Influence of Cell Detachment on the Respiration Rate of Tumor and Endothelial Cells

PubMed Central

Danhier, Pierre; Copetti, Tamara; De Preter, Géraldine; Leveque, Philippe; Feron, Olivier; Jordan, Bénédicte F.; Sonveaux, Pierre; Gallez, Bernard

2013-01-01

Cell detachment is a procedure routinely performed in cell culture and a necessary step in many biochemical assays including the determination of oxygen consumption rates (OCR) in vitro. In vivo, cell detachment has been shown to exert profound metabolic influences notably in cancer but also in other pathologies, such as retinal detachment for example. In the present study, we developed and validated a new technique combining electron paramagnetic resonance (EPR) oximetry and the use of cytodex 1 and collagen-coated cytodex 3 dextran microbeads, which allowed the unprecedented comparison of the OCR of adherent and detached cells with high sensitivity. Hence, we demonstrated that both B16F10 melanoma cells and human umbilical vein endothelial cells (HUVEC) experience strong OCR decrease upon trypsin or collagenase treatments. The reduction of cell oxygen consumption was more pronounced with a trypsin compared to a collagenase treatment. Cells remaining in suspension also encounter a marked intracellular ATP depletion and an increase in the lactate production/glucose uptake ratio. These findings highlight the important influence exerted by cell adhesion/detachment on cell respiration, which can be probed with the unprecedented experimental assay that was developed and validated in this study. PMID:23382841

Dissecting the roles of ROCK isoforms in stress-induced cell detachment.

PubMed

Shi, Jianjian; Surma, Michelle; Zhang, Lumin; Wei, Lei

2013-05-15

The homologous Rho kinases, ROCK1 and ROCK2, are involved in stress fiber assembly and cell adhesion and are assumed to be functionally redundant. Using mouse embryonic fibroblasts (MEFs) derived from ROCK1(-/-) and ROCK2(-/-) mice, we have recently reported that they play different roles in regulating doxorubicin-induced stress fiber disassembly and cell detachment: ROCK1 is involved in destabilizing the actin cytoskeleton and cell detachment, whereas ROCK2 is required for stabilizing the actin cytoskeleton and cell adhesion. Here, we present additional insights into the roles of ROCK1 and ROCK2 in regulating stress-induced impairment of cell-matrix and cell-cell adhesion. In response to doxorubicin, ROCK1(-/-) MEFs showed significant preservation of both focal adhesions and adherens junctions, while ROCK2(-/-) MEFs exhibited impaired focal adhesions but preserved adherens junctions compared with the wild-type MEFs. Additionally, inhibition of focal adhesion or adherens junction formations by chemical inhibitors abolished the anti-detachment effects of ROCK1 deletion. Finally, ROCK1(-/-) MEFs, but not ROCK2(-/-) MEFs, also exhibited preserved central stress fibers and reduced cell detachment in response to serum starvation. These results add new insights into a novel mechanism underlying the anti-detachment effects of ROCK1 deletion mediated by reduced peripheral actomyosin contraction and increased actin stabilization to promote cell-cell and cell-matrix adhesion. Our studies further support the differential roles of ROCK isoforms in regulating stress-induced loss of central stress fibers and focal adhesions as well as cell detachment.

Modeling cell-substrate de-adhesion dynamics under fluid shear

NASA Astrophysics Data System (ADS)

Maan, Renu; Rani, Garima; Menon, Gautam I.; Pullarkat, Pramod A.

2018-07-01

Changes in cell-substrate adhesion are believed to signal the onset of cancer metastasis, but such changes must be quantified against background levels of intrinsic heterogeneity between cells. Variations in cell-substrate adhesion strengths can be probed through biophysical measurements of cell detachment from substrates upon the application of an external force. Here, we investigate, theoretically and experimentally, the detachment of cells adhered to substrates when these cells are subjected to fluid shear. We present a theoretical framework within which we calculate the fraction of detached cells as a function of shear stress for fast ramps as well as the decay in this fraction at fixed shear stress as a function of time. Using HEK and 3T3 fibroblast cells as experimental model systems, we extract characteristic force scales for cell adhesion as well as characteristic detachment times. We estimate force-scales of  ∼500 pN associated to a single focal contact, and characteristic time-scales of s representing cell-spread-area dependent mean first passage times to the detached state at intermediate values of the shear stress. Variations in adhesion across cell types are especially prominent when cell detachment is probed by applying a time-varying shear stress. These methods can be applied to characterizing changes in cell adhesion in a variety of contexts, including metastasis.

Comparing the chlorine disinfection of detached biofilm clusters with those of sessile biofilms and planktonic cells in single- and dual-species cultures.

PubMed

Behnke, Sabrina; Parker, Albert E; Woodall, Dawn; Camper, Anne K

2011-10-01

Although the detachment of cells from biofilms is of fundamental importance to the dissemination of organisms in both public health and clinical settings, the disinfection efficacies of commonly used biocides on detached biofilm particles have not been investigated. Therefore, the question arises whether cells in detached aggregates can be killed with disinfectant concentrations sufficient to inactivate planktonic cells. Burkholderia cepacia and Pseudomonas aeruginosa were grown in standardized laboratory reactors as single species and in coculture. Cluster size distributions in chemostats and biofilm reactor effluent were measured. Chlorine susceptibility was assessed for planktonic cultures, attached biofilm, and particles and cells detached from the biofilm. Disinfection tolerance generally increased with a higher percentage of larger cell clusters in the chemostat and detached biofilm. Samples with a lower percentage of large clusters were more easily disinfected. Thus, disinfection tolerance depended on the cluster size distribution rather than sample type for chemostat and detached biofilm. Intact biofilms were more tolerant to chlorine independent of species. Homogenization of samples led to significantly increased susceptibility in all biofilm samples as well as detached clusters for single-species B. cepacia, B. cepacia in coculture, and P. aeruginosa in coculture. The disinfection efficacy was also dependent on species composition; coculture was advantageous to the survival of both species when grown as a biofilm or as clusters detached from biofilm but, surprisingly, resulted in a lower disinfection tolerance when they were grown as a mixed planktonic culture.

Improved light-induced cell detachment on rutile TiO₂ nanodot films.

PubMed

Cheng, Kui; Sun, Yu; Wan, Hongping; Wang, Xiaozhao; Weng, Wenjian; Lin, Jun; Wang, Huiming

2015-10-01

Anatase TiO2 nanodot films have been found to be able to release cells under light illumination with excellent efficiency and safety. In the present study, we investigated the effects of rutile contents in TiO2 nanodot films on such light induced cell detachment behavior. The results showed that TiO2 nanodot films with different contents of rutile phase have been prepared successfully. The content of rutile phase increased with the increase in calcination temperature. All films possessed good cell adhesion but there was a decrease in cell proliferation with the increasing content of rutile phase. Single cell detachment assay showed that the films with high rutile contents (calcined at 900°C and 1100°C) showed better cell detachment performance. That was ascribed to the changes of the secondary structure of extracellular proteins adsorbed on the nanodot surface after ultraviolet (365 nm, UV365) illumination. In addition, cell sheets detached through UV365 illumination maintained high activity and could be further used in tissue engineering. The present work showed that the existence of rutile phase is helpful in cell detachment behavior and it could be utilized to optimize light-induced cell detachment behavior. This work discovers that the presence of rutile phase in TiO2 nanodot films could improve the light-induced cell detachment behavior, although rutile phase is inferior to anatase phase on light induced superhydrophilicity. That strongly supported that the behaviors of adsorbed proteins are crucial in acquiring cell sheet with light illumination. In fact, the state and behavior of adsorbed protein greatly affect the interaction between biomaterials and living cells. Therefore, we consider this work is not only important in harvesting cells or cell sheets through light illumination, but also helpful in further understanding of interaction between biomaterials and cells. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Comparing the Chlorine Disinfection of Detached Biofilm Clusters with Those of Sessile Biofilms and Planktonic Cells in Single- and Dual-Species Cultures ▿ †

PubMed Central

Behnke, Sabrina; Parker, Albert E.; Woodall, Dawn; Camper, Anne K.

2011-01-01

Although the detachment of cells from biofilms is of fundamental importance to the dissemination of organisms in both public health and clinical settings, the disinfection efficacies of commonly used biocides on detached biofilm particles have not been investigated. Therefore, the question arises whether cells in detached aggregates can be killed with disinfectant concentrations sufficient to inactivate planktonic cells. Burkholderia cepacia and Pseudomonas aeruginosa were grown in standardized laboratory reactors as single species and in coculture. Cluster size distributions in chemostats and biofilm reactor effluent were measured. Chlorine susceptibility was assessed for planktonic cultures, attached biofilm, and particles and cells detached from the biofilm. Disinfection tolerance generally increased with a higher percentage of larger cell clusters in the chemostat and detached biofilm. Samples with a lower percentage of large clusters were more easily disinfected. Thus, disinfection tolerance depended on the cluster size distribution rather than sample type for chemostat and detached biofilm. Intact biofilms were more tolerant to chlorine independent of species. Homogenization of samples led to significantly increased susceptibility in all biofilm samples as well as detached clusters for single-species B. cepacia, B. cepacia in coculture, and P. aeruginosa in coculture. The disinfection efficacy was also dependent on species composition; coculture was advantageous to the survival of both species when grown as a biofilm or as clusters detached from biofilm but, surprisingly, resulted in a lower disinfection tolerance when they were grown as a mixed planktonic culture. PMID:21856824

Tauroursodeoxycholic Acid (TUDCA) Protects Photoreceptors from Cell Death after Experimental Retinal Detachment

PubMed Central

Mantopoulos, Dimosthenis; Murakami, Yusuke; Comander, Jason; Thanos, Aristomenis; Roh, Miin; Miller, Joan W.; Vavvas, Demetrios G.

2011-01-01

Background Detachment of photoreceptors from the underlying retinal pigment epithelium is seen in various retinal disorders such as retinal detachment and age-related macular degeneration and leads to loss of photoreceptors and vision. Pharmacologic inhibition of photoreceptor cell death may prevent this outcome. This study tests whether systemic administration of tauroursodeoxycholic acid (TUDCA) can protect photoreceptors from cell death after experimental retinal detachment in rodents. Methodology/Principal Findings Retinal detachment was created in rats by subretinal injection of hyaluronic acid. The animals were treated daily with vehicle or TUDCA (500 mg/kg). TUNEL staining was used to evaluate cell death. Photoreceptor loss was evaluated by measuring the relative thickness of the outer nuclear layer (ONL). Macrophage recruitment, oxidative stress, cytokine levels, and caspase levels were also quantified. Three days after detachment, TUDCA decreased the number of TUNEL-positive cells compared to vehicle (651±68/mm2 vs. 1314±68/mm2, P = 0.001) and prevented the reduction of ONL thickness ratio (0.84±0.03 vs. 0.65±0.03, P = 0.002). Similar results were obtained after 5 days of retinal detachment. Macrophage recruitment and expression levels of TNF-a and MCP-1 after retinal detachment were not affected by TUDCA treatment, whereas increases in activity of caspases 3 and 9 as well as carbonyl-protein adducts were almost completely inhibited by TUDCA treatment. Conclusions/Significance Systemic administration of TUDCA preserved photoreceptors after retinal detachment, and was associated with decreased oxidative stress and caspase activity. TUDCA may be used as a novel therapeutic agent for preventing vision loss in diseases that are characterized by photoreceptor detachment. PMID:21961034

Cell-Adhesive and Cell-Repulsive Zwitterionic Oligopeptides for Micropatterning and Rapid Electrochemical Detachment of Cells

PubMed Central

Kakegawa, Takahiro; Mochizuki, Naoto; Sadr, Nasser; Suzuki, Hiroaki

2013-01-01

In this study, we describe the development of oligopeptide-modified cell culture surfaces from which adherent cells can be rapidly detached by application of an electrical stimulus. An oligopeptide, CGGGKEKEKEK, was designed with a terminal cysteine residue to mediate binding to a gold surface via a gold–thiolate bond. The peptide forms a self-assembled monolayer through the electrostatic force between the sequence of alternating charged glutamic acid (E) and lysine (K) residues. The dense and electrically neutral oligopeptide zwitterionic layer of the modified surface was resistant to nonspecific adsorption of proteins and adhesion of cells, while the surface was altered to cell adhesive by the addition of a second oligopeptide (CGGGKEKEKEKGRGDSP) containing the RGD cell adhesion motif. Application of a negative electrical potential to this gold surface cleaved the gold–thiolate bond, leading to desorption of the oligopeptide layer, and rapid (within 2 min) detachment of virtually all cells. This approach was applicable not only to detachment of cell sheets but also for transfer of cell micropatterns to a hydrogel. This electrochemical approach of cell detachment may be a useful tool for tissue-engineering applications. PMID:22853640

Effectiveness of EDTA and Modified Salt Solution to Detach and Kill Cells from Enterococcus faecalis Biofilm.

PubMed

de Almeida, Josiane; Hoogenkamp, Michel; Felippe, Wilson T; Crielaard, Wim; van der Waal, Suzette V

2016-02-01

Disruption of the matrix of endodontic biofilms will aid in their removal from a root canal. Therefore, the aim of this study was to investigate the efficacy of EDTA and a modified salt solution (MSS) to detach bacteria from biofilms. Forty-eight-hour-old Enterococcus faecalis biofilms were grown on glass coverslips and then treated for 1 hour by immersion in 17% EDTA or MSS. Phosphate-buffered saline served as a negative control. Then, residual biofilm cells on the substrate and the detached cells in the supernatant were collected. Viability was verified by the colony-forming unit (CFU) counting method. Propidium monoazide (PMA) treatment in conjunction with quantitative polymerase chain reaction (qPCR) was also performed to detect the presence of E. faecalis 16S ribonucleic RNA genes. Data were analyzed using 1-way analysis of variance and Tukey or Kruskal-Wallis and Dunn tests. The Pearson R test evaluated the correlation between results from CFU and PMA (α = 5%). qPCR showed that EDTA detached 99% of biofilm cells, and MSS detached 94% of biofilm cells (both P < .001). In contrast to EDTA, MSS was highly antimicrobial. The treatment promoted an ample log 7 reduction of the attached cells (P < .001), and almost no live cells were detected in the supernatant (P < .001). Positive correlations between CFU and qPCR with PMA were observed (r = 0.959 and r = 0.729). EDTA detached cells in biofilms with a minor antimicrobial effect. Besides a great antimicrobial effect, MSS also detached biofilm cells. These dispersals of biofilms give insights into new endodontic biofilm removal strategies. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evidence that ganglion cells react to retinal detachment.

PubMed

Coblentz, Francie E; Radeke, Monte J; Lewis, Geoffrey P; Fisher, Steven K

2003-03-01

Growth associated protein 43 (GAP 43) is involved in synapse formation and it is expressed in the retina in a very specific pattern. Although GAP 43 is downregulated at the time of synapse formation, it can be re-expressed following injury such as axotomy or ischemia. Because of this we sought to characterize the expression of GAP 43 after retinal detachment (RD). Immunoblot, immunocytochemical and quantitative polymerase chain reaction (QPCR) techniques were used to assess the level of GAP 43 expression after experimental RD. GAP 43 was localized to three sublaminae of the inner plexiform layer of the normal retina. GAP 43 became upregulated in a subset of retinal ganglion cells following at least 7 days of RD. By immunoblot GAP 43 could be detected by 3 days. QPCR shows the upregulation of GAP 43 message by 6hr of detachment. To further characterize changes in ganglion cells, we used an antibody to neurofilament 70 and 200kDa (NF) proteins. Anti-NF labels horizontal cells, ganglion cell dendrites in the inner plexiform layer, and ganglion cell axons (fasicles) in the normal retina. Following detachment it is upregulated in horizontal cells and ganglion cells. When detached retina was double labelled with anti-GAP 43 and anti-NF, some cells were labelled with both markers, while others labelled with only one. We have previously shown that second order neurons respond to detachment; here we show that third order neurons are responding as well. Cellular remodelling of this type in response to detachment may explain the slow recovery of vision that often occurs after reattachment, or those changes that are often assumed to be permanent.

A Direct Cell Quenching Method for Cell-Culture Based Metabolomics

EPA Science Inventory

A crucial step in metabolomic analysis of cellular extracts is the cell quenching process. The conventional method first uses trypsin to detach cells from their growth surface. This inevitably changes the profile of cellular metabolites since the detachment of cells from the extr...

Noncontact laser microsurgery of three-dimensional living objects for use in reproductive and regenerative medicine

NASA Astrophysics Data System (ADS)

Sitnikov, D. S.; Ilina, I. V.; Kosheleva, N. V.; Khramova, Yu V.; Filatov, M. A.; Semenova, M. L.; Zurina, I. M.; Gorkun, A. A.; Saburina, I. N.

2018-01-01

Laser microsurgery has enabled us to make highly precise and delicate processing of living biological specimens. We present the results of using femtosecond (fs) laser pulses in assisted reproductive technologies. Femtosecond laser dissection of outer shells of embryos (so-called laser-assisted hatching) as well as laser-mediated detachment of the desired amount of trophectoderm cells (so-called embryo biopsy) required for preimplantaion genetic diagnosis were successfully performed. The parameters of laser radiation were optimized so as to efficiently perform embryo biopsy and preserve the viability of the treated embryos. Effects of application of fs-laser radiation in the infrared (1028 nm) and visible (514 nm) wavelength ranges were studied. We also applied laser microsurgery to develop a new simple reproducible model for studying repair and regeneration in vitro. Nanosecond laser pulses were applied to perform localized microdissection of cell spheroids. After microdissection, the edges of the wound surface opened, the destruction of the initial spheroid structure was observed in the wound area, with surviving cells changing their shape into a round one. It was shown that the spheroid form partially restored in the first six hours with subsequent complete restoration within seven days due to remodeling of surviving cells.

Quantifying cell adhesion through impingement of a controlled microjet.

PubMed

Visser, Claas Willem; Gielen, Marise V; Hao, Zhenxia; Le Gac, Séverine; Lohse, Detlef; Sun, Chao

2015-01-06

The impingement of a submerged, liquid jet onto a cell-covered surface allows assessing cell attachment on surfaces in a straightforward and quantitative manner and in real time, yielding valuable information on cell adhesion. However, this approach is insufficiently characterized for reliable and routine use. In this work, we both model and measure the shear stress exerted by the jet on the impingement surface in the micrometer-domain, and subsequently correlate this to jet-induced cell detachment. The measured and numerically calculated shear stress data are in good agreement with each other, and with previously published values. Real-time monitoring of the cell detachment reveals the creation of a circular cell-free area upon jet impingement, with two successive detachment regimes: 1), a dynamic regime, during which the cell-free area grows as a function of both the maximum shear stress exerted by the jet and the jet diameter; followed by 2), a stationary regime, with no further evolution of the cell-free area. For the latter regime, which is relevant for cell adhesion strength assessment, a relationship between the jet Reynolds number, the cell-free area, and the cell adhesion strength is proposed. To illustrate the capability of the technique, the adhesion strength of HeLa cervical cancer cells is determined ((34 ± 14) N/m(2)). Real-time visualization of cell detachment in the dynamic regime shows that cells detach either cell-by-cell or by collectively (for which intact parts of the monolayer detach as cell sheets). This process is dictated by the cell monolayer density, with a typical threshold of (1.8 ± 0.2) × 10(9) cells/m(2), above which the collective behavior is mostly observed. The jet impingement method presents great promises for the field of tissue engineering, as the influence of both the shear stress and the surface characteristics on cell adhesion can be systematically studied. Copyright © 2015 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Nitric Oxide Regulates Lung Carcinoma Cell Anoikis through Inhibition of Ubiquitin-Proteasomal Degradation of Caveolin-1*

PubMed Central

Chanvorachote, Pithi; Nimmannit, Ubonthip; Lu, Yongju; Talbott, Siera; Jiang, Bing-Hua; Rojanasakul, Yon

2009-01-01

Anoikis, a detachment-induced apoptosis, is a principal mechanism of inhibition of tumor cell metastasis. Tumor cells can acquire anoikis resistance which is frequently observed in metastatic lung cancer. This phenomenon becomes an important obstacle of efficient cancer therapy. Recently, signaling mediators such as caveolin-1 (Cav-1) and nitric oxide (NO) have garnered attention in metastasis research; however, their role and the underlying mechanisms of metastasis regulation are largely unknown. Using human lung carcinoma H460 cells, we show that NO impairs the apoptotic function of the cells after detachment. The NO donors sodium nitroprusside and diethylenetriamine NONOate inhibit detachment-induced apoptosis, whereas the NO inhibitors aminoguanidine and 2-(4-carboxyphenyl) tetramethylimidazoline-1-oxyl-3-oxide promote this effect. Resistance to anoikis in H460 cells is mediated by Cav-1, which is significantly down-regulated after cell detachment through a non-transcriptional mechanism involving ubiquitin-proteasomal degradation. NO inhibits this down-regulation by interfering with Cav-1 ubiquitination through a process that involves protein S-nitrosylation, which prevents its proteasomal degradation and induction of anoikis by cell detachment. These findings indicate a novel pathway for NO regulation of Cav-1, which could be a key mechanism of anoikis resistance in tumor cells. PMID:19706615

Nitric oxide regulates lung carcinoma cell anoikis through inhibition of ubiquitin-proteasomal degradation of caveolin-1.

PubMed

Chanvorachote, Pithi; Nimmannit, Ubonthip; Lu, Yongju; Talbott, Siera; Jiang, Bing-Hua; Rojanasakul, Yon

2009-10-09

Anoikis, a detachment-induced apoptosis, is a principal mechanism of inhibition of tumor cell metastasis. Tumor cells can acquire anoikis resistance which is frequently observed in metastatic lung cancer. This phenomenon becomes an important obstacle of efficient cancer therapy. Recently, signaling mediators such as caveolin-1 (Cav-1) and nitric oxide (NO) have garnered attention in metastasis research; however, their role and the underlying mechanisms of metastasis regulation are largely unknown. Using human lung carcinoma H460 cells, we show that NO impairs the apoptotic function of the cells after detachment. The NO donors sodium nitroprusside and diethylenetriamine NONOate inhibit detachment-induced apoptosis, whereas the NO inhibitors aminoguanidine and 2-(4-carboxyphenyl) tetramethylimidazoline-1-oxyl-3-oxide promote this effect. Resistance to anoikis in H460 cells is mediated by Cav-1, which is significantly down-regulated after cell detachment through a non-transcriptional mechanism involving ubiquitin-proteasomal degradation. NO inhibits this down-regulation by interfering with Cav-1 ubiquitination through a process that involves protein S-nitrosylation, which prevents its proteasomal degradation and induction of anoikis by cell detachment. These findings indicate a novel pathway for NO regulation of Cav-1, which could be a key mechanism of anoikis resistance in tumor cells.

Detachment of Chain-Forming Neuroblasts by Fyn-Mediated Control of cell-cell Adhesion in the Postnatal Brain.

PubMed

Fujikake, Kazuma; Sawada, Masato; Hikita, Takao; Seto, Yayoi; Kaneko, Naoko; Herranz-Pérez, Vicente; Dohi, Natsuki; Homma, Natsumi; Osaga, Satoshi; Yanagawa, Yuchio; Akaike, Toshihiro; García-Verdugo, Jose Manuel; Hattori, Mitsuharu; Sobue, Kazuya; Sawamoto, Kazunobu

2018-05-09

In the rodent olfactory system, neuroblasts produced in the ventricular-subventricular zone of the postnatal brain migrate tangentially in chain-like cell aggregates toward the olfactory bulb (OB) through the rostral migratory stream (RMS). After reaching the OB, the chains are dissociated and the neuroblasts migrate individually and radially toward their final destination. The cellular and molecular mechanisms controlling cell-cell adhesion during this detachment remain unclear. Here we report that Fyn, a nonreceptor tyrosine kinase, regulates the detachment of neuroblasts from chains in the male and female mouse OB. By performing chemical screening and in vivo loss-of-function and gain-of-function experiments, we found that Fyn promotes somal disengagement from the chains and is involved in neuronal migration from the RMS into the granule cell layer of the OB. Fyn knockdown or Dab1 (disabled-1) deficiency caused p120-catenin to accumulate and adherens junction-like structures to be sustained at the contact sites between neuroblasts. Moreover, a Fyn and N-cadherin double-knockdown experiment indicated that Fyn regulates the N-cadherin-mediated cell adhesion between neuroblasts. These results suggest that the Fyn-mediated control of cell-cell adhesion is critical for the detachment of chain-forming neuroblasts in the postnatal OB. SIGNIFICANCE STATEMENT In the postnatal brain, newly born neurons (neuroblasts) migrate in chain-like cell aggregates toward their destination, where they are dissociated into individual cells and mature. The cellular and molecular mechanisms controlling the detachment of neuroblasts from chains are not understood. Here we show that Fyn, a nonreceptor tyrosine kinase, promotes the somal detachment of neuroblasts from chains, and that this regulation is critical for the efficient migration of neuroblasts to their destination. We further show that Fyn and Dab1 (disabled-1) decrease the cell-cell adhesion between chain-forming neuroblasts, which involves adherens junction-like structures. Our results suggest that Fyn-mediated regulation of the cell-cell adhesion of neuroblasts is critical for their detachment from chains in the postnatal brain. Copyright © 2018 the authors 0270-6474/18/384599-12$15.00/0.

Round Cell Tumors: Classification and Immunohistochemistry.

PubMed

Sharma, Shweta; Kamala, R; Nair, Divya; Ragavendra, T Raju; Mhatre, Swapnil; Sabharwal, Robin; Choudhury, Basanta Kumar; Rana, Vivek

2017-01-01

Round cell tumors as the name suggest are comprised round cells with increased nuclear-cytoplasmic ratio. This group of tumor includes entities such as peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilms' tumor, and desmoplastic small round cell tumor. These round cells tumors are characterized by typical histological pattern, immunohistochemical, and electron microscopic features that can help in differential diagnosis. The present article describes the classification and explains the histopathology and immunohistochemistry of some important round cell tumors.

Rapamycin regulates autophagy and cell adhesion in induced pluripotent stem cells.

PubMed

Sotthibundhu, Areechun; McDonagh, Katya; von Kriegsheim, Alexander; Garcia-Munoz, Amaya; Klawiter, Agnieszka; Thompson, Kerry; Chauhan, Kapil Dev; Krawczyk, Janusz; McInerney, Veronica; Dockery, Peter; Devine, Michael J; Kunath, Tilo; Barry, Frank; O'Brien, Timothy; Shen, Sanbing

2016-11-15

Cellular reprogramming is a stressful process, which requires cells to engulf somatic features and produce and maintain stemness machineries. Autophagy is a process to degrade unwanted proteins and is required for the derivation of induced pluripotent stem cells (iPSCs). However, the role of autophagy during iPSC maintenance remains undefined. Human iPSCs were investigated by microscopy, immunofluorescence, and immunoblotting to detect autophagy machinery. Cells were treated with rapamycin to activate autophagy and with bafilomycin to block autophagy during iPSC maintenance. High concentrations of rapamycin treatment unexpectedly resulted in spontaneous formation of round floating spheres of uniform size, which were analyzed for differentiation into three germ layers. Mass spectrometry was deployed to reveal altered protein expression and pathways associated with rapamycin treatment. We demonstrate that human iPSCs express high basal levels of autophagy, including key components of APMKα, ULK1/2, BECLIN-1, ATG13, ATG101, ATG12, ATG3, ATG5, and LC3B. Block of autophagy by bafilomycin induces iPSC death and rapamycin attenuates the bafilomycin effect. Rapamycin treatment upregulates autophagy in iPSCs in a dose/time-dependent manner. High concentration of rapamycin reduces NANOG expression and induces spontaneous formation of round and uniformly sized embryoid bodies (EBs) with accelerated differentiation into three germ layers. Mass spectrometry analysis identifies actin cytoskeleton and adherens junctions as the major targets of rapamycin in mediating iPSC detachment and differentiation. High levels of basal autophagy activity are present during iPSC derivation and maintenance. Rapamycin alters expression of actin cytoskeleton and adherens junctions, induces uniform EB formation, and accelerates differentiation. IPSCs are sensitive to enzyme dissociation and require a lengthy differentiation time. The shape and size of EBs also play a role in the heterogeneity of end cell products. This research therefore highlights the potential of rapamycin in producing uniform EBs and in shortening iPSC differentiation duration.

ETV4 is a useful marker for the diagnosis of CIC-rearranged undifferentiated round-cell sarcomas: a study of 127 cases including mimicking lesions.

PubMed

Le Guellec, Sophie; Velasco, Valérie; Pérot, Gaëlle; Watson, Sarah; Tirode, Franck; Coindre, Jean-Michel

2016-12-01

Subsets of primitive round-cell sarcomas remain difficult to diagnose and classify. Among these is a rare round-cell sarcoma that harbors a CIC gene rearrangement known as CIC-rearranged undifferentiated round-cell sarcoma, which is most commonly fused to the DUX4 gene. Owing to its aggressive clinical behavior and potential therapeutic implications, accurate identification of this novel soft tissue sarcoma is necessary. Definitive diagnosis requires molecular confirmation, but only a few centers are as yet able to perform this test. Several studies have shown that PEA3 subfamily genes, notably ETV4 (belonging to the family of ETS transcription factors), are upregulated in CIC-rearranged undifferentiated round-cell sarcomas. We performed a detailed immunohistochemical analysis to investigate ETV4 expression in CIC-rearranged undifferentiated round-cell sarcomas and their potential mimics (especially Ewing sarcomas). The study cohort included 17 cases of CIC-rearranged undifferentiated round-cell sarcomas, and 110 tumors that morphologically mimic CIC-rearranged undifferentiated round-cell sarcomas: 43 Ewing sarcomas, 25 alveolar rhabdomyosarcomas, 20 poorly differentiated round-cell synovial sarcomas, 10 desmoplastic round-cell tumors, 5 BCOR-CCNB3 sarcomas, 5 lymphoblastic lymphomas, and 2 rhabdoid tumors. All CIC-rearranged undifferentiated round-cell sarcomas (on core needle biopsies and open biopsies) were ETV4-positive with a strong diffuse nuclear pattern. Among the other 110 tumors, only six cases (four Ewing sarcomas, one alveolar rhabdomyosarcoma, and one desmoplastic round-cell tumor) showed focal (<5% of tumor cells) and very weak nuclear expression of ETV4; all other tumors were completely negative for ETV4. We conclude that systematic immunohistochemical analysis of ETV4 makes it possible to diagnose undifferentiated round-cell sarcomas (with no molecular markers for sarcoma-associated translocation) such as CIC-rearranged undifferentiated round-cell sarcoma.

Flow-induced detachment of red blood cells adhering to surfaces by specific antigen-antibody bonds.

PubMed

Xia, Z; Goldsmith, H L; van de Ven, T G

1994-04-01

Fixed spherical swollen human red blood cells of blood type B adhering on a glass surface through antigen-antibody bonds to monoclonal mouse antihuman IgM, adsorbed or covalently linked on the surface, were detached by known hydrodynamic forces created in an impinging jet. The dynamic process of detachment of the specifically bound cells was recorded and analyzed. The fraction of adherent cells remaining on the surface decreased with increasing hydrodynamic force. For an IgM coverage of 0.26%, a tangential force on the order of 100 pN was able to detach almost all of the cells from the surface within 20 min. After a given time of exposure to hydrodynamic force, the fraction of adherent cells remaining increased with time, reflecting an increase in adhesion strength. The characteristic time for effective aging was approximately 4 h. Results from experiments in which the adsorbed antibody molecules were immobilized through covalent coupling and from evanescent wave light scattering of adherent cells, imply that deformation of red cells at the contact area was the principal cause for aging, rather than local clustering of the antibody through surface diffusion. Experiments with latex beads specifically bound to red blood cells suggest that, instead of breaking the antigen-antibody bonds, antigen molecules were extracted from the cell membrane during detachment.

A single-cell scraper based on an atomic force microscope for detaching a living cell from a substrate

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

Iwata, Futoshi, E-mail: iwata.futoshi@shizuoka.ac.jp; Research Institute of Electronics, Shizuoka University, Johoku, Naka-ku, Hamamatsu 432-8011; Adachi, Makoto

We describe an atomic force microscope (AFM) manipulator that can detach a single, living adhesion cell from its substrate without compromising the cell's viability. The micrometer-scale cell scraper designed for this purpose was fabricated from an AFM micro cantilever using focused ion beam milling. The homemade AFM equipped with the scraper was compact and standalone and could be mounted on a sample stage of an inverted optical microscope. It was possible to move the scraper using selectable modes of operation, either a manual mode with a haptic device or a computer-controlled mode. The viability of the scraped single cells wasmore » evaluated using a fluorescence dye of calcein-acetoxymethl ester. Single cells detached from the substrate were collected by aspiration into a micropipette capillary glass using an electro-osmotic pump. As a demonstration, single HeLa cells were selectively detached from the substrate and collected by the micropipette. It was possible to recultivate HeLa cells from the single cells collected using the system.« less

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

NASA Astrophysics Data System (ADS)

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V.; Noll, Thomas; Funk, Richard H. W.; Engelmann, Katrin; Werner, Carsten

2015-08-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)-the effect of biomolecular ligands to balance cell adhesion and stimulated detachment.

PubMed

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V; Noll, Thomas; Funk, Richard H W; Engelmann, Katrin; Werner, Carsten

2015-08-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly( N -isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na + /K + -ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro . The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty.

Thermo-responsive cell culture carriers based on poly(vinyl methyl ether)—the effect of biomolecular ligands to balance cell adhesion and stimulated detachment

PubMed Central

Teichmann, Juliane; Nitschke, Mirko; Pette, Dagmar; Valtink, Monika; Gramm, Stefan; Härtel, Frauke V; Noll, Thomas; Funk, Richard H W; Engelmann, Katrin; Werner, Carsten

2015-01-01

Two established material systems for thermally stimulated detachment of adherent cells were combined in a cross-linked polymer blend to merge favorable properties. Through this approach poly(N-isopropylacrylamide) (PNiPAAm) with its superior switching characteristic was paired with a poly(vinyl methyl ether)-based composition that allows adjusting physico-chemical and biomolecular properties in a wide range. Beyond pure PNiPAAm, the proposed thermo-responsive coating provides thickness, stiffness and swelling behavior, as well as an apposite density of reactive sites for biomolecular functionalization, as effective tuning parameters to meet specific requirements of a particular cell type regarding initial adhesion and ease of detachment. To illustrate the strength of this approach, the novel cell culture carrier was applied to generate transplantable sheets of human corneal endothelial cells (HCEC). Sheets were grown, detached, and transferred onto planar targets. Cell morphology, viability and functionality were analyzed by immunocytochemistry and determination of transepithelial electrical resistance (TEER) before and after sheet detachment and transfer. HCEC layers showed regular morphology with appropriate TEER. Cells were positive for function-associated marker proteins ZO-1, Na+/K+-ATPase, and paxillin, and extracellular matrix proteins fibronectin, laminin and collagen type IV before and after transfer. Sheet detachment and transfer did not impair cell viability. Subsequently, a potential application in ophthalmology was demonstrated by transplantation onto de-endothelialized porcine corneas in vitro. The novel thermo-responsive cell culture carrier facilitates the generation and transfer of functional HCEC sheets. This paves the way to generate tissue engineered human corneal endothelium as an alternative transplant source for endothelial keratoplasty. PMID:27877823

Bim, a Proapoptotic Protein, Up-regulated via Transcription Factor E2F1-dependent Mechanism, Functions as a Prosurvival Molecule in Cancer*

PubMed Central

Gogada, Raghu; Yadav, Neelu; Liu, Junwei; Tang, Shaohua; Zhang, Dianmu; Schneider, Andrea; Seshadri, Athul; Sun, Leimin; Aldaz, C. Marcelo; Tang, Dean G.; Chandra, Dhyan

2013-01-01

Proapoptotic Bcl-2 homology 3-only protein Bim plays an important role in Bax/Bak-mediated cytochrome c release and apoptosis. Here, we provide evidence for a novel prosurvival function of Bim in cancer cells. Bim was constitutively overexpressed in multiple prostate and breast cancer cells as well as in primary tumor cells. Quantitative real time PCR analysis showed that Bim was transcriptionally up-regulated. We have identified eight endogenous E2F1-binding sites on the Bim promoter using in silico analysis. Luciferase assay demonstrated that Bim expression was E2F1-dependent as mutation of the E2F1-binding sites on the Bim promoter inhibited luciferase activities. In support, E2F1 silencing led to the loss of Bim expression in cancer cells. Bim primarily localized to mitochondrial and cytoskeleton-associated fractions. Bim silencing or microinjection of anti-Bim antibodies into the cell cytoplasm resulted in cell rounding, detachment, and subsequent apoptosis. We observed up-regulation of prosurvival proteins Bcl-xL and Mcl-1, which sequester Bim in cancer cells. In addition, a phosphorylated form of Bim was also elevated in cancer cells. These findings suggest that the constitutively overexpressed Bim may function as a prosurvival molecule in epithelial cancer cells, and phosphorylation and association with Bcl-xL/Mcl-1 block its proapoptotic functions. PMID:23152504

Diverse matrix metalloproteinase functions regulate cancer amoeboid migration

PubMed Central

Orgaz, Jose L.; Pandya, Pahini; Viros, Amaya; Albrengues, Jean; Nestle, Frank O.; Ridley, Anne J.; Gaggioli, Cedric; Marais, Richard; Karagiannis, Sophia N.; Sanz-Moreno, Victoria

2014-01-01

Rounded-amoeboid cancer cells use actomyosin contractility driven by Rho-ROCK and JAK-STAT3 to migrate efficiently. It has been suggested that rounded-amoeboid cancer cells do not require matrix metalloproteinases (MMPs) to invade. Here we compare MMP levels in rounded-amoeboid and elongated-mesenchymal melanoma cells. Surprisingly, we find that rounded-amoeboid melanoma cells secrete higher levels of several MMPs, including collagenase MMP-13 and gelatinase MMP-9. As a result, rounded-amoeboid melanoma cells degrade collagen I more efficiently than elongated-mesenchymal cells. Furthermore, using a non-catalytic mechanism, MMP-9 promotes rounded-amoeboid 3D migration through regulation of actomyosin contractility via CD44 receptor. MMP-9 is upregulated in a panel of rounded-amoeboid compared with elongated-mesenchymal melanoma cell lines and its levels are controlled by ROCK-JAK-STAT3 signalling. MMP-9 expression increases during melanoma progression and it is particularly prominent in the invasive fronts of lesions, correlating with cell roundness. Therefore, rounded-amoeboid cells use both catalytic and non-catalytic activities of MMPs for invasion. PMID:24963846

Inhibition of Ebola virus glycoprotein-mediated cytotoxicity by targeting its transmembrane domain and cholesterol.

PubMed

Hacke, Moritz; Björkholm, Patrik; Hellwig, Andrea; Himmels, Patricia; Ruiz de Almodóvar, Carmen; Brügger, Britta; Wieland, Felix; Ernst, Andreas M

2015-07-09

The high pathogenicity of the Ebola virus reflects multiple concurrent processes on infection. Among other important determinants, Ebola fusogenic glycoprotein (GP) has been associated with the detachment of infected cells and eventually leads to vascular leakage and haemorrhagic fever. Here we report that the membrane-anchored GP is sufficient to induce the detachment of adherent cells. The results show that the detachment induced through either full-length GP1,2 or the subunit GP2 depends on cholesterol and the structure of the transmembrane domain. These data reveal a novel molecular mechanism in which GP regulates Ebola virus assembly and suggest that cholesterol-reducing agents could be useful as therapeutics to counteract GP-mediated cell detachment.

Multi-scale computational study of the mechanical regulation of cell mitotic rounding in epithelia

PubMed Central

Xu, Zhiliang; Zartman, Jeremiah J.; Alber, Mark

2017-01-01

Mitotic rounding during cell division is critical for preventing daughter cells from inheriting an abnormal number of chromosomes, a condition that occurs frequently in cancer cells. Cells must significantly expand their apical area and transition from a polygonal to circular apical shape to achieve robust mitotic rounding in epithelial tissues, which is where most cancers initiate. However, how cells mechanically regulate robust mitotic rounding within packed tissues is unknown. Here, we analyze mitotic rounding using a newly developed multi-scale subcellular element computational model that is calibrated using experimental data. Novel biologically relevant features of the model include separate representations of the sub-cellular components including the apical membrane and cytoplasm of the cell at the tissue scale level as well as detailed description of cell properties during mitotic rounding. Regression analysis of predictive model simulation results reveals the relative contributions of osmotic pressure, cell-cell adhesion and cortical stiffness to mitotic rounding. Mitotic area expansion is largely driven by regulation of cytoplasmic pressure. Surprisingly, mitotic shape roundness within physiological ranges is most sensitive to variation in cell-cell adhesivity and stiffness. An understanding of how perturbed mechanical properties impact mitotic rounding has important potential implications on, amongst others, how tumors progressively become more genetically unstable due to increased chromosomal aneuploidy and more aggressive. PMID:28531187

Cell sheet mechanics: How geometrical constraints induce the detachment of cell sheets from concave surfaces.

PubMed

Yamashita, Tadahiro; Kollmannsberger, Philip; Mawatari, Kazuma; Kitamori, Takehiko; Vogel, Viola

2016-11-01

Despite of the progress made to engineer structured microtissues such as BioMEMS and 3D bioprinting, little control exists how microtissues transform as they mature, as the misbalance between cell-generated forces and the strength of cell-cell and cell-substrate contacts can result in unintended tissue deformations and ruptures. To develop a quantitative perspective on how cellular contractility, scaffold curvature and cell-substrate adhesion control such rupture processes, human aortic smooth muscle cells were grown on glass substrates with submillimeter semichannels. We quantified cell sheet detachment from 3D confocal image stacks as a function of channel curvature and cell sheet tension by adding different amounts of Blebbistatin and TGF-β to inhibit or enhance cell contractility, respectively. We found that both higher curvature and higher contractility increased the detachment probability. Variations of the adhesive strength of the protein coating on the substrate revealed that the rupture plane was localized along the substrate-extracellular matrix interface for non-covalently adsorbed adhesion proteins, while the collagen-integrin interface ruptured when collagen I was covalently crosslinked to the substrate. Finally, a simple mechanical model is introduced that quantitatively explains how the tuning of substrate curvature, cell sheet contractility and adhesive strength can be used as tunable parameters as summarized in a first semi-quantitative phase diagram. These parameters can thus be exploited to either inhibit or purposefully induce a collective detachment of sheet-like microtissues for the use in tissue engineering and regenerative therapies. Despite of the significant progress in 3D tissue fabrication technologies at the microscale, there is still no quantitative model that can predict if cells seeded on a 3D structure maintain the imposed geometry while they form a continuous microtissue. Especially, detachment or loss of shape control of growing tissue is a major concern when designing 3D-structured scaffolds. Utilizing semi-cylindrical channels and vascular smooth muscle cells, we characterized how geometrical and mechanical parameters such as curvature of the substrate, cellular contractility, or protein-substrate adhesion strength tune the catastrophic detachment of microtissue. Observed results were rationalized by a theoretical model. The phase diagram showing how unintended tissue detachment progresses would help in designing of mechanically-balanced 3D scaffolds in future tissue engineering applications. Copyright © 2016. Published by Elsevier Ltd.

Hypoxic HepG2 cell adaptation decreases ATP synthase dimers and ATP production in inflated cristae by mitofilin down-regulation concomitant to MICOS clustering.

PubMed

Plecitá-Hlavatá, Lydie; Engstová, Hana; Alán, Lukáš; Špaček, Tomáš; Dlasková, Andrea; Smolková, Katarína; Špačková, Jitka; Tauber, Jan; Strádalová, Vendula; Malínský, Jan; Lessard, Mark; Bewersdorf, Joerg; Ježek, Petr

2016-05-01

The relationship of the inner mitochondrial membrane (IMM) cristae structure and intracristal space (ICS) to oxidative phosphorylation (oxphos) is not well understood. Mitofilin (subunit Mic60) of the mitochondrial contact site and cristae organizing system (MICOS) IMM complex is attached to the outer membrane (OMM) via the sorting and assembly machinery/topogenesis of mitochondrial outer membrane β-barrel proteins (SAM/TOB) complex and controls the shape of the cristae. ATP synthase dimers determine sharp cristae edges, whereas trimeric OPA1 tightens ICS outlets. Metabolism is altered during hypoxia, and we therefore studied cristae morphology in HepG2 cells adapted to 5% oxygen for 72 h. Three dimensional (3D), super-resolution biplane fluorescence photoactivation localization microscopy with Eos-conjugated, ICS-located lactamase-β indicated hypoxic ICS expansion with an unchanged OMM (visualized by Eos-mitochondrial fission protein-1). 3D direct stochastic optical reconstruction microscopy immunocytochemistry revealed foci of clustered mitofilin (but not MICOS subunit Mic19) in contrast to its even normoxic distribution. Mitofilin mRNA and protein decreased by ∼20%. ATP synthase dimers vs monomers and state-3/state-4 respiration ratios were lower during hypoxia. Electron microscopy confirmed ICS expansion (maximum in glycolytic cells), which was absent in reduced or OMM-detached cristae of OPA1- and mitofilin-silenced cells, respectively. Hypoxic adaptation is reported as rounding sharp cristae edges and expanding cristae width (ICS) by partial mitofilin/Mic60 down-regulation. Mitofilin-depleted MICOS detaches from SAM while remaining MICOS with mitofilin redistributes toward higher interdistances. This phenomenon causes partial oxphos dormancy in glycolytic cells via disruption of ATP synthase dimers.-Plecitá-Hlavatá, L., Engstová, H., Alán, L., Špaček, T., Dlasková, A., Smolková, K., Špačková, J., Tauber, J., Strádalová, V., Malínský, J., Lessard, M., Bewersdorf, J., Ježek, P. Hypoxic HepG2 cell adaptation decreases ATP synthase dimers and ATP production in inflated cristae by mitofilin down-regulation concomitant to MICOS clustering. © FASEB.

Role of apoptosis and mitosis during human eye development.

PubMed

Bozanić, Darka; Tafra, Robert; Saraga-Babić, Mirna

2003-08-01

The spatial and temporal distribution as well as ultrastructural and biochemical characteristics of apoptotic and mitotic cells during human eye development were investigated in 14 human conceptuses of 4-9 postovulatory weeks, using electron and light microscopy. In the 5th developmental week, apoptotic and mitotic cells were found in the neuroepithelium of the optic cup and stalk, being the most numerous at the borderline between the two layers of the optic cup, and at the place of transition of the optic cup into stalk. They were also found at the region of detachment of the lens pit from the surface ectoderm. In the later developmental stages (the 6th-the 9th week), apoptotic and mitotic cells were observed in the neural retina and the anterior lens epithelium. Throughout all stages examined, mitotic cells were found exclusively adjacent to the lumen either of the intraretinal space or the optic stalk ventricle, or were restricted to the superficial epithelial layer of the lens primordium. Unlike mitotic cells, apoptotic cells occurred throughout the whole width both of the neuroepithelium and the surface epithelium. Ultrastructurally, apoptotic cells were characterised by round- or crescent-shaped condensations of chromatin near the nuclear membrane, while in the more advanced stages of apoptosis by apoptotic bodies. The distribution of caspase-3-positive cells coincided with the location of apoptotic cells described by morphological techniques indicating that the caspase-3-dependent apoptotic pathway operates during the all stages of human eye development. The location of cells positive for anti-apoptotic bcl-2 protein was in accordance with the regions of eye with high mitotic activity, confirming the role of bcl-2 in protecting cells from apoptosis. In the earliest stage of eye development, apoptosis and mitosis might be associated with the sculpturing of the walls of optic cup and stalk, while high mitotic activity along the intraretinal space and optic stalk ventricle indicates its role in the gradual luminal closure. These processes also participate in the detachment of the lens pit epithelium from the surface ectoderm as well as in further closure of the lens vesicle. Later on, both processes seem to be involved in the neural retina differentiation, lens morphogenesis and secondary lens fibre differentiation.

Antitumor Effects In Vitro and In Vivo and Mechanisms of Protection against Melanoma B16F10-Nex2 Cells By Fastuosain, a Cysteine Proteinase from Bromelia fastuosa1

PubMed Central

Guimarães-Ferreira, Carla A; Rodrigues, Elaine G; Mortara, Renato A; Cabral, Hamilton; Serrano, Fabiana A; Ribeiro-dos-Santos, Ricardo; Travassos, Luiz R

2007-01-01

In the present work, the antitumor effect of fastuosain, a cysteine proteinase from Bromelia fastuosa, was investigated. In the intravenous model of lung colonization in C57Bl/6 mice, fastuosain and bromelain injected intraperitoneally were protective, and very few nodules of B16F10-Nex2 melanoma cells were detected. Tumor cells treated with fastuosain showed reduced expression of CD44 and decreased invasion through Matrigel, lost their cytoplasmic extensions and substrate adherence, and became round and detached, forming strongly bound cell clusters in suspension. Peritoneal cells recruited and activated by fastuosain treatment (mainly monocytic cells and lymphocytes) migrated to the lung, where pulmonary melanoma metastases grew. Adoptive transference of peritoneal cells recruited by fastuosain had no protective effect against lung metastases in recipient mice. Treatment of green fluorescent protein-chimeric animals with fastuosain did not change the number of cells that migrated to the lung, compared to PBS-injected control mice, but the number of positive major histocompatibility complex class II cells increased with fastuosain treatment. Murine antibodies against fastuosain, bromelain, and cathepsins B and L cross-reacted in ELISA and recognized surface and cytoplasmic components expressed on B16F10-Nex2 cells. Anti-fastuosain antibodies were cytotoxic/lytic to B16F10-Nex2 cells. Antitumor effects of fastuosain involve mainly the direct effect of the enzyme and elicitation of protective antibodies. PMID:17898868

Experiments versus modeling of buoyant drying of porous media

NASA Astrophysics Data System (ADS)

Salin, D.; Yiotis, A.; Tajer, E.; Yortsos, Y. C.

2012-12-01

Experiments versus modeling of buoyant drying of porous media D. Salin and A.G. Yiotis, Laboratoire FAST, Univ Pierre & Marie Curie, Univ. Paris-Sud, CNRS, Orsay 91405, France and E.S. Tajer and Y.C. Yortsos, Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1450 A series of isothermal drying experiments in packed glass beads saturated with volatile hydrocarbons (hexane or pentane) are conducted. The transparent glass cells containing the packing allow for the visual monitoring of the phase distribution patterns below the surface, including the formation of liquid films, as the gaseous phase invades the pore space, and for the control of the thickness of the diffusive mass boundary layer over the packing. We demonstrate the existence of an early Constant Rate Period, CRP, that lasts as long as the films saturate the surface of the packing, and of a subsequent Falling Rate Period, FRP, that begins practically after the detachment of the film tips from the external surface. During the CRP, the process is controlled by diffusion within the stagnant gaseous phase in the upper part of the cells, yielding a Stefan tube problem solution. During the FRP, the process is controlled by diffusion within the packing, with a drying rate inversely proportional to the observed position of the film tips in the cell. The critical residual liquid saturation that marks the transition between these two regimes is found to be a function of the average bead size in our packs and the incline of the cells with respect to the flat vertical, with larger beads and angles closer to the vertical position leading to earlier film detachment times and higher critical saturations. We developed a model for the drying of porous media in the presence of gravity. It incorporated effects of corner film flow, internal and external mass transfer and the effect of gravity. Analytical results were derived when gravity opposes drying and hence leads to a stable percolation drying front. We are thus able to obtain results for the drying rates, the critical saturation and the extent of the film region with respect to the various dimensionless numbers that describe the process; the Bond (Bo)number, a film-based Capillary (Ca) number and the dimensionless extent of the mass boundary layer (Sh). The experimental results agree very well with the theory, provided that the latter is generalized to account for the effects of corner roundness in the film region which were neglected in our analytical approach. The agreement is achieved for a specific value of the roundness of the films, which is found to be constant and equal to 0.2 for various conditions, and verify the theoretical dependence on Ca, Bo and Sh numbers.

Mitotic cells contract actomyosin cortex and generate pressure to round against or escape epithelial confinement

PubMed Central

Sorce, Barbara; Escobedo, Carlos; Toyoda, Yusuke; Stewart, Martin P.; Cattin, Cedric J.; Newton, Richard; Banerjee, Indranil; Stettler, Alexander; Roska, Botond; Eaton, Suzanne; Hyman, Anthony A.; Hierlemann, Andreas; Müller, Daniel J.

2015-01-01

Little is known about how mitotic cells round against epithelial confinement. Here, we engineer micropillar arrays that subject cells to lateral mechanical confinement similar to that experienced in epithelia. If generating sufficient force to deform the pillars, rounding epithelial (MDCK) cells can create space to divide. However, if mitotic cells cannot create sufficient space, their rounding force, which is generated by actomyosin contraction and hydrostatic pressure, pushes the cell out of confinement. After conducting mitosis in an unperturbed manner, both daughter cells return to the confinement of the pillars. Cells that cannot round against nor escape confinement cannot orient their mitotic spindles and more likely undergo apoptosis. The results highlight how spatially constrained epithelial cells prepare for mitosis: either they are strong enough to round up or they must escape. The ability to escape from confinement and reintegrate after mitosis appears to be a basic property of epithelial cells. PMID:26602832

Mitotic cells contract actomyosin cortex and generate pressure to round against or escape epithelial confinement

NASA Astrophysics Data System (ADS)

Sorce, Barbara; Escobedo, Carlos; Toyoda, Yusuke; Stewart, Martin P.; Cattin, Cedric J.; Newton, Richard; Banerjee, Indranil; Stettler, Alexander; Roska, Botond; Eaton, Suzanne; Hyman, Anthony A.; Hierlemann, Andreas; Müller, Daniel J.

2015-11-01

Little is known about how mitotic cells round against epithelial confinement. Here, we engineer micropillar arrays that subject cells to lateral mechanical confinement similar to that experienced in epithelia. If generating sufficient force to deform the pillars, rounding epithelial (MDCK) cells can create space to divide. However, if mitotic cells cannot create sufficient space, their rounding force, which is generated by actomyosin contraction and hydrostatic pressure, pushes the cell out of confinement. After conducting mitosis in an unperturbed manner, both daughter cells return to the confinement of the pillars. Cells that cannot round against nor escape confinement cannot orient their mitotic spindles and more likely undergo apoptosis. The results highlight how spatially constrained epithelial cells prepare for mitosis: either they are strong enough to round up or they must escape. The ability to escape from confinement and reintegrate after mitosis appears to be a basic property of epithelial cells.

Multicellular detachment generates metastatic spheroids during intra-abdominal dissemination in epithelial ovarian cancer.

PubMed

Al Habyan, Sara; Kalos, Christina; Szymborski, Joseph; McCaffrey, Luke

2018-05-23

Ovarian cancer is the most lethal gynecological cancer, where survival rates have had modest improvement over the last 30 years. Metastasis of cancer cells is a major clinical problem, and patient mortality occurs when ovarian cancer cells spread beyond the confinement of ovaries. Disseminated ovarian cancer cells typically spread within the abdomen, where ascites accumulation aids in their transit. Metastatic ascites contain multicellular spheroids, which promote chemo-resistance and recurrence. However, little is known about the origin and mechanisms through which spheroids arise. Using live-imaging of 3D culture models and animal models, we report that epithelial ovarian cancer (EOC) cells, the most common type of ovarian cancer, can spontaneously detach as either single cells or clusters. We report that clusters are more resistant to anoikis and have a potent survival advantage over single cells. Using in vivo lineage tracing, we found that multicellular spheroids arise preferentially from collective detachment, rather than aggregation in the abdomen. Finally, we report that multicellular spheroids from collective detachment are capable of seeding intra-abdominal metastases that retain intra-tumoral heterogeneity from the primary tumor.

Exogenous ROS-induced cell sheet transfer based on hematoporphyrin-polyketone film via a one-step process.

PubMed

Koo, Min-Ah; Lee, Mi Hee; Kwon, Byeong-Ju; Seon, Gyeung Mi; Kim, Min Sung; Kim, Dohyun; Nam, Ki Chang; Park, Jong-Chul

2018-04-01

To date, most of invasive cell sheet harvesting methods have used culture surface property variations, such as wettability, pH, electricity, and magnetism, to induce cell detachment. These methods that rely on surface property changes are effective when cell detachment prior to application is necessary, but of limited use when used for cell sheet transfer to target regions. The study reports a new reactive oxygen species (ROS)-induced strategy based on hematoporphyrin-incorporated polyketone film (Hp-PK film) to transfer cell sheets directly to target areas without an intermediate harvesting process. After green LED (510 nm) irradiation, production of exogenous ROS from the Hp-PK films induces cell sheet detachment and transfer. The study suggests that ROS-induced cell detachment property of the Hp-PK film is closely related to conformational changes of extracellular matrix (ECM) proteins. Also, this strategy with the Hp-PK film can be applied by regulating production rate of exogenous ROS in various types of cells, including fibroblasts, mesenchymal stem cells and keratinocytes. In conclusion, ROS-induced method using the Hp-PK film can be used for one-step cell sheet transplantation and has potential in biomedical applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Mesothelial cell proliferation in the scala tympani: a reaction to the rupture of the round window membrane.

PubMed

Sone, M

1998-10-01

The inner layer of the round window membrane is composed of mesothelial cells and this mesothelial cell layer extends to the scala tympani. This study describes the histopathologic findings of temporal bone analysis from a patient with bilateral perilymphatic fistula of the round window membrane. The left ear showed proliferation of mesothelial cells in the scala tympani of the basal turn adjoining the round window membrane. This cell proliferation is thought to be a reaction to the rupture of the round window membrane.

Proliferative vitreoretinopathy in the Swine-a new model.

PubMed

Umazume, Kazuhiko; Barak, Yoreh; McDonald, Kevin; Liu, Lanhsin; Kaplan, Henry J; Tamiya, Shigeo

2012-07-24

To develop a large animal model of proliferative vitreoretinopathy (PVR) in the swine to eventually study disease pathophysiology, as well as novel therapies. PVR was induced in domestic swine by creation of a posterior vitreous detachment, creation of a retinal detachment by the injection of subretinal fluid, and intravitreal injection of green fluorescent protein-positive retinal pigment epithelial (GFP+ RPE) cells. Control eyes had the same surgical procedures without RPE cell injection. PVR was clinically graded on days 3, 7, and 14. Animals were euthanized on day 14, and enucleated eyes were analyzed by light microscopy and immunohistochemistry. Injection of GFP+ RPE cells into the vitreous cavity produced localized, traction retinal detachments by day 14 in all eyes (14 of 14); in contrast, the retina spontaneously reattached by day 3 and remained attached in all control eyes (10 of 10). Contractile epiretinal membranes on the inner retinal surface that caused the traction retinal detachments consisted predominantly of GFP+ RPE cells. These cells stained positive for cytokeratin, confirming their epithelial origin, and also expressed α-SMA and fibronectin, markers for myofibroblasts and fibrosis, respectively. We established a swine PVR model that recapitulates key clinical features found in humans and, thus, can be used to study the pathophysiology of PVR, as well as new novel therapies. GFP+ RPE cells injected into the vitreous cavity formed contractile membranes on the inner retinal surface and caused localized traction retinal detachments.

Affinity adsorption of cells to surfaces and strategies for cell detachment.

PubMed

Hubble, John

2007-01-01

The use of bio-specific interactions for the separation and recovery of bio-molecules is now widely established and in many cases the technique has successfully crossed the divide between bench and process scale operation. Although the major specificity advantage of affinity-based separations also applies to systems intended for cell fractionation, developments in this area have been slower. Many of the problems encountered result from attempts to take techniques developed for molecular systems and, with only minor modification to the conditions used, apply them for the separation of cells. This approach tends to ignore or at least trivialise the problems, which arise from the heterogeneous nature of a cell suspension and the multivalent nature of the cell/surface interaction. To develop viable separation processes on a larger scale, effective contacting strategies are required in separators that also allow detachment or recovery protocols that overcome the enhanced binding strength generated by multivalent interactions. The effects of interaction valency on interaction strength needs to be assessed and approaches developed to allow effective detachment and recovery of adsorbed cells without compromising cell viability. This article considers the influence of operating conditions on cell attachment and the extent to which multivalent interactions determine the strength of cell binding and subsequent detachment.

Biofilms’ Role in Planktonic Cell Proliferation

PubMed Central

Bester, Elanna; Wolfaardt, Gideon M.; Aznaveh, Nahid B.; Greener, Jesse

2013-01-01

The detachment of single cells from biofilms is an intrinsic part of this surface-associated mode of bacterial existence. Pseudomonas sp. strain CT07gfp biofilms, cultivated in microfluidic channels under continuous flow conditions, were subjected to a range of liquid shear stresses (9.42 mPa to 320 mPa). The number of detached planktonic cells was quantified from the effluent at 24-h intervals, while average biofilm thickness and biofilm surface area were determined by confocal laser scanning microscopy and image analysis. Biofilm accumulation proceeded at the highest applied shear stress, while similar rates of planktonic cell detachment was maintained for biofilms of the same age subjected to the range of average shear rates. The conventional view of liquid-mediated shear leading to the passive erosion of single cells from the biofilm surface, disregards the active contribution of attached cell metabolism and growth to the observed detachment rates. As a complement to the conventional conceptual biofilm models, the existence of a biofilm surface-associated zone of planktonic cell proliferation is proposed to highlight the need to expand the traditional perception of biofilms as promoting microbial survival, to include the potential of biofilms to contribute to microbial proliferation. PMID:24201127

DUX4 Immunohistochemistry Is a Highly Sensitive and Specific Marker for CIC-DUX4 Fusion-positive Round Cell Tumor.

PubMed

Siegele, Bradford; Roberts, Jon; Black, Jennifer O; Rudzinski, Erin; Vargas, Sara O; Galambos, Csaba

2017-03-01

The histologic differential diagnosis of pediatric and adult round cell tumors is vast and includes the recently recognized entity CIC-DUX4 fusion-positive round cell tumor. The diagnosis of CIC-DUX4 tumor can be suggested by light microscopic and immunohistochemical features, but currently, definitive diagnosis requires ancillary genetic testing such as conventional karyotyping, fluorescence in situ hybridization, or molecular methods. We sought to determine whether DUX4 expression would serve as a fusion-specific immunohistochemical marker distinguishing CIC-DUX4 tumor from potential histologic mimics. A cohort of CIC-DUX4 fusion-positive round cell tumors harboring t(4;19)(q35;q13) and t(10;19)(q26;q13) translocations was designed, with additional inclusion of a case with a translocation confirmed to involve the CIC gene without delineation of the partner. Round cell tumors with potentially overlapping histologic features were also collected. Staining with a monoclonal antibody raised against the C-terminus of the DUX4 protein was applied to all cases. DUX4 immunohistochemistry exhibited diffuse, crisp, strong nuclear staining in all CIC-DUX4 fusion-positive round cell tumors (5/5, 100% sensitivity), and exhibited negative staining in nuclei of all of the other tested round cell tumors, including 20 Ewing sarcomas, 1 Ewing-like sarcoma, 11 alveolar rhabdomyosarcomas, 9 embryonal rhabdomyosarcomas, 12 synovial sarcomas, 7 desmoplastic small round cell tumors, 3 malignant rhabdoid tumors, 9 neuroblastomas, and 4 clear cell sarcomas (0/76, 100% specificity). Thus, in our experience, DUX4 immunostaining distinguishes CIC-DUX4 tumors from other round cell mimics. We recommend its use when CIC-DUX4 fusion-positive round cell tumor enters the histologic differential diagnosis.

Congressing kinetochores progressively load Ska complexes to prevent force-dependent detachment

PubMed Central

Auckland, Philip; Clarke, Nicholas I.

2017-01-01

Kinetochores mediate chromosome congression by either sliding along the lattice of spindle microtubules or forming end-on attachments to their depolymerizing plus-ends. By following the fates of individual kinetochores as they congress in live cells, we reveal that the Ska complex is required for a distinct substep of the depolymerization-coupled pulling mechanism. Ska depletion increases the frequency of naturally occurring, force-dependent P kinetochore detachment events, while being dispensable for the initial biorientation and movement of chromosomes. In unperturbed cells, these release events are followed by reattachment and successful congression, whereas in Ska-depleted cells, detached kinetochores remain in a futile reattachment/detachment cycle that prevents congression. We further find that Ska is progressively loaded onto bioriented kinetochore pairs as they congress. We thus propose a model in which kinetochores mature through Ska complex recruitment and that this is required for improved load-bearing capacity and silencing of the spindle assembly checkpoint. PMID:28495837

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho–ROCK–myosin II signaling pathway to ensure formation of a basal constriction

PubMed Central

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie

2017-01-01

Background: Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto‐ and endodermal epithelia is unknown. Results: Histological sections and staining of F‐actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F‐actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Conclusions: Our data suggest an essential role of FGFR and a Rho‐ROCK‐myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502–516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists PMID:28411398

Bud detachment in hydra requires activation of fibroblast growth factor receptor and a Rho-ROCK-myosin II signaling pathway to ensure formation of a basal constriction.

PubMed

Holz, Oliver; Apel, David; Steinmetz, Patrick; Lange, Ellen; Hopfenmüller, Simon; Ohler, Kerstin; Sudhop, Stefanie; Hassel, Monika

2017-07-01

Hydra propagates asexually by exporting tissue into a bud, which detaches 4 days later as a fully differentiated young polyp. Prerequisite for detachment is activation of fibroblast growth factor receptor (FGFR) signaling. The mechanism which enables constriction and tissue separation within the monolayered ecto- and endodermal epithelia is unknown. Histological sections and staining of F-actin by phalloidin revealed conspicuous cell shape changes at the bud detachment site indicating a localized generation of mechanical forces and the potential enhancement of secretory functions in ectodermal cells. By gene expression analysis and pharmacological inhibition, we identified a candidate signaling pathway through Rho, ROCK, and myosin II, which controls bud base constriction and rearrangement of the actin cytoskeleton. Specific regional myosin phosphorylation suggests a crucial role of ectodermal cells at the detachment site. Inhibition of FGFR, Rho, ROCK, or myosin II kinase activity is permissive for budding, but represses myosin phosphorylation, rearrangement of F-actin and constriction. The young polyp remains permanently connected to the parent by a broad tissue bridge. Our data suggest an essential role of FGFR and a Rho-ROCK-myosin II pathway in the control of cell shape changes required for bud detachment. Developmental Dynamics 246:502-516, 2017. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists. © 2017 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Isolation of Canine parvovirus with a view to identify the prevalent serotype on the basis of partial sequence analysis.

PubMed

Kaur, Gurpreet; Chandra, Mudit; Dwivedi, P N; Sharma, N S

2015-01-01

The aim of this study was to isolate Canine parvovirus (CPV) from suspected dogs on madin darby canine kidney (MDCK) cell line and its confirmation by polymerase chain reaction (PCR) and nested PCR (NPCR). Further, VP2 gene of the CPV isolates was amplified and sequenced to determine prevailing antigenic type. A total of 60 rectal swabs were collected from dogs showing signs of gastroenteritis, processed and subjected to isolation in MDCK cell line. The samples showing cytopathic effects (CPE) were confirmed by PCR and NPCR. These samples were subjected to PCR for amplification of VP2 gene of CPV, sequenced and analyzed to study the prevailing antigenic types of CPV. Out of the 60 samples subjected to isolation in MDCK cell line five samples showed CPE in the form of rounding of cells, clumping of cells and finally detachment of the cells. When these samples and the two commercially available vaccines were subjected to PCR for amplification of VP2 gene, a 1710 bp product was amplified. The sequence analysis revealed that the vaccines belonged to the CPV-2 type and the samples were of CPV-2b type. It can be concluded from the present study that out of a total of 60 samples 5 samples exhibited CPE as observed in MDCK cell line. Sequence analysis of the VP2 gene among the samples and vaccine strains revealed that samples belonged to CPV-2b type and vaccines belonging to CPV-2.

Hypercellular round cell liposarcoma: A comprehensive cytomorphologic study and review of 8 cases.

PubMed

Chufal, Sanjay S; Chufal, Kundan S; Pant, Prabhat; Rizvi, Ghazala; Pandey, Hari S; Shahi, Kedar S

2017-01-01

Myxoid and round cell liposarcomas (RCL) are low and high-grade counterparts of a common subtype of liposarcomas (LPS), representing a histologic continuum. The aim was to study the cytomorphology of hypercellular RCL and to look for features that differentiate RCL from other sarcomas displaying round cells with myxoid change. Eight cases of hypercellular RCL were identified retrospectively in which round cell component constituted greater than 75% of the area. Cytomorphological features were studied in detail. Four cases were predominantly composed of round cells, out of which 2 were entirely composed of round cells. Myxoid metachromatic stroma was absent in 2 cases, while it was present in ample amounts in the remaining 6 cases. Spindle cells were completely absent in 5 cases and lipoblasts were observed in a single case of RCL. Plexiform vascular capillaries were seen in 4 cases. Adherence of neoplastic round cells around thin capillaries (ANAC) was observed in 7 cases. Plexiform capillary plexus and ANAC should be separately evaluated. The latter feature is the most consistent one, and is an important clue to the adipocytic nature of the neoplasm when hypercellular round cell areas are aspirated. Confident diagnosis of hypercellular RCL can be made on the basis of this feature. Lipoblasts, although specific, are seen in few cases. The rest of the features are nonspecific and useful only in combination.

Effects of the plasmid-encoded toxin of enteroaggregative Escherichia coli on focal adhesion complexes

PubMed Central

Cappello, Renato E; Estrada-Gutierrez, Guadalupe; Irles, Claudine; Giono-Cerezo, Silvia; Bloch, Robert J; Nataro, James P

2011-01-01

Enteroaggregative Escherichia coli (EAEC) is an emerging diarrheal pathogen. Many EAEC strains produce the plasmid encoded toxin (Pet), which elicits cytotoxic effects on human intestinal tissue. Pet-intoxicated HEp-2 cells exhibit rounding and detachment from the substratum, accompanied by loss of F-actin stress fibers and condensation of the spectrin-containing membrane cytoskeleton. Although studies suggest that Pet directly cleaves spectrin, it is not known if this is the essential mode of action of the toxin. In addition, the effects of Pet on cytoskeletal elements other than actin and spectrin have not been reported. Here, we demonstrate by immunofluorescence that upon Pet intoxication, HEp-2 and HT29 cells lose focal adhesion complexes (FAC), a process that includes redistribution of focal adhesion kinase (FAK), α-actinin, paxillin, vinculin, F-actin, and spectrin itself. This redistribution was coupled with depletion of phosphotyrosine labeling at FACs. Immunoblotting and immunoprecipitation experiments revealed that FAK was tyrosine dephosphorylated, prior to the redistribution of FAK and spectrin. Moreover, phosphatase inhibition blocked cell retraction, suggesting that tyrosine dephosphorylation is an event that precedes FAK cleavage. Finally, we show that in vitro tyrosine-dephophorylated FAK was susceptible to Pet cleavage. These data suggest that mechanisms other than spectrin redistribution occur during Pet intoxication. PMID:21205005

Unstructured CFD Aerodynamic Analysis of a Generic UCAV Configuration

NASA Technical Reports Server (NTRS)

Frink, Neal T.; Tormalm, Magnus; Schmidt, Stefan

2011-01-01

Three independent studies from the United States (NASA), Sweden (FOI), and Australia (DSTO) are analyzed to assess the state of current unstructured-grid computational fluid dynamic tools and practices for predicting the complex static and dynamic aerodynamic and stability characteristics of a generic 53-degree swept, round-leading-edge uninhabited combat air vehicle configuration, called SACCON. NASA exercised the USM3D tetrahedral cell-centered flow solver, while FOI and DSTO applied the FOI/EDGE general-cell vertex-based solver. The authors primarily employ the Reynolds Averaged Navier-Stokes (RANS) assumption, with a limited assessment of the EDGE Detached Eddy Simulation (DES) extension, to explore sensitivities to grids and turbulence models. Correlations with experimental data are provided for force and moments, surface pressure, and off-body flow measurements. The vortical flow field over SACCON proved extremely difficult to model adequately. As a general rule, the prospect of obtaining reasonable correlations of SACCON pitching moment characteristics with the RANS formulation is not promising, even for static cases. Yet, dynamic pitch oscillation results seem to produce a promising characterization of shapes for the lift and pitching moment hysteresis curves. Future studies of this configuration should include more investigation with higher-fidelity turbulence models, such as DES.

Establishment of a new cell line susceptible to Cyprinid herpesvirus 3 (CyHV-3) and possible latency of CyHV-3 by temperature shift in the cells.

PubMed

Imajoh, M; Fujioka, H; Furusawa, K; Tamura, K; Yamasaki, K; Kurihara, S; Yamane, J; Kawai, K; Oshima, S

2015-06-01

A new cell line named CCF-K104 predominantly consisting of fibroblastic cells showed optimal growth at temperatures from 25 °C to 30 °C. Serial morphological changes in the cells induced by Cyprinid herpesvirus 3 (CyHV-3) included cytoplasmic vacuolar formation, cell rounding and detachment. Mature virions were purified from CyHV-3-infected CCF-K104 cells by sucrose gradient ultracentrifugation and had a typical herpesvirus structure on electron microscopy. Infectious CyHV-3 was produced stably in CCF-K104 cells over 30 viral passages. Our findings showed that CCF-K104 is a useful cell line for isolation and productive replication of CyHV-3. A temperature shift from 25 °C to 15 °C or 35 °C did not allow serial morphological changes as observed at 25 °C for 14 days. Under the same conditions, real-time PCR showed that CyHV-3 was present with low viral DNA loads, suggesting that CyHV-3 may establish latent infection in CCF-K104 cells. Amplification of the left and right terminal repeat sequences of the CyHV-3 genome arranged in a head-to-tail manner was detected by nested PCR following an upshift in temperature from 25 °C to 35 °C. The PCR results suggested that the circular genome may represent a latent form of CyHV-3. © 2014 John Wiley & Sons Ltd.

The role of immunohistochemistry in the analysis of the spectrum of small round cell tumours at a tertiary care centre.

PubMed

D'cruze, Lawrence; Dutta, Ruma; Rao, Shalinee; R, Anuradha; Varadarajan, Suresh; Kuruvilla, Sarah

2013-07-01

The term, "Small Round - Cell Tumours" (SRCT) describes a group of highly aggressive malignant neoplasms which are composed predominantly of small and monotonous undifferentiated cells with high nucleocytoplasmic ratios. Immunohistochemistry (IHC) plays a crucial role in catagorizing the small round - cell tumours. This study was done to analyse the spectrum of small round cell tumours over a period of five years at a tertiary care centre and to study the relevance of immunohistochemistry in making precise diagnoses of the small round cell tumours. Formalin - fixed, paraffin - embedded sections of tumours which were diagnosed as small round cell tumours on small biopsies and resected specimens were retrieved from the files of the Department of Pathology of Sri Ramachandra Medical College and Research institute, in the period from January 2005 to December 2009. This study was confined to the bone and the soft tissues. Decalcification was performed on the bony tissues before the routine processing was done. The patients belonging to all age groups were included in this study. The small round cell tumours of the bone marrow, the spleen and the lymph node was excluded from our study. Immunohistochemical stains were performed to differentiate and categorise the small round blue cell tumours. The immunomarkers which were utilised in this study included CD45/LCA (the lymphocyte common antigen), CD20, CD3, CD99 (cluster of differentiation 99 also known as MIC2), desmin, EMA (epithelial membrane antigen), CK(cytokeratin), synaptophysin, chromogranin and GFAP (Glial fibrillary acidic protein). Forty three cases of small round cell tumours were analysed, which included 19 cases of NHL (non Hodgkin's lymphoma), 6 cases of Ewing/PNETs (primitive neuroectodermal tumours), 3 cases of atypical carcinoid, 3 cases of olfactory neuroblastoma, 2 cases each of rhabdomyosarcoma, Wilms tumour, neuroblastoma and synovial sarcoma and 1 case each of small cell osteosarcoma, small (oat) cell carcinoma, medulloblastoma and hepatoblastoma. By using a panel of monoclonal antibodies, we could arrive at a final diagnosis for all the 40 cases in which immunohistochemistry was performed. Our study showed that the use of immunohistochemistry was extremely beneficial. A majority of the small round cell tumours occurred between the ages of 15-45 years and the most common small round cell tumour was Non-Hodgkins lymphoma (extra lymphoreticular).

Coaxial atomization of a round liquid jet in a high speed gas stream: A phenomenological study

NASA Astrophysics Data System (ADS)

Mayer, W. O. H.

1994-05-01

Coaxial injectors have proven to be advantageous for the injection, atomization and mixing of propellants in cryogenic H2/O2 rocket engines. Thereby, a round liquid oxygen jet is atomized by a fast, coaxial gaseous hydrogen jet. This article summarizes phenomenological studies of coaxial spray generation under a broad variation of influencing parameters including injector design, inflow, and fluid conditions. The experimental investigations, performed using spark light photography and high speed cinematography in a shadow graph setup as main diagnostic means, illuminate the most important processes leading to atomization. These are identified as turbulence in the liquid jet, surface instability, surface wave growth and droplet detachment. Numerical simulations including free surface flow phenomena are a further diagnostic tool to elucidate some atomization particulars. The results of the study are of general importance in the field of liquid atomization.

Traction force microscopy in rapidly moving cells reveals separate roles for ROCK and MLCK in the mechanics of retraction.

PubMed

Morin, Timothy R; Ghassem-Zadeh, Sean A; Lee, Juliet

2014-08-15

Retraction is a major rate-limiting step in cell motility, particularly in slow moving cell types that form large stable adhesions. Myosin II dependent contractile forces are thought to facilitate detachment by physically pulling up the rear edge. However, retraction can occur in the absence of myosin II activity in cell types that form small labile adhesions. To investigate the role of contractile force generation in retraction, we performed traction force microscopy during the movement of fish epithelial keratocytes. By correlating changes in local traction stress at the rear with the area retracted, we identified four distinct modes of retraction. "Recoil" retractions are preceded by a rise in local traction stress, while rear edge is temporarily stuck, followed by a sharp drop in traction stress upon detachment. This retraction type was most common in cells generating high average traction stress. In "pull" type retractions local traction stress and area retracted increase concomitantly. This was the predominant type of retraction in keratocytes and was observed mostly in cells generating low average traction stress. "Continuous" type retractions occur without any detectable change in traction stress, and are seen in cells generating low average traction stress. In contrast, to many other cell types, "release" type retractions occur in keratocytes following a decrease in local traction stress. Our identification of distinct modes of retraction suggests that contractile forces may play different roles in detachment that are related to rear adhesion strength. To determine how the regulation of contractility via MLCK or Rho kinase contributes to the mechanics of detachment, inhibitors were used to block or augment these pathways. Modulation of MLCK activity led to the most rapid change in local traction stress suggesting its importance in regulating attachment strength. Surprisingly, Rho kinase was not required for detachment, but was essential for localizing retraction to the rear. We suggest that in keratocytes MLCK and Rho kinase play distinct, complementary roles in the respective temporal and spatial control of rear detachment that is essential for maintaining rapid motility. Copyright © 2014 Elsevier Inc. All rights reserved.

Congressing kinetochores progressively load Ska complexes to prevent force-dependent detachment.

PubMed

Auckland, Philip; Clarke, Nicholas I; Royle, Stephen J; McAinsh, Andrew D

2017-06-05

Kinetochores mediate chromosome congression by either sliding along the lattice of spindle microtubules or forming end-on attachments to their depolymerizing plus-ends. By following the fates of individual kinetochores as they congress in live cells, we reveal that the Ska complex is required for a distinct substep of the depolymerization-coupled pulling mechanism. Ska depletion increases the frequency of naturally occurring, force-dependent P kinetochore detachment events, while being dispensable for the initial biorientation and movement of chromosomes. In unperturbed cells, these release events are followed by reattachment and successful congression, whereas in Ska-depleted cells, detached kinetochores remain in a futile reattachment/detachment cycle that prevents congression. We further find that Ska is progressively loaded onto bioriented kinetochore pairs as they congress. We thus propose a model in which kinetochores mature through Ska complex recruitment and that this is required for improved load-bearing capacity and silencing of the spindle assembly checkpoint. © 2017 Auckland et al.

Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

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

Ramp, W.K.; Lenz, L.G.; Galvin, R.J.

1991-05-01

Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase weremore » concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of ({sup 3}H)proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of ({sup 3}H)hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of ({sup 3}H)thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone.« less

Drying in porous media with gravity-stabilized fronts: experimental results.

PubMed

Yiotis, A G; Salin, D; Tajer, E S; Yortsos, Y C

2012-08-01

In a recent paper [Yiotis et al., Phys. Rev. E 85, 046308 (2012)] we developed a model for the drying of porous media in the presence of gravity. It incorporated effects of corner film flow, internal and external mass transfer, and the effect of gravity. Analytical results were derived when gravity opposes drying and hence leads to a stable percolation drying front. In this paper, we test the theory using laboratory experiments. A series of isothermal drying experiments in glass bead packings saturated with volatile hydrocarbons is conducted. The transparent glass cells containing the packing allow for the visual monitoring of the phase distribution patterns below the surface, including the formation of liquid films, as the gaseous phase invades the pore space, and for the control of the thickness of the diffusive mass boundary layer over the packing. The experimental results agree very well with theory, provided that the latter is generalized to account for the effects of corner roundness in the film region (which was neglected in the theoretical part). We demonstrate the existence of an early constant rate period (CRP), which lasts as long as the films saturate the surface of the packing, and of a subsequent falling rate period (FRP), which begins practically after the detachment of the film tips from the external surface. During the CRP, the process is controlled by diffusion within the stagnant gaseous phase in the upper part of the cells, yielding a Stefan tube problem solution. During the FRP, the process is controlled by diffusion within the packing, with a drying rate inversely proportional to the observed position of the film tips in the cell. Theoretical and experimental results compare favorably for a specific value of the roundness of the films, which is found to be constant and equal to 0.2 for various conditions, and verify the theoretical dependence on the capillary Ca(f), Bond Bo, and Sherwood Sh numbers.

The Vibrio alginolyticus T3SS effectors, Val1686 and Val1680, induce cell rounding, apoptosis and lysis of fish epithelial cells

PubMed Central

Zhao, Zhe; Liu, Jinxin; Deng, Yiqin; Huang, Wen; Ren, Chunhua; Call, Douglas R.; Hu, Chaoqun

2018-01-01

ABSTRACT Vibrio alginolyticus is a Gram-negative bacterium that is an opportunistic pathogen of both marine animals and people. Its pathogenesis likely involves type III secretion system (T3SS) mediated induction of rapid apoptosis, cell rounding and osmotic lysis of infected eukaryotic cells. Herein, we report that effector proteins, Val1686 and Val1680 from V. alginolyticus, were responsible for T3SS-mediated death of fish cells. Val1686 is a Fic-domain containing protein that not only contributed to cell rounding by inhibiting Rho guanosine triphosphatases (GTPases), but was requisite for the induction of apoptosis because the deletion mutant (Δval1686) was severely weakened in its ability to induce cell rounding and apoptosis in fish cells. In addition, Val1686 alone was sufficient to induce cell rounding and apoptosis as evidenced by the transfection of Val1686 into fish cells. Importantly, the Fic-domain essential for cell rounding activity was equally important to activation of apoptosis of fish cells, indicating that apoptosis is a downstream event of Val1686-dependent GTPase inhibition. V. alginolyticus infection likely activates JNK and ERK pathways with sequential activation of caspases (caspase-8/-10, -9 and -3) and subsequent apoptosis. Val1680 contributed to T3SS-dependent lysis of fish cells in V. alginolyticus, but did not induce autophagy as has been reported for its homologue (VopQ) in V. parahaemolyticus. Together, Val1686 and Val1680 work together to induce apoptosis, cell rounding and cell lysis of V. alginolyticus-infected fish cells. These findings provide new insights into the mechanism of cell death caused by T3SS of V. alginolyticus. PMID:29252102

Bilateral orbital infarction and retinal detachment in a previously undiagnosed sickle cell hemoglobinopathy African child

PubMed Central

Helen, Onakpoya Oluwatoyin; Ajite, K. O.; Oyelami, O. A.; Asaleye, C. M.; Adeoye, A. O.

2013-01-01

Bone infarction involving the orbit in sickle cell disease is not common. Bilateral orbital infarction in a previously undiagnosed sickle cell hemoglobinopathy has not been previously reported. In this report, we present a case of an 11-year-old previously undiagnosed sickle cell disease Nigerian girl with severe acute bilateral orbital infarction and retinal detachment to highlight that hemoglobinopathy induced orbital infarction should be considered in African children with acute onset proptosis with or without previous history of sickle cell hemoglobinopathy. PMID:23901183

Optimization of low energy sonication treatment for granular activated carbon colonizing biomass assessment.

PubMed

Saccani, G; Bernasconi, M; Antonelli, M

2014-01-01

This study is aimed at optimizing a low energy sonication (LES) treatment for granular activated carbon (GAC)-colonizing biomass detachment and determination, evaluating detachment efficiency and the effects of ultrasound exposure on bacterial cell viability. GAC samples were collected from two filters fed with groundwater. Conventional heterotrophic plate count (HPC) and fluorescence microscopy with a double staining method were used to evaluate cell viability, comparing two LES procedures, without and with periodical bulk substitution. A 20 min LES treatment, with bulk substitution after cycles of 5 min as maximum treatment time, allowed to recover 87%/100% of attached biomass, protecting detached bacteria from ultrasound damaging effects. Observed viable cell inactivation rate was 6.5/7.9% cell/min, with membrane-compromised cell damage appearing to be even higher (11.5%/13.1% cell/min). Assessing bacterial detachment and damaging ultrasound effects, fluorescence microscopy turned out to be more sensitive compared to conventional HPC. The optimized method revealed a GAC-colonizing biomass of 9.9 x 10(7) cell/gGAC for plant 1 and 8.8 x 10(7) cell/gGAC for plant 2, 2 log lower than reported in literature. The difference between the two GAC-colonizing biomasses is higher in terms of viable cells (46.3% of total cells in plant 1 GAC-colonizing biomass compared to the 33.3% in plant 2). Studying influent water contamination through multivariate statistical analyses, apossible combined toxic and genotoxic effect of chromium VI and trichloroethylene was suggested as a reason for the lower viable cell fraction observed in plant 2 GAC-colonizing population.

Analysis of Bacterial Detachment from Substratum Surfaces by the Passage of Air-Liquid Interfaces

PubMed Central

Gómez-Suárez, Cristina; Busscher, Henk J.; van der Mei, Henny C.

2001-01-01

A theoretical analysis of the detachment of bacteria adhering to substratum surfaces upon the passage of an air-liquid interface is given, together with experimental results for bacterial detachment in the absence and presence of a conditioning film on different substratum surfaces. Bacteria (Streptococcus sobrinus HG1025, Streptococcus oralis J22, Actinomyces naeslundii T14V-J1, Bacteroides fragilis 793E, and Pseudomonas aeruginosa 974K) were first allowed to adhere to hydrophilic glass and hydrophobic dimethyldichlorosilane (DDS)-coated glass in a parallel-plate flow chamber until a density of 4 × 106 cells cm−2 was reached. For S. sobrinus HG1025, S. oralis J22, and A. naeslundii T14V-J1, the conditioning film consisted of adsorbed salivary components, while for B. fragilis 793E and P. aeruginosa 974K, the film consisted of adsorbed human plasma components. Subsequently, air bubbles were passed through the flow chamber and the bacterial detachment percentages were measured. For some experimental conditions, like with P. aeruginosa 974K adhering to DDS-coated glass and an air bubble moving at high velocity (i.e., 13.6 mm s−1), no bacteria detached upon passage of an air-liquid interface, while for others, detachment percentages between 80 and 90% were observed. The detachment percentage increased when the velocity of the passing air bubble decreased, regardless of the bacterial strain and substratum surface hydrophobicity involved. However, the variation in percentages of detachment by a passing air bubble depended greatly upon the strain and substratum surface involved. At low air bubble velocities the hydrophobicity of the substratum had no influence on the detachment, but at high air bubble velocities all bacterial strains were more efficiently detached from hydrophilic glass substrata. Furthermore, the presence of a conditioning film could either inhibit or stimulate detachment. The shape of the bacterial cell played a major role in detachment at high air bubble velocities, and spherical strains (i.e., streptococci) detached more efficiently than rod-shaped organisms. The present results demonstrate that methodologies to study bacterial adhesion which include contact with a moving air-liquid interface (i.e., rinsing and dipping) yield detachment of an unpredictable number of adhering microorganisms. Hence, results of studies based on such methodologies should be referred as “bacterial retention” rather than “bacterial adhesion”. PMID:11375160

Analysis of bacterial detachment from substratum surfaces by the passage of air-liquid interfaces.

PubMed

Gómez-Suárez, C; Busscher, H J; van der Mei, H C

2001-06-01

A theoretical analysis of the detachment of bacteria adhering to substratum surfaces upon the passage of an air-liquid interface is given, together with experimental results for bacterial detachment in the absence and presence of a conditioning film on different substratum surfaces. Bacteria (Streptococcus sobrinus HG1025, Streptococcus oralis J22, Actinomyces naeslundii T14V-J1, Bacteroides fragilis 793E, and Pseudomonas aeruginosa 974K) were first allowed to adhere to hydrophilic glass and hydrophobic dimethyldichlorosilane (DDS)-coated glass in a parallel-plate flow chamber until a density of 4 x 10(6) cells cm(-2) was reached. For S. sobrinus HG1025, S. oralis J22, and A. naeslundii T14V-J1, the conditioning film consisted of adsorbed salivary components, while for B. fragilis 793E and P. aeruginosa 974K, the film consisted of adsorbed human plasma components. Subsequently, air bubbles were passed through the flow chamber and the bacterial detachment percentages were measured. For some experimental conditions, like with P. aeruginosa 974K adhering to DDS-coated glass and an air bubble moving at high velocity (i.e., 13.6 mm s(-1)), no bacteria detached upon passage of an air-liquid interface, while for others, detachment percentages between 80 and 90% were observed. The detachment percentage increased when the velocity of the passing air bubble decreased, regardless of the bacterial strain and substratum surface hydrophobicity involved. However, the variation in percentages of detachment by a passing air bubble depended greatly upon the strain and substratum surface involved. At low air bubble velocities the hydrophobicity of the substratum had no influence on the detachment, but at high air bubble velocities all bacterial strains were more efficiently detached from hydrophilic glass substrata. Furthermore, the presence of a conditioning film could either inhibit or stimulate detachment. The shape of the bacterial cell played a major role in detachment at high air bubble velocities, and spherical strains (i.e., streptococci) detached more efficiently than rod-shaped organisms. The present results demonstrate that methodologies to study bacterial adhesion which include contact with a moving air-liquid interface (i.e., rinsing and dipping) yield detachment of an unpredictable number of adhering microorganisms. Hence, results of studies based on such methodologies should be referred as "bacterial retention" rather than "bacterial adhesion".

Immunohistochemical expression of E-cadherin does not distinguish canine cutaneous histiocytoma from other canine round cell tumors.

PubMed

Ramos-Vara, J A; Miller, M A

2011-05-01

Immunohistochemistry for E-cadherin (ECAD) has been used to distinguish canine cutaneous histiocytoma from other leukocytic neoplasms ("round cell tumors"). To determine the specificity of this test, 5 types of canine cutaneous round cell tumors were evaluated for immunohistochemical expression of ECAD. Tumors of all 5 types had variable cytoplasmic, plasma membrane, and/or paranuclear ECAD expression: All 13 cutaneous histiocytomas were ECAD+; all but 1 of 14 mast cell tumors expressed ECAD; 10 of 12 epitheliotropic lymphomas reacted with E-cadherin antibody; of 72 plasmacytomas, 54 were ECAD+; and 5 of 5 histiocytic sarcomas were positive. Conclusions based on these results include the following: First, immunoreactivity for ECAD is not limited to leukocytes of cutaneous histiocytoma; second, antibody to ECAD also labels neoplastic cells in most mast cell tumors, plasmacytomas, cutaneous histiocytic sarcomas, and epitheliotropic lymphomas; third, although most histiocytomas have membranous ECAD expression, the immunoreactivity varies among round cell tumors and is frequently concurrent in different cellular compartments; fourth, the distinctively paranuclear ECAD expression pattern in epitheliotropic lymphomas might distinguish them from other round cell tumors; and, fifth, ECAD should be used with other markers (eg, MUM1 for plasmacytomas, KIT for mast cell tumors, CD3 and CD79a for lymphomas) to distinguish among canine round cell tumors.

Progerin phosphorylation in interphase is lower and less mechanosensitive than lamin-A,C in iPS-derived mesenchymal stem cells

PubMed Central

Cho, Sangkyun; Abbas, Amal; Ivanovska, Irena L.; Xia, Yuntao; Tewari, Manu; Discher, Dennis E.

2018-01-01

ABSTRACT Interphase phosphorylation of lamin-A,C depends dynamically on a cell's microenvironment, including the stiffness of extracellular matrix. However, phosphorylation dynamics is poorly understood for diseased forms such as progerin, a permanently farnesylated mutant of LMNA that accelerates aging of stiff and mechanically stressed tissues. Here, fine-excision alignment mass spectrometry (FEA-MS) is developed to quantify progerin and its phosphorylation levels in patient iPS cells differentiated to mesenchymal stem cells (MSCs). The stoichiometry of total A-type lamins (including progerin) versus B-type lamins measured for Progeria iPS-MSCs prove similar to that of normal MSCs, with total A-type lamins more abundant than B-type lamins. However, progerin behaves more like farnesylated B-type lamins in mechanically-induced segregation from nuclear blebs. Phosphorylation of progerin at multiple sites in iPS-MSCs cultured on rigid plastic is also lower than that of normal lamin-A and C. Reduction of nuclear tension upon i) cell rounding/detachment from plastic, ii) culture on soft gels, and iii) inhibition of actomyosin stress increases phosphorylation and degradation of lamin-C > lamin-A > progerin. Such mechano-sensitivity diminishes, however, with passage as progerin and DNA damage accumulate. Lastly, transcription-regulating retinoids exert equal effects on both diseased and normal A-type lamins, suggesting a differential mechano-responsiveness might best explain the stiff tissue defects in Progeria. PMID:29619860

Carbonate pseudotachylite? from a Miocene extensional detachment, W. Cyclades, Greece.

NASA Astrophysics Data System (ADS)

Rice, A. Hugh N.; Grasemann, Bernhard

2016-04-01

Most pseudotachylites, both impact- and fault-related, occur in silicate-rich rocks, typically with 'granitoid' compositions. Examples of melting in carbonate rocks, excluding magmatic sources, are restricted to impact-events, except for a carbonate pseudotachylite in the Canalone Fault, S. Italy (Viganò et al. 2011). Another potential example of carbonate pseudotachylite, shown here, comes from the Miocene-aged W. Cycladic Detachment System, in Greece. Top-SSE ductile to brittle movement on this detachment, with a maximum displacement estimated at tens of kilometers, exhumed of HP-rocks. The carbonate pseudotachylite occurs within an <200 mm thick zone of cataclasites developed between footwall carbonate ultramylonites, containing thin layers and cm-scale boudins of quartzite, and hanging wall breccias; no contacts with the footwall ultramylonites or hanging wall breccias has been found (yet). The cataclasite zone, which can be traced along-strike for at least 90 m, over ~20 m elevation, comprises several distinct layers. In the sample described, five layers occur. The lowest (A; >43 mm thick), consists of dark (hematitic) red, ultra-fine grained unlayered carbonate with up to 40x10 mm rather rounded clasts of earlier generations of cataclasite, many with a quartzite composition. These clasts are fractured and partially separated, with a fine red carbonate matrix. No layering of the matrix or clasts is apparent. The clasts become finer and more abundant towards the boundary with Layer B. Layers B and D (~57 & ~20 mm thick) dominantly comprises protocataclasite with greyish quartz fragments separated by a carbonate matrix along narrow fractures. Zone C and E (~23 m & >15 mm thick) comprise pale pink carbonate-dominated rocks with abundant <30x5 mm-sized red carbonate clasts (+/- quartz fragments) of earlier cataclasite generations. These elongate clasts lie parallel to the overall banding, which is parallel to the ultramylonitic foliation (detachment surface). Smaller clasts are markedly more rounded and comprise carbonate and quartzite material and may have darker (?reaction) rims. No layering is seen in the pale pink groundmass although this is present in some elongate clasts. All layer boundaries are irregular and no principle slip surfaces have been seen. Injection veins from 1 to 9 mm wide and up to at least 100 mm long derive from the central layer (C), cutting the overall layering at a high angle and branching in several places. These veins contain clasts comparable to those in Layer C. Both thick and thin injection-veins are rimmed by impersistent white calcite suggesting that injection was associated with precipitation of calcite. Whether Layer C (and perhaps E also) is a carbonate pseudotachylite is unknown. Although the injection veins are suggestive of this, these also occur in conjunction with ultracataclasites (Craddock et al. 2012). The irregular boundaries between the layers and the lack of any principal slip surfaces might indicate decarbonation and/or fluidization of gouge layer (Rowe and Griffith, 2015). Finally, abundant tubules, with rounded profiles and mostly sub-circular shapes up to 1.2 mm across, occur in Layers C and E, and less so D; these could be interpreted to reflect vents formed by partial carbonate degassing during melting.

Evolution of Cell Size Homeostasis and Growth Rate Diversity during Initial Surface Colonization of Shewanella oneidensis.

PubMed

Lee, Calvin K; Kim, Alexander J; Santos, Giancarlo S; Lai, Peter Y; Lee, Stella Y; Qiao, David F; Anda, Jaime De; Young, Thomas D; Chen, Yujie; Rowe, Annette R; Nealson, Kenneth H; Weiss, Paul S; Wong, Gerard C L

2016-09-06

Cell size control and homeostasis are fundamental features of bacterial metabolism. Recent work suggests that cells add a constant size between birth and division ("adder" model). However, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. Shewanella oneidensis MR-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (EET), which can impact growth, metabolism, and size diversity. Here, we track bacterial surface communities at single-cell resolution to show that not only do bacterial motility appendages influence the transition from two- to three-dimensional biofilm growth and control postdivisional cell fates, they strongly impact cell size homeostasis. For every generation, we find that the average growth rate for cells that stay on the surface and continue to divide (nondetaching population) and that for cells that detach before their next division (detaching population) are roughly constant. However, the growth rate distribution is narrow for the nondetaching population, but broad for the detaching population in each generation. Interestingly, the appendage deletion mutants (ΔpilA, ΔmshA-D, Δflg) have significantly broader growth rate distributions than that of the wild type for both detaching and nondetaching populations, which suggests that Shewanella appendages are important for sensing and integrating environmental inputs that contribute to size homeostasis. Moreover, our results suggest multiplexing of appendages for sensing and motility functions contributes to cell size dysregulation. These results can potentially provide a framework for generating metabolic diversity in S. oneidensis populations to optimize EET in heterogeneous environments.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications.

PubMed

Khalili, Amelia Ahmad; Ahmad, Mohd Ridzuan

2015-08-05

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events.

A Review of Cell Adhesion Studies for Biomedical and Biological Applications

PubMed Central

Ahmad Khalili, Amelia; Ahmad, Mohd Ridzuan

2015-01-01

Cell adhesion is essential in cell communication and regulation, and is of fundamental importance in the development and maintenance of tissues. The mechanical interactions between a cell and its extracellular matrix (ECM) can influence and control cell behavior and function. The essential function of cell adhesion has created tremendous interests in developing methods for measuring and studying cell adhesion properties. The study of cell adhesion could be categorized into cell adhesion attachment and detachment events. The study of cell adhesion has been widely explored via both events for many important purposes in cellular biology, biomedical, and engineering fields. Cell adhesion attachment and detachment events could be further grouped into the cell population and single cell approach. Various techniques to measure cell adhesion have been applied to many fields of study in order to gain understanding of cell signaling pathways, biomaterial studies for implantable sensors, artificial bone and tooth replacement, the development of tissue-on-a-chip and organ-on-a-chip in tissue engineering, the effects of biochemical treatments and environmental stimuli to the cell adhesion, the potential of drug treatments, cancer metastasis study, and the determination of the adhesion properties of normal and cancerous cells. This review discussed the overview of the available methods to study cell adhesion through attachment and detachment events. PMID:26251901

Isolation of Canine parvovirus with a view to identify the prevalent serotype on the basis of partial sequence analysis

PubMed Central

Kaur, Gurpreet; Chandra, Mudit; Dwivedi, P. N.; Sharma, N. S.

2015-01-01

Aim: The aim of this study was to isolate Canine parvovirus (CPV) from suspected dogs on madin darby canine kidney (MDCK) cell line and its confirmation by polymerase chain reaction (PCR) and nested PCR (NPCR). Further, VP2 gene of the CPV isolates was amplified and sequenced to determine prevailing antigenic type. Materials and Methods: A total of 60 rectal swabs were collected from dogs showing signs of gastroenteritis, processed and subjected to isolation in MDCK cell line. The samples showing cytopathic effects (CPE) were confirmed by PCR and NPCR. These samples were subjected to PCR for amplification of VP2 gene of CPV, sequenced and analyzed to study the prevailing antigenic types of CPV. Results: Out of the 60 samples subjected to isolation in MDCK cell line five samples showed CPE in the form of rounding of cells, clumping of cells and finally detachment of the cells. When these samples and the two commercially available vaccines were subjected to PCR for amplification of VP2 gene, a 1710 bp product was amplified. The sequence analysis revealed that the vaccines belonged to the CPV-2 type and the samples were of CPV-2b type. Conclusion: It can be concluded from the present study that out of a total of 60 samples 5 samples exhibited CPE as observed in MDCK cell line. Sequence analysis of the VP2 gene among the samples and vaccine strains revealed that samples belonged to CPV-2b type and vaccines belonging to CPV-2. PMID:27046996

Effect of the PTFE content in the gas diffusion layer on water transport in polymer electrolyte fuel cells (PEFCs)

NASA Astrophysics Data System (ADS)

Mortazavi, Mehdi; Tajiri, Kazuya

2014-01-01

The dynamic behavior of a liquid water droplet emerging and detaching from the surface of the gas diffusion layer (GDL) is investigated. The droplet growth and detachment are studied for different polytetrafluoroethylene (PTFE) contents within the GDL and for different superficial gas velocities flowing in the gas channel. To simulate the droplet behavior in the cathode and anode of an operating polymer electrolyte fuel cell, separate experiments are conducted with air and hydrogen being supplied in the gas channel, respectively. Both the superficial gas velocity and the PTFE content within the GDL are found to impact the droplet detachment diameter. Increasing the superficial gas velocity increases the drag force applied on the droplet sitting on the GDL surface. It is observed that the droplet detaches at a smaller diameter for higher superficial gas velocities. The droplets also detach at smaller diameters from GDLs with a higher amount of PTFE. Such observation is justified according to two different points of view: (1) heterogeneous through-plane PTFE distribution through the GDL and (2) reduced GDL surface roughness caused by PTFE loading.

Primary desmoplastic small round cell tumor in the left orbit: a case report and literature review.

PubMed

He, Xue-Rui; Liu, Zheng; Wei, Jing; Li, Wan-Jun; Liu, Tao

2018-01-30

Desmoplastic small round cell tumor is a rare malignant neoplasm that most often occurs in the abdomen or pelvis of young men. We herein describe a rare case of desmoplastic small round cell tumor arising from the left orbit in a 16-year-old male. A biopsy was performed and the histology showed the nests of tumor cells with small round cell morphology. The tumor cells showed immunopositivity for desmin, CD99, CD56, SMA, NSE, CgA, SYN, Ki67 and vimentin. Fluorescence in situ hybridization study using EWSR1 break-apart probe was positive for EWSR1 gene rearrangement. After complete surgical resection of the tumor, we did not find tumor recurrence or metastasis with one-year follow-up. Furthermore, a review of the relevant English literature has been discussed. In the present study, for the first time, we report a case of desmoplastic small round cell tumor which is located in the orbital region.

Developing a Continuous Bioprocessing Approach to Stromal Cell Manufacture.

PubMed

Miotto, Martina; Gouveia, Ricardo; Abidin, Fadhilah Zainal; Figueiredo, Francisco; Connon, Che J

2017-11-29

To this day, the concept of continuous bioprocessing has been applied mostly to the manufacture of molecular biologics such as proteins, growth factors, and secondary metabolites with biopharmaceutical uses. The present work now sets to explore the potential application of continuous bioprocess methods to source large numbers of human adherent cells with potential therapeutic value. To this purpose, we developed a smart multifunctional surface coating capable of controlling the attachment, proliferation, and subsequent self-detachment of human corneal stromal cells. This system allowed the maintenance of cell cultures under steady-state growth conditions, where self-detaching cells were continuously replenished by the proliferation of those remaining attached. This facilitated a closed, continuous bioprocessing platform with recovery of approximately 1% of the total adherent cells per hour, a yield rate that was maintained for 1 month. Moreover, both attached and self-detached cells were shown to retain their original phenotype. Together, these results represent the proof-of-concept for a new high-throughput, high-standard, and low-cost biomanufacturing strategy with multiple potentials and important downstream applications.

Loss of anchorage primarily induces non-apoptotic cell death in a human mammary epithelial cell line under atypical focal adhesion kinase signaling.

PubMed

Ishikawa, F; Ushida, K; Mori, K; Shibanuma, M

2015-01-22

Anchorage dependence of cellular growth and survival prevents inappropriate cell growth or survival in ectopic environments, and serves as a potential barrier to metastasis of cancer cells. Therefore, obtaining a better understanding of anchorage-dependent responses in normal cells is the first step to understand and impede anchorage independence of growth and survival in cancer cells and finally to eradicate cancer cells during metastasis. Anoikis, a type of apoptosis specifically induced by lack of appropriate cell-extracellular matrix adhesion, has been established as the dominant response of normal epithelial cells to anchorage loss. For example, under detached conditions, the untransformed mammary epithelial cell (MEC) line MCF-10 A, which exhibits myoepithelial characteristics, underwent anoikis dependent on classical ERK signaling. On the other hand, recent studies have revealed a variety of phenotypes resulting in cell death modalities distinct from anoikis, such as autophagy, necrosis, and cornification, in detached epithelial cells. In the present study, we characterized detachment-induced cell death (DICD) in primary human MECs immortalized with hTERT ((Tert)HMECs), which are bipotent progenitor-like cells with a differentiating phenotype to luminal cells. In contrast to MCF-10 A cells, apoptosis was not observed in detached (Tert)HMECs; instead, non-apoptotic cell death marked by features of entosis, cornification, and necrosis was observed along with downregulation of focal adhesion kinase (FAK) signaling. Cell death was overcome by anchorage-independent activities of FAK but not PI3K/AKT, SRC, and MEK/ERK, suggesting critical roles of atypical FAK signaling pathways in the regulation of non-apoptotic cell death. Further analysis revealed an important role of TRAIL (tumor necrosis factor (TNF)-related apoptosis-inducing ligand) as a mediator of FAK signaling in regulation of entosis and necrosis and a role of p38 MAPK in the induction of necrosis. Overall, the present study highlighted outstanding cell subtype or differentiation stage specificity in cell death phenotypes induced upon anchorage loss in human MECs.

Morus alba Leaf Lectin (MLL) Sensitizes MCF-7 Cells to Anoikis by Inhibiting Fibronectin Mediated Integrin-FAK Signaling through Ras and Activation of P38 MAPK

PubMed Central

Saranya, Jayaram; Shilpa, Ganesan; Raghu, Kozhiparambil G.; Priya, Sulochana

2017-01-01

Lectins are a unique class of carbohydrate binding proteins/glycoproteins, and many of them possess anticancer properties. They can induce cell cycle arrest and apoptosis, inhibit protein synthesis, telomerase activity and angiogenesis in cancer cells. In the present study, we have demonstrated the effect of Morus alba leaf lectin (MLL) on anoikis induction in MCF-7 cells. Anoikis induction in cancer cells has a significant role in preventing early stage metastasis. MLL treatment in monolayers of MCF-7 cells caused significant detachment of cells in a time and concentration dependent manner. The detached cells failed to re-adhere and grew even to culture plates coated with different matrix proteins. DNA fragmentation, membrane integrity studies, annexin V staining, caspase 9 activation and upregulation of Bax/Bad confirmed that the detached cells underwent apoptosis. Upregulation of matrix metalloproteinase 9 (MMP-9) caused a decrease in fibronectin (FN) production which facilitated the cells to detach by blocking the FN mediated downstream signaling. On treatment with MLL, we have observed downregulation of integrin expression, decreased phosphorylation of focal adhesion kinase (FAK), loss in FAK-integrin interaction and active Ras. MLL treatment downregulated the levels of phosphorylated Akt and PI3K. Also, we have studied the effect of MLL on two stress activated protein kinases p38 MAPK and JNK. p38 MAPK activation was found to be elevated, but there was no change in the level of JNK. Thus our study substantiated the possible antimetastatic effect of MLL by inducing anoikis in MCF-7 cells by activation of caspase 9 and proapoptotic Bax/Bad by blockage of FN mediated integrin/FAK signaling and partly by activation of p38 MAPK. PMID:28223935

Adaptation and Molecular Characterization of Two Malaysian Very Virulent Infectious Bursal Disease Virus Isolates Adapted in BGM-70 Cell Line

PubMed Central

Lawal, Nafi'u; Arshad, Siti Suri

2017-01-01

Two Malaysian very virulent infectious bursal disease virus (vvIBDV) strains UPM0081 and UPM190 (also known as UPMB00/81 and UPM04/190, respectively) isolated from local IBD outbreaks were serially passaged 12 times (EP12) in specific pathogen free (SPF) chicken embryonated eggs (CEE) by chorioallantoic membrane (CAM) route. The EP12 isolate was further adapted and serially propagated in BGM-70 cell line up to 20 passages (P20). Characteristic cytopathic effects (CPEs) were subtly observed at P1 in both isolates 72 hours postinoculation (pi). The CPE became prominent at P5 with cell rounding, cytoplasmic vacuoles, granulation, and detachment from flask starting from day 3 pi, up to 7 days pi with titers of 109.50 TCID50/mL and log109.80 TCID50/mL for UPM0081 and UPM190, respectively. The CPE became subtle at P17 and disappeared by P18 and P19 for UPM0081 and UPM190, respectively. However, the presence of IBDV was confirmed by immunoperoxidase, immunofluorescence, and RT-PCR techniques. Phylogenetic analysis showed that these two isolates were of the vvIBDV. It appears that a single mutation of UPM190 and UPM0081 IBDV isolates at D279N could facilitate vvIBDV strain adaptability in CEE and BGM-70 cultures. PMID:29230245

Microscopic Behavior Of Colloidal Particles Under The Effect Of Acoustic Stimulations In The Ultrasonic To Megasonic Range

NASA Astrophysics Data System (ADS)

Abdel-Fattah, Amr I.; Roberts, Peter M.

2006-05-01

It is well known that colloid attachment and detachment at solid surfaces are influenced strongly by physico-chemical conditions controlling electric double layer (EDL) and solvation-layer effects. We present experimental observations demonstrating that, in addition, acoustic waves can produce strong effects on colloid/surface interactions that can alter the behavior of colloid and fluid transport in porous media. Microscopic colloid visualization experiments were performed with polystyrene micro-spheres suspended in water in a parallel-plate glass flow cell. When acoustic energy was applied to the cell at frequencies from 500 kHz to 5 MHz, changes in colloid attachment to and detachment from the glass cell surfaces were observed. Quantitative measurements of acoustically-induced detachment of 300-nm microspheres in 0.1M NaCl solution demonstrated that roughly 30% of the colloids that were attached to the glass cell wall during flow alone could be detached rapidly by applying acoustics at frequencies in the range of 0.7 to 1.2 MHz. The remaining attached colloids could not be detached by acoustics. This implies the existence of both "strong" and "weak" attachment sites at the cell surface. Subsequent re-attachment of colloids with acoustics turned off occurred only at new, previously unoccupied sites. Thus, acoustics appears to accelerate simultaneously both the deactivation of existing weak sites where colloids are already attached, and the activation of new weak sites where future attachments can occur. Our observations indicate that acoustics (and, in general, dynamic stress) can influence colloid-colloid and colloid-surface interactions in ways that could cause significant changes in porous-media permeability and mass transport. This would occur due to either buildup or release of colloids present in the porous matrix.

Novel round cells in urine sediment and their clinical implications.

PubMed

Shukuya, Kenichi; Ogura, Sayoko; Tokuhara, Yasunori; Okubo, Shigeo; Yatomi, Yutaka; Tozuka, Minoru; Shimosawa, Tatsuo

2016-06-01

Voided urine contains a variety of cells from the kidney and urinary tract and urinalysis provides us various information by investigating cellular components. We investigated urine sediment from renal impaired patients. We found 'round cell' to be distinct from known cells in sediment and is close to proximal convoluted tubule-derived cells based on morphology and molecular marker expression (GGT1 but not podocalyxin). Also it was positive for undifferentiated cell markers, including PAX2, WT1, OSR1, and SIX2. They were observed in end-stage renal failure patients and the number of cells was correlated with the severity of chronic kidney disease. A prospective analysis revealed that patients who had more round cells were more likely to require hemodialysis within a year. Round cells are a novel marker that can be used to predict the need for hemodialysis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Enhanced antiadhesive properties of chitosan/hyaluronic acid polyelectrolyte multilayers driven by thermal annealing: Low adherence for mammalian cells and selective decrease in adhesion for Gram-positive bacteria.

PubMed

Muzzio, Nicolás E; Pasquale, Miguel A; Diamanti, Eleftheria; Gregurec, Danijela; Moro, Marta Martinez; Azzaroni, Omar; Moya, Sergio E

2017-11-01

The development of antifouling coatings with restricted cell and bacteria adherence is fundamental for many biomedical applications. A strategy for the fabrication of antifouling coatings based on the layer-by-layer assembly and thermal annealing is presented. Polyelectrolyte multilayers (PEMs) assembled from chitosan and hyaluronic acid were thermally annealed in an oven at 37°C for 72h. The effect of annealing on the PEM properties and topography was studied by atomic force microscopy, ζ-potential, circular dichroism and contact angle measurements. Cell adherence on PEMs before and after annealing was evaluated by measuring the cell spreading area and aspect ratio for the A549 epithelial, BHK kidney fibroblast, C2C12 myoblast and MC-3T3-E1 osteoblast cell lines. Chitosan/hyaluronic acid PEMs show a low cell adherence that decreases with the thermal annealing, as observed from the reduction in the average cell spreading area and more rounded cell morphology. The adhesion of S. aureus (Gram-positive) and E. coli (Gram-negative) bacteria strains was quantified by optical microscopy, counting the number of colony-forming units and measuring the light scattering of bacteria suspension after detachment from the PEM surface. A 20% decrease in bacteria adhesion was selectively observed in the S. aureus strain after annealing. The changes in mammalian cell and bacteria adhesion correlate with the changes in topography of the chitosan/hyaluronic PEMs from a rough fibrillar 3D structure to a smoother and planar surface after thermal annealing. Copyright © 2017. Published by Elsevier B.V.

Accelerated cell-sheet recovery from a surface successively grafted with polyacrylamide and poly(N-isopropylacrylamide).

PubMed

Akiyama, Yoshikatsu; Kikuchi, Akihiko; Yamato, Masayuki; Okano, Teruo

2014-08-01

A double polymeric nanolayer consisting of poly(N-isopropylacrylamide) (PIPAAm) and hydrophilic polyacrylamide (PAAm) was deposited on tissue culture polystyrene (TCPS) surfaces using electron beam irradiation to form a new temperature-responsive cell culture surface in which the basal hydrophilic PAAm component in the double polymeric layer promotes the hydration of the upper PIPAAm layer and induces rapid cell detachment compared to a conventional temperature-responsive cell culture surface, PIPAAm-grafted TCPS (PIPAAm-TCPS). Take-off angle-dependent X-ray photoelectron spectroscopy spectral analysis demonstrated that the grafted PIPAAm and PAAm components were located in the upper and basal regions of the double polymeric layer, respectively, suggesting that the double polymeric layer forms an inter-penetrating-network-like structure with PAAm at the basal portion of the PIPAAm grafted chains. The wettability of the temperature-responsive cell culture surfaces with the double polymeric layer tended to be more hydrophilic, with an increase in the basal PAAm graft density at a constant PIPAAm graft density. However, when the graft densities of the upper PIPAAm and basal PAAm were optimized, the resulting temperature-responsive cell culture surface with the double polymeric layer exhibited rapid cell detachment while maintaining cell adhesive character comparable to that of PIPAAm-TCPS. The cell adhesive character was altered from cell-adhesive to cell-repellent with increasing PAAm or PIPAAm graft density. The cell adhesive character of the temperature-responsive cell culture surfaces was relatively consistent with their contact angles. These results strongly suggest that the basal PAAm surface properties affect the degree of hydration and dehydration of the subsequently grafted PIPAAm. In addition, the roles of the hydrophilic component in accelerating cell detachment are further discussed in terms of the mobility of the grafted PIPAAm chains. Applications of this insight might be useful for designing temperature-responsive cell culture surfaces for achieving efficient cell culture and quick target cell detachment. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Human dental pulp stem cell adhesion and detachment in polycaprolactone electrospun scaffolds under direct perfusion

PubMed Central

Paim, A.; Braghirolli, D.I.; Cardozo, N.S.M.; Pranke, P.; Tessaro, I.C.

2018-01-01

Cell adhesion in three-dimensional scaffolds plays a key role in tissue development. However, stem cell behavior in electrospun scaffolds under perfusion is not fully understood. Thus, an investigation was made on the effect of flow rate and shear stress, adhesion time, and seeding density under direct perfusion in polycaprolactone electrospun scaffolds on human dental pulp stem cell detachment. Polycaprolactone scaffolds were electrospun using a solvent mixture of chloroform and methanol. The viable cell number was determined at each tested condition. Cell morphology was analyzed by confocal microscopy after various incubation times for static cell adhesion with a high seeding density. Scanning electron microscopy images were obtained before and after perfusion for the highest flow rate tested. The wall pore shear stress was calculated for all tested flow rates (0.005–3 mL/min). An inversely proportional relationship between adhesion time with cell detachment under perfusion was observed. Lower flow rates and lower seeding densities reduced the drag of cells by shear stress. However, there was an operational limit for the lowest flow rate that can be used without compromising cell viability, indicating that a flow rate of 0.05 mL/min might be more suitable for the tested cell culture in electrospun scaffolds under direct perfusion. PMID:29590258

Cell shape changes induced by cationic anesthetics

PubMed Central

1976-01-01

The effects of local anesthetics on cultivated macrophages were studied in living preparations and recorded in still pictures and time-lapse cine-micrographs. Exposure to 12mM lidocaine or 1.5 mM tetracaine resulted in rounding in 10-15 min. Rounding was characterized by cell contraction, marked increase in retraction fibrils, withdrawal of cell processes, and, in late stages, pulsation-like activity and zeiosis. Cells showed appreciable membrane activity as they rounded. Respreading was complete within 15 min of perfusion in drug-free medium and entailed a marked increase in surface motility over control periods. As many as eight successive cycles of rounding and spreading were obtained with lidocaine without evidence of cell damage. The effects of anesthetics were similar to those observed with EDTA, but ethylene- glycol-bis(beta-aminoethylether)-N, N'-tetraacetic acid-Mg was ineffective. Rounding was also induced by benzocaine, an anesthetic nearly uncharged at pH 7.0. Quaternary (nondischargeable) compounds were of low activity, presumably because they are slow permeants. Lidocaine induced rounding at 10 degrees C and above but was less effective at 5 degrees C and ineffective at 0 degrees C. Rounding by the anesthetic was also obtained in media depleted or Na or enriched with 10 mM Ca or Mg. The latter finding, together with the failure of tetrodotoxin to induce rounding, suggests that the anesthetic effect is unrelated to inhibition of sodium conductance. It is possible that the drugs influence divalent ion fluxes or some component of the contractile cells' machinery, but a metabolic target of action cannot yet be excluded. PMID:814194

Array-based DNA-methylation profiling in sarcomas with small blue round cell histology provides valuable diagnostic information.

PubMed

Koelsche, Christian; Hartmann, Wolfgang; Schrimpf, Daniel; Stichel, Damian; Jabar, Susanne; Ranft, Andreas; Reuss, David E; Sahm, Felix; Jones, David T W; Bewerunge-Hudler, Melanie; Trautmann, Marcel; Klingebiel, Thomas; Vokuhl, Christian; Gessler, Manfred; Wardelmann, Eva; Petersen, Iver; Baumhoer, Daniel; Flucke, Uta; Antonescu, Cristina; Esteller, Manel; Fröhling, Stefan; Kool, Marcel; Pfister, Stefan M; Mechtersheimer, Gunhild; Dirksen, Uta; von Deimling, Andreas

2018-03-23

Undifferentiated solid tumors with small blue round cell histology and expression of CD99 mostly resemble Ewing sarcoma. However, they also may include other tumors such as mesenchymal chondrosarcoma, synovial sarcoma, or small cell osteosarcoma. Definitive classification usually requires detection of entity-specific mutations. While this approach identifies the majority of Ewing sarcomas, a subset of lesions remains unclassified and, therefore, has been termed "Ewing-like sarcomas" or small blue round cell tumors not otherwise specified. We developed an approach for further characterization of small blue round cell tumors not otherwise specified using an array-based DNA-methylation profiling approach. Data were analyzed by unsupervised clustering and t-distributed stochastic neighbor embedding analysis and compared with a reference methylation data set of 460 well-characterized prototypical sarcomas encompassing 18 subtypes. Verification was performed by additional FISH analyses, RNA sequencing from formalin-fixed paraffin-embedded material or immunohistochemical marker analyses. In a cohort of more than 1,000 tumors assumed to represent Ewing sarcomas, 30 failed to exhibit the typical EWS translocation. These tumors were subjected to methylation profiling and could be assigned to Ewing sarcoma in 14 (47%), to small blue round cell tumors with CIC alteration in 6 (20%), to small blue round cell tumors with BCOR alteration in 4 (13%), to synovial sarcoma and to malignant rhabdoid tumor in 2 cases each. One single case each was allotted to mesenchymal chondrosarcoma and adamantinoma. 12/14 tumors classified as Ewing sarcoma could be verified by demonstrating either a canonical EWS translocation evading initial testing, by identifying rare breakpoints or fusion partners. The methylation-based assignment of the remaining small blue round cell tumors not otherwise specified also could be verified by entity-specific molecular alterations in 13/16 cases. In conclusion, array-based DNA-methylation analysis of undifferentiated tumors with small blue round cell histology is a powerful tool for precisely classifying this diagnostically challenging tumor group.

Parametric study on the vortex-induced motions of semi-submersibles: Effect of rounded ratios of the column and pontoon

NASA Astrophysics Data System (ADS)

Liu, Mingyue; Xiao, Longfei; Yang, Jianmin; Tian, Xinliang

2017-05-01

The vortex-induced motions (VIMs) of semi-submersibles have emerged as an important issue in offshore engineering, as they pose a threat to safe and reliable operations and severely affect the fatigue lives of risers and mooring systems. The VIM response depends on the shape of the submerged structure and thus is significantly influenced by the design parameters related to the columns and pontoons. Numerical simulations by the detached Eddy simulation method are validated by experimental data and then used for parametric analysis of the VIM performance of various semi-submersibles with different column rounded ratios (Rc/L ) and pontoon rounded ratios (Rp/Lp ). The results show that the transverse amplitudes of a semi-submersible with circular columns at a 0° current heading are twice as large as those at a 45° current heading. However, the semi-submersible with rounded square columns shows more significant transverse motions at a 45° current heading than at a 0° current heading. Furthermore, at the 45° current heading, the transverse amplitudes of the semi-submersibles show a rapid increase as the column radius increases in the range of Rc/L <0.1 . The peak values remain roughly the same for 0.1 ≤Rc/L ≤0.2 and then decrease as the column radius increases (Rc/L ≥0.3 ). In addition, the effect of the pontoon shape on the transverse response is negligible for semi-submersibles with sharp square columns, while for semi-submersibles with rounded square columns or circular columns, the sharp rectangular pontoons greatly mitigate the VIM response.

Mechanism by Which Cold Shock Evokes Exocytosis of Symbiotic Algae in Marine Cnidarians

DTIC Science & Technology

1993-05-30

shock, and UV irradiation, and the mode of release of zooxanthellae was investigated. It was determined that all three types of acute stress evoked...detachment and expulsion of intact host endoderm cells containing zooxanthellae . To determine how cold shock evokes cell detachment we have formulated...Coral Reefs 11:143-154. Bil’, K., P. Kolmakov. and L. Muscatine (1992) Photosynthetic products of zooxanthellae of the reef building corals

Near-IR laser-triggered target cell collection using a carbon nanotube-based cell-cultured substrate.

PubMed

Sada, Takao; Fujigaya, Tsuyohiko; Niidome, Yasuro; Nakazawa, Kohji; Nakashima, Naotoshi

2011-06-28

Unique near-IR optical properties of single-walled carbon nanotube (SWNTs) are of interest in many biological applications. Here we describe the selective cell detachment and collection from an SWNT-coated cell-culture dish triggered by near-IR pulse laser irradiation. First, HeLa cells were cultured on an SWNT-coated dish prepared by a spraying of an aqueous SWNT dispersion on a glass dish. The SWNT-coated dish was found to show a good cell adhesion behavior as well as a cellular proliferation rate similar to a conventional glass dish. We discovered, by near-IR pulse laser irradiation (at the laser power over 25 mW) to the cell under optical microscopic observation, a quick single-cell detachment from the SWNT-coated surface. Shockwave generation from the irradiated SWNTs is expected to play an important role for the cell detachment. Moreover, we have succeeded in catapulting the target single cell from the cultured medium when the depth of the medium was below 150 μm and the laser power was stronger than 40 mW. The captured cell maintained its original shape. The retention of the genetic information of the cell was confirmed by the polymerase chain reaction (PCR) technique. A target single-cell collection from a culture medium under optical microscopic observation is significant in wide fields of single-cell studies in biological areas.

Lipid tethering of breast tumor cells enables real-time imaging of free-floating cell dynamics and drug response

PubMed Central

Whipple, Rebecca A.; Zhang, Peipei; Sooklal, Elisabeth L.; Martin, Stuart S.; Jewell, Christopher M.

2016-01-01

Free-floating tumor cells located in the blood of cancer patients, known as circulating tumor cells (CTCs), have become key targets for studying metastasis. However, effective strategies to study the free-floating behavior of tumor cells in vitro have been a major barrier limiting the understanding of the functional properties of CTCs. Upon extracellular-matrix (ECM) detachment, breast tumor cells form tubulin-based protrusions known as microtentacles (McTNs) that play a role in the aggregation and re-attachment of tumor cells to increase their metastatic efficiency. In this study, we have designed a strategy to spatially immobilize ECM-detached tumor cells while maintaining their free-floating character. We use polyelectrolyte multilayers deposited on microfluidic substrates to prevent tumor cell adhesion and the addition of lipid moieties to tether tumor cells to these surfaces through interactions with the cell membranes. This coating remains optically clear, allowing capture of high-resolution images and videos of McTNs on viable free-floating cells. In addition, we show that tethering allows for the real-time analysis of McTN dynamics on individual tumor cells and in response to tubulin-targeting drugs. The ability to image detached tumor cells can vastly enhance our understanding of CTCs under conditions that better recapitulate the microenvironments they encounter during metastasis. PMID:26871289

Practical selection methods for rat and mouse round spermatids without DNA staining by flow cytometric cell sorting.

PubMed

Hayama, Tomonari; Yamaguchi, Tomoyuki; Kato-Itoh, Megumi; Ishii, Yumiko; Mizuno, Naoaki; Umino, Ayumi; Sato, Hideyuki; Sanbo, Makoto; Hamanaka, Sanae; Masaki, Hideki; Hirabayashi, Masumi; Nakauchi, Hiromitsu

2016-06-01

Round spermatid injection (ROSI) into unfertilized oocytes enables a male with a severe spermatogenesis disorder to have children. One limitation of the application of this technique in the clinic is the identification and isolation of round spermatids from testis tissue. Here we developed an efficient and simple method to isolate rodent haploid round spermatids using flow cytometric cell sorting, based on DNA content (stained with Hoechst 33342 or Dye Cycle Violet) or by cell diameter and granularity (forward and side scatter). ROSI was performed with round spermatids selected by flow cytometry, and we obtained healthy offspring from unstained cells. This non-invasive method could therefore be an effective option for breeding domestic animals and human male infertility treatment. Mol. Reprod. Dev. 83: 488-496, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Thermo-responsive cell culture carrier: Effects on macrophage functionality and detachment efficiency.

PubMed

Rennert, Knut; Nitschke, Mirko; Wallert, Maria; Keune, Natalie; Raasch, Martin; Lorkowski, Stefan; Mosig, Alexander S

2017-01-01

Harvesting cultivated macrophages for tissue engineering purposes by enzymatic digestion of cell adhesion molecules can potentially result in unintended activation, altered function, or behavior of these cells. Thermo-responsive polymer is a promising tool that allows for gentle macrophage detachment without artificial activation prior to subculture within engineered tissue constructs. We therefore characterized different species of thermo-responsive polymers for their suitability as cell substrate and to mediate gentle macrophage detachment by temperature shift. Primary human monocyte- and THP-1-derived macrophages were cultured on thermo-responsive polymers and characterized for phagocytosis and cytokine secretion in response to lipopolysaccharide stimulation. We found that both cell types differentially respond in dependence of culture and stimulation on thermo-responsive polymers. In contrast to THP-1 macrophages, primary monocyte-derived macrophages showed no signs of impaired viability, artificial activation, or altered functionality due to culture on thermo-responsive polymers compared to conventional cell culture. Our study demonstrates that along with commercially available UpCell carriers, two other thermo-responsive polymers based on poly(vinyl methyl ether) blends are attractive candidates for differentiation and gentle detachment of primary monocyte-derived macrophages. In summary, we observed similar functionality and viability of primary monocyte-derived macrophages cultured on thermo-responsive polymers compared to standard cell culture surfaces. While this first generation of custom-made thermo-responsive polymers does not yet outperform standard culture approaches, our results are very promising and provide the basis for exploiting the unique advantages offered by custom-made thermo-responsive polymers to further improve macrophage culture and recovery in the future, including the covalent binding of signaling molecules and the reduction of centrifugation and washing steps. Optimizing these and other benefits of thermo-responsive polymers could greatly improve the culture of macrophages for tissue engineering applications.

Cell-matrix adhesion characterization using multiple shear stress zones in single stepwise microchannel

NASA Astrophysics Data System (ADS)

Kim, Min-Ji; Doh, Il; Bae, Gab-Yong; Cha, Hyuk-Jin; Cho, Young-Ho

2014-08-01

This paper presents a cell chip capable to characterize cell-matrix adhesion by monitoring cell detachment rate. The proposed cell chip can supply multiple levels of shear stress in single stepwise microchannel. As epithelial-mesenchymal transition (EMT), one of hallmarks of cancer metastasis is closely associated to the interaction with extracelluar matrix (ECM), we took advantage of two lung cancer cell models with different adhesion properties to ECM depending their epithelial or mesenchymal properties, including the pair of lung cancer cells with (A549sh) or without E-cadherin expression (A549sh-Ecad), which would be optimal model to examine the alteration of adhesion properties after EMT induction. The cell-matrix adhesion resisting to shear stress appeared to be remarkably differed between lung cancer cells. The detachment rate of epithelial-like H358 and mesenchymal-like H460 cells was 53%-80% and 25%-66% in the shear stress range of 34-60 dyn/cm2, respectively. A549sh-Ecad cells exhibits lower detachment rate (5%-9%) compared to A549sh cells (14%-40%). By direct comparison of adhesion between A549sh and A549sh-Ecad, we demonstrated that A549shE-cad to mimic EMT were more favorable to the ECM attachment under the various levels of shear stress. The present method can be applied to quantitative analysis of tumor cell-ECM adhesion.

Transfer of fibroblast sheets cultured on thermoresponsive dishes with membranes.

PubMed

Kawecki, Marek; Kraut, Małgorzata; Klama-Baryła, Agnieszka; Łabuś, Wojciech; Kitala, Diana; Nowak, Mariusz; Glik, Justyna; Sieroń, Aleksander L; Utrata-Wesołek, Alicja; Trzebicka, Barbara; Dworak, Andrzej; Szweda, Dawid

2016-06-01

In cell or tissue engineering, it is essential to develop a support for cell-to-cell adhesion, which leads to the generation of cell sheets connected by extracellular matrix. Such supports must be hydrophobic and should result in a detachable cell sheet. A thermoresponsive support that enables the cultured cell sheet to detach using only a change in temperature could be an interesting alternative in regenerative medicine. The aim of this study was to evaluate plates covered with thermoresponsive polymers as supports for the formation of fibroblast sheets and to develop a damage-free procedure for cell sheet transfer with the use of membranes as transfer tools. Human skin fibroblasts were seeded on supports coated with a thermoresponsive polymer: commercial UpCell™ dishes (NUNC™) coated with thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and dishes coated with thermoresponsive poly(tri(ethylene glycol) monoethyl ether methacrylate) (P(TEGMA-EE)). Confluent fibroblast sheets were effectively cultured and harvested from both commercial PNIPAM-coated dishes and laboratory P(TEGMA-EE)-coated dishes. To transfer a detached cell sheet, two membranes, Immobilon-P(®) and SUPRATHEL(®), were examined. The use of SUPRATHEL for relocating the cell sheets opens a new possibility for the clinical treatment of wounds. This study established the background for implementing thermoresponsive supports for transplanting in vitro cultured fibroblasts.

ROCK inhibition promotes microtentacles that enhance reattachment of breast cancer cells

PubMed Central

Bhandary, Lekhana; Whipple, Rebecca A.; Vitolo, Michele I.; Charpentier, Monica S.; Boggs, Amanda E.; Chakrabarti, Kristi R.; Thompson, Keyata N.; Martin, Stuart S.

2015-01-01

The presence of circulating tumor cells (CTCs) in blood predicts poor patient outcome and CTC frequency is correlated with higher risk of metastasis. Recently discovered, novel microtubule-based structures, microtentacles, can enhance reattachment of CTCs to the vasculature. Microtentacles are highly dynamic membrane protrusions formed in detached cells and occur when physical forces generated by the outwardly expanding microtubules overcome the contractile force of the actin cortex. Rho-associated kinase (ROCK) is a major regulator of actomyosin contractility and Rho/ROCK over-activation is implicated in tumor metastasis. ROCK inhibitors are gaining popularity as potential cancer therapeutics based on their success in reducing adherent tumor cell migration and invasion. However, the effect of ROCK inhibition on detached cells in circulation is largely unknown. In this study, we use breast tumor cells in suspension to mimic detached CTCs and show that destabilizing the actin cortex through ROCK inhibition in suspended cells promotes the formation of microtentacles and enhances reattachment of cells from suspension. Conversely, increasing actomyosin contraction by Rho over-activation reduces microtentacle frequency and reattachment. Although ROCK inhibitors may be effective in reducing adherent tumor cell behavior, our results indicate that they could inadvertently increase metastatic potential of non-adherent CTCs by increasing their reattachment efficacy. PMID:25749040

Assessment of the biocompatibility, stability, and suitability of novel thermoresponsive films for the rapid generation of cellular constructs

NASA Astrophysics Data System (ADS)

Reed, Jamie A.

2011-12-01

Stimuli responsive polymers (SRP) are of great interest in the bioengineering community due to their use in applications such as drug delivery and tissue engineering. One example of an SRP is poly(N-isopropyl acrylamide) or pNIPAM. This SRP has the capability of changing its conformation with a slight temperature change: adherent mammalian cells spontaneously release as a confluent cell sheet, which can be harvested for cell sheet engineering purposes. Since its initial use in 1968, many researchers have used pNIPAM to obtain a cell sheet composed of their cell type of interest. The differing protocols used for these diverse cell types, such as the conditions used for cell detachment, and the varying methods used for derivatizing substrates with pNIPAM have all led to conflicting reports on the utility of pNIPAM for cell sheet engineering purposes, as well as the relative cytotoxicity of the polymer. In this work, some of the key inconsistencies in the literature and previously unaddressed challenges when utilizing pNIPAM films are overcome for the purpose of rapid generation of cellular constructs, specifically spheroids. Pertinent characteristics of low temperature detachment are investigated for their effect on the kinetics of cell detachment. In addition, a novel, inexpensive method for obtaining pNIPAM films for mammalian cell detachment, combining pNIPAM with a sol-gel, was optimized and compared to plasma polymerization deposition. Furthermore, proper storage conditions (e.g. temperature and relative humidity) for these films were investigated to increase stability of the films for using tissue culture conditions. To increase the speed of generation of cell sheets, electrospun mats and hydrogels with a high surface area-to-volume ratio were developed. The result is a platform appropriate for the rapid formation of cellular constructs, such as engineered tissues and spheroids for cancer cell research.

Feline morbillivirus, a previously undescribed paramyxovirus associated with tubulointerstitial nephritis in domestic cats

PubMed Central

Woo, Patrick C. Y.; Lau, Susanna K. P.; Wong, Beatrice H. L.; Fan, Rachel Y. Y.; Wong, Annette Y. P.; Zhang, Anna J. X.; Wu, Ying; Choi, Garnet K. Y.; Li, Kenneth S. M.; Hui, Janet; Wang, Ming; Zheng, Bo-Jian; Chan, K. H.; Yuen, Kwok-Yung

2012-01-01

We describe the discovery and isolation of a paramyxovirus, feline morbillivirus (FmoPV), from domestic cat (Felis catus). FmoPV RNA was detected in 56 (12.3%) of 457 stray cats (53 urine, four rectal swabs, and one blood sample) by RT-PCR. Complete genome sequencing of three FmoPV strains showed genome sizes of 16,050 bases, the largest among morbilliviruses, because of unusually long 5′ trailer sequences of 400 nt. FmoPV possesses identical gene contents (3′-N-P/V/C-M-F-H-L-5′) and is phylogenetically clustered with other morbilliviruses. IgG against FmoPV N protein was positive in 49 sera (76.7%) of 56 RT-PCR–positive cats, but 78 (19.4%) of 401 RT-PCR–negative cats (P < 0.0001) by Western blot. FmoPV was isolated from CRFK feline kidney cells, causing cytopathic effects with cell rounding, detachment, lysis, and syncytia formation. FmoPV could also replicate in subsequent passages in primate Vero E6 cells. Infected cell lines exhibited finely granular and diffuse cytoplasmic fluorescence on immunostaining for FmoPV N protein. Electron microscopy showed enveloped virus with typical “herringbone” appearance of helical N in paramyxoviruses. Histological examination of necropsy tissues in two FmoPV-positive cats revealed interstitial inflammatory infiltrate and tubular degeneration/necrosis in kidneys, with decreased cauxin expression in degenerated tubular epithelial cells, compatible with tubulointerstitial nephritis (TIN). Immunohistochemical staining revealed FmoPV N protein-positive renal tubular cells and mononuclear cells in lymph nodes. A case-control study showed the presence of TIN in seven of 12 cats with FmoPV infection, but only two of 15 cats without FmoPV infection (P < 0.05), suggesting an association between FmoPV and TIN. PMID:22431644

Immature germ cells in semen - correlation with total sperm count and sperm motility.

PubMed

Patil, Priya S; Humbarwadi, Rajendra S; Patil, Ashalata D; Gune, Anita R

2013-07-01

Current data regarding infertility suggests that male factor contributes up to 30% of the total cases of infertility. Semen analysis reveals the presence of spermatozoa as well as a number of non-sperm cells, presently being mentioned in routine semen report as "round cells" without further differentiating them into leucocytes or immature germ cells. The aim of this work was to study a simple, cost-effective, and convenient method for differentiating the round cells in semen into immature germ cells and leucocytes and correlating them with total sperm counts and motility. Semen samples from 120 males, who had come for investigation for infertility, were collected, semen parameters recorded, and stained smears studied for different round cells. Statistical analysis of the data was done to correlate total sperm counts and sperm motility with the occurrence of immature germ cells and leucocytes. The average shedding of immature germ cells in different groups with normal and low sperm counts was compared. The clinical significance of "round cells" in semen and their differentiation into leucocytes and immature germ cells are discussed. Round cells in semen can be differentiated into immature germ cells and leucocytes using simple staining methods. The differential counts mentioned in a semen report give valuable and clinically relevant information. In this study, we observed a negative correlation between total count and immature germ cells, as well as sperm motility and shedding of immature germ cells. The latter was statistically significant with a P value 0.000.

Pathogenesis of rhegmatogenous retinal detachment: predisposing anatomy and cell biology.

PubMed

Mitry, Danny; Fleck, Brian W; Wright, Alan F; Campbell, Harry; Charteris, David G

2010-01-01

The pathogenesis of rhegmatogenous retinal detachment is complex, and our knowledge of the exact mechanism of vitreoretinal attachment and detachment remains incomplete. We performed a Medline, Ovid, and EMBASE search using search words rhegmatogenous, retinal detachment, vitreous, and retinal adhesion. All appropriate articles were reviewed, and the evidence was compiled. Cortical vitreous contains fibrillar collagens type II, V/XI, and IX. The inner limiting membrane of the retina contains collagens type I, IV, VI, and XVIII as well as numerous other glycoproteins and potential adhesion molecules. The distribution and age-related changes in the structure of these molecules play an important role in the formation of a retinal break, which may compromise and disrupt the normal mechanisms of neurosensory retinal adhesion. Rhegmatogenous retinal detachment development is intimately related to changes in the fibrillar structure of the aging vitreous culminating in posterior vitreous detachment with regions of persistent and tangential vitreoretinal traction predisposing to retinal tear formation. A complex interplay of factors such as weakening of vitreoretinal adhesion, posterior migration of the vitreous base, and molecular changes at the vitreoretinal interface are important in predisposing to focal areas of vitreoretinal traction precipitating rhegmatogenous retinal detachment. Once formed, the passage of liquefied vitreous through a retinal break may overwhelm normal neurosensory-retinal pigment epithelium adhesion perpetuating and extending detachment and causing visual loss. To understand the molecular events underlying rhegmatogenous retinal detachment so that new therapies can be developed, it is important to appreciate the structural organization of the vitreous, the biology underlying vitreous liquefaction and posterior vitreous detachment, and the mechanisms of vitreoretinal attachment and detachment.

Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices--an in vitro study.

PubMed

Busscher, Henk J; White, Don J; Atema-Smit, Jelly; van der Mei, Henny C

2007-04-01

The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle surface chemistry to improve cleansing or discourage renewed plaque formation. It is the aim of this paper to analyze in vitro detachment of co-aggregating oral actinomyces and streptococci from pellicle surfaces by dentifrice supernates and to study subsequent de novo streptococcal deposition. Detachment by dentifrices of a co-adhering bacterial pair was studied in the parallel plate flow chamber on a 16 h pellicle coated surface. After detachment by perfusing the chamber with a dentifrice, re-deposition was initiated by flowing with a fresh streptococcal suspension. The dentifrices included both a regular, SLS-fluoride based formulation as well a pyrophosphate, anticalculus and antimicrobial formulations. All dentifrice supernates containing SLS were effective in detaching co-adhering bacteria from pellicles surfaces, except in combination with SnF(2). When hexametaphosphate was added immediate detachment was relatively low, but continued even during re-deposition. The re-deposition of streptococci after detachment by other, NaF containing dentifrices involved relatively few large aggregates, presumably because fluoride was able to block bi-dentate calcium binding sites on the bacterial cell surfaces, mediating co-adhesion. When pyrophosphate was present in addition to NaF, re-deposition involved significantly more large aggregates, likely because pyrophosphate served as a bi-dentate bridge between calcium bound on the bacterial cell surfaces. Commercially available dentifrice formulations differ in their ability to stimulate bacterial detachment from pellicles and dependent on their composition yield the formation of large co-adhering aggregates of actinomyces and streptococci in de novo deposition.

Simple and reliable identification of the human round spermatid by inverted phase-contrast microscopy.

PubMed

Verheyen, G; Crabbé, E; Joris, H; Van Steirteghem, A

1998-06-01

Based on the results of animal studies, round spermatid injection (ROSI) has been introduced into the clinical practice of several in-vitro fertilization (IVF) centres. The efficiency of this procedure in terms of fertilization rates and pregnancy rates, however, remains very poor. An essential aspect which does not receive enough attention is the correct identification of this type of round cell within a heterogeneous population of testicular cells. A Nikon inverted microscope equipped with phase-contrast optics (DLL) provided a clear image which allowed reliable recognition of round spermatids in cell suspensions smeared at the glass bottom of the dish. Fluorescent in-situ hybridization confirmed the haploid status of the selected cells. However, exploration of several biopsies from patients with non-obstructive azoospermia showing no spermatozoa after extensive search did not reveal any round spermatids. This observation questions whether enough effort is spent on searching for mature spermatozoa or late spermatids. Experimental investigations should precede the introduction of ROSI into the clinical practice of any IVF centre.

Structure, development, and cytochemical properties of the nucleolus-associated "round body" in rat spermatocytes and early spermatids.

PubMed

Schultz, M C; Hermo, L; Leblond, C P

1984-09-01

The "round body," a spherical structure typically associated with a nucleolus in male germ cells of the rat, has been examined in the electron microscope using routine and cytochemical methods to determine its structure, composition, and mode of development. Cytochemical analysis indicates that the round body includes neither nucleic acid nor lipid, but is composed of nonhistone protein which appears in the form of 1.6-nm-wide fibrils. Development begins in late leptotene, when a single round body appears in each spermatocyte as an irregular spheroid located along the inner surface of the nuclear envelope. During subsequent stages of the meiotic prophase, the round body leaves the nuclear envelope, becomes a regular sphere, and gradually enlarges from a diameter of 0.4 micron in leptotene to 1.6 micron in diplotene. Concurrently, lacunae appear within its substance and enlarge. At each maturation division, the amount of round-body material is decreased by about half, presumably because the constituent proteins are dissociated at metaphase, distributed between the two daughter cells at telophase, and reconstituted into half-sized round bodies. As spermiogenesis proceeds, the round body shrinks gradually and disappears at step 8. Soon after its appearance at leptotene, the round body becomes associated with and is surrounded by the pars granulosa of one of the nucleoli. Moreover, 3H-uridine incorporation into nucleolar RNA is high as long as the size of the round body increases, but is low or absent when it decreases. It is possible, therefore, that the round body exerts some control on nucleolar activity in meiotic cells.

Desmoplastic small round cell tumor with sphere-like clusters mimicking adenocarcinoma.

PubMed

Hattori, Yukinori; Yoshida, Akihiko; Sasaki, Naoshi; Shibuki, Yasuo; Tamura, Kenji; Tsuta, Koji

2015-03-01

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive neoplasm that predominantly affects young men. DSRCT often presents as multiple nodules on the serosal surface and is histologically categorized as a small round cell tumor. However, the cytological spectrum of DSRCT is not fully understood because of its rarity. Here, we report an unusual case of DSRCT that showed spheres of cells without stromal cores in pleural fluid cytology material, a finding that is typically associated with metastatic adenocarcinoma and mesothelioma. The specimen from a simultaneous needle biopsy showed the classic histology of DSRCT, comprising nests of small round cells set in desmoplasia. The diagnosis of DSRCT was further supported by immunohistochemical coexpression of cytokeratin and desmin, as well as Ewing sarcoma breakpoint region 1 gene rearrangement, which was determined by fluorescence in situ hybridization. The unusual cytological finding in this case illustrates a potential pitfall of the cytological diagnosis of pleural fluid or ascites. DSRCT should not be excluded from the differential diagnosis when sphere-like round cell clusters are observed in pleural or abdominal effusion, particularly in young male patients. © 2014 Wiley Periodicals, Inc.

Matrix detachment and proteasomal inhibitors diminish Sulf-2 expression in breast cancer cell lines and mouse xenografts

PubMed Central

Khurana, Ashwani; Jung-Beom, Deok; He, Xiaoping; Kim, Sung-Hoon; Busby, Robert C.; Lorenzon, Laura; Villa, Massimo; Baldi, Alfonso; Molina, Julian; Goetz, Matthew P.; Shridhar, Viji

2013-01-01

Sulfatase 2 (Sulf-2) has been previously shown to be upregulated in breast cancer. Sulf-2 removes sulfate moieties on heparan sulfate proteoglycans which in turn modulate heparin binding growth factor signaling. Here we report that matrix detachment resulted in decreased Sulf-2 expression in breast cancer cells and increased cleavage of poly ADP-ribose polymerase. Silencing of Sulf-2 promotes matrix detachment induced cell death in MCF10DCIS cells. In an attempt to identify Sulf-2 specific inhibitor, we found that proteasomal inhibitors such as MG132, Lactacystin and Bortezomib treatment abolished Sulf-2 expression in multiple breast cancer cell lines. Additionally, we show that Bortezomib treatment of MCF10DCIS cell xenografts in mouse mammary fat pads significantly reduced tumor size, caused massive apoptosis and more importantly reduced Sulf-2 levels in vivo. Finally, our immunohistochemistry analysis of Sulf-2 expression in cohort of patient derived breast tumors indicates that Sulf-2 is significantly upregulated in autologous metastatic lesions compared to primary tumors (p < 0.037, Pearson correlation, Chi-Square analysis). In all, our data suggest that Sulf-2 might play an important role in breast cancer progression from ductal carcinoma in situ into an invasive ductal carcinoma potentially by resisting cell death. PMID:23412907

Synchronous induction of detachment and reattachment of symbiotic Chlorella spp. from the cell cortex of the host Paramecium bursaria.

PubMed

Kodama, Yuuki; Fujishima, Masahiro

2013-09-01

Paramecium bursaria harbor several hundred symbiotic Chlorella spp. Each alga is enclosed in a perialgal vacuole membrane, which can attach to the host cell cortex. How the perialgal vacuole attaches beneath the host cell cortex remains unknown. High-speed centrifugation (> 1000×g) for 1min induces rapid detachment of the algae from the host cell cortex and concentrates the algae to the posterior half of the host cell. Simultaneously, most of the host acidosomes and lysosomes accumulate in the anterior half of the host cell. Both the detached algae and the dislocated acidic vesicles recover their original positions by host cyclosis within 10min after centrifugation. These recoveries were inhibited if the host cytoplasmic streaming was arrested by nocodazole. Endosymbiotic algae during the early reinfection process also show the capability of desorption after centrifugation. These results demonstrate that adhesion of the perialgal vacuole beneath the host cell cortex is repeatedly inducible, and that host cytoplasmic streaming facilitates recovery of the algal attachment. This study is the first report to illuminate the mechanism of the induction to desorb for symbiotic algae and acidic vesicles, and will contribute to the understanding of the mechanism of algal and organelle arrangements in Paramecium. Copyright © 2013 Elsevier GmbH. All rights reserved.

Effect of Rho family GTP-binding proteins on Amoeba proteus.

PubMed

Kłopocka, W; Redowicz, M J

2003-03-01

While there is a number of studies on the effects of Rho GTPases on the actin-based cytoskeleton in higher eukaryotes, studies in protozoans are rather limited. The problem seems to be intriguing since the structure of protozoan cytoskeletons is distinct from most vertebrate cells. By blocking endogenous Rho family proteins of highly motile Amoeba proteus with C3 transferase and antibodies against human RhoA and Rac1, we tried to assess the in vivo role of these proteins in amoebae. In migrating amoebae, both proteins are concentrated in the cortical layer and seem to colocalize with filamentous actin. Endogenous Rac1, but not RhoA, is accumulated in the perinuclear cytoskeleton. Blocking Rac- or Rho-like proteins caused distinct and irreversible changes in the locomotive shape of the examined amoebae and significant inhibition of their migration. Amoebae microinjected with anti-Rac1 antibodies were contracted, shortened, and developed only few wide pseudopodia. More pronounced changes were observed in cells treated with anti-RhoA antibodies. They exhibited an atypical locomotion not leading to their effective displacement. After treatment with 50 microg of C3 transferase per ml, cells rapidly contracted and almost completely rounded up, became refractile with the granules beaten into a dense mass, detached from the surface and died. Ten times lower concentration of the enzyme caused similar changes as the inhibition of endogenous RhoA-like protein. These results indicate that Rho family-based regulation plays a key role in amoebic migration.

Mechanochemical switching between growth and differentiation during fibroblast growth factor-stimulated angiogenesis in vitro: role of extracellular matrix

PubMed Central

1989-01-01

The angiogenic factor, basic fibroblast growth factor (FGF), either stimulates endothelial cell growth or promotes capillary differentiation depending upon the microenvironment in which it acts. Analysis of various in vitro models of spontaneous angiogenesis, in combination with time-lapse cinematography, demonstrated that capillary tube formation was greatly facilitated by promoting multicellular retraction and cell elevation above the surface of the rigid culture dish or by culturing endothelial cells on malleable extracellular matrix (ECM) substrata. These observations suggested to us that mechanical (i.e., tension-dependent) interactions between endothelial cells and ECM may serve to regulate capillary development. To test this hypothesis, FGF-stimulated endothelial cells were grown in chemically defined medium on bacteriological (nonadhesive) dishes that were precoated with different densities of fibronectin. Extensive cell spreading and growth were promoted by fibronectin coating densities that were highly adhesive (greater than 500 ng/cm2), whereas cell rounding, detachment, and loss of viability were observed on dishes coated with low fibronectin concentrations (less than 100 ng/cm2). Intermediate fibronectin coating densities (100-500 ng/cm2) promoted cell extension, but they could not completely resist cell tractional forces. Partial retraction of multicellular aggregates resulted in cell shortening, cessation of growth, and formation of branching tubular networks within 24-48 h. Multicellular retraction and subsequent tube formation also could be elicited on highly adhesive dishes by overcoming the mechanical resistance of the substratum using higher cell plating numbers. Dishes coated with varying concentrations of type IV collagen or gelatin produced similar results. These results suggest that ECM components may act locally to regulate the growth and pattern- regulating actions of soluble FGF based upon their ability to resist cell-generated mechanical loads. Thus, we propose that FGF-stimulated endothelial cells may be "switched" between growth, differentiation, and involution modes during angiogenesis by altering the adhesivity or mechanical integrity of their ECM. PMID:2473081

Status of Photovoltaic Calibration and Measurement Standards

NASA Technical Reports Server (NTRS)

Baraona, Cosmo; Bailey, Sheila; Curtis, Henry; Brinker, David; Jenkins, Phillip; Scheiman, David

2001-01-01

The 7th International Workshop on Space Solar Cell Calibration and Measurement was held on September 25-27, 2000 in Girdwood, Alaska. Representatives from eight countries discussed international standards for single and multijunction solar cell measurement and calibration methods, round robin intercomparisons, and irradiation test methods for space solar cells. Progress toward adoption of an ISO standard on single junction cells was made. Agreement was reached to begin work on new standards for multijunction cells and irradiation testing. Progress on present single junction round robin measurements was discussed and future multijunction round robins were planned. The next workshop will be held in Germany in October 2001.

Aggregation of Culture Expanded Human Mesenchymal Stem Cells in Microcarrier-based Bioreactor.

PubMed

Yuan, Xuegang; Tsai, Ang-Chen; Farrance, Iain; Rowley, Jon; Ma, Teng

2018-03-15

Three-dimensional aggregation of human mesenchymal stem cells (hMSCs) has been used to enhance their therapeutic properties but current fabrication protocols depend on laboratory methods and are not scalable. In this study, we developed thermal responsive poly(N-isopropylacrylamide) grafted microcarriers (PNIPAM-MCs), which supported expansion and thermal detachment of hMSCs at reduced temperature (23.0 °C). hMSCs were cultured on the PNIPAM-MCs in both spinner flask (SF) and PBS Vertical-Wheel (PBS-VW) bioreactors for expansion. At room temperature, hMSCs were detached as small cell sheets, which subsequently self-assembled into 3D hMSC aggregates in PBS-VW bioreactor and remain as single cells in SF bioreactor owing to different hydrodynamic conditions. hMSC aggregates generated from the bioreactor maintained comparable immunomodulation and cytokine secretion properties compared to the ones made from the AggreWell ® . The results of the current study demonstrate the feasibility of scale-up production of hMSC aggregates in the suspension bioreactor using thermal responsive microcarriers for integrated cell expansion and 3D aggregation in a close bioreactor system and highlight the critical role of hydrodynamics in self-assembly of detached hMSC in suspension.

Actomyosin Pulls to Advance the Nucleus in a Migrating Tissue Cell

PubMed Central

Wu, Jun; Kent, Ian A.; Shekhar, Nandini; Chancellor, T.J.; Mendonca, Agnes; Dickinson, Richard B.; Lele, Tanmay P.

2014-01-01

The cytoskeletal forces involved in translocating the nucleus in a migrating tissue cell remain unresolved. Previous studies have variously implicated actomyosin-generated pushing or pulling forces on the nucleus, as well as pulling by nucleus-bound microtubule motors. We found that the nucleus in an isolated migrating cell can move forward without any trailing-edge detachment. When a new lamellipodium was triggered with photoactivation of Rac1, the nucleus moved toward the new lamellipodium. This forward motion required both nuclear-cytoskeletal linkages and myosin activity. Apical or basal actomyosin bundles were found not to translate with the nucleus. Although microtubules dampen fluctuations in nuclear position, they are not required for forward translocation of the nucleus during cell migration. Trailing-edge detachment and pulling with a microneedle produced motion and deformation of the nucleus suggestive of a mechanical coupling between the nucleus and the trailing edge. Significantly, decoupling the nucleus from the cytoskeleton with KASH overexpression greatly decreased the frequency of trailing-edge detachment. Collectively, these results explain how the nucleus is moved in a crawling fibroblast and raise the possibility that forces could be transmitted from the front to the back of the cell through the nucleus. PMID:24411232

FACS selection of valuable mutant mouse round spermatids and strain rescue via round spermatid injection.

PubMed

Zhu, Lian; Zhou, Wei; Kong, Peng-Cheng; Wang, Mei-Shan; Zhu, Yan; Feng, Li-Xin; Chen, Xue-Jin; Jiang, Man-Xi

2015-06-01

Round spermatid injection (ROSI) into mammalian oocytes can result in the development of viable embryos and offspring. One current limitation to this technique is the identification of suitable round spermatids. In the current paper, round spermatids were selected from testicular cells with phase contrast microscopy (PCM) and fluorescence-activated cell sorting (FACS), and ROSI was performed in two strains of mice. The rates of fertilization, embryonic development and offspring achieved were the same in all strains. Significantly, round spermatids selected by PCM and FACS were effectively used to rescue the infertile Pten-null mouse. The current results indicate that FACS selection of round spermatids can not only provide high-purity and viable round spermatids for use in ROSI, but also has no harmful effects on the developmental capacity of subsequently fertilized embryos. It was concluded that round spermatids selected by FACS are useful for mouse strain rederivation and rescue of infertile males; ROSI should be considered as a powerful addition to the armamentarium of assisted reproduction techniques applicable in the mouse.

Detachment strength of human osteoblasts cultured on hydroxyapatite with various surface roughness. Contribution of integrin subunits.

PubMed

Kokkinos, Petros A; Koutsoukos, Petros G; Deligianni, Despina D

2012-06-01

Hydroxyapatite (HA) has been widely used as a bone substitute in dental, maxillofacial and orthopaedic surgery and as osteoconductive bone substitute or precoating of pedicle screws and cages in spine surgery. The aim of the present study was to investigate the osteoblastic adhesion strength on HA substrata with different surface topography and biochemistry (pre-adsorption of fibronectin) after blocking of specific integrin subunits with monoclonal antibodies. Stoichiometric HA was prepared by precipitation followed by ageing and characterized by SEM, EDX, powder XRD, Raman spectroscopy, TGA, and specific surface area analysis. Human bone marrow derived osteoblasts were cultured on HA disc-shaped substrata which were sintered and polished resulting in two surface roughness grades. For attachment evaluation, cells were incubated with monoclonal antibodies and seeded for 2 h on the substrata. Cell detachment strength was determined using a rotating disc device. Cell detachment strength was surface roughness, fibronectin preadsorption and intergin subunit sensitive.

Modification of HTPB-based polyurethane with temperature-sensitive poly(N-isopropyl acrylamide) for biomaterial usage.

PubMed

Yang, Jen Ming; Yang, Shu Jyuan; Lin, Hao Tzu; Chen, Jan Kan

2007-01-01

Hydroxyl-terminated polybutadiene (HTPB)-based polyurethane with dimethyol propionic acid (DPA) as chain extender was synthesized by solution polymerization. The HTPB-based polyurethane was modified by UV radiation with N-isopropyl acrylamide monomer to get poly(N-isopropyl acrylamide)-modified polyurethane (PUDPANIPAAm). The cohesive energy (E(coh)), molar volume (V), solubility parameter (delta), molecular weight (W(M)), volume per gram (V(g)), and the density (1/V(g)) of PUDPANIPAAm were calculated by group contribution methods. To evaluate the application of PUDPANIPAAm for wound dressing and transplantation of cell sheet, the measurement of water content, water vapor transmission rate, and gas permeation on the PUDPANIPAAm membrane was evaluated. The biocompatibility of these membranes, cell adhesion, and proliferation assay were conducted in the cell culture. The effect of thermosensitivity of poly(N-isopropyl acrylamide) on cell detachment was also evaluated in the primary study. The results showed that these PUDPANIPAAm membranes are thermosensitive. The modification of PU with poly(N-isopropyl acrylamide) reduced the water vapor transmission rate and permeability of gas through PUDPANIPAAm membrane. PUDPANIPAAm membranes could support cell adhesion and growth. Owing to the thermosensitive nature of poly(N-isopropyl acrylamide), the relative cell numbers detached from PUDPANIPAAm membranes were larger than those detached from the polystyrene dish. 2006 Wiley Periodicals, Inc.

Differential effects of temperature on reactive oxygen/nitrogen species production in rat pachytene spermatocytes and round spermatids.

PubMed

Pino, José A; Osses, Nelson; Oyarzún, Daniela; Farías, Jorge G; Moreno, Ricardo D; Reyes, Juan G

2013-02-01

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) like superoxide and nitric oxide are produced by testis and spermatogenic cells in response to heat stress. However, the magnitude and mechanisms of this production in spermatogenic cells have not been described. In this work, we evaluated ROS/RNS production, its pharmacology, mitochondrial oxidative metabolism, membrane potential and antioxidant capacity at different temperatures in isolated rat pachytene spermatocytes and round spermatids. Our results showed an increment in ROS/RNS production by pachytene spermatocytes when increasing the temperature to 40 °C. Instead, ROS/RNS production by round spermatids did not change at temperatures higher than 33 °C. ROS/RNS production was sensitive to NADPH oxidase inhibitor diphenylene iodonium or the mitochondrial complex I inhibitor rotenone. No additive effects were observed for these two compounds. Our results suggest an important mitochondrial ROS/RNS production in spermatogenic cells. Oligomycin-insensitive oxygen consumption (uncoupled oxygen consumption) increased with temperature and was significantly larger in round spermatids than pachytene spermatocytes, indicating a likely round spermatid mitochondrial uncoupling at high temperatures. A similar conclusion can be reached by measuring the mitochondrial membrane potential using rhodamine 123 fluorescence in permeabilized cells or JC-1 fluorescence in intact cells. The antioxidant capacity was higher in round spermatids than pachytene spermatocytes at 40 °C. Our results strongly suggest that at high temperatures (40 °C) pachytene spermatocytes are more susceptible to oxidative stress, but round spermatids are more protected because of a temperature-induced mitochondrial uncoupling together with a larger antioxidant capacity.

A study on sonoporation of cells cultured on a soft collagen gel scaffold

NASA Astrophysics Data System (ADS)

Kudo, Nobuki; Kinoshita, Yuto

2012-11-01

Efficiencies of sonoporation were investigated using four types of monolayer-cell samples: cells cultured directly on a cover slip, cells cultured on a cover slip coated with collagen gel of several μm in thickness, and cells cultured on collagen gel scaffolds of 0.4 and 1.0 mm in thicknesses. Cell samples attached with Levovist microbubbles were irradiated by one shot of a three- or 10,000-cycle ultrasound pulse, and cell detachment and membrane perforation were investigated. Experimental results showed that rates of cell detachment and membrane damage were markedly decreased in the presence of soft gel layer of 0.4 and 1.0 mm in thicknesses under the cells and that these rates were inversely proportional to the thickness of the gel layer. These results indicate that optimum conditions of sonoporation in vitro should be carefully translated into those in vivo.

Histological and immunohistochemical characteristics of undifferentiated small round cell sarcomas associated with CIC-DUX4 and BCOR-CCNB3 fusion genes.

PubMed

Yamada, Yuichi; Kuda, Masaaki; Kohashi, Kenichi; Yamamoto, Hidetaka; Takemoto, Junkichi; Ishii, Takeaki; Iura, Kunio; Maekawa, Akira; Bekki, Hirofumi; Ito, Takamichi; Otsuka, Hiroshi; Kuroda, Makoto; Honda, Yumi; Sumiyoshi, Shinji; Inoue, Takeshi; Kinoshita, Naoe; Nishida, Atsushi; Yamashita, Kyoko; Ito, Ichiro; Komune, Shizuo; Taguchi, Tomoaki; Iwamoto, Yukihide; Oda, Yoshinao

2017-04-01

CIC-DUX4 and BCOR-CCNB3 fusion-gene-associated small round cell sarcomas account for a proportion of pediatric small round cell sarcomas, but their pathological features have not been sufficiently clarified. We reviewed a large number of soft tissue tumors registered at our institution, retrieved the cases of unclassified tumors with a small round cell component, and subjected them to histopathological, immunohistochemical, and gene profile analysis. We reviewed 164 cases of unclassified tumors with a small round cell component and analyzed them by RT-PCR and FISH. Tumors positive for a specific fusion-gene were also subjected to histopathological and immunohistochemical examinations. We identified 16 cases of BCOR-CCNB3/CIC-associated (CIC-DUX4 or CIC gene rearrangement-positive) sarcomas. These included seven BCOR-CCNB3 sarcomas and nine CIC-associated sarcomas. Heterogeneous elements included a myxoid spindle cell component in three BCOR-CCNB3 sarcomas and an epithelioid cell component in two CIC-associated sarcomas (one CIC-DUX4-positive and one CIC-DUX4-negative sarcomas). Mitotic activity was low in both heterogeneous components. By immunohistochemistry, in seven BCOR-CCNB3 sarcomas expression of EMA was positive in two cases, of p63 in three, of CD56 in six, of TLE1 in seven, of NKX2.2 in two, of CCNB3 in seven, and of BCOR in six cases (one case could not be tested for BCOR). In nine cases of CIC-associated sarcoma, CD56 was expressed in five, alpha-smooth muscle actin in one, ERG in three, and CD99, WT1 and TLE1 each in eight cases. Both sarcoma types showed not only a small round cell component, but also a myxoid/epithelioid component with low mitotic activity.

Baseline and annual repeat rounds of screening: implications for optimal regimens of screening.

PubMed

Henschke, Claudia I; Salvatore, Mary; Cham, Matthew; Powell, Charles A; DiFabrizio, Larry; Flores, Raja; Kaufman, Andrew; Eber, Corey; Yip, Rowena; Yankelevitz, David F

2018-03-01

Differences in results of baseline and subsequent annual repeat rounds provide important information for optimising the regimen of screening. A prospective cohort study of 65,374 was reviewed to examine the frequency/percentages of the largest noncalcified nodule (NCN), lung cancer cell types and Kaplan-Meier (K-M) survival rates, separately for baseline and annual rounds. Of 65,374 baseline screenings, NCNs were identified in 28,279 (43.3%); lung cancer in 737 (1.1%). Of 74,482 annual repeat screenings, new NCNs were identified in 4959 (7%); lung cancer in 179 (0.24%). Only adenocarcinoma was diagnosed in subsolid NCNs. Percentages of lung cancers by cell type were significantly different (p < 0.0001) in the baseline round compared with annual rounds, reflecting length bias, as were the ratios, reflecting lead times. Long-term K-M survival rate was 100% for typical carcinoids and for adenocarcinomas manifesting as subsolid NCNs; 85% (95% CI 81-89%) for adenocarcinoma, 74% (95% CI 63-85%) for squamous cell, 48% (95% CI 34-62%) for small cell. The rank ordering by lead time was the same as the rank ordering by survival rates. The significant differences in the frequency of NCNs and frequency and aggressiveness of diagnosed cancers in baseline and annual repeat need to be recognised for an optimal regimen of screening. • Lung cancer aggressiveness varies considerably by cell type and nodule consistency. • Kaplan-Meier survival rates varied by cell type between 100% and 48%. • The percentages of lung cancers by cell type in screening rounds reflect screening biases. • Rank ordering by cell type survival is consistent with that by lead times. • Empirical evidence provides critical information for the regimen of screening.

Therapeutic Trial for Patients With Ewing Sarcoma Family of Tumor and Desmoplastic Small Round Cell Tumors

ClinicalTrials.gov

2017-09-18

Desmoplastic Small Round Cell Tumor; Ewing Sarcoma of Bone or Soft Tissue; Localized Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; Metastatic Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor

Fibronectin matrix-mediated cohesion suppresses invasion of prostate cancer cells.

PubMed

Jia, Dongxuan; Entersz, Ildiko; Butler, Christine; Foty, Ramsey A

2012-03-20

Invasion is an important early step in the metastatic cascade and is the primary cause of death of prostate cancer patients. In order to invade, cells must detach from the primary tumor. Cell-cell and cell-ECM interactions are important regulators of cohesion--a property previously demonstrated to mediate cell detachment and invasion. The studies reported here propose a novel role for α5β1 integrin--the principle mediator of fibronectin matrix assembly (FNMA)--as an invasion suppressor of prostate cancer cells. Using a combination of biophysical and cell biological methods, and well-characterized prostate cancer cell lines of varying invasiveness, we explore the relationship between cohesion, invasiveness, and FNMA. We show that cohesion is inversely proportional to invasive capacity. We also show that more invasive cells express lower levels of α5β1 integrin and lack the capacity for FNMA. Cells were generated to over-express either wild-type α5 integrin or an integrin in which the cytoplasmic domain of α5 was replaced with that of α2. The α2 construct does not promote FNMA. We show that only wild-type α5 integrin promotes aggregate compaction, increases cohesion, and reduces invasion of the more aggressive cells, and that these effects can be blocked by the 70-kDa fibronectin fragment. We propose that restoring capacity for FNMA in deficient cells can increase tumor intercellular cohesion to a point that significantly reduces cell detachment and subsequent invasion. In prostate cancer, this could be of therapeutic benefit by blocking an early key step in the metastatic cascade.

Separation of abscission zone cells in detached Azolla roots depends on apoplastic pH.

PubMed

Fukuda, Kazuma; Yamada, Yoshiya; Miyamoto, Kensuke; Ueda, Junichi; Uheda, Eiji

2013-01-01

In studies on the mechanism of cell separation during abscission, little attention has been paid to the apoplastic environment. We found that the apoplastic pH surrounding abscission zone cells in detached roots of the water fern Azolla plays a major role in cell separation. Abscission zone cells of detached Azolla roots were separated rapidly in a buffer at neutral pH and slowly in a buffer at pH below 4.0. However, cell separation rarely occurred at pH 5.0-5.5. Light and electron microscopy revealed that cell separation was caused by a degradation of the middle lamella between abscission zone cells at both pH values, neutral and below 4.0. Low temperature and papain treatment inhibited cell separation. Enzyme(s) in the cell wall of the abscission zone cells might be involved in the degradation of the pectin of the middle lamella and the resultant, pH-dependent cell separation. By contrast, in Phaseolus leaf petioles, unlike Azolla roots, cell separation was slow and increased only at acidic pH. The rapid cell separation, as observed in Azolla roots at neutral pH, did not occur. Indirect immunofluorescence microscopy, using anti-pectin monoclonal antibodies, revealed that the cell wall pectins of the abscission zone cells of Azolla roots and Phaseolus leaf petioles looked similar and changed similarly during cell separation. Thus, the pH-related differences in cell separation mechanisms of Azolla and Phaseolus might not be due to differences in cell wall pectin, but to differences in cell wall-located enzymatic activities responsible for the degradation of pectic substances. A possible enzyme system is discussed. Copyright © 2012 Elsevier GmbH. All rights reserved.

Antimitochondrial Autoantibodies in Pemphigus Vulgaris

PubMed Central

Marchenko, Steve; Chernyavsky, Alexander I.; Arredondo, Juan; Gindi, Vivian; Grando, Sergei A.

2010-01-01

A loss of epidermal cohesion in pemphigus vulgaris (PV) results from autoantibody action on keratinocytes (KCs) activating the signaling kinases and executioner caspases that damage KCs, causing their shrinkage, detachment from neighboring cells, and rounding up (apoptolysis). In this study, we found that PV antibody binding leads to activation of epidermal growth factor receptor kinase, Src, p38 MAPK, and JNK in KCs with time pattern variations from patient to patient. Both extrinsic and intrinsic apoptotic pathways were also activated. Although Fas ligand neutralizing antibody could inhibit the former pathway, the mechanism of activation of the latter remained unknown. PV antibodies increased cytochrome c release, suggesting damage to mitochondria. The immunoblotting experiments revealed penetration of PVIgG into the subcellular mitochondrial fraction. The antimitochondrial antibodies from different PV patients recognized distinct combinations of antigens with apparent molecular sizes of 25, 30, 35, 57, 60, and 100 kDa. Antimitochondrial antibodies were pathogenic because their absorption abolished the ability of PVIgG to cause keratinocyte detachment both in vitro and in vivo. The downstream signaling of antimitochondrial antibodies involved JNK and late p38 MAPK activation, whereas the signaling of anti-desmoglein 3 (Dsg3) antibody involved JNK and biphasic p38 MAPK activation. Using KCs grown from Dsg3−/− mice, we determined that Dsg3 did not serve as a surrogate antigen allowing antimitochondrial antibodies to enter KCs. The PVIgG-induced activation of epidermal growth factor receptor and Src was affected neither in Dsg3−/− KCs nor due to absorption of antimitochondrial antibodies. These results demonstrated that apoptolysis in PV is a complex process initiated by at least three classes of autoantibodies directed against desmosomal, mitochondrial, and other keratinocyte self-antigens. These autoantibodies synergize with the proapoptotic serum and tissue factors to trigger both extrinsic and intrinsic pathways of cell death and break the epidermal cohesion, leading to blisters. Further elucidation of the primary signaling events downstream of PV autoantigens will be crucial for the development of a more successful therapy for PV patients. PMID:20007702

ICAM-1 and AMPK regulate cell detachment and apoptosis by N-methyl-N Prime -nitro-N-nitrosoguanidine, a widely spread environmental chemical, in human hormone-refractory prostate cancers

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

Chen, Yi-Cheng; Lu, Pin-Hsuan; Hsu, Jui-Ling

2011-12-15

Poly(ADP-ribose) polymerase-1 (PARP-1), a sensor of DNA damage, plays a crucial role in the regulation of DNA repair. PARP-1 hyperactivation causes DNA damage and cell death. The underlying mechanism is complicated and is through diverse pathways. The understanding of responsible signaling pathways may offer implications for effective therapies. After concentration-response determination of N-Methyl-N Prime -Nitro-N-Nitrosoguanidine (MNNG, a PARP-1 activating agent and an environmental mutagen) in human hormone-refractory prostate cancers, the data showed that concentrations below 5 {mu}M did not change cell survival but cause a time-dependent up-regulation of intracellular adhesion molecule-1 (ICAM-1) in mRNA, total protein and cell surface levels.more » Detection of phosphorylation and degradation of I{kappa}B-{alpha} and nuclear translocation of NF-{kappa}B showed that MNNG induced the activation of NF-{kappa}B that was responsible for the ICAM-1 up-regulation since PDTC (a NF-{kappa}B inhibitor) significantly abolished this effect. However, higher concentrations (e.g., 10 {mu}M) of MNNG induced a 61% detachment of the cells which were apoptosis associated with the activation of AMP-activated protein kinase (AMPK), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Further identification showed that both AMPK and JNK other than p38 MAPK functionally contributed to cell death. The remaining 39% attached cells were survival associated with high ICAM-1 expression. In conclusion, the data suggest that NF-{kappa}B-dependent up-regulation of ICAM-1 plays a key role on cell attachment and survival; whereas, activation of AMPK and JNK participates in cytotoxic signaling pathways in detached cells caused by PARP-1 activation. Highlights: Black-Right-Pointing-Pointer Low level of DNA damage helps cell attachment and survival via ICAM-1 upregulation. Black-Right-Pointing-Pointer High level of DNA damage causes AMPK- and JNK-involved cell detachment and death. Black-Right-Pointing-Pointer The study provides an anticancer approach targeting PARP-1 and DNA damage response.« less

Citrate, not phosphate, can dissolve calcium oxalate monohydrate crystals and detach these crystals from renal tubular cells.

PubMed

Chutipongtanate, Somchai; Chaiyarit, Sakdithep; Thongboonkerd, Visith

2012-08-15

Dissolution therapy of calcium oxalate monohydrate (COM) kidney stone disease has not yet been implemented due to a lack of well characterized COM dissolution agents. The present study therefore aimed to identify potential COM crystal dissolution compounds. COM crystals were treated with deionized water (negative control), 5 mM EDTA (positive control), 5 mM sodium citrate, or 5mM sodium phosphate. COM crystal dissolution activities of these compounds were evaluated by phase-contrast and video-assisted microscopic examinations, semi-quantitative analysis of crystal size, number and total mass, and spectrophotometric oxalate-dissolution assay. In addition, effects of these compounds on detachment of COM crystals, which adhered tightly onto renal tubular cell surface, were also investigated. The results showed that citrate, not phosphate, had a significant dissolution effect on COM crystals as demonstrated by significant reduction of crystal size (approximately 37% decrease), crystal number (approximately 53% decrease) and total crystal mass (approximately 72% decrease) compared to blank and negative controls. Spectrophotometric oxalate-dissolution assay successfully confirmed the COM crystal dissolution property of citrate. Moreover, citrate could detach up to 85% of the adherent COM crystals from renal tubular cell surface. These data indicate that citrate is better than phosphate for dissolution and detachment of COM crystals. Copyright © 2012 Elsevier B.V. All rights reserved.

Detachment of affinity-captured bioparticles by elastic deformation of a macroporous hydrogel

PubMed Central

Dainiak, Maria B.; Kumar, Ashok; Galaev, Igor Yu.; Mattiasson, Bo

2006-01-01

Adsorption of bioparticles to affinity surfaces involves polyvalent interactions, complicating greatly the recovery of the adsorbed material. A unique system for the efficient binding and release of different cells and particles is described. Affinity-bound bioparticles and synthetic particles are detached from the macroporous hydrogel matrix, a so-called cryogel, when the cryogel undergoes elastic deformation. The particle detachment upon elastic deformation is believed to be due to breaking of many of the multipoint attachments between the particles and the affinity matrix and the change in the distance between affinity ligands when the matrix is deformed. However, no release of affinity-bound protein occurred upon elastic deformation. The phenomenon of particle detachment upon elastic deformation is believed to be of a generic nature, because it was demonstrated for a variety of bioparticles of different sizes and for synthetic particles, for different ligand–receptor pairs (IgG–protein A, sugar–ConA, metal ion–chelating ligand), and when the deformation was caused by either external forces (mechanical deformation) or internal forces (the shrinkage of thermosensitive, macroporous hydrogel upon an increase in temperature). The elasticity of cryogel monoliths ensures high recovery of captured cells under mild conditions, with highly retained viability. This property, along with their continuous porous structure makes cryogel monoliths very attractive for applications in affinity cell separation. PMID:16418282

Effects of Different Cell-Detaching Methods on the Viability and Cell Surface Antigen Expression of Synovial Mesenchymal Stem Cells.

PubMed

Tsuji, Kunikazu; Ojima, Miyoko; Otabe, Koji; Horie, Masafumi; Koga, Hideyuki; Sekiya, Ichiro; Muneta, Takeshi

2017-06-09

Flow cytometric analysis of cell surface antigens is a powerful tool for the isolation and characterization of stem cells residing in adult tissues. In contrast to the collection of hematopoietic stem cells, the process of enzymatic digestion is usually necessary to prepare mesenchymal stem cells (MSCs) suspensions, which can influence the expression of cell surface markers. In this study, we examined the effects of various cell-detaching reagents and digestion times on the expression of stem cell-related surface antigens and MSC functions. Human MSCs were detached from dishes using four different reagents: trypsin, TrypLE, collagenase, and a nonenzymatic cell dissociation reagent (C5789; Sigma-Aldrich). Following dissociation reagent incubations ranging from 5 to 120 min, cell surface markers were analyzed by flow cytometry. Trypsin and TrypLE quickly dissociated the cells within 5 min, while collagenase and C5789 required 60 min to obtain maximum cell yields. C5789 significantly decreased cell viability at 120 min. Trypsin treatment significantly reduced CD44+, CD55+, CD73+, CD105+, CD140a+, CD140b+, and CD201+ cell numbers within 30 min. Collagenase treatment reduced CD140a expression by 30 min. In contrast, TrypLE treatment did not affect the expression of any cell surface antigens tested by 30 min. Despite the significant loss of surface antigen expression after 60 min of treatment with trypsin, adverse effects of enzymatic digestion on multipotency of MSCs were limited. Overall, our data indicated that TrypLE is advantageous over other cell dissociation reagents tested for the rapid preparation of viable MSC suspensions.

Visible light controls cell adhesion on a photoswitchable biointerface.

PubMed

Ming, Zunzhen; Hua, Xin; Xue, Yuan; Lin, Qiuning; Bao, Chunyan; Zhu, Linyong

2018-05-04

Bioactive surfaces with specific interactions with cells have been greatly interested due to their potential applications in biosensors and tissue engineering. Herein, we fabricated a dopamine contained photoswitch molecule (compound 1) which could form self-assembled monolayer (SAM) on substrates. The SAM showed a good photoswitch ability and manifested excellent fatigue resistance, which displayed its potential application as a biologically friendly surface coating. Contact angle analysis and cell experiments exhibited that the SAM surface was hydrophobic before irradiation which favored cell adhesion, while, it turned hydrophilic and induced cell unfouling or detachment after light irradiation. The uses of visible light stimulation (λ ex  = 530 nm) and the reversible regulation on cell adhesion and detachment should open up new avenues for bioacitve surfaces in biomedical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Fourteen babies born after round spermatid injection into human oocytes

PubMed Central

Tanaka, Atsushi; Nagayoshi, Motoi; Takemoto, Youichi; Tanaka, Izumi; Kusunoki, Hiroshi; Watanabe, Seiji; Kuroda, Keiji; Takeda, Satoru; Ito, Masahiko; Yanagimachi, Ryuzo

2015-01-01

During the human in vitro fertilization procedure in the assisted reproductive technology, intracytoplasmic sperm injection is routinely used to inject a spermatozoon or a less mature elongating spermatid into the oocyte. In some infertile men, round spermatids (haploid male germ cells that have completed meiosis) are the most mature cells visible during testicular biopsy. The microsurgical injection of a round spermatid into an oocyte as a substitute is commonly referred to as round spermatid injection (ROSI). Currently, human ROSI is considered a very inefficient procedure and of no clinical value. Herein, we report the birth and development of 14 children born to 12 women following ROSI of 734 oocytes previously activated by an electric current. The round spermatids came from men who had been diagnosed as not having spermatozoa or elongated spermatids by andrologists at other hospitals after a first Micro-TESE. A key to our success was our ability to identify round spermatids accurately before oocyte injection. As of today, all children born after ROSI in our clinic are without any unusual physical, mental, or epigenetic problems. Thus, for men whose germ cells are unable to develop beyond the round spermatid stage, ROSI can, as a last resort, enable them to have their own genetic offspring. PMID:26575628

Fourteen babies born after round spermatid injection into human oocytes.

PubMed

Tanaka, Atsushi; Nagayoshi, Motoi; Takemoto, Youichi; Tanaka, Izumi; Kusunoki, Hiroshi; Watanabe, Seiji; Kuroda, Keiji; Takeda, Satoru; Ito, Masahiko; Yanagimachi, Ryuzo

2015-11-24

During the human in vitro fertilization procedure in the assisted reproductive technology, intracytoplasmic sperm injection is routinely used to inject a spermatozoon or a less mature elongating spermatid into the oocyte. In some infertile men, round spermatids (haploid male germ cells that have completed meiosis) are the most mature cells visible during testicular biopsy. The microsurgical injection of a round spermatid into an oocyte as a substitute is commonly referred to as round spermatid injection (ROSI). Currently, human ROSI is considered a very inefficient procedure and of no clinical value. Herein, we report the birth and development of 14 children born to 12 women following ROSI of 734 oocytes previously activated by an electric current. The round spermatids came from men who had been diagnosed as not having spermatozoa or elongated spermatids by andrologists at other hospitals after a first Micro-TESE. A key to our success was our ability to identify round spermatids accurately before oocyte injection. As of today, all children born after ROSI in our clinic are without any unusual physical, mental, or epigenetic problems. Thus, for men whose germ cells are unable to develop beyond the round spermatid stage, ROSI can, as a last resort, enable them to have their own genetic offspring.

Influence of airway wall compliance on epithelial cell injury and adhesion during interfacial flows

PubMed Central

Higuita-Castro, Natalia; Mihai, Cosmin; Hansford, Derek J.

2014-01-01

Interfacial flows during cyclic airway reopening are an important source of ventilator-induced lung injury. However, it is not known how changes in airway wall compliance influence cell injury during airway reopening. We used an in vitro model of airway reopening in a compliant microchannel to investigate how airway wall stiffness influences epithelial cell injury. Epithelial cells were grown on gel substrates with different rigidities, and cellular responses to substrate stiffness were evaluated in terms of metabolic activity, mechanics, morphology, and adhesion. Repeated microbubble propagations were used to simulate cyclic airway reopening, and cell injury and detachment were quantified via live/dead staining. Although cells cultured on softer gels exhibited a reduced elastic modulus, these cells experienced less plasma membrane rupture/necrosis. Cells on rigid gels exhibited a minor, but statistically significant, increase in the power law exponent and also exhibited a significantly larger height-to-length aspect ratio. Previous studies indicate that this change in morphology amplifies interfacial stresses and, therefore, correlates with the increased necrosis observed during airway reopening. Although cells cultured on stiff substrates exhibited more plasma membrane rupture, these cells experienced significantly less detachment and monolayer disruption during airway reopening. Western blotting and immunofluorescence indicate that this protection from detachment and monolayer disruption correlates with increased focal adhesion kinase and phosphorylated paxillin expression. Therefore, changes in cell morphology and focal adhesion structure may govern injury responses during compliant airway reopening. In addition, these results indicate that changes in airway compliance, as occurs during fibrosis or emphysema, may significantly influence cell injury during mechanical ventilation. PMID:25213636

Species-dependent hydrodynamics of flagellum-tethered bacteria in early biofilm development.

PubMed

Bennett, Rachel R; Lee, Calvin K; De Anda, Jaime; Nealson, Kenneth H; Yildiz, Fitnat H; O'Toole, George A; Wong, Gerard C L; Golestanian, Ramin

2016-02-01

Monotrichous bacteria on surfaces exhibit complex spinning movements. Such spinning motility is often a part of the surface detachment launch sequence of these cells. To understand the impact of spinning motility on bacterial surface interactions, we develop a hydrodynamic model of a surface-bound bacterium, which reproduces behaviours that we observe in Pseudomonas aeruginosa, Shewanella oneidensis and Vibrio cholerae, and provides a detailed dictionary for connecting observed spinning behaviour to bacteria-surface interactions. Our findings indicate that the fraction of the flagellar filament adhered to the surface, the rotation torque of this appendage, the flexibility of the flagellar hook and the shape of the bacterial cell dictate the likelihood that a microbe will detach and the optimum orientation that it should have during detachment. These findings are important for understanding species-specific reversible attachment, the key transition event between the planktonic and biofilm lifestyle for motile, rod-shaped organisms. © 2016 The Author(s).

Models of dynamic extraction of lipid tethers from cell membranes.

PubMed

Nowak, Sarah A; Chou, Tom

2010-05-07

When a ligand that is bound to an integral membrane receptor is pulled, the membrane and the underlying cytoskeleton can deform before either the membrane delaminates from the cytoskeleton or the ligand detaches from the receptor. If the membrane delaminates from the cytoskeleton, it may be further extruded and form a membrane tether. We develop a phenomenological model for this process by assuming that deformations obey Hooke's law up to a critical force at which the cell membrane locally detaches from the cytoskeleton and a membrane tether forms. We compute the probability of tether formation and show that tethers can be extruded only within an intermediate range of force loading rates and pulling velocities. The mean tether length that arises at the moment of ligand detachment is computed as are the force loading rates and pulling velocities that yield the longest tethers.

The Globoside Receptor Triggers Structural Changes in the B19 Virus Capsid That Facilitate Virus Internalization▿

PubMed Central

Bönsch, Claudia; Zuercher, Christoph; Lieby, Patricia; Kempf, Christoph; Ros, Carlos

2010-01-01

Globoside (Gb4Cer), Ku80 autoantigen, and α5β1 integrin have been identified as cell receptors/coreceptors for human parvovirus B19 (B19V), but their role and mechanism of interaction with the virus are largely unknown. In UT7/Epo cells, expression of Gb4Cer and CD49e (integrin alpha-5) was high, but expression of Ku80 was insignificant. B19V colocalized with Gb4Cer and, to a lesser extent, with CD49e. However, only anti-Gb4Cer antibodies could disturb virus attachment. Only a small proportion of cell-bound viruses were internalized, while the majority became detached from the receptor. When added to uninfected cells, the receptor-detached virus showed superior cell binding capacity and infectivity. Attachment of B19V to cells triggered conformational changes in the capsid leading to the accessibility of the N terminus of VP1 (VP1u) to antibodies, which was maintained in the receptor-detached virus. VP1u became similarly accessible to antibodies following incubation of B19V particles with increasing concentrations of purified Gb4Cer. The receptor-mediated exposure of VP1u is critical for virus internalization, since capsids lacking VP1 could bind to cells but were not internalized. Moreover, an antibody against the N terminus of VP1u disturbed virus internalization, but only when present during and not after virus attachment, indicating the involvement of this region in binding events required for internalization. These results suggest that Gb4Cer is not only the primary receptor for B19V attachment but also the mediator of capsid rearrangements required for subsequent interactions leading to virus internalization. The capacity of the virus to detach and reattach again would enhance the probability of productive infections. PMID:20826697

CD44S-hyaluronan interactions protect cells resulting from EMT against anoikis

PubMed Central

Cieply, Benjamin; Koontz, Colton; Frisch, Steven M.

2016-01-01

The detachment of normal epithelial cells from matrix triggers an apoptotic response known as anoikis, during homeostatic turnover. Metastatic tumor cells evade anoikis, by mechanisms that are only partly characterized. In particular, the epithelial–mesenchymal transition (EMT) in a subset of invasive tumor cells confers anoikis-resistance. In some cases, EMT up-regulates the cancer stem cell marker CD44S and the enzyme hyaluronic acid synthase-2 (HAS2). CD44S is the major receptor for hyaluronan in the extracellular matrix. Herein, we demonstrate that CD44S, unlike the CD44E isoform expressed in normal epithelial cells, contributes to the protection against anoikis. This protection requires the interaction of CD44S with hyaluronan (HA). CD44S–HA interaction is proposed to play an important role in tumor metastasis through enhanced cell survival under detached conditions. PMID:25937513

Fine-needle aspiration in desmoplastic small round cell tumor: a report of 10 new tumors in 8 patients with clinicopathological and molecular correlations with review of the literature.

PubMed

Klijanienko, Jerzy; Colin, Pierre; Couturier, Jérôme; Lagacé, Réal; Fréneaux, Paul; Pierron, Gaëlle; Laé, Marick; Klijanienko, Alice; Brisse, Hervé; Orbach, Daniel; Theocharis, Stamatios

2014-05-01

Desmoplastic small round cell tumor (DSRCT) is a rare round cell sarcoma entity characterized by a specific t(11;22)(p13;q12) translocation, usually intra-abdominal localization and an aggressive clinical outcome. To date, only 35 DSRCT cases diagnosed by fine-needle aspiration have been described. This study reports the cytological diagnosis of DSRCT. Ten tumors from 8 patients were sampled for diagnosis and analyzed to search the characteristic translocation using fluorescence in situ hybridization or reverse transcription polymerase chain reaction methods. Smears were always hypercellular and consisted of nonspecific round cell sarcoma. Nuclei were polymorphic round, kidney-, or heart-shaped. Nuclear molding was usually present. Paranuclear cytoplasmic densities were obvious and noted in 7 cases. Cytonuclear atypia, mitotic figures, numerous crushed nuclei, and apoptosis were frequently seen. Purple-stained stroma was present in 8 cases (ranging from few connective tissue fragments to large hyalinized deposits). Molecular studies based on cytological aspirates were performed in 8 patients. The presence of the fusion gene EWSR1-WT 1 transcript was identified in all, which confirmed the diagnosis of DSRCT. Smears showing poorly differentiated round cells associated with cytoplasmic densities and connective stoma, in a specific clinical context, young adult age, intra-abdominal localization, suggestive immunocytochemical profile, and a unique cytogenetic abnormality are highly specific and allow an accurate diagnosis of DSRCT. © 2014 American Cancer Society.

Accelerated cell sheet detachment by copolymerizing hydrophilic PEG side chains into PNIPAm nanocomposite hydrogels.

PubMed

Liu, Dan; Wang, Tao; Liu, Xinxing; Tong, Zhen

2012-10-01

One-end-connected short poly(ethylene glycol) (PEG) side chains were facilely introduced into the poly(N-isopropylacrylamide) (PNIPAm) nanocomposite hydrogel (NC gel) via in situ copolymerization of NIPAm monomer and PEG macromonomer in the aqueous suspension of hectorite clay Laponite XLS. The NC gels were characterized with Fourier transform infrared and x-ray photoelectron spectroscopy for the composition, DSC and transmittance for the phase separation temperature, dynamic mechanical spectra and swelling ratio for the interaction. Increasing the PEG content led to a small increase in the storage modulus and the lower critical solution temperature (LCST) of the copolymerized NC gels, and the LCST of the copolymerized NC gels was still below 37 °C. The L929 cell adhesion and proliferation on the surface of these NC gels were not suppressed by the incorporation of hydrophilic PEG side chains. By lowering temperature below the LCST, the cell sheet spontaneously detached from the copolymerized NC gels. The surface morphology and surface wettability of the NC gels were detected by atom force microscope and contact angle measurement. A rough and hydrophilic surface induced by a small amount of PEG side chains was found to be favorable to accelerate the cell sheet detachment, probably due to the enhanced water permeation into the gel-cell sheet interface.

Vitreous Microparticle Shedding in Retinal Detachment: A Prospective Comparative Study.

PubMed

Tumahai, Perle; Saas, Philippe; Ricouard, Fanny; Biichlé, Sabéha; Puyraveau, Marc; Laheurte, Caroline; Delbosc, Bernard; Saleh, Maher

2016-01-01

Microparticles (MPs) are membrane-derived vesicles measuring less than 1 μm in diameter. They are shed from nearly every activated or preapoptotic cell and may exhibit biologic activities in inflammation or apoptosis settings. The main purpose of this study was to determine whether MP shedding was higher in the vitreous of patients with retinal detachment (RD). This was a prospective, comparative study. Levels of vitreous MPs (including phosphatidylserine [PS]-expressing MPs, photoreceptor cell-derived MPs, and photoreceptor cell-derived MPs expressing PS) and soluble proinflammatory factors (i.e., monocyte chemoattractant protein-1, intercellular adhesion molecule-1, and IL-6) were analyzed by flow cytometry. Samples were obtained from 49 eyes undergoing RD surgery and 41 control eyes. Vitreous levels of all the MPs studied were significantly increased in the RD group. Vitreous MP levels were correlated with levels of at least one proinflammatory factor depending on MP subsets. Concerning clinical parameters, vitreous PS-expressing MP and PS-expressing photoreceptor cell-derived MP levels were higher depending on the duration of RD at surgery, the detached retina surface, and the macula status and were found more sensitive than proinflammatory factors only for the duration of RD at surgery. Vitreous concentrations of MPs (mainly derived from photoreceptor cells) are higher after rhegmatogenous RD and found to be correlated with soluble proinflammatory factors.

Selective reactivity of monochloramine with extracellular matrix components affects the disinfection of biofilm and detached clusters.

PubMed

Xue, Zheng; Lee, Woo Hyoung; Coburn, Kimberly M; Seo, Youngwoo

2014-04-01

The efficiency of monochloramine disinfection was dependent on the quantity and composition of extracellular polymeric substances (EPS) in biofilms, as monochloramine has a selective reactivity with proteins over polysaccharides. Biofilms with protein-based (Pseudomonas putida) and polysaccharide based EPS (Pseudomonas aeruginosa), as well as biofilms with varied amount of polysaccharide EPS (wild-type and mutant P. aeruginosa), were compared. The different reactivity of EPS components with monochloramine influenced disinfectant penetration, biofilm inactivation, as well as the viability of detached clusters. Monochloramine transport profiling measured by a chloramine-sensitive microelectrode revealed a broader diffusion boundary layer between bulk and biofilm surface in the P. putida biofilm compared to those of P. aeruginosa biofilms. The reaction with proteins in P. putida EPS multiplied both the time and the monochloramine mass required to achieve a full biofilm penetration. Cell viability in biofilms was also spatially influenced by monochloramine diffusion and reaction within biofilms, showing a lower survival in the surface section and a higher persistence in the middle section of the P. putida biofilm compared to the P. aeruginosa biofilms. While polysaccharide EPS promoted biofilm cell viability by obstructing monochloramine reactive sites on bacterial cells, protein EPS hindered monochloramine penetration by reacting with monochloramine and reduced its concentration within biofilms. Furthermore, the persistence of bacterial cells detached from biofilm (over 70% for P. putida and ∼40% for polysaccharide producing P. aeruginosa) suggested that currently recommended monochloramine residual levels may underestimate the risk of water quality deterioration caused by biofilm detachment.

Mitochondrial clearance by the STK38 kinase supports oncogenic Ras-induced cell transformation

PubMed Central

Bettoun, Audrey; Surdez, Didier; Vallerand, David; Gundogdu, Ramazan; Sharif, Ahmad A.D.; Gomez, Marta; Cascone, Ilaria; Meunier, Brigitte; White, Michael A.; Codogno, Patrice; Parrini, Maria Carla; Camonis, Jacques H.; Hergovich, Alexander

2016-01-01

Oncogenic Ras signalling occurs frequently in many human cancers. However, no effective targeted therapies are currently available to treat patients suffering from Ras-driven tumours. Therefore, it is imperative to identify downstream effectors of Ras signalling that potentially represent promising new therapeutic options. Particularly, considering that autophagy inhibition can impair the survival of Ras-transformed cells in tissue culture and mouse models, an understanding of factors regulating the balance between autophagy and apoptosis in Ras-transformed human cells is needed. Here, we report critical roles of the STK38 protein kinase in oncogenic Ras transformation. STK38 knockdown impaired anoikis resistance, anchorage-independent soft agar growth, and in vivo xenograft growth of Ras-transformed human cells. Mechanistically, STK38 supports Ras-driven transformation through promoting detachment-induced autophagy. Even more importantly, upon cell detachment STK38 is required to sustain the removal of damaged mitochondria by mitophagy, a selective autophagic process, to prevent excessive mitochondrial reactive oxygen species production that can negatively affect cancer cell survival. Significantly, knockdown of PINK1 or Parkin, two positive regulators of mitophagy, also impaired anoikis resistance and anchorage-independent growth of Ras-transformed human cells, while knockdown of USP30, a negative regulator of PINK1/Parkin-mediated mitophagy, restored anchorage-independent growth of STK38-depleted Ras-transformed human cells. Therefore, our findings collectively reveal novel molecular players that determine whether Ras-transformed human cells die or survive upon cell detachment, which potentially could be exploited for the development of novel strategies to target Ras-transformed cells. PMID:27283898

Surface design of antibody-immobilized thermoresponsive cell culture dishes for recovering intact cells by low-temperature treatment.

PubMed

Kobayashi, Jun; Hayashi, Masaki; Ohno, Takahiro; Nishi, Masanori; Arisaka, Yoshinori; Matsubara, Yoshinori; Kakidachi, Hiroshi; Akiyama, Yoshikatsu; Yamato, Masayuki; Horii, Akihiro; Okano, Teruo

2014-11-01

Antibody-immobilized thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide) [poly(IPAAm-co-CIPAAm)]-grafted cell culture surfaces were designed to enhance both the initial adhesion of weakly adhering cells and the ability of cells to detach in response to low temperature through the regulation of affinity binding between immobilized antibodies and antigens on the cellular surface. Ty-82 cells and neonatal normal human dermal fibroblasts (NHDFs), which express CD90 on the cell surface, adhered to anti-CD90 antibody-immobilized thermoresponsive surfaces at 37°C, a condition at which the grafted thermoresponsive polymer chains shrank. Adherent Ty-82 cells were detached from the surfaces by lowering the temperature to 20°C and applying external forces, such as pipetting, whereas cultured NHDF sheets spontaneously detached themselves from the surface in response to reduced temperature alone. When the temperature was decreased to 20°C, the swelling of grafted thermoresponsive polymer chains weakened the affinity binding between immobilized antibody and antigen on the cells due to the increasing steric hindrance of the polymer chains around the antigen-recognition site of the immobilized antibodies. No contamination was detected on cells harvested from covalently immobilized antibodies on the culture surfaces by low-temperature treatment, whereas a carryover of the antibody and avidin from the avidin-biotin binding surface was observed. Furthermore, the initial adhesion of adipose tissue-derived cells, which adhere weakly to PIPAAm-grafted surfaces, was enhanced on the antibody-immobilized thermoresponsive surfaces. © 2013 Wiley Periodicals, Inc.

Calcium-Oxidant Signaling Network Regulates AMP-activated Protein Kinase (AMPK) Activation upon Matrix Deprivation*

PubMed Central

Sundararaman, Ananthalakshmy; Amirtham, Usha; Rangarajan, Annapoorni

2016-01-01

The AMP-activated protein kinase (AMPK) has recently been implicated in anoikis resistance. However, the molecular mechanisms that activate AMPK upon matrix detachment remain unexplored. In this study, we show that AMPK activation is a rapid and sustained phenomenon upon matrix deprivation, whereas re-attachment to the matrix leads to its dephosphorylation and inactivation. Because matrix detachment leads to loss of integrin signaling, we investigated whether integrin signaling negatively regulates AMPK activation. However, modulation of focal adhesion kinase or Src, the major downstream components of integrin signaling, failed to cause a corresponding change in AMPK signaling. Further investigations revealed that the upstream AMPK kinases liver kinase B1 (LKB1) and Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ) contribute to AMPK activation upon detachment. In LKB1-deficient cells, we found AMPK activation to be predominantly dependent on CaMKKβ. We observed no change in ATP levels under detached conditions at early time points suggesting that rapid AMPK activation upon detachment was not triggered by energy stress. We demonstrate that matrix deprivation leads to a spike in intracellular calcium as well as oxidant signaling, and both these intracellular messengers contribute to rapid AMPK activation upon detachment. We further show that endoplasmic reticulum calcium release-induced store-operated calcium entry contributes to intracellular calcium increase, leading to reactive oxygen species production, and AMPK activation. We additionally show that the LKB1/CaMKK-AMPK axis and intracellular calcium levels play a critical role in anchorage-independent cancer sphere formation. Thus, the Ca2+/reactive oxygen species-triggered LKB1/CaMKK-AMPK signaling cascade may provide a quick, adaptable switch to promote survival of metastasizing cancer cells. PMID:27226623

Correlation between refraction level and retinal breaks in myopic eye.

PubMed

Alimanović-Halilović, Emina

2008-11-01

In this study we analyzed 180 myopic eyes in order to determine the refraction that is "critical" for the occurrence of retinal breaks as a main cause of retinal detachment. Detachment of retina involves separation of the neurosensory retina from the pigmented epithelium with the severe impairment of vision. After the focused ophthalmological assessment, determination of objective refraction, indirect binocular ophthalmoscopy, we compared the diagnosed retinal breaks according to the shape with the refraction. All the examined eyes were divided into six groups according to the axis length. Mean age of our patients was between 48,43 and 51,60 years with SD ranging from 13,88 to 18,45. The age differences among the groups were not statistically significant. This study included 102 (56,7%) male and 78 (43,3%) female patients and no statistically significant differences between genders was found regarding the occurrence of retinal breaks compared to refraction. The most dominant ruptures were the round ones (28,2%), followed by oval (25%), the category of multiple small holes (19,2%), horseshoe shaped (15,3%), and finally holes with operculum. In cases with myopic refraction ranging between 3,50 and 7,49 dsph, the frequency of retinal breaks statistically significantly differs from all other analyzed refractions. Also, there is positive correlation between the above mentioned myopic refraction and the frequency of retinal breaks. In order to prevent retinal detachment in a myopic eye, we suggest further thorough examinations of the eye fundus in patients with the above mentioned myopia. Diagnosing retinal breaks involves the application of adequate therapy: laser photocoagulation, cryotherapy, sclera buckling and pneumatic retinopexy.

Transient Proliferation of Proanthocyanidin-Accumulating Cells on the Epidermal Apex Contributes to Highly Aluminum-Resistant Root Elongation in Camphor Tree1[W

PubMed Central

Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

2011-01-01

Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree. PMID:21045123

Transient proliferation of proanthocyanidin-accumulating cells on the epidermal apex contributes to highly aluminum-resistant root elongation in camphor tree.

PubMed

Osawa, Hiroki; Endo, Izuki; Hara, Yukari; Matsushima, Yuki; Tange, Takeshi

2011-01-01

Aluminum (Al) is a harmful element that rapidly inhibits the elongation of plant roots in acidic soils. The release of organic anions explains Al resistance in annual crops, but the mechanisms that are responsible for superior Al resistance in some woody plants remain unclear. We examined cell properties at the surface layer of the root apex in the camphor tree (Cinnamomum camphora) to understand its high Al resistance mechanism. Exposure to 500 μm Al for 8 d, more than 20-fold higher concentration and longer duration than what soybean (Glycine max) can tolerate, only reduced root elongation in the camphor tree to 64% of the control despite the slight induction of citrate release. In addition, Al content in the root apices was maintained at low levels. Histochemical profiling revealed that proanthocyanidin (PA)-accumulating cells were present at the adjacent outer layer of epidermis cells at the root apex, having distinctive zones for cell division and the early phase of cell expansion. Then the PA cells were gradually detached off the root, leaving thin debris behind, and the root surface was replaced with the elongating epidermis cells at the 3- to 4-mm region behind the tip. Al did not affect the proliferation of PA cells or epidermis cells, except for the delay in the start of expansion and the accelerated detachment of the former. In soybean roots, the innermost lateral root cap cells were absent in both PA accumulation and active cell division and failed to protect the epidermal cell expansion at 25 μm Al. These results suggest that transient proliferation and detachment of PA cells may facilitate the expansion of epidermis cells away from Al during root elongation in camphor tree.

Amarogentin secoiridoid inhibits in vivo cancer cell growth in xenograft mice model and induces apoptosis in human gastric cancer cells (SNU-16) through G2/M cell cycle arrest and PI3K/Akt signalling pathway.

PubMed

Zhao, Jian-Guo; Zhang, Ling; Xiang, Xiao-Jun; Yu, Feng; Ye, Wan-Li; Wu, Dong-Ping; Wang, Jian-Fang; Xiong, Jian-Ping

2016-01-01

To investigate the in vitro and in vivo antitumor effects of amarogentin in SNU-16 human gastric cancer cells as well as in nude mice xenograft model. The effects of this compound on cell apoptosis, cell cycle phase distribution and PI3K/Akt and m-TOR signalling pathways were also studied in detail. MTT assay was used to study the effect of amarogentin on SNU-16 cell viability while clonogenic assay indicated the effect of the compound on colony formation tendency of these cells. Phase contrast microscopy revealed the effect on cellular morphology while flow cytometry was engaged to study the effects on cell apoptosis and cell cycle arrest. SNU-16 cancer cells were subcutaneously inoculated into nude mice to investigate the in vivo antitumor effects of amarogentin. Amarogentin induced potent, dose-dependent as well as time-dependent cytotoxic effects on the growth of SNU-16 human gastric cancer cells. Amarogentin also inhibited the colony forming capability of these tumor cells and its treatment led to morphological alterations in these cells in which the cells became withered and rounded, detached from one another and adopted irregular shapes while floating freely in the culture medium. In comparison to untreated control cells, the amarogentin treated cells with 10, 50 and 75 μM exhibited 32.5, 45.2 and 57.1 % apoptotic cells, respectively. Amarogentin induced potent and dose-dependent G2/M cell cycle arrest in these cells and led to downregulation of m-TOR, p-PI3K, PI3K, p-Akt and Akt and upregulation of cyclin D1 and cyclin E protein expressions. The tumor tissues obtained from the amarogentin-treated mice were much smaller than the tumor tissues derived from the control group. Amarogentin exerts potent in vitro and in vivo antitumor effects in SNU-16 cell model as well as in nude mice xenograft model. These antitumor effects were found to be mediated through apoptosis induction, G2/M cell cycle arrest and downregulation of PI3K/Akt/m-TOR signalling pathways.

Round cell sarcoma with CIC-DUX4 gene fusion: Discussion of the distinctive cytomorphologic, immunohistochemical, and molecular features in the differential diagnosis of round cell tumors.

PubMed

Chebib, Ivan; Jo, Vickie Y

2016-05-01

Undifferentiated round cell sarcomas are a heterogeneous group, and include tumors that resemble the Ewing sarcoma family. Although a subset defined by recurrent CIC-DUX4 gene fusion has been recently characterized, data regarding the cytomorphologic features are currently limited. Two recent fine-needle aspiration (FNA) cases prompted review of the spectrum of round cell tumors in the differential diagnosis to determine distinctive diagnostic features. Two genetically confirmed FNA cases were identified. Cytomorphologic features were evaluated on FNA smears and hematoxylin and eosin-stained cell block and concurrent needle biopsy sections, and immunohistochemical studies performed on cell block and biopsy sections were reviewed. The 2 patients were a 24-year-old man with a posterior mediastinal mass and a 69-year-old woman with a gluteal mass. FNA smears were cellular with tumor cells present in large groups and singly dispersed. Tumor cells had large, round-to-ovoid, hyperchromatic nuclei with irregular membranes, frequent large nucleoli, and a moderate amount of vacuolated cytoplasm. Both cases demonstrated necrosis, and one case had prominent myxoid stroma. Immunohistochemistry demonstrated focal-to-multifocal CD99 positivity and diffuse nuclear staining for WT1; staining for cytokeratin, desmin, S-100, CD34, CD45, and TdT were negative. Fluorescence in situ hybridization demonstrated CIC-DUX4 fusion in both cases. CIC-DUX4 round cell sarcoma differs from Ewing sarcoma in that it has more atypical cytologic features and lacks the diffuse membranous CD99 staining pattern characteristic of Ewing sarcoma. The differential diagnosis is broad, and requires the judicious use of ancillary studies. Focal-to-multifocal CD99 immunoreactivity and diffuse nuclear WT1 positivity is characteristic of CIC-DUX4 sarcoma, and should prompt molecular testing. Cancer Cytopathol 2016;124:350-61. © 2016 American Cancer Society. © 2016 American Cancer Society.

Anti-tumor effect of in vivo IL-2 and GM-CSF electrogene therapy in murine hepatoma model.

PubMed

Chi, Chau-Hwa; Wang, Yu-Shan; Lai, Yen-Shuae; Chi, Kwan-Hwa

2003-01-01

We evaluated the effect of in vivo electrogene therapy (EGT), a newly-developed gene transfer method using electroporation on the induction of anti-cancer immunity. The in vivo EGT was carried out by direct injection of plasmid DNAs encoding mouse interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in a subcutaneous murine hepatoma model of 1MEA.7R.1 cells. Six electric pulses were generated in situ from a square-wave electroporator fitted with a circular, six-needle electrode array. 1MEA.7R1 cells in vitro were modified to secret IL-2 (1MEA.7R.1/IL-2 cells). The 1MEA.7R.1/IL-2 cells had a similar cell doubling-time as their parent cells but showed a much slower growth rate on Balb/C mice. One, or 3 rounds of single gene EGT with IL-2 gene showed a dose-responsive effect of growth retardation. Co-administration of 3 rounds of IL-2/GM-CSF double genes EGT had a stronger growth inhibition effect than 3 rounds of IL-2 single gene EGT. Three rounds of IL-2/GM-CSF EGT rendered the tumor to a growth rate of stably transfected 1MEA.7R.1/IL-2 cells. Seven rounds of IL-2/GM-CSF EGT markedly inhibited the tumor growth. Reverse transciptase-polymerase chain reaction confirmed the expression of IL-2, GM-CSF and interferon-gamma within treated tumors. Systemic inhibitory effects can be demonstrated from tumor-re-challenged experiments on mice which received 3 rounds of double-gene EGT. The T cell proliferation assay revealed an increased T cell proliferation in double-gene EGT-treated mice. This experiment showed that partial systemic immunity can be provoked by IL-2/GM-CSF double-gene EGT. These findings suggest that our immuno-gene therapy protocol has the potential for future clinical applications.

A Novel Cell Type Enables B. subtilis to Escape from Unsuccessful Sporulation in Minimal Medium.

PubMed

Defeu Soufo, Hervé Joël

2016-01-01

Sporulation is the most enduring survival strategy developed by several bacterial species. However, spore development of the model organism Bacillus subtilis has mainly been studied by means of media or conditions optimized for the induction of sporogenesis. Here, I show that during prolonged growth during stationary phase in minimal medium, B. subtilis undergoes an asymmetric cell division that produces small and round-shaped, DNA containing cells. In contrast to wild-type cells, mutants harboring spo0A or spoIIIE / sftA double mutations neither sporulate nor produce this special cell type, providing evidence that the small round cells emerge from the abortion of endospore formation. In most cases observed, the small round cells arise in the presence of sigma H but absence of sigma F activity, different from cases of abortive sporulation described for rich media. These data suggest that in minimal media, many cells are able to initiate but fail to complete spore development, and therefore return to normal growth as rods. This work reveals that the continuation of asymmetric cell division, which results in the formation of the small round cells, is a way for cells to delay or escape from-unsuccessful-sporulation. Based on these findings, I suggest to name the here described cell type as "dwarf cells" to distinguish them from the well-known minicells observed in mutants defective in septum placement or proper chromosome partitioning.

Establishment of highly metastatic KRAS mutant lung cancer cell sublines in long-term three-dimensional low attachment cultures

PubMed Central

Nakano, Tomoyuki; Kanai, Yoshihiko; Amano, Yusuke; Yoshimoto, Taichiro; Matsubara, Daisuke; Shibano, Tomoki; Tamura, Tomoko; Oguni, Sachiko; Katashiba, Shizuka; Ito, Takeshi; Murakami, Yoshinori; Fukayama, Masashi; Murakami, Takashi; Endo, Shunsuke; Niki, Toshiro

2017-01-01

Decreased cell-substratum adhesion is crucially involved in metastasis. Previous studies demonstrated that lung cancer with floating cell clusters in histology is more likely to develop metastasis. In the present study, we investigated whether cancer cells in long-term, three-dimensional low attachment cultures acquire high metastatic potential; these cells were then used to examine the mechanisms underlying metastasis. Two KRAS-mutated adenocarcinoma cell lines (A549 and H441) were cultured and selected on ultra-low attachment culture dishes, and the resulting cells were defined as FL (for floating) sublines. Cancer cells were inoculated into NOD/SCID mice via an intracardiac injection, and metastasis was evaluated using luciferase-based imaging and histopathology. In vitro cell growth (in attachment or suspension cultures), migration, and invasion were assayed. A whole genomic analysis was performed to identify key molecular alterations in FL sublines. Upon detachment on low-binding dishes, parental cells initially formed rounded spheroids with limited growth activity. However, over time in cultures, cells gradually formed smaller spheroids that grew slowly, and, after 3–4 months, we obtained FL sublines that regained prominent growth potential in suspension cultures. On ordinary dishes, FL cells reattached and exhibited a more spindle-shaped morphology than parental cells. No marked differences were observed in cell growth with attachment, migration, or invasion between FL sublines and parental cell lines; however, FL cells exhibited markedly increased growth potential under suspended conditions in vitro and stronger metastatic abilities in vivo. A genomic analysis identified epithelial-mesenchymal transition (EMT) and c-Myc amplification in A549-FL and H441-FL cells, respectively, as candidate mechanisms for metastasis. The growth potential of FL cells was markedly inhibited by lentiviral ZEB1 knockdown in A549-FL cells and by the inhibition of c-Myc through lentiviral knockdown or the pharmacological inhibitor JQ1 in H441-FL cells. Long-term three-dimensional low attachment cultures may become a useful method for investigating the mechanisms underlying metastasis mediated by decreased cell-substratum adhesion. PMID:28786996

Roles of the first and second round of DNA replication in the regulation of zygotic gene activation in mice.

PubMed

Sonehara, Hiroki; Nagata, Masao; Aoki, Fugaku

2008-10-01

In the mouse embryo, expression of zygotic genes starts in the S/G2 phase of the 1-cell stage and greatly increases during the 2-cell stage. Although the timing of zygotic gene activation (ZGA) is thus established, the mechanism regulating ZGA is poorly understood. Previous studies using reporter genes have suggested that a transcriptionally repressive state is established during the 2-cell stage and that the first and second rounds of DNA replication are involved in this process. To further elucidate the respective roles of the two rounds of DNA replication in ZGA, we analyzed the expression of four ZGA genes (hsp70.1, eif-1a, muerv and zscan4d) in embryos whose DNA replication was inhibited by treatment with aphidicolin, an inhibitor of DNA polymerase. Inhibiting the first round increased the expression levels of hsp70.1, eif-1a and zscan4d but decreased that of muerv, while inhibiting the second round increased the expression levels of all four genes. These results suggest that the transcriptionally repressive state seems to be established after the second round of DNA replication.

Distinct c-Met activation mechanisms induce cell rounding or invasion through pathways involving integrins, RhoA and HIP1.

PubMed

Mai, Anja; Muharram, Ghaffar; Barrow-McGee, Rachel; Baghirov, Habib; Rantala, Juha; Kermorgant, Stéphanie; Ivaska, Johanna

2014-05-01

Many carcinomas have acquired oncogenic mechanisms for activating c-Met, including c-Met overexpression and excessive autocrine or paracrine stimulation with hepatocyte growth factor (HGF). However, the biological outcome of c-Met activation through these distinct modes remains ambiguous. Here, we report that HGF-mediated c-Met stimulation triggers a mesenchymal-type collective cell invasion. By contrast, the overexpression of c-Met promotes cell rounding. Moreover, in a high-throughput siRNA screen that was performed using a library of siRNAs against putative regulators of integrin activity, we identified RhoA and the clathrin-adapter protein HIP1 as crucial c-Met effectors in these morphological changes. Transient RhoA activation was necessary for the HGF-induced invasion, whereas sustained RhoA activity regulated c-Met-induced cell rounding. In addition, c-Met-induced cell rounding correlated with the phosphorylation of filamin A and the downregulation of active cell-surface integrins. By contrast, a HIP1-mediated increase in β1-integrin turnover was required for the invasion triggered by HGF. Taken together, our results indicate that c-Met induces distinct cell morphology alterations depending on the stimulus that activates c-Met.

Cyto-histopathological and outcome features of the prepuce squamous cell carcinoma of a mixed breed dog

PubMed Central

2014-01-01

Abstract Background Squamous cell carcinomas (SCCs) are uncommon, high-grade tumors, predominantly composed of round cells in the prepuce. The aim of this study is to better define the clinicopathologic features of this neoplasm. Case report We conducted cyto-histopathologic analysis on the manifestations of the prepuce SCC by H & E staining in a terrier mix dog. Grossly, tumor was large, multiple erythematous patch, and ulcerated masses frequently affecting the prepuce and deeply invading to distal prepuce out from the ventro-lateral of penis and the tumor covered by a necrotic discharge. Cytological evaluation of fine-needle aspirates from the cutaneous mass from the prepuce comprised of round nuclei, coarse chromatin pattern, distinct nucleoli and nuclear pleomorphism. Furthermore, the neoplastic cells were pleomorphic, round to caudate in shape, exhibiting prominent anisokaryosis and anisocytosis with rare mitotic features. Microscopically, the lesions were predominantly composed of atypical round cells disposed in interlacing fascicles. Frequent findings include keratin formation, horn pearls, mitoses and cellular atypia. The cells showed distinct borders, ranged from polygonal to round or elongate and had moderate amounts of eosinophilic cytoplasm. Conclusion The histopathologic features coupled with the cytopathology findings led to a diagnosis of squamous cell carcinoma. To the authors’ knowledge, this is the first time that multiple erythematous plaques have undergone malignant transformation in a terrier mix dog. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5748771971272873 PMID:24903567

A Taz1- and Microtubule-Dependent Regulatory Relationship between Telomere and Centromere Positions in Bouquet Formation Secures Proper Meiotic Divisions

PubMed Central

Katsumata, Kazuhiro; Hirayasu, Ami; Miyoshi, Junpei; Nishi, Eriko; Ichikawa, Kento; Tateho, Kazuki; Wakuda, Airi; Matsuhara, Hirotada; Yamamoto, Ayumu

2016-01-01

During meiotic prophase, telomeres cluster, forming the bouquet chromosome arrangement, and facilitate homologous chromosome pairing. In fission yeast, bouquet formation requires switching of telomere and centromere positions. Centromeres are located at the spindle pole body (SPB) during mitotic interphase, and upon entering meiosis, telomeres cluster at the SPB, followed by centromere detachment from the SPB. Telomere clustering depends on the formation of the microtubule-organizing center at telomeres by the linker of nucleoskeleton and cytoskeleton complex (LINC), while centromere detachment depends on disassembly of kinetochores, which induces meiotic centromere formation. However, how the switching of telomere and centromere positions occurs during bouquet formation is not fully understood. Here, we show that, when impaired telomere interaction with the LINC or microtubule disruption inhibited telomere clustering, kinetochore disassembly-dependent centromere detachment and accompanying meiotic centromere formation were also inhibited. Efficient centromere detachment required telomere clustering-dependent SPB recruitment of a conserved telomere component, Taz1, and microtubules. Furthermore, when artificial SPB recruitment of Taz1 induced centromere detachment in telomere clustering-defective cells, spindle formation was impaired. Thus, detachment of centromeres from the SPB without telomere clustering causes spindle impairment. These findings establish novel regulatory mechanisms, which prevent concurrent detachment of telomeres and centromeres from the SPB during bouquet formation and secure proper meiotic divisions. PMID:27611693

Fabrication of thermo-responsive PNIPAAm-g-ETFE for cell culture dishes by pre-irradiation grafting

NASA Astrophysics Data System (ADS)

Yamahara, Yumi; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Oshima, Akihiro; Washio, Masakazu

2018-01-01

Thermo-responsive templates for the cell cultivation based on Poly(tetrafluoroethylene-co-ethylene) (ETFE) were fabricated by pre-irradiation grafting of N-isoproplyacrylamide (NIPAAm) monomer by electron beam (EB) irradiation under nitrogen gas atmosphere at room temperature, and their characteristic properties were studied. The detachment of cultured HeLa cells from fabricated thermo-responsive templates were attempted. Furthermore, the reaction mechanism is proposed using ESR spectroscopy and FT-IR spectroscopy. It is confirmed that the cultured HeLa cells were detached from fabricated thermo-responsive templates at 20 °C. Water contact angle analysis indicated that obtained templates had thermo-response around 30 °C. It is suggested that the grafted polymer chains would mainly react with peroxy radicals (-CF2-CF(OO･)-) on tetrafluoroethylene unit in ETFE.

Paratesticular desmoplastic small round cell tumour: an unusual tumour with an unusual fusion; cytogenetic and molecular genetic analysis combining RT-PCR and COBRA-FISH.

PubMed

Cliteur, Vincent Pm; Szuhai, Károly; Baelde, Hans J; van Dam, Jurriaan; Gelderblom, Hans; Hogendoorn, Pancras Cw

2012-01-25

Desmoplastic small round cell tumour is a rare malignant tumour with a male to female ratio of 4:1. It manifests mostly at serosal sites. Here we present a case of a 28-year-old male patient, who presented with a fast growing paratesticular mass. On biopsy nests and cords of small round cells, without a clear morphological lineage of differentiation were seen. Occasionally desmoplatic small round cell tumour shows different lines of differentiation. An unequivocal histological diagnosis might be difficult in such cases. Here we demonstrate by a combination of methods the characteristic immunohistochemical profile and - albeit unusual - molecular background and discuss the eventual link with Ewing sarcoma.Immunohistochemical studies showed a membranous staining of Keratine AE1/3 and a dot-like staining of Desmine, confirming its diagnosis. Using COBRA-FISH following a metaphase approach we demonstrated a balanced translocation, t(11;22)(p13;q12) and in RT-PCR formation of the EWSR1-WT1 fusion product, a specific translocation of desmoplastic round cell tumour. The fusion involves exon 9 of EWSR1 to exon 8 of WT1, an unusual fusion product, though earlier described in a case of a desmoplastic small round cell tumour of the hand. The EWSR1-WT1 chimera seems to function as an oncogenic transcription factor. Here the zinc finger domain of the WT1 acts with affinity with certain promoter domains influencing the expression of various downstream proteins such as: PDGFA, PAX2, insulin-like growth factor 1 receptor, epidermal growth factor receptor, IL2 receptor beta, BAIAP3, MLF1, TALLA-1, LRRC15 and ENT. We discuss their potential oncogenic roles and potential therapeutic consequences.

Paratesticular desmoplastic small round cell tumour: an unusual tumour with an unusual fusion; cytogenetic and molecular genetic analysis combining RT-PCR and COBRA-FISH

PubMed Central

2012-01-01

Desmoplastic small round cell tumour is a rare malignant tumour with a male to female ratio of 4:1. It manifests mostly at serosal sites. Here we present a case of a 28-year-old male patient, who presented with a fast growing paratesticular mass. On biopsy nests and cords of small round cells, without a clear morphological lineage of differentiation were seen. Occasionally desmoplatic small round cell tumour shows different lines of differentiation. An unequivocal histological diagnosis might be difficult in such cases. Here we demonstrate by a combination of methods the characteristic immunohistochemical profile and - albeit unusual - molecular background and discuss the eventual link with Ewing sarcoma. Immunohistochemical studies showed a membranous staining of Keratine AE1/3 and a dot-like staining of Desmine, confirming its diagnosis. Using COBRA-FISH following a metaphase approach we demonstrated a balanced translocation, t(11;22)(p13;q12) and in RT-PCR formation of the EWSR1-WT1 fusion product, a specific translocation of desmoplastic round cell tumour. The fusion involves exon 9 of EWSR1 to exon 8 of WT1, an unusual fusion product, though earlier described in a case of a desmoplastic small round cell tumour of the hand. The EWSR1-WT1 chimera seems to function as an oncogenic transcription factor. Here the zinc finger domain of the WT1 acts with affinity with certain promoter domains influencing the expression of various downstream proteins such as: PDGFA, PAX2, insulin-like growth factor 1 receptor, epidermal growth factor receptor, IL2 receptor beta, BAIAP3, MLF1, TALLA-1, LRRC15 and ENT. We discuss their potential oncogenic roles and potential therapeutic consequences. PMID:22587803

Thermo-responsive methylcellulose hydrogels as temporary substrate for cell sheet biofabrication.

PubMed

Altomare, Lina; Cochis, Andrea; Carletta, Andrea; Rimondini, Lia; Farè, Silvia

2016-05-01

Methylcellulose (MC), a water-soluble polymer derived from cellulose, was investigated as a possible temporary substrate having thermo-responsive properties favorable for cell culturing. MC-based hydrogels were prepared by a dispersion technique, mixing MC powder (2, 4, 6, 8, 10, 12 % w/v) with selected salts (sodium sulphate, Na2SO4), sodium phosphate, calcium chloride, or phosphate buffered saline, to evaluate the influence of different compositions on the thermo-responsive behavior. The inversion test was used to determine the gelation temperatures of the different hydrogel compositions; thermo-mechanical properties and thermo-reversibility of the MC hydrogels were investigated by rheological analysis. Gelation temperatures and rheological behavior depended on the MC concentration and type and concentration of salt used in hydrogel preparation. In vitro cytotoxicity tests, performed using L929 mouse fibroblasts, showed no toxic release from all the tested hydrogels. Among the investigated compositions, the hydrogel composed of 8 % w/v MC with 0.05 M Na2SO4 had a thermo-reversibility temperature at 37 °C. For that reason, this formulation was thus considered to verify the possibility of inducing in vitro spontaneous detachment of cells previously seeded on the hydrogel surface. A continuous cell layer (cell sheet) was allowed to grow and then detached from the hydrogel surface without the use of enzymes, thanks to the thermo-responsive behavior of the MC hydrogel. Immunofluorescence observation confirmed that the detached cell sheet was composed of closely interacting cells.

Significant partial response of metastatic intra-abdominal and pelvic round cell liposarcoma to a small-molecule VEGFR-2 tyrosine kinase inhibitor apatinib: A case report.

PubMed

Dong, Min; Bi, Jingwang; Liu, Xiaohong; Wang, Baocheng; Wang, Jun

2016-08-01

Myxoid/round cell liposarcoma is the second most common subtype of liposarcoma. Chemotherapy and radiotherapy have a limited efficacy for treating advanced myxoid/round cell liposarcoma, with relatively serious side effects. We herein present a 68-year-old Chinese woman initially diagnosed with advanced multiple intra-abdominal and pelvic round cell liposarcoma.She refused to receive cytotoxic chemotherapy and received apatinib as the first-line therapy, a novel tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 that has been used in the treatment of patients with metastatic gastric cancer who progressed with 2 or more chemotherapy regimens. This patient was partially responsive to apatinib with a dose of 500 mg daily. No serious drug-related side effects were observed. Our findings indicate that some cases of liposarcoma may be responsive to antiangiogenic agent apatinib. Randomized clinical studies are needed to further confirm the efficacy and safety of apatinib in the clinical treatment of liposarcoma.

Generation, cryopreservation, function and in vivo persistence of ex-vivo expanded cynomolgus monkey regulatory T cells

PubMed Central

Guo, Hao; Zhang, Hong; Lu, Lien; Ezzelarab, Mohamed B.; Thomson, Angus W.

2015-01-01

We expanded flow-sorted Foxp3+ cynomolgus monkey regulatory T cells (Treg) >1000-fold after three rounds of stimulation with anti-CD3 mAb-loaded artificial antigen-presenting cells, rapamycin (first round only) and IL-2. The expanded Treg maintained their expression of Treg signature markers, CD25, CD27, CD39, Foxp3, Helios, and CTLA-4, as well as CXCR3, which plays an important role in T cell migration to sites of inflammation. In contrast to expanded effector T cells (Teff), expanded Treg produced minimal IFN-γ and IL-17 and no IL-2 and potently suppressed Teff proliferation. Following cryopreservation, thawed Treg were less viable than their freshly-expanded counterparts, although no significant changes in phenotype or suppressive ability were observed. Additional rounds of stimulation/expansion restored maximal viability. Furthermore, adoptively-transferred autologous Treg expanded from cryopreserved second round stocks and labeled with CFSE or VPD450 were detected in blood and secondary lymphoid tissues of normal or immunosuppressed recipients at least two months after their systemic infusion. PMID:25732601

Cellular Uptake of Clostridium botulinum C2 Toxin Requires Acid Sphingomyelinase Activity.

PubMed

Nagahama, Masahiro; Takehara, Masaya; Takagishi, Teruhisa; Seike, Soshi; Miyamoto, Kazuaki; Kobayashi, Keiko

2017-04-01

Clostridium botulinum C2 toxin consists of an enzyme component (C2I) and a binding component (C2II). Activated C2II (C2IIa) binds to a cell receptor, giving rise to lipid raft-dependent oligomerization, and it then assembles with C2I. The whole toxin complex is then endocytosed into the cytosol, resulting in the destruction of the actin cytoskeleton and cell rounding. Here, we showed that C2 toxin requires acid sphingomyelinase (ASMase) activity during internalization. In this study, inhibitors of ASMase and lysosomal exocytosis blocked C2 toxin-induced cell rounding. C2IIa induced Ca 2+ influx from the extracellular medium to cells. C2 toxin-induced cell rounding was enhanced in the presence of Ca 2+ ASMase was released extracellularly when cells were incubated with C2IIa in the presence of Ca 2+ Small interfering RNA (siRNA) knockdown of ASMase reduced C2 toxin-induced cell rounding. ASMase hydrolyzes sphingomyelin to ceramide on the outer leaflet of the membrane at acidic pH. Ceramide was detected in cytoplasmic vesicles containing C2IIa. These results indicated that ASMase activity is necessary for the efficient internalization of C2 toxin into cells. Inhibitors of ASMase may confer protection against infection. Copyright © 2017 American Society for Microbiology.

Dynamics of Bovine Sperm Interaction with Epithelium Differ Between Oviductal Isthmus and Ampulla1

PubMed Central

Ardon, Florencia; Markello, Ross D.; Hu, Lian; Deutsch, Zarah I.; Tung, Chih-Kuan; Wu, Mingming; Suarez, Susan S.

2016-01-01

In mammals, many sperm that reach the oviduct are held in a reservoir by binding to epithelium. To leave the reservoir, sperm detach from the epithelium; however, they may bind and detach again as they ascend into the ampulla toward oocytes. In order to elucidate the nature of binding interactions along the oviduct, we compared the effects of bursts of strong fluid flow (as would be caused by oviductal contractions), heparin, and hyperactivation on detachment of bovine sperm bound in vitro to epithelium on intact folds of isthmic and ampullar mucosa. Intact folds of oviductal mucosa were used to represent the strong attachments of epithelial cells to each other and to underlying connective tissue that exist in vivo. Effects of heparin on binding were tested because heparin binds to the Binder of SPerm (BSP) proteins that attach sperm to oviductal epithelium. Sperm bound by their heads to beating cilia on both isthmic and ampullar epithelia and could not be detached by strong bursts of fluid flow. Addition of heparin immediately detached sperm from isthmic epithelium but not ampullar epithelium. Addition of 4-aminopyridine immediately stimulated hyperactivation of sperm but did not detach them from isthmic or ampullar epithelium unless added with heparin. These observations indicate that the nature of binding of sperm to ampullar epithelium differs from that of binding to isthmic epithelium; specifically, sperm bound to isthmic epithelium can be detached by heparin alone, while sperm bound to ampullar epithelium requires both heparin and hyperactivation to detach from the epithelium. PMID:27605344

Dynamics of Bovine Sperm Interaction with Epithelium Differ Between Oviductal Isthmus and Ampulla.

PubMed

Ardon, Florencia; Markello, Ross D; Hu, Lian; Deutsch, Zarah I; Tung, Chih-Kuan; Wu, Mingming; Suarez, Susan S

2016-10-01

In mammals, many sperm that reach the oviduct are held in a reservoir by binding to epithelium. To leave the reservoir, sperm detach from the epithelium; however, they may bind and detach again as they ascend into the ampulla toward oocytes. In order to elucidate the nature of binding interactions along the oviduct, we compared the effects of bursts of strong fluid flow (as would be caused by oviductal contractions), heparin, and hyperactivation on detachment of bovine sperm bound in vitro to epithelium on intact folds of isthmic and ampullar mucosa. Intact folds of oviductal mucosa were used to represent the strong attachments of epithelial cells to each other and to underlying connective tissue that exist in vivo. Effects of heparin on binding were tested because heparin binds to the Binder of SPerm (BSP) proteins that attach sperm to oviductal epithelium. Sperm bound by their heads to beating cilia on both isthmic and ampullar epithelia and could not be detached by strong bursts of fluid flow. Addition of heparin immediately detached sperm from isthmic epithelium but not ampullar epithelium. Addition of 4-aminopyridine immediately stimulated hyperactivation of sperm but did not detach them from isthmic or ampullar epithelium unless added with heparin. These observations indicate that the nature of binding of sperm to ampullar epithelium differs from that of binding to isthmic epithelium; specifically, sperm bound to isthmic epithelium can be detached by heparin alone, while sperm bound to ampullar epithelium requires both heparin and hyperactivation to detach from the epithelium. © 2016 by the Society for the Study of Reproduction, Inc.

Modalities to enumerate circulating tumor cells in the bloodstream for cancer prognosis and to monitor the response to the therapy.

PubMed

Romano, G

2017-09-01

Certain malignant cells may detach from the primary tumor and enter the vascular system, forming so-called circulating tumor cells (CTCs). Clusters of malignant cells associated with other cell types can also be observed in the peripheral blood of oncological patients. Such cell clusters are termed circulating tumor microemboli (CTM). The isolation and quantification of CTCs and/or CTM from blood samples allow for an accurate prognosis of the clinical course of the disease and to monitor the response to therapy. Current protocols rely on epithelial markers for the isolation of CTCs and/or CTM from hematopoietic cells. However, epithelial markers may be silenced during the progression of the epithelial-mesenchymal transition, which regulates the detachment and migration of malignant cells from the primary tumor. This review summarizes the achievements and challenges of various modalities for the isolation, enrichment, analysis and enumeration of CTCs and/or CTM, in order to assess the advancement of the disease and the response to therapy.

Gelatin promotes murine fibrosarcoma L929 cell detachment and protects the cells from TNFα-induced cytotoxicity.

PubMed

Wang, Hong-Ju; Li, Meng-Qi; Liu, Wei; Yao, Guo-Dong; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

2016-07-01

Gelatin has been considered to exist as intermediate substance of collagen catabolism in tissue remodeling or under inflammatory conditions. We have initiated the study on possible biological functions of gelatin that can exist temporally and locally under the conditions of remodeling and inflammation Materials and methods: To this purpose, we investigated cell proliferation and survival on gelatin-coated dishes and the response to tumor necrosis factor α (TNFα)-induced cytotoxicity in L929 cells. Autophagy level, ATP level, and ROS generation are examined. L929 cells detached from the gelatin-coated dishes and formed multicellular aggregates. TNFα-induced cytotoxicity in L929 cells was inhibited by gelatin-coating culture. The cells on gelatin-coated dishes showed reduced cellular ATP levels and increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation, leading to increased ROS generation and autophagy. This study showed that gelatin-coated culture protected L929 cells from TNFα-induced cytotoxicity and suggested for a possible pathophysiological function of gelatin in regulating cellular functions.

An Investigation of Transonic Resonance in a Mach 2.2 Round Convergent-Divergent Nozzle

NASA Technical Reports Server (NTRS)

Dippold, Vance F., III; Zaman, Khairul B. M. Q.

2015-01-01

Hot-wire and acoustic measurements were taken for a round convergent nozzle and a round convergent-divergent (C-D) nozzle at a jet Mach number of 0.61. The C-D nozzle had a design Mach number of 2.2. Compared to the convergent nozzle jet flow, the Mach 2.2 nozzle jet flow produced excess broadband noise (EBBN). It also produced a transonic resonance tone at 1200 Herz. Computational simulations were performed for both nozzle flows. A steady Reynolds-Averaged Navier-Stokes simulation was performed for the convergent nozzle jet flow. For the Mach 2.2 nozzle flow, a steady RANS simulation, an unsteady RANS (URANS) simulation, and an unsteady Detached Eddy Simulation (DES) were performed. The RANS simulation of the convergent nozzle showed good agreement with the hot-wire velocity and turbulence measurements, though the decay of the potential core was over-predicted. The RANS simulation of the Mach 2.2 nozzle showed poor agreement with the experimental data, and more closely resembled an ideally-expanded jet. The URANS simulation also showed qualitative agreement with the hot-wire data, but predicted a transonic resonance at 1145 Herz. The DES showed good agreement with the hot-wire velocity and turbulence data. The DES also produced a transonic tone at 1135 Herz. The DES solution showed that the destabilization of the shock-induced separation region inside the nozzle produced increased levels of turbulence intensity. This is likely the source of the EBBN.

Development of an Improved Mammalian Overexpression Method for Human CD62L

PubMed Central

Brown, Haley A.; Roth, Gwynne; Holzapfel, Genevieve; Shen, Sarek; Rahbari, Kate; Ireland, Joanna; Zou, Zhongcheng; Sun, Peter D.

2014-01-01

We have previously developed a glutamine synthetase (GS)-based mammalian recombinant protein expression system that is capable of producing 5 to 30 mg/L recombinant proteins. The over expression is based on multiple rounds of target gene amplification driven by methionine sulfoximine (MSX), an inhibitor of glutamine synthetase. However, like other stable mammalian over expression systems, a major shortcoming of the GS-based expression system is its lengthy turn-around time, typically taking 4–6 months to produce. To shorten the construction time, we replaced the muti-round target gene amplifications with single-round in situ amplifications, thereby shortening the cell line construction to 2 months. The single-round in situ amplification method resulted in highest recombinant CD62L expressing CHO cell lines producing ~5mg/L soluble CD62L, similar to those derived from the multi-round amplification and selection method. In addition, we developed a MSX resistance assay as an alternative to utilizing ELISA for evaluating the expression level of stable recombinant CHO cell lines. PMID:25286402

Human cell exposure assays of Bacillus thuringiensis commercial insecticides: production of Bacillus cereus-like cytolytic effects from outgrowth of spores.

PubMed Central

Tayabali, A F; Seligy, V L

2000-01-01

Most contemporary bioinsecticides are derived from scaled-up cultures of Bacillus thuringiensis subspecies israelensis (Bti) and kurstaki (Btk), whose particulate fractions contain mostly B. thuringiensis spores (> 10(12)/L) and proteinaceous aggregates, including crystal-like parasporal inclusion bodies (PIB). Based on concerns over relatedness to B. cereus-group pathogens, we conducted extensive testing of B. thuringiensis (BT) products and their subfractions using seven human cell types. The Bti/Btk products generated nonspecific cytotoxicities involving loss in bioreduction, cell rounding, blebbing and detachment, degradation of immunodetectable proteins, and cytolysis. Their threshold dose (Dt approximately equal.5 times 10(-14)% BT product/target cell) equated to a single spore and a target cell half-life (tLD(50)) of approximately 16 hr. At Dts > 10(4), the tLD(50) rapidly shifted to < 4 hr; with antibiotic present, no component, including PIB-related [delta]-endotoxins, was cytolytic up to an equivalent of approximately 10(9 )Dt. The cytolytic agent(s) within the Bti/Btk-vegetative cell exoprotein (VCP) pool is an early spore outgrowth product identical to that of B. cereus and acting possibly by arresting protein synthesis. No cytolytic effects were seen with VCP from B. subtilis and Escherichia coli. These data, including recent epidemiologic work indicate that spore-containing BT products have an inherent capacity to lyse human cells in free and interactive forms and may also act as immune sensitizers. To critically impact at the whole body level, the exposure outcome would have to be an uncontrolled infection arising from intake of Btk/Bti spores. For humans, such a condition would be rare, arising possibly in equally rare exposure scenarios involving large doses of spores and individuals with weak or impaired microbe-clearance capacities and/or immune response systems. PMID:11049810

[Intra-abdominal desmoplastic small round cell tumour].

PubMed

Briseño-Hernández, Andrés Alejandro; Quezada-López, Deissy Roxana; Corona-Cobián, Lilia Edith; Castañeda-Chávez, Agar; Duarte-Ojeda, Alfonso Tonatiuh; Macías-Amezcua, Michel Dassaejv

2015-01-01

The desmoplastic small round cell tumour is a rare and aggressive intra-abdominal neoplasia, with only 200 cases reported, and a higher incidence in men and predilection for the second decade of life. Histologically characterized by the presence of small nests of undifferentiated tumour cells, wrapped in fibrous desmoplastic stroma. A 24 year old male started with abdominal pain of 4 weeks onset in the right upper quadrant, colic type, sporadic, self-limiting and accompanied by early satiety, decreased appetite, and involuntary weight loss of 10 kg in 3 months. At the time of admission the abdomen was globular, with decreased peristalsis, soft, depressible. Computed tomography of the abdomen showed multiple enlarged lymph nodes in the abdominal-pelvic cavity. A laparotomy was performed, with a subsequent omentum resection due to the presence of multiple tumours, which microscopically were characterised by groups of small, round, blue cells, separated by a desmoplastic stroma. The immunohistochemistry was positive for desmin (> 75%), epithelial membrane antigen (> 75%), CD99 (> 50%), and S100 (25%), concluding with an abdominal tumour of small, round, blue cells as a diagnosis. Chemotherapy treatment was initiated based on IMAP plus GM-CSF. The desmoplastic small round cell tumour is a rare neoplasia, with diagnostic complexity and a lethal course. Its clinical presentation is unspecific. Histologically, it is classified as an aggressive soft tissue sarcoma that shares similar characteristics with the family of the small and blue cells tumours. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

A Novel Cell Type Enables B. subtilis to Escape from Unsuccessful Sporulation in Minimal Medium

PubMed Central

Defeu Soufo, Hervé Joël

2016-01-01

Sporulation is the most enduring survival strategy developed by several bacterial species. However, spore development of the model organism Bacillus subtilis has mainly been studied by means of media or conditions optimized for the induction of sporogenesis. Here, I show that during prolonged growth during stationary phase in minimal medium, B. subtilis undergoes an asymmetric cell division that produces small and round-shaped, DNA containing cells. In contrast to wild-type cells, mutants harboring spo0A or spoIIIE/sftA double mutations neither sporulate nor produce this special cell type, providing evidence that the small round cells emerge from the abortion of endospore formation. In most cases observed, the small round cells arise in the presence of sigma H but absence of sigma F activity, different from cases of abortive sporulation described for rich media. These data suggest that in minimal media, many cells are able to initiate but fail to complete spore development, and therefore return to normal growth as rods. This work reveals that the continuation of asymmetric cell division, which results in the formation of the small round cells, is a way for cells to delay or escape from—unsuccessful—sporulation. Based on these findings, I suggest to name the here described cell type as “dwarf cells” to distinguish them from the well-known minicells observed in mutants defective in septum placement or proper chromosome partitioning. PMID:27891124

Histopathology of human superficial herpes simplex keratitis.

PubMed Central

Maudgal, P. C.; Missotten, L.

1978-01-01

In vivo corneal replicas were made in 20 cases of patients with superficial dendritic ulcers of the cornea. Histopathological study of the replicas and superficial epithelial cells showed that the dendrites are composed of rounded epithelial cells and variable sized syncytia containing bizarre shaped nuclei. Pseudopodia-like processes containing DNA and some RNA extend from the syncytia into the surrounding epithelial cells, which on coming into contact with these processes become rounded and liquefied to give rise to another syncytium. The epithelial cells adjacent to the dendrite and elongated and usually orientated parallel to the long axis of the lesion. Surrounding the terminal bulbs, they are disposed in an arcuate fashion. These cells show C-mitotic lesions, intranuclear and cytoplasmic inclusion bodies, and polykaryocyte formation. Microscopic examination of the corneal replicas shows the intranuclear lesions and rounding of cells up to about 2 mm away from the dendritic ulcers. These areas appear normal on clinical examination. Images PMID:629910

CUB domain-containing protein 1 and the epidermal growth factor receptor cooperate to induce cell detachment.

PubMed

Law, Mary E; Ferreira, Renan B; Davis, Bradley J; Higgins, Paul J; Kim, Jae-Sung; Castellano, Ronald K; Chen, Sixue; Luesch, Hendrik; Law, Brian K

2016-08-05

While localized malignancies often respond to available therapies, most disseminated cancers are refractory. Novel approaches, therefore, are needed for the treatment of metastatic disease. CUB domain-containing protein1 (CDCP1) plays an important role in metastasis and drug resistance; the mechanism however, is poorly understood. Breast cancer cell lines were engineered to stably express EGFR, CDCP1 or phosphorylation site mutants of CDCP1. These cell lines were used for immunoblot analysis or affinity purification followed by immunoblot analysis to assess protein phosphorylation and/or protein complex formation with CDCP1. Kinase activity was evaluated using phosphorylation site-specific antibodies and immunoblot analysis in in vitro kinase assays. Protein band excision and mass spectrometry was utilized to further identify proteins complexed with CDCP1 or ΔCDCP1, which is a mimetic of the cleaved form of CDCP1. Cell detachment was assessed using cell counting. This paper reports that CDCP1 forms ternary protein complexes with Src and EGFR, facilitating Src activation and Src-dependent EGFR transactivation. Importantly, we have discovered that a class of compounds termed Disulfide bond Disrupting Agents (DDAs) blocks CDCP1/EGFR/Src ternary complex formation and downstream signaling. CDCP1 and EGFR cooperate to induce detachment of breast cancer cells from the substratum and to disrupt adherens junctions. Analysis of CDCP1-containing complexes using proteomics techniques reveals that CDCP1 associates with several proteins involved in cell adhesion, including adherens junction and desmosomal cadherins, and cytoskeletal elements. Together, these results suggest that CDCP1 may facilitate loss of adhesion by promoting activation of EGFR and Src at sites of cell-cell and cell-substratum contact.

Fungi that Infect Humans.

PubMed

Köhler, Julia R; Hube, Bernhard; Puccia, Rosana; Casadevall, Arturo; Perfect, John R

2017-06-01

Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and resistance to immune defenses, including elevated body temperatures. Morphogenesis between small round, detachable cells and long, connected cells is the mechanism by which fungi solve problems of locomotion around or through host barriers. Secretion of lytic enzymes, and uptake systems for the released nutrients, are necessary if a fungus is to nutritionally utilize human tissue. Last, the potent human immune system evolved in the interaction with potential fungal pathogens, so few fungi meet all four conditions for a healthy human host. Paradoxically, the advances of modern medicine have made millions of people newly susceptible to fungal infections by disrupting immune defenses. This article explores how different members of four fungal phyla use different strategies to fulfill the four criteria to infect humans: the Entomophthorales, the Mucorales, the Ascomycota, and the Basidiomycota. Unique traits confer human pathogenic potential on various important members of these phyla: pathogenic Onygenales comprising thermal dimorphs such as Histoplasma and Coccidioides ; the Cryptococcus spp. that infect immunocompromised as well as healthy humans; and important pathogens of immunocompromised patients- Candida , Pneumocystis , and Aspergillus spp. Also discussed are agents of neglected tropical diseases important in global health such as mycetoma and paracoccidiomycosis and common pathogens rarely implicated in serious illness such as dermatophytes. Commensalism is considered, as well as parasitism, in shaping genomes and physiological systems of hosts and fungi during evolution.

Astrocyte structural reactivity and plasticity in models of retinal detachment.

PubMed

Luna, Gabriel; Keeley, Patrick W; Reese, Benjamin E; Linberg, Kenneth A; Lewis, Geoffrey P; Fisher, Steven K

2016-09-01

Although retinal neurodegenerative conditions such as age-related macular degeneration, glaucoma, diabetic retinopathy, retinitis pigmentosa, and retinal detachment have different etiologies and pathological characteristics, they also have many responses in common at the cellular level, including neural and glial remodeling. Structural changes in Müller cells, the large radial glia of the retina in retinal disease and injury have been well described, that of the retinal astrocytes remains less so. Using modern imaging technology to describe the structural remodeling of retinal astrocytes after retinal detachment is the focus of this paper. We present both a review of critical literature as well as novel work focusing on the responses of astrocytes following rhegmatogenous and serous retinal detachment. The mouse presents a convenient model system in which to study astrocyte reactivity since the Mϋller cell response is muted in comparison to other species thereby allowing better visualization of the astrocytes. We also show data from rat, cat, squirrel, and human retina demonstrating similarities and differences across species. Our data from immunolabeling and dye-filling experiments demonstrate previously undescribed morphological characteristics of normal astrocytes and changes induced by detachment. Astrocytes not only upregulate GFAP, but structurally remodel, becoming increasingly irregular in appearance, and often penetrating deep into neural retina. Understanding these responses, their consequences, and what drives them may prove to be an important component in improving visual outcome in a variety of therapeutic situations. Our data further supports the concept that astrocytes are important players in the retina's overall response to injury and disease. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Isolation of dendritic-cell-like S100β-positive cells in rat anterior pituitary gland.

PubMed

Horiguchi, Kotaro; Fujiwara, Ken; Yoshida, Saishu; Higuchi, Masashi; Tsukada, Takehiro; Kanno, Naoko; Yashiro, Takashi; Tateno, Kozue; Osako, Shunji; Kato, Takako; Kato, Yukio

2014-07-01

S100β-protein-positive cells in the anterior pituitary gland appear to possess multifunctional properties. Because of their pleiotropic features, S100β-positive cells are assumed to be of a heterogeneous or even a non-pituitary origin. The observation of various markers has allowed these cells to be classified into populations such as stem/progenitor cells, epithelial cells, astrocytes and dendritic cells. The isolation and characterization of each heterogeneous population is a prerequisite for clarifying the functional character and origin of the cells. We attempt to isolate two of the subpopulations of S100β-positive cells from the anterior lobe. First, from transgenic rats that express green fluorescent protein (GFP) driven by the S100β protein promoter, we fractionate GFP-positive cells with a cell sorter and culture them so that they can interact with laminin, a component of the extracellular matrix. We observe that one morphological type of GFP-positive cells possesses extended cytoplasmic processes and shows high adhesiveness to laminin (process type), whereas the other is round in shape and exhibits low adherence to laminin (round type). We successfully isolate cells of the round type from the cultured GFP-positive cells by taking advantage of their low affinity to laminin and then measure mRNA levels of the two cell types by real-time polymerase chain reaction. The resultant data show that the process type expresses vimentin (mesenchymal cell marker) and glial fibrillary acidic protein (astrocyte marker). The round type expresses dendritic cell markers, CD11b and interleukin-6. Thus, we found a method for isolating dendritic-cell-like S100β-positive cells by means of their property of adhering to laminin.

Data of continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surfaces

PubMed Central

Yeh, Chin-Chen; Muduli, Saradaprasan; Peng, I-Chia; Lu, Yi-Tung; Ling, Qing-Dong; Alarfaj, Abdullah A.; Munusamy, Murugan A.; Kumar, S. Suresh; Murugan, Kadarkarai; Chen, Da-Chung; Lee, Hsin-chung; Chang, Yung; Higuchi, Akon

2016-01-01

This data article contains two figures and one table supporting the research article entitled: “Continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surface” [1]. The table shows coating conditions of three copolymers, poly(styrene-co-acrylic acid) grafted with oligovitronectin, poly(styrene-co-N-isopropylacrylamide) and poly(styrene-co-polyethylene glycol methacrylate) to prepare thermoresponsive surface. XPS spectra show the nitrogen peak of the polystyrene surface coated with poly(styrene-co-acrylic acid) grafted with oligovitronectin. The surface coating density analyzed from sorption of poly(styrene-co-acrylic acid) grafted with oligovitronectin by UV–vis spectroscopy is also presented. PMID:26909373

Blastocyst production after intracytoplasmic sperm injection with semen from a stallion with testicular degeneration.

PubMed

Roels, K; Smits, K; Ververs, C; Govaere, J; D'Herde, K; Van Soom, A

2018-06-01

In horse breeding, intracytoplasmic sperm injection (ICSI) has gained interest to obtain offspring from subfertile individuals. This paper presents a case report of a stallion with severe testicular degeneration. Semen analysis showed very low motility and 83.5% of detached heads. Histology of a testicular biopsy showed severely decreased spermatogenesis, while transmission electron microscopy of the sperm cells revealed no significant abnormalities. A total of 39 oocytes were fertilized by ICSI with frozen-thawed spermatozoa of this stallion: 25 oocytes with intact spermatozoa and 24 with detached heads. When using intact sperm cells, 8 out of the 25 oocytes cleaved, and 1 developed to the blastocyst stage 9 days after ICSI. None of the oocytes injected with a detached sperm head cleaved. Studies on the paternal influence on ICSI outcome are limited in the horse and further research is needed to define which stallion factors may influence ICSI results. Here, we report the possibility to produce a blastocyst by ICSI of a stallion suffering from testicular degeneration with a poor spermiogram, as long as an intact sperm cell containing a centriole is selected. © 2018 Blackwell Verlag GmbH.

In-vitro maturation of round spermatids using co-culture on Vero cells.

PubMed

Cremades, N; Bernabeu, R; Barros, A; Sousa, M

1999-05-01

In an attempt to determine whether co-culture could promote sperm maturation, three patients with non-obstructive azoospermia, two with maturation arrest at the level of primary spermatocytes and one patient with <1% tubules showing complete spermatogenesis, and one patient with total globozoospermia, gave consent to experimentally co-culture round spermatids retrieved from the testicle on Vero cell monolayers. In all azoospermic patients elongating spermatids could be obtained from round spermatids. In one case of maturation arrest, of 37 round spermatids co-cultured for up to 5 days, 30% developed flagella, 46% matured to elongating and 19% to elongated spermatids, with one mature spermatozoon also obtained (3%). In the same patient, primary cultures of three round spermatids with flagella enabled development of one further mature spermatozoon. In the case with total globozoospermia, of six round spermatids co-cultured for up to 5 days, one mature spermatozoon was obtained, with a flagellum and normal head morphology. These preliminary findings suggest that it may be possible to overcome the round spermatid block, and even the triggering of morphological abnormalities arising at the spermiogenic level, by in-vitro maturation under special environmental conditions.

Microbial cell surface characteristics: Elucidating attachment/detachment using hydrophobicity and electrokinetic measurements

EPA Science Inventory

The surface properties of microorganisms play an important role in their behavior within the environment. Electrophoretic mobility and cell surface hydrophobicity of bacterial cells influence their initial interaction with surfaces and mediate their stability within an aqueous su...

Results from an International Measurement Round Robin of III-V Triple Junction Solar Cells under Air Mass Zero

NASA Technical Reports Server (NTRS)

Jenkins, Phillip; Scheiman, Chris; Goodbody, Chris; Baur, Carsten; Sharps, Paul; Imaizumi, Mitsuru; Yoo, Henry; Sahlstrom, Ted; Walters, Robert; Lorentzen, Justin;

Desmoplastic small round cell tumor of the lung.

PubMed

Muramatsu, Takashi; Shimamura, Mie; Furuichi, Motohiko; Nishii, Tatsuhiko; Takeshita, Shinji; Shiono, Motomi

2010-12-01

We report a rare case of desmoplastic small round cell tumor, which arose from the left lung. A 25-year-old man was found to have an abnormal shadow during a routine physical examination and was admitted to our hospital. A thoracoscopic tumor biopsy was performed under general anesthesia. According to the histopathologic findings of permanent sections, the tumor was composed of sharply outlined nests, clusters, and trabeculae of small round to oval cells separated by a spindle-shaped desmoplastic stroma. A gene analysis revealed chimera genes of Ewing's sarcoma and Wilms' tumor by reverse transcription polymerase chain reaction. Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Superficial EWSR1-negative undifferentiated small round cell sarcoma with CIC/DUX4 gene fusion: a new variant of Ewing-like tumors with locoregional lymph node metastasis.

PubMed

Machado, Isidro; Cruz, Julia; Lavernia, Javier; Rubio, Luis; Campos, Jorge; Barrios, María; Grison, Camille; Chene, Virginie; Pierron, Gaelle; Delattre, Olivier; Llombart-Bosch, Antonio

2013-12-01

The present study describes a new case of EWSR1-negative undifferentiated sarcoma with CIC/DUX4 gene fusion. This case is similar to tumors described as primitive undifferentiated round cell sarcomas that occur mainly in the trunk and display an aggressive behavior. To our knowledge, this is the first report of such a tumor presenting locoregional lymph node metastasis. In view of previous studies that prove the existence of a particular variant of undifferentiated sarcoma with Ewing-like morphology and CIC/DUX-4 gene fusion, a search for this gene fusion in all undifferentiated round cell sarcomas should be considered if a conclusive diagnosis cannot be reached following other conventional studies. Although additional cases with more extensive follow-up studies are needed, we believe that EWSR1-negative undifferentiated small round cell sarcoma with CIC/DUX4 gene fusion should be added to the list of new sarcoma variants with the possibility of lymph node metastasis.

Significant partial response of metastatic intra-abdominal and pelvic round cell liposarcoma to a small-molecule VEGFR-2 tyrosine kinase inhibitor apatinib

PubMed Central

Dong, Min; Bi, Jingwang; Liu, Xiaohong; Wang, Baocheng; Wang, Jun

2016-01-01

Abstract Introduction: Myxoid/round cell liposarcoma is the second most common subtype of liposarcoma. Chemotherapy and radiotherapy have a limited efficacy for treating advanced myxoid/round cell liposarcoma, with relatively serious side effects. Case presentation: We herein present a 68-year-old Chinese woman initially diagnosed with advanced multiple intra-abdominal and pelvic round cell liposarcoma. She refused to receive cytotoxic chemotherapy and received apatinib as the first-line therapy, a novel tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 that has been used in the treatment of patients with metastatic gastric cancer who progressed with 2 or more chemotherapy regimens. This patient was partially responsive to apatinib with a dose of 500 mg daily. No serious drug-related side effects were observed. Conclusion: Our findings indicate that some cases of liposarcoma may be responsive to antiangiogenic agent apatinib. Randomized clinical studies are needed to further confirm the efficacy and safety of apatinib in the clinical treatment of liposarcoma. PMID:27495042

Influence of Deposition Pressure on the Properties of Round Pyramid Textured a-Si:H Solar Cells for Maglev.

PubMed

Lee, Jaehyeong; Choi, Wonseok; Lee, Kyuil; Lee, Daedong; Kang, Hyunil

2016-05-01

HIT (Heterojunction with Intrinsic Thin-layer) photovoltaic cells is one of the highest efficiencies in the commercial solar cells. The pyramid texturization for reducing surface reflectance of HIT solar cells silicon wafers is widely used. For the low leakage current and high shunt of solar cells, the intrinsic amorphous silicon (a-Si:H) on substrate must be uniformly thick of pyramid structure. However, it is difficult to control the thickness in the traditional pyramid texturing process. Thus, we textured the intrinsic a-Si:H thin films with the round pyramidal structure by using HNO3, HF, and CH3COOH solution. The characteristics of round pyramid a-Si:H solar cells deposited at pressure of 500, 1000, 1500, and 2000 mTorr by PECVD (Plasma Enhanced Chemical Vapor Deposition) was investigated. The lifetime, open circuit voltage, fill factor and efficiency of a-Si:H solar cells were investigated with respect to various deposition pressure.

Microphysical modeling of Titan's detached haze layer in a 3D GCM

NASA Astrophysics Data System (ADS)

Larson, Erik J. L.; Toon, Owen B.; West, Robert A.; Friedson, A. James

2015-07-01

We use a 3D GCM with coupled aerosol microphysics to investigate the formation and seasonal cycle of the detached haze layer in Titan's upper atmosphere. The base of the detached haze layer is defined by a local minimum in the vertical extinction profile. The detached haze is seen at all latitudes including the south pole as seen in Cassini images from 2005-2012. The layer merges into the winter polar haze at high latitudes where the Hadley circulation carries the particles downward. The hemisphere in which the haze merges with the polar haze varies with season. We find that the base of the detached haze layer occurs where there is a near balance between vertical winds and particle fall velocities. Generally the vertical variation of particle concentration in the detached haze region is simply controlled by sedimentation, so the concentration and the extinction vary roughly in proportion to air density. This variation explains why the upper part of the main haze layer, and the bulk of the detached haze layer follow exponential profiles. However, the shape of the profile is modified in regions where the vertical wind velocity is comparable to the particle fall velocity. Our simulations closely match the period when the base of the detached layer in the tropics is observed to begin its seasonal drop in altitude, and the total range of the altitude drop. However, the simulations have the base of the detached layer about 100 km lower than observed, and the time for the base to descend is slower in the simulations than observed. These differences may point to the model having somewhat lower vertical winds than occur on Titan, or somewhat too large of particle sizes, or some combination of both. Our model is consistent with a dynamical origin for the detached haze rather than a chemical or microphysical one. This balance between the vertical wind and particle fall velocities occurs throughout the summer hemisphere and tropics. The particle concentration gradients that are established in the summer hemisphere are transported to the winter hemisphere by meridional winds from the overturning Hadley cell. Our model is consistent with the disappearance of the detached haze layer in early 2014. Our simulations predict the detached haze and gap will reemerge at its original high altitude between mid 2014 and early 2015.

Plasmodium falciparum CRK4 directs continuous rounds of DNA replication during schizogony.

PubMed

Ganter, Markus; Goldberg, Jonathan M; Dvorin, Jeffrey D; Paulo, Joao A; King, Jonas G; Tripathi, Abhai K; Paul, Aditya S; Yang, Jing; Coppens, Isabelle; Jiang, Rays H Y; Elsworth, Brendan; Baker, David A; Dinglasan, Rhoel R; Gygi, Steven P; Duraisingh, Manoj T

2017-02-17

Plasmodium parasites, the causative agents of malaria, have evolved a unique cell division cycle in the clinically relevant asexual blood stage of infection 1 . DNA replication commences approximately halfway through the intracellular development following invasion and parasite growth. The schizont stage is associated with multiple rounds of DNA replication and nuclear division without cytokinesis, resulting in a multinucleated cell. Nuclei divide asynchronously through schizogony, with only the final round of DNA replication and segregation being synchronous and coordinated with daughter cell assembly 2,3 . However, the control mechanisms for this divergent mode of replication are unknown. Here, we show that the Plasmodium-specific kinase PfCRK4 is a key cell-cycle regulator that orchestrates multiple rounds of DNA replication throughout schizogony in Plasmodium falciparum. PfCRK4 depletion led to a complete block in nuclear division and profoundly inhibited DNA replication. Quantitative phosphoproteomic profiling identified a set of PfCRK4-regulated phosphoproteins with greatest functional similarity to CDK2 substrates, particularly proteins involved in the origin of replication firing. PfCRK4 was required for initial and subsequent rounds of DNA replication during schizogony and, in addition, was essential for development in the mosquito vector. Our results identified an essential S-phase promoting factor of the unconventional P. falciparum cell cycle. PfCRK4 is required for both a prolonged period of the intraerythrocytic stage of Plasmodium infection, as well as for transmission, revealing a broad window for PfCRK4-targeted chemotherapeutics.

PHOX2B reliably distinguishes neuroblastoma among small round blue cell tumours.

PubMed

Hung, Yin P; Lee, John P; Bellizzi, Andrew M; Hornick, Jason L

2017-11-01

Neuroblastoma shows considerable histological overlap with other small round blue cell tumours. PHOX2B, a transcription factor that is essential for autonomic nervous system development, has been reported as an immunohistochemical marker for neuroblastoma. The aim of this study was to validate the specificity and diagnostic utility of PHOX2B for peripheral neuroblastic tumours. We evaluated 240 cases (133 in whole-tissue sections; 107 in tissue microarrays), including 76 peripheral neuroblastic tumours (median age 2 years; including four adults) and 164 other tumours: 44 Wilms tumours; 20 Ewing sarcomas; 10 each of CIC-rearranged round cell sarcomas, poorly differentiated synovial sarcomas, lymphoblastic lymphomas, alveolar rhabdomyosarcomas, embryonal rhabdomyosarcomas, mesenchymal chondrosarcomas, Merkel cell carcinomas, olfactory neuroblastomas, and melanomas; and five each of NUT midline carcinomas and desmoplastic small round cell tumours. Immunohistochemistry for PHOX2B was performed with a rabbit monoclonal antibody. PHOX2B positivity was defined as the presence of nuclear immunoreactivity in ≥5% of cells. PHOX2B was positive in 70 (92%) peripheral neuroblastic tumours, including 68 of 72 (94%) paediatric and two of four (50%) adult cases. Furthermore, PHOX2B was consistently negative in all non-peripheral neuroblastic tumours, with staining being absent in 160 cases and limited in four cases. PHOX2B is a highly sensitive and specific immunohistochemical marker for peripheral neuroblastic tumours, including neuroblastoma. PHOX2B reliably distinguishes neuroblastoma from histological mimics such as Wilms tumour, Ewing sarcoma, and CIC-rearranged round cell sarcoma. PHOX2B negativity in two of four adult neuroblastoma cases raises the possibility that some adult neuroblastomas are of a different lineage than paediatric cases. © 2017 John Wiley & Sons Ltd.

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

PubMed

Hasegawa, Tomoka; Li, Minqi; Hara, Kuniko; Sasaki, Muneteru; Tabata, Chihiro; de Freitas, Paulo Henrique Luiz; Hongo, Hiromi; Suzuki, Reiko; Kobayashi, Masatoshi; Inoue, Kiichiro; Yamamoto, Tsuneyuki; Oohata, Noboru; Oda, Kimimitsu; Akiyama, Yasuhiro; Amizuka, Norio

2011-08-01

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Kidney and bladder calculi in spontaneously hypertensive rats.

PubMed Central

Wexler, B. C.; McMurtry, J. P.

1981-01-01

Naturally occurring kidney stones are rare in animals. The Japanese strains of spontaneously hypertensive rats (SHR) are normotensive at birth but develop high blood pressure, hyperglycaemia and hyperlipidaemia as they mature. The SHR strain is prone to develop kidney stones. A unique sub-strain of SHR has been developed in which some animals develop hypothalamic obesity concomitantly with their rising blood pressure, i.e. Obese/SHR. The Obese/SHR characteristically develop microscopic kidney stones which become detached at an early stage of formation, migrate to the bladder, and grow by concretion into huge, rounded calculi. The stone nidus starts as a subepithelial cyst-like focus containing oedema, colloidal acidic mucoprotein, and red and white blood cells suspended on a delicate network of fibrils. THe nidi grow by concretion of an admixture of calcium and acidic protein in a lamellar arrangement. The disparate morphogenesis and anatomic location of kidney stones in Obese is opposed to non-obese/SHR suggest that calculus formation may be governed by specific differences in genetic programming. The incidence of kidney stones parallels the severity and chronicity of the hypertension in SHR, non-obese and Obese/SHR, and the Cushingoid habitus in the Obese/SHR. Images Fig. 1 Fig. 3 Fig. 2 Fig. 4 Fig. 5 Fig. 6 PMID:7295530

Inhibition of Late and Early Phases of Cancer Metastasis by the NF-κB Inhibitor DHMEQ Derived from Microbial Bioactive Metabolite Epoxyquinomicin: A Review.

PubMed

Lin, Yinzhi; Ukaji, Tamami; Koide, Naoki; Umezawa, Kazuo

2018-03-03

We previously designed and synthesized dehydroxyepoxyquinomicin (DHMEQ) as an inhibitor of NF-κB based on the structure of microbial secondary metabolite epoxyquinomicin C. DHMEQ showed anti-inflammatory and anticancer activity in various in vivo disease models without toxicity. On the other hand, the process of cancer metastasis consists of cell detachment from the primary tumor, invasion, transportation by blood or lymphatic vessels, invasion, attachment, and formation of secondary tumor. Cell detachment from the primary tumor and subsequent invasion are considered to be early phases of metastasis, while tumor cell attachment to the tissue and secondary tumor formation the late phases. The assay system for the latter phase was set up with intra-portal-vein injection of pancreatic cancer cells. Intraperitoneal administration of DHMEQ was found to inhibit liver metastasis possibly by decreasing the expression of MMP-9 and IL-8. Also, when the pancreatic cancer cells treated with DHMEQ were inoculated into the peritoneal cavity of mice, the metastatic foci formation was inhibited. These results indicate that DHMEQ is likely to inhibit the late phase of metastasis. Meanwhile, we have recently employed three-dimensional (3D) culture of breast cancer cells for the model of early phase metastasis, since the 3D invasion just includes cell detachment and invasion into the matrix. DHMEQ inhibited the 3D invasion of breast cancer cells at 3D-nontoxic concentrations. In this way, DHMEQ was shown to inhibit the late and early phases of metastasis. Thus, DHMEQ is likely to be useful for the suppression of cancer metastasis.

Directing Stem Cell Differentiation via Electrochemical Reversible Switching between Nanotubes and Nanotips of Polypyrrole Array.

PubMed

Wei, Yan; Mo, Xiaoju; Zhang, Pengchao; Li, Yingying; Liao, Jingwen; Li, Yongjun; Zhang, Jinxing; Ning, Chengyun; Wang, Shutao; Deng, Xuliang; Jiang, Lei

2017-06-27

Control of stem cell behaviors at solid biointerfaces is critical for stem-cell-based regeneration and generally achieved by engineering chemical composition, topography, and stiffness. However, the influence of dynamic stimuli at the nanoscale from solid biointerfaces on stem cell fate remains unclear. Herein, we show that electrochemical switching of a polypyrrole (Ppy) array between nanotubes and nanotips can alter surface adhesion, which can strongly influence mechanotransduction activation and guide differentiation of mesenchymal stem cells (MSCs). The Ppy array, prepared via template-free electrochemical polymerization, can be reversibly switched between highly adhesive hydrophobic nanotubes and poorly adhesive hydrophilic nanotips through an electrochemical oxidation/reduction process, resulting in dynamic attachment and detachment to MSCs at the nanoscale. Multicyclic attachment/detachment of the Ppy array to MSCs can activate intracellular mechanotransduction and osteogenic differentiation independent of surface stiffness and chemical induction. This smart surface, permitting transduction of nanoscaled dynamic physical inputs into biological outputs, provides an alternative to classical cell culture substrates for regulating stem cell fate commitment. This study represents a general strategy to explore nanoscaled interactions between stem cells and stimuli-responsive surfaces.

A Case of Desmoplastic Small Round Cell Tumor.

PubMed

Reisner, David; Brahee, Deborah; Patel, Shweta; Hartman, Matthew

2015-08-01

Desmoplastic small round cell tumor is a rare, aggressive tumor primarily affecting young males. It is considered a childhood cancer, and is characterized by a unique chromosomal translocation which leads to failure to suppress tumor growth. It is classified as a soft tissue sarcoma, sharing some features with other small round cell tumors such as Ewing's Sarcoma and primitive neuroectodermal tumor. Typical imaging findings include multiple heterogeneous, lobular abdominal masses, which can grow very large. Often there is a dominant mass with additional peritoneal, omental, retroperitoneal and retrovesical masses. Prognosis is relatively poor with a 3 year survival rate of 50% in those treated aggressively with surgical resection, chemotherapy, and radiation therapy. The clinical presentation, imaging characteristics and pathology are discussed in regards to a recent case.

Fundus autofluorescence findings in a mouse model of retinal detachment.

PubMed

Secondi, Roberta; Kong, Jian; Blonska, Anna M; Staurenghi, Giovanni; Sparrow, Janet R

2012-08-07

Fundus autofluorescence (fundus AF) changes were monitored in a mouse model of retinal detachment (RD). RD was induced by transscleral injection of hyaluronic acid (Healon) or sterile balanced salt solution (BSS) into the subretinal space of 4-5-day-old albino Abca4 null mutant and Abca4 wild-type mice. Images acquired by confocal scanning laser ophthalmoscopy (Spectralis HRA) were correlated with spectral domain optical coherence tomography (SD-OCT), infrared reflectance (IR), fluorescence spectroscopy, and histologic analysis. Results. In the area of detached retina, multiple hyperreflective spots in IR images corresponded to punctate areas of intense autofluorescence visible in fundus AF mode. The puncta exhibited changes in fluorescence intensity with time. SD-OCT disclosed undulations of the neural retina and hyperreflectivity of the photoreceptor layer that likely corresponded to histologically visible photoreceptor cell rosettes. Fluorescence emission spectra generated using flat-mounted retina, and 488 and 561 nm excitation, were similar to that of RPE lipofuscin. With increased excitation wavelength, the emission maximum shifted towards longer wavelengths, a characteristic typical of fundus autofluorescence. In detached retinas, hyper-autofluorescent spots appeared to originate from photoreceptor outer segments that were arranged within retinal folds and rosettes. Consistent with this interpretation is the finding that the autofluorescence was spectroscopically similar to the bisretinoids that constitute RPE lipofuscin. Under the conditions of a RD, abnormal autofluorescence may arise from excessive production of bisretinoid by impaired photoreceptor cells.

Photoreceptor cell death and rescue in retinal detachment and degenerations

PubMed Central

Murakami, Yusuke; Notomi, Shoji; Hisatomi, Toshio; Nakazawa, Toru; Ishibashi, Tatsuro; Miller, Joan W.; Vavvas, Demetrios G.

2013-01-01

Photoreceptor cell death is the ultimate cause of vision loss in various retinal disorders, including retinal detachment (RD). Photoreceptor cell death has been thought to occur mainly through apoptosis, which is the most characterized form of programmed cell death. The caspase family of cysteine proteases plays a central role for inducing apoptosis, and in experimental models of RD, dying photoreceptor cells exhibit caspase activation; however, there is a paradox that caspase inhibition alone does not provide a sufficient protection against photoreceptor cell loss, suggesting that other mechanisms of cell death are involved. Recent accumulating evidence demonstrates that non-apoptotic forms of cell death, such as autophagy and necrosis, are also regulated by specific molecular machinery, such as those mediated by autophagy-related proteins and receptor-interacting protein kinases, respectively. Here we summarize the current knowledge of cell death signaling and its roles in photoreceptor cell death after RD and other retinal degenerative diseases. A body of studies indicate that not only apoptotic but also autophagic and necrotic signaling are involved in photoreceptor cell death, and that combined targeting of these pathways may be an effective neuroprotective strategy for retinal diseases associated with photoreceptor cell loss. PMID:23994436

Edaravone, an ROS Scavenger, Ameliorates Photoreceptor Cell Death after Experimental Retinal Detachment

PubMed Central

Roh, Mi In; Murakami, Yusuke; Thanos, Aristomenis; Miller, Joan W.

2011-01-01

Purpose. To investigate whether edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one), a free radical scavenger, would be neuroprotective against photoreceptor cell death in a rat model of retinal detachment (RD). Methods. RD was induced in adult Brown Norway rats by subretinal injection of sodium hyaluronate. Edaravone (3, 5, or 10 mg/kg) or physiologic saline was administered intraperitoneally once a day until death on day 3 or 5. Oxidative stress in the retina was assessed by 4-hydroxynonenal staining or ELISA for protein carbonyl content. Photoreceptor death was assessed by TUNEL and measurement of the outer nuclear layer thickness. Western blot analysis and caspase activity assays were performed. Inflammatory cytokine secretion and inflammatory cell infiltration were evaluated by ELISA and immunostaining, respectively. Results. RD resulted in increased generation of ROS. Treatment with 5 mg/kg edaravone significantly reduced the ROS level, along with a decrease in TUNEL-positive cells in the photoreceptor layer. A caspase assay also confirmed decreased activation of caspase-3, -8, and -9 in RD treated with edaravone. The level of the antiapoptotic Bcl-2 was increased in detached retinas after edaravone treatment, whereas the levels of the stress-activated p-ERK1/2 were decreased. In addition, edaravone treatment resulted in a significant decrease in the levels of TNF-α, MCP-1, and macrophage infiltration. Conclusions. Oxidative stress plays an important role in photoreceptor cell death after RD. Edaravone treatment may aid in preventing photoreceptor cell death after RD by suppressing ROS-induced photoreceptor damage. PMID:21310909

Detachable glass microelectrodes for recording action potentials in active moving organs.

PubMed

Barbic, Mladen; Moreno, Angel; Harris, Tim D; Kay, Matthew W

2017-06-01

Here, we describe new detachable floating glass micropipette electrode devices that provide targeted action potential recordings in active moving organs without requiring constant mechanical constraint or pharmacological inhibition of tissue motion. The technology is based on the concept of a glass micropipette electrode that is held firmly during cell targeting and intracellular insertion, after which a 100-µg glass microelectrode, a "microdevice," is gently released to remain within the moving organ. The microdevices provide long-term recordings of action potentials, even during millimeter-scale movement of tissue in which the device is embedded. We demonstrate two different glass micropipette electrode holding and detachment designs appropriate for the heart (sharp glass microdevices for cardiac myocytes in rats, guinea pigs, and humans) and the brain (patch glass microdevices for neurons in rats). We explain how microdevices enable measurements of multiple cells within a moving organ that are typically difficult with other technologies. Using sharp microdevices, action potential duration was monitored continuously for 15 min in unconstrained perfused hearts during global ischemia-reperfusion, providing beat-to-beat measurements of changes in action potential duration. Action potentials from neurons in the hippocampus of anesthetized rats were measured with patch microdevices, which provided stable base potentials during long-term recordings. Our results demonstrate that detachable microdevices are an elegant and robust tool to record electrical activity with high temporal resolution and cellular level localization without disturbing the physiological working conditions of the organ. NEW & NOTEWORTHY Cellular action potential measurements within tissue using glass micropipette electrodes usually require tissue immobilization, potentially influencing the physiological relevance of the measurement. Here, we addressed this limitation with novel 100-µg detachable glass microelectrodes that can be precisely positioned to provide long-term measurements of action potential duration during unconstrained tissue movement. Copyright © 2017 the American Physiological Society.

Epithelial tricellular junctions act as interphase cell shape sensors to orient mitosis

PubMed Central

Bosveld, Floris; Markova, Olga; Guirao, Boris; Martin, Charlotte; Wang, Zhimin; Pierre, Anaëlle; Balakireva, Maria; Gaugue, Isabelle; Ainslie, Anna; Christophorou, Nicolas; Lubensky, David K.; Minc, Nicolas; Bellaïche, Yohanns

2017-01-01

The orientation of cell division along the interphase cell long-axis, the century old Hertwig’s rule, has profound roles in tissue proliferation, morphogenesis, architecture and mechanics1,2. In epithelial tissues, the shape of the interphase cell is influenced by cell adhesion, mechanical stress, neighbour topology, and planar polarity pathways3–12. At mitosis, epithelial cells usually round up to ensure faithful chromosome segregation and to promote morphogenesis1. The mechanisms underlying interphase cell shape sensing in tissues are therefore unknown. We found that in Drosophila epithelia, tricellular junctions (TCJ) localize microtubule force generators, orienting cell division via the Dynein associated protein Mud independently of the classical Pins/Gαi pathway. Moreover, as cells round up during mitosis, TCJs serve as spatial landmarks, encoding information about interphase cell shape anisotropy to orient division in the rounded mitotic cell. Finally, experimental and simulation data show that shape and mechanical strain sensing by the TCJ emerge from a general geometric property of TCJ distributions in epithelial tissues. Thus, in addition to their function as epithelial barrier structures, TCJs serve as polarity cues promoting geometry and mechanical sensing in epithelial tissues. PMID:26886796

Clinicopathologic Diversity of Undifferentiated Sarcoma With BCOR-CCNB3 Fusion: Analysis of 11 Cases With a Reappraisal of the Utility of Immunohistochemistry for BCOR and CCNB3.

PubMed

Matsuyama, Atsuji; Shiba, Eisuke; Umekita, Yoshihisa; Nosaka, Kanae; Kamio, Takihiro; Yanai, Hiroyuki; Miyasaka, Chika; Watanabe, Reiko; Ito, Ichiro; Tamaki, Tomoko; Hayashi, Shinichi; Hisaoka, Masanori

2017-12-01

Undifferentiated sarcoma harboring the BCOR-CCNB3 fusion is characterized by its predilection to affect skeletons of adolescent males, cellular small round/spindle cell morphology, and CCNB3 immunoreactivity. We analyzed 11 cases of BCOR-CCNB3 sarcoma, 10 of which were identified in a reverse transcription-polymerase chain reaction-based screen of 85 patient samples recorded in our database as unclassified small round or spindle cell sarcomas. BCOR rearrangements were confirmed by fluorescence in situ hybridization in 8 tumors. All patients were males aged between 6 and 31 years. In addition to 5 tumors in soft tissue and 4 in the axial or appendicular skeletons, which are typical locations, a tumor was located in the paranasal sinus and another in the lung. Microscopically, the tumors comprised proliferating atypical spindle and/or small round cells with diverse morphologic features such as small concentric whorls, myxoid stroma, a hemangiopericytomatous appearance, and/or hyalinized collagen resembling a solitary fibrous tumor, and angiomatous or slit-like spaces containing extravasated erythrocytes. Tumor cells were immunoreactive to CCNB3 (9/11), BCOR (10/10), TLE1 (6/10), bcl-2 (9/11), CD99 (8/10), CD56 (8/10), c-kit (4/10), and cyclin D1 (10/10). In an immunohistochemical analysis of an additional 412 small round or spindle cell tumors, CCNB3 was detected in 6 (1.5%) and BCOR in 18 (4.4%). Our analysis highlights the varying clinicopathologic features of this tumor, which partially overlap with other small round or spindle cell tumors, including solitary fibrous tumor and vascular tumors. Because CCNB3 and BCOR immunohistochemistry lacks adequate sensitivity and specificity, a molecular genetic approach remains essential for diagnosis.

Microphysical Modeling of Titan's Detached Haze Layer in a 3D GCM

NASA Astrophysics Data System (ADS)

Larson, Erik J.; Toon, Owen B.; West, Robert A.; Friedson, A. James

2015-11-01

We investigate the formation and seasonal cycle of the detached haze layer in Titan’s upper atmosphere using a 3D GCM with coupled aerosol microphysics. The base of the detached haze layer is defined by a local minimum in the vertical extinction profile. The detached haze is seen at all latitudes including the south pole as seen in Cassini images from 2005-2012. The layer merges into the winter polar haze at high latitudes where the Hadley circulation carries the particles downward. The hemisphere in which the haze merges with the polar haze varies with season. We find that the base of the detached haze layer occurs where there is a near balance between vertical winds and particle fall velocities. Generally the vertical variation of particle concentration in the detached haze region is simply controlled by sedimentation, so the concentration and the extinction vary roughly in proportion to air density. This variation explains why the upper part of the main haze layer, and the bulk of the detached haze layer follow exponential profiles. However, the shape of the profile is modified in regions where the vertical wind velocity is comparable to the particle fall velocity. Our simulations closely match the period when the base of the detached layer in the tropics is observed to begin its seasonal drop in altitude, and the total range of the altitude drop. However, the simulations have the base of the detached layer about 100 km lower than observed, and the time for the base to descend is slower in the simulations than observed. These differences may point to the model having somewhat lower vertical winds than occur on Titan, or somewhat too large of particle sizes, or some combination of both. Our model is consistent with a dynamical origin for the detached haze rather than a chemical or microphysical one. This balance between the vertical wind and particle fall velocities occurs throughout the summer hemisphere and tropics. The particle concentration gradients that are established in the summer hemisphere are transported to the winter hemisphere by meridional winds from the overturning Hadley cell. Our model is consistent with the disappearance of the detached haze layer in early 2014.

Interobserver variation in CD30 immunohistochemistry interpretation; consequences for patient selection for targeted treatment.

PubMed

Koens, Lianne; van de Ven, Peter M; Hijmering, Nathalie J; Kersten, Marie José; Diepstra, Arjan; Chamuleau, Martine; de Jong, Daphne

2018-05-14

CD30 immunohistochemistry (IHC) in malignant lymphoma is used for selection of patients in clinical trials using brentuximab vedotin, an antibody drug-conjugate targeting the CD30 molecule. For reliable implementation in daily practice and meaningful selection of patients for clinical trials, information on technical variation and interobserver reproducibility of CD30 IHC staining is required. We conducted a 3-round reproducibility assessment of CD30 scoring for categorized frequency and intensity, including a technical validation, a "live polling" pre- and post-instruction scoring round, and a web-based round including individual scoring with additional IHC information to mimic daily diagnostic practice. Agreement in all three scoring rounds was poor to fair (κ=0,12 to 0,35 for CD30 positive tumor cell percentage, and κ=0,16 to 0,41 for staining intensity), even when allowing for one category of freedom in percentage of tumor cell positivity (κ=0,30 to 0,61). The first round with CD30 staining performed in 5 independent laboratories showed objective differences in staining intensity. In the second round, about half of the pathologists changed their opinion on CD30 frequency after a discussion on potential pitfalls, highlighting hesitancy in decision-making. Using fictional cut-off points for percentage of tumor cell positivity, agreement was still suboptimal (κ=0,35 to 0,60). Lack of agreement in cases with heterogeneous expression is shown to influence patient eligibility for treatment with brentuximab vedotin both in clinical practice and within the context of clinical trials, and limits the potential predictive value of the relative frequency of CD30 positive neoplastic cells for clinical response. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Tetraspanin CD151 regulates alpha6beta1 integrin adhesion strengthening

NASA Technical Reports Server (NTRS)

Lammerding, Jan; Kazarov, Alexander R.; Huang, Hayden; Lee, Richard T.; Hemler, Martin E.

2003-01-01

The tetraspanin CD151 molecule associates specifically with laminin-binding integrins, including alpha6beta1. To probe strength of alpha6beta1-dependent adhesion to laminin-1, defined forces (0-1.5 nN) were applied to magnetic laminin-coated microbeads bound to NIH 3T3 cells. For NIH 3T3 cells bearing wild-type CD151, adhesion strengthening was observed, as bead detachment became more difficult over time. In contrast, mutant CD151 (with the C-terminal region replaced) showed impaired adhesion strengthening. Static cell adhesion to laminin-1, and detachment of beads coated with fibronectin or anti-alpha6 antibody were all unaffected by CD151 mutation. Hence, CD151 plays a key role in selectively strengthening alpha6beta1 integrin-mediated adhesion to laminin-1.

International round-robin inter-comparison of dye-sensitized and crystalline silicon solar cells

NASA Astrophysics Data System (ADS)

Chen, Chia-Yuan; Ahn, Seung Kyu; Aoki, Dasiuke; Kokubo, Junichi; Yoon, Kyung Hoon; Saito, Hidenori; Lee, Kyung Sik; Magaino, Shinichi; Takagi, Katsuhiko; Lin, Ling-Chuan; Lee, Kun-Mu; Wu, Chun-Guey; Zhou, Hong; Igari, Sanekazu

2017-02-01

An international round-robin inter-comparison of the spectral responsivity (SR) and current-voltage (I-V) characteristics for dye-sensitized solar cells (DSCs) and crystalline silicon solar cells is reported for the first time. The crystalline silicon cells with various spectral responsivities were also calibrated by AIST to validate this round-robin activity. On the basis of the remarkable consistency in Pmax (within ±1.4% among participants) and Isc (within ±1.2% compared to the primary calibration of AIST) of the silicon specimens, the discrepancy in the SR and photovoltaic parameters of five DSCs among three national laboratories can be verified and diagnosed. Recommendations about sample packages, SR and I-V measurement methods as well as the inter-comparison protocol for improving the performance characterization of the mesoscopic DSCs are presented according to the consolidated data and the experience of the participants.

Design of a stateless low-latency router architecture for green software-defined networking

NASA Astrophysics Data System (ADS)

Saldaña Cercós, Silvia; Ramos, Ramon M.; Ewald Eller, Ana C.; Martinello, Magnos; Ribeiro, Moisés. R. N.; Manolova Fagertun, Anna; Tafur Monroy, Idelfonso

2015-01-01

Expanding software defined networking (SDN) to transport networks requires new strategies to deal with the large number of flows that future core networks will have to face. New south-bound protocols within SDN have been proposed to benefit from having control plane detached from the data plane offering a cost- and energy-efficient forwarding engine. This paper presents an overview of a new approach named KeyFlow to simultaneously reduce latency, jitter, and power consumption in core network nodes. Results on an emulation platform indicate that round trip time (RTT) can be reduced above 50% compared to the reference protocol OpenFlow, specially when flow tables are densely populated. Jitter reduction has been demonstrated experimentally on a NetFPGA-based platform, and 57.3% power consumption reduction has been achieved.

A GXXXA motif in the transmembrane domain of the Ebola virus glycoprotein is required for tetherin antagonism.

PubMed

González-Hernández, Mariana; Hoffmann, Markus; Brinkmann, Constantin; Nehls, Julia; Winkler, Michael; Schindler, Michael; Pöhlmann, Stefan

2018-04-18

The interferon-induced antiviral host cell protein tetherin can inhibit the release of several enveloped viruses from infected cells. The Ebola virus (EBOV) glycoprotein (GP) antagonizes tetherin but the domains and amino acids in GP that are required for tetherin antagonism have not been fully defined. A GXXXA motif within the transmembrane domain (TMD) of EBOV-GP was previously shown to be important for GP-mediated cellular detachment. Here, we investigated whether this motif also contributes to tetherin antagonism. Mutation of the GXXXA motif did not impact GP expression or particle incorporation and only modestly reduced EBOV-GP-driven entry. In contrast, the GXXXA motif was required for tetherin antagonism in transfected cells. Moreover, alteration of the GXXXA motif increased tetherin-sensitivity of a replication-competent vesicular stomatitis virus (VSV) chimera encoding EBOV-GP. Although these results await confirmation with authentic EBOV, they indicate that a GXXXA motif in the TMD of EBOV-GP is important for tetherin antagonism. Moreover, they provide the first evidence that GP can antagonize tetherin in the context of an infectious EBOV surrogate. IMPORTANCE The glycoprotein (GP) of Ebola virus (EBOV) inhibits the antiviral host cell protein tetherin and may promote viral spread in tetherin-positive cells. However, tetherin antagonism by GP has so far only been demonstrated using virus-like particles and it is unknown whether GP can block tetherin in infected cells. Moreover, a mutation in GP that selectively abrogates tetherin antagonism is unknown. Here, we show that a GXXXA motif in the transmembrane domain of EBOV-GP, which was previously reported to be required for GP-mediated cell rounding, is also important for tetherin counteraction. Moreover, analysis of this mutation in the context of vesicular stomatitis virus chimeras encoding EBOV-GP revealed that GP-mediated tetherin counteraction is operative in infected cells. To our knowledge, these findings demonstrate for the first time that GP can antagonize tetherin in infected cells and provide a tool to study the impact of GP-dependent tetherin counteraction on EBOV spread. Copyright © 2018 American Society for Microbiology.

Merkel Cell Carcinoma Metastatic to Pleural Fluid: A Case Report.

PubMed

Rhee, Ye-Young; Kim, Soo Hee; Kim, Eun Kyung; Kim, Se Hoon

2018-05-01

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine carcinoma of the skin that shows locoregional or distant metastasis. Metastasis of MCC to body cavity effusion is extremely rare; only three cases have been reported so far. Metastatic MCC in effusion cytology shows small blue round cells with fine stippled chromatin like other small blue round cell tumors such as small cell lung carcinoma or lymphoma. The diagnosis of metastatic MCC can grant patients good chances at recently advanced therapeutic options. Here, we present a case of metastatic MCC to pleural effusion with characteristic single file-like pattern.

Developmental potential of elongating and elongated spermatids obtained after in-vitro maturation of isolated round spermatids.

PubMed

Cremades, N; Sousa, M; Bernabeu, R; Barros, A

2001-09-01

Round spermatid injections are associated with disappointing clinical outcomes, and although these cells have been shown to mature into late spermatids in vitro, the developmental potential of such gametes remains to be demonstrated. Round spermatids were isolated from 12 testicle samples of patients with obstructive azoospermia, hypoplasia, complete maturation arrest, and incomplete Sertoli cell-only syndrome. They were cultured for 7 days at 32 degrees C, 5% CO(2)in air, in microdrops of Vero cell-conditioned medium containing 10% synthetic serum substitute. From the 238 round spermatids cultured, 25.2% attained the elongating and 5.5% the elongated spermatid stage (3-4 days per step). Relatively higher maturation rates were found in cases with obstructive azoospermia, but differences were significant only for elongated spermatids (9.3%). No differences were found in maturation rates between cases with non-obstructive azoospermia (4.3% of elongated spermatids). Experimental microinjections with elongating and elongated spermatids revealed a low fertilization rate (40.9%) but a normal blastocyst formation rate (60%). Late spermatids resulting from in-vitro culture of round spermatids in conditioned medium, either in controls in cases with a spermiogenetic block, appeared able to successfully fertilize the human oocyte and elicit normal embryo development.

Diagnosis of Retrobulbar Round Cell Neoplasia in a Macaroni Penguin ( Eudyptes chrysolophus ) Through Use of Computed Tomography.

PubMed

Woodhouse, Sarah J; Rose, Michelle; Desjardins, Danielle R; Agnew, Dalen W

2015-03-01

A 25-year-old female macaroni penguin (Eudyptes chrysolophus) was diagnosed with exophthalmos secondary to retrobulbar neoplasia through use of computed tomography (CT). Histopathologic examination of the mass supported a diagnosis of malignant round cell neoplasia. Immunohistochemical (IHC) labeling was applied to determine cell origin; the neoplastic cells did not label with T-cell marker CD3 or B-cell marker BLA.36 and could not be further characterized. The scleral ossicles precluded evaluation of the retrobulbar space by ultrasonography; therefore, CT scanning is recommended for examination of intraorbital structures in penguin and other avian species.

Glaucoma with Descemet's membrane detachment in five horses.

PubMed

Henriksen, Michala de Linde; La Croix, Noelle; Wilkie, David A; Lassaline-Utter, Mary; Brantman, Karen R; Beamer, Gillian L; Teixeira, Leandro B C; Dubielzig, Richard R

2017-05-01

To describe the clinical and histopathologic features of glaucoma associated with Descemet's membrane (DM) detachment in five horses without prior history of intraocular surgery. Three Appaloosa horses and two Thoroughbreds were included in this study. The affected horses ranged in age from 16 to 27 years and presented with severe diffuse corneal edema. Five eyes were enucleated due to intraocular hypertension and/or chronic corneal ulceration. The enucleated globes were evaluated by the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW). Each globe was routinely processed for histopathology and analyzed by light microscopy. A histologic diagnosis of glaucoma was reached by demonstrating a loss of optic nerve axonal tissue by measuring neurofilament-immunopositive axons with automated image analysis software. All five horses presented with unilateral severe diffuse corneal edema that had developed between 2 and 16 weeks prior to enucleation. Intraocular pressures for the affected eyes were between 9 and 87 mmHg prior to enucleation. Descemet's membrane detachment was identified histopathologically in all five globes (5/5, 100%). All five eyes had an avascular spindle cell proliferation filling the space between the displaced peripheral DM and the corneal stroma. Neurofilament immunostaining revealed axonal loss consistent with glaucoma. Equine glaucoma may be associated with Descemet's membrane detachment. This detachment and glaucoma is a possible differential diagnosis for severe equine corneal edema. In this case series, an eye with a DM detachment had a poor prognosis for retention. © 2016 American College of Veterinary Ophthalmologists.

The Effects of Transient Retinal Detachment on Cavity Size and Glial and Neural Remodeling in a Mouse Model of X-Linked Retinoschisis

PubMed Central

Luna, Gabriel; Kjellstrom, Sten; Verardo, Mark R.; Lewis, Geoffrey P.; Byun, Jiyun; Sieving, Paul A.; Fisher, Steven K.

2009-01-01

Purpose To determine the cellular consequences of retinal detachment in retinoschisin knockout (Rs1-KO) mice, a model for retinoschisin in humans. Methods Experimental retinal detachments (RDs) were induced in the right eyes of both Rs1-KO and wild-type (wt) control mice. Immunocytochemistry was performed on retinal tissue at 1, 7, or 28 days after RD with antibodies to anti-GFAP, -neurofilament, and -rod opsin to examine cellular changes after detachment. Images of the immunostained tissue were captured by laser scanning confocal microscopy. Quantitative analysis was performed to measure the number of Hoechst-stained photoreceptor nuclei and their density, number, and size of inner retinal cavities, as well as the number of subretinal glial scars. Results Since detachments were created with balanced salt solution, by examination, all retinas had spontaneously reattached by 1 day. Cellular responses common to many photoreceptor degenerations occurred in the nondetached retinas of Rs1-KO mice, and, of importance, RD did not appear to significantly accentuate these responses. The number of schisis cavities was not changed after detachment, but their size was reduced. Conclusions These data indicate that large short-term RD in Rs1-KO mice, followed by a period of reattachment may cause a slight increase in photoreceptor cell death, but detachments do not accentuate the gliosis and neurite sprouting already present and may in fact reduce the size of existing retinal cavities. This finding suggests that performing subretinal injections to deliver therapeutic agents may be a viable option in the treatment of patients with retinoschisis without causing significant cellular damage to the retina. PMID:19387072

GENE EXPRESSION PROFILING OF HUMAN LIVER CARCINOMA (HepG2) CELLS EXPOSED TO THE MARINE TOXIN OKADAIC ACID

PubMed Central

Fieber, Lynne A.; Greer, Justin B.; Guo, Fujiang; Crawford, Douglas C.; Rein, Kathleen S.

2012-01-01

The marine toxin, okadaic acid (OA) is produced by dinoflagellates of the genera Prorocentrum and Dinophysis and is the causative agent of the syndrome known as diarrheic shellfish poisoning (DSP). In addition, OA acts as both a tumor promoter, attributed to OA-induced inhibition of protein phosphatases as well as an inducer of apoptosis. To better understand the potentially divergent toxicological profile of OA, the concentration dependent cytotoxicity and alterations in gene expression on the human liver tumor cell line HepG2 upon OA exposure were determined using RNA microarrays, DNA fragmentation, and cell proliferation assays as well as determinations of cell detachment and cell death in different concentrations of OA. mRNA expression was quantified for approximately 15,000 genes. Cell attachment and proliferation were both negatively correlated with OA concentration. Detached cells displayed necrotic DNA signatures but apoptosis also was broadly observed. Data suggest that OA has a concentration dependent effect on cell cycle, which might explain the divergent effects that at low concentration OA stimulates genes involved in the cell cycle and at high concentrations it stimulates apoptosis. PMID:23172983

Quantifying the effect of electric current on cell adhesion studied by single-cell force spectroscopy.

PubMed

Jaatinen, Leena; Young, Eleanore; Hyttinen, Jari; Vörös, János; Zambelli, Tomaso; Demkó, László

2016-03-20

This study presents the effect of external electric current on the cell adhesive and mechanical properties of the C2C12 mouse myoblast cell line. Changes in cell morphology, viability, cytoskeleton, and focal adhesion structure were studied by standard staining protocols, while single-cell force spectroscopy based on the fluidic force microscopy technology provided a rapid, serial quantification and detailed analysis of cell adhesion and its dynamics. The setup allowed measurements of adhesion forces up to the μN range, and total detachment distances over 40 μm. Force-distance curves have been fitted with a simple elastic model including a cell detachment protocol in order to estimate the Young's modulus of the cells, as well as to reveal changes in the dynamic properties as functions of the applied current dose. While the cell spreading area decreased monotonously with increasing current doses, small current doses resulted only in differences related to cell elasticity. Current doses above 11 As/m(2), however, initiated more drastic changes in cell morphology, viability, cellular structure, as well as in properties related to cell adhesion. The observed differences, eventually leading to cell death toward higher doses, might originate from both the decrease in pH and the generation of reactive oxygen species.

Diffuse large B-cell lymphoma presenting as a unilateral solitary round pulmonary hilar node infarction.

PubMed

Yonemori, Kan; Kusumoto, Masahiko; Matsuno, Yoshihiro; Tateishi, Ukihide; Watanabe, Shun-Ichi; Watanabe, Takashi; Moriyama, Noriyuki

2006-03-01

Unilateral solitary pulmonary hilar node adenopathy is a rare presentation of diffuse large B-cell lymphoma. In this report, the authors present a case with a solitary pulmonary hilar lymph node infarction caused by diffuse large B-cell lymphoma. Enhanced CT examinations revealed a well-defined round mass with homogenous low attenuation in the left pulmonary hilum. Both radiological imaging and pathological examination can provide useful information for the interpretation of abnormalities and may enable the diagnosis of rare aetiologies.

Long-term effects of short-term retinal bleb detachments in rabbits.

PubMed

Ivert, Lena; Kjeldbye, Hild; Gouras, Peter

2002-03-01

To examine the effects of saline-induced bleb detachments in rabbit retina. Retinal bleb detachments were produced by the injection of 50 microl of balanced salt solution (BSS) into the subretinal space of one eye of each of six rabbits using a glass pipette with a flat tip, 50 microm in diameter. The retina was examined by biomicroscopy, scanning laser ophthalmoscopy (SLO), auto-fluorescence and simultaneous fluorescein and indocyanine green (ICG) angiography. Histological examination was carried out at 1, 2, 3 and 4 months after surgery. All rabbits showed leakage of fluorescein for at least a day after detachment, but within 1 month the leakage ceased. ICG staining developed gradually at the level of the RPE or Bruch's membrane near sites of previous staining. Lipofuscin fluorescence also developed gradually around areas of staining. Histology revealed the source of the excessive lipofuscin to be in the RPE layer, especially in cells migrating away from Bruch's membrane. Short-term bleb detachments cause a transient breakdown in the blood-retinal barrier, long-term ICG staining at or deep to the RPE layer, hyperlipofuscinosis and migration of the RPE. The abnormal lipofuscin accumulation is apparent on fluorescence ophthalmoscopy and can be confused with markers such as green fluorescent protein.

Development of AM 1.5 global measurement procedures and international cell measurement round robin

NASA Technical Reports Server (NTRS)

Mueller, R.

1985-01-01

The development of the capability for measurement under global irradiance spectral distribution is reported. The airmass 1.5 global measurement procedure is given. Also given is the procedure and justification for using the large area pulsed solar simulator (LAPSS). The status of the international round robin of reference cell measurements managed by the Commission of European Communities (CEC) is described.

SU-F-T-678: Clotrimazole Sensitizes MCF-7 Breast Cancer Cell Line to Radiation

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

Garcia, L; Tambasco, M

2016-06-15

Purpose: To study the effects of Clotrimazole (CLT) on radiosensitivity of MCF-7 Cells in correlation to detachment of Hexokinase II from the Voltage Dependent Anion Channel on the outer membrane of the mitochondria. Apoptotic fractions were also analyzed in relation to the detachment of Hexokinase. Methods: This study focused on the mammary adenocarcinoma cell line, MCF-7. Colony forming assays were used to analyze radiosensitization by CLT. Flow cytometry methods were used to analyze apoptotic vs necrotic fractions after treatment with CLT. Spectrophotometery was used to analyze the mitochondrial bound and soluble fraction of Hexokinase by means of relative enzymatic activity.more » Results: Our preliminary data have shown that CLT sensitizes MCF-7 cells to radiation in a dose and incubation time dependent manner up. We have also demonstrated that there are two radiosensitizing periods in MCF-7 cells with the first corresponding to the cycle arrest after 24 hours observed in other cell lines. The second radiosensitizing period occurs with incubation in CLT after irradiation which reaches maximum effect around 24 hours of incubation time. Preliminary data from our Hexokinase detachment assay show a factor of two increase in the ratio of unbound to bound Hexokinase when comparing incubation for 24 hours in media containing 0 and 20 µM CLT. Conclusion: This study and others indicate CLT as a possible radiosensitizing agent in cancer therapies. While CLT itself shows toxicity to the liver in high doses, this study further demonstrates that disruption of the Warburg Effect and unbinding of mitochondrial bound Hexokinase as a possible pathway for cancer treatment.« less

Fundus Autofluorescence Findings in a Mouse Model of Retinal Detachment

PubMed Central

Secondi, Roberta; Kong, Jian; Blonska, Anna M.; Staurenghi, Giovanni; Sparrow, Janet R.

2012-01-01

Purpose. Fundus autofluorescence (fundus AF) changes were monitored in a mouse model of retinal detachment (RD). Methods. RD was induced by transscleral injection of hyaluronic acid (Healon) or sterile balanced salt solution (BSS) into the subretinal space of 4–5-day-old albino Abca4 null mutant and Abca4 wild-type mice. Images acquired by confocal scanning laser ophthalmoscopy (Spectralis HRA) were correlated with spectral domain optical coherence tomography (SD-OCT), infrared reflectance (IR), fluorescence spectroscopy, and histologic analysis. Results. In the area of detached retina, multiple hyperreflective spots in IR images corresponded to punctate areas of intense autofluorescence visible in fundus AF mode. The puncta exhibited changes in fluorescence intensity with time. SD-OCT disclosed undulations of the neural retina and hyperreflectivity of the photoreceptor layer that likely corresponded to histologically visible photoreceptor cell rosettes. Fluorescence emission spectra generated using flat-mounted retina, and 488 and 561 nm excitation, were similar to that of RPE lipofuscin. With increased excitation wavelength, the emission maximum shifted towards longer wavelengths, a characteristic typical of fundus autofluorescence. Conclusions. In detached retinas, hyper-autofluorescent spots appeared to originate from photoreceptor outer segments that were arranged within retinal folds and rosettes. Consistent with this interpretation is the finding that the autofluorescence was spectroscopically similar to the bisretinoids that constitute RPE lipofuscin. Under the conditions of a RD, abnormal autofluorescence may arise from excessive production of bisretinoid by impaired photoreceptor cells. PMID:22786896

A case report of CIC-rearranged undifferentiated small round cell sarcoma in the cerebrum.

PubMed

Ito, Mayumi; Ishikawa, Misawo; Kitajima, Masateru; Narita, Jun; Hattori, Shinya; Endo, Otone; Goto, Keisuke

2016-10-01

CIC-rearranged undifferentiated small round cell sarcoma (CIC-rearranged USRCS) is a recently established type of Ewing-like small round cell sarcomas, characterized by CIC gene rearrangement, most commonly CIC-DUX4 fusion. This report presents the second case of CIC-rearranged USRCS arising primarily in the cerebrum. A 64-year-old otherwise healthy woman presented with a 1 × 1 cm sized hemorrhagic subcortical tumor in the left temporo-parietal lobe. The tumor repeatedly recurred, and the patient underwent three surgeries, chemotherapy with doxorubicin and ifosfamide, and radiotherapy, as well as gamma knife surgery. Systemic examination revealed no other extracranial masses. Imprint cytology revealed small to moderate-sized round-to-ovoid tumor cells with mild pleomorphism and variations in size and shape. The nuclei contained finely granular chromatin, and some had easily-recognizable nucleoli. The tumor exhibited a mainly cytoplasmic pattern of CD99 immunostaining, rather than a diffuse membranous pattern. The tumor also exhibited diffuse positivity for calretinin and p16, as well as partial positivity for WT1 (nuclear and cytoplasmic staining pattern) and D2-40. FISH assessment showed CIC split signals. In conclusion, CIC-rearranged USRCSs can occur primarily in the cerebrum. It would be impossible to diagnose them through cytology alone, but cytology would be useful to rule out other small round cell brain tumors including gliomas, lymphomas, carcinomas, and germinoma. Immunohistochemical analysis including tests for CD99, calretinin, and WT1 would help to suggest CIC-rearranged USRCSs and distinguish them from Ewing sarcomas. Additionally, immunohistochemistry for p16 might be useful in the diagnosis. Diagn. Cytopathol. 2016;44:828-832. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Feasibility studies of oncornavirus production in microcarrier cultures.

PubMed

Manousos, M; Ahmed, M; Torchio, C; Wolff, J; Shibley, G; Stephens, R; Mayyasi, S

1980-06-01

Studies conducted with virus-infected monolayer cell cultures have demonstrated the feasibility of producing several tumor-associated viruses in microcarrier (mc) cultures (Sephadex G50 beads treated with DEAE-chloride). The efficiency of cell adherence to mc varied with the cell type, the pH of the growth medium, and the stirring force applied to keep the mc in suspension. Most cells attached firmly to the mc and could not be removed easily with routine trypsinization procedures. Techniques using Enzar-T and Pronase were effective in detaching cells from mc in 10 to 15 min while retaining 95% cell viability. After detachment, Ficoll gradients were used for rapid and complete separation of viable cell suspensions from the mc. Retrovirus production in large volumes of mc cultures was investigated with periodic harvesting of growth fluids. Physical, biochemical, and biological properties of the Mason-Pfizer monkey virus and the RD114 virus recovered from the mc cultures were identical to those produced in conventional cultures. The utilization of mc has several applications in research and short-term cultures, but the as-yet-unsolved technical problems met were found to be serious limitations when attempting mass cell culturing on a long-term basis.

An investigation of cell growth and detachment from thermoresponsive physically crosslinked networks.

PubMed

Healy, Deirdre; Nash, Maria; Gorleov, Alexander; Thompson, Kerry; Dockery, Peter; Rochev, Yury

2017-11-01

The primary aim of this investigation was to determine the biocompatibility and cell culture potential of a newly designed class of thermoresponsive polymers. The attractiveness of these polymers lies in the fact that they swell rather than dissolve when the temperature is reduced below their respective lower critical solution temperature, due to the incorporation of octadecyl methacrylate (ODMA). The ODMA monomer acts as a physical crosslinker, preventing polymer dissolution upon temperature reduction. Two polymers were studied in this investigation poly(N isorpoylacrylamide (NIPAm)(99.25%)-co-ODMA(0.75%)) and poly(NIPAm(65%)-co-N-tert-butylacrylamide (NtBAm)(34.25%)-co-ODMA(0.75%)). Thin thermoresponsive films of the polymers were prepared via spin coating. 3T3 cells were then seeded on the prepared films and cell viability was assessed quantitatively through cell viability and activity assays and qualitatively by light microscopy. Cells were successfully seeded and grown on the poly(NIPAm-co-ODMA) and poly(NIPAm-co-NtBAm-co-ODMA) copolymer films after film modification with cell adhesion promoters (CAPs). Cell sheets successfully detached from the CAP coated poly(NIPAm-co-ODMA) platforms upon temperature reduction. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of G, a Growth Regulator from Eucalyptus grandis, on Photosynthesis

PubMed Central

Sharkey, Thomas D.; Stevenson, Gay F.; Paton, Dugald M.

1982-01-01

A growth regulator (G; 4-ethyl-1-hydroxy-4,8,8,10,10 pentamethyl-7,9-dioxo-2,3 dioxyabicyclo (4.4.0) decene-5) from Eucalyptus grandis (Maiden) reduced stomatal conductance and also photosynthetic capacity when fed through the transpiration stream of detached leaves. The concentration of G required for this effect was high (10−4 molar), but the amount of G taken up (dose) was below the level which has previously been found in E. grandis leaves. Similar effects were observed in detached leaves of Xanthium strumarium L. though almost 10 times more G was required. G reduced CO2-dependent O2 evolution from isolated cells of X. strumarium. In spinach (Spinacia oleracea L.) chloroplasts, electron transport through photosystem II was reduced by G. It is proposed that G affects stomatal conductance and photosynthesis by reducing photosystem II activity in both the guard cell chloroplasts and mesophyll cell chloroplasts. PMID:16662322

Mangiferin protects mitochondrial function by preserving mitochondrial hexokinase-II in vessel endothelial cells.

PubMed

Song, Junna; Li, Yi; Song, Junmei; Hou, Fangjie; Liu, Baolin; Li, Aiying

2017-07-01

Hexokinase-II (HK-II) confers protection against cell death and this study was designed to investigate the effect of mangiferin on the regulation of mitochondrial HK-II. In vessel endothelial cells, saturated fatty acid palmitate (PA) stimulation induced HK-II detachment from mitochondria due to cellular acidification. Mangiferin reduced lactate accumulation by improving pyruvate dehydrogenase activity, promoted Akt translocation to HK-II and prevented HK-II detachment from mitochondria. Knockdown of Akt2 diminished the protective effect of mangiferin on mitochondrial HK-II, confirming the role of Akt in the regulation of HK-II. Mangiferin prevented mitochondrial permeability transition pore opening, restored mitochondrial membrane potential and thereby protected cell from apoptosis. In high-fat diet fed mice, oral administration of mangiferin induced Akt phosphorylation, increased HK-II binding to mitochondria and resultantly protected vessel endothelial function, demonstrating its protective effect on endothelial integrity in vivo. This finding provided a novel strategy for the protection of mitochondrial function in the endothelium. Copyright © 2017 Elsevier B.V. All rights reserved.

CellSort: a support vector machine tool for optimizing fluorescence-activated cell sorting and reducing experimental effort.

PubMed

Yu, Jessica S; Pertusi, Dante A; Adeniran, Adebola V; Tyo, Keith E J

2017-03-15

High throughput screening by fluorescence activated cell sorting (FACS) is a common task in protein engineering and directed evolution. It can also be a rate-limiting step if high false positive or negative rates necessitate multiple rounds of enrichment. Current FACS software requires the user to define sorting gates by intuition and is practically limited to two dimensions. In cases when multiple rounds of enrichment are required, the software cannot forecast the enrichment effort required. We have developed CellSort, a support vector machine (SVM) algorithm that identifies optimal sorting gates based on machine learning using positive and negative control populations. CellSort can take advantage of more than two dimensions to enhance the ability to distinguish between populations. We also present a Bayesian approach to predict the number of sorting rounds required to enrich a population from a given library size. This Bayesian approach allowed us to determine strategies for biasing the sorting gates in order to reduce the required number of enrichment rounds. This algorithm should be generally useful for improve sorting outcomes and reducing effort when using FACS. Source code available at http://tyolab.northwestern.edu/tools/ . k-tyo@northwestern.edu. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

3D Non-Woven Polyvinylidene Fluoride Scaffolds: Fibre Cross Section and Texturizing Patterns Have Impact on Growth of Mesenchymal Stromal Cells

PubMed Central

Schellenberg, Anne; Ross, Robin; Abagnale, Giulio; Joussen, Sylvia; Schuster, Philipp; Arshi, Annahit; Pallua, Norbert; Jockenhoevel, Stefan; Gries, Thomas; Wagner, Wolfgang

2014-01-01

Several applications in tissue engineering require transplantation of cells embedded in appropriate biomaterial scaffolds. Such structures may consist of 3D non-woven fibrous materials whereas little is known about the impact of mesh size, pore architecture and fibre morphology on cellular behavior. In this study, we have developed polyvinylidene fluoride (PVDF) non-woven scaffolds with round, trilobal, or snowflake fibre cross section and different fibre crimp patterns (10, 16, or 28 needles per inch). Human mesenchymal stromal cells (MSCs) from adipose tissue were seeded in parallel on these scaffolds and their growth was compared. Initial cell adhesion during the seeding procedure was higher on non-wovens with round fibres than on those with snowflake or trilobal cross sections. All PVDF non-woven fabrics facilitated cell growth over a time course of 15 days. Interestingly, proliferation was significantly higher on non-wovens with round or trilobal fibres as compared to those with snowflake profile. Furthermore, proliferation increased in a wider, less dense network. Scanning electron microscopy (SEM) revealed that the MSCs aligned along the fibres and formed cellular layers spanning over the pores. 3D PVDF non-woven scaffolds support growth of MSCs, however fibre morphology and mesh size are relevant: proliferation is enhanced by round fibre cross sections and in rather wide-meshed scaffolds. PMID:24728045

Vero/BC-F: an efficient packaging cell line stably expressing F protein to generate single round-infectious human parainfluenza virus type 2 vector.

PubMed

Ohtsuka, J; Fukumura, M; Tsurudome, M; Hara, K; Nishio, M; Kawano, M; Nosaka, T

2014-08-01

A stable packaging cell line (Vero/BC-F) constitutively expressing fusion (F) protein of the human parainfluenza virus type 2 (hPIV2) was established for production of the F-defective and single round-infectious hPIV2 vector in a strategy for recombinant vaccine development. The F gene expression has not evoked cytostatic or cytotoxic effects on the Vero/BC-F cells and the F protein was physiologically active to induce syncytial formation with giant polykaryocytes when transfected with a plasmid expressing hPIV2 hemagglutinin-neuraminidase (HN). Transduction of the F-defective replicon RNA into the Vero/BC-F cells led to the release of the infectious particles that packaged the replicon RNA (named as hPIV2ΔF) without detectable mutations, limiting the infectivity to a single round. The maximal titer of the hPIV2ΔF was 6.0 × 10(8) median tissue culture infections dose per ml. The influenza A virus M2 gene was inserted into hPIV2ΔF, and the M2 protein was found to be highly expressed in a human lung cancer cell line after transduction. Furthermore, in vivo airway infection experiments revealed that the hPIV2ΔF was capable of delivering transgenes to hamster tracheal cells. Thus, non-transmissible or single round-infectious hPIV2 vector will be potentially applicable to human gene therapy or recombinant vaccine development.

Final screening round of the NELSON lung cancer screening trial: the effect of a 2.5-year screening interval.

PubMed

Yousaf-Khan, Uraujh; van der Aalst, Carlijn; de Jong, Pim A; Heuvelmans, Marjolein; Scholten, Ernst; Lammers, Jan-Willem; van Ooijen, Peter; Nackaerts, Kristiaan; Weenink, Carla; Groen, Harry; Vliegenthart, Rozemarijn; Ten Haaf, Kevin; Oudkerk, Matthijs; de Koning, Harry

2017-01-01

In the USA annual lung cancer screening is recommended. However, the optimal screening strategy (eg, screening interval, screening rounds) is unknown. This study provides results of the fourth screening round after a 2.5-year interval in the Dutch-Belgian Lung Cancer Screening trial (NELSON). Europe's largest, sufficiently powered randomised lung cancer screening trial was designed to determine whether low-dose CT screening reduces lung cancer mortality by ≥25% compared with no screening after 10 years of follow-up. The screening arm (n=7915) received screening at baseline, after 1 year, 2 years and 2.5 years. Performance of the NELSON screening strategy in the final fourth round was evaluated. Comparisons were made between lung cancers detected in the first three rounds, in the final round and during the 2.5-year interval. In round 4, 46 cancers were screen-detected and there were 28 interval cancers between the third and fourth screenings. Compared with the second round screening (1-year interval), in round 4 a higher proportion of stage IIIb/IV cancers (17.3% vs 6.8%, p=0.02) and higher proportions of squamous-cell, bronchoalveolar and small-cell carcinomas (p=0.001) were detected. Compared with a 2-year interval, the 2.5-year interval showed a higher non-significant stage distribution (stage IIIb/IV 17.3% vs 5.2%, p=0.10). Additionally, more interval cancers manifested in the 2.5-year interval than in the intervals of previous rounds (28 vs 5 and 28 vs 19). A 2.5-year interval reduced the effect of screening: the interval cancer rate was higher compared with the 1-year and 2-year intervals, and proportion of advanced disease stage in the final round was higher compared with the previous rounds. ISRCTN63545820. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Combining light-harvesting with detachability in high-efficiency thin-film silicon solar cells.

PubMed

Ram, Sanjay K; Desta, Derese; Rizzoli, Rita; Bellettato, Michele; Lyckegaard, Folmer; Jensen, Pia B; Jeppesen, Bjarke R; Chevallier, Jacques; Summonte, Caterina; Larsen, Arne Nylandsted; Balling, Peter

2017-06-01

Efforts to realize thin-film solar cells on unconventional substrates face several obstacles in achieving good energy-conversion efficiency and integrating light-management into the solar cell design. In this report a technique to circumvent these obstacles is presented: transferability and an efficient light-harvesting scheme are combined for thin-film silicon solar cells by the incorporation of a NaCl layer. Amorphous silicon solar cells in p-i-n configuration are fabricated on reusable glass substrates coated with an interlayer of NaCl. Subsequently, the solar cells are detached from the substrate by dissolution of the sacrificial NaCl layer in water and then transferred onto a plastic sheet, with a resultant post-transfer efficiency of 9%. The light-trapping effect of the surface nanotextures originating from the NaCl layer on the overlying solar cell is studied theoretically and experimentally. The enhanced light absorption in the solar cells on NaCl-coated substrates leads to significant improvement in the photocurrent and energy-conversion efficiency in solar cells with both 350 and 100 nm thick absorber layers, compared to flat-substrate solar cells. Efficient transferable thin-film solar cells hold a vast potential for widespread deployment of off-grid photovoltaics and cost reduction.

Single-cell adhesion probed in-situ using optical tweezers: A case study with Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Castelain, Mickaël; Rouxhet, Paul G.; Pignon, Frédéric; Magnin, Albert; Piau, Jean-Michel

2012-06-01

A facile method of using optical trapping to measure cell adhesion forces is presented and applied to the adhesion of Saccharomyces cerevisiae on glass, in contact with solutions of different compositions. Trapping yeast cells with optical tweezers (OT) is not perturbed by cell wall deformation or cell deviation from a spherical shape. The trapping force calibration requires correction not only for the hydrodynamic effect of the neighboring wall but also for spherical aberrations affecting the focal volume and the trap stiffness. Yeast cells trapped for up to 5 h were still able to undergo budding but showed an increase of doubling time. The proportion of adhering cells showed the expected variation according to the solution composition. The detachment force varied in the same way. This observation and the fact that the detachment stress was exerted parallel to the substrate surface point to the role of interactions involving solvated macromolecules. Both the proportion of adhering cells and the removal force showed a distribution which, in our experimental conditions, must be attributed to a heterogeneity of surface properties at the cell level or at the subcellular scale. As compared with magnetic tweezers, atomic force microscopy, and more conventional ways of studying cell adhesion (shear-flow cells), OT present several advantages that are emphasized in this paper.

Phage display screening without repetitious selection rounds.

PubMed

't Hoen, Peter A C; Jirka, Silvana M G; Ten Broeke, Bradley R; Schultes, Erik A; Aguilera, Begoña; Pang, Kar Him; Heemskerk, Hans; Aartsma-Rus, Annemieke; van Ommen, Gertjan J; den Dunnen, Johan T

2012-02-15

Phage display screenings are frequently employed to identify high-affinity peptides or antibodies. Although successful, phage display is a laborious technology and is notorious for identification of false positive hits. To accelerate and improve the selection process, we have employed Illumina next generation sequencing to deeply characterize the Ph.D.-7 M13 peptide phage display library before and after several rounds of biopanning on KS483 osteoblast cells. Sequencing of the naive library after one round of amplification in bacteria identifies propagation advantage as an important source of false positive hits. Most important, our data show that deep sequencing of the phage pool after a first round of biopanning is already sufficient to identify positive phages. Whereas traditional sequencing of a limited number of clones after one or two rounds of selection is uninformative, the required additional rounds of biopanning are associated with the risk of losing promising clones propagating slower than nonbinding phages. Confocal and live cell imaging confirms that our screen successfully selected a peptide with very high binding and uptake in osteoblasts. We conclude that next generation sequencing can significantly empower phage display screenings by accelerating the finding of specific binders and restraining the number of false positive hits. Copyright © 2011 Elsevier Inc. All rights reserved.

Immunohistochemical expression of WT1 by desmoplastic small round cell tumor: a comparative study with other small round cell tumors.

PubMed

Barnoud, R; Sabourin, J C; Pasquier, D; Ranchère, D; Bailly, C; Terrier-Lacombe, M J; Pasquier, B

2000-06-01

Desmoplastic small round cell tumors (DSRCTs) present a reciprocal chromosomal translocation, t(11;22)(p13;q12), that results in fusion of Ewing's sarcoma and Wilms' tumor (WT1) genes. The authors evaluated 15 DSRCTs and 71 other tumors often considered in the differential diagnosis for immunoreactivity using a polyclonal antibody directed against the WT1 part of the chimeric protein resulting from this translocation. WT1 immunostaining was performed on paraffin material using the WT(C-19) antibody after heat-antigen retrieval. All the DSRCTs (15 of 15, 100%) demonstrated strong WT1 nuclear immunoreactivity. Ten of 14 nephroblastomas (71%) disclosed WT1-positive nuclei in accordance with the staining reported by others, and rare and focal nuclear positivity was detected in two of 17 rhabdomyosarcomas. WT1 immunoreactivity was not observed in Ewing's sarcoma/primitive neuroectodermal tumors (zero of 21, 0%), neuroblastomas (zero of 17, 0%), or rhabdoid tumors of the kidney (zero of two, 0%). In nephroblastoma, differential diagnosis with DSRCT was not difficult: Clinical and morphologic data are not similar for these two entities. The current study validates WT1 immunoreactivity as a useful marker to separate DSRCT from other small round cell tumors.

Prognostic significance of MRI findings in patients with myxoid-round cell liposarcoma.

PubMed

Tateishi, Ukihide; Hasegawa, Tadashi; Beppu, Yasuo; Kawai, Akira; Satake, Mitsuo; Moriyama, Noriyuki

2004-03-01

The aims of this study were to determine the prognostic significance of MRI findings in patients with myxoid-round cell liposarcomas and to clarify which MRI features best indicate tumors with adverse clinical behavior. The initial MRI studies of 36 pathologically confirmed myxoid-round cell liposarcomas were retrospectively reviewed, and observations from this review were correlated with the histopathologic features. MR images were evaluated by two radiologists with agreement by consensus, and both univariate and multivariate analyses were conducted to evaluate survival with a median clinical follow-up of 33 months (range, 9-276 months). Statistically significant MRI findings that favored a diagnosis of intermediate- or high-grade tumor were large tumor size (> 10 cm), deeply situated tumor, tumor possessing irregular contours, absence of lobulation, absence of thin septa, presence of thick septa, absence of tumor capsule, high-intensity signal pattern, pronounced enhancement, and globular or nodular enhancement. Of these MRI findings, thin septa (p < 0.05), a tumor capsule (p < 0.01), and pronounced enhancement (p < 0.01) were associated significantly, according to univariate analysis, with overall survival. Multivariate analysis indicated that pronounced enhancement was associated significantly with overall survival (p < 0.05). Contrast-enhanced MRI findings can indicate a good or adverse prognosis in patients with myxoid-round cell liposarcomas.

Diffusion-weighted magnetic resonance imaging in the characterization of testicular germ cell neoplasms: Effect of ROI methods on apparent diffusion coefficient values and interobserver variability.

PubMed

Tsili, Athina C; Ntorkou, Alexandra; Astrakas, Loukas; Xydis, Vasilis; Tsampalas, Stavros; Sofikitis, Nikolaos; Argyropoulou, Maria I

2017-04-01

To evaluate the difference in apparent diffusion coefficient (ADC) measurements at diffusion-weighted (DW) magnetic resonance imaging of differently shaped regions-of-interest (ROIs) in testicular germ cell neoplasms (TGCNS), the diagnostic ability of differently shaped ROIs in differentiating seminomas from nonseminomatous germ cell neoplasms (NSGCNs) and the interobserver variability. Thirty-three TGCNs were retrospectively evaluated. Patients underwent MR examinations, including DWI on a 1.5-T MR system. Two observers measured mean tumor ADCs using four distinct ROI methods: round, square, freehand and multiple small, round ROIs. The interclass correlation coefficient was analyzed to assess interobserver variability. Statistical analysis was used to compare mean ADC measurements among observers, methods and histologic types. All ROI methods showed excellent interobserver agreement, with excellent correlation (P<0.001). Multiple, small ROIs provided the lower mean ADC in TGCNs. Seminomas had lower mean ADC compared to NSGCNs for each ROI method (P<0.001). Round ROI proved the most accurate method in characterizing TGCNS. Interobserver variability in ADC measurement is excellent, irrespective of the ROI shape. Multiple, small round ROIs and round ROI proved the more accurate methods for ADC measurement in the characterization of TGCNs and in the differentiation between seminomas and NSGCNs, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

Inversin modulates the cortical actin network during mitosis

PubMed Central

Werner, Michael E.; Ward, Heather H.; Phillips, Carrie L.; Miller, Caroline; Gattone, Vincent H.

2013-01-01

Mutations in inversin cause nephronophthisis type II, an autosomal recessive form of polycystic kidney disease associated with situs inversus, dilatation, and kidney cyst formation. Since cyst formation may represent a planar polarity defect, we investigated whether inversin plays a role in cell division. In developing nephrons from inv−/− mouse embryos we observed heterogeneity of nuclear size, increased cell membrane perimeters, cells with double cilia, and increased frequency of binuclear cells. Depletion of inversin by siRNA in cultured mammalian cells leads to an increase in bi- or multinucleated cells. While spindle assembly, contractile ring formation, or furrow ingression appears normal in the absence of inversin, mitotic cell rounding and the underlying rearrangement of the cortical actin cytoskeleton are perturbed. We find that inversin loss causes extensive filopodia formation in both interphase and mitotic cells. These cells also fail to round up in metaphase. The resultant spindle positioning defects lead to asymmetric division plane formation and cell division. In a cell motility assay, fibroblasts isolated from inv−/− mouse embryos migrate at half the speed of wild-type fibroblasts. Together these data suggest that inversin is a regulator of cortical actin required for cell rounding and spindle positioning during mitosis. Furthermore, cell division defects resulting from improper spindle position and perturbed actin organization contribute to altered nephron morphogenesis in the absence of inversin. PMID:23515530

Dynamics of water droplets detached from porous surfaces of relevance to PEM fuel cells.

PubMed

Theodorakakos, A; Ous, T; Gavaises, M; Nouri, J M; Nikolopoulos, N; Yanagihara, H

2006-08-15

The detachment of liquid droplets from porous material surfaces used with proton exchange membrane (PEM) fuel cells under the influence of a cross-flowing air is investigated computationally and experimentally. CCD images taken on a purpose-built transparent fuel cell have revealed that the water produced within the PEM is forming droplets on the surface of the gas-diffusion layer. These droplets are swept away if the velocity of the flowing air is above a critical value for a given droplet size. Static and dynamic contact angle measurements for three different carbon gas-diffusion layer materials obtained inside a transparent air-channel test model have been used as input to the numerical model; the latter is based on a Navier-Stokes equations flow solver incorporating the volume of fluid (VOF) two-phase flow methodology. Variable contact angle values around the gas-liquid-solid contact-line as well as their dynamic change during the droplet shape deformation process, have allowed estimation of the adhesion force between the liquid droplet and the solid surface and successful prediction of the separation line at which droplets loose their contact from the solid surface under the influence of the air stream flowing around them. Parametric studies highlight the relevant importance of various factors affecting the detachment of the liquid droplets from the solid surface.

Stripe-patterned thermo-responsive cell culture dish for cell separation without cell labeling.

PubMed

Kumashiro, Yoshikazu; Ishihara, Jun; Umemoto, Terumasa; Itoga, Kazuyoshi; Kobayashi, Jun; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo

2015-02-11

A stripe-patterned thermo-responsive surface is prepared to enable cell separation without labeling. The thermo-responsive surface containing a 3 μm striped pattern exhibits various cell adhesion and detachment properties. A mixture of three cell types is separated on the patterned surface based on their distinct cell-adhesion properties, and the composition of the cells is analyzed by flow cytometry. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolation and identification of group A rotaviruses among neonatal diarrheic calves, Morocco.

PubMed

Ennima, Imane; Sebbar, Ghizlane; Harif, Bachir; Amzazi, Saaid; Loutfi, Chafiqa; Touil, Nadia

2016-05-05

Group A rotaviruses (RVA) are the main cause of neonatal calve diarrhea (NCD) in Morocco. In this study, we isolated RVA strains from NCD clinical samples in order to support RVA disease control in Morocco. This isolation process constitutes a first step toward vaccine development. Thirteen fecal samples were obtained from calves with a single episode of neonate calf diarrhea at three different dairies and two samples were collected from field during a severe NCD outbreak. Diagnosis of RVA infection was based on fecal immune-chromatographic rapid test and further evaluated for their hemagglutination (HA) activity. RVA isolation was carried out on MA104 cells after inoculates were treated with different concentrations of trypsin TPCK. All RVA isolates were confirmed by LSI VetMAX™ Triplex Ruminant Rotavirus & Coronavirus Real-Time PCR kit. G and P typing were determined by direct sequencing of the VP4 and VP7 amplicons. RVA isolation was achieved for nine clinical samples following one or two passages (60 %) and was properly depended on HA activity and trypsin treatment of inoculates. The first sign of CPE detected consisted of increased cell granularity, obscure cell boundaries, cell rounding, and eventual degeneration and detachment of cells. At lower TPCK concentration (3-10 μg/inoculum), no changes at the cellular level were observed, while cells activated with 25-30 μg of trypsin/inoculums, they degenerated and trypsin cytotoxicity was enhanced. Appreciable changes in cell's morphology were detected with optimal trypsin concentration of 15-20 μg trypsin/inoculums. Data from qRT-PCR confirmed that unsuccessful cultivations have No-Ct, and all nine isolates have Ct values ranged between 12.17 and 24.69. Analysis sequencing revealed that field isolates were of G6 P[5] serotype and isolates from the dairy NCD samples were of G10 P[14] serotype. To our knowledge, this is the first study in Morocco which reports the circulation of G10P[14] in NCD on dairy farms and G6P[5] in the field. Our study constitutes a crucial and a necessary step allowing preventive and veterinary medicine to support RVA disease controls in the country.

Three-dimensional alginate spheroid culture system of murine osteosarcoma.

PubMed

Akeda, Koji; Nishimura, Akinobu; Satonaka, Haruhiko; Shintani, Ken; Kusuzaki, Katsuyuki; Matsumine, Akihiko; Kasai, Yuichi; Masuda, Koichi; Uchida, Atsumasa

2009-11-01

Osteosarcoma (OS) is the most common primary malignant tumor of the bone and often forms pulmonary metastases, which are the most important prognostic factor. For further elucidation of the mechanism underlying the progression and metastasis of human OS, a culture system mimicking the microenvironment of the tumor in vivo is needed. We report a novel three-dimensional (3D) alginate spheroid culture system of murine osteosarcoma. Two different metastatic clones, the parental Dunn and its derivative line LM8, which has a higher metastatic potential to the lungs, were encapsulated in alginate beads to develop the 3D culture system. The beads containing murine OS cells were also transplanted into mice to determine their metastatic potential in vivo. In this culture system, murine OS cells encapsulated in alginate beads were able to grow in a 3D structure with cells detaching from the alginate environment. The number of detaching cells was higher in the LM8 cell line than the Dunn cell line. In the in vivo alginate bead transplantation model, the rate of pulmonary metastasis was higher with LM8 cells compared with that of Dunn cells. The cell characteristics and kinetics in this culture system closely reflect the original malignant potential of the cells in vivo.

Role of biofilm roughness and hydrodynamic conditions in Legionella pneumophila adhesion to and detachment from simulated drinking water biofilms.

PubMed

Shen, Yun; Monroy, Guillermo L; Derlon, Nicolas; Janjaroen, Dao; Huang, Conghui; Morgenroth, Eberhard; Boppart, Stephen A; Ashbolt, Nicholas J; Liu, Wen-Tso; Nguyen, Thanh H

2015-04-07

Biofilms in drinking water distribution systems (DWDS) could exacerbate the persistence and associated risks of pathogenic Legionella pneumophila (L. pneumophila), thus raising human health concerns. However, mechanisms controlling adhesion and subsequent detachment of L. pneumophila associated with biofilms remain unclear. We determined the connection between L. pneumophila adhesion and subsequent detachment with biofilm physical structure characterization using optical coherence tomography (OCT) imaging technique. Analysis of the OCT images of multispecies biofilms grown under low nutrient condition up to 34 weeks revealed the lack of biofilm deformation even when these biofilms were exposed to flow velocity of 0.7 m/s, typical flow for DWDS. L. pneumophila adhesion on these biofilm under low flow velocity (0.007 m/s) positively correlated with biofilm roughness due to enlarged biofilm surface area and local flow conditions created by roughness asperities. The preadhered L. pneumophila on selected rough and smooth biofilms were found to detach when these biofilms were subjected to higher flow velocity. At the flow velocity of 0.1 and 0.3 m/s, the ratio of detached cell from the smooth biofilm surface was from 1.3 to 1.4 times higher than that from the rough biofilm surface, presumably because of the low shear stress zones near roughness asperities. This study determined that physical structure and local hydrodynamics control L. pneumophila adhesion to and detachment from simulated drinking water biofilm, thus it is the first step toward reducing the risk of L. pneumophila exposure and subsequent infections.

Changes in Ect2 Localization Couple Actomyosin-Dependent Cell Shape Changes to Mitotic Progression

PubMed Central

Matthews, Helen K.; Delabre, Ulysse; Rohn, Jennifer L.; Guck, Jochen; Kunda, Patricia; Baum, Buzz

2012-01-01

Summary As they enter mitosis, animal cells undergo profound actin-dependent changes in shape to become round. Here we identify the Cdk1 substrate, Ect2, as a central regulator of mitotic rounding, thus uncovering a link between the cell-cycle machinery that drives mitotic entry and its accompanying actin remodeling. Ect2 is a RhoGEF that plays a well-established role in formation of the actomyosin contractile ring at mitotic exit, through the local activation of RhoA. We find that Ect2 first becomes active in prophase, when it is exported from the nucleus into the cytoplasm, activating RhoA to induce the formation of a mechanically stiff and rounded metaphase cortex. Then, at anaphase, binding to RacGAP1 at the spindle midzone repositions Ect2 to induce local actomyosin ring formation. Ect2 localization therefore defines the stage-specific changes in actin cortex organization critical for accurate cell division. PMID:22898780

Primary undifferentiated small round cell sarcoma of the deep abdominal wall with a novel variant of t(10;19) CIC-DUX4 gene fusion.

PubMed

Tsukamoto, Yoshitane; Futani, Hiroyuki; Yoshiya, Shinichi; Watanabe, Takahiro; Kihara, Takako; Matsuo, Shohei; Hirota, Seiichi

2017-10-01

We experienced a 38-year-old Japanese male with t(10;19) CIC-DUX4 -positive undifferentiated small round cell sarcoma in the deep abdominal wall. Three months before his first visit to our hospital, he noticed a mass in his right abdominal wall. Computed tomography on admission revealed a solid abdominal tumor 70×53mm in size and multiple small tumors in both lungs. The biopsy of the abdominal tumor revealed undifferentiated small round cell sarcoma, suggestive of Ewing sarcoma. Under the clinical diagnosis of Ewing-like sarcoma of the abdominal wall with multiple lung metastases, several cycles of ICE (ifosfamide, carboplatin and etoposide) therapy were performed. After the chemotherapy, the lung metastases disappeared, while the primary lesion rapidly grew. Additional VDC (vincristine, doxorubicin and cyclophosphamide) therapy was carried out without apparent effect. Although the surgical removal of the primary lesion was done, peritoneal dissemination and a huge metastatic liver tumor appeared thereafter. The patient died of disease progression two months after the surgery. The total clinical course was approximately one year, showing that the tumor was extremely aggressive. The tumor cells of the surgical specimen were positive for CD99, WT1, calretinin, INI1, ERG and Fli1 by immunohistochemistry. Fusion gene analyses using the frozen surgical material revealed negativity for EWSR1-Fli1, EWSR1-ERG and t(4;19) CIC-DUX4 fusions, but positivity for t(10;19) CIC-DUX4 fusion. Thus, we made a final pathological diagnosis of t(10;19) CIC-DUX4-positive undifferentiated small round cell sarcoma. To our knowledge, this is the 13th case of t(10;19) CIC-DUX4 undifferentiated small round cell sarcoma with precise clinicopathological information. Especially in our case, two types of t(10;19) CIC-DUX4 fusion transcripts were observed, both of which are in-frame and novel. Copyright © 2017 Elsevier GmbH. All rights reserved.

Miniature Dielectric Barrier Discharge Nonthermal Plasma Induces Apoptosis in Lung Cancer Cells and Inhibits Cell Migration.

PubMed

Karki, Surya B; Yildirim-Ayan, Eda; Eisenmann, Kathryn M; Ayan, Halim

2017-01-01

Traditional cancer treatments like radiotherapy and chemotherapy have drawbacks and are not selective for killing only cancer cells. Nonthermal atmospheric pressure plasmas with dielectric barrier discharge (DBD) can be applied to living cells and tissues and have emerged as novel tools for localized cancer therapy. The purpose of this study was to investigate the different effects caused by miniature DBD (mDBD) plasma to A549 lung cancer cells. In this study, A549 lung cancer cells cultured in 12 well plates were treated with mDBD plasma for specified treatment times to assess the changes in the size of the area of cell detachment, the viability of attached or detached cells, and cell migration. Furthermore, we investigated an innovative mDBD plasma-based therapy for localized treatment of lung cancer cells through apoptotic induction. Our results indicate that plasma treatment for 120 sec causes apoptotic cell death in 35.8% of cells, while mDBD plasma treatment for 60 sec, 30 sec, or 15 sec causes apoptotic cell death in 20.5%, 14.1%, and 6.3% of the cell population, respectively. Additionally, we observed reduced A549 cell migration in response to mDBD plasma treatment. Thus, mDBD plasma system can be a viable platform for localized lung cancer therapy.

IDENTIFICATION BADGE WITH DETACHABLE CLIP

DOEpatents

Burns, M.T.

1962-09-18

The clip has a long slot with a round enlarged end, flat on one side. The badge has a headed member that is circular except for a flat side. The badge is connected to, or disconnected from, the clip by insertion of the headed member through the enlarged end of the slot in the clip. The badge is unlikely to be accidentally disconnected from the clip while being worn on a worker's clothing, because the weight of the badge keeps the headed member away from the enlarged end of the slot in the clip, and the headed member can pass through the enlarged end of the slot only at one relative angular position between badge and clip, namely, that angle at which the flat side of the headed member is coincident with the flat side of the enlarged end of the slot. (AEC)

Some tradeoffs in ingot shaping and price of solar photovoltaic modules

NASA Technical Reports Server (NTRS)

Daud, T.

1982-01-01

Growth of round ingots is cost-effective for sheets but leaves unused space when round cells are packed into a module. This reduces the packing efficiency, which approaches 95% for square cells, to about 78% and reduces the conversion efficiency of the module by the same ratio. Shaping these ingots into squares with regrowth of cut silicon improves the packing factor, but increases growth cost. The cost impact on solar cell modules was determined by considering shaping ingots in stages from full round to complete square. The sequence of module production with relevant price allocation guidelines is outlined. The severe penalties in add-on price due to increasing slice thickness and kerf are presented. Trade-offs between advantages of recycling silicon and shaping costs are developed for different slicing scenarios. It is shown that shaping results in cost saving of up to 21% for a 15 cm dia. ingot.

Standardization of the Descemet membrane endothelial keratoplasty technique: Outcomes of the first 450 consecutive cases.

PubMed

Satué, M; Rodríguez-Calvo-de-Mora, M; Naveiras, M; Cabrerizo, J; Dapena, I; Melles, G R J

2015-08-01

To evaluate the clinical outcome of the first 450 consecutive cases after Descemet membrane endothelial keratoplasty (DMEK), as well as the effect of standardization of the technique. Comparison between 3 groups: Group I: (cases 1-125), as the extended learning curve; Group II: (cases 126-250), transition to technique standardization; Group III: (cases 251-450), surgery with standardized technique. Best corrected visual acuity, endothelial cell density, pachymetry and intra- and postoperative complications were evaluated before, and 1, 3 and 6 months after DMEK. At 6 months after surgery, 79% of eyes reached a best corrected visual acuity of≥0.8 and 43%≥1.0. Mean preoperative endothelial cell density was 2,530±220 cells/mm2 and 1,613±495 at 6 months after surgery. Mean pachymetry measured 668±92 μm and 526±46 μm pre- and (6 months) postoperatively, respectively. There were no significant differences in best corrected visual acuity, endothelial cell density and pachymetry between the 3 groups (P > .05). Graft detachment presented in 17.3% of the eyes. The detachment rate declined from 24% to 12%, and the rate of secondary surgeries from 9.6% to 3.5%, from group I to III respectively. Visual outcomes and endothelial cell density after DMEK are independent of the technique standardization. However, technique standardization may have contributed to a lower graft detachment rate and a relatively low number of secondary interventions required. As such, DMEK may become the first choice of treatment in corneal endothelial disease. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Dynamic morphology applied to human and animal leukemia cells.

PubMed

Haemmerli, G; Felix, H; Sträuli, P

1979-08-01

Dynamic morphology, which describes the shape and surface architecture of fixed cells in terms related to their behavior in the living state, is based on the concurrent use of two methods: scanning electron microscopy and microcinematography. This combination has both advantages and disadvantages. In this study on leukemic cells, we were able to draw the following conclusions about the usefulness of dynamic morphology. It confirms that white blood cells do not flatten on a glass substrate; they stay spherical and are either round or polarized. Round cells of similar size, whatever their origin, cannot be classified by dynamic morphology. Polarized cells can be classified as blasts, promyelocytes, myelocytes, granulocytes and lymphocytes, although polarized blast cells of different origins cannot be differentiated. Dynamic morphology cannot classify the same cell type as benign or malignant.

Anoikis evasion in inflammatory breast cancer cells is mediated by Bim-EL sequestration

PubMed Central

Buchheit, C L; Angarola, B L; Steiner, A; Weigel, K J; Schafer, Z T

2015-01-01

Inflammatory breast cancer (IBC) is a rare and highly invasive type of breast cancer, and patients diagnosed with IBC often face a very poor prognosis. IBC is characterized by the lack of primary tumor formation and the rapid accumulation of cancerous epithelial cells in the dermal lymphatic vessels. Given that normal epithelial cells require attachment to the extracellular matrix (ECM) for survival, a comprehensive examination of the molecular mechanisms underlying IBC cell survival in the lymphatic vessels is of paramount importance to our understanding of IBC pathogenesis. Here we demonstrate that, in contrast to normal mammary epithelial cells, IBC cells evade ECM-detachment-induced apoptosis (anoikis). ErbB2 and EGFR knockdown in KPL-4 and SUM149 cells, respectively, causes decreased colony growth in soft agar and increased caspase activation following ECM detachment. ERK/MAPK signaling was found to operate downstream of ErbB2 and EGFR to protect cells from anoikis by facilitating the formation of a protein complex containing Bim-EL, LC8, and Beclin-1. This complex forms as a result of Bim-EL phosphorylation on serine 59, and thus Bim-EL cannot localize to the mitochondria and cause anoikis. These results reveal a novel mechanism that could be targeted with innovative therapeutics to induce anoikis in IBC cells. PMID:25526094

Anoikis evasion in inflammatory breast cancer cells is mediated by Bim-EL sequestration.

PubMed

Buchheit, C L; Angarola, B L; Steiner, A; Weigel, K J; Schafer, Z T

2015-08-01

Inflammatory breast cancer (IBC) is a rare and highly invasive type of breast cancer, and patients diagnosed with IBC often face a very poor prognosis. IBC is characterized by the lack of primary tumor formation and the rapid accumulation of cancerous epithelial cells in the dermal lymphatic vessels. Given that normal epithelial cells require attachment to the extracellular matrix (ECM) for survival, a comprehensive examination of the molecular mechanisms underlying IBC cell survival in the lymphatic vessels is of paramount importance to our understanding of IBC pathogenesis. Here we demonstrate that, in contrast to normal mammary epithelial cells, IBC cells evade ECM-detachment-induced apoptosis (anoikis). ErbB2 and EGFR knockdown in KPL-4 and SUM149 cells, respectively, causes decreased colony growth in soft agar and increased caspase activation following ECM detachment. ERK/MAPK signaling was found to operate downstream of ErbB2 and EGFR to protect cells from anoikis by facilitating the formation of a protein complex containing Bim-EL, LC8, and Beclin-1. This complex forms as a result of Bim-EL phosphorylation on serine 59, and thus Bim-EL cannot localize to the mitochondria and cause anoikis. These results reveal a novel mechanism that could be targeted with innovative therapeutics to induce anoikis in IBC cells.

Adenoviral vector gene delivery via the round window membrane in guinea pigs.

PubMed

Suzuki, Mitsuya; Yamasoba, Tatsuya; Suzukawa, Keigo; Kaga, Kimitaka

2003-10-27

We have found that damage from a local anesthetic solution containing phenol permitted beta-galactosidase (beta-gal) gene delivery to the guinea pig inner ear via the round window membrane (RWM). RWM damage was evident as degeneration of the outer epithelium. After adenovirus lacZ vector was applied to the damaged RWM, immunohistochemistry showed strong beta-gal expression in the RWM, mesothelial cells, organ of Corti, spiral limbus, spiral ligament and spiral ganglion. In the vestibular labyrinth, expression was seen in the sensory and supporting cells, transitional cells, and the dark-cell area. Thus, adenovirus can transfect a variety of inner ear cells in the guinea pig through a damaged RWM.

Adhesion strength of a living cell to various substrates measured using a cup-attached atomic force microscopy chip

NASA Astrophysics Data System (ADS)

Kim, Hyonchol; Ishibashi, Kenta; Matsuo, Kosuke; Kira, Atsushi; Onomura, Yui; Okada, Tomoko; Nakamura, Chikashi

2018-03-01

Cell adhesion strengths to various substrates were quantitatively measured using atomic force microscopy (AFM). A cup-shaped metal hemisphere was attached to the apex of the AFM cantilever, the “cup-chip” approached a cell (FP10SC2) to pick it up, the captured cell approached any one of six different substrates [gold (Au), nickel (Ni), bovine serum albumin (BSA), an amino group (NH2), poly(tetrafluoroethylene) (PTFE), and structured PTFE (sPTFE)], and the cell adhesion strength at the initial contact period was evaluated by detaching the cell from the substrate. The results obtained showed that the force needed to detach the cell from the NH2 substrate was more than 3-fold larger than that of metal substrates (Au and Ni), more than 15-fold larger than that of biochemically treated substrates (BSA), and more than 20-fold larger than that of hydrophobic substrates (PTFE and sPTFE). Using differences in adhesion strengths, a cell on a sPTFE substrate was picked up using a BSA-coated cup-chip, placed on a NH2 substrate, repeating this cell manipulation five times, and line patterning of cells was achieved. These results indicate that measurements of cell adhesion strength are fundamental to fabricate desired cell networks and the cup-chip is a useful tool for achieving easy cell manipulation.

Detection of alveolar rhabdomyosarcoma in pleural fluid with immunocytochemistry on cell block and determination of PAX/FKHR fusion mRNA by reverse transcription-polymerase chain reaction.

PubMed

Sawangpanich, Ruchchadol; Larbcharoensub, Noppadol; Jinawath, Artit; Pongtippan, Atcharaporn; Anurathapan, Usanarat; Hongeng, Suradej

2011-11-01

Alveolar rhabdomyosarcoma is a primitive malignant round cell neoplasm, which shows skeletal muscle differentiation. Although their histopathologic and immunohistochemical findings are well known, the cytology, immunocytochemistry and molecular study on pleural effusion have not been well documented. To apply molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma. The case of a 14-year-old Thai male, who presented with dyspnea and left pleural effusion. Computed tomography of the chest and abdomen showed a huge heterogeneous enhancing mass at the left retroperitoneum. Pleural fluid cytology showed malignant small round blue cells. Immunocytochemical stains on cell block material showed positive reactivity to vimentin, sarcomeric actin, desmin, MyoD1, myogenin, and CD56 in round cell tumor Reverse transcription-polymerase chain reaction (RT-PCR) demonstrated PAX/FKHR fusion transcript. The patient received chemotherapeutic regimen for advanced-stage rhabdomyosarcoma. Finally, he succumbed to the disease, thirteen months after the diagnosis. Immunocytochemistry on cell block in conjunction with determination of PAX/FKHR fusion mRNA by RT-PCR is a molecular method in the diagnosis and monitoring of alveolar rhabdomyosarcoma inpleural fluid.

Peripheral neuroblastoma in a young Beagle dog.

PubMed

Matsushima, S; Maruyama, T; Torii, M

1998-01-01

A peripheral neuroblastoma was found in the abdominal cavity of a young male beagle dog. The large tumor mass involved the left kidney and both adrenal glands. Histologically, a major portion of the neoplasm consisted of lobulated sheets of small round cells with hyperchromatic nuclei mixed with polygonal cells and neuropil. Small clusters of polygonal cells with abundant eosinophilic cytoplasm and a trabecular growth pattern were observed adjacent to some of the tumor lobules. Small, round neoplastic cells metastasized to lumbar lymph nodes and also to the adrenal glands. The neoplastic cells were positive for neuron-specific enolase, synaptophysin, and neurofilament protein. Electron micrographs revealed intracytoplasmic dense core granules, microtubules, intermediate filaments, and desmosomes in the cytoplasm of the neoplastic cells.

Impact of 10% SF6 Gas Compared to 100% Air Tamponade in Descemet's Membrane Endothelial Keratoplasty.

PubMed

Rickmann, Annekatrin; Szurman, Peter; Jung, Sacha; Boden, Karl Thomas; Wahl, Silke; Haus, Arno; Boden, Katrin; Januschowski, Kai

2018-04-01

To compare the clinical outcomes following Descemet's membrane endothelial keratoplasty (DMEK) with 100% air tamponade versus 10% sulfur hexafluoride (SF 6 ) tamponade. Retrospective analysis of 108 consecutive DMEK cases subdivided by anterior chamber tamponade with 54 eyes receiving 10% SF 6 and 54 eyes receiving 100% air injection. A post-hoc matched analysis revealed no statistically significant differences between the groups. The main outcome measurements were the complication rate, including intra- and postoperative complications and graft detachment rate requiring re-bubbling. Clinical outcome included best-corrected visual acuity (BCVA), endothelial cell count (ECC), and central corneal thickness (CCT) measured 1, 3, and 6 months after DMEK surgery. The graft detachment rate with consecutive re-bubbling was 18.5% in the air group and 22.2% in the SF 6 group (p = 0.2). Remaining small peripheral graft detachments with a clear cornea occurred more often in the 100% air group (air: 22.2%; 12/54, 6/12 inferior compared to SF 6 : 7.4%; 4/54, 2/4 inferior; p = 0.06). The primary graft failure rate was comparable between the two groups. No complete graft detachment occurred. Outcome results for BCVA, ECC, and CCT at all follow-up time points were comparable between the two groups. The clinical outcomes (including re-bubbling rate, primary graft failure rate, and endothelial cell loss) were comparable with 100% air versus 10% SF 6 tamponade, whereas other studies suggest that a higher SF 6 concentration (20%) may result in a lower re-bubbling rate.

Impact of biofilm formation and detachment on the transmission of bacterial antibiotic resistance in drinking water distribution systems.

PubMed

Zhang, Junpeng; Li, Weiying; Chen, Jiping; Qi, Wanqi; Wang, Feng; Zhou, Yanyan

2018-07-01

There is growing awareness of the antibiotic-resistance crisis and its implications for public health among clinicians, researchers, politicians, and the public. We studied bacterial antibiotic resistance transition and the role of biofilms in a drinking water distribution system (DWDS). We tracked several different antibiotic resistant bacteria (ARB) with resistance to tetracycline, sulfamethoxazole, clindamycin, and norfloxacin for one year in a DWDS. The results indicated that the amount of ARB increased in tap water, presumably due to biofilm detachment. The effect of biofilm detachment on the transmission of antibiotic resistance from biofilms to tap water was explored by using a bacterial annular reactor. The percentage of ARB of inlet water, outlet water, and biofilms ranged from 0.26% to 9.85%, 1.08%-16.29%, and 0.52%-29.97%, respectively in a chlorinated system, and from 0.23% to 9.89%, 0.84%-16.84%, and 0.35%-17.77%, respectively, in a chloraminated system. The relative abundances of antibiotic resistance Acinetobacter, Sphingomonas, and Bradyrhizobium were higher in outlet water than in inlet water, as determined by high throughout sequencing. The amount of ARB percentage varied with the concentration of viable but non-culturable (VBNC) cells (r = 0.21, n = 160, P < 0.05) in biofilm, suggesting a higher antibiotic resistance mutation rate in VBNC cells. Our results suggest that biofilm detachment was promoted by disinfectant and affected the overall bacterial antibiotic resistance of microbes in tap water. Copyright © 2018 Elsevier Ltd. All rights reserved.

A New In Vitro Model of Breast Cancer Metastasis to Bone

DTIC Science & Technology

2010-04-01

excessive cell vacuolization, ruffled cell margins , and increasing rates of cell-surface detachment. Thus, conventional tissue-culture strategies...determined. 3050 DHURJATI ET AL. apoptotic bodies, cytoplasmic vesiculation, and chromatin margination (Fig. 3) and a distinct loss of insoluble ECM...respond abnormally to various hor- mones and cytokines compared to normal, differen- tiated human osteoblasts. In effort to overcome these limitations

[CD34(+)/CD123(+) cell sorting from the patients with leukemia by Midi MACS method].

PubMed

Wang, Guang-Ping; Cao, Xin-Yu; Xin, Hong-Ya; Li, Qun; Qi, Zhen-Hua; Chen, Fang-Ping

2006-10-01

The aim of this study was to sort the CD34(+)/CD123(+) cells from the bone marrow cells of patients with acute myeloid leukemia (AML) by Midi MACS method. Firstly, the bone marrow mononuclear cells (BMMNC) were isolated from the patients with AML with Ficoll Paque, CD34(+) cells were then isolated by Midi MACS method followed by the isolation of CD34(+)/CD123(+) cells from the fraction of CD34(+) cells. The enrichment and recovery of CD34(+) and CD34(+)/CD123(+) cells were assayed by FACS technique. The results showed that the enrichment of CD34(+) cells was up to 98.73%, its average enrichment was 95.6%, and the recovery of CD34(+) was 84.6%, its average recovery was 51% after the first round sorting, by the second round sorting, the enrichment of CD34(+)/CD123(+) cells was up to 99.23%, its average enrichment was 83%. With regard to BMMNCs before sorting, the recovery of CD34(+)/CD123(+) was 34%. But, on the CD34(+) cells obtained by the first round sorting, its recovery was 56%. In conclusion, these results confirmed that the method of Midi MACS sorting can be applied to sort CD34(+)/CD123(+) cells from the bone marrow cells of AML patients, which give rise to the similar enrichment and recovery of the sorted cells with that of literature reported by the method of FACS.

BCOR-CCNB3-positive soft tissue sarcoma with round-cell and spindle-cell histology: a series of four cases highlighting the pitfall of mimicking poorly differentiated synovial sarcoma.

PubMed

Li, Wan-Shan; Liao, I-Chuang; Wen, Mei-Chin; Lan, Howard Haw-Chang; Yu, Shih-Chen; Huang, Hsuan-Ying

2016-11-01

BCOR-CCNB3 sarcoma is a genetically defined undifferentiated malignancy with Ewing sarcoma (ES)-like round cells, and preferentially affects the bones of male adolescents. Sarcomas harbouring BCOR-CCNB3 rarely arise from soft tissues; therefore, we aimed to report four cases to expand the clinicopathological spectrum. By reverse transcription polymerase chain reaction and confirmatory sequencing, we detected a BCOR-CCNB3 transcript in primary undifferentiated sarcomas of the deep musculature of four male patients, comprising two teenagers (aged 14 and 17 years) and two adults (aged 34 and 44 years). The tumours originated in the back (n = 2), pelvis (n = 1), and thigh (n = 1), and were 70-140 mm in size (mean, 107 mm). All tumours showed sheets of primitive round or ovoid cells with vesicular nuclei, active mitosis (28-41/10 high-power fields), variably prominent nucleoli, and geographical necrosis. This major component transformed into fascicles of elongated spindle cells with staghorn vessels and a myxoid reticular stroma, accounting for 10-50% of areas. All cases were positive for CD99, three were positive for TLE1, and one was positive for EMA, indicating poorly differentiated synovial sarcomas (PDSSs). Nuclear cyclin B3 reactivity was present in all cases, but not in molecularly confirmed atypical ESs and PDSSs. At the last follow-up (median, 13.5 months), one patient had died of lung metastasis, two were alive with tumours, and one was tumour-free. BCOR-CCNB3-positive sarcomas may primarily occur in soft tissues of adults and show PDSS-mimicking round-cell and spindle-cell histology with aggressive behaviour. Cyclin B3 is useful for selecting candidates for BCOR-CCNB3 molecular testing. © 2016 John Wiley & Sons Ltd.

Interactions of Entamoeba Histolytica with Host Cells in the Gut Mucosa,

DTIC Science & Technology

1977-01-01

amebae were observed close to the cecal epithelium, the apposing epithelial cell was found to have protruded in the lumen and making contact with the... amebae . Such cells often had become detached from their basal lamina and intercellular tight junctions, affording spaces through which amebae invaded the...mucosa. Other epithelial cells in close proximity to amebae showed degenerative changes characterized by swelling of mitochondria and endoplasmic

Positioning of the sensor cell on the sensing area using cell trapping pattern in incubation type planar patch clamp biosensor.

PubMed

Wang, Zhi-Hong; Takada, Noriko; Uno, Hidetaka; Ishizuka, Toru; Yawo, Hiromu; Urisu, Tsuneo

2012-08-01

Positioning the sensor cell on the micropore of the sensor chip and keeping it there during incubation are problematic tasks for incubation type planar patch clamp biosensors. To solve these problems, we formed on the Si sensor chip's surface a cell trapping pattern consisting of a lattice pattern with a round area 5 μm deep and with the micropore at the center of the round area. The surface of the sensor chip was coated with extra cellular matrix collagen IV, and HEK293 cells on which a chimera molecule of channel-rhodopsin-wide-receiver (ChR-WR) was expressed, were then seeded. We examined the effects of this cell trapping pattern on the biosensor's operation. In the case of a flat sensor chip without a cell trapping pattern, it took several days before the sensor cell covered the micropore and formed an almost confluent state. As a result, multi-cell layers easily formed and made channel current measurements impossible. On the other hand, the sensor chip with cell trapping pattern easily trapped cells in the round area, and formed the colony consisted of the cell monolayer covering the micropore. A laser (473 nm wavelength) induced channel current was observed from the whole cell arrangement formed using the nystatin perforation technique. The observed channel current characteristics matched measurements made by using a pipette patch clamp. Copyright © 2012 Elsevier B.V. All rights reserved.

Alternating sequential chemotherapy with high-dose ifosfamide and doxorubicin/cyclophosphamide for adult non-small round cell soft tissue sarcomas.

PubMed

Kawai, Akira; Umeda, Toru; Wada, Takuro; Ihara, Koichiro; Isu, Kazuo; Abe, Satoshi; Ishii, Takeshi; Sugiura, Hideshi; Araki, Nobuhito; Ozaki, Toshifumi; Yabe, Hiroo; Hasegawa, Tadashi; Tsugane, Shoichiro; Beppu, Yasuo

2005-05-01

Doxorubicin and ifosfamide are the two most active agents used to treat soft tissue sarcomas. However, because of their overlapping side effects, concurrent administration to achieve optimal doses of each agent is difficult. We therefore conducted a Phase II trial to investigate the efficacy and feasibility of a novel alternating sequential chemotherapy regimen consisting of high dose ifosfamide and doxorubicin/cyclophosphamide in advanced adult non-small round cell soft tissue sarcomas. Adult patients with non-small round cell soft tissue sarcomas were enrolled. The treatment consisted of four sequential courses of chemotherapy that was planned for every 3 weeks. Cycles 1 and 3 consisted of ifosfamide (14 g/m(2)), and cycles 2 and 4 consisted of doxorubicin (60 mg/m(2)) and cyclophosphamide (1200 mg/m(2)). Forty-two patients (median age 47 years) were enrolled. Of the 36 assessable patients, 1 complete response and 16 partial responses were observed, for a response rate of 47.2%. Responses were observed in 57% of patients who had received no previous chemotherapy and 13% of those who had previously undergone chemotherapy. Grade 3-4 neutropenia was observed during 70% of all cycles. Sequential administration of high-dose ifosfamide and doxorubicin/cyclophosphamide has promising activity with manageable side effects in patients with advanced adult non-small round cell soft tissue sarcomas.

FIBER AND INTEGRATED OPTICS: Optical anisotropy induced in a round trip through single-mode optical waveguides and methods for suppression of this anisotropy

NASA Astrophysics Data System (ADS)

Gelikonov, V. M.; Leonov, V. I.; Novikov, M. A.

1989-09-01

An analysis is made of the characteristics of the transformation of the polarization of light in the course of a round trip in a single-mode fiber waveguide. The Poincaré equivalence theorems are generalized for a round trip through such fibers. An investigation is reported of round-trip anisotropic properties which can be used to compensate for a regular and an irregular anisotropy of a fiber waveguide. A description is given of a compensation system containing a Faraday cell and an experimental check of the theoretical conclusions is reported.

Numerical simulations used for a validity check on the laser induced photo-detachment diagnostic method in electronegative plasmas

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

Oudini, N.; Taccogna, F.; Bendib, A.

2014-06-15

Laser photo-detachment is used as a method to measure or determine the negative ion density and temperature in electronegative plasmas. In essence, the method consists of producing an electropositive channel (negative ion free region) via pulsed laser photo-detachment within an electronegative plasma bulk. Electrostatic probes placed in this channel measure the change in the electron density. A second pulse might be used to track the negative ion recovery. From this, the negative ion density and temperature can be determined. We study the formation and relaxation of the electropositive channel via a two-dimensional Particle-In-Cell/Mote Carlo collision model. The simulation is mainlymore » carried out in a Hydrogen plasma with an electronegativity of α = 1, with a parametric study for α up to 20. The temporal and spatial evolution of the plasma potential and the electron densities shows the formation of a double layer (DL) confining the photo-detached electrons within the electropositive channel. This DL evolves into two fronts that move in the opposite directions inside and outside of the laser spot region. As a consequence, within the laser spot region, the background and photo-detached electron energy distribution function relaxes/thermalizes via collisionless effects such as Fermi acceleration and Landau damping. Moreover, the simulations show that collisional effects and the DL electric field strength might play a non-negligible role in the negative ion recovery within the laser spot region, leading to a two-temperature negative ion distribution. The latter result might have important effects in the determination of the negative ion density and temperature from laser photo detachment diagnostic.« less

Effectiveness of a dynein team in a tug of war helped by reduced load sensitivity of detachment: evidence from the study of bidirectional endosome transport in D. discoideum.

PubMed

Bhat, Deepak; Gopalakrishnan, Manoj

2012-08-01

Bidirectional cargo transport by molecular motors in cells is a complex phenomenon in which the cargo (usually a vesicle) alternately moves in retrograde and anterograde directions. In this case, teams of oppositely pulling motors (e.g., kinesin and dynein) bind to the cargo, simultaneously, and 'coordinate' their activity such that the motion consists of spells of positively and negatively directed segments, separated by pauses of varying duration. A set of recent experiments have analyzed the bidirectional motion of endosomes in the amoeba D. discoideum in detail. It was found that in between directional switches, a team of five to six dyneins stall a cargo against a stronger kinesin in a tug of war, which lasts for almost a second. As the mean detachment time of a kinesin under its stall load was also observed to be ∼1 s, we infer that the collective detachment time of the dynein assembly must also be similar. Here, we analyze this inference from a modeling perspective, using experimentally measured single-molecule parameters as inputs. We find that the commonly assumed exponential load-dependent detachment rate is inconsistent with observations, as it predicts that a five-dynein assembly will detach under its combined stall load in less than a hundredth of a second. A modified model where the load-dependent unbinding rate is assumed to saturate at stall-force level for super-stall loads gives results which are in agreement with experimental data. Our analysis suggests that the load-dependent detachment of a dynein in a team is qualitatively different at sub-stall and super-stall loads, a conclusion which is likely to have implications in other situations involving collective effects of many motors.

Numerical simulations used for a validity check on the laser induced photo-detachment diagnostic method in electronegative plasmas

NASA Astrophysics Data System (ADS)

Oudini, N.; Taccogna, F.; Bendib, A.; Aanesland, A.

2014-06-01

Laser photo-detachment is used as a method to measure or determine the negative ion density and temperature in electronegative plasmas. In essence, the method consists of producing an electropositive channel (negative ion free region) via pulsed laser photo-detachment within an electronegative plasma bulk. Electrostatic probes placed in this channel measure the change in the electron density. A second pulse might be used to track the negative ion recovery. From this, the negative ion density and temperature can be determined. We study the formation and relaxation of the electropositive channel via a two-dimensional Particle-In-Cell/Mote Carlo collision model. The simulation is mainly carried out in a Hydrogen plasma with an electronegativity of α = 1, with a parametric study for α up to 20. The temporal and spatial evolution of the plasma potential and the electron densities shows the formation of a double layer (DL) confining the photo-detached electrons within the electropositive channel. This DL evolves into two fronts that move in the opposite directions inside and outside of the laser spot region. As a consequence, within the laser spot region, the background and photo-detached electron energy distribution function relaxes/thermalizes via collisionless effects such as Fermi acceleration and Landau damping. Moreover, the simulations show that collisional effects and the DL electric field strength might play a non-negligible role in the negative ion recovery within the laser spot region, leading to a two-temperature negative ion distribution. The latter result might have important effects in the determination of the negative ion density and temperature from laser photo detachment diagnostic.

Morphologic and functional alterations induced by low doses of mercuric chloride in the kidney OK cell line: ultrastructural evidence for an apoptotic mechanism of damage.

PubMed

Carranza-Rosales, Pilar; Said-Fernández, Salvador; Sepúlveda-Saavedra, Julio; Cruz-Vega, Delia E; Gandolfi, A Jay

2005-06-01

Mercury produces acute renal failure in experimental animal models, but the mechanism of tubular injury has not completely been clarified. There is an increased interest in the role of apoptosis in the pathogenesis of renal diseases that result primarily from injury to renal tubular epithelial cells. However, detailed studies of morpho-functional alterations induced by mercuric chloride in kidney cell lines are scarce. This work characterizes these alterations in OK cell cultures. Morphological alterations were profiled using light microscopy, transmission electron microscopy, and confocal microscopy, as well as mitochondrial functional assays in the cells exposed to low concentrations of HgCl2. At concentrations of 1 and 10 microM of HgCl2 there were no morphological or ultrastructural alterations, but the mitochondrial function (MTT assay) and intracellular ATP content was increased, especially at longer incubation times (6 and 9 h). At 15 microM HgCl2, both the mitochondrial activity and the endogenous ATP decreased significantly. At this concentration the OK cells rounded up, had increased number of cytoplasmic vacuoles, and detached from the cell monolayer. At 15 microM HgCl2 ultrastructural changes were characterized by dispersion of the ribosomes, dilatation of the cisterns of the rough endoplasmic reticulum, increase of number of cytoplasmic vacuoles, chromatin condensation, invaginations of the nuclear envelope, presence of cytoplasmic inclusion bodies, and alterations in the size and morphology of mitochondria. At 15 microM HgCl2 apoptotic signs included membrane blebbing, chromatin condensation, mitochondrial alterations, apoptotic bodies, and nuclear envelope rupture. Using confocal microscopy and the mitochondrial specific dye MitoTracker Red, it was possible to establish qualitative changes induced by mercury on the mitochondrial membrane potential after incubation of the cells for 6 and 9h with 15 microM HgCl2. This effect was not observed at short times (1 and 3h) with this same concentration, neither with 1 and 10 microM HgCl2 in all the studied times. Taken together, these findings indicate that low concentrations of HgCl2 induce apoptosis by inhibiting mitochondrial function, and the OK cell line may be considered a useful tool for the study of programmed cell death involving mercurial species and other heavy metals.

Anti-trypanosomal activity of cationic N-heterocyclic carbene gold(I) complexes.

PubMed

Winter, Isabel; Lockhauserbäumer, Julia; Lallinger-Kube, Gertrud; Schobert, Rainer; Ersfeld, Klaus; Biersack, Bernhard

2017-06-01

Two gold(I) N-heterocyclic carbene complexes 1a and 1b were tested for their anti-trypanosomal activity against Trypanosoma brucei parasites. Both gold compounds exhibited excellent anti-trypanosomal activity (IC 50 =0.9-3.0nM). The effects of the gold complexes 1a and 1b on the T. b. brucei cytoskeleton were evaluated. Rapid detachment of the flagellum from the cell body occurred after treatment with the gold complexes. In addition, a quick and complete degeneration of the parasitic cytoskeleton was induced by the gold complexes, only the microtubules of the detached flagellum remained intact. Both gold compounds 1a and 1b feature selective anti-trypanosomal agents and were distinctly more active against T. b. brucei cells than against human HeLa cells. Thus, the gold complexes 1a and 1b feature promising drug candidates for the treatment of trypanosome infections such as sleeping sickness (human African Trypanosomiasis caused by Trypanosoma brucei parasites). Copyright © 2017 Elsevier B.V. All rights reserved.

Network theory inspired analysis of time-resolved expression data reveals key players guiding P. patens stem cell development.

PubMed

Busch, Hauke; Boerries, Melanie; Bao, Jie; Hanke, Sebastian T; Hiss, Manuel; Tiko, Theodhor; Rensing, Stefan A

2013-01-01

Transcription factors (TFs) often trigger developmental decisions, yet, their transcripts are often only moderately regulated and thus not easily detected by conventional statistics on expression data. Here we present a method that allows to determine such genes based on trajectory analysis of time-resolved transcriptome data. As a proof of principle, we have analysed apical stem cells of filamentous moss (P. patens) protonemata that develop from leaflets upon their detachment from the plant. By our novel correlation analysis of the post detachment transcriptome kinetics we predict five out of 1,058 TFs to be involved in the signaling leading to the establishment of pluripotency. Among the predicted regulators is the basic helix loop helix TF PpRSL1, which we show to be involved in the establishment of apical stem cells in P. patens. Our methodology is expected to aid analysis of key players of developmental decisions in complex plant and animal systems.

Growth Angle - a Microscopic View

NASA Technical Reports Server (NTRS)

Mazurak, K.; Volz, M. P.; Croll, A.

2017-01-01

The growth angle that is formed between the side of the growing crystal and the melt meniscus is an important parameter in the detached Bridgman crystal growth method, where it determines the extent of the crystal-crucible wall gap, and in the Czochralski and float zone methods, where it influences the size and stability of the crystals. The growth angle is a non-equilibrium parameter, defined for the crystal growth process only. For a melt-crystal interface translating towards the crystal (melting), there is no specific angle defined between the melt and the sidewall of the solid. In this case, the corner at the triple line becomes rounded, and the angle between the sidewall and the incipience of meniscus can take a number of values, depending on the position of the triple line. In this work, a microscopic model is developed in which the fluid interacts with the solid surface through long range van der Waals or Casimir dispersive forces. This growth angle model is applied to Si and Ge and compared with the macroscopic approach of Herring. In the limit of a rounded corner with a large radius of curvature, the wetting of the melt on the crystal is defined by the contact angle. The proposed microscopic approach addresses the interesting issue of the transition from a contact angle to a growth angle as the radius of curvature decreases.

Solid-Pattern Desmoplastic Small Round Cell Tumor.

PubMed

Ali, Ahmed; Mohamed, Mustafa; Chisholm, Julia; Thway, Khin

2017-04-01

Desmoplastic small round cell tumor (DSRCT) is an aggressive small round cell sarcoma that typically occurs intra-abdominally in adolescents and young adults, and is characterized by a recurrent t(11;22)(p13;q12) translocation leading to generation of the EWSR1-WT1 fusion gene, which codes for a chimeric protein with transcriptional regulatory activity. DSRCT has a characteristic histologic appearance of nests of uniform small cells within prominent fibroblastic stroma and immunohistochemically it shows multidirectional differentiation, with expression of epithelial, neural, and muscle markers. We illustrate a case of DSRCT that presented as a large intra-abdominal mass, which harbored EWSR1 rearrangement by fluorescence in situ hybridization and EWSR1-WT1 fusion transcripts by reverse transcription-polymerase chain reaction (RT-PCR), and which histologically had an entirely solid morphology, lacking evidence of desmoplastic stroma. This purely solid variant emphasizes that even when occurring at a typical location, DSRCT may be difficult to recognize when lacking nonclassical morphology. This is of clinical relevance, as DSRCT with this pattern could be misdiagnosed as Ewing sarcoma if RT-PCR is not performed, with resulting prognostic and therapeutic implications.

NUTM2A-CIC fusion small round cell sarcoma: a genetically distinct variant of CIC-rearranged sarcoma.

PubMed

Sugita, Shintaro; Arai, Yasuhito; Aoyama, Tomoyuki; Asanuma, Hiroko; Mukai, Wakako; Hama, Natsuko; Emori, Makoto; Shibata, Tatsuhiro; Hasegawa, Tadashi

2017-07-01

CIC-rearranged sarcoma is a new entity of undifferentiated small round cell sarcoma characterized by chimeric fusions with CIC rearrangement. We report a NUTM2A-CIC fusion sarcoma in a 43-year-old woman who died of rapidly progressive disease. Histologic analysis revealed multinodular proliferation of small round tumor cells with mild nuclear pleomorphism. The sclerotic fibrous septa separated the tumor into multiple nodules. Immunohistochemistry showed that the tumor cells were diffusely positive for vimentin, focally positive for cytokeratin, and negative for CD99 and NKX2.2. Tumor cells were also negative for ETV4, which was recently identified as a specific marker for CIC-rearranged sarcoma. High-throughput RNA sequencing of a formalin-fixed, paraffin-embedded clinical sample unveiled a novel NUTM2A-CIC fusion between NUTM2A exon 7 and CIC exon 12, and fluorescence in situ hybridization identified CIC and NUTM2A split signals. This case shared several clinicopathological findings with previously reported CIC-rearranged cases. We recognized the tumor as a genetically distinct variant of CIC-rearranged sarcomas with a novel NUTM2A-CIC fusion. Copyright © 2017. Published by Elsevier Inc.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis.

PubMed

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Suárez-Rivero, Juan Miguel; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia; Sánchez-Alcázar, José A

2017-11-11

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new "two coffins" hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis.

Dynamic Reorganization of the Cytoskeleton during Apoptosis: The Two Coffins Hypothesis

PubMed Central

Povea-Cabello, Suleva; Oropesa-Ávila, Manuel; de la Cruz-Ojeda, Patricia; Villanueva-Paz, Marina; de la Mata, Mario; Álvarez-Córdoba, Mónica; Villalón-García, Irene; Cotán, David; Ybot-González, Patricia

2017-01-01

During apoptosis, cells undergo characteristic morphological changes in which the cytoskeleton plays an active role. The cytoskeleton rearrangements have been mainly attributed to actinomyosin ring contraction, while microtubule and intermediate filaments are depolymerized at early stages of apoptosis. However, recent results have shown that microtubules are reorganized during the execution phase of apoptosis forming an apoptotic microtubule network (AMN). Evidence suggests that AMN is required to maintain plasma membrane integrity and cell morphology during the execution phase of apoptosis. The new “two coffins” hypothesis proposes that both AMN and apoptotic cells can adopt two morphological patterns, round or irregular, which result from different cytoskeleton kinetic reorganization during the execution phase of apoptosis induced by genotoxic agents. In addition, round and irregular-shaped apoptosis showed different biological properties with respect to AMN maintenance, plasma membrane integrity and phagocyte responses. These findings suggest that knowing the type of apoptosis may be important to predict how fast apoptotic cells undergo secondary necrosis and the subsequent immune response. From a pathological point of view, round-shaped apoptosis can be seen as a physiological and controlled type of apoptosis, while irregular-shaped apoptosis can be considered as a pathological type of cell death closer to necrosis. PMID:29137119

Annexin A2 in Proliferative Vitreoretinopathy

DTIC Science & Technology

2017-10-01

cells , leading to formation of an epiretinal membrane, retinal detachment, and loss of vision. At present, there are no reliable means of...type versus annexin A2- deficient mice, [2] define the role of A2 in the function of activated macrophages and RPE cells in PVR, and [3] examine the...expression is needed in both macrophages and RPE cells , and that A2 is extensively expressed within cells of epiretinal membranes in human PVR. Our

NKX2.2 is a useful immunohistochemical marker for Ewing sarcoma.

PubMed

Yoshida, Akihiko; Sekine, Shigeki; Tsuta, Koji; Fukayama, Masashi; Furuta, Koh; Tsuda, Hitoshi

2012-07-01

Ewing sarcoma is a high-grade round cell sarcoma that affects bones and soft tissues in children and young adults. Its diagnosis can be challenging, and the differential diagnoses include a wide variety of small round cell tumors. CD99 and FLI-1 are the currently accepted immunohistochemical markers for Ewing sarcoma, but their accuracy has been controversial. NKX2.2 is a homeodomain-containing transcription factor that plays a critical role in neuroendocrine/glial differentiation. The NKX2.2 gene was recently identified as a target of EWS-FLI-1, the fusion protein specific to Ewing sarcoma, and was shown to be differentially upregulated in Ewing sarcoma on the basis of array-based gene expression analysis. However, the immunohistochemical diagnostic potential of this marker has not been tested. We immunostained representative sections of 30 genetically confirmed Ewing sarcomas and 130 non-Ewing small round cell tumors by using an antibody to NKX2.2. Nuclear staining in at least 5% of the cells was deemed positive. Twenty-eight (93%) of the 30 Ewing sarcomas were positive for NKX2.2. The staining was diffuse (>50%) in all the positive cases and was moderate or strong in intensity for most cases (25 of 28). NKX2.2 was also positive in 14 non-Ewing tumors, including all the olfactory neuroblastomas and a minor subset of small cell carcinomas, synovial sarcomas, mesenchymal chondrosarcomas, and malignant melanomas. All the other non-Ewing tumors tested were negative for this marker. NKX2.2 is a valuable marker for Ewing sarcoma, with a sensitivity of 93% and a specificity of 89%, and aids in the differential diagnosis of small round cell tumors.

Extracting archaeal populations from iron oxidizing systems

NASA Astrophysics Data System (ADS)

Whitmore, L. M.; Hutchison, J.; Chrisler, W.; Jay, Z.; Moran, J.; Inskeep, W.; Kreuzer, H.

2013-12-01

Unique environments in Yellowstone National Park offer exceptional conditions for studying microorganisms in extreme and constrained systems. However, samples from some extreme systems often contain inorganic components that pose complications during microbial and molecular analysis. Several archaeal species are found in acidic, geothermal ferric-oxyhydroxide mats; these species have been shown to adhere to mineral surfaces in flocculated colonies. For optimal microbial analysis, (microscopy, flow cytometry, genomic extractions, proteomic analysis, stable isotope analysis, and others), improved techniques are needed to better facilitate cell detachment and separation from mineral surfaces. As a requirement, these techniques must preserve cell structure while simultaneously minimizing organic carryover to downstream analysis. Several methods have been developed for removing sediments from mixed prokaryotic populations, including ultra-centrifugation, nycodenz gradient, sucrose cushions, and cell straining. In this study we conduct a comparative analysis of mechanisms used to detach archaeal cell populations from the mineral interface. Specifically, we evaluated mechanical and chemical approaches for cell separation and homogenization. Methods were compared using confocal microscopy, flow cytometry analyses, and real-time PCR detection. The methodology and approaches identified will be used to optimize biomass collection from environmental specimens or isolates grown with solid phases.

Transcriptional reprogramming of gene expression in bovine somatic cell chromatin transfer embryos

PubMed Central

Rodriguez-Osorio, Nelida; Wang, Zhongde; Kasinathan, Poothappillai; Page, Grier P; Robl, James M; Memili, Erdogan

2009-01-01

Background Successful reprogramming of a somatic genome to produce a healthy clone by somatic cells nuclear transfer (SCNT) is a rare event and the mechanisms involved in this process are poorly defined. When serial or successive rounds of cloning are performed, blastocyst and full term development rates decline even further with the increasing rounds of cloning. Identifying the "cumulative errors" could reveal the epigenetic reprogramming blocks in animal cloning. Results Bovine clones from up to four generations of successive cloning were produced by chromatin transfer (CT). Using Affymetrix bovine microarrays we determined that the transcriptomes of blastocysts derived from the first and the fourth rounds of cloning (CT1 and CT4 respectively) have undergone an extensive reprogramming and were more similar to blastocysts derived from in vitro fertilization (IVF) than to the donor cells used for the first and the fourth rounds of chromatin transfer (DC1 and DC4 respectively). However a set of transcripts in the cloned embryos showed a misregulated pattern when compared to IVF embryos. Among the genes consistently upregulated in both CT groups compared to the IVF embryos were genes involved in regulation of cytoskeleton and cell shape. Among the genes consistently upregulated in IVF embryos compared to both CT groups were genes involved in chromatin remodelling and stress coping. Conclusion The present study provides a data set that could contribute in our understanding of epigenetic errors in somatic cell chromatin transfer. Identifying "cumulative errors" after serial cloning could reveal some of the epigenetic reprogramming blocks shedding light on the reprogramming process, important for both basic and applied research. PMID:19393066

Histopathological and immunohistochemical findings associated with a null mutation in the Norrie disease gene.

PubMed

Schroeder, B; Hesse, L; Brück, W; Gal, A

1997-06-01

To determine the clinical, histopathological, and immunohistochemical ocular changes associated with a null mutation in the Norrie disease protein (NDP) gene. Tissue from a six-month-old boy with bilateral retrolental membranes and retinal detachment was obtained during vitreoretinal surgery. Histological sections were stained immunohistochemically with specific antibodies. No eye diseases with severe visual impairment or blindness were reported in the parents and their families. The NDP gene was analyzed by standard molecular genetic methods. A severe reduction in the number of retinal ganglion cells and a largely disarranged and hypoplastic inner nuclear layer were visible in the tissue specimen. Areas of the tissue with advanced pathology displayed massive fibrovascular proliferation in the vitreous cavity. Shrinkage and traction resulted in folding and detachment of the outer retina. Immunohistochemical reactivity for MIB(1) antigen demonstrated many proliferating cells in the vitreous, but no proliferative activity in the neuroretina. Retinal neurons showed a high grade of differentiation and expressed uniformly neuron-specific enolase and synaptophysin. A 1-base pair insertion (544/545insA) in the NDP gene was found in the affected boy. This mutation predicts a 'functional null-allele' due to a shift in the reading frame and, thus, a premature termination of mRNA translation after 55 instead of 133 amino acids. Loss of function of the NDP gene causes marked hypoplasia of the inner retinal cell layers and fibrovascular proliferation in the vitreous cavity, leading to retinal folding and detachment. The NDP therefore seems to play a critical role in terminal differentiation of the inner retinal cell layers and establishment and maintaining of anti-proliferative cellular interactions in the vitreous.

User-centered development of a smart phone mobile application delivering personalized real-time advice on sun protection.

PubMed

Buller, David B; Berwick, Marianne; Shane, James; Kane, Ilima; Lantz, Kathleen; Buller, Mary Klein

2013-09-01

Smart phones are changing health communication for Americans. User-centered production of a mobile application for sun protection is reported. Focus groups (n = 16 adults) provided input on the mobile application concept. Four rounds of usability testing were conducted with 22 adults to develop the interface. An iterative programming procedure moved from a specification document to the final mobile application, named Solar Cell. Adults desired a variety of sun protection advice, identified few barriers to use and were willing to input personal data. The Solar Cell prototype was improved from round 1 (seven of 12 tasks completed) to round 2 (11 of 12 task completed) of usability testing and was interoperable across handsets and networks. The fully produced version was revised during testing. Adults rated Solar Cell as highly user friendly (mean = 5.06). The user-centered process produced a mobile application that should help many adults manage sun safety.

Inconspicuous Insertion 22;12 in Myxoid/Round Cell Liposarcoma Accompanied by the Secondary Structural Abnormality der(16)t(1;16)

PubMed Central

Birch, Nathan C.; Antonescu, Cristina R.; Nelson, Marilu; Sarran, Lisa; Neff, James R.; Seemayer, Thomas; Bridge, Julia A.

2003-01-01

In myxoid/round cell liposarcoma, the t(12;16)(q13;p11) and its associated fusion transcript, FUS-CHOP, characterize greater than 95% of cases. The variant translocation t(12;22)(q13;q12) and associated EWS-CHOP fusion transcript are rare. A second non-random aberration observed in roughly 20% of Ewing’s sarcomas, and to a lesser extent other select sarcomas, is the unbalanced 1;16 translocation. Recognition of this secondary aberration in the absence of an obvious primary karyotypic abnormality strongly suggests that the use of other genetic approaches will be informative in uncovering a clinically suspected primary anomaly. The following case illustrates the utility of molecular cytogenetic and reverse transcriptase-polymerase chain reaction techniques in diagnosing an ins(22;12)(q12;q13q14) and associated EWS-CHOP fusion transcript in a myxoid/round cell liposarcoma exhibiting a der(16)t(1;16)(q11;q11). PMID:12876210

Inconspicuous insertion 22;12 in myxoid/round cell liposarcoma accompanied by the secondary structural abnormality der(16)t(1;16).

PubMed

Birch, Nathan C; Antonescu, Cristina R; Nelson, Marilu; Sarran, Lisa; Neff, James R; Seemayer, Thomas; Bridge, Julia A

2003-08-01

In myxoid/round cell liposarcoma, the t(12;16)(q13;p11) and its associated fusion transcript, FUS-CHOP, characterize greater than 95% of cases. The variant translocation t(12;22)(q13;q12) and associated EWS-CHOP fusion transcript are rare. A second non-random aberration observed in roughly 20% of Ewing's sarcomas, and to a lesser extent other select sarcomas, is the unbalanced 1;16 translocation. Recognition of this secondary aberration in the absence of an obvious primary karyotypic abnormality strongly suggests that the use of other genetic approaches will be informative in uncovering a clinically suspected primary anomaly. The following case illustrates the utility of molecular cytogenetic and reverse transcriptase-polymerase chain reaction techniques in diagnosing an ins(22;12)(q12;q13q14) and associated EWS-CHOP fusion transcript in a myxoid/round cell liposarcoma exhibiting a der(16)t(1;16)(q11;q11).

Oocyte-activating capacity of fresh and frozen-thawed spermatids in the common marmoset (Callithrix jacchus).

PubMed

Ogonuki, Narumi; Inoue, Hiroki; Matoba, Shogo; Kurotaki, Yoko K; Kassai, Hidetoshi; Abe, Yukiko; Sasaki, Erika; Aiba, Atsu; Ogura, Atsuo

2018-02-19

The common marmoset (Callithrix jacchus) represents a promising nonhuman primate model for the study of human diseases because of its small size, ease of handling, and availability of gene-modified animals. Here, we aimed to devise reproductive technology for marmoset spermatid injection using immature males for a possible rapid generational turnover. Spermatids at each step could be identified easily by their morphology under differential interference microscopy: thus, early round spermatids had a round nucleus with a few nucleolus-like structures and abundant cytoplasm, as in other mammals. The spermatids acquired oocyte-activating capacity at the late round spermatid stage, as confirmed by the resumption of meiosis and Ca 2+ oscillations upon injection into mouse oocytes. The spermatids could be cryopreserved efficiently with a simple medium containing glycerol and CELL BANKER®. Late round or elongated spermatids first appeared at 10-12 months of age, 6-8 months before sexual maturation. Marmoset oocytes microinjected with frozen-thawed late round or elongated spermatids retrieved from a 12-month-old male marmoset developed to the 8-cell stage without the need for artificial oocyte activation stimulation. Thus, it might be possible to shorten the intergeneration time by spermatid injection, from 2 years (by natural mating) to 13-15 months including gestation. © 2018 Wiley Periodicals, Inc.

Intraabdominal desmoplastic small round cell tumor: Report of a case and literature review.

PubMed

Koniari, Katerina; Mahera, Helen; Nikolaou, Marinos; Chatzis, Odysseas; Glezakou, Ourania; Magiasis, Vasilios; Kiratzis, Georgios

2011-01-01

Desmoplastic small round cell tumor is a rare malignancy with poor prognosis that predominantly affects young males. Its etiopathogenesis is still unknown and diagnosis can be achieved only by immunohistochemistry and cytogenetic studies. Due to our limited knowledge of the pathologic and clinical nature of this disease, there is no clear consensus regarding the optimal therapeutic procedures for treating this neoplasm. A high degree of care and improvements in diagnostic capabilities are required in order to identify this entity and avoid misdiagnosis. We report a new case of a 29-year-old male who proceeded to our Emergency Department complaining about non-specific abdominal pain. Physical examination revealed no abnormalities except for a palpable mass in the lower abdomen and a diffuse abdominal pain. Computed Tomography scan showed enlarged paraortic and mesenteric lymphadenopathy, thickness of the small bowel wall and dispersed masses intraperitoneally. He underwent an exploratory laparotomy and the resultant biopsy revealed desmoplastic small round cell tumor. Diagnosis of desmoplastic small round cell tumor can easily be missed because it presents with few early warning symptoms and signs, while the routine blood tests are within normal limits. A high degree of suspicion, a thorough physical examination, a full imaging check and an aggressive therapeutic approach are required in order to identify this disease and fight for a better quality of life for these patients. In addition we make a review of the literature in an effort to clarify the epidemiological, clinical and pathological aspects of this entity.

Gene Transcription Profile of the Detached Retina (An AOS Thesis)

PubMed Central

Zacks, David N.

2009-01-01

Purpose: Separation of the neurosensory retina from the retinal pigment epithelium (RPE) yields many morphologic and functional consequences, including death of the photoreceptor cells, Müller cell hypertrophy, and inner retinal rewiring. Many of these changes are due to the separation-induced activation of specific genes. In this work, we define the gene transcription profile within the retina as a function of time after detachment. We also define the early activation of kinases that might be responsible for the detachment-induced changes in gene transcription. Methods: Separation of the retina from the RPE was induced in Brown-Norway rats by the injection of 1% hyaluronic acid into the subretinal space. Retinas were harvested at 1, 7, and 28 days after separation. Gene transcription profiles for each time point were determined using the Affymetrix Rat 230A gene microarray chip. Transcription levels in detached retinas were compared to those of nondetached retinas with the BRB-ArrayTools Version 3.6.0 using a random variance analysis of variance (ANOVA) model. Confirmation of the significant transcriptional changes for a subset of the genes was performed using microfluidic quantitative real-time polymerase chain reaction (qRT-PCR) assays. Kinase activation was explored using Western blot analysis to look for early phosphorylation of any of the 3 main families of mitogen-activated protein kinases (MAPK): the p38 family, the Janus kinase family, and the p42/p44 family. Results: Retinas separated from the RPE showed extensive alterations in their gene transcription profile. Many of these changes were initiated as early as 1 day after separation, with significant increases by 7 days. ANOVA analysis defined 144 genes that had significantly altered transcription levels as a function of time after separation when setting a false discovery rate at ≤0.1. Confirmatory RT-PCR was performed on 51 of these 144 genes. Differential transcription detected on the microarray chip was confirmed by qRT-PCR for all 51 genes. Western blot analysis showed that the p42/p44 family of MAPK was phosphorylated within 2 hours of retinal-RPE separation. This phosphorylation was detachment-induced and could be inhibited by specific inhibitors of MAPK phosphorylation. Conclusions: Separation of the retina from the RPE induces significant alteration in the gene transcription profile within the retina. These profiles are not static, but change as a function of time after detachment. These gene transcription changes are preceded by the activation of the p42/p44 family of MAPK. This altered transcription may serve as the basis for many of the morphologic, biochemical, and functional changes seen within the detached retina. PMID:20126507

Rapid Identification of Cell-Specific, Internalizing RNA Aptamers with Bioinformatics Analyses of a Cell-Based Aptamer Selection

PubMed Central

Thiel, William H.; Bair, Thomas; Peek, Andrew S.; Liu, Xiuying; Dassie, Justin; Stockdale, Katie R.; Behlke, Mark A.; Miller, Francis J.; Giangrande, Paloma H.

2012-01-01

Background The broad applicability of RNA aptamers as cell-specific delivery tools for therapeutic reagents depends on the ability to identify aptamer sequences that selectively access the cytoplasm of distinct cell types. Towards this end, we have developed a novel approach that combines a cell-based selection method (cell-internalization SELEX) with high-throughput sequencing (HTS) and bioinformatics analyses to rapidly identify cell-specific, internalization-competent RNA aptamers. Methodology/Principal Findings We demonstrate the utility of this approach by enriching for RNA aptamers capable of selective internalization into vascular smooth muscle cells (VSMCs). Several rounds of positive (VSMCs) and negative (endothelial cells; ECs) selection were performed to enrich for aptamer sequences that preferentially internalize into VSMCs. To identify candidate RNA aptamer sequences, HTS data from each round of selection were analyzed using bioinformatics methods: (1) metrics of selection enrichment; and (2) pairwise comparisons of sequence and structural similarity, termed edit and tree distance, respectively. Correlation analyses of experimentally validated aptamers or rounds revealed that the best cell-specific, internalizing aptamers are enriched as a result of the negative selection step performed against ECs. Conclusions and Significance We describe a novel approach that combines cell-internalization SELEX with HTS and bioinformatics analysis to identify cell-specific, cell-internalizing RNA aptamers. Our data highlight the importance of performing a pre-clear step against a non-target cell in order to select for cell-specific aptamers. We expect the extended use of this approach to enable the identification of aptamers to a multitude of different cell types, thereby facilitating the broad development of targeted cell therapies. PMID:22962591

Identification of a Novel, Putative Rho-specific GDP/GTP Exchange Factor and a RhoA-binding Protein: Control of Neuronal Morphology

PubMed Central

Gebbink, Martijn F.B.G.; Kranenburg, Onno; Poland, Mieke; van Horck, Francis P.G.; Houssa, Brahim; Moolenaar, Wouter H.

1997-01-01

The small GTP-binding protein Rho has been implicated in the control of neuronal morphology. In N1E-115 neuronal cells, the Rho-inactivating C3 toxin stimulates neurite outgrowth and prevents actomyosin-based neurite retraction and cell rounding induced by lysophosphatidic acid (LPA), sphingosine-1-phosphate, or thrombin acting on their cognate G protein–coupled receptors. We have identified a novel putative GDP/GTP exchange factor, RhoGEF (190 kD), that interacts with both wild-type and activated RhoA, but not with Rac or Cdc42. RhoGEF, like activated RhoA, mimics receptor stimulation in inducing cell rounding and in preventing neurite outgrowth. Furthermore, we have identified a 116-kD protein, p116Rip, that interacts with both the GDP- and GTP-bound forms of RhoA in N1E-115 cells. Overexpression of p116Rip stimulates cell flattening and neurite outgrowth in a similar way to dominant-negative RhoA and C3 toxin. Cells overexpressing p116Rip fail to change their shape in response to LPA, as is observed after Rho inactivation. Our results indicate that (a) RhoGEF may link G protein–coupled receptors to RhoA activation and ensuing neurite retraction and cell rounding; and (b) p116Rip inhibits RhoA-stimulated contractility and promotes neurite outgrowth. PMID:9199174

Production of Prnp-/- goats by gene targeting in adult fibroblasts.

PubMed

Zhu, Caihong; Li, Bei; Yu, Guohua; Chen, Jianquan; Yu, Huiqing; Chen, Juan; Xu, Xujun; Wu, Youbing; Zhang, Aimin; Cheng, Guoxiang

2009-04-01

Homozygous mice devoid of functional Prnp are resistant to scrapie and prion propagation, but heterozygous mice for Prnp disruption still suffer from prion disease and prion deposition. We have previously generated heterozygous cloned goats with one allele of Prnp functional disruption. To obtain goats with both alleles of Prnp be disrupted which would be resistant to scrapie completely, a second-round gene targeting was applied to disrupt the wild type allele of Prnp in the heterozygous goats. By second-round gene targeting, we successfully disrupted the wild type allele of Prnp in primary Prnp (+/-) goat skin fibroblasts and obtained a Prnp (-/-) cell line without Prnp expression. This is the first report on successful targeting modification in primary adult somatic cells of animals. These cells were used as nuclear donors for somatic cell cloning to produce Prnp (-/-) goats. A total of 57 morulae or blastocytes developed from the reconstructed embryos were transferred to 31 recipients, which produced 7 pregnancies at day 35. At 73 days of gestation, we obtained one cloned fetus with Prnp (-/-) genotype. Our research not only indicated that multiple genetic modifications could be accomplished by multi-round gene targeting in primary somatic cells, but also provided strong evidence that gene targeting in adult cells other than fetal cells could be applied to introduce precise genetic modifications in animals without destroying the embryos.

The ``Swiss cheese'' instability of bacterial biofilms

NASA Astrophysics Data System (ADS)

Jang, Hongchul; Rusconi, Roberto; Stocker, Roman

2012-11-01

Bacteria often adhere to surfaces, where they develop polymer-encased communities (biofilms) that display dramatic resistance to antibiotic treatment. A better understanding of cell detachment from biofilms may lead to novel strategies for biofilm disruption. Here we describe a new detachment mode, whereby a biofilm develops a nearly regular array of ~50-100 μm holes. Using surface-treated microfluidic devices, we create biofilms of controlled shape and size. After the passage of an air plug, the break-up of the residual thin liquid film scrapes and rearranges bacteria on the surface, such that a ``Swiss cheese'' pattern is left in the residual biofilm. Fluorescent staining of the polymeric matrix (EPS) reveals that resistance to cell dislodgement correlates with local biofilm age, early settlers having had more time to hunker down. Because few survivors suffice to regrow a biofilm, these results point at the importance of considering microscale heterogeneity in assessing the effectiveness of biofilm removal strategies.

Rapid fabrication of detachable three-dimensional tissues by layering of cell sheets with heating centrifuge.

PubMed

Haraguchi, Yuji; Kagawa, Yuki; Hasegawa, Akiyuki; Kubo, Hirotsugu; Shimizu, Tatsuya

2018-01-18

Confluent cultured cells on a temperature-responsive culture dish can be harvested as an intact cell sheet by decreasing temperature below 32°C. A three-dimensional (3-D) tissue can be fabricated by the layering of cell sheets. A resulting 3-D multilayered cell sheet-tissue on a temperature-responsive culture dish can be also harvested without any damage by only temperature decreasing. For shortening the fabrication time of the 3-D multilayered constructs, we attempted to layer cell sheets on a temperature-responsive culture dish with centrifugation. However, when a cell sheet was attached to the culture surface with a conventional centrifuge at 22-23°C, the cell sheet hardly adhere to the surface due to its noncell adhesiveness. Therefore, in this study, we have developed a heating centrifuge. In centrifugation (55g) at 36-37°C, the cell sheet adhered tightly within 5 min to the dish without significant cell damage. Additionally, centrifugation accelerated the cell sheet-layering process. The heating centrifugation shortened the fabrication time by one-fifth compared to a multilayer tissue fabrication without centrifugation. Furthermore, the multilayered constructs were finally detached from the dishes by decreasing temperature. This rapid tissue-fabrication method will be used as a valuable tool in the field of tissue engineering and regenerative therapy. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

Mechanics of membrane-cytoskeleton attachment in Paramecium

NASA Astrophysics Data System (ADS)

Campillo, C.; Jerber, J.; Fisch, C.; Simoes-Betbeder, M.; Dupuis-Williams, P.; Nassoy, P.; Sykes, C.

2012-12-01

In this paper we assess the role of the protein MKS1 (Meckel syndrome type 1) in the cortical membrane mechanics of the ciliated protist Paramecium. This protein is known to be crucial in the process of cilium formation, and we investigate its putative role in membrane-cytoskeleton attachment. Therefore, we compare cells where the gene coding for MKS1 is silenced to wild-type cells. We found that scanning electron microscopy observation of the cell surface reveals a cup-like structure in wild-type cells that is lost in silenced cells. Since this structure is based on the underlying cytoskeleton, one hypothesis to explain this observation is a disruption of membrane attachment to the cytoskeleton in the absence of MKS1 that should affect plasma membrane mechanics. We test this by probing the mechanics of wild-type and silenced cells by micropipette aspiration. Strikingly, we observe that, at the same aspiration pressure, the membrane of silenced cells is easily aspirated by the micropipette whereas that of wild-type cells enters only at a moderate velocity, an effect that suggests a detachment of the membrane from the underlying cytoskeleton in silenced cells. We quantify this detachment by measuring the deformation of the cell cortex and the rate of cell membrane entry in the micropipette. This study offers a new perspective for the characterization of membrane-cytoskeleton attachment in protists and paves the way for a better understanding of the role of membrane-cortex attachment in cilium formation.

Round Trip Energy Efficiency of NASA Glenn Regenerative Fuel Cell System

NASA Technical Reports Server (NTRS)

Garcia, Christopher P.; Chang, Bei-jiann; Johnson, Donald W.; Bents, David J.; Scullin, Vincent J.; Jakupca, Ian J.; Scullin, Vincent J.; Jakupca, Ian J.

2006-01-01

NASA Glenn Research Center (GRC) has recently demonstrated a Polymer Electrolyte Membrane (PEM) based hydrogen/oxygen regenerative fuel cell system (RFCS) that operated for a charge/discharge cycle with round trip efficiency (RTE) greater than 50 percent. The regenerative fuel cell system (RFCS) demonstrated closed loop energy storage over a pressure range of 90 to 190 psig. In charge mode, a constant electrical power profile of 7.1 kWe was absorbed by the RFCS and stored as pressurized hydrogen and oxygen gas. In discharge mode, the system delivered 3 to 4 kWe of electrical power along with product water. Fuel cell and electrolyzer power profiles and polarization performance are documented in this paper. Individual cell performance and the variation of cell voltages within the electrochemical stacks are also reported. Fuel cell efficiency, electrolyzer efficiency, and the system RTE were calculated from the test data and are included below.

Malignant mast cell tumor of the thymus in an Royal College of Surgeons (RCS) rat.

PubMed

Terayama, Yui; Matsuura, Tetsuro; Ozaki, Kiyokazu

2017-01-01

A 152-week-old male Royal College of Surgeons (RCS) rat kept as a non-treated animal in a long-term animal study presented with a soft mass in the anterior mediastinum, which adhered to the pleura of the lung. Histopathologically, the mass mainly consisted of round to short spindle-shaped tumor cells that had infiltrated through the hyperplastic thymic tissue. The tumor cells were arranged in loose to dense sheets. Nuclei were moderate in size and round to spindle-shaped, with small nucleoli. Almost all tumor cells exhibited abundant eosinophilic cytoplasm, including eosinophilic granules of a range of sizes. The granules of tumor cells exhibited metachromasia with toluidine blue stain and were positive for c-kit and mast cell protease II. These findings indicate that the tumor described here represents a rare case of spontaneous malignant mast cell tumor with thymic epithelial hyperplasia.

Overcoming Multidrug Resistance through the GLUT1-Mediated and Enzyme-Triggered Mitochondrial Targeting Conjugate with Redox-Sensitive Paclitaxel Release.

PubMed

Ma, Pengkai; Chen, Jianhua; Bi, Xinning; Li, Zhihui; Gao, Xing; Li, Hongpin; Zhu, Hongyu; Huang, Yunfang; Qi, Jing; Zhang, Yujie

2018-04-18

Multidrug resistance (MDR) is thought to be the major obstacle leading to the failure of paclitaxel (PTX) chemotherapy. To solve this problem, a glucose transporter-mediated and matrix metalloproteinase 2 (MMP2)-triggered mitochondrion-targeting conjugate [glucose-polyethylene glycol (PEG)-peptide-triphenylphosponium-polyamidoamine (PAMAM)-PTX] composed of a PAMAM dendrimer and enzymatic detachable glucose-PEG was constructed for mitochondrial delivery of PTX. The conjugate was characterized by a 30 nm sphere particle, MMP2-sensitive PEG outer layer detachment from PAMAM, and glutathione (GSH)-sensitive PTX release. It showed higher cellular uptake both in glucose transporter 1 (GLUT1) overexpressing MCF-7/MDR monolayer cell (2D) and multicellular tumor spheroids (3D). The subcellular location study showed that it could specifically accumulate in the mitochondria. Moreover, it exhibited higher cytotoxicity against MCF-7/MDR cells, which significantly reverse the MDR of MCF-7/MDR cells. The MDR reverse might be caused by reducing the ATP content through destroying the mitochondrial membrane as well as by down-regulating P-gp expression. In vivo imaging and tissue distribution indicated more conjugate accumulated in the tumor of the tumor-bearing mice model. Consequently, the conjugate showed better tumor inhibition rate and lower body weight loss, which demonstrated that it possessed high efficiency and low toxicity. This study provides glucose-mediated GLUT targeting, MMP2-responsive PEG detachment, triphenylphosponium-mediated mitochondria targeting, and a GSH-sensitive intracellular drug release conjugate that has the potential to be exploited for overcoming MDR of PTX.

Altered sensitivity to ellagic acid in neuroblastoma cells undergoing differentiation with 12-O-tetradecanoylphorbol-13-acetate and all-trans retinoic acid.

PubMed

Alfredsson, Christina Fjæraa; Rendel, Filip; Liang, Qui-Li; Sundström, Birgitta E; Nånberg, Eewa

2015-12-01

Ellagic acid has previously been reported to induce reduced proliferation and activation of apoptosis in several tumor cell lines including our own previous data from non-differentiated human neuroblastoma SH-SY5Y cells. The aim of this study was now to investigate if in vitro differentiation with the phorbol ester 12-O- tetradecanoylphorbol-13-acetate or the vitamin A derivative all-trans retinoic acid altered the sensitivity to ellagic acid in SH-SY5Y cells. The methods used were cell counting and LDH-assay for evaluation of cell number and cell death, flow cytometric analysis of SubG1- and TUNEL-analysis for apoptosis and western blot for expression of apoptosis-associated proteins. In vitro differentiation was shown to reduce the sensitivity to ellagic acid with respect to cell detachment, loss of viability and activation of apoptosis. The protective effect was phenotype-specific and most prominent in all-trans retinoic acid-differentiated cultures. Differentiation-dependent up-regulation of Bcl-2 and integrin expression is introduced as possible protective mechanisms. The presented data also point to a positive correlation between proliferative activity and sensitivity to ellagic-acid-induced cell detachment. In conclusion, the presented data emphasize the need to consider degree of neuronal differentiation and phenotype of neuroblastoma cells when discussing a potential pharmaceutical application of ellagic acid in tumor treatment. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach.

PubMed

Thompson, Lester Dr

2017-01-01

One of the most challenging diagnostic categories within tumors of the sinonasal tract is the small round blue cell tumors. Biopsies are usually small and limited, resulting in considerable diagnostic difficulty for practicing surgical pathologists. These tumors share several overlapping histologic and immunophenotypic findings while also showing considerable variation within and between cases. Specific tumor site of origin, imaging findings, and clinical findings must be combined with the histology and pertinent ancillary studies if the correct diagnosis is to be reached. Discrimination between neoplasms is critical as there are significant differences in therapy and overall outcome. It is important to have a well developed differential diagnosis for this category of tumors, where each of the diagnoses is considered, evaluated, and either confirmed or excluded from further consideration. In an undifferentiated tumor, showing a small round blue cell morphology, using the mnemonic 'MR SLEEP' helps to highlight tumors to consider: melanoma, mesenchymal chondrosarcoma, rhabdomyosarcoma, sinonasal undifferentiated carcinoma, squamous cell carcinoma (including NUT carcinoma), small cell osteosarcoma, lymphoma, esthesioneuroblastoma (olfactory neuroblastoma), Ewing sarcoma/primitive neuroectodermal tumor, pituitary adenoma, and plasmacytoma. A panel of pertinent immunohistochemistry studies, histochemistries and/or molecular tests should aid in reaching a diagnosis, especially when taking the pattern and intensity of reactions into consideration.

Whole-body irradiation increases the magnitude and persistence of adoptively transferred T cells associated with tumor regression in a mouse model of prostate cancer

PubMed Central

Ward-Kavanagh, Lindsay K.; Zhu, Junjia; Cooper, Timothy K.; Schell, Todd D.

2014-01-01

Adoptive immunotherapy has demonstrated efficacy in a subset of clinical and preclinical studies, but the T cells used for therapy often are rendered rapidly non-functional in tumor-bearing hosts. Recent evidence indicates that prostate cancer can be susceptible to immunotherapy, but most studies using autochthonous tumor models demonstrate only short-lived T-cell responses in the tolerogenic prostate microenvironment. Here, we assessed the efficacy of sublethal whole-body irradiation (WBI) to enhance the magnitude and duration of adoptively transferred CD8+ T cells in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. We demonstrate that WBI promoted high-level accumulation of granzyme B (GzB)-expressing donor T cells both in lymphoid organs and in the prostate of TRAMP mice. Donor T cells remained responsive to vaccination in irradiated recipients, but a single round of WBI-enhanced adoptive immunotherapy failed to impact significantly the existing disease. Addition of a second round of immunotherapy promoted regression of established disease in half of the treated mice, with no progressions observed. Regression was associated with long-term persistence of effector/memory phenotype CD8+ donor cells. Administration of the second round of adoptive immunotherapy led to reacquisition of GzB expression by persistent T cells from the first transfer. These results indicate that WBI conditioning amplifies tumor-specific T cells in the TRAMP prostate and lymphoid tissue, and suggest that the initial treatment alters the tolerogenic microenvironment to increase antitumor activity by a second wave of donor cells. PMID:24801834

Noninterleaved round beam lattice for light sources

NASA Astrophysics Data System (ADS)

Agapov, Ilya; Brinkmann, Reinhard; Keil, Joachim; Wanzenberg, Rainer

2018-05-01

A conceptual design and performance of a round beam lattice for synchrotron light sources based on the phase space exchange principle and the noninterleaved sextupole distribution is presented. Optics design is performed for an approximately 30 pm emittance 6 GeV machine of 2300 m circumference which combines cells with and without straight sections for the insertion devices.

Predictors of round window accessibility for adult cochlear implantation based on pre-operative CT scan: a prospective observational study.

PubMed

Park, Edward; Amoodi, Hosam; Kuthubutheen, Jafri; Chen, Joseph M; Nedzelski, Julian M; Lin, Vincent Y W

2015-05-28

Cochlear implantation has become a mainstream treatment option for patients with severe to profound sensorineural hearing loss. During cochlear implant, there are key surgical steps which are influenced by anatomical variations between each patient. The aim of this study is to determine if there are potential predictors of difficulties that may be encountered during the cortical mastoidectomy, facial recess approach and round window access in cochlear implant surgery based upon pre-operative temporal bone CT scan. Fifty seven patients undergoing unilateral cochlear implantation were analyzed. Difficulty with 1) cortical mastoidectomy, 2) facial recess approach, and 3) round window access were scored intra-operatively by the surgeon in a blinded fashion (1 = "easy", 2 = "moderate", 3 = "difficult"). Pre-operative temporal bone CT scans were analyzed for 1) degree of mastoid aeration; 2) location of the sigmoid sinus; 3) height of the tegmen; 4) the presence of air cells in the facial recess, and 5) degree of round window bony overhang. Poor mastoid aeration and lower tegmen position, but not the location of sigmoid sinus, are associated with greater difficulty with the cortical mastoidectomy. Presence of an air cell around the facial nerve was predictive of easier facial recess access. However, the degree of round window bony overhang was not predictive of difficulty associated with round window access. Certain parameters on the pre-operative temporal bone CT scan may be useful in predicting potential difficulties encountered during the key steps involved in cochlear implant surgery.

Optical volume and mass measurements show that mammalian cells swell during mitosis

PubMed Central

Zlotek-Zlotkiewicz, Ewa; Monnier, Sylvain; Cappello, Giovanni; Le Berre, Mael

2015-01-01

The extent, mechanism, and function of cell volume changes during specific cellular events, such as cell migration and cell division, have been poorly studied, mostly because of a lack of adequate techniques. Here we unambiguously report that a large range of mammalian cell types display a significant increase in volume during mitosis (up to 30%). We further show that this increase in volume is tightly linked to the mitotic state of the cell and not to its spread or rounded shape and is independent of the presence of an intact actomyosin cortex. Importantly, this volume increase is not accompanied by an increase in dry mass and thus corresponds to a decrease in cell density. This mitotic swelling might have important consequences for mitotic progression: it might contribute to produce strong pushing forces, allowing mitotic cells to round up; it might also, by lowering cytoplasmic density, contribute to the large change of physicochemical properties observed in mitotic cells. PMID:26598614

The in vitro toxicity of peritoneal dialysis fluid.

PubMed

Manuprasert, Wasin; Kanchanabuch, Sirigul; Eiam-Ong, Somchai; Kanjanabuch, Talerngsak

2011-09-01

To investigate the toxicity of peritoneal dialysis fluid (PDF) components on peritoneal changes in primary human mesothelial cell. To investigate the mechanism of changes, primary human peritoneal mesothelial cells (HPMCs) were isolated from human omental tissue and were exposed for 15 hours with the various concentrations of conventional PDF and various PDF components. The mesothelial injury was determined by calculating a ratio of supernatant and total intracellular LDH while mesothelial apoptosis was assessed and counted by positive TUNEL staining and flow cytometry, respectively. PDF caused mesothelial detachment, de-differentiation, cell injuries, and apoptosis and this depended on the concentrations of PDF. The acidic condition and high glucose concentration likely played a major role in the HPMC injuries and detachment while individual PDF component could not yield mesothelial apoptosis as severe as the whole PDF effects. Thus, the additive effects of PDF composition, instead of the effect of each component, contributed to dialysis-related HPMC damages. PDF showed concentration dependent fashion-induced HPMC injury, dedifferentiation, and apoptosis. All of the abnormalities occurred by the additive effects of PDF components.

Inter-dependent apical microtubule and actin dynamics orchestrate centrosome retention and neuronal delamination

PubMed Central

Kasioulis, Ioannis

2017-01-01

Detachment of newborn neurons from the neuroepithelium is required for correct neuronal architecture and functional circuitry. This process, also known as delamination, involves adherens-junction disassembly and acto-myosin-mediated abscission, during which the centrosome is retained while apical/ciliary membranes are shed. Cell-biological mechanisms mediating delamination are, however, poorly understood. Using live-tissue and super-resolution imaging, we uncover a centrosome-nucleated wheel-like microtubule configuration, aligned with the apical actin cable and adherens-junctions within chick and mouse neuroepithelial cells. These microtubules maintain adherens-junctions while actin maintains microtubules, adherens-junctions and apical end-foot dimensions. During neuronal delamination, acto-myosin constriction generates a tunnel-like actin-microtubule configuration through which the centrosome translocates. This movement requires inter-dependent actin and microtubule activity, and we identify drebrin as a potential coordinator of these cytoskeletal dynamics. Furthermore, centrosome compromise revealed that this organelle is required for delamination. These findings identify new cytoskeletal configurations and regulatory relationships that orchestrate neuronal delamination and may inform mechanisms underlying pathological epithelial cell detachment. PMID:29058679

P38 delta MAPK promotes breast cancer progression and lung metastasis by enhancing cell proliferation and cell detachment.

PubMed

Wada, M; Canals, D; Adada, M; Coant, N; Salama, M F; Helke, K L; Arthur, J S; Shroyer, K R; Kitatani, K; Obeid, L M; Hannun, Y A

2017-11-23

The protein p38 mitogen-activated protein kinase (MAPK) delta isoform (p38δ) is a poorly studied member of the MAPK family. Data analysis from The Cancer Genome Atlas database revealed that p38δ is highly expressed in all types of human breast cancers. Using a human breast cancer tissue array, we confirmed elevation in cancer tissue. The breast cancer mouse model, MMTV-PyMT (PyMT), developed breast tumors with lung metastasis; however, mice deleted in p38δ (PyMT/p38δ -/- ) exhibited delayed primary tumor formation and highly reduced lung metastatic burden. At the cellular level, we demonstrate that targeting of p38δ in breast cancer cells, MCF-7 and MDA-MB-231 resulted in a reduced rate of cell proliferation. In addition, cells lacking p38δ also displayed an increased cell-matrix adhesion and reduced cell detachment. This effect on cell adhesion was molecularly supported by the regulation of the focal adhesion kinase by p38δ in the human breast cell lines. These studies define a previously unappreciated role for p38δ in breast cancer development and evolution by regulating tumor growth and altering metastatic properties. This study proposes MAPK p38δ protein as a key factor in breast cancer. Lack of p38δ resulted in reduced primary tumor size and blocked the metastatic potential to the lungs.

Revealing Early Steps of α2β1 Integrin-mediated Adhesion to Collagen Type I by Using Single-Cell Force Spectroscopy

PubMed Central

Taubenberger, Anna; Cisneros, David A.; Friedrichs, Jens; Puech, Pierre-Henri; Muller, Daniel J.

2007-01-01

We have characterized early steps of α2β1 integrin-mediated cell adhesion to a collagen type I matrix by using single-cell force spectroscopy. In agreement with the role of α2β1 as a collagen type I receptor, α2β1-expressing Chinese hamster ovary (CHO)-A2 cells spread rapidly on the matrix, whereas α2β1-negative CHO wild-type cells adhered poorly. Probing CHO-A2 cell detachment forces over a contact time range of 600 s revealed a nonlinear adhesion response. During the first 60 s, cell adhesion increased slowly, and forces associated with the smallest rupture events were consistent with the breakage of individual integrin–collagen bonds. Above 60 s, a fraction of cells rapidly switched into an activated adhesion state marked by up to 10-fold increased detachment forces. Elevated overall cell adhesion coincided with a rise of the smallest rupture forces above the value required to break a single-integrin–collagen bond, suggesting a change from single to cooperative receptor binding. Transition into the activated adhesion mode and the increase of the smallest rupture forces were both blocked by inhibitors of actomyosin contractility. We therefore propose a two-step mechanism for the establishment of α2β1-mediated adhesion as weak initial, single-integrin–mediated binding events are superseded by strong adhesive interactions involving receptor cooperativity and actomyosin contractility. PMID:17314408

Exposure to Bordetella pertussis adenylate cyclase toxin affects integrin-mediated adhesion and mechanics in alveolar epithelial cells.

PubMed

Angely, Christelle; Nguyen, Ngoc-Minh; Andre Dias, Sofia; Planus, Emmanuelle; Pelle, Gabriel; Louis, Bruno; Filoche, Marcel; Chenal, Alexandre; Ladant, Daniel; Isabey, Daniel

2017-08-01

The adenylate cyclase (CyaA) toxin is a major virulent factor of Bordetella pertussis, the causative agent of whooping cough. CyaA toxin is able to invade eukaryotic cells where it produces high levels of cyclic adenosine monophosphate (cAMP) affecting cellular physiology. Whether CyaA toxin can modulate cell matrix adhesion and mechanics of infected cells remains largely unknown. In this study, we use a recently proposed multiple bond force spectroscopy (MFS) with an atomic force microscope to assess the early phase of cell adhesion (maximal detachment and local rupture forces) and cell rigidity (Young's modulus) in alveolar epithelial cells (A549) for toxin exposure <1 h. At 30 min of exposure, CyaA toxin has a minimal effect on cell viability (>95%) at CyaA concentration of 0.5 nM, but a significant effect (≈81%) at 10 nM. MFS performed on A549 for three different concentrations (0.5, 5 and 10 nM) demonstrates that CyaA toxin significantly affects both cell adhesion (detachment forces are decreased) and cell mechanics (Young's modulus is increased). CyaA toxin (at 0.5 nM) assessed at three indentation/retraction speeds (2, 5 and 10 μm/s) significantly affects global detachment forces, local rupture events and Young modulus compared with control conditions, while an enzymatically inactive variant CyaAE5 has no effect. These results reveal the loading rate dependence of the multiple bonds newly formed between the cell and integrin-specific coated probe as well as the individual bond kinetics which are only slightly affected by the patho-physiological dose of CyaA toxin. Finally, theory of multiple bond force rupture enables us to deduce the bond number N which is reduced by a factor of 2 upon CyaA exposure (N ≈ 6 versus N ≈ 12 in control conditions). MFS measurements demonstrate that adhesion and mechanical properties of A549 are deeply affected by exposure to the CyaA toxin but not to an enzymatically inactive variant. This indicates that the alteration of cell mechanics triggered by CyaA is a consequence of the increase in intracellular cAMP in these target cells. These results suggest that mechanical and adhesion properties of the cells appear as pertinent markers of cytotoxicity of CyaA toxin. © 2017 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

Anchored but not internalized: shape dependent endocytosis of nanodiamond

NASA Astrophysics Data System (ADS)

Zhang, Bokai; Feng, Xi; Yin, Hang; Ge, Zhenpeng; Wang, Yanhuan; Chu, Zhiqin; Raabova, Helena; Vavra, Jan; Cigler, Petr; Liu, Renbao; Wang, Yi; Li, Quan

2017-04-01

Nanoparticle-cell interactions begin with the cellular uptake of the nanoparticles, a process that eventually determines their cellular fate. In the present work, we show that the morphological features of nanodiamonds (NDs) affect both the anchoring and internalization stages of their endocytosis. While a prickly ND (with sharp edges/corners) has no trouble of anchoring onto the plasma membrane, it suffers from difficult internalization afterwards. In comparison, the internalization of a round ND (obtained by selective etching of the prickly ND) is not limited by its lower anchoring amount and presents a much higher endocytosis amount. Molecular dynamics simulation and continuum modelling results suggest that the observed difference in the anchoring of round and prickly NDs likely results from the reduced contact surface area with the cell membrane of the former, while the energy penalty associated with membrane curvature generation, which is lower for a round ND, may explain its higher probability of the subsequent internalization.

Investigations on the nephrotoxicity and hepatotoxicity of trivalent and hexavalent chromium compounds.

PubMed

Dartsch, P C; Hildenbrand, S; Kimmel, R; Schmahl, F W

1998-09-01

In contrast to trivalent chromium (Cr(III)) compounds, hexavalent chromium ((Cr(VI)) compounds are oxidizing agents capable of directly inducing tissue damage and possessing carcinogenic, mutagenic and teratogenic potency. After oral or dermal absorption of Cr(VI), the kidney is the main target organ for chromium accumulation, which might result in acute tubular necrosis in humans. In contrast, an acute toxic effect of Cr(VI) on the liver has not yet been described. Therefore, we used two established epithelial cell lines from the kidney (Opossum kidney cells) and the liver (Hep G2 cells) to design an in vitro-assay which is able to examine acute toxic effects of chromium compounds. Cells of both cell lines were treated with various concentrations of Cr(III) and Cr(VI) ranging from 0.01 micromol/l to 1 mmol/l for 24 h. Thereafter, cell morphology, organization of the intracellular cytoskeleton, number of viable cells and mean cell volume were examined. The results show that Cr(VI), but not Cr(III), has an acute cytotoxic effect and causes a dose-dependent loss in cell viability. The effective dose that caused 50% of cell death was 5 micromol/l for kidney epithelial cells and 50 micromol/l for liver epithelial cells. This means that kidney epithelial cells are 10 times more sensitive towards Cr(VI) treatment than liver epithelial cells and this might explain the known nephrotoxicity in vivo. The loss in cell viability was accompanied by a rounding and detachment of the cells and a marked reduction of intracellular F-actin-containing stress fibers. Microtubules and intermediate-sized filaments were observed to be unaffected. Only in the case of kidney epithelial cells, a dose-dependent cell volume increase was observed after Cr(VI) treatment at concentrations up to 50 micromol/l. At higher concentrations, the cell volume decreased due to the high number of cells undergoing lysis and the appearance of cellular fragments. Various chloride channel blockers with different specificities, molecular structures and inhibitory potentials were tested for their ability to prevent Cr(VI)-induced cell damage. None of the channel blockers was able to inhibit cell damage, suggesting that the uptake of Cr(VI) through the general anion transport system of the cell membrane might be only one facet of cellular uptake and toxification. The data presented here not only confirm the different organ-specific effects of Cr(III) and Cr(VI), but also provide a basis for future experiments on the understanding of acute toxicity of Cr(VI) compounds. Moreover, the results demonstrate that the designed in vitro-assay might be a useful tool to prove whether non-toxic Cr(III) can be oxidized to Cr(VI) under specific industrial conditions (for example, in the leather or chrome industry).

Multifocal Adenomatous Oncocytic Hyperplasia of the Parotid Gland

PubMed Central

Kinoshita, Yuichi; Harada, Hiroshi; Kobayashi, Tadao K.; Yoshizawa, Katsuhiko; Yuri, Takashi; Takasu, Kosho; Tsubura, Airo; Shikata, Nobuaki

2014-01-01

Multifocal adenomatous oncocytic hyperplasia (MAOH) is a non-neoplastic lesion that is classified as oncocytosis. MAOH is a rare entity of the parotid gland and accounts for approximately 0.1% of salivary gland lesions. Here, we report a case of MAOH of the parotid gland. The patient was a 71-year-old woman who presented with discomfort at the left side of her neck. Fine-needle aspiration cytology of the parotid gland revealed a loose sheet-like cluster of round to polygonal cells with granular cytoplasm against a hemorrhagic background. The cells had round to oval, centrally located nuclei with granular chromatin and without distinct nucleoli. Histologically, the lesion was formed of many variable-sized nodules, comprising oncocyte-like cells with small round nuclei and eosinophilic granular cytoplasm that was positive for mitochondrial antibodies. The diagnosis of MAOH is difficult to make by cytology alone, because the findings overlap with those of other oncocytic lesions. In particular, the cytological findings of MAOH have not been sufficiently reported to date. A correlation of cytology and histology was expected. PMID:25580104

Effusion cytomorphology of small round cell tumors.

PubMed

Ikeda, Katsuhide; Tsuta, Koji

2016-01-01

Small round cell tumors (SRCTs) are a group of tumors composed of small, round, and uniform cells with high nuclear/cytoplasmic (N/C) ratios. The appearance of SRCT neoplastic cells in the effusion fluid is very rare. We reported the cytomorphological findings of SRCTs in effusion cytology, and performed statistical and mathematical analyses for a purpose to distinguish SRCTs. We analyzed the cytologic findings of effusion samples from 40 SRCT cases and measured the lengths of the nuclei, cytoplasms, and the cell cluster areas. The SRCT cases included 14 Ewing sarcoma (EWS)/primitive neuroectodermal tumor cases, 5 synovial sarcoma cases, 6 rhabdomyosarcoma cases, 9 small cell lung carcinoma (SCLC) cases, and 6 diffuse large B-cell lymphoma (DLBL) cases. Morphologically, there were no significant differences in the nuclear and cytoplasmic lengths in cases of EWS, synovial sarcoma, and rhabdomyosarcoma. The cytoplasmic lengths in cases of SCLC and DLBL were smaller than those of EWS, synovial sarcoma, and rhabdomyosarcoma. The nuclear density of the cluster in SCLC was higher than that in other SRCTs, and cases of DLBL showed a lack of anisokaryosis and anisocytosis. We believe that it might be possible to diagnose DLBL and SCLC from cytologic analysis of effusion samples but it is very difficult to use this method to distinguish EWS, synovial sarcoma, and rhabdomyosarcoma. Statistical and mathematical analyses indicated that nuclear density and dispersion of nuclear and cytoplasmic sizes are useful adjuncts to conventional cytologic diagnostic criteria, which are acquired from experience.

An Assessment of Molten Metal Detachment Hazards for Electron Beam Welding in the Space Environment: Analysis and Test Results

NASA Technical Reports Server (NTRS)

Nunes, A. C., Jr.; Russell, C.; Bhat, B.; Fragomeni, J. M.

1998-01-01

Conditions under which molten metal detachments might occur in a space welding environment are analyzed. A weld pool detachment parameter specifying conditions for pool detachment by impact is derived and corroborated by experimental evidence. Impact detachment for the pool is unlikely. Impact detachment for a drop of metal on the end of the weld wire may be possible under extreme conditions. Other potential causes of molten metal detachment considered, vaporization pressure forces and wire flickout from the pool, did not appear to present significant detachment threats.

The influence of tectonic inheritance on crustal extension style following failed subduction of continental crust: applications to metamorphic core complexes in Papua New Guinea

NASA Astrophysics Data System (ADS)

Biemiller, J.; Ellis, S. M.; Little, T.; Mizera, M.; Wallace, L. M.; Lavier, L.

2017-12-01

The structural, mechanical and geometric evolution of rifted continental crust depends on the lithospheric conditions in the region prior to the onset of extension. In areas where tectonic activity preceded rift initiation, structural and physical properties of the previous tectonic regime may be inherited by the rift and influence its development. Many continental rifts form and exhume metamorphic core complexes (MCCs), coherent exposures of deep crustal rocks which typically surface as arched or domed structures. MCCs are exhumed in regions where the faulted upper crust is displaced laterally from upwelling ductile material along a weak detachment fault. Some MCCs form during extensional inversion of a subduction thrust following failed subduction of continental crust, but the degree to which lithospheric conditions inherited from the preceding subduction phase control the extensional style in these systems remains unclear. For example, the Dayman Dome in Southeastern Papua New Guinea exposes prehnite-pumpellyite to greenschist facies rocks in a smooth 3 km-high dome exhumed with at least 24 km of slip along one main detachment normal fault, the Mai'iu Fault, which dips 21° at the surface. The extension driving this exhumation is associated with the cessation of northward subduction of Australian continental crust beneath the oceanic lithosphere of the Woodlark Plate. We use geodynamic models to explore the effect of pre-existing crustal structures inherited from the preceding subduction phase on the style of rifting. We show that different geometries and strengths of inherited subduction shear zones predict three distinct modes of subsequent rift development: 1) symmetric rifting by newly formed high-angle normal faults; 2) asymmetric rifting along a weak low-angle detachment fault extending from the surface to the brittle-ductile transition; and 3) extension along a rolling-hinge structure which exhumes deep crustal rocks in coherent rounded exposures. We propose the latter mode as an exhumation model for Dayman Dome and compare the model predictions to regional geophysical and geological evidence. Our models find that tectonically inherited subduction structures may strongly control subsequent extension style when the subduction thrust is weak and well-oriented for reactivation.

Effect of Current and SOC on Round-Trip Energy Efficiency of a Lithium-Iron Phosphate (LiFePO4) Battery Pack (SAE Paper 2015-01-1186)

EPA Science Inventory

While equivalent circuit modeling is an effective way to model the performance and energy efficiency of automotive Li-ion batteries, in some applications it is more convenient to refer directly to round-trip energy efficiency. Energy efficiency of either cells or full packs is se...

Transplantation of reprogrammed embryonic stem cells improves visual function in a mouse model for retinitis pigmentosa.

PubMed

Wang, Nan-Kai; Tosi, Joaquin; Kasanuki, Jennifer Mie; Chou, Chai Lin; Kong, Jian; Parmalee, Nancy; Wert, Katherine J; Allikmets, Rando; Lai, Chi-Chun; Chien, Chung-Liang; Nagasaki, Takayuki; Lin, Chyuan-Sheng; Tsang, Stephen H

2010-04-27

To study whether C57BL/6J-Tyr/J (C2J) mouse embryonic stem (ES) cells can differentiate into retinal pigment epithelial (RPE) cells in vitro and then restore retinal function in a model for retinitis pigmentosa: Rpe65/Rpe65 C57BL6 mice. Yellow fluorescent protein (YFP)-labeled C2J ES cells were induced to differentiate into RPE-like structures on PA6 feeders. RPE-specific markers are expressed from differentiated cells in vitro. After differentiation, ES cell-derived RPE-like cells were transplanted into the subretinal space of postnatal day 5 Rpe65/Rpe65 mice. Live imaging of YFP-labeled C2J ES cells demonstrated survival of the graft. Electroretinograms (ERGs) were performed on transplanted mice to evaluate the functional outcome of transplantation. RPE-like cells derived from ES cells sequentially express multiple RPE-specific markers. After transplantation, YFP-labeled cells can be tracked with live imaging for as long as 7 months. Although more than half of the mice were complicated with retinal detachments or tumor development, one fourth of the mice showed increased electroretinogram responses in the transplanted eyes. Rpe65/Rpe65 mice transplanted with RPE-like cells showed significant visual recovery during a 7-month period, whereas those injected with saline, PA6 feeders, or undifferentiated ES cells showed no rescue. ES cells can differentiate, morphologically, and functionally, into RPE-like cells. Based on these findings, differentiated ES cells have the potential for the development of new therapeutic approaches for RPE-specific diseases such as certain forms of retinitis pigmentosa and macular degeneration. Nevertheless, stringent control of retinal detachment and teratoma development will be necessary before initiation of treatment trials.

Rapid detachment of Giardia lamblia trophozoites as a mechanism of antimicrobial action of the isoflavone formononetin

PubMed Central

Lauwaet, Tineke; Andersen, Yolanda; Van de Ven, Liesbeth; Eckmann, Lars; Gillin, Frances D.

2010-01-01

Objectives Attachment to the small intestinal mucosa is crucial for initiating and maintaining Giardia infection. We tested the effect of isoflavones on Giardia attachment. Methods We evaluated the effect of formononetin on trophozoite attachment to glass, to intestinal epithelial cell layers in vitro and to murine small intestinal explants, and on the intestinal load in mice. Results We found that the isoflavone formononetin inhibits both attachment and flagellar motility within minutes and reduces the trophozoite load of Giardia in mice within 1.5 h after treatment. Conclusions The antigiardial activity of formononetin is at least partially due to its capacity to rapidly detach trophozoites. PMID:20067984

Mechanical control of mitotic progression in single animal cells

PubMed Central

Cattin, Cedric J.; Düggelin, Marcel; Martinez-Martin, David; Gerber, Christoph; Müller, Daniel J.; Stewart, Martin P.

2015-01-01

Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback–controlled confinement of single cells while characterizing their progression through mitosis. We identify three force regimes according to the cell response: small forces (∼5 nN) that accelerate mitotic progression, intermediate forces where cells resist confinement (50–100 nN), and yield forces (>100 nN) where a significant decline in cell height impinges on microtubule spindle function, thereby inhibiting mitotic progression. Yield forces are coincident with a nonlinear drop in cell height potentiated by persistent blebbing and loss of cortical F-actin homogeneity. Our results suggest that a buildup of actomyosin-dependent cortical tension and intracellular pressure precedes mechanical failure, or herniation, of the cell cortex at the yield force. Thus, we reveal how the mechanical properties of mitotic cells and their response to external forces are linked to mitotic progression under conditions of mechanical confinement. PMID:26305930

Dictyostelium cell death: early emergence and demise of highly polarized paddle cells.

PubMed

Levraud, Jean-Pierre; Adam, Myriam; Luciani, Marie-Françoise; de Chastellier, Chantal; Blanton, Richard L; Golstein, Pierre

2003-03-31

Cell death in the stalk of Dictyostelium discoideum, a prototypic vacuolar cell death, can be studied in vitro using cells differentiating as a monolayer. To identify early events, we examined potentially dying cells at a time when the classical signs of Dictyostelium cell death, such as heavy vacuolization and membrane lesions, were not yet apparent. We observed that most cells proceeded through a stereotyped series of differentiation stages, including the emergence of "paddle" cells showing high motility and strikingly marked subcellular compartmentalization with actin segregation. Paddle cell emergence and subsequent demise with paddle-to-round cell transition may be critical to the cell death process, as they were contemporary with irreversibility assessed through time-lapse videos and clonogenicity tests. Paddle cell demise was not related to formation of the cellulose shell because cells where the cellulose-synthase gene had been inactivated underwent death indistinguishable from that of parental cells. A major subcellular alteration at the paddle-to-round cell transition was the disappearance of F-actin. The Dictyostelium vacuolar cell death pathway thus does not require cellulose synthesis and includes early actin rearrangements (F-actin segregation, then depolymerization), contemporary with irreversibility, corresponding to the emergence and demise of highly polarized paddle cells.

Molecular Memory of Morphologies by Septins during Neuron Generation Allows Early Polarity Inheritance.

PubMed

Boubakar, Leila; Falk, Julien; Ducuing, Hugo; Thoinet, Karine; Reynaud, Florie; Derrington, Edmund; Castellani, Valérie

2017-08-16

Transmission of polarity established early during cell lineage history is emerging as a key process guiding cell differentiation. Highly polarized neurons provide a fascinating model to study inheritance of polarity over cell generations and across morphological transitions. Neural crest cells (NCCs) migrate to the dorsal root ganglia to generate neurons directly or after cell divisions in situ. Using live imaging of vertebrate embryo slices, we found that bipolar NCC progenitors lose their polarity, retracting their processes to round for division, but generate neurons with bipolar morphology by emitting processes from the same locations as the progenitor. Monitoring the dynamics of Septins, which play key roles in yeast polarity, indicates that Septin 7 tags process sites for re-initiation of process growth following mitosis. Interfering with Septins blocks this mechanism. Thus, Septins store polarity features during mitotic rounding so that daughters can reconstitute the initial progenitor polarity. Copyright © 2017 Elsevier Inc. All rights reserved.

Preprocessing with Photoshop Software on Microscopic Images of A549 Cells in Epithelial-Mesenchymal Transition.

PubMed

Ren, Zhou-Xin; Yu, Hai-Bin; Shen, Jun-Ling; Li, Ya; Li, Jian-Sheng

2015-06-01

To establish a preprocessing method for cell morphometry in microscopic images of A549 cells in epithelial-mesenchymal transition (EMT). Adobe Photoshop CS2 (Adobe Systems, Inc.) was used for preprocessing the images. First, all images were processed for size uniformity and high distinguishability between the cell and background area. Then, a blank image with the same size and grids was established and cross points of the grids were added into a distinct color. The blank image was merged into a processed image. In the merged images, the cells with 1 or more cross points were chosen, and then the cell areas were enclosed and were replaced in a distinct color. Except for chosen cellular areas, all areas were changed into a unique hue. Three observers quantified roundness of cells in images with the image preprocess (IPP) or without the method (Controls), respectively. Furthermore, 1 observer measured the roundness 3 times with the 2 methods, respectively. The results between IPPs and Controls were compared for repeatability and reproducibility. As compared with the Control method, among 3 observers, use of the IPP method resulted in a higher number and a higher percentage of same-chosen cells in an image. The relative average deviation values of roundness, either for 3 observers or 1 observer, were significantly higher in Controls than in IPPs (p < 0.01 or 0.001). The values of intraclass correlation coefficient, both in Single Type or Average, were higher in IPPs than in Controls both for 3 observers and 1 observer. Processed with Adobe Photoshop, a chosen cell from an image was more objective, regular, and accurate, creating an increase of reproducibility and repeatability on morphometry of A549 cells in epithelial to mesenchymal transition.

Plasma detachment in divertor tokamaks

NASA Astrophysics Data System (ADS)

Leonard, A. W.

2018-04-01

Observations of divertor plasma detachment in tokamaks are reviewed. Plasma detachment is characterized in terms of transport and dissipation of power, momentum and particle flux along the open field lines from the midplane to the divertor. Asymmetries in detachment onset and other characteristics between the inboard and outboard divertor plasmas is found to be primarily driven by plasma E× B drifts. The effect of divertor plate geometry and magnetic configuration on divertor detachment is summarized. Control of divertor detachment has progressed with a development of a number of diagnostics to characterize the detached state in real-time. Finally the compatibility of detached divertor operation with high performance core plasmas is examined.

Meta-Analysis of Postoperative Outcome Parameters Comparing Descemet Membrane Endothelial Keratoplasty Versus Descemet Stripping Automated Endothelial Keratoplasty.

PubMed

Pavlovic, Ivana; Shajari, Mehdi; Herrmann, Eva; Schmack, Ingo; Lencova, Anna; Kohnen, Thomas

2017-12-01

This meta-analysis compares Descemet membrane endothelial keratoplasty (DMEK) with Descemet stripping automated endothelial keratoplasty (DSAEK) to evaluate their strength and weakness profiles. Meta-analysis. We performed a meta-analysis and searched the peer-reviewed literature in PubMed, Cochrane Library, Web of Science, and Embase following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospective and retrospective trials performing and comparing DMEK and DSAEK were included. Effects were calculated as odds ratios or standardized mean differences. A total of 11 studies with a total of 723 eyes (350 DMEK and 373 DSAEK) were included. No significant difference was found regarding the total detachment rate, graft failure, and rejection. One of 340 eyes undergoing DMEK showed total detachment and 5 of 363 eyes undergoing DSAEK showed total detachment (P = 0.28). Six of 280 eyes undergoing DMEK showed graft failure; 1 of 313 eyes undergoing DSAEK developed this complication (P = 0.18). No rejection was observed in 158 eyes undergoing DMEK; 4 cases of rejection occurred in 196 eyes undergoing DSAEK (P = 0.37). No significant difference was found regarding endothelial cell loss (P = 0.48). There was a significantly higher partial detachment rate with DMEK: 88 of 340 eyes undergoing DMEK showed partial detachment; 16 of 363 eyes undergoing DSAEK showed this complication (P < 0.00001). DMEK was superior in best-corrected visual acuity after 6 months (P < 0.001), subjective evaluation of visual acuity (P = 0.001), patient satisfaction (P < 0.001), and was the method preferred by patients (P = 0.001). DMEK and DSAEK have a similar complication profile. However, the superiority in the visual outcome and patient satisfaction makes DMEK the preferred option for most patients.

GRAFT-VERSUS-HOST DISEASE PANUVEITIS AND BILATERAL SEROUS DETACHMENTS: MULTIMODAL IMAGING ANALYSIS.

PubMed

Jung, Jesse J; Chen, Michael H; Rofagha, Soraya; Lee, Scott S

2017-01-01

To report the multimodal imaging findings and follow-up of a case of graft-versus-host disease-induced bilateral panuveitis and serous retinal detachments after allogenic bone marrow transplant for acute myeloid leukemia. A 75-year-old black man presented with acute decreased vision in both eyes for 1 week. Clinical examination and multimodal imaging, including spectral domain optical coherence tomography, fundus autofluorescence, fluorescein angiography, and swept-source optical coherence tomography angiography (Investigational Device; Carl Zeiss Meditec Inc) were performed. Clinical examination of the patient revealed anterior and posterior inflammation and bilateral serous retinal detachments. Ultra-widefield fundus autofluorescence demonstrated hyperautofluorescence secondary to subretinal fluid; and fluorescein angiography revealed multiple areas of punctate hyperfluorescence, leakage, and staining of the optic discs. Spectral domain and enhanced depth imaging optical coherence tomography demonstrated subretinal fluid, a thickened, undulating retinal pigment epithelium layer, and a thickened choroid in both eyes. En-face swept-source optical coherence tomography angiography did not show any retinal vascular abnormalities but did demonstrate patchy areas of decreased choriocapillaris flow. An extensive systemic infectious and malignancy workup was negative and the patient was treated with high-dose oral prednisone immunosuppression. Subsequent 6-month follow-up demonstrated complete resolution of the inflammation and bilateral serous detachments after completion of the prednisone taper over a 3-month period. Graft-versus-host disease panuveitis and bilateral serous retinal detachments are rare complications of allogenic bone marrow transplant for acute myeloid leukemia and can be diagnosed with clinical and multimodal imaging analysis. This form of autoimmune inflammation may occur after the recovery of T-cell activity within the donor graft targeting the host. Infectious and recurrent malignancy must be ruled out before initiation of immunosuppression, which can affectively treat this form of graft-versus-host disease.

Effects of membrane deformability and bond formation/dissociation rates on adhesion dynamics of a spherical capsule in shear flow.

PubMed

Zhang, Ziying; Du, Jun; Wei, Zhengying; Wang, Zhen; Li, Minghui

2018-02-01

Cellular adhesion plays a critical role in biological systems and biomedical applications. Cell deformation and biophysical properties of adhesion molecules are of significance for the adhesion behavior. In the present work, dynamic adhesion of a deformable capsule to a planar substrate, in a linear shear flow, is numerically simulated to investigate the combined influence of membrane deformability (quantified by the capillary number) and bond formation/dissociation rates on the adhesion behavior. The computational model is based on the immersed boundary-lattice Boltzmann method for the capsule-fluid interaction and a probabilistic adhesion model for the capsule-substrate interaction. Three distinct adhesion states, detachment, rolling adhesion and firm adhesion, are identified and presented in a state diagram as a function of capillary number and bond dissociation rate. The impact of bond formation rate on the state diagram is further investigated. Results show that the critical bond dissociation rate for the transition of rolling or firm adhesion to detachment is strongly related to the capsule deformability. At the rolling-adhesion state, smaller off rates are needed for larger capillary number to increase the rolling velocity and detach the capsule. In contrast, the critical off rate for firm-to-detach transition slightly increases with the capillary number. With smaller on rate, the effect of capsule deformability on the critical off rates is more pronounced and capsules with moderate deformability are prone to detach by the shear flow. Further increasing of on rate leads to large expansion of both rolling-adhesion and firm-adhesion regions. Even capsules with relatively large deformability can maintain stable rolling adhesion at certain off rate.

Mitosis can drive cell cannibalism through entosis

PubMed Central

Durgan, Joanne; Tseng, Yun-Yu; Hamann, Jens C; Domart, Marie-Charlotte; Collinson, Lucy; Overholtzer, Michael; Florey, Oliver

2017-01-01

Entosis is a form of epithelial cell cannibalism that is prevalent in human cancer, typically triggered by loss of matrix adhesion. Here, we report an alternative mechanism for entosis in human epithelial cells, driven by mitosis. Mitotic entosis is regulated by Cdc42, which controls mitotic morphology. Cdc42 depletion enhances mitotic deadhesion and rounding, and these biophysical changes, which depend on RhoA activation and are phenocopied by Rap1 inhibition, permit subsequent entosis. Mitotic entosis occurs constitutively in some human cancer cell lines and mitotic index correlates with cell cannibalism in primary human breast tumours. Adherent, wild-type cells can act efficiently as entotic hosts, suggesting that normal epithelia may engulf and kill aberrantly dividing neighbours. Finally, we report that Paclitaxel/taxol promotes mitotic rounding and subsequent entosis, revealing an unconventional activity of this drug. Together, our data uncover an intriguing link between cell division and cannibalism, of significance to both cancer and chemotherapy. DOI: http://dx.doi.org/10.7554/eLife.27134.001 PMID:28693721

Dictyostelium cell death

PubMed Central

Levraud, Jean-Pierre; Adam, Myriam; Luciani, Marie-Françoise; de Chastellier, Chantal; Blanton, Richard L.; Golstein, Pierre

2003-01-01

Cell death in the stalk of Dictyostelium discoideum, a prototypic vacuolar cell death, can be studied in vitro using cells differentiating as a monolayer. To identify early events, we examined potentially dying cells at a time when the classical signs of Dictyostelium cell death, such as heavy vacuolization and membrane lesions, were not yet apparent. We observed that most cells proceeded through a stereotyped series of differentiation stages, including the emergence of “paddle” cells showing high motility and strikingly marked subcellular compartmentalization with actin segregation. Paddle cell emergence and subsequent demise with paddle-to-round cell transition may be critical to the cell death process, as they were contemporary with irreversibility assessed through time-lapse videos and clonogenicity tests. Paddle cell demise was not related to formation of the cellulose shell because cells where the cellulose-synthase gene had been inactivated underwent death indistinguishable from that of parental cells. A major subcellular alteration at the paddle-to-round cell transition was the disappearance of F-actin. The Dictyostelium vacuolar cell death pathway thus does not require cellulose synthesis and includes early actin rearrangements (F-actin segregation, then depolymerization), contemporary with irreversibility, corresponding to the emergence and demise of highly polarized paddle cells. PMID:12654899

Coupling between apical tension and basal adhesion allow epithelia to collectively sense and respond to substrate topography over long distances.

PubMed

Broaders, Kyle E; Cerchiari, Alec E; Gartner, Zev J

2015-12-01

Epithelial sheets fold into complex topographies that contribute to their function in vivo. Cells can sense and respond to substrate topography in their immediate vicinity by modulating their interfacial mechanics, but the extent to which these mechanical properties contribute to their ability to sense substrate topography across length scales larger than a single cell has not been explored in detail. To study the relationship between the interfacial mechanics of single cells and their collective behavior as tissues, we grew cell-sheets on substrates engraved with surface features spanning macroscopic length-scales. We found that many epithelial cell-types sense and respond to substrate topography, even when it is locally nearly planar. Cells clear or detach from regions of local negative curvature, but not from regions with positive or no curvature. We investigated this phenomenon using a finite element model where substrate topography is coupled to epithelial response through a balance of tissue contractility and adhesive forces. The model correctly predicts the focal sites of cell-clearing and epithelial detachment. Furthermore, the model predicts that local tissue response to substrate curvature is a function of the surrounding topography of the substrate across long distances. Analysis of cell-cell and cell-substrate contact angles suggests a relationship between these single-cell interfacial properties, epithelial interfacial properties, and collective epithelial response to substrate topography. Finally, we show that contact angles change upon activation of oncogenes or inhibition of cell-contractility, and that these changes correlate with collective epithelial response. Our results demonstrate that in mechanically integrated epithelial sheets, cell contractility can be transmitted through multiple cells and focused by substrate topography to affect a behavioral response at distant sites.

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum

NASA Astrophysics Data System (ADS)

Fujiwara, Yoshihisa; Tomishige, Masahiko; Itoh, Yasuhiro; Fujiwara, Masao; Shibata, Naho; Kosaka, Toshikazu; Hosoya, Hiroshi; Tanimoto, Yoshifumi

2006-05-01

Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum was studied by using a superconducting magnet. Around a centre of a round vessel, random swimming at 0 T and aligned swimming parallel to the magnetic field (MF) of 8 T were observed. Near a wall of the vessel, however, swimming round and round along the wall at 0 T and aligned swimming of turning at right angles upon collision with the wall, which was remarkable around 1-4 T, were detected. It was experimentally revealed that the former MF-induced parallel swimming at the vessel centre was caused physicochemically by the parallel magnetic orientation of the cell itself. From magnetic field dependence of the extent of the orientation, the magnetic susceptibility anisotropy (χ ∥-χ ⊥) was first obtained to be 3.4× 10-23 emu cell-1 at 298 K for Paramecium caudatum. The orientation of the cell was considered to result from the magnetic orientation of the cell membrane. On the other hand, although mechanisms of the latter swimming near the vessel wall regardless of the absence and presence of the magnetic field are unclear at present, these experimental results indicate that whether the cell exists near the wall alters the magnetic field effect on the swimming in the horizontal magnetic field.

Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma.

PubMed

Doi, Takuya; Kotani, Yuri; Takahashi, Kazuaki; Hashimoto, Satomi; Yamada, Naoaki; Kokoshima, Hiroko; Tomonari, Yuki; Wako, Yumi; Tsuchitani, Minoru

2010-06-01

Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers.

Orbital embryonal rhabdomyosarcoma with metastasis in a young dog.

PubMed

Kato, Y; Notake, H; Kimura, J; Murakami, M; Hirata, A; Sakai, H; Yanai, T

2012-01-01

A 2-year-old male Welsh corgi dog was brought to an animal hospital because of left upper eyelid enlargement with lachrymal gland protrusion. The lachrymal and orbital cavity mass was removed surgically. Microscopically, the orbital mass consisted of a mixture of large rhabdomyoblastic and small round tumour cells. Immunohistochemically, the rhabdomyoblastic cells expressed desmin and myoglobin and the small round cells expressed desmin, myogenin and MyoD1. A diagnosis of embryonal rhabdomyosarcoma (ERS) was made. One month later, multiple masses throughout the body were identified, in particular around the cervical region. One of these lesions was sampled and diagnosed as metastatic ERS. The dog died 84 days after the time of first admission. Copyright © 2012 Elsevier Ltd. All rights reserved.

In Vivo Analysis of Alternative Modes of Breast Cancer Cell Invasion

DTIC Science & Technology

2008-05-01

characterized in 3-D culture by time-lapse videomicroscopy . Bright field time-lapse videomicroscopy revealed that the MMTV-neu cells moved as both rounded...intricacies of cell signalling, and the role that cell signalling pathways play in tumor cell behavior. Working with 3-D gels and time-lapse videomicroscopy

Desmoplastic small round cell tumor of the middle ear: A case report.

PubMed

Xu, Jing; Yao, Mengwei; Yang, Xinxin; Liu, Tao; Wang, Shaohua; Ma, Dengdian; Li, Xiaoyu

2018-04-01

Desmoplastic small round cell tumor (DSRCT) is a rare, aggressive and malignant tumor. This report describes a case involving DSRCT of the middle ear which no case has been reported in the literature till date. A 59-year-old Chinese man with a 40-year history of repeated suppuration of his right ear and 1-year history of drooping of the angle of mouth. The CT of the middle ear and brain scan and enhanced MRI showed space occupying lesion in the right middle ear. Desmoplastic small round cell tumor of the middle ear. After relevant examinations, radical mastoidectomy and subtotal temporal bone resection were performed on the right ear under general anesthesia. The patient underwent postoperative adjuvant chemoradiation therapy. The patient was counterchecked regularly,there was norecurrence of DSRCT of the middle ear. Four years after surgery, the CT and MRI of the middle ear mastoid showed right middle ear soft tissue shadow,but postoperative pathological results showed proliferative fibrous and vascular tissues with chronic inflammatory cell infiltration and necrosis. DSRCT is a relatively aggressive, malignant mesenchymal tumor, with a very poor prognosis.The diagnosis of DSRCT relies on immunohistological data. Early diagnosis, radical surgery, chemotherapy, and radiotherapy are considered a reasonable way to prolong survival.

This Just In… The Latest Research Findings

MedlinePlus

... shows that people who exercise have longer leukocyte telomeres. Telomeres are the ends of chromosomes. As cells go through normal rounds of division, the telomeres shrink, and eventually the cell can no longer ...

Mediastinal mature teratoma with coexistence of angiosarcoma, granulocytic sarcoma and a hematopoietic region in the tumor: a rare case of association between hematological malignancy and mediastinal germ cell tumor.

PubMed

Saito, A; Watanabe, K; Kusakabe, T; Abe, M; Suzuki, T

1998-09-01

An association between mediastinal germ cell tumors (MGCT) and hematological malignancies (e.g. acute leukemia, malignant histiocytosis) has been recognized since 1984. A rare case of mediastinal mature teratoma with angiosarcoma, a hematopoietic region and granulocytic sarcoma is reported in a 29-year-old male. The resected tumor was 9.0 x 6.5 cm, weighed 65 g and showed extensive necrosis, forming a cyst. The histological features of the tumor showed a mature teratoma, which contained a large gland lined by ciliated epithelium, hyalinous cartilage, a paraganglion-like structure, well-differentiated angiosarcoma with atypical hematopoiesis composed of CD34-positive cells, and malignant round cells. The malignant round cells did not stain for CD34 but were positive for leukocyte common antigen (LCA) and c-kit product. From these findings, the round cells were diagnosed as granulocytic sarcoma. The patient died of metastasis of the granulocytic sarcoma in the tonsils and cervical lymph nodes 8 months after surgery. A leukemic condition was not present throughout the clinical course. The association between MGCT and hematological malignancy is a distinctive syndrome. However, its pathogenesis is still obscure and the origin of the hematopoietic malignancy has not been fully elucidated. In this particular case, it is suggested that the granulocytic sarcoma might have arisen from the abnormal hematopoietic area in the mediastinal teratoma.

Rate and Localization of Graft Detachment in Descemet Membrane Endothelial Keratoplasty.

PubMed

Maier, Anna-Karina B; Gundlach, Enken; Pilger, Daniel; Rübsam, Anne; Klamann, Matthias K J; Gonnermann, Johannes; Bertelmann, Eckart; Joussen, Antonia M; Torun, Necip

2016-03-01

To investigate the rate and localization of graft detachment after Descemet membrane endothelial keratoplasty. Sixty-six consecutive cases operated between June and August 2014 at the Charité-Universitätsmedizin Berlin were examined prospectively 1 week postoperatively. A single masked observer analyzed the rate and localization of graft detachment using optical coherence tomography (OCT), and the rebubbling rate was measured. Localization of graft detachment was correlated to the incision approach. Preoperative data were correlated to the rate of graft detachment and rebubbling. Graft detachment occurred in more than 2 clock hours and with postoperative corneal edema in 33.3% and required rebubbling. In 33.3%, graft detachment occurred in more than 2 clock hours and with postoperative corneal edema and required rebubbling. The mean graft detachment rate was 8.3% per clock hour. A significantly higher graft detachment rate was noted in the inferior clock hours (21.1%, P < 0.0001, 16.7%, P = 0.003). Only higher age of the patient correlated to a higher rate of graft detachment (P = 0.022). No correlation was found between localization of graft detachment and the incision approach (P = 0.615). The graft detachment rate is high after Descemet membrane endothelial keratoplasty, but detachment is usually peripheral, partial and mainly inferior and involves only a few clock hours. Only higher age of the patient is strongly associated with a higher rate of graft detachment. The incision approach is not significantly correlated with the localization of graft detachment. Therefore, the postoperative supine position of the patient seems to be of major importance.Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT02020044.

Role of Outer Membrane C-Type Cytochromes MtrC and OmcA in Shewanella Oneidensis MR-1 Cell Production, Accumulation, and Detachment During Respiration on Hematite

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

Mitchell, Andrew C.; Peterson, L.; Reardon, Catherine L.

2012-07-01

Solid phase iron oxides are considered to be important terminal electron acceptors for microbial respiration in many anoxic environments. Besides the knowledge that cells attach to and reduce these substrates, other aspects of surface-associated cell behavior and the related cell surface components that influence cell-mineral interactions are not well understood. In the present study, wild-type cells of the dissimilatory iron-reducing bacterium Shewanella oneidensis MR-1 formed thin biofilms one-to-two cell layers in thickness when respiring on natural specular hematite under flow conditions similar to those which exist in aquatic sediments and subsurface environments. The distribution of cells within the biofilm indicatedmore » that direct contact was not required for electron transfer from cells to the mineral surface. Detached biomass in the form of single cells represented >99% of the surface-associated wild-type cell production from respiration on hematite over the biofilm life cycle. A mutant deficient in the outer membrane c35 type cytochrome OmcA, while still able to respire and replicate on hematite, established a lower steady-state cell density on the mineral surface than that of the wild-type strain. A mutant deficient in MtrC, another outer membrane c-type cytochrome, and a mutant deficient in both cytochromes were unable to reduce sufficient amounts of hematite to support detectable growth on the mineral surface. When considered in the context of previous work, the results support a growing body of evidence that the relative importance of OmcA and MtrC to cell respiration and replication depends on the form of iron oxide available as terminal electron acceptor.« less

Ag+ alters cell growth, neurite extension, cardiomyocyte beating, and fertilized egg constriction.

PubMed

Conrad, A H; Tramp, C R; Long, C J; Wells, D C; Paulsen, A Q; Conrad, G W

1999-11-01

The Russian Space Agency uses electrochemically generated silver ions (Ag+) to purify drinking water for their space station, Mir, and their portion of the International Space Station. U.S. EPA guidelines allow 10.6 micromol x L(-1) Ag+ in human drinking water for up to 10 d. Studies correlate Ag+ exposure with tissue dysfunction in humans, rats, and mice, and with altered ion transport, skeletal muscle contraction, and embryonic cell constriction in other animal cells. Ag+ effects on cell shape change-related functions have not been assessed. Immortalized embryonic human intestinal epithelial cells, freshly explanted embryonic avian nerve cells and cardiomyocytes, and marine fertilized eggs were grown in vitro in medium containing AgNO3. Intestinal cells detach from the substratum and viable cell number decreases by 5-6 d at 5 micromol x L(-1) AgNO3, and faster at higher concentrations. Microtubules appear unaltered in adherent cells. Detached cells are nonviable. Neurite outgrowth and glial cell migration from dorsal root ganglia are inhibited by 3 d at 15 micromol x L(-1) AgNO3 or greater. Contractions stop temporarily in most cardiomyocytes by 5 min at 5 micromol x L(-1) AgNO3 or more, but some cardiomyocytes beat 3 times faster than normal at 7.5-20 micromol x L(-1) AgNO3. Picomolar Ag+ increases marine egg polar lobe constriction within an hour, even in the absence of microtubules. Ag+ alters animal cell growth and shape changes by a MT-independent mechanism. This is the first report of Ag+ effects on vertebrate neurite outgrowth, glial cell migration, or cardiomyocyte beat rate.

Plasma detachment in divertor tokamaks

DOE PAGES

Leonard, A. W.

2018-02-07

In this study, observations of divertor plasma detachment in tokamaks are reviewed. Plasma detachment is characterized in terms of transport and dissipation of power, momentum and particle flux along the open field lines from the midplane to the divertor. Asymmetries in detachment onset and other characteristics between the inboard and outboard divertor plasmas is found to be primarily driven by plasmamore » $$\\vec{E}$$ x $$\\vec{B}$$ drifts. The effect of divertor plate geometry and magnetic configuration on divertor detachment is summarized. Control of divertor detachment has progressed with a development of a number of diagnostics to characterize the detached state in real-time. Finally the compatibility of detached divertor operation with high performance core plasmas is examined.« less

Plasma detachment in divertor tokamaks

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

Leonard, A. W.

In this study, observations of divertor plasma detachment in tokamaks are reviewed. Plasma detachment is characterized in terms of transport and dissipation of power, momentum and particle flux along the open field lines from the midplane to the divertor. Asymmetries in detachment onset and other characteristics between the inboard and outboard divertor plasmas is found to be primarily driven by plasmamore » $$\\vec{E}$$ x $$\\vec{B}$$ drifts. The effect of divertor plate geometry and magnetic configuration on divertor detachment is summarized. Control of divertor detachment has progressed with a development of a number of diagnostics to characterize the detached state in real-time. Finally the compatibility of detached divertor operation with high performance core plasmas is examined.« less

Detachment of solids and nitrifiers in integrated, fixed-film activated sludge systems.

PubMed

Maas, Carol L A; Parker, Wayne J; Legge, Raymond L

2008-12-01

Despite the importance of detachment to biofilm processes, detachment phenomena are not well understood. In this study, researchers investigated biofilm detachment from free-floating biofilm carriers that were established in an integrated, fixed-film activated sludge (IFAS) installation in Mississauga, Ontario. A method for assessing detachment from biofilm carrier systems was devised, evaluated, and refined during this study. In the absence of substrate, superficial air velocity significantly affected the 24-hour detachment rates of total suspended solids from the carriers. Short-term growth conditions did not appear to significantly affect the rate of detachment of solids and nitrifiers. The measured solids-detachment rates were found to be described by a second order function of biofilm attached growth total solids with a detachment coefficient of 0.006 +/- 0.0008 (g/m x d)(-1).

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.

Probing cytoskeletal pre-stress and nuclear mechanics in endothelial cells with spatiotemporally controlled (de-)adhesion kinetics on micropatterned substrates

PubMed Central

Versaevel, Marie; Riaz, Maryam; Corne, Tobias; Grevesse, Thomas; Lantoine, Joséphine; Mohammed, Danahe; Bruyère, Céline; Alaimo, Laura; De Vos, Winnok H.; Gabriele, Sylvain

2017-01-01

ABSTRACT The mechanical properties of living cells reflect their propensity to migrate and respond to external forces. Both cellular and nuclear stiffnesses are strongly influenced by the rigidity of the extracellular matrix (ECM) through reorganization of the cyto- and nucleoskeletal protein connections. Changes in this architectural continuum affect cell mechanics and underlie many pathological conditions. In this context, an accurate and combined quantification of the mechanical properties of both cells and nuclei can contribute to a better understanding of cellular (dys-)function. To address this challenge, we have established a robust method for probing cellular and nuclear deformation during spreading and detachment from micropatterned substrates. We show that (de-)adhesion kinetics of endothelial cells are modulated by substrate stiffness and rely on the actomyosin network. We combined this approach with measurements of cell stiffness by magnetic tweezers to show that relaxation dynamics can be considered as a reliable parameter of cellular pre-stress in adherent cells. During the adhesion stage, large cellular and nuclear deformations occur over a long time span (>60 min). Conversely, nuclear deformation and condensed chromatin are relaxed in a few seconds after detachment. Finally, our results show that accumulation of farnesylated prelamin leads to modifications of the nuclear viscoelastic properties, as reflected by increased nuclear relaxation times. Our method offers an original and non-intrusive way of simultaneously gauging cellular and nuclear mechanics, which can be extended to high-throughput screens of pathological conditions and potential countermeasures. PMID:27111836

Probing cytoskeletal pre-stress and nuclear mechanics in endothelial cells with spatiotemporally controlled (de-)adhesion kinetics on micropatterned substrates.

PubMed

Versaevel, Marie; Riaz, Maryam; Corne, Tobias; Grevesse, Thomas; Lantoine, Joséphine; Mohammed, Danahe; Bruyère, Céline; Alaimo, Laura; De Vos, Winnok H; Gabriele, Sylvain

2017-01-02

The mechanical properties of living cells reflect their propensity to migrate and respond to external forces. Both cellular and nuclear stiffnesses are strongly influenced by the rigidity of the extracellular matrix (ECM) through reorganization of the cyto- and nucleoskeletal protein connections. Changes in this architectural continuum affect cell mechanics and underlie many pathological conditions. In this context, an accurate and combined quantification of the mechanical properties of both cells and nuclei can contribute to a better understanding of cellular (dys-)function. To address this challenge, we have established a robust method for probing cellular and nuclear deformation during spreading and detachment from micropatterned substrates. We show that (de-)adhesion kinetics of endothelial cells are modulated by substrate stiffness and rely on the actomyosin network. We combined this approach with measurements of cell stiffness by magnetic tweezers to show that relaxation dynamics can be considered as a reliable parameter of cellular pre-stress in adherent cells. During the adhesion stage, large cellular and nuclear deformations occur over a long time span (>60 min). Conversely, nuclear deformation and condensed chromatin are relaxed in a few seconds after detachment. Finally, our results show that accumulation of farnesylated prelamin leads to modifications of the nuclear viscoelastic properties, as reflected by increased nuclear relaxation times. Our method offers an original and non-intrusive way of simultaneously gauging cellular and nuclear mechanics, which can be extended to high-throughput screens of pathological conditions and potential countermeasures.

Intracellular Pressure Dynamics in Blebbing Cells

PubMed Central

Strychalski, Wanda; Guy, Robert D.

2016-01-01

Blebs are pressure-driven protrusions that play an important role in cell migration, particularly in three-dimensional environments. A bleb is initiated when the cytoskeleton detaches from the cell membrane, resulting in the pressure-driven flow of cytosol toward the area of detachment and local expansion of the cell membrane. Recent experiments involving blebbing cells have led to conflicting hypotheses regarding the timescale of intracellular pressure propagation. The interpretation of one set of experiments supports a poroelastic model of the cytoplasm that leads to slow pressure equilibration when compared to the timescale of bleb expansion. A different study concludes that pressure equilibrates faster than the timescale of bleb expansion. To address this discrepancy, a dynamic computational model of the cell was developed that includes mechanics of and the interactions among the cytoplasm, the actin cortex, the cell membrane, and the cytoskeleton. The model results quantify the relationship among cytoplasmic rheology, pressure, and bleb expansion dynamics, and provide a more detailed picture of intracellular pressure dynamics. This study shows the elastic response of the cytoplasm relieves pressure and limits bleb size, and that both permeability and elasticity of the cytoplasm determine bleb expansion time. Our model with a poroelastic cytoplasm shows that pressure disturbances from bleb initiation propagate faster than the timescale of bleb expansion and that pressure equilibrates slower than the timescale of bleb expansion. The multiple timescales in intracellular pressure dynamics explain the apparent discrepancy in the interpretation of experimental results. PMID:26958893

The nature of thrombosis induced by platinum and tungsten coils in saccular aneurysms.

PubMed

Byrne, J V; Hope, J K; Hubbard, N; Morris, J H

1997-01-01

To compare the efficacy and biocompatability of electrolytic and mechanically detachable embolization coils of two metal types. Experimental saccular aneurysms in pigs were used to assess embolization induced by platinum or tungsten coils. Longitudinal angiographic and histologic studies were performed on treated and untreated (control) aneurysms to compare thrombosis and cellular responses after embolization with electrolytically detachable platinum coils and with mechanically detached tungsten coils. Fewer tungsten than platinum coils were needed to induce thrombosis. The inflammatory response within the aneurysmal lumen was more florid in embolized aneurysms than in control aneurysms. No difference was found in the timing or extent of accumulation of eosinophils, lymphocytes, or polymorphs between the two coils used. Giant cell responses were more marked in treated aneurysms; tungsten coils more than platinum coils. The amount of collagen and fibrosis present increased over the study period and was similar in treated and control aneurysms. The coil type influenced the initial cellular response but had little effect on the rate or degree to which blood clot within the aneurysm was replaced by fibrous tissue.

Physicochemical approach to freshwater microalgae harvesting with magnetic particles.

PubMed

Prochazkova, Gita; Podolova, Nikola; Safarik, Ivo; Zachleder, Vilem; Branyik, Tomas

2013-12-01

Magnetic harvesting of microalgal biomass provides an attractive alternative to conventional methods. The approach to this issue has so far been pragmatic, focused mainly on finding cheap magnetic agents in combination with harvestable microalgae species. The aim of this work was to study experimentally and theoretically the mechanisms leading to cell-magnetic agent attachment/detachment using real experiments and predictions made by colloidal adhesion (XDLVO) model. Two types of well defined magnetic beads (MBs) carrying ion exchange functional groups (DEAE - diethylaminoethyl and PEI - polyethylenimine) were studied in connection with microalgae (Chlorella vulgaris). Optimal harvesting efficiencies (>90%) were found for DEAE and PEI MBs, while efficient detachment was achieved only for DEAE MBs (>90%). These findings were in accordance with the predictions by XDLVO model. Simultaneously there was found a discrepancy between the XDLVO prediction and the poor detachment of PEI MBs from microalgal surface. This can be ascribed to an additional interaction (probably covalent bonds) between PEI and algal surface, which the XDLVO model is unable to capture given by its non-covalent nature. Copyright © 2013 Elsevier B.V. All rights reserved.

Folding of a detachment and fault - Modified detachment folding along a lateral ramp, southwestern Montana, USA

NASA Astrophysics Data System (ADS)

Schmidt, Christopher; Whisner, S. Christopher; Whisner, Jennifer B.

2014-12-01

The inversion of the Middle Proterozoic Belt sedimentary basin during Late Cretaceous thrusting in Montana produced a large eastwardly-convex salient, the southern boundary of which is a 200 km-long oblique to lateral ramp subtended by a detachment between the Belt rocks and Archean basement. A 10 km-long lateral ramp segment exposes the upper levels of the detachment where hanging wall Belt rocks have moved out over the Paleozoic and Mesozoic section. The hanging wall structure consists of a train of high amplitude, faulted, asymmetrical detachment folds. Initial west-east shortening produced layer parallel shortening fabrics and dominantly strike slip faulting followed by symmetrical detachment folding. 'Lock-up' of movement on the detachment surface produced regional simple shear and caused the detachment folds to become asymmetrical and faulted. Folding of the detachment surface after lock-up modified the easternmost detachment folds further into a southeast-verging, overturned fold pair with a ramp-related fault along the base of the stretched mutual limb.

Isoform-specific functions of Mud/NuMA mediate binucleation of Drosophila male accessory gland cells.

PubMed

Taniguchi, Kiichiro; Kokuryo, Akihiko; Imano, Takao; Minami, Ryunosuke; Nakagoshi, Hideki; Adachi-Yamada, Takashi

2014-12-20

In standard cell division, the cells undergo karyokinesis and then cytokinesis. Some cells, however, such as cardiomyocytes and hepatocytes, can produce binucleate cells by going through mitosis without cytokinesis. This cytokinesis skipping is thought to be due to the inhibition of cytokinesis machinery such as the central spindle or the contractile ring, but the mechanisms regulating it are unclear. We investigated them by characterizing the binucleation event during development of the Drosophila male accessory gland, in which all cells are binucleate. The accessory gland cells arrested the cell cycle at 50 hours after puparium formation (APF) and in the middle of the pupal stage stopped proliferating for 5 hours. They then restarted the cell cycle and at 55 hours APF entered the M-phase synchronously. At this stage, accessory gland cells binucleated by mitosis without cytokinesis. Binucleating cells displayed the standard karyokinesis progression but also showed unusual features such as a non-round shape, spindle orientation along the apico-basal axis, and poor assembly of the central spindle. Mud, a Drosophila homolog of NuMA, regulated the processes responsible for these three features, the classical isoform Mud(PBD) and the two newly characterized isoforms Mud(L) and Mud(S) regulated them differently: Mud(L) repressed cell rounding, Mud(PBD) and Mud(S) oriented the spindle along the apico-basal axis, and Mud(S) and Mud(L) repressed central spindle assembly. Importantly, overexpression of Mud(S) induced binucleation even in standard proliferating cells such as those in imaginal discs. We characterized the binucleation in the Drosophila male accessory gland and examined mechanisms that regulated unusual morphologies of binucleating cells. We demonstrated that Mud, a microtubule binding protein regulating spindle orientation, was involved in this binucleation. We suggest that atypical functions exerted by three structurally different isoforms of Mud regulate cell rounding, spindle orientation and central spindle assembly in binucleation. We also propose that Mud(S) is a key regulator triggering cytokinesis skipping in binucleation processes.

Mesoporous silica nanoparticles engineered for ultrasound-induced uptake by cancer cells.

PubMed

Paris, Juan L; Manzano, Miguel; Cabañas, M Victoria; Vallet-Regí, María

2018-04-05

A novel smart hierarchical ultrasound-responsive mesoporous silica nanocarrier for cancer therapy is presented here. This dynamic nanosystem has been designed to display different surface characteristics during its journey towards tumor cells. Initially, the anticancer-loaded nanocarriers are shielded with a polyethylene glycol layer. Upon exposure to high frequency ultrasound, the polymer shell detaches from the nanoparticles, exposing a positively charged surface. This favors the internalization in human osteosarcoma cells, where the release of topotecan takes place, drastically enhancing the cytotoxic effect.

Protein disulfide isomerases in the endoplasmic reticulum promote anchorage-independent growth of breast cancer cells.

PubMed

Wise, Randi; Duhachek-Muggy, Sara; Qi, Yue; Zolkiewski, Michal; Zolkiewska, Anna

2016-06-01

Metastatic breast cancer cells are exposed to stress of detachment from the extracellular matrix (ECM). Cultured breast cancer cells that survive this stress and are capable of anchorage-independent proliferation form mammospheres. The purpose of this study was to explore a link between mammosphere growth, ECM gene expression, and the protein quality control system in the endoplasmic reticulum (ER). We compared the mRNA and protein levels of ER folding factors in SUM159PT and MCF10DCIS.com breast cancer cells grown as mammospheres versus adherent conditions. Publicly available gene expression data for mammospheres formed by primary breast cancer cells and for circulating tumor cells (CTCs) were analyzed to assess the status of ECM/ER folding factor genes in clinically relevant samples. Knock-down of selected protein disulfide isomerase (PDI) family members was performed to examine their roles in SUM159PT mammosphere growth. We found that cells grown as mammospheres had elevated expression of ECM genes and ER folding quality control genes. CTC gene expression data for an index patient indicated that upregulation of ECM and ER folding factor genes occurred at the time of acquired therapy resistance and disease progression. Knock-down of PDI, ERp44, or ERp57, three members of the PDI family with elevated protein levels in mammospheres, in SUM159PT cells partially inhibited the mammosphere growth. Thus, breast cancer cell survival and growth under detachment conditions require enhanced assistance of the ER protein folding machinery. Targeting ER folding factors, in particular members of the PDI family, may improve the therapeutic outcomes in metastatic breast cancer.

Quantitative Analysis of Complex Glioma Cell Migration on Electrospun Polycaprolactone Using Time-Lapse Microscopy

PubMed Central

Johnson, Jed; Nowicki, M. Oskar; Lee, Carol H.; Chiocca, E. Antonio; Viapiano, Mariano S.; Lawler, Sean E.

2009-01-01

Malignant gliomas are the most common tumors originating within the central nervous system and account for over 15,000 deaths annually in the United States. The median survival for glioblastoma, the most common and aggressive of these tumors, is only 14 months. Therapeutic strategies targeting glioma cells migrating away from the tumor core are currently hampered by the difficulty of reproducing migration in the neural parenchyma in vitro. We utilized a tissue engineering approach to develop a physiologically relevant model of glioma cell migration. This revealed that glioma cells display dramatic differences in migration when challenged by random versus aligned electrospun poly-ɛ-caprolactone nanofibers. Cells on aligned fibers migrated at an effective velocity of 4.2 ± 0.39 μm/h compared to 0.8 ± 0.08 μm/h on random fibers, closely matching in vivo models and prior observations of glioma spread in white versus gray matter. Cells on random fibers exhibited extension along multiple fiber axes that prevented net motion; aligned fibers promoted a fusiform morphology better suited to infiltration. Time-lapse microscopy revealed that the motion of individual cells was complex and was influenced by cell cycle and local topography. Glioma stem cell–containing neurospheres seeded on random fibers did not show cell detachment and retained their original shape; on aligned fibers, cells detached and migrated in the fiber direction over a distance sixfold greater than the perpendicular direction. This chemically and physically flexible model allows time-lapse analysis of glioma cell migration while recapitulating in vivo cell morphology, potentially allowing identification of physiological mediators and pharmacological inhibitors of invasion. PMID:19199562

ELECTRON MICROSCOPIC STUDY OF CHANGES IN LIVER CELLS AFTER COMBINED TREATMENT WITH CARBON TETRACHLORIDE AND X RAYS (in Italian)

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

Longostrevi, G.P.; Lombardi, L.

Adult rats were treated with low doses of both CCl/sub 4/ and x rays, shown previously not to produce ultrastructural changes in liver parenchymal cells when given separately. The rats were exposed to a single, whole-body, 200- r dose of 160-kv x rays and then injected subcutaneously with 0.1 ml of a 30% solution of CCl/sub 4/ in peanut oil, corresponding to 0.15 ml CCl/sub 4/ per 100 g body wt. When the rats were sacrificed three days later, all showed pronounced changes in mitochondria and endoplasmic reticulum of liver cells, which were not seen following either individual treatment. Themore » mitochondria showed marked swelling, detachment of cristae, and accumulation of granular material in their interior. Endoplasmic reticulum underwent dilatation and detachment of normally adherent ribonucleoprotein granules. A different picture was observed following injection of toxic doses of CCl/sub 4/ (0.5 m1/100 g body wt). This produced marked disruption and ballooning of mitochondria and endoplasmic reticulum. The results indicate that subliminal doses of CCl/sub 4/ and x rays, presumably acting by different mechanisms, synergistically damage the liver cell, particularly its mitochondria. (BBB)« less

Morphodifferentiation of Gené's organ in engorged Amblyomma sculptum Berlese, 1888 female ticks (Acari: Ixodidae).

PubMed

Dos Santos, Marcelo Francisco; Maltauro Soares, Magna Aparecida; Lallo, Maria Anete; Barros-Battesti, Darci Moraes; de Lima-Netto, Solange; Spadacci-Morena, Diva Denelle

2018-03-01

The Gené's organ (GO) secretes a waxy substance on eggs that reduces water loss and has antimicrobial properties. The current study evaluated morphological and histochemical aspects of GO in Amblyomma sculptum from the period of post-feeding - when ticks detach from the host - to the stage just before oviposition. In this species, GO is composed of a corpus and two pairs of glands, namely, cranial and caudal. Glandular cells are joined laterally by a system of interdigitating membranes with junctional complexes. Histochemistry showed that lipid droplets became more evident as GO developed, while glycogen gradually disappeared, and proteins were detected only near the onset of oviposition. The ultrastructural results revealed a marked distension of the cuticle filled with an amorphous material. Glandular cells showed poor endoplasmatic reticulum, many mitochondria mainly in the basal cell poles and a very developed basal labyrinth. We concluded that the development of GO in A. sculptum ticks was continuous and progressive, and it started after detachment from the host. Additionally, the ultrastructure study suggests that gland cells have an important absorption ability and a low synthetic activity, which indicates that the majority of wax precursors are derived from haemolymph. Copyright © 2018 Elsevier GmbH. All rights reserved.

Selective killing of ovarian cancer cells through induction of apoptosis by nonequilibrium atmospheric pressure plasma

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

Iseki, Sachiko; Tanaka, Hiromasa; Kondo, Hiroki

2012-03-12

Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. Flow cytometry and western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers.

Group choreography: mechanisms orchestrating the collective movement of border cells

PubMed Central

Montell, Denise J.; Yoon, Wan Hee; Starz-Gaiano, Michelle

2014-01-01

Cell movements are essential for animal development and homeostasis but also contribute to disease. Moving cells typically extend protrusions towards a chemoattractant, adhere to the substrate, contract and detach at the rear. It is less clear how cells that migrate in interconnected groups in vivo coordinate their behaviour and navigate through natural environments. The border cells of the Drosophila melanogaster ovary have emerged as an excellent model for the study of collective cell movement, aided by innovative genetic, live imaging, and photomanipulation techniques. Here we provide an overview of the molecular choreography of border cells and its more general implications. PMID:23000794

GENUS DESULFOMICROBIUM

EPA Science Inventory

Short, straight rod- or ellipsoidal-shaped cells (0.5-0.9 x 1.3-2.9 |m) with rounded ends, either singly or in pairs (Sharak Genthner et al., 1994). Gram-negative stain reaction and cell-wall structure. Cells are motile, usually by a single polar flagellum. Obligate anaerobe. End...

Acid Sphingomyelinase Promotes Cellular Internalization of Clostridium perfringens Iota-Toxin.

PubMed

Nagahama, Masahiro; Takehara, Masaya; Miyamoto, Kazuaki; Ishidoh, Kazumi; Kobayashi, Keiko

2018-05-20

Clostridium perfringens iota-toxin is a binary actin-ADP-ribosylating toxin composed of the enzymatic component Ia and receptor binding component Ib. Ib binds to a cell surface receptor, forms Ib oligomer in lipid rafts, and associates with Ia. The Ia-Ib complex then internalizes by endocytosis. Here, we showed that acid sphingomyelinase (ASMase) facilitates the cellular uptake of iota-toxin. Inhibitions of ASMase and lysosomal exocytosis by respective blockers depressed cell rounding induced by iota-toxin. The cytotoxicity of the toxin increased in the presence of Ca 2+ in extracellular fluids. Ib entered target cells in the presence but not the absence of Ca 2+ . Ib induced the extracellular release of ASMase in the presence of Ca 2+ . ASMase siRNA prevented the cell rounding induced by iota-toxin. Furthermore, treatment of the cells with Ib resulted in the production of ceramide in cytoplasmic vesicles. These observations showed that ASMase promotes the internalization of iota-toxin into target cells.

Acid Sphingomyelinase Promotes Cellular Internalization of Clostridium perfringens Iota-Toxin

PubMed Central

Nagahama, Masahiro; Takehara, Masaya; Miyamoto, Kazuaki; Ishidoh, Kazumi; Kobayashi, Keiko

2018-01-01

Clostridium perfringens iota-toxin is a binary actin-ADP-ribosylating toxin composed of the enzymatic component Ia and receptor binding component Ib. Ib binds to a cell surface receptor, forms Ib oligomer in lipid rafts, and associates with Ia. The Ia-Ib complex then internalizes by endocytosis. Here, we showed that acid sphingomyelinase (ASMase) facilitates the cellular uptake of iota-toxin. Inhibitions of ASMase and lysosomal exocytosis by respective blockers depressed cell rounding induced by iota-toxin. The cytotoxicity of the toxin increased in the presence of Ca2+ in extracellular fluids. Ib entered target cells in the presence but not the absence of Ca2+. Ib induced the extracellular release of ASMase in the presence of Ca2+. ASMase siRNA prevented the cell rounding induced by iota-toxin. Furthermore, treatment of the cells with Ib resulted in the production of ceramide in cytoplasmic vesicles. These observations showed that ASMase promotes the internalization of iota-toxin into target cells. PMID:29783772

Distinct molecular and cellular contributions to stabilizing selectin-mediated rolling under flow

PubMed Central

Yago, Tadayuki; Leppänen, Anne; Qiu, Haiying; Marcus, Warren D.; Nollert, Matthias U.; Zhu, Cheng; Cummings, Richard D.; McEver, Rodger P.

2002-01-01

Leukocytes roll on selectins at nearly constant velocities over a wide range of wall shear stresses. Ligand-coupled microspheres roll faster on selectins and detach quickly as wall shear stress is increased. To examine whether the superior performance of leukocytes reflects molecular features of native ligands or cellular properties that favor selectin-mediated rolling, we coupled structurally defined selectin ligands to microspheres or K562 cells and compared their rolling on P-selectin. Microspheres bearing soluble P-selectin glycoprotein ligand (sPSGL)-1 or 2-glycosulfopeptide (GSP)-6, a GSP modeled after the NH2-terminal P-selectin–binding region of PSGL-1, rolled equivalently but unstably on P-selectin. K562 cells displaying randomly coupled 2-GSP-6 also rolled unstably. In contrast, K562 cells bearing randomly coupled sPSGL-1 or 2-GSP-6 targeted to a membrane-distal region of the presumed glycocalyx rolled more like leukocytes: rolling steps were more uniform and shear resistant, and rolling velocities tended to plateau as wall shear stress was increased. K562 cells treated with paraformaldehyde or methyl-β-cyclodextrin before ligand coupling were less deformable and rolled unstably like microspheres. Cells treated with cytochalasin D were more deformable, further resisted detachment, and rolled slowly despite increases in wall shear stress. Thus, stable, shear-resistant rolling requires cellular properties that optimize selectin–ligand interactions. PMID:12177042

A Dwarf Planet Class Object in the 21:5 Resonance with Neptune

NASA Astrophysics Data System (ADS)

Holman, Matthew J.; Payne, Matthew J.; Fraser, Wesley; Lacerda, Pedro; Bannister, Michele T.; Lackner, Michael; Chen, Ying-Tung; Lin, Hsing Wen; Smith, Kenneth W.; Kokotanekova, Rosita; Young, David; Chambers, K.; Chastel, S.; Denneau, L.; Fitzsimmons, A.; Flewelling, H.; Grav, Tommy; Huber, M.; Induni, Nick; Kudritzki, Rolf-Peter; Krolewski, Alex; Jedicke, R.; Kaiser, N.; Lilly, E.; Magnier, E.; Mark, Zachary; Meech, K. J.; Micheli, M.; Murray, Daniel; Parker, Alex; Protopapas, Pavlos; Ragozzine, Darin; Veres, Peter; Wainscoat, R.; Waters, C.; Weryk, R.

2018-03-01

We report the discovery of an H r = 3.4 ± 0.1 dwarf planet candidate by the Pan-STARRS Outer Solar System Survey. 2010 JO179 is red with (g ‑ r) = 0.88 ± 0.21, roughly round, and slowly rotating, with a period of 30.6 hr. Estimates of its albedo imply a diameter of 600–900 km. Observations sampling the span between 2005 and 2016 provide an exceptionally well determined orbit for 2010 JO179, with a semimajor axis of 78.307 ± 0.009 au; distant orbits known to this precision are rare. We find that 2010 JO179 librates securely within the 21:5 mean-motion resonance with Neptune on 100 Myr timescales, joining the small but growing set of known distant dwarf planets on metastable resonant orbits. These imply a substantial trans-Neptunian population that shifts between stability in high-order resonances, the detached population, and the eroding population of the scattering disk.

Transconjunctival drainage of serous and hemorrhagic choroidal detachment.

PubMed

Rezende, Flávio A; Kickinger, Mônica C; Li, Gisèle; Prado, Renata F; Regis, Luiz Gustavo T

2012-02-01

To describe a novel surgical technique for drainage of bullous serous and hemorrhagic choroidal detachments. A prospective, consecutive case series of 6 eyes with serous and/or hemorrhagic choroidal detachments secondary to intraocular surgery was documented to evaluate the feasibility of using the 25-gauge and 20-gauge transconjunctival trocar/cannula systems to drain choroidal detachments. Two eyes had expulsive hemorrhagic choroidal detachments and 4 eyes had serous choroidal detachments after glaucoma surgeries. A 25-gauge infusion line was placed in the anterior chamber. A 20-gauge (in eyes with hemorrhagic choroidal detachments) or a 25-gauge (in eyes with serous detachments) trocar/cannula system was inserted into the suprachoroidal space 7.0 mm from limbus. After drainage, the cannulas were removed and no sutures were placed. Pars plana vitrectomy was performed only in eyes with concomitant pathology that demanded the additional procedure. The primary outcome measure was presence of choroidal detachment at 1 week, 2 weeks, and 1 month postoperatively. Secondary outcome measures were visual acuity at 6 months and intraocular pressure at 1 week and 1, 3, and 6 months postoperatively. Drainage of hemorrhagic choroidal detachments resulted in resolution of the detachments by 1 month postoperatively. In eyes with serous detachments, resolution was achieved by 1 week postdrainage. In both groups, intraocular pressure increased to at least 10 mmHg by postoperative Week 1. The visual acuity improved in all eyes. No complications related to the transconjunctival technique were noted. Transconjunctival drainage of serous and hemorrhagic choroidal detachments seems to be a feasible and simple surgical option with minimal scleral and conjunctival damage. Pars plana vitrectomy may not be necessary when draining choroidal detachments in this manner.

Surface Charge and Hydrophobicity of Endospores of Bacillus anthracis and Related Species in Aqueous Solution

EPA Science Inventory

The surface properties of microorganisms play an important role in attachment and detachment in the environment. The change in surface charge can effect coagulation, disinfection, adhesion to surfaces, uptake of chemicals, and environmental transport. In aqueous solution, cell s...

Chalk-Ex: Transport of Optically Active Particles from the Surface Mixed Layer

DTIC Science & Technology

2002-09-30

and K. A. Kilpatrick. 1998. Scattering and attenuation properties of Emiliania huxleyi cells and their detached coccoliths. Limnol. Oceanogr. 43...coccolithophore Emiliania huxleyi under steady-state light-limited growth. Marine Ecology Progress Series. 142: 87-97. Bidigare, R. R. , M. Latasa, Z

Light Scattering by Marine Particles: Modeling with Non-spherical Shapes

DTIC Science & Technology

2008-01-01

Emiliania huxleyi, Limnology and Oceanography, 46, 1438−1454. Gordon, H.R., 2004, Inverse Radiative Transfer, Coccolith Backscattering, and Light Scattering...16430. Voss, K.J., W.M. Balch, and K.A. Kilpatrick, 1998, Scattering and attenuation properties of Emiliania huxleyi cells and their detached

Development of patient-derived xenograft models from a spontaneously immortal low-grade meningioma cell line, KCI-MENG1.

PubMed

Michelhaugh, Sharon K; Guastella, Anthony R; Varadarajan, Kaushik; Klinger, Neil V; Parajuli, Prahlad; Ahmad, Aamir; Sethi, Seema; Aboukameel, Amro; Kiousis, Sam; Zitron, Ian M; Ebrahim, Salah A; Polin, Lisa A; Sarkar, Fazlul H; Bollig-Fischer, Aliccia; Mittal, Sandeep

2015-07-15

There is a paucity of effective therapies for recurrent/aggressive meningiomas. Establishment of improved in vitro and in vivo meningioma models will facilitate development and testing of novel therapeutic approaches. A primary meningioma cell line was generated from a patient with an olfactory groove meningioma. The cell line was extensively characterized by performing analysis of growth kinetics, immunocytochemistry, telomerase activity, karyotype, and comparative genomic hybridization. Xenograft models using immunocompromised SCID mice were also developed. Histopathology of the patient tumor was consistent with a WHO grade I typical meningioma composed of meningothelial cells, whorls, and occasional psammoma bodies. The original tumor and the early passage primary cells shared the standard immunohistochemical profile consistent with low-grade, good prognosis meningioma. Low passage KCI-MENG1 cells were composed of two cell types with spindle and round morphologies, showed linear growth curve, had very low telomerase activity, and were composed of two distinct unrelated clones on cytogenetic analysis. In contrast, high passage cells were homogeneously round, rapidly growing, had high telomerase activity, and were composed of a single clone with a near triploid karyotype containing 64-66 chromosomes with numerous aberrations. Following subcutaneous and orthotopic transplantation of low passage cells into SCID mice, firm tumors positive for vimentin and progesterone receptor (PR) formed, while subcutaneous implant of high passage cells yielded vimentin-positive, PR-negative tumors, concordant with a high-grade meningioma. Although derived from a benign meningioma specimen, the newly-established spontaneously immortal KCI-MENG1 meningioma cell line can be utilized to generate xenograft tumor models with either low- or high-grade features, dependent on the cell passage number (likely due to the relative abundance of the round, near-triploid cells). These human meningioma mouse xenograft models will provide biologically relevant platforms from which to investigate differences in low- vs. high-grade meningioma tumor biology and disease progression as well as to develop novel therapies to improve treatment options for poor prognosis or recurrent meningiomas.

Quantitative Fundus Autofluorescence in Best Vitelliform Macular Dystrophy: RPE Lipofuscin is not Increased in Non-Lesion Areas of Retina

PubMed Central

Duncker, Tobias; Woods, Russell; Delori, François C.

2018-01-01

Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina. PMID:26427423

Quantitative Fundus Autofluorescence in Best Vitelliform Macular Dystrophy: RPE Lipofuscin is not Increased in Non-Lesion Areas of Retina.

PubMed

Sparrow, Janet R; Duncker, Tobias; Woods, Russell; Delori, François C

2016-01-01

Since the lipofuscin of retinal pigment epithelial (RPE) cells has been implicated in the pathogenesis of Best vitelliform macular dystrophy, we quantified fundus autofluorescence (quantitative fundus autofluorescence, qAF) as an indirect measure of RPE lipofuscin levels. Mean non-lesion qAF was found to be within normal limits for age. By spectral domain optical coherence tomography (SD-OCT) vitelliform lesions presented as fluid-filled subretinal detachments containing reflective material. We discuss photoreceptor outer segment debris as the source of the intense fluorescence of these lesions and loss of anion channel functioning as an explanation for the bullous photoreceptor-RPE detachment. Unexplained is the propensity of the disease for central retina.

Quantification of surface tension and internal pressure generated by single mitotic cells

NASA Astrophysics Data System (ADS)

Fischer-Friedrich, Elisabeth; Hyman, Anthony A.; Jülicher, Frank; Müller, Daniel J.; Helenius, Jonne

2014-08-01

During mitosis, adherent cells round up, by increasing the tension of the contractile actomyosin cortex while increasing the internal hydrostatic pressure. In the simple scenario of a liquid cell interior, the surface tension is related to the local curvature and the hydrostatic pressure difference by Laplace's law. However, verification of this scenario for cells requires accurate measurements of cell shape. Here, we use wedged micro-cantilevers to uniaxially confine single cells and determine confinement forces while concurrently determining cell shape using confocal microscopy. We fit experimentally measured confined cell shapes to shapes obeying Laplace's law with uniform surface tension and find quantitative agreement. Geometrical parameters derived from fitting the cell shape, and the measured force were used to calculate hydrostatic pressure excess and surface tension of cells. We find that HeLa cells increase their internal hydrostatic pressure excess and surface tension from ~ 40 Pa and 0.2 mNm-1 during interphase to ~ 400 Pa and 1.6 mNm-1 during metaphase. The method introduced provides a means to determine internal pressure excess and surface tension of rounded cells accurately and with minimal cellular perturbation, and should be applicable to characterize the mechanical properties of various cellular systems.

A novel platform for minimally invasive delivery of cellular therapy as a thin layer across the subretina for treatment of retinal degeneration

NASA Astrophysics Data System (ADS)

Rotenstreich, Ygal; Tzameret, Adi; Kalish, Sapir E.; Belkin, Michael; Meir, Amilia; Treves, Avraham J.; Nagler, Arnon; Sher, Ifat

2015-03-01

Incurable retinal degenerations affect millions worldwide. Stem cell transplantation rescued visual functions in animal models of retinal degeneration. In those studies cells were transplanted in subretinal "blebs", limited number of cells could be injected and photoreceptor rescue was restricted to areas in proximity to the injection sites. We developed a minimally-invasive surgical platform for drug and cell delivery in a thin layer across the subretina and extravascular spaces of the choroid. The novel system is comprised of a syringe with a blunt-tipped needle and an adjustable separator. Human bone marrow mesenchymal stem cells (hBM-MSCs) were transplanted in eyes of RCS rats and NZW rabbits through a longitudinal triangular scleral incision. No immunosuppressants were used. Retinal function was determined by electroretinogram analysis and retinal structure was determined by histological analysis and OCT. Transplanted cells were identified as a thin layer across the subretina and extravascular spaces of the choroid. In RCS rats, cell transplantation delayed photoreceptor degeneration across the entire retina and significantly enhanced retinal functions. No retinal detachment or choroidal hemorrhages were observed in rabbits following transplantation. This novel platform opens a new avenue for drug and cell delivery, placing the transplanted cells in close proximity to the damaged RPE and retina as a thin layer, across the subretina and thereby slowing down cell death and photoreceptor degeneration, without retinal detachment or choroidal hemorrhage. This new transplantation system may increase the therapeutic effect of other cell-based therapies and therapeutic agents. This study is expected to directly lead to phase I/II clinical trials for autologous hBM-MSCs transplantation in retinal degeneration patients.

In Vivo Analysis of Alternative Modes of Breast Cancer Cell Invasion

DTIC Science & Technology

2009-05-01

lapse videomicroscopy . Bright field time-lapse videomicroscopy revealed that the MMTV-neu cells moved as both round ed and e longated cells on a...behavior. Working with 3-D gel s and time-lapse videomicroscopy I hav e also gained an apprec iation of the way in which mammary tumor cells

pH dependent growth of poly( L-lysine)/poly( L-glutamic) acid multilayer films and their cell adhesion properties

NASA Astrophysics Data System (ADS)

Richert, Ludovic; Arntz, Youri; Schaaf, Pierre; Voegel, Jean-Claude; Picart, Catherine

2004-10-01

The short-term interaction of chondrosarcoma cells with (PGA/PLL) polyelectrolyte multilayers was investigated in a serum-containing medium for films built at different pHs and subsequently exposed to the culture medium. The buildup of the films and their stability was first investigated by means of optical waveguide lightmode spectroscopy, quartz crystal microbalance, streaming potential measurements and atomic force microscopy. While film growth is linear at all pHs, after a few layers have been deposited the growth is much larger for the films built at basic pH and even more pronounced for those built at acidic pH. However, these latter films remain stable in the culture medium only if they have been crosslinked prior to the ionic strength and pH jumps. The films built at acidic pH were found to swell in water by about 200% whereas those built at other pHs did not swell in a physiological buffer. For thin films (≈20 nm) built at pH = 7.4, the detachment forces were dependent on the outermost layer, the forces being significantly higher on PLL-ending films than on PGA-ending ones. In contrast, for the thick films built at pH = 4.4 and at pH = 10.4 (thickness of the order of few hundred of nanometers), the detachment forces were independent of the outermost layer of the film. The films built at pH = 10.4, which shrink in contact with salt containing solutions, were highly cell adhesive whereas those built at acidic pH were highly cell resistant. Protein adsorption and film roughness (as measured by AFM) could not explain these striking differences. The high adhesion observed on the film built at pH 10.4 may rather be related to the secondary structure of the film and to its relatively low swellability in water, whereas the cell resistance of the films built at pH 4.4 may be linked to their high swellability. Therefore, for the PGA/PLL films, the cell adhesion properties can be tuned depending on the deposition pH of the polyelectrolyte solutions. This study reveals the importance of the multilayer structure and architecture to control the detachment force of cells onto such films.

Cultures of human liver cells in simulated microgravity environment

NASA Astrophysics Data System (ADS)

Yoffe, B.; Darlington, G. J.; Soriano, H. E.; Krishnan, B.; Risin, D.; Pellis, N. R.; Khaoustov, V. I.

1999-01-01

We used microgravity-simulated bioreactors that create the unique environment of low shear force and high-mass transfer to establish long-term cultures of primary human liver cells (HLC). To assess the feasibility of establishing HLC cultures, human liver cells obtained either from cells dissociated by collagenase perfusion or minced tissues were cultured in rotating vessels. Formation of multidimensional tissue-like spheroids (up to 1.0 cm) comprised of hepatocytes and biliary epithelial cells that arranged as bile duct-like structures along newly formed vascular sprouts were observed. Electron microscopy revealed clusters of round hepatocytes and bile canaliculi with multiple microvilli and tight junctions. Scanning EM revealed rounded hepatocytes that were organized in tight clusters surrounded by a complex mesh of extracellular matrix. Also, we observed that co-culture of hepatocytes with endothelial cells stimulate albumin mRNA expression. In summary, a simulated microgravity environment is conducive for the establishment of long-term HLC cultures and allows the dissection of the mechanism of liver regeneration and cell-to-cell interactions that resembles in vivo conditions.

Psychological Detachment Mediating the Daily Relationship between Workload and Marital Satisfaction

PubMed Central

Germeys, Lynn; De Gieter, Sara

2017-01-01

Scholars already demonstrated that psychologically detaching from work after workhours can diminish or avoid the negative effects of job demands on employees' well-being. In this study, we examined a curvilinear relationship between workload and psychological detachment. Moreover, we investigated the moderating influence of an employee's work-home segmentation preference on the relation between detachment and marital satisfaction. In addition, we applied and extended the stressor-detachment model by examining detachment as a mediator of the relation between workload and marital satisfaction. A total of 136 employees participated in our daily diary survey study during 10 consecutive working days. The results of the Bayesian 2-level path analyses revealed a negative linear and curvilinear relationship between workload and psychological detachment on a daily basis. Daily detachment positively related to marital satisfaction, with one's preference to segment work from home reinforcing this relationship. Moreover, psychological detachment fully mediated the daily relationship between workload and marital satisfaction. Implications for practice and suggestions for future research are discussed. PMID:28101076

Femtosecond laser cutting of multiple thin corneal stromal lamellae for endothelial bioengineering.

PubMed

Bernard, Aurélien; He, Zhiguo; Forest, Fabien; Gauthier, Anne-Sophie; Peocʼh, Michel; Dumollard, Jean-Marc; Acquart, Sophie; Montard, Romain; Delbosc, Bernard; Gain, Philippe; Thuret, Gilles

2015-02-01

To assess the feasibility of cutting multiple thin stromal lamellae in human donor corneas using a commercial femtosecond laser (FSL) to provide cell carriers for future endothelial graft bioengineering. Eight edematous organ-cultured corneas not suitable for grafting for endothelial reasons were mounted on a Ziemer anterior chamber and cut with a Z6 FSL with 6 successive parallel cuts, from depth to surface. Target thickness of each lamella ranged from 100 to 150 μm depending on initial corneal thickness. Thickness was measured using anterior segment optical coherence tomography before and after cutting on mounted corneas, and on each stromal lamella after detachment. Scanning electron microscopy observation was performed on 4 lamellae and histological cross sections on 1 cornea before detachment. A median of 5 (minimum 3, maximum 7) lamellae was obtained per cornea. All lamellae still attached were the most posterior ones, suggesting that FSL was less efficient because of light scattering by edematous stroma. Cut precision and postdetachment swelling were correlated with anterior-posterior position within the cornea. Median lamella thickness was 127 μm (56-222 μm) before detachment and 196 μm (80-304 μm) after detachment. Surface state was consistent with previously reported FSL lamellar cuts during Descemet stripping automated endothelial keratoplasty. Up to 7 thin lamellae can be cut in stored corneas with an FSL. This method, once optimized primarily by using deswelled, more transparent corneas, could prove effective for recycling unsuitable donor corneas in corneal bioengineering processes.

Psychological Detachment in the Relationship between Job Stressors and Strain

PubMed Central

Safstrom, My; Hartig, Terry

2013-01-01

We investigated the mediating versus moderating role of psychological detachment in the relationship between job stressors and psychological strain. Our sample consisted of 173 university students invested in challenging programs of advanced professional studies, who could find it difficult to detach from work. Hierarchical regression analyses of cross-sectional survey data affirmed the role of psychological detachment as a mediator in the relationship between job demands and perceived stress. Detachment also mediated the relationship between job demands and satisfaction with life, although the association disappeared when controlling for negative affectivity. Detachment did not mediate relationships between job demands and cognitive failures. Psychological detachment did not moderate any of the investigated relationships. The study contributes to a view of psychological detachment as less subject to individual differences than to the imposition of stressors in the given context. PMID:25379246

Bi-Directional Reflectance Measurements of the Ocean Bottom

DTIC Science & Technology

2001-09-30

waters”, 1998, Limnol. and Ocean., 43: 1198 - 1206. K J. Voss, W. M. Balch, K. A. Kilpatrick, "Scattering and attenuation properties of Emiliania ... huxleyi cells and their detached coccoliths", 1998, Limnol. and Ocean., 43: 870-876. J. S. Bartlett, K. J. Voss, S. Sathyendranath, and A. Vodacek

Development of quality indicators for transition from pediatric to adult care in sickle cell disease: A modified Delphi survey of adult providers.

PubMed

Sobota, Amy E; Shah, Nishita; Mack, Jennifer W

2017-06-01

Transition from pediatric to adult care is a vulnerable time for young adults with sickle cell disease (SCD); however, improvements in transition are limited by a lack of quality indicators. The purpose of this study was to establish quality indicators for transition in SCD and to determine the optimal timing between the final pediatric visit and the first adult provider visit. We conducted a modified Delphi survey to reach a consensus on which quality indicators are most important for a successful transition. Our expert panel consisted of members of the Sickle Cell Adult Provider Network. In the first round, the participants ranked a list of quality indicators by importance. In the second round, the participants chose their "top 5" quality indicators in terms of importance and also ranked them on feasibility. The response rates for the two rounds were 68 and 96%, respectively. Nine quality indicators were chosen as "top 5" by a majority of respondents, including communication between pediatric and adult providers, timing of first adult visit, patient self-efficacy, quality of life, and trust with their adult provider. Based on the comments from round 1, respondents were also asked for the optimal timing between leaving pediatric care and entering adult care. Most recommended a first adult visit within 2 months of the final pediatric visit. By using these quality indicators chosen by the majority of respondents, we can better develop and evaluate transition programs for young adults with SCD and improve health outcomes for these vulnerable patients. © 2016 Wiley Periodicals, Inc.

Molecular Alterations that Reduce Cortical Containment of Tubulin Microtentacles and their Impact on Breast Tumor Metastasis

DTIC Science & Technology

2010-04-01

This technique provides a reliable method of determining cellular plasticity and metastatic potential [5, 6]. These studies are nearing completion and...directed chemotherapies could influence CTCs and high- lights the need to investigate these effects. Current methods for detecting CTCs in metastatic...understanding of how these compounds influence detached and circulating tumor cells. Materials and methods Cell culture MCF-10A human MECs were

Diagnostic utility of cyclin D1 in the diagnosis of small round blue cell tumors in children and adolescents.

PubMed

Magro, Gaetano; Salvatorelli, Lucia; Alaggio, Rita; D'Agata, Velia; Nicoletti, Ferdinando; Di Cataldo, Andrea; Parenti, Rosalba

2017-02-01

Small round blue cell tumors (SRBCTs) of children and adolescents are often diagnostically challenging lesions. With the increasing diagnostic approach based on small biopsies, there is the need of specific immunomarkers that can help in the differential diagnosis among the different tumor histotypes to assure the patient a correct diagnosis for proper treatment. Based on our recent studies showing cyclin D1 overexpression in both Ewing sarcoma/primitive peripheral neuroectodermal tumor (EWS/pPNET) and peripheral neuroblastic tumors (neuroblastoma and ganglioneuroblastoma), we immunohistochemically assessed cyclin D1 immunoreactivity in 128 cases of SRBCTs in children and adolescents to establish its potential utility in the differential diagnosis. All cases of EWS/pPNET and the undifferentiated/poorly differentiated neuroblastomatous component of all peripheral neuroblastic tumors exhibited strong and diffuse nuclear staining (>50% of neoplastic cells) for cyclin D1. In contrast, this marker was absent from rhabdomyosarcoma (regardless of subtype) and lymphoblastic lymphoma (either B- or T-cell precursors), whereas it was only focally detected (<5% of neoplastic cells) in some cases of Wilms tumor (blastemal component) and desmoplastic small round cell tumor. Our findings suggest that cyclin D1 can be exploitable as a diagnostic adjunct to conventional markers in confirming the diagnosis of EWS/pPNET or neuroblastoma/ganglioneuroblastoma. Its use in routine practice may also be helpful for those cases of SRBCT with undifferentiated morphology that are difficult to diagnose after application of the conventional markers. Copyright © 2016 Elsevier Inc. All rights reserved.

Cell-specific occupancy of an extended repertoire of CREM and CREB binding loci in male germ cells

PubMed Central

2010-01-01

Background CREB and CREM are closely related factors that regulate transcription in response to various stress, metabolic and developmental signals. The CREMτ activator isoform is selectively expressed in haploid spermatids and plays an essential role in murine spermiogenesis. Results We have used chromatin immunoprecipitation coupled to sequencing (ChIP-seq) to map CREM and CREB target loci in round spermatids from adult mouse testis and spermatogonia derived GC1-spg cells respectively. We identify more than 9000 genomic loci most of which are cell-specifically occupied. Despite the fact that round spermatids correspond to a highly specialised differentiated state, our results show that they have a remarkably accessible chromatin environment as CREM occupies more than 6700 target loci corresponding not only to the promoters of genes selectively expressed in spermiogenesis, but also of genes involved in functions specific to other cell types. The expression of only a small subset of these target genes are affected in the round spermatids of CREM knockout animals. We also identify a set of intergenic binding loci some of which are associated with H3K4 trimethylation and elongating RNA polymerase II suggesting the existence of novel CREB and CREM regulated transcripts. Conclusions We demonstrate that CREM and CREB occupy a large number of promoters in highly cell specific manner. This is the first study of CREM target promoters directly in a physiologically relevant tissue in vivo and represents the most comprehensive experimental analysis of CREB/CREM regulatory potential to date. PMID:20920259

Are core self-evaluations a suitable moderator in stressor-detachment relationships? A study among managers' perceived job demands, detachment and strain reactions.

PubMed

Hentrich, Stephan; Zimber, Andreas; Sosnowsky-Waschek, Nadia; Gregersen, Sabine; Petermann, Franz

2018-01-01

The relationships among job demands, personality factors, recovery and psychological health receive increasing attention but are not well understoodOBJECTIVE:Therefore, the present study tests moderating effects among a sample of managers as proposed by the stressor-detachment model. We aimed to determine whether core self-evaluations (CSE) had an influence on the correlations between detachment and strain reactions (depressive symptoms, irritation, exhaustion) and between job demands and detachment. Further, we tested whether detachment attenuates the positive relation between job demands and strain reactions. A convenience sample of managers in three German settings (N = 282) participated in the cross-sectional study. Results based on hierarchical regression analysis showed that high CSE significantly weakened the negative relationship between detachment and depressive symptoms in this sample. However, CSE did not moderate the negative relationship between job demands and detachment. Moreover, results revealed that detachment moderated the positive relation between job demands and exhaustion. The authors tested whether CSE was able to moderate the relationship between job demands, psychological detachment and different stress reactions. Although we found a significant interaction effect, CSE may be too distal to moderate all respective associations.

Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

PubMed

Shimazu, Akihito; Matsudaira, Ko; Jonge, Jan DE; Tosaka, Naoya; Watanabe, Kazuhiro; Takahashi, Masaya

2016-06-10

This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement.

Psychological detachment from work during non-work time: linear or curvilinear relations with mental health and work engagement?

PubMed Central

SHIMAZU, Akihito; MATSUDAIRA, Ko; DE JONGE, Jan; TOSAKA, Naoya; WATANABE, Kazuhiro; TAKAHASHI, Masaya

2016-01-01

This study examined whether a higher level of psychological detachment during non-work time is associated with better employee mental health (Hypothesis 1), and examined whether psychological detachment has a curvilinear relation (inverted U-shaped pattern) with work engagement (Hypothesis 2). A large cross-sectional Internet survey was conducted among registered monitors of an Internet survey company in Japan. The questionnaire included scales for psychological detachment, employee mental health, and work engagement as well as for job characteristics and demographic variables as potential confounders. The hypothesized model was tested with moderated structural equation modeling techniques among 2,234 respondents working in the tertiary industries with regular employment. Results showed that psychological detachment had curvilinear relations with mental health as well as with work engagement. Mental health improved when psychological detachment increased from a low to higher levels but did not benefit any further from extremely high levels of psychological detachment. Work engagement showed the highest level at an intermediate level of detachment (inverted U-shaped pattern). Although high psychological detachment may enhance employee mental health, moderate levels of psychological detachment are most beneficial for his or her work engagement. PMID:26829972

Efficacy of ONC201 in Desmoplastic Small Round Cell Tumor.

PubMed

Hayes-Jordan, Andrea A; Ma, Xiao; Menegaz, Brian A; Lamhamedi-Cherradi, Salah-Eddine; Kingsley, Charles V; Benson, Jalen A; Camacho, Pamela E; Ludwig, Joseph A; Lockworth, Cynthia R; Garcia, Gloria E; Craig, Suzanne L

2018-05-01

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare sarcoma tumor of adolescence and young adulthood, which harbors a recurrent chromosomal translocation between the Ewing's sarcoma gene (EWSR1) and the Wilms' tumor suppressor gene (WT1). Patients usually develop multiple abdominal tumors with liver and lymph node metastasis developing later. Survival is poor using a multimodal therapy that includes chemotherapy, radiation and surgical resection, new therapies are needed for better management of DSRCT. Triggering cell apoptosis is the scientific rationale of many cancer therapies. Here, we characterized for the first time the expression of pro-apoptotic receptors, tumor necrosis-related apoptosis-inducing ligand receptors (TRAILR1-4) within an established human DSRCT cell line and clinical samples. The molecular induction of TRAIL-mediated apoptosis using agonistic small molecule, ONC201 in vitro cell-based proliferation assay and in vivo novel orthotopic xenograft animal models of DSRCT, was able to inhibit cell proliferation that was associated with caspase activation, and tumor growth, indicating that a cell-based delivery of an apoptosis-inducing factor could be relevant therapeutic agent to control DSRCT. Copyright © 2018. Published by Elsevier Inc.

CD56-positive small round cell tumor: osseous plasmacytoma manifested in osteolytic tumors of the iliac bone and femora.

PubMed

Kouno, Tsutomu; Watanabe, Takashi; Umeda, Toru; Beppu, Yasuo; Kojima, Rie; Sungwon, Kim; Kobayashi, Yukio; Tobinai, Kensei; Hasegawa, Tadashi; Matsuno, Yoshihiro

2005-02-01

Monoclonal gammopathy of undetermined significance does not overexpress cluster of differentiation (CD) 56, but plasma cell myeloma frequently overexpressed it. However, plasma cell leukemia and extramedullary plasmacytoma usually down-regulate CD56 expression. Plasmacytoma, especially 'solitary plasmacytoma of bone', is difficult to diagnose as plasma cell neoplasm, because it occasionally appears similar to other bone tumors, both clinically and pathologically, and is rarely accompanied by monoclonal protein in the serum or urine. The present case was a patient with an osteolytic 'small round cell tumor' of the iliac bone, which also invaded the femora. An immunohistopathological finding of CD56 expression played a key role in making a diagnosis. The definitive diagnosis of plasmacytoma was made based on the electron microscopic findings. The plasma cells which infiltrated her sternum showed the same restriction to kappa light chain expression in their cytoplasms as that of the iliac bone tumor cells, but did not express CD56. Locally infiltrating osteolytic bone tumors should be examined for surface immunoglobulin light chains as well as CD56 expression when plasmacytoma is suspected.

Establishment of a Monarch Butterfly (Danaus plexippus, Lepidoptera: Danaidae) Cell Line and its Susceptibility to Insect Viruses

USDA-ARS?s Scientific Manuscript database

A cell line from the monarch butterfly Danaus plexippus designated BCIRL-DP-AM/JG was established from adult ovaries. The cell line consisted mainly of round cells and took a prolonged period of time in the growth medium ExCell 401 containing 10% fetal bovine serum and antibiotics before it could be...

Testicular histology and germ cell cytology during spermatogenesis in the Mississippi map turtle, Graptemys pseudogeographica kohnii, from Northeast Arkansas.

PubMed

Lancaster, Kelsey; Trauth, Stanley E; Gribbins, Kevin M

2014-01-01

The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year resulting in a single spermiation event with sperm stored within the epididymis until the next spring mating season.

Testicular histology and germ cell cytology during spermatogenesis in the Mississippi map turtle, Graptemys pseudogeographica kohnii, from Northeast Arkansas

PubMed Central

Lancaster, Kelsey; Trauth, Stanley E; Gribbins, Kevin M

2014-01-01

The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year resulting in a single spermiation event with sperm stored within the epididymis until the next spring mating season. PMID:26413408

Diagnostic Exercise: Circling and Behavioral Changes in a Cat.

PubMed

Faller, K; Leach, J; Gutierrez-Quintana, R; Finck, M; Hammond, G; Penderis, J; Marchesi, F

2015-07-01

A 4-year old spayed male domestic shorthair cat was presented with a history of circling and behavioral changes. Neurologic examination showed mild proprioceptive deficits. The lesion was localized in the forebrain, and magnetic resonance imaging revealed the presence of a large midline intracranial mass extending from the frontal lobe to the tentorial region of the brain. Euthanasia was elected due to poor prognosis. Histopathologic evaluation confirmed the presence of a mass composed by sheets and aggregates of large round/polygonal cells and multinucleate cells associated with deposits of cholesterol clefts, scattered hemorrhages and hemosiderin-laden macrophages. Immunohistochemistry showed that the round/polygonal cells and multinucleate cells were strongly positive for major histocompatibility complex class II antigen, variably positive for CD18, and occasionally positive for S100. Subsets of spindle cells showing variable expression of vimentin, S100, and neuron-specific enolase were also present. The final diagnosis was cholesterol granuloma. Differential diagnosis with meningioma is discussed. © The Author(s) 2014.

Reduction of Defects in Germanium-Silicon

NASA Technical Reports Server (NTRS)

2003-01-01

Crystals grown without contact with a container have far superior quality to otherwise similar crystals grown in direct contact with a container. In addition to float-zone processing, detached- Bridgman growth is a promising tool to improve crystal quality, without the limitations of float zoning or the defects introduced by normal Bridgman growth. Goals of this project include the development of the detached Bridgman process to be reproducible and well understood and to quantitatively compare the defect and impurity levels in crystals grown by these three methods. Germanium (Ge) and germanium-silicon (Ge-Si) alloys are being used. At MSFC, we are responsible for the detached Bridgman experiments intended to differentiate among proposed mechanisms of detachment, and to confirm or refine our understanding of detachment. Because the contact angle is critical to determining the conditions for detachment, the sessile drop method was used to measure the contact angles as a function of temperature and composition for a large number of substrates made of potential ampoule materials. Growth experiments have used pyrolytic boron nitride (pBN) and fused silica ampoules with the majority of the detached results occurring predictably in the pBN. Etch pit density (EPD) measurements of normal and detached Bridgman-grown Ge samples show a two order of magnitude improvement in the detached-grown samples. The nature and extent of detachment is determined by using profilometry in conjunction with optical and electron microscopy. The stability of detachment has been analyzed, and an empirical model for the conditions necessary to achieve sufficient stability to maintain detached growth for extended periods has been developed. We have investigated the effects on detachment of ampoule material, pressure difference above and below the melt, and Si concentration; samples that are nearly completely detached can be grown repeatedly in pBN. Current work is concentrated on developing a method to make in situ pressure measurements in the growth ampoules.

A New Theory of Nucleate Pool Boiling in Arbitrary Gravity

NASA Technical Reports Server (NTRS)

Buyevich, Y. A.; Webbon, Bruce W.

1995-01-01

Heat transfer rates specific to nucleate pool boiling under various conditions are determined by the dynamics of vapour bubbles that are originated and grow at nucleation sites of a superheated surface. A new dynamic theory of these bubbles has been recently developed on the basis of the thermodynamics of irreversible processes. In contrast to other existing models based on empirically postulated equations for bubble growth and motion, this theory does not contain unwarrantable assumptions, and both the equations are rigorously derived within the framework of a unified approach. The conclusions of the theory are drastically different from those of the conventional models. The bubbles are shown to detach themselves under combined action of buoyancy and a surface tension force that is proven to add to buoyancy in bubble detachment, but not the other way round as is commonly presumed. The theory ensures a sound understanding of a number of so far unexplained phenomena, such as effect caused by gravity level and surface tension on the bubble growth rate and dependence of the bubble characteristics at detachment on the liquid thermophysical parameters and relevant temperature differences. The theoretical predictions are shown to be in a satisfactory qualitative and quantitative agreement with observations. When being applied to heat transfer at nucleate pool boiling, this bubble dynamic theory offers an opportunity to considerably improve the main formulae that are generally used to correlate experimental findings and to design boiling heat removal in various industrial applications. Moreover, the theory makes possible to pose and study a great deal of new problems of essential impact in practice. Two such problems are considered in detail. One problem concerns the development of a principally novel physical model for the first crisis of boiling. This model allows for evaluating critical boiling heat fluxes under various conditions, and in particular at different gravity levels, with a good agreement with experimental evidence. The other problem bears upon equilibrium shapes of a detached bubble near a heated surface in exceedingly low gravity. In low gravity or in weightlessness, the bubble can remain in the close vicinity of the surface for a long time, and its shape is greatly affected by the Marangoni effect due to both temperature and possible surfactant concentration being nonuniform along the interface. The bubble performs at these conditions like a heat pipe, with evaporation at the bubble lower boundary and condensation at its upper boundary, and ultimately ensures a substantial increase in heat removal as compared with that in normal gravity. Some other problems relevant to nucleate pool and forced convection boiling heat transfer are also discussed.

Mesothelial Cysts of the Round Ligament of the Uterus in 9 Patients: a 15-year experience.

PubMed

Tirnaksiz, Mehmet; Erkan, Arman; Dogrul, Ahmet Bulent; Abbasoglu, Osman

2016-04-04

Aim of this study was to evaluate the characteristic features of patients with mesothelial cyst of the round ligament of the uterus and the incidence of this entity. This was a retrospective review of 3065 patients who underwent inguinal exploration for groin mass from 1998 to 2013. Clinical, radiological and histopathological features of patients with a diagnosis of mesothelial cyst of the round ligament were analyzed. Of the 405 female patients reviewed 9 mesothelial cysts of the round ligament were identified (2.2%). The median age was 37 (range 19-82 years). In all patients the groin mass was manually irreducible on physical examination. The lesions were on the right side in 6 (66.6%) patients. These were identified before surgery in 4 (all by groin ultrasonography). Three were misidentified as a hernia before surgery. The remaining 2 (22%) had both hernia and the mesothelial cyst of the round ligament. The cysts were identified after surgery at the time of histopathological examination in these two patients. In all patients histopathological examination revealed multilobular cystic lesion lined by a single layer of mesothelial cells. Cystic lesions arising from the round ligament were identified and excised along with the round ligament in 7 patients. In the remaining 2, a hernia repair was also performed. There was no recurrence at follow-up. Mesothelial cysts of the round ligament are rare. They are easily misidentified as groin hernia. An accurate diagnosis requires a high index of suspicion and is greatly aided by preoperative imaging studies.

Macular dysfunction in patients with macula-on rhegmatogenous retinal detachments.

PubMed

Akiyama, Kunihiko; Fujinami, Kaoru; Watanabe, Ken; Noda, Toru; Miyake, Yozo; Tsunoda, Kazushige

2018-06-01

To assess macular function in patients with macula-on rhegmatogenous retinal detachments (RRDs) using focal macular electroretinography (FMERG). This is a prospective, observational case series of 27 patients diagnosed with a macula-on RRD. Foveal attachment was confirmed on spectral-domain optical coherence tomography. Eyes with any macular disorder, cataract, vitreous opacity or vitreous haemorrhage were excluded. FMERG was recorded in the affected and fellow eyes using a round stimulus 15° in diameter. The status of four retinal factors in the affected eyes was examined, that is, the number of involved quadrants, number of quadrants with retinal breaks, presence of an RRD invading the vascular arcade, and presence of a giant retinal tear. The implicit time and amplitude of the a-wave, b-wave and oscillatory potentials (OPs) were compared between the affected and fellow eyes using Wilcoxon signed-rank test. The influence of the four retinal factors on each FMERG component of the affected eyes was also evaluated using Mann-Whitney U  test and Kruskal-Wallis test. Significant reductions in the amplitudes of the a-waves (p=0.001), b-waves (p<0.001) and OPs (p=0.001) were observed in the affected eyes compared with the fellow eyes. There was no significant difference between the affected and fellow eyes in the implicit times of any components. None of the four retinal factors affected the parameters in the affected eyes. Altered FMERG responses suggested the presence of macular dysfunction in eyes with macula-on RRDs. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Is Laser Assisted Capsulotomy better than standard CCC?

PubMed

Gavriș, Monica; Mateescu, Radu; Belicioiu, Roxana; Olteanu, Ioana

2017-01-01

Objectives: To compare the safety and intraoperative difficulties of two capsulorhexis techniques for white intumescent cataract: Femtolaser-assisted capsulorhexis and manual capsulorhexis performed in 2-3 stages, with the Utrata forceps. Materials and methods: A prospective comparative study that included 28 eyes divided into 2 equal groups in which capsulorhexis was performed by using the 2 methods. In the first group, the capsulorhexis was executed by using LenSx Femtolaser. In the second group, an Utrata forceps was used to perform a manual 2-3 steps capsulorhexis as follows: a small 2-3 mm capsulorhexis was performed after the staining of the anterior capsule with Trypan Blue along with a good pressurization with viscoelastic substance. The liquefied cortex was aspirated, followed by the enlargement of the capsulorhexis. In some cases, the enlargement was made after IOL implantation. Results: In the Femtolaser group, the capsule was completely detached in 13 cases and only in one case, the capsule had a few bridges which detached easily, without endangering the capsulorhexis integrity. Its size was 4,9 mm in all cases. In the group in which capsulorhexis was performed with the Utrata forceps in 2-3 stages, this was complete, circular and relatively well centered in all cases, but the size varied between 4,5 and 5,5 mm. Conclusions: Femtosecond laser-assisted capsulorhexis was round, well centered and of a desired size of 4,9 mm. The manual capsulorhexis with the Utrata forceps depends on the surgeon's skill and experience and requires a good local anesthesia, the coloring of the anterior capsule with Tripan Blue, using a large quantity of cohesive viscoelastic substances and sometimes using micro incision forceps for helpful maneuvers. The size and centering of the capsulorhexis are not always identical with the intended ones.

Happy, healthy, and productive: the role of detachment from work during nonwork time.

PubMed

Fritz, Charlotte; Yankelevich, Maya; Zarubin, Anna; Barger, Patricia

2010-09-01

Mentally distancing oneself from work during nonwork time can help restore resources lost because of work demands. In this study, we examined possible outcomes of such psychological detachment from work, specifically well-being and job performance. Although employees may need to mentally detach from work to restore their well-being, high levels of detachment may require a longer time to get back into "working mode," which may be negatively associated with job performance. Our results indicate that higher levels of self-reported detachment were associated with higher levels of significant other-reported life satisfaction as well as lower levels of emotional exhaustion. In addition, we found curvilinear relationships between psychological detachment and coworker reported job performance (task performance and proactive behavior). Thus, although high psychological detachment may enhance employee well-being, it seems that medium levels of detachment are most beneficial for job performance. Copyright 2010 APA, all rights reserved

Quaternary low-angle slip on detachment faults in Death Valley, California

USGS Publications Warehouse

Hayman, N.W.; Knott, J.R.; Cowan, D.S.; Nemser, E.; Sarna-Wojcicki, A. M.

2003-01-01

Detachment faults on the west flank of the Black Mountains (Nevada and California) dip 29??-36?? and cut subhorizontal layers of the 0.77 Ma Bishop ash. Steeply dipping normal faults confined to the hanging walls of the detachments offset layers of the 0.64 Ma Lava Creek B tephra and the base of 0.12-0.18 Ma Lake Manly gravel. These faults sole into and do not cut the low-angle detachments. Therefore the detachments accrued any measurable slip across the kinematically linked hanging-wall faults. An analysis of the orientations of hundreds of the hanging-wall faults shows that extension occurred at modest slip rates (<1 mm/yr) under a steep to vertically oriented maximum principal stress. The Black Mountain detachments are appropriately described as the basal detachments of near-critical Coulomb wedges. We infer that the formation of late Pleistocene and Holocene range-front fault scarps accompanied seismogenic slip on the detachments.

Dedifferentiated liposarcoma composed predominantly of rhabdoid/epithelioid cells: a frequently misdiagnosed highly aggressive variant.

PubMed

Agaimy, Abbas; Michal, Michael; Hadravsky, Ladislav; Michal, Michal

2018-01-04

Dedifferentiated liposarcoma is one of the most common sarcoma types in adults with a predilection for the retroperitoneum. We have recently encountered 6 cases of DDL composed predominantly of rounded, rhabdoid or epithelioid cells mimicking rhabdoid melanoma, epithelioid rhabdomyosarcoma or undifferentiated carcinoma. Patients were 5 males and one female aged 64 to 81 years (median, 68). Tumors originated in the retroperitoneum (n=5; 3 in the psoas muscle) and deep soft tissue of the thigh (n=1). All 3 patients with follow-up died of metastatic disease within 4 to 8 months. Preoperative biopsy diagnoses never suggested dedifferentiated liposarcoma as a possibility; instead carcinoma, rhabdomyosarcoma and lymphoma were on top of suggestions. Five resected tumors were composed predominantly (70-100%) of anaplastic rounded to oval rhabdoid cells with prominent central nucleoli and paranuclear rhabdoid inclusions. Bi- and multinucleation was a constant feature. The background stroma showed variable myxoid changes and minor mixed inflammatory cells. Two cases showed homologous dedifferentiation and another had sclerosing spindle cell nodule but a well differentiated lipomatous component was not seen in any. One biopsied case showed solely monotonous small round blue cells with scattered rhabdoid cells. Immunohistochemistry showed expression of MDM2 (6/6), CDK4 (5/6), pancytokeratin AE/1AE3 (4/6) and diffusely desmin + myogenin (2/6). All cases showed high-level co-amplification of MDM2/CDK4 by in-situ-hybridization. The SWI/SNF complex components (SMARCB1, SMARCA2, SMARCA4, ARID1A and PBRM1) were intact in all cases. This highly aggressive liposarcoma variant needs to be distinguished from a variety of neoplasms including undifferentiated carcinoma, melanoma, lymphoma, rhabdomyosarcoma and others. Copyright © 2018. Published by Elsevier Inc.

Hearing and the round goby: Understanding the auditory system of the round goby (Neogobius melanostomus)

NASA Astrophysics Data System (ADS)

Belanger, Andrea J.; Higgs, Dennis M.

2005-04-01

The round goby (Neogobius melanostomus), is an invasive species in the Great Lakes watershed. Adult round gobies show behavioral responses to conspecific vocalizations but physiological investigations have not yet been conducted to quantify their hearing abilities. We have been examining the physiological and morphological development of the auditory system in the round goby. Various frequencies (100 Hz to 800 Hz and conspecific sounds), at various intensities (120 dB to 170 dB re 1 Pa) were presented to juveniles and adults and their auditory brain-stem responses (ABR) were recorded. Round gobies only respond physiologically to tones from 100-600 Hz, with threshold varying between 145 to 155 dB re 1 Pa. The response threshold to conspecific sounds was 140 dB re 1 Pa. There was no significant difference in auditory threshold between sizes of fish for either tones or conspecific sounds. Saccular epithelia were stained using phalloidin and there was a trend towards an increase in both hair cell number and density with an increase in fish size. These results represent a first attempt to quantify auditory abilities in this invasive species. This is an important step in understanding their reproductive physiology, which could potentially aid in their population control. [Funded by NSERC.

Fine Tuning Cell Migration by a Disintegrin and Metalloproteinases

PubMed Central

Theodorou, K.

2017-01-01

Cell migration is an instrumental process involved in organ development, tissue homeostasis, and various physiological processes and also in numerous pathologies. Both basic cell migration and migration towards chemotactic stimulus consist of changes in cell polarity and cytoskeletal rearrangement, cell detachment from, invasion through, and reattachment to their neighboring cells, and numerous interactions with the extracellular matrix. The different steps of immune cell, tissue cell, or cancer cell migration are tightly coordinated in time and place by growth factors, cytokines/chemokines, adhesion molecules, and receptors for these ligands. This review describes how a disintegrin and metalloproteinases interfere with several steps of cell migration, either by proteolytic cleavage of such molecules or by functions independent of proteolytic activity. PMID:28260841

Biophysics of cancer progression and high-throughput mechanical characterization of biomaterials

NASA Astrophysics Data System (ADS)

Osborne, Lukas Dylan

Cancer metastasis involves a series of events known as the metastatic cascade. In this complex progression, cancer cells detach from the primary tumor, invade the surrounding stromal space, transmigrate the vascular system, and establish secondary tumors at distal sites. Specific mechanical phenotypes are likely adopted to enable cells to successfully navigate the mechanical environments encountered during metastasis. To examine the role of cell mechanics in cancer progression, I employed force-consistent biophysical and biochemical assays to characterize the mechanistic links between stiffness, stiffness response and cell invasion during the epithelial to mesenchymal transition (EMT). EMT is an essential physiological process, whose abnormal reactivation has been implicated in the detachment of cancer cells from epithelial tissue and their subsequent invasion into stromal tissue. I demonstrate that epithelial-state cells respond to force by evoking a stiffening response, and that after EMT, mesenchymal-state cells have reduced stiffness but also lose the ability to increase their stiffness in response to force. Using loss and gain of function studies, two proteins are established as functional connections between attenuated stiffness and stiffness response and the increased invasion capacity acquired after EMT. To enable larger scale assays to more fully explore the connection between biomechanics and cancer, I discuss the development of an automated array high throughput (AHT) microscope. The AHT system is shown to implement passive microbead rheology to accurately characterize the mechanical properties of biomaterials. Compared to manually performed mechanical characterizations, the AHT system executes experiments in two orders of magnitude less time. Finally, I use the AHT microscope to study the effect of gain of function oncogenic molecules on cell stiffness. I find evidence that our assay can identify alterations in cell stiffness due to constitutive activation of cancer pathways.

A Study of Parameters Affecting Fibroblast Morphology in Response to an Applied Mechanical Force

NASA Technical Reports Server (NTRS)

Grymes, Rosalind A.; Sawyer, Christine

1994-01-01

A precisely controlled stretch/relaxation regimen (20% elongation at 6.6 cycles/min) was applied to normal human fetal, neonatal and aged dermal fibroblasts cultured on flexible membranes. Culture conditions included poly (NH2) or collagen type I coated substrate membranes; control cultures were grown on the same pliable material in the absence of applied stretch. Direct observation and immunofluorescence analyses revealed a progressive change in cell body orientation limited to the stretched dermal fibroblast cultures. Monolayers gradually (over 4 days) acquired a symmetric, radial distribution equivalent to the biaxial array of the applied force. At high seeding density, alignment was inhibited in the fetal cell cultures. This cell strain required collagen type I coating for optimal attachment to the flexible membrane, preferring growth in three-dimensional cell 'balls' on the poly(NH2) coated substrate. Neonatal cells also required the collagen type I coating, but both neonatal and aged dermal fibroblasts aligned efficiently at all seeding densities examined. The randomly oriented neonatal cells on the unstretched control membranes spontaneously detached at confluence, as a single cell sheet. Their aligned counterparts did not detach until the applied stretch stimulus was removed. Low concentrations of cytochalasin D (62.5 ng/ml) disrupted the stretch-related alignment response. Rhodamine phalloidin staining visualized fewer actin stress fibers in stretched, aligned cells than in controls. Both intercellular interactions and cytoskeletal integrity mediate the response to mechanical strain. Normal rabbit corneal stroma fibroblasts (NRC) were also analyzed, and failed to orient under these conditions. This cell type may require a different regimen, or a longer time period, to demonstrate alignment behavior. Supported by NASA Space Biology RTOP 199-40-22 and the NASA-ARC Director's Discretionary Fund.

Renal myofibroblasts contract collagen I matrix lattices in vitro.

PubMed

Kelynack, K J; Hewitson, T D; Pedagogos, E; Nicholls, K M; Becker, G J

1999-01-01

Myofibroblasts, cells with both fibroblastic and smooth muscle cell features, have been implicated in renal scarring. In addition to synthetic properties, contractile features and integrin expression may allow myofibroblasts to rearrange and contract interstitial collagenous proteins. Myofibroblasts from normal rat kidneys were grown in cell-populated collagen lattices to measure cell generated contraction. Following detachment of cell populated collagen lattices, myofibroblasts progressively contracted collagen lattices, reducing lattice diameter by 42% at 24 h. Alignment of myofibroblasts, rearrangement of fibrils and beta(1) integrin expression were observed within lattices. We postulate that interstitial myofibroblasts contribute to renal scarring through manipulation of collagenous proteins. Copyright 1999 S. Karger AG, Basel

Detachment of secondary dendrite arm in a directionally solidified Sn-Ni peritectic alloy under deceleration growth condition

PubMed Central

Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie; Fu, Hengzhi

2016-01-01

In order to better understand the detachment mechanism of secondary dendrite arm during peritectic solidification, the detachment of secondary dendrite arm from the primary dendrite arms in directionally solidified Sn-36at.%Ni peritectic alloys is investigated at different deceleration rates. Extensive detachment of secondary dendrite arms from primary stem is observed below peritectic reaction temperature TP. And an analytical model is established to characterize the detachment process in terms of the secondary dendrite arm spacing λ2, the root radius of detached arms and the specific surface area (SV) of dendrites. It is found that the detachment mechanism is caused by not only curvature difference between the tips and roots of secondary branches, but also that between the thicker secondary branches and the thinner ones. Besides, this detachment process is significantly accelerated by the temperature gradient zone melting (TGZM) effect during peritectic solidification. It is demonstrated that the reaction constant (f) which is used to characterize the kinetics of peritectic reaction is crucial for the determination of the detachment process. The value of f not only changes with growth rate but also with solidification time at a given deceleration rate. In conclusion, these findings help the better understanding of the detachment mechanism. PMID:27270334

An Assessment of Molten Metal Detachment Hazards During Electron Beam Welding in Space

NASA Technical Reports Server (NTRS)

Fragomeni, James M.; Nunes, Arthur C., Jr.

1998-01-01

The safety issue has been raised with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. This investigation was undertaken to evaluate if molten metal could detach and come in contact with astronauts and burn through the fabric of the astronauts' Extravehicular Mobility Unit (EMU) during electron beam welding in space. Molten metal detachments from either the weld/cut substrate or weld wire could present harm to a astronaut if the detachment was to burn through the fabric of the EMU. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at Low Earth Orbit (LEO). The primary molten metal detachment concerns were those cases of molten metal separation from the metal surface due to metal cutting, weld pool splashing, entrainment and release of molten metal due to filler wire snap-out from the weld puddle, and molten metal accumulation and release from the end of the weld wire. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were developed for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. The surface tension represents the force opposing the liquid metal drop from detaching whereas the weight of the liquid metal droplet represents a force that is tending to detach the molten metal drop. Theoretical calculations have indicated that only a small amount of energy is required to detach a liquid metal drop; however, much of the energy of an impact is absorbed in the sample or weld plate before it reaches the metal drop on the cut edge or surface. The tendency for detachment is directly proportional to the weld pool radius and metal density and inversely proportional to the surface tension of the liquid metal. For a detachment the initial kinetic energy of the weld pool with respect to the plate has to exceed the energy to form the extra surface required for the detachment of the pool. The difficulty is in transferring the energy from the point of impact through the plate and sample to the cut edge. It is likely that not all of the kinetic energy is available for detaching the pool; some may be sequestered in weld pool oscillations. The coefficient of restitution for the collision will be lower than one if irreversible deformation, for example plastic flow deformation, takes place during the collision. Thus determining the amount of energy from an impact that actually reaches the molten metal droplet is critical. Various molten metal detachment scenarios were tested experimentally in an enclosed vacuum chamber using the Ukrainian Universal Hand Tool, an electron beam welder designed for space welding. The experimental testing was performed in a 4 ft. X 4 ft. vacuum chamber at Marshall Space Flight Center, evacuated to vacuum levels of at least 50 microTorr, and also some welding garment material was utilized to observe the effect of the molten metal detachments on the material. A "carillon" apparatus consisting of four pendulum hammer strikers, each weighing approximately 3.65 lbs, raised to predetermined specific heights was used to apply an impact force to the weld sample/plate during electron beam welding and cutting exercises. The strikers were released by switching on an electric motor to rotate a pin holding wires retaining the strikers at desired heights. The specimens were suspended so as to be free to respond to the blows with a sudden velocity increment. The specimens were mounted on a hinged plate for minimizing effective mass with the option to fasten it down so as to raise its effective mass closer to that anticipated for an actual space welding scenario. Measurements were made of the impact energy and the horizontal fling distances of the detached metal drops. It was not particularly easy to generate the detachments for this experiment. This document presents the details of the theoretical modeling effort and a summary of the experimental effort to measure molten metal drop detachments from terrestrial electron beam welding in the enclosed vacuum chamber. The results of the experimental effort have shown that molten metal detachments can occur from the sample/weld plate only if a sufficiently large impact force is applied to the weld plate. A "weld pool detachment parameter" was determined to indicate whether detachment would occur. Detachment can be either full or partial (dripping), Partial detachment means that the weld pool detached from one side of the liquid-solid boundary so as to leave a hole at the puddle site but remained attached over part of the liquid-solid boundary and dripped down the plate with no fully detached material detected. Full detachment, however, does not necessarily mean that the whole pool fully detached; in some cases only a smaller portion of the pool detached, the remainder dripping down the plate. The weld pool detachment parameter according to theory and according to the empirical data allows a determination of whether full detachments might occur. Theoretical calculations indicated titanium alloy would be the most difficult from which to detach molten metal droplets followed by stainless steel and then by aluminum. The experimental results were for the most part consistent with the theoretical analysis and predictions. The above theory is applicable to other situations as desired for assessing the potential for molten metal detachments.

Dynamics of Single Hydrogen Bubbles at a Platinum Microelectrode.

PubMed

Yang, Xuegeng; Karnbach, Franziska; Uhlemann, Margitta; Odenbach, Stefan; Eckert, Kerstin

2015-07-28

Bubble dynamics, including the formation, growth, and detachment, of single H2 bubbles was studied at a platinum microelectrode during the electrolysis of 1 M H2SO4 electrolyte. The bubbles were visualized through a microscope by a high-speed camera. Electrochemical measurements were conducted in parallel to measure the transient current. The periodic current oscillations, resulting from the periodic formation and detachment of single bubbles, allow the bubble lifetime and size to be predicted from the transient current. A comparison of the bubble volume calculated from the current and from the recorded bubble image shows a gas evolution efficiency increasing continuously with the growth of the bubble until it reaches 100%. Two different substrates, glass and epoxy, were used to embed the Pt wire. While nearly no difference was found with respect to the growth law for the bubble radius, the contact angle differs strongly for the two types of cell. Data provided for the contact point evolution further complete the image of single hydrogen bubble growth. Finally, the velocity field driven by the detached bubble was measured by means of PIV, and the effects of the convection on the subsequent bubble were evaluated.

Improved Round Trip Efficiency for Regenerative Fuel Cell Systems

DTIC Science & Technology

2012-05-11

advanced components that enable closed-loop, zero emission, low signature energy storage. The system utilizes proton exchange membrane ( PEM ) fuel cell ...regenerative fuel cell (RFC) systems based on proton exchange membrane ( PEM ) technology. An RFC consists of a fuel cell powerplant, an electrolysis...based on an air independent, hydrogen-oxygen, PEM RFC is feasible within the near term if development efforts proceed forward. Fuel Cell

A simple 2D biofilm model yields a variety of morphological features.

PubMed

Hermanowicz, S W

2001-01-01

A two-dimensional biofilm model was developed based on the concept of cellular automata. Three simple, generic processes were included in the model: cell growth, internal and external mass transport and cell detachment (erosion). The model generated a diverse range of biofilm morphologies (from dense layers to open, mushroom-like forms) similar to those observed in real biofilm systems. Bulk nutrient concentration and external mass transfer resistance had a large influence on the biofilm structure.

Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching.

PubMed

Bieri, Tamaki; Onishi, Masayuki; Xiang, Tingting; Grossman, Arthur R; Pringle, John R

2016-01-01

When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged.

Relative Contributions of Various Cellular Mechanisms to Loss of Algae during Cnidarian Bleaching

PubMed Central

Bieri, Tamaki; Onishi, Masayuki; Xiang, Tingting; Grossman, Arthur R.; Pringle, John R

2016-01-01

When exposed to stress such as high seawater temperature, corals and other cnidarians can bleach due to loss of symbiotic algae from the host tissue and/or loss of pigments from the algae. Although the environmental conditions that trigger bleaching are reasonably well known, its cellular and molecular mechanisms are not well understood. Previous studies have reported the occurrence of at least four different cellular mechanisms for the loss of symbiotic algae from the host tissue: in situ degradation of algae, exocytic release of algae from the host, detachment of host cells containing algae, and death of host cells containing algae. The relative contributions of these several mechanisms to bleaching remain unclear, and it is also not known whether these relative contributions change in animals subjected to different types and/or durations of stresses. In this study, we used a clonal population of the small sea anemone Aiptasia, exposed individuals to various precisely controlled stress conditions, and quantitatively assessed the several possible bleaching mechanisms in parallel. Under all stress conditions tested, except for acute cold shock at 4°C, expulsion of intact algae from the host cells appeared to be by far the predominant mechanism of bleaching. During acute cold shock, in situ degradation of algae and host-cell detachment also became quantitatively significant, and the algae released under these conditions appeared to be severely damaged. PMID:27119147

Divertor detachment

NASA Astrophysics Data System (ADS)

Krasheninnikov, Sergei

2015-11-01

The heat exhaust is one of the main conceptual issues of magnetic fusion reactor. In a standard operational regime the large heat flux onto divertor target reaches unacceptable level in any foreseeable reactor design. However, about two decades ago so-called ``detached divertor'' regimes were found. They are characterized by reduced power and plasma flux on divertor targets and look as a promising solution for heat exhaust in future reactors. In particular, it is envisioned that ITER will operate in a partly detached divertor regime. However, even though divertor detachment was studied extensively for two decades, still there are some issues requiring a new look. Among them is the compatibility of detached divertor regime with a good core confinement. For example, ELMy H-mode exhibits a very good core confinement, but large ELMs can ``burn through'' detached divertor and release large amounts of energy on the targets. In addition, detached divertor regimes can be subject to thermal instabilities resulting in the MARFE formation, which, potentially, can cause disruption of the discharge. Finally, often inner and outer divertors detach at different plasma conditions, which can lead to core confinement degradation. Here we discuss basic physics of divertor detachment including different mechanisms of power and momentum loss (ionization, impurity and hydrogen radiation loss, ion-neutral collisions, recombination, and their synergistic effects) and evaluate the roles of different plasma processes in the reduction of the plasma flux; detachment stability; and an impact of ELMs on detachment. We also evaluate an impact of different magnetic and divertor geometries on detachment onset, stability, in- out- asymmetry, and tolerance to the ELMs. Supported by the U.S. Department of Energy Office of Science, Office of Fusion Energy Sciences under Award Number DE-DE-FG02-04ER54739 at UCSD.

Evaluation of hyaloid-retinal relationship during triamcinolone-assisted vitrectomy for primary rhegmatogenous retinal detachment.

PubMed

Sundar, Dheepak; Takkar, Brijesh; Venkatesh, Pradeep; Chawla, Rohan; Temkar, Shreyas; Azad, Shorya Vardhan; Vohra, Rajpal

2018-03-01

To determine hyaloid-retinal relationship in primary rhegmatogenous retinal detachment during vitreous surgery. This is a prospective, interventional study of patients (n = 72) undergoing triamcinolone-assisted 25G vitreous surgery for primary rhegmatogenous retinal detachment. Hyaloid-retinal relationship was noted intraoperatively to identify regions and patterns of firm attachment and was classified into subgroups. Analysis was done to determine association between hyaloid-retinal relationship patterns and preoperative findings: posterior vitreous detachment, proliferative vitreoretinopathy, type of retinal tear, the presence of peripheral degenerations, and postoperative outcomes. Three patterns of hyaloid-retinal relationship were identified: type1 (complete absence of posterior vitreous detachment (21%)), type 2 (incomplete posterior vitreous detachment (47%)) and type 3 (complete posterior vitreous detachment (32%)). Posterior vitreous detachment in some form was present in 84% of the cases with retinal tears as the causative break but none of the cases with retinal holes (p < 0.001). None of the cases with vitreoretinal degeneration had complete posterior vitreous detachment (p = 0.001). 69% of proliferative vitreoretinopathy-C cases had type 1 hyaloid-retinal relationship as compared to 11% cases with no proliferative vitreoretinopathy (p < 0.001). Proliferative vitreoretinopathy-related anatomical failure was seen in 7.5%, and 80% of these eyes with recurrent RD had type 1 hyaloid-retinal relationship (p<0.001). Nearly half the patients diagnosed as complete posterior vitreous detachment preoperatively were found to have incomplete posterior vitreous detachment intraoperatively. Majority of the cases with rhegmatogenous retinal detachment have some form of strong vitreoretinal adhesion. Hyaloid-retinal relationship varies with types of retinal breaks, retinal degeneration, and proliferative vitreoretinopathy. Intraoperative hyaloid-retinal relationship is frequently different from that assessed before surgery and the proposed classification may improve surgical decision making and prognostication.

Heat transport in bubbling turbulent convection

PubMed Central

Lakkaraju, Rajaram; Stevens, Richard J. A. M.; Oresta, Paolo; Verzicco, Roberto; Lohse, Detlef; Prosperetti, Andrea

2013-01-01

Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to numerous mechanisms, many of which are not understood in quantitative detail. An important component of the overall process is that the buoyancy of the bubble compounds with that of the liquid to give rise to a much-enhanced natural convection. In this article, we focus specifically on this enhancement and present a numerical study of the resulting two-phase Rayleigh–Bénard convection process in a cylindrical cell with a diameter equal to its height. We make no attempt to model other aspects of the boiling process such as bubble nucleation and detachment. The cell base and top are held at temperatures above and below the boiling point of the liquid, respectively. By keeping this difference constant, we study the effect of the liquid superheat in a Rayleigh number range that, in the absence of boiling, would be between 2 × 106 and 5 × 109. We find a considerable enhancement of the heat transfer and study its dependence on the number of bubbles, the degree of superheat of the hot cell bottom, and the Rayleigh number. The increased buoyancy provided by the bubbles leads to more energetic hot plumes detaching from the cell bottom, and the strength of the circulation in the cell is significantly increased. Our results are in general agreement with recent experiments on boiling Rayleigh–Bénard convection. PMID:23696657

Heat transport in bubbling turbulent convection.

PubMed

Lakkaraju, Rajaram; Stevens, Richard J A M; Oresta, Paolo; Verzicco, Roberto; Lohse, Detlef; Prosperetti, Andrea

2013-06-04

Boiling is an extremely effective way to promote heat transfer from a hot surface to a liquid due to numerous mechanisms, many of which are not understood in quantitative detail. An important component of the overall process is that the buoyancy of the bubble compounds with that of the liquid to give rise to a much-enhanced natural convection. In this article, we focus specifically on this enhancement and present a numerical study of the resulting two-phase Rayleigh-Bénard convection process in a cylindrical cell with a diameter equal to its height. We make no attempt to model other aspects of the boiling process such as bubble nucleation and detachment. The cell base and top are held at temperatures above and below the boiling point of the liquid, respectively. By keeping this difference constant, we study the effect of the liquid superheat in a Rayleigh number range that, in the absence of boiling, would be between 2 × 10(6) and 5 × 10(9). We find a considerable enhancement of the heat transfer and study its dependence on the number of bubbles, the degree of superheat of the hot cell bottom, and the Rayleigh number. The increased buoyancy provided by the bubbles leads to more energetic hot plumes detaching from the cell bottom, and the strength of the circulation in the cell is significantly increased. Our results are in general agreement with recent experiments on boiling Rayleigh-Bénard convection.

Long-Time Plasma Membrane Imaging Based on a Two-Step Synergistic Cell Surface Modification Strategy.

PubMed

Jia, Hao-Ran; Wang, Hong-Yin; Yu, Zhi-Wu; Chen, Zhan; Wu, Fu-Gen

2016-03-16

Long-time stable plasma membrane imaging is difficult due to the fast cellular internalization of fluorescent dyes and the quick detachment of the dyes from the membrane. In this study, we developed a two-step synergistic cell surface modification and labeling strategy to realize long-time plasma membrane imaging. Initially, a multisite plasma membrane anchoring reagent, glycol chitosan-10% PEG2000 cholesterol-10% biotin (abbreviated as "GC-Chol-Biotin"), was incubated with cells to modify the plasma membranes with biotin groups with the assistance of the membrane anchoring ability of cholesterol moieties. Fluorescein isothiocyanate (FITC)-conjugated avidin was then introduced to achieve the fluorescence-labeled plasma membranes based on the supramolecular recognition between biotin and avidin. This strategy achieved stable plasma membrane imaging for up to 8 h without substantial internalization of the dyes, and avoided the quick fluorescence loss caused by the detachment of dyes from plasma membranes. We have also demonstrated that the imaging performance of our staining strategy far surpassed that of current commercial plasma membrane imaging reagents such as DiD and CellMask. Furthermore, the photodynamic damage of plasma membranes caused by a photosensitizer, Chlorin e6 (Ce6), was tracked in real time for 5 h during continuous laser irradiation. Plasma membrane behaviors including cell shrinkage, membrane blebbing, and plasma membrane vesiculation could be dynamically recorded. Therefore, the imaging strategy developed in this work may provide a novel platform to investigate plasma membrane behaviors over a relatively long time period.

Nisin and lysostaphin activity against preformed biofilm of Staphylococcus aureus involved in bovine mastitis.

PubMed

Ceotto-Vigoder, H; Marques, S L S; Santos, I N S; Alves, M D B; Barrias, E S; Potter, A; Alviano, D S; Bastos, M C F

2016-07-01

The biofilm produced by Staphylococcus aureus isolates involved in clinical or subclinical bovine mastitis and the activity of nisin and lysostaphin against the preformed biofilm produced by these strains were investigated. Eighteen strains were tested and all produced biofilm. Eight strains with distinct biofilm composition were selected for the antimicrobial activity assays. The minimal inhibitory concentration of each bacteriocin was determined against the planktonic cells and ranged from 15·6 to 500 μg ml(-1) for nisin, and from 3·9 to 50 μg ml(-1) , for lysostaphin. Lysostaphin treatment (0·4 μg ml(-1) ) for 4 h caused a strong Staph. aureus 4181 biofilm detachment and death of the majority of the sessile cells, while nisin treatment (100 μg ml(-1) ) for the same time caused only a great reduction in cell viability. Additionally, combination of both bacteriocins for 4 h resulted in significant death of the sessile cells but no biofilm detachment. The treatment with lysostaphin alone or in combination with nisin was effective in killing most biofilm sessile cells. The action of lysostaphin, either alone or in combination with nisin, against established staphylococcal biofilm may represent an alternative to bovine mastitis control. However, the duration of the treatment should be considered for its application so that the best effectiveness can be achieved. © 2016 The Society for Applied Microbiology.

Detachment-induced E-cadherin expression promotes 3D tumor spheroid formation but inhibits tumor formation and metastasis of lung cancer cells.

PubMed

Powan, Phattrakorn; Luanpitpong, Sudjit; He, Xiaoqing; Rojanasakul, Yon; Chanvorachote, Pithi

2017-11-01

The epithelial-to-mesenchymal transition is proposed to be a key mechanism responsible for metastasis-related deaths. Similarly, cancer stem cells (CSCs) have been proposed to be a key driver of tumor metastasis. However, the link between the two events and their control mechanisms is unclear. We used a three-dimensional (3D) tumor spheroid assay and other CSC-indicating assays to investigate the role of E-cadherin in CSC regulation and its association to epithelial-to-mesenchymal transition in lung cancer cells. Ectopic overexpression and knockdown of E-cadherin were found to promote and retard, respectively, the formation of tumor spheroids in vitro but had opposite effects on tumor formation and metastasis in vivo in a xenograft mouse model. We explored the discrepancy between the in vitro and in vivo results and demonstrated, for the first time, that E-cadherin is required as a component of a major survival pathway under detachment conditions. Downregulation of E-cadherin increased the stemness of lung cancer cells but had an adverse effect on their survival, particularly on non-CSCs. Such downregulation also promoted anoikis resistance and invasiveness of lung cancer cells. These results suggest that anoikis assay could be used as an alternative method for in vitro assessment of CSCs that involves dysregulated adhesion proteins. Our data also suggest that agents that restore E-cadherin expression may be used as therapeutic agents for metastatic cancers. Copyright © 2017 the American Physiological Society.

Detached-Eddy Simulations of Attached and Detached Boundary Layers

NASA Astrophysics Data System (ADS)

Caruelle, B.; Ducros, F.

2003-12-01

This article presents Detached-Eddy Simulations (DESs) of attached and detached turbulent boundary layers. This hybrid Reynolds Averaged Navier-Stokes (RANS) / Large Eddy Simulation (LES) model goes continuously from RANS to LES according to the mesh definition. We propose a parametric study of the model over two "academic" configurations, in order to get information on the influence of the mesh to correctly treat complex flow with attached and detached boundary layers.

Evolution-guided optimization of biosynthetic pathways.

PubMed

Raman, Srivatsan; Rogers, Jameson K; Taylor, Noah D; Church, George M

2014-12-16

Engineering biosynthetic pathways for chemical production requires extensive optimization of the host cellular metabolic machinery. Because it is challenging to specify a priori an optimal design, metabolic engineers often need to construct and evaluate a large number of variants of the pathway. We report a general strategy that combines targeted genome-wide mutagenesis to generate pathway variants with evolution to enrich for rare high producers. We convert the intracellular presence of the target chemical into a fitness advantage for the cell by using a sensor domain responsive to the chemical to control a reporter gene necessary for survival under selective conditions. Because artificial selection tends to amplify unproductive cheaters, we devised a negative selection scheme to eliminate cheaters while preserving library diversity. This scheme allows us to perform multiple rounds of evolution (addressing ∼10(9) cells per round) with minimal carryover of cheaters after each round. Based on candidate genes identified by flux balance analysis, we used targeted genome-wide mutagenesis to vary the expression of pathway genes involved in the production of naringenin and glucaric acid. Through up to four rounds of evolution, we increased production of naringenin and glucaric acid by 36- and 22-fold, respectively. Naringenin production (61 mg/L) from glucose was more than double the previous highest titer reported. Whole-genome sequencing of evolved strains revealed additional untargeted mutations that likely benefit production, suggesting new routes for optimization.

Mammalian Auditory Hair Cell Bundle Stiffness Affects Frequency Tuning by Increasing Coupling along the Length of the Cochlea.

PubMed

Dewey, James B; Xia, Anping; Müller, Ulrich; Belyantseva, Inna A; Applegate, Brian E; Oghalai, John S

2018-06-05

The stereociliary bundles of cochlear hair cells convert mechanical vibrations into the electrical signals required for auditory sensation. While the stiffness of the bundles strongly influences mechanotransduction, its influence on the vibratory response of the cochlear partition is unclear. To assess this, we measured cochlear vibrations in mutant mice with reduced bundle stiffness or with a tectorial membrane (TM) that is detached from the sensory epithelium. We found that reducing bundle stiffness decreased the high-frequency extent and sharpened the tuning of vibratory responses obtained postmortem. Detaching the TM further reduced the high-frequency extent of the vibrations but also lowered the partition's resonant frequency. Together, these results demonstrate that the bundle's stiffness and attachment to the TM contribute to passive longitudinal coupling in the cochlea. We conclude that the stereociliary bundles and TM interact to facilitate passive-wave propagation to more apical locations, possibly enhancing active-wave amplification in vivo. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Investigation of plasma behavior during noble gas injection in the end-cell of GAMMA 10/PDX by using the multi-fluid code ‘LINDA’

NASA Astrophysics Data System (ADS)

Islam, M. S.; Nakashima, Y.; Hatayama, A.

2017-12-01

The linear divertor analysis with fluid model (LINDA) code has been developed in order to simulate plasma behavior in the end-cell of linear fusion device GAMMA 10/PDX. This paper presents the basic structure and simulated results of the LINDA code. The atomic processes of hydrogen and impurities have been included in the present model in order to investigate energy loss processes and mechanism of plasma detachment. A comparison among Ar, Kr and Xe shows that Xe is the most effective gas on the reduction of electron and ion temperature. Xe injection leads to strong reduction in the temperature of electron and ion. The energy loss terms for both the electron and the ion are enhanced significantly during Xe injection. It is shown that the major energy loss channels for ion and electron are charge-exchange loss and radiative power loss of the radiator gas, respectively. These outcomes indicate that Xe injection in the plasma edge region is effective for reducing plasma energy and generating detached plasma in linear device GAMMA 10/PDX.

Extending metabolome coverage for untargeted metabolite profiling of adherent cultured hepatic cells.

PubMed

García-Cañaveras, Juan Carlos; López, Silvia; Castell, José Vicente; Donato, M Teresa; Lahoz, Agustín

2016-02-01

MS-based metabolite profiling of adherent mammalian cells comprises several challenging steps such as metabolism quenching, cell detachment, cell disruption, metabolome extraction, and metabolite measurement. In LC-MS, the final metabolome coverage is strongly determined by the separation technique and the MS conditions used. Human liver-derived cell line HepG2 was chosen as adherent mammalian cell model to evaluate the performance of several commonly used procedures in both sample processing and LC-MS analysis. In a first phase, metabolite extraction and sample analysis were optimized in a combined manner. To this end, the extraction abilities of five different solvents (or combinations) were assessed by comparing the number and the levels of the metabolites comprised in each extract. Three different chromatographic methods were selected for metabolites separation. A HILIC-based method which was set to specifically separate polar metabolites and two RP-based methods focused on lipidome and wide-ranging metabolite detection, respectively. With regard to metabolite measurement, a Q-ToF instrument operating in both ESI (+) and ESI (-) was used for unbiased extract analysis. Once metabolite extraction and analysis conditions were set up, the influence of cell harvesting on metabolome coverage was also evaluated. Therefore, different protocols for cell detachment (trypsinization or scraping) and metabolism quenching were compared. This study confirmed the inconvenience of trypsinization as a harvesting technique, and the importance of using complementary extraction solvents to extend metabolome coverage, minimizing interferences and maximizing detection, thanks to the use of dedicated analytical conditions through the combination of HILIC and RP separations. The proposed workflow allowed the detection of over 300 identified metabolites from highly polar compounds to a wide range of lipids.

Opposite effects of flurbiprofen and the nitroxybutyl ester of flurbiprofen on apoptosis in cultured guinea-pig gastric mucous cells

PubMed Central

Johal, Kamaljit; Hanson, Peter J

2000-01-01

The nitric oxide (NO)-donating nitroxybutyl ester of flurbiprofen (NO-flurbiprofen), shows reduced gastro-intestinal toxicity relative to flurbiprofen. NO may exert either pro- or anti-apoptotic effects, while non-steroidal anti-inflammatory drugs may induce apoptosis. The aim of the present work was therefore to compare the effects of flurbiprofen and NO-flurbiprofen on apoptosis in guinea-pig gastric mucous cells. Apoptotic activity was assessed by assay of caspase activity and from the fragmentation and condensation of nuclei. Incubation with flurbiprofen for 24 h produced a concentration-dependent induction of apoptosis in cells attached to the culture plate (caspase 3-like activity increased by 257% at 500 μM), while NO-flurbiprofen inhibited basal apoptosis (caspase 3-like activity decreased by 71% at 500 μM). Caspase activity and nuclear fragmentation were substantially increased in cells that had spontaneously detached from the culture plate. NO-flurbiprofen inhibited caspase activity (55% at 500 μM) but not nuclear fragmentation in these detached cells. NO flurbiprofen inhibited the activation of apoptosis by 25 μM C6-ceramide in cells attached to the culture plate. Inhibition of caspase activity by NO-flurbiprofen was detectable after 6 h of incubation with intact cells, but by contrast with the NO-donor S-nitrosyl-N-acetyl-penicillamine, was not demonstrable with cell homogenates. Activation of caspase 3-like activity by flurbiprofen was slow (>6 h incubation needed) and was inhibited by cycloheximide. The presence of a nitroxybutyl ester moiety on flurbiprofen prevents the pro-apoptotic activity of the parent compound and may contribute to the reduced gastro-intestinal toxicity of NO-flurbiprofen. PMID:10864887

HPW-RX40 restores anoikis sensitivity of human breast cancer cells by inhibiting integrin/FAK signaling

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

Chen, I-Hua; Shih, Hsin-Chu; Hsieh, Pei-Wen

Anoikis is defined as apoptosis, which is induced by inappropriate cell–matrix interactions. Cancer cells with anoikis resistance tend to undergo metastasis, and this phenomenon has been reported to be associated with integrin and FAK activity. HPW-RX40 is a derivative of 3,4-methylenedioxy-β-nitrostyrene, which is known to prevent platelet aggregation by inhibition of integrin. In the present study, we investigated the effect of HPW-RX40 on an anoikis-resistant human breast cancer cell line MDA-MB-231. HPW-RX40 inhibited cell aggregation and induced cell death in suspending MDA-MB-231 cells, but had only little effect on the monolayer growth of adherent cells. Analysis of caspase activation andmore » poly (ADP-ribose) polymerase (PARP) cleavage confirmed anoikis in HPW-RX40-treated suspending cancer cells. HPW-RX40 also affected the Bcl-2 family proteins in detached cancer cells. Furthermore, HPW-RX40 inhibited detachment-induced activation of FAK and the downstream phosphorylation of Src and paxillin, but did not affect this pathway in adherent cancer cells. We also found that the expression and activation of β1 integrin in MDA-MB-231 cells were reduced by HPW-RX40. The combination of HPW-RX40 with an EGFR inhibitor led to enhanced anoikis and inhibition of the FAK pathway in breast cancer cells. Taken together, our results suggest that HPW-RX40 restores the anoikis sensitivity in the metastatic breast cancer cells by inhibiting integrin and subsequent FAK activation, and reveal a potential strategy for prevention of tumor metastasis. - Highlights: • The β-nitrostyrene derivative, HPW-RX40, induces anoikis in human breast cancer cells. • HPW-RX40 inhibits the integrin/FAK signaling pathway. • The combination of HPW-RX40 with an EGFR inhibitor leads to enhanced anoikis. • HPW-RX40 may have a potential to prevent the spread of metastatic breast cancer.« less

Cell-to-cell signaling through light: just a ghost of chance?

PubMed Central

2013-01-01

Despite the large number of reports attributing the signaling between detached cell cultures to the electromagnetic phenomena, almost no report so far included a rigorous analysis of the possibility of such signaling. In this paper, we examine the physical feasibility of the electromagnetic communication between cells, especially through light, with regard to the ambient noise illumination. We compare theoretically attainable parameters of communication with experimentally obtained data of the photon emission from cells without a specially pronounced ability of bioluminescence. We show that the weak intensity of the emission together with an unfavorable signal-to-noise ratio, which is typical for natural conditions, represent an important obstacle to the signal detection by cells. PMID:24219796

Ploidy-Dependent Unreductional Meiotic Cell Division in Polyploid Wheat

USDA-ARS?s Scientific Manuscript database

Meiosis includes one round of DNA replication and two successive nuclear divisions, i.e. meiosis I (reductional) and meiosis II (equational). This specialized cell division reduces chromosomes in half and generates haploid gametes in sexual reproduction of eukaryotes. It ensures faithful transmiss...

The effect of hypergravity on the lens, cornea and tail regeneration in Urodela

NASA Astrophysics Data System (ADS)

Grigoryan, E. N.; Dvorochkin, N.; Poplinskaya, V. A.; Yousuf, R.; Radugina, E. A.; Almeida, E. A.

2017-09-01

In previous experiments onboard Russian Bion/Foton satellites it was found that exposure to microgravity causes changes in eye lens regeneration of Urodela. The changes included higher rate of regeneration, increased cell proliferation in lens anlage, and synchronization of lens restoration. Similar changes were observed regarding tail regeneration. Recently, investigations were performed to find out whether exposure to hypergravity could also alter lens, cornea and tail regeneration in the newt P. waltl. Nine days prior to exposure the left lens was surgically removed through corneal incision and distal 1/3 of the tail was amputated, thus initiating regeneration. The experimental animals were allowed to recover for 9 days at 1 g and then exposed to 2 g for 12 days in an 8 ft diameter centrifuge at NASA Ames Research Center. The experimental animals were divided into 1 g controls, 2 g centrifugation animals, basal controls, and aquarium controls. Lens and corneal regeneration appeared to be inhibited in 2 g group compared to 1 g animals. In all 1 g controls, lens regeneration reached stages VII-IX in a synchronous fashion and corneal regeneration was nearly complete. In the 2 g newts, neural retinal detachment from the pigmented epithelium was seen in most operated eyes. It was also observed in the non-operated (right) eyes of the animals exposed to 2 g. The level of retinal detachment varied and could have been caused by hypergravity-induced high intraocular pressure. Regeneration (when it could be assessed) proceeded asynchronously, reaching stages from II to IX. Corneal restoration was also noticeably delayed and corneal morphology changed. Cell proliferation was measured using BrdU; the results were not comparable to the 1 g data because of retinal detachment. Previous investigations demonstrated that lens regeneration was controlled by the neural retina; therefore, lower regeneration rate at 2 g was, at least in part, associated with retinal detachment. FGF2 release by the neural retina and FGFR2 expression in the iris and other tissues could accelerate lens proliferation whereas its delay could be caused by retinal detachment, which may explain compromised regeneration at 2 g. Hypergravity (both 1 g and 2 g) increased tissue growth compared to aquarium control (as measured by regenerate volume) and altered the shape of tail regenerates - they became curved downwards. The experimental results emphasize the important and versatile role gravity plays in tissue regeneration. They also suggest that, when considering hypergravity as a countermeasure that can be used in future space missions, its potential impact on the eye should not be ignored.

Comprehensive adipocytic and neurogenic tissue microarray analysis of NY-ESO-1 expression - a promising immunotherapy target in malignant peripheral nerve sheath tumor and liposarcoma

PubMed Central

Shurell, Elizabeth; Vergara-Lluri, Maria E.; Li, Yunfeng; Crompton, Joseph G.; Singh, Arun; Bernthal, Nicholas; Wu, Hong; Eilber, Fritz C.; Dry, Sarah M.

2016-01-01

Background Immunotherapy targeting cancer-testis antigen NY-ESO-1 shows promise for tumors with poor response to chemoradiation. Malignant peripheral nerve sheath tumors (MPNSTs) and liposarcomas (LPS) are chemoresistant and have few effective treatment options. Materials Methods Using a comprehensive tissue microarray (TMA) of both benign and malignant tumors in primary, recurrent, and metastatic samples, we examined NY-ESO-1 expression in peripheral nerve sheath tumor (PNST) and adipocytic tumors. The PNST TMA included 42 MPNSTs (spontaneous n = 26, NF1-associated n = 16), 35 neurofibromas (spontaneous n = 22, NF-1 associated n = 13), 11 schwannomas, and 18 normal nerves. The LPS TMA included 48 well-differentiated/dedifferentiated (WD/DD) LPS, 13 myxoid/round cell LPS, 3 pleomorphic LPS, 8 lipomas, 1 myelolipoma, and 3 normal adipocytic tissue samples. Stained in triplicate, NY-ESO-1 intensity and density were scored. Results NY-ESO-1 expression was exclusive to malignant tumors. 100% of myxoid/round cell LPS demonstrated NY-ESO-1 expression, while only 6% of WD/DD LPS showed protein expression, one of which was WD LPS. Of MPNST, 4/26 (15%) spontaneous and 2/16 (12%) NF1-associated MPNSTs demonstrated NY-ESO-1 expression. Strong NY-ESO-1 expression was observed in myxoid/round cell and dedifferentiated LPS, and MPNST in primary, neoadjuvant, and metastatic settings. Conclusions We found higher prevalence of NY-ESO-1 expression in MPNSTs than previously reported, highlighting a subset of MPNST patients who may benefit from immunotherapy. This study expands our understanding of NY-ESO-1 in WD/DD LPS and is the first demonstration of staining in a WD LPS and metastatic/recurrent myxoid/round cell LPS. These results suggest immunotherapy targeting NY-ESO-1 may benefit patients with aggressive tumors resistant to conventional therapy. PMID:27655679

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.

Modeling of Detached Solidification

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.; Popov, Dmitri

1997-01-01

Our long term goal is to develop techniques to achieve detached solidification reliably and reproducibly, in order to produce crystals with fewer defects. To achieve this goal it is necessary to understand thoroughly the physics of detached solidification. It was the primary objective of the current project to make progress toward this complete understanding. 'Me products of this grant are attached. These include 4 papers and a preliminary survey of the observations of detached solidification in space. We have successfully modeled steady state detached solidification, examined the stability of detachment, and determined the influence of buoyancy-driven convection under different conditions. Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Indeed, under the Soviet microgravity program the major objective was to achieve detached solidification with its resulting improvement in perfection and properties. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past three years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification.

Results of the First Italian External Quality Assurance Scheme for somatic EGFR mutation testing in non-small-cell lung cancer.

PubMed

Normanno, Nicola; Pinto, Carmine; Taddei, Gianluigi; Gambacorta, Marcello; Castiglione, Francesca; Barberis, Massimo; Clemente, Claudio; Marchetti, Antonio

2013-06-01

The Italian Association of Medical Oncology (AIOM) and the Italian Society of Pathology and Cytology organized an external quality assessment (EQA) scheme for EGFR mutation testing in non-small-cell lung cancer. Ten specimens, including three small biopsies with known epidermal growth factor receptor (EGFR) mutation status, were validated in three referral laboratories and provided to 47 participating centers. The participants were requested to perform mutational analysis, using their usual method, and to submit results within a 4-week time frame. According to a predefined scoring system, two points were assigned to correct genotype and zero points to false-negative or false-positive results. The threshold to pass the EQA was set at higher than 18 of 20 points. Two rounds were preplanned. All participating centers submitted the results within the time frame. Polymerase chain reaction (PCR)/sequencing was the main methodology used (n = 37 laboratories), although a few centers did use pyrosequencing (n = 8) or real-time PCR (n = 2). A significant number of analytical errors were observed (n = 20), with a high frequency of false-positive results (n = 16). The lower scores were obtained for the small biopsies. Fourteen of 47 centers (30%) that did not pass the first round, having a score less than or equal to 18 points, used PCR/sequencing, whereas 10 of 10 laboratories, using pyrosequencing or real-time PCR, passed the first round. Eight laboratories passed the second round. Overall, 41of 47 centers (87%) passed the EQA. The results of the EQA for EGFR testing in non-small-cell lung cancer suggest that good quality EGFR mutational analysis is performed in Italian laboratories, although differences between testing methods were observed, especially for small biopsies.

Rapid discovery of peptide capture candidates with demonstrated specificity for structurally similar toxins

NASA Astrophysics Data System (ADS)

Sarkes, Deborah A.; Hurley, Margaret M.; Coppock, Matthew B.; Farrell, Mikella E.; Pellegrino, Paul M.; Stratis-Cullum, Dimitra N.

2016-05-01

Peptides have emerged as viable alternatives to antibodies for molecular-based sensing due to their similarity in recognition ability despite their relative structural simplicity. Various methods for peptide capture reagent discovery exist, including phage display, yeast display, and bacterial display. One of the primary advantages of peptide discovery by bacterial display technology is the speed to candidate peptide capture agent, due to both rapid growth of bacteria and direct utilization of the sorted cells displaying each individual peptide for the subsequent round of biopanning. We have previously isolated peptide affinity reagents towards protective antigen of Bacillus anthracis using a commercially available automated magnetic sorting platform with improved enrichment as compared to manual magnetic sorting. In this work, we focus on adapting our automated biopanning method to a more challenging sort, to demonstrate the specificity possible with peptide capture agents. This was achieved using non-toxic, recombinant variants of ricin and abrin, RiVax and abrax, respectively, which are structurally similar Type II ribosomal inactivating proteins with significant sequence homology. After only two rounds of biopanning, enrichment of peptide capture candidates binding abrax but not RiVax was achieved as demonstrated by Fluorescence Activated Cell Sorting (FACS) studies. Further sorting optimization included negative sorting against RiVax, proper selection of autoMACS programs for specific sorting rounds, and using freshly made buffer and freshly thawed protein target for each round of biopanning for continued enrichment over all four rounds. Most of the resulting candidates from biopanning for abrax binding peptides were able to bind abrax but not RiVax, demonstrating that short peptide sequences can be highly specific even at this early discovery stage.

PNET-like features of synovial sarcoma of the lung: a pitfall in the cytologic diagnosis of soft-tissue tumors.

PubMed

Hummel, P; Yang, G C; Kumar, A; Cohen, J M; Winkler, B; Melamed, J; Scholes, J V; Jagirdar, J

2001-04-01

Fine-needle aspiration (FNA) cytology of soft-tissue tumors is evolving. As more experience is gained, we are becoming aware of potential pitfalls. We describe 2 cases of synovial sarcoma of the lung, primary and metastatic, in patients who had FNA biopsy performed on a lung mass. The cytologic smears showed extremely cellular groups of malignant small round cells, intersected by small blood vessels, with numerous loose single cells, in a background of macrophages and mature lymphocytes. The tumors displayed monomorphic cells forming rosettes and displaying occasional mitoses. A diagnosis of neuroendocrine tumor/primitive neuroepithelial tumor (PNET) was suspected. Furthermore, this suspicion was supported by immunohistochemical stains, which showed positivity for a neuroendocrine marker, Leu 7 (case 1), and for a neural marker, CD 99 (O 13 or HBA 71) (both cases); and negativity for cytokeratins (case 1). The resection specimen of case 1 had mostly tightly packed small round cells, with occasional rosettes, similar to the FNA biopsy, and focal areas composed of spindle cells, organized in a focal fibrosarcoma-like and hemangiopericytoma-like pattern. A balanced translocation between chromosomes X and 18, demonstrated by both karyotyping and fluorescent in situ hybridization (FISH), enabled us to make a diagnosis of synovial sarcoma, which was histologically classified as poorly differentiated. Case 2 was a metastatic biphasic synovial sarcoma of the arm, with a prominent epithelial component. Synovial sarcoma, when composed mainly of small round cells on cytologic smears, is a great mimicker of neuroendocrine/PNET tumors, with light microscopic and immunohistochemical overlap. Awareness of this potential pitfall may aid in preventing a misdiagnosis. Its recognition is of major concern, especially for the poorly differentiated variant, because it is associated with a worse prognosis. Copyright 2001 Wiley-Liss, Inc.

Reappraisal of mesenchymal chondrosarcoma: novel morphologic observations of the hyaline cartilage and endochondral ossification and beta-catenin, Sox9, and osteocalcin immunostaining of 22 cases.

PubMed

Fanburg-Smith, Julie C; Auerbach, Aaron; Marwaha, Jayson S; Wang, Zengfeng; Rushing, Elisabeth J

2010-05-01

Mesenchymal chondrosarcoma, a rare malignant round cell and hyaline cartilage tumor, is most commonly intraosseous but can occur in extraskeletal sites. We intensively observed the morphology and applied Sox9 (master regulator of chondrogenesis), beta-catenin (involved in bone formation, thought to inhibit chondrogenesis in a Sox9-dependent manner), and osteocalcin (a marker for osteoblastic phenotype) to 22 central nervous system and musculoskeletal mesenchymal chondrosarcoma. Cases of mesenchymal chondrosarcoma were retrieved and reviewed from our files. Immunohistochemistry and follow-up were obtained on mesenchymal chondrosarcoma and tumor controls. Twenty-two mesenchymal chondrosarcomas included 5 central nervous system (all female; mean age, 30.2; mean size, 7.8 cm; in frontal lobe [n = 4] and spinal cord [n = 1]) and 17 musculoskeletal (female-male ratio, 11:6; mean age, 31.1; mean size, 6.2 cm; 3 each of humerus and vertebrae; 2 each of pelvis, rib, tibia, neck soft tissue; one each of femur, unspecified bone, and elbow soft tissue). The hyaline cartilage in most tumors revealed a consistent linear progression of chondrocyte morphology, from resting to proliferating to hypertrophic chondrocytes. Sixty-seven percent of cases demonstrated cell death and acquired osteoblastic phenotype, cells positive for osteocalcin at the site of endochondral ossification. Small round cells of mesenchymal chondrosarcoma were negative for osteocalcin. SOX9 was positive in both components of 21 of 22 cases of mesenchymal chondrosarcoma. beta-Catenin highlighted rare nuclei at the interface between round cells and hyaline cartilage in 35% cases. Control skull and central nervous system cases were compared, including chondrosarcomas and small cell osteosarcoma, the latter positive for osteocalcin in small cells. Mesenchymal chondrosarcoma demonstrates centrally located hyaline cartilage with a linear progression of chondrocytes from resting to proliferative to hypertrophic, which undergoes endochondral ossification, recapitulating growth plate cartilage and suggesting that this component of mesenchymal chondrosarcoma may be a differentiated (benign or metaplastic) component of a malignant metastasizing tumor. This hyaline cartilage component is morphologically different from cartilage of control chondrosarcoma. Mesenchymal chondrosarcoma can be separated from small cell osteosarcoma, using Sox 9 for cartilage and osteocalcin for osteoblastic phenotype. Rare nuclear beta-catenin expression at the interface between hyaline cartilage and small round cells potentially implicates the APC/Wnt pathway during endochondral ossification in morphologically benign hyaline cartilage component of mesenchymal chondrosarcoma. Published by Elsevier Inc.

Detached Bridgman Growth of Germanium and Germanium-Silicon Alloy Crystals

NASA Technical Reports Server (NTRS)

Szofran, F. R.; Volz, M. P.; Schweizer, M.; Cobb, S. D.; Motakef, S.; Croell, A.; Dold, P.; Curreri, Peter A. (Technical Monitor)

2002-01-01

Earth based experiments on the science of detached crystal growth are being conducted on germanium and germanium-silicon alloys (2 at% Si average composition) in preparation for a series of experiments aboard the International Space Station (ISS). The purpose of the microgravity experiments includes differentiating among proposed mechanisms contributing to detachment, and confirming or refining our understanding of the detachment mechanism. Because large contact angle are critical to detachment, sessile drop measurements were used to determine the contact angles as a function of temperature and composition for a large number of substrates made of potential ampoule materials. Growth experiments have used pyrolytic boron nitride (pBN) and fused silica ampoules with the majority of the detached results occurring predictably in the pBN. The contact angles were 173 deg (Ge) and 165 deg (GeSi) for pBN. For fused silica, the contact angle decreases from 150 deg to an equilibrium value of 117 deg (Ge) or from 129 deg to an equilibrium value of 100 deg (GeSi) over the duration of the experiment. The nature and extent of detachment is determined by using profilometry in conjunction with optical and electron microscopy. The stability of detachment has been analyzed, and an empirical model for the conditions necessary to achieve sufficient stability to maintain detached growth for extended periods has been developed. Results in this presentation will show that we have established the effects on detachment of ampoule material, pressure difference above and below the melt, and silicon concentration; samples that are nearly completely detached can be grown repeatedly in pBN.

Paediatric retinal detachment: aetiology, characteristics and outcomes.

PubMed

McElnea, Elizabeth; Stephenson, Kirk; Gilmore, Sarah; O'Keefe, Michael; Keegan, David

2018-01-01

To provide contemporary data on the aetiology, clinical features and outcomes of paediatric retinal detachment. A retrospective review of all those under 16y who underwent surgical repair for retinal detachment at a single centre between the years 2008 and 2015 inclusive was performed. In each case the cause of retinal detachment, the type of detachment, the presence or absence of macular involvement, the number and form of reparative surgeries undertaken, and the surgical outcome achieved was recorded. Twenty-eight eyes of 24 patients, 15 (62.5%) of whom were male and 9 (37.5%) of whom were female, their mean age being 11.6y and range 2-16y developed retinal detachment over the eight year period studied. Trauma featured in the development of retinal detachment in 14 (50.0%) cases. Retinal detachment was associated with other ocular and/or systemic conditions in 11 (39.3%) cases. A mean of 3.0 procedures with a range of 1-9 procedures per patient were undertaken in the management of retinal detachment. Complex vitrectomy combined with scleral buckling or complex vitrectomy alone were those most frequently performed. Mean postoperative visual acuity was 1.2 logMAR with range 0.0-3.0 logMAR. In 22 of 26 (84.6%) cases which underwent surgical repair the retina was attached at last follow-up. Aggressive management of paediatric retinal detachment including re-operation increases the likelihood of anatomical success. In cases where the retinal detachment can be repaired by an external approach alone there is a more favourable visual outcome.

A cell impedance measurement device for the cytotoxicity assay dependent on the velocity of supplied toxic fluid

NASA Astrophysics Data System (ADS)

Kang, Yoon-Tae; Kim, Min-Ji; Cho, Young-Ho

2018-04-01

We present a cell impedance measurement chip capable of characterizing the toxic response of cells depending on the velocity of the supplied toxic fluid. Previous impedance-based devices using a single open-top chamber have been limited to maintaining a constant supply velocity, and devices with a single closed-top chamber present difficulties in simultaneous cytotoxicity assay for varying levels of supply velocities. The present device, capable of generating constant and multiple levels of toxic fluid velocity simultaneously within a single stepwise microchannel, performs a cytotoxicity assay dependent on toxic fluid velocity, in order to find the effective velocity of toxic fluid to cells for maximizing the cytotoxic effect. We analyze the cellular toxic response of 5% ethanol media supplied to cancer cells within a toxic fluid velocity range of 0-8.3 mm s-1. We observe the velocity-dependent cell detachment rate, impedance, and death rate. We find that the cell detachment rate decreased suddenly to 2.4% at a velocity of 4.4 mm s-1, and that the change rates of cell resistance and cell capacitance showed steep decreases to 8% and 41%, respectively, at a velocity of 5.7 mm s-1. The cell death rate and impedance fell steeply to 32% at a velocity of 5.7 mm s-1. We conclude that: (1) the present device is useful in deciding on the toxic fluid velocity effective to cytotoxicity assay, since the cellular toxic response is dependent on the velocity of toxic fluid, and; (2) the cell impedance analysis facilitates a finer cellular response analysis, showing better correlation with the cell death rate, compared to conventional visual observation. The present device, capable of performing the combinational analysis of toxic fluid velocity and cell impedance, has potential for application to the fine cellular toxicity assay of drugs with proper toxic fluid velocity.

32 CFR 700.723 - Administration and discipline: Separate and detached command.

Code of Federal Regulations, 2010 CFR

2010-07-01

... detached command. 700.723 Section 700.723 National Defense Department of Defense (Continued) DEPARTMENT OF... Administration and discipline: Separate and detached command. Any flag or general officer in command, any officer... are separate or detached commands. Such officer shall state in writing that it is a separate or...

32 CFR 700.723 - Administration and discipline: Separate and detached command.

Code of Federal Regulations, 2014 CFR

2014-07-01

... detached command. 700.723 Section 700.723 National Defense Department of Defense (Continued) DEPARTMENT OF... Administration and discipline: Separate and detached command. Any flag or general officer in command, any officer... are separate or detached commands. Such officer shall state in writing that it is a separate or...

32 CFR 700.723 - Administration and discipline: Separate and detached command.

Code of Federal Regulations, 2011 CFR

2011-07-01

... detached command. 700.723 Section 700.723 National Defense Department of Defense (Continued) DEPARTMENT OF... Administration and discipline: Separate and detached command. Any flag or general officer in command, any officer... are separate or detached commands. Such officer shall state in writing that it is a separate or...

32 CFR 700.723 - Administration and discipline: Separate and detached command.

Code of Federal Regulations, 2013 CFR

2013-07-01

... detached command. 700.723 Section 700.723 National Defense Department of Defense (Continued) DEPARTMENT OF... Administration and discipline: Separate and detached command. Any flag or general officer in command, any officer... are separate or detached commands. Such officer shall state in writing that it is a separate or...

32 CFR 700.723 - Administration and discipline: Separate and detached command.

Code of Federal Regulations, 2012 CFR

2012-07-01

... detached command. 700.723 Section 700.723 National Defense Department of Defense (Continued) DEPARTMENT OF... Administration and discipline: Separate and detached command. Any flag or general officer in command, any officer... are separate or detached commands. Such officer shall state in writing that it is a separate or...

Clearance of apoptotic photoreceptors: elimination of apoptotic debris into the subretinal space and macrophage-mediated phagocytosis via phosphatidylserine receptor and integrin alphavbeta3.

PubMed

Hisatomi, Toshio; Sakamoto, Taiji; Sonoda, Koh-Hei; Tsutsumi, Chikako; Qiao, Hong; Enaida, Hiroshi; Yamanaka, Ichiro; Kubota, Toshiaki; Ishibashi, Tatsuro; Kura, Shinobu; Susin, Santos A; Kroemer, Guido

2003-06-01

The effective phagocytotic clearance of apoptotic debris is fundamental to the maintenance of neural tissues during apoptosis. Retinal photoreceptors undergo apoptosis after retinal detachment. Although their induction phase of apoptosis has been well discussed, their phagocytotic process remains quite unclear. We herein demonstrate that apoptotic photoreceptors are selectively eliminated from their physiological localization, the outer nuclear layer, to the subretinal space, and then phagocytosed by monocyte-derived macrophages. This could be shown by an ultrastructural and immunophenotypic analysis. Moreover, in chimera mice expressing transgenic green fluorescent protein in bone marrow-derived cells, the local infiltration of macrophages could be detected after retinal detachment-induced photoreceptor apoptosis. The local injection of an antibody blocking the phosphatidylserine receptor (PSR) or a peptide (GRGDSP)-blocking integrin alphavbeta3 revealed that phagocytotic clearance involves the PSR as well as integrin alphavbeta3 in vivo. Importantly, the level of blockade obtained with these reagents was different. Although anti-PSR increased the frequency of apoptotic cells that fail to bind to macrophages, GRGDSP prevented the engulfment (but not the recognition) of apoptotic photoreceptor cells by macrophages. To our knowledge, this is the first report describing the mechanisms through which apoptotic photoreceptors are selectively eliminated via a directional process in the subretinal space.

Clearance of Apoptotic Photoreceptors

PubMed Central

Hisatomi, Toshio; Sakamoto, Taiji; Sonoda, Koh-hei; Tsutsumi, Chikako; Qiao, Hong; Enaida, Hiroshi; Yamanaka, Ichiro; Kubota, Toshiaki; Ishibashi, Tatsuro; Kura, Shinobu; Susin, Santos A.; Kroemer, Guido

2003-01-01

The effective phagocytotic clearance of apoptotic debris is fundamental to the maintenance of neural tissues during apoptosis. Retinal photoreceptors undergo apoptosis after retinal detachment. Although their induction phase of apoptosis has been well discussed, their phagocytotic process remains quite unclear. We herein demonstrate that apoptotic photoreceptors are selectively eliminated from their physiological localization, the outer nuclear layer, to the subretinal space, and then phagocytosed by monocyte-derived macrophages. This could be shown by an ultrastructural and immunophenotypic analysis. Moreover, in chimera mice expressing transgenic green fluorescent protein in bone marrow-derived cells, the local infiltration of macrophages could be detected after retinal detachment-induced photoreceptor apoptosis. The local injection of an antibody blocking the phosphatidylserine receptor (PSR) or a peptide (GRGDSP)-blocking integrin αvβ3 revealed that phagocytotic clearance involves the PSR as well as integrin αvβ3 in vivo. Importantly, the level of blockade obtained with these reagents was different. Although anti-PSR increased the frequency of apoptotic cells that fail to bind to macrophages, GRGDSP prevented the engulfment (but not the recognition) of apoptotic photoreceptor cells by macrophages. To our knowledge, this is the first report describing the mechanisms through which apoptotic photoreceptors are selectively eliminated via a directional process in the subretinal space. PMID:12759244

Cell contact regulates neuroblast formation in the Caenorhabditis elegans lateral epidermis.

PubMed

Austin, J; Kenyon, C

1994-02-01

A single line of epidermal seam cells lies along each side of the nematode C. elegans. During normal development, one of these cells, V5, produces a neuroblast that will give rise to a sensory structure, the postdeirid. If seam cells located either anterior or posterior to V5 are ablated however, this neuroblast formation is blocked. Because of this requirement for the presence of adjacent seam cells, we have asked whether V5's ability to produce a neuroblast depends on direct contact with its seam cell neighbors. We find that direct contact between seam cells is required for commitment to neuroblast production. Seam cells lose and reform their contacts with each other as they go through rounds of cell division during larval development. Signaling required for neuroblast formation occurs when the seam cells make contact after their first round of division. If this contact is prevented, no neuroblast is made; when it is delayed, the time of signaling is also delayed. The characteristics of these signals suggest that a seam cell must be part of a continuous epithelium in order to develop normally and that signaling may occur via a cell recognition/cell adhesion pathway. The effect of seam cell ablations on neuroblast formation is altered in mab-5(-) animals, suggesting that this HOM-C gene is part of the pathway by which seam cell signaling controls the decision to make a postdeirid neuroblast.

X-Ray Induced DNA Damage and Repair in Germ Cells of PARP1−/− Male Mice

PubMed Central

Villani, Paola; Fresegna, Anna Maria; Ranaldi, Roberto; Eleuteri, Patrizia; Paris, Lorena; Pacchierotti, Francesca; Cordelli, Eugenia

2013-01-01

Poly(ADP-ribose)polymerase-1 (PARP1) is a nuclear protein implicated in DNA repair, recombination, replication, and chromatin remodeling. The aim of this study was to evaluate possible differences between PARP1−/− and wild-type mice regarding induction and repair of DNA lesions in irradiated male germ cells. Comet assay was applied to detect DNA damage in testicular cells immediately, and two hours after 4 Gy X-ray irradiation. A similar level of spontaneous and radiation-induced DNA damage was observed in PARP1−/− and wild-type mice. Conversely, two hours after irradiation, a significant level of residual damage was observed in PARP1−/− cells only. This finding was particularly evident in round spermatids. To evaluate if PARP1 had also a role in the dynamics of H2AX phosphorylation in round spermatids, in which γ-H2AX foci had been shown to persist after completion of DNA repair, we carried out a parallel analysis of γ-H2AX foci at 0.5, 2, and 48 h after irradiation in wild-type and PARP1−/− mice. No evidence was obtained of an effect of PARP1 depletion on H2AX phosphorylation induction and removal. Our results suggest that, in round spermatids, under the tested experimental conditions, PARP1 has a role in radiation-induced DNA damage repair rather than in long-term chromatin modifications signaled by phosphorylated H2AX. PMID:24009020

CIC-DUX4 Induces Small Round Cell Sarcomas Distinct from Ewing Sarcoma.

PubMed

Yoshimoto, Toyoki; Tanaka, Miwa; Homme, Mizuki; Yamazaki, Yukari; Takazawa, Yutaka; Antonescu, Cristina R; Nakamura, Takuro

2017-06-01

CIC-DUX4 sarcoma (CDS) or CIC-rearranged sarcoma is a subcategory of small round cell sarcoma resembling the morphological phenotypes of Ewing sarcoma (ES). However, recent clinicopathologic and molecular genetic analyses indicate that CDS is an independent disease entity from ES. Few ancillary markers have been used in the differential diagnosis of CDS, and additional CDS-specific biomarkers are needed for more definitive classification. Here, we report the generation of an ex vivo mouse model for CDS by transducing embryonic mesenchymal cells (eMC) with human CIC-DUX4 cDNA. Recipient mice transplanted with eMC-expressing CIC-DUX4 rapidly developed an aggressive, undifferentiated sarcoma composed of small round to short spindle cells. Gene-expression profiles of CDS and eMC revealed upregulation of CIC-DUX4 downstream genes such as PEA3 family genes, Ccnd2, Crh , and Zic1 IHC analyses for both mouse and human tumors showed that CCND2 and MUC5AC are reliable biomarkers to distinguish CDS from ES. Gene silencing of CIC-DUX4 as well as Ccnd2, Ret , and Bcl2 effectively inhibited CDS tumor growth in vitro The CDK4/6 inhibitor palbociclib and the soft tissue sarcoma drug trabectedin also blocked the growth of mouse CDS. In summary, our mouse model provides important biological information about CDS and provides a useful platform to explore biomarkers and therapeutic agents for CDS. Cancer Res; 77(11); 2927-37. ©2017 AACR . ©2017 American Association for Cancer Research.

Water hyacinths for upgrading sewage lagoons to meet advanced wastewater treatment standards, part 2

NASA Technical Reports Server (NTRS)

Wolverton, B. C.; Mcdonald, R. C.

1976-01-01

Field tests using water hyacinths as biological filtration agents were conducted in the Mississippi gulf coast region. The plants were installed in one single cell and one multiple cell sewage lagoon systems. Water hyacinths demonstrated the ability to maintain BOD5 and total suspended solid (TSS) levels within the Environmental Protection Agency's prescribed limits of 30 mg/lBOD5 and 30 mg/l TSS. A multiple cell sewage lagoon system consisting of two aerated and one water hyacinth covered cell connected in series demonstrated the ability to maintain BOD5 and TSS levels below 30 mg/l year-round. A water hyacinth covered lagoon with a surface area of 0.28 hectare containing a total volume of 6.8 million liters demonstrated the capacity to treat 437,000 to 1,893,000 liters of sewage influent from 2.65 hectares of aerated lagoons daily and produce an effluent that met or exceeded standards year-round.

Neuroendocrine carcinoma in the nasal cavity of ten dogs.

PubMed

Sako, T; Shimoyama, Y; Akihara, Y; Ohmachi, T; Yamashita, K; Kadosawa, T; Nakade, T; Uchida, E; Okamoto, M; Hirayama, K; Taniyama, H

2005-01-01

Neuroendocrine (NE) carcinoma was diagnosed in 10 dogs. In six cases examined by cephalometric radiography and computerized tomography, a large mass was seen to fill the nasal cavity. Histopathologically, sheets, nests or ribbons of neoplastic cells were separated by delicate or thick fibrovascular stroma. The neoplastic cells were round, oval, or spindle-shaped; cytoplasmic granules and hyperchromatic nuclei with prominent nucleoli were present. Neoplastic cells were invariably immunohistochemically positive for cytokeratin (CK) AE1/AE3, neuron-specific enolase, chromogranin A and vasoactive intestinal polypeptide. Eight dogs were positive for S100 protein, seven for synaptophysin, five for protein gene product 9.5, two for somatostatin, and one for Leu-7. Immunolabelling gave negative results for CK 8, CK 19, calcitonin, calcitonin gene-related polypeptide, neurofilaments, serotonin, gastrin and glial fibrillary acidic protein. Ultrastructurally, the neoplastic cells contained a large number of round, membrane-bounded, densely-cored granules corresponding to neurosecretory granules. These observations were consistent with the neuroendocrine nature of the carcinomas.

Contractility of the cell rear drives invasion of breast tumor cells in 3D Matrigel

PubMed Central

Poincloux, Renaud; Collin, Olivier; Lizárraga, Floria; Romao, Maryse; Debray, Marcel; Piel, Matthieu; Chavrier, Philippe

2011-01-01

Cancer cells use different modes of migration, including integrin-dependent mesenchymal migration of elongated cells along elements of the 3D matrix as opposed to low-adhesion-, contraction-based amoeboid motility of rounded cells. We report that MDA-MB-231 human breast adenocarcinoma cells invade 3D Matrigel with a characteristic rounded morphology and with F-actin and myosin-IIa accumulating at the cell rear in a uropod-like structure. MDA-MB-231 cells display neither lamellipodia nor bleb extensions at the leading edge and do not require Arp2/3 complex activity for 3D invasion in Matrigel. Accumulation of phospho-MLC and blebbing activity were restricted to the uropod as reporters of actomyosin contractility, and velocimetric analysis of fluorescent beads embedded within the 3D matrix showed that pulling forces exerted to the matrix are restricted to the side and rear of cells. Inhibition of actomyosin contractility or β1 integrin function interferes with uropod formation, matrix deformation, and invasion through Matrigel. These findings support a model whereby actomyosin-based uropod contractility generates traction forces on the β1 integrin adhesion system to drive cell propulsion within the 3D matrix, with no contribution of lamellipodia extension or blebbing to movement. PMID:21245302

Cell behaviors underlying notochord formation and extension in avian embryos: quantitative and immunocytochemical studies.

PubMed

Sausedo, R A; Schoenwolf, G C

1993-09-01

Formation and extension of the notochord is one of the earliest and most obvious events of axis development in vertebrate embryos. In birds, prospective notochord cells arise from Hensen's node and come to lie beneath the midline of the neural plate, where they assist in the process of neurulation and initiate the dorsoventral patterning of the neural tube through sequential inductive interactions. In the present study, we examined notochord development in avian embryos with quantitative and immunological procedures. Extension of the notochord occurs principally through accretion, that is, the addition of cells to its caudal end, a process that involves considerable cell rearrangement at the notochord-Hensen's node interface. In addition, cell division and cell rearrangement within the notochord proper contribute to notochord extension. Thus, extension of the notochord occurs in a manner that is significantly different from that of the adjacent, overlying, midline region of the neural plate (i.e., the median hinge-point region or future floor plate of the neural tube), which as shown in one of the previous studies from our laboratory (Schoenwolf and Alvarez: Development 106:427-439, 1989), extends caudally as its cells undergo two rounds of mediolateral cell-cell intercalation and two-three rounds of cell division.

Management of inadvertent needle penetration resulting in subretinal triamcinolone acetonide and retinal detachment.

PubMed

Tran, Kimberly D; Crane, Ashley M; Flynn, Harry W

2018-06-01

To report management of inadvertent needle penetration during subtenons triamcinolone acetonide administration resulting in retinal detachment. A 71-year-old female with history of diabetes, hypothyroidism, and mild myopia underwent subtenons triamcinolone acetonide (TA) injection in the right eye for nodular scleritis. There was unexpected patient movement concurrent with the injection resulting in needle penetration, subretinal and intravitreal injection of TA, superotemporal retinal break, and macula-involving retinal detachment. The patient underwent partial subretinal TA removal, successful retinal detachment repair, and recovered 20/25 visual acuity. In spite of prominent subretinal TA and retinal detachment, successful repair of retinal detachment and recovery of good visual acuity is possible.

A history of detachable coils: 1987-2012.

PubMed

Hui, Ferdinand K; Fiorella, David; Masaryk, Thomas J; Rasmussen, Peter A; Dion, Jacques E

2014-03-01

The development of detachable coils is one of the most pivotal developments in neurointervention, providing a tool that could be used to treat a wide variety of hemorrhagic stroke. From the original Guglielmi detachable coil, a number of different coil designs and delivery designs have evolved. This article reviews the history of commercially available detachable coils. A timeline of detachable coils was constructed and coil design philosophies were reviewed. A complete list of commercially available coils is presented in a timeline format. Detachable coil technology continues to evolve. Advances in construction and design have yielded products which may benefit patients in terms of safety, radiation dose reduction and cost of treatment. Continued evolution is expected, irrespective of competing disruptive technologies.

Innervation of taste buds revealed with Brainbow-labeling in mouse.

PubMed

Zaidi, Faisal N; Cicchini, Vanessa; Kaufman, Daniel; Ko, Elizabeth; Ko, Abraham; Van Tassel, Heather; Whitehead, Mark C

2016-12-01

Nerve fibers that surround and innervate the taste bud were visualized with inherent fluorescence using Brainbow transgenic mice that were generated by mating the founder line L with nestin-cre mice. Multicolor fluorescence revealed perigemmal fibers as branched within the non-taste epithelium and ending in clusters of multiple rounded swellings surrounding the taste pore. Brainbow-labeling also revealed the morphology and branching pattern of single intragemmal fibers. These taste bud fibers frequently innervated both the peripheral bud, where immature gemmal cells are located, and the central bud, where mature, differentiated cells are located. The fibers typically bore preterminal and terminal swellings, growth cones with filopodia, swellings, and rounded retraction bulbs. These results establish an anatomical substrate for taste nerve fibers to contact and remodel among receptor cells at all stages of their differentiation, an interpretation that was supported by staining with GAP-43, a marker for growing fibers and growth cones. © 2016 Anatomical Society.

French National Registry of Rare Peritoneal Surface Malignancies

ClinicalTrials.gov

2017-08-18

Rare Peritoneal Surface Malignancies; Pseudomyxoma Peritonei; Peritoneal Mesothelioma; Desmoplastic Small Round Cell Tumor; Psammocarcinoma; Primary Peritoneal Serous Carcinoma; Diffuse Peritoneal Leiomyomatosis; Appendiceal Mucinous Neoplasms

The Relationship between Job Demands and Employees' Counterproductive Work Behaviors: The Mediating Effect of Psychological Detachment and Job Anxiety.

PubMed

Chen, Yang; Li, Shuang; Xia, Qing; He, Chao

2017-01-01

This study aims to explore the relation between job demands and counterproductive work behaviors (CWBs). A cross-sectional sample of 439 coal miners completed a self-report questionnaire that assessed their job demands, psychological detachment, job anxiety, and CWBs in a Chinese context. The conceptual model, based on the stressor-detachment model, was examined using structural equation modeling. The results suggest that psychological detachment mediates not only the relation between job demands and job anxiety but also that between job demands and CWBs. Furthermore, the relation between job demands and CWBs is sequentially mediated by psychological detachment and job anxiety. Our findings validate the effectiveness of the stressor-detachment model. Moreover, we demonstrate that the underlying mechanism of the relation between job demands and CWBs can be explained by psychological detachment and job anxiety.

The Relationship between Job Demands and Employees’ Counterproductive Work Behaviors: The Mediating Effect of Psychological Detachment and Job Anxiety

PubMed Central

Chen, Yang; Li, Shuang; Xia, Qing; He, Chao

2017-01-01

This study aims to explore the relation between job demands and counterproductive work behaviors (CWBs). A cross-sectional sample of 439 coal miners completed a self-report questionnaire that assessed their job demands, psychological detachment, job anxiety, and CWBs in a Chinese context. The conceptual model, based on the stressor-detachment model, was examined using structural equation modeling. The results suggest that psychological detachment mediates not only the relation between job demands and job anxiety but also that between job demands and CWBs. Furthermore, the relation between job demands and CWBs is sequentially mediated by psychological detachment and job anxiety. Our findings validate the effectiveness of the stressor-detachment model. Moreover, we demonstrate that the underlying mechanism of the relation between job demands and CWBs can be explained by psychological detachment and job anxiety. PMID:29163274

Dose-dependent effects of ouabain on spiral ganglion neurons and Schwann cells in mouse cochlea.

PubMed

Zhang, Zhi-Jian; Guan, Hong-Xia; Yang, Kun; Xiao, Bo-Kui; Liao, Hua; Jiang, Yang; Zhou, Tao; Hua, Qing-Quan

2017-10-01

This study aimed in fully investigating the toxicities of ouabain to mouse cochlea and the related cellular environment, and providing an optimal animal model system for cell transplantation in the treatment of auditory neuropathy (AN) and sensorineural hearing loss (SNHL). Different dosages of ouabain were applied to mouse round window. The auditory brainstem responses and distortion product otoacoustic emissions were used to evaluate the cochlear function. The immunohistochemical staining and cochlea surface preparation were performed to detect the spiral ganglion neurons (SGNs), Schwann cells and hair cells. Ouabain at the dosages of 0.5 mM, 1 mM and 3 mM selectively and permanently destroyed SGNs and their functions, while leaving the hair cells relatively intact. Ouabain at 3 mM resulted in the most severe SGNs loss and induced significant loss of Schwann cells started as early as 7 days and with further damages at 14 and 30 days after ouabain exposure. The application of ouabain to mouse round window induces damages of SGNs and Schwann cells in a dose- and time-dependent manner, this study established a reliable and accurate animal model system of AN and SNHL.

Grid-Optimization Program for Photovoltaic Cells

NASA Technical Reports Server (NTRS)

Daniel, R. E.; Lee, T. S.

1986-01-01

CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

Otoancorin Knockout Mice Reveal Inertia is the Force for Hearing

NASA Astrophysics Data System (ADS)

Weddell, Thomas; Legan, P. Kevin; Lukashkina, Victoria A.; Goodyear, Richard J.; Welstead, Lindsy; Petit, Chistine; Russell, Ian J.; Lukashkin, Andrei N.; Richardson, Guy P.

2011-11-01

We demonstrate that in Otoa-/- mice, in which the inner-ear-specific protein otoancorin is absent, excitation of the outer hair cells and cochlear amplification is normal. This finding is remarkable because the tectorial membrane (TM), although remaining functionally attached to the outer hair cell bundles, is completely detached from the spiral limbus. Therefore, as in ancestral vertebrate auditory organs, where inertia provides the excitatory force to the hair cells, it is the inertia of the TM that must be important for exciting the outer hair cells, setting the sensitivity of their transducer conductance, and determining the precise timing of cochlear amplification.

Importance of anisotropy in detachment rates for force production and cargo transport by a team of motor proteins.

PubMed

Takshak, Anjneya; Kunwar, Ambarish

2016-05-01

Many cellular processes are driven by collective forces generated by a team consisting of multiple molecular motor proteins. One aspect that has received less attention is the detachment rate of molecular motors under mechanical force/load. While detachment rate of kinesin motors measured under backward force increases rapidly for forces beyond stall-force; this scenario is just reversed for non-yeast dynein motors where detachment rate from microtubule decreases, exhibiting a catch-bond type behavior. It has been shown recently that yeast dynein responds anisotropically to applied load, i.e. detachment rates are different under forward and backward pulling. Here, we use computational modeling to show that these anisotropic detachment rates might help yeast dynein motors to improve their collective force generation in the absence of catch-bond behavior. We further show that the travel distance of cargos would be longer if detachment rates are anisotropic. Our results suggest that anisotropic detachment rates could be an alternative strategy for motors to improve the transport properties and force production by the team. © 2016 The Protein Society.

Atomistic investigation on the detachment of oil molecules from defective alumina surface

NASA Astrophysics Data System (ADS)

Xie, W. K.; Sun, Y. Z.; Liu, H. T.

2017-12-01

The mechanism of oil detachment from defective alumina surface in aqueous solution was investigated via atomistic molecular dynamics (MD) simulations. Special attention was focused on the effect of surface defect on the oil detachment. Our simulation results suggest that compared with perfect Al2O3 surface, defective substrate surface provides much more sites for the adsorption of oil molecules, thus it has higher oil adsorption energy. However, higher oil-solid adsorption energy does not mean that oil contaminants are much more difficult to be detached. It is found that surface defect could induce the spontaneous imbibition of water molecules, effectively promoting the detachment of oil molecules. Thus, compared with perfect alumina surface, the detachment of oil molecules from defective alumina surface tends to be much easier. Moreover, surface defect could lead to the oil residues inside surface defect. In water solution, the entire detachment process of oil molecules on defective surface consists of following stages, including the early detachment of oil molecules inside surface defect induced by capillary-driven spontaneous imbibition of water molecules, the following conformational change of oil molecules on topmost surface and the final migration of detached oil molecules from solid surface. These findings may help to sufficiently enrich the removal mechanism of oil molecules adhered onto defective solid surface.

Early wound healing of laser in situ keratomileusis-like flaps after treatment with human corneal stromal stem cells.

PubMed

Morgan, Siân R; Dooley, Erin P; Kamma-Lorger, Christina; Funderburgh, James L; Funderburgh, Martha L; Meek, Keith M

2016-02-01

To use a well-established organ culture model to investigate the effects of corneal stromal stem cells on the optical and biomechanical properties of corneal wounds after laser in situ keratomileusis (LASIK)-like flap creation. School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom. Experimental study. The LASIK-like flaps were produced in sheep corneas. The flap beds were treated with corneal stromal stem cells and were then replaced and allowed to heal for different periods of up to 3 weeks in organ culture. The optical transmission of the cornea, the force required to detach the flap, and the presence of myofibroblasts near the flap bed were measured. Corneal stromal stem cell-treated flap beds were statistically significantly more transparent after 3 weeks in culture than the untreated controls. At 3 weeks, the mean force necessary to detach the flap was more than twice the force required for the respective control samples. Concurrently, there were 44% activated cells immediately below the flap margin of the controls compared with 29% in the same region of the corneal stromal stem cell-treated flaps. In this system, the presence of corneal stromal stem cells at the wound margin significantly increased the adherence of LASIK-like flaps while maintaining corneal transparency. It is postulated that this is achieved by the deposition of extracellular connective tissue similar to that found in the normal cornea and by the paucity of activated keratocytes (myofibroblasts), which are known to scatter a significant amount of the incident light. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Final Act of an Oceanic Detachment Fault Revealed by Submersible Dives at 13°48'N on the Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Parnell-Turner, R. E.; Mittelstaedt, E. L.; Kurz, M. D.; Klein, F.

2017-12-01

A large proportion of crustal accretion on the slow-spreading Mid-Atlantic Ridge occurs under the influence of slip on low-angle detachment faults. The final stages of activity on an individual detachment system remain poorly understood, since it is difficult to place age constraints on exposed fault surfaces or lava flows. We use data from a combination of manned (Alvin) and autonomous (Sentry) submersible dives on a detachment near 13°48'N, to infer the history of slip and volcanism on a detachment fault which has recently become extinct. The corrugated surface, near the toe of the detachment, is cross-cut by a volcanic ridge, where pillow lavas have been photographed and sampled. Sub-bottom (CHIRP) profiles acquired by Sentry provide estimates of sediment thickness, which we use as a proxy for seafloor age, thus providing a relative dating tool for the exposed detachment footwall and erupted lavas. Sediments covering the footwall are 2 m thinner than those on lavas which cut across the detachment, implying that slip continued for 150 ka after eruption (assuming a constant sedimentation rate of 7 ± 2 mm/yr). Alternatively, sediment on the footwall may have been mass-wasted, and volcanism could have been contemporaneous with detachment inactivity. These results demonstrate that detachment faults may be highly sensitive to local changes in magma supply, and that direct seafloor observations are crucial to understanding slow-spreading ridge mechanics.

Screening and Identification of Peptides Specifically Targeted to Gastric Cancer Cells from a Phage Display Peptide Library

PubMed

Sahin, Deniz; Taflan, Sevket Onur; Yartas, Gizem; Ashktorab, Hassan; Smoot, Duane T

2018-04-25

Background: Gastric cancer is the second most common cancer among the malign cancer types. Inefficiency of traditional techniques both in diagnosis and therapy of the disease makes the development of alternative and novel techniques indispensable. As an alternative to traditional methods, tumor specific targeting small peptides can be used to increase the efficiency of the treatment and reduce the side effects related to traditional techniques. The aim of this study is screening and identification of individual peptides specifically targeted to human gastric cancer cells using a phage-displayed peptide library and designing specific peptide sequences by using experimentally-eluted peptide sequences. Methods: Here, MKN-45 human gastric cancer cells and HFE-145 human normal gastric epithelial cells were used as the target and control cells, respectively. 5 rounds of biopannning with a phage display 12-peptide library were applied following subtraction biopanning with HFE-145 control cells. The selected phage clones were established by enzyme-linked immunosorbent assay and immunofluorescence detection. We first obtain random phage clones after five biopanning rounds, determine the binding levels of each individual clone. Then, we analyze the frequencies of each amino acid in best binding clones to determine positively overexpressed amino acids for designing novel peptide sequences. Results: DE532 (VETSQYFRGTLS) phage clone was screened positive, showing specific binding on MKN-45 gastric cancer cells. DE-Obs (HNDLFPSWYHNY) peptide, which was designed by using amino acid frequencies of experimentally selected peptides in the 5th round of biopanning, showed specific binding in MKN-45 cells. Conclusion: Selection and characterization of individual clones may give us specifically binding peptides, but more importantly, data extracted from eluted phage clones may be used to design theoretical peptides with better binding properties than even experimentally selected ones. Both peptides, experimental and designed, may be potential candidates to be developed as useful diagnostic or therapeutic ligand molecules in gastric cancer research. Creative Commons Attribution License

Smart polymeric nanoparticles with pH-responsive and PEG-detachable properties for co-delivering paclitaxel and survivin siRNA to enhance antitumor outcomes.

PubMed

Jin, Mingji; Jin, Guangming; Kang, Lin; Chen, Liqing; Gao, Zhonggao; Huang, Wei

2018-01-01

The co-delivery of chemotherapeutic agents and small interfering RNA (siRNA) within one cargo can enhance the anticancer outcomes through its synergistic therapeutic effects. We prepared smart polymeric nanoparticles (NPs) with pH-responsive and poly(ethylene glycol) (PEG)-detachable properties to systemically co-deliver paclitaxel (PTX) and siRNA against survivin gene for lung cancer therapy. The cationic polyethyleneimine-block-polylactic acid (PEI-PLA) was first synthesized and characterized, with good biocompatibility. PTX was encapsulated into the hydrophobic core of the PEI-PLA polymers by dialysis, and then the survivin siRNA was loaded onto the PTX-loaded NPs (PEI-PLA/PTX) through electrostatic interaction between siRNA and PEI block. Finally, the negatively charged poly(ethylene glycol)-block-poly(L-aspartic acid sodium salt) (PEG-PAsp) was coated onto the surface of NPs by electrostatic interaction to form final smart polymeric NPs with mean particle size of 82.4 nm and zeta potential of 4.1 mV. After uptake of NPs by tumor cells, the PEG-PAsp segments became electrically neutral owing to the lower endosome pH and consequently detached from the smart NPs. This process allowed endosomal escape of the NPs through the proton-sponge effect of the exposed PEI moiety. The resulting NPs achieved drug loading of 6.04 wt% and exhibited good dispersibility within 24 h in 10% fetal bovine serum (FBS). At pH 5.5, the NPs presented better drug release and cellular uptake than at pH 7.4. The NPs with survivin siRNA effectively knocked down the expression of survivin mRNA and protein owing to enhanced cell uptake of NPs. Cell counting kit-8 (CCK-8) assay showed that the NPs presented low systemic toxicity and improved antiproliferation effect of PTX on A549 cells. Moreover, in vivo studies demonstrated that accumulated NPs in the tumor site were capable of inhibiting the tumor growth and extending the survival rate of the mice by silencing the survivin gene and delivering PTX into tumor cells simultaneously. These results indicate that the prepared nano-vectors could be a promising co-delivery system for novel chemo/gene combination therapy.

New Insights into PhaM-PhaC-Mediated Localization of Polyhydroxybutyrate Granules in Ralstonia eutropha H16

PubMed Central

Bresan, Stephanie

2017-01-01

ABSTRACT The formation and localization of polyhydroxybutyrate (PHB) granules in Ralstonia eutropha are controlled by PhaM, which interacts both with the PHB synthase (PhaC) and with the bacterial nucleoid. Here, we studied the importance of proline and lysine residues of two C-terminal PAKKA motifs in PhaM for their importance in attaching PHB granules to DNA by in vitro and in vivo methods. Substitution of the lysine residues but not of the proline residues resulted in detachment of formed PHB granules from the nucleoid. Instead, formation of PHB granule clusters at polar regions of the rod-shaped cells and an unequal distribution of PHB granules to daughter cells were observed. The formation of PHB granules was studied by the expression of chromosomally anchored gene fusions of fluorescent proteins with PhaM and PhaC in different backgrounds. PhaM and PhaC fusions showed a distinct colocalization at formed PHB granules in the nucleoid region of the wild type. In a ΔphaC background, PhaM and the catalytically inactive PhaCC319A protein were not able to form fluorescent foci, indicating that correct positioning requires the formation of PHB. Furthermore, time-lapse experiments revealed that PhaC and PhaM proteins detach from formed PHB granules at later stages, resulting in a nonhomogeneous population of PHB granules. This could explain why growth of individual PHB granules stops under PHB-permissive conditions at a certain size. IMPORTANCE PHB granules are storage compounds for carbon and energy in many prokaryotes. Equal distribution of accumulated PHB granules during cell division is therefore important for optimal fitness of the daughter cells. In R. eutropha, PhaM is responsible for maximal activity of PHB synthase, for initiation of PHB granule formation at discrete regions in the cells, and for association of formed PHB granules with the nucleoid. Here we found that four lysine residues of C-terminal PhaM sequence motifs are essential for association of PHB granules with the nucleoid. Furthermore, we followed PHB granule formation by time-lapse microscopy and provide evidence for aging of PHB granules that is manifested by detachment of previously PHB granule-associated PhaM and PHB synthase. PMID:28389545

Smart polymeric nanoparticles with pH-responsive and PEG-detachable properties for co-delivering paclitaxel and survivin siRNA to enhance antitumor outcomes

PubMed Central

Jin, Mingji; Jin, Guangming; Kang, Lin; Chen, Liqing; Gao, Zhonggao; Huang, Wei

2018-01-01

Background The co-delivery of chemotherapeutic agents and small interfering RNA (siRNA) within one cargo can enhance the anticancer outcomes through its synergistic therapeutic effects. Materials and methods We prepared smart polymeric nanoparticles (NPs) with pH-responsive and poly(ethylene glycol) (PEG)-detachable properties to systemically co-deliver paclitaxel (PTX) and siRNA against survivin gene for lung cancer therapy. The cationic polyethyleneimine-block-polylactic acid (PEI-PLA) was first synthesized and characterized, with good biocompatibility. PTX was encapsulated into the hydrophobic core of the PEI-PLA polymers by dialysis, and then the survivin siRNA was loaded onto the PTX-loaded NPs (PEI-PLA/PTX) through electrostatic interaction between siRNA and PEI block. Finally, the negatively charged poly(ethylene glycol)-block-poly(L-aspartic acid sodium salt) (PEG-PAsp) was coated onto the surface of NPs by electrostatic interaction to form final smart polymeric NPs with mean particle size of 82.4 nm and zeta potential of 4.1 mV. After uptake of NPs by tumor cells, the PEG-PAsp segments became electrically neutral owing to the lower endosome pH and consequently detached from the smart NPs. This process allowed endosomal escape of the NPs through the proton-sponge effect of the exposed PEI moiety. Results The resulting NPs achieved drug loading of 6.04 wt% and exhibited good dispersibility within 24 h in 10% fetal bovine serum (FBS). At pH 5.5, the NPs presented better drug release and cellular uptake than at pH 7.4. The NPs with survivin siRNA effectively knocked down the expression of survivin mRNA and protein owing to enhanced cell uptake of NPs. Cell counting kit-8 (CCK-8) assay showed that the NPs presented low systemic toxicity and improved antiproliferation effect of PTX on A549 cells. Moreover, in vivo studies demonstrated that accumulated NPs in the tumor site were capable of inhibiting the tumor growth and extending the survival rate of the mice by silencing the survivin gene and delivering PTX into tumor cells simultaneously. Conclusion These results indicate that the prepared nano-vectors could be a promising co-delivery system for novel chemo/gene combination therapy. PMID:29719390

Analytical method for determining rill detachment rate of purple soil as compared with that of loess soil

USDA-ARS?s Scientific Manuscript database

Rill detachment is an important process in rill erosion. The rill detachment rate is the fundamental basis for determination of the parameters of a rill erosion model. In this paper, an analytical method was proposed to estimate the rill detachment rate. The method is based on the exact analytical s...

Repair of Traumatic Rhegmatogenous Retinal Detachment Combined with Congenital Falciform Retinal Detachment.

PubMed

Mano, Fukutaro; Chang, Kuo-Chung; Mano, Tomiya

2018-01-01

To report a case of surgical repair of traumatic rhegmatogenous retinal detachment combined with congenital falciform retinal detachment (FRD). A retrospective case report. A 36-year-old man with traumatic rhegmatogenous retinal detachment complicating a previously known FRD was successfully treated despite residual FRD following pars plana lensectomy, vitrectomy, and encircling scleral buckling. His best corrected visual acuity improved from hand motion at 50 cm to 20/1,000. We concluded that the root of the FRD is susceptible to trauma because of the contraction of fibrovascular tissue. The early intervention of modern vitrectomy to traumatic rhegmatogenous retinal detachment complicating a previously known FRD is an important consideration for enhanced quality of care and optimal patient outcomes.

Repair of Traumatic Rhegmatogenous Retinal Detachment Combined with Congenital Falciform Retinal Detachment

PubMed Central

Mano, Fukutaro; Chang, Kuo-Chung; Mano, Tomiya

2018-01-01

Purpose To report a case of surgical repair of traumatic rhegmatogenous retinal detachment combined with congenital falciform retinal detachment (FRD). Methods A retrospective case report. Results A 36-year-old man with traumatic rhegmatogenous retinal detachment complicating a previously known FRD was successfully treated despite residual FRD following pars plana lensectomy, vitrectomy, and encircling scleral buckling. His best corrected visual acuity improved from hand motion at 50 cm to 20/1,000. Conclusion We concluded that the root of the FRD is susceptible to trauma because of the contraction of fibrovascular tissue. The early intervention of modern vitrectomy to traumatic rhegmatogenous retinal detachment complicating a previously known FRD is an important consideration for enhanced quality of care and optimal patient outcomes. PMID:29643782

Ocular toxoplasmosis and retinal detachment: five case reports.

PubMed

Kianersi, F; Naderi Beni, A; Ghanbari, H; Fazel, F

2012-10-01

Ocular toxoplasmosis is a potentially blinding cause of posterior uveitis. Retinal detachment is rare complication of ocular toxoplasmosis. To report the clinical course and prognosis of retinal breaks and detachments occurring in patients with ocular toxoplasmosis. This study was a retrospective, non-comparative case series of five patients with ocular toxoplasmosis who had consulted us with retinal detachment. All of the participants had retinal detachment after severe and treatment resistant toxoplasmic retinochoroiditis, leaving one of them with decreased visual acuity to light perception in spite of treatment and final visual acuity was 20/100 or better in four patients. The functional prognosis for the patients with retinal detachment was poor. Careful retinal examination in ocular toxoplasmosis is warranted, especially in patients with severe intraocular inflammation.

Acute tissue reactions, inner segment pathology, and effects of the antioxidant α1-microglobulin in an in vitro model of retinal detachment.

PubMed

Ghosh, Fredrik; Åkerström, Bo; Bergwik, Jesper; Abdshill, Hodan; Gefors, Lina; Taylor, Linnéa

2018-04-18

The purpose of this study was to explore acute tissue reactions, ultrastructural photoreceptor morphology with emphasis on inner segments, and the effect of antioxidant treatment in an in vitro model of rhegmatogenous retinal detachment (RRD). A previously described method of RRD simulation was used with adult retinal porcine explants kept free-floating in culture medium with or without treatment with the radical scavenger α 1 -microglobulin (A1M). Explants were examined at 5 time points from 1 to 24 h using transmission electron microscopy as well as quantitative real-time PCR (RT-PCR) to quantify gene expression of the cell stress marker heat shock protein 70 (Hsp70) and oxidative stress marker heme oxygenase (HO-1). The culture medium level of the cell damage marker lactate dehydrogenase (LDH) and oxidative stress DNA damage marker 8-Oxo-2'-deoxyguanosine (8-OHdG) was also assessed at each time point. We found that the levels of Hsp70 and LDH rapidly increased in both groups, and at 3 and 6 h, Hsp70 was significantly higher in A1M treated retinas. At 24 h, Hsp70 and LDH, as well as 8-OHdG were significantly lower compared with controls, whereas the tissue level of HO-1 was significantly higher. Progressive ultrastructural photoreceptor changes were seen in untreated control explants from 1 h and onwards including outer segment shortening and loss, disruption of organelles within the inner segments and loss of perikarya in the outer nuclear layer. Inner segment pathology was more rapid and extensive in rods compared with in cones. In A1M treated counterparts, damage to rod inner segment mitochondria was significantly higher after 1 h of culture, but after this time, no statistical difference was found. At 24 h, cone inner segment mitochondrial disruption was significantly higher in control retinas and the number of surviving perikarya lower. From our results, we conclude that retinal explants elicit acute cell stress reactions when placed in culture without physical support simulating a detached retina floating in the vitreous space. Photoreceptors rapidly display degenerative changes including extensive damage to inner segment mitochondria indicating loss of energy transduction as an early key event. A1M increases initial mitochondrial stress in the rods, however, subsequent pathology is attenuated by the treatment, highlighting the dynamics of protective as well as disruptive oxidative stress reactions in the detached retina. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparison of Sulfur Hexafluoride (SF6) and Air Tamponade in Noniridectomized Descemet Membrane Endothelial Keratoplasty.

PubMed

Einan-Lifshitz, Adi; Sorkin, Nir; Boutin, Tanguy; Showail, Mahmood; Borovik, Armand; Jamshidi, Farzad; Chan, Clara C; Rootman, David S

2018-03-01

To compare the efficacy and safety of 20% sulfur hexafluoride gas (SF6) and air tamponade in patients who underwent noniridectomized Descemet membrane endothelial keratoplasty (DMEK). A retrospective chart review of patients who underwent DMEK with either air or SF6 tamponade: 41 eyes received air tamponade (group 1) and 41 received SF6 tamponade (group 2). Best spectacle-corrected visual acuity, endothelial cell density, and complications including graft detachment and elevated intraocular pressure were compared. The mean follow-up time was 8 ± 4 months in group 1 and 3 ± 2 months in group 2. Mean best spectacle-corrected visual acuity improved from 1.12 ± 0.88 to 0.64 ± 0.78 logarithm of the minimum angle of resolution (logMAR) in group 1 (P = 0.009) and from 1.00 ± 0.78 to 0.62 ± 0.53 logMAR in group 2 (P = 0.006). The graft detachment rate was 39% (16 eyes) in group 1 and 42% (17 eyes) in group 2 (P = 0.822). The rate of graft detachment larger than one third of the graft area was 17% in group 1 and 20% in group 2 (P = 0.775). Rebubbling was performed in 26.8% and 20% of eyes in group 1 and 2, respectively (P = 0.43). Average endothelial cell loss was 32% in group 1 and 33% in group 2 (P = 0.83). In the immediate postoperative period, elevated intraocular pressure was observed in 2 eyes (5%) in group 1 and in 4 eyes (10%) in group 2 (P = 0.4). There was 1 primary graft failure in each group. Use of air with it being readily available and short acting is a good method of Descemet membrane tamponade in noniridectomized DMEK.

Characterizing the adhesion of motile and nonmotile Escherichia coli to a glass surface using a parallel-plate flow chamber.

PubMed

McClaine, Jennifer W; Ford, Roseanne M

2002-04-20

A parallel-plate flow chamber was used to measure the attachment and detachment rates of Escherichia coli to a glass surface at various fluid velocities. The effect of flagella on adhesion was investigated by performing experiments with several E. coli strains: AW405 (motile); HCB136 (nonmotile mutant with paralyzed flagella); and HCB137 (nonmotile mutant without flagella). We compared the total attachment rates and the fraction of bacteria retained on the surface to determine how the presence and movement of the flagella influence transport to the surface and adhesion strength in this dynamic system. At the lower fluid velocities, there was no significant difference in the total attachment rates for the three bacterial strains; nonmotile strains settled at a rate that was of the same order of magnitude as the diffusion rate of the motile strain. At the highest fluid velocity, the effect of settling was minimized to better illustrate the importance of motility, and the attachment rates of both nonmotile strains were approximately five times slower than that of the motile bacteria. Thus, different processes controlled the attachment rate depending on the parameter regime in which the experiment was performed. The fractions of motile bacteria retained on the glass surface increased with increasing velocity, whereas the opposite trend was found for the nonmotile strains. This suggests that the rotation of the flagella enables cells to detach from the surface (at the lower fluid velocities) and strengthens adhesion (at higher fluid velocities), whereas nonmotile cells detach as a result of shear. There was no significant difference in the initial attachment rates of the two nonmotile species, which suggests that merely the presence of flagella was not important in this stage of biofilm development. Copyright 2002 Wiley Periodicals, Inc.

Serpina3n accelerates tissue repair in a diabetic mouse model of delayed wound healing.

PubMed

Hsu, I; Parkinson, L G; Shen, Y; Toro, A; Brown, T; Zhao, H; Bleackley, R C; Granville, D J

2014-10-09

Chronic, non-healing wounds are a major complication of diabetes and are characterized by chronic inflammation and excessive protease activity. Although once thought to function primarily as a pro-apoptotic serine protease, granzyme B (GzmB) can also accumulate in the extracellular matrix (ECM) during chronic inflammation and cleave ECM proteins that are essential for proper wound healing, including fibronectin. We hypothesized that GzmB contributes to the pathogenesis of impaired diabetic wound healing through excessive ECM degradation. In the present study, the murine serine protease inhibitor, serpina3n (SA3N), was administered to excisional wounds created on the dorsum of genetically induced type-II diabetic mice. Wound closure was monitored and skin wound samples were collected for analyses. Wound closure, including both re-epithelialization and contraction, were significantly increased in SA3N-treated wounds. Histological and immunohistochemical analyses of SA3N-treated wounds revealed a more mature, proliferative granulation tissue phenotype as indicated by increased cell proliferation, vascularization, fibroblast maturation and differentiation, and collagen deposition. Skin homogenates from SA3N-treated wounds also exhibited greater levels of full-length intact fibronectin compared with that of vehicle wounds. In addition, GzmB-induced detachment of mouse embryonic fibroblasts correlated with a rounded and clustered phenotype that was prevented by SA3N. In summary, topical administration of SA3N accelerated wound healing. Our findings suggest that GzmB contributes to the pathogenesis of diabetic wound healing through the proteolytic cleavage of fibronectin that is essential for normal wound closure, and that SA3N promotes granulation tissue maturation and collagen deposition.

Border cell release: Cell separation without cell wall degradation?

PubMed

Mravec, Jozef

2017-07-03

Plant border cells are specialized cells derived from the root cap with roles in the biomechanics of root growth and in forming a barrier against pathogens. The mechanism of highly localized cell separation which is essential for their release to the environment is little understood. Here I present in situ analysis of Brachypodium distachyon, a model organism for grasses which possess type II primary cell walls poor in pectin content. Results suggest similarity in spatial dynamics of pectic homogalacturonan during dicot and monocot border cell release. Integration of observations from different species leads to the hypothesis that this process most likely does not involve degradation of cell wall material but rather uses unique cell wall structural and compositional means enabling both the rigidity of the root cap as well as detachability of given cells on its surface.

Impact of Cross-field Drifts on Detachment in DIII-D

NASA Astrophysics Data System (ADS)

Jaervinen, A. E.; Allen, S. L.; McLean, A. G.; Rognlien, T. D.; Samuell, C. M.; Porter, G. D.; Groth, M.; Hill, D. N.; Leonard, A. W.

2017-10-01

Simulations of DIII-D plasmas have revealed the strong role of E ×B-drifts in the low field side (LFS) detachment structure. High confinement modes (H-mode) with the ∇B-drift towards the X-point (fwd BT) enter detachment at 20% higher upstream density, ne,sep, than plasmas with the ∇B-drift away from the X-point (rev BT). In contrast, low confinement modes (L-mode) enter detachment at 10% lower ne,sep in fwd BT. Despite this, both L- and H-modes detached plasmas show strong target flux, JSAT, reduction with increasing ne,sep in fwd BT, while only a modest reduction occurs in rev BT. In fwd BT H-mode, a step-wise transition from attached to strongly detached conditions is observed with increasing ne,sep. UEDGE simulations indicate that the strong poloidal E ×B-drift in the private flux region in H-mode drives the difference for the detachment onset relative to L-mode. In fwd BT, the dependence of this poloidal E ×B-drift on the divertor conditions can reinforce the plasma into either attached or strongly detached state. In rev BT, radial E ×B-drift depletes strike-line ne, limiting the degree of detachment. Work supported by the US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, and LLNL LDRD project 17-ERD-020.

Risk of progression in macula-on rhegmatogenous retinal detachment.

PubMed

Callizo, Josep; Pfeiffer, Sebastian; Lahme, Eva; van Oterendorp, Christian; Khattab, Mohammed; Bemme, Sebastian; Kulanga, Miroslav; Hoerauf, Hans; Feltgen, Nicolas

2017-08-01

To identify factors that may lead to a rapid progression in macula-on rhegmatogenous retinal detachment (RRD), in particular, those that may lead to macular involvement. Observational, prospective, single-center study. Patients referred for surgery due to primary rhegmatogenous retinal detachment with the macula on between 2009 and 2013 were included. Relevant factors analyzed included age, time delay until surgery, lens status, myopia, the detachment's location and configuration as well as number, size and type of retinal breaks. Eyes underwent optical coherence tomography to detect macular detachment. A multivariate analysis was performed to investigate the effect of several factors in the progression of retinal detachment. A total of 116 eyes of 116 patients were included. Mean time delay between admission and surgery was 1.8 ± 1.4 days. Progression was observed in 19.8% of the eyes. Of those, 47.8% presented macular detachment. Ten of the 11 (90.9%) eyes presenting progression involving the macula also exhibited a bullous configuration, which was the only parameter that correlated significantly with detachment progression in patients with (p = 0.0036) and without (p = 0.0014) macular involvement. For the first time in a prospective trial, a bullous configuration was found to be a highly significant predictor for progression in macula-on detachments. Our data support prompt surgery in patients diagnosed with bullous macula-on RRD.

Exploring children's seasonal play to promote active lifestyles in Auckland, New Zealand.

PubMed

Ergler, Christina R; Kearns, Robin; Witten, Karen

2016-09-01

Studies of seasonal barriers for outdoor activities seldom view families' play practices as grounded in the everyday experience of the natural elements. This paper brings 20 families' mundane outdoor play experiences in Auckland's temperate climate to the fore. Through drawings and interviews, families residing in both suburban detached houses and central city apartments revealed locally constituted beliefs about appropriate play spaces (e.g. garden, park). While the majority of participants retreated to indoor activities during winter, some children and their parents viewed the outdoors as the only opportunity for 'real fun'. We advocate the importance of a better understanding of children's seasonal outdoor play. In particular, we argue that in order to promote year-round healthy levels of outdoor activities it is necessary to understand variations in societal, neighbourhood and family values attributed to outdoor activities. Further, to develop a more nuanced understanding of the locational complexities of outdoor play it is important to understand the meanings of, and practices associated with, seasonal and weather conditions in different international locations. Copyright © 2016 Elsevier Ltd. All rights reserved.

31 CFR 358.6 - What is the procedure for converting bearer corpora and detached bearer coupons to book-entry?

Code of Federal Regulations, 2011 CFR

2011-07-01

... bearer corpora and detached bearer coupons to book-entry? 358.6 Section 358.6 Money and Finance: Treasury... PUBLIC DEBT REGULATIONS GOVERNING BOOK-ENTRY CONVERSION OF BEARER CORPORA AND DETACHED BEARER COUPONS § 358.6 What is the procedure for converting bearer corpora and detached bearer coupons to book-entry...

Round cell sarcomas beyond Ewing: emerging entities.

PubMed

Antonescu, Cristina

2014-01-01

Primitive small blue round cell tumours (SBRCT) of childhood and young adults have been problematic to diagnose and classify. Diagnosis is also complicated in cases with atypical morphology, aberrant immunoprofiles and unusual clinical presentations. Even with the increased use of ancillary techniques in archival material, such as immunohistochemistry and molecular/genetic methods, a proportion of these tumours cannot be subclassified into specific histological types. A subset of tumours resembling microscopically the Ewing sarcoma family of tumours (EFT), being composed of primitive small round cells and occurring in paediatric or young adult age groups, remain unclassified, being negative for EWSR1, SS18(SYT), DDIT3(CHOP) and FOXO1(FKHR) gene rearrangements by FISH/RT-PCR. A small number of cases sharing the undifferentiated EFT appearance have been characterized recently carrying BCOR-CCNB3 or CIC-DUX4 fusions. However, based on the somewhat limited number of cases, it remains unclear if these newly defined genetic entities belong to any of the pre-existing clinicopathological disorders or represent altogether novel conditions. This review presents the latest molecular findings related to these SBRCTs, beyond the common EWSR1-ETS fusions. Specific attention has been paid to morphological features not associated typically with classic EFT, and the value of ancillary tests that can be applied when dealing with EWSR1-negative SBRCTs is discussed. © 2013 John Wiley & Sons Ltd.

[Desmoplastic small round cell tumor in children, adolescents and young adults].

PubMed

de Marcellus, Charles; Sarnacki, Sabine; Pierron, Gaëlle; Ranchère-Vince, Dominique; Scalabre, Aurélien; Bolle, Stéphanie; Minard-Colin, Véronique; Corradini, Nadège; Fayard, Cindy; Orbach, Daniel

2018-05-01

Desmoplastic small round cell tumor (DSRCT) is a rare sarcoma that typically affects pediatric and young adult patients with a median age in the general and in the pediatric population of 24.6 years (range 4-58 years) and 15.0 years (range 0-21 years) respectively, with a strong male predominance. This tumor is characterized by a specific t(11;22)(p13;q12) that results in fusion of EWS and WT1 genes which can be demonstrated by RT-PCR or by FISH. DSRCT most frequently presents as an intra-abdominal primary mass associated with peritoneal seeding and a highly aggressive pattern of spread. Generally, all tumors showed the typical histologic findings of variably sized clusters of poly-phenotypic small, round, or spindled cells lying in a desmoplastic stroma. Treatment of this malignancy remains a challenge. The combination of polychemotherapy regimens and aggressive surgery followed by whole abdomen radiation therapy represents nowadays a classical protocol for DSRCT. The survival rate of DSRCT patients is still disappointing around 20 %. However, the survival of patients who had complete resection of the tumor appears better. Hopes are turning to targeted therapeutics against this simple genomic sarcoma. Authors summarize medical knowledge of this rare tumor. Copyright © 2018 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

SQUAMOUS CELL CARCINOMA IN THE GULF MENHADEN, 'BREVOORTIA PATRONUS' GOODE

EPA Science Inventory

The communication reports a case (RTLA 3618) of squamous cell carcinoma from the gulf menhaden, Brevoortia patronus Goode, the first tumor reported from the species. The affected fish was collected in a gill net on 15 January 1986 in the northern Gulf of Mexico near Round Island,...

Video Views and Reviews: Gastrulation and the Fashioning of Animal Embryos

ERIC Educational Resources Information Center

Watters, Christopher

2005-01-01

Most science students readily understand that following fertilization, a single-celled egg must undergo multiple rounds of cell division to become a multicellular organism. This transformation is so universal among animal embryos that developmental biologists refer to the process with a single term: ''gastrulation.'' During gastrulation, many if…

Extremely thin layer plastification for focused-ion beam scanning electron microscopy: an improved method to study cell surfaces and organelles of cultured cells.

PubMed

VAN Donselaar, E G; Dorresteijn, B; Popov-Čeleketić, D; VAN DE Wetering, W J; Verrips, T C; Boekhout, T; Schneijdenberg, C T W M; Xenaki, A T; VAN DER Krift, T P; Müller, W H

2018-03-25

Since the recent boost in the usage of electron microscopy in life-science research, there is a great need for new methods. Recently minimal resin embedding methods have been successfully introduced in the sample preparation for focused-ion beam scanning electron microscopy (FIB-SEM). In these methods several possibilities are given to remove as much resin as possible from the surface of cultured cells or multicellular organisms. Here we introduce an alternative way in the minimal resin embedding method to remove excess of resin from two widely different cell types by the use of Mascotte filter paper. Our goal in correlative light and electron microscopic studies of immunogold-labelled breast cancer SKBR3 cells was to visualise gold-labelled HER2 plasma membrane proteins as well as the intracellular structures of flat and round cells. We found a significant difference (p < 0.001) in the number of gold particles of selected cells per 0.6 μm 2 cell surface: on average a flat cell contained 2.46 ± 1.98 gold particles, and a round cell 5.66 ± 2.92 gold particles. Moreover, there was a clear difference in the subcellular organisation of these two cells. The round SKBR3 cell contained many organelles, such as mitochondria, Golgi and endoplasmic reticulum, when compared with flat SKBR3 cells. Our next goal was to visualise crosswall associated organelles, septal pore caps, of Rhizoctonia solani fungal cells by the combined use of a heavy metal staining and our extremely thin layer plastification (ETLP) method. At low magnifications this resulted into easily finding septa which appeared as bright crosswalls in the back-scattered electron mode in the scanning electron microscope. Then, a septum was selected for FIB-SEM. Cross-sectioned views clearly revealed the perforate septal pore cap of R. solani next to other structures, such as mitochondria, endoplasmic reticulum, lipid bodies, dolipore septum, and the pore channel. As the ETLP method was applied on two widely different cell types, the use of the ETLP method will be beneficial to correlative studies of other cell model systems and multicellular organisms. © 2018 The Authors. Journal of Microscopy published by JohnWiley & Sons Ltd on behalf of Royal Microscopical Society.

Credit BG. View looking west down into Test Stand "D" ...

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

Credit BG. View looking west down into Test Stand "D" vertical vacuum cell with top removed. Access to cell is normally through large round port seen in view. Piping and cradling toward bottom of cell was last used in tests of Viking space probe engines - Jet Propulsion Laboratory Edwards Facility, Test Stand D, Edwards Air Force Base, Boron, Kern County, CA

Improved Crystal Quality By Detached Solidification in Microgravity

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.; Wang, Yaz-Hen; Wang, Jian-Bin

2003-01-01

Many microgravity directional solidification experiments yielded ingots with portions that grew without contacting the ampoule wall, leading to greatly improved crystallographic perfection. Our long term goals have been: (1) To develop a complete understanding of all of the phenomena of detached solidification.; (2) To make it possible to achieve detached solidification reproducibly; (3) To increase crystallographic perfection through detached solidification. We have three major achievements to report here: (1) We obtained a new material balance solution for the Moving Meniscus Model of detached solidification. This solution greatly clarifies the physics as well as the roles of the parameters in the system; (2) We achieved detached solidification of InSb growing on earth in BN-coated ampoules; (3) We performed an extensive series of experiments on freezing water that showed how to form multiple gas bubbles or tubes on the ampoule wall. However, these did not propagate around the wall and lead to fully detached solidification unless the ampoule wall was extremely rough and non-wetted.

The Death Valley turtlebacks reinterpreted as Miocene­ Pliocene folds of a major detachment surface

USGS Publications Warehouse

Holm, Daniel K.; Fleck, Robert J.; Lux, Daniel R.

1994-01-01

Determining the origin of extension parallel folds in metamorphic core complexes is fundamental to understanding the development of detachment faults. An excellent example of such a feature occurs in the Death Valley region of California where a major, undulatory, detachment fault is exposed along the well-known turtleback (antiformal) surfaces of the Black Mountains. In the hanging wall of this detachment fault are deformed strata of the Copper Canyon Formation. New age constraints indicate that the Copper Canyon Formation was deposited from ~6 to 3 Ma. The formation was folded during deposition into a SE-plunging syncline with an axial surface coplanar with that of a synform in the underlying detachment. This relation suggests the turtlebacks are a folded detachment surface formed during large-scale extension in an overall constrictional strain field. The present, more planar, Black Mountains frontal fault system may be the result of out-stepping of a normal fault system away from an older detachment fault that was deactivated by folding.

Chromosome Bridges Maintain Kinetochore-Microtubule Attachment throughout Mitosis and Rarely Break during Anaphase.

PubMed

Pampalona, Judit; Roscioli, Emanuele; Silkworth, William T; Bowden, Brent; Genescà, Anna; Tusell, Laura; Cimini, Daniela

2016-01-01

Accurate chromosome segregation during cell division is essential to maintain genome stability, and chromosome segregation errors are causally linked to genetic disorders and cancer. An anaphase chromosome bridge is a particular chromosome segregation error observed in cells that enter mitosis with fused chromosomes/sister chromatids. The widely accepted Breakage/Fusion/Bridge cycle model proposes that anaphase chromosome bridges break during mitosis to generate chromosome ends that will fuse during the following cell cycle, thus forming new bridges that will break, and so on. However, various studies have also shown a link between chromosome bridges and aneuploidy and/or polyploidy. In this study, we investigated the behavior and properties of chromosome bridges during mitosis, with the idea to gain insight into the potential mechanism underlying chromosome bridge-induced aneuploidy. We find that only a small number of chromosome bridges break during anaphase, whereas the rest persist through mitosis into the subsequent cell cycle. We also find that the microtubule bundles (k-fibers) bound to bridge kinetochores are not prone to breakage/detachment, thus supporting the conclusion that k-fiber detachment is not the cause of chromosome bridge-induced aneuploidy. Instead, our data suggest that while the microtubules bound to the kinetochores of normally segregating chromosomes shorten substantially during anaphase, the k-fibers bound to bridge kinetochores shorten only slightly, and may even lengthen, during anaphase. This causes some of the bridge kinetochores/chromosomes to lag behind in a position that is proximal to the cell/spindle equator and may cause the bridged chromosomes to be segregated into the same daughter nucleus or to form a micronucleus.

Pemphigus autoimmunity: Hypotheses and realities

PubMed Central

Grando, Sergei A

2011-01-01

The goal of contemporary research in pemphigus vulgaris and pemphigus foliaceus is to achieve and maintain clinical remission without corticosteroids. Recent advances of knowledge on pemphigus autoimmunity scrutinize old dogmas, resolve controversies, and open novel perspectives for treatment. Elucidation of intimate mechanisms of keratinocyte detachment and death in pemphigus has challenged the monopathogenic explanation of disease immunopathology. Over 50 organ-specific and non-organ-specific antigens can be targeted by pemphigus autoimmunity, including desmosomal cadherins and other adhesion molecules, PERP cholinergic and other cell membrane (CM) receptors, and mitochondrial proteins. The initial insult is sustained by the autoantibodies to the cell membrane receptor antigens triggering the intracellular signaling by Src, epidermal growth factor receptor kinase, protein kinases A and C, phospholipase C, mTOR, p38 MAPK, JNK, other tyrosine kinases, and calmodulin that cause basal cell shrinkage and ripping desmosomes off the CM. Autoantibodies synergize with effectors of apoptotic and oncotic pathways, serine proteases, and inflammatory cytokines to overcome the natural resistance and activate the cell death program in keratinocytes. The process of keratinocyte shrinkage/detachment and death via apoptosis/oncosis has been termed apoptolysis to emphasize that it is triggered by the same signal effectors and mediated by the same cell death enzymes. The natural course of pemphigus has improved due to a substantial progress in developing of the steroid-sparing therapies combining the immunosuppressive and direct anti-acantholytic effects. Further elucidation of the molecular mechanisms mediating immune dysregulation and apoptolysis in pemphigus should improve our understanding of disease pathogenesis and facilitate development of steroid-free treatment of patients. PMID:21939410

Hydrogels with Modulated Ionic Load for Mammalian Cell Harvesting with Reduced Bacterial Adhesion.

PubMed

Gallardo, Alberto; Martínez-Campos, Enrique; García, Carolina; Cortajarena, Aitziber L; Rodríguez-Hernández, Juan

2017-05-08

In this manuscript, we describe the fabrication of hydrogel supports for mammalian cell handling that can simultaneously prevent materials from microbial contamination and therefore allow storage in aqueous media. For that purpose, hydrogels based on the antifouling polymer polyvinylpyrrolidone (PVP) were functionalized with different ionic groups (anionic, cationic, or two types of zwitterions). In order to prevent bacterial adhesion in the long-term, we took advantage of the synergistic effect of inherently antifouling PVP and additional antifouling moieties incorporated within the hydrogel structure. We evaluated, in a separated series of experiments, both the capability of the materials to act as supports for the growth of mammalian cell monolayers for transplantation (using C-166-GFP endothelial cell line), as well their antifouling properties against Staphylococcus aureus, were studied. All of the hydrogels are structurally pseudodouble networks with high swelling (around 90%) and similar mechanical properties (in the low range for hydrogel materials with Young modulus below 1250 kPa). With some differences, all the charged hydrogels were capable of hosting mouse endothelial cell line C166-GFP to confluence, as well as a monolayer detachment and transplantation through simple mechanical agitation. On the contrary, the uncharged hydrogel was not capable to detach a full monolayer for transplantation. Bacterial adhesion and proliferation was highly sensitive to the functionality (type of charge and density). In particular, we evidenced that monomers bearing zwitterionic sulfobetaine groups, those negatively charged as well as "electro neutral" hydrogels fabricated from stoichiometric amounts of positive and negative units, exhibit excellent antifouling properties both at initial adhesion times and during longer periods up to 72 h.

Scar-free wound healing and regeneration following tail loss in the leopard gecko, Eublepharis macularius.

PubMed

Delorme, Stephanie Lynn; Lungu, Ilinca Mihaela; Vickaryous, Matthew Kenneth

2012-10-01

Many lizards are able to undergo scar-free wound healing and regeneration following loss of the tail. In most instances, lizard tail loss is facilitated by autotomy, an evolved mechanism that permits the tail to be self-detached at pre-existing fracture planes. However, it has also been reported that the tail can regenerate following surgical amputation outside the fracture plane. In this study, we used the leopard gecko, Eublepharis macularius, to investigate and compare wound healing and regeneration following autotomy at a fracture plane and amputation outside the fracture plane. Both forms of tail loss undergo a nearly identical sequence of events leading to scar-free wound healing and regeneration. Early wound healing is characterized by transient myofibroblasts and the formation of a highly proliferative wound epithelium immunoreactive for the wound keratin marker WE6. The new tail forms from what is commonly referred to as a blastema, a mass of proliferating mesenchymal-like cells. Blastema cells express the protease matrix metalloproteinase-9. Apoptosis (demonstrated by activated caspase 3 immunostaining) is largely restricted to isolated cells of the original and regenerating tail tissues, although cell death also occurs within dermal structures at the original-regenerated tissue interface and among clusters of newly formed myocytes. Furthermore, the autotomized tail is unique in demonstrating apoptosis among cells adjacent to the fracture planes. Unlike mammals, transforming growth factor-β3 is not involved in wound healing. We demonstrate that scar-free wound healing and regeneration are intrinsic properties of the tail, unrelated to the location or mode of tail detachment. Copyright © 2012 Wiley Periodicals, Inc.

Effect of the plant Cupressus macro-carpa (Cupressacea) on some haematolo-gical and biochemical parameters of Biomphalaria alexandrina snails.

PubMed

El-Sayed, Kamelia A

2006-12-01

The dry powder of the plant aereal part; Cupressus macro-carpa (Cupressacea) was tested against Biomphalaria alexandrina. LC50 & LC90 values were 59.5 & 98.8 ppm, respec-tively. Exposure of B. alexandrina to sublethal concentrations (LC0, LC10 & LC25) of C. macrocarpa for three weeks signi-ficantly decreased the number of circulating hemocytes. The magnitude of reduction was increased with increasing of the tested concentration. The main type of cell in the hemolymph of B. alexandrina was the granulocyte (71.8%), followed by large round cells or hyalinocytes (19.0%) and small round cells or undifferentiate cells (9.2%). The percentage of different hemocyte categories was changed in treated snails. In snails maintained at LC25, showed significantly higher percentages of small round cells than controls, 56.2% & 9.2% respectively. Maintainence of B. alexandrina in sublethal concentrations for three weeks significantly reduced protein & hemoglobin content in the hemolymph. Reduction in enzyme activities occurred in the hemolymph and tissues of treated snails. The enzymes were pyruvate kinase (PK), lactat dehydrogenase (LDH), hexokinase (HK) and phosphoenol pyruvate carboxy kinase (PEPCK) which are very important in metabolism of the protein and carbohydrate. The infectivity of Schistosoma mansoni miracidia was greatly reduced by exposure to the sublethal concentrations (LC0, LC10 & LC25) of Cupressus. Infection rate of B. alexandrina reached to 54.5%, 37.5% & 16.7%, respectively compared to control (81.25%). Duration of cercarial shedding and the total periodic cercarial production/snail showed significant reduction while the parasite incubation period was significantly longer (p<0.05).