fermentor under the same conditions.

Changes in metabolic markers in insulin-producing β-cells during hypoxia-induced cell death as studied by NMR metabolomics.

PubMed

Tian, Lianji; Kim, Hoe Suk; Kim, Heyonjin; Jin, Xing; Jung, Hye Seung; Park, Kyong Soo; Cho, Kyoung Won; Park, Sunghyouk; Moon, Woo Kyung

2013-08-02

This study was designed to investigate changes in the metabolites in the intracellular fluid of the pancreatic β-cell line INS-1 to identify potential early and late biomarkers for predicting hypoxia-induced cell death. INS-1 cells were incubated under normoxic conditions (95% air, 5% CO₂) or hypoxic conditions (1% O₂, 5% CO₂, 95% N₂) for 2, 4, 6, 12, or 24 h. The biological changes indicating the process of cell death were analyzed using the MTT assay, flow cytometry, Western blotting, and immunostaining. Changes in the metabolic profiles from cell lysates were identified using ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, and the spectra were analyzed by the multivariate model Orthogonal Projections to Latent Structure-Discriminant Analysis. Cell viability decreased approximately 40% after 12-24 h of hypoxia, coincident with a high level of cleaved caspase-3. A high level of HIF-1α was detected in the 12-24 h hypoxic conditions. The metabolite profiles were altered according to the degree of exposure to hypoxia. A spectral analysis showed significant differences in creatine-containing compounds at the early stage (2-6 h) and taurine-containing compounds at the late stage (12-24 h), with the detection of HIF-1α and cleaved caspase-3 in cells exposed to hypoxia compared to normoxia. Glycerophosphocholine decreased during the early stage hypoxia. The change in taurine- and creatine-containing compounds and choline species could be involved in the β-cell death process as inhibitors or activators of cell death. Our results imply that assessment by ¹H NMR spectroscopy would be a useful tool to predict the cell death process and to identify molecules regulating hypoxia-induced cell death mechanisms.

Apoptosis induced by tumor necrosis factor-alpha in rat hepatocyte cell lines expressing hepatitis B virus.

PubMed Central

Guilhot, S.; Miller, T.; Cornman, G.; Isom, H. C.

1996-01-01

Three well differentiated SV40-immortalized rat hepatocyte cell lines, CWSV1, CWSV2, and CWSV14, and Hepatitis B Virus (HBV)-producing cell lines derived from them were examined for sensitivity to tumor necrosis factor (TNF)-alpha. CWSV1, CWSV2, and CWSV14 cells were co-transfected with a DNA construct containing a dimer of the HBV genome and the neo gene and selected in G418 to generate stable cell lines. Characterization of these cell lines indicated that they contain integrated HBV DNA, contain low molecular weight HBV DNA compatible with the presence of HBV replication intermediates, express HBV transcripts, and produce HBV proteins. The viability of CWSV1, CWSV2, and CWSV2 cells was not significantly altered when they were treated with TNF-alpha at concentrations as high as 20,000 U/ml. The HBV-expressing CWSV1 cell line, SV1di36, and the HBV-expressing CWSV14 cell line, SV14di208, were also not killed when treated with TNF-alpha. However, the HBV-expressing CWSV2 cell line, SV2di366, was extensively killed when treated with TNF-alpha at concentrations ranging from 200 to 20,000 U/ml. Analysis of several different HBV-producing CWSV2 cell lines indicated that TNF-alpha killing depended upon the level of HBV expression. The TNF-alpha-induced cell killing in high HBV-producing CWSV2 cell lines was accompanied by the presence of an oligonucleosomal DNA ladder characteristic of apoptosis. Images Figure 2 Figure 3 Figure 4 Figure 6 Figure 9 Figure 10 Figure 11 PMID:8774135

Stability of Materials in High Temperature Water Vapor: SOFC Applications

NASA Technical Reports Server (NTRS)

Opila, E. J.; Jacobson, N. S.

2010-01-01

Solid oxide fuel cell material systems require long term stability in environments containing high-temperature water vapor. Many materials in fuel cell systems react with high-temperature water vapor to form volatile hydroxides which can degrade cell performance. In this paper, experimental methods to characterize these volatility reactions including the transpiration technique, thermogravimetric analysis, and high pressure mass spectrometry are reviewed. Experimentally determined data for chromia, silica, and alumina volatility are presented. In addition, data from the literature for the stability of other materials important in fuel cell systems are reviewed. Finally, methods for predicting material recession due to volatilization reactions are described.

Effect of Bromouracil-containing Deoxyribonucleic Acid on Bacillus subtilis

PubMed Central

Gimlin, Dixie M.; Hardman, Sue D.; Kelley, Betty N.; Butler, Grace C.; Leach, Franklin R.

1966-01-01

Gimlin, Dixie M. (Oklahoma State University, Stillwater), Sue D. Hardman, Betty N. Kelley, Grace C. Butler, and Franklin R. Leach. Effect of bromouracil-containing deoxyribonucleic acid on Bacillus subtilis. J. Bacteriol. 92:366–374. 1966.—Replacement of one-half of the thymine with bromouracil in Bacillus subtilis transforming deoxyribonucleic acid (DNA) resulted in a slight decrease in transforming activity, but, when used at high concentrations, this DNA preparation inhibited cell growth. Acid-hydrolyzed DNA, or addition of equivalent concentrations of the free base bromouracil in a transforming mixture, was without effect on cell growth. Treatment of the DNA preparation with deoxyribonuclease completely destroyed transforming activity and killing effect, whereas treatments with ribonuclease and trypsin were without effect on either transformation or killing activity. Growth of competent B. subtilis cells in test tubes was inhibited by high concentrations of both normal and bromouracil-containing DNA, with the bromouracil-containing DNA being significantly more inhibitory. This type of inhibition was also reflected in the time of division of the cells. The inhibitory effect was not due to viscosity, or to mutagenicity. The time course of killing paralleled transformation, and competency was required. These results can be interpreted as being due to uptake of homologous but imperfect DNA (containing bromouracil instead of thymine) by means of the systems involved in transformation, followed by either integration (resulting in lethal transformation, activation of a defective, nonlytic but lethal prophage) or interference with the recombination mechanism. PMID:16562122

3D printed sample holder for in-operando EPR spectroscopy on high temperature polymer electrolyte fuel cells

NASA Astrophysics Data System (ADS)

Niemöller, Arvid; Jakes, Peter; Kayser, Steffen; Lin, Yu; Lehnert, Werner; Granwehr, Josef

2016-08-01

Electrochemical cells contain electrically conductive components, which causes various problems if such a cell is analyzed during operation in an EPR resonator. The optimum cell design strongly depends on the application and it is necessary to make certain compromises that need to be individually arranged. Rapid prototyping presents a straightforward option to implement a variable cell design that can be easily adapted to changing requirements. In this communication, it is demonstrated that sample containers produced by 3D printing are suitable for EPR applications, with a particular emphasis on electrochemical applications. The housing of a high temperature polymer electrolyte fuel cell (HT-PEFC) with a phosphoric acid doped polybenzimidazole membrane was prepared from polycarbonate by 3D printing. Using a custom glass Dewar, this fuel cell could be operated at temperatures up to 140 °C in a standard EPR cavity. The carbon-based gas diffusion layer showed an EPR signal with a characteristic Dysonian line shape, whose evolution could be monitored in-operando in a non-invasive manner.

3D printed sample holder for in-operando EPR spectroscopy on high temperature polymer electrolyte fuel cells.

PubMed

Niemöller, Arvid; Jakes, Peter; Kayser, Steffen; Lin, Yu; Lehnert, Werner; Granwehr, Josef

2016-08-01

Electrochemical cells contain electrically conductive components, which causes various problems if such a cell is analyzed during operation in an EPR resonator. The optimum cell design strongly depends on the application and it is necessary to make certain compromises that need to be individually arranged. Rapid prototyping presents a straightforward option to implement a variable cell design that can be easily adapted to changing requirements. In this communication, it is demonstrated that sample containers produced by 3D printing are suitable for EPR applications, with a particular emphasis on electrochemical applications. The housing of a high temperature polymer electrolyte fuel cell (HT-PEFC) with a phosphoric acid doped polybenzimidazole membrane was prepared from polycarbonate by 3D printing. Using a custom glass Dewar, this fuel cell could be operated at temperatures up to 140°C in a standard EPR cavity. The carbon-based gas diffusion layer showed an EPR signal with a characteristic Dysonian line shape, whose evolution could be monitored in-operando in a non-invasive manner. Copyright © 2016. Published by Elsevier Inc.

Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

PubMed

Shiba, Tomonori; Mii, Masahiro

2005-12-01

Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

Mitotic control of human papillomavirus genome-containing cells is regulated by the function of the PDZ-binding motif of the E6 oncoprotein.

PubMed

Marsh, Elizabeth K; Delury, Craig P; Davies, Nicholas J; Weston, Christopher J; Miah, Mohammed A L; Banks, Lawrence; Parish, Joanna L; Higgs, Martin R; Roberts, Sally

2017-03-21

The function of a conserved PDS95/DLG1/ZO1 (PDZ) binding motif (E6 PBM) at the C-termini of E6 oncoproteins of high-risk human papillomavirus (HPV) types contributes to the development of HPV-associated malignancies. Here, using a primary human keratinocyte-based model of the high-risk HPV18 life cycle, we identify a novel link between the E6 PBM and mitotic stability. In cultures containing a mutant genome in which the E6 PBM was deleted there was an increase in the frequency of abnormal mitoses, including multinucleation, compared to cells harboring the wild type HPV18 genome. The loss of the E6 PBM was associated with a significant increase in the frequency of mitotic spindle defects associated with anaphase and telophase. Furthermore, cells carrying this mutant genome had increased chromosome segregation defects and they also exhibited greater levels of genomic instability, as shown by an elevated level of centromere-positive micronuclei. In wild type HPV18 genome-containing organotypic cultures, the majority of mitotic cells reside in the suprabasal layers, in keeping with the hyperplastic morphology of the structures. However, in mutant genome-containing structures a greater proportion of mitotic cells were retained in the basal layer, which were often of undefined polarity, thus correlating with their reduced thickness. We conclude that the ability of E6 to target cellular PDZ proteins plays a critical role in maintaining mitotic stability of HPV infected cells, ensuring stable episome persistence and vegetative amplification.

Two Distinct States of Escherichia coli Cells That Overexpress Recombinant Heterogeneous β-Galactosidase*

PubMed Central

Zhao, Yun; He, Wei; Liu, Wei-Feng; Liu, Chun-Chun; Feng, Li-Kui; Sun, Lei; Yan, Yong-Bin; Hang, Hai-Ying

2012-01-01

The mechanism by which inclusion bodies form is still not well understood, partly because the dynamic processes of the inclusion body formation and its solubilization have hardly been investigated at an individual cell level, and so the important detailed information has not been acquired for the mechanism. In this study, we investigated the in vivo folding and aggregation of Aspergillus phoenicis β-d-galactosidase fused to a red fluorescence protein in individual Escherichia coli cells. The folding status and expression level of the recombinant β-d-galactosidase at an individual cell level was analyzed by flow cytometry in combination with transmission electron microscopy and Western blotting. We found that individual E. coli cells fell into two distinct states, one containing only inclusion bodies accompanied with low galactosidase activity and the other containing the recombinant soluble galactosidase accompanied with high galactosidase activity. The majority of the E. coli cells in the later state possessed no inclusion bodies. The two states of the cells were shifted to a cell state with high enzyme activity by culturing the cells in isopropyl 1-thio-β-d-galactopyranoside-free medium after an initial protein expression induction in isopropyl 1-thio-β-d-galactopyranoside-containing medium. This shift of the cell population status took place without the level change of the β-d-galactosidase protein in individual cells, indicating that the factor(s) besides the crowdedness of the recombinant protein play a major role in the cell state transition. These results shed new light on the mechanism of inclusion body formation and will facilitate the development of new strategies in improving recombinant protein quality. PMID:22303013

Localization of tritiated vitamin A in lymph nodes of the mouse: an autoradiographic study of vitamin A-storing cells

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

Hirosawa, K.; Yamada, E.

1981-07-01

Localization of tritiated vitamin A in lymph nodes of the mouse was investigated by the use of light- and electron-microscopic autoradiography. Young male mice were fed a diet containing 3H-vitamin A acetate for a week. Lymph nodes were removed and prepared for autoradiography. Lipid droplets in fibroblast-like cells showed high concentrations of radioactivity. These cells were distributed around lymphatic sinuses and blood vessels. The cells can, therefore, be classified as ''vitamin A-storing cells'' according to criteria proposed earlier by Yamada and Hirosawa (1976). Control animals from the same litter were maintained on ordinary laboratory food for the same period andmore » examined by electron microscopy. Lipid-droplet-containing cells were found in the same areas as in the experimental animals but in fewer numbers. This suggests that the increased number of vitamin A-containing lipid droplets is due to hypervitaminosis A in the experimental animals. The presence of some cells containing these droplets in the control animals would imply that even under normal feeding conditions the animals ingested excess amounts of vitamin A, which was retained in lipid droplets. The stored vitamin A probably participates in metabolic processes such as the formation of glycoproteins in ground substance.« less

High-Performance Non-Fullerene Organic Solar Cells Based on a Selenium-Containing Polymer Donor and a Twisted Perylene Bisimide Acceptor

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

Liu, Tao; Meng, Dong; Cai, Yunhao

2016-04-23

A novel polymer donor (PBDTS-Se) is designed to match with a non-fullerene acceptor (SdiPBI-S). The corresponding solar cells show a high efficiency of 8.22%, which result from synergetic improvements of light harvesting, charge carrier transport and collection, and morphology. The results indicate that rational design of novel donor materials is important for non-fullerene organic solar cells.

Thrombopoietin contributes to the formation and the maintenance of hematopoietic progenitor-containing cell clusters in the aorta-gonad-mesonephros region.

PubMed

Harada, Kaho; Nobuhisa, Ikuo; Anani, Maha; Saito, Kiyoka; Taga, Tetsuya

2017-07-01

In the midgestation mouse embryo, hematopoietic cell clusters containing hematopoietic stem/progenitor cells arise in the aorta-gonad-mesonephros (AGM) region. We have previously reported that forced expression of the Sox17 transcription factor in CD45 low c-Kit high AGM cells, which are the hematopoietic cellular component of the cell clusters, and subsequent coculture with OP9 stromal cells in the presence of three cytokines, stem cell factor (SCF), interleukin-3 (IL-3), and thrombopoietin (TPO), led to the formation and the maintenance of cell clusters with cells at an undifferentiated state in vitro. In this study, we investigated the role of each cytokine in the formation of hematopoietic cell clusters. We cultured Sox17-transduced AGM cells with each of the 7 possible combinations of the three cytokines. The size and the number of Sox17-transduced cell clusters in the presence of TPO, either alone or in combination, were comparable to that observed with the complete set of the three cytokines. Expression of TPO receptor, c-Mpl was almost ubiquitously expressed and maintained in Sox17-transduced hematopoietic cell clusters. In addition, the expression level of c-Mpl was highest in the CD45 low c-Kit high cells among the Sox17-transduced cell clusters. Moreover, c-Mpl protein was highly expressed in the intra-aortic hematopoietic cell clusters in comparison with endothelial cells of dorsal aorta. Finally, stimulation of the endothelial cells prepared from the AGM region by TPO induced the production of hematopoietic cells. These results suggest that TPO contributes to the formation and the maintenance of hematopoietic cell clusters in the AGM region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of recombinant adenovirus containing human interlukin-4 gene.

PubMed

Mojarrad, Majid; Abdolazimi, Yassan; Hajati, Jamshid; Modarressi, Mohammad Hossein

2011-11-01

Recombinant adenoviruses are currently used for a variety of purposes, including in vitro gene transfer, in vivo vaccination, and gene therapy. Ability to infect many cell types, high efficiency in gene transfer, entering both dividing and non dividing cells, and growing to high titers make this virus a good choice for using in various experiments. In the present experiment, a recombinant adenovirus containing human IL-4 coding sequence was made. IL-4 has several characteristics that made it a good choice for using in cancer gene therapy, controlling inflammatory diseases, and studies on autoimmune diseases. In brief, IL-4 coding sequence was amplified by and cloned in pAd-Track-CMV. Then, by means of homologous recombination between recombinant pAd-Track-CMV and Adeasy-1 plasmid in bacteria, recombinant adenovirus complete genome was made and IL-4 containing shuttle vector was incorporated into the viral backbone. After linearization, for virus packaging, viral genome was transfected into HEK-293 cell line. Viral production was conveniently followed with the aid of green fluorescent protein. Recombinant adenovirus produced here, was capable to infecting cell lines and express interlukin-4 in cell. This system can be used as a powerful, easy, and cost benefit tool in various studies on cancer gene therapy and also studies on immunogenetics.

Perovskites in the comb roof base of hornets: their possible function.

PubMed

Ishay, J S; Joseph, Z; Galushko, D; Ermakov, N; Bergman, D J; Barkay, Z; Stokroos, I; van der Want, J

2005-04-01

On the ceiling of the Oriental hornet comb cell, there are mineral granules of polycrystalline material known to belong to the group of perovskites. In a comb cell intended to house a worker hornet, the roof base usually carries one or several such perovskite granules containing titanium (Ti), whereas in the roof base of a cell housing a developing queen, there are usually several granules containing a high percentage of silicon (Si), aluminum (Al), calcium (Ca), and iron (Fe), but very little if any Ti. In worker comb cells, Ti usually appears as ilmenite (FeTiO3). Besides documenting the above-mentioned facts, this report discusses possible reasons for the appearance of ilmenite crystals in worker cells only and not in queen cells. (c) 2005 Wiley-Liss, Inc.

Prevalence of antibodies to soluble antigen of Epstein-Barr virus-producing cells (P3HR-1) in the sera of hamadryas baboons of the high lymphoma incidence stock.

PubMed

Voevodin, A F; Lapin, B A; Yakovleva, L A; Ponomarjova, T I; Agrba, V Z

1979-01-01

Soluble antigen of P3HR-1 cells (SA-P3HR-1) was identified in indirect double immunodiffusion enhanced with tannic acid using serum of a nasopharyngeal carcinoma patient containing high-titer antibodies to Epstein-Barr virus (EBV) antigens. SA-P3HR-1 was nonidentical to soluble antigen of Raji cells. Human and baboon sera containing antibodies to all the known antigen of EBV and HVP respectively were anti-SA-3HR-1-positive. Human and baboon sera containing antibodies to all the known antigens of EBV and herpesvirus Papio (HVP) were also anti-SA-P3HR-1-negative. Prevalence of anti-SA-P3HR-1 was very high in two groups of the high-lymphoma incidence stock of hamadryas baboons of the Sukhumi monkey colony. 54% (15 of 28) and 38% (13 of 34) of clinically lymphomatous and clinical normal monkeys, respectively, were anti-SA-P3HR-1-positive.. Only 1 of 30 normal baboons studied, living in the forest and having no contacts with the baboons in the main stock of the Sukhumi monkey colony, was anti-SA-P3HR-1-positive (3%).

High-Throughput Cryopreservation of Plant Cell Cultures for Functional Genomics

PubMed Central

Ogawa, Yoichi; Sakurai, Nozomu; Oikawa, Akira; Kai, Kosuke; Morishita, Yoshihiko; Mori, Kumiko; Moriya, Kanami; Fujii, Fumiko; Aoki, Koh; Suzuki, Hideyuki; Ohta, Daisaku; Saito, Kazuki; Shibata, Daisuke

2012-01-01

Suspension-cultured cell lines from plant species are useful for genetic engineering. However, maintenance of these lines is laborious, involves routine subculturing and hampers wider use of transgenic lines, especially when many lines are required for a high-throughput functional genomics application. Cryopreservation of these lines may reduce the need for subculturing. Here, we established a simple protocol for cryopreservation of cell lines from five commonly used plant species, Arabidopsis thaliana, Daucus carota, Lotus japonicus, Nicotiana tabacum and Oryza sativa. The LSP solution (2 M glycerol, 0.4 M sucrose and 86.9 mM proline) protected cells from damage during freezing and was only mildly toxic to cells kept at room temperature for at least 2 h. More than 100 samples were processed for freezing simultaneously. Initially, we determined the conditions for cryopreservation using a programmable freezer; we then developed a modified simple protocol that did not require a programmable freezer. In the simple protocol, a thick expanded polystyrene (EPS) container containing the vials with the cell–LSP solution mixtures was kept at −30°C for 6 h to cool the cells slowly (pre-freezing); samples from the EPS containers were then plunged into liquid nitrogen before long-term storage. Transgenic Arabidopsis cells were subjected to cryopreservation, thawed and then re-grown in culture; transcriptome and metabolome analyses indicated that there was no significant difference in gene expression or metabolism between cryopreserved cells and control cells. The simplicity of the protocol will accelerate the pace of research in functional plant genomics. PMID:22437846

Peptides containing antigenic and cationic domains have enhanced, multivalent immunogenicity when bound to DNA vaccines.

PubMed

Riedl, Petra; Reimann, Jörg; Schirmbeck, Reinhold

2004-02-01

We explored strategies to codeliver DNA- and peptide-based vaccines in a way that enhances the immunogenicity of both components of the combination vaccine for T cells. Specific CD8(+) T cell responses to an antigenic peptide are primed when the peptide is fused to a cationic peptide domain that is bound to plasmid DNA or oligonucleotides (ODN; with or without CpG motifs). Plasmid DNA mixed with antigenic/cationic peptides or histones forms large complexes with different biological properties depending on the molar ratios of peptide/protein and polynucleotide. Complexes containing high (but not low) molar ratios of cationic peptide to DNA facilitate transfection (DNA uptake and expression of the plasmid-encoded product) of cells. In contrast, complexes containing low (but not high) molar ratios of cationic peptide to DNA prime potent multispecific T cell responses after a single intramuscular injection of the complexes. The general validity of this observation was confirmed mixing different antigenic/cationic peptides with different DNA vaccines. In these vaccine formulations, multispecific CD8(+) T cell responses specific for epitopes of the peptide- as well as the DNA-based vaccine were efficiently coprimed, together with humoral antibody responses to conformational determinants of large viral antigens encoded by the DNA vaccine. The data indicate that mixtures of DNA vaccines with antigenic, cationic peptides are immunogenic vaccine formulations particularly suited for the induction of multispecific T cell responses.

The Role of Electrolyte Upon the SEI Formation Characteristics and Low Temperature Performance of Lithium-Ion Cells With Graphite Anodes

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Greenbaum, S.; Surampudi, S.

2000-01-01

Quarternary lithium-ion battery electrolyte solutions containing ester co-solvents in mixtures of carbonates have been demonstrated to have high conductivity at low temperatures (< -20C). However, in some cases the presence of such co-solvents does not directly translate into improved low temperature cell performance, presumably due to the formation of ionically resistive surface films on carbonaceous anodes. In order to understand this behavior, a number of lithium-graphite cells have been studied containing electrolytes with various ester co-solvents, including methyl acetate (MA), ethyl acetate (EA), ethyl propionate (EP), and ethyl butyrate (EB). The charge/discharge characterization of these cells indicates that the higher molecular weight esters result in electrolytes which possess superior low temperature performance in contrast to the lower molecular weight ester-containing solutions, even though these solutions display lower conductivity values.

From coin cells to 400 mAh pouch cells: Enhancing performance of high-capacity lithium-ion cells via modifications in electrode constitution and fabrication

NASA Astrophysics Data System (ADS)

Trask, Stephen E.; Li, Yan; Kubal, Joseph J.; Bettge, Martin; Polzin, Bryant J.; Zhu, Ye; Jansen, Andrew N.; Abraham, Daniel P.

2014-08-01

In this article we describe efforts to improve performance and cycle life of cells containing Li1.2Ni0.15Mn0.55Co0.1O2-based positive and graphite-based negative electrodes. Initial work to identify high-performing materials, compositions, fabrication variables, and cycling conditions is conducted in coin cells. The resulting information is then used for the preparation of double-sided electrodes, assembly of pouch cells, and electrochemical testing. We report the cycling performance of cells with electrodes prepared under various conditions. Our data indicate that cells with positive electrodes containing 92 wt.% Li1.2Ni0.15Mn0.55Co0.1O2, 4 wt.% carbons (no graphite), and 4 wt.% PVdF (92-4-4) show ∼20% capacity fade after 1000 cycles in the 2.5-4.4 V range, significantly better than our baseline cells that show the same fade after only 450 cycles. Our analyses indicate that the major contributors to cell energy fade are capacity loss and impedance rise. Therefore incorporating approaches that minimize capacity fade and impedance rise, such as electrode coatings and electrolyte additives, can significantly enhance calendar and cycle life of this promising cell chemistry.

From coin cells to 400 mAh pouch cells: Enhancing performance of high-capacity lithium-ion cells via modifications in electrode constitution and fabrication

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

Trask, Stephen E.; Li, Yan; Kubal, Joseph J.

2014-08-01

In this article we describe efforts to improve performance and cycle life of cells containing Li1.2Ni0.15Mn0.55Co0.1O2-based positive and graphite-based negative electrodes. Initial work to identify high-performing materials, compositions, fabrication variables, and cycling conditions is conducted in coin cells. The resulting information is then used for the preparation of double-sided electrodes, assembly of pouch cells, and electrochemical testing. We report the cycling performance of cells with electrodes prepared under various conditions. Our data indicate that cells with positive electrodes containing 92 wt% Li1.2Ni0.15Mn0.55Co0.1O2, 4 wt% carbons (no graphite), and 4 wt% PVdF (92-4-4) show ~20% capacity fade after 1000 cycles inmore » the 2.5-4.4V range, significantly better than our baseline cells that show the same fade after only 450 cycles. Our analyses indicate that the major contributors to cell energy fade are capacity loss and impedance rise. Therefore incorporating approaches that minimize capacity fade and impedance rise, such as electrode coatings and electrolyte additives, can significantly enhance calendar and cycle life of this promising cell chemistry.« less

Apparatus and process for the electrolytic reduction of uranium and plutonium oxides

DOEpatents

Poa, David S.; Burris, Leslie; Steunenberg, Robert K.; Tomczuk, Zygmunt

1991-01-01

An apparatus and process for reducing uranium and/or plutonium oxides to produce a solid, high-purity metal. The apparatus is an electrolyte cell consisting of a first container, and a smaller second container within the first container. An electrolyte fills both containers, the level of the electrolyte in the first container being above the top of the second container so that the electrolyte can be circulated between the containers. The anode is positioned in the first container while the cathode is located in the second container. Means are provided for passing an inert gas into the electrolyte near the lower end of the anode to sparge the electrolyte and to remove gases which form on the anode during the reduction operation. Means are also provided for mixing and stirring the electrolyte in the first container to solubilize the metal oxide in the electrolyte and to transport the electrolyte containing dissolved oxide into contact with the cathode in the second container. The cell is operated at a temperature below the melting temperature of the metal product so that the metal forms as a solid on the cathode.

PD-1(HIGH) Follicular CD4 T Helper Cell Subsets Residing in Lymph Node Germinal Centers Correlate with B Cell Maturation and IgG Production in Rhesus Macaques.

PubMed

Xu, Huanbin; Wang, Xiaolei; Lackner, Andrew A; Veazey, Ronald S

2014-01-01

CD4+ T follicular helper (TFH) cells guide development and maturation of B cells and are crucial for effective antibody responses. Here we found rhesus macaque TFH cells, defined as CXCR5+CD4 T cells, contain two major populations: PD-1(INT) and PD-1(HIGH) cells. Of these, PD-1(HIGH)CD4+ T cells highly co-express ICOS but little CCR7, and reside in lymph node germinal centers (GCs), but not in blood. These cells secrete IL-21 and express transcriptional factor Bcl-6 at higher levels than CXCR5+PD-1(INT)CD4+ T cells. In addition, the frequency of PD-1(HIGH)CD4+ T cells is low in lymph nodes of newborns, but increases with age. Levels of PD-1(HIGH)CD4+ T cells correlate with mature B cells in lymph nodes, and PD-1 blockade in PD-1(HIGH)CD4+ T and B cell co-cultures significantly inhibits IgG production. In summary, PD-1(HIGH)CD4+ T cells residing in GC represent a specific TFH subset that contributes to maturation of B cells and IgG production.

High Cell Surface Expression of CD4 Allows Distinction of CD4+CD25+ Antigen-specific Effector T Cells from CD4+CD25+ Regulatory T Cells in Murine Experimental Autoimmune Encephalomyelitis

PubMed Central

Li, Jinzhu; Ridgway, William; Fathman, C. Garrison; Tse, Harley Y.; Shaw, Michael K.

2008-01-01

Analysis of T regulatory cells (Treg) and T effector cells (Teff) in experimental autoimmune encephalomyelitis is complicated by the fact that both cell types express CD4 and CD25. We demonstrate that encephalitogenic T cells, following antigen recognition, up regulate cell surface expression of CD4. The CD4high sub-population contains all of the antigen response as shown by proliferation and cytokine secretion, and only these cells are capable of transferring EAE to naive animals. On the other hand, a FACS separable CD25+ sub-population of cells displayed consistent levels of CD4 prior to and after antigen stimulation. These cells displayed characteristics of Treg, such as expressing high levels of the Foxp3 gene and the ability to suppress mitogenic T cell responses. PMID:17920698

ABCB1 identifies a subpopulation of uveal melanoma cells with high metastatic propensity

PubMed Central

Landreville, Solange; Agapova, Olga A.; Kneass, Zachary T.; Salesse, Christian; Harbour, J. William

2011-01-01

SUMMARY Metastasis of tumor cells to distant organs is the leading cause of death in melanoma. Yet, the mechanisms of metastasis remain poorly understood. One key question is whether all cells in a primary tumor are equally likely to metastasize or whether subpopulations of cells preferentially give rise to metastases. Here, we identified a subpopulation of uveal melanoma cells expressing the multidrug resistance transporter ABCB1 that are highly metastatic compared to ABCB1− bulk tumor cells. ABCB1+ cells also exhibited enhanced clonogenicity, anchorage independent growth, tumorigenicity and mitochondrial activity compared to ABCB1− cells. A375 cutaneous melanoma cells contained a similar subpopulation of highly metastatic ABCB1+ cells. These findings suggest that some uveal melanoma cells have greater potential for metastasis than others, and that a better understanding of such cells may be necessary for more successful therapies for metastatic melanoma. PMID:21575142

Crosslinked polybenzimidazoles containing branching structure as membrane materials with excellent cell performance and durability for fuel cell applications

NASA Astrophysics Data System (ADS)

Hu, Meishao; Ni, Jiangpeng; Zhang, Boping; Neelakandan, Sivasubramaniyan; Wang, Lei

2018-06-01

Crosslinking is an effective method to improve the properties of high temperature proton exchange membranes based on polybenzimidazole. However, the compact structure of crosslinked polybenzimidazole hinders the phosphoric acid absorption of the membranes, resulting in a relatively poor fuel cell performance. Recently, we find that branched polymers can absorb more phosphoric acid with a larger free volume, but suffer from deteriorated mechanical strength. In this work, a new method is proposed to obtain excellent over-all properties of high temperature proton exchange membranes. A series of crosslinked polybenzimidazoles containing branching structure as membrane materials are successfully prepared for the first time. Compared with conventional crosslinked membranes, these crosslinked polybenzimidazole membranes containing branching structure exhibit a higher phosphoric acid doping level and proton conductivity, improved durability, lower swelling rate and comparable mechanical strength. In particular, the fuel cell base on the crosslinked and branched membrane with a 10% ratio of crosslinker in non-humidified hydrogen/air at 160 °C achieves a power density of 404 mW cm-2. The results indicate that the combination of crosslinking and branching is an effective approach to improve the properties of polybenzimidazole membrane materials.

Functional characterization of cell hybrids generated by induced fusion of primary porcine mesenchymal stem cells with an immortal murine cell line.

PubMed

Islam, M Q; Ringe, J; Reichmann, E; Migotti, R; Sittinger, M; da S Meirelles, L; Nardi, N B; Magnusson, P; Islam, K

2006-10-01

Bone marrow mesenchymal stem cells (MSC) integrate into various organs and contribute to the regeneration of diverse tissues. However, the mechanistic basis of the plasticity of MSC is not fully understood. The change of cell fate has been suggested to occur through cell fusion. We have generated hybrid cell lines by polyethylene-glycol-mediated cell fusion of primary porcine MSC with the immortal murine fibroblast cell line F7, a derivative of the GM05267 cell line. The hybrid cell lines display fibroblastic morphology and proliferate like immortal cells. They contain tetraploid to hexaploid porcine chromosomes accompanied by hypo-diploid murine chromosomes. Interestingly, many hybrid cell lines also express high levels of tissue-nonspecific alkaline phosphatase, which is considered to be a marker of undifferentiated embryonic stem cells. All tested hybrid cell lines retain osteogenic differentiation, a few of them also retain adipogenic potential, but none retain chondrogenic differentiation. Conditioned media from hybrid cells enhance the proliferation of both early-passage and late-passage porcine MSC, indicating that the hybrid cells secrete diffusible growth stimulatory factors. Murine F7 cells thus have the unique property of generating immortal cell hybrids containing unusually high numbers of chromosomes derived from normal cells. These hybrid cells can be employed in various studies to improve our understanding of regenerative biology. This is the first report, to our knowledge, describing the generation of experimentally induced cell hybrids by using normal primary MSC.

What to Do about Zero Frequency Cells when Estimating Polychoric Correlations

ERIC Educational Resources Information Center

Savalei, Victoria

2011-01-01

Categorical structural equation modeling (SEM) methods that fit the model to estimated polychoric correlations have become popular in the social sciences. When population thresholds are high in absolute value, contingency tables in small samples are likely to contain zero frequency cells. Such cells make the estimation of the polychoric…

Recombinant Bacillus subtilis That Grows on Untreated Plant Biomass

PubMed Central

Anderson, Timothy D.; Miller, J. Izaak; Fierobe, Henri-Pierre

2013-01-01

Lignocellulosic biomass is a promising feedstock to produce biofuels and other valuable biocommodities. A major obstacle to its commercialization is the high cost of degrading biomass into fermentable sugars, which is typically achieved using cellulolytic enzymes from Trichoderma reesei. Here, we explore the use of microbes to break down biomass. Bacillus subtilis was engineered to display a multicellulase-containing minicellulosome. The complex contains a miniscaffoldin protein that is covalently attached to the cell wall and three noncovalently associated cellulase enzymes derived from Clostridium cellulolyticum (Cel48F, Cel9E, and Cel5A). The minicellulosome spontaneously assembles, thus increasing the practicality of the cells. The recombinant bacteria are highly cellulolytic and grew in minimal medium containing industrially relevant forms of biomass as the primary nutrient source (corn stover, hatched straw, and switch grass). Notably, growth did not require dilute acid pretreatment of the biomass and the cells achieved densities approaching those of cells cultured with glucose. An analysis of the sugars released from acid-pretreated corn stover indicates that the cells have stable cellulolytic activity that enables them to break down 62.3% ± 2.6% of the biomass. When supplemented with beta-glucosidase, the cells liberated 21% and 33% of the total available glucose and xylose in the biomass, respectively. As the cells display only three types of enzymes, increasing the number of displayed enzymes should lead to even more potent cellulolytic microbes. This work has important implications for the efficient conversion of lignocellulose to value-added biocommodities. PMID:23183968

Aryl- and alkyl-phosphorus-containing flame retardants induced mitochondrial impairment and cell death in Chinese hamster ovary (CHO-k1) cells.

PubMed

Huang, Chao; Li, Na; Yuan, Shengwu; Ji, Xiaoya; Ma, Mei; Rao, Kaifeng; Wang, Zijian

2017-11-01

Phosphorus-containing flame retardants (PFRs) are increasingly in demand worldwide as replacements for brominated flame retardants (BFRs), but insufficient available toxicological information on PFRs makes assessing their health risks challenging. Mitochondria are important targets of various environmental pollutants, and mitochondrial dysfunction may lead to many common diseases. In the present study, mitochondria impairment-related endpoints were measured by a high content screening (HCS) assay for 11 selected non-halogen PFRs in Chinese hamster ovary (CHO-k1) cells. A cluster analysis was used to categorize these PFRs into three groups according to their structural characteristics and results from the HCS assay. Two groups, containing long-chain alkyl-PFRs and all aryl-PFRs, were found to cause mitochondrial impairment but showed different mechanisms of toxicity. Due to the high correlation between cell death and mitochondrial impairment, two PFRs with different structures, trihexyl phosphate (THP) and cresyl diphenyl phosphate (CDP), were selected and compared with chlorpyrifos (CPF) to elucidate their mechanism of inducing cell death. THP (an alkyl-PFR) was found to utilize a similar pathway as CPF to induce apoptosis. However, cell death induced by CDP (an aryl-PFR) was different from classical necrosis based on experiments to discriminate among the different modes of cell death. These results confirm that mitochondria might be important targets for some PFRs and that differently structured PFRs could function via distinct mechanisms of toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of defined mixtures of persistent organic pollutants (POPs) on multiple cellular responses in the human hepatocarcinoma cell line, HepG2, using high content analysis screening

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

Wilson, Jodie; Berntsen, Hanne Friis; Zimmer, Karin Elisabeth

Persistent organic pollutants (POPs) are toxic substances, highly resistant to environmental degradation, which can bio-accumulate and have long-range atmospheric transport potential. Most studies focus on single compound effects, however as humans are exposed to several POPs simultaneously, investigating exposure effects of real life POP mixtures on human health is necessary. A defined mixture of POPs was used, where the compound concentration reflected its contribution to the levels seen in Scandinavian human serum (total mix). Several sub mixtures representing different classes of POPs were also constructed. The perfluorinated (PFC) mixture contained six perfluorinated compounds, brominated (Br) mixture contained seven brominated compounds,more » chlorinated (Cl) mixture contained polychlorinated biphenyls and also p,p’-dichlorodiphenyldichloroethylene, hexachlorobenzene, three chlordanes, three hexachlorocyclohexanes and dieldrin. Human hepatocarcinoma (HepG2) cells were used for 2 h and 48 h exposures to the seven mixtures and analysis on a CellInsight™ NXT High Content Screening platform. Multiple cytotoxic endpoints were investigated: cell number, nuclear intensity and area, mitochondrial mass and membrane potential (MMP) and reactive oxygen species (ROS). Both the Br and Cl mixtures induced ROS production but did not lead to apoptosis. The PFC mixture induced ROS production and likely induced cell apoptosis accompanied by the dissipation of MMP. Synergistic effects were evident for ROS induction when cells were exposed to the PFC + Br mixture in comparison to the effects of the individual mixtures. No significant effects were detected in the Br + Cl, PFC + Cl or total mixtures, which contain the same concentrations of chlorinated compounds as the Cl mixture plus additional compounds; highlighting the need for further exploration of POP mixtures in risk assessment. - Highlights: • High content analysis (HCA) is a novel approach for determining toxicity of complex mixtures. • Multiple cytotoxic endpoints were investigated for defined mixtures of persistent organic pollutants (POPs). • POP mixtures are based on levels relevant to human exposure. • POP mixtures can increase ROS induction and impact mitochondrial health, which could result in apoptosis. • HCA can detect pre-lethal and reversible signs of cellular stress.« less

High-temperature-measuring device

DOEpatents

Not Available

1981-01-27

A temperature measuring device for very high design temperatures (to 2000/sup 0/C) is described. The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensonally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

High temperature measuring device

DOEpatents

Tokarz, Richard D.

1983-01-01

A temperature measuring device for very high design temperatures (to 2,000.degree. C.). The device comprises a homogenous base structure preferably in the form of a sphere or cylinder. The base structure contains a large number of individual walled cells. The base structure has a decreasing coefficient of elasticity within the temperature range being monitored. A predetermined quantity of inert gas is confined within each cell. The cells are dimensionally stable at the normal working temperature of the device. Increases in gaseous pressure within the cells will permanently deform the cell walls at temperatures within the high temperature range to be measured. Such deformation can be correlated to temperature by calibrating similarly constructed devices under known time and temperature conditions.

High-Precision Photothermal Ablation Using Biocompatible Palladium Nanoparticles and Laser Scanning Microscopy

PubMed Central

2018-01-01

Herein, we report a straightforward method for the scalable preparation of Pd nanoparticles (Pd-NPs) with reduced inherent cytotoxicity and high photothermal conversion capacity. These Pd-NPs are rapidly taken up by cells and able to kill labeled cancer cells upon short exposure to near-infrared (NIR) light. Following cell treatment with Pd-NPs, ablated areas were patterned with high precision by laser scanning microscopy, allowing one to perform cell migration assays with unprecedented accuracy. Using coherent Raman microscopy, cells containing Pd-NPs were simultaneously ablated and imaged. This novel methodology was combined with intravital imaging to mediate microablation of cancerous tissue in tumor xenografts in mice. PMID:29320154

Fluorine-containing nanoemulsions for MRI cell tracking

PubMed Central

Janjic, Jelena M.; Ahrens, Eric T.

2009-01-01

In this article we review the chemistry and nanoemulsion formulation of perfluorocarbons used for in vivo 19F MRI cell tracking. In this application, cells of interest are labeled in culture using a perfluorocarbon nanoemulsion. Labeled cells are introduced into a subject and tracked using 19F MRI or NMR spectroscopy. In the same imaging session, a high-resolution, conventional (1H) image can be used to place the 19F-labeled cells into anatomical context. Perfluorocarbon-based 19F cell tracking is a useful technology because of the high specificity for labeled cells, ability to quantify cell accumulations, and biocompatibility. This technology can be widely applied to studies of inflammation, cellular regenerative medicine, and immunotherapy. PMID:19920872

High pressure and high temperature apparatus

DOEpatents

Voronov, Oleg A.

2005-09-13

A design for high pressure/high temperature apparatus and reaction cell to achieve .about.30 GPa pressure in .about.1 cm volume and .about.100 GPa pressure in .about.1 mm volumes and 20-5000.degree. C. temperatures in a static regime. The device includes profiled anvils (28) action on a reaction cell (14, 16) containing the material (26) to be processed. The reaction cell includes a heater (18) surrounded by insulating layers and screens. Surrounding the anvils are cylindrical inserts and supporting rings (30-48) whose hardness increases towards the reaction cell. These volumes may be increased considerably if applications require it, making use of presses that have larger loading force capability, larger frames and using larger anvils.

Mineralization and Expression of Col1a1-3.6GFP Transgene in Primary Dental Pulp Culture

PubMed Central

Balic, Anamaria; Rodgers, Barbara; Mina, Mina

2008-01-01

We have examined and compared the effects of various differentiation-inducing media on mineralization, cell morphology and expression of pOBCol3.6GFP (3.6-GFP) in primary dental pulp cultures derived from 3.6-GFP transgenic mice. Our results show that media containing ascorbic acid only could not induce mineralization in primary dental pulp cultures. On the other hand, media containing ascorbic acid and β-glycerophosphate induced formation of mineralized matrix-containing dentin. The amount of mineralized matrix was increased by addition of dexamethasone. Cells treated with ascorbic acid and β-glycerophosphate were fibroblast like and cells treated with dexamethasone were cuboidal. In all culture conditions, high levels of 3.6-GFP were expressed in areas of mineralization PMID:18781059

Highly efficient, nonpeptidic oligoguanidinium vectors that selectively internalize into mitochondria.

PubMed

Fernández-Carneado, Jimena; Van Gool, Michiel; Martos, Vera; Castel, Susanna; Prados, Pilar; de Mendoza, Javier; Giralt, Ernest

2005-01-26

Oligoguanidinium-based cell delivery systems have gained broad interest in the drug delivery field since one decade ago. Thus, arginine-containing peptides as Tat or Antp, oligoarginine peptides, and derived peptoids have been described as shuttles for delivering nonpermeant drugs inside cancer cells. Herein we report a new family of tetraguanidinium cell penetrating vectors efficiently internalized in human tumor cells. Their high internalization, studied by confocal microscopy and flow cytometry, as well as their specific accumulation in mitochondria makes these new vectors likely vehicles for the targeted delivery of anticancer drugs to mitochondria.

Activatable Fluorescence Probe via Self-Immolative Intramolecular Cyclization for Histone Deacetylase Imaging in Live Cells and Tissues.

PubMed

Liu, Xianjun; Xiang, Meihao; Tong, Zongxuan; Luo, Fengyan; Chen, Wen; Liu, Feng; Wang, Fenglin; Yu, Ru-Qin; Jiang, Jian-Hui

2018-05-01

Histone deacetylases (HDACs) play essential roles in transcription regulation and are valuable theranostic targets. However, there are no activatable fluorescent probes for imaging of HDAC activity in live cells. Here, we develop for the first time a novel activatable two-photon fluorescence probe that enables in situ imaging of HDAC activity in living cells and tissues. The probe is designed by conjugating an acetyl-lysine mimic substrate to a masked aldehyde-containing fluorophore via a cyanoester linker. Upon deacetylation by HDAC, the probe undergoes a rapid self-immolative intramolecular cyclization reaction, producing a cyanohydrin intermediate that is spontaneously rapidly decomposed into the highly fluorescent aldehyde-containing two-photon fluorophore. The probe is shown to exhibit high sensitivity, high specificity, and fast response for HDAC detection in vitro. Imaging studies reveal that the probe is able to directly visualize and monitor HDAC activity in living cells. Moreover, the probe is demonstrated to have the capability of two-photon imaging of HDAC activity in deep tissue slices up to 130 μm. This activatable fluorescent probe affords a useful tool for evaluating HDAC activity and screening HDAC-targeting drugs in both live cell and tissue assays.

Cyclic interconversion of methionine containing peptide between oxidized and reduced phases monitored by reversed-phase HPLC and ESI-MS/MS.

PubMed

Jin, Yulong; Huang, Yanyan; Xie, Yunfeng; Hu, Wenbing; Wang, Fuyi; Liu, Guoquan; Zhao, Rui

2012-01-30

The cyclic oxidation and reduction of methionine (Met) containing peptides and proteins play important roles in biological system. This work was contributed to analysis the cyclic oxidation and reduction processes of a methionine containing peptide which is very likely to relate in the cell signal transduction pathways. To mimic the biological oxidation condition, hydrogen peroxide was used as the reactive oxygen species to oxidize the peptide. Reversed-phase high-performance liquid chromatography and mass spectrometry were employed to monitor the reactions and characterize the structural changes of the products. A rapid reduction procedure was developed by simply using KI as the reductant, which is green and highly efficient. By investigation of the cyclic oxidation and reduction process, our work provides a new perspective to study the function and mechanism of Met containing peptides and proteins during cell signaling processes as well as diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

[Stimulation of mouse encephalomyocarditis virus reproduction by non-multiplying poliomyelitis virus in several transplantable tissue culture lines].

PubMed

Maslova, S V; Shirman, G A; Gavrilovskaia, I N

1977-01-01

Reproduction of mouse encephalomyocarditis virus (EMC) was studied in 5 continuous primate cell lines: HeLa, Fl, Detroit-6, P/7, and MIO inoculated with guanidine-dependent variant of poliomyelitis virus in the absence of guanidine. Poliomyelitis virus stimulated EMC virus reproduction in all cell lines under study. This stimulation effect was studied at length in HeLa and MIO cells. In HeLa cells, stimulation was observed at a low and moderate multiplicity of infection of EMC virus but not at a high (100 PEU/cell) multiplicity. Also, when EMC virus reproduction was stimulated, a shortening of the latent period of its multiplication cycle, an increase in the number of antigen-containing cells and the number of infectious centers were observed. In MIO cells, stimulation was found to occur both with low and high doses of EMC virus but not to be accompanied by a shortening in the latent period of EMC reproduction cycle, or any increase in the antigen-containing cells or number of infectious centers. In both cell types upon mixed infection the synthesis of virus-specific RNA's of EMC virus was enhanced. It is suggested that the stimulating effect of poliomyelitis virus is realized in HeLa and MIO cells at different stages of EMC virus reproduction.

Cortical cell and neuron density estimates in one chimpanzee hemisphere.

PubMed

Collins, Christine E; Turner, Emily C; Sawyer, Eva Kille; Reed, Jamie L; Young, Nicole A; Flaherty, David K; Kaas, Jon H

2016-01-19

The density of cells and neurons in the neocortex of many mammals varies across cortical areas and regions. This variability is, perhaps, most pronounced in primates. Nonuniformity in the composition of cortex suggests regions of the cortex have different specializations. Specifically, regions with densely packed neurons contain smaller neurons that are activated by relatively few inputs, thereby preserving information, whereas regions that are less densely packed have larger neurons that have more integrative functions. Here we present the numbers of cells and neurons for 742 discrete locations across the neocortex in a chimpanzee. Using isotropic fractionation and flow fractionation methods for cell and neuron counts, we estimate that neocortex of one hemisphere contains 9.5 billion cells and 3.7 billion neurons. Primary visual cortex occupies 35 cm(2) of surface, 10% of the total, and contains 737 million densely packed neurons, 20% of the total neurons contained within the hemisphere. Other areas of high neuron packing include secondary visual areas, somatosensory cortex, and prefrontal granular cortex. Areas of low levels of neuron packing density include motor and premotor cortex. These values reflect those obtained from more limited samples of cortex in humans and other primates.

A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation

PubMed Central

Lan, Rong; Tao, Shanwen

2016-01-01

In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm2 are achieved when biomass—bamboo charcoal and wood, respectively–is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required CO32− or CO42− ions for continuous operation. The dissolved O2− ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency. PMID:27540588

A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation.

PubMed

Lan, Rong; Tao, Shanwen

2016-08-01

In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm(2) are achieved when biomass-bamboo charcoal and wood, respectively-is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required [Formula: see text] or [Formula: see text] ions for continuous operation. The dissolved [Formula: see text] ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency.

Stimulation of glioma cell motility by expression, proteolysis, and release of the L1 neural cell recognition molecule.

PubMed

Yang, Muhua; Adla, Shalini; Temburni, Murali K; Patel, Vivek P; Lagow, Errin L; Brady, Owen A; Tian, Jing; Boulos, Magdy I; Galileo, Deni S

2009-10-29

Malignant glioma cells are particularly motile and can travel diffusely through the brain parenchyma, apparently without following anatomical structures to guide their migration. The neural adhesion/recognition protein L1 (L1CAM; CD171) has been implicated in contributing to stimulation of motility and metastasis of several non-neural cancer types. We explored the expression and function of L1 protein as a stimulator of glioma cell motility using human high-grade glioma surgical specimens and established rat and human glioma cell lines. L1 protein expression was found in 17 out of 18 human high-grade glioma surgical specimens by western blotting. L1 mRNA was found to be present in human U-87/LacZ and rat C6 and 9L glioma cell lines. The glioma cell lines were negative for surface full length L1 by flow cytometry and high resolution immunocytochemistry of live cells. However, fixed and permeablized cells exhibited positive staining as numerous intracellular puncta. Western blots of cell line extracts revealed L1 proteolysis into a large soluble ectodomain (~180 kDa) and a smaller transmembrane proteolytic fragment (~32 kDa). Exosomal vesicles released by the glioma cell lines were purified and contained both full-length L1 and the proteolyzed transmembrane fragment. Glioma cell lines expressed L1-binding alphavbeta5 integrin cell surface receptors. Quantitative time-lapse analyses showed that motility was reduced significantly in glioma cell lines by 1) infection with an antisense-L1 retroviral vector and 2) L1 ectodomain-binding antibodies. Our novel results support a model of autocrine/paracrine stimulation of cell motility in glioma cells by a cleaved L1 ectodomain and/or released exosomal vesicles containing L1. This mechanism could explain the diffuse migratory behavior of high-grade glioma cancer cells within the brain.

Stimulation of glioma cell motility by expression, proteolysis, and release of the L1 neural cell recognition molecule

PubMed Central

Yang, Muhua; Adla, Shalini; Temburni, Murali K; Patel, Vivek P; Lagow, Errin L; Brady, Owen A; Tian, Jing; Boulos, Magdy I; Galileo, Deni S

2009-01-01

Background Malignant glioma cells are particularly motile and can travel diffusely through the brain parenchyma, apparently without following anatomical structures to guide their migration. The neural adhesion/recognition protein L1 (L1CAM; CD171) has been implicated in contributing to stimulation of motility and metastasis of several non-neural cancer types. We explored the expression and function of L1 protein as a stimulator of glioma cell motility using human high-grade glioma surgical specimens and established rat and human glioma cell lines. Results L1 protein expression was found in 17 out of 18 human high-grade glioma surgical specimens by western blotting. L1 mRNA was found to be present in human U-87/LacZ and rat C6 and 9L glioma cell lines. The glioma cell lines were negative for surface full length L1 by flow cytometry and high resolution immunocytochemistry of live cells. However, fixed and permeablized cells exhibited positive staining as numerous intracellular puncta. Western blots of cell line extracts revealed L1 proteolysis into a large soluble ectodomain (~180 kDa) and a smaller transmembrane proteolytic fragment (~32 kDa). Exosomal vesicles released by the glioma cell lines were purified and contained both full-length L1 and the proteolyzed transmembrane fragment. Glioma cell lines expressed L1-binding αvβ5 integrin cell surface receptors. Quantitative time-lapse analyses showed that motility was reduced significantly in glioma cell lines by 1) infection with an antisense-L1 retroviral vector and 2) L1 ectodomain-binding antibodies. Conclusion Our novel results support a model of autocrine/paracrine stimulation of cell motility in glioma cells by a cleaved L1 ectodomain and/or released exosomal vesicles containing L1. This mechanism could explain the diffuse migratory behavior of high-grade glioma cancer cells within the brain. PMID:19874583

The development of primary and secondary lymphoid tissues in the nurse shark Ginglymostoma cirratum: B-cell zones precede dendritic cell immigration and T-cell zone formation during ontogeny of the spleen.

PubMed

Rumfelt, L L; McKinney, E C; Taylor, E; Flajnik, M F

2002-08-01

Secondary lymphoid tissue and immunoglobulin (Ig) production in mammals is not fully developed at birth, requiring time postnatally to attain all features required for adaptive immune responses. The immune system of newborn sharks - the oldest vertebrate group having adaptive immunity - also displays immature characteristics such as low serum IgM concentration and high levels of IgM1gj, an innate-like Ig. Primary and secondary lymphoid tissues in sharks and other cartilaginous fish were identified previously, but their cellular organization was not examined in detail. In this study of nurse shark lymphoid tissue, we demonstrate that the adult spleen contains well-defined, highly vascularized white pulp (WP) areas, composed of a central T-cell zone containing a major histocompatibility complex (MHC) class II+ dendritic cell (DC) network and a small number of Ig+ secretory cells, surrounded by smaller zones of surface Ig+ (sIg+) B cells. In neonates, splenic WPs are exclusively B-cell zones containing sIgM+-MHC class IIlow B cells; thus compartmentalized areas with T cells and DCs, as well as surface Ig novel antigen receptor (sIgNAR)-expressing B cells are absent at birth. Not until the pups are 5 months old do these WP areas become adult-like; concomitantly, sIgNAR+ B cells are readily detectable, indicating that this Ig class requires a 'mature immune-responsive environment'. The epigonal organ is the major site of neonatal B lymphopoiesis, based on the presence of developing B cells and recombination-activating gene 1 (RAG1)/terminal deoxynucleotidyl transferase (TdT) expression, indicative of antigen receptor rearrangement; such expression persists into adult life, whereas the spleen has negligible lymphopoietic activity. In adults but not neonates, many secretory B cells reside in the epigonal organ, suggesting, like in mammals, that B cells home to this primary lymphoid tissue after activation in other areas of the body.

Self-contained high-pressure cell, apparatus, and procedure for the preparation of encapsulated proteins dissolved in low viscosity fluids for nuclear magnetic resonance spectroscopy

NASA Astrophysics Data System (ADS)

Peterson, Ronald W.; Wand, A. Joshua

2005-09-01

The design of a sample cell for high-performance nuclear magnetic resonance (NMR) at elevated pressure is described. The cell has been optimized for the study of encapsulated proteins dissolved in low viscosity fluids but is suitable for more general nuclear magnetic resonance (NMR) spectroscopy of biomolecules at elevated pressure. The NMR cell is comprised of an alumina-toughened zirconia tube mounted on a self-sealing nonmagnetic metallic valve. The cell has several advantages, including relatively low cost, excellent NMR performance, high-pressure tolerance, chemical inertness, and a relatively large active volume. Also described is a low volume sample preparation device that allows for the preparation of samples under high hydrostatic pressure and their subsequent transfer to the NMR cell.

Project Themis Supercritical Cold Flow Facility, Experiment Design and Modeling for the Study of Fluid Mixing

DTIC Science & Technology

2012-06-01

AFRL facility was well suited for the Themis cold flow experiment. A test cell was selected that contained an insulated cryogenic oxygen tank that...could be used for the LN2 supply. Adjacent to the test cell is a cryogenic storage bunker that contained a helium supply tank with existing high...venturi to the fuel bunker tank was very low (less than 25 psi) while the helium pressure drop from the cryogenic storage bunker was almost 2000 psi

A series of terpyridine containing flexible amino diethylacetate derivatives with large two-photon action cross-sections for effective mitochondrial imaging in living liver cancerous cells

NASA Astrophysics Data System (ADS)

Jia, Ran; Zhu, Yingying; Hu, Lei; Xiong, Qiru; Zhao, Meng; Zhang, Mingzhu; Tian, Xiaohe

2018-01-01

Small molecules possess large two-photon action cross sections (Φσ) are highly demanded for biological purpose. Herein, three novel terpyridine containing flexible amino diethylacetate organic small molecules (A1, A2 and A3) were rationally designed and their photophysical properties were investigated both experimentally and theoretically. The results revealed that the three chromophores possess large Φσ and remarkable Stokes' shift in high polar solvents, which are particularly benefit for further biological imaging application. One chromophore (A1) displayed an effective intracellular uptake against lung cancerous living cells A549. Colocalization studies suggested the internalized subcellular compartment was mitochondria. Consequently, chromophore A1 provides a promising platform to directly monitor mitochondria in living cells under two-photon confocal laser scanning microscopy.

Magnetic Luminescent Porous Silicon Microparticles for Localized Delivery of Molecular Drug Payloads

PubMed Central

Gu, Luo; Park, Ji-Ho; Duong, Kim H.; Ruoslahti, Erkki; Sailor, Michael J.

2011-01-01

Magnetic manipulation, fluorescent tracking, and localized delivery of a drug payload to cancer cells in vitro is demonstrated, using nanostructured porous silicon microparticles as a carrier. The multifunctional microparticles are prepared by electrochemical porosification of a silicon wafer in a hydrofluoric acid-containing electrolyte, followed by removal and fracture of the porous layer into particles using ultrasound. The intrinsically luminescent particles are loaded with superparamagnetic iron oxide nanoparticles and the anti-cancer drug doxorubicin. The drug-containing particles are delivered to human cervical cancer (HeLa) cells in vitro, under the guidance of a magnetic field. The high concentration of particles in the proximity of the magnetic field results in a high concentration of drug being released in that region of the Petri dish, and localized cell death is confirmed by cellular viability assay (Calcein AM). PMID:20814923

Magnetic luminescent porous silicon microparticles for localized delivery of molecular drug payloads.

PubMed

Gu, Luo; Park, Ji-Ho; Duong, Kim H; Ruoslahti, Erkki; Sailor, Michael J

2010-11-22

Magnetic manipulation, fluorescent tracking, and localized delivery of a drug payload to cancer cells in vitro is demonstrated, using nanostructured porous silicon microparticles as a carrier. The multifunctional microparticles are prepared by electrochemical porosification of a silicon wafer in a hydrofluoric acid-containing electrolyte, followed by removal and fracture of the porous layer into particles using ultrasound. The intrinsically luminescent particles are loaded with superparamagnetic iron oxide nanoparticles and the anti-cancer drug doxorubicin. The drug-containing particles are delivered to human cervical cancer (HeLa) cells in vitro, under the guidance of a magnetic field. The high concentration of particles in the proximity of the magnetic field results in a high concentration of drug being released in that region of the Petri dish, and localized cell death is confirmed by cellular viability assay (Calcein AM).

The biosynthesis, processing, and secretion of laminin by human choriocarcinoma cells.

PubMed

Peters, B P; Hartle, R J; Krzesicki, R F; Kroll, T G; Perini, F; Balun, J E; Goldstein, I J; Ruddon, R W

1985-11-25

Laminin, a glycoprotein component of basal laminae, is synthesized and secreted in culture by a human malignant cell line (JAR) derived from gestational choriocarcinoma. Biosynthetically labeled human laminin subunits A (Mr approximately 400,000) and B (Mr = 200,000 doublet) are glycoslyated with asparagine-linked high mannose oligosaccharides that are processed to complex oligosaccharides before the laminin molecule is externalized by the cell. The rate-limiting step in the processing of the asparagine-linked glycans of laminin is at the point of action of alpha-mannosidase I since the principal laminin forms that accumulate in JAR cells contain Man9GlcNAc2 and Man8GlcNAc2 oligosaccharide units. The combination of subunits to form the disulfide-linked laminin molecule (Mr approximately 950,000) occurs rapidly within the cell at a time when the subunits contain these high mannose oligosaccharides. The production of laminin is limited by the availability of the A subunit such that excess B subunit forms accumulate intracellularly as uncombined B and a disulfide-linked B dimer. Pulse-chase kinetic studies establish these B forms as intermediates in the assembly of the laminin molecule. The fully assembled laminin undergoes further oligosaccharide processing and translocation to the cell surface, but uncombined B and B dimer are neither processed nor secreted to any significant extent. Therefore, laminin subunit combination appears to be a prerequisite for intracellular translocation, processing, and secretion. The mature laminin that contains complex oligosaccharides does not accumulate intracellularly but is rapidly externalized upon completion, either secreted into the culture medium (25%) or associated with the cell surface (75%) as determined by susceptibility to degradation by trypsin. About one-third of the laminin molecules secreted or shed by JAR cells into the chase medium contain a smaller A subunit form that appears to have been modified by limited proteolytic cleavage. The putative proteolytic event is closely timed to the release of the laminin into the culture medium.

Multiple scale model for cell migration in monolayers: Elastic mismatch between cells enhances motility

NASA Astrophysics Data System (ADS)

Palmieri, Benoit; Bresler, Yony; Wirtz, Denis; Grant, Martin

2015-07-01

We propose a multiscale model for monolayer of motile cells that comprise normal and cancer cells. In the model, the two types of cells have identical properties except for their elasticity; cancer cells are softer and normal cells are stiffer. The goal is to isolate the role of elasticity mismatch on the migration potential of cancer cells in the absence of other contributions that are present in real cells. The methodology is based on a phase-field description where each cell is modeled as a highly-deformable self-propelled droplet. We simulated two types of nearly confluent monolayers. One contains a single cancer cell in a layer of normal cells and the other contains normal cells only. The simulation results demonstrate that elasticity mismatch alone is sufficient to increase the motility of the cancer cell significantly. Further, the trajectory of the cancer cell is decorated by several speed “bursts” where the cancer cell quickly relaxes from a largely deformed shape and consequently increases its translational motion. The increased motility and the amplitude and frequency of the bursts are in qualitative agreement with recent experiments.

The smallest natural high-active luciferase: cloning and characterization of novel 16.5-kDa luciferase from copepod Metridia longa.

PubMed

Markova, Svetlana V; Larionova, Marina D; Burakova, Ludmila P; Vysotski, Eugene S

2015-01-30

Coelenterazine-dependent copepod luciferases containing natural signal peptide for secretion are a very convenient analytical tool as they enable monitoring of intracellular events with high sensitivity, without destroying cells or tissues. This property is well suited for application in biomedical research and development of cell-based assays for high throughput screening. We report the cloning of cDNA gene encoding a novel secreted non-allelic 16.5-kDa isoform (MLuc7) of Metridia longa luciferase, which, in fact, is the smallest natural luciferase of known for today. Despite the small size, isoform contains 10 conservative Cys residues suggesting the presence of up to 5 SS bonds. This hampers the efficient production of functionally active recombinant luciferase in bacterial expression systems. With the use of the baculovirus expression system, we produced substantial amounts of the proper folded MLuc7 luciferase with a yield of ∼3 mg/L of a high purity protein. We demonstrate that MLuc7 produced in insect cells is highly active and extremely thermostable, and is well suited as a secreted reporter when expressed in mammalian cells ensuring higher sensitivity of detection as compared to another Metridia luciferase isoform (MLuc164) which is widely employed in real-time imaging. Copyright © 2014 Elsevier Inc. All rights reserved.

Ambient temperature secondary lithium cells containing inorganic electrolyte

NASA Astrophysics Data System (ADS)

Schlaikjer, Carl R.

The history and current status of rechargeable lithium cells using electrolytes based on liquid sulfur dioxide are reviewed. Three separate approaches currently under development include lithium/lithium dithionite/carbon cells with a supporting electrolyte salt; lithium/cupric chloride cells using sulfur dioxide/lithium tetrachloroaluminate; and several adaptations of a lithium/carbon cell using sulfur dioxide/lithium tetrachloroaluminate in which the discharge reaction involves the incorporation of aluminum into the positive electrode. The latter two chemistries have been studied in prototype hardware. For AA size cells with cupric chloride, 157 Whr/1 at 24 W/1 for 230 cycles was reported. For AA size cells containing 2LiCl-CaCl2-4AlCl3-12SO2, energy densities as high as 265 Whr/liter and 100 Whr/kg have been observed, but, at 26 W/1, for only 10 cycles. The advantages and remaining problems are discussed.

Characterization of side population in thyroid cancer cell lines: cancer stem-like cells are enriched partly but not exclusively.

PubMed

Mitsutake, Norisato; Iwao, Atsuhiko; Nagai, Kazuhiro; Namba, Hiroyuki; Ohtsuru, Akira; Saenko, Vladimir; Yamashita, Shunichi

2007-04-01

There is increasing evidence that cancers contain their own stem-like cells called cancer stem cells (CSCs). A small subset of cells, termed side population (SP), has been identified using flow cytometric analysis. The SP cells have the ability to exclude the DNA binding dye, Hoechst33342, and are highly enriched for stem cells in many kinds of normal tissues. Because CSCs are thought to be drug resistant, SP cells in cancers might contain CSCs. We initially examined the presence of SP cells in several human thyroid cancer cell lines. A small percentage of SP cells were found in ARO (0.25%), FRO (0.1%), NPA (0.06%), and WRO (0.02%) cells but not TPC1 cells. After sorting, the SP cells generated both SP and non-SP cells in culture. The clonogenic ability of SP cells was significantly higher than that of non-SP cells. Moreover, the SP prevalence was dependent on cell density in culture, suggesting that SP cells preferentially survived at lower cell density. Microarray experiment revealed differential gene expression profile between SP and non-SP cells, and several genes related to stemness were up-regulated. However, non-SP population also contained cells that were tumorigenic in nude mice, and non-SP cells generated a small number of SP cells. These results suggest that cancer stem-like cells are partly, but not exclusively, enriched in SP population. Clarifying the key tumorigenic population might contribute to the establishment of a novel therapy for thyroid cancer.

Increase in Pancreatic Proinsulin and Preservation of β-Cell Mass in Autoantibody-Positive Donors Prior to Type 1 Diabetes Onset

PubMed Central

Rodriguez-Calvo, Teresa; Zapardiel-Gonzalo, Jose; Amirian, Natalie; Castillo, Ericka; Lajevardi, Yasaman; Krogvold, Lars; Dahl-Jørgensen, Knut

2017-01-01

Type 1 diabetes is characterized by the loss of insulin production caused by β-cell dysfunction and/or destruction. The hypothesis that β-cell loss occurs early during the prediabetic phase has recently been challenged. Here we show, for the first time in situ, that in pancreas sections from autoantibody-positive (Ab+) donors, insulin area and β-cell mass are maintained before disease onset and that production of proinsulin increases. This suggests that β-cell destruction occurs more precipitously than previously assumed. Indeed, the pancreatic proinsulin-to-insulin area ratio was also increased in these donors with prediabetes. Using high-resolution confocal microscopy, we found a high accumulation of vesicles containing proinsulin in β-cells from Ab+ donors, suggesting a defect in proinsulin conversion or an accumulation of immature vesicles caused by an increase in insulin demand and/or a dysfunction in vesicular trafficking. In addition, islets from Ab+ donors were larger and contained a higher number of β-cells per islet. Our data indicate that β-cell mass (and function) is maintained until shortly before diagnosis and declines rapidly at the time of clinical onset of disease. This suggests that secondary prevention before onset, when β-cell mass is still intact, could be a successful therapeutic strategy. PMID:28137793

Self-Supported Mesostructured Pt-Based Bimetallic Nanospheres Containing an Intermetallic Phase as Ultrastable Oxygen Reduction Electrocatalysts.

PubMed

Kim, Ho Young; Cho, Seonghun; Sa, Young Jin; Hwang, Sun-Mi; Park, Gu-Gon; Shin, Tae Joo; Jeong, Hu Young; Yim, Sung-Dae; Joo, Sang Hoon

2016-10-01

Developing highly active and stable cathode catalysts is of pivotal importance for proton exchange membrane fuel cells (PEMFCs). While carbon-supported nanostructured Pt-based catalysts have so far been the most active cathode catalysts, their durability and single-cell performance are yet to be improved. Herein, self-supported mesostructured Pt-based bimetallic (Meso-PtM; M = Ni, Fe, Co, Cu) nanospheres containing an intermetallic phase are reported, which can combine the beneficial effects of transition metals (M), an intermetallic phase, a 3D interconnected framework, and a mesoporous structure. Meso-PtM nanospheres show enhanced oxygen reduction reaction (ORR) activity, compared to Pt black and Pt/C catalysts. Notably, Meso-PtNi containing an intermetallic phase exhibits ultrahigh stability, showing enhanced ORR activity even after 50 000 potential cycles, whereas Pt black and Pt/C undergo dramatic degradation. Importantly, Meso-PtNi with an intermetallic phase also demonstrated superior activity and durability when used in a PEMFC single-cell, with record-high initial mass and specific activities. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MtDNA depleted PC3 cells exhibit Warburg effect and cancer stem cell features

PubMed Central

Li, Xiaoran; Zhong, Yali; Lu, Jie; Axcrona, Karol; Eide, Lars; Syljuåsen, Randi G.; Peng, Qian; Wang, Junbai; Zhang, Hongquan; Goscinski, Mariusz Adam; Kvalheim, Gunnar; Nesland, Jahn M.; Suo, Zhenhe

2016-01-01

Reducing mtDNA content was considered as a critical step in the metabolism restructuring for cell stemness restoration and further neoplastic development. However, the connections between mtDNA depletion and metabolism reprograming-based cancer cell stemness in prostate cancers are still lack of studies. Here, we demonstrated that human CRPC cell line PC3 tolerated high concentration of the mtDNA replication inhibitor ethidium bromide (EtBr) and the mtDNA depletion triggered a universal metabolic remodeling process. Failure in completing that process caused lethal consequences. The mtDNA depleted (MtDP) PC3 cells could be steadily maintained in the special medium in slow cycling status. The MtDP PC3 cells contained immature mitochondria and exhibited Warburg effect. Furthermore, the MtDP PC3 cells were resistant to therapeutic treatments and contained greater cancer stem cell-like subpopulations: CD44+, ABCG2+, side-population and ALDHbright. In conclusion, these results highlight the association of mtDNA content, mitochondrial function and cancer cell stemness features. PMID:27248169

[Isolation, purification and primary culture of rat pancreatic beta-cells].

PubMed

Liu, Yu-Pu; Lü, Qing-Guo; Tong, Nan-Wei

2009-01-01

To isolate and purify rat pancreatic beta-cells and to explore the best conditions for the primary culture of the pancreatic beta-cells in vitro. The pancreas of Norman Wistar rats were digested by collagenase V. The islets were purified by mesh sieve. The activity of the islets was stimulated by different concentrations of glucose and detected by dithizone dye. The purified islets were put into RPMI-1640 nutritive medium for culture overnight. The cultured islets were digested again with trypsin and DNAase to obtain the suspension containing single pancreatic cells. The beta-cells were separated and purified in a fluorescence-activated cell sorter (FACS) in the medium containing 2.8 mmol/L glucose. The purified beta-cells were identified by immunohistochemistry and glucose stimulating test. Ham's F-10 with different concentrations of glucose and 3-Isobutyl-1-methylxanthine (IBMX) were used as nutritive medium for the primary cell culture for 24 hours. The best conditions for the culture were identified. An average of 550 +/- 90 islets with fine activities were obtained per rat. The purification with FACS obtained about 5688 beta-cells per rat, with a recovery rate of (93.69 +/- 1.26)% and a purity of (85.5 +/- 1.24)%. A concentration of 10.0 mmol/L and 16.0 mmol/L glucose in primary culture for 24 hours produced the highest survival rates of beta-cells, but IBMX did not increase the survival rates of beta-cells. FACS is effective in purifying pancreatic beta-cells from the suspension with a medium containing 2.8 mmol/L glucose. Pancreatic beta-cells maintain relatively high activities in Ham's F-10 medium containing 10.0-16.0 mmol/L glucose in primary culture.

Gigantism in a bacterium, Epulopiscium fishelsoni, correlates with complex patterns in arrangement, quantity, and segregation of DNA.

PubMed

Bresler, V; Montgomery, W L; Fishelson, L; Pollak, P E

1998-11-01

Epulopiscium fishelsoni, gut symbiont of the brown surgeonfish (Acanthurus nigrofuscus) in the Red Sea, attains a larger size than any other eubacterium, varies 10- to 20-fold in length (and >2, 000-fold in volume), and undergoes a complex daily life cycle. In early morning, nucleoids contain highly condensed DNA in elongate, chromosome-like structures which are physically separated from the general cytoplasm. Cell division involves production of two (rarely three) nucleoids within a cell, deposition of cell walls around expanded nucleoids, and emergence of daughter cells from the parent cell. Fluorescence measurements of DNA, RNA, and other cell components indicate the following. DNA quantity is proportional to cell volume over cell lengths of approximately 30 micrometers to >500 micrometers. For cells of a given size, nucleoids of cells with two nucleoids (binucleoid) contain approximately equal amounts of DNA. And each nucleoid of a binucleoid cell contains one-half the DNA of the single nucleoid in a uninucleoid cell of the same size. The life cycle involves approximately equal subdivision of DNA among daughter cells, formation of apical caps of condensed DNA from previously decondensed and diffusely distributed DNA, and "pinching" of DNA near the middle of the cell in the absence of new wall formation. Mechanisms underlying these patterns remain unclear, but formation of daughter nucleoids and cells occurs both during diurnal periods of host feeding and bacterial cell growth and during nocturnal periods of host inactivity when mean bacterial cell size declines.

Microvesicles Derived from Adult Human Bone Marrow and Tissue Specific Mesenchymal Stem Cells Shuttle Selected Pattern of miRNAs

PubMed Central

Collino, Federica; Deregibus, Maria Chiara; Bruno, Stefania; Sterpone, Luca; Aghemo, Giulia; Viltono, Laura; Tetta, Ciro; Camussi, Giovanni

2010-01-01

Background Cell-derived microvesicles (MVs) have been described as a new mechanism of cell-to-cell communication. MVs after internalization within target cells may deliver genetic information. Human bone marrow derived mesenchymal stem cells (MSCs) and liver resident stem cells (HLSCs) were shown to release MVs shuttling functional mRNAs. The aim of the present study was to evaluate whether MVs derived from MSCs and HLSCs contained selected micro-RNAs (miRNAs). Methodology/Principal Findings MVs were isolated from MSCs and HLSCs. The presence in MVs of selected ribonucleoproteins involved in the traffic and stabilization of RNA was evaluated. We observed that MVs contained TIA, TIAR and HuR multifunctional proteins expressed in nuclei and stress granules, Stau1 and 2 implicated in the transport and stability of mRNA and Ago2 involved in miRNA transport and processing. RNA extracted from MVs and cells of origin was profiled for 365 known human mature miRNAs by real time PCR. Hierarchical clustering and similarity analysis of miRNAs showed 41 co-expressed miRNAs in MVs and cells. Some miRNAs were accumulated within MVs and absent in the cells after MV release; others were retained within the cells and not secreted in MVs. Gene ontology analysis of predicted and validated targets showed that the high expressed miRNAs in cells and MVs could be involved in multi-organ development, cell survival and differentiation. Few selected miRNAs shuttled by MVs were also associated with the immune system regulation. The highly expressed miRNAs in MVs were transferred to target cells after MV incorporation. Conclusions This study demonstrated that MVs contained ribonucleoproteins involved in the intracellular traffic of RNA and selected pattern of miRNAs, suggesting a dynamic regulation of RNA compartmentalization in MVs. The observation that MV-highly expressed miRNAs were transferred to target cells, rises the possibility that the biological effect of stem cells may, at least in part, depend on MV-shuttled miRNAs. Data generated from this study, stimulate further functional investigations on the predicted target genes and pathways involved in the biological effect of human adult stem cells. PMID:20668554

Expansion of Endothelial Progenitor Cells in High Density Dot Culture of Rat Bone Marrow Cells

PubMed Central

Wang, Ling; Kretlow, James D.; Zhou, Guangdong; Cao, Yilin; Liu, Wei; Zhang, Wen Jie

2014-01-01

In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2×105 cells/cm2) by seeding total 9×105 cells into six high density dots or cultured in regular density (1.6×104 cells/cm2) with the same total number of cells. Flow cytometric analyses of the cells cultured for 15 days showed that high density cells exhibited smaller cell size and higher levels of marker expression related to EPCs when compared to regular density cultured cells. Functionally, these cells exhibited strong angiogenic potentials with better tubal formation in vitro and potent rescue of mouse ischemic limbs in vivo with their integration into neo-capillary structure. Global gene chip and ELISA analyses revealed up-regulated gene expression of adhesion molecules and enhanced protein release of pro-angiogenic growth factors in high density cultured cells. In summary, high density cell culture promotes expansion of bone marrow contained EPCs that are able to enhance tissue angiogenesis via paracrine growth factors and direct differentiation into endothelial cells. PMID:25254487

Erythrocyte haemolysate interacts with ATP-Fe to form a complex containing iron, ATP and 13 800 MW polypeptide.

PubMed

Weaver, J; Zhan, H; Pollack, S

1993-01-01

Iron first entering the reticulocyte is bound to ATP in the low MW cytosolic pool; some is also 'loosely bound' to haemoglobin, coeluting with haemoglobin from a molecular sieve column though not incorporated into haem. When haemolysate is mixed with ATP-Fe in vitro a similar high MW iron-containing complex is formed: the ATP-Fe interacts with a non-haemoglobin constituent of the haemolysate to form a high MW ATP-Fe complex in which the ratio of ATP:Fe (originally 6:1) is reversed, so that the complex contains more iron than ATP. The high MW ATP-Fe complex is formed even when ATP is in 150-fold molar excess and is formed without detectable hydrolysis of the ATP. The activity of haemolysate in forming the high MW ATP-Fe complex is not diminished by dialysis; all of the activity is recovered in the haemoglobin-containing fraction obtained from an Ultrogel AcA 44 column. The activity does not derive from haemoglobin since 85% of the activity is removed when haemoglobin is purified from haemolysate with DEAE-Sephadex. The chelatable iron pool of the cell probably includes both the high MW ATP-Fe complex and low MW ATP-Fe. Shunting of ATP-Fe to a high MW aggregate reduces the amount of iron present in the highly reactive low MW form and thus probably serves to limit the formation of cell damaging radicals.

Influence of curcumin-loaded cationic liposome on anticancer activity for cervical cancer therapy.

PubMed

Saengkrit, Nattika; Saesoo, Somsak; Srinuanchai, Wanwisa; Phunpee, Sarunya; Ruktanonchai, Uracha Rungsardthong

2014-02-01

The delivery of curcumin has been explored in the form of liposomal nanoparticles to treat various cancer cells. Since curcumin is water insoluble and an effective delivery route is through encapsulation in liposomes, which were modified with three components of DDAB, cholesterol and non-ionic surfactant. The purpose of this study was to establish a critical role of DDAB in liposomes containing curcumin at cellular response against two types of cell lines (HeLa and SiHa). Here, we demonstrate that DDAB is a potent inducer of cell uptake and cell death in both cell lines. The enhanced cell uptake was found on DDAB-containing liposome, but not on DDAB-free liposome. However, the cytotoxicity of DDAB-containing liposomes was high and needs to be optimized. The cytotoxicity of liposomal curcumin was more pronounced than free curcumin in both cells, suggesting the benefits of using nanocarrier. In addition, the anticancer efficiency and apoptosis effect of the liposomal curcumin formulations with DDAB was higher than those of DDAB-free liposomes. Therefore curcumin loaded liposomes indicate significant potential as delivery vehicles for the treatment of cervical cancers. Copyright © 2013 Elsevier B.V. All rights reserved.

Dye laser amplifier including a dye cell contained within a support vessel

DOEpatents

Davin, James

1992-01-01

A large (high flow rate) dye laser amplifier in which a continous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell.

Three dimensional metafilms with dual channel unit cells

DOE PAGES

Burckel, D. Bruce; Campione, Salvatore; Davids, Paul S.; ...

2017-04-04

Three-dimensional (3D) metafilms composed of periodic arrays of silicon unit cells containing single and multiple micrometer-scale vertical split ring resonators (SRRs) per unit cell were fabricated. In contrast to planar and stacked planar structures, these 3D metafilms have a thickness t ~λ d/4, allowing for classical thin film effects in the long wavelength limit. The infrared specular far-field scattering response was measured for metafilms containing one and two resonators per unit cell and compared to numerical simulations. Excellent agreement in the frequency region below the onset of diffractive scattering was obtained. For dense arrays of unit cells containing single SRRs,more » normally incident linearly polarized plane waves which do not excite a resonant response result in thin film interference fringes in the reflected spectra and are virtually indistinguishable from the scattering response of an undecorated array of unit cells. For the resonant linear polarization, the specular reflection for arrays is highly dependent on the SRR orientation on the vertical face for gap-up, gap-down, and gap-right orientations. For dense arrays of unit cells containing two SRRs per unit cell positioned on adjacent faces, the specular reflection spectra are slightly modified due to near-field coupling between the orthogonally oriented SRRs but otherwise exhibit reflection spectra largely representative of the corresponding single-SRR unit cell structures. Lastly, the ability to pack the unit cell with multiple inclusions which can be independently excited by choice of incident polarization suggests the construction of dual-channel films where the scattering response is selected by altering the incident polarization.« less

Imaging mesenchymal stem cells containing single wall nanotube nanoprobes in a 3D scaffold using photo-thermal optical coherence tomography

NASA Astrophysics Data System (ADS)

Connolly, Emma; Subhash, Hrebesh M.; Leahy, Martin; Rooney, Niall; Barry, Frank; Murphy, Mary; Barron, Valerie

2014-02-01

Despite the fact, that a range of clinically viable imaging modalities, such as magnetic resonance imaging (MRI), computed tomography (CT), photo emission tomography (PET), ultrasound and bioluminescence imaging are being optimised to track cells in vivo, many of these techniques are subject to limitations such as the levels of contrast agent required, toxic effects of radiotracers, photo attenuation of tissue and backscatter. With the advent of nanotechnology, nanoprobes are leading the charge to overcome these limitations. In particular, single wall nanotubes (SWNT) have been shown to be taken up by cells and as such are effective nanoprobes for cell imaging. Consequently, the main aim of this research is to employ mesenchymal stem cells (MSC) containing SWNT nanoprobes to image cell distribution in a 3D scaffold for cartilage repair. To this end, MSC were cultured in the presence of 32μg/ml SWNT in cell culture medium (αMEM, 10% FBS, 1% penicillin/streptomycin) for 24 hours. Upon confirmation of cell viability, the MSC containing SWNT were encapsulated in hyaluronic acid gels and loaded on polylactic acid polycaprolactone scaffolds. After 28 days in complete chondrogenic medium, with medium changes every 2 days, chondrogenesis was confirmed by the presence of glycosaminoglycan. Moreover, using photothermal optical coherence tomography (PT-OCT), the cells were seen to be distributed through the scaffold with high resolution. In summary, these data reveal that MSC containing SWNT nanoprobes in combination with PT-OCT offer an exciting opportunity for stem cell tracking in vitro for assessing seeding scaffolds and in vivo for determining biodistribution.

An antisymmetric cell structure for high-performance zinc bromine flow battery

NASA Astrophysics Data System (ADS)

Kim, Yongbeom; Jeon, Joonhyeon

2017-12-01

Zinc-bromine flow batteries (ZBBs) remain a problem of designing a cell with high coulombic efficiency and stability. This problem is caused intrinsically by different phase transition in each side of the half-cells during charge-discharge process. This paper describes a ZBB with an antisymmetric cell structure, which uses anode and cathode with different surface morphologies, for high-discharge capacity and reliability. The structure of the antisymmetric ZBB cell contains a carbon-surface electrode and a carbon-volume electrode in zinc and bromine half cells, respectively. To demonstrate the effectiveness of this proposed ZBB cell structure, Cyclic Voltammetry measurement is performed on a graphite foil and a carbon felt which are used as the surface and electrodes. Charge and discharge cyclic operations are also carried out with symmetric and antisymmetric ZBB cells combined with the two electrode types. Experimental results show that the arrangement of antisymmetric cell structure in ZBB provides a solution to the high performance and durability.

Tissue-selective alteration of ethanolamine plasmalogen metabolism in dedifferentiated colon mucosa.

PubMed

Lopez, Daniel H; Bestard-Escalas, Joan; Garate, Jone; Maimó-Barceló, Albert; Fernández, Roberto; Reigada, Rebeca; Khorrami, Sam; Ginard, Daniel; Okazaki, Toshiro; Fernández, José A; Barceló-Coblijn, Gwendolyn

2018-08-01

Human colon lipid analysis by imaging mass spectrometry (IMS) demonstrates that the lipid fingerprint is highly sensitive to a cell's pathophysiological state. Along the colon crypt axis, and concomitant to the differentiation process, certain lipid species tightly linked to signaling (phosphatidylinositols and arachidonic acid (AA)-containing diacylglycerophospholipids), change following a rather simple mathematical expression. We extend here our observations to ethanolamine plasmalogens (PlsEtn), a unique type of glycerophospholipid presenting a vinyl ether linkage at sn-1 position. PlsEtn distribution was studied in healthy, adenomatous, and carcinomatous colon mucosa sections by IMS. In epithelium, 75% of PlsEtn changed in a highly regular manner along the crypt axis, in clear contrast with diacyl species (67% of which remained constant). Consistently, AA-containing PlsEtn species were more abundant at the base, where stem cells reside, and decreased while ascending the crypt. In turn, mono-/diunsaturated species experienced the opposite change. These gradients were accompanied by a gradual expression of ether lipid synthesis enzymes. In lamina propria, 90% of stromal PlsEtn remained unchanged despite the high content of AA and the gradient in AA-containing diacylglycerophospholipids. Finally, both lipid and protein gradients were severely affected in polyps and carcinoma. These results link PlsEtn species regulation to cell differentiation for the first time and confirm that diacyl and ether species are differently regulated. Furthermore, they reaffirm the observations on cell lipid fingerprint image sensitivity to predict cell pathophysiological status, reinforcing the translational impact both lipidome and IMS might have in clinical research. Copyright © 2018 Elsevier B.V. All rights reserved.

The Evaluation of Triphenyl Phosphate as a Flame Retardant Additive to Improve the Safety of Lithium-Ion Battery Electrolytes

NASA Technical Reports Server (NTRS)

Smart, M. C.; Krause, F. C.; Hwang, C.; West, W. C.; Soler, J.; Prakash, G. K. S.; Ratnakumar, B. V.

2011-01-01

With the intent of improving the safety characteristics of lithium ion cells, electrolytes containing flame retardant additives have been investigated. A number of triphenyl phosphate-containing electrolytes were evaluated in both coin cells and experimental three electrode lithium-ion cells (containing reference electrodes). A number of chemistries were investigated, including MCMB carbon/LiNi(0.8)Co(0.2)O2 (NCO), graphite/LiNi(0.8)Co(0.15)Al(0.05)O2 (NCA), Li/Li(Li(0.17)Ni(0.25)Mn(0.58))O2, Li/LiNiMnCoO2 (NMC) and graphite/LiNiMnCoO2 (NMC), to study the effect that different electrolyte compositions have upon performance. A wide range of TPP-containing electrolytes were demonstrated to have good compatibility with the C/NCO, C/NCA, and Li/NMC systems, however, poor performance was initially observed with the high voltage C/NMC system. This necessitated the development of improved electrolytes with stabilizing additives, leading to formulations containing lithium bis(oxalato)borate (LiBOB) that displayed substantially improved performance.

Pyrene-Labeled Amphiphiles: Dynamic And Structural Probes Of Membranes And Lipoproteins

NASA Astrophysics Data System (ADS)

Pownall, Henry J.; Homan, Reynold; Massey, John B.

1987-01-01

Lipids and proteins are important functional and structural components of living organisms. Although proteins are frequently found as soluble components of plasma or the cell cytoplasm, many lipids are much less soluble and separate into complex assemblies that usually contain proteins. Cell membranes and plasma lipoproteins' are two important macro-molecular assemblies that contain both lipids and proteins. Cell membranes are composed of a variety of lipids and proteins that form an insoluble bilayer array that has relatively little curvature over distances of several nm. Plasma lipoproteins are different in that they are much smaller, water-soluble, and have highly curved surfaces. A model of a high density lipoprotein (HDL) is shown in Figure 1. This model (d - 10 nm) contains a surface of polar lipids and proteins that surrounds a small core of insoluble lipids, mostly triglycerides and cholesteryl esters. The low density (LDL) (d - 25 nm) and very low density (VLDL) (d 90 nm) lipoproteins have similar architectures, except the former has a cholesteryl ester core and the latter a core that is almost exclusively triglyceride (Figure 1). The surface proteins of HDL are amphiphilic and water soluble; the single protein of LDL is insoluble, whereas VLDL contains both soluble and insoluble proteins. The primary structures of all of these proteins are known.

Oxide modified air electrode surface for high temperature electrochemical cells

DOEpatents

Singh, Prabhakar; Ruka, Roswell J.

1992-01-01

An electrochemical cell is made having a porous cermet electrode (16) and a porous lanthanum manganite electrode (14), with solid oxide electrolyte (15) between them, where the lanthanum manganite surface next to the electrolyte contains a thin discontinuous layer of high surface area cerium oxide and/or praseodymium oxide, preferably as discrete particles (30) in contact with the air electrode and electrolyte.

High-throughput imaging of heterogeneous cell organelles with an X-ray laser (CXIDB ID 25)

DOE Data Explorer

Hantke, Max, F.

2014-11-17

Preprocessed detector images that were used for the paper "High-throughput imaging of heterogeneous cell organelles with an X-ray laser". The CXI file contains the entire recorded data - including both hits and blanks. It also includes down-sampled images and LCLS machine parameters. Additionally, the Cheetah configuration file is attached that was used to create the pre-processed data.

Production of Recombinant Adenovirus Containing Human Interlukin-4 Gene

PubMed Central

Mojarrad, Majid; Abdolazimi, Yassan; Hajati, Jamshid; Modarressi, Mohammad Hossein

2011-01-01

Objective(s) Recombinant adenoviruses are currently used for a variety of purposes, including in vitro gene transfer, in vivo vaccination, and gene therapy. Ability to infect many cell types, high efficiency in gene transfer, entering both dividing and non dividing cells, and growing to high titers make this virus a good choice for using in various experiments. In the present experiment, a recombinant adenovirus containing human IL-4 coding sequence was made. IL-4 has several characteristics that made it a good choice for using in cancer gene therapy, controlling inflammatory diseases, and studies on autoimmune diseases. Materials and Methods In brief, IL-4 coding sequence was amplified by and cloned in pAd-Track-CMV. Then, by means of homologous recombination between recombinant pAd-Track-CMV and Adeasy-1 plasmid in bacteria, recombinant adenovirus complete genome was made and IL-4 containing shuttle vector was incorporated into the viral backbone. After linearization, for virus packaging, viral genome was transfected into HEK-293 cell line. Viral production was conveniently followed with the aid of green fluorescent protein. Results Recombinant adenovirus produced here, was capable to infecting cell lines and express interlukin-4 in cell. Conclusion This system can be used as a powerful, easy, and cost benefit tool in various studies on cancer gene therapy and also studies on immunogenetics. PMID:23493491

Quantitation of the cellular content of saliva and buccal swab samples.

PubMed

Theda, Christiane; Hwang, Seo Hye; Czajko, Anna; Loke, Yuk Jing; Leong, Pamela; Craig, Jeffrey M

2018-05-02

Buccal swabs and saliva are the two most common oral sampling methods used for medical research. Often, these samples are used interchangeably, despite previous evidence that both contain buccal cells and blood leukocytes in different proportions. For some research, such as epigenetic studies, the cell types contributing to the analysis are highly relevant. We collected such samples from twelve children and twenty adults and, using Papanicolaou staining, measured the proportions of epithelial cells and leukocytes through microscopy. To our knowledge, no studies have compared cellular heterogeneity in buccal swab and saliva samples from adults and children. We confirmed that buccal swabs contained a higher proportion of epithelial cells than saliva and that children have a greater proportion of such cells in saliva compared to adults. At this level of resolution, buccal swabs and saliva contained similar epithelial cell subtypes. Gingivitis in children was associated with a higher proportion of leukocytes in saliva samples but not in buccal swabs. Compared to more detailed and costly methods such as flow cytometry or deconvolution methods used in epigenomic analysis, the procedure described here can serve as a simple and low-cost method to characterize buccal and saliva samples. Microscopy provides a low-cost tool to alert researchers to the presence of oral inflammation which may affect a subset of their samples. This knowledge might be highly relevant to their specific research questions, may assist with sample selection and thus might be crucial information despite the ability of data deconvolution methods to correct for cellular heterogeneity.

Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

PubMed Central

Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

2017-01-01

Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and recorded, and at the end of experiments, tumor xenografts were removed for Western blot and immunohistochemical analyses. Compared to control groups (negative control, regular-dose icotinib [IcoR], high-dose icotinib [IcoH], and docetaxel [DTX]) and regular icotinib dose (60 mg/kg) with docetaxel, treatment of mice with a high-dose (1200 mg/kg) of icotinib plus sequential docetaxel for 3 weeks (IcoH-DTX) had an additive effect on suppression of tumor xenograft size and volume (P < 0.05). Icotinib-containing treatments markedly reduced phosphorylation of EGFR, mitogen activated protein kinase (MAPK), and protein kinase B (Akt), but only the high-dose icotinib-containing treatments showed an additive effect on CD34 inhibition (P < 0.05), an indication of reduced microvessel density in tumor xenografts. Moreover, high-dose icotinib plus docetaxel had a similar effect on mouse weight loss (a common way to measure adverse reactions in mice), compared to the other treatment combinations. The study indicate that the high dose of icotinib plus sequential docetaxel (IcoH-DTX) have an additive effect on suppressing the growth of wild-type EGFR NSCLC cell nude mouse xenografts, possibly through microvessel density reduction. Future clinical trials are needed to confirm the findings of this study. PMID:27852073

Vacuolar morphology of Saccharomyces cerevisiae during the process of wine making and Japanese sake brewing.

PubMed

Izawa, Shingo; Ikeda, Kayo; Miki, Takeo; Wakai, Yoshinori; Inoue, Yoshiharu

2010-09-01

Although ethanol and osmotic stress affect the vacuolar morphology of Saccharomyces cerevisiae, little information is available about changes in vacuolar morphology during the processes of wine making and Japanese sake (rice wine) brewing. Here, we elucidated changes in the morphology of yeast vacuoles using Zrc1p-GFP, a vacuolar membrane protein, so as to better understand yeast physiology during the brewing process. Wine yeast cells (OC-2 and EC1118) contained highly fragmented vacuoles in the sake mash (moromi) as well as in the grape must. Although sake yeast cells (Kyokai no. 9 and no. 10) also contained highly fragmented vacuoles during the wine-making process, they showed quite a distinct vacuolar morphology during sake brewing. Since the environment surrounding sake yeast cells in the sake mash did not differ much from that surrounding wine yeast cells, the difference in vacuolar morphology during sake brewing between wine yeast and sake yeast was likely caused by innate characters.

Design of serum-free medium for suspension culture of CHO cells on the basis of general commercial media.

PubMed

Miki, Hideo; Takagi, Mutsumi

2015-08-01

The design of serum-free media for suspension culture of genetically engineered Chinese hamster ovary (CHO) cells using general commercial media as a basis was investigated. Subcultivation using a commercial serum-free medium containing insulin-like growth factor (IGF)-1 with or without FCS necessitated additives other than IGF-1 to compensate for the lack of FCS and improve cell growth. Suspension culture with media containing several combinations of growth factors suggested the effectiveness of addition of both IGF-1 and the lipid signaling molecule lysophosphatidic acid (LPA) for promoting cell growth. Subcultivation of CHO cells in suspension culture using the commercial serum-free medium EX-CELL™302, which contained an IGF-1 analog, supplemented with LPA resulted in gradually increasing specific growth rate comparable to the serum-containing medium and in almost the same high antibody production regardless of the number of generations. The culture with EX-CELL™302 supplemented with LPA in a jar fermentor with pH control at 6.9 showed an apparently higher cell growth rate than the cultures without pH control and with pH control at 6.8. The cell growth in the medium supplemented with aurintricarboxylic acid (ATA), which was much cheaper than IGF-1, in combination with LPA was synergistically promoted similarly to that in the medium supplemented with IGF-1 and LPA. In conclusion, the serum-free medium designed on the basis of general commercial media could support the growth of CHO cells and antibody production comparable to serum-containing medium in suspension culture. Moreover, the possibility of cost reduction by the substitution of IGF-1 with ATA was also shown.

Functional expression of calcium-permeable canonical transient receptor potential 4-containing channels promotes migration of medulloblastoma cells.

PubMed

Wei, Wei-Chun; Huang, Wan-Chen; Lin, Yu-Ping; Becker, Esther B E; Ansorge, Olaf; Flockerzi, Veit; Conti, Daniele; Cenacchi, Giovanna; Glitsch, Maike D

2017-08-15

The proton sensing ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) promotes expression of the canonical transient receptor potential channel subunit TRPC4 in normal and transformed cerebellar granule precursor (DAOY) cells. OGR1 and TRPC4 are prominently expressed in healthy cerebellar tissue throughout postnatal development and in primary cerebellar medulloblastoma tissues. Activation of TRPC4-containing channels in DAOY cells, but not non-transformed granule precursor cells, results in prominent increases in [Ca 2+ ] i and promotes cell motility in wound healing and transwell migration assays. Medulloblastoma cells not arising from granule precursor cells show neither prominent rises in [Ca 2+ ] i nor enhanced motility in response to TRPC4 activation unless they overexpressTRPC4. Our results suggest that OGR1 enhances expression of TRPC4-containing channels that contribute to enhanced invasion and metastasis of granule precursor-derived human medulloblastoma. Aberrant intracellular Ca 2+ signalling contributes to the formation and progression of a range of distinct pathologies including cancers. Rises in intracellular Ca 2+ concentration occur in response to Ca 2+ influx through plasma membrane channels and Ca 2+ release from intracellular Ca 2+ stores, which can be mobilized in response to activation of cell surface receptors. Ovarian cancer G protein coupled receptor 1 (OGR1, aka GPR68) is a proton-sensing G q -coupled receptor that is most highly expressed in cerebellum. Medulloblastoma (MB) is the most common paediatric brain tumour that arises from cerebellar precursor cells. We found that nine distinct human MB samples all expressed OGR1. In both normal granule cells and the transformed human cerebellar granule cell line DAOY, OGR1 promoted expression of the proton-potentiated member of the canonical transient receptor potential (TRPC) channel family, TRPC4. Consistent with a role for TRPC4 in MB, we found that all MB samples also expressed TRPC4. In DAOY cells, activation of TRPC4-containing channels resulted in large Ca 2+ influx and enhanced migration, while in normal cerebellar granule (precursor) cells and MB cells not derived from granule precursors, only small levels of Ca 2+ influx and no enhanced migration were observed. Our results suggest that OGR1-dependent increases in TRPC4 expression may favour formation of highly Ca 2+ -permeable TRPC4-containing channels that promote transformed granule cell migration. Increased motility of cancer cells is a prerequisite for cancer invasion and metastasis, and our findings may point towards a key role for TRPC4 in progression of certain types of MB. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

CD32-Expressing CD4 T Cells Are Phenotypically Diverse and Can Contain Proviral HIV DNA.

PubMed

Martin, Genevieve E; Pace, Matthew; Thornhill, John P; Phetsouphanh, Chansavath; Meyerowitz, Jodi; Gossez, Morgane; Brown, Helen; Olejniczak, Natalia; Lwanga, Julianne; Ramjee, Gita; Kaleebu, Pontiano; Porter, Kholoud; Willberg, Christian B; Klenerman, Paul; Nwokolo, Nneka; Fox, Julie; Fidler, Sarah; Frater, John

2018-01-01

Efforts to both characterize and eradicate the HIV reservoir have been limited by the rarity of latently infected cells and the absence of a specific denoting biomarker. CD32a (FcγRIIa) has been proposed to be a marker for an enriched CD4 T cell HIV reservoir, but this finding remains controversial. Here, we explore the expression of CD32 on CD3 + CD4 + cells in participants from two primary HIV infection studies and identify at least three distinct phenotypes (CD32 low , CD32 + CD14 + , and CD32 high ). Of note, CD4 negative enrichment kits remove the majority of CD4 + CD32 + T cells, potentially skewing subsequent analyses if used. CD32 high CD4 T cells had higher levels of HLA-DR and HIV co-receptor expression than other subsets, compatible with their being more susceptible to infection. Surprisingly, they also expressed high levels of CD20, TCRαβ, IgD, and IgM (but not IgG), markers for both T cells and naïve B cells. Compared with other populations, CD32 low cells had a more differentiated memory phenotype and high levels of immune checkpoint receptors, programmed death receptor-1 (PD-1), Tim-3, and TIGIT. Within all three CD3 + CD4 + CD32 + phenotypes, cells could be identified in infected participants, which contained HIV DNA. CD32 expression on CD4 T cells did not correlate with HIV DNA or cell-associated HIV RNA (both surrogate measures of overall reservoir size) or predict time to rebound viremia following treatment interruption, suggesting that it is not a dominant biomarker for HIV persistence. Our data suggest that while CD32 + T cells can be infected with HIV, CD32 is not a specific marker of the reservoir although it might identify a population of HIV enriched cells in certain situations.

Transepithelial Bicarbonate Secretion: Lessons from the Pancreas

PubMed Central

Park, Hyun Woo; Lee, Min Goo

2012-01-01

Many cystic fibrosis transmembrane conductance regulator (CFTR)-expressing epithelia secrete bicarbonate (HCO3−)-containing fluids. Recent evidence suggests that defects in epithelial bicarbonate secretion are directly involved in the pathogenesis of cystic fibrosis, in particular by building up hyperviscous mucus in the ductal structures of the lung and pancreas. Pancreatic juice is one of the representative fluids that contain a very high concentration of bicarbonate among bodily fluids that are secreted from CFTR-expressing epithelia. We introduce up-to-date knowledge on the basic principles of transepithelial bicarbonate transport by showing the mechanisms involved in pancreatic bicarbonate secretion. The model of pancreatic bicarbonate secretion described herein may also apply to other exocrine epithelia. As a central regulator of bicarbonate transport at the apical membrane, CFTR plays an essential role in both direct and indirect bicarbonate secretion. The major role of CFTR in bicarbonate secretion would be variable depending on the tissue and cell type. For example, in epithelial cells that produce a low concentration of bicarbonate-containing fluid (up to 80 mm), either CFTR-dependent Cl−/HCO3− exchange or CFTR anion channel with low bicarbonate permeability would be sufficient to generate such fluid. However, in cells that secrete high-bicarbonate-containing fluids, a highly selective CFTR bicarbonate channel activity is required. Therefore, understanding the molecular mechanism of transepithelial bicarbonate transport and the role of CFTR in each specific epithelium will provide therapeutic strategies to recover from epithelial defects induced by hyposecretion of bicarbonate in cystic fibrosis. PMID:23028131

Long-term protection against SHIV89.6P replication in HIV-1 Tat vaccinated cynomolgus monkeys.

PubMed

Maggiorella, Maria Teresa; Baroncelli, Silvia; Michelini, Zuleika; Fanales-Belasio, Emanuele; Moretti, Sonia; Sernicola, Leonardo; Cara, Andrea; Negri, Donatella R M; Buttò, Stefano; Fiorelli, Valeria; Tripiciano, Antonella; Scoglio, Arianna; Caputo, Antonella; Borsetti, Alessandra; Ridolfi, Barbara; Bona, Roberta; ten Haaft, Peter; Macchia, Iole; Leone, Pasqualina; Pavone-Cossut, Maria Rosaria; Nappi, Filomena; Ciccozzi, Massimo; Heeney, Jonathan; Titti, Fausto; Cafaro, Aurelio; Ensoli, Barbara

2004-09-03

Vaccination with a biologically active Tat protein or tat DNA contained infection with the highly pathogenic SHIV89.6P virus, preventing CD4 T-cell decline and disease onset. Here we show that protection was prolonged, since neither CD4 T-cell decline nor active virus replication was observed in all vaccinated animals that controlled virus replication up to week 104 after the challenge. In contrast, virus persisted and replicated in peripheral blood mononuclear cells and lymph nodes of infected animals, two of which died. Tat-specific antibody, CD4 and CD8 T-cell responses were high and stable only in the animals controlling the infection. In contrast, Gag-specific antibody production and CD4 and CD8 T-cell responses were consistently and persistently positive only in the monkeys that did not control primary virus replication. These results indicate that vaccination with Tat protein or DNA induced long-term memory Tat-specific immune responses and controlled primary infection at its early stages allowing a long-term containment of virus replication and spread in blood and tissues.

Organic fuel cell methods and apparatus

NASA Technical Reports Server (NTRS)

Narayanan, Sekharipuram R. (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Surampudi, Subbarao (Inventor); Prakash, G. K. Surya (Inventor); Vamos, Eugene (Inventor); Olah, George A. (Inventor)

2001-01-01

A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

Organic fuel cell methods and apparatus

NASA Technical Reports Server (NTRS)

Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Frank, Harvey A. (Inventor); Prakash, G. K. Surya (Inventor)

2004-01-01

A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

Organic fuel cell methods and apparatus

NASA Technical Reports Server (NTRS)

Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Surampudi, Subbarao (Inventor); Olah, George A. (Inventor); Vamos, Eugene (Inventor); Narayanan, Sekharipuram R. (Inventor); Prakash, G. K. Surya (Inventor)

2008-01-01

A liquid organic, fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

NASA Technical Reports Server (NTRS)

Olah, George A. (Inventor); Surampudi, Subbarao (Inventor); Vamos, Eugene (Inventor); Halpert, Gerald (Inventor); Narayanan, Sekharipuram R. (Inventor); Frank, Harvey A. (Inventor); Prakash, G. K. Surya (Inventor)

1997-01-01

A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

Active RNA replication of hepatitis C virus downregulates CD81 expression.

PubMed

Ke, Po-Yuan; Chen, Steve S-L

2013-01-01

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81.

Active RNA Replication of Hepatitis C Virus Downregulates CD81 Expression

PubMed Central

Ke, Po-Yuan; Chen, Steve S.-L.

2013-01-01

So far how hepatitis C virus (HCV) replication modulates subsequent virus growth and propagation still remains largely unknown. Here we determine the impact of HCV replication status on the consequential virus growth by comparing normal and high levels of HCV RNA expression. We first engineered a full-length, HCV genotype 2a JFH1 genome containing a blasticidin-resistant cassette inserted at amino acid residue of 420 in nonstructural (NS) protein 5A, which allowed selection of human hepatoma Huh7 cells stably-expressing HCV. Short-term establishment of HCV stable cells attained a highly-replicating status, judged by higher expressions of viral RNA and protein as well as higher titer of viral infectivity as opposed to cells harboring the same genome without selection. Interestingly, maintenance of highly-replicating HCV stable cells led to decreased susceptibility to HCV pseudotyped particle (HCVpp) infection and downregulated cell surface level of CD81, a critical HCV entry (co)receptor. The decreased CD81 cell surface expression occurred through reduced total expression and cytoplasmic retention of CD81 within an endoplasmic reticulum -associated compartment. Moreover, productive viral RNA replication in cells harboring a JFH1 subgenomic replicon containing a similar blasticidin resistance gene cassette in NS5A and in cells robustly replicating full-length infectious genome also reduced permissiveness to HCVpp infection through decreasing the surface expression of CD81. The downregulation of CD81 surface level in HCV RNA highly-replicating cells thus interfered with reinfection and led to attenuated viral amplification. These findings together indicate that the HCV RNA replication status plays a crucial determinant in HCV growth by modulating the expression and intracellular localization of CD81. PMID:23349980

Exploration Gap Assessment (FY13 Update)

DOE Data Explorer

Dan Getman

2013-09-30

This submission contains an update to the previous Exploration Gap Assessment funded in 2012, which identify high potential hydrothermal areas where critical data are needed (gap analysis on exploration data). The uploaded data are contained in two data files for each data category: A shape (SHP) file containing the grid, and a data file (CSV) containing the individual layers that intersected with the grid. This CSV can be joined with the map to retrieve a list of datasets that are available at any given site. A grid of the contiguous U.S. was created with 88,000 10-km by 10-km grid cells, and each cell was populated with the status of data availability corresponding to five data types: 1. well data 2. geologic maps 3. fault maps 4. geochemistry data 5. geophysical data

High stability of nuclear microsatellite loci during the early stages of somatic embryogenesis in Norway spruce.

PubMed

Helmersson, Andreas; von Arnold, Sara; Burg, Kornel; Bozhkov, Peter V

2004-10-01

Somatic embryos of Norway spruce (Picea abies (L.) Karst.) differentiate from proembryogenic masses (PEMs), which are subject to autodestruction through programmed cell death. In PEMs, somatic embryo formation and activation of programmed cell death are interrelated processes. We sought to determine if activation of programmed cell death in PEMs is caused by genetic aberrations during somatic embryogenesis. Based on the finding that withdrawal of auxin and cytokinin induces programmed cell death in PEMs, 1-week-old cell suspensions were cultured in medium either with or without auxin and cytokinin and then transferred to maturation medium containing abscisic acid. We analyzed the stability of three nuclear simple sequence repeat (SSR) microsatellite markers at successive stages of somatic embryogenesis in two cell lines. There were no mutations at the SSR loci at any of the successive developmental stages from PEMs to cotyledonary embryos, irrespective of whether or not the proliferation medium in which cell suspensions had been cultured contained auxin or cytokinin. The morphologies of plants regenerated from the cultures were similar, although withdrawal of auxin and cytokinin significantly stimulated the yield of both embryos and plants. We conclude, therefore, that the high genetic stability of somatic embryos in Norway spruce is unaffected by the induction of programmed cell death caused by withdrawal of auxin and cytokinin.

Highly efficient siRNA delivery from core-shell mesoporous silica nanoparticles with multifunctional polymer caps

NASA Astrophysics Data System (ADS)

Möller, Karin; Müller, Katharina; Engelke, Hanna; Bräuchle, Christoph; Wagner, Ernst; Bein, Thomas

2016-02-01

A new general route for siRNA delivery is presented combining porous core-shell silica nanocarriers with a modularly designed multifunctional block copolymer. Specifically, the internal storage and release of siRNA from mesoporous silica nanoparticles (MSN) with orthogonal core-shell surface chemistry was investigated as a function of pore-size, pore morphology, surface properties and pH. Very high siRNA loading capacities of up to 380 μg per mg MSN were obtained with charge-matched amino-functionalized mesoporous cores, and release profiles show up to 80% siRNA elution after 24 h. We demonstrate that adsorption and desorption of siRNA is mainly driven by electrostatic interactions, which allow for high loading capacities even in medium-sized mesopores with pore diameters down to 4 nm in a stellate pore morphology. The negatively charged MSN shell enabled the association with a block copolymer containing positively charged artificial amino acids and oleic acid blocks, which acts simultaneously as capping and endosomal release agent. The potential of this multifunctional delivery platform is demonstrated by highly effective cell transfection and siRNA delivery into KB-cells. A luciferase reporter gene knock-down of up to 80-90% was possible using extremely low cell exposures with only 2.5 μg MSN containing 0.5 μg siRNA per 100 μL well.A new general route for siRNA delivery is presented combining porous core-shell silica nanocarriers with a modularly designed multifunctional block copolymer. Specifically, the internal storage and release of siRNA from mesoporous silica nanoparticles (MSN) with orthogonal core-shell surface chemistry was investigated as a function of pore-size, pore morphology, surface properties and pH. Very high siRNA loading capacities of up to 380 μg per mg MSN were obtained with charge-matched amino-functionalized mesoporous cores, and release profiles show up to 80% siRNA elution after 24 h. We demonstrate that adsorption and desorption of siRNA is mainly driven by electrostatic interactions, which allow for high loading capacities even in medium-sized mesopores with pore diameters down to 4 nm in a stellate pore morphology. The negatively charged MSN shell enabled the association with a block copolymer containing positively charged artificial amino acids and oleic acid blocks, which acts simultaneously as capping and endosomal release agent. The potential of this multifunctional delivery platform is demonstrated by highly effective cell transfection and siRNA delivery into KB-cells. A luciferase reporter gene knock-down of up to 80-90% was possible using extremely low cell exposures with only 2.5 μg MSN containing 0.5 μg siRNA per 100 μL well. Electronic supplementary information (ESI) available: MSN synthesis and analysis, sample preparation for cell transfections as well as additional studies including experiments with a second cell line and a toxicity assay. See DOI: 10.1039/c5nr06246b

Aqueous-Containing Precursor Solutions for Efficient Perovskite Solar Cells.

PubMed

Liu, Dianyi; Traverse, Christopher J; Chen, Pei; Elinski, Mark; Yang, Chenchen; Wang, Lili; Young, Margaret; Lunt, Richard R

2018-01-01

Perovskite semiconductors have emerged as competitive candidates for photovoltaic applications due to their exceptional optoelectronic properties. However, the impact of moisture instability on perovskite films is still a key challenge for perovskite devices. While substantial effort is focused on preventing moisture interaction during the fabrication process, it is demonstrated that low moisture sensitivity, enhanced crystallization, and high performance can actually be achieved by exposure to high water content (up to 25 vol%) during fabrication with an aqueous-containing perovskite precursor. The perovskite solar cells fabricated by this aqueous method show good reproducibility of high efficiency with average power conversion efficiency (PCE) of 18.7% and champion PCE of 20.1% under solar simulation. This study shows that water-perovskite interactions do not necessarily negatively impact the perovskite film preparation process even at the highest efficiencies and that exposure to high contents of water can actually enable humidity tolerance during fabrication in air.

Radioprotective Effects of Sulfur-containing Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells.

PubMed

Heidari, A H; Shabestani Monfared, A; Mozdarani, H; Mahmoudzadeh, A; Razzaghdoust, A

2017-12-01

We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed). Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy). 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE) and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/PCEs+NCEs) (P < 0.001) in sulfur-containing hot spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.

Incorporation of radioactivity from [14C]lactate into the glycogen of cultured mouse astroglial cells. Evidence for gluconeogenesis in brain cells.

PubMed

Dringen, R; Schmoll, D; Cesar, M; Hamprecht, B

1993-05-01

A pure population of astroglial cells was selected from heterogeneous astroglia-rich primary cultures in a medium containing sorbitol instead of glucose. It was shown that astroglial cells synthesize glycogen when they are returned to a glucose-containing medium, and that when [14C]lactate is also present the synthesized glycogen is radioactively labelled. Compared with the degree of incorporation of radioactivity in the presence of tritiated glucose, the incorporation of radioactivity from lactate was small but significant. After incubation of astroglial cells with radioactively labelled lactate, the glycogen was isolated and enzymatically hydrolysed to glucose, which was found to be radioactively labelled. Astrocytes are therefore able to convert lactate to glucosyl residues, a metabolic pathway known as gluconeogenesis. It is proposed that astrocytic gluconeogenesis may consume lactic acid formed in neighboring cells such as neurons, during anaerobic glycolysis at times of high energy demand.

Guidelines for the Procurement of Aerospace Nickel Cadmium Cells

NASA Technical Reports Server (NTRS)

Thierfelder, Helmut

1997-01-01

NASA has been using a Modular Power System containing "standard" nickel cadmium (NiCd) batteries, composed of "standard" NiCd cells. For many years the only manufacturer of the NASA "standard" NiCd cells was General Electric Co. (subsequently Gates Aerospace and now SAFT). This standard cell was successfully used in numerous missions. However, uncontrolled technical changes, and changes in industrial restructuring require a new approach. General Electric (now SAFT Aerospace Batteries) had management changes, new manufacturers entered the market (Eagle-Picher Industries, ACME Electric Corporation, Aerospace Division, Sanyo Electric Co.) and battery technology advanced. New NASA procurements for aerospace NiCd cells will have specifications unique to the spacecraft and mission requirements. This document provides the user/customer guidelines for the new approach to procuring of and specifying performance requirements for highly reliable NiCd cells and batteries. It includes details of key parameters and their importance. The appendices contain a checklist, detailed calculations, and backup information.

Kidney cell electrophoresis in space flight: Rationale, methods, results and flow cytometry applications

NASA Technical Reports Server (NTRS)

Todd, P.; Morrison, Dennis R.; Barlow, Grant H.; Lewis, Marian L.; Lanham, J. W.; Cleveland, C.; Williams, K.; Kunze, M. E.; Goolsby, C. L.

1988-01-01

Cultures of human embryonic kidney cells consistently contain an electrophoretically separable subpopulation of cells that produce high levels of urokinase and have an electrophoretic mobility about 85 percent as high as that of the most mobile human embryonic kidney cells. This subpopulation is rich in large epithelioid cells that have relatively little internal structure. When resolution and throughput are adequate, free fluid electrophoresis can be used to isolate a broad band of low mobility cells which also produces high levels of plasminogen activators (PAs). In the course of performing this, it was discovered that all electrophoretic subpopulations of cultured human embryonic kidney cells produce some PAs and that separate subpopulations produce high quantities of different types of PA's. This information and the development of sensitive assays for this project have provided new insights into cell secretion mechanisms related to fibrinolysis. These advances would probably not have been made without the NASA program to explore fundamental questions of free fluid electrophoresis in space.

Photovoltaic: Instructional Manual. The North Dakota High Technology Mobile Laboratory Project.

ERIC Educational Resources Information Center

Auer, Herbert J.

This instructional manual contains 11 learning activity packets for use in a workshop on photovoltaic converters. The lessons cover the following topics: introduction; solar radiation--input for photovoltaic converters; photovoltaic cells; solar electric generator systems; characteristics of silicon cells; photovoltaic module source resistance;…

Exploiting translational coupling for the selection of cells producing toxic recombinant proteins from expression vectors.

PubMed

Tagliavia, Marcello; Cuttitta, Angela

2016-01-01

High rates of plasmid instability are associated with the use of some expression vectors in Escherichia coli, resulting in the loss of recombinant protein expression. This is due to sequence alterations in vector promoter elements caused by the background expression of the cloned gene, which leads to the selection of fast-growing, plasmid-containing cells that do not express the target protein. This phenomenon, which is worsened when expressing toxic proteins, results in preparations containing very little or no recombinant protein, or even in clone loss; however, no methods to prevent loss of recombinant protein expression are currently available. We have exploited the phenomenon of translational coupling, a mechanism of prokaryotic gene expression regulation, in order to select cells containing plasmids still able to express recombinant proteins. Here we designed an expression vector in which the cloned gene and selection marker are co-expressed. Our approach allowed for the selection of the recombinant protein-expressing cells and proved effective even for clones encoding toxic proteins.

Regulated Apoptosis of Genetically-Modified Hematopoietic Stem and Progenitor Cells via an Inducible Caspase-9 Suicide Gene in Rhesus Macaques

PubMed Central

Barese, Cecilia N.; Felizardo, Tania C.; Sellers, Stephanie E.; Keyvanfar, Keyvan; Di Stasi, Antonio; Metzger, Mark E.; Krouse, Allen E.; Donahue, Robert E.; Spencer, David M.; Dunbar, Cynthia E.

2014-01-01

The high risk of insertional oncogenesis reported in clinical trials utilizing integrating retroviral vectors to genetically-modify hematopoietic stem and progenitor cells (HSPC) requires the development of safety strategies to minimize risks associated with novel cell and gene therapies. The ability to ablate genetically modified cells in vivo is desirable, should an abnormal clone emerge. Inclusion of “suicide genes” in vectors to facilitate targeted ablation of vector-containing abnormal clones in vivo is one potential safety approach. We tested whether the inclusion of the “inducible Caspase-9” (iCasp9) suicide gene in a gamma-retroviral vector facilitated efficient elimination of vector-containing HSPCs and their hematopoietic progeny in vivo long-term, in an autologous non-human primate transplantation model. Following stable engraftment of iCasp9 expressing hematopoietic cells in rhesus macaques, administration of AP1903, a chemical inducer of dimerization able to activate iCasp9, specifically eliminated vector-containing cells in all hematopoietic lineages long-term, suggesting activity at the HSPC level. Between 75–94% of vector-containing cells were eliminated by well-tolerated AP1903 dosing, but lack of complete ablation was linked to lower iCasp9 expression in residual cells. Further investigation of resistance mechanisms demonstrated upregulation of Bcl-2 in hematopoietic cell lines transduced with the vector and resistant to AP1903 ablation. These results demonstrate both the potential and the limitations of safety approaches utilizing iCasp9 to HSPC-targeted gene therapy settings, in a model with great relevance to clinical development. PMID:25330775

Intravenous administration of stabilized antisense lipid particles (SALP) leads to activation and expansion of liver natural killer cells.

PubMed

Bramson, J L; Bodner, C A; Johnson, J; Semple, S; Hope, M J

2000-06-01

Stabilized antisense lipid particles (SALP) have been developed for the systemic delivery of oligonucleotides. The impact of intravenous SALP administration was measured with respect to activation of natural killer (NK) and NK1.1+ T (NKT) cells in the livers of immunocompetent mice. Treatment with a SALP containing a highly mitogenic oligonucleotide (INX-6295) generated an increase in NK cytolytic activity and cell number within the liver but did not appear to affect the number of hepatic NKT cells or their cytolytic activity. The same results were observed after intravenous administration of the mitogenic oligonucleotide alone. Interestingly, treatment with a SALP containing a weakly mitogenic oligonucleotide (INX-6300) also activated the liver NK cells, whereas the oligonucleotide alone was unable to elicit these effects. The NK stimulatory activity of a SALP containing INX-6300 required both lipid and oligonucleotide components. These results demonstrate that in addition to modifying the pharmacokinetics and biodistribution of intravenously administered oligonucleotides, SALP possess immunostimulatory activity independent of oligonucleotide mitogenicity, which can serve as an adjuvant to antisense therapies for cancer.

KOH concentration effect on cycle life of nickel-hydrogen cells

NASA Technical Reports Server (NTRS)

Lim, Hong S.; Verzwyvelt, S. A.

1987-01-01

A cycle life test of Ni/H2 cells containing electrolytes of various KOH concentrations and a sintered type nickel electrode was carried out at 23 C using a 45 min accelerated low Earth orbit (LEO) cycle regime at 80 percent depth of discharge. One of three cells containing 26 percent KOH has achieved over 28,000 cycles, and the other two 19,000 cycles, without a sign of failure. Two other cells containing 31 percent KOH electrolyte, which is the concentration presently used in aerospace cells, failed after 2,979 and 3,620 cycles. This result indicates that the cycle life of the present type of Ni/H2 cells may be extended by a factor of 5 to 10 simply by lowering the KOH concentration. Long cycle life of a Ni/H2 battery at high depth-of-discharge operation is desired, particularly for an LEO spacecraft application. Typically, battery life of about 30,000 cycles is required for a five year mission in an LEO. Such a cycle life with presently available cells can be assured only at a very low depth-of-discharge operation. Results of testing already show that the cycle life of an Ni/H2 cell is tremendously improved by simply using an electrolyte of low KOH concentration.

Characterization of an in vitro system for the synthesis of mRNA from human parainfluenza virus type 3.

PubMed

De, B P; Galinski, M S; Banerjee, A K

1990-03-01

A cell extract derived from human parainfluenza virus type 3-infected human lung carcinoma (HLC) cells synthesized mRNA in vitro. Under optimal conditions, the extract was able to support transcription of all virus-encoded genes as determined by hybridization analyses. The RNA products contained full-length poly(A)-containing mRNA species similar to those observed in acutely infected cells. Further purification of the viral nucleocapsids from the infected HLC cell extract resulted in total loss of the capacity of the extract to synthesize mRNA in vitro. However, the addition of cytoplasmic extracts from uninfected HLC cells to the nucleocapsid preparations restored transcription to levels observed in the infected cell lysates, indicating requirement of a host factor(s) in the human parainfluenza virus type 3 transcription process. In distinction to the abundant transcription observed in the cell extract from HLC cells, cell extract prepared from CV-1 cells failed to support transcription in vitro. High levels of RNase activity in the cell extract from CV-1 cells appears to be the principal reason for this difference.

Reduction of high-energy shock-wave-induced renal tubular injury by selenium.

PubMed

Strohmaier, W L; Lahme, S; Weidenbach, P M; Bichler, K H

1999-10-01

In shock-wave-induced renal injury cavitation-generated free radicals play an important role. Using an in vitro model with Madin-Darby canine kidney (MDCK) cells, we investigated the influence of selenium, a free radical scavenger, in shock-wave-induced tubular cell injury. Suspensions of MDCK cells (33 x 10(6) cells/ml) were placed in small containers (volume 1.1 ml) for shock wave exposure. Two groups of 12 containers each were examined: (1) control (no medication), (2) selenium (0.4 microg/ml nutrient medium). Six containers in each group were exposed to shock waves (impulse rate 256, frequency 60 Hz, generator voltage 18 kV), while the other six containers in each group served as a control. After shock wave exposure, the concentration of cellular enzymes such as lactate dehydrogenase (LDH), N-acetyl-beta-glucosaminidase (NAG), glutamate oxaloacetate transaminase (GOT) and glutamate lactate dehydrogenase (GLDH) in the nutrient medium was examined. Following shock wave exposure there was a significant rise in LDH, NAG, GOT and GLDH concentrations. Selenium reduced this enzyme leakage significantly. Thus we conclude that selenium protects renal tubular cells against shock-wave-induced injury. Since selenium is an essential part of glutathione peroxidase, this effect seems to be mediated by a reduction in reactive oxygen species.

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

PubMed Central

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

2016-01-01

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently. PMID:26955791

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties

NASA Astrophysics Data System (ADS)

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T.; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F.; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W.

2016-03-01

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently.

Silver nanoparticle-enriched diamond-like carbon implant modification as a mammalian cell compatible surface with antimicrobial properties.

PubMed

Gorzelanny, Christian; Kmeth, Ralf; Obermeier, Andreas; Bauer, Alexander T; Halter, Natalia; Kümpel, Katharina; Schneider, Matthias F; Wixforth, Achim; Gollwitzer, Hans; Burgkart, Rainer; Stritzker, Bernd; Schneider, Stefan W

2016-03-09

The implant-bone interface is the scene of competition between microorganisms and distinct types of tissue cells. In the past, various strategies have been followed to support bony integration and to prevent bacterial implant-associated infections. In the present study we investigated the biological properties of diamond-like carbon (DLC) surfaces containing silver nanoparticles. DLC is a promising material for the modification of medical implants providing high mechanical and chemical stability and a high degree of biocompatibility. DLC surface modifications with varying silver concentrations were generated on medical-grade titanium discs, using plasma immersion ion implantation-induced densification of silver nanoparticle-containing polyvinylpyrrolidone polymer solutions. Immersion of implants in aqueous liquids resulted in a rapid silver release reducing the growth of surface-bound and planktonic Staphylococcus aureus and Staphylococcus epidermidis. Due to the fast and transient release of silver ions from the modified implants, the surfaces became biocompatible, ensuring growth of mammalian cells. Human endothelial cells retained their cellular differentiation as indicated by the intracellular formation of Weibel-Palade bodies and a high responsiveness towards histamine. Our findings indicate that the integration of silver nanoparticles into DLC prevents bacterial colonization due to a fast initial release of silver ions, facilitating the growth of silver susceptible mammalian cells subsequently.

Distal Regeneration Involves the Age Dependent Activity of Branchial Sac Stem Cells in the Ascidian Ciona intestinalis.

PubMed

Jeffery, William R

2015-02-01

Tunicates have high capacities for regeneration but the underlying mechanisms and their relationship to life cycle progression are not well understood. Here we investigate the regeneration of distal structures in the ascidian tunicate Ciona intestinalis . Analysis of regenerative potential along the proximal-distal body axis indicated that distal organs, such as the siphons, their pigmented sensory organs, and the neural complex, could only be replaced from body fragments containing the branchial sac. Distal regeneration involves the formation of a blastema composed of cells that undergo cell proliferation prior to differentiation and cells that differentiate without cell proliferation. Both cell types originate in the branchial sac and appear in the blastema at different times after distal injury. Whereas the branchial sac stem cells are present in young animals, they are depleted in old animals that have lost their regeneration capacity. Thus Ciona adults contain a population of age-related stem cells located in the branchial sac that are a source of precursors for distal body regeneration.

Potential Roles of GLUT12 for Glucose Sensing and Cellular Migration in MCF-7 Human Breast Cancer Cells Under High Glucose Conditions.

PubMed

Matsui, Chihiro; Takatani-Nakase, Tomoka; Maeda, Sachie; Nakase, Ikuhiko; Takahashi, Koichi

2017-12-01

Recent reports have indicated that hyperglycaemia is associated with breast cancer progression. High glucose conditions corresponding to hyperglycaemia significantly promote migration of MCF-7 human breast cancer cells, however, little is known about the mechanisms of glucose sensing for the acquisition of migratory properties by MCF-7 cells. This study investigated glucose sensing and mediation, which are responsible for the high motility of MCF-7 cells. We evaluated the migration of MCF-7 cells cultured in high glucose-containing medium and essential regulatory factors from the perspective of the glucose transport system. We demonstrated that glucose transporter 12 (GLUT12) protein level increased in MCF-7 cells and co-localized with actin organization under high glucose conditions. Moreover, GLUT12-knockdown completely abrogated high glucose-induced migration, indicating that GLUT12 functionally participates in sensing high glucose concentrations. GLUT12 plays a critical role in the model of breast cancer progression through high glucose concentrations. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

PubMed Central

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di-Jia

2015-01-01

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A⋅cm−3 at 0.9 V or 450 A⋅cm−3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed. PMID:26261338

Highly efficient nonprecious metal catalyst prepared with metal–organic framework in a continuous carbon nanofibrous network

DOE PAGES

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; ...

2015-08-25

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report heremore » a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A∙cm -3 at 0.9 V or 450 A∙cm -3 extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.« less

Highly efficient nonprecious metal catalyst prepared with metal-organic framework in a continuous carbon nanofibrous network.

PubMed

Shui, Jianglan; Chen, Chen; Grabstanowicz, Lauren; Zhao, Dan; Liu, Di-Jia

2015-08-25

Fuel cell vehicles, the only all-electric technology with a demonstrated >300 miles per fill travel range, use Pt as the electrode catalyst. The high price of Pt creates a major cost barrier for large-scale implementation of polymer electrolyte membrane fuel cells. Nonprecious metal catalysts (NPMCs) represent attractive low-cost alternatives. However, a significantly lower turnover frequency at the individual catalytic site renders the traditional carbon-supported NPMCs inadequate in reaching the desired performance afforded by Pt. Unconventional catalyst design aiming at maximizing the active site density at much improved mass and charge transports is essential for the next-generation NPMC. We report here a method of preparing highly efficient, nanofibrous NPMC for cathodic oxygen reduction reaction by electrospinning a polymer solution containing ferrous organometallics and zeolitic imidazolate framework followed by thermal activation. The catalyst offers a carbon nanonetwork architecture made of microporous nanofibers decorated by uniformly distributed high-density active sites. In a single-cell test, the membrane electrode containing such a catalyst delivered unprecedented volumetric activities of 3.3 A ⋅ cm(-3) at 0.9 V or 450 A ⋅ cm(-3) extrapolated at 0.8 V, representing the highest reported value in the literature. Improved fuel cell durability was also observed.

Gigantism in a Bacterium, Epulopiscium fishelsoni, Correlates with Complex Patterns in Arrangement, Quantity, and Segregation of DNA

PubMed Central

Bresler, V.; Montgomery, W. L.; Fishelson, L.; Pollak, P. E.

1998-01-01

Epulopiscium fishelsoni, gut symbiont of the brown surgeonfish (Acanthurus nigrofuscus) in the Red Sea, attains a larger size than any other eubacterium, varies 10- to 20-fold in length (and >2,000-fold in volume), and undergoes a complex daily life cycle. In early morning, nucleoids contain highly condensed DNA in elongate, chromosome-like structures which are physically separated from the general cytoplasm. Cell division involves production of two (rarely three) nucleoids within a cell, deposition of cell walls around expanded nucleoids, and emergence of daughter cells from the parent cell. Fluorescence measurements of DNA, RNA, and other cell components indicate the following. DNA quantity is proportional to cell volume over cell lengths of ∼30 μm to >500 μm. For cells of a given size, nucleoids of cells with two nucleoids (binucleoid) contain approximately equal amounts of DNA. And each nucleoid of a binucleoid cell contains one-half the DNA of the single nucleoid in a uninucleoid cell of the same size. The life cycle involves approximately equal subdivision of DNA among daughter cells, formation of apical caps of condensed DNA from previously decondensed and diffusely distributed DNA, and “pinching” of DNA near the middle of the cell in the absence of new wall formation. Mechanisms underlying these patterns remain unclear, but formation of daughter nucleoids and cells occurs both during diurnal periods of host feeding and bacterial cell growth and during nocturnal periods of host inactivity when mean bacterial cell size declines. PMID:9791108

Further studies of the anodic dissolution in sodium chloride electrolyte of aluminium alloys containing tin and gallium

NASA Astrophysics Data System (ADS)

Nestoridi, Maria; Pletcher, Derek; Wharton, Julian A.; Wood, Robert J. K.

As part of a programme to develop a high power density, Al/air battery with a NaCl brine electrolyte, the high rate dissolution of an aluminium alloy containing tin and gallium was investigated in a small volume cell. The objective was to define the factors that limit aluminium dissolution in condition that mimic a high power density battery. In a cell with a large ratio of aluminium alloy to electrolyte, over a range of current densities the extent of dissolution was limited to ∼1000 C cm -2 of anode surface by a thick layer of loosely bound, crystalline deposit on the Al alloy anode formed by precipitation from solution. This leads to a large increase in impedance and acts as a barrier to transport of ions.

Three-Dimensional mRNA Measurements Reveal Minimal Regional Heterogeneity in Esophageal Squamous Cell Carcinoma

PubMed Central

Yan, Wusheng; Shih, Joanna; Rodriguez-Canales, Jaime; Tangrea, Michael A.; Player, Audrey; Diao, Lixia; Hu, Nan; Goldstein, Alisa M.; Wang, Jing; Taylor, Philip R.; Lippman, Scott M.; Wistuba, Ignacio I.; Emmert-Buck, Michael R.; Erickson, Heidi S.

2014-01-01

The classic tumor clonal evolution theory postulates that cancers change over time to produce unique molecular subclones within a parent neoplasm, presumably including regional differences in gene expression. More recently, however, this notion has been challenged by studies showing that tumors maintain a relatively stable transcript profile. To examine these competing hypotheses, we microdissected discrete subregions containing approximately 3000 to 8000 cells (500 to 1500 μm in diameter) from ex vivo esophageal squamous cell carcinoma (ESCC) specimens and analyzed transcriptomes throughout three-dimensional tumor space. Overall mRNA profiles were highly similar in all 59 intratumor comparisons, in distinct contrast to the markedly different global expression patterns observed in other dissected cell populations. For example, normal esophageal basal cells contained 1918 and 624 differentially expressed genes at a greater than twofold level (95% confidence level of <5% false positives), compared with normal differentiated esophageal cells and ESCC, respectively. In contrast, intratumor regions had only zero to four gene changes at a greater than twofold level, with most tumor comparisons showing none. The present data indicate that, when analyzed using a standard array-based method at this level of histological resolution, ESCC contains little regional mRNA heterogeneity. PMID:23219752

The three subtypes of atrial natriuretic peptide (ANP) receptors are expressed in the rat adrenal gland.

PubMed

Grandclément, B; Ronsin, B; Morel, G

1997-03-01

Atrial natriuretic peptide (ANP) actions are mediated by highly selective and specific receptors. Three subtypes have been characterized and cloned: ANP receptor-A (or GC-A), -B (or GC-B) and -C (the so-called clearance receptor). In rat adrenal gland, the mRNA for each subtype was detected using 35S-dUTP or digoxigenin-11-dUTP specific labeled probes, and in situ hybridization at light and electron microscopic levels respectively. The three subtypes were expressed the most abundantly in the zona glomerulosa. The amount of GC-A mRNA expression, quantified using macro-autoradiography and densitometry, was higher than the amounts of GC-B mRNA and ANPR-C mRNA both in zona glomerulosa and medullary of adrenal gland. At electron microscopic level, the three subtypes of ANPR were revealed in glomerulosa cells. A noticeable signal was also present in the medullary area, especially for GC-A mRNA, in adrenaline-containing chromaffin cells. No signal was detected in noradrenaline-containing chromaffin cells. The subcellular localization of the three mRNAs is similar: in the cytoplasmic matrix and in the euchromatin of the nucleus in each cell of glomerulosa, and in the same compartments of the adrenaline-containing chromaffin cells. These data indicate that the adrenal gland is an important target tissue for ANP action both in glomerulosa cells and adrenaline-containing chromaffin cells. The mRNA expression levels were different for each ANPR subtype.

Fuel cell generator containing a gas sealing means

DOEpatents

Makiel, J.M.

1987-02-03

A high temperature solid electrolyte electrochemical generator is made, operating with flowing fuel gas and oxidant gas, the generator having a thermal insulation layer, and a sealing means contacting or contained within the insulation, where the sealing means is effective to control the contact of the various gases utilized in the generator. 5 figs.

C. elegans flavin-containing monooxygenase-4 is essential for osmoregulation in hypotonic stress

PubMed Central

Hirani, Nisha; Westenberg, Marcel; Seed, Paul T.; Petalcorin, Mark I. R.; Dolphin, Colin T.

2016-01-01

ABSTRACT Studies in Caenorhabditis elegans have revealed osmoregulatory systems engaged when worms experience hypertonic conditions, but less is known about measures employed when faced with hypotonic stress. Inactivation of fmo-4, which encodes flavin-containing monooxygenase-4, results in dramatic hypoosmotic hypersensitivity; worms are unable to prevent overwhelming water influx and swell rapidly, finally rupturing due to high internal hydrostatic pressure. fmo-4 is expressed prominently in hypodermis, duct and pore cells but is excluded from the excretory cell. Thus, FMO-4 plays a crucial osmoregulatory role by promoting clearance of excess water that enters during hypotonicity, perhaps by synthesizing an osmolyte that acts to establish an osmotic gradient from excretory cell to duct and pore cells. C. elegans FMO-4 contains a C-terminal extension conserved in all nematode FMO-4s. The coincidently numbered human FMO4 also contains an extended C-terminus with features similar to those of FMO-4. Although these shared sequence characteristics suggest potential orthology, human FMO4 was unable to rescue the fmo-4 osmoregulatory defect. Intriguingly, however, mammalian FMO4 is expressed predominantly in the kidney – an appropriate site if it too is, or once was, involved in osmoregulation. PMID:27010030

Preventing Ultraviolet Light-Induced Damage: The Benefits of Antioxidants

ERIC Educational Resources Information Center

Yip, Cheng-Wai

2007-01-01

Extracts of fruit peels contain antioxidants that protect the bacterium "Escherichia coli" against damage induced by ultraviolet light. Antioxidants neutralise free radicals, thus preventing oxidative damage to cells and deoxyribonucleic acid. A high survival rate of UV-exposed cells was observed when grapefruit or grape peel extract was…

CD44 staining of cancer stem-like cells is influenced by down-regulation of CD44 variant isoforms and up-regulation of the standard CD44 isoform in the population of cells that have undergone epithelial-to-mesenchymal transition.

PubMed

Biddle, Adrian; Gammon, Luke; Fazil, Bilal; Mackenzie, Ian C

2013-01-01

CD44 is commonly used as a cell surface marker of cancer stem-like cells in epithelial tumours, and we have previously demonstrated the existence of two different CD44(high) cancer stem-like cell populations in squamous cell carcinoma, one having undergone epithelial-to-mesenchymal transition and the other maintaining an epithelial phenotype. Alternative splicing of CD44 variant exons generates a great many isoforms, and it is not known which isoforms are expressed on the surface of the two different cancer stem-like cell phenotypes. Here, we demonstrate that cancer stem-like cells with an epithelial phenotype predominantly express isoforms containing the variant exons, whereas the cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition down-regulate these variant isoforms and up-regulate expression of the standard CD44 isoform that contains no variant exons. In addition, we find that enzymatic treatments used to dissociate cells from tissue culture or fresh tumour specimens cause destruction of variant CD44 isoforms at the cell surface whereas expression of the standard CD44 isoform is preserved. This results in enrichment within the CD44(high) population of cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition and depletion from the CD44(high) population of cancer stem-like cells that maintain an epithelial phenotype, and therefore greatly effects the characteristics of any cancer stem-like cell population isolated based on expression of CD44. As well as effecting the CD44(high) population, enzymatic treatment also reduces the percentage of the total epithelial cancer cell population staining CD44-positive, with potential implications for studies that aim to use CD44-positive staining as a prognostic indicator. Analyses of the properties of cancer stem-like cells are largely dependent on the ability to accurately identify and assay these populations. It is therefore critical that consideration be given to use of multiple cancer stem-like cell markers and suitable procedures for cell isolation in order that the correct populations are assayed.

Identification of selenium-containing proteins in HEK 293 kidney cells using multiple chromatographies, LC-ICPMS and nano-LC-ESIMS.

PubMed

Chitta, Karnakar R; Landero-Figueroa, Julio A; Kodali, Phanichand; Caruso, Joseph A; Merino, Edward J

2013-09-30

Our previous studies using HeLa and HEK 293 cells demonstrated that selenomethionine, SeMet, exerts more of an antagonistic effect on arsenic than other selenium species. These studies attributed the antagonistic effect of SeMet to decreased levels of reactive oxygen species, ROS, changes in protein phosphorylation and possible incorporation of SeMet into proteins. The present study employs a metallomics approach to identify the selenium-containing proteins in HEK 293 cells raised with SeMet. The proteins were screened and separated using two dimensional high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICPMS), size exclusion chromatography (SEC) and reversed-phase chromatography (RPC). The Se-containing proteins were identified by peptide mapping using nano-HPLC-Chip-electrospray ionization mass spectrometry (ESIMS). Copyright © 2013 Elsevier B.V. All rights reserved.

Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

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

Ulsh, Michael; Porter, Jason M.; Bittinat, Daniel C.

2016-04-01

Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDEmore » containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.« less

A High-Performance and Recyclable Al-Air Coin Cell Based on Eco-Friendly Chitosan Hydrogel Membranes.

PubMed

Liu, Yisi; Sun, Qian; Yang, Xiaofei; Liang, Jianneng; Wang, Biqiong; Koo, Alicia; Li, Ruying; Li, Jie; Sun, Xueliang

2018-05-18

Aluminum-air batteries are a promising power supply for electronics due to its low cost and high energy density. However, portable coin-type Al-air batteries operating under ambient air condition for small electronic appliances have rarely been reported. Herein, coin cell-type Al-air batteries using cost-effective and eco-friendly chitosan hydrogel membranes modified by SiO2, SnO2, and ZnO have been prepared and assembled. The Al-air coin cell employing chitosan hydrogel membrane containing 10 wt.% SiO2 as a separator exhibits better discharge performance with a higher flat voltage plateau, longer discharge duration, and higher power density than the cells using a chitosan hydrogel membrane containing SnO2 or ZnO. Moreover, we also demonstrate that the presented Al-air coin cell can be recycled by a series of eco-friendly procedures using food grade ingredients, resulting in recycled products that are environmentally safe and ready for reuse. The Al-air coin cell adopting a recycled cathode from a fully discharged Al-air coin cell using the above-mentioned procedure has shown comparable performance to cells assembled with a new cathode. With these merits of enhanced electrochemical performance and recyclability, this new Al-air coin cell with modified chitosan hydrogel membrane can find wide applications for powering portable and small-size electronics.

The Epstein-Barr virus DNA load in the peripheral blood of transplant recipients does not accurately reflect the burden of infected cells.

PubMed

Fink, Susanne; Tsai, Ming-Han; Schnitzler, Paul; Zeier, Martin; Dreger, Peter; Wuchter, Patrick; Bulut, Olcay C; Behrends, Uta; Delecluse, Henri-Jacques

2017-01-01

Transplant recipients frequently exhibit an increased Epstein-Barr virus (EBV) load in the peripheral blood. Here, we quantitated the EBV-infected cells in the peripheral blood of these patients and defined the mode of viral infection, latent or lytic. These data indicated that there is no strong correlation between the number of infected cells and the EBV load (EBVL). This can be explained by a highly variable number of EBV copies per infected cell and by lytic replication in some cells. The plasma of these patients did not contain any free infectious viruses, but contained nevertheless EBV DNA, sometimes in large amounts, that probably originates from cell debris and contributed to the total EBVL. Some of the investigated samples carried a highly variable number of infected cells in active latency, characterized by an expression of the Epstein-Barr nuclear antigens (EBNA2) protein. However, a third of the samples expressed neither EBNA2 nor lytic proteins. Patients with an increased EBVL represent a heterogeneous group of patients whose infection cannot be characterized by this method alone. Precise characterization of the origin of an increased EBVL, in particular, in terms of the number of EBV-infected cells, requires additional investigations including the number of EBV-encoded small RNA-positive cells. © 2016 Steunstichting ESOT.

Lithium Batteries and Supercapacitors Capable of Operating at Low Temperatures for Planetary Exploration

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; West, W. C.; Brandon, E. J.

2012-01-01

Demonstrated improved performance with wide operating temperature electrolytes containing ester co - solvents (i.e., methyl propionate and ethyl butyrate) in a number of prototype cells: center dot Successfully scaled up low temperature technology to 12 Ah size prismatic Li - ion cells (Quallion, LCC), and demonstrated good performance down to - 60 o C. center dot Demonstrated wide operating temperature range performance ( - 60 o to +60 o C) in A123 Systems LiFePO 4 - based lithium - ion cells containing methyl butyrate - based low temperature electrolytes. These systems were also demonstrated to have excellent cycle life performance at ambient temperatures, as well as the ability to be cycled up to high temperatures.

Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, Thomas C.; McLarnon, Frank R.; Cairns, Elton J.

1995-01-01

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing one or more hydroxides having the formula M(OH), one or more fluorides having the formula MF, and one or more carbonates having the formula M.sub.2 CO.sub.3, where M is a metal selected from the group consisting of alkali metals. The electrolyte inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

Properties of Polyhydroxyalkanoate Granules and Bioemulsifiers from Pseudomonas sp. and Burkholderia sp. Isolates Growing on Glucose.

PubMed

Sacco, Laís Postai; Castellane, Tereza Cristina Luque; Lopes, Erica Mendes; de Macedo Lemos, Eliana Gertrudes; Alves, Lúcia Maria Carareto

2016-03-01

A Burkholderia and Pseudomonas species designated as AB4 and AS1, respectively, were isolated from soil containing decomposing straw or sugar cane bagasse collected from Brazil. This study sought to evaluate the capacities of culture media, cell-free medium, and crude lysate preparations (containing PHB inclusion bodies) from bacterial cell cultures to stabilize emulsions with several hydrophobic compounds. Four conditions showed good production of bioemulsifiers (E24 ≥ 50 %), headed by substantially cell-free media from bacterial cell cultures in which bacterial isolates from Burkholderia sp. strain AB4 and Pseudomonas sp. strain AS1 were grown. Our results revealed that the both isolates (AB4 and AS1 strains) exhibited high emulsification indices (indicating usefulness in bioremediation) and good stabilities.

Organic solvents, electrolytes, and lithium ion cells with good low temperature performance

NASA Technical Reports Server (NTRS)

Huang, Chen-Kuo (Inventor); Smart, Marshall C. (Inventor); Surampudi, Subbarao (Inventor); Bugga, Ratnakumar V. (Inventor)

2002-01-01

Multi-component organic solvent systems, electrolytes and electrochemical cells characterized by good low temperature performance are provided. In one embodiment, an improved organic solvent system contains a ternary mixture of ethylene carbonate, dimethyl carbonate and diethyl carbonate. In other embodiments, quaternary systems include a fourth component, i.e, an aliphatic ester, an asymmetric alkyl carbonate or a compound of the formula LiOX, where X is R, COOR, or COR, where R is alkyl or fluoroalkyl. Electrolytes based on such organic solvent systems are also provided and contain therein a lithium salt of high ionic mobility, such as LiPF.sub.6. Reversible electrochemical cells, particularly lithium ion cells, are constructed with the improved electrolytes, and preferably include a carbonaceous anode, an insertion type cathode, and an electrolyte interspersed therebetween.

Electrolyte for high voltage Li/LiMn 1.9Co 0.1O 4 cells

NASA Astrophysics Data System (ADS)

Hayashi, Katsuya; Nemoto, Yasue; Tobishima, Shin-ichi; Yamaki, Jun-ichi

An electrolyte for high voltage lithium metal anode cells must simultaneously satisfy at least the following requirements; (i) high cycling efficiency on the lithium metal anode; (ii) higher oxidation potential than the charging voltage, and (iii) high specific conductivity. We have examined various electrolytes for lithium metal anode cells using a high voltage cathode, LiMn 1.9Co 0.1O 4. Of the electrolytes resistant to high voltage that we used, a system containing 60 to 90 vol.% of dimethyl carbonate (DMC) mixed with ethylene carbonate (EC) and 1.0 M lithium hexafluorophosphate (LiPF 6) provided the best cycling efficiency on a lithium metal anode, as well as a high specific conductivity around 10 mS cm -1 at 20 °C.

Independent and high-level dual-gene expression in adult stem-progenitor cells from a single lentiviral vector.

PubMed

Tian, J; Andreadis, S T

2009-07-01

Expression of multiple genes from the same target cell is required in several technological and therapeutic applications such as quantitative measurements of promoter activity or in vivo tracking of stem cells. In spite of such need, reaching independent and high-level dual-gene expression cannot be reliably accomplished by current gene transfer vehicles. To address this issue, we designed a lentiviral vector carrying two transcriptional units separated by polyadenylation, terminator and insulator sequences. With this design, the expression level of both genes was as high as that yielded from lentiviral vectors containing only a single transcriptional unit. Similar results were observed with several promoters and cell types including epidermal keratinocytes, bone marrow mesenchymal stem cells and hair follicle stem cells. Notably, we demonstrated quantitative dynamic monitoring of gene expression in primary cells with no need for selection protocols suggesting that this optimized lentivirus may be useful in high-throughput gene expression profiling studies.

Tracking the Invasion of Small Numbers of Cells in Paper-Based Assays with Quantitative PCR.

PubMed

Truong, Andrew S; Lochbaum, Christian A; Boyce, Matthew W; Lockett, Matthew R

2015-11-17

Paper-based scaffolds are an attractive material for culturing mammalian cells in a three-dimensional environment. There are a number of previously published studies, which utilize these scaffolds to generate models of aortic valves, cardiac ischemia and reperfusion, and solid tumors. These models have largely relied on fluorescence imaging and microscopy to quantify cells in the scaffolds. We present here a polymerase chain reaction (PCR)-based method, capable of quantifying multiple cell types in a single culture with the aid of DNA barcodes: unique sequences of DNA introduced to the genome of individual cells or cell types through lentiviral transduction. PCR-based methods are highly specific and are amenable to high-throughput and multiplexed analyses. To validate this method, we engineered two different breast cancer lines to constitutively express either a green or red fluorescent protein. These cells lines allowed us to directly compare the ability of fluorescence imaging (of the fluorescent proteins) and qPCR (of the unique DNA sequences of the fluorescent proteins) to quantify known numbers of cells in the paper based-scaffolds. We also used both methods to quantify the distribution of these breast cell lines in homotypic and heterotypic invasion assays. In the paper-based invasion assays, a single sheet of paper containing cells suspended in a hydrogel was sandwiched between sheets of paper containing only hydrogel. The stack was incubated, and the cells invaded the adjacent layers. The individual sheets of the invasion assay were then destacked and the number of cells in each layer quantified. Our results show both methods can accurately detect cell populations of greater than 500 cells. The qPCR method can repeatedly and accurately detect as few as 50 cells, allowing small populations of highly invasive cells to be detected and differentiated from other cell types.

Exosomes from HIV-1-infected Cells Stimulate Production of Pro-inflammatory Cytokines through Trans-activating Response (TAR) RNA*

PubMed Central

Sampey, Gavin C.; Saifuddin, Mohammed; Schwab, Angela; Barclay, Robert; Punya, Shreya; Chung, Myung-Chul; Hakami, Ramin M.; Asad Zadeh, Mohammad; Lepene, Benjamin; Klase, Zachary A.; El-Hage, Nazira; Young, Mary; Iordanskiy, Sergey; Kashanchi, Fatah

2016-01-01

HIV-1 infection results in a chronic illness because long-term highly active antiretroviral therapy can lower viral titers to an undetectable level. However, discontinuation of therapy rapidly increases virus burden. Moreover, patients under highly active antiretroviral therapy frequently develop various metabolic disorders, neurocognitive abnormalities, and cardiovascular diseases. We have previously shown that exosomes containing trans-activating response (TAR) element RNA enhance susceptibility of undifferentiated naive cells to HIV-1 infection. This study indicates that exosomes from HIV-1-infected primary cells are highly abundant with TAR RNA as detected by RT-real time PCR. Interestingly, up to a million copies of TAR RNA/μl were also detected in the serum from HIV-1-infected humanized mice suggesting that TAR RNA may be stable in vivo. Incubation of exosomes from HIV-1-infected cells with primary macrophages resulted in a dramatic increase of proinflammatory cytokines, IL-6 and TNF-β, indicating that exosomes containing TAR RNA could play a direct role in control of cytokine gene expression. The intact TAR molecule was able to bind to PKR and TLR3 effectively, whereas the 5′ and 3′ stems (TAR microRNAs) bound best to TLR7 and -8 and none to PKR. Binding of TAR to PKR did not result in its phosphorylation, and therefore, TAR may be a dominant negative decoy molecule in cells. The TLR binding through either TAR RNA or TAR microRNA potentially can activate the NF-κB pathway and regulate cytokine expression. Collectively, these results imply that exosomes containing TAR RNA could directly affect the proinflammatory cytokine gene expression and may explain a possible mechanism of inflammation observed in HIV-1-infected patients under cART. PMID:26553869

Effect of bisphosphonates on macrophagic THP-1 cell survival in bisphosphonate-related osteonecrosis of the jaw (BRONJ).

PubMed

Hoefert, Sebastian; Sade Hoefert, Claudia; Munz, Adelheid; Schmitz, Inge; Grimm, Martin; Yuan, Anna; Northoff, Hinnak; Reinert, Siegmar; Alexander, Dorothea

2016-03-01

Immune deficiency and bacterial infection have been suggested to play a role in the pathophysiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Zoledronate was previously found to promote THP-1 cell death. To examine this hypothesis with all commonly prescribed bisphosphonates, we tested the effect of (nitrogen-containing) ibandronate, risedronate, alendronate, pamidronate, and (non-nitrogen-containing) clodronate on macrophagic THP-1 cells. Activated THP-1 cells were exposed to .5 to 50 μM of nitrogen-containing bisphosphonates and .5 to 500 μM of clodronate. Cell adherence and survival were assessed in vitro using the xCELLigence real-time monitoring system. Results were confirmed histologically and verified with Live/Dead staining. All bisphosphonates inhibited THP-1 cell adherence and survival dose and time dependently, significant for zoledronate, alendronate, pamidronate, and clodronate in high concentrations (50 μM and 500 μM; P < .05). Low concentrations (0.5 μM) of risedronate, alendronate, and pamidronate prolonged the inflexion points of THP-1 cell survival compared with controls (P < .05). THP-1 cells exhibited no cytomorphologic changes at all concentrations. Commonly prescribed bisphosphonates inhibit the survival of macrophagic THP-1 cells dose-dependently without altering morphology. This may suggest a local immune dysfunction reflective of individual bisphosphonate potency leading to the pathogenesis of BRONJ. Copyright © 2016 Elsevier Inc. All rights reserved.

Activation of Antigen-Specific CD8(+) T Cells by Poly-DL-Lactide/Glycolide (PLGA) Nanoparticle-Primed Gr-1(high) Cells.

PubMed

Luo, Wen-Hui; Yang, Ya-Wun

2016-04-01

The aim of this study was to investigate the induction of antigen-specific T cell activation and cell cycle modulation by a poly-DL-lactide/glycolide (PLGA) nanoparticle (NP)-primed CD11b(+)Gr-1(high) subset isolated from mouse bone marrow. PLGA NPs containing the ovalbumin (OVA) antigen were prepared using the double emulsion and solvent evaporation method, and protein release rate and cell viability were determined. The Lin2(¯)CD11b(+)Gr-1(high)Ly6c(low) (Gr-1(high)) subset was sorted from the bone marrow of C57BL/6 J mice by fluorescence-activated cell sorting (FACS) and co-cultured with OT-I CD8(+) splenic T cells. Proliferation of OT-I CD8(+) T cells was monitored, and cell cycles were determined by 5-bromo-2'-deoxyuridine (BrdU) labeling. Treatment of Gr-1(high) cells with PLGA/OVA NPs upregulated expression of the SIINFEKL-H2K(b) complex in the context of MHC I. Co-cultures of OT-I CD8(+) T cells with the PLGA/OVA NP-primed Gr-1(high) cells induced the proliferation of T cells in vitro and modulated cell division and morphology. Treatment of Gr-1(high) cells with PLGA/OVA NPs also induced cell apoptosis and necrosis. This study demonstrated the function of PLGA/OVA NPs in the activation of OT-I CD8(+) T cells and the capability of cross-presentation via the Gr-1(high) polymorphonuclear subset from mouse bone marrow.

Upregulation of CYP 450s expression of immortalized hepatocyte-like cells derived from mesenchymal stem cells by enzyme inducers

PubMed Central

2011-01-01

Background The strenuous procurement of cultured human hepatocytes and their short lives have constrained the cell culture model of cytochrome P450 (CYP450) induction, xenobiotic biotransformation, and hepatotoxicity. The development of continuous non-tumorous cell line steadily containing hepatocyte phenotypes would substitute the primary hepatocytes for these studies. Results The hepatocyte-like cells have been developed from hTERT plus Bmi-1-immortalized human mesenchymal stem cells to substitute the primary hepatocytes. The hepatocyte-like cells had polygonal morphology and steadily produced albumin, glycogen, urea and UGT1A1 beyond 6 months while maintaining proliferative capacity. Although these hepatocyte-like cells had low basal expression of CYP450 isotypes, their expressions could be extensively up regulated to 80 folds upon the exposure to enzyme inducers. Their inducibility outperformed the classical HepG2 cells. Conclusion The hepatocyte-like cells contained the markers of hepatocytes including CYP450 isotypes. The high inducibility of CYP450 transcripts could serve as a sensitive model for profiling xenobiotic-induced expression of CYP450. PMID:21961524

The terminator mouse: salvation for primary cell culture.

PubMed

Kabgani, Nazanin; Moeller, Marcus J

2013-11-01

The Terminator had to come back from the future already several times in an effort to bring salvation to mankind. In the present issue of Kidney International, Guo et al. brought us a novel transgenic mouse model: the terminator mouse. This highly elegant mouse may facilitate significantly the derivation of primary cultures of a specific cell type from a tissue containing multiple cell populations.

Mechanical phenotyping of tumor cells using a microfluidic cell squeezer device

NASA Astrophysics Data System (ADS)

Khan, Zeina S.; Kamyabi, Nabiollah; Vanapalli, Siva A.

2013-03-01

Studies have indicated that cancer cells have distinct mechanical properties compared to healthy cells. We are investigating the potential of cell mechanics as a biophysical marker for diagnostics and prognosis of cancer. To establish the significance of mechanical properties for cancer diagnostics, a high throughput method is desired. Although techniques such as atomic force microscopy are very precise, they are limited in throughput for cellular mechanical property measurements. To develop a device for high throughput mechanical characterization of tumor cells, we have fabricated a microfludic cell squeezer device that contains narrow micrometer-scale pores. Fluid flow is used to drive cells into these pores mimicking the flow-induced passage of circulating tumor cells through microvasculature. By integrating high speed imaging, the device allows for the simultaneous characterization of five different parameters including the blockage pressure, cell velocity, cell size, elongation and the entry time into squeezer. We have tested a variety of in vitro cell lines, including brain and prostate cancer cell lines, and have found that the entry time is the most sensitive measurement capable of differentiating between cell lines with differing invasiveness.

The PSA−/lo prostate cancer cell population harbors self-renewing long-term tumor-propagating cells that resist castration

PubMed Central

Qin, Jichao; Liu, Xin; Laffin, Brian; Chen, Xin; Choy, Grace; Jeter, Collene; Calhoun-Davis, Tammy; Li, Hangwen; Palapattu, Ganesh S.; Pang, Shen; Lin, Kevin; Huang, Jiaoti; Ivanov, Ivan; Li, Wei; Suraneni, Mahipal V.; Tang, Dean G.

2012-01-01

SUMMARY Prostate cancer (PCa) is heterogeneous and contains both differentiated and undifferentiated tumor cells, but the relative functional contribution of these two cell populations remains unclear. Here we report distinct molecular, cellular, and tumor-propagating properties of PCa cells that express high (PSA+) and low (PSA−/lo) levels of the differentiation marker PSA. PSA−/lo PCa cells are quiescent and refractory to stresses including androgen deprivation, exhibit high clonogenic potential, and possess long-term tumor-propagating capacity. They preferentially express stem cell genes and can undergo asymmetric cell division generating PSA+ cells. Importantly, PSA−/lo PCa cells can initiate robust tumor development and resist androgen ablation in castrated hosts, and harbor highly tumorigenic castration-resistant PCa cells that can be prospectively enriched using ALDH+CD44+α2β1+ phenotype. In contrast, PSA+ PCa cells possess more limited tumor-propagating capacity, undergo symmetric division and are sensitive to castration. Together, our study suggests PSA−/lo cells may represent a critical source of castration-resistant PCa cells. PMID:22560078

Mammalian cells loaded with platinum-containing molecules are sensitized to fast atomic ions.

PubMed

Usami, N; Furusawa, Y; Kobayashi, K; Lacombe, S; Reynaud-Angelin, A; Sage, E; Wu, Ting-Di; Croisy, A; Guerquin-Kern, J-L; Le Sech, C

2008-07-01

This work investigates whether a synergy in cell death induction exists in combining atomic ions irradiation and addition of platinum salts. Such a synergy could be of interest in view of new cancer therapy protocol based on atomic ions--hadrontherapy--with the addition of radiosensitizing agents containing high-Z atoms. The experiment consists in irradiating by fast ions cultured cells previously exposed to dichloroterpyridine Platinum (PtTC) and analyzing cell survival by a colony-forming assay. Chinese Hamster Ovary (CHO) cells were incubated for six hours in medium containing 350 microM PtTC, and then irradiated by fast ions C(6+) and He(2+), with Linear Energy Transfer (LET) within range 2-70 keV/microm. In some experiments, dimethyl sulfoxide (DMSO) was added to investigate the role of free radicals. The intracellular localization of platinum was determined by Nano Secondary Ion Mass Spectroscopy (Nano-SIMS). For all LET examined, cell death rate is largely enhanced when irradiating in presence of PtTC. At fixed irradiation dose, cell death rate increases with increasing LET, while the platinum relative effect is larger at low LET. This finding suggests that hadrontherapy or protontherapy therapeutic index could be improved by combining irradiation procedure with concomitant chemotherapy protocols using platinum salts.

Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

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

Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji

Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated andmore » cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.« less

Involvement of H-ras in erythroid differentiation of TF1 and human umbilical cord blood CD34 cells.

PubMed

Ge, Y; Li, Z H; Marshall, M S; Broxmeyer, H E; Lu, L

1998-06-01

To investigate the role of the ras gene in erythroid differentiation, a human erythroleukemic cell line, TF1, was transduced with a selectable retroviral vector carrying a mammalian wild type H-ras gene or a cytoplasmic dominant negative RAS1 gene. Transduction of TF1 cells with the wild type H-ras gene resulted in changes of cell types and up-regulation of erythroid-specific gene expression similar to that seen in differentiating erythroid cells. The number of red blood cell containing colonies derived from TF1 cells transduced with wild type H-ras cDNA was significantly increased and the cells in the colonies were more hemoglobinized as estimated by a deeper red color compared to those colony cells from mock or dominant negative RAS1 gene transduced TF1 cells, suggesting increased erythroid differentiation of TF1 cells after transduction of wild type H-ras in vitro. The mRNA levels of beta- and gamma-, but not alpha-, globin genes were significantly higher in H-ras transduced TF1 cells than those in TF1 cells transduced with mock or dominant negative RAS1 gene. Moreover, a 4kb pre-mRNA of the Erythropoietin receptor (EpoR) was highly expressed only in H-ras transduced TF1 cells. Additionally, human umbilical cord blood (CB) CD34 cells which are highly enriched for hematopoietic stem/progenitor cells were transduced with the same retroviral vectors to evaluate in normal primary cells the activities of H-ras in erythroid differentiation. Increased numbers of erythroid cell containing colonies (BFU-E and CFU-GEMM) were observed in CD34 cells transduced with the H-ras cDNA, compared to that from mock transduced cells. These data suggest a possible role for ras in erythroid differentiation.

Estrogen biosynthesis in THP1 cells is regulated by promoter switching of the aromatase (CYP19) gene.

PubMed

Shozu, M; Zhao, Y; Simpson, E R

1997-12-01

The expression of aromatase, the enzyme responsible for estrogen biosynthesis, has been studied in THP-1 cells of human mononuclear leukemic origin, which exhibit high rates of aromatase activity. These cells have the capacity to differentiate in the presence of vitamin D into cells with osteoclast-like properties. Differentiated cells displayed higher rates of aromatase than undifferentiated cells, and, in both cases, activity was stimulated 10- to 20-fold by dexamethasone. Phorbol esters also increased aromatase activity, but the effect was the same in differentiated as in undifferentiated cells. In a similar fashion to adipose stromal cells, serum potentiated the response to dexamethasone but had no effect on phorbol ester-stimulated activity. By contrast to its action in adipose stromal cells, (Bu)2cAMP markedly inhibited aromatase activity of THP-1 cells, as did factors whose actions are mediated by cAMP, such as PTH and PTH-related peptide. This was true of control cells, as well as of dexamethasone- and phorbol ester-stimulated cells. Previously we have shown that type 1 cytokines as well as tumor necrosis factor-alpha stimulate aromatase activity of adipose stromal cells in the presence of dexamethasone. By contrast, interleukin-6, interleukin-11, and leukemia-inhibitory factor had no effect on aromatase activity of THP-1 cells, whereas tumor necrosis factor-alpha, oncostatin M, and platelet-derived growth factor were slightly inhibitory of aromatase activity. Exon-specific Southern analysis of rapid amplification of cDNA ends-amplified transcripts was employed to examine the distribution of the various 5'-termini of aromatase transcripts. In the control group, most of the clones contained transcripts specific for the proximal promoter II, whereas in dexamethasone-treated cells, most transcripts contained exon I.4. In the phorbol ester-treated cells, a broader spectrum of transcripts was present, with equal proportions of I.4, II, and I.3-containing clones. Additionally, one clone containing a new sequence, exon I.6, was found. This was shown to be located about 1 kb upstream of exon II. By contrast, all clones from cells treated with (Bu)2cAMP contained promoter II-specific sequences. In addition to these transcripts, two clones in the library from the dexamethasone-treated cells contained the sequence previously defined as the brain-specific sequence, 1f. In one of these, the 1f sequence was fused downstream of exon I.4, indicative that its expression likely employed promoter I.4. These results point to similarities and important differences between aromatase expression in THP-1 cells and other cells such as adipose stromal cells, indicative of unique regulatory pathways governing aromatase expression in these cells.

Cell lineage analysis in human brain using endogenous retroelements

PubMed Central

Evrony, Gilad D.; Lee, Eunjung; Mehta, Bhaven K.; Benjamini, Yuval; Johnson, Robert M.; Cai, Xuyu; Yang, Lixing; Haseley, Psalm; Lehmann, Hillel S.; Park, Peter J.; Walsh, Christopher A.

2015-01-01

Summary Somatic mutations occur during brain development and are increasingly implicated as a cause of neurogenetic disease. However, the patterns in which somatic mutations distribute in the human brain are unknown. We used high-coverage whole-genome sequencing of single neurons from a normal individual to identify spontaneous somatic mutations as clonal marks to track cell lineages in human brain. Somatic mutation analyses in >30 locations throughout the nervous system identified multiple lineages and sub-lineages of cells marked by different LINE-1 (L1) retrotransposition events and subsequent mutation of poly-A microsatellites within L1. One clone contained thousands of cells limited to the left middle frontal gyrus, whereas a second distinct clone contained millions of cells distributed over the entire left hemisphere. These patterns mirror known somatic mutation disorders of brain development, and suggest that focally distributed mutations are also prevalent in normal brains. Single-cell analysis of somatic mutation enables tracing of cell lineage clones in human brain. PMID:25569347

Nuclear factor of activated T cells (NFAT) in pearl oyster Pinctada fucata: molecular cloning and functional characterization.

PubMed

Huang, Xian-De; Wei, Guo-jian; Zhang, Hua; He, Mao-Xian

2015-01-01

Nuclear factor of activated T cells (NFAT) plays an important role in nonimmune cells and also in T cells and many other cells of the immune system, by regulating the expression of a variety of genes involved in the immune response, organ development, developmental apoptosis and angiogenesis. In the present study, the NFAT homology gene, PfNFAT, from the pearl oyster Pinctada fucata was cloned and its genomic structure and promoter were analyzed. PfNFAT encodes a putative protein of 1226 amino acids, and contains a highly conserved Rel homology region (RHR) with DNA-binding specificity, and a regulatory domain (NFAT homology region, NHR) containing a potent transactivation domain (TAD). The PfNFAT gene consists of 12 exons and 11 introns, and its promoter contains potential binding sites for transcription factors such as NF-κB (Nuclear factor κB), STATx (signal transducer and activator of transcription), AP-1 (activator protein-1) and Sox-5/9 (SRY type HMG box-5/9), MyoD (Myogenic Differentiation Antigen) and IRF (Interferon regulatory factor). Comparison and phylogenetic analysis revealed that PfNFAT shows high identity with other invertebrate NFAT, and clusters with the NFAT5 subgroup. Furthermore, gene expression analysis revealed that PfNFAT is involved in the immune response to lipopolysaccharide (LPS) and Polyinosinic-polycytidylic acid (poly I:C) stimulation and in the nucleus inserting operation. The study of PfNFAT may increase understanding of molluscan innate immunity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Human a-L-fucosidase-1 attenuates the invasive properties of thyroid cancer.

PubMed

Vecchio, Giancarlo; Parascandolo, Alessia; Allocca, Chiara; Ugolini, Clara; Basolo, Fulvio; Moracci, Marco; Strazzulli, Andrea; Cobucci-Ponzano, Beatrice; Laukkanen, Mikko O; Castellone, Maria Domenica; Tsuchida, Nobuo

2017-04-18

Glycans containing α-L-fucose participate in diverse interactions between cells and extracellular matrix. High glycan expression on cell surface is often associated with neoplastic progression. The lysosomal exoenzyme, α-L-fucosidase-1 (FUCA-1) removes fucose residues from glycans. The FUCA-1 gene is down-regulated in highly aggressive and metastatic human tumors. However, the role of FUCA-1 in tumor progression remains unclear. It is speculated that its inactivation perturbs glycosylation of proteins involved in cell adhesion and promotes cancer. FUCA-1 expression of various thyroid normal and cancer tissues assayed by immunohistochemical (IHC) staining was high in normal thyroids and papillary thyroid carcinomas (PTC), whereas it progressively decreased in poorly differentiated, metastatic and anaplastic thyroid carcinomas (ATC). FUCA-1 mRNA expression from tissue samples and cell lines and protein expression levels and enzyme activity in thyroid cancer cell lines paralleled those of IHC staining. Furthermore, ATC-derived 8505C cells adhesion to human E-selectin and HUVEC cells was inhibited by bovine α-L-fucosidase or Lewis antigens, thus pointing to an essential role of fucose residues in the adhesive phenotype of this cancer cell line. Finally, 8505C cells transfected with a FUCA-1 containing plasmid displayed a less invasive phenotype versus the parental 8505C. These results demonstrate that FUCA-1 is down-regulated in ATC compared to PTC and normal thyroid tissues and cell lines. As shown for other human cancers, the down-regulation of FUCA-1 correlates with increased aggressiveness of the cancer type. This is the first report indicating that the down-regulation of FUCA-1 is related to the increased aggressiveness of thyroid cancer.

Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

PubMed

Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

2015-01-01

The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

Smooth Muscle-Like Tissue Constructs with Circumferentially Oriented Cells Formed by the Cell Fiber Technology

PubMed Central

Hsiao, Amy Y.; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

2015-01-01

The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments. PMID:25734774

Erythroid colony induction without erythropoietin by Friend leukemia virus in vitro.

PubMed

Clarke, B J; Axelrad, A A; Shreeve, M M; McLeod, D L

1975-09-01

Erythroid colonies could be produced without the addition of erythropeietin in plasma cultures seeded with bone marrow cells from normal C3Hf/Bi mice by exposure of the cells in vitro to medium from a cell line (IS) that continuously produces Friend leukemia virus in culture. The activity in the culture medium was viral rather than erythropoietin-like, since it was sedimentable by high-speed centrifugation and heat labile. Erythroid colonies did not develop when the bone marrow cells exposed to virus-containing medium were from mice genetically resistant to Friend virus. IS culture medium contained both Friend spleen focus-forming and XC-plaque-forming activities. No erythroid colonies were induced when genetically sensitive cells were exposed to a preparation from which the spleen focus-forming activity had been removed, but which contained XC plaque-forming activity in high concentration. Thus the spleen focus-forming component of Friend virus appeared to be responsible for inducing erythroid colony formation without erythropoietin in vitro. Some erythroid colonies were also found in control cultures to which neither virus nor erythropoietin had been added. Reduction in the concentration of fetal calf serum in the culture medium substantially decreased the number of these colonies but had only a minor effect on the number of virus-induced colonies. The number of erythroid colonies produced after 2 days of culture without erythropoietin or fetal calf serum was approximately proportional to the titer of Friend spleen focus-forming virus to whcih the bone marrow cells had been exposed. This system should prove useful for investigation in vitro of Friend virus--host cell interactions which lead to erythropoietin-independent erythropoiesis.

Microchip-Based Single-Cell Functional Proteomics for Biomedical Applications

PubMed Central

Lu, Yao; Yang, Liu; Wei, Wei; Shi, Qihui

2017-01-01

Cellular heterogeneity has been widely recognized but only recently have single cell tools become available that allow characterizing heterogeneity at the genomic and proteomic levels. We review the technological advances in microchip-based toolkits for single-cell functional proteomics. Each of these tools has distinct advantages and limitations, and a few have advanced toward being applied to address biological or clinical problems that fail to be addressed by traditional population-based methods. High-throughput single-cell proteomic assays generate high-dimensional data sets that contain new information and thus require developing new analytical framework to extract new biology. In this review article, we highlight a few biological and clinical applications in which the microchip-based single-cell proteomic tools provide unique advantages. The examples include resolving functional heterogeneity and dynamics of immune cells, dissecting cell-cell interaction by creating well-contolled on-chip microenvironment, capturing high-resolution snapshots of immune system functions in patients for better immunotherapy and elucidating phosphoprotein signaling networks in cancer cells for guiding effective molecularly targeted therapies. PMID:28280819

Activity of the rat osteocalcin basal promoter in osteoblastic cells is dependent upon homeodomain and CP1 binding motifs.

PubMed

Towler, D A; Bennett, C D; Rodan, G A

1994-05-01

A detailed analysis of the transcriptional machinery responsible for osteoblast-specific gene expression should provide tools useful for understanding osteoblast commitment and differentiation. We have defined three cis-elements important for basal activity of the rat osteocalcin (OC) promoter, located at about -200 to -180, -170 to -138, and -121 to -64 relative to the transcription initiation site. A motif (TCTGATTGTGT) present in the region between -200 and -170 that binds a multisubunit CP1/NFY/CBF-like CAAT factor complex contributes significantly to high level basal activity and presumably functions as the CAAT box for the rat OC promoter. We show that the region -121 to 32 is sufficient to confer osteoblastic cell type specificity in transient transfection assays of cultured cell lines using luciferase as a reporter. The basal promoter is active in rodent osteoblastic cell lines, but not in rodent fibroblastic or muscle cell lines. Although the rat OC box (-100 to -74) contains a CAAT motif, we could not detect CP1-like CAAT factor binding to this region. In fact, we demonstrate that a Msx-1 (Hox 7.1) homeodomain binding motif (ACTAATTG; bottom strand) in the 3'-end of the rat OC box is necessary for high level activity of the rat OC basal promoter in osteoblastic cells. A nuclear factor that recognizes this motif appears to be present in osteoblastic ROS 17/2.8 cells, which produce OC, but not in fibroblastic ROS 25/1 cells, which fail to express OC. This ROS 17/2.8 nuclear factor also recognizes the A/T-rich DNA cognates of the homeodomain-containing POU family of transcription factors. Taken together, these data suggest that a ubiquitous CP1-like CAAT factor and a cell type-restricted homeodomain containing (Msx or POU family) transcription factor interact with the proximal rat OC promoter to direct appropriate basal OC transcription in osteoblastic cells.

Ultra-High-Throughput Screening of an In Vitro-Synthesized Horseradish Peroxidase Displayed on Microbeads Using Cell Sorter

PubMed Central

Zhu, Bo; Mizoguchi, Takuro; Kojima, Takaaki; Nakano, Hideo

2015-01-01

The C1a isoenzyme of horseradish peroxidase (HRP) is an industrially important heme-containing enzyme that utilizes hydrogen peroxide to oxidize a wide variety of inorganic and organic compounds for practical applications, including synthesis of fine chemicals, medical diagnostics, and bioremediation. To develop a ultra-high-throughput screening system for HRP, we successfully produced active HRP in an Escherichia coli cell-free protein synthesis system, by adding disulfide bond isomerase DsbC and optimizing the concentrations of hemin and calcium ions and the temperature. The biosynthesized HRP was fused with a single-chain Cro (scCro) DNA-binding tag at its N-terminal and C-terminal sites. The addition of the scCro-tag at both ends increased the solubility of the protein. Next, HRP and its fusion proteins were successfully synthesized in a water droplet emulsion by using hexadecane as the oil phase and SunSoft No. 818SK as the surfactant. HRP fusion proteins were displayed on microbeads attached with double-stranded DNA (containing the scCro binding sequence) via scCro-DNA interactions. The activities of the immobilized HRP fusion proteins were detected with a tyramide-based fluorogenic assay using flow cytometry. Moreover, a model microbead library containing wild type hrp (WT) and inactive mutant (MUT) genes was screened using fluorescence-activated cell-sorting, thus efficiently enriching the WT gene from the 1:100 (WT:MUT) library. The technique described here could serve as a novel platform for the ultra-high-throughput discovery of more useful HRP mutants and other heme-containing peroxidases. PMID:25993095

Purification of proteins from solutions containing residual host cell proteins via preparative crystallization.

PubMed

Hekmat, Dariusch; Breitschwerdt, Peter; Weuster-Botz, Dirk

2015-09-01

To investigate quantitatively and reproducibly a scalable, preparative crystallization method in novel stirred tanks using three different protein solutions containing residual microbial host cell proteins (HCP). Lysozyme from solutions being spiked with up to 15% host cell proteins (HCP) (corresponding to 176,500 ppm) was crystallized within a 2.4-4.6 h at 93.7% yield using NaCl and glycerol. Lipase was crystallized under comparable conditions using NaCl and a mixture of two polyethylene glycols (PEG). Enhanced green fluorescent protein (eGFP) was overexpressed in E. coli yielding a solution containing 23% target protein. Residual HCP content after pre-treatment was 7-16%. eGFP was crystallized from these solutions within 1.75-4 h at 88.7% step yield using ethanol and the same mixture of two PEG as in the case of lipase. HCP contained in the solvent channels of the protein crystals could be removed by diffusive washing yielding final purities at or above 99%. Preparative crystallization can be carried out with fast kinetics and high yields from solutions containing residual impurities and may represent an attractive alternative purification method compared to preparative chromatography, especially at large production scales.

Abortive replication of Bombyx mori nucleopolyhedrovirus in Sf9 and High Five cells: Defective nuclear transport of the virions

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

Katou, Yasuhiro; Ikeda, Motoko; Kobayashi, Michihiro

2006-04-10

Despite close genetic relationship, Bombyx mori nucleopolyhedrovirus (BmNPV) and Autographa californica multicapsid NPV (AcMNPV) display a distinct host range property. Here, BmNPV replication was examined in Sf9 and High Five cells that were nonproductive for BmNPV infection but supported high titers of AcMNPV replication. Recombinant BmNPV, vBm/gfp/lac, containing bm-ie1 promoter-driven egfp showed that few Sf9 and High Five cells infected with vBm/gfp/lac expressed EGFP, while large proportion of EGFP-expressing cells was observed when transfected with vBm/gfp/lac DNA. Immunocytochemical analysis showed that BmNPV was not imported into the nucleus of these two cell lines, while recombinant BmNPV, vBm{delta}64/ac-gp64 possessing AcMNPV gp64more » was imported into the nucleus, yielding progeny virions in High Five cells, but not Sf9 cells. These results indicate that the defective nuclear import of infected virions due to insufficient BmNPV GP64 function is involved in the restricted BmNPV replication in Sf9 and High Five cells.« less

One-to-one encapsulation based on alternating droplet generation

NASA Astrophysics Data System (ADS)

Hirama, Hirotada; Torii, Toru

2015-10-01

This paper reports the preparation of encapsulated particles as models of cells using an alternating droplet generation encapsulation method in which the number of particles in a droplet is controlled by a microchannel to achieve one-to-one encapsulation. Using a microchannel in which wettability is treated locally, the fluorescent particles used as models of cells were successfully encapsulated in uniform water-in-oil-in-water (W/O/W) emulsion droplets. Furthermore, 20% of the particle-containing droplets contained one particle. Additionally, when a surfactant with the appropriate properties was used, the fluorescent particles within each inner aqueous droplet were enclosed in the merged droplet by spontaneous droplet coalescence. This one-to-one encapsulation method based on alternating droplet generation could be used for a variety of applications, such as high-throughput single-cell assays, gene transfection into cells or one-to-one cell fusion.

One-to-one encapsulation based on alternating droplet generation.

PubMed

Hirama, Hirotada; Torii, Toru

2015-10-21

This paper reports the preparation of encapsulated particles as models of cells using an alternating droplet generation encapsulation method in which the number of particles in a droplet is controlled by a microchannel to achieve one-to-one encapsulation. Using a microchannel in which wettability is treated locally, the fluorescent particles used as models of cells were successfully encapsulated in uniform water-in-oil-in-water (W/O/W) emulsion droplets. Furthermore, 20% of the particle-containing droplets contained one particle. Additionally, when a surfactant with the appropriate properties was used, the fluorescent particles within each inner aqueous droplet were enclosed in the merged droplet by spontaneous droplet coalescence. This one-to-one encapsulation method based on alternating droplet generation could be used for a variety of applications, such as high-throughput single-cell assays, gene transfection into cells or one-to-one cell fusion.

Hydrogen embrittlement in nickel-hydrogen cells

NASA Technical Reports Server (NTRS)

Gross, Sidney

1989-01-01

It was long known that many strong metals can become weakened and brittle as the result of the accumulation of hydrogen within the metal. When the metal is stretched, it does not show normal ductile properties, but fractures prematurely. This problem can occur as the result of a hydrogen evolution reaction such as corrosion or electroplating, or due to hydrogen in the environment at the metal surface. High strength alloys such as steels are especially susceptible to hydrogen embrittlement. Nickel-hydrogen cells commonly use Inconel 718 alloy for the pressure container, and this also is susceptible to hydrogen embrittlement. Metals differ in their susceptibility to embrittlement. Hydrogen embrittlement in nickel-hydrogen cells is analyzed and the reasons why it may or may not occur are discussed. Although Inconel 718 can display hydrogen embrittlement, experience has not identified any problem with nickel-hydrogen cells. No hydrogen embrittlement problem is expected with the 718 alloy pressure container used in nickel-hydrogen cells.

Towards a needle-free diagnosis of malaria: in vivo identification and classification of red and white blood cells containing haemozoin.

PubMed

Burnett, Jennifer L; Carns, Jennifer L; Richards-Kortum, Rebecca

2017-11-07

Optical detection of circulating haemozoin has been suggested as a needle free method to diagnose malaria using in vivo microscopy. Haemozoin is generated within infected red blood cells by the malaria parasite, serving as a highly specific, endogenous biomarker of malaria. However, phagocytosis of haemozoin by white blood cells which persist after the infection is resolved presents the potential for false positive diagnosis; therefore, the focus of this work is to identify a feature of the haemozoin signal to discriminate between infected red blood cells and haemozoin-containing white blood cells. Conventional brightfield microscopy of thin film blood smears was used to analyse haemozoin absorbance signal in vitro. Cell type and parasite maturity were morphologically determined using colocalized DAPI staining. The ability of features to discriminate between infected red blood cells and haemozoin-containing white blood cells was evaluated using images of smears from subjects infected with two species of Plasmodium, Plasmodium yoelii and Plasmodium falciparum. Discriminating features identified by blood smear microscopy were characterized in vivo in P. yoelii-infected mice. Two features of the haemozoin signal, haemozoin diameter and normalized intensity difference, were identified as potential parameters to differentiate infected red blood cells and haemozoin-containing white blood cells. Classification performance was evaluated using the area under the receiver operating characteristic curve, with area under the curve values of 0.89 for the diameter parameter and 0.85 for the intensity parameter when assessed in P. yoelii samples. Similar results were obtained from P. falciparum blood smears, showing an AUC of 0.93 or greater for both classification features. For in vivo investigations, the intensity-based metric was the best classifier, with an AUC of 0.91. This work demonstrates that size and intensity features of haemozoin absorbance signal collected by in vivo microscopy are effective classification metrics to discriminate infected red blood cells from haemozoin-containing white blood cells. This reduces the potential for false positive results associated with optical imaging strategies for in vivo diagnosis of malaria based on the endogenous biomarker haemozoin.

Surface Molecules Released by Trypanosoma cruzi Metacyclic Forms Downregulate Host Cell Invasion

PubMed Central

Clemente, Tatiana Mordente; Cortez, Cristian; Novaes, Antônio da Silva; Yoshida, Nobuko

2016-01-01

Background The question whether metacylic trypomastigote (MT) forms of different T. cruzi strains differentially release surface molecules, and how they affect host cell invasion, remains to be fully clarified. We addressed that question using T. cruzi strains that differ widely in the ability to invade cells. Methodology/Principal Findings Metacyclic forms were incubated at 37°C for 1 h in complete D10 medium or in nutrient-deprived PBS containing Ca2+ and Mg2+ (PBS++). The conditioned medium (CM), collected after parasite centrifugation, was used for cell invasion assays and Western blot analysis, using monoclonal antibodies directed to gp82 and gp90, the MT surface molecules that promote and negatively regulate invasion, respectively. CM of poorly invasive G strain (G-CM) contained high amounts of gp90 and gp82, either in vesicles or as soluble molecules. CM of highly invasive CL strain (CL-CM) contained gp90 and gp82 at very low levels. HeLa cells were incubated for 1 h with CL strain MT in D10, in absence or in the presence of G-CM or CL-CM. Parasite invasion was significantly inhibited by G-CM, but not by CL-CM. As G strain MT invasion rate in D10 is very low, assays with this strain were performed in PBS++, which induces invasion-promoting lysosome-spreading. G-CM, but not CL-CM, significantly inhibited G strain internalization, effect that was counteracted by preincubating G-CM with an anti-gp90 monoclonal antibody or anti-gp82 polyclonal antibody that do not recognize live MT. G strain CM generated in PBS++ contained much lower amounts of gp90 and gp82 as compared to CM produced in D10, and exhibited lower inhibitory effect on host cell invasion. Conclusion/Significance Our data suggest that the surface molecules spontaneously released by MT impair parasite-host cell interaction, gp82 presumably competing with the molecule expressed on MT surface for the host cell receptor, and gp90 further contributing to down modulate invasion. PMID:27483135

Optical parameters of the tunable Bragg reflectors in squid.

PubMed

Ghoshal, Amitabh; Demartini, Daniel G; Eck, Elizabeth; Morse, Daniel E

2013-08-06

Cephalopods (e.g. octopus, squid and cuttlefish) dynamically tune the colour and brightness of their skin for camouflage and communication using specialized skin cells called iridocytes. We use high-resolution microspectrophotometry to investigate individual tunable Bragg structures (consisting of alternating reflectin protein-containing, high-refractive index lamellae and low-refractive index inter-lamellar spaces) in live and chemically fixed iridocytes of the California market squid, Doryteuthis opalescens. This subcellular, single-stack microspectrophotometry allows for spectral normalization, permitting use of a transfer-matrix model of Bragg reflectance to calculate all the parameters of the Bragg stack-the refractive indices, dimensions and numbers of the lamellae and inter-lamellar spaces. Results of the fitting analyses show that eight or nine pairs of low- and high-index layers typically contribute to the observed reflectivity in live cells, whereas six or seven pairs of low- and high-index layers typically contribute to the reflectivity in chemically fixed cells. The reflectin-containing, high-index lamellae of live cells have a refractive index proportional to the peak reflectivity, with an average of 1.405 ± 0.012 and a maximum around 1.44, while the reflectin-containing lamellae in fixed tissue have a refractive index of 1.413 ± 0.015 suggesting a slight increase of refractive index in the process of fixation. As expected, incremental changes in refractive index contribute to the greatest incremental changes in reflectivity for those Bragg stacks with the most layers. The excursions in dimensions required to tune the measured reflected wavelength from 675 (red) to 425 nm (blue) are a decrease from ca 150 to 80 nm for the high-index lamellae and from ca 120 to 50 nm for the low-index inter-lamellar spaces. Fixation-induced dimensional changes also are quantified, leading us to suggest that further microspectrophotometric analyses of this iridocyte system can be used as a model system to quantify the effects of various methods of tissue fixation. The microspectrophotometry technique described can be expected to provide deeper insights into the molecular and physical mechanisms governing other biophotonically active cells and structures.

Optical parameters of the tunable Bragg reflectors in squid

PubMed Central

Ghoshal, Amitabh; DeMartini, Daniel G.; Eck, Elizabeth; Morse, Daniel E.

2013-01-01

Cephalopods (e.g. octopus, squid and cuttlefish) dynamically tune the colour and brightness of their skin for camouflage and communication using specialized skin cells called iridocytes. We use high-resolution microspectrophotometry to investigate individual tunable Bragg structures (consisting of alternating reflectin protein-containing, high-refractive index lamellae and low-refractive index inter-lamellar spaces) in live and chemically fixed iridocytes of the California market squid, Doryteuthis opalescens. This subcellular, single-stack microspectrophotometry allows for spectral normalization, permitting use of a transfer-matrix model of Bragg reflectance to calculate all the parameters of the Bragg stack—the refractive indices, dimensions and numbers of the lamellae and inter-lamellar spaces. Results of the fitting analyses show that eight or nine pairs of low- and high-index layers typically contribute to the observed reflectivity in live cells, whereas six or seven pairs of low- and high-index layers typically contribute to the reflectivity in chemically fixed cells. The reflectin-containing, high-index lamellae of live cells have a refractive index proportional to the peak reflectivity, with an average of 1.405 ± 0.012 and a maximum around 1.44, while the reflectin-containing lamellae in fixed tissue have a refractive index of 1.413 ± 0.015 suggesting a slight increase of refractive index in the process of fixation. As expected, incremental changes in refractive index contribute to the greatest incremental changes in reflectivity for those Bragg stacks with the most layers. The excursions in dimensions required to tune the measured reflected wavelength from 675 (red) to 425 nm (blue) are a decrease from ca 150 to 80 nm for the high-index lamellae and from ca 120 to 50 nm for the low-index inter-lamellar spaces. Fixation-induced dimensional changes also are quantified, leading us to suggest that further microspectrophotometric analyses of this iridocyte system can be used as a model system to quantify the effects of various methods of tissue fixation. The microspectrophotometry technique described can be expected to provide deeper insights into the molecular and physical mechanisms governing other biophotonically active cells and structures. PMID:23740489

High Photoluminescence Quantum Yield in Band Gap Tunable Bromide Containing Mixed Halide Perovskites.

PubMed

Sutter-Fella, Carolin M; Li, Yanbo; Amani, Matin; Ager, Joel W; Toma, Francesca M; Yablonovitch, Eli; Sharp, Ian D; Javey, Ali

2016-01-13

Hybrid organic-inorganic halide perovskite based semiconductor materials are attractive for use in a wide range of optoelectronic devices because they combine the advantages of suitable optoelectronic attributes and simultaneously low-cost solution processability. Here, we present a two-step low-pressure vapor-assisted solution process to grow high quality homogeneous CH3NH3PbI3-xBrx perovskite films over the full band gap range of 1.6-2.3 eV. Photoluminescence light-in versus light-out characterization techniques are used to provide new insights into the optoelectronic properties of Br-containing hybrid organic-inorganic perovskites as a function of optical carrier injection by employing pump-powers over a 6 orders of magnitude dynamic range. The internal luminescence quantum yield of wide band gap perovskites reaches impressive values up to 30%. This high quantum yield translates into substantial quasi-Fermi level splitting and high "luminescence or optically implied" open-circuit voltage. Most importantly, both attributes, high internal quantum yield and high optically implied open-circuit voltage, are demonstrated over the entire band gap range (1.6 eV ≤ Eg ≤ 2.3 eV). These results establish the versatility of Br-containing perovskite semiconductors for a variety of applications and especially for the use as high-quality top cell in tandem photovoltaic devices in combination with industry dominant Si bottom cells.

Temporal metabolomic responses of cultured HepG2 liver cells to high fructose and high glucose exposures.

PubMed

Meissen, John K; Hirahatake, Kristin M; Adams, Sean H; Fiehn, Oliver

2015-06-01

High fructose consumption has been implicated with deleterious effects on human health, including hyperlipidemia elicited through de novo lipogenesis. However, more global effects of fructose on cellular metabolism have not been elucidated. In order to explore the metabolic impact of fructose-containing nutrients, we applied both GC-TOF and HILIC-QTOF mass spectrometry metabolomic strategies using extracts from cultured HepG2 cells exposed to fructose, glucose, or fructose + glucose. Cellular responses were analyzed in a time-dependent manner, incubated in media containing 5.5 mM glucose + 5.0 mM fructose in comparison to controls incubated in media containing either 5.5 mM glucose or 10.5 mM glucose. Mass spectrometry identified 156 unique known metabolites and a large number of unknown compounds, which revealed metabolite changes due to both utilization of fructose and high-carbohydrate loads independent of hexose structure. Fructose was shown to be partially converted to sorbitol, and generated higher levels of fructose-1-phosphate as a precursor for glycolytic intermediates. Differentially regulated ratios of 3-phosphoglycerate to serine pathway intermediates in high fructose media indicated a diversion of carbon backbones away from energy metabolism. Additionally, high fructose conditions changed levels of complex lipids toward phosphatidylethanolamines. Patterns of acylcarnitines in response to high hexose exposure (10.5 mM glucose or glucose/fructose combination) suggested a reduction in mitochondrial beta-oxidation.

Production of laccase by Coriolus versicolor and its application in decolorization of dyestuffs: (II). Decolorization of dyes by laccase containing fermentation broth with or without self-immobilized mycelia.

PubMed

Lin, Jian-Ping; Lian, Wei; Xia, Li-Ming; Cen, Pei-Lin

2003-01-01

The capability of decolorization for commercial dyes by Coriolus versicolor fermentation broth containing laccase with or without immobilized mycelium was evaluated. With cell-free fermentation broth containing laccase, high decolorization ratio was achieved foracid orange 7, but not for the other dyes concerned. The immobilized mycelium was proved to be more efficient than the cell-free system. All the four dyestuffs studied were found being decolourized with certain extent by immobilized mycelium. The repeated-batch decolorization was carried out with satisfactory results. The experimental data showed that the continuous decolorization of wastewater from a printing and dyeing industry was possible by using the self-immobilized C. versicolor.

Solid oxide fuel cell generator with removable modular fuel cell stack configurations

DOEpatents

Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

1998-04-21

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

Solid oxide fuel cell generator with removable modular fuel cell stack configurations

DOEpatents

Gillett, James E.; Dederer, Jeffrey T.; Zafred, Paolo R.; Collie, Jeffrey C.

1998-01-01

A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack.

Cell migration without a lamellipodium: translation of actin dynamics into cell movement mediated by tropomyosin.

PubMed

Gupton, Stephanie L; Anderson, Karen L; Kole, Thomas P; Fischer, Robert S; Ponti, Aaron; Hitchcock-DeGregori, Sarah E; Danuser, Gaudenz; Fowler, Velia M; Wirtz, Denis; Hanein, Dorit; Waterman-Storer, Clare M

2005-02-14

The actin cytoskeleton is locally regulated for functional specializations for cell motility. Using quantitative fluorescent speckle microscopy (qFSM) of migrating epithelial cells, we previously defined two distinct F-actin networks based on their F-actin-binding proteins and distinct patterns of F-actin turnover and movement. The lamellipodium consists of a treadmilling F-actin array with rapid polymerization-dependent retrograde flow and contains high concentrations of Arp2/3 and ADF/cofilin, whereas the lamella exhibits spatially random punctae of F-actin assembly and disassembly with slow myosin-mediated retrograde flow and contains myosin II and tropomyosin (TM). In this paper, we microinjected skeletal muscle alphaTM into epithelial cells, and using qFSM, electron microscopy, and immunolocalization show that this inhibits functional lamellipodium formation. Cells with inhibited lamellipodia exhibit persistent leading edge protrusion and rapid cell migration. Inhibition of endogenous long TM isoforms alters protrusion persistence. Thus, cells can migrate with inhibited lamellipodia, and we suggest that TM is a major regulator of F-actin functional specialization in migrating cells.

Thermal and overcharge abuse analysis of a redox shuttle for overcharge protection of LiFePO4

NASA Astrophysics Data System (ADS)

Lamb, Joshua; Orendorff, Christopher J.; Amine, Khalil; Krumdick, Gregory; Zhang, Zhengcheng; Zhang, Lu; Gozdz, Antoni S.

2014-02-01

This work investigated the performance and abuse tolerance of cells protected using the redox shuttle 1,4-bis(2-methoxyethoxy)-2,5-di-tert-butylbenzene. The thermal efficiencies were evaluated using isothermal battery calorimetry. Cells containing the overcharge shuttle were observed to reach a steady state value of approximately 3.8 V, with a small variance in direct proportion to the applied current. In all cases the heat output from the cells was measured to reach ∼90% of the total input power. The heat output was also measured using isothermal calorimetry. At higher rates of overcharge, the data shows that the cell containing the shuttle rapidly reaches a steady state voltage, while the temperature increases until a moderately high steady state temperature is reached. The control cell meanwhile rapidly increases in both applied voltage and cell temperature until cell failure. Two cells in series were taken deliberately out of balance individually, then charged as a single pack to observe the time needed to bring the cells into balance with one another.

Stimulation of the cell cycle and maize transformation by disruption of the plant retinoblastoma pathway

PubMed Central

Gordon-Kamm, William; Dilkes, Brian P.; Lowe, Keith; Hoerster, George; Sun, Xifan; Ross, Margit; Church, Laura; Bunde, Chris; Farrell, Jeff; Hill, Patrea; Maddock, Sheila; Snyder, Jane; Sykes, Louisa; Li, Zhongsen; Woo, Young-min; Bidney, Dennis; Larkins, Brian A.

2002-01-01

The genome of the Mastreviruses encodes a replication-associated protein (RepA) that interacts with members of the plant retinoblastoma-related protein family, which are putative cell cycle regulators. Expression of ZmRb1, a maize retinoblastoma-related gene, and RepA inhibited and stimulated, respectively, cell division in tobacco cell cultures. The effect of RepA was mitigated by over-expression of ZmRb1. RepA increased transformation frequency and callus growth rate of high type II maize germplasm. RepA-containing transgenic maize calli remained embryogenic, were readily regenerable, and produced fertile plants that transmitted transgene expression in a Mendelian fashion. In high type II, transformation frequency increased with the strength of the promoter driving RepA expression. When a construct in which RepA was expressed behind its native LIR promoter was used, primary transformation frequencies did not improve for two elite Pioneer maize inbreds. However, when LIR:RepA-containing transgenic embryos were used in subsequent rounds of transformation, frequencies were higher in the RepA+ embryos. These data demonstrate that RepA can stimulate cell division and callus growth in culture, and improve maize transformation. PMID:12185243

Geminivirus vectors for high-level expression of foreign proteins in plant cells.

PubMed

Mor, Tsafrir S; Moon, Yong-Sun; Palmer, Kenneth E; Mason, Hugh S

2003-02-20

Bean yellow dwarf virus (BeYDV) is a monopartite geminivirus that can infect dicotyledonous plants. We have developed a high-level expression system that utilizes elements of the replication machinery of this single-stranded DNA virus. The replication initiator protein (Rep) mediates release and replication of a replicon from a DNA construct ("LSL vector") that contains an expression cassette for a gene of interest flanked by cis-acting elements of the virus. We used tobacco NT1 cells and biolistic delivery of plasmid DNA for evaluation of replication and expression of reporter genes contained within an LSL vector. By codelivery of a GUS reporter-LSL vector and a Rep-supplying vector, we obtained up to 40-fold increase in expression levels compared to delivery of the reporter-LSL vectors alone. High-copy replication of the LSL vector was correlated with enhanced expression of GUS. Rep expression using a whole BeYDV clone, a cauliflower mosaic virus 35S promoter driving either genomic rep or an intron-deleted rep gene, or 35S-rep contained in the LSL vector all achieved efficient replication and enhancement of GUS expression. We anticipate that this system can be adapted for use in transgenic plants or plant cell cultures with appropriately regulated expression of Rep, with the potential to greatly increase yield of recombinant proteins. Copyright 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 430-437, 2003.

Genotoxicity of mercury used in chromosome aberration tests.

PubMed

Akiyama, M; Oshima, H; Nakamura, M

2001-01-01

The purpose of this study was to investigate the genotoxic effects of Hg released from dental amalgams. The chromosome aberration test was conducted using original extracts and their diluted solutions of conventional type amalgam and high copper amalgam. The concentrations of Hg, Cu and Ag in the original extract of high copper amalgam were 17.64, 7.97 and 43.90 microM, respectively. Those in the original extract of conventional type amalgam were 20.63, 7.87 and 14.79 microM, respectively. 10 and 30 microM Hg(2+) were also used for comparison. The frequency of chromosome aberrations was below 5% with 0 microM Hg(2+) and with a triple dilution of high copper amalgam extract, containing 5.88 microM Hg, 14.63 microM Cu and 2.65 microM Ag. However, 9.5% of the cells showed chromosome aberrations with a quadruple dilution of conventional type amalgam, containing 5.15 microM Hg, 3.69 microM Cu and 1.96 microM Ag. The amount of Hg in the quadruple dilution of conventional type amalgam was less than that in the triple dilution of high copper amalgam extract and 10 microM Hg(2+). A concentration of 30 microM Hg(2+) caused 34.5% of the cells to show chromosome aberrations while with a two-thirds dilution of high copper amalgam extract, containing 11.76 microM Hg, 29.26 microM Cu and 5.31 microM Ag, 58.5% of the cells showed chromosome aberrations. A two-thirds dilution of high copper amalgam extract induced more chromosome aberrations than 30 microM Hg(2+), although the amount of Hg was less than 30 microM Hg(2+). A triple dilution of conventional type amalgam extract, original extracts of conventional type amalgam and high copper amalgam and 100 microM Hg(2+) were induced few metaphases. It was revealed that the conventional type amalgam induced chromosome aberrations with quadruple dilution where cell viability was about 80% and that the high copper amalgam induced a high level of chromosome aberrations with the two-thirds dilution. The effects of low level Hg on humans are not clear.

Halophilic Archaea determined from geothermal steam vent aerosols.

PubMed

Ellis, Dean G; Bizzoco, Richard W; Kelley, Scott T

2008-06-01

Hydrothermal vents, known as 'fumaroles', are ubiquitous features of geothermal areas. Although their geology has been extensively characterized, little is known about the subsurface microbial ecology of fumaroles largely because of the difficulty in collecting sufficient numbers of cells from boiling steam water for DNA extraction and culture isolation. Here we describe the first collection, molecular analysis and isolation of microbes from fumarole steam waters in Russia (Kamchatka) and the USA (Hawaii, New Mexico, California and Wyoming). Surprisingly, the steam vent waters from all the fumaroles contained halophilic Archaea closely related to the Haloarcula spp. found in non-geothermal salt mats, saline soils, brine pools and salt lakes around the world. Microscopic cell counting estimated the cell dispersal rate at approximately 1.6 x 10(9) cells year(-1) from a single fumarole. We also managed to enrich microbes in high-salt media from every vent sample, and to isolate Haloarcula from a Yellowstone vent in a 20% salt medium after a month-long incubation, demonstrating both salt tolerance and viability of cells collected from high-temperature steam. Laboratory tests determined that microbes enriched in salt media survived temperatures greater than 75 degrees C for between 5 and 30 min during the collection process. Hawaiian fumaroles proved to contain the greatest diversity of halophilic Archaea with four new lineages that may belong to uncultured haloarchaeal genera. This high diversity may have resulted from the leaching of salts and minerals through the highly porous volcanic rock, creating a chemically complex saline subsurface.

Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

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

Wiberg, Gustav K. H., E-mail: gustav.wiberg@gmail.com, E-mail: m.arenz@chem.ku.dk; Fleige, Michael; Arenz, Matthias, E-mail: gustav.wiberg@gmail.com, E-mail: m.arenz@chem.ku.dk

2015-02-15

We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allowsmore » an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.« less

Semen inhibits Zika virus infection of cells and tissues from the anogenital region.

PubMed

Müller, Janis A; Harms, Mirja; Krüger, Franziska; Groß, Rüdiger; Joas, Simone; Hayn, Manuel; Dietz, Andrea N; Lippold, Sina; von Einem, Jens; Schubert, Axel; Michel, Manuela; Mayer, Benjamin; Cortese, Mirko; Jang, Karen S; Sandi-Monroy, Nathallie; Deniz, Miriam; Ebner, Florian; Vapalahti, Olli; Otto, Markus; Bartenschlager, Ralf; Herbeuval, Jean-Philippe; Schmidt-Chanasit, Jonas; Roan, Nadia R; Münch, Jan

2018-06-07

Zika virus (ZIKV) causes severe birth defects and can be transmitted via sexual intercourse. Semen from ZIKV-infected individuals contains high viral loads and may therefore serve as an important vector for virus transmission. Here we analyze the effect of semen on ZIKV infection of cells and tissues derived from the anogenital region. ZIKV replicates in all analyzed cell lines, primary cells, and endometrial or vaginal tissues. However, in the presence of semen, infection by ZIKV and other flaviviruses is potently inhibited. We show that semen prevents ZIKV attachment to target cells, and that an extracellular vesicle preparation from semen is responsible for this anti-ZIKV activity. Our findings suggest that ZIKV transmission is limited by semen. As such, semen appears to serve as a protector against sexual ZIKV transmission, despite the availability of highly susceptible cells in the anogenital tract and high viral loads in this bodily fluid.

Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

NASA Astrophysics Data System (ADS)

Wiberg, Gustav K. H.; Fleige, Michael; Arenz, Matthias

2015-02-01

We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

Accumulation of high OPDA level correlates with reduced ROS and elevated GSH benefiting white cell survival in variegated leaves

USDA-ARS?s Scientific Manuscript database

Variegated Epipremnum aureum ‘Marble Queen’ plant has white (VMW) and green (VMG) sectors within the same leaf. The white sector cells containing undifferentiated chloroplasts are viable, but the underlying mechanism for their survival is not clear. Because phytohormones are important for plant grow...

High-polyphenol sorghum bran extract inhibits cancer cell growth through DNA damage, cell cycle arrest, and apoptosis

USDA-ARS?s Scientific Manuscript database

As diet is one of the major controllable factors in cancer development, potentially chemopreventive foods are of significant interest to public health. One such food is sorghum (Sorghum bicolor), a cereal grain that contains varying concentrations of polyphenols. In a panel of 15 sorghum germplasm...

Electrospun Nafion®/Polyphenylsulfone Composite Membranes for Regenerative Hydrogen Bromine Fuel Cells.

PubMed

Park, Jun Woo; Wycisk, Ryszard; Pintauro, Peter N; Yarlagadda, Venkata; Van Nguyen, Trung

2016-02-29

The regenerative H₂/Br₂-HBr fuel cell, utilizing an oxidant solution of Br₂ in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA) ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion ® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU), for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion ® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H₂-Br₂ fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion ® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H₂/Br₂-HBr systems.

Parasagittal solitary fibrous tumor resembling hemangiopericytoma.

PubMed

Shidoh, Satoka; Yoshida, Kazunari; Takahashi, Satoshi; Mikami, Shuji; Mukai, Makio; Kawase, Takeshi

2010-04-01

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor in the central nervous system, and the clinical behavior of this tumor is similar to that of meningioma. We report the case of a Japanese woman with parasagittal SFT that resembled hemangiopericytoma (HPC). Histological examination revealed that the tumor was highly cellular, with cells containing oval- or spindle-shaped nuclei arranged in sheets or a pattern-less growth mode. Focal vascular proliferation was also observed. Some areas showed intercellular stroma containing remarkable eosinophilic collagens. Tumor cells showed a strong immunoreactivity for CD34 but were negative for S-100 protein and epithelial membrane antigen. MIB-1 labeling index of the tumor was 6.6%. Owing to the high cellularity, high MIB-1 labeling index, and focal vascular proliferation, it was difficult to distinguish this lesion from HPC. However, the tumor was finally diagnosed as SFT on the basis of the strong immunostaining for CD34 and absence of pericellular reticulin.

Rapid one-step purification of single-cells encapsulated in alginate microcapsules from oil to aqueous phase using a hydrophobic filter paper: implications for single-cell experiments.

PubMed

Lee, Do-Hyun; Jang, Miran; Park, Je-Kyun

2014-10-01

By virtue of the biocompatibility and physical properties of hydrogel, picoliter-sized hydrogel microcapsules have been considered to be a biometric signature containing several features similar to that of encapsulated single cells, including phenotype, viability, and intracellular content. To maximize the experimental potential of encapsulating cells in hydrogel microcapsules, a method that enables efficient hydrogel microcapsule purification from oil is necessary. Current methods based on centrifugation for the conventional stepwise rinsing of oil, are slow and laborious and decrease the monodispersity and yield of the recovered hydrogel microcapsules. To remedy these shortcomings we have developed a simple one-step method to purify alginate microcapsules, containing a single live cell, from oil to aqueous phase. This method employs oil impregnation using a commercially available hydrophobic filter paper without multistep centrifugal purification and complicated microchannel networks. The oil-suspended alginate microcapsules encapsulating single cells from mammalian cancer cell lines (MCF-7, HepG2, and U937) and microorganisms (Chlorella vulgaris) were successfully exchanged to cell culture media by quick (~10 min) depletion of the surrounding oil phase without coalescence of neighboring microcapsules. Cell proliferation and high integrity of the microcapsules were also demonstrated by long-term incubation of microcapsules containing a single live cell. We expect that this method for the simple and rapid purification of encapsulated single-cell microcapsules will attain widespread adoption, assisting cell biologists and clinicians in the development of single-cell experiments. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research on treatment of wastewater containing heavy metal by microbial fuel cell

NASA Astrophysics Data System (ADS)

Chen, Zixuan; Lu, Xun; Yin, Ruixia; Luo, Yunyi; Mai, Hanjian; Zhang, Nan; Xiong, Jingfang; Zhang, Hongguo; Tang, Jinfeng; Luo, Dinggui

2018-02-01

With rapid development of social economy, serious problem has been caused by wastewater containing heavy metals, which was difficult to be treated by many kinds of traditional treatment methods, such as complex processes, high cost or easy to cause secondary pollution. As a novel biological treatment technology, microbial fuel cells (MFC) can generate electric energy while dealing with wastewater, which was proposed and extensively studied. This paper introduced the working principle of MFC, the classification of cathode, and the research progress on the treatment of wastewater containing Cr(VI), Cu(II), Ag(I), Mn(II) and Cd(II) by MFC. The study found that different cathode, different heavy metals anddifferent hybrid systems would affect the performance of the system and removal effect for heavy metal in MFC. MFC was a highly potential pollution control technology. Until now, the research was still in the laboratory stage. Its industrial application for recovery of heavy metal ion, improving the energy recovery rate and improvement or innovation of system were worthy of further research.

A dinucleotide motif in oligonucleotides shows potent immunomodulatory activity and overrides species-specific recognition observed with CpG motif.

PubMed

Kandimalla, Ekambar R; Bhagat, Lakshmi; Zhu, Fu-Gang; Yu, Dong; Cong, Yan-Ping; Wang, Daqing; Tang, Jimmy X; Tang, Jin-Yan; Knetter, Cathrine F; Lien, Egil; Agrawal, Sudhir

2003-11-25

Bacterial and synthetic DNAs containing CpG dinucleotides in specific sequence contexts activate the vertebrate immune system through Toll-like receptor 9 (TLR9). In the present study, we used a synthetic nucleoside with a bicyclic heterobase [1-(2'-deoxy-beta-d-ribofuranosyl)-2-oxo-7-deaza-8-methyl-purine; R] to replace the C in CpG, resulting in an RpG dinucleotide. The RpG dinucleotide was incorporated in mouse- and human-specific motifs in oligodeoxynucleotides (oligos) and 3'-3-linked oligos, referred to as immunomers. Oligos containing the RpG motif induced cytokine secretion in mouse spleen-cell cultures. Immunomers containing RpG dinucleotides showed activity in transfected-HEK293 cells stably expressing mouse TLR9, suggesting direct involvement of TLR9 in the recognition of RpG motif. In J774 macrophages, RpG motifs activated NF-kappa B and mitogen-activated protein kinase pathways. Immunomers containing the RpG dinucleotide induced high levels of IL-12 and IFN-gamma, but lower IL-6 in time- and concentration-dependent fashion in mouse spleen-cell cultures costimulated with IL-2. Importantly, immunomers containing GTRGTT and GARGTT motifs were recognized to a similar extent by both mouse and human immune systems. Additionally, both mouse- and human-specific RpG immunomers potently stimulated proliferation of peripheral blood mononuclear cells obtained from diverse vertebrate species, including monkey, pig, horse, sheep, goat, rat, and chicken. An immunomer containing GTRGTT motif prevented conalbumin-induced and ragweed allergen-induced allergic inflammation in mice. We show that a synthetic bicyclic nucleotide is recognized in the C position of a CpG dinucleotide by immune cells from diverse vertebrate species without bias for flanking sequences, suggesting a divergent nucleotide motif recognition pattern of TLR9.

Comparison of antimicrobial activity of selected, commercially available wound dressing materials.

PubMed

Szweda, Piotr; Gorczyca, Grzegorz; Tylingo, Robert

2018-05-02

The aim of our study was to examine the antimicrobial potential of eight selected, commercially available wound dressings containing different antimicrobial agents: silver, chlorhexidine acetate, povidone-iodine, and manuka honey. The materials were tested against four reference strains of bacteria: Staphylococcus aureus (PCM 2051), Staphylococcus epidermidis (PCM 2118), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (K12), using the disc diffusion-like method and a time-killing assay. For both experiments, the highest activity against all four tested strains of bacteria was observed in the case of Mepilex Ag, which contains silver as an antibacterial agent. Incubation for four hours of a 10x10mm 2 piece of this material in 10ml cells suspension (concentration: 10 9 -10 10 CFU/ml) resulted in complete elimination of bacteria of all four strains tested. The same results were obtained for a povidone-iodine containing dressing, Inadine, though its activity was lower in the disc diffusion assay. Silvercel, Aquacel Ag and Melgisorb Ag, which also contain silver, also exhibited a satisfactory level of activity. In the case of Aquacel Ag, 24 hours' incubation resulted in complete elimination of the cells of both Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa.The Escherichia coli cells were killed after only four hours' treatment. High effectiveness against Escherichia coli was also demonstrated for Silvercel. However, 24 hours' includation was required for complete elimination of the cells of this bacteria strain. High activity against all tested bacteria, but only in the disc diffusion assay, was observed for Algivon, which contains manuka honey. The Medisorb Silver Pad, containing silver, and Bactigras, which contains chlorhexidine acetate, revealed much lower antimicrobial activity, particularly noticeable in the time-killing assay. In addition, we also tested the anti-staphylococcal activity of a biopolymer material impregnated with lysostaphin. Results revealed that its activity against Staphylococcus aureus was comparable to the most active wound dressings impregnated with silver or inadine. Some important differences in the antimicrobial potential of investigated materials have been found. The presented results could be of interest to clinicians managing wounds.

Two estrogen response element sequences near the PCNA gene are not responsible for its estrogen-enhanced expression in MCF7 cells.

PubMed

Wang, Cheng; Yu, Jie; Kallen, Caleb B

2008-01-01

The proliferating cell nuclear antigen (PCNA) is an essential component of DNA replication, cell cycle regulation, and epigenetic inheritance. High expression of PCNA is associated with poor prognosis in patients with breast cancer. The 5'-region of the PCNA gene contains two computationally-detected estrogen response element (ERE) sequences, one of which is evolutionarily conserved. Both of these sequences are of undocumented cis-regulatory function. We recently demonstrated that estradiol (E2) enhances PCNA mRNA expression in MCF7 breast cancer cells. MCF7 cells proliferate in response to E2. Here, we demonstrate that E2 rapidly enhanced PCNA mRNA and protein expression in a process that requires ERalpha as well as de novo protein synthesis. One of the two upstream ERE sequences was specifically bound by ERalpha-containing protein complexes, in vitro, in gel shift analysis. Yet, each ERE sequence, when cloned as a single copy, or when engineered as two tandem copies of the ERE-containing sequence, was not capable of activating a luciferase reporter construct in response to E2. In MCF7 cells, neither ERE-containing genomic region demonstrated E2-dependent recruitment of ERalpha by sensitive ChIP-PCR assays. We conclude that E2 enhances PCNA gene expression by an indirect process and that computational detection of EREs, even when evolutionarily conserved and when near E2-responsive genes, requires biochemical validation.

The synthesis and coupling of photoreactive collagen-based peptides to restore integrin reactivity to an inert substrate, chemically-crosslinked collagen

PubMed Central

Malcor, Jean-Daniel; Bax, Daniel; Hamaia, Samir W.; Davidenko, Natalia; Best, Serena M.; Cameron, Ruth E.; Farndale, Richard W.; Bihan, Dominique

2016-01-01

Collagen is frequently advocated as a scaffold for use in regenerative medicine. Increasing the mechanical stability of a collagen scaffold is widely achieved by cross-linking using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). However, this treatment consumes the carboxylate-containing amino acid sidechains that are crucial for recognition by the cell-surface integrins, abolishing cell adhesion. Here, we restore cell reactivity to a cross-linked type I collagen film by covalently linking synthetic triple-helical peptides (THPs), mimicking the structure of collagen. These THPs are ligands containing an active cell-recognition motif, GFOGER, a high-affinity binding site for the collagen-binding integrins. We end-stapled peptide strands containing GFOGER by coupling a short diglutamate-containing peptide to their N-terminus, improving the thermal stability of the resulting THP. A photoreactive Diazirine group was grafted onto the end-stapled THP to allow covalent linkage to the collagen film upon UV activation. Such GFOGER-derivatized collagen films showed restored affinity for the ligand-binding I domain of integrin α2β1, and increased integrin-dependent cell attachment and spreading of HT1080 and Rugli cell lines, expressing integrins α2β1 and α1β1, respectively. The method we describe has wide application, beyond collagen films or scaffolds, since the photoreactive diazirine will react with many organic carbon skeletons. PMID:26854392

49 CFR 173.230 - Fuel cell cartridges containing hazardous material.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Fuel cell cartridges containing hazardous material... Than Class 1 and Class 7 § 173.230 Fuel cell cartridges containing hazardous material. (a) Requirements for Fuel Cell Cartridges. Fuel cell cartridges, including when contained in or packed with equipment...

Glucose metabolism-targeted therapy and withaferin A are effective for epidermal growth factor receptor tyrosine kinase inhibitor-induced drug-tolerant persisters.

PubMed

Kunimasa, Kei; Nagano, Tatsuya; Shimono, Yohei; Dokuni, Ryota; Kiriu, Tatsunori; Tokunaga, Shuntaro; Tamura, Daisuke; Yamamoto, Masatsugu; Tachihara, Motoko; Kobayashi, Kazuyuki; Satouchi, Miyako; Nishimura, Yoshihiro

2017-07-01

In pathway-targeted cancer drug therapies, the relatively rapid emergence of drug-tolerant persisters (DTPs) substantially limits the overall therapeutic benefit. However, little is known about the roles of DTPs in drug resistance. In this study, we investigated the features of epidermal growth factor receptor-tyrosine kinase inhibitor-induced DTPs and explored a new treatment strategy to overcome the emergence of these DTPs. We used two EGFR-mutated lung adenocarcinoma cell lines, PC9 and II-18. They were treated with 2 μM gefitinib for 6, 12, or 24 days or 6 months. We analyzed the mRNA expression of the stem cell-related markers by quantitative RT-PCR and the expression of the cellular senescence-associated proteins. Then we sorted DTPs according to the expression pattern of CD133 and analyzed the features of sorted cells. Finally, we tried to ablate DTPs by glucose metabolism targeting therapies and a stem-like cell targeting drug, withaferin A. Drug-tolerant persisters were composed of at least two types of cells, one with the properties of cancer stem-like cells (CSCs) and the other with the properties of therapy-induced senescent (TIS) cells. The CD133 high cell population had CSC properties and the CD133 low cell population had TIS properties. The CD133 low cell population containing TIS cells showed a senescence-associated secretory phenotype that supported the emergence of the CD133 high cell population containing CSCs. Glucose metabolism inhibitors effectively eliminated the CD133 low cell population. Withaferin A effectively eliminated the CD133 high cell population. The combination of phloretin and withaferin A effectively suppressed gefitinib-resistant tumor growth. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Suitability of shredded tyres as a substitute for a landfill leachate collection medium.

PubMed

Park, Jae K; Edil, Tuncer B; Kim, Jae Y; Huh, Mock; Lee, Sung Ho; Lee, Jung Jun

2003-06-01

A series of tests were conducted to investigate the fate of heavy metals and gasoline components in a simulated landfill, consisting of a 30 cm thick clay liner and a leachate collection layer containing tyres as well as in two test cells installed in a landfill. Arsenic, selenium, mercury, barium, and lead concentrations were lower while zinc concentration was higher in the tank containing tyre-chips than the tank without tyre-chips. When samples were filtered, however, concentrations of zinc as well as other inorganics were lower in the tank containing tyre-chips, indicating that metals in the leachate exposed to tyre-chips travel more slowly in a subsurface environment due to filtering effect. In a test cell study, arsenic, cobalt, lead and nickel concentrations were lower in the cell containing tyre-chips than in the cell without tyre-chips, except iron and zinc. Both tests indicate that some inorganic contaminants are sorbed to tyre-chips. Gasoline components were also significantly sorbed by tyre-chips in field cell tests. Although tyre-chips are known to leach organic and inorganic contaminants, concentrations in field conditions will be lower than the reported experimental results since the tests were performed under worst-case scenarios. If tyre-chips are used in areas where contamination levels are high, then they can be used as a sorbent for environmental clean-up.

Performance enhancement of direct ethanol fuel cell using Nafion composites with high volume fraction of titania

NASA Astrophysics Data System (ADS)

Matos, B. R.; Isidoro, R. A.; Santiago, E. I.; Fonseca, F. C.

2014-12-01

The present study reports on the performance enhancement of direct ethanol fuel cell (DEFC) at 130 °C with Nafion-titania composite electrolytes prepared by sol-gel technique and containing high volume fractions of the ceramic phase. It is found that for high volume fractions of titania (>10 vol%) the ethanol uptake of composites is largely reduced while the proton conductivity at high-temperatures is weakly dependent on the titania content. Such tradeoff between alcohol uptake and conductivity resulted in a boost of DEFC performance at high temperatures using Nafion-titania composites with high fraction of the inorganic phase.

In vitro and in vivo evaluation of a new nanocomposite, containing high density polyethylene, tricalcium phosphate, hydroxyapatite, and magnesium oxide nanoparticles.

PubMed

Pourdanesh, Fereydoun; Jebali, Ali; Hekmatimoghaddam, Seyedhossein; Allaveisie, Azra

2014-07-01

In this study, a new nanocomposite, which contained high density polyethylene (HDPE), tricalcium phosphate (Ca3(PO4)2) nanoparticles (TCP NPs), hydroxyapatite nanoparticles (HA NPs), and magnesium oxide nanoparticles (MgO NPs) was prepared. As in vitro experiment, human osteoblasts (HOB) cells were exposed to pristine HDPE and its nanocomposite for a period of 1, 4, and 7 days at 37 °C, and then different assays were carried out, including osteoblast cell proliferation, Trypan blue staining, cell viability, alkaline phosphatase (ALP), and cell adhesion. Antibacterial property of pristine HDPE and its nanocomposite was evaluated, and also their mechanical properties were measured after 2 and 4 months. As in vivo experiment, pristine HDPE and its nanocomposite were separately implanted on calvarium bone of rabbits, and tissue inflammation and osteogenesis were investigated after 2, 4, and 6 months. In case of HOB cells treated with HDPE or nanocomposite, as incubation time was increased, cell proliferation, live/dead ratio, and cell viability were decreased. But, the ALP activity and cell adhesion of HOB cells which treated with nanocomposite were raised after increase of incubation time. This study demonstrated that although the mechanical properties of nanocomposite were similar to HDPE sheet, but their antibacterial property was not similar. The in vivo experiment showed that both pristine HDPE and its nanocomposite had same inflammation responses. Interestingly, osteogenesis was observed after 2 months at bone/nanocomposite interface, and was highly increased after 4 and 6 months. It must be noted that such pattern was not seen at bone/HDPE interface. Copyright © 2014 Elsevier B.V. All rights reserved.

Immunofluorescent staining of nuclear antigen in lymphoid cells transformed by Herpesvirus papio (HVP).

PubMed

Schmitz, H

1981-01-01

An improved fixation method for antigen detection in lymphoblastoid cells is described. Herpesvirus papio nuclear antigen (HUPNA) could be stained in several transformed lymphoid cell lines by anti-complement immunofluorescence (ACIF). Antibody to HUPNA was detected in many human sera containing antibodies to Epstein-Barr virus capsid and nuclear antigen (EBNA). Rheumatoid arthritis sera showed a high incidence of both anti-EBNA and anti-HUPNA antibodies.

Research, Development and Fabrication of Lithium Solar Cells, Part 2

NASA Technical Reports Server (NTRS)

Iles, P. A.

1972-01-01

The development and fabrication of lithium solar cells are discussed. Several single-step, lithium diffusion schedules using lower temperatures and times are described. A comparison was made using evaporated lithium metal as the lithium source, and greatly improved consistency in lithium concentrations was obtained. It was possible to combine all processing steps to obtain lithium doped cells of high output which also contained adequate lithium to ensure good recoverability.

Bacterial Cell Surface Adsorption of Rare Earth Elements

NASA Astrophysics Data System (ADS)

Jiao, Y.; Park, D.; Reed, D.; Fujita, Y.; Yung, M.; Anderko, A.; Eslamimanesh, A.

2015-12-01

Rare earth elements (REE) play a critical role in many emerging clean energy technologies, including high-power magnets, wind turbines, solar panels, hybrid/electric vehicle batteries and lamp phosphors. In order to sustain demand for such technologies given current domestic REE shortages, there is a need to develop new approaches for ore processing/refining and recycling of REE-containing materials. To this end, we have developed a microbially-mediated bioadsorption strategy with application towards enrichment of REE from complex mixtures. Specifically, the bacterium Caulobacter crescentus was genetically engineered to display lanthanide binding tags (LBTs), short peptides that possess high affinity and specificity for rare earth elements, on its cell surface S-layer protein. Under optimal conditions, LBT-displayed cells adsorbed greater than 5-fold more REE than control cells lacking LBTs. Competition binding experiments with a selection of REEs demonstrated that our engineered cells could facilitate separation of light- from heavy- REE. Importantly, binding of REE onto our engineered strains was much more favorable compared to non-REE metals. Finally, REE bound to the cell surface could be stripped off using citrate, providing an effective and non-toxic REE recovery method. Together, this data highlights the potential of our approach for selective REE enrichment from REE containing mixtures.

The cellular magnetic response and biocompatibility of biogenic zinc- and cobalt-doped magnetite nanoparticles

NASA Astrophysics Data System (ADS)

Moise, Sandhya; Céspedes, Eva; Soukup, Dalibor; Byrne, James M.; El Haj, Alicia J.; Telling, Neil D.

2017-01-01

The magnetic moment and anisotropy of magnetite nanoparticles can be optimised by doping with transition metal cations, enabling their properties to be tuned for different biomedical applications. In this study, we assessed the suitability of bacterially synthesized zinc- and cobalt-doped magnetite nanoparticles for biomedical applications. To do this we measured cellular viability and activity in primary human bone marrow-derived mesenchymal stem cells and human osteosarcoma-derived cells. Using AC susceptibility we studied doping induced changes in the magnetic response of the nanoparticles both as stable aqueous suspensions and when associated with cells. Our findings show that the magnetic response of the particles was altered after cellular interaction with a reduction in their mobility. In particular, the strongest AC susceptibility signal measured in vitro was from cells containing high-moment zinc-doped particles, whilst no signal was observed in cells containing the high-anisotropy cobalt-doped particles. For both particle types we found that the moderate dopant levels required for optimum magnetic properties did not alter their cytotoxicity or affect osteogenic differentiation of the stem cells. Thus, despite the known cytotoxicity of cobalt and zinc ions, these results suggest that iron oxide nanoparticles can be doped to sufficiently tailor their magnetic properties without compromising cellular biocompatibility.

The cellular magnetic response and biocompatibility of biogenic zinc- and cobalt-doped magnetite nanoparticles

PubMed Central

Moise, Sandhya; Céspedes, Eva; Soukup, Dalibor; Byrne, James M.; El Haj, Alicia J.; Telling, Neil D.

2017-01-01

The magnetic moment and anisotropy of magnetite nanoparticles can be optimised by doping with transition metal cations, enabling their properties to be tuned for different biomedical applications. In this study, we assessed the suitability of bacterially synthesized zinc- and cobalt-doped magnetite nanoparticles for biomedical applications. To do this we measured cellular viability and activity in primary human bone marrow-derived mesenchymal stem cells and human osteosarcoma-derived cells. Using AC susceptibility we studied doping induced changes in the magnetic response of the nanoparticles both as stable aqueous suspensions and when associated with cells. Our findings show that the magnetic response of the particles was altered after cellular interaction with a reduction in their mobility. In particular, the strongest AC susceptibility signal measured in vitro was from cells containing high-moment zinc-doped particles, whilst no signal was observed in cells containing the high-anisotropy cobalt-doped particles. For both particle types we found that the moderate dopant levels required for optimum magnetic properties did not alter their cytotoxicity or affect osteogenic differentiation of the stem cells. Thus, despite the known cytotoxicity of cobalt and zinc ions, these results suggest that iron oxide nanoparticles can be doped to sufficiently tailor their magnetic properties without compromising cellular biocompatibility. PMID:28045082

FluBlok, a next generation influenza vaccine manufactured in insect cells.

PubMed

Cox, Manon M J; Hollister, Jason R

2009-06-01

FluBlok, a recombinant trivalent hemagglutinin (rHA) vaccine produced in insect cell culture using the baculovirus expression system, provides an attractive alternative to the current egg-based trivalent inactivated influenza vaccine (TIV). Its manufacturing process presents the possibility for safe and expeditious vaccine production. FluBlok contains three times more HA than TIV and does not contain egg-protein or preservatives. The high purity of the antigen enables administration at higher doses without a significant increase in side-effects in human subjects. The insect cell-baculovirus production technology is particularly suitable for influenza where annual adjustment of the vaccine is required. The baculovirus-insect expression system is generally considered a safe production system, with limited growth potential for adventitious agents. Still regulators question and challenge the safety of this novel cell substrate as FluBlok continues to advance toward product approval. This review provides an overview of cell substrate characterization for expresSF cell line used for the manufacturing of FluBlok. In addition, this review includes an update on the clinical development of FluBlok. The highly purified protein vaccine, administered at three times higher antigen content than TIV, is well tolerated and results in stronger immunogenicity, a long lasting immune response and provides cross-protection against drift influenza viruses.

High-power beam steering using phase conjugation through Brillouin-induced four-wave mixing.

PubMed

Jones, D C; Cook, G; Ridley, K D; Scott, A M

1991-10-15

We report an experimental demonstration of a beam-steering concept. A high-reflectivity phase-conjugate mirror is used to steer a high-power phase-conjugate beam using a low-power signal beam. The high reflectivity phase conjugation is achieved using Brillouin-induced four-wave mixing in a cell containing carbon disulfide.

System and method for liquid silicon containment

DOEpatents

Cliber, James A; Clark, Roger F; Stoddard, Nathan G; Von Dollen, Paul

2013-05-28

This invention relates to a system and a method for liquid silicon containment, such as during the casting of high purity silicon used in solar cells or solar modules. The containment apparatus includes a shielding member adapted to prevent breaching molten silicon from contacting structural elements or cooling elements of a casting device, and a volume adapted to hold a quantity of breaching molten silicon with the volume formed by a bottom and one or more sides.

System and method for liquid silicon containment

DOEpatents

Cliber, James A; Clark, Roger F; Stoddard, Nathan G; Von Dollen, Paul

2014-06-03

This invention relates to a system and a method for liquid silicon containment, such as during the casting of high purity silicon used in solar cells or solar modules. The containment apparatus includes a shielding ember adapted to prevent breaching molten silicon from contacting structural elements or cooling elements of a casting device, and a volume adapted to hold a quantity of breaching molten silicon with the volume formed by a bottom and one or more sides.

A majority of mice show long-term expression of a human. beta. -globin gene after retrovirus transfer into hematopoietic stem cells

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

Bender, M.A.; Gelinas, R.E.; Miller

1989-04-01

Murine bone marrow was infected with a high-titer retrovirus vector containing the human {beta}-globin and neomycin phosphotransferase genes. Anemic W/W/sup v/ mice were transplanted with infected marrow which in some cases had been exposed to the selective agent G418. Human {beta}-globin expression was monitored in transplanted animals by using a monoclonal antibody specific for human {beta}-globin polypeptide, and hematopoietic reconstitution was monitored by using donor and recipient mice which differed in hemoglobin type. In some experiments all transplanted mice expressed the human {beta}-globin polypeptide for over 4 months, and up to 50% of peripheral erythrocytes contained detectable levels of polypeptide.more » DNA analysis of transplanted animals revealed that virtually every myeloid cell contained a provirus. Integration site analysis and reconstitution of secondary marrow recipients suggested that every mouse was reconstituted with at least one infected stem cell which had extensive repopulation capability. The ability to consistently transfer an active {beta}-globin gene into mouse hematopoietic cells improves the feasibility of using these techniques for somatic cell gene therapy in humans.« less

Specific Mutation of a Gammaherpesvirus-Expressed Antigen in Response to CD8 T Cell Selection In Vivo

PubMed Central

Loh, Joy; Popkin, Daniel L.; Droit, Lindsay; Braaten, Douglas C.; Zhao, Guoyan; Zhang, Xin; Vachharajani, Punit; Myers, Nancy; Hansen, Ted H.

2012-01-01

Herpesviruses are thought to be highly genetically stable, and their use as vaccine vectors has been proposed. However, studies of the human gammaherpesvirus, Epstein-Barr virus, have found viral isolates containing mutations in HLA class I-restricted epitopes. Using murine gammaherpesvirus 68 expressing ovalbumin (OVA), we examined the stability of a gammaherpesvirus antigenic locus under strong CD8 T cell selection in vivo. OVA-specific CD8 T cells selected viral isolates containing mutations in the OVA locus but minimal alterations in other genomic regions. Thus, a CD8 T cell response to a gammaherpesvirus-expressed antigen that is not essential for replication or pathogenesis can result in selective mutation of that antigen in vivo. This finding may have relevance for the use of herpesvirus vectors for chronic antigen expression in vivo. PMID:22171269

Pancreatic Beta Cells Synthesize Neuropeptide Y and Can Rapidly Release Peptide Co-Transmitters

PubMed Central

Whim, Matthew D.

2011-01-01

Background In addition to polypeptide hormones, pancreatic endocrine cells synthesize a variety of bioactive molecules including classical transmitters and neuropeptides. While these co-transmitters are thought to play a role in regulating hormone release little is known about how their secretion is regulated. Here I investigate the synthesis and release of neuropeptide Y from pancreatic beta cells. Methodology/Principal Findings NPY appears to be an authentic co-transmitter in neonatal, but not adult, beta cells because (1) early in mouse post-natal development, many beta cells are NPY-immunoreactive whereas no staining is observed in beta cells from NPY knockout mice; (2) GFP-expressing islet cells from an NPY(GFP) transgenic mouse are insulin-ir; (3) single cell RT-PCR experiments confirm that the NPY(GFP) cells contain insulin mRNA, a marker of beta cells. The NPY-immunoreactivity previously reported in alpha and delta cells is therefore likely to be due to the presence of NPY-related peptides. INS-1 cells, a beta cell line, are also NPY-ir and contain NPY mRNA. Using the FMRFamide tagging technique, NPY secretion was monitored from INS-1 beta cells with high temporal resolution. Peptide release was evoked by brief depolarizations and was potentiated by activators of adenylate cyclase and protein kinase A. Following a transient depolarization, NPY-containing dense core granules fused with the cell membrane and discharged their contents within a few milliseconds. Conclusions These results indicate that after birth, NPY expression in pancreatic islets is restricted to neonatal beta cells. The presence of NPY suggests that peptide co-transmitters could mediate rapid paracrine or autocrine signaling within the endocrine pancreas. The FMRFamide tagging technique may be useful in studying the release of other putative islet co-transmitters in real time. PMID:21559341

High-temperature sorbent method for removal of sulfur-containing gases from gaseous mixtures

DOEpatents

Young, J.E.; Jalan, V.M.

1982-07-07

A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorbtion capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

High-temperature sorbent method for removal of sulfur containing gases from gaseous mixtures

DOEpatents

Young, J.E.; Jalan, V.M.

1984-06-19

A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorption capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

High-temperature sorbent method for removal of sulfur containing gases from gaseous mixtures

DOEpatents

Young, John E.; Jalan, Vinod M.

1984-01-01

A copper oxide-zinc oxide mixture is used as a sorbent for removing hydrogen sulfide and other sulfur containing gases at high temperatures from a gaseous fuel mixture. This high-temperature sorbent is especially useful for preparing fuel gases for high temperature fuel cells. The copper oxide is initially reduced in a preconditioning step to elemental copper and is present in a highly dispersed state throughout the zinc oxide which serves as a support as well as adding to the sulfur sorption capacity. The spent sorbent is regenerated by high-temperature treatment with an air fuel, air steam mixture followed by hydrogen reduction to remove and recover the sulfur.

Efficient genome editing by FACS enrichment of paired D10A Cas9 nickases coupled with fluorescent proteins.

PubMed

Gopalappa, Ramu; Song, Myungjae; Chandrasekaran, Arun Pandian; Das, Soumyadip; Haq, Saba; Koh, Hyun Chul; Ramakrishna, Suresh

2018-05-31

Targeted genome editing by clustered regularly interspaced short palindromic repeats (CRISPR-Cas9) raised concerns over off-target effects. The use of double-nicking strategy using paired Cas9 nickase has been developed to minimize off-target effects. However, it was reported that the efficiency of paired nickases were comparable or lower than that of either corresponding nuclease alone. Recently, we conducted a systematic comparison of the efficiencies of several paired Cas9 with their corresponding Cas9 nucleases and showed that paired D10A Cas9 nickases are sometimes more efficient than individual nucleases for gene disruption. However, sometimes the designed paired Cas9 nickases exhibited significantly lower mutation frequencies than nucleases, hampering the generation of cells containing paired Cas9 nickase-induced mutations. Here we implemented IRES peptide-conjugation of fluorescent protein to Cas9 nickase and subjected for fluorescence-activated cell sorting. The sorted cell populations are highly enriched with cells containing paired Cas9 nickase-induced mutations, by a factor of up to 40-fold as compared with the unsorted population. Furthermore, gene-disrupted single cell clones using paired nickases followed by FACS sorting strategy were generated highly efficiently, without compromising with its low off-target effects. We envision that our fluorescent protein coupled paired nickase-mediated gene disruption, facilitating efficient and highly specific genome editing in medical research.

Corrosive effects of fluoride on titanium: investigation by X-ray photoelectron spectroscopy, atomic force microscopy, and human epithelial cell culturing.

PubMed

Stájer, Anette; Ungvári, Krisztina; Pelsoczi, István K; Polyánka, Hilda; Oszkó, Albert; Mihalik, Erzsébet; Rakonczay, Zoltán; Radnai, Márta; Kemény, Lajos; Fazekas, András; Turzó, Kinga

2008-11-01

High fluoride (F(-)) concentrations and acidic pH impair the corrosion resistance of titanium (Ti). Effects of F(-)-containing caries-preventive prophylactic rinses, and gels on Ti were investigated by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Human epithelial cell attachment and proliferation were investigated by dimethylthiazol-diphenyl tetrazolium bromide (MTT) and protein content assays. Aqueous 1% NaF solution (3800 ppm F(-), pH 4.5) or high (12,500 ppm) F(-) content gel (pH 4.8) strongly corroded the surface and modified its composition. XPS revealed formation of a strongly bound F(-)-containing complex (Na(2)TiF(6)). AFM indicated an increase in roughness (R(a)) of the surfaces: 10-fold for the NaF solution and smaller for the gel or a mouthwash (250 ppm F(-), pH 4.4). MTT revealed that cell attachment was significantly increased by the gel, but was not disturbed by either the mouthwash or the NaF. Cell proliferation determined by MTT decreased significantly only for the NaF-treated samples; protein content assay experiments showed no such effect. This study indicates that epithelial cell culturing results can depend on the method used, and the adverse effects of a high F(-) concentration and low pH should be considered when prophylactic gels are applied by patients with Ti implants or other dental devices.

Membraneless enzymatic ethanol/O2 fuel cell: Transitioning from an air-breathing Pt-based cathode to a bilirubin oxidase-based biocathode

NASA Astrophysics Data System (ADS)

Aquino Neto, Sidney; Milton, Ross D.; Hickey, David P.; De Andrade, Adalgisa R.; Minteer, Shelley D.

2016-08-01

The bioelectrooxidation of ethanol was investigated in a fully enzymatic membraneless ethanol/O2 biofuel cell assembly using hybrid bioanodes containing multi-walled carbon nanotube (MWCNT)-decorated gold metallic nanoparticles with either a pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) enzyme or a nicotinamide adenine dinucleotide (NAD+)-dependent ADH enzyme. The biofuel cell anode was prepared with the PQQ-dependent enzyme and designed using either a direct electron transfer (DET) architecture or via a mediated electron transfer (MET) configuration through a redox polymer, 1,1‧-dimethylferrocene-modified linear polyethyleneimine (FcMe2-C3-LPEI). In the case of the bioanode containing the NAD+-dependent enzyme, only the mediated electron transfer mechanism was employed using an electropolymerized methylene green film to regenerate the NAD+ cofactor. Regardless of the enzyme being employed at the anode, a bilirubin oxidase-based biocathode prepared within a DET architecture afforded efficient electrocatalytic oxygen reduction in an ethanol/O2 biofuel cell. The power curves showed that DET-based bioanodes via the PQQ-dependent ADH still lack high current densities, whereas the MET architecture furnished maximum power density values as high as 226 ± 21 μW cm-2. Considering the complete membraneless enzymatic biofuel cell with the NAD+-dependent ADH-based bioanode, power densities as high as 111 ± 14 μW cm-2 were obtained. This shows the advantage of PQQ-dependent ADH for membraneless ethanol/O2 biofuel cell applications.

Highly Stable, Anion Conductive, Comb-Shaped Copolymers for Alkaline Fuel Cells

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

Li, NW; Leng, YJ; Hickner, MA

2013-07-10

To produce an anion-conductive and durable polymer electrolyte for alkaline fuel cell applications, a series of quaternized poly(2,6-dimethyl phenylene oxide)s containing long alkyl side chains pendant to the nitrogen-centered cation were synthesized using a Menshutkin reaction to form comb-shaped structures. The pendant alkyl chains were responsible for the development of highly conductive ionic domains, as confirmed by small-angle X-ray scattering (SAXS). The comb-shaped polymers having one alkyl side chain showed higher hydroxide conductivities than those with benzyltrimethyl ammonium moieties or structures with more than one alkyl side chain per cationic site. The highest conductivity was observed for comb-shaped polymers withmore » benzyldimethylhexadecyl ammonium cations. The chemical stabilities of the comb-shaped membranes were evaluated under severe, accelerated-aging conditions, and degradation was observed by measuring IEC and ion conductivity changes during aging. The comb-shaped membranes retained their high ion conductivity in 1 M NaOH at 80 degrees C for 2000 h. These cationic polymers were employed as ionomers in catalyst layers for alkaline fuel cells. The results indicated that the C-16 alkyl side chain ionomer had a slightly better initial performance, despite its low IEC value, but very poor durability in the fuel cell. In contrast, 90% of the initial performance was retained for the alkaline fuel cell with electrodes containing the C-6 side chain after 60 h of fuel cell operation.« less

Eradication of melanoma in vitro and in vivo via targeting with a Killer-Red-containing telomerase-dependent adenovirus.

PubMed

Takehara, Kiyoto; Yano, Shuya; Tazawa, Hiroshi; Kishimoto, Hiroyuki; Narii, Nobuhiro; Mizuguchi, Hiroyuki; Urata, Yasuo; Kagawa, Shunsuke; Fujiwara, Toshiyoshi; Hoffman, Robert M

2017-08-18

Melanoma is a highly recalcitrant cancer and transformative therapy is necessary for the cure of this disease. We recently developed a telomerase-dependent adenovirus containing the fluorescent protein Killer-Red. In the present report, we first determined the efficacy of Killer-Red adenovirus combined with laser irradiation on human melanoma cell lines in vitro. Cell viability of human melanoma cells was reduced in a dose-dependent and irradiation-time-dependent manner. We used an intradermal xenografted melanoma model in nude mice to determine efficacy of the Killer-Red adenovirus. Intratumoral injection of Killer-Red adenovirus, combined with laser irradiation, eradicated the melanoma indicating the potential of a new paradigm of cancer therapy.

In situ hybridisation of EBV DNA-DNA hybrids using wet heat in polypropylene containers.

PubMed Central

Labrecque, L G

1992-01-01

AIMS: To explore procedures designed to optimise DNA-DNA in situ hybridisation, using cells infected with Epstein-Barr virus (EBV) and tissues and subfragments of the EBV DNA as probes. METHODS: The denaturation step occurred in a polypropylene container, using wet heat generated by a hot water container, the pressure cooker, or the microwave oven, without coverslips, reaching a temperature of 121 degrees C or more in these two last systems. Two different visualisation systems were used. RESULTS: Fixed cells and tumours harbouring a high and medium to low copy number (a few hundreds to 33 copies per cell), were clearly labelled, using a simple reiterated subfragment (BamW) of the EBV DNA, and fresh frozen cells, harbouring a very low copy number (one to two on average) labelled using BamW as well as BamH (single non-reiterated 6 kilobase subfragment). CONCLUSION: This is a valuable alternative technique for DNA-DNA ISH that can be used in fresh frozen samples as well as fixed samples. Images PMID:1336018

Microgravity mediated changes in phytoferritin accumulation in soybean root cap cells

NASA Technical Reports Server (NTRS)

Klymchuk, D. O.; Kordyum, E. L.; Vorobyova, T. V.; Brown, C. S.; Chapman, D. K.

2000-01-01

Phytoferritin is an iron-protein complex analogous to the ferritin found in mammalian, bacteria and fungi cells. Phytoferritin molecules are large proteins, about 10.5 nm in diameter, visualised in an electron microscope as discrete, electron dense particles with iron-containing core, where several thousand atoms of iron lie within the proteinaceous shell (apoferritin). In higher plants, a plastid stroma is the site of phytoferritin storage. Phytoferritin is seen in all types of plastids. It is considered to be a mechanism used by cells to store iron in a non-toxic form. Phytoferritin-bound iron may subsequently be used to form iron-containing components. It was shown that low levels of phytoferritin are synthesised in normal green leaves, whereas chlorotic leaves do not have a measurable amount of phytoferritin and leaves of iron-loaded seedlings contain a high level of total iron, and phytoferritin well-filled by iron. Phytoferritin accumulation was observed in photosynthetic inactivity chloroplasts during senescence and disease. In this study we analised the effects of microgravity and ethylene on production of phytoferritin in the root cap columella cells of soybean seedlings.

Comparative effects of kainic, quisqualic, and ibotenic acids on phenylethanolamine-N-methyltransferase-containing cells of rat retina.

PubMed

Cohen, J

1989-02-01

Phenylethanolamine-N-methyltransferase (PNMT) activity is located in a subpopulation of amacrine cells in the inner nuclear layer of the rat retina. Kainic, quisqualic, and ibotenic acids, all of which are analogues of glutamic acid, were injected intravitreally to the right and saline to the contralateral left eyes of adult male rats in order to determine the effect of these agents upon retinal PNMT activity. Animals were sacrificed 1 week later for tissue removal. The effect of these agents was measured by radiometric assay for PNMT. The fall in PNMT activity was used to measure the sensitivity of the PNMT-containing cells to these agents. Kainic acid was the most potent, producing the greatest reduction in PNMT activity in the smallest doses. Quisqualic acid was intermediate in potency to that of kainic and ibotenic acids. Ibotenic acid reduced PNMT activity only in extremely high doses. The PNMT-containing cells are sensitive to the toxic actions of kainic and quisqualic acids, but relatively insensitive to the actions of ibotenic acid.

High oxygen condition facilitates the differentiation of mouse and human pluripotent stem cells into pancreatic progenitors and insulin-producing cells.

PubMed

Hakim, Farzana; Kaitsuka, Taku; Raeed, Jamiruddin Mohd; Wei, Fan-Yan; Shiraki, Nobuaki; Akagi, Tadayuki; Yokota, Takashi; Kume, Shoen; Tomizawa, Kazuhito

2014-04-04

Pluripotent stem cells have potential applications in regenerative medicine for diabetes. Differentiation of stem cells into insulin-producing cells has been achieved using various protocols. However, both the efficiency of the method and potency of differentiated cells are insufficient. Oxygen tension, the partial pressure of oxygen, has been shown to regulate the embryonic development of several organs, including pancreatic β-cells. In this study, we tried to establish an effective method for the differentiation of induced pluripotent stem cells (iPSCs) into insulin-producing cells by culturing under high oxygen (O2) conditions. Treatment with a high O2 condition in the early stage of differentiation increased insulin-positive cells at the terminus of differentiation. We found that a high O2 condition repressed Notch-dependent gene Hes1 expression and increased Ngn3 expression at the stage of pancreatic progenitors. This effect was caused by inhibition of hypoxia-inducible factor-1α protein level. Moreover, a high O2 condition activated Wnt signaling. Optimal stage-specific treatment with a high O2 condition resulted in a significant increase in insulin production in both mouse embryonic stem cells and human iPSCs and yielded populations containing up to 10% C-peptide-positive cells in human iPSCs. These results suggest that culturing in a high O2 condition at a specific stage is useful for the efficient generation of insulin-producing cells.

Phenotypic, molecular, and functional characterization of human peripheral blood CD34+/THY1+ cells.

PubMed

Humeau, L; Bardin, F; Maroc, C; Alario, T; Galindo, R; Mannoni, P; Chabannon, C

1996-02-01

A subset of mobilized CD34+ cells present in patient aphereses expresses Thy1 (CDw90). This population contains most long-term culture initiating cells, as assayed with a murine stromal cell line. It also contains a significant proportion of colony-forming unit granulocyte macrophage, but very few burst-forming unit erythroid. The limited differentiation towards the erythroid lineage is further confirmed by the absence of GATA-1 mRNA in the CD34+/Thy1+ subset, and by the low level of c-kit expression. The CD34+/Thy1+ subset appears phenotypically and functionally heterogeneous, a finding consistent with its high representation, compared to phenotypes such as CD34+/CD38-. Therefore, while at least some of CD34+/Thy1+ cells may be infectable by retroviral vectors, as shown by the presence of a transcript for the receptor for murine amphotropic retroviruses, the use of this selection strategy to specifically target human stem cells appears questionable.

Neutral beam monitoring

DOEpatents

Fink, Joel H.

1981-08-18

Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

Physiological Response of Lactobacillus plantarum to Salt and Nonelectrolyte Stress

PubMed Central

Glaasker, Erwin; Tjan, Frans S. B.; Ter Steeg, Pieter F.; Konings, Wil N.; Poolman, Bert

1998-01-01

In this report, we compared the effects on the growth of Lactobacillus plantarum of raising the medium molarity by high concentrations of KCl or NaCl and iso-osmotic concentrations of nonionic compounds. Analysis of cellular extracts for organic constituents by nuclear magnetic resonance spectroscopy showed that salt-stressed cells do not contain detectable amounts of organic osmolytes, whereas sugar-stressed cells contain sugar (and some sugar-derived) compounds. The cytoplasmic concentrations of lactose and sucrose in growing cells are always similar to the concentrations in the medium. By using the activity of the glycine betaine transport system as a measure of hyperosmotic conditions, we show that, in contrast to KCl and NaCl, high concentrations of sugars (lactose or sucrose) impose only a transient osmotic stress because external and internal sugars equilibrate after some time. Analysis of lactose (and sucrose) uptake also indicates that the corresponding transport systems are neither significantly induced nor activated directly by hyperosmotic conditions. The systems operate by facilitated diffusion and have very high apparent affinity constants for transport (>50 mM for lactose), which explains why low sugar concentrations do not protect against hyperosmotic conditions. We conclude that the more severe growth inhibition by salt stress than by equiosmolal concentrations of sugars reflects the inability of the cells to accumulate K+ (or Na+) to levels high enough to restore turgor as well as deleterious effects of the electrolytes intracellularly. PMID:9721316

PD-1HIGH Follicular CD4 T Helper Cell Subsets Residing in Lymph Node Germinal Centers Correlate with B Cell Maturation and IgG Production in Rhesus Macaques

PubMed Central

Xu, Huanbin; Wang, Xiaolei; Lackner, Andrew A.; Veazey, Ronald S.

2014-01-01

CD4+ T follicular helper (TFH) cells guide development and maturation of B cells and are crucial for effective antibody responses. Here we found rhesus macaque TFH cells, defined as CXCR5+CD4 T cells, contain two major populations: PD-1INT and PD-1HIGH cells. Of these, PD-1HIGHCD4+ T cells highly co-express ICOS but little CCR7, and reside in lymph node germinal centers (GCs), but not in blood. These cells secrete IL-21 and express transcriptional factor Bcl-6 at higher levels than CXCR5+PD-1INTCD4+ T cells. In addition, the frequency of PD-1HIGHCD4+ T cells is low in lymph nodes of newborns, but increases with age. Levels of PD-1HIGHCD4+ T cells correlate with mature B cells in lymph nodes, and PD-1 blockade in PD-1HIGHCD4+ T and B cell co-cultures significantly inhibits IgG production. In summary, PD-1HIGHCD4+ T cells residing in GC represent a specific TFH subset that contributes to maturation of B cells and IgG production. PMID:24678309

Electrokinetically pumped high pressure sprays

DOEpatents

Schoeniger, Joseph S [Oakland, CA; Paul, Phillip H [Livermore, CA; Schoeniger, Luke [Pittsford, NY

2005-11-01

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

Electrokinetically pumped high pressure sprays

DOEpatents

Schoeniger, Joseph S.; Paul, Phillip H.; Schoeniger, Luke

2002-01-01

An electrokinetic pump capable of producing high pressure is combined with a nozzle having a submicron orifice to provide a high pressure spray device. Because of its small size, the device can be contained within medical devices such as an endoscope for delivering biological materials such as DNA, chemo therapeutic agents, or vaccines to tissues and cells.

Anaplastic thyroid carcinoma with rhabdoid features.

PubMed

Feng, Gong; Laskin, William B; Chou, Pauline M; Lin, Xiaoqi

2015-05-01

Anaplastic thyroid carcinoma (ATC) is a rare, highly aggressive neoplasm, characterized by complete or partial composition by undifferentiated cells. We report a case of ATC with rhabdoid features in a 68-year-old male, who presented with a rapidly enlarging neck mass. Fine-needle aspiration (FNA) of the thyroid mass showed discohesive, pleomorphic round to polygonal rhabdoid cells with one to multiple eccentric, large, rounded nuclei with a prominent nucleolus, moderate to abundant, globoid cytoplasm which oftentimes harbor a pale para-nuclear inclusion. The cytoplasm of some cells contained variously sized, eosinophilic granules. Rare cells contained neutrophils in their cytoplasm. Mitoses including atypical mitotic figures and necrosis were readily seen. Histologic examination of needle core biopsy (NCB) revealed individual dispersed and sheets of pleomorphic neoplastic cells with similar cytomorphologic features as described above. The tumor extensively infiltrated a myxocollagenous stroma containing lymphocytes and neutrophils, and demonstrated foci of necrosis. Tumor cells were immunoreactive for keratins AE1/AE3, CAM5.2, and CK19; PAX-8, and p63, but negative for S-100, HMB-45, calcitonin, TTF-1, thyroglobulin, CD56, HBME-1, glypican-3, PAX-5, myogenin, CD31, and INI-1. The differential diagnosis of this malignant rhabdoid tumor is discussed. © 2015 Wiley Periodicals, Inc.

Distal regeneration involves the age dependent activity of branchial sac stem cells in the ascidian Ciona intestinalis

PubMed Central

2014-01-01

Abstract Tunicates have high capacities for regeneration but the underlying mechanisms and their relationship to life cycle progression are not well understood. Here we investigate the regeneration of distal structures in the ascidian tunicate Ciona intestinalis. Analysis of regenerative potential along the proximal−distal body axis indicated that distal organs, such as the siphons, their pigmented sensory organs, and the neural complex, could only be replaced from body fragments containing the branchial sac. Distal regeneration involves the formation of a blastema composed of cells that undergo cell proliferation prior to differentiation and cells that differentiate without cell proliferation. Both cell types originate in the branchial sac and appear in the blastema at different times after distal injury. Whereas the branchial sac stem cells are present in young animals, they are depleted in old animals that have lost their regeneration capacity. Thus Ciona adults contain a population of age‐related stem cells located in the branchial sac that are a source of precursors for distal body regeneration. PMID:25893097

Isolation of intact RNA from murine CD4+ T cells after intracellular cytokine staining and fluorescence-activated cell sorting.

PubMed

Kunnath-Velayudhan, Shajo; Porcelli, Steven A

2018-05-01

Intracellular cytokine staining (ICS) is a powerful method for identifying functionally distinct lymphocyte subsets, and for isolating these by fluorescence activated cell sorting (FACS). Although transcriptomic analysis of cells sorted on the basis of ICS has many potential applications, this is rarely performed because of the difficulty in isolating intact RNA from cells processed using standard fixation and permeabilization buffers for ICS. To address this issue, we compared three buffers shown previously to preserve RNA in nonhematopoietic cells subjected to intracellular staining for their effects on RNA isolated from T lymphocytes processed for ICS. Our results showed that buffers containing the recombinant ribonuclease inhibitor RNasin or high molar concentrations of salt yielded intact RNA from fixed and permeabilized T cells. As proof of principle, we successfully used the buffer containing RNasin to isolate intact RNA from CD4 + T cells that were sorted by FACS on the basis of specific cytokine production, thus demonstrating the potential of this approach for coupling ICS with transcriptomic analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

Single-hit mechanism of tumour cell killing by radiation.

PubMed

Chapman, J D

2003-02-01

To review the relative importance of the single-hit mechanism of radiation killing for tumour response to 1.8-2.0 Gy day(-1) fractions and to low dose-rate brachytherapy. Tumour cell killing by ionizing radiation is well described by the linear-quadratic equation that contains two independent components distinguished by dose kinetics. Analyses of tumour cell survival curves that contain six or more dose points usually provide good estimates of the alpha- and beta-inactivation coefficients. Superior estimates of tumour cell intrinsic radiosensitivity are obtained when synchronized populations are employed. The characteristics of single-hit inactivation of tumour cells are reviewed and compared with the characteristics of beta-inactivation. Potential molecular targets associated with single-hit inactivation are discussed along with strategies for potentiating cell killing by this mechanism. The single-hit mechanism of tumour cell killing shows no dependence on dose-rate and, consequently, no evidence of sublethal damage repair. It is uniquely potentiated by high linear-energy-transfer radiation, exhibits a smaller oxygen enhancement ratio and exhibits a larger indirect effect by hydroxyl radicals than the beta-mechanism. alpha-inactivation coefficients vary slightly throughout interphase but mitotic cells exhibit extremely high alpha-coefficients in the range of those observed for lymphocytes and some repair-deficient cells. Evidence is accumulating to suggest that chromatin in compacted form could be a radiation-hypersensitive target associated with single-hit radiation killing. Analyses of tumour cell survival curves demonstrate that it is the single-hit mechanism (alpha) that determines the majority of cell killing after doses of 2Gy and that this mechanism is highly variable between tumour cell lines. The characteristics of single-hit inactivation are qualitatively and quantitatively distinct from those of beta-inactivation. Compacted chromatin in tumour cells should be further investigated as a radiation-hypersensitive target that could be modulated for therapeutic advantage.

Exosome release and low pH belong to a framework of resistance of human melanoma cells to cisplatin.

PubMed

Federici, Cristina; Petrucci, Francesco; Caimi, Stefano; Cesolini, Albino; Logozzi, Mariantonia; Borghi, Martina; D'Ilio, Sonia; Lugini, Luana; Violante, Nicola; Azzarito, Tommaso; Majorani, Costanza; Brambilla, Daria; Fais, Stefano

2014-01-01

Intrinsic resistance to cytotoxic drugs has been a main issue in cancer therapy for decades. Microenvironmental acidity is a simple while highly efficient mechanism of chemoresistance, exploited through impairment of drug delivery. The latter is achieved by extracellular protonation and/or sequestration into acidic vesicles. This study investigates the importance of extracellular acidosis and nanovesicle (exosome) release in the resistance of human tumour cell to cisplatin (CisPt); in parallel to proton pump inhibitors (PPI) ability of interfering with these tumour cell features. The results showed that CisPt uptake by human tumour cells was markedly impaired by low pH conditions. Moreover, exosomes purified from supernatants of these cell cultures contained various amounts of CisPt, which correlated to the pH conditions of the culture medium. HPLC-Q-ICP-MS analysis revealed that exosome purified from tumour cell culture supernatants contained CisPt in its native form. PPI pre-treatment increased cellular uptake of CisPt, as compared to untreated cells, in an acidic-depend manner. Furthermore, it induced a clear inhibition of exosome release by tumour cells. Human tumours obtained from xenografts pretreated with PPI contained more CisPt as compared to tumours from xenografts treated with CisPt alone. Further analysis showed that in vivo PPI treatment induced a clear reduction in the plasmatic levels of tumour-derived exosomes which also contained lower level of CisPt. Altogether, these findings point to the identification of a double mechanism that human malignant melanoma use in resisting to a dreadful cellular poison such as cisplatin. This framework of resistance includes both low pH-dependent extracellular sequestration and an exosome-mediated elimination. Both mechanisms are markedly impaired by proton pump inhibition, leading to an increased CisPt-dependent cytotoxicity.

Exosome Release and Low pH Belong to a Framework of Resistance of Human Melanoma Cells to Cisplatin

PubMed Central

Federici, Cristina; Petrucci, Francesco; Caimi, Stefano; Cesolini, Albino; Logozzi, Mariantonia; Borghi, Martina; D'Ilio, Sonia; Lugini, Luana; Violante, Nicola; Azzarito, Tommaso; Majorani, Costanza; Brambilla, Daria; Fais, Stefano

2014-01-01

Intrinsic resistance to cytotoxic drugs has been a main issue in cancer therapy for decades. Microenvironmental acidity is a simple while highly efficient mechanism of chemoresistance, exploited through impairment of drug delivery. The latter is achieved by extracellular protonation and/or sequestration into acidic vesicles. This study investigates the importance of extracellular acidosis and nanovesicle (exosome) release in the resistance of human tumour cell to cisplatin (CisPt); in parallel to proton pump inhibitors (PPI) ability of interfering with these tumour cell features. The results showed that CisPt uptake by human tumour cells was markedly impaired by low pH conditions. Moreover, exosomes purified from supernatants of these cell cultures contained various amounts of CisPt, which correlated to the pH conditions of the culture medium. HPLC-Q-ICP-MS analysis revealed that exosome purified from tumour cell culture supernatants contained CisPt in its native form. PPI pre-treatment increased cellular uptake of CisPt, as compared to untreated cells, in an acidic-depend manner. Furthermore, it induced a clear inhibition of exosome release by tumour cells. Human tumours obtained from xenografts pretreated with PPI contained more CisPt as compared to tumours from xenografts treated with CisPt alone. Further analysis showed that in vivo PPI treatment induced a clear reduction in the plasmatic levels of tumour-derived exosomes which also contained lower level of CisPt. Altogether, these findings point to the identification of a double mechanism that human malignant melanoma use in resisting to a dreadful cellular poison such as cisplatin. This framework of resistance includes both low pH-dependent extracellular sequestration and an exosome-mediated elimination. Both mechanisms are markedly impaired by proton pump inhibition, leading to an increased CisPt-dependent cytotoxicity. PMID:24516610

High-efficiency GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy

PubMed Central

2011-01-01

We report the initial results of GaAs and GaInP solar cells grown by all solid-state molecular-beam-epitaxy (MBE) technique. For GaAs single-junction solar cell, with the application of AlInP as the window layer and GaInP as the back surface field layer, the photovoltaic conversion efficiency of 26% at one sun concentration and air mass 1.5 global (AM1.5G) is realized. The efficiency of 16.4% is also reached for GaInP solar cell. Our results demonstrate that the MBE-grown phosphide-contained III-V compound semiconductor solar cell can be quite comparable to the metal-organic-chemical-vapor-deposition-grown high-efficiency solar cell. PMID:22040124

A-π-D-π-A Electron-Donating Small Molecules for Solution-Processed Organic Solar Cells: A Review.

PubMed

Wang, Zhen; Zhu, Lingyun; Shuai, Zhigang; Wei, Zhixiang

2017-11-01

Organic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution-processed solar cells containing A-π-D-π-A-type small molecules and fullerenes have reached 11%. However, the method for designing high-performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A-π-D-π-A electron-donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CD133-targeted gene transfer into long-term repopulating hematopoietic stem cells.

PubMed

Brendel, Christian; Goebel, Benjamin; Daniela, Abriss; Brugman, Martijn; Kneissl, Sabrina; Schwäble, Joachim; Kaufmann, Kerstin B; Müller-Kuller, Uta; Kunkel, Hana; Chen-Wichmann, Linping; Abel, Tobias; Serve, Hubert; Bystrykh, Leonid; Buchholz, Christian J; Grez, Manuel

2015-01-01

Gene therapy for hematological disorders relies on the genetic modification of CD34(+) cells, a heterogeneous cell population containing about 0.01% long-term repopulating cells. Here, we show that the lentiviral vector CD133-LV, which uses a surface marker on human primitive hematopoietic stem cells (HSCs) as entry receptor, transfers genes preferentially into cells with high engraftment capability. Transduction of unstimulated CD34(+) cells with CD133-LV resulted in gene marking of cells with competitive proliferative advantage in vitro and in immunodeficient mice. The CD133-LV-transduced population contained significantly more cells with repopulating capacity than cells transduced with vesicular stomatitis virus (VSV)-LV, a lentiviral vector pseudotyped with the vesicular stomatitis virus G protein. Upon transfer of a barcode library, CD133-LV-transduced cells sustained gene marking in vivo for a prolonged period of time with a 6.7-fold higher recovery of barcodes compared to transduced control cells. Moreover, CD133-LV-transduced cells were capable of repopulating secondary recipients. Lastly, we show that this targeting strategy can be used for transfer of a therapeutic gene into CD34(+) cells obtained from patients suffering of X-linked chronic granulomatous disease. In conclusion, direct gene transfer into CD133(+) cells allows for sustained long-term engraftment of gene corrected cells.

Combining cetuximab with killer lymphocytes synergistically inhibits human cholangiocarcinoma cells in vitro.

PubMed

Morisaki, Takashi; Umebayashi, Masayo; Kiyota, Akifumi; Koya, Norihiro; Tanaka, Hiroto; Onishi, Hideya; Katano, Mitsuo

2012-06-01

We explored the possibility of combining adoptive immunotherapy with cytokine-activated killer (CAK) cells and the epidermal growth factor receptor monoclonal antibody, cetuximab, as a treatment for cholangiocarcinoma. CAK cells were cultured with a high-dose of interleukin-2 and anti-CD3 monoclonal antibodies. This cell population contained both activated CD16+/CD56+ (NK) cells and CD3+/NKG2D(high+) T-cells. The effect of CAK cells and cetuximab, alone and in combination, on the viability of human cholangiocarcinoma cells was evaluated. Culture of CAK cells alone, but not cetuximab alone, exhibited modest cytotoxicity toward cholangiocarcinoma cells. However, combining CAK cells with cetuximab significantly enhanced cytotoxicity. This enhancement was inhibited by the addition of excess human immunoglobulins, suggesting that antibody-dependent cytotoxicity, mediated by activated NK cells in the CAK cell culture was involved in this mechanism. Cetuximab may be used to enhance CAK cell therapeutic activity in patients with cholangiocarcinoma, by potentiating antibody-dependent cellular cytotoxicity.

Noninvasive and label-free detection of circulating melanoma cells by in vivo photoacoustic flow cytometry

NASA Astrophysics Data System (ADS)

Yang, Ping; Liu, Rongrong; Niu, Zhenyu; Suo, Yuanzhen; He, Hao; Wei, Xunbin

2015-03-01

Melanoma is a malignant tumor of melanocytes. Circulating melanoma cell has high light absorption due to melanin highly contained in melanoma cells. This property is employed for the detection of circulating melanoma cell by in vivo photoacoustic flow cytometry (PAFC). PAFC is based on photoacoustic effect. Compared to in vivo flow cytometry based on fluorescence, PAFC can employ high melanin content of melanoma cells as endogenous biomarkers to detect circulating melanoma cells in vivo. In our research, we developed in vitro experiments to prove the ability of PAFC system of detecting PA signals from melanoma cells. For in vivo experiments, we constructed a model of melanoma tumor bearing mice by inoculating highly metastatic murine melanoma cancer cells B16F10 with subcutaneous injection. PA signals were detected in the blood vessels of mouse ears in vivo. By counting circulating melanoma cells termly, we obtained the number variation of circulating melanoma cells as melanoma metastasized. Those results show that PAFC is a noninvasive and label-free method to detect melanoma metastases in blood or lymph circulation. Our PAFC system is an efficient tool to monitor melanoma metastases, cancer recurrence and therapeutic efficacy.

EFG solar modules

NASA Technical Reports Server (NTRS)

1978-01-01

Six photovoltaic modules using solar cells fabricated from silicon ribbons were assembled and delivered to JPL. Each module was comprised of four separate submodules which were parallel connected. The submodules contained 45 EFG cells which were series interconnected by a shingle or overlapping design. The inherent rectangular shape of the cells allowed a high packing factor to be achieved. The average efficiency of the six modules, corrected to AM1 at 28 C was 8.7%, which indicates that the average encapsulated cell efficiency was 10.0%.

Biological response of Sr-containing coating with various surface treatments on titanium substrate for medical applications

NASA Astrophysics Data System (ADS)

Yang, Shih-Ping; Lee, Tzer-Min; Lui, Truan-Sheng

2015-08-01

An implant requires a suitable surface to trigger osteointegration. The surface characteristics and chemical composition are important factors in this process. Plasma spraying and micro-arc oxidation can be used to fabricate rough and porous structures for medical applications. Strontium (Sr) has been shown to prevent osteoporosis in vitro and in vivo. However, few scientists have evaluated the biological response of Sr-containing coatings on different surface treatments. In this study, a sand-blasted (SB) surface (as the control), plasma-sprayed hydroxyapatite (HA) and Sr-substituted HA coatings (HAPS and SrHAPS, respectively), calcium phosphate and Sr-containing calcium phosphate micro-arc oxidation surface (CPM and SrCPM, respectively) were analyzed in terms of human osteoblastic cell (MG63) response. Sr was confirmed to be incorporated into the surface. SrHAPS and SrCPM specimens had higher cell responses than those of the HAPS and CPM groups, respectively. The cells cultured on SrCPM and SrHAPS specimens exhibited high proliferation and differentiation. However, CPM and SrCPM specimens stimulated more ECM-like structures than other specimens. The results show that Sr-containing coatings have good characteristics that enhance cell response. The SrCPM coating is a suitable implant surface treatment for clinical applications.

Probing Prokaryotic Social Behaviors with Bacterial “Lobster Traps”

PubMed Central

Connell, Jodi L.; Wessel, Aimee K.; Parsek, Matthew R.; Ellington, Andrew D.; Whiteley, Marvin; Shear, Jason B.

2010-01-01

Bacteria are social organisms that display distinct behaviors/phenotypes when present in groups. These behaviors include the abilities to construct antibiotic-resistant sessile biofilm communities and to communicate with small signaling molecules (quorum sensing [QS]). Our understanding of biofilms and QS arises primarily from in vitro studies of bacterial communities containing large numbers of cells, often greater than 108 bacteria; however, in nature, bacteria often reside in dense clusters (aggregates) consisting of significantly fewer cells. Indeed, bacterial clusters containing 101 to 105 cells are important for transmission of many bacterial pathogens. Here, we describe a versatile strategy for conducting mechanistic studies to interrogate the molecular processes controlling antibiotic resistance and QS-mediated virulence factor production in high-density bacterial clusters. This strategy involves enclosing a single bacterium within three-dimensional picoliter-scale microcavities (referred to as bacterial “lobster traps”) defined by walls that are permeable to nutrients, waste products, and other bioactive small molecules. Within these traps, bacteria divide normally into extremely dense (1012 cells/ml) clonal populations with final population sizes similar to that observed in naturally occurring bacterial clusters. Using these traps, we provide strong evidence that within low-cell-number/high-density bacterial clusters, QS is modulated not only by bacterial density but also by population size and flow rate of the surrounding medium. We also demonstrate that antibiotic resistance develops as cell density increases, with as few as ~150 confined bacteria exhibiting an antibiotic-resistant phenotype similar to biofilm bacteria. Together, these findings provide key insights into clinically relevant phenotypes in low-cell-number/high-density bacterial populations. PMID:21060734

Anthracene-containing wide-band-gap conjugated polymers for high-open-circuit-voltage polymer solar cells.

PubMed

Gong, Xue; Li, Cuihong; Lu, Zhen; Li, Guangwu; Mei, Qiang; Fang, Tao; Bo, Zhishan

2013-07-25

The synthesis, characterization, and photophysical and photovoltaic properties of two anthracene-containing wide-band-gap donor and acceptor (D-A) alternating conjugated polymers (P1 and P2) are described. These two polymers absorb in the range of 300-600 nm with a band gap of about 2.12 eV. Polymer solar cells with P1:PC71 BM as the active layer demonstrate a power conversion efficiency (PCE) of 2.23% with a high Voc of 0.96 V, a Jsc of 4.4 mA cm(-2) , and a comparable fill factor (FF) of 0.53 under simulated solar illumination of AM 1.5 G (100 mW cm(-2) ). In addition, P2:PC71 BM blend-based solar cells exhibit a PCE of 1.42% with a comparable Voc of 0.89 V, a Jsc of 3.0 mA cm(-2) , and an FF of 0.53. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diverse fates of uracilated HIV-1 DNA during infection of myeloid lineage cells.

PubMed

Hansen, Erik C; Ransom, Monica; Hesselberth, Jay R; Hosmane, Nina N; Capoferri, Adam A; Bruner, Katherine M; Pollack, Ross A; Zhang, Hao; Drummond, Michael Bradley; Siliciano, Janet M; Siliciano, Robert; Stivers, James T

2016-09-20

We report that a major subpopulation of monocyte-derived macrophages (MDMs) contains high levels of dUTP, which is incorporated into HIV-1 DNA during reverse transcription (U/A pairs), resulting in pre-integration restriction and post-integration mutagenesis. After entering the nucleus, uracilated viral DNA products are degraded by the uracil base excision repair (UBER) machinery with less than 1% of the uracilated DNA successfully integrating. Although uracilated proviral DNA showed few mutations, the viral genomic RNA was highly mutated, suggesting that errors occur during transcription. Viral DNA isolated from blood monocytes and alveolar macrophages (but not T cells) of drug-suppressed HIV-infected individuals also contained abundant uracils. The presence of viral uracils in short-lived monocytes suggests their recent infection through contact with virus producing cells in a tissue reservoir. These findings reveal new elements of a viral defense mechanism involving host UBER that may be relevant to the establishment and persistence of HIV-1 infection.

Rhodamine Inhibitors of P-glycoprotein: An Amide/Thioamide “Switch” for ATPase Activity

PubMed Central

Gannon, Michael K.; Holt, Jason J.; Bennett, Stephanie M.; Wetzel, Bryan R.; Loo, Tip W.; Bartlett, M. Claire; Clarke, David M.; Sawada, Geri A.; Higgins, J. William; Tombline, Gregory; Raub, Thomas J.; Detty, Michael R.

2012-01-01

We have examined 46 tetramethylrosamine/rhodamine derivatives with structural diversity in the heteroatom of the xanthylium core, the amino substituents of the 3- and 6-positions, and the alkyl, aryl, or heteroaryl group at the 9-substituent. These compounds were examined for affinity and ATPase stimulation in isolated MDR3 CL P-gp and human P-gp-His10, for their ability to promote uptake of calcein AM and vinblastine in multidrug-resistant MDCKII-MDR1 cells, and for transport in monolayers of MDCKII-MDR1 cells. Thioamide 31-S gave KM of 0.087 μM in human P-gp. Small changes in structure among this set of compounds affected affinity as well as transport rate (or flux) even though all derivatives examined were substrates for P-gp. With isolated protein, tertiary amide groups dictate high affinity and high stimulation while tertiary thioamide groups give high affinity and inhibition of ATPase activity. In MDCKII-MDR1 cells, the tertiary thioamide-containing derivatives promote uptake of calcein AM and have very slow passive, absorptive, and secretory rates of transport relative to transport rates for tertiary amide-containing derivatives. Thioamide 31-S promoted uptake of calcein AM and inhibited efflux of vinblastine with IC50’s of ~2 μM in MDCKII-MDR1 cells. PMID:19402665

High-efficiency power production from natural gas with carbon capture

NASA Astrophysics Data System (ADS)

Adams, Thomas A.; Barton, Paul I.

A unique electricity generation process uses natural gas and solid oxide fuel cells at high electrical efficiency (74%HHV) and zero atmospheric emissions. The process contains a steam reformer heat-integrated with the fuel cells to provide the heat necessary for reforming. The fuel cells are powered with H 2 and avoid carbon deposition issues. 100% CO 2 capture is achieved downstream of the fuel cells with very little energy penalty using a multi-stage flash cascade process, where high-purity water is produced as a side product. Alternative reforming techniques such as CO 2 reforming, autothermal reforming, and partial oxidation are considered. The capital and energy costs of the proposed process are considered to determine the levelized cost of electricity, which is low when compared to other similar carbon capture-enabled processes.

High voltage photovoltaic power converter

DOEpatents

Haigh, Ronald E.; Wojtczuk, Steve; Jacobson, Gerard F.; Hagans, Karla G.

2001-01-01

An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

Polycistronic lentiviral vector for "hit and run" reprogramming of adult skin fibroblasts to induced pluripotent stem cells.

PubMed

Chang, Chia-Wei; Lai, Yi-Shin; Pawlik, Kevin M; Liu, Kaimao; Sun, Chiao-Wang; Li, Chao; Schoeb, Trenton R; Townes, Tim M

2009-05-01

We report the derivation of induced pluripotent stem (iPS) cells from adult skin fibroblasts using a single, polycistronic lentiviral vector encoding the reprogramming factors Oct4, Sox2, and Klf4. Porcine teschovirus-1 2A sequences that trigger ribosome skipping were inserted between human cDNAs for these factors, and the polycistron was subcloned downstream of the elongation factor 1 alpha promoter in a self-inactivating (SIN) lentiviral vector containing a loxP site in the truncated 3' long terminal repeat (LTR). Adult skin fibroblasts from a humanized mouse model of sickle cell disease were transduced with this single lentiviral vector, and iPS cell colonies were picked within 30 days. These cells expressed endogenous Oct4, Sox2, Nanog, alkaline phosphatase, stage-specific embryonic antigen-1, and other markers of pluripotency. The iPS cells produced teratomas containing tissue derived from all three germ layers after injection into immunocompromised mice and formed high-level chimeras after injection into murine blastocysts. iPS cell lines with as few as three lentiviral insertions were obtained. Expression of Cre recombinase in these iPS cells resulted in deletion of the lentiviral vector, and sequencing of insertion sites demonstrated that remnant 291-bp SIN LTRs containing a single loxP site did not interrupt coding sequences, promoters, or known regulatory elements. These results suggest that a single, polycistronic "hit and run" vector can safely and effectively reprogram adult dermal fibroblasts into iPS cells.

Polyploidization of liver cells.

PubMed

Celton-Morizur, Séverine; Desdouets, Chantal

2010-01-01

Eukaryotic organisms usually contain a diploid complement of chromosomes. However, there are a number of exceptions. Organisms containing an increase in DNA content by whole number multiples of the entire set of chromosomes are defined as polyploid. Cells that contain more than two sets of chromosomes were first observed in plants about a century ago and it is now recognized that polyploidy cells form in many eukaryotes under a wide variety of circumstance. Although it is less common in mammals, some tissues, including the liver, show a high percentage of polyploid cells. Thus, during postnatal growth, the liver parenchyma undergoes dramatic changes characterized by gradual polyploidization during which hepatocytes of several ploidy classes emerge as a result of modified cell-division cycles. This process generates the successive appearance of tetraploid and octoploid cell classes with one or two nuclei (mononucleated or binucleated). Liver cells polyploidy is generally considered to indicate terminal differentiation and senescence and to lead both to the progressive loss of cell pluripotency and a markedly decreased replication capacity. In adults, liver polyploidization is differentially regulated upon loss of liver mass and liver damage. Interestingly, partial hepatectomy induces marked cell proliferation followed by an increase in liver ploidy. In contrast, during hepatocarcinoma (HCC), growth shifts to a nonpolyploidizing pattern and expansion of the diploid hepatocytes population is observed in neoplastic nodules. Here we review the current state of understanding about how polyploidization is regulated during normal and pathological liver growth and detail by which mechanisms hepatocytes become polyploid.

Performance improvement of PEFC modules with cell containing low amount of platinum

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

Miyake, Y.; Kadowaki, M.; Hamada, A.

1996-12-31

Cell components of the PEFC module were studied to improve the module performance. The cell performance in a high air utilization region was improved by selecting an air channel design of the separator in which high air flow speed was obtained. Optimization of Teflon{reg_sign} amount on the cathode backing carbon paper also contributed the cell performance. Modifications of the gas channel design and the backing carbon paper were carried out in a 200 cm{sup 2} x 20-cell module and 36-cell module. Dependence of air utilization on module performance was remarkably improved and power density of more than 0.3 W/cm{sup 2}more » was achieved in spite of the platinum amount in the cells was decreased to 1.1 Mg/cm{sup 2}.« less

Enhanced Requirement for TNFR2 in Graft Rejection Mediated by Low Affinity Memory CD8+ T Cells During Heterologous Immunity

PubMed Central

Krummey, Scott M.; Chen, Ching-Wen; Guasch, Sara A.; Liu, Danya; Wagener, Maylene; Larsen, Christian P; Ford, Mandy L.

2016-01-01

The affinity of a T cell receptor (TCR) binding to peptide:MHC profoundly impacts the phenotype and function of effector and memory cell differentiation. Little is known about the effect of low affinity priming on memory cell generation and function, which is particularly important in heterologous immunity, when microbe-specific T cells cross-react with allogeneic antigen and mediate graft rejection. We found that low affinity primed memory CD8+ T cells produced high levels of TNF ex vivo in response to heterologous rechallenge compared to high affinity primed memory T cells. Low affinity secondary effectors significantly upregulated TNFR2 on the cell surface and contained a higher frequency of TNFR2hi proliferating cells. Low affinity primed secondary effectors concurrently downregulated TNF production. Importantly, blockade of TNFR2 attenuated graft rejection in low but not high affinity primed animals. These data establish a functional connection between TNF signaling and TCR priming affinity and have implications for the immunomodulation of pathogenic T cell responses during transplantation. PMID:27481849

Progressive Failure of a Unidirectional Fiber-Reinforced Composite Using the Method of Cells: Discretization Objective Computational Results

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Bednarcyk, Brett A.; Waas, Anthony M.; Arnold, Steven M.

2012-01-01

The smeared crack band theory is implemented within the generalized method of cells and high-fidelity generalized method of cells micromechanics models to capture progressive failure within the constituents of a composite material while retaining objectivity with respect to the size of the discretization elements used in the model. An repeating unit cell containing 13 randomly arranged fibers is modeled and subjected to a combination of transverse tension/compression and transverse shear loading. The implementation is verified against experimental data (where available), and an equivalent finite element model utilizing the same implementation of the crack band theory. To evaluate the performance of the crack band theory within a repeating unit cell that is more amenable to a multiscale implementation, a single fiber is modeled with generalized method of cells and high-fidelity generalized method of cells using a relatively coarse subcell mesh which is subjected to the same loading scenarios as the multiple fiber repeating unit cell. The generalized method of cells and high-fidelity generalized method of cells models are validated against a very refined finite element model.

Phenol-formaldehyde intumescent coating composition and coating prepared therefrom

NASA Technical Reports Server (NTRS)

Salyer, Ival O. (Inventor); Fox, Bernard L. (Inventor)

1986-01-01

Intumescent coatings which form a thick, uniform, fine celled, low density foam upon exposure to a high intensity heat flux or flame are disclosed, the invention coatings comprise phenolic resin prepolymer containing a blowing agent and a nucleating agent; in the preferred embodiments the coatings also contains a silicone surfactant, the coatings are useful in thermal and fire protection systems.

Cell wall polysaccharides from fern leaves: evidence for a mannan-rich Type III cell wall in Adiantum raddianum.

PubMed

Silva, Giovanna B; Ionashiro, Mari; Carrara, Thalita B; Crivellari, Augusto C; Tiné, Marco A S; Prado, Jefferson; Carpita, Nicholas C; Buckeridge, Marcos S

2011-12-01

Primary cell walls from plants are composites of cellulose tethered by cross-linking glycans and embedded in a matrix of pectins. Cell wall composition varies between plant species, reflecting in some instances the evolutionary distance between them. In this work the monosaccharide compositions of isolated primary cell walls of nine fern species and one lycophyte were characterized and compared with those from Equisetum and an angiosperm dicot. The relatively high abundance of mannose in these plants suggests that mannans may constitute the major cross-linking glycan in the primary walls of pteridophytes and lycophytes. Pectin-related polysaccharides contained mostly rhamnose and uronic acids, indicating the presence of rhamnogalacturonan I highly substituted with galactose and arabinose. Structural and fine-structural analyses of the hemicellulose fraction of leaves of Adiantum raddianum confirmed this hypothesis. Linkage analysis showed that the mannan contains mostly 4-Man with very little 4,6-Man, indicating a low percentage of branching with galactose. Treatment of the mannan-rich fractions with endo-β-mannanase produced characteristic mannan oligosaccharides. Minor amounts of xyloglucan and xylans were also detected. These data and those of others suggest that all vascular plants contain xyloglucans, arabinoxylans, and (gluco)mannans, but in different proportions that define cell wall types. Whereas xyloglucan and pectin-rich walls define Type I walls of dicots and many monocots, arabinoxylans and lower proportion of pectin define the Type II walls of commelinoid monocots. The mannan-rich primary walls with low pectins of many ferns and a lycopod indicate a fundamentally different wall type among land plants, the Type III wall. Copyright © 2011 Elsevier Ltd. All rights reserved.

Plants and Photosynthesis: Level III, Unit 3, Lesson 1; The Human Digestive System: Lesson 2; Functions of the Blood: Lesson 3; Human Circulation and Respiration: Lesson 4; Reproduction of a Single Cell: Lesson 5; Reproduction by Male and Female Cells: Lesson 6; The Human Reproductive System: Lesson 7; Genetics and Heredity: Lesson 8; The Nervous System: Lesson 9; The Glandular System: Lesson 10. Advanced General Education Program. A High School Self-Study Program.

ERIC Educational Resources Information Center

Manpower Administration (DOL), Washington, DC. Job Corps.

This self-study program for the high-school level contains lessons in the following subjects: Plants and Photosynthesis; The Human Digestive System; Functions of the Blood; Human Circulation and Respiration; Reproduction of a Single Cell; Reproduction by Male and Female Cells; The Human Reproductive System; Genetics and Heredity; The Nervous…

Layer-by-layer buildup of polysaccharide-containing films: Physico-chemical properties and mesenchymal stem cells adhesion.

PubMed

Kulikouskaya, Viktoryia I; Pinchuk, Sergei V; Hileuskaya, Kseniya S; Kraskouski, Aliaksandr N; Vasilevich, Irina B; Matievski, Kirill A; Agabekov, Vladimir E; Volotovski, Igor D

2018-03-22

Layer-by-Layer assembled polyelectrolyte films offer the opportunity to control cell attachment and behavior on solid surfaces. In the present study, multilayer films based on negatively charged biopolymers (pectin, dextran sulfate, carboxymethylcellulose) and positively charged polysaccharide chitosan or synthetic polyelectrolyte polyethyleneimine has been prepared and evaluated. Physico-chemical properties of the formed multilayer films, including their growth, morphology, wettability, stability, and mechanical properties, have been studied. We demonstrated that chitosan-containing films are characterized by the linear growth, the defect-free surface, and predominantly viscoelastic properties. When chitosan is substituted for the polyethyleneimine in the multilayer system, the properties of the formed films are significantly altered: the rigidity and surface roughness increases, the film growth acquires the exponential character. The multilayer films were subsequently used for culturing mesenchymal stem cells. It has been determined that stem cells effectively adhered to chitosan-containing films and formed on them the monolayer culture of fibroblast-like cells with high viability. Our results show that cell attachment is a complex process which is not only governed by the surface functionality because one of the key parameter effects on cell adhesion is the stiffness of polyelectrolyte multilayer films. We therefore propose our Layer-by-Layer films for applications in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2018. © 2018 Wiley Periodicals, Inc.

High-Content Analysis of CRISPR-Cas9 Gene-Edited Human Embryonic Stem Cells.

PubMed

Carlson-Stevermer, Jared; Goedland, Madelyn; Steyer, Benjamin; Movaghar, Arezoo; Lou, Meng; Kohlenberg, Lucille; Prestil, Ryan; Saha, Krishanu

2016-01-12

CRISPR-Cas9 gene editing of human cells and tissues holds much promise to advance medicine and biology, but standard editing methods require weeks to months of reagent preparation and selection where much or all of the initial edited samples are destroyed during analysis. ArrayEdit, a simple approach utilizing surface-modified multiwell plates containing one-pot transcribed single-guide RNAs, separates thousands of edited cell populations for automated, live, high-content imaging and analysis. The approach lowers the time and cost of gene editing and produces edited human embryonic stem cells at high efficiencies. Edited genes can be expressed in both pluripotent stem cells and differentiated cells. This preclinical platform adds important capabilities to observe editing and selection in situ within complex structures generated by human cells, ultimately enabling optical and other molecular perturbations in the editing workflow that could refine the specificity and versatility of gene editing. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

CD44 Staining of Cancer Stem-Like Cells Is Influenced by Down-Regulation of CD44 Variant Isoforms and Up-Regulation of the Standard CD44 Isoform in the Population of Cells That Have Undergone Epithelial-to-Mesenchymal Transition

PubMed Central

Biddle, Adrian; Gammon, Luke; Fazil, Bilal; Mackenzie, Ian C.

2013-01-01

CD44 is commonly used as a cell surface marker of cancer stem-like cells in epithelial tumours, and we have previously demonstrated the existence of two different CD44high cancer stem-like cell populations in squamous cell carcinoma, one having undergone epithelial-to-mesenchymal transition and the other maintaining an epithelial phenotype. Alternative splicing of CD44 variant exons generates a great many isoforms, and it is not known which isoforms are expressed on the surface of the two different cancer stem-like cell phenotypes. Here, we demonstrate that cancer stem-like cells with an epithelial phenotype predominantly express isoforms containing the variant exons, whereas the cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition down-regulate these variant isoforms and up-regulate expression of the standard CD44 isoform that contains no variant exons. In addition, we find that enzymatic treatments used to dissociate cells from tissue culture or fresh tumour specimens cause destruction of variant CD44 isoforms at the cell surface whereas expression of the standard CD44 isoform is preserved. This results in enrichment within the CD44high population of cancer stem-like cells that have undergone an epithelial-to-mesenchymal transition and depletion from the CD44high population of cancer stem-like cells that maintain an epithelial phenotype, and therefore greatly effects the characteristics of any cancer stem-like cell population isolated based on expression of CD44. As well as effecting the CD44high population, enzymatic treatment also reduces the percentage of the total epithelial cancer cell population staining CD44-positive, with potential implications for studies that aim to use CD44-positive staining as a prognostic indicator. Analyses of the properties of cancer stem-like cells are largely dependent on the ability to accurately identify and assay these populations. It is therefore critical that consideration be given to use of multiple cancer stem-like cell markers and suitable procedures for cell isolation in order that the correct populations are assayed. PMID:23437366

Growth response of Escherichia coli ATCC 35218 adapted to several concentrations of sodium benzoate and potassium sorbate.

PubMed

Santiesteban-López, N Angélica; Rosales, Mónica; Palou, Enrique; López-Malo, Aurelio

2009-11-01

Escherichia coli ATCC 35218 growth response was evaluated after repetitive cultivation in stepwise increasing antimicrobial agent concentrations (potassium sorbate or sodium benzoate) to observe its adaptation process to high weak-acid concentrations. The effect of antimicrobial (potassium sorbate or sodium benzoate) concentration (0 to 7,000 ppm) was tested using laboratory media. Cells adapted at 1,000 ppm were inoculated in media containing the same concentration of the antimicrobial; after that, cells were transferred to media containing a higher concentration, followed by repetitive cultivations. In every case, viable cells were determined by surface plating every hour up to 48 h. Logarithmic representations of survival or growing fraction were modeled using the Gompertz equation. Adapted and nonadapted cells were analyzed for plasmid presence as well as phosphofructokinase and succinate dehydrogenase activity. Bacterial growth was observed after adaptation processes in media formulated up to 7,000 ppm of potassium sorbate or sodium benzoate. Analyses of variance demonstrated that no significant difference (P > 0.05) in lag time or growth rate was observed among adapted cells cultured in media containing the studied concentrations for each of the antimicrobials tested. These results suggest that E. coli can be adapted to high weak-acid concentrations if the exposure is performed under sublethal conditions. Furthermore, there was demonstrated inhibition of the enzymes phosphofructokinase and succinate dehydrogenase by action of sodium benzoate and potassium sorbate, respectively. E. coli adaptation to antimicrobial agents was not related to plasmid presence but appears to be due to other action mechanisms.

Flow cytometry on the stromal-vascular fraction of white adipose tissue.

PubMed

Brake, Danett K; Smith, C Wayne

2008-01-01

Adipose tissue contains cell types other than adipocytes that may contribute to complications linked to obesity. For example, macrophages have been shown to infiltrate adipose tissue in response to a high-fat diet. Isolation of the stromal-vascular fraction of adipose tissue allows one to use flow cytometry to analyze cell surface markers on leukocytes. Here, we present a technical approach to identify subsets of leukocytes that differentially express cell surface markers.

Decontamination Of Bacterial Spores by a Peptide-Mimic

DTIC Science & Technology

2006-11-01

consisting of a thin cell wall and the outer cortex. The cell wall guarantees the maintenance of cellular integrity after germination. Lytic- enzymes ...percent of the water content of the vegetative cell. The enzymes contained in the core become active on germination. All minerals (mainly Ca2+, Mn2+ and...such as amino acids and sugars, by enzymes , by high hydrostatic pressure and by some non-nutrient chemicals such as dodecylamine (see next section

Development of metallization process. FSA project, cell and module formation research area

NASA Technical Reports Server (NTRS)

Garcia, A., III

1984-01-01

New pastes were evaluated that contained additives to aid in the silicon-to-metallization contact. None were completely successful. A reevaluation of the molybdenum oxide paste and the two-step screen printing process was done. The oxide paste did not show promise. The two-step process enabled soldering of the cells but the cells still had a high series resistance. Pastes are on order from a different manufacturer.

High-throughput deterministic single-cell encapsulation and droplet pairing, fusion, and shrinkage in a single microfluidic device.

PubMed

Schoeman, Rogier M; Kemna, Evelien W M; Wolbers, Floor; van den Berg, Albert

2014-02-01

In this article, we present a microfluidic device capable of successive high-yield single-cell encapsulation in droplets, with additional droplet pairing, fusion, and shrinkage. Deterministic single-cell encapsulation is realized using Dean-coupled inertial ordering of cells in a Yin-Yang-shaped curved microchannel using a double T-junction, with a frequency over 2000 Hz, followed by controlled droplet pairing with a 100% success rate. Subsequently, droplet fusion is realized using electrical actuation resulting in electro-coalescence of two droplets, each containing a single HL60 cell, with 95% efficiency. Finally, volume reduction of the fused droplet up to 75% is achieved by a triple pitchfork structure. This droplet volume reduction is necessary to obtain close cell-cell membrane contact necessary for final cell electrofusion, leading to hybridoma formation, which is the ultimate aim of this research. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gap Junction Protein Connexin 43 Serves as a Negative Marker for a Stem Cell-Containing Population of Human Limbal Epithelial Cells

PubMed Central

Chen, Zhuo; Evans, W. Howard; Pflugfelder, Stephen C.; Li, De-Quan

2010-01-01

This study evaluated whether the gap junction protein connexin (Cx) 43 could serve as a negative cell surface marker for human corneal epithelial stem cells. Cx43 expression was evaluated in corneo-limbal tissue and primary limbal epithelial cultures. Immunofluorescent staining and laser scanning confocal microscopy showed that Cx43 was strongly expressed in the corneal and limbal suprabasal epithelial cells, but the basal cells of the limbal epithelium were negative. Cx43 antibody stained mainly large cells but not small cells in primary limbal epithelial cultures. As determined by semiquantitative reverse transcription polymerase chain reaction (PCR) and real-time PCR, Cx43 mRNA was more abundant in the corneal than limbal epithelia, and it was expressed in higher levels in mature limbal epithelial cultures. Using GAP11, a rabbit polyclonal antibody against the Cx32 extracellular loop 2 (151–187), a sequence that is highly homologous in Cx43, the Cx43dim and Cx43bright cells were selected from primary limbal epithelial cultures by fluorescence-activated cell sorting and were evaluated for stem cell properties. These Cx43dim and Cx43bright cells were confirmed by their expression levels of Cx43 protein and mRNA. The Cx43dim cells were found to contain higher percentages of slow-cycling bromodeoxyuridine (BrdU)-label retaining cells and the cells that were positive for stem cell-associated markers p63, ABCG2, and integrin β1 and negative for differentiation markers K3 and involucrin. The Cx43dim cells possessed a greater proliferative potential than Cx43bright cells and nonfractionated cells as evaluated by BrdU incorporation, colony-forming efficiency, and growth capacity. Our findings suggest that human limbal basal cells do not express connexin 43, which could serve as a negative cell surface marker for the stem cell-containing population of human limbal epithelial cells. PMID:16424398

Construction and properties of a cell line constitutively expressing the herpes simplex virus glycoprotein B dependent on functional alpha 4 protein synthesis.

PubMed Central

Arsenakis, M; Hubenthal-Voss, J; Campadelli-Fiume, G; Pereira, L; Roizman, B

1986-01-01

We report the construction of a cell line constitutively expressing the glycoprotein B (gB) of herpes simplex virus (HSV) 1. The cell line was constructed in two steps. In the first, a baby hamster kidney cell line was transfected with the DNA of a plasmid containing the neomycin phosphotransferase gene that confers resistance to the antibiotic G418 and the gene specifying a temperature-sensitive (ts-) alpha 4 protein of HSV-1, the major viral regulatory protein. A clonal cell line, alpha 4/c113, selected for resistance to the antibiotic G418, expressed high levels of alpha 4 protein constitutively. Superinfection of these cells with HSV-2 resulted in twofold induction of the resident HSV-1 alpha 4 gene. In the second step, alpha 4/c113 cells were transfected with the DNA of a plasmid carrying the gB gene and the mouse methotrexate resistance dihydrofolate reductase gene. A clonal cell line, alpha 4/c113/gB, selected for methotrexate resistance expressed gB constitutively. Expression of both gB and alpha 4 continued unabated for at least 32 serial passages. Cells passaged serially in medium containing both methotrexate and G418 after passage 10 contained a higher copy number of the alpha 4 gene and produced larger amounts of both gB and alpha 4 proteins than did cells maintained in medium containing methotrexate alone. Expression of gB was dependent on the presence of functional alpha 4 protein inasmuch as expression of gB ceased on shift up to nonpermissive temperatures, when shifted to permissive temperatures, the cell line reinitiated expression of gB after a delay commensurate with the length of incubation at the nonpermissive temperature, and the cell-resident HSV-1 gB gene was expressed at the nonpermissive temperature in cells infected with a recombinant expressing a ts+ alpha 4 protein and an HSV-2 gB. The properties of the alpha 4/c113 cell line suggest that it may express other viral genes induced by alpha 4 protein constitutively, provided that the product is not toxic to the cells. Images PMID:3022001

Differences in the incorporation of bromodeoxyuridine by human lymphoblastoid cell lines

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

Henderson, E.E.; Strauss, B.

1975-08-01

Long term human lymphoblastoid lines differ in their ability to grow in medium containing bromodeoxyuridine (BrdU) and to incorporate analog into their DNA. Eight Burkitts' lymphoma cell lines divided at least twice in BrdU-containing medium and made DNA in which over 90 percent of the thymidine residues were substituted with analog in both strands. Three infectious mononucleosis-derived lines and 24 lines transformed in vitro were inhibited by BrdU after one cell division and made only hybrid DNA in which one strand was substituted with analog. One out of eight normal individuals from whom long term lines were prepared gave cellmore » lines which divided at least twice in BrdU and gave DNA in which both strands were substituted with analog. It would appear that intrinsic cellular factors regulate the response to BrdU and that Burkitt's tumor lines are characterized by their ability to make stable doubly substituted DNA containing a high proportion of halogenated analog.« less

Electrochemical cell having cylindrical electrode elements

DOEpatents

Nelson, Paul A.; Shimotake, Hiroshi

1982-01-01

A secondary, high temperature electrochemical cell especially adapted for lithium alloy negative electrodes, transition metal chalcogenide positive electrodes and alkali metal halide or alkaline earth metal halide electrolyte is disclosed. The cell is held within an elongated cylindrical container in which one of the active materials is filled around the outside surfaces of a plurality of perforate tubular current collectors along the length of the container. Each of the current collector tubes contain a concentric tubular layer of electrically insulative ceramic as an interelectrode separator. The active material of opposite polarity in elongated pin shape is positioned longitudinally within the separator layer. A second electrically conductive tube with perforate walls can be swagged or otherwise bonded to the outer surface of the pin as a current collector and the electrically insulative ceramic layer can be coated or otherwise layered onto the outer surface of this second current collector. Alternatively, the central pin electrode can include an axial core as a current collector.

Biosurfactant production by halotolerant Rhodococcus fascians from Casey Station, Wilkes Land, Antarctica.

PubMed

Gesheva, Victoria; Stackebrandt, Erko; Vasileva-Tonkova, Evgenia

2010-08-01

Isolate A-3 from Antarctic soil in Casey Station, Wilkes Land, was characterized for growth on hydrocarbons. Use of glucose or kerosene as a sole carbon source in the culture medium favoured biosynthesis of surfactant which, by thin-layer chromatography, indicated the formation of a rhamnose-containing glycolipid. This compound lowered the surface tension at the air/water interface to 27 mN/m as well as inhibited the growth of B. subtilis ATCC 6633 and exhibited hemolytic activity. A highly hydrophobic surface of the cells suggests that uptake occurs via a direct cell-hydrocarbon substrate contact. Strain A-3 is Gram-positive, halotolerant, catalase positive, urease negative and has rod-coccus shape. Its cell walls contained meso-diaminopimelic acid. Phylogenetic analysis based on comparative analysis of 16S rRNA gene sequences revealed that strain A-3 is closely related to Rhodococcus fascians with which it shares 100% sequence similarity. This is the first report on rhamnose-containing biosurfactant production by Rhodococcus fascians isolated from Antarctic soil.

Plasmid ColE1 as a Molecular Vehicle for Cloning and Amplification of DNA

PubMed Central

Hershfield, Vickers; Boyer, Herbert W.; Yanofsky, Charles; Lovett, Michael A.; Helinski, Donald R.

1974-01-01

DNA fragments obtained from EcoRI endonuclease digestion of bacteriophage ϕ80pt190 (trp+) and the plasmid ColE1 were covalently joined with polynucleotide ligase. Transformation of Escherichia coli trp- strains to tryptophan independence with the recombined DNA selected for reconstituted ColE1 plasmids containing the tryptophan operon and the ϕ80 immunity region. Similarly, an EcoRI endonuclease generated fragment of plasmid pSC105 DNA containing the genetic determinant of kanamycin resistance was inserted into the ColE1 plasmid and recovered in E. coli. The plasmids containing the trp operon (ColE1-trp) and the kanamycin resistance gene were maintained under logarithmic growth conditions at a level of 25-30 copies per cell and accumulate to the extent of several hundred copies per cell in the presence of chloramphenicol. Cells carrying the ColE1-trp plasmid determined the production of highly elevated levels of trp operon-specific mRNA and tryptophan biosynthetic enzymes. Images PMID:4610576

Cytoplasmic DNA synthesis in Amoeba proteus. I. On the particulate nature of the DNA-containing elements.

PubMed

RABINOVITCH, M; PLAUT, W

1962-12-01

The incorporation of tritiated thymidine in Amoeba proteus was reinvestigated in order to see if it could be associated with microscopically detectable structures. Staining experiments with basic dyes, including the fluorochrome acridine orange, revealed the presence of large numbers of 0.3 to 0.5 micro particles in the cytoplasm of all cells studied. The effect of nuclease digestion on the dye affinity of the particles suggests that they contain DNA as well as RNA. Centrifugation of living cells at 10,000 g leads to the sedimentation of the particles in the centrifugal third of the ameba near the nucleus. Analysis of centrifuged cells which had been incubated with H(3)-thymidine showed a very high degree of correlation between the location of the nucleic acid-containing granules and that of acid-insoluble, deoxyribonuclease-sensitive labeled molecules and leads to the conclusion that cytoplasmic DNA synthesis in Amoeba proteus occurs in association with these particles.

The parallel reaction monitoring method contributes to a highly sensitive polyubiquitin chain quantification

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

Tsuchiya, Hikaru; Tanaka, Keiji, E-mail: tanaka-kj@igakuken.or.jp; Saeki, Yasushi, E-mail: saeki-ys@igakuken.or.jp

2013-06-28

Highlights: •The parallel reaction monitoring method was applied to ubiquitin quantification. •The ubiquitin PRM method is highly sensitive even in biological samples. •Using the method, we revealed that Ufd4 assembles the K29-linked ubiquitin chain. -- Abstract: Ubiquitylation is an essential posttranslational protein modification that is implicated in a diverse array of cellular functions. Although cells contain eight structurally distinct types of polyubiquitin chains, detailed function of several chain types including K29-linked chains has remained largely unclear. Current mass spectrometry (MS)-based quantification methods are highly inefficient for low abundant atypical chains, such as K29- and M1-linked chains, in complex mixtures thatmore » typically contain highly abundant proteins. In this study, we applied parallel reaction monitoring (PRM), a quantitative, high-resolution MS method, to quantify ubiquitin chains. The ubiquitin PRM method allows us to quantify 100 attomole amounts of all possible ubiquitin chains in cell extracts. Furthermore, we quantified ubiquitylation levels of ubiquitin-proline-β-galactosidase (Ub-P-βgal), a historically known model substrate of the ubiquitin fusion degradation (UFD) pathway. In wild-type cells, Ub-P-βgal is modified with ubiquitin chains consisting of 21% K29- and 78% K48-linked chains. In contrast, K29-linked chains are not detected in UFD4 knockout cells, suggesting that Ufd4 assembles the K29-linked ubiquitin chain(s) on Ub-P-βgal in vivo. Thus, the ubiquitin PRM is a novel, useful, quantitative method for analyzing the highly complicated ubiquitin system.« less

High-throughput monitoring of major cell functions by means of lensfree video microscopy

PubMed Central

Kesavan, S. Vinjimore; Momey, F.; Cioni, O.; David-Watine, B.; Dubrulle, N.; Shorte, S.; Sulpice, E.; Freida, D.; Chalmond, B.; Dinten, J. M.; Gidrol, X.; Allier, C.

2014-01-01

Quantification of basic cell functions is a preliminary step to understand complex cellular mechanisms, for e.g., to test compatibility of biomaterials, to assess the effectiveness of drugs and siRNAs, and to control cell behavior. However, commonly used quantification methods are label-dependent, and end-point assays. As an alternative, using our lensfree video microscopy platform to perform high-throughput real-time monitoring of cell culture, we introduce specifically devised metrics that are capable of non-invasive quantification of cell functions such as cell-substrate adhesion, cell spreading, cell division, cell division orientation and cell death. Unlike existing methods, our platform and associated metrics embrace entire population of thousands of cells whilst monitoring the fate of every single cell within the population. This results in a high content description of cell functions that typically contains 25,000 – 900,000 measurements per experiment depending on cell density and period of observation. As proof of concept, we monitored cell-substrate adhesion and spreading kinetics of human Mesenchymal Stem Cells (hMSCs) and primary human fibroblasts, we determined the cell division orientation of hMSCs, and we observed the effect of transfection of siCellDeath (siRNA known to induce cell death) on hMSCs and human Osteo Sarcoma (U2OS) Cells. PMID:25096726

Direct Measurement of T Cell Receptor Affinity and Sequence from Naïve Anti-Viral T Cells

PubMed Central

Zhang, Shuqi; Parker, Patricia; Ma, Keyue; He, Chenfeng; Shi, Qian; Cui, Zhonghao; Williams, Chad; Wendel, Ben S.; Meriwether, Amanda; Salazar, Mary A.; Jiang, Ning

2016-01-01

T cells recognize and kill a myriad of pathogen-infected or cancer cells using a diverse set of T cell receptors (TCR). The affinity of TCR to cognate antigen is of high interest in adoptive T cell transfer immunotherapy and antigen-specific T cell repertoire immune profiling because it is widely known to correlate with downstream T cell responses. Here, we introduce the in situ TCR affinity and sequence test (iTAST) for simultaneous measurement of TCR affinity and sequence from single primary CD8+ T cells in human blood. We demonstrate that the repertoire of primary antigen-specific T cells from pathogen inexperienced individuals has a surprisingly broad affinity range of 1000-fold composed of diverse TCR sequences. Within this range, samples from older individuals contained a reduced frequency of high affinity T cells compared to young individuals, demonstrating an age-related effect of T cell attrition that could cause holes in the repertoire. iTAST should enable the rapid selection of high affinity TCRs ex vivo for adoptive immunotherapy and measurement of T cell response for immune monitoring applications. PMID:27252176

Visualization of the entire differentiation process of murine M cells: suppression of their maturation in cecal patches.

PubMed

Kimura, S; Yamakami-Kimura, M; Obata, Y; Hase, K; Kitamura, H; Ohno, H; Iwanaga, T

2015-05-01

The microfold (M) cell residing in the follicle-associated epithelium is a specialized epithelial cell that initiates mucosal immune responses by sampling luminal antigens. The differentiation process of M cells remains unclear due to limitations of analytical methods. Here we found that M cells were classified into two functionally different subtypes based on the expression of Glycoprotein 2 (GP2) by newly developed image cytometric analysis. GP2-high M cells actively took up luminal microbeads, whereas GP2-negative or low cells scarcely ingested them, even though both subsets equally expressed the other M-cell signature genes, suggesting that GP2-high M cells represent functionally mature M cells. Further, the GP2-high mature M cells were abundant in Peyer's patch but sparse in the cecal patch: this was most likely due to a decrease in the nuclear translocation of RelB, a downstream transcription factor for the receptor activator of nuclear factor-κB signaling. Given that murine cecum contains a protrusion of beneficial commensals, the restriction of M-cell activity might contribute to preventing the onset of any excessive immune response to the commensals through decelerating the M-cell-dependent uptake of microorganisms.

78 FR 49528 - Consolidation of Wound Care Products Containing Live Cells

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-14

...] Consolidation of Wound Care Products Containing Live Cells AGENCY: Food and Drug Administration, HHS. ACTION... certain wound care products containing live cells from the Center for Devices and Radiological Health... CDRH and CBER. FDA believes that as more wound care products containing live cells are developed such...

Ermelin, an endoplasmic reticulum transmembrane protein, contains the novel HELP domain conserved in eukaryotes.

PubMed

Suzuki, Akiko; Endo, Takeshi

2002-02-06

We have cloned a cDNA encoding a novel protein referred to as ermelin from mouse C2 skeletal muscle cells. This protein contained six hydrophobic amino acid stretches corresponding to transmembrane domains, two histidine-rich sequences, and a sequence homologous to the fusion peptides of certain fusion proteins. Ermelin also contained a novel modular sequence, designated as HELP domain, which was highly conserved among eukaryotes, from yeast to higher plants and animals. All these HELP domain-containing proteins, including mouse KE4, Drosophila Catsup, and Arabidopsis IAR1, possessed multipass transmembrane domains and histidine-rich sequences. Ermelin was predominantly expressed in brain and testis, and induced during neuronal differentiation of N1E-115 neuroblastoma cells but downregulated during myogenic differentiation of C2 cells. The mRNA was accumulated in hippocampus and cerebellum of brain and central areas of seminiferous tubules in testis. Epitope-tagging experiments located ermelin and KE4 to a network structure throughout the cytoplasm. Staining with the fluorescent dye DiOC(6)(3) identified this structure as the endoplasmic reticulum. These results suggest that at least some, if not all, of the HELP domain-containing proteins are multipass endoplasmic reticulum membrane proteins with functions conserved among eukaryotes.

Interactions between the promoter and first intron are involved in transcriptional control of alpha 1(I) collagen gene expression.

PubMed Central

Bornstein, P; McKay, J; Liska, D J; Apone, S; Devarayalu, S

1988-01-01

The first intron of the human collagen alpha 1(I) gene contains several positively and negatively acting elements. We have studied the transcription of collagen-human growth hormone fusion genes, containing deletions and rearrangements of collagen intronic sequences, by transient transfection of chick tendon fibroblasts and NIH 3T3 cells. In chick tendon fibroblasts, but not in 3T3 cells, inversion of intronic sequences containing a previously studied 274-base-pair segment, A274, resulted in markedly reduced human growth hormone mRNA levels as determined by an RNase protection assay. This inhibitory effect was largely alleviated when deletions were introduced in the collagen promoter of plasmids containing negatively oriented intronic sequences. Evidence for interaction of the promoter with the intronic segment, A274, was obtained by gel mobility shift assays. We suggest that promoter-intron interactions, mediated by DNA-binding proteins, regulate collagen gene transcription. Inversion of intronic segments containing critical interactive elements might then lead to an altered geometry and reduced activity of a transcriptional complex in those cells with sufficiently high levels of appropriate transcription factors. We further suggest that the deleted promoter segment plays a key role in directing DNA interactions involved in transcriptional control. Images PMID:3211130

Combinatorial electrochemical cell array for high throughput screening of micro-fuel-cells and metal/air batteries.

PubMed

Jiang, Rongzhong

2007-07-01

An electrochemical cell array was designed that contains a common air electrode and 16 microanodes for high throughput screening of both fuel cells (based on polymer electrolyte membrane) and metal/air batteries (based on liquid electrolyte). Electrode materials can easily be coated on the anodes of the electrochemical cell array and screened by switching a graphite probe from one cell to the others. The electrochemical cell array was used to study direct methanol fuel cells (DMFCs), including high throughput screening of electrode catalysts and determination of optimum operating conditions. For screening of DMFCs, there is about 6% relative standard deviation (percentage of standard deviation versus mean value) for discharge current from 10 to 20 mAcm(2). The electrochemical cell array was also used to study tin/air batteries. The effect of Cu content in the anode electrode on the discharge performance of the tin/air battery was investigated. The relative standard deviations for screening of metal/air battery (based on zinc/air) are 2.4%, 3.6%, and 5.1% for discharge current at 50, 100, and 150 mAcm(2), respectively.

Implementation of a Smeared Crack Band Model in a Micromechanics Framework

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Bednarcyk, Brett A.; Waas, Anthony M.; Arnold, Steven M.

2012-01-01

The smeared crack band theory is implemented within the generalized method of cells and high-fidelity generalized method of cells micromechanics models to capture progressive failure within the constituents of a composite material while retaining objectivity with respect to the size of the discretization elements used in the model. An repeating unit cell containing 13 randomly arranged fibers is modeled and subjected to a combination of transverse tension/compression and transverse shear loading. The implementation is verified against experimental data (where available), and an equivalent finite element model utilizing the same implementation of the crack band theory. To evaluate the performance of the crack band theory within a repeating unit cell that is more amenable to a multiscale implementation, a single fiber is modeled with generalized method of cells and high-fidelity generalized method of cells using a relatively coarse subcell mesh which is subjected to the same loading scenarios as the multiple fiber repeating unit cell. The generalized method of cells and high-fidelity generalized method of cells models are validated against a very refined finite element model.

Acyl-gelatins for cell-hybrid biomaterials: preparation of gelatins with high melting point and affinity for hydrophobic surfaces.

PubMed

Miyamoto, Keiichi; Chinzei, Hiroko; Komai, Takashi

2002-12-01

In the development of cell-hybrid biomaterials, the functional activity of cells depends on the selective binding of cells to artificial ligands on the biomaterials. The extracellular matrix (ECM) is the most important ligand for cell activity. ECM is known to contain collagen, one of whose constituents is gelatin. Although natural gelatin has good cell attachment properties, the melting point of gelatin hydrogel is lower than body temperature. Thus, non-chemically cross-linked gelatin hydrogel is not a biomaterial that is used for prostheses. In the present study, we report the preparation of acyl-gelatin hydrogels with high melting point (>37 degrees C) and high affinity for hydrophobic surfaces for easy handling for transportation and adhesion activities on the hydrophobic surfaces. In addition, the doubling time of endothelial cells on the coated cell culture plate was faster than that of natural gelatin owing to the higher adhesion activity of acyl-gelatin. The results clearly demonstrated that the acyl-gelatin acted as an interface that enabled cell adhesion to artificial materials surfaces.

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells

PubMed Central

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A.; de Boer, Jan; Watt, Fiona M.

2016-01-01

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation. PMID:26757610

Scalable topographies to support proliferation and Oct4 expression by human induced pluripotent stem cells.

PubMed

Reimer, Andreas; Vasilevich, Aliaksei; Hulshof, Frits; Viswanathan, Priyalakshmi; van Blitterswijk, Clemens A; de Boer, Jan; Watt, Fiona M

2016-01-13

It is well established that topographical features modulate cell behaviour, including cell morphology, proliferation and differentiation. To define the effects of topography on human induced pluripotent stem cells (iPSC), we plated cells on a topographical library containing over 1000 different features in medium lacking animal products (xeno-free). Using high content imaging, we determined the effect of each topography on cell proliferation and expression of the pluripotency marker Oct4 24 h after seeding. Features that maintained Oct4 expression also supported proliferation and cell-cell adhesion at 24 h, and by 4 days colonies of Oct4-positive, Sox2-positive cells had formed. Computational analysis revealed that small feature size was the most important determinant of pluripotency, followed by high wave number and high feature density. Using this information we correctly predicted whether any given topography within our library would support the pluripotent state at 24 h. This approach not only facilitates the design of substrates for optimal human iPSC expansion, but also, potentially, identification of topographies with other desirable characteristics, such as promoting differentiation.

Plant nuclei can contain extensive grooves and invaginations

NASA Technical Reports Server (NTRS)

Collings, D. A.; Carter, C. N.; Rink, J. C.; Scott, A. C.; Wyatt, S. E.; Allen, N. S.; Brown, C. S. (Principal Investigator)

2000-01-01

Plant cells can exhibit highly complex nuclear organization. Through dye-labeling experiments in untransformed onion epidermal and tobacco culture cells and through the expression of green fluorescent protein targeted to either the nucleus or the lumen of the endoplasmic reticulum/nuclear envelope in these cells, we have visualized deep grooves and invaginations into the large nuclei of these cells. In onion, these structures, which are similar to invaginations seen in some animal cells, form tubular or planelike infoldings of the nuclear envelope. Both grooves and invaginations are stable structures, and both have cytoplasmic cores containing actin bundles that can support cytoplasmic streaming. In dividing tobacco cells, invaginations seem to form during cell division, possibly from strands of the endoplasmic reticulum trapped in the reforming nucleus. The substantial increase in nuclear surface area resulting from these grooves and invaginations, their apparent preference for association with nucleoli, and the presence in them of actin bundles that support vesicle motility suggest that the structures might function both in mRNA export from the nucleus and in protein import from the cytoplasm to the nucleus.

Characterization of Epithelial Progenitors in Normal Human Palatine Tonsils and Their HPV16 E6/E7-Induced Perturbation

PubMed Central

Kang, Sung Yoon Catherine; Kannan, Nagarajan; Zhang, Lewei; Martinez, Victor; Rosin, Miriam P.; Eaves, Connie J.

2015-01-01

Summary Human palatine tonsils are oropharyngeal lymphoid tissues containing multiple invaginations (crypts) in which the continuity of the outer surface epithelium is disrupted and the isolated epithelial cells intermingle with other cell types. We now show that primitive epithelial cells detectable in vitro in 2D colony assays and in a 3D culture system are CD44+NGFR+ and present in both surface and crypt regions. Transcriptome analysis indicated a high similarity between CD44+NGFR+ cells in both regions, although those isolated from the crypt contained a higher proportion of the most primitive (holo)clonogenic cells. Lentiviral transduction of CD44+NGFR+ cells from both regions with human papillomavirus 16-encoded E6/E7 prolonged their growth in 2D cultures and caused aberrant differentiation in 3D cultures. Our findings therefore reveal a shared, site-independent, hierarchical organization, differentiation potential, and transcriptional profile of normal human tonsillar epithelial progenitor cells. They also introduce a new model for investigating the mechanisms of their transformation. PMID:26527383

Plant Nuclei Can Contain Extensive Grooves and InvaginationsW⃞W⃞

PubMed Central

Collings, David A.; Carter, Crystal N.; Rink, Jochen C.; Scott, Amie C.; Wyatt, Sarah E.; Allen, Nina Strömgren

2000-01-01

Plant cells can exhibit highly complex nuclear organization. Through dye-labeling experiments in untransformed onion epidermal and tobacco culture cells and through the expression of green fluorescent protein targeted to either the nucleus or the lumen of the endoplasmic reticulum/nuclear envelope in these cells, we have visualized deep grooves and invaginations into the large nuclei of these cells. In onion, these structures, which are similar to invaginations seen in some animal cells, form tubular or planelike infoldings of the nuclear envelope. Both grooves and invaginations are stable structures, and both have cytoplasmic cores containing actin bundles that can support cytoplasmic streaming. In dividing tobacco cells, invaginations seem to form during cell division, possibly from strands of the endoplasmic reticulum trapped in the reforming nucleus. The substantial increase in nuclear surface area resulting from these grooves and invaginations, their apparent preference for association with nucleoli, and the presence in them of actin bundles that support vesicle motility suggest that the structures might function both in mRNA export from the nucleus and in protein import from the cytoplasm to the nucleus. PMID:11148288

High Photoluminescence Quantum Yield in Band Gap Tunable Bromide Containing Mixed Halide Perovskites

DOE PAGES

Sutter-Fella, Carolin M.; Li, Yanbo; Amani, Matin; ...

2015-12-21

Hybrid organic-inorganic halide perovskite based semiconductor materials are attractive for use in a wide range of optoelectronic devices because they combine the advantages of suitable optoelectronic attributes and simultaneously low-cost solution processability. Here, we present a two-step low-pressure vapor-assisted solution process to grow high quality homogeneous CH 3NH 3PbI 3-xBr x perovskite films over the full band gap range of 1.6-2.3 eV. Photoluminescence light-in versus light-out characterization techniques are used to provide new insights into the optoelectronic properties of Br-containing hybrid organic-inorganic perovskites as a function of optical carrier injection by employing pump-powers over a 6 orders of magnitude dynamicmore » range. The internal luminescence quantum yield of wide band gap perovskites reaches impressive values up to 30%. This high quantum yield translates into substantial quasi-Fermi level splitting and high "luminescence or optically implied" open-circuit voltage. Most importantly, both attributes, high internal quantum yield and high optically implied open-circuit voltage, are demonstrated over the entire band gap range (1.6 eV ≤ E g ≤ 2.3 eV). These results establish the versatility of Br-containing perovskite semiconductors for a variety of applications and especially for the use as high-quality top cell in tandem photovoltaic devices in combination with industry dominant Si bottom cells. (Figure Presented).« less

Functional cooperativity between two TPA responsive elements in undifferentiated F9 embryonic stem cells.

PubMed Central

Okuda, A; Imagawa, M; Sakai, M; Muramatsu, M

1990-01-01

We have recently identified an enhancer, termed GPEI, in the 5'-flanking region of the rat glutathione transferase P gene, that is composed of two imperfect TPA (phorbol 12-O-tetradecanoate 13-acetate) responsive elements (TREs). Unlike other TRE-containing enhancers, GPEI exhibits a strong transcriptional enhancing activity in F9 embryonic stem cells. Mutational analyses have revealed that the high activity of GPEI is mediated by two imperfect TREs. Each TRE-like sequence has no activity by itself but acts synergistically to form a strong enhancer which is active even in the very low level of AP-1 activity in F9 cells. Furthermore, we show that synthetic DNAs containing two perfect TREs in certain arrangements have strong transcriptional enhancing activities in F9 cells and the activity is greatly influenced by the relative orientation and the distance of two TREs. Images Fig. 1. Fig. 2. Fig. 3. PMID:2323334

Localization of androgen receptors and estrogen receptors in the same cells of the songbird brain.

PubMed Central

Gahr, M

1990-01-01

Estrogens and androgens each have unique effects but act together for the neural differentiation and control of sexual behaviors in male vertebrates, such as the canary. The neuronal basis for these synergistic effects is elusive because the spatial relation between estrogen target cells and androgen target cells is unknown. This study localized estrogen receptor (ER)-containing cells by using immunocytochemistry and androgen receptor (AR)-containing cells by using autoradiography in the same sections of the male canary brain. Three cell types, those containing only ER, those containing only AR, and those containing both ER and AR, were found in tissue-specific frequencies. The midbrain nucleus intercollicularis exhibited the highest number of cells expressing both ER and AR, whereas ER and AR are expressed only in disjunctive cell populations in the forebrain nucleus hyperstriatalis ventrale, pars caudale. Synergistic effects of androgens and estrogens for the neural behavorial control could result from cells containing both ER and AR (intracellular) and from neural circuits containing ER and AR in different cells (intercellular). Images PMID:2251286

Lon Protease of Azorhizobium caulinodans ORS571 Is Required for Suppression of reb Gene Expression

PubMed Central

Nakajima, Azusa; Tsukada, Shuhei; Siarot, Lowela; Ogawa, Tetsuhiro; Oyaizu, Hiroshi

2012-01-01

Bacterial Lon proteases play important roles in a variety of biological processes in addition to housekeeping functions. In this study, we focused on the Lon protease of Azorhizobium caulinodans, which can fix nitrogen both during free-living growth and in stem nodules of the legume Sesbania rostrata. The nitrogen fixation activity of an A. caulinodans lon mutant in the free-living state was not significantly different from that of the wild-type strain. However, the stem nodules formed by the lon mutant showed little or no nitrogen fixation activity. By microscopic analyses, two kinds of host cells were observed in the stem nodules formed by the lon mutant. One type has shrunken host cells containing a high density of bacteria, and the other type has oval or elongated host cells containing a low density or no bacteria. This phenotype is similar to a praR mutant highly expressing the reb genes. Quantitative reverse transcription-PCR analyses revealed that reb genes were also highly expressed in the lon mutant. Furthermore, a lon reb double mutant formed stem nodules showing higher nitrogen fixation activity than the lon mutant, and shrunken host cells were not observed in these stem nodules. These results suggest that Lon protease is required to suppress the expression of the reb genes and that high expression of reb genes in part causes aberrance in the A. caulinodans-S. rostrata symbiosis. In addition to the suppression of reb genes, it was found that Lon protease was involved in the regulation of exopolysaccharide production and autoagglutination of bacterial cells. PMID:22752172

Metabolic enzyme microarray coupled with miniaturized cell-culture array technology for high-throughput toxicity screening.

PubMed

Lee, Moo-Yeal; Dordick, Jonathan S; Clark, Douglas S

2010-01-01

Due to poor drug candidate safety profiles that are often identified late in the drug development process, the clinical progression of new chemical entities to pharmaceuticals remains hindered, thus resulting in the high cost of drug discovery. To accelerate the identification of safer drug candidates and improve the clinical progression of drug candidates to pharmaceuticals, it is important to develop high-throughput tools that can provide early-stage predictive toxicology data. In particular, in vitro cell-based systems that can accurately mimic the human in vivo response and predict the impact of drug candidates on human toxicology are needed to accelerate the assessment of drug candidate toxicity and human metabolism earlier in the drug development process. The in vitro techniques that provide a high degree of human toxicity prediction will be perhaps more important in cosmetic and chemical industries in Europe, as animal toxicity testing is being phased out entirely in the immediate future.We have developed a metabolic enzyme microarray (the Metabolizing Enzyme Toxicology Assay Chip, or MetaChip) and a miniaturized three-dimensional (3D) cell-culture array (the Data Analysis Toxicology Assay Chip, or DataChip) for high-throughput toxicity screening of target compounds and their metabolic enzyme-generated products. The human or rat MetaChip contains an array of encapsulated metabolic enzymes that is designed to emulate the metabolic reactions in the human or rat liver. The human or rat DataChip contains an array of 3D human or rat cells encapsulated in alginate gels for cell-based toxicity screening. By combining the DataChip with the complementary MetaChip, in vitro toxicity results are obtained that correlate well with in vivo rat data.

Release and fate of fluorocarbons in a shredder residue landfill cell: 2. Field investigations.

PubMed

Scheutz, Charlotte; Fredenslund, Anders M; Nedenskov, Jonas; Kjeldsen, Peter

2010-11-01

The shredder residues from automobiles, home appliances and other metal containing products are often disposed in landfills, as recycling technologies for these materials are not common in many countries. Shredder waste contains rigid and soft foams from cushions and insulation panels blown with fluorocarbons. The objective of this study was to determine the gas composition, attenuation, and emission of fluorocarbons in a monofill shredder residue landfill cell by field investigation. Landfill gas generated within the shredder waste primarily consisted of CH(4) (27%) and N(2) (71%), without CO(2), indicating that the gas composition was governed by chemical reactions in combination with anaerobic microbial reactions. The gas generated also contained different fluorocarbons (up to 27 μg L(-1)). The presence of HCFC-21 and HCFC-31 indicated that anaerobic degradation of CFC-11 occurred in the landfill cell, as neither of these compounds has been produced for industrial applications. This study demonstrates that a landfill cell containing shredder waste has a potential for attenuating CFC-11 released from polyurethane (PUR) insulation foam in the cell via aerobic and anaerobic biodegradation processes. In deeper, anaerobic zones of the cell, reductive dechlorination of CFCs to HCFCs was evident, while in the shallow, oxic zones, there was a high potential for biooxidation of both methane and lesser chlorinated fluorocarbons. These findings correlated well with both laboratory results (presented in a companion paper) and surface emission measurements that, with the exception from a few hot spots, indicated that surface emissions were negative or below detection. Copyright © 2010 Elsevier Ltd. All rights reserved.

Processing of N-linked oligosaccharide depends on its location in the anion exchanger, AE1, membrane glycoprotein.

PubMed

Li, J; Quilty, J; Popov, M; Reithmeier, R A

2000-07-01

The human erythrocyte anion exchanger (AE)1 (Band 3) contains a single complex N-linked oligosaccharide that is attached to Asn(642) in the fourth extracellular loop of this polytopic membrane protein, while other isoforms (AE2, AE3 and trout AE1) are N-glycosylated on the preceding extracellular loop. Human AE1 expressed in transfected human embryonic kidney (HEK)-293 or COS-7 cells contained a high-mannose oligosaccharide. The lack of oligosaccharide processing was not due to retention of AE1 in the endoplasmic reticulum since biotinylation assays showed that approx. 30% of the protein was expressed at the cell surface. Moving the N-glycosylation site to the preceding extracellular loop in an AE1 glycosylation mutant (N555) resulted in processing of the oligosaccharide and production of a complex form of AE1. A double N-glycosylation mutant (N555/N642) contained both a high-mannose and a complex oligosaccharide chain. The complex form of the N555 mutant could be biotinylated showing that this form of the glycoprotein was at the cell surface. Pulse-chase experiments showed that the N555 mutant was efficiently converted from a high-mannose to a complex oligosaccharide with a half-time of approx. 4 h, which reflected the time course of trafficking of AE1 from the endoplasmic reticulum to the plasma membrane. The turnover of the complex form of the N555 mutant occurred with a half-life of approx. 15 h. The results show that the oligosaccharide attached to the endogenous site in extracellular loop 4 in human AE1 is not processed in HEK-293 or COS-7 cells, while the oligosaccharide attached to the preceding loop is converted into the complex form.

Hematological and metabolic responses to training in racing sled dogs fed diets containing medium, low, or zero carbohydrate.

PubMed

Kronfeld, D S; Hammel, E P; Ramberg, C F; Dunlap, H L

1977-03-01

In a 28 week study, 18 racing sled dogs were trained to maximal fitness in 12 weeks, sustained through a racing season of 12 weeks, followed by gradual of training of 4 weeks. The dogs were fed a predominantly cereal diet prior to the study; experimental diets containing more chicken and meat by products were introduced from the 2nd to the 4th week of training. On an energy basis, the diets contained protein, fat, and carbohydrate in the proportions of 39:61:0 (diet A), 32:45:23 (diet B), and 28:34:38 (diet C). Blood samples were taken at rest just before the start of training, at 6, 12,24 and 28 weeks; 33 variables were measured on most samples. The results were subjected to analysis of variance. No adverse effects were observed in dogs fed the extreme diet A. Significant relationships to training were shown by serum glutamic oxaloacetic transaminase, creatinine, packed cell volume, calcium, hemoglobin, and globulin. Serum cholesterol concentration increased with the introduction of the higher protein-fat diets; the high concentrations attenuated with time but rose again when training was abated. Dogs on diet A maintained higher serum concentrations of albumin, calcium, magnesium, and free fatty acids during the racing season than did dogs fed diets B or C. They also exhibited the greatest increases in red cell count, hemoglobin concentration, and packed cell volume during training. High values of red cell indices were not sustained through the racing season in dogs fed diet C. In addition to attributes already widely appreciated, viz. a higher energy density an digestibility, the carbohydrate-free, high-fat diet A appeared to confer advantages for prolonged strenuous running in terms of certain metabolic responses to training.

Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

PubMed

Norris, J S; Kohler, P O

1978-01-01

Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

Oligosaccharide ligands for NKR-P1 protein activate NK cells and cytotoxicity

NASA Astrophysics Data System (ADS)

Bezouška, Karel; Yuen, Chun-Ting; O'Brien, Jacqui; Childs, Robert A.; Chai, Wengang; Lawson, Alexander M.; Drbal, Karel; Fišerová, Anna; Posíšil, Miloslav; Feizi, Ten

1994-11-01

A diversity of high-affinity Oligosaccharide ligands are identified for NKR-P1, a membrane protein on natural killer (NK) cells which contains an extracellular Ca2+-dependent lectin domain. Interactions of such oligosaccharides on the target cell surface with NKR-P1 on the killer cell surface are crucial both for target cell recognition and for delivery of stimulatory or inhibitory signals linked to the NK cytolytic machinery. NK-resistant tumour cells are rendered susceptible by preincubation with liposomes expressing NKR-P1 ligands, suggesting that purging of tumour or virally infected cells in vivo may be a therapeutic possibility.

Chromatographic measurements of hemoglobin A2 in blood samples that contain sickle hemoglobin.

PubMed

Shokrani, M; Terrell, F; Turner, E A; Aguinaga, M D

2000-04-01

In the sickle cell syndromes, Hb A2 measurements aid in the differential diagnosis of sickle cell anemia from sickle-beta-thalassemia. The purpose of this study is to assess the Hb A2 levels in samples containing sickle hemoglobin (Hb S) by the use of an automated high performance liquid chromatography system (HPLC-Variant beta-thalassemia Short Program). The blood samples analyzed were from individuals of African descent living in the state of Tennessee who had either sickle cell trait (Hb AS), sickle cell disease (Hb SS), or sickle cell-hemoglobin C disease (Hb SC). Interestingly, the Hb A2 levels determined by HPLC were found elevated in samples containing Hb S. The Hb A2 mean in Hb AS samples (n=146) is 4.09% (SD +/- 0.42, range 2.20 to 5.20%); in Hb SS samples (n=33) it is 3.90% (SD +/- 1.08, range 0.60 to 5.90%); and in Hb SC samples (n=27) it is 4.46% (SD +/- 0.70, range 2.30 to 5.91%). The Hb A2 mean by HPLC in normal individuals (Hb AA, n=70) is 2.57% (SD +/- 0.25, range 2.1 to 3.0%), and the Hb A2 range in beta-thalassemia carriers is 4 to 9%. Our results show that the Hb A2 levels in Hb S-containing samples partially overlap with those expected from beta-thalassemia carriers. The hemoglobinopathy laboratory should be aware of this apparent elevation in Hb A2 levels determined by HPLC in individuals carrying Hb S. Other factors, such as family history and clinical symptoms, should be taken into account before a diagnosis of sickle cell trait, sickle-beta-thalassemia, or sickle cell anemia is made.

Factors Affecting Transformation of Micrococcus lysodeikticus

PubMed Central

Kloos, Wesley E.

1969-01-01

Relatively high transfo mation frequencies were obtained with Micrococcus lysodeikticus cells, previou[ill]sly grown in defined broth, with a tris(hydroxymethyl)-aminomethane-glutamate b uffer containing Mg++, Ca++, Ba++, or Sr++. PMID:5788710

A fuzzy logic approach to control anaerobic digestion.

PubMed

Domnanovich, A M; Strik, D P; Zani, L; Pfeiffer, B; Karlovits, M; Braun, R; Holubar, P

2003-01-01

One of the goals of the EU-Project AMONCO (Advanced Prediction, Monitoring and Controlling of Anaerobic Digestion Process Behaviour towards Biogas Usage in Fuel Cells) is to create a control tool for the anaerobic digestion process, which predicts the volumetric organic loading rate (Bv) for the next day, to obtain a high biogas quality and production. The biogas should contain a high methane concentration (over 50%) and a low concentration of components toxic for fuel cells, e.g. hydrogen sulphide, siloxanes, ammonia and mercaptanes. For producing data to test the control tool, four 20 l anaerobic Continuously Stirred Tank Reactors (CSTR) are operated. For controlling two systems were investigated: a pure fuzzy logic system and a hybrid-system which contains a fuzzy based reactor condition calculation and a hierachial neural net in a cascade of optimisation algorithms.

Aggregation-Induced Emission (AIE) Fluorophore Exhibits a Highly Ratiometric Fluorescent Response to Zn2+ in vitro and in Human Liver Cancer Cells.

PubMed

Mehdi, Hassan; Gong, Weitao; Guo, Huimin; Watkinson, Michael; Ma, Hua; Wajahat, Ali; Ning, Guiling

2017-09-21

Two novel organic fluorophores, containing bis-naphthylamide and quinoline motifs, have been designed and synthesized. One of the fluorophores contains an isobutylene unit and exhibits a significant aggregation-induced emission (AIE) and a remarkable highly selective ratiometric fluorescence response towards Zn 2+ in solution as well as in human liver cancer cells. The AIE behavior of this fluorophore was fully verified by fluorescence and UV/Vis spectroscopy, quantum yield calculations, and single-crystal X-ray diffraction, which revealed an intricate crystal packing system. Conversely, a fluorophore that lacks the isobutylene moiety did not exhibit any significant fluorescent properties as a result of its more flexible molecular structure that presumably allows free intramolecular rotational processes to occur. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Autothermal reforming catalyst having perovskite structure

DOEpatents

Krumpel, Michael [Naperville, IL; Liu, Di-Jia [Naperville, IL

2009-03-24

The invention addressed two critical issues in fuel processing for fuel cell application, i.e. catalyst cost and operating stability. The existing state-of-the-art fuel reforming catalyst uses Rh and platinum supported over refractory oxide which add significant cost to the fuel cell system. Supported metals agglomerate under elevated temperature during reforming and decrease the catalyst activity. The catalyst is a perovskite oxide or a Ruddlesden-Popper type oxide containing rare-earth elements, catalytically active firs row transition metal elements, and stabilizing elements, such that the catalyst is a single phase in high temperature oxidizing conditions and maintains a primarily perovskite or Ruddlesden-Popper structure under high temperature reducing conditions. The catalyst can also contain alkaline earth dopants, which enhance the catalytic activity of the catalyst, but do not compromise the stability of the perovskite structure.

Enhancing Sulfur Tolerance of Ni-Based Cermet Anodes of Solid Oxide Fuel Cells by Ytterbium-Doped Barium Cerate Infiltration.

PubMed

Li, Meng; Hua, Bin; Luo, Jing-Li; Jiang, San Ping; Pu, Jian; Chi, Bo; Li, Jian

2016-04-27

Conventional anode materials for solid oxide fuel cells (SOFCs) are Ni-based cermets, which are highly susceptible to deactivation by contaminants in hydrocarbon fuels. Hydrogen sulfide is one of the commonly existed contaminants in readily available natural gas and gasification product gases of pyrolysis of biomasses. Development of sulfur tolerant anode materials is thus one of the critical challenges for commercial viability and practical application of SOFC technologies. Here we report a viable approach to enhance substantially the sulfur poisoning resistance of a Ni-gadolinia-doped ceria (Ni-GDC) anode through impregnation of proton conducting perovskite BaCe0.9Yb0.1O3-δ (BCYb). The impregnation of BCYb nanoparticles improves the electrochemical performance of the Ni-GDC anode in both H2 and H2S containing fuels. Moreover, more importantly, the enhanced stability is observed in 500 ppm of H2S/H2. The SEM and XPS analysis indicate that the infiltrated BCYb fine particles inhibit the adsorption of sulfur and facilitate sulfur removal from active sites, thus preventing the detrimental interaction between sulfur and Ni-GDC and the formation of cerium sulfide. The preliminary results of the cell with the BCYb+Ni-GDC anode in methane fuel containing 5000 ppm of H2S show the promising potential of the BCYb infiltration approach in the development of highly active and stable Ni-GDC-based anodes fed with hydrocarbon fuels containing a high concentration of sulfur compounds.

Selective Cytotoxic Activity of Se-Methyl-Seleno-L-Cysteine- and Se-Polysaccharide-Containing Extracts from Shiitake Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

PubMed

Klimaszewska, Marzenna; Górska, Sandra; Dawidowski, Maciej; Podsadni, Piotr; Szczepanska, Agnieszka; Orzechowska, Emilia; Kurpios-Piec, Dagmara; Grosicka-Maciag, Emilia; Rahden-Staroń, Iwonna; Turło, Jadwiga

2017-01-01

Numerous formulations derived from the shiitake medicinal mushroom, Lentinus edodes, demonstrate anticancer activities. We hypothesized that isolates from selenium (Se)-enriched mycelia of L. edodes would possess stronger cancer-preventive properties than current preparations. The aim of this study was to investigate whether the presence of Se-methyl-seleno-L-cysteine in mycelial extracts of L. edodes affects their cytotoxic activity (makes them stronger) or whether they are as effective as Se-containing polysaccharides. Extracts were prepared from Se-containing mycelia under various conditions and assayed for cytotoxic activity in cancer (PC3 and HeLa) and normal (HMEC-1) cell lines. The chemical composition of the extracts was examined; specifically, the amounts of potentially cytotoxic Se compounds (methylselenocysteine, selenomethionine, and Se-containing polysaccharides) were measured. The relationship between extract composition and biological activity was characterized. Mycelial cultures were cultivated in a 10-L bioreactor in medium enriched with sodium selenite. Mycelial extracts were prepared either at 100°C or at 4°C in acidic solution. Total Se content was determined using the atomic absorption spectrometry method, and methylselenocysteine and selenomethionine contents were measured using reverse-phase high-performance liquid chromatography. Protein, carbohydrate, and polyphenolic contents were determined with spectrophotometric methods, and Se-containing polysaccharides were measured with the use of precipitation. Anticancer activity of mycelial extracts was examined using the MTT cell viability assay. Extracts containing Se-methyl-seleno-L-cysteine or Se-polysaccharides prepared at 4°C and 100°C, respectively, display moderate, time-dependent, specific cytotoxic activity in HeLa and PC3 cell lines. The effect in HeLa cells is more pronounced in the extract prepared at 4°C than at 100°C. The effect is almost equal for the PC3 cell line. However, both extracts have no effect or only slightly stimulate normal (HMEC-1) cell viability. The selective cytotoxic activity of L. edodes extracts in cancer (PC3 and HeLa) cells is due to the presence of both Se-methyl-seleno-L-cysteine and selenated polysaccharides, perhaps in combination with other active ingredients.

Somaclonal variation: a morphogenetic and biochemical analysis of Mandevilla velutina cultured cells.

PubMed

Maraschin, M; Sugui, J A; Wood, K V; Bonham, C; Buchi, D F; Cantao, M P; Carobrez, S G; Araujo, P S; Peixoto, M L; Verpoorte, R; Fontana, J D

2002-06-01

Cell cultures of Mandevilla velutina have proved to be an interesting production system for biomass and secondary metabolites able to inhibit the hypotensive activity of bradykinin, a nonapeptide generated in plasma during tissue trauma. The crude ethyl acetate extract of cultured cells contains about 31- to 79-fold more potent anti-bradykinin compounds (e.g., velutinol A) than that obtained with equivalent extracts of tubers. Somaclonal variation may be an explanation for the wide range of inhibitor activity found in the cell cultures. The heterogeneity concerning morphology, differentiation, carbon dissimilation, and velutinol A production in M. velutina cell cultures is reported. Cell cultures showed an asynchronous growth and cells in distinct developmental stages. Meristematic cells were found as the major type, with several morphological variations. Cell aggregates consisting only of meristematic cells, differentiated cells containing specialized cell structures such as functional chloroplasts (cytodifferentiation) and cells with embryogenetic characteristics were observed. The time course for sucrose metabolism indicated cell populations with significant differences in growth and metabolic rates, with the highest biomass-producing cell line showing a cell cycle 60% shorter and a metabolic rate 33.6% higher than the control (F2 cell population). MALDI-TOF mass spectrometric analysis of velutinol A in selected cell lines demonstrated the existence of velutinol A producing and nonproducing somaclones. These results point to a high genetic heterogeneity in general and also in terms of secondary metabolite content.

Subcellular distribution of glutathione and its dynamic changes under oxidative stress in the yeast Saccharomyces cerevisiae

PubMed Central

Zechmann, Bernd; Liou, Liang-Chun; Koffler, Barbara E; Horvat, Lucija; Tomašić, Ana; Fulgosi, Hrvoje; Zhang, Zhaojie

2011-01-01

Glutathione is an important antioxidant in most prokaryotes and eukaryotes. It detoxifies reactive oxygen species and is also involved in the modulation of gene expression, in redox signaling, and in the regulation of enzymatic activities. In this study, the subcellular distribution of glutathione was studied in Saccharomyces cerevisiae by quantitative immunoelectron microscopy. Highest glutathione contents were detected in mitochondria and subsequently in the cytosol, nuclei, cell walls, and vacuoles. The induction of oxidative stress by hydrogen peroxide (H2O2) led to changes in glutathione-specific labeling. Three cell types were identified. Cell types I and II contained more glutathione than control cells. Cell type II differed from cell type I in showing a decrease in glutathione-specific labeling solely in mitochondria. Cell type III contained much less glutathione contents than the control and showed the strongest decrease in mitochondria, suggesting that high and stable levels of glutathione in mitochondria are important for the protection and survival of the cells during oxidative stress. Additionally, large amounts of glutathione were relocated and stored in vacuoles in cell type III, suggesting the importance of the sequestration of glutathione in vacuoles under oxidative stress. PMID:22093747

Detection of Human Papillomavirus Type 2 Related Sequence in Oral Papilloma

PubMed Central

Yamaguchi, Taihei; Shindoh, Masanobu; Amemiya, Akira; Inoue, Nobuo; Kawamura, Masaaki; Sakaoka, Hiroshi; Inoue, Masakazu; Fujinaga, Kei

1998-01-01

Oral papilloma is a benign tumourous lesion. Part of this lesion is associated with human papillomavirus (HPV) infection. We analysed the genetical and histopathological evidence for HPV type 2 infection in three oral papillomas. Southern blot hybridization showed HPV 2a sequence in one lesion. Cells of the positive specimen appeared to contain high copy numbers of the viral DNA in an episomal state. In situ staining demonstrated virus capsid antigen in koilocytotic cells and surrounding cells in the hyperplastic epithelial layer. Two other specimens contained no HPV sequences by labeled probe of full length linear HPVs 2a, 6b, 11, 16, 18, 31 and 33 DNA under low stringency hybridization conditions. These results showed the possibility that HPV 2 plays a role in oral papilloma. PMID:9699941

Specific Interaction between Redox Phospholipid Polymers and Plastoquinone in Photosynthetic Electron Transport Chain.

PubMed

Tanaka, Kenya; Kaneko, Masahiro; Ishikawa, Masahito; Kato, Souichiro; Ito, Hidehiro; Kamachi, Toshiaki; Kamiya, Kazuhide; Nakanishi, Shuji

2017-04-19

Redox phospholipid polymers added in culture media are known to be capable of extracting electrons from living photosynthetic cells across bacterial cell membranes with high cytocompatibility. In the present study, we identify the intracellular redox species that transfers electrons to the polymers. The open-circuit electrochemical potential of an electrolyte containing the redox polymer and extracted thylakoid membranes shift to positive (or negative) under light irradiation, when an electron transport inhibitor specific to plastoquinone is added upstream (or downstream) in the photosynthetic electron transport chain. The same trend is also observed for a medium containing living photosynthetic cells of Synechococcus elongatus PCC7942. These results clearly indicate that the phospholipid redox polymers extract photosynthetic electrons mainly from plastoquinone. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates

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

Nelson, Cassandra E.; Beri, Nina R.; Gardner, Jeffrey G.

Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interactionmore » between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. Furthermore, we applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.« less

Custom fabrication of biomass containment devices using 3-D printing enables bacterial growth analyses with complex insoluble substrates

DOE PAGES

Nelson, Cassandra E.; Beri, Nina R.; Gardner, Jeffrey G.

2016-09-21

Physiological studies of recalcitrant polysaccharide degradation are challenging for several reasons, one of which is the difficulty in obtaining a reproducibly accurate real-time measurement of bacterial growth using insoluble substrates. Current methods suffer from several problems including (i) high background noise due to the insoluble material interspersed with cells, (ii) high consumable and reagent cost and (iii) significant time delay between sampling and data acquisition. A customizable substrate and cell separation device would provide an option to study bacterial growth using optical density measurements. To test this hypothesis we used 3-D printing to create biomass containment devices that allow interactionmore » between insoluble substrates and microbial cells but do not interfere with spectrophotometer measurements. Evaluation of materials available for 3-D printing indicated that UV-cured acrylic plastic was the best material, being superior to nylon or stainless steel when examined for heat tolerance, reactivity, and ability to be sterilized. Cost analysis of the 3-D printed devices indicated they are a competitive way to quantitate bacterial growth compared to viable cell counting or protein measurements, and experimental conditions were scalable over a 100-fold range. The presence of the devices did not alter growth phenotypes when using either soluble substrates or insoluble substrates. Furthermore, we applied biomass containment to characterize growth of Cellvibrio japonicus on authentic lignocellulose (non-pretreated corn stover), and found physiological evidence that xylan is a significant nutritional source despite an abundance of cellulose present.« less

Genetic instability caused by loss of MutS homolog 3 in human colorectal cancer

PubMed Central

Haugen, Astrid C.; Goel, Ajay; Yamada, Kanae; Marra, Giancarlo; Nguyen, Thuy-Phuong; Nagasaka, Takeshi; Kanazawa, Shinsaku; Koike, Junichi; Kikuchi, Yoshinori; Zhong, Xiaoling; Arita, Michitsune; Shibuya, Kazutoshi; Oshimura, Mitsuo; Hemmi, Hiromichi; Boland, Clement Richard; Koi, Minoru

2008-01-01

Microsatellite instability (MSI) is a hallmark of mismatch repair deficiency. High levels of MSI at mono- and dinucleotide repeats in colorectal cancer (CRC) are attributed to inactivation of the mismatch repair genes, hMLH1 and hMSH2. CRC with low levels of MSI (MSI-L) exists; however its molecular basis is unclear. There is another type of MSI - “elevated microsatellite alterations at selected tetranucleotide repeats” - (EMAST) where loci containing [AAAG]n or [ATAG]n repeats are unstable. EMAST is frequent in non-colorectal cancers; however the incidence of EMAST and its cause in CRC is not known. Here, we report that MSH3-knock-down or MSH3-deficient cells exhibit the EMAST phenotype and low levels of mutations at dinucleotide repeats. About 60% of 117 sporadic CRC cases exhibit EMAST. All of the cases defined as MSI-H (16 cases) exhibited high levels of EMAST. Among 101 non-MSI-H cases, all 19 cases of MSI-L and 35 of 82 cases of MSS exhibited EMAST. Although non-MSI-H CRC tissues contained MSH3-negative tumor cells ranging from 2-50% of the total tumor cell population, the tissues exhibiting EMAST contained more MSH3-negative cells (average 31.5%) than did the tissues not exhibiting EMAST (8.4%). Taken together, our results support the idea that MSH3-deficiency causes EMAST or EMAST with low levels of MSI at the loci with dinucleotide repeats in CRC. PMID:18922920

Electrospun Nafion ®/Polyphenylsulfone composite membranes for regenerative Hydrogen bromine fuel cells

DOE PAGES

Park, Jun; Wycisk, Ryszard; Pintauro, Peter N.; ...

2016-02-29

Here, the regenerative H 2/Br 2-HBr fuel cell, utilizing an oxidant solution of Br 2 in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA) ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion ® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU), for mechanicalmore » reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion ® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H 2-Br 2 fuel cell power output with a 65 m thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 m Nafion ® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H 2/Br 2-HBr systems.« less

High αv Integrin Level of Cancer Cells Is Associated with Development of Brain Metastasis in Athymic Rats

PubMed Central

WU, YINGJEN JEFFREY; PAGEL, MICHAEL A.; MULDOON, LESLIE L.; FU, RONGWEI; NEUWELT, EDWARD A.

2018-01-01

Background/Aim Brain metastases commonly occur in patients with malignant skin, lung and breast cancers resulting in high morbidity and poor prognosis. Integrins containing an αv subunit are cell adhesion proteins that contribute to cancer cell migration and cancer progression. We hypothesized that high expression of αv integrin cell adhesion protein promoted metastatic phenotypes in cancer cells. Materials and Methods Cancer cells from different origins were used and studied regarding their metastatic ability and intetumumab, anti-αv integrin mAb, sensitivity using in vitro cell migration assay and in vivo brain metastases animal models. Results The number of brain metastases and the rate of occurrence were positively correlated with cancer cell αv integrin levels. High αv integrin-expressing cancer cells showed significantly faster cell migration rate in vitro than low αv integrin-expressing cells. Intetumumab significantly inhibited cancer cell migration in vitro regardless of αv integrin expression level. Overexpression of αv integrin in cancer cells with low αv integrin level accelerated cell migration in vitro and increased the occurrence of brain metastases in vivo. Conclusion αv integrin promotes brain metastases in cancer cells and may mediate early steps in the metastatic cascade, such as adhesion to brain vasculature. Targeting αv integrin with intetumumab could provide clinical benefit in treating cancer patients who develop metastases. PMID:28739685

The Use of Transcription Terminators to Generate Transgenic Lines of Chinese Hamster Ovary Cells (CHO) with Stable and High Level of Reporter Gene Expression.

PubMed

Gasanov, N B; Toshchakov, S V; Georgiev, P G; Maksimenko, O G

2015-01-01

Mammalian cell lines are widely used to produce recombinant proteins. Stable transgenic cell lines usually contain many insertions of the expression vector in one genomic region. Transcription through transgene can be one of the reasons for target gene repression after prolonged cultivation of cell lines. In the present work, we used the known transcription terminators from the SV40 virus, as well as the human β- and γ-globin genes, to prevent transcription through transgene. The transcription terminators were shown to increase and stabilize the expression of the EGFP reporter gene in transgenic lines of Chinese hamster ovary (CHO) cells. Hence, transcription terminators can be used to create stable mammalian cells with a high and stable level of recombinant protein production.

Clonal foraging in perennial wheatgrasses: A strategy for exploiting patchy soil nutrients

USGS Publications Warehouse

Humphrey, L. David; Pyke, David A.

1997-01-01

1. Foraging by means of plasticity in placement of tillers in response to low- and high-nutrient patches was examined in the rhizomatous wheatgrass Elymus lanceolatus ssp. lanceolatus. Its ability to exploit soil nutrient patches was compared to that of the closely related but caespitose E. lanceolatus ssp. wawawaiensis.2. Clones of 14 genets of each taxon were planted in boxes consisting of two 30 × 30 cm cells: the `origin cell' where clones were planted, and the adjacent `destination cell', with each cell containing soil with either low or high levels of nutrients.3. The rhizomatous taxon, which can produce intravaginal, short-rhizome and long-rhizome tillers, preferentially produced short-rhizome and intravaginal tillers in high-nutrient destination cells. Effects of nutrient status of the origin cell as well as of the destination cell on total tiller numbers indicated clonal integration, yet tiller placement responded to local conditions.4. Roots of both taxa accessed nutrients in destination cells (the caespitose subspecies by root growth only), and above-ground biomass of both taxa increased to a similar extent with high-nutrient destination cells. With the patch sizes used in this experiment, root growth was as important as ramet placement in exploiting nutrients in destination cells. 5 There was no relationship between degree of plasticity in ramet placement and biomass of the clone when high-nutrient destination cells were present.

Diversification of both KIR and NKG2 natural killer cell receptor genes in macaques - implications for highly complex MHC-dependent regulation of natural killer cells.

PubMed

Walter, Lutz; Petersen, Beatrix

2017-02-01

The killer immunoglobulin-like receptors (KIR) as well as their MHC class I ligands display enormous genetic diversity and polymorphism in macaque species. Signals resulting from interaction between KIR or CD94/NKG2 receptors and their cognate MHC class I proteins essentially regulate the activity of natural killer (NK) cells. Macaque and human KIR share many features, such as clonal expression patterns, gene copy number variations, specificity for particular MHC class I allotypes, or epistasis between KIR and MHC class I genes that influence susceptibility and resistance to immunodeficiency virus infection. In this review article we also annotated publicly available rhesus macaque BAC clone sequences and provide the first description of the CD94-NKG2 genomic region. Besides the presence of genes that are orthologous to human NKG2A and NKG2F, this region contains three NKG2C paralogues. Hence, the genome of rhesus macaques contains moderately expanded and diversified NKG2 genes in addition to highly diversified KIR genes. The presence of two diversified NK cell receptor families in one species has not been described before and is expected to require a complex MHC-dependent regulation of NK cells. © 2016 John Wiley & Sons Ltd.

Cyclometalated Iminophosphorane Gold(III) and Platinum(II) Complexes. A Highly Permeable Cationic Platinum(II) Compound with Promising Anticancer Properties

PubMed Central

2015-01-01

New organometallic gold(III) and platinum(II) complexes containing iminophosphorane ligands are described. Most of them are more cytotoxic to a number of human cancer cell lines than cisplatin. Cationic Pt(II) derivatives 4 and 5, which differ only in the anion, Hg2Cl62– or PF6– respectively, display almost identical IC50 values in the sub-micromolar range (25–335-fold more active than cisplatin on these cell lines). The gold compounds induced mainly caspase-independent cell death, as previously reported for related cycloaurated compounds containing IM ligands. Cycloplatinated compounds 3, 4, and 5 can also activate alternative caspase-independent mechanisms of death. However, at short incubation times cell death seems to be mainly caspase dependent, suggesting that the main mechanism of cell death for these compounds is apoptosis. Mercury-free compound 5 does not interact with plasmid (pBR322) DNA or with calf thymus DNA. Permeability studies of 5 by two different assays, in vitro Caco-2 monolayers and a rat perfusion model, have revealed a high permeability profile for this compound (comparable to that of metoprolol or caffeine) and an estimated oral fraction absorbed of 100%, which potentially makes it a good candidate for oral administration. PMID:26147404

Isolation of a hemidesmosome-rich fraction from a human squamous cell carcinoma cell line

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

Hirako, Yoshiaki, E-mail: s47526a@cc.nagoya-u.ac.jp; Yonemoto, Yuki; Yamauchi, Tomoe

2014-06-10

Hemidesmosomes are cell-to-matrix adhesion complexes anchoring keratinocytes to basement membranes. For the first time, we present a method to prepare a fraction from human cultured cells that are highly enriched in hemidesmosomal proteins. Using DJM-1 cells derived from human squamous cell carcinoma, accumulation of hemidesmosomes was observed when these cells were cultured for more than 10 days in a commercial serum-free medium without supplemental calcium. Electron microscopy demonstrated that numerous electron-dense adhesion structures were present along the basal cell membranes of DJM-1 cells cultured under the aforementioned conditions. After removing cellular materials using an ammonia solution, hemidesmosomal proteins and depositedmore » extracellular matrix were collected and separated by electrophoresis. There were eight major polypeptides, which were determined to be plectin, BP230, BP180, integrin α6 and β4 subunits, and laminin-332 by immunoblotting and mass spectrometry. Therefore, we designated this preparation as a hemidesmosome-rich fraction. This fraction contained laminin-332 exclusively in its unprocessed form, which may account for the promotion of laminin deposition, and minimal amounts of Lutheran blood group protein, a nonhemidesmosomal transmembrane protein. This hemidesmosome-rich fraction would be useful not only for biological research on hemidesmosomes but also for developing a serum test for patients with blistering skin diseases. - Highlights: • A defined condition promoted accumulation of hemidesmosomes in human cultured cells. • A fraction isolated from the cells contained eight major polypeptides. • The polypeptides were the five major hemidesmosome proteins and laminin-332. • The cultured cells deposited laminin-332 in its unprocessed form under the condition. • We report a method to prepare a fraction highly enriched in hemidesmosome proteins.« less

Biodistribution of modular nanotransporter carrying Auger electron emitter and targeted at melanoma cells in murine tumor model

NASA Astrophysics Data System (ADS)

Vorontsova, M. S.; Morozova, N. B.; Karmakova, T. A.; Rosenkranz, A. A.; Slastnikova, T. A.; Petriev, V. M.; Smoryzanova, O. A.; Tischenko, V. K.; Yakubovskaya, R. I.; Kaprin, A. D.; Sobolev, A. S.

2017-09-01

Recombinant modular nanotransporter containing α-melanocyte-stimulating hormone peptide sequence (MNT-MSH) as a ligand module was designed for nucleus-targeted delivery of cytotoxic agents into melanoma cells. MNT-MSH radiolabeled with Auger electron emitter (111In-NOTA-MNT-MSH) showed a high antitumor efficacy in mice bearing syngeneic melanoma after intratumoral (i.t.) injection. This study is aimed at evaluating the biodistribution of the radioconjugate in melanoma tumor model in vivo. 111In-NOTA-MNT-MSH was administered i.t. in C57Bl/6j mice bearing subcutaneously implanted B16-F1 murine melanoma cells, expressing high levels of MCR1. The tissue uptake of radioactivity was determined ex vivo by γ-counter measurements. The intravenous route of administration did not provide a desirable level of radioactivity accumulation in the tumor, possibly, due to a high uptake of the transporter in liver tissue. After i.t. administration 111In-NOTA-MNT-MSH provided a high local retention of radionuclide, ranged from 400 to 350 %ID/g within at least 48 hours post-injection. MNT containing Auger electron emitter and α-MSH peptide as vector ligand could be a promising basis for radiopharmaceutical preparations intended for melanoma treatment.

Sialoglycoproteins and N-glycans from secreted exosomes of ovarian carcinoma cells.

PubMed

Escrevente, Cristina; Grammel, Nicolas; Kandzia, Sebastian; Zeiser, Johannes; Tranfield, Erin M; Conradt, Harald S; Costa, Júlia

2013-01-01

Exosomes consist of vesicles that are secreted by several human cells, including tumor cells and neurons, and they are found in several biological fluids. Exosomes have characteristic protein and lipid composition, however, the results concerning glycoprotein composition and glycosylation are scarce. Here, protein glycosylation of exosomes from ovarian carcinoma SKOV3 cells has been studied by lectin blotting, NP-HPLC analysis of 2-aminobenzamide labeled glycans and mass spectrometry. An abundant sialoglycoprotein was found enriched in exosomes and it was identified by peptide mass fingerprinting and immunoblot as the galectin-3-binding protein (LGALS3BP). Exosomes were found to contain predominantly complex glycans of the di-, tri-, and tetraantennary type with or without proximal fucose and also high mannose glycans. Diantennary glycans containing bisecting N-acetylglucosamine were also detected. This work provides detailed information about glycoprotein and N-glycan composition of exosomes from ovarian cancer cells, furthermore it opens novel perspectives to further explore the functional role of glycans in the biology of exosomes.

Mechanical cell disruption of Parachlorella kessleri microalgae: Impact on lipid fraction composition.

PubMed

Clavijo Rivera, E; Montalescot, V; Viau, M; Drouin, D; Bourseau, P; Frappart, M; Monteux, C; Couallier, E

2018-05-01

Samples of nitrogen-starved Parachlorella kessleri containing intact cells (IC), cells ground by bead milling (BM), and cells subjected to high-pressure cell disruption (HPD), together with their supernatants after centrifugation, were compared for granulometry and lipid profiles. The effects of disruption on the lipid profile and organisation were evaluated. The quantity of lipids available for extraction increased with disruption, and up to 81% could be recovered in supernatants after centrifugation, but a marked reorganization occurred. The proportion of amphiphilic free fatty acids and lysophosphatidylcholine increased during disruption due to their release or owing to lipid degradation by enzymes or physical conditions. This effect was more marked in HPD than in BM. Lipids contained in the aqueous phase, after disruption and centrifugation, were enriched in unsaturated fatty acids, BM leading to larger droplets than HPD. The larger liquid lipid droplet would be easier to recover in the following downstream processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Minichromosome assembly of non-integrated plasmid DNA transfected into mammalian cells.

PubMed Central

Reeves, R; Gorman, C M; Howard, B

1985-01-01

The nucleoprotein structures formed on various plasmid expression vectors transfected into mammalian cells by both the calcium phosphate and DEAE-dextran methods have been studied. We demonstrate by a variety of means that mammalian cells are capable of rapidly assembling non-integrated circular plasmids (both replicating and non-replicating) into typical "minichromosomes" containing nucleosomes with a 190 bp repetitive spacing. Treatment of recipient cells with sodium butyrate for a short period of time (12-16 h) immediately following transfection markedly increased the DNase I digestion sensitivity of the newly assembled plasmid chromatin. Furthermore, minichromosomes isolated from such butyrate-treated cells are depleted in histone H1 and contain highly acetylated forms of histone H4. These findings are entirely consistent with our earlier speculation (Gorman et al., Nucleic Acids Res. 11, 1044; 1983) that appropriate butyrate treatment might stimulate transient expression of newly transfected genes by facilitating their assembly into an "active" type of chromatin structure. Images PMID:3859838

Synthesis, Characterization, and Preliminary Investigation of Cell Interaction of Magnetic Nanoparticles with Catechol-Containing Shells

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

Wagner, Kerstin; Seemann, Thomas; Wyrwa, Ralf

2010-12-02

Superparamagnetic iron oxide cores were synthesized by co-precipitation of Fe(II) and Fe(III) salts and subsequently stabilized by coating with different catechols (levodopa, dopamine, hydrocaffeic acid, dopamine-containing carboxymethyl dextran) known to act as high-affinity, bidentate ligands for Fe(III). The prepared stable magnetic fluids were characterized with regard to their chemical composition (content of iron and shell material, Fe(II)/Fe(III) ratio) and their physical properties (size, surface charge, magnetic parameters). The nanoparticles showed no or only slight cytotoxic effects within 1 and 4 days of incubation with 3T3 fibroblast cells. Preliminary experiments were performed to study the interaction of the prepared nanoparticles withmore » human MCF-7 breast cancer cells and leukocytes. An intense interaction of the MCF-7 cells with these particles was found whereas the leukocytes showed a lower tendency of interaction. Based on these finding, the novel magnetic nanoparticles possess the potential for use in depletion of tumor cells from peripheral blood.« less

Influence of Malaria Infection on the Elaboration of Soluble Mediators by Adherent Mononuclear Cells

PubMed Central

Wyler, David J.; Oppenheim, Joost J.; Koontz, Louis C.

1979-01-01

Malaria results in two seemingly paradoxical perturbations of the immune response: polyclonal B-cell activation and immunosuppression. To determine what immunoregulatory role mediators secreted by adherent cells might play in these alterations, we cultured adherent cells from uninfected mice and from mice at different times during infection with Plasmodium berghei or P. yoelii. Culture supernatants obtained from these cells were tested for their ability to enhance the in vitro proliferative responses of thymocytes to suboptimal concentrations of concanavalin A or to inhibit the mitogen-stimulated proliferation of normal spleen cells. Supernatants obtained from adherent cells of mice early in infection (days 1 to 3) contained significantly elevated levels of enhancing activity which on Bio-Gel P-100 chromatography resembled lymphocyte-activating factor. Later in infection (days 4 and 5), these supernatants contained inhibitory activity. Normal adherent cells, when cocultivated in vitro with parasitized erythrocytes, ingested parasite debris and were stimulated to produce the enhancing factor. At high parasite/adherent-cell ratios, cells elaborated an inhibitory factor. These findings suggest that during malaria, adherent cells are converted from a nonspecific helper role to a nonspecific suppressor role. This modulation in function may be due to the direct interaction between adherent cells and parasitized erythrocytes. PMID:457269

Terrestrial evolution of polymerization of amino acids - Heat to ATP

NASA Technical Reports Server (NTRS)

Fox, S. W.; Nakashima, T.

1981-01-01

Sets of amino acids containing sufficient trifunctional monomer are thermally polymerized at temperatures such as 65 deg; the amino acids order themselves. Various polymers have diverse catalytic activities. The polymers aggregate, in aqueous solution, to cell-like structures having those activities plus emergent properties, e.g. proliferatability. Polyamino acids containing sufficient lysine catalyze conversion of free amino acids, by ATP, to small peptides and a high molecular weight fraction. The lysine-rich proteinoid is active in solution, within suspensions of cell-like particles, or in other particles composed of lysine-rich proteinoid and homopolyribonucleotide. Selectivities are observed. An archaic polyamino acid prelude to coded protein synthesis is indicated.

The Nano-Patch-Clamp Array: Microfabricated Glass Chips for High-Throughput Electrophysiology

NASA Astrophysics Data System (ADS)

Fertig, Niels

2003-03-01

Electrophysiology (i.e. patch clamping) remains the gold standard for pharmacological testing of putative ion channel active drugs (ICADs), but suffers from low throughput. A new ion channel screening technology based on microfabricated glass chip devices will be presented. The glass chips contain very fine apertures, which are used for whole-cell voltage clamp recordings as well as single channel recordings from mammalian cell lines. Chips containing multiple patch clamp wells will be used in a first bench-top device, which will allow perfusion and electrical readout of each well. This scalable technology will allow for automated, rapid and parallel screening on ion channel drug targets.

Interlaboratory comparison of Taq Nuclease Assays for the quantification of the toxic cyanobacteria Microcystis sp

PubMed Central

Schober, Eva; Werndl, Michael; Laakso, Kati; Korschineck, Irina; Sivonen, Kaarina; Kurmayer, Rainer

2011-01-01

Summary The application of quantitative real time PCR has been proposed for the quantification of toxic genotypes of cyanobacteria. We have compared the Taq Nuclease Assay (TNA) in quantifying the toxic cyanobacteria Microcystis sp. via the intergenic spacer region of the phycocyanin operon (PC) and mcyB indicative of the production of the toxic heptapeptide microcystin between three research groups employing three instruments (ABI7300, GeneAmp5700, ABI7500). The estimates of mcyB genotypes were compared using (i) DNA of a mcyB containing strain and a non-mcyB containing strain supplied in different mixtures across a low range of variation (0-10% of mcyB) and across a high range of variation (20-100%), and (ii) DNA from field samples containing Microcystis sp. For all three instruments highly significant linear regression curves between the proportion of the mcyB containing strain and the percentage of mcyB genotypes both within the low range and within the high range of mcyB variation were obtained. The regression curves derived from the three instruments differed in slope and within the high range of mcyB variation mcyB proportions were either underestimated (0-50%) or overestimated (0-72%). For field samples cell numbers estimated via both TNAs as well as mcyB proportions showed significant linear relationships between the instruments. For all instruments a linear relationship between the cell numbers estimated as PC genotypes and the cell numbers estimated as mcyB genotypes was observed. The proportions of mcyB varied from 2-28% and did not differ between the instruments. It is concluded that the TNA is able to provide quantitative estimates on mcyB genotype numbers that are reproducible between research groups and is useful to follow variation in mcyB genotype proportion occurring within weeks to months. PMID:17258828

Prednisolone phosphate-containing TRX-20 liposomes inhibit cytokine and chemokine production in human fibroblast-like synovial cells: a novel approach to rheumatoid arthritis therapy.

PubMed

Harigai, Takashi; Hagiwara, Hitomi; Ogawa, Yumi; Ishizuka, Takanobu; Kaneda, Shinichi; Kimura, Junji

2007-01-01

To evaluate the potential of using prednisolone phosphate (PSLP)-containing 3,5-dipentadecyloxybenzamidine hydrochloride (TRX-20) liposomes to treat rheumatoid arthritis (RA), we examined their ability to bind human fibroblast-like synovial (HFLS) cells and their effects in these cells. To test for binding, Lissamine rhodamine B-1, 2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (rhodamine)-labelled PSLP-containing TRX-20 liposomes were added to HFLS cells, and the fluorescence intensity of the rhodamine bound to the cells was evaluated. Rhodamine-labelled PSLP-containing liposomes without TRX-20 were used as a negative control. To evaluate the uptake of liposomes by the HFLS cells, we used TRX-20 liposomes containing 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) and p-xylene-bis-pyridinium bromide (DPX), and observed the cells by fluorescence microscopy. The effects of the PSLP in TRX-20 liposomes on HFLS cells were assessed by the inhibition of the production of two inflammatory cytokines (interleukin 6 and granulocyte macrophage colony-stimulating factor) and one inflammatory chemokine (interleukin 8). The interaction of the PSLP-containing TRX-20 liposomes with HFLS cells was approximately 40 times greater than that of PSLP-containing liposomes without TRX-20. PSLP-containing TRX-20 liposomes bound to HFLS cells primarily via chondroitin sulfate. TRX-20 liposomes taken up by the cell were localized to acidic compartments. Furthermore, the PSLP-containing TRX-20 liposomes inhibited the production of the inflammatory cytokines and the chemokine more effectively than did the PSLP-containing liposomes without TRX-20. These results indicate that PSLP-containing TRX-20 liposomes show promise as a novel drug delivery system that could enhance the clinical use of glucocorticoids for treating RA.

Morphology of the Epidermis of the Neotropical Catfish Pimelodella lateristriga (Lichtenstein, 1823) with Emphasis in Club Cells

PubMed Central

Damasceno, Eduardo Medeiros; Monteiro, Juliana Castro; Duboc, Luiz Fernando; Dolder, Heidi; Mancini, Karina

2012-01-01

The epidermis of Ostariophysi fish is composed of 4 main cell types: epidermal cells (or filament containing cells), mucous cells, granular cells and club cells. The morphological analysis of the epidermis of the catfish Pimelodella lateristriga revealed the presence of only two types of cells: epidermal and club cells. The latter were evident in the middle layer of the epidermis, being the largest cells within the epithelium. Few organelles were located in the perinuclear region, while the rest of the cytoplasm was filled with a non-vesicular fibrillar substance. Club cells contained two irregular nuclei with evident nucleoli and high compacted peripheral chromatin. Histochemical analysis detected prevalence of protein within the cytoplasm other than carbohydrates, which were absent. These characteristics are similar to those described to most Ostariophysi studied so far. On the other hand, the epidermal cells differ from what is found in the literature. The present study described three distinct types, as follows: superficial, abundant and dense cells. Differences among them were restricted to their cytoplasm and nucleus morphology. Mucous cells were found in all Ostariophysi studied so far, although they were absent in P. lateristriga, along with granular cells, also typical of other catfish epidermis. The preset study corroborates the observations on club cells' morphology in Siluriformes specimens, and shows important differences in epidermis composition and cell structure of P. lateristriga regarding the literature data. PMID:23226253

Cell wall composition profiling of parasitic giant dodder (Cuscuta reflexa) and its hosts: a priori differences and induced changes.

PubMed

Johnsen, Hanne R; Striberny, Bernd; Olsen, Stian; Vidal-Melgosa, Silvia; Fangel, Jonatan U; Willats, William G T; Rose, Jocelyn K C; Krause, Kirsten

2015-08-01

Host plant penetration is the gateway to survival for holoparasitic Cuscuta and requires host cell wall degradation. Compositional differences of cell walls may explain why some hosts are amenable to such degradation while others can resist infection. Antibody-based techniques for comprehensive profiling of cell wall epitopes and cell wall-modifying enzymes were applied to several susceptible hosts and a resistant host of Cuscuta reflexa and to the parasite itself. Infected tissue of Pelargonium zonale contained high concentrations of de-esterified homogalacturonans in the cell walls, particularly adjacent to the parasite's haustoria. High pectinolytic activity in haustorial extracts and high expression levels of pectate lyase genes suggest that the parasite contributes directly to wall remodeling. Mannan and xylan concentrations were low in P. zonale and in five susceptible tomato introgression lines, but high in the resistant Solanum lycopersicum cv M82, and in C. reflexa itself. Knowledge of the composition of resistant host cell walls and the parasite's own cell walls is useful in developing strategies to prevent infection by parasitic plants. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Preparation of Labeled Aflatoxins with High Specific Activities

PubMed Central

Hsieh, D. P. H.; Mateles, R. I.

1971-01-01

Resting cells of Aspergillus parasiticus ATCC 15517 were used to prepare highly labeled aflatoxins from labeled acetate. High synthetic activity in growing cells was evidenced only during 40 to 70 hr of incubation. Glucose was required for high incorporation efficiency, whereas the concentration of the labeled acetate determined the specific activity of the product. When labeled acetate was continuously added to maintain a concentration near but not exceeding 10 mm, in a culture containing 30 g of glucose per liter, 2% of its labels could be recovered in the purified aflatoxins which have a specific activity more than three times that of the labeled acetate. PMID:4329435

Mitochondrial transcription factor A serves as a danger signal by augmenting plasmacytoid dendritic cell responses to DNA.

PubMed

Julian, Mark W; Shao, Guohong; Bao, Shengying; Knoell, Daren L; Papenfuss, Tracey L; VanGundy, Zachary C; Crouser, Elliott D

2012-07-01

Plasmacytoid dendritic cells (pDC) are potent APCs known to regulate immune responses to self-Ags, particularly DNA. The mitochondrial fraction of necrotic cells was found to most potently promote human pDC activation, as reflected by type I IFN release, which was dependent upon the presence of mitochondrial DNA and involved TLR9 and receptors for advanced glycation end products. Mitochondrial transcription factor A (TFAM), a highly abundant mitochondrial protein that is functionally and structurally homologous to high mobility group box protein 1, was observed to synergize with CpG-containing oligonucleotide, type A, DNA to promote human pDC activation. pDC type I IFN responses to TFAM and CpG-containing oligonucleotide, type A, DNA indicated their engagement with receptors for advanced glycation end products and TLR9, respectively, and were dependent upon endosomal processing and PI3K, ERK, and NF-κB signaling. Taken together, these results indicate that pDC contribute to sterile immune responses by recognizing the mitochondrial component of necrotic cells and further incriminate TFAM and mitochondrial DNA as likely mediators of pDC activation under these circumstances.

(−)-Xanthatin Selectively Induces GADD45γ and Stimulates Caspase-Independent Cell Death in Human Breast Cancer MDA-MB-231 Cells

PubMed Central

Takeda, Shuso; Matsuo, Kazumasa; Yaji, Kentaro; Okajima-Miyazaki, Shunsuke; Harada, Mari; Miyoshi, Hiroko; Okamoto, Yoshiko; Amamoto, Toshiaki; Shindo, Mitsuru; Omiecinski, Curtis J.; Aramaki, Hironori

2014-01-01

exo-Methylene lactone group-containing compounds, such as (−)-xanthatin, are present in a large variety of biologically active natural products, including extracts of Xanthium strumarium (Cocklebur). These substances are reported to possess diverse functional activities, exhibiting anti-inflammatory, antimalarial, and anticancer potential. In this study, we synthesized six structurally related xanthanolides containing exo-methylene lactone moieties, including (−)-xanthatin and (+)-8-epi-xanthatin, and examined the effects of these chemically defined substances on the highly aggressive and farnesyltransferase inhibitor (FTI)-resistant MDA-MB-231 cancer cell line. The results obtained demonstrate that (−)-xanthatin was a highly effective inhibitor of MDA-MB-231 cell growth, inducing caspase-independent cell death, and that these effects were independent of FTase inhibition. Further, our results show that among the GADD45 isoforms, GADD45γ was selectively induced by (−)-xanthatin and that GADD45γ-primed JNK and p38 signaling pathways are, at least in part, involved in mediating the growth inhibition and potential anticancer activities of this agent. Given that GADD45γ is becoming increasingly recognized for its tumor suppressor function, the results presented here suggest the novel possibility that (−)-xanthatin may have therapeutic value as a selective inducer of GADD45γ in human cancer cells, in particular in FTI-resistant aggressive breast cancers. PMID:21568272

Comprehensive Identification of Meningococcal Genes and Small Noncoding RNAs Required for Host Cell Colonization

PubMed Central

Capel, Elena; Zomer, Aldert L.; Nussbaumer, Thomas; Bole, Christine; Izac, Brigitte; Frapy, Eric; Meyer, Julie; Bouzinba-Ségard, Haniaa; Bille, Emmanuelle; Jamet, Anne; Cavau, Anne; Letourneur, Franck; Bourdoulous, Sandrine; Rattei, Thomas; Coureuil, Mathieu

2016-01-01

ABSTRACT Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia, affecting infants and adults worldwide. N. meningitidis is also a common inhabitant of the human nasopharynx and, as such, is highly adapted to its niche. During bacteremia, N. meningitidis gains access to the blood compartment, where it adheres to endothelial cells of blood vessels and causes dramatic vascular damage. Colonization of the nasopharyngeal niche and communication with the different human cell types is a major issue of the N. meningitidis life cycle that is poorly understood. Here, highly saturated random transposon insertion libraries of N. meningitidis were engineered, and the fitness of mutations during routine growth and that of colonization of endothelial and epithelial cells in a flow device were assessed in a transposon insertion site sequencing (Tn-seq) analysis. This allowed the identification of genes essential for bacterial growth and genes specifically required for host cell colonization. In addition, after having identified the small noncoding RNAs (sRNAs) located in intergenic regions, the phenotypes associated with mutations in those sRNAs were defined. A total of 383 genes and 8 intergenic regions containing sRNA candidates were identified to be essential for growth, while 288 genes and 33 intergenic regions containing sRNA candidates were found to be specifically required for host cell colonization. PMID:27486197

Investigation of gold nanoparticle radiosensitization mechanisms using a free radical scavenger and protons of different energies.

PubMed

Jeynes, J C G; Merchant, M J; Spindler, A; Wera, A-C; Kirkby, K J

2014-11-07

Gold nanoparticles (GNPs) have been shown to sensitize cancer cells to x-ray radiation, particularly at kV energies where photoelectric interactions dominate and the high atomic number of gold makes a large difference to x-ray absorption. Protons have a high cross-section for gold at a large range of relevant clinical energies, and so potentially could be used with GNPs for increased therapeutic effect.Here, we investigate the contribution of secondary electron emission to cancer cell radiosensitization and investigate how this parameter is affected by proton energy and a free radical scavenger. We simulate the emission from a realistic cell phantom containing GNPs after traversal by protons and x-rays with different energies. We find that with a range of proton energies (1-250 MeV) there is a small increase in secondaries compared to a much larger increase with x-rays. Secondary electrons are known to produce toxic free radicals. Using a cancer cell line in vitro we find that a free radical scavenger has no protective effect on cells containing GNPs irradiated with 3 MeV protons, while it does protect against cells irradiated with x-rays. We conclude that GNP generated free radicals are a major cause of radiosensitization and that there is likely to be much less dose enhancement effect with clinical proton beams compared to x-rays.

High voltage solar cell power generating system

NASA Technical Reports Server (NTRS)

Levy, E., Jr.; Opjorden, R. W.; Hoffman, A. C.

1974-01-01

A laboratory solar power system regulated by on-panel switches has been delivered for operating high power (3 kW), high voltage (15,000 volt) loads (communication tubes, ion thrusters). The modular system consists of 26 solar arrays, each with an integral light source and cooling system. A typical array contains 2,560 series-connected cells. Each light source consists of twenty 500-watt tungsten iodide lamps providing plus or minus 5 percent uniformity at one solar constant. An array temperature of less than 40 C is achieved using an infrared filter, a water-cooled plate, a vacuum hold-down system, and air flushing.

Diffusion length measurement using the scanning electron microscope. [for silicon solar cell

NASA Technical Reports Server (NTRS)

Weizer, V. G.

1975-01-01

The present work describes a measuring technique employing the scanning electron microscope in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through application of highly doped surface field layers. The effects of high injection level and low-high junction current generation are investigated. Results obtained with this technique are compared to those obtained by a penetrating radiation (X-ray) method, and a close agreement is found. The SEM technique is limited to cells that contain a back surface field layer.

Synthesis and Characterization of Polymers for Fuel Cells Application

NASA Technical Reports Server (NTRS)

Tytko, Stephen F.

2003-01-01

The goal of this summer research is to prepare Polymer Exchange Membranes (PEM s) for fuel cell application. Several high temperature polymers such as polybenzimidazoles and polyether ketones were known to possess good high temperature stability and had been investigated by post-sulfonation to yield sulfonated polymers. The research project will involve two approaches: 1. Synthesis of polybenzimidazoles and then react with alkyl sultonse to attach an aliphatic sulfonic groups. 2. Synthesis of monomers containing sulfonic acid units either on a aromatic ring or on an aliphatic chain and then polymerize the monomers to form high molecular weight sulfonate polymers.

Macrophage and T cell dynamics during the development and disintegration of mycobacterial granulomas.

PubMed

Egen, Jackson G; Rothfuchs, Antonio Gigliotti; Feng, Carl G; Winter, Nathalie; Sher, Alan; Germain, Ronald N

2008-02-01

Granulomas play a key role in host protection against mycobacterial pathogens, with their breakdown contributing to exacerbated disease. To better understand the initiation and maintenance of these structures, we employed both high-resolution multiplex static imaging and intravital multiphoton microscopy of Mycobacterium bovis BCG-induced liver granulomas. We found that Kupffer cells directly capture blood-borne bacteria and subsequently nucleate formation of a nascent granuloma by recruiting both uninfected liver-resident macrophages and blood-derived monocytes. Within the mature granuloma, these myeloid cell populations formed a relatively immobile cellular matrix that interacted with a highly dynamic effector T cell population. The efficient recruitment of these T cells was highly dependent on TNF-alpha-derived signals, which also maintained the granuloma structure through preferential effects on uninfected macrophage populations. By characterizing the migration of both innate and adaptive immune cells throughout the process of granuloma development, these studies provide a new perspective on the cellular events involved in mycobacterial containment and escape.

Overexpression of TRIM44 is related to invasive potential and malignant outcomes in esophageal squamous cell carcinoma.

PubMed

Kawaguchi, Tsutomu; Komatsu, Shuhei; Ichikawa, Daisuke; Hirajima, Shoji; Nishimura, Yukihisa; Konishi, Hirotaka; Shiozaki, Atsushi; Fujiwara, Hitoshi; Okamoto, Kazuma; Tsuda, Hitoshi; Otsuji, Eigo

2017-06-01

Recent studies have shown that some members of the tripartite motif-containing protein family function as important regulators for carcinogenesis. In this study, we investigated whether tripartite motif-containing protein 44 acts as a cancer-promoting gene through its overexpression in esophageal squamous cell carcinoma. We analyzed esophageal squamous cell carcinoma cell lines to evaluate malignant potential and also analyzed 68 primary tumors to evaluate clinical relevance of tripartite motif-containing protein 44 protein in esophageal squamous cell carcinoma patients. Expression of the tripartite motif-containing protein 44 protein was detected in esophageal squamous cell carcinoma cell lines (8/14 cell lines; 57%) and primary tumor samples of esophageal squamous cell carcinoma (39/68 cases; 57%). Knockdown of tripartite motif-containing protein 44 expression in esophageal squamous cell carcinoma cells using several specific small interfering RNAs inhibited cell migration and invasion, but not cell proliferation. Immunohistochemical analysis demonstrated that the overexpression of the tripartite motif-containing protein 44 protein in the tumor infiltrated region was associated with the status of lymph node metastasis ( p = 0.049), and the overall survival rates were significantly worse among patients with tripartite motif-containing protein 44-overexpressing tumors than those with non-expressing tumors ( p = 0.029). Moreover, multivariate Cox regression model identified that overexpression of the tripartite motif-containing protein 44 protein was an independent worse prognostic factor (hazard ratio = 2.815; p = 0.041), as well as lymphatic invasion (hazard ratio = 2.735; p = 0.037). These results suggest that tripartite motif-containing protein 44 protein could play a crucial role in tumor invasion through its overexpression and highlight its usefulness as a predictor and potential therapeutic target in esophageal squamous cell carcinoma.

Co-Cultivation of Fungal and Microalgal Cells as an Efficient System for Harvesting Microalgal Cells, Lipid Production and Wastewater Treatment

PubMed Central

Wrede, Digby; Taha, Mohamed; Miranda, Ana F.; Kadali, Krishna; Stevenson, Trevor; Ball, Andrew S.; Mouradov, Aidyn

2014-01-01

The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm), large (over 300 µm), heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification. PMID:25419574

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

Daud, A.I.; Bumpus, F.M.; Husain, A.

Ovarian angiotensin I (Ang I)-converting enzyme (ACE), estimated by the specific binding of the ACE inhibitor (125I)iodo-MK-351A, is localized on multiple ovarian structures, including follicular granulosa cells, corpora lutea, terminal epithelium, and ovarian blood vessels, but total ovarian ACE does not display a cyclic pattern of variation during the rat estrous cycle. We have previously shown that ACE is localized on the granulosa cell layer of a subpopulation of rat ovarian follicles. Our present study shows that ovarian granulosa cells contain high affinity (binding site affinity (Kd), approximately 90 pM) and low capacity (binding site density (Bmax), approximately 12 fmol/2.5more » X 10(5) cells) (125I)iodo-MK-351A-binding sites and convert (125I)iodo-Ang I to (125I)iodo-Ang II (greater than 85% of this conversion was inhibited by the ACE inhibitor captopril). Throughout the rat estrous cycle, 94-100% of developing follicles and 89-96% of atretic follicles contained high levels of ACE; however, ACE was either not observed or its levels were very low in preovulatory follicles. These findings indicate the presence of high levels of biologically active ACE on the surface of granulosa cells and suggest a potential role for follicular ACE in early stages of follicular maturation and atresia. Although ACE is known to process a variety of peptides found within the ovary, and these peptides may have opposing effects on follicular maturation, we attempted to define the cumulative effect of ACE inhibition on follicular maturation.« less

Co-cultivation of fungal and microalgal cells as an efficient system for harvesting microalgal cells, lipid production and wastewater treatment.

PubMed

Wrede, Digby; Taha, Mohamed; Miranda, Ana F; Kadali, Krishna; Stevenson, Trevor; Ball, Andrew S; Mouradov, Aidyn

2014-01-01

The challenges which the large scale microalgal industry is facing are associated with the high cost of key operations such as harvesting, nutrient supply and oil extraction. The high-energy input for harvesting makes current commercial microalgal biodiesel production economically unfeasible and can account for up to 50% of the total cost of biofuel production. Co-cultivation of fungal and microalgal cells is getting increasing attention because of high efficiency of bio-flocculation of microalgal cells with no requirement for added chemicals and low energy inputs. Moreover, some fungal and microalgal strains are well known for their exceptional ability to purify wastewater, generating biomass that represents a renewable and sustainable feedstock for biofuel production. We have screened the flocculation efficiency of the filamentous fungus A. fumigatus against 11 microalgae representing freshwater, marine, small (5 µm), large (over 300 µm), heterotrophic, photoautotrophic, motile and non-motile strains. Some of the strains are commercially used for biofuel production. Lipid production and composition were analysed in fungal-algal pellets grown on media containing alternative carbon, nitrogen and phosphorus sources contained in wheat straw and swine wastewater, respectively. Co-cultivation of algae and A. fumigatus cells showed additive and synergistic effects on biomass production, lipid yield and wastewater bioremediation efficiency. Analysis of fungal-algal pellet's fatty acids composition suggested that it can be tailored and optimised through co-cultivating different algae and fungi without the need for genetic modification.

Ultra-high throughput detection of single cell β-galactosidase activity in droplets using micro-optical lens array

NASA Astrophysics Data System (ADS)

Lim, Jiseok; Vrignon, Jérémy; Gruner, Philipp; Karamitros, Christos S.; Konrad, Manfred; Baret, Jean-Christophe

2013-11-01

We demonstrate the use of a hybrid microfluidic-micro-optical system for the screening of enzymatic activity at the single cell level. Escherichia coli β-galactosidase activity is revealed by a fluorogenic assay in 100 pl droplets. Individual droplets containing cells are screened by measuring their fluorescence signal using a high-speed camera. The measurement is parallelized over 100 channels equipped with microlenses and analyzed by image processing. A reinjection rate of 1 ml of emulsion per minute was reached corresponding to more than 105 droplets per second, an analytical throughput larger than those obtained using flow cytometry.

Transparent Conductive Nanofiber Paper for Foldable Solar Cells

PubMed Central

Nogi, Masaya; Karakawa, Makoto; Komoda, Natsuki; Yagyu, Hitomi; Nge, Thi Thi

2015-01-01

Optically transparent nanofiber paper containing silver nanowires showed high electrical conductivity and maintained the high transparency, and low weight of the original transparent nanofiber paper. We demonstrated some procedures of optically transparent and electrically conductive cellulose nanofiber paper for lightweight and portable electronic devices. The nanofiber paper enhanced high conductivity without any post treatments such as heating or mechanical pressing, when cellulose nanofiber dispersions were dropped on a silver nanowire thin layer. The transparent conductive nanofiber paper showed high electrical durability in repeated folding tests, due to dual advantages of the hydrophilic affinity between cellulose and silver nanowires, and the entanglement between cellulose nanofibers and silver nanowires. Their optical transparency and electrical conductivity were as high as those of ITO glass. Therefore, using this conductive transparent paper, organic solar cells were produced that achieved a power conversion of 3.2%, which was as high as that of ITO-based solar cells. PMID:26607742

Characterization of SIS1, a Saccharomyces cerevisiae homologue of bacterial dnaJ proteins

PubMed Central

1991-01-01

The Saccharomyces cerevisiae SIS1 gene was identified as a high copy number suppressor of the slow growth phenotype of strains containing mutations in the SIT4 gene, which encodes a predicted serine/threonine protein phosphatase. The SIS1 protein is similar to bacterial dnaJ proteins in the amino-terminal third and carboxyl-terminal third of the proteins. In contrast, the middle third of SIS1 is not similar to dnaJ proteins. This region of SIS1 contains a glycine/methionine-rich region which, along with more amino-terminal sequences, is required for SIS1 to associate with a protein of apparent molecular mass of 40 kD. The SIS1 gene is essential. Strains limited for the SIS1 protein accumulate cells that appear blocked for migration of the nucleus from the mother cell into the daughter cell. In addition, many of the cells become very large and contain a large vacuole. The SIS1 protein is localized throughout the cell but is more concentrated at the nucleus. About one- fourth of the SIS1 protein is released from a nuclear fraction upon treatment with RNase. We also show that overexpression of YDJ1, another yeast protein with similarity to bacterial dnaJ proteins, can not substitute for SIS1. PMID:1714460

Localization of beta-D-glucosidase activity and glucovanillin in vanilla bean (Vanilla planifolia Andrews).

PubMed

Odoux, E; Escoute, J; Verdeil, J-L; Brillouet, J-M

2003-09-01

The morphology, anatomy and histology of mature green vanilla beans were examined by light and transmission electron microscopy. Beans have a triangular cross-section with a central cavity containing seeds. Each angle is lined with tubular cells, or papillae, while the cavity sides consist of placental laminae. The epicarp and endocarp are formed by one or two layers of very small cells, while the mesocarp contains large, highly vacuolarized cells, the cytoplasm being restricted to a thin layer along the cell walls. The radial distributions of glucovanillin and beta-glucosidase activity, measured on p-nitrophenyl-beta-glucopyranoside and glucovanillin, are superimposable and show how beta-glucosidase activity increases from the epicarp towards the placental zone, whereas glucovanillin is exclusively located in the placentae and papillae. Subcellular localization of beta-glucosidase activity was achieved by incubating sections of vanilla beans in a buffer containing 5-bromo-4-chloro-3-indolyl-beta-d-glucopyranoside as a substrate. Activity was observed in the cytoplasm (and/or the periplasm) of mesocarp and endocarp cells, with a more diffuse pattern observed in the papillae. A possible mechanism for the hydrolysis of glucovanillin and release of the aromatic aglycon vanillin involves the decompartmentation of cytoplasmic (and/or periplasmic) beta-glucosidase and vacuolar glucovanillin.

Localization of β-d-Glucosidase Activity and Glucovanillin in Vanilla Bean (Vanilla planifolia Andrews)

PubMed Central

ODOUX, E.; ESCOUTE, J.; VERDEIL, J. -L.; BRILLOUET, J. -M.

2003-01-01

The morphology, anatomy and histology of mature green vanilla beans were examined by light and transmission electron microscopy. Beans have a triangular cross-section with a central cavity containing seeds. Each angle is lined with tubular cells, or papillae, while the cavity sides consist of placental laminae. The epicarp and endocarp are formed by one or two layers of very small cells, while the mesocarp contains large, highly vacuolarized cells, the cytoplasm being restricted to a thin layer along the cell walls. The radial distributions of glucovanillin and β-glucosidase activity, measured on p-nitrophenyl-β-glucopyranoside and glucovanillin, are superimposable and show how β-glucosidase activity increases from the epicarp towards the placental zone, whereas glucovanillin is exclusively located in the placentae and papillae. Subcellular localization of β-glucosidase activity was achieved by incubating sections of vanilla beans in a buffer containing 5-bromo-4-chloro-3-indolyl-β-d-glucopyranoside as a substrate. Activity was observed in the cytoplasm (and/or the periplasm) of mesocarp and endocarp cells, with a more diffuse pattern observed in the papillae. A possible mechanism for the hydrolysis of glucovanillin and release of the aromatic aglycon vanillin involves the decompartmentation of cytoplasmic (and/or periplasmic) β-glucosidase and vacuolar glucovanillin. PMID:12871846

Grape seed procyanidin extract modulates proliferation and apoptosis of pancreatic beta-cells.

PubMed

Cedó, Lídia; Castell-Auví, Anna; Pallarès, Victor; Blay, Mayte; Ardévol, Anna; Arola, Lluís; Pinent, Montserrat

2013-05-01

Grape seed procyanidin extract (GSPE) modulates glucose homeostasis and insulinemia in several animal models. Under pathological conditions, insulin levels are dependent on pancreatic beta-cell functionality, as well as on the beta-cell mass expansion or apoptosis in the pancreas. In this study, we analysed the effects of GSPE on modulating apoptosis and proliferation in beta-cells. We tested the effects of GSPE in the INS-1E pancreatic beta-cell line, either under basal or altered conditions with high glucose, insulin or palmitate levels. GSPE enhanced the pro-apoptotic effect of high glucose and showed clear antiproliferative effects under high glucose, insulin and palmitate conditions. These antiproliferative effects are likely due to high molecular weight compounds contained in the extract. GSPE also modulated pro- and anti-apoptotic markers in the pancreas of rats fed a cafeteria diet, with the effect depending on the dose of GSPE and duration of treatment. Thus, GSPE is able to modulate apoptosis and proliferation of beta-cells under altered, but not basal, conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Radiation-induced chromosome aberrations in ataxia telangiectasia cells: high frequency of deletions and misrejoining detected by fluorescence in situ hybridization

NASA Technical Reports Server (NTRS)

Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Uno, Takashi; Isobe, Kouichi; Cucinotta, Francis A.

2003-01-01

The mechanisms underlying the hyper-radiosensitivity of AT cells were investigated by analyzing chromosome aberrations in the G(2) and M phases of the cell cycle using a combination of chemically induced premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) with chromosome painting probes. Confluent cultures of normal fibroblast cells (AG1522) and fibroblast cells derived from an individual with AT (GM02052) were exposed to gamma rays and allowed to repair at 37 degrees C for 24 h. At doses that resulted in 10% survival, GM02052 cells were approximately five times more sensitive to gamma rays than AG1522 cells. For a given dose, GM02052 cells contained a much higher frequency of deletions and misrejoining than AG1522 cells. For both cell types, a good correlation was found between the percentage of aberrant cells and cell survival. The average number of color junctions, which represent the frequency of chromosome misrejoining, was also found to correlate well with survival. However, in a similar surviving population of GM02052 and AG1522 cells, induced by 1 Gy and 6 Gy, respectively, AG1522 cells contained four times more color junctions and half as many deletions as GM02052 cells. These results indicate that both repair deficiency and misrepair may be involved in the hyper-radiosensitivity of AT cells.

Radiation-induced chromosome aberrations in ataxia telangiectasia cells: high frequency of deletions and misrejoining detected by fluorescence in situ hybridization.

PubMed

Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Uno, Takashi; Isobe, Kouichi; Cucinotta, Francis A

2003-05-01

The mechanisms underlying the hyper-radiosensitivity of AT cells were investigated by analyzing chromosome aberrations in the G(2) and M phases of the cell cycle using a combination of chemically induced premature chromosome condensation (PCC) and fluorescence in situ hybridization (FISH) with chromosome painting probes. Confluent cultures of normal fibroblast cells (AG1522) and fibroblast cells derived from an individual with AT (GM02052) were exposed to gamma rays and allowed to repair at 37 degrees C for 24 h. At doses that resulted in 10% survival, GM02052 cells were approximately five times more sensitive to gamma rays than AG1522 cells. For a given dose, GM02052 cells contained a much higher frequency of deletions and misrejoining than AG1522 cells. For both cell types, a good correlation was found between the percentage of aberrant cells and cell survival. The average number of color junctions, which represent the frequency of chromosome misrejoining, was also found to correlate well with survival. However, in a similar surviving population of GM02052 and AG1522 cells, induced by 1 Gy and 6 Gy, respectively, AG1522 cells contained four times more color junctions and half as many deletions as GM02052 cells. These results indicate that both repair deficiency and misrepair may be involved in the hyper-radiosensitivity of AT cells.

High-performance single cell genetic analysis using microfluidic emulsion generator arrays.

PubMed

Zeng, Yong; Novak, Richard; Shuga, Joe; Smith, Martyn T; Mathies, Richard A

2010-04-15

High-throughput genetic and phenotypic analysis at the single cell level is critical to advance our understanding of the molecular mechanisms underlying cellular function and dysfunction. Here we describe a high-performance single cell genetic analysis (SCGA) technique that combines high-throughput microfluidic emulsion generation with single cell multiplex polymerase chain reaction (PCR). Microfabricated emulsion generator array (MEGA) devices containing 4, 32, and 96 channels are developed to confer a flexible capability of generating up to 3.4 x 10(6) nanoliter-volume droplets per hour. Hybrid glass-polydimethylsiloxane diaphragm micropumps integrated into the MEGA chips afford uniform droplet formation, controlled generation frequency, and effective transportation and encapsulation of primer functionalized microbeads and cells. A multiplex single cell PCR method is developed to detect and quantify both wild type and mutant/pathogenic cells. In this method, microbeads functionalized with multiple forward primers targeting specific genes from different cell types are used for solid-phase PCR in droplets. Following PCR, the droplets are lysed and the beads are pooled and rapidly analyzed by multicolor flow cytometry. Using Escherichia coli bacterial cells as a model, we show that this technique enables digital detection of pathogenic E. coli O157 cells in a high background of normal K12 cells, with a detection limit on the order of 1/10(5). This result demonstrates that multiplex SCGA is a promising tool for high-throughput quantitative digital analysis of genetic variation in complex populations.

High-Performance Single Cell Genetic Analysis Using Microfluidic Emulsion Generator Arrays

PubMed Central

Zeng, Yong; Novak, Richard; Shuga, Joe; Smith, Martyn T.; Mathies, Richard A.

2010-01-01

High-throughput genetic and phenotypic analysis at the single cell level is critical to advance our understanding of the molecular mechanisms underlying cellular function and dysfunction. Here we describe a high-performance single cell genetic analysis (SCGA) technique that combines high-throughput microfluidic emulsion generation with single cell multiplex PCR. Microfabricated emulsion generator array (MEGA) devices containing 4, 32 and 96 channels are developed to confer a flexible capability of generating up to 3.4 × 106 nanoliter-volume droplets per hour. Hybrid glass-polydimethylsiloxane diaphragm micropumps integrated into the MEGA chips afford uniform droplet formation, controlled generation frequency, and effective transportation and encapsulation of primer functionalized microbeads and cells. A multiplex single cell PCR method is developed to detect and quantify both wild type and mutant/pathogenic cells. In this method, microbeads functionalized with multiple forward primers targeting specific genes from different cell types are used for solid-phase PCR in droplets. Following PCR, the droplets are lysed, the beads are pooled and rapidly analyzed by multi-color flow cytometry. Using E. coli bacterial cells as a model, we show that this technique enables digital detection of pathogenic E. coli O157 cells in a high background of normal K12 cells, with a detection limit on the order of 1:105. This result demonstrates that multiplex SCGA is a promising tool for high-throughput quantitative digital analysis of genetic variation in complex populations. PMID:20192178

Highly narrow nanogap-containing Au@Au core-shell SERS nanoparticles: size-dependent Raman enhancement and applications in cancer cell imaging

NASA Astrophysics Data System (ADS)

Hu, Chongya; Shen, Jianlei; Yan, Juan; Zhong, Jian; Qin, Weiwei; Liu, Rui; Aldalbahi, Ali; Zuo, Xiaolei; Song, Shiping; Fan, Chunhai; He, Dannong

2016-01-01

Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (~15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (~1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (~76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection.Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (~15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (~1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (~76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06919j

Cryopreservation of Brain Endothelial Cells Derived from Human Induced Pluripotent Stem Cells Is Enhanced by Rho-Associated Coiled Coil-Containing Kinase Inhibition.

PubMed

Wilson, Hannah K; Faubion, Madeline G; Hjortness, Michael K; Palecek, Sean P; Shusta, Eric V

2016-12-01

The blood-brain barrier (BBB) maintains brain homeostasis but also presents a major obstacle to brain drug delivery. Brain microvascular endothelial cells (BMECs) form the principal barrier and therefore represent the major cellular component of in vitro BBB models. Such models are often used for mechanistic studies of the BBB in health and disease and for drug screening. Recently, human induced pluripotent stem cells (iPSCs) have emerged as a new source for generating BMEC-like cells for use in in vitro human BBB studies. However, the inability to cryopreserve iPSC-BMECs has impeded implementation of this model by requiring a fresh differentiation to generate cells for each experiment. Cryopreservation of differentiated iPSC-BMECs would have a number of distinct advantages, including enabling production of larger scale lots, decreasing lead time to generate purified iPSC-BMEC cultures, and facilitating use of iPSC-BMECs in large-scale screening. In this study, we demonstrate that iPSC-BMECs can be successfully cryopreserved at multiple differentiation stages. Cryopreserved iPSC-BMECs retain high viability, express standard endothelial and BBB markers, and reach a high transendothelial electrical resistance (TEER) of ∼3000 Ω·cm 2 , equivalent to nonfrozen controls. Rho-associated coiled coil-containing kinase (ROCK) inhibitor Y-27632 substantially increased survival and attachment of cryopreserved iPSC-BMECs, as well as stabilized TEER above 800 Ω·cm 2 out to 7 days post-thaw. Overall, cryopreservation will ease handling and storage of high-quality iPSC-BMECs, reducing a key barrier to greater implementation of these cells in modeling the human BBB.

High Efficiency Transformation of Cultured Tobacco Cells 1

PubMed Central

An, Gynheung

1985-01-01

Tobacco calli were transformed at levels up to 50% by cocultivation of tobacco cultured cells with Agrobacterium tumefaciens harboring the binary transfer-DNA vector, pGA472, containing a kanamycin resistance marker. Transformation frequency was dependent on the physiological state of the tobacco cells, the nature of Agrobacterium strain and, less so, on the expression of the vir genes of the tumor-inducing plasmid. Maximum transformation frequency was obtained with exponentially growing plant cells, suggesting that rapid growth of plant cells is an essental factor for efficient transformation of higher plants. Images Fig. 1 PMID:16664453

High-velocity DC-VPS for diffusion and protecting barrier layers in solid oxide fuel cells (SOFCs)

NASA Astrophysics Data System (ADS)

Henne, R. H.; Franco, T.; Ruckdäschel, R.

2006-12-01

High-temperature fuel cells of the solid oxide fuel cell (SOFC) type as direct converter of chemical into electrical energy show a high potential for reducing considerably the specific energy consumption in different application fields. Of particular interest are advanced lightweight planar cells for electricity supply units in cars and other mobile systems. Such cells, in one new design, consist mainly of metallic parts, for example, of ferrite steels. These cells shall operate in the temperature range of 700 to 800 °C where oxidation and diffusion processes can be of detrimental effect on cell performance for long-term operation. Problems arise in particular by diffusion of chromium species from the interconnect or the cell containment into the electrolyte/cathode interface forming insulating phases and by the mutual diffusion of substrate and anode material, for example, iron and chromium from the ferrite into the anode and nickel from the anode into the ferrite, which in both cases reduces performance and system lifetime. Additional intermediate layers of perovskite-type material, (e.g., doped LaCrO3) applied with high-velocity direct-current vacuum plasma spraying (DC-VPS) can reduce such effects considerably if they are stable and of high electronic conductivity.

Multiple roles for the actin cytoskeleton during regulated exocytosis

PubMed Central

Porat-Shliom, Natalie; Milberg, Oleg; Masedunskas, Andrius; Weigert, Roberto

2014-01-01

Regulated exocytosis is the main mechanism utilized by specialized secretory cells to deliver molecules to the cell surface by virtue of membranous containers (i.e. secretory vesicles). The process involves a series of highly coordinated and sequential steps, which include the biogenesis of the vesicles, their delivery to the cell periphery, their fusion with the plasma membrane and the release of their content into the extracellular space. Each of these steps is regulated by the actin cytoskeleton. In this review, we summarize the current knowledge regarding the involvement of actin and its associated molecules during each of the exocytic steps in vertebrates, and suggest that the overall role of the actin cytoskeleton during regulated exocytosis is linked to the architecture and the physiology of the secretory cells under examination. Specifically, in neurons, neuroendocrine, endocrine, and hematopoietic cells, which contain small secretory vesicles that undergo rapid exocytosis (on the order of milliseconds), the actin cytoskeleton plays a role in pre-fusion events, where it acts primarily as a functional barrier and facilitates docking. In exocrine and other secretory cells, which contain large secretory vesicles that undergo slow exocytosis (seconds to minutes), the actin cytoskeleton plays a role in post-fusion events, where it regulates the dynamics of the fusion pore, facilitates the integration of the vesicles into the plasma membrane, provides structural support, and promotes the expulsion of large cargo molecules. PMID:22986507

Effect of icodextrin peritoneal dialysis solution on cell proliferation in vitro.

PubMed

Cooker, L A; Choo, C G; Luneburg, P; Lamela, J; Holmes, C J

1999-01-01

Peritoneal dialysis solutions containing icodextrin are ideal for providing sustained ultrafiltration during long dwells, and they have replaced high glucose for long dwells in some patients. The biocompatibility of these solutions, especially in regard to glucose degradation products, has not been studied in depth. The object of this study was to compare the effects of commercially available dextrose-containing dialysis solutions to those of icodextrin-containing solutions on fibroblast proliferation in vitro. We measured the effect of solutions on cell growth by exposing murine fibroblasts to pH-adjusted test solutions mixed with culture medium, and by comparing cell growth to growth in culture medium only. No statistical difference was observed in the growth of cells exposed to heat-sterilized Extraneal [7.5% icodextrin (Baxter Healthcare, Deerfield, Illinois, U.S.A.)], heat-sterilized Dianeal [1.5% dextrose (Baxter Healthcare)], or filter-sterilized Dianeal [4.25% dextrose (Baxter Healthcare]. Also, no difference was observed in the growth of fibroblasts exposed to heat-sterilized Extraneal or to filter-sterilized Extraneal, but heat-sterilized Dianeal [4.25% dextrose (Baxter Healthcare)] caused a significant reduction in cell growth. Glucose degradation products (GDPs) are known to contribute to reduced cell growth in vitro. Extraneal had lower levels of the GDP acetaldehyde compared to Dianeal (2.5% or 4.25% dextrose). The results demonstrate enhanced in vitro biocompatibility characteristics for Extraneal, possibly related to low GDP levels in Extraneal.

Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

DOEpatents

Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

2008-02-05

The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.

Epigenetic Alterations Associated With CCCTC-Binding Factor Deregulation in Prostate Cancer

DTIC Science & Technology

2011-07-01

HPV16 E6 and/or E7 prostate cell lines. We have established stable cell lines containing inducible CTCF shRNA in pTRIPZ vector in PPC-1, LNCaPs, 293T...and non-tumorigenic HPV16 E6 and/or E7 prostate cell lines. We are in process of conducting CTCF knockdown experiments using transient transfection...which express high levels of endogenous CTCF and in non- tumorigenic HPV16 E6 and/or E7 prostate cell lines. We see efficient knockdown of CTCF

Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells

PubMed Central

Liu, Yuhang; Zhao, Jingbo; Li, Zhengke; Mu, Cheng; Hu, Huawei; Jiang, Kui; Lin, Haoran; Ade, Harald; Yan, He

2014-01-01

Although the field of polymer solar cell has seen much progress in device performance in the past few years, several limitations are holding back its further development. For instance, current high-efficiency (>9.0%) cells are restricted to material combinations that are based on limited donor polymers and only one specific fullerene acceptor. Here we report the achievement of high-performance (efficiencies up to 10.8%, fill factors up to 77%) thick-film polymer solar cells for multiple polymer:fullerene combinations via the formation of a near-ideal polymer:fullerene morphology that contains highly crystalline yet reasonably small polymer domains. This morphology is controlled by the temperature-dependent aggregation behaviour of the donor polymers and is insensitive to the choice of fullerenes. The uncovered aggregation and design rules yield three high-efficiency (>10%) donor polymers and will allow further synthetic advances and matching of both the polymer and fullerene materials, potentially leading to significantly improved performance and increased design flexibility. PMID:25382026

In vitro ability of beer fermentation residue and yeast-based products to bind aflatoxin B1.

PubMed

Bovo, Fernanda; Franco, Larissa Tuanny; Rosim, Roice Eliana; Barbalho, Ricardo; de Oliveira, Carlos Augusto Fernandes

2015-06-01

This study aimed to verify the in vitro ability of beer fermentation residue (BFR) containing Saccharomyces cerevisiae cells and five commercial products that differed in the viability and integrity of S. cerevisiae cells to remove aflatoxin B1 (AFB1) from a citrate-phosphate buffer solution (CPBS). BFR was collected at a microbrewery and prepared by drying and milling. The commercial yeast-based products were as follows: inactive intact yeast cells from beer alcoholic fermentation, inactive intact yeast cells from sugarcane alcoholic fermentation, hydrolyzed yeast cells, yeast cell walls and active yeast cells. Adsorption assays were performed in CPBS spiked with 1.0 μg AFB1/mL at pH 3.0 and 6.0 for a contact time of 60 min at room temperature. Analysis of AFB1 in the samples was performed by high performance liquid chromatography. AFB1 adsorption by the products ranged from 45.5% to 69.4% at pH 3.0 and from 24.0% to 63.8% at pH 6.0. The higher percentages (p < 0.05) of AFB1 binding at both pH values were achieved with products containing hydrolyzed yeast cells or yeast cell walls rather than intact cells. The AFB1 binding percentages of BFR were 55.0 ± 5.0% at pH 3.0 and 49.2 ± 4.5% at pH 6.0, which was not significantly different (p > 0.05) from commercial products containing inactive intact yeast cells. The results of this trial indicate that the yeast-based products tested, especially the BFR, have potential applications in animal feeds as a suitable biological method for reducing the adverse effects of aflatoxins.

In vitro ability of beer fermentation residue and yeast-based products to bind aflatoxin B1

PubMed Central

Bovo, Fernanda; Franco, Larissa Tuanny; Rosim, Roice Eliana; Barbalho, Ricardo; de Oliveira, Carlos Augusto Fernandes

2015-01-01

This study aimed to verify the in vitro ability of beer fermentation residue (BFR) containing Saccharomyces cerevisiae cells and five commercial products that differed in the viability and integrity of S. cerevisiae cells to remove aflatoxin B1 (AFB1) from a citrate-phosphate buffer solution (CPBS). BFR was collected at a microbrewery and prepared by drying and milling. The commercial yeast-based products were as follows: inactive intact yeast cells from beer alcoholic fermentation, inactive intact yeast cells from sugarcane alcoholic fermentation, hydrolyzed yeast cells, yeast cell walls and active yeast cells. Adsorption assays were performed in CPBS spiked with 1.0 μg AFB1/mL at pH 3.0 and 6.0 for a contact time of 60 min at room temperature. Analysis of AFB1 in the samples was performed by high performance liquid chromatography. AFB1 adsorption by the products ranged from 45.5% to 69.4% at pH 3.0 and from 24.0% to 63.8% at pH 6.0. The higher percentages (p < 0.05) of AFB1 binding at both pH values were achieved with products containing hydrolyzed yeast cells or yeast cell walls rather than intact cells. The AFB1 binding percentages of BFR were 55.0 ± 5.0% at pH 3.0 and 49.2 ± 4.5% at pH 6.0, which was not significantly different (p > 0.05) from commercial products containing inactive intact yeast cells. The results of this trial indicate that the yeast-based products tested, especially the BFR, have potential applications in animal feeds as a suitable biological method for reducing the adverse effects of aflatoxins. PMID:26273277

Contrasting performance of donor-acceptor copolymer pairs in ternary blend solar cells and two-acceptor copolymers in binary blend solar cells.

PubMed

Khlyabich, Petr P; Rudenko, Andrey E; Burkhart, Beate; Thompson, Barry C

2015-02-04

Here two contrasting approaches to polymer-fullerene solar cells are compared. In the first approach, two distinct semi-random donor-acceptor copolymers are blended with phenyl-C61-butyric acid methyl ester (PC61BM) to form ternary blend solar cells. The two poly(3-hexylthiophene)-based polymers contain either the acceptor thienopyrroledione (TPD) or diketopyrrolopyrrole (DPP). In the second approach, semi-random donor-acceptor copolymers containing both TPD and DPP acceptors in the same polymer backbone, termed two-acceptor polymers, are blended with PC61BM to give binary blend solar cells. The two approaches result in bulk heterojunction solar cells that have the same molecular active-layer components but differ in the manner in which these molecular components are mixed, either by physical mixing (ternary blend) or chemical "mixing" in the two-acceptor (binary blend) case. Optical properties and photon-to-electron conversion efficiencies of the binary and ternary blends were found to have similar features and were described as a linear combination of the individual components. At the same time, significant differences were observed in the open-circuit voltage (Voc) behaviors of binary and ternary blend solar cells. While in case of two-acceptor polymers, the Voc was found to be in the range of 0.495-0.552 V, ternary blend solar cells showed behavior inherent to organic alloy formation, displaying an intermediate, composition-dependent and tunable Voc in the range from 0.582 to 0.684 V, significantly exceeding the values achieved in the two-acceptor containing binary blend solar cells. Despite the differences between the physical and chemical mixing approaches, both pathways provided solar cells with similar power conversion efficiencies, highlighting the advantages of both pathways toward highly efficient organic solar cells.

Enzyme and Microbial Development | Bioenergy | NREL

Science.gov Websites

samples of powdered biomass into a reactor plate, part of the high-throughput biomass recalcitrance the molecular weight of cellA on blue and white containers of SDS PAGE gel in a laboratory

The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant.

PubMed

Zhang, Li; Lilley, Catherine J; Imren, Mustafa; Knox, J Paul; Urwin, Peter E

2017-01-01

Plant-parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida , Heterodera glycines , Heterodera avenae and Heterodera filipjevi , in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines . Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium function.

The Complex Cell Wall Composition of Syncytia Induced by Plant Parasitic Cyst Nematodes Reflects Both Function and Host Plant

PubMed Central

Zhang, Li; Lilley, Catherine J.; Imren, Mustafa; Knox, J. Paul; Urwin, Peter E.

2017-01-01

Plant–parasitic cyst nematodes induce the formation of specialized feeding structures, syncytia, within their host roots. These unique plant organs serve as the sole nutrient resource for development and reproduction throughout the biotrophic interaction. The multinucleate syncytium, which arises through local dissolution of cell walls and protoplast fusion of multiple adjacent cells, has dense cytoplasm containing numerous organelles, surrounded by thickened outer cell walls that must withstand high turgor pressure. However, little is known about how the constituents of the syncytial cell wall and their conformation support its role during nematode parasitism. We used a set of monoclonal antibodies, targeted to a range of plant cell wall components, to reveal the microstructures of syncytial cell walls induced by four of the most economically important cyst nematode species, Globodera pallida, Heterodera glycines, Heterodera avenae and Heterodera filipjevi, in their respective potato, soybean, and spring wheat host roots. In situ fluorescence analysis revealed highly similar cell wall composition of syncytia induced by G. pallida and H. glycines. Both consisted of abundant xyloglucan, methyl-esterified homogalacturonan and pectic arabinan. In contrast, the walls of syncytia induced in wheat roots by H. avenae and H. filipjevi contain little xyloglucan but are rich in feruloylated xylan and arabinan residues, with variable levels of mixed-linkage glucan. The overall chemical composition of syncytial cell walls reflected the general features of root cell walls of the different host plants. We relate specific components of syncytial cell walls, such as abundant arabinan, methyl-esterification status of pectic homogalacturonan and feruloylation of xylan, to their potential roles in forming a network to support both the strength and flexibility required for syncytium function. PMID:28680436

Modulation of JB6 Mouse Epidermal Cell Transformation Response by the Prostaglandin F2 Alpha Receptor

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

Weber, Thomas J.; Markillie, Lye MENG.; Chrisler, William B.

2002-12-01

Prostaglandin F2a (PGF2a) has been associated with the modulation of clonal selection processes in the mouse skin model of carcinogenesis. We have investigated whether JB6 mouse epidermal cells express a functional PGF2a receptor (FP) coupled to the regulation of anchorage-dependent and -independent growth. Treatment of JB6 cells with a FP receptor ligand (fluprostenol) potently (pM-nM) increased anchorage-dependent and -independent growth, as determined by a battery of in vitro assays. Treatment of JB6 cells with PGF2a and fluprostenol increased inositol phospholipid accumulation and extracellular signal regulated kinase (ERK) activity, consistent with FP receptor-related signaling. FP receptor mRNA was detected by reversemore » transcription-polymerase chain reaction and a radiolabel binding assay determined the average specific [3H]PGF2a binding to be 8.25 + 0.95 fmol/mg protein. Treatment of cells with fluprostenol as a single exposure resulted in a significant increase in anchorage-dependent and -independent growth in media containing low (0.1-0.5%), but not high (5%) concentrations of fetal bovine serum (FBS). In contrast, treatment of cells with fluprostenol at two day intervals resulted in a more robust growth response under anchorage-dependent conditions only in media containing low FBS concentrations; and under anchorage-independent conditions only in media containing high FBS concentrations. ERK activation and colony size were increased by cotreatment of JB6 cells with EGF and fluprostenol to a greater extent than either treatment alone, while the cotreatment effect on colony number appeared to be simply additive. In summary, FBS concentration and signal oscillation exert pronounced effects on the biological response to a FP receptor agonist. The data raise the possibility that the FP receptor may independently contribute to clonal selection processes, but may play a more important role as a response modifier.« less

Residual Gas Effects on Detached Solidification in Microgravity

NASA Technical Reports Server (NTRS)

Wilcox, William R.; Regel, Liya L.; Ramakrishnan; Kota, Arun; Anand, Gaurav

2004-01-01

Our long term goal has been to make detached solidification reproducible, which requires a full understanding of the mechanisms underlying it. Our Moving Meniscus Model of steady-state detachment predicts that it depends strongly on the surface tension of the melt and the advancing contact angle with the ampoule wall. Thus, the objective of the current project was to determine the influence of residual gases on the surface tension and contact angle of molten semiconductors on typical ampoule materials. Our focus was on the influence of oxygen on indium antimonide on clean silica ("quartz"). The research was performed by three chemical engineering graduate students, the third of whom will complete his research in the summer of 2005. Originally, we had planned to use a sealed silica cell containing a zirconia electrochemical element to control the oxygen partial pressure. However, zirconia requires an operating temperature above the 530 C melting point of InSb and is difficult to form a gas-tight seal with silica. Thus, we decided instead to flow an oxygen-containing gas through the cell. A special apparatus was designed, built and perfected. A piece of InSb was placed on a horizontal silica plate in a quartz cell. High purity argon, helium or hydrogen-containing gas is passed continuously through the cell while the oxygen concentration in the effluent gas is measured. The shape of the resulting drop was used to determine contact angle and surface tension of Ga-doped and high purity InSb. Oxygen appeared to decrease the contact angle, and definitely did not increase it. The following section gives the background for the research. Section 2 summarizes the results obtained on Ga-doped InSb with relatively high oxygen concentrations. Section 3 describes recent improvements made to the apparatus and methods of analysis. Section 4 gives recent results for high-purity InSb at low oxygen concentrations. Final results will be obtained only this summer (2005). Each section has its own references.

Albumin nanocapsules containing fenretinide: pre-clinical evaluation of cytotoxic activity in experimental models of human non-small cell lung cancer.

PubMed

Pignatta, Sara; Orienti, Isabella; Falconi, Mirella; Teti, Gabriella; Arienti, Chiara; Medri, Laura; Zanoni, Michele; Carloni, Silvia; Zoli, Wainer; Amadori, Dino; Tesei, Anna

2015-02-01

The present study deals with the preparation of albumin nanocapsules containing fenretinide and their evaluation in experimental models of human non-small cell lung cancer. These nanocapsules showed enhanced antitumor activity with respect to free fenretinide due to the solubilization effect of albumin on the hydrophobic drug, known to improve bioavailability. The high expression of caveolin-1 on the A549 cell surface further enhanced the antitumor activity of the nanoencapsulated fenretinide. Caveolin-1 favored albumin uptake and improved the efficacy of the fenretinide-loaded albumin nanocapsules, especially in 3-D cultures where the densely packed 3-D structures impaired drug diffusibility and severely reduced the activity of the free drug. The efficacy of the fenretinide albumin nanocapsules was further confirmed in tumor xenograft models of A549 by the significant delay in tumor progression observed with respect to control after intravenous administration of the novel formulation. This study describes the preparation of fenretinide containing albumin nanocapsules and their evaluation in experimental models of non-small cell lung cancer, showing enhanced antitumor activity compared to free fenretinide. Copyright © 2015 Elsevier Inc. All rights reserved.

Strategic incorporation of fluorine in the drug discovery of new-generation antitubercular agents targeting bacterial cell division protein FtsZ⋆

PubMed Central

Ojima, Iwao; Awasthi, Divya; Wei, Longfei; Haranahalli, Krupanandan

2016-01-01

This article presents an account of our research on the discovery and development of new-generation fluorine-containing antibacterial agents against drug-resistant tuberculosis, targeting FtsZ. FtsZ is an essential protein for bacterial cell division and a highly promising therapeutic target for antibacterial drug discovery. Through design, synthesis and semi-HTP screening of libraries of novel benzimidazoles, followed by SAR studies, we identified highly potent lead compounds. However, these lead compounds were found to lack sufficient metabolic and plasma stabilities. Accordingly, we have performed extensive study on the strategic incorporation of fluorine into lead compounds to improve pharmacological properties. This study has led to the development of highly efficacious fluorine-containing benzimidazoles as potential drug candidates. We have also performed computational docking analysis of these novel FtsZ inhibitors to identify their putative binding site. Based on the structural data and docking analysis, a plausible mode-of-action for this novel class of FtsZ inhibitors is proposed. PMID:28555087

Properties of Vacancy Complexes with Hydrogen and Helium Atoms in Tungsten from First Principles

DOE PAGES

Samolyuk, German D.; Osetsky, Yury N.; Stoller, Roger E.

2016-12-03

Tungsten and its alloys are the primary candidate materials for plasma-facing components in fusion reactors. The material is exposed to high-energy neutrons and the high flux of helium and hydrogen atoms. In this paper, we have studied the properties of vacancy clusters and their interaction with H and He in W using density functional theory. Convergence of calculations with respect to modeling cell size was investigated. It is demonstrated that vacancy cluster formation energy converges with small cells with a size of 6 × 6 × 6 (432 lattice sites) enough to consider a microvoid of up to six vacanciesmore » with high accuracy. Most of the vacancy clusters containing fewer than six vacancies are unstable. Introducing He or H atoms increases their binding energy potentially making gas-filled bubbles stable. Finally, according to the results of the calculations, the H 2 molecule is unstable in clusters containing six or fewer vacancies.« less

Association of white cell and red cell antibodies in human sera

PubMed Central

Ross, Jill M.; James, D. C. O.

1973-01-01

Five hundred and eighteen human sera containing known red cell antibodies were tested for lymphocytotoxic antibodies and 81 sera were found to contain them. Thirty-nine antibodies were fully characterized. The frequencies of anti-I, K, Vw, and Wra were significantly greater in those of the 518 sera which also contained white cell antibodies. Four hundred and ninety-four of the 518 sera containing red cell antibodies contained anti-Rh and anti-Kell. The frequency of white cell antibodies in this group was 15% compared with a frequency of 12% in a series of 923 antenatal samples not containing anti-Rh or anti-Kell. The frequencies of different anti-HL-A specificities were compared in the two groups with or without anti-Rh and anti-Kell antibodies. Anti-HL-A 1, 7, and 8 occurred more frequently in the absence of these red cell antibodies and anti-HL-A 12 occurred more frequently in their presence. No correlation was found between particular red cell and white cell antibodies. PMID:4197543

Photoacoustic detection of hemozoin in human mononuclear cells as an early indicator of malaria infection

NASA Astrophysics Data System (ADS)

Custer, Jonathan R.; Kariuki, Michael; Beerntsen, Brenda T.; Viator, John A.

2010-02-01

Malaria is a blood borne infection affecting hundreds of millions of people worldwide2. The parasites reproduce within the blood cells, eventually causing their death and lysis. This process releases the parasites into the blood, continuing the cycle of infection. Usually, malaria is diagnosed only after a patient presents symptoms, including high fever, nausea, and, in advanced cases, coma and death. While invading the bloodstream of a host, malaria parasites convert hemoglobin into an insoluble crystal, known as hemozoin. These crystals, approximately several hundred nanometers in size, are contained within red blood cells and white blood cells that ingest free hemozoin in the blood. Thus, infected red blood cells and white blood cells contain a unique optical absorber that can be detected in blood samples using static photoacoustic detection methods. We separated the white blood cells from malaria infected blood and tested it in a photoacoustic set up using a tunable laser system consisting of an optical parametric oscillator pumped by an Nd:YAG laser with pulse duration of 5 ns. Our threshold of detection was 10 infected white blood cells per microliter, which is more sensitive than current diagnosis methods using microscopic analysis of blood.

A quick and efficient method to generate mammalian stable cell lines based on a novel inducible alphavirus DNA/RNA layered system.

PubMed

Aranda, Alejandro; Bezunartea, Jaione; Casales, Erkuden; Rodriguez-Madoz, Juan R; Larrea, Esther; Prieto, Jesus; Smerdou, Cristian

2014-12-01

We report a new method to generate high-expressing mammalian cell lines in a quick and efficient way. For that purpose, we developed a master cell line (MCL) containing an inducible alphavirus vector expressing GFP integrated into the genome. In the MCL, recombinant RNA levels increased >4,600-fold after induction, due to a doxycycline-dependent RNA amplification loop. The MCL maintained inducibility and expression during 50 passages, being more efficient for protein expression than a conventional cell line. To generate new cell lines, mutant LoxP sites were inserted into the MCL, allowing transgene and selection gene exchange by Cre-directed recombination, leading to quick generation of inducible cell lines expressing proteins of therapeutic interest, like human cardiotrophin-1 and oncostatin-M at several mg/l/24 h. These proteins contained posttranslational modifications, showed bioactivity, and were efficiently purified. Remarkably, this system allowed production of toxic proteins, like oncostatin-M, since cells able to express it could be grown to the desired amount before induction. These cell lines were easily adapted to growth in suspension, making this methodology very attractive for therapeutic protein production.

Construction of recombinant FGFR1 containing full-length gene and its potential application.

PubMed

Zhou, Yali; Luo, Wenjuan; Zheng, Lei; Li, Miao; Zhang, Yanmin

2010-07-01

FGFR1, one of the four fibroblast growth factor receptors, has been found to be over-expressed in many cancers. In this study, a full-length expression plasmid for FGFR1 was obtained by fragment amplification. The amplified PCR product was then digested and inserted into the pcDNA3.1(+) vector. A recombinant eukaryotic expression vector containing the complete CDS region of FGFR1 was successfully constructed. After it was transfected to Hek293 cell, the expression of the FGFR1 receptor in recombinant Hek293/FGFR1 was 18 times higher than that of Hek293 cell. The biological activities of high expression FGFR1 cell (Hek293/FGFR1) were verified by FCM, immunofluorescent, RT-PCR, western blot and cell cycle analysis. Then, Hek293/FGFR1 was used to screen taspine with cell membrane chromatography (CMC). Finally, we analyzed the effects of taspine on Hek293/FGFR1 cell and MCF-7 cell. In conclusion, Hek293/FGFR1 was successfully constructed. The results demonstrate that taspine can down-regulate phosphorylation of FGFR1 and ERK, and inhibit Hek293/FGFR1 and MCF-7 cell proliferation. Copyright 2010 Elsevier Inc. All rights reserved.

Liposomal CpG-ODN: An in vitro and in vivo study on macrophage subtypes responses, biodistribution and subsequent therapeutic efficacy in mice models of cancers.

PubMed

Nikoofal-Sahlabadi, Sara; Matbou Riahi, Maryam; Sadri, Kayvan; Badiee, Ali; Nikpoor, Amin Reza; Jaafari, Mahmoud Reza

2018-07-01

CpG oligodeoxynucleotides (CpG-ODN), a common immune stimulator and vaccine adjuvant, was reported to switch Tumor Associated Macrophages (TAMs) from M2 to M1 phenotype inducing anti-tumor responses. Liposomes are of the successfully applied carriers for CpG-ODN. The aim of present study was design and preparation of a liposomal formulation containing phosphodiester CpG-ODN, evaluation of its effect on macrophages responses, and subsequent antitumor responses in mice. Liposomal formulations containing phosphodiester CpG-ODN or non-CpG-ODN were prepared and characterized. MTT reduction assay in four different cell lines, uptake, arginase and iNOS activity evaluation in macrophage cell lines, biodistribution study and therapeutic anti-tumor effects of formulations in mice bearing C26 colon carcinoma or B16F0 melanoma were carried out. The size of liposomes containing CpG-ODN was ~200 nm with the encapsulation efficiency of 33%. The iNOS activity assay showed high nitric oxide (NO) level in M2 phenotype of macrophage cell lines treated by liposomes containing CpG-ODN. In mice which received liposomes containing CpG-ODN as a monotherapy, maximum tumor growth delay with remarkable survival improvement was observed compared to control groups. Biodistribution study showed the accumulation of liposomal formulation in tumor micro-environment. In conclusion, considerable anti-tumor responses observed by liposomes containing CpG-ODN was due to enhanced delivery of CpG-ODN to immune cells and subsequent initiation of anti-tumoral immune responses. Copyright © 2018 Elsevier B.V. All rights reserved.

Immunobiology of HPV and HPV vaccines.

PubMed

Stanley, Margaret

2008-05-01

Genital human papillomavirus (HPV) infection with both low- and high-risk types is common, but most infections resolve as a result of a cell-mediated immune response. Failure to induce an effective immune response is related to inefficient activation of innate immunity and ineffective priming of the adaptive immune response; this defective immune response facilitates viral persistence, a key feature of high-risk HPV infection. This milieu becomes operationally HPV antigen tolerant, and the host's defenses become irrevocably compromised. HPV antigen-specific effector cells are poorly recruited to the infected focus and their activity is downregulated; neoplastic HPV containing cervical keratinocytes expressing high levels of E6 and E7 oncoproteins are not killed in this immunosuppressive, tolerant milieu, and progression to high-grade disease and cancer can result. Highly efficacious prophylactic HPV L1 virus-like particle (VLP) vaccines circumvent viral epithelial evasion strategies since they are delivered by intramuscular injection. The stromal dendritic cells of the muscle that encounter the highly immunogenic repeat structure of the VLP then migrate with their cargo to the lymph node, initiating an immune cascade that results in a robust T-cell dependent B-cell response, which generates high levels of L1-specific serum neutralizing antibodies and immune memory.

Epidermal growth factor stimulates mouse placental lactogen I but inhibits mouse placental lactogen II secretion in vitro.

PubMed Central

Yamaguchi, M; Ogren, L; Endo, H; Thordarson, G; Kensinger, R; Talamantes, F

1992-01-01

This study was undertaken to determine whether epidermal growth factor (EGF) regulates the secretion of mouse placental lactogen (mPL)-I and mPL-II. Primary cell cultures were prepared from placentas from days 7, 9, and 11 of pregnancy and cultured for up to 5 days. Addition of EGF (20 ng/ml) to the medium resulted in significant stimulation of mPL-I secretion by the second day of culture in cells from days 7 and 9 of pregnancy and significant inhibition of mPL-II secretion by the third or fourth day of culture in cells from days 7, 9, and 11. Dose-response studies carried out with cells from day 7 of pregnancy demonstrated that the minimum concentration of EGF that stimulated mPL-I secretion and inhibited mPL-II secretion was 1.0 ng/ml. EGF did not affect the DNA content of the cells or cell viability, assessed by trypan blue exclusion, nor did it have a general effect on protein synthesis. There are three types of PL-containing giant cells in mouse placental cell cultures: cells that contain either mPL-I or mPL-II and cells that contain both hormones. Immunocytochemical analysis and the reverse hemolytic plaque assay indicated that EGF treatment was accompanied by a significant increase in the number of cells that produce mPL-I, but among the PL cells that contained mPL-I, there was no change in the fraction of cells that contained only mPL-I or the fraction that contained both mPL-I and mPL-II. In contrast, EGF treatment did affect the distribution of mPL-II among PL cells. In control cultures, about 75% of the cells that contained mPL-II also contained mPL-I, but in EGF-treated cultures, all of the cells that contained mPL-II also contained mPL-I. These data suggest that EGF regulates mPL-I and mPL-II secretion at least partly by regulating PL cell differentiation. PMID:1454826

Overexpression of TRIM25 in Lung Cancer Regulates Tumor Cell Progression.

PubMed

Qin, Ying; Cui, He; Zhang, Hua

2016-10-01

Lung cancer is one of the most common causes of cancer-related deaths worldwide. Although great efforts and progressions have been made in the study of the lung cancer in the recent decades, the mechanism of lung cancer formation remains elusive. To establish effective therapeutic methods, new targets implied in lung cancer processes have to be identified. Tripartite motif-containing 25 has been associated with ovarian and breast cancer and is thought to positively promote cell growth by targeting the cell cycle. However, whether tripartite motif-containing 25 has a function in lung cancer development remains unknown. In this study, we found that tripartite motif-containing 25 was overexpressed in human lung cancer tissues. Expression of tripartite motif-containing 25 in lung cancer cells is important for cell proliferation and migration. Knockdown of tripartite motif-containing 25 markedly reduced proliferation of lung cancer cells both in vitro and in vivo and reduced migration of lung cancer cells in vitro Meanwhile, tripartite motif-containing 25 silencing also increased the sensitivity of doxorubicin and significantly increased death and apoptosis of lung cancer cells by doxorubicin were achieved with knockdown of tripartite motif-containing 25. We also observed that tripartite motif-containing 25 formed a complex with p53 and mouse double minute 2 homolog (MDM2) in both human lung cancer tissues and in lung cancer cells and tripartite motif-containing 25 silencing increased the expression of p53. These results provide evidence that tripartite motif-containing 25 contributes to the pathogenesis of lung cancer probably by promoting proliferation and migration of lung cancer cells. Therefore, targeting tripartite motif-containing 25 may provide a potential therapeutic intervention for lung cancer. © The Author(s) 2015.

A time- and matrix-dependent TGFBR3–JUND–KRT5 regulatory circuit in single breast epithelial cells and basal-like premalignancies

PubMed Central

Wang, Chun-Chao; Bajikar, Sameer S.; Jamal, Leen; Atkins, Kristen A.; Janes, Kevin A.

2014-01-01

Basal-like breast carcinoma is characterized by poor prognosis and high intratumor heterogeneity. In an immortalized basal-like breast epithelial cell line, we identified two anti-correlated gene-expression programs that arise among single extracellular matrix (ECM)-attached cells during organotypic 3D culture. The first contains multiple TGFβ-related genes including TGFBR3, whereas the second contains JUND and the basal-like marker, KRT5. TGFBR3 and JUND interconnect through four negative-feedback loops to form a circuit that exhibits spontaneous damped oscillations in 3D culture. The TGFBR3–JUND circuit appears conserved in some premalignant lesions that heterogeneously express KRT5. The circuit depends on ECM engagement, as detachment causes a rewiring that is triggered by RPS6 dephosphorylation and maintained by juxtacrine tenascin C, which is critical for intraductal colonization of basal-like breast cancer cells in vivo. Intratumor heterogeneity need not stem from partial differentiation and could instead reflect dynamic toggling of cells between expression states that are not cell autonomous. PMID:24658685

The structure of tissue on cell culture-extracted thyroglobulin is independent of its iodine content.

PubMed

Delain, E; Aouani, A; Vignal, A; Couture-Tosi, E; Hovsépian, S; Fayet, G

1987-02-01

The major protein synthesized in vitro by the ovine thyroid cell line OVNIS 6H is the prothyroid hormone thyroglobulin. Purified from serum-free cell culture media using sucrose gradient centrifugation, the thyroglobulin dimer was analysed for iodine content and observed by electron microscopy. In their usual medium, the OVNIS 6H cells produce a very poorly iodinated thyroglobulin containing 0.05 I atom per molecule. When cultured with methimazole or propylthiouracil, two inhibitors of iodide organification, less than 0.007 I atom/molecules was found. These molecules purified from cell cultures were compared to those purified from ovine thyroid tissue containing 26 I atoms/mol. Despite large differences in iodine content, the three preparations all consist of 19 S thyroglobulin dimers with the classical ovoidal shape. The variability in size measurements remains in a 2% range for all thyroglobulin types. Consequently, no real significant variation can be found between the highly iodinated thyroglobulin isolated from tissue, and the poorly or non-iodinated thyroglobulins isolated from cells cultured with or without methimazole or propylthiouracil.

β-galactosidase-catalyzed synthesis of galactosyl chlorphenesin and its characterization.

PubMed

Lee, Sang-Eun; Jo, Tae-Min; Lee, Hyang-Yeol; Lee, Jongsung; Jung, Kyung-Hwan

2013-11-01

We synthesized galactosyl chlorphenesin (CPN-G) using β-gal-containing Escherichia coli (E. coli) cells in which the conversion yield of chlorphenesin (CPN) to CPN-G reached about 64 % during 12 h. CPN-G was identified and characterized using high-performance liquid chromatography, liquid chromatography-mass spectrometry, Fourier transform-infrared spectrometry, and nuclear magnetic resonance analysis ((1)H and (13)C). We verified that a galactose was covalently bound to a CPN alcohol group during CPN-G synthesis throughout these analyses. In particular, by the hydrolysis of CPN-G using β-gal, it was confirmed that a galactose was bound to CPN. The minimal inhibitory concentration (MIC) results showed that the CPN-G MICs were fairly similar to those of CPN. HACAT cell viability was significantly higher in CPN-G-treated cells than in CPN-treated cells at concentrations of 0.0-20.0 mM. Finally, we accomplished the synthesis of less toxic CPN-G, compared with CPN, using β-gal-containing E. coli cells as whole cells without changes in the MICs against microorganisms.

Multiplexed screening assay for mRNA combining nuclease protection with luminescent array detection.

PubMed

Martel, Ralph R; Botros, Ihab W; Rounseville, Matthew P; Hinton, James P; Staples, Robin R; Morales, David A; Farmer, John B; Seligmann, Bruce E

2002-11-01

The principles and performance are described for the ArrayPlate mRNA assay, a multiplexed mRNA assay for high-throughput and high-content screening and drug development. THP-1 monocytes grown and subjected to compound treatments in 96-well plates were subjected to a multiplexed nuclease protection assay in situ. The nuclease protection assay destroyed all cell-derived mRNA, but left intact stoichiometric amounts of 16 target-specific oligonucleotide probes. Upon transfer of processed cell lysates to a microplate that contained a 16-element oligonucleotide array at the bottom of each well, the various probe species were separated by immobilization at predefined elements of the array. Quantitative detection of array-bound probes was by enzyme-mediated chemiluminescence. A high-resolution charge-coupled device imager was used for the simultaneous readout of all 1536 array elements in a 96-well plate. For the measurement of 16 genes in samples of 25000 cells, the average standard deviation from well to well within a plate was 8.6% of signal intensity and was 10.8% from plate to plate. Assay response was linear and reproducibility was constant for all detected genes in samples ranging from 1000 to 50000 cells. When THP-1 monocytes were differentiated with phorbol ester and subsequently activated with bacterial lipopolysaccharide that contained different concentrations of dexamethasone, dose-dependent effects of dexamethasone on the mRNA levels of several genes were observed.

Extracellular matrix controls tubulin monomer levels in hepatocytes by regulating protein turnover

NASA Technical Reports Server (NTRS)

Mooney, D. J.; Hansen, L. K.; Langer, R.; Vacanti, J. P.; Ingber, D. E.

1994-01-01

Cells have evolved an autoregulatory mechanism to dampen variations in the concentration of tubulin monomer that is available to polymerize into microtubules (MTs), a process that is known as tubulin autoregulation. However, thermodynamic analysis of MT polymerization predicts that the concentration of free tubulin monomer must vary if MTs are to remain stable under different mechanical loads that result from changes in cell adhesion to the extracellular matrix (ECM). To determine how these seemingly contradictory regulatory mechanisms coexist in cells, we measured changes in the masses of tubulin monomer and polymer that resulted from altering cell-ECM contacts. Primary rat hepatocytes were cultured in chemically defined medium on bacteriological petri dishes that were precoated with different densities of laminin (LM). Increasing the LM density from low to high (1-1000 ng/cm2), promoted cell spreading (average projected cell area increased from 1200 to 6000 microns2) and resulted in formation of a greatly extended MT network. Nevertheless, the steady-state mass of tubulin polymer was similar at 48 h, regardless of cell shape or ECM density. In contrast, round hepatocytes on low LM contained a threefold higher mass of tubulin monomer when compared with spread cells on high LM. Furthermore, similar results were obtained whether LM, fibronectin, or type I collagen were used for cell attachment. Tubulin autoregulation appeared to function normally in these cells because tubulin mRNA levels and protein synthetic rates were greatly depressed in round cells that contained the highest level of free tubulin monomer. However, the rate of tubulin protein degradation slowed, causing the tubulin half-life to increase from approximately 24 to 55 h as the LM density was lowered from high to low and cell rounding was promoted. These results indicate that the set-point for the tubulin monomer mass in hepatocytes can be regulated by altering the density of ECM contacts and changing cell shape. This finding is consistent with a mechanism of MT regulation in which the ECM stabilizes MTs by both accepting transfer of mechanical loads and altering tubulin degradation in cells that continue to autoregulate tubulin synthesis.

High-yield cell-free synthesis of human EGFR by IRES-mediated protein translation in a continuous exchange cell-free reaction format

PubMed Central

Quast, Robert B.; Sonnabend, Andrei; Stech, Marlitt; Wüstenhagen, Doreen A.; Kubick, Stefan

2016-01-01

Cell-free protein synthesis systems derived from eukaryotic sources often provide comparatively low amounts of several μg per ml of de novo synthesized membrane protein. In order to overcome this, we herein demonstrate the high-yield cell-free synthesis of the human EGFR in a microsome-containing system derived from cultured Sf21 cells. Yields were increased more than 100-fold to more than 285 μg/ml by combination of IRES-mediated protein translation with a continuous exchange cell-free reaction format that allowed for prolonged reaction lifetimes exceeding 24 hours. In addition, an orthogonal cell-free translation system is presented that enabled the site-directed incorporation of p-Azido-L-phenylalanine by amber suppression. Functionality of cell-free synthesized receptor molecules is demonstrated by investigation of autophosphorylation activity in the absence of ligand and interaction with the cell-free synthesized adapter molecule Grb2. PMID:27456041

Single-Cell Electric Lysis on an Electroosmotic-Driven Microfluidic Chip with Arrays of Microwells

PubMed Central

Jen, Chun-Ping; Amstislavskaya, Tamara G.; Liu, Ya-Hui; Hsiao, Ju-Hsiu; Chen, Yu-Hung

2012-01-01

Accurate analysis at the single-cell level has become a highly attractive tool for investigating cellular content. An electroosmotic-driven microfluidic chip with arrays of 30-μm-diameter microwells was developed for single-cell electric lysis in the present study. The cellular occupancy in the microwells when the applied voltage was 5 V (82.4%) was slightly higher than that at an applied voltage of 10 V (81.8%). When the applied voltage was increased to 15 V, the cellular occupancy in the microwells dropped to 64.3%. More than 50% of the occupied microwells contain individual cells. The results of electric lysis experiments at the single-cell level indicate that the cells were gradually lysed as the DC voltage of 30 V was applied; the cell was fully lysed after 25 s. Single-cell electric lysis was demonstrated in the proposed microfluidic chip, which is suitable for high-throughput cell lysis. PMID:22969331

Naringin ameliorates the high glucose-induced rat mesangial cell inflammatory reaction by modulating the NLRP3 Inflammasome.

PubMed

Chen, Fenqin; Wei, Guozhu; Xu, Jiao; Ma, Xiaoyu; Wang, Qiuyue

2018-06-22

The Nucleotide binding and oligomerization domain-like receptorfamily pyrin domain-containing 3 (NLRP3)-inflammasome plays an important role in various diseases, including a variety of kidney diseases. Naringin exhibits anti-inflammatory and anti-oxidation effects among others, but its specific mechanisms are not clear. We investigated the expression of the NLRP3-inflammasome under high-glucose conditions, assessed the effects of naringin on that process, and further elucidated the role of naringin in the pathogenesis of diabetic kidney disease(DKD). To assess the therapeutic potential of naringin and the mechanisms involved, we cultured rat glomerular mesangial cells and grouped them according to different glucose concentrations, different action times, different concentrations of MCC950, and different concentrations of naringin.The cell proliferation was measured by MTT assay. The expression of Interleukin-1β(IL-1β) and Interleukin18 (IL-18) in the cell supernatant were detected by ELISA. The expression and activity of NLPR3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and Caspase-1 were detected by Western Blot. The expressions of NLRP3, ASC, caspase-1, IL-1β, and IL-18 in rat glomerular mesangial cells were significantly higher in the high glucose (HG) group than in the control normal glucose (NG) group and exhibited time-dependence activity. The expression levels of NLRP3, caspase-1, IL-1β, and IL-18 in different treatment groups were significantly lower compared with the HG group after 48 h of MCC950 pre-treatment (p < 0.05). Pre-treatment with naringin produced the same results. Naringin also inhibited the proliferation of cells. The NLRP3-inflammasome potentially plays a role in the process of activation and inflammation of glomerular mesangial cells as induced by high-glucose conditions. Naringin inhibited the proliferation of cells that were induced by high glucose. Further, it reduced the expression of inflammatory factors that are mediated by NLRP3 through the NLRP3-caspase-1-IL-1β/IL-18 signaling pathway, which makes naringin a potentially novel treatment for DKD disease.

Dry cell battery poisoning

MedlinePlus

Batteries - dry cell ... Acidic dry cell batteries contain: Manganese dioxide Ammonium chloride Alkaline dry cell batteries contain: Sodium hydroxide Potassium hydroxide Lithium dioxide dry cell batteries ...

Phenotypically non-suppressive cells predominate among FoxP3-positive cells in oral lichen planus.

PubMed

Schreurs, Olav; Karatsaidis, Andreas; Schenck, Karl

2016-11-01

Oral lichen planus (OLP) is a common T-cell-dominated oral chronic inflammatory disease occurring in periods of remission, quiescence, activity with pronounced inflammation, and acute ulceration. Cell infiltrates in OLP contain varying numbers of CD4 + T cells expressing the transcription factor FoxP3. FoxP3 + CD4 + T cells are, however, a heterogeneous cell population containing suppressive and non-suppressive cells, and their distribution in infiltrates from OLP is unknown. Biopsies were taken from normal oral mucosa (n = 8) and OLP lesions (n = 19), and a set of in situ methods for the determination of the functional phenotype of FoxP3 + CD4 + T cells was applied. Numbers of FoxP3 + CD4 + T cells were highest in the atrophic form of the disease, yet low in the ulcerative form. The main FoxP3 + CD4 + T-cell population observed was FoxP3 + CD45RA - CD25 + CD45RO + and CD15s - , a phenotype delineating a non-suppressive subset. Numbers of cells with an actively suppressing phenotype (FoxP3 + CD45RA - CD25 + CD45RO + and CD15s + ) were, however, about twice as high in reticular lesions as compared with the atrophic form. Many FoxP3 + CD4 + T cells expressed T-bet, the hallmark transcription factor for IFN-γ-producing T cells, indicating that they may enhance immune and inflammatory responses rather than suppress them. The absence of actively suppressing FoxP3 + CD4 + T cells may in part explain why OLP is a remarkably persisting condition, in spite of the presence of substantially high numbers of FoxP3 + CD4 + T cells. The findings emphasize that it is crucial to examine not only numbers but also functional phenotype of FoxP3 + CD4 + T cells in human tissues. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Notch1 stimulation induces a vascularization switch with pericyte-like cell differentiation of glioblastoma stem cells.

PubMed

Guichet, Pierre-Olivier; Guelfi, Sophie; Teigell, Marisa; Hoppe, Liesa; Bakalara, Norbert; Bauchet, Luc; Duffau, Hugues; Lamszus, Katrin; Rothhut, Bernard; Hugnot, Jean-Philippe

2015-01-01

Glioblastoma multiforms (GBMs) are highly vascularized brain tumors containing a subpopulation of multipotent cancer stem cells. These cells closely interact with endothelial cells in neurovascular niches. In this study, we have uncovered a close link between the Notch1 pathway and the tumoral vascularization process of GBM stem cells. We observed that although the Notch1 receptor was activated, the typical target proteins (HES5, HEY1, and HEY2) were not or barely expressed in two explored GBM stem cell cultures. Notch1 signaling activation by expression of the intracellular form (NICD) in these cells was found to reduce their growth rate and migration, which was accompanied by the sharp reduction in neural stem cell transcription factor expression (ASCL1, OLIG2, and SOX2), while HEY1/2, KLF9, and SNAI2 transcription factors were upregulated. Expression of OLIG2 and growth were restored after termination of Notch1 stimulation. Remarkably, NICD expression induced the expression of pericyte cell markers (NG2, PDGFRβ, and α-smooth muscle actin [αSMA]) in GBM stem cells. This was paralleled with the induction of several angiogenesis-related factors most notably cytokines (heparin binding epidermal growth factor [HB-EGF], IL8, and PLGF), matrix metalloproteinases (MMP9), and adhesion proteins (vascular cell adhesion molecule 1 [VCAM1], intercellular adhesion molecule 1 [ICAM1], and integrin alpha 9 [ITGA9]). In xenotransplantation experiments, contrasting with the infiltrative and poorly vascularized tumors obtained with control GBM stem cells, Notch1 stimulation resulted in poorly disseminating but highly vascularized grafts containing large vessels with lumen. Notch1-stimulated GBM cells expressed pericyte cell markers and closely associated with endothelial cells. These results reveal an important role for the Notch1 pathway in regulating GBM stem cell plasticity and angiogenic properties. © 2014 AlphaMed Press.

Comparison of EpCAMhighCD44+ cancer stem cells with EpCAMhighCD44- tumor cells in colon cancer by single-cell sequencing.

PubMed

Liu, Mingshan; Di, Jiabo; Liu, Yang; Su, Zhe; Jiang, Beihai; Wang, Zaozao; Su, Xiangqian

2018-03-26

Cancer stem cells (CSCs) are considered to be responsible for tumorigenesis and cancer relapse. EpCAM high CD44 + tumor cells are putative colorectal CSCs that express high levels of stem cell genes, while the EpCAM high CD44 - population mostly contains differentiated tumor cells (DTCs). This study aims to determine whether single CSC (EpCAM high CD44 + ) and DTC (EpCAM high CD44 - ) can be distinguished in terms of somatic copy number alterations (SCNAs). We applied fluorescence-activated cell sorting to isolate the CD45 - EpCAM high CD44 + and CD45 - EpCAM high CD44 - populations from two primary colon tumors, on which low-coverage single-cell whole-genome sequencing (WGS) was then performed ∼0.1x depth. We compared the SCNAs of the CSCs and DTCs at single-cell resolution. In total, 47 qualified single cells of the two populations underwent WGS. The single-cell SCNA profiles showed that there were obvious SCNAs in both the CSCs and DTCs of each patient, and each patient had a specific copy number alteration pattern. Hierarchical clustering and correlation analysis both showed that the SCNA profiles of CSCs and DTCs from the same patient had similar SCNA pattern, while there were regional differences in the CSCs and DTCs in certain patient. SCNAs of CSCs in the same patient were highly reproducible. Our data suggest that major SCNAs occurred at an early stage and were inherited steadily. The similarity of ubiquitous SCNAs between the CSCs and DTCs might have arisen from lineage differentiation. CSCs from the same patient had reproducible SCNA profiles, indicating that gain or loss in certain chromosome is required for colon cancer development.

NREL Driving Research on Hydrogen Fuel Cells | News | NREL

Science.gov Websites

embrittlement and to reduce the high capital costs of installing completely independent infrastructure. Lowering carbon. The high-pressure hydrogen gas cylinders on board release just enough hydrogen through the stack make containers, but without some of the added chemicals. NREL is examining which chemicals can be

Arsenic-Containing Phosphatidylcholines: A New Group of Arsenolipids Discovered in Herring Caviar.

PubMed

Viczek, Sandra A; Jensen, Kenneth B; Francesconi, Kevin A

2016-04-18

A new group of arsenolipids based on cell-membrane phosphatidylcholines has been discovered in herring caviar (fish roe). A combination of HPLC with elemental and molecular mass spectrometry was used to identify five arsenic-containing phosphatidylcholines; the same technique applied to salmon caviar identified an arsenic-containing phosphatidylethanolamine. The arsenic group in these membrane lipids might impart particular properties to the molecules not displayed by their non-arsenic analogues. Additionally, the new compounds have human health implications according to recent results showing high cytotoxicity for some arsenolipids.

The Poisson distribution and beyond: methods for microfluidic droplet production and single cell encapsulation.

PubMed

Collins, David J; Neild, Adrian; deMello, Andrew; Liu, Ai-Qun; Ai, Ye

2015-09-07

There is a recognized and growing need for rapid and efficient cell assays, where the size of microfluidic devices lend themselves to the manipulation of cellular populations down to the single cell level. An exceptional way to analyze cells independently is to encapsulate them within aqueous droplets surrounded by an immiscible fluid, so that reagents and reaction products are contained within a controlled microenvironment. Most cell encapsulation work has focused on the development and use of passive methods, where droplets are produced continuously at high rates by pumping fluids from external pressure-driven reservoirs through defined microfluidic geometries. With limited exceptions, the number of cells encapsulated per droplet in these systems is dictated by Poisson statistics, reducing the proportion of droplets that contain the desired number of cells and thus the effective rate at which single cells can be encapsulated. Nevertheless, a number of recently developed actively-controlled droplet production methods present an alternative route to the production of droplets at similar rates and with the potential to improve the efficiency of single-cell encapsulation. In this critical review, we examine both passive and active methods for droplet production and explore how these can be used to deterministically and non-deterministically encapsulate cells.

Automated detection of analyzable metaphase chromosome cells depicted on scanned digital microscopic images

NASA Astrophysics Data System (ADS)

Qiu, Yuchen; Wang, Xingwei; Chen, Xiaodong; Li, Yuhua; Liu, Hong; Li, Shibo; Zheng, Bin

2010-02-01

Visually searching for analyzable metaphase chromosome cells under microscopes is quite time-consuming and difficult. To improve detection efficiency, consistency, and diagnostic accuracy, an automated microscopic image scanning system was developed and tested to directly acquire digital images with sufficient spatial resolution for clinical diagnosis. A computer-aided detection (CAD) scheme was also developed and integrated into the image scanning system to search for and detect the regions of interest (ROI) that contain analyzable metaphase chromosome cells in the large volume of scanned images acquired from one specimen. Thus, the cytogeneticists only need to observe and interpret the limited number of ROIs. In this study, the high-resolution microscopic image scanning and CAD performance was investigated and evaluated using nine sets of images scanned from either bone marrow (three) or blood (six) specimens for diagnosis of leukemia. The automated CAD-selection results were compared with the visual selection. In the experiment, the cytogeneticists first visually searched for the analyzable metaphase chromosome cells from specimens under microscopes. The specimens were also automated scanned and followed by applying the CAD scheme to detect and save ROIs containing analyzable cells while deleting the others. The automated selected ROIs were then examined by a panel of three cytogeneticists. From the scanned images, CAD selected more analyzable cells than initially visual examinations of the cytogeneticists in both blood and bone marrow specimens. In general, CAD had higher performance in analyzing blood specimens. Even in three bone marrow specimens, CAD selected 50, 22, 9 ROIs, respectively. Except matching with the initially visual selection of 9, 7, and 5 analyzable cells in these three specimens, the cytogeneticists also selected 41, 15 and 4 new analyzable cells, which were missed in initially visual searching. This experiment showed the feasibility of applying this CAD-guided high-resolution microscopic image scanning system to prescreen and select ROIs that may contain analyzable metaphase chromosome cells. The success and the further improvement of this automated scanning system may have great impact on the future clinical practice in genetic laboratories to detect and diagnose diseases.

THE SKIN | Functional morphology of the integumentary system in fishes

USGS Publications Warehouse

Elliott, D.G.; Farrell, Anthony P.

2011-01-01

The integument that covers the outer surface of a fish’s body and fins is a multifunctional organ, with morphological features highly adapted to carry out these functions. The integument consists of two layers. The outer layer, the epidermis, is essentially cellular in structure, comprised of a multilayered epithelium that usually includes specialized cells. The inner layer, the dermis, is primarily a fibrous structure with relatively few cells, although it may contain scales, nerves, blood vessels, adipose tissue, and pigment cells.

Droplet-based microfluidic analysis and screening of single plant cells.

PubMed

Yu, Ziyi; Boehm, Christian R; Hibberd, Julian M; Abell, Chris; Haseloff, Jim; Burgess, Steven J; Reyna-Llorens, Ivan

2018-01-01

Droplet-based microfluidics has been used to facilitate high-throughput analysis of individual prokaryote and mammalian cells. However, there is a scarcity of similar workflows applicable to rapid phenotyping of plant systems where phenotyping analyses typically are time-consuming and low-throughput. We report on-chip encapsulation and analysis of protoplasts isolated from the emergent plant model Marchantia polymorpha at processing rates of >100,000 cells per hour. We use our microfluidic system to quantify the stochastic properties of a heat-inducible promoter across a population of transgenic protoplasts to demonstrate its potential for assessing gene expression activity in response to environmental conditions. We further demonstrate on-chip sorting of droplets containing YFP-expressing protoplasts from wild type cells using dielectrophoresis force. This work opens the door to droplet-based microfluidic analysis of plant cells for applications ranging from high-throughput characterisation of DNA parts to single-cell genomics to selection of rare plant phenotypes.

High-temperature, high-pressure optical cell

NASA Technical Reports Server (NTRS)

Harris, R. P. (Inventor); Holland, L. R. (Inventor); Smith, R. E. (Inventor)

1986-01-01

The invention is an optical cell for containment of chemicals under conditions of high temperature and high pressure. The cell is formed of a vitreous silica tube, two optical windows comprising a vitreous silica rod inserted into the ends of a tube, and fused into position in the tube ends. Windows are spaced apart to form a cavity enclosed by the tube and the windows. A hole is drilled radially through the tube and into the cavity. Another vitreous silica tube is fused to the silica tube around the hole to form the stem, which is perpendicular to the long axis of the tube. The open end of the stem is used to load chemicals into the cavity. Then the stem may be sealed, and if desired, it may be shortened in order to reduce the volume of the cavity, which extends into the stem.